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PMC10521587
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Cureus
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Eosinophilic Enteritis Flare-Up Mimicking Acute Gastroenteritis: A Rare Case
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27-08-2023
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Eosinophilic enteritis is a rare subset of eosinophilic gastrointestinal disorders. It typically presents with chronic symptoms of abdominal pain, nausea, vomiting, diarrhea, and ascites. However, the clinical presentation can vary due to acute flare-ups. Here, we present a case of eosinophilic enteritis in a young female patient with intractable vomiting and diarrhea, mimicking acute gastroenteritis in the absence of other gastrointestinal symptoms. This case illustrates the challenge of diagnosing acute and diverse presentations of eosinophilic enteritis. It also highlights the importance of promptly treating and confirming the diagnosis through urgent tissue histopathology in adolescents with unexplained vomiting and diarrhea.
|
[
"Eosinophilic gastrointestinal by its association with GI symptoms and eosinophil-rich infiltration of the intestinal mucosa, without secondary intestinal eosinophilia [ ]. After eosinophilic esophagitis, both eosinophilic gastroenteritis and EE represent the most frequent subset of disorders [ ]. Although the disease has been described in case reports and reviewed multiple times, estimating its true incidence remains challenging due to many undiagnosed and unreported patients.",
"The exact pathogenesis of EE is unknown; however, the literature suggests the roles of immunoglobulin E with intractable vomiting, diarrhea, and severe dehydration. In the absence of fever and abdominal pain, she was managed as a suspected acute gastroenteritis. Her blood workup revealed peripheral eosinophilia, elevated serum IgE levels, and high C-reactive protein scan of the abdomen showed findings of multiple areas of segmental thickening of the bowel wall in the duodenum and proximal jejunum, as noted in Figure .",
"Suspected for an underlying gastric outlet obstruction and/or inflammatory bowel disease, upper GI endoscopy was performed on the third day of hospitalization. Although non-specific, endoscopic findings ruled out gastric outlet obstruction but displayed patchy areas of erythema in the duodenum and proximal jejunum, as shown in Figure . The biopsy was taken from multiple segments of the intestine, and histopathology was ordered. With findings consistent with eosinophilic GI disease, i.e., peripheral eosinophilia, elevated IgE levels, and non-specific erosions on endoscopy, she was empirically started on dexamethasone infusion of 30 mg per day.",
"On the fifth day of hospitalization, her symptoms started improving. Her vomiting and diarrhea resolved completely by the tenth day in hospital. She was shifted to oral prednisolone 20 mg twice daily, montelukast 10 mg once daily, and ketotifen 2 mg once daily. A repeated blood count performed on December 11, 2022, showed normal eosinophil count, normal CRP levels, decreasing IgE levels, and declining pattern in ESR. Subsequently, she was discharged to home on oral medications.",
"Upon follow-up a week later, this patient had no GI complaint, and a tapering regimen of prednisolone was planned at 5 mg per week for four weeks until discontinuation. The allergy food panel was found to be normal. Furthermore, her histopathology report, which was also available at the follow-up visit, revealed dense infiltrates of eosinophils with degranulation in the lamina propria and muscularis mucosa of the duodenum and jejunum, as shown in Figure . This confirmed our suspected diagnosis of EE.",
"Eosinophilic GI diseases are a rare group of chronic and immune-mediated conditions that can affect any segments of the GI tract, including esophagus and pro-inflammatory cytokines within the gut wall, amplifying inflammation. Additional factors such as interleukin-33, eosinophilic-like receptors), seen in nearly 20%-80% of patients [ ]. Similarly, other non-specific laboratory findings such as elevated IgE levels, hypoalbuminemia, iron deficiency, and increased inflammatory markers such as CRP and ESR may also be present [ ]. Imaging studies are highly non-specific and may show gut wall thickening. It may also help in excluding other secondary causes of GI disease [ ]. Likewise, upper GI endoscopy may also show non-specific findings of erythema, erosions, edema, or nodules [ ]. In our patient’s case, peripheral eosinophilia, elevated IgE levels, and high CRP and ESR levels were observed, with the latter two returning to baseline after treatment. In the absence of secondary causes of eosinophilia, the biopsy confirmed our final diagnosis of EE.",
"The treatment of EE poses a challenge due to the absence of clear guidelines. Non-pharmacological approaches involve the elimination of diets that trigger atopy and/or allergic reactions, although data on dietary elimination are insufficient in the current literature. Pharmacological therapies are the mainstay of treatment. Prednisolone is a widely used regimen, given at the dose of 1 mg per kg per day for few weeks followed by a gradual tapering over 6 to 8 weeks. Other therapies options include leukotriene inhibitors (e.g., montelukast 10 mg once daily), mast cell stabilizers (e.g., sodium cromoglycate 200 mg thrice daily), anti-histamines (e.g., ketotifen 1-2 mg twice daily), and medications such as azathioprine and biologics (e.g., mepolizumab, omalizumab, infliximab, adalimumab) [ , ]. Our patient received IV dexamethasone initially and subsequently took oral prednisolone for a duration of eight weeks, along with montelukast and ketotifen for 12 weeks. She responded very well to this combination therapy. Moreover, during the three-month follow-up, no disease flare was observed.",
"EE is a rare disorder characterized by a constellation of non-specific GI symptoms, laboratory findings, and imaging abnormalities. Our case presents a unique manifestation of EE, marked by intractable vomiting and diarrhea upon presentation, imitating the symptoms of acute gastroenteritis. In a case such as ours, it is essential to remember that EE can exhibit an acute flare and create diagnostic and therapeutic challenges for physicians. A high index of suspicion becomes imperative in such cases. Given the scarcity of literature on the acute flare aspect of EE, we emphasize the need for further extensive research to comprehend the diverse facets of this intricate disorder."
] |
PMC10813894
|
Children
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Statins—Beyond Their Use in Hypercholesterolemia: Focus on the Pediatric Population
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17-01-2024
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Statins are a class of medications primarily used in adults to lower cholesterol levels and reduce the risk of cardiovascular events. However, the use of statins in children is generally limited and carefully considered despite the well-documented anti-inflammatory, anti-angiogenic, and pro-apoptotic effects, as well as their effect on cell signaling pathways. These multifaceted effects, known as pleiotropic effects, encompass enhancements in endothelial function, a significant reduction in oxidative stress, the stabilization of atherosclerotic plaques, immunomodulation, the inhibition of vascular smooth muscle proliferation, an influence on bone metabolism, anti-inflammatory properties, antithrombotic effects, and a diminished risk of dementia. In children, recent research revealed promising perspectives on the use of statins in various conditions including neurological, cardiovascular, and oncologic diseases, as well as special situations, such as transplanted children. The long-term safety and efficacy of statins in children are still subjects of ongoing research, and healthcare providers carefully assess the individual risk factors and benefits before prescribing these medications to pediatric patients. The use of statins in children is generally less common than in adults, and it requires close monitoring and supervision by healthcare professionals. Further research is needed to fully assess the pleiotropic effects of statins in the pediatric population.
|
[
"Statins primarily function by inhibiting 3-hydroxy-3-methylglutaryl-coenzyme A primarily due to elevated LDL cholesterol, can be attributed to the cumulative effect of multiple single nucleotide variants scattered throughout the genome [ ]. These individuals are at a high risk of developing atherosclerosis due to lifelong exposure to elevated LDL-C levels [ ]. Therefore, early intervention is crucial in managing this condition and reducing the risk of complications.",
"For children diagnosed with heterozygous familial hypercholesterolemia levels remain persistently elevated despite 3–6 months of lifestyle modifications [ ]. In cases where children with heterozygous FH have more severe LDL-C abnormalities, statin treatment may be initiated alongside therapeutic lifestyle changes [ ].",
"The therapy initiation algorithm is based on fasting LDL-C values and the presence or absence of cardiovascular risk factors. Children and adolescents with LDL-C ≥ 250 mg/dL and/or triglycerides levels in children and adolescents with hypercholesterolemia. A recent meta-analysis comprising data from eight randomized controlled trials and 1025 children with familial hypercholesterolemia demonstrated that the lipid profile was significantly improved after statin therapy with a mean reduction of 75 mg/dL in the case of TC, 11.5 mg/dL in the case of TG, and 75 mg/dL in the case of LDL-C, with a mean increase of 14.3 mg/dL in the case of HDL-C [ ]. In another comprehensive meta-analysis of 10 randomized controlled trials involving 1191 children aged 13.3 ± 2.5 years, statins have shown effectiveness in reducing TC by 25% and TG by 8% while increasing HDL-C by 3% when compared with a placebo [ ].",
"While statins are generally well tolerated, there are some potential safety concerns to be aware of. Common side effects of statin use in children may include gastrointestinal symptoms such as abdominal pain, nausea, or diarrhea [ ]. Muscle-related side effects, such as myalgia or elevated creatine kinase levels, can also occur but are rare in children [ ]. Serious adverse events associated with statin use, such as liver dysfunction or rhabdomyolysis, have been also rarely reported in the pediatric population [ ]. According to Khoury et al., liver toxicity, myositis, and rhabdomyolysis were no more frequently reported in children receiving statins than in those receiving placebos and had no impact on growth or development [ ]. However, in the case of pre-existing liver disease, such as non-alcoholic fatty liver disease, liver function and transaminase levels should be monitored more closely when initiating statin therapy [ ]. A fasting lipid-profile should be recommended 4 to 8 weeks after statin initiation; if adequate LDL-C reduction is observed, a fasting lipid profile should be repeated every 3–6 months in the first 112 months and longitudinally every 6–12 months [ ]. Transaminases and creatine phosphokinase levels should be checked at baseline and also in the case of new symptoms [ ]. Following the initiation of statin therapy, it is recommended to regularly monitor liver enzymes and creatine phosphokinase levels at 1–2 months, assess liver enzymes at 3–6 months, and periodically thereafter. It is important to note that the routine monitoring of creatine phosphokinase is not necessary as it may lead to incidental elevations of muscular enzymes that could be attributed to physical activity [ ].",
"Up to the present, no cases of rhabdomyolysis were reported in children [ ]. In a cohort of 1501 children aged 14 ± 4 years old treated with one of two low dose statins, among other medications, macrolides, antifungal azoles, protease inhibitors, cyclosporine, and grapefruit should be avoided, with dose adjustments often needed for calcium channel blockers and amiodarone [ ]. In the case of fluvastatin, pitavastatin, and rosuvastatin, which are substrates of CYP2C9, cyclosporine should be avoided [ ]. As pravastatin is the only statin not metabolized by a CYP isoenzyme, it may be a more appropriate choice for patients at risk for adverse drug interactions [ ]. Also, the concurrent use of statins and gemfibrozil should be avoided, as gemfibrozil inhibits OATP1B1, a hepatic drug membrane transporter, and can hinder the hepatic glucuronidation of statins, leading to elevated plasma concentrations of statins and their metabolites [ ].",
"While specific prevalence rates may vary across different regions and populations, studies have indicated an overall increase in the prevalence of lipid metabolism disorders in children, not only as a consequence of an increasing number of primary hypercholesterolemia cases, but also due to an epidemic of secondary hypercholesterolemia cases [ ]. The various causes of secondary hypercholesterolemia are detailed in .",
"In diabetes, the role of HMG-CoA reductase inhibitors is controversial and unclear [ ]. Joyce et al. reported a positive association with an increased likelihood of developing type 2 diabetes in children without dyslipidemia who took statins, not observed in statin-treated dyslipidemia children [ ]. Unfortunately, this article fails to explicitly identify the actual indications for statin use in the non-dyslipidemia group, and only compares the outcomes in the statin-exposed and non-exposed groups in terms of type 2 diabetes occurrence. In this respect, one needs to keep in mind the rapid progression of adolescent- and young adult-onset type 2 diabetes [ ] and the high number of complications and severe metabolic phenotypes, as shown by studies such as TODAY and RISE [ , , ].",
"Although cited as a secondary cause of hypercholesterolemia, the association between dyslipidemia and atherosclerosis in Kawasaki disease is still not certain [ ]. In this context, we will further discuss the use of statins in Kawasaki disease due to their pleiotropic effects.",
"Kawasaki disease, also known as Kawasaki syndrome, is an acute febrile illness of unknown cause primarily observed in children under the age of 5. While it is generally considered a rare disease [ ], it can have serious complications if left untreated due to the development of coronary artery abnormalities, which can lead to coronary artery aneurysms, depressed myocardial contractility and heart failure, myocardial infarction, and arrhythmias [ ].",
"As statins have been found to have positive effects on inflammation, endothelial function, and oxidative stress, recommendations from the American Heart Association [ , ] and Japanese Circulation Society [ ] encourage the empirical use of statins for children with Kawasaki disease and past or current aneurysms.",
"In this context, it is important to understand the mechanisms beyond the positive impact on inflammation and coronary artery abnormalities. In a murine study, atorvastatin demonstrated anti-atherosclerotic effects by enhancing the function of endothelial cells in artificially induced Kawasaki-like vasculitis [ ]. Motoji et al. showed that the use of statins may be able to prevent the cardiovascular events associated with Kawasaki disease by stimulating the expression of endothelial nitric oxide synthase and no apparent adverse effect on growth or development were reported [ ].",
"The safety of atorvastatin was also investigated in a Phase I/IIa 2-center dose-escalation study including 34 children aged 2–17 years old with Kawasaki disease complicated by a coronary artery aneurysm [ ]. The authors concluded that after 6 weeks of treatment with 0.75 mg/kg/day of atorvastatin, no serious adverse events were reported [ ]. Additionally, a small study including 13 male children aged 2–10 years found that 6 months of pravastatin therapy improved chronic vascular inflammation and endothelial dysfunction in children with Kawasaki disease with minimal to no adverse effects [ ].",
"Besides Kawasaki disease, the statins showed potential benefits in chronic vasculitis such as Behçet’s and rheumatoid arthritis due to their anti-inflammatory, anti-oxidant, and endothelial-repairing properties [ ]. Recent research showed that the anti-inflammatory effects of statins are based on complex mechanisms: statins can suppress TLR4 stabilization [ ]. However, further studies are needed to unravel the potential use of these mechanisms in pediatric cardiovascular and inflammatory diseases. As statins exhibit both a lipid-lowering effect in addition to an anti-inflammatory effect [ ], their use was also investigated in heart-transplanted patients. In adults, statins have been found to have several beneficial effects [ ], and early use reduced the cardiac allograft vasculopathy and the risk of the accelerated progression of atherosclerosis [ ]. In heart-transplanted children, the pleiotropic effects of statins are still understudied. Moreover, the results of the available studies on the impact of statins in this particular population show controversial and even conflicting results. In a study comprising 78 children aged 4.8 to 14.7 years old who underwent a heart transplant, the use of statins was associated with a significant decrease in the incidence of acute cellular rejection and post-transplant lymphoproliferative disease, but with no significant decrease in the risk of coronary artery vasculopathy even with early statin initiation [ ]. In a retrospective study including 964 heart transplant recipients aged 5–18 years old, Greenway et al. reported no effects of statin use regarding overall survival up to 5 years post-transplant and the risk of cardiac allograft vasculopathy and post-transplant lymphoproliferative disease [ ]. These results are concordant with a recent study conducted by Townsend et al. in 3485 pediatric heart transplant recipients, showing no statistically significant difference regarding the graft survival and the incidence of cardiac allograft vasculopathy between children receiving consecutive statin therapy and those with intermediate use or no statin therapy [ ]. Interestingly, pravastatin effectively lowered the TC and LDL-C and improved the compositional properties of LDL and HDL due to their anti-inflammatory properties. In a randomized, double-blind study, Moazen-Zadeh et al. reported a positive impact on irritability and hyperactivity/noncompliance in children aged 4–12 years old treated with risperidone is limited and even conflicting. In a murine study, Mucha et al. reported that simvastatin did not improve the clinical and biological patterns of mdx in a study of 15 patients aged between 6 and 31 years old [ ]. The role of statins in Rett syndrome, an X-linked disease characterized by the progressive development of neurological and motor dysfunction, was suggested by a murine study conducted by Buchovecky et al., in which statins had a favorable impact on the systemic imbalance of the lipid profile, motor symptoms, and longevity in Mecp2 pathway, whose activation may result in medulloblastoma, and, unlike other inhibitors of this pathway, such as sonedigib and vismodegib, effectively suppressed tumor growth in young mice, without causing any defects in bone development [ ]. In humans, a phase 1 study conducted in children with relapsed/refractory solid and central nervous system tumors reported that plasma interleukin 6 in contrast to data from the group receiving atorvastatin, which was associated with a tumor incidence of 12.5% and mean tumor volume of 2.3 ± 0.2 mm^(3) [ ]. In humans, the results of the available observational and randomized studies are controversial and insufficient to establish a consensus regarding the use of statins as chemo-preventive drugs in children [ ].",
"The future perspectives of statin use in children are promising, considering their pleiotropic effects in various diseases. While the primary indication for statins in pediatric populations remains the management of dyslipidemia, their potential applications in autoimmune and inflammatory diseases, neurological disorders, and oncologic diseases warrant further investigation.",
"Future research should focus on optimizing dosing, evaluating long-term safety, and conducting well-designed clinical trials to establish the efficacy and safety of statins in children with various conditions. In the context of pediatric cancers, the use of statins is still in its early stages, and more research is needed to fully understand their efficacy and safety in this specific population. Future studies may focus on investigating the potential benefits of statins as adjuvant therapy in combination with standard cancer treatments, such as chemotherapy or radiation therapy.",
"The potential of statins to prevent cancers is also an area of ongoing research and investigation. While some studies suggest that statins may have a chemo-preventive effect and reduce the risk of certain cancers, the evidence is not yet conclusive. Further research, including large-scale clinical trials and long-term studies, is needed to better understand the role of statins in cancer prevention.",
"Also, it would be valuable to examine the mechanisms of action through which statins may exert their effects on neurologic conditions in children, as well as the optimal dosage and duration of treatment. As the prevalence of autism in children has shown an increasing trend over the past few decades [ ], long-term follow-up studies are needed to assess the safety and efficacy of statins in this specific context.",
"Statin therapy has proven to be highly effective in reducing cardiovascular events and mortality in patients with dyslipidemia. However, there is considerable heterogeneity in the treatment response among patients, highlighting the need for personalized medicine approaches. The identification of specific biomarkers that can predict treatment response to statins is crucial for optimizing patient outcomes and resource allocation. It would be valuable to assess the significance of specific biomarkers regarding the suitable moment of treatment initiation, the early identification of potential complications, and the effectiveness in targeting specific diseases. For instance, endothelial function markers such as endothelial nitric oxide synthase in genes involved in lipid metabolism, have shown promise in predicting statin response [ ]. The role of specific genes as strong candidate genes including CETP , HMGCR , SLCO1B1 , ABCB1 , and CYP3A4 / 5 should be further studied in relation with treatment outcomes [ ]. By incorporating genetic, lipid, inflammatory, and metabolic biomarkers into clinical decision-making, clinicians can better tailor statin treatment to individual patients. Further research and validation of these biomarkers are warranted to establish their clinical utility and integration into routine practice. This personalized approach has the potential to improve treatment outcomes, reduce adverse effects, and optimize resource allocation.",
"The pleiotropic effects of statins sparked interest in exploring their potential use in various diseases. In addition to lipid-lowering effects, statins have been shown to have anti-inflammatory, antioxidant, and immunomodulatory properties. In children, HMG-CoA reductase inhibitors showed incontestable benefits with minimal side effects in various conditions associated with disturbances in lipid profile parameters. Besides the role of statins in hypercholesterolemia, innovative potential indications include neurological, oncologic, and cardiovascular diseases, as well as special situations such as transplanted children. While the use of statins in children for these conditions is still being studied, their pleiotropic effects offer promising possibilities for expanding their therapeutic applications beyond cholesterol management. However, it is important to note that further research is needed to fully understand the safety and efficacy of statins in these contexts before widespread use can be recommended."
] |
PMC10137892
|
Gels
|
Nano-Gels: Recent Advancement in Fabrication Methods for Mitigation of Skin Cancer
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13-04-2023
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In the 21st century, melanoma and non-melanoma skin cancers have become an epidemic outbreak worldwide. Therefore, the exploration of all potential preventative and therapeutic measures based on either physical or bio-chemical mechanisms is essential via understanding precise pathophysiological pathways (Mitogen-activated protein kinase, Phosphatidylinositol 3-kinase Pathway, and Notch signaling pathway) and other aspects of such skin malignancies. Nano-gel, a three-dimensional polymeric cross-linked porous hydrogel having a diameter of 20–200 nm, possesses dual properties of both hydrogel and nanoparticle. The capacity of high drug entrapment efficiency with greater thermodynamic stability, remarkable solubilization potential, and swelling behavior of nano-gel becomes a promising candidate as a targeted drug delivery system in the treatment of skin cancer. Nano-gel can be either synthetically or architectonically modified for responding to either internal or external stimuli, including radiation, ultrasound, enzyme, magnetic, pH, temperature, and oxidation-reduction to achieve controlled release of pharmaceuticals and several bio-active molecules such as proteins, peptides, genes via amplifying drug aggregation in the active targeted tissue and reducing adverse pharmacological effects. Several drugs, such as anti-neoplastic biomolecules having short biological half-lives and prompt enzyme degradability capacity, must be appropriate for administration employing either chemically bridged or physically constructed nano-gel frameworks. The comprehensive review summarizes the advancement in the preparation and characterization methods of targeted nano-gel with enhanced pharmacological potential and preserved intracellular safety limits for the mitigation of skin malignancies with a special emphasize on skin cancer inducing pathophysiological pathways and prospective research opportunities for skin malignancy targeted nano-gels.
|
[
"The concept “novel drug delivery system” into different categories such as physically-chemically cross-linked, hybrid nano-gel, polymeric, bio-mimetic nano-gel, pH, thermo, magnetic, hypoxia, ultrasound, enzyme, and reduction responsive nano-gel on the basis of synthesis procedure, nature of materials used and responsive towards stimuli respectively [ , ]. The swellable property of nano-gel makes them able to expand when in contact with physiological fluids providing flexibility to be near the targeted region drugs under particular physiological circumstances and increasing the dispersion of medicaments [ ]. Nano-gels can be either synthetically modified to incorporate numerous ligands for targeted drug delivery or controlled drug release or primarily a transporter architecture for delivering pharmaceuticals and several bio-active compounds such as genes, proteins, etc. [ , , ]. Depending on the type and properties of both drug and nano-gel being utilized as well as desired release pattern, there are many techniques to load drugs into them, such as physical entrapment, immunosuppressive disorders, use of heavy metals, pesticides, etc. resulting in the damage of DNA molecule of melanocytes that raises intracellular oxygen radicals. These mutations cause uncontrollable cell proliferation, expression, and immortalization, attributing to the unrestricted stimulation of multiple cell signaling pathways [ ]. The pathogenesis, signaling, and cellular pathways of melanomas are described below:",
"Almost all forms of melanomas stimulate the MAPK cascade that controls cell proliferation, growth, and migration. Melanoma instances are characterized by excessive activation when the growth factors stimulate tyrosine kinase receptors after binding with it and resulting in the activation of the RAS family monomeric G protein, Neuroblastoma RAS viral oncogene homolog of BRAF gene mutations are caused by the conversion of thymidine to adenine, and the kinase domain of the protein molecule is activated as a result of the valine being switched out for glutamate [ , ]. Other protein substitutions, available in V600K mutations tumor suppressor gene, which inhibits NRAS signaling, as well as the amplification and/or subsequent activation of a number of growth factor receptors, including c-MET, the epidermal growth factor receptor exhibited activating RAS mutations, with NRAS mutations becoming the most prevalent. Exceptionally frequent NRAS and BRAF mutations demonstrate that merely a single mutation in any one of the two genes is adequate to trigger the MAPK pathway [ ]. The predominance of NRAS mutations is identified in congenital nevi, which are infrequent in nevi. Spitz nevi and NRAS mutations are typically linked [ ]. Mutations in the NRAS or BRAF genes are found in 80% of cases of melanocytic nevi activation, a key regulator necessary for myocyte maturation having an impact on the recurrence of some melanomas or cognitive debilitation of phosphatase and tensin homolog deleted on chromosome 10 are phosphorylated as a result of AKT [ ]. Tumor development is also associated with the amplification of the tyrosine kinase receptor c-MET along with its ligand HGF is mainly responsible for mediating the hypoxia response resulting in the activation of numerous genes related to angiogenesis, invasion, and metastasis and promotion of PI3K pathway developing tumor and transforming melanocyte in the hypoxic human skin microenvironment. Due to inadequate vascularization, tumor hypoxia develops with melanoma growth, which raises HIF and promotes melanogenesis, and melanoma progression, having a detrimental prognostic impact [ ].",
"The Notch signaling system, comprised of regulatory proteins, negative and positive regulators, a family of the receptor synthesized photo-chemically stable citric acid and pentane-1,2,5-triol loaded spherical and negatively, click chemistry cross-linking, and photo-induced cross-linking are some examples of chemical cross-linking techniques. The study reported that curcumin-loaded Carbopol, capmul [ ]. Many variables, such as the choice of surface active agents, the quantity of both monomer and cross-linker and the pH of specific reaction media, all have an impact on the size of nano-gels [ ]. The drawback of the method is that the reaction media is an organic solvent. The purification of the produced nano-gels will be problematic if emulsifiers or co-emulsifiers are present. A degradable poly polymerization technique, a polymer developed a pH-responsive doxorubicin-loaded silica-polymethacrylic acid nano-gel via RAFT polymerization technique for the treatment of breast cancer [ ].",
"Click Chemistry Cross-linking polymerization technique and ortho ester diacrylamide [ ].",
"Photo-induced cross-linking was used in the development of docetaxel lipid-coated nano-gel [ , ].",
"In this process, polymers are first synthesized, followed by the cross-linking of the polymeric molecular chains to form nano-gels. This approach is particularly appropriate for creating nano-gels from natural polymers [ ]. The approach can be one of several different forms, including precipitation/cross-linking, emulsification/cross-linking, self-assembly/cross-linking, and micro-template forming/cross-linking, depending on the mechanism of nano-gel formation. Since the feature of the 3D network structure of nano-gels allows them to be carried with both hydrophilic and hydrophobic chemicals, nano-gels offer a platform for drug co-delivery. The study reported that phase-transition temperature emulsification was used to load doxorubicin and glycyrrhizic acid into alginate-based nano-gels, demonstrating synergistic anti-neoplastic effects mediated by both components of nano-gels in addition to their ability to target hepatocellular carcinoma [ ]. The nano-curcumin and Sulph loaded ethosomal nano-gel were prepared using a combination of both thin-film hydration and phase transition temperature process [ ].",
"Several pathogenic variables.",
"Vesicle size, size distribution, zeta potential, and morphology of diluted nano-gel are analyzed by zetasizer and Transmission or Scanning electron microscope, respectively. Kriti et al. and globule size also observed well defined sealed, lamellar, spherical structure of brucine-loaded trans-liposomal nano-gel with uniform size distribution via Zetasizer instrument and TEM using the dynamic light scattering approach. The transmission electron micrograph also indicated the absence of crystalline brucine, confirming the complete entrapment of brucine inside the vesicular architecture [ ].",
"The nano-gels are diluted to get the required concentration using a suitable solvent, and the absorbance is measured at spectroscopy according to the monograph; therefore, the following formulas were used for the determination of entrapment efficiency and drug content.",
"Ganesh et al. and pH, consistency as the property of nano-gel may alter due to physical changes such as pH. Both nano-gels are converted to pellet form via a hydraulic pelletizer; therefore, the dry weight through a dialysis membrane at 37 ± 0.5 °C. A definite amount of nano-gel is placed on the Franz diffusion cell after being transferred to the cellophane membrane, and to keep and ensure the initial consistent volume, a specific volume of aliquots is taken out at intervals and replaced with an equal volume of fresh phosphate buffer. Thereafter the samples are examined using the specific spectroscopic technique as per the monograph [ ]. The release kinetics modeling is done from cumulative percent release, whereas less than 30% of curcumin released at pH 7.4 buffer solution favoring tumor site-specific drug delivery [ ]. In vitro drug release in open-sink conditions demonstrated a sustained daily release of 7–10% of loaded curcumin with a zero-order kinetics in PBS at 25 °C. Very sustained curcumin release was observed at pH 7.4 and 25 °C with the first-order kinetics of the daily 7–10% drug release [ ]. A consistent release over an extended period was also observed to achieve a constant therapeutic benefit via controlling curcumin release rate from the multiple layer-by-layer also reported that HPMC-based quercetin of surface area and 7.5 mL of volume operating in continuous stirring mode, and a definite amount of formulation is placed on top of it. For 24 h, the receptor media was maintained at a constant temperature of 37 ± 0.5 °C and a constant mixing speed in terms of rpm. To promote skin hydration, the donor compartment and receiver compartment solution are equilibrated for one hour. A specific quantity of aliquot is removed from the receiver compartment and replaced with fresh PBS at the designated times and therefore analyzed via spectroscopic techniques as per the monograph [ ]. Studies showed significant of skin and time for the epidermis and dermis and assess T_(skinmax), C_(skinmax), AUC murine melanoma cell lines value have been effectively developed and assessed [ ]. Hormone therapies are effective for tumors linked to hormones [ ] but several hormonal therapies have been linked to elevated risk factors for diabetes mellitus and thrombosis [ ]. Nano-gels designed for targeted medication delivery in these cancer types are not linked to such risk factors. The most prevalent type of cancer in people is skin cancer.",
"“Skin cancer” refers to a variety of medical conditions that develop from distinct epidermal and dermal cells. Skin cancer has been successfully treated with loaded nano-gels of chitin-polymerized curcumin [ ]. The therapeutic effectiveness of the B16-F10 melanoma tumor was improved by a thermo-sensitive nano-hydrogel co-loaded with DOX, IL-2, and IFN-γ, which boosted tumor cell death and enhanced replication of CD3+/CD4+ and CD3+/CD8+ T cells [ ]. Drugs having high molecular weight have been formulated as nano-gels to enhance their solubility. For instance, tacrolimus, an immune-suppressive drug, was loaded in polyglycerol polymerized thermo-sensitive topical nano-gel and found to be improved adsorption of the drug through the layers of skin, attributing to the elevated body temperature for inflammation resulting in remarkable anti-proliferative activity [ ]. pH-responsive biodegradable 5-fluorouracil-loaded chitosan nano-gel was developed to treat melanoma in the mild acidic cancer micro-environment, effectively preserving the integrity of the skin layer in comparison with other traditional melanoma formulations [ ]. Transdermal curcumin nano-gels were developed to improve the solubility, transdermal permeability, and significant release of curcumin with lower toxicity attributed to their physicochemical characteristics when compared to traditional curcumin formulations [ ]. In order to create hydrophilic and thermo-responsive three-dimensional crosslinked nano-gels that can improve the penetration of both smaller and larger molecules through the squamous cells and aggregate within the hair follicles, dendrimers made of dendritic polyglycerol, providing a unique strategy against skin melanoma [ ]. A chemo-preventive study revealed that the average integer of UVB-inducing tumor, tumor volume was less in a remarkable manner in the quercetin-titanium dioxide nano-gel treated animals with improved quercetin deposition on the skin via down-regulating COX-2, EP3, EP4, PCNA, and cyclin D1 expressions [ ]. Therefore, for applications in targeted medication delivery, diagnostics, bio-sensing, and the separation of biological constituents, nano-gels have gained significant research interest.",
"Due to its distinctive features, nano-gel is increasingly being recognized as significant material for a variety of applications. Nano-gels can be used in different branches of science like drug delivery, tissue engineering, cosmetics, etc. Patent search with keywords “Nano-gel” and “Nano-gel” + “Skin Cancer” in the title, abstract, and claim showed 1238 and 9 patent results, respectively. The patent export data of nano-gel indicate that in recent years the number of patents increasing drastically to more than 100 per year with application fields like cellular, ocular, dental, and skin delivery of therapeutics and biologicals. A new class of research includes 3D-printed polymeric nano-gel particles. Out of 1238 patents on nano-gel, around 500 were active, and 400 were pending status; the United States of America with the highest number of 406 applications, followed by China with 332. C lists the major inventor in this field, and D shows that to date, 253 patents have been granted and 922 patent applications.",
"The possible development of nano-gels holds out considerable promise and provides researchers with new chances for medication delivery against a wide range of diseases and ailments. We can achieve optimal drug loading in the nano-gels by modifying the nano-gel system and precisely adjusting its composition, such as polymer type, molecular weight, and cross-linking density. In addition, other functional components like imaging probes and targeting moieties can be easily bonded onto nano-gels to investigate their potential for tailored therapeutic effects. Because of their multi-functionality, 3-dimensional polymer construction, and stimuli-responsive qualities, the ideal nano-sized properties of these agents would make nano-gels very appealing for topical targeted cancer therapy with minimal toxicity burden on patients. Nano-gels have the potential to open the door to effective target medication delivery to tissues and cancerous cells. Many factors, including those relating to patients and drugs, interact during cancer chemotherapy. Overall, in vitro and in vivo stability of dosage forms is crucial to ensure that it reaches the target site undamaged. When administered intravenously, which is the primary method of delivery for most cancer medications, nano-gels have shown to be a very stable dosage form that can deliver the required payload to malignant areas. As biocompatible biomimetic hydrogels are predicted to avoid the reticuloendothelial system and change the nuclear phagocytic system, they are likely to play a substantial impact on intracellular drug carriers resulting in a prolonged in vivo circulation period. Hence, drug delivery investigators must concentrate on these new kinds of nano-gels while also utilizing biocompatible, stable, and biodegradable natural polymers. The usage of polymer hybrids, or molecular blends made of a combination of synthetic and natural polymers, is another feature of nano-gels that will catch the interest of formulation scientists in the ensuing 10 years. Natural polymers would have a beneficial impact on biocompatibility and biodegradability, while synthetic polymers would offer more functionality. Natural polymers would provide an excellent candidate for implant delivery systems for anticancer medications because they do not produce hazardous breakdown products, in contrast to some synthetic polymers. When nano-gels are implanted into malignant regions, drug release will take place as expected owing to the engineering techniques used during formulation. This technique of delivery will significantly lessen off-target toxicities linked to the systemic distribution of various anticancer medicines by reducing drug migration to undesirable regions. The potential for one of the most significant breakthroughs in targeted cancer therapy has been expanded owing to nano-gel formulations of anticancer medications. Future applications of nano-gels in targeted cancer therapy have shown considerable promise in preliminary studies. For nano-gel formulations, there is a need to standardize procedures with a good manufacturing practice manual. In order to establish the safety profile of nano-gels and further our understanding of them, it is crucial to scale up research on nano-gels for targeted cancer therapy. The potential for using nano-gels as a target delivery method for anticancer medications is still quite great, and emerging pharma companies are anticipated to take advantage of this potential to improve the translational research of these medications."
] |
PMC10369066
|
Frontiers in Immunology
|
Gut colonization with an obesity-associated enteropathogenic microbe modulates the premetastatic niches to promote breast cancer lung and liver metastasis
|
12-07-2023
|
Introduction Obesity, an independent risk factor for breast cancer growth and metastatic progression, is also closely intertwined with gut dysbiosis; and both obese state and dysbiosis promote each other. Enteric abundance of Bacteroides fragilis is strongly linked with obesity, and we recently discovered the presence of B. fragilis in malignant breast cancer. Given that enterotoxigenic B. fragilis or ETBF, which secretes B. fragilis toxin (BFT), has been identified as a procarcinogenic microbe in breast cancer, it is necessary to examine its impact on distant metastasis and underlying systemic and localized alterations promoting metastatic progression of breast cancer. Methods We used syngeneic mammary intraductal (MIND) model harboring gut colonization with ETBF to query distant metastasis of breast cancer cells. Alterations in the immune network and cytokines/chemokines in the tumor microenvironment and distant metastatic sites were examined using flow cytometry, immunohistochemistry, and multiplex arrays. Results ETBF infection initiates a systemic inflammation aiding in the establishment of the premetastatic niche formation in vital organs via increased proinflammatory and protumorigenic cytokines like IL17A, IL17E, IL27p28, IL17A/F, IL6, and IL10 in addition to creating a prometastatic immunosuppressive environment in the liver and lungs rich in myeloid cells, macrophages, and T regulatory cells. It induces remodeling of the tumor microenvironment via immune cell and stroma infiltration, increased vasculogenesis, and an EMT-like response, thereby encouraging early metastatic dissemination ready to colonize the conducive environment in liver and lungs of the breast tumor-bearing mice. Discussion In this study, we show that enteric ETBF infection concomitantly induces systemic inflammation, reshapes the tumor immune microenvironment, and creates conducive metastatic niches to potentiate early dissemination and seeding of metastases to liver and lung tissues in agreement with the “seed and soil hypothesis.” Our results also support the ETBF-induced “parallel model” of metastasis that advocates for an early dissemination of tumor cells that form metastatic lesions independent of the primary tumor load.
|
[
"The impact of obesity on breast cancer can be appreciated by the fact that a 5-unit increase in body mass index. Adiposity and altered body fat composition can significantly influence breast cancer outcomes through an upsurge of proinflammatory cytokines and immune modulation. Likewise, dysbiotic gut microbiota can also influence breast cancer via several means including small metabolite-induced oncogenic signaling, systemic inflammation, and altered hormone regulation. Accordingly, several studies and clinical trials have implied the connection between obesity-induced dysbiosis and poor breast cancer outcomes, although the involvement of specific microbes is currently unclear.",
"It has been estimated that 13% of global cancer burden can be attributed to microbial infections. Of the 500–1,000 members of the microbiota and ~10^(12) known microbes on earth, only 10 have been characterized as Group I human carcinogens. While there is no dearth of data demonstrating the influence of microbiota in causation and therapeutic outcomes in colorectal and pancreatic cancers, the research in breast cancer is in its infancy. The insufficiency can be attributed to the fact that the breast has been considered a sterile organ until recently. Recent studies confirm the presence of a distinct breast microbiota that is clearly distinguishable between healthy and cancerous breast tissue. In fact, breast tumors are found to be the richest and most biodiverse among the nine tumor types examined, and the tumor-specific microbes reside within tumor as well as immune cells in a cell wall-deficient intracellular state. Translocation of oral microbes via the bloodstream into breast cancers has been confirmed. Also, distinct differences in gut microbiota have been observed between breast cancer patients and healthy controls, suggesting an association with breast cancer initiation and progression. Interestingly, tumor-resident intratumoral bacteria may drive metastatic colonization of breast cancer by inducing cytoskeletal reorganization in circulating tumor cells, thereby enhancing resistance to mechanical stress in the circulation. Microbes are enzyme factories, and microbiota-derived metabolites, such as Lipopolysaccharide. Moreover, bacterial quorum-sensing molecules have also been shown to enhance proliferation and potentiate angiogenesis and invasion of breast cancer cells. Dysbiosis also influences metabolism and bioavailability of drugs, therefore regulating therapy response. A spontaneous mammary tumorigenesis model infected with Helicobacter hepaticus yields more aggressive multifocal mammary tumors with significantly higher accumulation of neutrophils around the periphery of the tumors and in the stroma, and interestingly, these protumor effects are inhibited by the elimination of neutrophils following antibody treatment. It seems that the effects of microbiota and its metabolites on breast cancers are mediated at least partially via the immune system, as the breast microbiota correlates with the immunological signatures of breast cancer and the extent and expression of tumor-infiltrating lymphocytes. It is intriguing how microbes can influence the tumor immune microenvironment and influence tumor progression.",
"Drawing connections between obesity, microbiota, and breast cancer, increased abundance of Firmicutes and decreased levels of Bacteroidetes have been shown in the obese state as well as in breast cancer versus normal breasts and malignant breast cancer versus benign breast disease. Overall, many microbial families and species enriched in the obese state are similar to those observed in breast cancer samples compared to normal breasts, suggesting a microbial link between obesity, dysbiosis, and breast cancer risk. Dysbiosis leads to increased gut permeability resulting in elevated circulating LPS levels causing inflammation and insulin resistance. Systemic LPS stimulates Adipocyte fatty acid binding protein. Microbiota is also known to regulate the gut endocannabinoid system that can potentially stimulate an obese phenotype. Bacteroides fragilis , a common gut colonizer, has been associated with childhood and adolescent obesity. Sun et al. demonstrated that B. fragilis colonization in high-fat diet-fed mice led to more severe metabolic dysfunction and hyperglycemia mediated by increased bile acid glycoursodeoxycholic acid. A decrease in obesity parameters including BMI, fat mass, blood glucose, blood lipid, and hepatic function is associated with a decrease in the abundance of B. fragilis in the gut. Using a stringent constrained linear regression analysis, Shen et al. demonstrated the association of obesity with intestinal B. fragilis abundance in perimenopausal and postmenopausal women. B. fragilis accelerates obesity, in part, by suppressing acetic acid levels; acetates fuel the growth of health-associated microbes responsible for producing propionate and butyrate that maintain the integrity of the gut mucosa. These studies have established a strong link between the enteric abundance of B. fragilis and obesity.",
"Most interestingly, we recently discovered that the female breast is inhabited by B. fragilis , which is more abundant in cancerous compared to normal breast tissue. Our recent study has shown that enteric as well as mammary duct colonization with enterotoxigenic B. fragilis . In the present study, we aim to decipher the impact of enteric ETBF infection on distant metastasis of breast cancer cells, specifically asking. For immunohistochemistry, rabbit monoclonal anti-E-cadherin, anti-cMyc, anti-Notch1, anti-NICD, anti-Oct4, anti-Nanog, anti-KLF4, and anti-Ki67 were purchased from Cell Signaling Technology, Beverly, MA, USA. Anti-β-catenin, anti-CD31, anti-Jagged1 antibodies were purchased from Santa Cruz Biotechnology, Santa Cruz, CA, USA. IHC-specific rabbit monoclonal cMyc was purchased from Abcam, Cambridge, MA, USA. Mouse monoclonal β-actin was purchased from Sigma-Aldrich, St. Louis, MO, USA. Anti-IL6 and anti-TNFα antibodies for ELISA were obtained from Santa Cruz Biotechnology, Santa Cruz, CA, USA. For flow cytometry, anti-CD3, anti-CD4, anti-CD8, anti-CD45, anti-CD11c, anti-CD11b, anti-FOXP3, anti-PD-L1, anti-F4/80, anti-granzyme B, anti-IFNγ, and anti-TNFα antibodies were purchased from BD Biosciences, San Jose, CA. Horseradish peroxidase-conjugated goat anti-rabbit IgG, goat anti-mouse IgG, and donkey anti-goat IgG were purchased from Sigma-Aldrich, St. Louis, MO, USA. Chemiluminescent peroxidase substrate and 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide.",
"Twice parous BALB/c mice were procured from Charles River, maintained in-house, and were given antibiotic cocktail.",
"For flow cytometric analysis of immune infiltrates, spleen, tumors, liver, and lungs were excised and immediately collected in harvest media and the Aperio Toolbox. Here, to examine the impact of ETBF on distant metastasis of breast cancer, we used the 4T1 breast cancer syngeneic mouse model. Using a mammary intraductal. To determine the mode of metastatic dissemination, mice were sacrificed at three different time points: week 1, week 2, and week 4 post-tumor cell implantation. In addition to accelerated tumor growth. Marked increase in lung and liver metastatic lesions were observed in the ETBF group compared to controls. Furthermore, we conducted in vivo whole-body bioluminescent imaging, ex situ imaging of lungs and liver, ex situ metastatic colony formation assay, and histological analysis to validate metastatic seeding. Whole-body bioluminescent imaging showed detectable spreading of the primary breast tumor to distant visceral organs, most likely lungs and liver in addition to bones, with the ETBF group exhibiting a higher metastatic spread. Interestingly, ex situ imaging of liver and lungs revealed no metastatic seeding in lungs and liver at weeks 1 and 2 post-tumor cell implantation in the control group, while seeding was evident from the luminescent signals starting at week 1 post-tumor cell implantation in ETBF-colonized mice, confirming significantly more and earlier metastatic dissemination and seeding in ETBF-infected mice. Similarly, in ex vivo metastatic cell colony formation assay, liver and lung explants from tumor-bearing mice were digested and seeded in the presence of 6-thioguanine. While no metastatic cell colonies formed in liver digests at week 1 post-tumor cell implantation, a significantly higher number of metastatic cell colonies formed at week 2 and 4 post-tumor cell implantation in the ETBF group compared to the control group. Metastatic cell colonies formed in lung digests in the ETBF group were considerably more in number and size in comparison to controls, starting at week 1 post-tumor cell implantation, suggesting that metastatic seeding in ETBF gut colonized mice started immediately after tumor implant regardless of tumor growth. In histological sections, although micrometastasis could not be detected at weeks 1 and 2 post-tumor cell implantation, widespread inflammation and neutrophil infiltration were evident in lungs and liver of ETBF-infected mice, while large metastases were evident at week 4 post-tumor cell implantation. It, therefore, suggested that the gut colonization with ETBF induced systemic inflammation in the distant organs, i.e., lungs and liver, which supported metastatic seeding in these mice. We also examined the tumors of respective groups by IHC. In line with tumor progression, Ki67 expression was notably higher in the ETBF-colonized group, as was the expression of cMyc in the nuclei of tumor cells. While β-catenin was completely membrane-bound or cytoplasmic in control tumors, it was mostly localized in nuclei in the ETBF-infected group. Notch1 expression was significantly denser in the tumors of ETBF-infected mice, as was the expression of cleaved-Notch1 in the nuclei. Vascular endothelial growth factor receptor 2. Collectively, these results show that gut colonization with ETBF accelerates breast cancer metastasis.",
"Since the pattern of metastatic dissemination was indicative of a more efficient seeding in ETBF-infected mice, we hypothesized that ETBF manipulated the premetastatic niche in the liver and lungs, supporting the establishment of secondary tumors in these organs. To test our hypothesis, non-tumor-bearing mice were infected with ETBF by oral gavage and sacrificed at day 5 post-infection, when the bacteria had stably colonized the gut. Serum and vital organs were analyzed to uncover the ETBF-induced changes. The serum was analyzed for 29 chemokines including proinflammatory chemokines, Th17 response chemokines, and cytokines using a multiplexed ELISA. While most of the circulating cytokines did not vary significantly between the sham control and ETBF-infected groups, some interesting patterns were apparent. Of the nine Th17 responsive chemokines, IL17A and IL17E were found to be significantly upregulated in the serum of ETBF-infected mice. Out of the six members of the IL17 family of cytokines, IL17A, IL17B, and IL17E have been found to aid in tumor growth, angiogenesis, metastasis, and chemoresistance. Of all the cytokines, a significant upsurge was observed only in IL15 and IL27p28. While IL15 has been shown to be associated with better prognosis in breast cancer, IL27p28 has been shown to be involved in growth and metastasis of triple-negative breast cancers and has been frequently detected in breast cancer patients but undetectable in normal women. With a significant increase in IL17A, IL17E, and IL27p28 levels, the circulatory cytokine milieu thus appears to be favorable for breast cancer progression.",
"Next, we investigated the effect of ETBF enteric infection on systemic immune modulation. As a surrogate for systemic immune modulation, spleens were isolated from mice harboring gut ETBF infection for 5 days and analyzed by flow cytometry. In the spleen, total CD4^(+) T-cell population remained fairly unchanged along with a static population of CD4^(+)Foxp3^(+) T regulatory cells and CD8^(+) T cells. However, there was a significant reduction in CD11c^(+) dendritic cells in the ETBF group, suggesting a systemic inflammatory response to ETBF infection. There was also a statistically significant decline in the proportion of myeloid cells. Stimulated CD8^(+) T cells trended toward increased granzyme B and IFNγ in the ETBF group, but the difference was not statistically significant, suggesting that while the CD4^(+) T cells were activated in ETBF-infected animals compared to the controls, the status of CD8^(+) T cells remained fairly unchanged.",
"We then sought to find out how ETBF enteric infection shaped the immune microenvironment of liver and lungs by flow cytometry. At day 5 post-ETBF infection, while lungs showed significantly higher accumulation of CD4^(+) T cells, CD4^(+)Foxp3^(+) T cells, CD8^(+) T cells, CD11b^(+) myeloid cells, CD11b^(+)F4/80^(+) macrophages, and CD11c^(+) dendritic cells in the ETBF group compared to the sham control group, the liver showed higher accumulation of CD4^(+)Foxp3^(+) T regulatory cells in the ETBF-infected group. Histologic evaluation of liver and lungs from ETBF-infected mice showed interesting alterations in comparison to the sham control group. Histology of the liver showed acute-phase inflammation, microgranuloma, dead cells between neutrophils, clusters of neutrophils, hemorrhage, accumulated neutrophils, necrosis <24 h old, extramedullary hematopoiesis. In the lungs from ETBF-infected mice, neutrophils and B cells around bronchiole and pulmonary vein were observed. To closely follow the course of events, we also tested the serum from ETBF-infected, 086Mut-infected, and sham control 4T1 tumor-bearing mice at day 3 and 4 weeks post-tumor cell implantation for the levels of early-response cytokines, IL6 and TNFα. Both the cytokines showed consistent and significant upregulation from day 3 through week 4 post-tumor cell implantation in the ETBF group. These results clearly demonstrate that ETBF gut colonization induces a systemic inflammation and prepares the premetastatic niche for the breast cancer cells.",
"Metastasis is a complex and inefficient process involving the escape of cancer cells from the primary tumors, also known as “the seed” and its establishment in distant organs, as known as “the soil.” The evolution of a tumor from benign to metastatic state involves multiple molecular mechanisms. After establishing that ETBF enteric infection causes systemic inflammation and prepares the lungs and liver as the potential metastatic sites, we asked whether it also alters the tumor microenvironment. Hence, we investigated the tumor microenvironment in both the sham control and ETBF-infected groups. Confirming the impression from H&E staining, trichrome staining showed significant stroma infiltration and fibrosis in the tumors from ETBF-infected mice. Fibronectin expression was also significantly higher in the ETBF-infected group compared to tumors from the sham control group, along with higher CD31 expression showing more tumor angiogenesis. While E-cadherin expression seemed to be diminished, N-cadherin was marginally higher in the ETBF-infected group. Mesenchymal marker vimentin also showed a higher expression in tumors from ETBF-infected mice in comparison to those from the sham control. These results suggested that an EMT response in mammary tumors was elicited by ETBF gut infection. Next, we evaluated the immune landscape of the tumors by flow cytometry and immunohistochemistry. Immunoblot analyses showed a higher expression of Notch as well as EMT markers in ETBF tumors compared to that in the control group. Tumor-infiltrating lymphocytes were evaluated by flow cytometry. While CD11b^(+) myeloid cells, CD11b^(+)F4/80^(+) macrophages, and CD11c^(+) dendritic cells trended toward higher accumulation at week 1 post-tumor cell implantation in the ETBF group, CD11b^(+)F4/80^(+) macrophages and CD11c^(+) dendritic cells showed significantly higher accumulation in tumors from ETBF-infected mice at 4 weeks post-tumor implantation. Also, CD4^(+) T cells showed a notable increase. IHC was performed to visualize the spatial organization of immune infiltrates. Macrophages and their precursors, monocytes, marked by IBA1 showed higher tumor infiltration both at week 1 and 4 post-tumor cell implantation in the ETBF group, while higher IBA1-positive cells were also observed in adjacent normal breast of ETBF-infected mice. In contrast, CD8α^(+) cell accumulation within tumor and adjacent normal breast was marginally different in ETBF-infected mice. As a surrogate for systemic immune modulation, spleens from tumor-bearing mice at 1 week and 4 weeks post-tumor cell implantation in the ETBF group were resected and analyzed by flow cytometry. Immune phenotyping showed a modulation in the proportion of CD8^(+) T cell and CD11b^(+)F4/80^(+) macrophage populations at week 1 post-tumor cell implantation ETBF group. Alterations were also observed at week 4 post-tumor cell implantation ETBF group, but only CD11b^(+)F4/80^(+) macrophages achieved statistical significance. On interrogating the serum cytokines in these tumor-bearing mice, we observed a significant upregulation of IL5 and IL27p28 in the ETBF group, similar to the non-tumor-bearing mice, reiterating the protumorigenic role of ETBF in this breast cancer model. Unlike non-tumor-bearing mice, there was no significant alteration in the levels of IL17A and IL17E between the two groups of tumor-bearing mice, but there was a significant increase in IL17A/F, heterodimer of IL17A and IL17F, which are known to work in concert to enhance breast cancer aggressiveness. Additionally, there was a significant upregulation of prometastatic cytokines IL10, IL6, and MCP1 in the circulation in ETBF-infected mice harboring 4T1 tumors in comparison to sham control mice with 4T1 tumors. Together, these results show that ETBF gut infection leads to modulation of the tumor microenvironment.",
"To further investigate the mechanism of distant metastasis aggravated by ETBF enteric infection, the organs were analyzed by immunohistochemistry and flow cytometry. Metastatic lesions in the lungs and liver of ETBF-infected mice were significantly larger compared to those of the sham control group. In the liver sections, most of the metastases and small clusters of immune cells stained strongly positive for Ki67, indicating that the cells in the metastatic lesions were proliferating in the ETBF group. Metastatic lesions were densely surrounded by CD3^(+) immune cells in the periphery. While the primary tumors expressed little N-cadherin, the metastases expressed detectable levels of both N-cadherin and E-cadherin in the ETBF-infected mice. Interestingly, similar to primary tumors, the metastatic liver in the ETBF-infected group exhibited very high fibronectin expression. The liver of ETBF-infected 4T1 tumor-bearing mice also expressed higher levels of CD31 and VEGFR2, suggesting profuse angiogenesis. While IHC did not show any difference in cytotoxic CD8α^(+) T-cell accumulation in the liver, significantly higher levels of monocytes and macrophages were detected in the liver of ETBF-infected mice by IBA1-specific IHC. By flow cytometry, statistically significant upregulation was observed only in the levels of CD11b^(+)F4/80^(+) macrophages and CD11b^(+) myeloid cells at week 1. Scrutinizing the lung metastatic lesions, we found that most of the lungs in the ETBF gut colonized mice were filled with metastatic cancer cells and immune infiltrates, majorly neutrophils, which were far less in the sham control group. One hundred percent of the metastases and surrounding neutrophils stained strongly positive for Ki67. In contrast, not only were the metastatic lesions smaller in the control group, they were not actively proliferating as well. While there was no difference in the density of CD3-positive cells in the lungs of the two groups, fibronectin level was lower in the lung metastases in the ETBF-infected group. Interestingly, both N-cadherin and E-cadherin levels were higher in the lung metastases in the ETBF-infected group. Mice harboring ETBF gut infection exhibited a higher expression of CD31 and VEGFR2 in the lung metastases that could support higher vasculogenesis to sustain proliferation of metastatic lesions. Flow cytometric analysis revealed significantly higher levels of CD8^(+) T cells and CD4^(+) T-cell infiltrates in lungs of 4-week ETBF-colonized mice, while other cell types did not vary significantly. IHC showed a significantly higher accumulation of IBA1-positive monocytes and macrophages and marginally lower accumulation of cytotoxic CD8α^(+) T cells in the lung metastases of ETBF-infected mice in comparison to those in sham control mice. These results unequivocally show that enteric infection with ETBF not only enhances early and efficient metastatic dissemination of cancer cells growing as primary tumors in mammary gland ducts but also causes systemic inflammation, modulates the tumor microenvironment, and primes potential metastatic niches to allow the development of metastatic lesions."
] |
PMC10785397
|
BMC Health Services Research
|
Causes and consequences of quack medicine in health care: a scoping review of global experience
|
11-01-2024
|
Background The field of health has been facing challenges with fraudulent practices and the prevalence of “quack medicine”. Many cases have given rise to this issue. Therefore, this study aims to comprehensively investigate and categorize the causes and consequences of quack medicine in the healthcare. Methods A scoping review, using the 5 stages of Arksey and O’Malley’s framework, was conducted to retrieve and analyze the literature. International databases including the PubMed, Scopus, Embase and Web of Science and also national Iranian databases were searched to find peer reviewed published literature in English and Persian languages. Grey literature was also included. Meta-Synthesis was applied to analyze the findings through an inductive approach. Results Out of 3794 initially identified studies, 30 were selected for this study. Based on the findings of this research, the causes of quackery in the health were divided into six categories: political, economic, socio-cultural, technical-organizational, legal and psychological. Additionally, the consequences of this issue were classified into three categories: health, economic and social. Economic and social factors were found to have a more significant impact on the prevalence of quackery in the health sector. Legal and technical-organizational factors played a crucial role in facilitating fraudulent practices, resulting in severe health consequences. Conclusion It is evident that governing bodies and health systems must prioritize addressing economic and social factors in combating quackery in the health sector. Special attention should be paid to the issue of cultural development and community education to strengthen the mechanisms that lead to the society access to standard affordable services. Efforts should be made also to improve the efficiency of legislation, implementation and evaluation systems to effectively tackle this issue.
|
[
"Issues such as quackery and charlatanism have long been a concern for human civilizations and communities since the development of health service delivery structures and processes. While the forms and severity of these issues may vary across nations, it can be argued that all health systems are susceptible to some level of quackery [ ]. In the health system, particularly in developing countries, a phenomenon known as “Quack Medicine” has been a persistent problem, causing harm in various branches of health care services. Quackery refers to unproven or fraudulent medical practices that there is no scientifically plausible rationale behind them. Furthermore, someone who does not have professional qualification, formal registration from a legitimated institution, or required knowledge of a particular branch of medicine but practices in the field of medicine, is called quack [ – ]. So quack medicine refers to the fraudulent practice of quacks in the medical field claiming to possess the ability and experience to diagnose and treat diseases, and pretending that the medicine or treatment they provide are effective, generally for personal and financial gain [ ]. A study from India defines the following individuals as quacks as well: practitioners of local types of medicine such as Indian Medicine Ayurvedic and Homeopathy who practice modern practice although they are not allowed to do so and those who engage in any type of medicine which have not been recognized by law [ ]. Other examples of this phenomenon include billing for services not provided, substituting substandard products for standard ones, taking unnecessary steps to get more reimbursement, and prescribing unnecessary medications for financial gain instead of addressing medical needs [ ].",
"In a historical survey conducted by the American Medical Ethics Association in 2000, it was found that in 1775, only 400 out of every 3,000 individuals claiming to be doctors had legitimate medical degrees from accredited universities and schools. Also, the vast geographical size of this country and the dispersion of experienced doctors led to the public seeking to refer to quack doctors. In the 19th and 20th centuries, these charlatans utilized pseudo-scientific terms and advanced equipment and technologies to deceive people, blurring the line between a legitimate doctor and a quack [ ]. In 2020, the Independent newspaper reported on this issue in Bangladesh, revealing that 75% of quack doctors were prescribing inappropriate medications to patients, with 7% prescribing drugs that were completely harmful and dangerous [ ].",
"The seriousness of this problem led the World Health Organization What are the main reasons for the prevalence of quack medicine in the healthcare? and International Transparency Organization. National Iranian databases were also searched for relevant literature in Persian. These databases included SID, Magiran and IranDoc. Furthermore, reference lists of selected documents were also scanned for additional relevant articles. The details of all the selected studies were saved in EndNote X7 software, which can be used to find duplication in extracted studies.",
"A total of 3794 documents were retrieved from the initial search, of which 2477 were removed due to duplication. Then two of authors reviewed the title of 1317 remained articles and 852 documents further removed as they were not found to address the topic directly. In the next step, after the first screening, the entire texts of 465 articles were checked based on the exclusion criteria established for the research, and 435 were rejected. Eventually 30 papers were included for the purpose of the study, and the causes and effects of charlatanism in the field of health were used to explain the results.",
"The process of study selection is shown in Fig. . The similar information was extracted for grey literature. In addition, the frequency of studies included in the research by date, type and design is shown in Table .",
"Meta-Synthesis was applied to analyze the findings through an inductive method. The full text of all finalized documents were studied carefully. Findings of the studies, the reasons and the consequences of quack medicine, were summarized in two separate tables. These summaries were then grouped into broader categories based on the similarities between them. During the final phase, the research team engaged in a thorough discussion regarding the initial categorization of reasons and consequences. Amendments were made as needed including paraphrasing headings, modifying classifications or transferring sub-categories. This iterative process continued until consensus was achieved. Tables and show the final categorization for factors contributing to quack medicine and its impacts on healthcare respectively.",
"",
"",
"Among the retrieved documents, the highest number of articles published within the period of 2011–2022 (13 out of 30). The number of included studies by type is 5 original studies, 5 review studies and 20 studies from other types. Furthermore, almost half of the selected studies were qualitative, followed by five review, three commentary, one cross-sectional and seven studies had no specific design. The frequency percentage of studies according to the mentioned characteristics is shown in the Table .",
""
] |
PMC10350961
|
The Journal of Physical Chemistry Letters
|
Bond Polarizability as a Probe of Local Crystal Fields
in Hybrid Lead-Halide Perovskites
|
05-07-2023
|
A rotating organic
cation and a dynamically disordered soft inorganic
cage are the hallmark features of organic-inorganic lead-halide perovskites.
Understanding the interplay between these two subsystems is a challenging
problem, but it is this coupling that is widely conjectured to be
responsible for the unique behavior of photocarriers in these materials.
In this work, we use the fact that the polarizability of the organic
cation strongly depends on the ambient electrostatic environment to
put the molecule forward as a sensitive probe of the local crystal
fields inside the lattice cell. We measure the average polarizability
of the C/N–H bond stretching mode by means of infrared spectroscopy,
which allows us to deduce the character of the motion of the cation
molecule, find the magnitude of the local crystal field, and place
an estimate on the strength of the hydrogen bond between the hydrogen
and halide atoms. Our results pave the way for understanding electric
fields in lead-halide perovskites using infrared bond spectroscopy.
|
[
"The efficiency\nof hybrid organic-inorganic\nlead-halide perovskite. The main reason for this choice is\nthat these modes are by far the strongest in terms of IR-intensity.^(17 , 30 , 41) Elementary counting of the degrees\nof freedom reveals. In C we show how the. To relate it to the polarizability\n⟨ α^(H) ⟩ measured in experiment, α _(ij)^(H) must be averaged over all\nspatial orientations of the bond and different configurations of . For MAPbBr_(3), which is cubic\n(on average) at room temperature, one can write):where the index H _(k) runs over the six longitudinal C(N)–H\nstretching\nmodes for further details.",
"The quantities ρ and α^(H) in can be determined theoretically from the\nliterature and DFT calculations\nfor different scenarios, such as the presence of defects. relates these theoretical\ncalculations to the measured average polarizability, ⟨ α^(H) ⟩, allowing one to investigate\nmicroscopic properties of HOIPs using molecules as experimental probes.",
"To illustrate the formal discussion above, we proceed with measuring\nthe average polarizability ⟨ α ^(H)⟩ for a bulk single crystal sample of MAPbBr_(3) in the cubic phase. For this purpose, we measure the group\nrefractive index n _(g)( ω ) in the mid-infrared frequency range relevant for vibrational degrees\nof freedom of methylammonium.^(17) The advantage\nof the group index for probing molecular polarizability, which in\ngeneral provides much weaker contribution to the refractive index\nas compared to the electronic one, lies in the fact that n _(g)( ω ) features stronger divergence\nnear resonances and is therefore more sensitive as compared to the\nphase index n _(ph)( ω ). Indeed, n _(g)( ω )/ n _(ph)( ω ) ≈\nΩ/( ω – Ω) near the resonance\nfrequency Ω.",
"To measure the group\nrefractive index in a direct manner, we develop\na time-resolved setup depicted in A. The setup utilizes two samples of single-crystal\nMAPbBr_(3): the actual test sample in which n _(g) is measured and a probe sample for a broadband\nultrafast detection of mid-infrared pulses by means of the optical\nKerr effect. By measuring the time of arrival of the mid-IR\npulse at the probe sample with and without the test sample, one obtains\nthe delay δt introduced by the test sample.\nThe time delay δt for the mid-IR pulse due\nto traveling through the perovskite sample of thickness d = 1.6 mm, is , where n _(g) and n _(g)^(air) ≈ 1 are the group refractive indices of MAPbBr_(3) and air, respectively; c is the speed of light.",
"The ultrafast optical Kerr effect in the probe sample is detected\nby the standard time-resolved pump-probe method in a balanced detection\nscheme). An\nexample of a time-resolved transient Kerr response for λ = 5 μm mid-IR pump with and without the test sample is\ndepicted in B. The difference in arrival time of the mid-IR pulse at the probe\nsample δt is measured as the distance between\nthe two peak positions; the inset shows the FTIR of the pump pulse\n(see ref). Performing\nsimilar measurements for other mid-IR wavelength values, one can extract\nthe perovskite group index n _(g)( ω ) = n _(g)^(air) + cδt / d over a broad range of wavelengths.",
"The measured\ngroup refractive index dispersion n _(g)( ω ) of bulk single crystal MAPbBr_(3) as a\nfunction of the photon energy, ℏω , is\ndisplayed in . Here, we identify two regions of absorption, one in the\nlow energy region at ∼0.17 eV) in\nthe region outside the immediate vicinity of the absorption band corresponding\nto the C(N)–H stretching modes justifies our assumption that\nthese modes can be approximated as isolated from the nearby C(N)–H\nbending modes.",
"To extract the molecular contribution to the refractive index,\nwe need to subtract the electronic contribution from the measured\ninfrared n _(g)( ω ).\n(Note that the electronic contribution to the refractive index is\ntypically the dominant one, since electrons are much lighter than\nions. Only close to a molecular resonance does the molecular contribution\nbecome important.) To this end, we use our previous measurements of\nthe phase index in the visible and near-IR region.^(45) In this high frequency range near the bulk band transition\nfrequency, ℏω ∼ Δ_(gap) and the refractive index is determined by the electronic polarizability\nof the lead-halide cage. By first fitting the high-frequency phase\nindex from ref with a Sellmeier expression, and then calculating the group index\nfrom it and extrapolating the result to the mid-IR frequencies, one\ncan obtain the electronic part n _(g,el)( ω ) of the total group refractive index n _(g)( ω ) coming from the crystal cage. n _(g,el)( ω ) in the mid-IR\nrange calculated this way is plotted as a light blue dashed line in providing an excellent\nfit to the data in the relevant frequency range away from the nearby\nabsorption band. The molecular part of the group index n _(g,mol) is found by subtracting the cage electronic contribution\nfrom the total refractive index: n _(g,mol)( ω ) = n _(g)( ω ) – n _(g,el)( ω )).",
"Once n _(g,mol)( ω ) is known, it is possible to calculate the polarizability\nof the\ngiven mode by fitting it to the classical resonance profile near the\nresonant frequency. We focus on the C(N)–H stretching modes\ncentered around ℏ Ω_(H) ≈ 0.37 eV–H bonds. However,\ndue to strong mass mismatch between H and C(N), the natural frequencies\nof these modes are very similar.^(17 , 30 , 41) If we assume that C and N are infinitely heavy compared\nto hydrogen, then each vibration of H along the C(N)–H bond\ncan be considered independent and decoupled from the rest. Within\nthis approximation.",
"To connect n _(g,mol)( ω ) to ⟨ α _(0)^(H)⟩, we account\nfor the screening effect due to the polarizable cage and write in\nthe vicinity of Ω_(H) for derivation),where is the electronic contribution\nof the phase\nrefractive index at Ω_(H), and ⟨ α _(0)^(H)⟩ is the average static( ω ) to the expression in . From the fit, we obtain ⟨ α _(0)^(H)⟩ ≈ and naively assume that the molecule\nrotations are uncorrelated with the inorganic cage. In terms of , this limit corresponds\nto , for which) the average polarizability\nremains unrenormalized even in the presence of strong crystal fields where α _(0)^(H)( E = 0) can be taken from C so that Å^(3). Since the discrepancy\nbetween this value and the experimental one above is beyond the error\nmargin of our approach, we can conclusively rule out uncorrelated\nmolecule-cage dynamics, in agreement with prior results.^(26 , 49 − 51) If, conversely, we fix the density matrix in in accordance with previous\nreports in the literature,^(28) then we arrive\nat the value for the local crystal field experienced by the N–H\nbond | E _(CF)| =). Therefore, to account for the relatively large\nvalue of E _(CF), we need to go beyond the\npoint-source approximation for the atoms in the inorganic cage. The\nlowest-order multipole moment would be the quadrupolar moment D of the bromine atom with the axis along Pb–Br–Pb.\nKnowing | E _(CF)| and the distance between\nH and Br one can estimate that D ∼ +1 eÅ^(2). Recalling now that a hydrogen bond can be defined as an\ninteraction between H and a multipole potential of a neighboring atom,^(52) we estimate it from the energy of the H–Br\nelectrostatic interaction eV). This value is in reasonable\nagreement with previous estimates^(50 , 53) of the energy\nof the H–Br hydrogen bond, illustrating that the proposed here\nmolecular probe can provide important insight into the existence of\nhydrogen bonding in HOIPs.^(54 , 55)",
"In conclusion,\nwe propose the semiautonomous A-site cations in\nHOIPs as a sensitive local probe for optical spectroscopy, which complements\nthe existing techniques such as NMR and NQR. To illustrate the formulated\ntheoretical framework, we have analyzed the average polarizability\nof the N–H stretching mode extracted by measuring the group\nrefractive index of a bulk single crystal sample of MAPbBr_(3) in the mid-IR wavelength range. Based on the analysis, we have ruled\nout the possibility of an uncorrelated motion of methylammonium cation\nin a PbBr cage and estimated local electric fields at the locus of\nthe C(N)–H bond. We also estimated the value of the quadrupole\nmoment for the Br atom, and the energy of the H–Br hydrogen\nbond. Our work proposes a new approach to the study of the complex\nbehavior of the dynamically disordered inorganic cage, which will\nprovide novel insight into fundamental properties of lead-halide perovskites.\nIn particular, being all-optical, our approach can be employed to\nstudy ultrafast transient behavior of lattice irregularities, for\nexample polaronic structures formed around photoexcitations. Since\nit is widely expected that the formation of such polarons underlies\nsome most important optoelectronic properties of lead halide perovskites,^(10) our results offer an approach to clarify some\nof the most pressing questions related to the solar energy harvesting\napplications of lead-halide perovskites."
] |
PMC10500542
|
Cureus
|
Hand Scrubbing and Donning of Sterile Surgical Gloves: An Observational Clinical Audit of Novice Dental Surgeons
|
15-08-2023
|
Background The most critical factors in the satisfactory recovery of a patient post-surgery are obedience to sterilization and aseptic protocol. Using aseptic principles, the standard hand scrubbing and gloving procedure prevents contamination of the surgical site and aids in infection control. Methods Eighty dental interns were observed during minor oral surgical procedures for hand scrubbing and donning sterile surgical gloves, following the steps and guidelines provided by World Health Organization (WHO). The dental interns were evaluated, and in order to enhance their understanding of hand scrubbing and donning surgical gloves, desensitization programs were conducted through lectures using PowerPoint presentations. After one week, the participants were observed and evaluated again. This program made the participants aware of asepsis and infection control in clinical practice. Results Prior to intervention, only 37.14% of young dental surgeons performed proper conventional hand hygiene practices. After the intervention, this percentage increased to 62.142%, indicating a significant improvement. Regarding the donning of sterile surgical gloves, 43.75% of participants followed the standard steps before the intervention. After the intervention, the percentage raised to 86.25% indicating substantial growth. Conclusion Observations before and after the evaluation demonstrated significant changes in the acceptance rates for the fundamental criteria of hand hygiene and donning sterile surgical gloves. Adhering to both procedures according to WHO guidelines will help to reduce the risk of infections and raise awareness about asepsis in the practice among young dental surgeons.
|
[
"Prevention of surgical site infections is critical for evaluating control mechanisms within healthcare systems and implementing the necessary changes. However, such monitoring can be costly, posing an enormous problem to healthcare systems around the world, particularly in impoverished countries [ ].",
"Putting on gloves before surgery and taking them off during surgery constitutes some of the most common ways for a surgeon to infect oneself and the disinfected operative area. There are two ways to depict donning sterile surgical gloves i.e., open and closed gloving technique. The scrub person's hands should remain inside the sleeves and not touch the cuffs when using the closed-glove technique. The scrubbing person's hands slip all through the sleeves and beyond the cuffs when using the open-glove technique. Previous research has shown that the interface between the glove cuff and the gown is where contamination occurs most frequently [ - ]. Scrubbing, barrier garments, gloving, drapes, and tool sterilization are all essential aseptic measures for maintaining the sterile field's integrity. However, due to the hurried nature of the operating room/IEC/2023/1071, this four-week clinical review was conducted at the Department of Oral and Maxillofacial Surgery's minor oral surgery room at Sharad Pawar Dental College, Wardha. The study included 80 young dental surgeons undergoing internship and having adequate knowledge about sterilization and asepsis, and hence the population was selected. To create the methodology, planning, and effects of this research, an in-depth review of the literature was executed.",
"Pre-evaluation",
"In the first week, all participants were monitored while scrubbing their hands and donning surgical gloves prior to minor oral surgery procedures. The observation was noted and compared to WHO standards for hand scrubbing and donning sterile surgical gloves. To assess all interns, we took the following evaluation criteria. The procedures outlined in the tables assess the effectiveness of young dental surgeons' hand hygiene and donning sterile surgical gloves. In Table for hand scrubbing, every 'yes' signifies one correct step followed and each 'no' indicates one incorrect step from an entire set of ten steps. Similarly in Table for donning sterile surgical gloves from a total of eight steps same criteria were applied. We calculated compliance with these 10 criteria for hand cleaning and eight criteria for donning sterile surgical gloves for each participant and totaled the outcomes of all those involved in each criterion individually. These percentages were mainly utilized to calculate the general compliance of all participants to each criterion.",
"The sensitization",
"Following the first week of gathering information and observation, everyone who participated was given a presentation. It comprises a demo video of the conventional hand scrubbing and surgical gloving approach according to WHO recommendations. Subsequently, third-year residents of the oral surgery department also gave an individual demonstration of performing each and every step of hand scrubbing and gloving in accordance with WHO guidelines in the minor oral surgical room to the participants. Subsequently, third-year residents of the oral surgery department also gave an individual demonstration in the minor oral surgical room to the participants. A pictorial guide for hand scrubbing was also displayed inside the minor oral surgical room.",
"Post-evaluation",
"After one week of intervention, all participants were inspected again for compliance with the hand scrubbing and standard surgical gloving criteria in the subsequent phase of the audit, i.e., the final week. Each correctly completed step received one mark, and all 10 stages for hand scrubbing and eight steps for donning sterile surgical gloves were examined free of constraints. Everyone was presented with a total score, and the average improvement was computed by putting all the compliance scores together. We calculated compliance with these 10 criteria for hand scrubbing and eight criteria for donning sterile surgical gloves for each participant and added the scores of all participants to each criterion independently. The overall conformance of all participants to each criterion was calculated using percentages.",
"Eighty young dental surgeons, 55 females and 25 males, were observed for the purpose of awareness and implementation of conventional hand hygiene skills, as well as their use of sterile surgical gloves. The cumulative percentages of compliance of all participants to each criterion separately for hand hygiene had the smallest difference of 20% because these processes were precisely followed by all participants. In addition, 30% of candidates disregarded criterion 3 for donning sterile surgical gloves: opening the outer package without touching it to the sterile surface and placing the inside packet on the sterile surface. The greatest rate of growth was shown in criteria 9, where 70% of participants gained knowledge to scrub their palms with their digits, with a 70% variance among pre-post-intervention. In the instance of hand hygiene, all participants accomplished 37.14% of the standard guidelines during pre-sensitized observation, however, 62.142% met them afterward the sensitization. The percentage of rise in before and after intervention, hand hygiene compliance rates remained exceptional at 30.002%. In the case of wearing sterile surgical gloves, interns met 43.75% of the demands during the pre-intervention inspection and 86.25% after the sensitization. The rate of increase in surgical glove compliance rates is impressive at 86.25%. After taking the feedback from the participants about the sensitization the maximum preferred was the individual demonstration as shown in. The result can be well depicted in the form of a bar chart given in. The bar chart displays pre-evaluation in blue color, post-evaluation in orange color and percentage improvement in grey color.",
"As in minor surgical procedures of oral surgery, while doing patients, two techniques are most important: hand hygiene and surgical gloving. Before we start a surgical procedure, we should follow all hand hygiene steps according to WHO guidelines. If bacteria and viruses enter the bloodstream through patients, it may cause serious infections like hepatitis, HIV, severe acute respiratory syndrome, etc. Following the aseptic technique is of utmost importance to prevent the spread of infection while doing minor procedures such as Exodontia, Arch bar placement, 3rd Molar surgery, etc. This surgical audit intends to evaluate the procedures like hand scrubbing and donning gloves in young dental surgeons in the Oral and Maxillofacial Surgery Department. In our study, the participants fulfilled Criteria 1, 4, and 6 in Table and Criteria 3 in Table . Before the intervention, the compliance rate at Lahore General Hospital was 70% and 55%, accordingly [ ]. According to a research report released in Nepal in 2022, the average compliance for criteria 4 and 5 is 89% [ ].",
"The most progress was shown by Criteria 9 in Table and Criteria 7 in Table which rose from 30% to 100% and 20% to 80%, respectively. Our participants showed better compliance rates by 100% in criteria 4, 7, 9, and 10 in Table and criteria 4 and 8 in Table respectively. However, in the study published by Biddhya and Bista, which was done in an operating room of an educational medical facility, the compliance rate reached 74 [ ]. According to 46 research conducted by various specialists all over the globe, hand hygiene (HH) compliance enhanced after the course of action, ranging from 1% to 66%, with the mean net change being a 26% rise [ ]. Hand hygiene and the use of sterile surgical gloves improved by 30.002% and 42.5%, respectively, in the study we conducted. In pre-evaluation, the study by Biddhya and Bista had a mean compliance of 88.88%, but our investigation had a mean of 37.14% and 43.75%, respectively [ ]. After observing this, we educated the interns with a pictorial guide, video demonstration, and individual demonstration to explain the steps according to WHO guidelines. After that, we performed a post-evaluation, which revealed that the average compliance was 62.14% and 86.25%, respectively.",
"According to a study on hand washing and gowning compliance conducted in Indonesia, 83.12% of surgical residents adhered to the rules [ ]. In the same study, taking off the gloves' covering by hand from beneath the sleeves of the garment had the lowest mean score, while in our analysis, criteria 9 in Table and criteria 7 in Table had the lowest mean. New research on the in vivo efficacy of alcohol-based hand scrubbing, as well as the low risk of rashes related to their use, is highlighted [ ].",
"An observational study done by Anargh et al. assessed the knowledge about hand hygiene among 100 healthcare workers in tertiary healthcare facilities. The study was questionnaire-based and concluded that inadequate compliance was seen despite training, and alcohol-based rubs provided a false sense of security [ ]. A similar study conducted in Nigeria on 173 healthcare workers which included hospital auxiliary staff showed good compliance with hand hygiene practices [ ]. After observing all the studies and the present survey conducted by our study, we realized the need to re-audit frequently and sensitize pictorial guides, video demonstrations and individual demonstrations to impart knowledge and improve compliance among healthcare workers.",
"Limitations of the study",
"The small sample size is the major limitation of this study. Such studies should be done at many centres for validity. Lack of sufficient review of the literature and original studies on aseptic procedures are other limitations.",
"This clinical audit was conducted for the first time in dental college, proving that additional audits must be conducted to improve patient safety. This study investigated how young dental surgeons knew before and after being evaluated for using the WHO-recommended standard sterile surgical glove technique. This study identified significant changes in the variables both before and after the intervention. Despite many interns' greatest attempts to follow the WHO recommendations for hand hygiene and surgical gloving methods, many still need to live up to expectations. On the contrary, as this study shows, the training sessions resulted in quite a lot of progress. Therefore, we must regularly undertake clinical audits and resensitize operating personnel to make optimistic changes to clinical practice. Based on the previous data, more regular audits should be performed to increase adherence to accepted protocols. This can result in a major improvement in eliminating health risks, which can still aid a nation's economy by lowering the number of prolonged hospital stays and the burden of iatrogenic diseases."
] |
PMC10757273
|
Clinics
|
Preliminary outcomes of five-year survival for ovarian malignancies in profiled Serbian Oncology Centre
|
04-05-2023
|
Highlights • Analyzing predictors of survival in patients with ovarian carcinoma is crucial. • Independent estimators of mortality in ovarian carcinoma, are more precise by identifying histopathologic tumor grade, FIGO, and NACT. • The aforementioned predictors also involve the number of therapeutic cycles, type of surgery, and chemotherapy response. • Poor chemotherapy response increases the hazard ratio for mortality. • Significant predictors of survival in ovarian carcinoma are the absence of recurrent disease and lymphovascular space invasion.
|
[
"With the aging of the world's population, the authors are faced with changes in morbidity and mortality causes and cancer is becoming the leading cause of death. It is estimated that in the continent of Europe, which counts close to 10% of the world's population, there are about 23.4% newly diagnosed cancers and about 20.3% cancer-related deaths. In the world population, lung cancer is the most common cancer type and the most common cause of death in cancer cases. Breast cancer is the most frequently diagnosed and the most common cause of cancer-related death among women .",
"Although ovarian cancer, per se , is not very common and accounts for only 3% of the general population of women, it is the fifth most common cause of death among women diagnosed with malignancy . Age-adjusted incidence is calculated as 12.5 per 100.000 women . The incidence and mortality rates are higher in older women and increase with age, hence the probability of getting this malignancy is higher in the n who are 50 years. However, the disease can be diagnosed at any age . Genetics is a significant risk factor for ovarian cancer, and there is also hereditary breast and ovarian cancer syndrome, which occurs in one in 500 women. That is the result of an autosomal dominant mutation of the BRCA1 or BRCA2 gene. Mutation of this specific gene . The majority of ovarian cancer patients are diagnosed in the advanced stage of the disease, which is associated with poor prognosis compared to localized disease where the 5-year survival is about 92% . In the case of the advanced tumor stage, the 5-year survival rate is low and is only about 29.2% . In addition, 70%‒90% of women with ovarian cancer in the late stage experience the recurrence of the disease within 18 months of diagnosis .",
"Several studies have focused on the immunology, pathogenesis, and therapy of ovarian cancer, suggesting the role of T-cell infiltration and Tumor-Associated Macrophage with its role in cell apoptosis and PD1/ PD-L1, and Progression-Free Survival . These long-term survivors also include a proportion of women with poor clinical characteristics at diagnosis, such as advanced-stage disease or performing suboptimal debulking surgery. The predictors of long-term survival are not well understood, and it remains unknown whether associations between patient characteristics and risk of mortality differ across the survival trajectory and whether these associations vary according to histologic type . The present study purposed to determine the characteristics of ovarian carcinoma and to analyze predictors of survival in patients with ovarian carcinoma.",
"This study was conducted according to the declaration of Helsinki and approved by the Ethical Board of Oncology Institute of Vojvodina under the 4/20/2-3707/2-6 approval number. It has been designed as a retrospective cohort study and included patients with diagnosed ovarian carcinoma treated at the Clinic of Operative Oncology, Oncology Institute of Vojvodina in the period from 2012 to 2016. Clinical and radiological assessment was performed during the five-year follow-up period. Of 75 patients with ovarian carcinoma 72 were included in the analysis. Three of 75 cases were excluded due to missing follow-up. The data about the histological type of tumor, disease stage in terms of median age. However, the FIGO stage had a significant impact on survival so women who were in FIGO I and II stage had a higher chance to survive compared with those in stages III and IV.",
"The preliminary results of the present study exhibited an expected 5-year survival of 40%. The patients with LVSI had significantly lower survival and poor prognosis compared with those without LVSI. This is comparable with data from the literature. Li and colleagues [26]. conducted a meta-analysis that also revealed an increased risk of non-survival in patients with LVSI. The authors calculated pooled HR for all 13 articles included in the analysis and demonstrated a significantly augmented risk of disease progression in patients with LVSI presence of participants. The advanced stage was significantly associated with an increased risk of LVSI presence, and the univariate analysis also revealed the expression of SNAI1 and SNAI2 were all positively correlated with LVSI presence. The advanced stage are diagnosed with FIGO stage III‒IV. In this setting, primary cytoreductive surgery followed by taxane- and platinum-based combination chemotherapy is a well-established management strategy. The goal of surgery should be the complete removal of all macroscopic diseases, as “complete cytoreduction” is one of the most important prognostic factors of survival. This is in accordance with the present analysis which also demonstrated a significant impact of surgery type on survival. In the analysis, there were more than 50% in the survivals group with at least optimal debulking surgery. Also, patients with stage IV disease who underwent Neoadjuvant Chemotherapy, while the median BMI was 25.0 kg/m^(2) (IQR 22.0‒29.7 kg/m^(2)), with 51 (21.4%) of patients were obese (BMI ≥ 30.0 kg/m^(2)). The majority of cases had tumors with serous histopathology (91.6%) and FIGO Stage III cancer (82.3%) and BRCA mutations were present in 22 cases (9.2%). The median CA-125 at diagnosis was 457 U/mL (IQR 134‒1367 U/mL). Debulking surgery was conducted in 94.1% of the cases. One hundred twenty-one (50.8%) patients did not have residual disease after surgery, while 60 (25.2%) and 34 (14.3%) had a < 1 cm or ≥ 1 cm residual disease, respectively. Approximately half (53.4%) of the patients received NACT. Most patients (93.3%) received carboplatin with paclitaxel as the first chemotherapy. As expected, the majority of patients (92.3%) responded to first-line chemotherapy (PR/CR). However, response rates dropped markedly with each additional line of treatment. By line 5, over 60% of patients had PD, while only 4.3% and 12.8% had a recurrence or progressive disease, respectively. The present analysis exhibited that disease recurrence significantly impacted survival in patients with ovarian carcinoma. In addition, response to chemotherapy was a significant predictor of survival in the present study. This is to the results of the above-mentioned work of Kessous et al. where the response to chemotherapy predicted OS regardless of the line of chemotherapy and the difference was most pronounced in the first line, where patients with recurrent carcinoma did not have significantly improved overall survival compared with those with progressive disease. Even some of the baseline characteristics were similar to the analysis, which further supports the authors’ work and results, even though the sample was smaller.",
"In conclusion, as expected, the percentage of high-grade, advanced-stage ovarian cancer patients, per se , possessing a complete response to chemotherapy, absence of recurrent disease, and lymphovascular space invasion were significant predictors of survival in patients with ovarian carcinoma. Herein, the present results are following the outcomes of the other authors. Given the fact that some authors have shown that some patients with complete response to chemotherapy did not have significantly higher survival even if the number of therapy cycles was higher than six. Of note, that indicates that efforts should be made to identify tumor characteristics that could determine patients who will benefit from the standard treatment and those who need other, tailored treatment, preventing overtreatment. Herewith, emerging data regarding precision medicine and molecular-based personalized treatment modalities are promising and will likely modify the way the authors provide multiple lines of treatments in the near future. Bene diagnoscitur bene curatur.",
"The clinical data used to support the findings of this study are available from the corresponding author upon request.",
"None declared.",
"Bojana Gutic: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Resources, Validation, Visualization, Writing – original draft. Tatjana Bozanovic: Investigation, Methodology, Project administration, Resources, Validation, Visualization. Aljosa Mandic: Investigation, Methodology, Project administration, Resources, Validation, Visualization. Stefan Dugalic: Investigation, Methodology, Project administration, Resources, Validation, Visualization. Jovana Todorovic: Investigation, Methodology, Project administration, Resources, Validation, Visualization. Miroslava Gojnic Dugalic: Investigation, Methodology, Project administration, Resources, Validation, Visualization. Demet Sengul: Investigation, Methodology, Resources, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing. Dzenana A. Detanac: Investigation, Methodology, Validation, Visualization, Writing – review & editing. Ilker Sengul: Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing. Dzemail Detanac: Investigation, Methodology, Validation, Visualization, Writing – review & editing. Tugrul Kesicioglu: Investigation, Methodology, Validation, Visualization. José Maria Soares Junior: Investigation, Methodology, Project administration, Software, Validation, Visualization, Writing – review & editing.",
"The authors declare no conflicts of interest."
] |
PMC10603682
|
Animals : an Open Access Journal from MDPI
|
Hepatitis E Virus in Livestock—Update on Its Epidemiology and Risk of Infection to Humans
|
17-10-2023
|
Simple Summary Hepatitis E virus (HEV) is a public health problem worldwide, as it is an important food pathogen that humans can obtain from animals. The most common way to infect humans is by consuming contaminated, undercooked meat or raw meat from infected pigs. However, domestic cattle, small ruminants such as sheep and goats, and farm rabbits should not be underestimated as possible sources of HEV infection for humans. Many studies have detected HEV in milk from infected ruminants. Thus, the consumption of raw milk might lead to infection. Among livestock, chickens are susceptible to avian HEV, which can cause symptomatic disease but is not dangerous to humans. Avoiding eating undercooked meat from certain livestock species and following basic hygiene rules when in contact with animals that may be a source of HEV are effective preventive measures for hepatitis E in humans. Abstract Hepatitis E virus (HEV) is a public health problem worldwide and an important food pathogen known for its zoonotic potential. Increasing numbers of infection cases with human HEV are caused by the zoonotic transmission of genotypes 3 and 4, mainly by consuming contaminated, undercooked or raw porcine meat. Pigs are the main reservoir of HEV. However, it should be noted that other animal species, such as cattle, sheep, goats, and rabbits, may also be a source of infection for humans. Due to the detection of HEV RNA in the milk and tissues of cattle, the consumption of infected uncooked milk and meat or offal from these species also poses a potential risk of zoonotic HEV infections. Poultry infected by avian HEV may also develop symptomatic disease, although avian HEV is not considered a zoonotic pathogen. HEV infection has a worldwide distribution with different prevalence rates depending on the affected animal species, sampling region, or breeding system.
|
[
"Hepatitis E is an important public health problem worldwide. The World Health Organization estimates that 20 million infections with Paslahepevirus balayani have higher HEV-related seroprevalence rates than the general population [ ]. All livestock professionals should be aware of the risk of zoonotic-acquired hepatitis E. Recent changes in HEV epidemiology might be related to the zoonotic nature of the disease.",
"In this paper, a bibliographic review of the literature on HEV is performed to gather the latest data regarding the prevalence among livestock species worldwide and the threat to humans due to HEV in livestock.",
"The HEV genome contains a positive-sense monopartite RNA of 6.4–7.2 kb with three open reading frames and Paslahepevirus alci, which was detected in moose [ , ]. Eight different genotypes have been assigned to the species P. balayani : HEV-1 to HEV-8 [ ]. HEV-1 to HEV-4 genotypes are commonly associated with HEV infection in humans. Of these genotypes, HEV-1 and HEV-2 are restricted to humans, whereas HEV-3 and HEV-4 are considered zoonotic. HEV-3 and HEV-4 are further classified based on phylogenetic grouping. Currently, a total of three main clades of HEV-3 can be distinguished: clade 3.1, which includes subtypes a, b, c, h, i, and j; clade 3.2, which includes subtypes e, f, and g; and clade 3.3, which contains rabbit strains corresponding to the HEV-3ra subtype [ , , ]. Nine subtypes were determined among HEV-4: 4a–4i [ ]. Subtypes 4a, 4b, 4d, and 4 h are isolated in over 80% of cases [ ].",
"Domestic pigs, while HEV-4 is less prevalent in the pig world population. Nevertheless, in some countries, especially in the Western Pacific region, like China, India, or Indonesia, HEV-4 is as prevalent as HEV-3 or represents a predominant genotype. Susceptible pigs acquire HEV mainly from other shedding pigs. However, swine are also susceptible to HEV-3 and HEV-4 isolated from humans [ ]. Moreover, experimental studies show that infection with HEV-3 from rabbits is also possible in these animals [ , ]. Nevertheless, no evidence of natural cross-species transmission has been provided [ ]. Unusually, a human HEV-1 strain was reported in a domestic pig in 2018 in Uruguay, although pigs are not considered a natural reservoir for this genotype. Molecular methods quantified the viral load in the stool, and sequence analyses were performed. The investigated animal was simultaneously infected with HEV-3 and appeared not to have clinical symptoms. The authors suggest that pigs may occasionally, and perhaps accidentally, act as reservoirs for HEV-1 through an inter-species transmission mechanism. Detection of both genotypes in one animal means multiple sources of infection. Pigs are omnivorous; hence, a plausible alternative source of contamination could be through the consumption of contaminated food [ ]. The remaining genotypes; it was much higher in comparison with the remaining countries in which molecular studies were performed, whose prevalence was between 0.93%. The horizontal transmission of HEV-3 from wild boar to domestic pigs has been proven experimentally [ ]. On the other hand, swine manure might be a source of HEV infection of wild boar and other wildlife, since it is often used as a soil fertilizer. In terms of public health, the density of the pig population in a given region does not appear to be associated with a higher risk of HEV seropositivity in humans living in Germany and Denmark [ , ].",
"Pigs, like humans, are frequently infected with HEV via the faecal-oral route. Nucleic acids of the virus were also detected by nested RT-PCR from inside and outside farm buildings, on trucks, and in utility vehicles. Hence, the indirect transmission of the pathogen, especially during the movement of trucks and utility vehicles, plays an important role in HEV dissemination at a slaughterhouse site and throughout an entire network [ ]. The infection is usually asymptomatic, and mild to moderate liver and lymph node changes can be found in infected animals [ ]. Typically, the viral load peaks at 4–6 months of age, when passive immunity wanes. Infected pigs start shedding the virus about a week after exposure, for an average of 3 weeks. Viremia persists for 1–2 weeks. Shedding the virus with faeces and other excretions, e.g., urine, is of great epidemiological importance. The primary factor that plays a pivotal role in spreading and maintaining infection within the population in different farms is the accumulation of the virus in the environment [ ]. HEV can probably persist in the farm environment for an extended period. HEV-3 shows high stability on different surfaces virus or Porcine circovirus-2 may result in the prolonged excretion of HEV in co-infected pigs [ ]. Cao et al. [ ] arbitrarily set 8 weeks after infection as the time point separating acute and chronic infections. Their results showed that immunocompromised pigs with chronic infection shed the virus for at least an additional 5 weeks beyond 8 weeks post-inoculation [ ]. Moreover, HEV shedding is significantly increased and dramatically extended in pigs co-infected with PRRSV in young sows and 53.4%. Evidence of HEV infection and/or contact with this pathogen was found in cattle [ ] to 47% [ ]. HEV RNA was also found in other studies conducted in China, with the prevalence ranging from 0% in serum [ ], from 8.8% [ ] in faeces, and from 0% [ ] in cattle milk. The seroprevalence in India reached 4% in Lao People’s Democratic Republic [ ], and 14.5% [ ]. In Korea, HEV RNA was found in 1% [ ]. Neither anti-HEV antibodies in bovine sera nor HEV RNA in bovine faeces were found in Spain [ ]. The bovine faeces samples in Hungary [ ], and milk samples in Germany [ ] were also free from HEV RNA. On the other hand, 29.2% [ ].",
"In Africa, the seroprevalence reached 21.6% [ ] to 26.4% [ ].",
"Variations in the prevalence of HEV in cattle observed by different researchers may result from different breeding practices, of which the most critical factor influencing the increase in the prevalence of HEV is mixed breeding, including for many species. For domestic cattle, sheep, and goats, the incidence of HEV infections appears to be higher in rural areas where traditional mixed farming systems consist of small family farms with pigs and other domestic animals [ , , , ]. Cross-species transmission between ruminants and pigs is suggested by the detection of HEV-3 and HEV-4 that are genetically closely related to the HEV identified in domestic and wild ruminants and pigs or wild boars in the same geographical areas [ , , ]. Moreover, the frequent mixed breeding of cattle and pigs in rural China and the simultaneous lower seroprevalence rates in cattle compared with pigs in the same region are also probably related to cross-species transmission of the virus [ ]. However, keeping cattle and pigs in close contact did not always contribute to infection; HEV RNA was not detected in the faeces and milk of cows reared on mixed farms, rearing pigs and cattle, in China [ ] and Belgium [ ]. In a longitudinal study, the lower seroprevalence in cattle than in pigs may be related to the lower permissivity and/or transient seropositivity observed in calves and adult cows [ ]. The lack of association between the age of the cattle and seropositivity, observed in the study of Tialla et al. [ ], can be explained by temporary seropositivity. According to Tialla et al. [ ], the type and intensity of interspecies contacts and the hygiene prevailing on the farm may also influence the prevalence of anti-HEV antibodies in cattle [ ]. Farm rabbits are also considered a reservoir of HEV; however, keeping rabbits and cattle in close contact on the same farm has not been identified as a risk factor for an increased HEV seroprevalence [ ]. HEV RNA was also found in sheep kept close to investigated yellow cattle. Genome sequences of HEV strains isolated from the yellow cattle exhibited 95.1–99.8% homology with sheep-derived strains. This suggests the existence of complex mechanisms for the interspecies transmission of HEV and its circulation between populations of different animal and human species [ ].",
"Sheep confirmed this finding [ , , ].",
"The occurrence of HEV in small ruminants has been previously reviewed by Di Profio et al. [ ]. According to the authors, seropositive sheep were found in numerous countries on different continents, such as Asia serum samples [ ]. Subsequent studies confirmed that HEV was circulating in the Chinese sheep population, as HEV RNA was present in the serum. Available data indicate that HEV is highly prevalent in the population of Italian small ruminants [ ]. Two different reports demonstrated the presence of HEV RNA in the serum and faecal samples collected from sheep [ , ]. The first study obtained serum and faecal specimens from 192 sheep [ ]. HEV RNA was detected in 10.4%. HEV RNA was found in specimens from two seropositive farms, and the overall prevalence reached 3% of sheep livers and 2% to HEV infection comes from 1998, when anti-HEV antibodies were detected in caprine samples [ ]. In 2007, in India [ ], 100%, such as China, the USA, Egypt, Nigeria, Italy, Spain, and Bulgaria, confirmed the presence of antibodies against HEV in the sera of goats, with seroprevalence ranging from 0.6% to 46.7% [ , ].",
"The first HEV RNA detection in caprine specimens has been reported by Di Martino [ ]. Noteworthily, previous studies conducted in China in which samples collected from seropositive goats were also tested for the presence of HEV RNA failed to detect HEV genetic material; nevertheless, in one of them, by using a monoclonal antibody-based enzyme immunoassay, HEV antigens were found in caprine sera [ , , ]. In the Italian study, 9.2% being to the wild boar strain identified in the same geographical area [ ]. The high HEV prevalence in goats was also observed in the Yunan Province of China, where raw mutton and goat milk are traditionally consumed [ ]. Results of this study showed that 74.04% of caprine liver samples collected at slaughterhouses in the Tai’an region, China [ ]. Obtained isolates were classified into HEV-4, subgenotype 4f, and were closely related and 0.71% are considered another major HEV reservoir [ ]. These animals are a natural host of the rabbit HEV strain of the samples were positive for HEV RNA. Moreover, anti-HEV antibodies were found in 57%. In Korea, HEV RNA was detected in specimens collected from farm rabbits. Positive faecal samples came from two out of six examined rabbit farms; the prevalence was 6.4% of bile samples from farm rabbits and 23% [ ]. Interestingly, none of the samples collected from farm rabbits were positive in this study. However, this could result from the low number of samples tested were HEV-RNA-positive. Nevertheless, the above data indicate that HEV circulates in the Italian rabbit population [ ]. The presence of HEV RNA was also confirmed in the samples collected from farm rabbits in Russia [ ]. Three out of six surveyed farms were HEV-positive, and the virus was detected in 9 out of 206 faecal samples [ ]. In contrast, despite testing 372 liver samples, no HEV circulation in wild rabbits has been found in Spain [ ]. HEV genetic material and anti-HEV antibodies were confirmed in faecal and serum samples collected from two rabbit farms in Virginia, USA [ ]. A total of 16.5% [ , ].",
"Members of the genus Avihepevirus are phylogenetically distinct from other viruses in the Orthohepevirinae subfamily and have a different host range. It has been found only in birds. Avihepevirus magniiecur were successfully infected with avian HEV, as evidenced by their seroconversion to anti-HEV antibodies, viremia, and faecal virus shedding [ ]. Various animal species kept close to infected poultry may seroconvert, indicating exposure to the virus and the development of a humoral response. In a study conducted in China, 8/16 rabbits, 9/30 ducks, and 6/24 geese in the investigation were positive for anti-avian HEV antibodies. Part of the faecal swabs in rabbits, ducks, and geese were positive in a PCR targeting the detection of avian HEV ORF1 or ORF2 sequences [ ]. Avian HEV has only 50% similarity to HEV sequences isolated from humans or pigs; nevertheless, HEVs found in birds and pigs are ubiquitous viruses. There is likely frequent contact between each other, creating the potential for mutations that may contribute to crossing the species barrier and enabling the replication of avian HEV in pigs.",
"The range of animals proven to be susceptible to HEV infection has grown over the past two decades. The susceptibility of animals to infection is determined based on the detection of viral RNA in the samples taken from these animals and the possibility of developing a humoral response against the pathogen in response to infection detected with serological tests [ ]. Hepatitis E in humans and its etiological agent were described in detail in 1983 [ ]. To date, it has been detected in the human population in almost every country [ ]. Later studies showed over 90% similarity between human HEV strains and those obtained from pigs [ , ]. Humans are vulnerable to infection from HEV-1 to HEV-4, representing the main reservoir of HEV-1 and HEV-2. Zoonotic transmission is widely documented for HEV-3 and HEV-4, and one case of human infection with HEV-7 with a zoonotic origin has been described [ ].",
"HEV zoonotic infection may be foodborne or due to direct contact with infected animals [ , ]. Pigs are considered the main and apparent reservoirs of HEV-3 and HEV-4. These genotypes have been found in all stages of the human food chain, and the main route of transmission from pigs to humans is via undercooked or uncooked porcine meat products and offal [ ]. It was reported that approximately 2% and 11% of pig livers sold in Japan and America, respectively, are positive for HEV RNA [ , ]. Besides foodborne transmission, direct contact with porcine body excretions may be another route for zoonotic HEV, since it has been detected in nasal and rectal swabs [ ] and urine specimens [ ] from experimentally infected pigs. However, animal species other than pigs may significantly contribute to the spread of zoonotic HEV genotypes to humans. Cattle and small ruminants are the source of food for humans. The possibility of cattle-to-human HEV transmission by drinking contaminated unpasteurised milk [ ] or eating contaminated undercooked meat [ ] and offal purchased from local grocery markets between February 2017 and July 2018 in Seoul, Korea. The nucleotide sequence indicated that the found HEV genotype was closely related. One of the samples was identified as HEV-3 [ ]. Huang et al. [ ] investigated fresh pasteurised milk available at the market supplied by local farmers in China. A gavage of raw or pasteurised milk contaminated with HEV led to active infection in rhesus macaques and the detection of HEV RNA in their faeces and blood. Interestingly, pasteurisation could not inactivate HEV, and the gavage of pasteurised milk resulted in an active HEV infection in monkeys. However, Huang et al. [ ] proved that short-time boiling at 100 °C for 3 min could inactivate the HEV completely. Viral RNA was not detectable in either faeces or serum of the rhesus macaques inoculated with cooked samples containing HEV material [ ]. Homology analysis based on the complete sequence of the bovine HEV discovered in this study indicated that it shared 99.2~99.4% similarity to human HEV. Phylogenetic analysis revealed that all the HEV isolates from cow/milk belong to genotype 4 and subtype 4 h [ ]. Similarly to cattle and goats, sheep can spread HEV through mammary gland secretions. Two separate studies from Türkiye and the Czech Republic indicated the presence of HEV genetic material in sheep’s milk; 12.3% and 1.4% of analysed specimens were positive, respectively [ , ]. The above findings are of great importance and indicate that milk from farm ruminants, especially when raw, represents a potential source of infection for consumers [ ]. Data from China demonstrated a significantly higher level of anti-HEV antibodies among rabbit slaughterhouse workers than in the general population, implying a risk of cross-species transmission of HEV from rabbits to humans by direct contact [ ]. The HEV-3ra strain [ ] was detected in immunocompromised and immunosuppressed human patients [ , ]. Moreover, it was reported that healthy blood donors tested positive for HEV, and an isolated virus was related to HEV3-ra [ ]. Interestingly, the positive individuals had had no contact with rabbits, and only two ate rabbit products that were always well-cooked; this phenomenon can suggest waterborne transmission of HEV3-ra to humans [ , , ]. As mentioned, human infection with the HEV-7 genotype has also been described [ ]. To date, the only confirmed case of human infection with zoonotic HEV-7 was documented in a patient who regularly consumed camel milk and meat [ ].",
"There is a strong interdependence between the health of humans and animals and the environment, which is known as the One Health concept [ ]. This collaborative, multidisciplinary approach aims to promote, improve, and protect the health of all species [ ]. Since infections, mainly with HEV-3 and HEV-4, can be transmitted zoonotically, they should be included in the multidisciplinary One Health concept to improve the surveillance and control of this emerging infection and to prevent the spread from animal hosts to people. Available data indicate that HEV is circulating globally in human and livestock populations, and infections with this agent in livestock animals are much more common than previously thought. Human hepatitis E associated with HEV-3 and HEV-4 of animal origin result from close contact with infected livestock or from ingesting contaminated meat products or milk and is often underdiagnosed. Therefore, the consumption of under-cooked raw meat products should be avoided, especially by individuals at high risk of developing severe hepatitis E. Pigs are the main animal reservoir of zoonotic HEVs. Infection in this species has been noted in numerous countries on almost every continent. Nevertheless, viral RNA of HEV-3 and HEV-4 and/or anti-HEV antibodies have also been detected in samples collected from other species of farm animals, including cattle, sheep, goats, and rabbits. Due to the possibility of cross-infection, domestic pigs, ruminants, rabbits, and even poultry should be kept without close contact. Avian HEV poses no threat to humans, although its circulation between livestock populations may lead to changes in the genome and lead to potential infectivity to mammals. It is crucial to highlight that good hygiene practices (e.g., changing clothes or showers after dealing with farm animals) among farmworkers and other people who have close contact with livestock are advisable to minimise the risk of zoonotic HEV infection and of spreading the pathogen among susceptible animals. Knowledge concerning the epidemiology of this virus is essential in view of public health concerns."
] |
PMC10752250
|
Ecology and Evolution
|
Between‐year and spatial variation in body condition across the breeding cycle in a pelagic seabird, the Red‐billed Tropicbird
|
27-12-2023
|
Abstract Body condition in pelagic seabirds impacts key fitness‐related traits such as reproductive performance and breeding frequency. Regulation of body condition can be especially important for species with long incubation periods and long individual incubation shifts between foraging trips. Here, we show that body condition of adult Red‐billed Tropicbirds ( Phaethon aethereus ) at St Helena Island, South Atlantic Ocean, exhibited considerable variation between years (2013–2017) and between different stages of the breeding cycle. Females took the first incubation shift following egg laying, after which males and females alternated incubation shifts of varying length, ranging from <1 to 12 days. Body condition declined in both sexes during an incubation shift by an average of 22 g (2.83% of starting mass) per day and over the incubation period; mass loss was significantly greater during longer incubation shifts, later within a shift and later in the total incubation period. There was also significant differences in incubation behaviour and body condition between years; in 2015, coinciding with a moderate coastal warming event along the Angolan‐Namibian coastlines, adults on average undertook longer incubation shifts than in other years and had lower body condition. This suggests that substantial between‐year prey fluctuations in the Angola Benguela upwelling system may influence prey availability, in turn affecting incubation behaviour and regulation of body condition. Adults rearing chicks showed a significant reduction in body condition when chicks showed the fastest rate of growth. Chick growth rates during 2017 from two localities in the Atlantic Ocean: an oceanic (St Helena) versus neritic (Cabo Verde) population were similar, but chicks from St Helena were overall heavier and larger at fledging. Results from this multi‐year study highlight that flexibility and adaptability in body condition regulation will be important for populations of threatened species to optimise resources as global climate change increasingly influences prey availability.
|
[
"Body condition in birds is a key factor underlying the success of breeding, migration and moult. In seabirds, parental body condition is known to influence and impact breeding and foraging regimes. In pelagic seabirds, spending much of their time at sea and only returning to land to breed, it is challenging to understand the pressures acting upon them, such as the energetic costs of breeding and how they respond to these costs. While body condition and its regulation in Procellariiformes Phaethontiformes.",
"In seabirds, the division of breeding duties can influence breeding success. Males and females generally share breeding duties equally, but differing parental investment between the sexes while breeding can occur in some species. Differences between sexes in breeding behaviour and regulation of body condition have been attributed to sexual size dimorphism. Tropicbirds are typically monomorphic, with limited or no sexual size dimorphism; however, sex differences in behaviour are also not uncommon in monomorphic seabirds.",
"Food resources are often scarce and patchily distributed in tropical marine environments. While provisioning for their chick, pelagic seabirds must therefore find an equilibrium between reaching productive areas, searching for prey, returning to the chick at regular intervals to feed and/or guard while the partner forages and self‐provisioning. Parental provisioning frequency and meal size can influence chick growth rate, along with attendance at the nest providing temperature regulation and protection from predators and rival territorial conspecifics.",
"Bimodal foraging strategies are known to influence body condition. This requires parent birds enduring extended fasting periods during incubation shifts, and balancing energy expenditure in provisioning for a chick with provisioning for themselves. Seabirds with long incubation periods typically lay a single egg clutch and fast while incubating while their partner is foraging at sea. The length of an incubation shift can substantially negatively affect adult body condition, although the rate of loss of condition is influenced by individual differences in metabolic rates. Chick provisioning periods in pelagic seabirds are also typically extended. These life history traits render species such as tropicbirds particularly vulnerable to unpredictable variations in food resources. There is a lack of knowledge of tropicbird chick growth rates, which have either been poorly documented and/or date from estimates obtained decades ago, when foraging conditions may have been very different.",
"Chick growth and adult body condition can also vary among breeding seasons and different localities, due to inter‐annual variation in oceanographic conditions caused by El Niño Southern Oscillation. In the South Atlantic, south‐east trade winds create inter‐annual fluctuations of the Angola Benguela upwelling system, leading to warm ‘Benguela Niño’ and cold ‘Benguela Niña’ events. Yet, in comparison with climate and oceanographic oscillations in the Pacific Ocean, where the effects have been extensively studied, little is known whether or how these oscillations might impact tropical south Atlantic ecosystems. Many seabird populations are located adjacent to continental shelves, where coastal upwelling systems can influence productivity, and thus local food availability can also influence adult body condition, breeding performance and foraging behaviour. In contrast, isolated oceanic populations that are out of reach of the coast or nearby land masses may be reliant on deep‐sea topographical features, such as seamounts for enhanced prey availability.",
"This study aimed to test several hypotheses about the role of body condition in mediating the breeding behaviour of Red‐billed Tropicbirds. Firstly, we tested for between‐year differences in adult body condition, predicting that adults would exhibit poorer body condition in years of reduced food availability possibly mirroring variation in the environment among years. Secondly, we tested for changes in adult body condition between and within breeding stages, expecting that body condition would decline across the breeding season due to energetic constraints and that body condition would be negatively associated with the length of individual incubation shifts when the incubating bird is unable to forage. Thirdly, we tested the null hypothesis of equal parental incubation and provisioning effort between the two sexes, predicting that due to the limited sexual size dimorphism of Red‐billed Tropicbirds parental investment is likely to be similar between the sexes. Fourthly, we tested for differences in parental body condition at nests with differing reproductive outcomes: St Helena in the central south Atlantic, located on the eastern edge of the South Atlantic subtropical Gyre in the path of the south‐east trade winds and the South Equatorial Current. Cabo Verde, consists of 10 volcanic islands that lie between 600 and 850 km west of Senegal, Africa, located at the eastern boundary of the North Atlantic subtropical gyre at the southern limit of the Canary Current. The waters around St Helena are characterised by a generally low chlorophyll a concentration with substantial variation in spatial distribution between years, whereas Cabo Verde is considered a more productive oceanic region with more enriched waters).",
"We obtained 1061 measures of adult body mass from 122 individuals as a reliable index of body condition. A minimum of 24 cavities per year were monitored between 21st August and 21st December, over a 5‐year period. Whenever possible, Bushnell Trophy Cameras were positioned near the entrance of cavities so that the arrival and departure of adults were continuously monitored. Cameras captured two pictures consecutively after the camera was triggered with a minimum interval of 5 s between successive triggers. All adults in cavities were caught by hand and fitted with a standard metal ring. To enable individual identification of breeding pairs without frequent capture or handling, any breeding adults were marked with a unique combination of colour marks on their head feathers and July to January at St Helena. Tropicbirds have an extended incubation period with incubation shifts lasting up to 16 days and chick rearing period that can last 12–13 weeks before fledging. Red‐billed Tropicbird populations were estimated to be up to 246 pairs at St Helena but as few as 1100 pairs at Cabo Verde.",
"Where possible, for each adult during incubation, we estimated the following covariates along with its weight:) was defined as the number of days from laying an egg to hatching a chick, based on known laying and/or hatch dates.. When weighing adults rearing chicks, we estimated the age of the chick and the growth stage of plumage.",
"Incubation shifts at St Helena were calculated using a combination of, known to weigh at least 500 g and absent from its cavity during subsequent observations, and/or camera images showed the chick leaving the cavity entrance at a near‐fledged stage.",
"Standard biometric measurements for all chicks at St Helena in the 2017 breeding season. Chick biometric data at Cabo Verde were pooled from two islands and one islet during the equivalent breeding season in 2017. A subset of biometrics implemented in R‐studio. All generalised linear mixed models, all likelihood ratio tests and all generalised additive mixed models or mgcv package, following Thomas and Lello ( ). Significant effects in final models were plotted using the R packages ggplot2 , ggpubr , hrbrtheme . Estimated parameters for the growth curves were calculated in the R package FlexParamCurve .",
"We tested for any effect of the monitoring period. We concluded that the variable was a significant predictor of body condition if the model containing the variable of interest was significantly better than the null model in case incubation shift length was influenced by breeding outcome) and the proportion of incubation shift completed. For the chick rearing period, we also included the age of the chick.",
"Descriptive statistics were generated for incubation shift frequency using a subset of data from pairs containing individuals of known sex, that were monitored from laying to hatching and where the shift sequence could be identified. We used GAMMs to explore whether variation in the time spent incubating an egg could be explained by any differences between sexes, years, hatching outcome or incubation periods. Given that our data were comprised of multiple incubation shifts from the same individuals and nesting attempts, we included the random effects of individual identity and nest identity. A gamma distribution with a log link function was used to model the response variable. The full model included sex, hatching outcome and year as additive terms, as well as an interaction between sex and day of incubation period, hypothesising that incubation shift length may differ between successful and unsuccessful nests, years and sexes. The interactive effect of sex and day of incubation period was included, as tropicbirds are known to alternate incubation duties between sexes. Model selection was based on a stepwise deletion process, by removing the least significant term at each step, evaluated by an ANOVA test and resulting change in AIC value until the model with the lowest AIC value was identified.",
"The rate of mass loss is a reliable index of energy costs incurred by fasting birds during incubation. The rate of mass loss during incubation was examined using the proportion of mass loss per day, calculated from a subset of masses during incubation from individuals that had more than one mass measurement during the same incubation shift. The difference between the two mass measures was divided by the number of days between measures, divided by the initial mass ×100, to give the proportional mass loss per day, for each individual. To investigate if the rate of mass loss during an incubation shift varied between years, sexes and between incubation outcome to allow for a regional comparison with Ascension Island. Binomial tests were used to examine using the equation:where y is the response variable.",
"To compare growth rates between geographical regions, we calculated the proportion of growth per day for each chick, firstly by calculating the difference in mass between two consecutive measures, then dividing the difference by the number of days between measures and by the initial mass. This gave the proportion of mass lost per day. A Gaussian GAMM with ‘identity’ link function was then used to test for effects of region on the proportion of growth by chick age. Nest identity was treated as a random effect to account for repeated measures from individual chicks and region as a fixed factor."
] |
PMC10246788
|
PLOS ONE
|
Trace quantification of GL-V9 and its glucuronide metabolites (5-O-glucuronide GL-V9) in Beagle dog plasma by UPLC–MS/MS and its application to a pharmacokinetic study
|
07-06-2023
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GL-V9, a new synthetic flavonoid derived from wogonin, has shown beneficial biological functions. In this study, accurate and sensitive UPLC–MS/MS methods were developed and validated for the quantification of GL-V9 and its glucuronide metabolite (5-O-glucuronide GL-V9) in Beagle dog plasma. The chromatographic separation was performed on a C 8 column (ACE Excel 5 C 8 50×3.0 mm) using 0.1% formic acid and acetonitrile were used as mobile phase. Mass detection was performed on a triple quadrupole tandem mass spectrometer equipped with an electrospray ionization (ESI) interface operating in positive ion mode. Quantitative analysis was performed in multiple reaction monitoring (MRM) mode with the transitions of m/z 410.2→126.1 for GL-V9, m/z 586.3→410.0 for 5-O-glucuronide GL-V9 and m/z 180.0→110.3 for phenacetin (internal standard), respectively. The calibration curves for GL-V9 and 5-O-glucuronide GL-V9 showed excellent linearity over the concentration range of 0.5–500 ng/mL with correlation coefficient greater than 0.99. The intra- and inter-day accuracies were within 99.86% to 109.20% for GL-V9 and 92.55% to 106.20% for 5-O-glucuronide GL-V9, respectively. The mean recovery was 88.64% ± 2.70% for GL-V9, and 92.31% ± 6.28% for 5-O-glucuronide GL-V9, respectively. The validated method was successfully applied to the pharmacokinetic study in Beagle dogs after oral and intravenous administration. The oral bioavailability of GL-V9 was approximately 2.47%~4.35% in Beagle dogs and reached steady state on the fifth day after repeated dosing.
|
[
"Cancer, the abnormal growth of cells, is an enigmatic and frightening disease or group of diseases that places an enormous burden on society worldwide. Cancer occurs with the involvement of a variety of factors, genes, and pathways and shows multiple stages [ , ]. In recent years, advances such as exploring molecular signaling pathways and modulating the cellular microenvironment have improved treatments of various cancer. Much effort is still needed to be done to discover and develop innovative drugs involved in various anticancer mechanisms.",
"5-hydroxy-8-methoxy-7-(4-(pyrrolidin-1-yl) butoxy)-4 Hchromen-4-one,, is composed of a typical chemical structure of flavonoids, with two benzene rings and senescent breast cancer cells [ ], upregulate expression of Trx-1 through activation of the AMPK/FOXO3a pathway and ameliorate the effect of DSS-induced colitis on oxidative stress [ ], induces p53 associated senescence and catastrophic mitosis in malignant T cells at sublethal doses [ ] and inhibits the expression and nuclear translocation of Trx-1, followed by inhibition of the DNA binding activity of HIF-1α, by suppressing the Trx-1/Ref-1 axis [ ], i.e. GL-V9 exhibited extensive anti-tumour mechanisms, including anti-tumor immunity, redox metabolism, cell proliferation, autophagy, apoptosis, cell cycle, and so on. On the other hand, for flavonoids, due to the presence of extensive hydroxy groups, phase II metabolism cannot be neglected [ ]. The literature had shown that GL-V9 showed extensive metabolism and the 5-O-glucuronide GL-V9 is the only glucuronide metabolite and the dominant product of GL-V9 phase II metabolism in vivo and in vitro in the previous study [ , ]. Wogonin and its glucuronidation metabolite may possess similar anticancer activities. The basic pharmacokinetic characteristics of GL-V9 in rats were investigated after oral and pulmonary administration. Double peaks were observed due to the presence of enterohepatic after oral administration and the bioavailability was about 8.54% in rat [ ]. These proven pharmacodynamic and pharmacokinetic properties of GL-V9 are just the tip of the iceberg, and much more work further needs to be done on GL-V9. Meanwhile, we should explore the characteristics of the its glucuronide metabolite and 5-O-glucuronide GL-V9 acetate were synthesized by China Pharmaceutical University [ ]. Phenacetin in Beagle dog plasma using one assay method and we actually did it, however, in evaluation of the specify, we found that the interference of 5-O-glucuronide GL-V9 to GL-V9 did not meet the acceptance criteria and when analyzing 5-O-glucuronide GL-V9 alone, we detected GL-V9, linear within a certain of concentration range. GL-V9 and other compounds reacted under the protection of nitrogen to synthetic 5-O-glucuronide GL-V9 [ ], that is, the standard of 5-O-glucuronide GL-V9 may mix with GL-V9. And the fact is that the standard of 5-O-glucuronide GL-V9 contains GL-V9.",
"The LLOQ for both analytes was 0.5 ng/mL, at which the signal-to-noise ratio was >10 and the accuracy and precision met the requirements.",
"The precision and accuracy were assessed at different concentration levels and the results are shown in . The result suggested that the two methods were accurate and reproducible for the determination of GL-V9 and 5-O-glucuronide GL-V9, respectively, in dog plasma.",
"The precision of internal standard normalization MF of GL-V9 and IS-thaw.",
"Reproducibility, assessed by repeating measurements of the QC samples to assess precision and accuracy, met the acceptance criteria, indicating the samples could reinject in case of instrument interruptions or other reasons such as equipment failure."
] |
PMC10754979
|
Frontiers in Neuroscience
|
TSPNet: a time-spatial parallel network for classification of EEG-based multiclass upper limb motor imagery BCI
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15-12-2023
|
The classification of electroencephalogram (EEG) motor imagery signals has emerged as a prominent research focus within the realm of brain-computer interfaces. Nevertheless, the conventional, limited categories (typically just two or four) offered by brain-computer interfaces fail to provide an extensive array of control modes. To address this challenge, we propose the Time-Spatial Parallel Network (TSPNet) for recognizing six distinct categories of upper limb motor imagery. Within TSPNet, temporal and spatial features are extracted separately, with the time dimension feature extractor and spatial dimension feature extractor performing their respective functions. Following this, the Time-Spatial Parallel Feature Extractor is employed to decouple the connection between temporal and spatial features, thus diminishing feature redundancy. The Time-Spatial Parallel Feature Extractor deploys a gating mechanism to optimize weight distribution and parallelize time-spatial features. Additionally, we introduce a feature visualization algorithm based on signal occlusion frequency to facilitate a qualitative analysis of TSPNet. In a six-category scenario, TSPNet achieved an accuracy of 49.1% ± 0.043 on our dataset and 49.7% ± 0.029 on a public dataset. Experimental results conclusively establish that TSPNet outperforms other deep learning methods in classifying data from these two datasets. Moreover, visualization results vividly illustrate that our proposed framework can generate distinctive classifier patterns for multiple categories of upper limb motor imagery, discerned through signals of varying frequencies. These findings underscore that, in comparison to other deep learning methods, TSPNet excels in intention recognition, which bears immense significance for non-invasive brain-computer interfaces.
|
[
"Brain-computer interface. Among various techniques, electroencephalography. A multitude of algorithms have been developed for EEG pattern classification in diverse BCI applications. In their research, Wang et al. redefined the common spatial pattern proposed a deep learning framework that incorporates convolutional and recurrent neural networks. EEG-based BCI applications commonly rely on four main types of neurophysiological patterns, namely, steady-state visual evoked potential, event-related potential, movement-related cortical potentials, and motor imagery. Among these EEG applications, MI has garnered increasing attention within BCI systems due to its ability to elicit oscillatory neural activity in specific frequency bands over the motor cortex region without external stimuli.",
"In previous research on MI, Duan et al. proposed a binary standard task-related component analysis method. Additionally, they adapted the structure of the bSTRCA method for multi-class standard task-related component analysis was developed by integrating filter bank selection into mSTRCA. This method is applied to classify multi-class limb movements by segmenting MRCP signals into low-frequency filter banks. It optimizes multi-channel signals within these banks using spatial filters to extract correlation features, which are then combined and classified using a support vector machine. Jin et al. introduced a sparse Bayesian ELM-based algorithm to enhance the classification performance of MI. Jin et al. proposed a correlation-based channel selection introduced a novel algorithm called temporally constrained sparse group spatial pattern presented a novel sparse group representation model introduced a new classification framework that incorporates the concept of Riemannian geometry into the manifold of covariance matrices. Aghaei et al. proposed separable common spatial-spectral patterns. Beyond its application in computer vision, DL has also found utility in various domains, including brain-computer interfaces have demonstrated that advancements in machine learning, such as batch normalization and exponential linear units, when combined with a carefully curated training strategy, have significantly enhanced the performance of deep convolutional neural networks introduced a two-modality, four-category BCI classifier based on motor imagery involving movements of the left and right wrists. Meanwhile, Hajinoroozi et al. put forward an innovative channel-wise convolutional neural network conducted a study on the classification of EEG motor imagery signals using convolutional neural networks, the Spatial Dimension Feature Extractor. Traditional signal processing methods are based on the theoretical analysis of linear systems, which inevitably results in the loss of a significant amount of information carried by the original signal. In order to extract complex features in the time dimension, we propose a Time Dimension Feature Extractor(·) can be defined as",
"where, x _(LT) represents the shallow time feature vector, x _(in) is the input vector for the shallow time feature extraction step, σ denotes the ReLU activation function, Γ represents the residual mapping to be learned, and w 1 × 1 64 and w 1 × 3 64 are the weights of 1 × 1 and 1 × 3 convolutional kernels with 64 channels, respectively. The shallow time feature extraction step uses residual convolutional blocks with kernel sizes of 1×1 and 1×3 in parallel to fuse different-level features of the input x _(in) into the shallow time feature vector. Similarly, the middle time feature extraction step H _(MT)(·) and the deep time feature extraction step H _(HT)(·) can be defined as",
"where x _(MT) represents the middle time feature vector, x _(HT) represents the deep time feature vector, and it is also the time dimension output feature vector of the TDFE module.",
"Regarding spatial dimension feature extraction, we introduce two spatial feature extractors. The Spatial Dimension Feature Extractor represents the spatial dimension output feature vector, β is the number of residual paths, σ denotes the ReLU activation function, Γ signifies the residual mapping to be learned, and w 1 × 1 512 , w 3 × 1 512 , and w 5 × 1 512 are the weights of 1 × 1, 3 × 1, and 5 × 1 convolutional kernels, each with 512 channels.",
"To extract parallel features from both the time and spatial dimensions, we propose a Time-Spatial Parallel Feature Extractor through X ∈ R ^(H × W)and transpose matrix X ^(⊤):",
"where, M ∈ ℝ^(H × H) represents a weight matrix. The elements of Q reflect the similarity between the time dimension and spatial dimension features. As M is a square matrix, its diagonalization can be expressed as:",
"where P is an invertible matrix, and D is a diagonal matrix. Subsequently, Eq., …, X ^(M)}. The real labels of the test dataset are denoted as Y = { y ^(1), …, y ^(M)}, where M represents the total number of test trials. f ( X , ω) is a well-trained TSPNet classifier, where ω represents the classifier's parameters. First, the test dataset T is input into the classifier to obtain the predicted labels Y _(p).",
"We then compare the predicted labels Y _(p) with the real labels Y to identify the correctly recognized test dataset, denoted as T _(c). Next, T _(c) is filtered using filters with frequency ranges, EEGSym, DeepConvNet, EEGNet-8,2] using two datasets. Finally, we perform experiments related to feature visualization.",
"Dataset I was collected through our experiments. We recruited 10 healthy participants aged between 24 and 38 years, with a mean age of 30 years and is available in the BNCI Horizon 2020 database at “http://bnci-horizon-2020.eu/database/data-sets.” It includes electroencephalography for model training, and the optimizer parameters are detailed in . The development of TSPNet is carried out using MATLAB R2020b, EEGSym, DeepConvNet, and EEGNet-8,2. These methods are based on convolutional neural networks for EEG signal classification. To adapt these models to our datasets, we modify the classification number of the output layer to six, as required by the two datasets used in this study. Originally designed for EEG signals of 128 and 250 Hz, we down-sample the EEG signals in Dataset I and Dataset II to match their respective architectures. Training these models follows the same procedure as that of the TSPNet model.",
"In this section, we evaluate the impact of the proposed TDFE, SDFE, and TSPFE modules on the performance of TSPNet. Additionally, we validate the influence of different structures within the TDFE and SDFE modules on TSPNet. The experiments were conducted on Dataset I. Consistent with the details outlined in the implementation, during each ablation experiment, the training set and test set maintained a 70%–30% ratio, ensuring equal and balanced numbers for all classes to guarantee an equal chance level for each class. The experimental results are presented in , and a detailed analysis is provided below.",
"1) Ablation studies for TDFE : To demonstrate the effectiveness of the TDFE module, we remove the TDFE module and refer to it as TSPNet-w/o-TDFE. As shown in , when compared to TSPNet-w/o-TDFE, TSPNet exhibits a 22.3% increase in mean classification accuracy, indicating that the TDFE module, convolved in the time dimension, is effective for TSPNet. Furthermore, we replace the TDFE module with the non-residual block TDFE, EEGSym, DeepConvNet, EEGNet-8,2]. The experimental results shown in and demonstrate that TSPNet achieves the best mean accuracy on Dataset I. Compared to EEGNet-8,2, our TSPNet achieves approximately a 14.7% improvement in mean classification accuracy Quantitative analysis on the Dataset II : We evaluate the proposed TSPNet on Dataset II to demonstrate its advantages. First, we use all 61-channel EEG signals in Dataset II for experiments. The classification accuracy experimental results of 15 subjects are listed in . It can be seen from and that our TSPNet achieves an average classification accuracy of 49.7 ± 0.029, which is superior to all other comparison methods. Compared with Ofner et al., the performance of TSPNet has improved, with a relative improvement of 24.5% higher than that of 16-channel data. One possible reason is that more channels contain more spatial information. The p -values of two-sample t -test for TSPNet and other comparison methods, as shown in , , indicate a significant difference in classification accuracy between TSPNet and the other comparison methods on Dataset II.",
"The TSPNet, as proposed in this article, is a brain-computer interface is employed to visualize the source estimation of EEG data for the two datasets utilized in this article. This source estimation reveals the contributions of multiple sources to scalp EEG signals within a single cortical map. displays the EEG signal source estimation for the same action in both datasets, with a time interval of 250 ms spanning from −0.5 to 1 s. corresponds to Dataset I, while corresponds to Dataset II. This visualization is independent of TSPNet. The routines from the toolbox were employed to compute the inverse solutions for this visualization. The toolbox is open-source and available for free download at “https://github.com/aojeda/headModel.” As demonstrated in , specific areas of the cerebral cortex become activated during motor imagination, resulting in corresponding changes in EEG signals.",
"To investigate how TSPNet can successfully decode information from EEG signals, is utilized to visualize the features extracted from TSPNet, and the results are presented in . The red circles in the indicate distinct classifier patterns that can be used for differentiation. It can be observed from that the movements hand open and hand close exhibit distinct classifier patterns in the frequency ranges θ: 3–7 Hz and α : 7–13 Hz. Similarly, the movements elbow flexion and elbow extension display distinctive patterns at δ : 0.5–3 Hz, θ: 3–7 Hz, and β: 13–200 Hz, while the movements forearm supination and forearm pronation feature unique classifier patterns at δ: 0.5–3 Hz and α: 7–13 Hz. These visualization results demonstrate that the proposed framework is capable of generating distinct classifier patterns for various upper limb motor imagery categories across different frequency bands in EEG signals.",
"To elucidate the pivotal role of the TSPFE module in TSPNet, we present the transformation of feature maps before and after the TSPFE module into scalp topography maps in . It can be observed that the features after the TSPFE module are more pronounced compared to those before the TSPFE. This is attributed to the fact that TSPFE module further extracts concurrent temporal and spatial features. The features before TSPFE undergo only time dimension feature extraction from the TDFE module and spatial feature extraction from the SDFE module. Combining the results of ablation experiments in , the absence of the TSPFE module results in a 24.3% accuracy decrease for TSPNet-w/o-TSPFE compared to TSPNet, while TSPNet-w/o-TDFE and TSPNet-w/o-SDFE experience decreases of 22.3 and 22.5%, respectively. This underscores the critical importance of TSPFE in TSPNet.",
"In this work, we introduced TSPNet, a convolutional neural network classification model for motor imagery brain-computer interfaces. It enables the classification of six classes of upper limb movements based on motor imagery EEG signals. Our work provides a detailed explanation of its three constituent structures, TDFE, SDFE, and TSPFE. We conducted classification experiments on TSPNet using two datasets, comparing it with other deep learning methods [MSATNet, EEGSym, DeepConvNet, EEGNet-8,2]. The experimental results demonstrate that our proposed TSPNet outperforms the compared methods in terms of classification accuracy. Additionally, results from the two-sample t -test indicate a significant difference in accuracy between TSPNet and the compared methods. Feature visualization results, as shown in , suggest that the TSPFE module plays a crucial role in TSPNet. Before TSPFE, the TSFE module only convolves to extract time dimension features, while the SDFE module only convolves to extract spatial dimension features. TSPFE decouples the connection between time and spatial features, reducing feature redundancy. It utilizes a gating mechanism to optimize weight distribution, ultimately parallelizing time and spatial features. Furthermore, the proposed feature visualization algorithm based on signal occlusion frequency, qualitatively analyzes TSPNet's performance, showing its ability to generate different classifier patterns for various classes across different frequency bands.",
"Compared to EEGNet and MSATNet, TSPNet utilizes a signal frequency range of 0.01–200 Hz. This range is significantly broader than the signal frequency ranges used by EEGNet in movement execution. This difference can be attributed to several factors. Firstly, Ofner et al. utilized low-frequency signals (0.3–3 Hz), and the signal sampling frequency was 256 Hz, which is lower than the 500 Hz used in this paper. Secondly, and importantly, Ofner et al. employed a traditional approach involving feature extraction combined with machine learning classification patterns. The classification performance was highly dependent on the performance of the feature extraction algorithm. In contrast, TSPNet is an end-to-end deep learning model based on convolutional neural networks, where feature extraction and classification interact throughout the entire training process with shared weights, providing a distinct advantage in multi-class tasks.",
"In terms of limitations, despite the superior performance of the proposed TSPNet compared to other methods used in this paper, the accuracy in the six-class motor imagery task remains relatively low. Under the current research results, it is insufficient to generate precise and error-free control signals for the motion control of neural prosthetics or robotic arms. Several factors contribute to this limitation. Firstly, the intrinsic complexity and variability of EEG signals make achieving high decoding accuracy challenging. Secondly, EEG signals are generated by electrical potentials from different regions of the brain but are measured through electrodes placed on the scalp. Due to the conductivity and geometric properties of the head tissues, the recorded signals are spatially ambiguous and cannot accurately represent the potential neural sources. To address the current limitation of low classification accuracy, in future research, we will explore the integration of transfer learning into the classification of motor imagery EEG signals to enhance the performance of the classification model. Simultaneously, we will develop a continuous decoding strategy to further improve the classification accuracy of motor imagery tasks through multiple consecutive decoding steps.",
"In this article, the TSPNet is proposed to achieve intention recognition for multiclass upper limb motor imagery. Ablation studies demonstrate the necessity of each module in the proposed TSPNet. Our proposed TSPNet achieved a classification accuracy of 49.1% ± 0.043 in Dataset I and 49.7% ± 0.029 in Dataset II for 6 categories of upper limb motor imagery EEG signals. Comparison results with other deep learning methods demonstrate the superior performance of the TSPNet model. Subsequently, we introduce a feature visualization algorithm based on signal occlusion frequency to qualitatively analyze TSPNet. These visualization results demonstrate that the proposed TSPNet is capable of generating distinct classifier patterns for various upper limb motor imagery categories across different frequency bands in EEG signals. The results show that the proposed TSPNet can achieve intention recognition for multiple category upper limb motor imagery, which is of special significance in non-invasive BCI applications and provides the possibility to increase the degrees of freedom for devices controlled by BCI, such as robots, manipulators, or nerve rehabilitation devices.",
"The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found at: https://dx.doi.org/10.21227/8qw6-f578.",
"JB: Data curation, Methodology, Validation, Visualization, Writing—original draft. MC: Conceptualization, Project administration, Supervision, Writing—review & editing. GW: Data curation, Formal analysis, Writing—review & editing. XG: Data curation, Formal analysis, Writing—review & editing."
] |
PMC10372701
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JAMA Network Open
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Low-Dose Aspirin and the Risk of Stroke and Intracerebral Bleeding in Healthy Older People
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26-07-2023
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The secondary analysis of a randomized clinical trial investigates the effect of low-dose aspirin on incidence of ischemic stroke and intracranial bleeding among healthy older people.
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[
"Aspirin is an antiplatelet agent that has been used in low doses",
"People aged 70 years or older. A total of 9525 participants were allocated to aspirin and 9589 participants to placebo. At baseline, randomized treatment groups were well matched in demographic and risk factors for stroke.^(21)",
"During follow-up, the rate of intracranial events including stroke was low, at 5.8 per 1000 person-years of follow-up A first stroke was experienced by 398 individuals. Of these events, 53 strokes were fatal, including 22 strokes, we found no evidence of a differential effect of aspirin across subgroups of age, sex, smoking, diabetes, dyslipidemia, frailty category, hypertension, or country. There were no associations between aspirin and ischemic stroke subtype.",
"Results for hemorrhagic stroke and intracranial bleeding based on anatomical location are displayed in the . Overall, there were 86 hemorrhagic strokes between individuals assigned to aspirin or placebo was not statistically significant. In absolute terms, this resulted from an excess of 29 first intracranial bleeding events among individuals assigned to aspirin, which exceeded the decrease of 20 fewer ischemic strokes. As with ischemic stroke, we found no evidence of a differential effect of aspirin on the risk of having a first intracranial bleeding event across subgroups, including frailty category.",
"shows the unadjusted model of ischemic stroke and hemorrhagic stroke subtypes during the course of the study. For first ischemic stroke, the model yielded an HR of 0.89 was driven by the increased risk of upper gastrointestinal bleeding with aspirin compared with placebo, as previously found.",
"Overall, results are in keeping with meta-analyses reported by the Antithrombotic Trialists’ Collaboration in 2009,^(9) US Preventive Services Task Force (USPSTF) in 2016,^(10) and a 2020 meta-analysis by Judge et al^(8) summarizing results of 11 primary prevention trials, including 3 major trials published in 2018.^(8) Most patients included in these reports were younger than those in ASPREE.^(8) Consistent findings across these studies were a small reduction of ischemic events accompanied by an increase in hemorrhagic events. Unlike in our study, the absolute decrease in ischemic strokes substantially outweighed the increase in hemorrhagic events, and this has probably resulted in a discounting of intracerebral bleeding as an important component of the risk-benefit trade-off in younger populations.",
"The lack of benefit and potential risks from aspirin in primary stroke prevention provide further evidence in support of the recently published draft recommendation of the USPSTF against the routine prescribing of low-dose aspirin as a primary prevention measure, especially in older persons.^(34) Clinicians should be aware that among older individuals prone to falls, risks of intracerebral bleeding with aspirin may be greater than was apparent in this trial. Our results are also cautionary with regard to the inclusion of aspirin in a polypill to prevent cardiovascular disease in healthy older adults.^(35 , 36) Studies of newer antiplatelet therapies, such as clopidogrel, ticagrelor, or prasugrel, have not been undertaken in a primary prevention setting and should not yet be considered as alternatives to aspirin for this indication.",
"Strengths of this data derive from its size coupled with virtually complete follow-up and systematic adjudication of stroke events by specialist clinicians. The study also has several limitations, including fewer than expected stroke and bleeding events occurring during follow-up and the lack of detailed investigation of stroke occurring in some older participants. Results are mainly generalizable to a White population (participation by individuals in racial and ethnic minority groups was largely limited to the US, where Black and Hispanic people aged ≥65 years were purposively recruited) with routine access to optimal blood pressure and lipid control. The balance of risks and benefits found in this study is not applicable to the use of aspirin for secondary prevention and may not be applicable to certain subgroups at substantially higher risk of ischemic stroke.",
"In this secondary analysis of a randomized clinical trial of older adults, there was no statistically significant benefit from aspirin in preventing stroke or any conventional stroke etiological subtype. However, aspirin significantly increased the overall risk of intracranial bleeding. These data support the recommendation of the USPSTF that low-dose aspirin should not be prescribed for primary prevention in healthy older adults."
] |
PMC10152627
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Journal of Neuroinflammation
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Role of macrophage autophagy in postoperative pain and inflammation in mice
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02-05-2023
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Background Postoperative pain and inflammation are significant complications following surgery. Strategies that aim to prevent excessive inflammation without hampering natural wound-healing are required for the management of postoperative pain and inflammation. However, the knowledge of the mechanisms and target pathways involved in these processes is lacking. Recent studies have revealed that autophagy in macrophages sequesters pro-inflammatory mediators, and it is therefore being recognized as a crucial process involved in regulating inflammation. In this study, we tested the hypothesis that autophagy in macrophages plays protective roles against postoperative pain and inflammation and investigated the underlying mechanisms. Methods Postoperative pain was induced by plantar incision under isoflurane anesthesia in mice lacking macrophage autophagy (Atg5flox/flox LysMCre +) and their control littermates (Atg5flox/flox). Mechanical and thermal pain sensitivity, changes in weight distribution, spontaneous locomotor activity, tissue inflammation, and body weight were assessed at baseline and 1, 3, and 7 days after surgery. Monocyte/macrophage infiltration at the surgical site and inflammatory mediator expression levels were evaluated. Results Atg5flox/flox LysMCre + mice compared with the control mice exhibited lower mechanical and thermal pain thresholds and surgical/non-surgical hindlimb weight-bearing ratios. The augmented neurobehavioral symptoms observed in the Atg5flox/flox LysMCre + mice were associated with more severe paw inflammation, higher pro-inflammatory mediator mRNA expression, and more monocytes/macrophages at the surgical site. Conclusion The lack of macrophage autophagy augmented postoperative pain and inflammation, which were accompanied by enhanced pro-inflammatory cytokine secretion and surgical-site monocyte/macrophage infiltration. Macrophage autophagy plays a protective role in postoperative pain and inflammation and can be a novel therapeutic target. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-023-02795-w.
|
[
"Postoperative pain is one of the most significant post-surgical complications and can delay functional recovery and impair patients’ quality of life. Inflammation plays crucial roles in the pathophysiology of postoperative pain. Once tissue damage occurs from surgical intervention, inflammatory cells proliferate at the surgical site, producing inflammatory mediators and causing tissue inflammation [ , ]. At the site of inflammation, the so-called inflammatory soup—a wide array of signaling molecules, such as cytokines, chemokines, and neurotransmitters—is generated, which triggers inflammatory pain [ ]. Conversely, inflammation also functions as a protective innate immune response that is essential for normal wound-healing and tissue remodeling [ ]. Therefore, a simple anti-inflammatory strategy may not be ideal for the treatment of postoperative pain, and often raises concerns regarding adverse effects, such as delayed wound-healing [ ]. Non-steroidal anti-inflammatory drugs, local anesthetics, and opioids have been widely used to treat postoperative pain; however, many of these drugs have immunosuppressive effects and can delay tissue recovery [ – ]. Therefore, strategies that aim to prevent excessive inflammation without hampering natural wound-healing, rather than those that simply suppress inflammation, are required for the management of postoperative pain and inflammation. However, the knowledge of the mechanisms and target pathways involved in these processes is lacking.",
"Autophagy, an intracellular self-degradation system, is an essential biological process that removes unnecessary cytosol, cytoplasmic organelles, and even microbes from cells [ – ]. Recent studies have revealed that autophagy in macrophages sequesters pro-inflammatory mediators, and it is therefore being recognized as a crucial process involved in regulating inflammation in various diseases, including atherosclerosis [ , ], inflammatory bowel disease [ ], uveitis [ ], infection [ – ], peripheral neuronal injury [ ], and brain ischemia [ ]. Considering that macrophages are key cells in the generation and resolution of inflammatory pain [ , , ], autophagy in macrophages can be expected to play pivotal roles in postoperative pain and inflammation as well as their resolution, and is therefore a potential therapeutic target.",
"This study aimed to investigate the potential involvement and protective roles of macrophage autophagy in postoperative pain and inflammation, and to describe the underlying mechanisms.",
"All experiments were conducted in accordance with the National Institutes of Health, National Academy of Science, and International Association for the Study of Pain guidelines for the care and use of laboratory animals. The experimental protocol was reviewed and approved by the University of Yamanashi Animal Care Committee and LysMCre. Atg5 f/f littermates served as the controls. C57BL/6J mice were purchased from Japan SLC were gently applied from below for 1 s. Positive responses were defined as flinching, shaking, licking, or retraction of the leg, representing a clear nociceptive perception to the mechanical stimulus [ ]. The experiments started with the 0.6-g filament, and the up–down method was used to determine the 50% withdrawal threshold [ , ].",
"Thermal withdrawal latencies were assessed using Hargreaves method [ ]. Briefly, animals were placed in the same plastic chamber used for the von Frey test on an elevated glass platform preheated at 29–30 °C. A radiant heat source. When a mouse was in a stable position for at least 3 s, the weight-bearing of the left and right hindlimbs was recorded, and the ratio was calculated. Trials were repeated three times, and mean values were recorded.",
"Spontaneous locomotor activity after surgery was assessed using the open-field test as previously described [ , ]. Animals were set loose in a 50 × 50 × 50-cm plastic chamber with 4 × 4 grid lines on the floor, making a total of 25 10 × 10 cm squares. The number of lines crossed with all paws in 5 min was recorded.",
"The mouse paws were dissected, and 20 µm-thick frozen sections were prepared using a cryostat, interleukin 6. The levels of the inflammatory mediators are reported in terms of the fold increase with the levels on the contralateral side of the Atg5 f/f mice defined as 1.0.",
"Statistical analysis was conducted using GraphPad Prism 9. Furthermore, Atg5 cKO mice exhibited significant SQSTM1/p62 accumulation. Autophagy deficiency in ATG5 cKO mice macrophages was also confirmed using immunofluorescence analysis. As shown in Fig. D and E, LC3 immuno-staining density was significantly lower in serum-starved macrophages from ATG5 cKO mice than in those from Atg5 f/f mice Similar results were confirmed in female mice. Mechanical and thermal sensitivities in the contralateral paws were not affected by the deficient macrophage autophagy. Although the weight-bearing ratio values were not significantly different between the groups on day 1, n = 6 each, P < 0.01, CD11c: 26 ± 6 vs. 84 ± 16 cells / 0.1mm^(2), n = 6 each, P < 0.05, Day3—Iba1: 31 ± 5 vs. 57 ± 10 cells / 0.1 mm^(2), P < 0.05, CD11c: 13 ± 3 vs. 38 ± 7 cells / 0.1 mm^(2), P < 0.01). In contrast, Atg5 cKO and Atg5 f/f mice showed similar numbers of CD206-positive cells in the dermis. In contrast, the mRNA levels of anti-inflammatory mediators (IL-10 and TGF-β1) were not significantly different between groups, demonstrating a shift toward the pro-inflammatory state in the macrophage autophagy-deficient Atg5 cKO mice."
] |
PMC10995625
|
Microbial Genomics
|
Optimising machine learning prediction of minimum inhibitory concentrations in Klebsiella pneumoniae
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26-03-2024
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Abstract Minimum Inhibitory Concentrations (MICs) are the gold standard for quantitatively measuring antibiotic resistance. However, lab-based MIC determination can be time-consuming and suffers from low reproducibility, and interpretation as sensitive or resistant relies on guidelines which change over time. Genome sequencing and machine learning promise to allow in silico MIC prediction as an alternative approach which overcomes some of these difficulties, albeit the interpretation of MIC is still needed. Nevertheless, precisely how we should handle MIC data when dealing with predictive models remains unclear, since they are measured semi-quantitatively, with varying resolution, and are typically also left- and right-censored within varying ranges. We therefore investigated genome-based prediction of MICs in the pathogen Klebsiella pneumoniae using 4367 genomes with both simulated semi-quantitative traits and real MICs. As we were focused on clinical interpretation, we used interpretable rather than black-box machine learning models, namely, Elastic Net, Random Forests, and linear mixed models. Simulated traits were generated accounting for oligogenic, polygenic, and homoplastic genetic effects with different levels of heritability. Then we assessed how model prediction accuracy was affected when MICs were framed as regression and classification. Our results showed that treating the MICs differently depending on the number of concentration levels of antibiotic available was the most promising learning strategy. Specifically, to optimise both prediction accuracy and inference of the correct causal variants, we recommend considering the MICs as continuous and framing the learning problem as a regression when the number of observed antibiotic concentration levels is large, whereas with a smaller number of concentration levels they should be treated as a categorical variable and the learning problem should be framed as a classification. Our findings also underline how predictive models can be improved when prior biological knowledge is taken into account, due to the varying genetic architecture of each antibiotic resistance trait. Finally, we emphasise that incrementing the population database is pivotal for the future clinical implementation of these models to support routine machine-learning based diagnostics.
|
[
"The scripts used to run and fit the models can be found athttps://github.com/gbatbiff/Kpneu_MIC_prediction. The Illumina sequences from Thorpe et al . are available from the European Nucleotide Archive under accession PRJEB27342 . All the other strains are available on https://www.bv-brc.org/ database.",
"Klebsiella pneumoniae is a leading cause of hospital and community acquired infections worldwide, highly contributing to the global burden of antimicrobial resistance). However, synergistic effects such as the inactivation of an outer membrane protein or overexpression of efflux pumps can occur, in resistance associated to polygenic traits [ ], where effect sizes greatly vary across the involved genes. Another example of synergistic effects is the epistatic interaction between pbp loci encoding for the penicillin-binding proteins, a measure of the concentration at which the antibiotic inhibits bacterial growth in standard culture conditions. Several MIC measuring methods exist, differing by the antibiotics and range of concentrations tested. For example, solid-based methods have an extended range of MICs compared to broth dilution, but are long and costly, and are limited to testing for one antibiotic at a time. MIC interpretation is based on threshold values called breakpoints, typically decided for each pathogen-antibiotic combination by experts at international organisations such as EUCAST have also been used for producing such catalogues [ ].",
"The application of supervised-machine learning has been introduced in genome-based diagnostics to build more accurate, although potentially less interpretable, predictors of antimicrobial susceptibility [ ]. However, model interpretability is key in the clinical context where the detection of specific genetic determinants of resistance is expected in order to provide confidence in the results’ accuracy. In addition, knowing which variants are selected from the model to infer the prediction is pivotal in the context of AMR [ ], as the use of black-box algorithms offers no insight into how the model produces its predictions. Therefore, the use of black-box algorithms has received only limited practical interest in clinical settings.",
"Indeed, prediction of resistance has exploited several interpretable machine learning models such as Gradient Boosting [ ], Random Forests [ ] and regularised linear regression [ ]. These models already achieved promising results in the prediction of quantitative traits in several bacterial species such as M. tuberculosis [ ], and nontyphoidal Salmonella [ ].",
"However, benchmarking these models is challenging since their accuracy can be affected by population structure and the different genetic architecture of each resistance trait [ ], potentially leading to false positive associations in highly clonal populations [ ]. Another limitation in these studies is caused by the specifics of MIC measurement and interpretation, which may affect the prediction accuracy and genotype-phenotype correlation [ ]. Due to the semi-quantitative nature of MICs and the limits on varying antibiotic-step concentrations, they can be considered censored, specifically right-censored, and those for David et al ., using lyophilized custom plates.",
"To preserve the complex genetic architecture of the K. pneumoniae species, we simulated quantitative traits based on real observed genotypes. To generate the data for the gene-based trait simulation, gene sequences were annotated using Prokka v1.14.6 [ ] and then clustered with Panaroo v1.2.8 [ ] in moderate mode, giving a pan-genome with a total of 35 380 genes. The presence absence matrix obtained from Panaroo v1.2.8 was converted to a VCF format by selecting the loci with minor allele frequency was high, as recommended for highly-recombinant species [ ]. This filtering step prevents strongly associated loci from being included in the phenotype simulation as causal markers.",
"To evaluate the predictive performance of each statistical model, quantitative MIC phenotypes were generated from the real genotypes in four different ways. Both genes and SNPs were used in the simulations.",
"In this bacterial population there are between 1–10 million unitigs, and it was simply computationally infeasible for us to complete this analysis with current Elastic Net and Random Forest implementations – the contribution of a specific locus to the genetic variance of the trait, and narrow-sense heritability, bla _(OXA) and bla _(KPC) involved in beta-lactam resistance were chosen to be causative of the trait.",
"A polygenic simulation selected 1000 random SNPs across the genome with same [ ].",
"A homoplastic simulation [ ] selected one causal SNP exhibiting homoplasy. Homoplastic sites were detected with HomoplasyFinder v0.9 [ ]. The SNP-based phylogeny required as input to HomoplasyFinder was inferred with IQ-tree v2.2.0 [ ], choosing the General Time Reversible, was chosen according to the consistency index and homoplasy values of the filtered MICs were used as labels for all machine learning tasks.",
"We used two machine learning models: Elastic Net and Random Forest. These were chosen due to their interpretability and scalability as well as accuracy [ ]. In addition, both these models allow us to apply population structure correction, as explained below.",
"To evaluate the performance of statistical models in detecting the causal markers, Elastic Net and Random Forest were tested on the simulated data, using independently two presence-absence matrices as input, coreSNPs- and genes-based respectively. Both regression and classification setups were used, allowing us to highlight how the framing of statistical problems affected the predictive accuracy of the models.",
"All the analyses run using Elastic Net and Random Forest were performed by splitting the dataset randomly into 70 % training and 30 % testing.",
"Regression and multinomial classification performance was assessed using the proportion of variance explained.",
"Balanced accuracy provides a clear interpretation of the model performance by computing the average of recall and L2 and their predictive accuracy tested on the held out test data. The most accurate, or most sparse model within an accuracy range, can be used to select the best hyperparameter. This procedure is automated within ‘glmnet’ package. It has previously been recommended that population-structure-based subclusters are used as the folds [ ]. We also show that using previous recommendations for a preset alpha, using as number of tests the amount of SNPs detected. Although Bonferroni is a highly conservative method that potentially suffers from false negative rate when variants are not independent, it works properly when the selected loci are not in strong linkage disequilibrium, i.e. LD 0.6.",
"Due to the complex dynamics of bacterial populations. This matrix accounts for genetic relatedness between strains and is included in the regression as a random effect.",
"In order to generate multiple realistic quantitative traits which account for different genetic scenarios, a total of four simulations were carried out, accounting for oligogenic, homoplastic and polygenic effects using two genes with fixed effect sizes, both using binary or continuous phenotypes [ ]. Despite these organisms being quite different, the heritability related to AMR is expected to be sizable across species, as the converse that resistance being caused entirely by non-genomic changes is unlikely.",
"We noted that different effect sizes used in this simulation do not significantly affect the density distributions of the simulated phenotypes, with heritability having a more important effect over this range. Since this preliminary analysis on our dataset confirmed that the separation of the trait by marker started at h² =~0.6, the quantitative traits through the four simulations were generated starting from high levels of h² .",
"Most machine learning methods rely on the assumption that observations and predictors are identically and independently distributed, which is rarely the case with genomic data, particularly highly structured bacterial populations. Therefore, accounting for population structure when using these models is recommended to avoid false positive and spurious associations [ ].",
"In this work, we benchmarked Elastic Net, Random Forest, interpretable and flexible machine learning methods able to handle high dimensional data where P N , both with the capability for regression and classification. In addition, Fast-LMM. Our analysis showed a decrease of the accuracy, with further decreases with more bins. For this reason, we also assessed the off-by-one prediction accuracy – discussed below – allowing us to improve the models interpretability whether the range of antibiotic-step concentrations is broader.",
"Specifically, when the binned quantitative simulated traits without applying the censoring were used, the Elastic Net and Random Forest perform similarly in the homoplasic simulation, where bACC range of Elastic Net was 0.55–0.88. Although we observed an increasing in accuracy only at h² =0.6, especially in case of two bins in the oligogenic, we observed that the Random Forest achieved a higher accuracy in all simulations. Albeit also the Elastic Net gained an improvement of the prediction accuracy where the traits were not censored, as previous studies have already assessed [ ].",
"In this setting, we considered 4, 6, 8 and 10 binned phenotypes of the simulations. Here, we calculated the performance using the R² value. Simultaneously we estimated the h² , since it represents the proportion of variance that can be attributed to the variation of genetic effects and thus the equivalent to the R² in regression analysis.",
"shows the performance of the two methods over the two levels of h² , where the dashed lines indicated the h² levels used to generate the quantitative simulated MICs. We pinpointed that the R² achieved by both the models increased overall proportionally with the number of the bins up to continuous distribution, as expected.",
"There was an overlapping trend between the models in the homoplasic and oligogenic, albeit the Random Forest exhibited an overall better fit compared with Elastic Net except for the oligogenic simulation, since we cannot vary the genetic effects such as effect size distribution and homoplasy. Therefore, we assessed the model performances in terms of accuracy by cross validation.",
"Since the K. pneumoniae strains were not always tested for the same antibiotics across the three datasets, we selected three antibiotic classes of interest where the MICs were largely available. Thus, Fluoroquinolones, Aminoglycosides and Beta-lactams were considered and a representative drug for each class was selected by including Gentamicin.",
"Dealing with MICs framed as classification, Elastic Net and Random Forest showed comparable balanced accuracy when dealing with Gentamicin, Meropenem and Piperacillin/Tazobactam, while in case of Ciprofloxacin the accuracy was higher when using the Elastic Net model. However, once the accuracy of classification prediction was measured by allowing one predicted class higher or lower as correct, we observed an increased performance in the accuracy of Elastic Net while the Random Forest did not exhibit any significant improvement, in contrast with what we observed in the simulations.",
"When the MICs were framed as regression, the Random Forest showed a better performance compared to the Elastic Net for all the antibiotics. Therefore the regression model could not possibly fit as if it dealt with a standard normal distribution, as expected.",
"In addition, both the Random Forest and Elastic Net showed better performance on the R² train set compared to the R² test set, suggesting that these models are prone to overfitting.",
"The results on real MICs highlighted how the classification model outperforms the regression one, with the only exemption of Random Forest when the prediction of Ciprofloxacin was assessed, showing an overlapping accuracy between the two cases.",
"We also benchmark Elastic Net, Random Forest and Pyseer for the h² estimation. The h² associated with antibiotic resistance is expected to be high, on the basis that the trait is largely determined by highly penetrant additive genetic variants directly causal for the resistance mechanism [ ]. Indeed, the h² estimation of the three models on Ciprofloxacin, Gentamicin and Piperacillin/Tazobactam indicates these traits as highly and moderately penetrant, whilst the estimated h² for Meropenem exhibits a lower level. These results suggested how the different intervals of estimated h² can be associated with the location of genetic causative variants of the antibiotic resistance. Indeed, when the resistance is mainly associated with genes carried on plasmids, the genetic variation can be poorly accounted in our model [ ], as possible implementation within a Bayesian framework via an ordinal regression model.",
"In conclusion, collections of high-quality genomes are increasingly populating global databases, and availability of MIC data would be equally recommended, possibly specifying details of the phenotypic test used. Subsequently, laboratory tests able to increase the range of antibiotic-step concentrations (e.g. E-test) should be considered – reducing the level of censored data – when building these models. Indeed, while it is easier to indicate a binary phenotype, this interpretation is not consistent over time, and results in permanent information loss. Having more information-rich phenotype data would allow more modelling possibilities, and especially as datasets grow may help improve prediction accuracy in future, as the number of samples increases far beyond what we have been able to study here."
] |
PMC10951280
|
Scientific Reports
|
Dietary linoleic acid supplementation protects against obesity-induced microglial reactivity in mice
|
19-03-2024
|
We investigated whether linoleic acid (LA) supplementation could modulate emotional behavior and microglia-related neuroinflammation. For that, male mice of C57BL/6J genetic background fed either a high-fat diet (HFD) or a standard diet (STD) for 12 weeks, were treated with a vehicle or LA solution for 5 weeks before being evaluated for emotional behavior using a battery of behavioral tests. The animals were subsequently sacrificed and their brains collected and processed for immunofluorescence staining, targeting microglia-specific calcium-binding proteins (IBA-1). Neuroinflammation severity was assessed in multiple hypothalamic, cortical and subcortical brain regions. We show an anxio-depressive-like effect of sustained HFD feeding that was neither alleviated nor worsened with LA supplementation. However, increased IBA-1 expression and microgliosis in the HFD group were largely attenuated by LA supplementation. These observations demonstrate that the anti-neuroinflammatory properties of LA are not restricted to hypothalamic areas but are also evident at the cortical and subcortical levels. This study discloses that neuroinflammation plays a role in the genesis of neuropsychiatric disorders in the context of obesity, and that LA supplementation is a useful dietary strategy to alleviate the impact of obesity-related neuroinflammation.
|
[
"The multifactorial etiology of obesity obscures the underlying biological mechanisms^(1). Besides genetic vulnerability^(2 , 3), a large number of obesity cases in Western countries are the consequence of malnutrition, i.e., overconsumption of fat-rich food. Prolonged high-fat diets lead to the emergence of metabolic, cardiac, respiratory and endocrinal comorbidities^(4 , 5), and obesity has been correlated with neuropsychiatric disorders such as anxiety and depression^(6 , 7) in clinical^(8 , 9) and preclinical studies^(10 – 13).",
"Obesity has drawn much scientific attention since the crucial role of gut microbiota in human health was demonstrated^(14). Increased concentrations of short-chain fatty acids:. Animals from the HFD group consumed significantly more calories than control animals.",
"We first evaluated the impact of feeding mice a HFD for 17 weeks on their emotional behavior, but 17 weeks of the HFD significantly reduced the time mice spent grooming themselves in the splash test. Contrary to expectations, HFD-VEH and STD-VEH mice approached the food in the novelty-supressed feeding. Furthermore, HFD-VEH animals showed typical anxious behavior in the light-dark box. However, no effect of the regimen was evidenced on the frequency of visiting the lit compartment, the time spent in the transition zone, and the total distance traveled during the test. Concerning the nestlet shredding test.",
"We secondly studied the effect of 5 weeks of LA supplementation, starting from the 12th week of the differential regimen, on the animals’ behavior. Contrary to expectations, no differences between the experimental groups were found, neither for HFD mice.",
"Microglial reactivity was assessed through ionized calcium-binding adapter molecule 1. In regard to IBA-1-related fluorescence intensity, a main effect of HFD was evidenced in the PVN, the PLH and the PSTN, as well as a tendency to increase in the STN. However, no differential IBA-1 expression between experimental conditions was found in the VMH, nor in the LH. Subsequently, the effect of the regimen was evaluated in the cortical structures. Microglial density of HFD individuals was significantly increased in all the cortical regions evaluated. The comparison between fluorescence intensities also showed a global significant increase in IBA-1 expression at the cortical level, with the only exception being the IL. Finally, a significant increase of microglial density consequence of the HFD was evidenced in all the subcortical brain regions studied, with the only exception of the LHb. IBA-1 relative expression was globally significantly increased at the subcortical level, with the exception of the VPPC, where only a tendency was detected, and of the dHipp and VPM, where no main effect of the regimen was evidenced.",
"The evaluation of the anti-inflammatory properties of LA supplementation in obese mice revealed an overall decrease in microglial density and IBA-1 expression. Hypothalamic microglial density significantly decreased after LA supplementation in all the structures evaluated. Compared to the HFD-VEH group, HFD-LA animals showed reduced hypothalamic IBA-1-related fluorescence in the PVN and PLH, and a tendency in the PSTN. However, no significant effect of LA supplementation on IBA-1-related fluorescence was observed in the STN. Five weeks of LA supplementation also reduced obese mice’s microglial density and IBA-1 expression at the cortical level, with the only exceptions being the aIC and the IL, respectively. Concerning the subcortical level, a global beneficial effect of LA administration was observed on HFD-induced microgliosis, though only a tendency was detected in the BLA, and no significant effect in the DLS. A significant decrease of IBA-1-related fluorescence intensity was observed in the DLS, dBNST, BLA, LHb and VPPC, as well as a tendency in the DMS and CeA.",
"Concerning LA supplementation in non-obese animals, microglial density was found unaltered regardless of the region evaluated. Concerning IBA-1 expression, LA supplementation increased relative fluorescence intensity only in the CeA, PSTN and STN of STD-LA mice compared to control animals, and a tendency was observed in the aIC, LHb and BLA. No other effects were observed.",
"Microglial reactivity was further investigated through the morphological adaptations induced by HFD and LA supplementation. Microglial complexity in terms of cell ramification was evaluated in three brain structures, i.e. the PVN, the ACC and the BLA, respectively representing the hypothalamic, cortical and subcortical anatomical groups.",
"As illustrated in Fig. a, the HFD regimen significantly increased microglia’s ramification in the PVN.",
"The evaluation of LA supplementation on microglia’s morphological complexity revealed a significant effect of the treatment in obese mice, with HFD-LA individuals having a less ramified microglia. In addition, a decrease of the process length of microglial cells was observed in obese individuals treated with the LA solution.",
"Regardless of the region investigated, LA supplementation in non-obese individuals did not affect microglia’s morphological complexity in terms of ramification.",
"Principal component analyses explain 58.64% of the total variance for the hypothalamic regions, 57.64% for the cortical regions and 59.46% for the subcortical regions. The loading values, cortical and subcortical regions, with PC1 increasing as microglial density and IBA-1 relative expression increase. Concerning the behavioral parameters, they mostly correlate with PC2 in hypothalamic and cortical regions, with the exception being the ST latency. In the subcortical data set, only the time spent in the lit compartment during the LDB test correlates with PC2. According to the PCA results, the observed increase in IBA-1 expression consequence of feeding the animals a HFD predicts local microgliosis in terms of cellular density. However, as illustrated in the PCA biplots, behavioral scores in the ST and the LDB test are only modestly predicted by the severity of microgliosis, irrespective of the anatomical location. The PCA scores of samples at the right of the PCA biplots illustrate the similarity of the experimental groups in terms of the parameters evaluated, and show two main clusters. These clusters suggest that microglial reactivity might differently account for emotional behavior characterizing. Mice with higher IBA-1 fluorescence intensities in these brain regions consistently spent shorter periods in the transition zone compared to those with lower IBA-1 intensities [DMS, r = − 0.426, p = 0.024; dHipp, r = − 0.594, p = 0.0007; LHb, r = − 0.597, p = 0.049; VPM, r = − 0.695, p < 0.0001; STN, r = − 0.599, p = 0.0006] and visited the lit compartment less often [dHipp, r = − 0.373, p = 0.047; LHb, r = − 0.341, p = 0.07; VPM, r = − 0.436, p = 0.018; STN, r = − 0.315, p = 0.10]. However, the variation in the data set explained by these linear models does not reach 50% for all the animals. Interestingly, if the HFD-VEH group is studied separately, the explained variance with these linear models. These observations therefore suggest that the identification of microglial heterogeneity and signature is crucial in order to study the relationship between neuroinflammation and emotional imbalance.",
"Combined, our findings support the use of dietary LA supplementation as a therapeutic tool for alleviating neuroinflammation associated with overconsumption of fatty food and obesity. Our results open new vistas in the management of obesity by the supplementation of linoleic acid, a long-chain fatty acid, in dietary interventions.",
"Forty 8-week-old male C57BL/6JRj mice and drinking water, vehicle or LA supplementation. All procedures were conducted in accordance with the Guide for the Care and Use of Laboratory Animals, and the remainder were treated with a LA solution. Figures were designed using GraphPad Prism version 10.2.0 for Windows (GraphPad Software, Boston, Massachusetts USA, www.graphpad.com). Assumptions for parametric analysis were verified using Shapiro–Wilk and Levene’s tests to respectively study the data sets’ normality of distribution and homogeneity of variance. The progression of body weight, food intake and liquid intake was evaluated with a repeated-measures ANOVA (RMA) design, including two (STD and HFD) or four (STD-VEH, STD-LA, HFD-VEH, and HFD-LA) groups (between-subject factor: regimen or treatment) and 12 or five measurements (within-subject factor: time). When the data sets did not meet assumptions for parametric analysis (behavioral, cellular density, immunofluorescence scores and morphometric scores), Kruskal–Wallis (KW) and Mann–Whitney U (MWU) tests were used. Gehan–Breslow Wilcoxon (GBW) tests were used to compare NSF score curves. Morphometric analyses aiming at evaluating microglia’s morphological complexity in terms of ramification (i.e. endpoints) and perimeter of action (i.e. process length) were performed using ImageJ Fiji software (National Institute of Health, Bethesda, Maryland, USA, https://imagej.net/ij/^(53)) as reported by Young and Morrison^(54). Principal component analyses (PCA) were performed in order to reduce redundancy of the information within the data sets and to maximize explanatory variance across measured parameters. The PCAs aimed to identify relevant components in the relationship between behavioral and microglia-related scores. For all analyses, the threshold for statistical significance was set at p < 0.05 and dependencies with p ≤ 0.1 were considered as trends."
] |
PMC10168656
|
ACS Omega
|
Polyethylene Glycol 20k. Does It Fluoresce?
|
06-04-2023
|
Polyethylene glycol (PEG) is a polyether compound commonly used in biological research and medicine because it is biologically inert. This simple polymer exists in variable chain lengths (and molecular weights). As they are devoid of any contiguous π-system, PEGs are expected to lack fluorescence properties. However, recent studies suggested the occurrence of fluorescence properties in non-traditional fluorophores like PEGs. Herein, a thorough investigation has been conducted to explore if PEG 20k fluoresces. Results of this combined experimental and computational study suggested that although PEG 20k could exhibit “through-space” delocalization of lone pairs of electrons in aggregates/clusters, formed via intermolecular and intramolecular interactions, the actual contributor of fluorescence between 300 and 400 nm is the stabilizer molecule, i.e., 3- tert -butyl-4-hydroxyanisole present in the commercially available PEG 20k. Therefore, the reported fluorescence properties of PEG should be taken with a grain of salt, warranting further investigation.
|
[
"Polyethylene glycol. The aqueous solution of unpurified PEG 20k was found to fluoresce at all wavelengths within the range, but the emission intensity was the highest at λ_(ex) ∼ 290 nm for the intervals chosen. In the present study, we decided to use a λ_(ex) of 295 nm due to its significance in protein studies. It should be noted that a comparison of PEG 20k. This was a deviation from the existing literature where PEG 2k to PEG 12k were reported to fluoresce at varying degrees.^(4 , 14) The earlier work by Sun et al.^(14) revealed an absence of a linear trend between the molecular weight and the extent of emission; PEG 8k exhibited the highest emission intensity when excited at 280 nm, whereas PEG 2k and PEG 12k exhibited very low emission intensity. As a significantly higher fluorescence intensity was observed for PEG 20k and almost no emission was observed from the lower molecular weight PEGs, it led us to investigate if any chemicals were present as impurities in the commercially available PEG 20k."
] |
PMC10512673
|
Turkish Journal of Pathology
|
ALK-Positive Histiocytosis: A Case Report and Literature Review
|
0-0-2021
|
ALK positive histiocytosis is a relatively new histiocytic proliferation disease with a characteristic gene translocation involving fusion of the ALK gene with different partners, mostly KIF5B. We report a case of ALK-positive histiocytosis with literature review. A 27-year-old male patient presented mainly with progressive lower limb weakness. Imaging studies showed an intradural extramedullary enhancing lesion at the L3 level. A 1.5 cm mass was excised from the sensory nerve root in the filum terminale at the level of L3. Histologic examination showed infiltration of the nerve by numerous histiocytes with moderate to abundant eosinophilic to clear-foamy and variably-vacuolated cytoplasm with irregular-to-smooth contoured nuclei. The histiocytes were positive for CD68 and ALK1 and negative for S100 and CD1a. KIF5B-ALK fusion was detected by real time-polymerase chain reaction. The patient is asymptomatic nine months after surgical excision. This is the first reported localized case occurring in the nerve root of an adult patient, thus expanding the clinical manifestations of this disease. An integrated histological, immunohistochemical and molecular approach is recommended for diagnosis. We recommend performing ALK1 immunohistochemical stain on all histiocytosis cases to increase awareness and detection of this newly described entity.
|
[
"ALK-positive histiocytosis is a relatively new histiocytic proliferation disease with a characteristic gene translocation involving fusion of the ALK gene with different partners, mostly KIF5B . The first reported cases were infants who presented with systemic manifestations including pallor, anemia, thrombocytopenia, and hepatosplenomegaly. A few years later, the same group expanded their cohort by reporting seven additional cases that involved older patients. In this article, we report a case of ALK-positive histiocytosis localized to the sensory nerve root of a 27-year-old man who presented with neurologic symptoms manifesting mainly as progressive lower limb weakness. Confirmatory molecular testing detected the presence of ALK-KIF5B gene fusion.",
"A 27-year-old male patient, not previously known to have any medical chronic disease, presented complaining of a 4-month history of progressive left lower limb weakness, low back pain, and left calf neuropathic pain. Physical examination showed left plantar flexion weakness.",
"Further workup that included a CT of the neck, chest, abdomen, and pelvis in addition to bone scan did not show any abnormalities. Nine months post-operatively the patient was completely asymptomatic and regained full power in the lower limbs. Contrasted lumbar spine MRI showed no recurrence.",
"We received the case as a consultation following an outside pathology diagnosis of Langerhans cell histiocytosis. They had fine chromatin with small nucleoli. Chronic lymphocytic cell infiltrates were seen in the background. Rare Touton-type multinucleated giant cells were found and rare mitotic figures were seen and negative for S100 protein, CD1a, and BRAF V600E immunostains. ALK-1 immunohistochemical stain showed diffuse positivity in the histiocytes. Therefore, ALK-positive histiocytosis was suspected and confirmatory molecular testing for the presence of ALK gene translocation, which was performed at an outside facility, showed the presence of KIF5B-ALK gene fusion by RT-PCR, confirming the diagnosis.",
"ALK-positive histiocytosis is a relatively recent entity among the histiocytic disorders. The first series was published in 2008 and the reported three cases were neonates and infants who presented with pallor, hepatosplenomegaly, anemia, and thrombocytopenia. The organs involved included the liver, spleen, bone marrow, and skin and showed infiltration by histiocytes with ALK expression by immunohistochemistry. Ten years later, the same group added seven more cases which included patients with a wider age range and broader clinical manifestations. A few additional cases have been reported that included localized and systemic involvement. In general, systemic disease is more common in infants and neonates. The classic presentation includes anemia, hepatosplenomegaly, and thrombocytopenia. Tissue biopsy shows a variable degree of histiocytic infiltration in the involved organs. The bone marrow usually shows subtle involvement although overt infiltration can be seen. Systemic involvement of other organs has been reported, including the kidneys, lungs, bone and intestine where symptoms reflect the organ involved. Despite the apparently complicated multi-organ clinical manifestations, gradual spontaneous recovery usually occurs, sometimes with a possible role for chemotherapy. Death from the disease can rarely happen. On the other hand, localized disease usually affects older children and adults with an age range of 2-50 years. The reported sites include the skin, breast, soft tissue of the foot, central nervous system and appendix. Generally, localized disease shows no evidence of local recurrence after surgical resection, when it is feasible.",
"The histiocytic infiltrate in the reported cases shared almost consistent histopathological and cytological features. For most cases, the histiocytes show abundant eosinophilic, glassy cytoplasm that may show fine vacuoles. Occasionally, histiocytes can show grayish foamy-to-fluffy cytoplasm and can be multinucleated. Typically, the nuclei are clefted or lobulated and show irregular folding in the nuclear membrane with fine chromatin and small nucleoli. Although the nuclear features are usually typical, rare cases can have oval to round nuclei without foldings or grooves. Occasionally, cells may show emperipolesis, phagocytosis of red blood cells or polymorphonuclear leukocytes. Touton-type multinucleated giant cells can be seen. Some variation in the pattern of histiocytic infiltration has been reported in the form of spindling of the histiocytes with associated fibrosis and a storiform pattern. When the liver is involved, the cells are present predominantly in the liver sinusoids with variable portal tract involvement. The bone marrow can show focal, patchy or diffuse involvement.",
"By immunohistochemistry, the histiocytes are positive for histiocytic markers. The ALK-1 immunostain is uniquely positive in a cytoplasmic and/or membranous pattern. The ALK1 expression by immunohistochemistry corresponds to translocation involving the ALK gene, most commonly with KIF5B which was initially described by Chan et al.. This translocation can be detected with either fluorescent in situ hybridization using a split apart probe for ALK or by RT-PCR and next generation sequencing which identifies the fusion partner. Despite being the most common fusion partner, other genes have been reported beside KIF5B, including TPM3 and COL1A2. Interestingly, the reported case with ALK-COL1A2 gene fusion showed the less common nuclear features of oval nuclei with distinct nucleoli and no irregularities or folds in the nuclear membrane.",
"In general, the constellation of clinical presentation and pattern of involvement, morphology, immunohistochemistry and molecular testing help in excluding the other main differential diagnoses. The differential diagnosis includes other histiocytic disorders including Erdheim-Chester disease, Rosai-Dorfman disease, Langerhans cell histiocytosis, and localized or disseminated juvenile xanthogranuloma. A summarized detailed description of the clinical, pathological and molecular findings of these diseases is provided in .",
"A benign localized subglottic histiocytic lesion harboring the KIF5B-ALK fusion that clinically mimicked subglottic infantile hemangioma was recently reported by Wolter et al.. They described an infiltrate of histiocytic cells with a mildly vacuolated and a slightly eosinophilic cytoplasm with small round nuclei and no nucleoli. There was no emperipolesis nor phagocytosis and the histiocytes were mixed with spindle cells. No Touton-type multinucleated giant cells were seen. The histiocytes but not the spindle cells were positive for ALK1 immunostain in an interesting pattern not described before: a perinuclear or cytoplasmic dot-like pattern. Those features, despite being partially present in some of the reported cases, prompted them to call the condition juvenile xanthogranuloma variant, ALK positive with KIF5B-ALK gene fusion. Whether this condition truly represents a variant of juvenile xanthogranuloma or a continuation of the spectrum of ALK-positive histiocytosis is debatable, although we favor the latter.",
"To the best of our knowledge, our case is the first to involve the sensory nerve root in the filum terminale of an adult patient, thus expanding the clinical manifestation of this disease. It also shows a spectrum of nuclear features that ranged from the classically folded nuclei to the less common rounded and smooth contoured. Central nervous system involvement has been described as a localized disease involving the cavernous sinus, the cerebellar vermis and cerebral cortex, and as part of a systemic involvement. All localized cases were in children. The reported symptoms for the localized cases included headache, vomiting and refractory seizures. Our patient presented mainly with progressive lower limb weakness. The reported outcome for localized disease is good with no local recurrence after surgical resection. However, some cases such as the cavernous sinus case may not be amenable to surgical resection. Interestingly, this patient showed excellent response to ALK-inhibitor therapy. Response to ALK-1 inhibitors has also been reported in KIF5B-ALK1 histiocytosis identified in two adults with liver and skin involvement and with the case who had CNS involvement with systemic disease.",
"In conclusion, we presented the case of a 27-year-old male who had ALK-positive histiocytosis involving the sensory nerve root in the filum terminale. This is the first reported localized case occurring in the nerve root of an adult patient, thus expanding the clinical manifestation of this newly described entity. It also shows a spectrum of nuclear features in the same case ranging from the folded to the smooth-rounded nuclei. ALK-positive histiocytosis is characterized by expression of ALK1 by immunohistochemical stain and shows fusion of the ALK gene with different partners, most commonly KIF5B . An integrated histological, immunohistochemical and molecular approach is recommended during the workup of histiocytic proliferative disorders. Of particular importance is ALK1, which we propose to be performed on all cases, not only to detect this probably under-recognized entity but also because of the therapeutic benefit that may be obtained from the use of ALK inhibitor therapy especially in unresectable or systemic diseases.",
"The authors declare no conflict of interest."
] |
PMC10560287
|
Nature Communications
|
UV-B irradiation-activated E3 ligase GmILPA1 modulates gibberellin catabolism to increase plant height in soybean
|
07-10-2023
|
Plant height is a key agronomic trait that affects yield and is controlled by both phytohormone gibberellin (GA) and ultraviolet-B (UV-B) irradiation. However, whether and how plant height is modulated by UV-B-mediated changes in GA metabolism are not well understood. It has not been reported that the E3 ubiquitin ligase Anaphase Promoting Complex/Cyclosome (APC/C) is involved in the regulation of plant growth in response to environmental factors. We perform a forward genetic screen in soybean and find that a mutation in Glycine max Increased Leaf Petiole Angle1 ( GmILPA1 ), encoding a subunit of the APC/C, lead to dwarfism under UV-B irradiation. UV-B promotes the accumulation of GmILPA1, which ubiquitinate the GA catabolic enzyme GA2 OXIDASE-like (GmGA2ox-like), resulting in its degradation in a UV-B-dependent manner. Another E3 ligase, GmUBL1, also ubiquitinate GmGA2ox-like and enhance the GmILPA1-mediated degradation of GmGA2ox-like, which suggest that GmILPA1-GmGA2ox-like module counteract the UV-B-mediated reduction of bioactive GAs. We also determine that GmILPA1 is a target of selection during soybean domestication and breeding. The deletion (Indel-665) in the promoter might facilitate the adaptation of soybean to high UV-B irradiation. This study indicates that an evolutionary GmILPA1 variant has the capability to develop ideal plant architecture with soybean cultivars.
|
[
"Ideotype breeding aims to achieve high yields in crops by combining multiple beneficial genetic traits into one variety. Plant height is an important feature of plant ideotypes. The application of semi dwarf varieties has significantly improved crop yield by increasing the planting density and the lodging resistance^(1 , 2). The gains in grain productivity during the Green Revolution were a direct consequence of optimal plant height^(3). Mutant alleles of the Green Revolution genes Semidwarf1 . Gmuid1 plants also had smaller leaves, shorter petioles, and a larger leaf petiole angle than in H12. We investigated the underlying cellular basis of the short internodes of Gmuid1 by measuring cell length in Gmuid1 and H12 plants. Compared to H12, longitudinal parenchyma cells in Gmuid1 internodes were significantly shorter. Furthermore, we observed no significant difference in the number of nodes along the main stem and branches between H12 and Gmuid1 ; however, the other agronomic traits, including number of pods, number of seeds per plant, grain weight per plant, and hundred-grain weight, were all lower in Gmuid1 than in H12.",
"To identify the causative gene responsible for the observed phenotypic changes, we crossed the soybean cultivar Williams 82 to the Gmuid1 mutant, yielding an F_(2) population comprising 201 individual F_(2) plants. Of these F_(2) plants, 153 showed the wild-type phenotype and 48 exhibited the mutant phenotype, thus fitting a 3:1 segregation ratio. Independently, we performed a bulk segregant analysis using two sets of pooled F_(2) plants exhibiting the mutant or wild-type, which was consistent with the map-based cloning above. Importantly, we identified one SNP. The single nucleotide substitution at the splicing site altered messenger RNA. Therefore, we identified a candidate gene for regulating plant height.",
"Additionally, Glyma.11G026400 was previously reported and named GmILPA1 . Similar to Gmuid1 , the Gmilpa1 mutant also showed a dwarf phenotype in the field. As expected, F_(1) plants from the cross between Gmuid1 and Gmilpa1 also exhibited the dwarf phenotype. Therefore, Gmuid1 is an allelic mutant of Gmilpa1 , we renamed the Gmuid1 as Gmilpa1-2 . In addition, we obtained transgenic lines overexpressing its coding sequence cloned in-frame with that of the green fluorescent protein gene. Collectively, all these results indicated that Glyma.11G026400 is GmUID1 . Reverse transcription quantitative PCR. We also transiently expressed a GmILPA1-GFP fusion construct driven by the cauliflower mosaic virus.",
"To further characterize the Gmilpa1-2 mutant, we performed phenotypic analyses in a glasshouse. To our surprise, Gmilpa1-2 plants did not have a dwarf phenotype under these conditions. Considering the differences between the light spectra of sunlight and white light-emitting diodes. We concluded that UV-B is essential for evoking the dwarf phenotype of the Gmilpa1 mutant.",
"To investigate how GmILPA1 regulates plant height in soybean, we performed a yeast two-hybrid. To confirm GmGA2ox-like is a functional GA2-oxidase, we performed the in vitro enzymatic activity assay using GA_(1) and GA_(4) as the substrates. The results showed that GmGA2ox-like converted GA_(1) and GA_(4) to their corresponding 2β-hydroxylated products GA_(8) and GA_(34), respectively. Next, we generated 3 lines overexpressing GmGA2ox-like , which displayed a dwarf phenotype compared to non-transgenic WT plants. Sequence analysis revealed that GmGA2ox-like harbors a typical D-box. The second clone encodes a protein with a RING/U-box domain that is predicted to have E3 ubiquitin ligase activity; we named this protein GmUBL1. To confirm these interactions in vivo, we performed bimolecular fluorescence complementation. We also confirmed these protein interactions by Co-IP assays as well. We asked whether GmGA2ox-like and GmUBL1 might also interact. We explored this possibility with Y2H, BiFC, and Co-IP assays. Indeed, we determined that GmGA2ox-like also interacts with GmUBL1 with all three assays. Together, our results demonstrated that GmILPA1, GmGA2ox-like, and GmUBL1 interact with each other. In addition, GmILPA1 and GmGA2ox-like, and GmILPA1 and GmUBL1 were co-localized, respectively, in the cytoplasm and nucleus by transient expression in N. benthamiana leaves.",
"As Gmilpa1-2 showed a dwarf phenotype only upon UV-B exposure, we investigated the potential effect of UV-B on the interaction between GmILPA1, GmGA2ox-like, and GmUBL1. BiFC assays indicated that UV-B treatment promotes the interaction between GmILPA1 and GmGA2ox-like in the cytoplasm, as evidenced by the three-fold higher relative fluorescence intensity detected in the cytoplasm following treatment with UV-B relative to controls maintained under white light throughout. We further tested the effect of UV-B on the interaction of GmILPA1 and GmGA2ox-like using Co-IP assays. The result showed that UV-B enhanced the interaction between GmILPA1 and GmGA2ox-like. However, UV-B treatment failed to affect the interaction between GmILPA1 and GmUBL1 or between GmGA2ox-like and GmUBL1. These results demonstrated that UV-B light promotes the interaction between GmILPA1 and GmGA2ox-like.",
"The APC/C facilitates the ubiquitination and subsequent degradation of specific proteins by the UPS, raising the possibility that GmGA2ox-like might be targeted for degradation by GmILPA1. To test this hypothesis, we co-expressed constructs encoding N-terminally FLAG-tagged ubiquitin, indicating that GmGA2ox-like is indeed subjected to polyubiquitination in plant cells. We then used a bioinformatics web tool to identify amino acids in GmGA2ox-like that are modified by ubiquitination, yielding the residues K394 and K407. We replaced each lysine residue by arginine which may indicate that K394 is the key residue for GmILPA1 ubiquitination.",
"To investigate whether GmILPA1 facilitates GmGA2ox-like degradation directly via ubiquitination, we performed in vitro ubiquitination assays. To this end, we used in vitro APC/C-ubiquitination assays, in which the APC/C complex. Indeed, GmILPA1 promoted the ubiquitination of GmGA2ox-like in vitro, as evidenced by the smear for GmGA2ox-like-MBP in immunoblots using anti-MBP antibodies; however, GmGA2ox-like^(K394R) cannot be ubiquitinated.",
"We co-expressed the GmGA2ox-like-GFP and GmILPA1-MYC in N. benthamiana leaves, followed by Co-IP with anti-myc antibodies and immunoblotting with anti-ubiquitin antibodies. We detected a remarkably increased smear signal representing poly-ubiquitinated GmGA2ox-like in the presence of GmILPA1. In addition, we used the same method to show that there was no remarkably increased smear signal of mGmGA2ox-like. We interpreted this result as evidence that GmGA2ox-like can be ubiquitinated by GmILPA1.",
"As GmUBL1 has potential E3 ubiquitin ligase activity, we wondered if GmUBL1 might facilitate ubiquitination of GmGA2ox-like. We co-expressed the GmGA2ox-like-GFP and GmUBL1-MYC constructs in N. benthamiana leaves, followed by Co-IP with anti-myc antibodies and immunoblotting with anti-ubiquitin antibodies. Similarly, we detected a remarkably increased smear representing poly-ubiquitinated GmGA2ox-like in the presence of GmUBL1. This result showed that GmGA2ox-like can be ubiquitinated by GmUBL1. To determine whether GmGA2ox-like can be ubiquitinated in soybean, we used a P62-agarose matrix that is capable of binding ubiquitinated proteins to enrich the ubiquitinated proteins from three independent transgenic seedlings stably expressing 35S:GmGA2ox-like-GFP or from wild-type plants as a negative control. The bound proteins were used for immunoblotting analysis with anti-GFP antibody. The ladder-like protein pattern was detected in the enriched proteins from three transgenic plants but not from WT plants. This result indicated that GmGA2ox-like can be ubiquitinated in soybean plants.",
"To understand how GmILPA1 regulates the protein stability of GmGA2ox-like in soybean plants, we examined the GmGA2ox-like protein levels by western blotting with anti-GA2ox-like antibody in WT and Gmilpa1-2 plants under both white light and white light supplemented with UV-B. Moreover, V2 stage-grown WT and Gmilpa1-2 mutant seedings under white light were transferred to white light supplemented with UV-B or continued to grow under white light for the indicated time periods, and our immunoblot data showed that there was no difference in the protein level of GmGA2ox-like between WT and Gmilpa1-2 under white light. However, GmGA2ox-like showed substantial degradation in WT exposed to white light supplemented with UV-B from 10 h, but not in Gmilpa1-2 under the same conditions. In addition, we performed cell-free degradation assays using total protein extracts from WT or Gmilpa1-2 plants exposed to UV-B or maintained under white light and examined GmGA2ox-like abundance with anti-GmGA2ox-like. We did not observe degradation of GmGA2ox-like in either WT or Gmilpa1-2 extracts in the absence of UV-B. However, GmGA2ox-like showed substantial degradation in WT extracts exposed to UV-B from 60 min,, but not in Gmilpa1-2 extracts under the same conditions. Incubation of MG132, an inhibitor of the 26 S proteasome degradation system, largely inhibited GmGA2ox-like degradation. We concluded that GmILPA1 promotes GmGA2ox-like degradation by a 26 S proteasome in UV-B-dependent manner.",
"In light of the interaction of GmUBL1 with both GmILPA1 and GmGA2ox-like, we asked whether GmUBL1 played a role in GmGA2ox-like degradation with cell-free degradation assays using total protein extracts from N. benthamiana leaves transiently expressing GmUBL1 or GmGA2ox-like . We determined that GmUBL1 can’t promote the degradation of GmGA2ox-like directly, but requires GmILPA1 for this process. The result showed that the protein degradation is apparent from 90 min to 150 min, and these results indicated that GmUBL1 enhanced the GmILPA1-mediated degradation of GmGA2ox-like.",
"The phytohormone GA contributes to internode elongation. We thus treated H12 and Gmilpa1-2 soybean seedlings with 100 µmol GA_(3) at the V1 stage. Treatment with the GA biosynthesis inhibitor paclobutrazol. Additionally, the exogenous application of GA_(3) rescued the PAC-induced growth deficiency of H12, Gmilpa1-2 , and Gmilpa1 seedlings and restored the dwarf phenotype of Gmilpa1-2 and Gmilpa1 treated with UV-B.",
"In addition, we measured the contents of endogenous GAs in H12 and Gmilpa1-2 under white light and white light supplemented with UV-B, such as bioactive GA_(1) and GA_(4), as well as their precursors, which demonstrated that UV-B reduced the GA level in soybean. In addition, in consistent with the phenotype observed, there was no difference in the levels of GAs between H12 and Gmilpa1-2 under white light, while the gibberellin GA_(1), GA_(4), GA_(20) and GA_(9) were more abundant in the WT plants than in Gmilpa1-2 under white light supplemented with UV-B conditions, the non-bioactive GA_(8) and GA_(34) accumulated at a relatively high level in Gmilpa1-2 relative to the H12 under same conditions, indicating the reduction rate of active GA in Gmilpa1-2 was higher than that in H12. Therefore, our results demonstrated that GmILPA1 repressed the UV-B-induced decreasing of active GA levels to improve the UV-B tolerance in soybean.",
"RT-qPCR analysis of GmILPA1 transcript levels in H12 seedlings treated with 100 µmol GA_(3) and UV-B for 2, 4, 8, or 12 h indicated that GmILPA1 was significantly upregulated compared to the control after GA_(3) treatment. However, relative GmILPA1 transcript levels did not respond to UV-B treatment in H12. In addition, we observed that GmILPA1 accumulated within 12 h of treatment with GA_(3) or UV-B light. The results showed that GA_(3) and UV-B induced GmILPA1 protein accumulation.",
"In addition, RNA interference, indicating that Gmilpa1-2 / GmGA2ox-like RNAi notably rescued the Gmilpa1-2 phenotype.",
"To understand the evolution of GmILPA1 during domestication, we investigated the selection signals over the promoter and genomic regions of GmILPA1 based on pairwise analyses of fixation index. All three values across a 100-kb region containing GmILPA1 revealed a clear selective sweep from the promoter and genomic regions of GmILPA1 . This result indicated that GmILPA1 underwent an artificial selection during soybean subsequent genetic improvement. To investigate the natural variation at GmILPA1 in germplasm resources, we performed a haplotype analysis across wild, landrace, and improved soybean populations^(55). We detected six main haplotypes, among which Hap5 . To explore the evolution and spread of the six GmILPA1 haplotypes during soybean domestication and breeding, we constructed its corresponding phylogenetic tree and haplotype network using 444 accessions. The analysis indicated that Hap1–4 have a close genetic relationship, with Hap3 perhaps representing the ancestral alleles from which all other haplotypes derived, and Hap5 and Hap6 are closely related to the wild soybean-specific haplotypes Hap3 and Hap4 , respectively.",
"We also noticed that the number of haplotypes decreased from six in wild soybeans to four in the landraces and improved cultivars, with the proportion of Hap1 Hap2 , Hap5 and Hap6 increasing from wild soybeans to the landraces, the proportion of Hap1 and Hap5 gradually increasing from wild soybeans to the landraces and to improved cultivars. The relative increase in Hap5 frequency was more substantial than the other haplotypes, suggesting that mainly Hap1 and Hap5 , especially Hap5 , have been strongly selected for by humans during soybean domestication and modern breeding efforts.",
"Sequence analysis using the Plant-CARE database identified six Haps . Of them, Hap5 was the only haplotype with an INDEL. We also did not observe a difference in GUS signal for GmILPA1pro ^(Hap5) :GUS regardless of UV-B exposure. However, the GUS signal for GmILPA1pro ^(Hap1) :GUS , GmILPA1pro ^(Hap3) :GUS , GmILPA1pro ^(Hap5/indel) :GUS and GmILPA1pro ^(Hap6) :GUS appeared higher than that of GmILPA1pro ^(Hap5) :GUS when the infiltrated leaves were exposed to UV-B. We confirmed these results with a quantitative GUS assay. We performed RT-qPCR on the gene bar on the GUS vector as infiltration controls. These results suggested that the differential transcriptional activities between Hap5 and other haplotypes under UV-B expose is caused by the deletion of CRE in the GmILPA1 promoter of Hap5 , which has a significant effect on the response to UV-B.",
"Modern breeding programs can progressively accumulate elite alleles. To further clarify whether accessions with improved cultivars differ from each other when grown under natural conditions, we measured their height. Haplotypes harboring Hap1 , Hap2 and Hap6 were taller than those with Hap5 . We also investigated other agronomic traits in accessions carrying different haplotypes, which revealed that Hap5 generally have fewer pods, while hundred-seed weight and grain weight per plant were significantly higher than in other haplotypes. These results suggested the high yield potential of Hap5 for soybean breeding programs."
] |
PMC10202156
|
Revista Brasileira de Epidemiologia (Brazilian Journal of Epidemiology)
|
Prevalence of allergic rhinitis symptoms and associated factors in six-year-old children in a municipality in southern Brazil
|
05-05-2023
|
ABSTRACT Objective: To estimate the prevalence of allergic rhinitis symptoms and associated factors in six-year-old children. Methods: Cross-sectional epidemiological study involving 956 six-year-old schoolchildren from Palhoça, Santa Catarina, Brazil. Home interviews were conducted with mothers in which socio-demographic and house environmental conditions information were obtained, and the International Study of Athma and Allergies in Childhood (ISAAC) questionnaire for allergic rhinitis symptoms was applied. Bivariate and multivariate hierarchical analyses were performed using Poisson regression with a robust estimator. Results: The prevalence of allergic rhinitis symptoms was 21.7%. Children whose mothers had over 8 years of education, or who had air conditioning equipment in the house, or whose bedroom walls presented mold or moisture showed statistically significant and independent 5% higher prevalence of allergic rhinitis. Similarly, children of smoker mothers or those who lived with fur or feather animals indoors showed a 4% higher prevalence. Conclusion: Significant associations were observed between socio-demographic factors and environmental conditions in child's home and allergic rhinitis symptoms in children aged six years.
|
[
"Rhinitis is a diffuse inflammation or dysfunction of nasal lining mucosa caused by the action of infectious, allergenic or hyperreactive agents. It is classified as allergic, non-allergic, infectious or mixed rhinitis^(1). Allergic rhinitis is defined as a chronic inflammatory disease mediated by immunoglobulin E presented symptoms of allergic rhinitis. The results obtained in the bivariate analysis among socio-demographic variables and environmental conditions in the child's home and the symptoms are shown in and .",
"The final model obtained in the hierarchical multivariate analysis is shown in . Variables associated with 5% significant and independent higher prevalence of symptoms of rhinitis were: mother's educational level greater than 8 years (PR=1.05; 95%CI 1.02–1.08) (p-value [p]=0.001); presence of an air conditioning unit in the child's room (PR=1.05; 95%CI 1.01–1.09) (p=0.014); and child living with fur or feather animals indoors (PR=1.05; 95%CI 1.01–1.08) (p=0.003). Variables associated with 4% significant and independent higher prevalence of symptoms of rhinitis were maternal smoker (PR=1.04; 95%CI 1.01–1.07) (p=0.044), and presence of mold or moisture on the walls of the child's room (PR= 1.04; 95%CI 1.01–1.09) (p=0.050).",
"In addition to the high prevalence (21.7%), this study showed significant associations between sociodemographic factors and environmental conditions in the child's home and symptoms of allergic rhinitis. These population-based results are a contribution to the national literature about the constant need to update epidemiological data in Brazil, a country of continental dimensions, with marked climatic, sociocultural, and economic differences. In India, another country with large dimensions and inequalities, the prevalence of allergic rhinitis among the 6–7 years age group was 11.3%^(20).",
"Back to Brazil, the ISAAC study Phase 3^(21) found a national mean prevalence, in this same age group in 2002–2003 of 25.7%, similar to that of the present study. Furthermore, the prevalence in the southern region of Brazil ranged from 20.6 to 39.2%. However, there was a decrease in the prevalence of allergic rhinitis diagnosis between 2011 (50.0%) and 2018 (30.0%) in the age group 0–9 years in a municipality of Rio Grande do Sul^(22 , 23).",
"Allergic rhinitis is a multifactorial disease^(24), which is why the hierarchical variable analysis model was used in this study. It is an IgE-mediated type 1 hypersensitivity illnesses triggered by a spectrum of environmental allergens from outdoor origin like pollen, and from indoor origin, like arthropod or mammalian derived allergens such as dust mites, cockroaches, cat allergens or molds^(25).",
"After evaluating the variables included in this study, it was found that higher maternal education, smoker mother, living with fur or feather animals indoors, air conditioning unit in the child's bedroom and the presence of mold or moisture on the walls of the child's bedroom were independently associated with a higher prevalence of allergic rhinitis symptoms.",
"The mother's higher education level was associated with a 5% higher prevalence. Since this is an indicator of socioeconomic development, something that could justify it is the Hygiene Hypothesis^(26), which suggests that for the development of the immune system, prior exposure to pathogenic agents that protect against the development of allergic diseases is necessary. However, in developed societies there are factors that limit children's contact with different pathogens and prevent the manifestation of acute infectious diseases in early childhood, inhibiting the action of Th1 lymphocytes and favoring the activation of Th2 lymphocytes, responsible for chronic allergic manifestations^(26).",
"Nevertheless, the fact that the mother's higher education is associated with the presence of rhinitis symptoms could be an indicative of greater access to products, such as air conditioning unit, curtains and rugs, in addition to the presence of pets at home. In this context, it can be assumed that social status might be a proxy measure for behavioral patterns^(27). Loo et al.^(28) also found that higher maternal education was a risk factor for allergic rhinitis. These results agree with a systematic review of 183 studies showing a higher prevalence of rhinitis in higher socioeconomic status groups^(29).",
"Regarding smoker mothers, there was a 4% higher prevalence of allergic rhinitis, corroborating the studies that confirm passive smoking as a triggering factor for chronic and respiratory diseases, with children being the most affected, as they spend more time exposed to fumes, especially when the mother or caregiver are the ones who smoke^(20 , 30). A study confirmed that maternal smoking was the strongest of all the associated features for allergic rhinitis, rhinoconjunctivitis, and eczema, especially in the 6-7 years age group^(20). Passive smoking was also found to be associated with allergic rhinitis in a case-control study in a hospital in Jiangxi^(31) as well as a risk factor for allergic rhinitis in children confirmed by a recent meta-analysis^(32), both in China.",
"Children living in contact with fur or feather animals indoors were associated with a 5% higher prevalence of allergic rhinitis symptoms compared to those not living with this kind of animals. This can be a triggering factor for allergic processes^(27). However, a study^(27) showed that the association between animal contact and allergic sensitization, atopic diseases or their symptoms are not homogeneous across social strata. The authors showed that cat contact was significantly associated with an increased odds of sensitization to cat only in children whose parents have a high level of education.",
"The presence of an air conditioning unit in the child's bedroom was also associated with a higher prevalence of allergic rhinitis. A study carried out with adults also found a higher prevalence of respiratory diseases in those children exposed to air conditioning units. The literature pointed out that the lack of proper maintenance of such equipment generates an accumulation of allergens such as fungi, animal hair and dust mites in the environment^(14 , 25), which could also be associated with an increased prevalence of the condition in the child population.",
"Another associated variable is the presence of mold or moisture on the child's bedroom walls. Recent data have shown the association between exposure to fungi in early childhood and the development of atopic conditions, including asthma, in late childhood^(33 , 34). Studies^(35 , 36) observed that humidity in classrooms was strongly associated with an increase in wheezing crises and a decrease in spirometry among students exposed to humid settings. There is sufficient evidence for the associations between moisture/mold damages and different health effects such as allergic respiratory diseases, asthma, allergic rhinitis, exogenous allergic alveolitis and respiratory tract infections/bronchitis. However, in comparison to other environmental allergens, the sensitizing potential of molds is estimated to be low^(37). These data indicate that it is important to investigate in cases of patients with anamnesis of respiratory allergies the possibility of exposure to fungi not only at home but also in day care centers, schools, and workplaces.",
"The present study has some limitations requiring caution in the analysis of the results presented. As ISAAC is a questionnaire applied to the mother, it is possible to admit eventually, the occurrence of memory bias. Also, as allergic rhinitis is an outcome self-reported by the mother, it can eventually be inferred that the relationship between higher education and better socioeconomic conditions is influencing a greater detection and reporting of rhinitis symptoms. Likewise, the use of the ISAAC does not allow for the diagnosis of rhinitis, but for the reporting of symptoms. However, most epidemiological studies have been performed in school-age children using the ISAAC questionnaire^(28).",
"This study reveals that allergic rhinitis is highly prevalent among children in the studied city, resulted from a complex interplay of socio-demographic and environmental factors. Due to the cross-sectional nature of the current study, it was only possible to evaluate associations and not etiologic relationships. It is necessary to plan further prospective analytical studies in order to establish the role of risk factors as predictors for allergic rhinitis in children in different regions and social strata in Brazil, providing basis for planning public health interventions. Public health measures may be outlined to combat these associated environmental factors and provide access to medical care to manage atopic disorders. In times of the COVID-19 pandemic, it is relevant to mention the need for managers and health professionals to know the possible relationship of symptoms between the two diseases^(38).",
"In conclusion, significant associations were observed between socio-demographic factors and environmental conditions in the child's home and symptoms of allergic rhinitis in children aged six in the city studied."
] |
PMC10411168
|
RBGO Gynecology & Obstetrics
|
Screening of Variants in the Transcript Profile of Eutopic Endometrium from Infertile Women with Endometriosis during the Implantation Window
|
01-07-2021
|
Objective Abnormalities in the eutopic endometrium of women with endometriosis may be related to disease-associated infertility. Although previous RNA-sequencing analysis did not show differential expression in endometrial transcripts of endometriosis patients, other molecular alterations could impact protein synthesis and endometrial receptivity. Our aim was to screen for functional mutations in the transcripts of eutopic endometria of infertile women with endometriosis and controls during the implantation window. Methods Data from RNA-Sequencing of endometrial biopsies collected during the implantation window from 17 patients (6 infertile women with endometriosis, 6 infertile controls, 5 fertile controls) were analyzed for variant discovery and identification of functional mutations. A targeted study of the alterations found was performed to understand the data into disease's context. Results None of the variants identified was common to other samples within the same group, and no mutation was repeated among patients with endometriosis, infertile and fertile controls. In the endometriosis group, nine predicted deleterious mutations were identified, but only one was previously associated to a clinical condition with no endometrial impact. When crossing the mutated genes with the descriptors endometriosis and/or endometrium , the gene CMKLR1 was associated either with inflammatory response in endometriosis or with endometrial processes for pregnancy establishment. Conclusion Despite no pattern of mutation having been found, we ponder the small sample size and the analysis on RNA-sequencing data. Considering the purpose of the study of screening and the importance of the CMKLR1 gene on endometrial modulation, it could be a candidate gene for powered further studies evaluating mutations in eutopic endometria from endometriosis patients.
|
[
"Endometriosis, a disease characterized by implantation and growth of endometrial tissue outside the uterine cavity, has a high prevalence, affecting between 6 and 10% of women in reproductive age. It is also frequently associated with infertility, being present in between 25 and 50% of infertile women, with 30 to 50% of endometriosis patients being infertile. However, the mechanisms underlying disease-related infertility are still poorly understood.",
"Evidence have suggested that changes in the endometrial receptivity, due to molecular and functional disorders in the eutopic endometrium, may be related to impaired fertility in women with endometriosis. The success of embryonic implantation depends on an adequate embryonic development, on the arrival of a competent embryo to a receptive endometrium, and on an efficient communication between the embryo and the endometrium. It is known that the human endometrium becomes receptive only during the implantation window, a certain period that results from the synchronized interaction of a variety of molecules, did not identify differentially expressed transcripts among the groups. Likewise, the miRNA sequencing in the eutopic endometrium of the same patients did not find changes in those post-transcriptional regulatory molecules. Together, the findings suggest that the eutopic endometrium of infertile women with the disease is molecularly similar to that of fertile women. However, the absence of alterations in mRNA and miRNA expression does not exclude the possibility of other molecular changes, with consequences for protein synthesis, which could impact the endometrial receptivity of these women. Single nucleotide variants. The study was approved by the Research Ethics Committee of the Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo ≤ 30 kg/m\n^(2)\n, absence of polycystic ovary syndrome and of other etiologies of chronic anovulation, hydrosalpinx and chronic diseases such as diabetes mellitus or other endocrinopathies, cardiovascular disease, dyslipidemia, systemic lupus erythematosus and other rheumatologic diseases, HIV infection, any active infection, alcohol, drugs or smoking habit, and use of hormonal medication or of anti-inflammatory drugs during the 3 months preceding the beginning of the study were included.",
"In the END group, 6 patients with infertility exclusively associated to pelvic endometriosis diagnosed and classified by videolaparoscopy according to the criteria of the American Society for Reproductive Medicine were included. Among them, 2 patients were diagnosed with stage I endometriosis, 1 with stage II endometriosis, 1 with stage III endometriosis and 2 with stage IV endometriosis.",
"In the IC group, 6 patients with infertility attributable to male and/or tubal factors who had ruled out endometriosis and other pelvic diseases by videolaparoscopy were included. The FC group was composed by 5 patients undergoing tubal ligation who were proven fertile\nand 24\n^(th)\ndays of the cycle). For data standardization, the ovulation day was considered as the 14\n^(th)\nday of a 28-day menstrual cycle.",
"Eutopic endometrial biopsies were collected during the implantation window from 17 patients was performed with STAR, following the best practices for variant discovery in RNA-Seq data, filtered using the hard filtering method.",
"All samples that proceeded to RNA-Seq were evaluated for total RNA integrity in the 2100 BioanalyzerTM. According to the predictors of pathogenicity, 42 variants were selected, 14 in the fertile control group, 19 in the infertile control group, and 9 in the endometriosis group. shows the data for the variants in each group after applying the filters. Within the endometriosis group, two samples did not present any mutation predicted as deleterious. In the other groups, all samples showed at least one mutation.",
"The search of functional mutations was, then, performed in the dbSNP and ClinVar databases. The general data for each variant are presented in . All the mutations found were classified as missense.",
"According to the findings, in the fertile control group, two patients had mutations corresponding to clinical conditions. Among them, patient 1 presented two mutations with associated pathological conditions, being one related to cardiomyopathy and the other to Adams-Oliver syndrome 2, both with benign significance. Patient 2 presented one mutation related to spermatogenic failure and ciliary dyskinesia, also with benign significance. The infertile control group did not have any mutations with an associated clinical condition. In the endometriosis group, only patient 4 presented a mutation associated to a clinical condition of eutopic endometria of infertile women with endometriosis and of controls during the implantation window, through the analysis of data previously generated by RNA-Seq.",
"According to the findings, none of the variants found were common to other samples within the same group, suggesting no pattern of mutations in those patients. Also, no variant was repeated among women with endometriosis, infertile controls, and fertile controls. Interestingly, the endometriosis group had the lower number of variants, followed by the fertile control group, with the infertile control group having the highest number of mutations. However, it is important to highlight the small sample size of the groups, which may represent a bias and precludes groups comparison. Powered studies are necessary to confirm those results.",
"All the filtered mutations were classified as missense, which means that the substitution of a single base pair alters the genetic code and produces an aminoacid which is different from the usual, which is able to affect the protein function. It is known that the phenotypic effects of a mutation can be more severe the greater the difference in the chemical nature of the side chains of the aminoacid residues, and that they also depend on the role that this residue plays in the structure and function of the protein. Nevertheless, in the endometriosis group, only one patient presented a mutation associated with a clinical condition with endometriosis and/or the endometrium. The CMKLR1 gene encodes a protein called chemerin, which is an adipokine expressed in several human organs. This protein has been associated with several systemic and focal inflammatory processes. It modulates chemotaxis and activates inflammatory macrophages and cytokines. The CMKLR1 gene is also associated with important endometrial events for pregnancy, such as accumulation of deciduous natural killer already associated with endometriosis, endometrial function, and initial gestational development.",
"Considering the aim of the present study of screening analysis and the importance of the CMKLR1 gene in endometrial modulation, CMKLR1 could be suggested as a candidate gene for further studies evaluating mutations in the eutopic endometrium from endometriosis patients. Thus, according to the present findings, future studies with appropriate casuistry, which investigate the CMKLR1 mutation in DNA samples (and not in transcripts) and evaluate the respective protein (chemerin) in the eutopic endometria of infertile women with endometriosis may clarify this issue and contribute to the understanding of endometriosis-related infertility."
] |
PMC10847414
|
Nature Communications
|
Antireflective vertical-cavity surface-emitting laser for LiDAR
|
06-02-2024
|
Multijunction vertical-cavity surface-emitting lasers (VCSELs) have gained popularity in automotive LiDARs, yet achieving a divergence of less than 16° (D86) is difficult for conventional extended cavity designs due to multiple-longitudinal-mode lasing. Our innovation, the antireflective vertical-cavity surface-emitting laser (AR-VCSEL), addresses this challenge by introducing an antireflective light reservoir, where the electric field intensity is substantially higher than the gain region. This reduces the required cavity length for minimal divergence, preserving the single-longitudinal-mode lasing. A 6-junction AR-VCSEL array showcases a halved divergence and tripled brightness compared to its conventional counterpart. Various multijunction AR-VCSEL array designs achieve a divergence range of 8° to 16° (D86). Notably, a 7 μm AR-VCSEL emitter achieves 28.4 mW in single transverse mode lasing. AR-VCSEL stands out among semiconductor lasers, offering a well-balanced power density and brightness, making it a cost-effective solution for long-distance LiDARs. The antireflective cavity concept may inspire diverse applications in photonic devices beyond LiDARs.
|
[
"Compactness, fast response, and high energy conversion efficiency have made vertical-cavity surface-emitting lasers, as the power flow per unit emission area A per unit solid-angle ΔΩ is preserved as the light beam travels through any ideal collimating lens systems^(18). It can only increase if any optics are nonideal during propagation. Similarly, the power can only be preserved or deteriorated for any optical loss during propagation. As a result, the brightness and the spectral brightness can only deteriorate or, at best, be preserved in a lossless ideal lens system. Therefore, in addition to perfecting the optics and increasing the laser emission power, reducing the etendue of the original laser beam from the bare chip is critical to achieving high brightness and high spectral brightness for distant objects.",
"Regarding the choice of the most suitable semiconductor laser source for commercial LiDAR^(19 , 20), there is an ongoing competition between edge-emitting lasers. Figure shows a long-cavity 6-junction VCSEL emitter structure with bottom and top distributed Bragg reflectors can be approximated as the electric field intensity-averaged refractive index, as shown in Eq.^(39). n _(eff) is the effective refractive index, n ( z ) is the refractive index in the z -axis direction, and | E ( z )|^(2) is the electric field intensity in the z -axis direction. \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$${n}_{{1}_{{{{{\\rm{eff}}}}}}}$$\\end{document} n 1 eff , \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$${n}_{{2}_{{{{{\\rm{eff}}}}}}}$$\\end{document} n 2 eff and \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\triangle {n}_{{{{{\\rm{eff}}}}}}$$\\end{document} △ n eff are the effective refractive indices inside and outside of the optical aperture in the horizontal plane and their difference. n _(1) and n _(2) are the refractive indices of the high-aluminum-content AlGaAs spectrum from the active region is ~20 nm wide at the half maximum is not acceptable for most applications, as it can cause potential problems such as temperature instability and efficiency loss from receiving filters.",
"Even though such multiwavelength lasing can be somewhat rectified by narrowing the top DBR stopband width with a reduced index contrast, the divergence is eventually limited by epitaxial thickness-induced stress, wafer bowing, and subsequent fabrication difficulties. Realizing a D86 full angle of less than 16° for a single-longitudinal-mode oxide VCSEL with more than 5 junctions is difficult. A better low-divergence design is needed to utilize the cavity length more efficiently.",
"Here, we propose a unique VCSEL structure with an antireflective cavity, including a multijunction active region, an antireflective mirror, and a light reservoir where the E-field intensity is exceptionally high, much higher than that in the active region. The total E-field energy stored in such an antireflective cavity is multiple times that in an ordinary extended cavity with an equal spatial volume. We will demonstrate that such an antireflective vertical-cavity surface-emitting laser phase shift. The photons generated from the active region traveling towards the bottom DBR interfere constructively at each antireflective layer and reach increasingly higher intensity until stabilization at the light reservoir. Figure shows a close-up electric field comparison at the active region/mirror interface between a traditional VCSEL structure in d and an AR-VCSEL in e. With a quarter wavelength spacer layer located between the active region and the antireflective mirror, the electric field antinode positions shift from their original index-decreasing interfaces in d to index-increasing interfaces in e along the direction from the active region to the bottom mirror. Supplementary Fig. further illustrates how the electric field is established in an AR-VCSEL.",
"Our unique design transforms a long cavity extension into a shorter extension but with a much stronger electric field. Such an antireflective cavity is more efficient in storing photons in each unit of cavity length, thus more effectively lowering Γ_(ox). The stored photons inside the reservoir feel almost no lateral confinement. They are essentially ‘free’ laterally, significantly reducing the overall divergence angle.",
"The strong electric field intensity inside the light reservoir lessens the dependence of the divergence angle on the thickness of the extended cavity. As a result, only a moderate thickness of the light reservoir is needed while maintaining a large FSR of ~16 nm to reach an even smaller divergence angle with a reduced Γ_(ox) of 0.027% while maintaining a single longitudinal mode.",
"Figure shows the comparison between the AR-VCSEL and the extended cavity VCSEL on the averaged M ^(2) factor of all individual emitters within each array, the near field, and the far field 115 cm away. The M ^(2) factor, which is proportional to the FF angle as \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$${M}^{2}=\\pi r\\theta /\\lambda=\\pi r\\varTheta /(2\\lambda )$$\\end{document} M 2 = π r θ / λ = π r Θ / ( 2 λ ) where Θ is the full angle in D86, is stable at different current injection levels for both the AR-VCSEL and the extended cavity VCSEL. The sparser speckles in AR-VCSEL near field image indicate fewer number of transverse modes, consistent with its reduced Γ_(ox). In Fig. , we compare the performance of the AR-VCSEL, our extended cavity VCSEL, the-state-of-the-art commercial multijunction VCSEL^(43), and the-state-of-the-art commercial multijunction EEL for LiDAR^(44), in terms of the light output power within a 10° field of view, the brightness, and the spectral brightness. The brightness and spectral brightness are calculated using Eqs. and \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\varDelta \\varOmega=\\pi {\\varTheta }^{2}/4$$\\end{document} Δ Ω = π Θ 2 / 4 , where Θ is the full angle in D86. Our extended cavity VCSEL has similar performances with the-state-of-the-art commercial multijunction VCSEL in all three metrics. In contrast, our AR-VCSEL has dramatically improved the performance in each of the three metrics. With identical array size and layout, our AR-VCSEL has more than double the power of our extended cavity VCSEL contained within a 10° field of view due to the increased higher order mode loss. Compared with the state-of-the-art commercial multijunction EEL for LiDAR, our AR-VCSEL has more than double the power within a 10° FOV. Although the brightness of our current AR-VCSEL is still lower than the state-of-the-art EEL, the spectral brightness is more than doubled, which is believed to substantially improve the performance of long- and medium-range LiDARs equipped with narrow bandwidth filters. Despite the fact that the EEL can reach a similar spectral brightness at a higher current, it is less valuable due to the lack of narrow bandwidth filters matching its large temperature coefficient of wavelength shift.",
"Note that the antireflective mirror and the light reservoir are not necessarily separable. An antireflective mirror can be built into a light reservoir. The structure and phase can be flexible as long as the E-field intensity is enhanced compared to the active region. An example is shown in Supplementary Fig. . The key to such E-field profile engineering is to guarantee that the accumulated phase shift over the whole light reservoir, or in other words, the optical distance between the active region and the bottom DBR, is a half-wave integer. Such flexibility of the light reservoir design provides great potential for engineering and tailoring the light intensity distribution in AR-VCSELs.",
"Note that the AR-VCSEL design is different from a double cavity design. Nearly all AR-VCSELs and extended VCSELs, regardless of the number of junctions, follow the same trending line. Through careful design, we have reached precise control of the divergence angle can vary for the same effective cavity length. Figure shows the 6-junction array brightness and spectral width of these AR-VCSELs and extended cavity VCSELs at 10 A. Figure shows the 6-junction array spectral brightness. The same junction number is used for a fair comparison between AR-VCSELs and extended cavity VCSELs. The highest brightness that we have achieved with 6 junctions in the 250 μm diameter AR-VCSEL array is ~40 kW mm^(−2) sr^(−1) and ~140 kW mm^(−2) sr^(−1) for single emitters due to fully utilized emission area. The spectral brightness we have achieved in AR-VCSEL at 10 A is ~75.6 kW nm^(−1) mm^(−2) sr^(−1) for arrays and ~260 kW nm^(−1) mm^(−2) sr^(−1) for single emitters, a similar level as the state-of-the-art LiDAR EEL^(44), which is typically ~120 kW nm^(−1) mm^(−2) sr^(−1) at a higher current and not useful without filter wavelength-shift-matching. As a reference, the state-of-the-art VCSELs for LiDAR^(43) have a moderate spectral brightness of only ~12 kW nm^(−1) mm^(−2) sr^(−1). Considering that the number of junctions can increase while the capacity of the light reservoir can be extensively enlarged, and the emission size of the array can be shrunk, there is great potential to further increase AR-VCSEL’s spectral brightness and power by several times or even an order of magnitude. For example, we have achieved over 100 kW mm^(−2)sr^(−1) on a 100 μm square array of 6 Junction AR-VCSELs. Overall, AR-VCSELs provide high spectral brightness, best beam quality, and great temperature stability while remaining most cost-effective for producing higher power per unit area.",
"In addition to varying the number of junctions and the oxide confinement factor, we investigated another critical parameter: the diameter of the optical aperture, all with the same epitaxial structure as shown in Fig. . Subsequently, we conducted measurements of their divergence angles and calculated the average M ^(2) values within these arrays. Our results reveal a clear correlation between OA size and M ^(2) values, as shown in Fig. . As the OA size decreases, M ^(2) values also decrease. Notably, when the aperture size is reduced to 7 μm, the M ^(2) approaches a value close to 1, suggesting that the majority of emitters might operate in nearly a single transverse mode lasing regime.",
"To delve deeper into the behavior of the 7 μm OA array sample and confirm the possibility of single-mode lasing, we employed a 100 ns pulse driver for testing. This allowed us to gain better control at lower currents, facilitating the determination of the transition point between single-mode and multimode lasing. We utilized a free-space lens to couple the emission of one specific emitter into an optical fiber. This confirms the achievement of high-power single transverse mode lasing in AR-VCSELs under the 100 ns pulse condition. The 28.4 mW peak power of this individual emitter surpassed the highest power of 14 mW for multijunction VCSEL single-mode lasing reported in the literature^(47). Notably, the 7 μm OA of the AR-VCSEL is considerably larger than the 3–4 μm typically required for traditional single-mode VCSELs without additional surface relief or complex structures.",
"Additionally, we obtained both near-field and far-field images of the light emitted from the aperture. The optical fields exhibit slightly elliptical shapes, likely attributed to the imperfect circular shape of the aperture. When analyzing the side views of the far-field intensity, their shapes closely resemble Gaussian curves. The far-field divergence of 9.4° for the 7 μm OA is almost at the diffraction limit, a key characteristic of single-mode operation.",
"It is essential to acknowledge that, at this stage, we cannot conclusively confirm the consistency of the optical mode between continuous wave. The ones in the upper-right corners will be favored in the competition for long-distance LiDARs.",
"Divergence and brightness : For a 200 m long-range scanning LiDAR, a collimated beam with divergence <0.03° is required to produce a spot size of 10 cm. PCSEL offers ~0.1° and can significantly reduce the size of the collimation lens or even possibly eliminate it for shorter distances or lower resolution. In this sense, PCSEL has advantages with a smaller etendue, allowing a smaller spot size after collimation. However, when the laser spot size becomes smaller than the sensor’s spatial resolution, there are no additional benefits. For today’s scanning LiDAR, a brightness of 10–20 kW mm^(−2) sr^(−1) is sufficient to match the sensor array with a 10 μm pitch. Our 30–60 kW mm^(−2) sr^(−1) brightness AR-VCSEL source is sufficient to match the next generation sensor array with ~6 μm pitch or 3 times the current pixel resolution, which may take a few years to be developed. The 100 kW mm^(−2) sr^(−1) brightness from our 100 μm square AR-VCSEL array could cover the needs of sub 5 μm detector pixels. With more junctions, smaller areas, fewer oxide layers, and stronger light reservoirs, we believe AR-VCSELs with a brightness of 200–1000 kW mm^(−2) sr^(−1) are achievable in the near future to match higher resolution sensor arrays.",
"Power density or kilowatt per chip area : The biggest advantage of AR-VCSELs over PCSELs is the power density. The chip area determines the number of chips produced in a fixed-sized semiconductor substrate, such as the 6-in. GaAs substrate, which is widely used for VCSEL production today. If the type of substrate, epitaxial thickness and times of regrowth, layers of fabrication and complexity, and on-wafer test hours are all similar, the production cost of the whole wafers would be similar. Then, the unit cost of the chip produced is directly proportional to the chip area. Therefore, to reduce costs, a smaller chip size is preferred to produce the same amount of power required. Although PCSELs may increase the power density by sacrificing beam quality, as reported experimentally, PCSEL’s peak power density is only ~60 W/mm^(2) ^(48). AR-VCSEL and VCSEL can go beyond 1000 W/mm^(2) easily. As shown in Fig. , a 100 μm square-shaped 6-junction AR-VCSEL array we recently fabricated can provide ~45 W peak power, with a power density of ~4500 W/mm^(2). A 250 μm diameter AR-VCSEL array with 14 junctions can produce ~240 W peak power and ~5000 W/mm^(2) power density. Based on these numbers, we predict that a 100 μm square shaped 18-junction AR-VCSEL array can possibly reach 15,000 W/mm^(2). Just considering the area usage of the semiconductor alone, AR-VCSEL costs 10–100 times less than PCSEL for generating the same optical power without accounting for PCSEL’s expensive lithography and regrowth process. Laser and sensor chips each take about 20–40% of the total cost of a LiDAR. Under current PCSEL technology, even if we completely eliminate the cost of the transmitting-end lens, topological cavities^(50), or metasurface structures^(51) to potentially realize higher output power and efficiency for these surface-emitting lasers.",
"In summary, an AR-VCSEL that combines an antireflective light reservoir and a multijunction gain region has a significantly reduced divergence angle, high brightness, and high spectral brightness while maintaining the single-longitudinal-mode lasing. By solely reconstructing epitaxial layers, this unique design requires neither complex device structures nor additional fabrication steps. With a standard low-cost VCSEL process, we have realized an ultrasmall full divergence angle of 8.0° boundary conditions, and final simulation results were obtained with an auto-shutoff minimum of 1E-5 and an auto-shutoff maximum of 1E5. Simulations of both with gain and without gain in the active layer were conducted. The simulated normalized | E ( z )|^(2) field intensity profiles with gain and without gain were compared with a difference of less than 0.1%, confirming a stable static distribution."
] |
PMC10191861
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Nature Aging
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Cold temperature extends longevity and prevents disease-related protein aggregation through PA28γ-induced proteasomes
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03-04-2023
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Aging is a primary risk factor for neurodegenerative disorders that involve protein aggregation. Because lowering body temperature is one of the most effective mechanisms to extend longevity in both poikilotherms and homeotherms, a better understanding of cold-induced changes can lead to converging modifiers of pathological protein aggregation. Here, we find that cold temperature (15 °C) selectively induces the trypsin-like activity of the proteasome in Caenorhabditis elegans through PSME-3, the worm orthologue of human PA28γ/PSME3. This proteasome activator is required for cold-induced longevity and ameliorates age-related deficits in protein degradation. Moreover, cold-induced PA28γ/PSME-3 diminishes protein aggregation in C. elegans models of age-related diseases such as Huntington’s and amyotrophic lateral sclerosis. Notably, exposure of human cells to moderate cold temperature (36 °C) also activates trypsin-like activity through PA28γ/PSME3, reducing disease-related protein aggregation and neurodegeneration. Together, our findings reveal a beneficial role of cold temperature that crosses evolutionary boundaries with potential implications for multi-disease prevention.
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[
"Extreme low temperatures are detrimental, but a moderate decrease in body temperature can have beneficial effects for the organism^(1). In fact, lowering body temperature extends longevity in both poikilotherms. However, adult control sterile worms had similar caspase-like and chymotrypsin-like proteasome activities across temperatures. The cold-induced effects on trypsin-like activity were not linked with sterility, as wild-type worms also had a similar increase when shifted from 20 °C to 15 °C during adulthood. In contrast, caspase-like and chymotrypsin-like activities remained similar or decreased in wild-type animals at cold temperature, respectively.",
"To assess whether cold temperature changes the levels of proteasome subunits, we used available quantitative proteomics data^(9). We did not find substantial differences in 20S subunits comparing adult worms at cold. Moreover, proteomic analysis did not detect significant changes in 19S subunits. Among PA28 subunits, C. elegans only expresses psme -3, the orthologue of human PA28γ/PSME3. By western blot, we confirmed that worms exhibit higher protein levels of PSME-3 at 15 °C when compared with 20 °C or 25 °C. The increase in PSME-3 protein levels correlated with an upregulation of the mRNA amounts at cold temperature. Because PA28γ/PSME3 selectively activates trypsin-like activity in vitro^(31 , 36), we asked whether PSME-3 is required for the elevated trypsin-like activity at 15 °C. Indeed, knockdown of psme-3 after development decreased trypsin-like activity at cold temperature, but not at standard temperature.",
"Because low temperature extends lifespan, we could not discard that the changes observed in day 6 adults ensue from differences in aging rates rather than a direct effect of PSME-3. To disentangle these possibilities, we examined worms at a younger age. Similar to day 6 adult worms, knockdown of psme-3 specifically blocked cold-induced trypsin-like activity in day 3 adults but had no effects at 20 °C. To assess younger ages, we started the cold temperature and RNAi treatments during development and assessed proteasome activity at day 1 of adulthood. Indeed, day 1 adults exhibited higher levels of trypsin-like activity at 15 °C when compared with age-matched worms at 20 °C. Although knockdown of psme-3 during development slightly decreased basal trypsin-like activity in day 1 adults at 20 °C, its inhibitory effects were much stronger at cold temperature. Thus, these data support a direct effect of cold-induced PSME-3 in the upregulation of trypsin-like proteasome activity.",
"Along these lines, overexpression of psme-3 was sufficient to further increase trypsin-like activity at 15 °C. In contrast, psme-3 overexpression did not induce trypsin-like activity at 20 °C, suggesting that PSME-3 function requires its activation by other factors that occurs upon cold temperature. Additionally, worms may also have mechanisms to inactivate PSME-3 at 20 °C. However, worms did not inhibit overexpressed PSME-3 when subjected to mild heat stress, resulting in a pronounced increase of trypsin-like activity at 25 °C. Altogether, we found that elevated PA28γ/PSME-3 function underlies the high levels of trypsin-like activity induced by cold temperature in C. elegans , while overexpression of PSME-3 can also promote trypsin-like proteasome activity at warm temperature, but not standard temperature.",
"In C. elegans , low temperature activates the cold-sensitive channel TRPA-1, which promotes lifespan extension^(11 , 12). We found that mutant worms lacking trpa-1 have lower trypsin-like activity when compared with wild-type animals at cold temperature, either at day 3 or 6 of adulthood. In contrast, loss of trpa-1 did not reduce basal trypsin-like activity at standard temperature. Moreover, lack of trpa-1 did not affect a different proteasome activity at 15 °C, supporting that activation of TRPA-1 channels contributes to the selective induction of trypsin-like activity at low temperature. Because loss of trpa-1 did not further decrease the low trypsin-like activity of psme-3 RNAi-treated worms at 15 °C, these results indicate that TRPA-1 channels modulate proteasome activity through PSME-3.",
"Indeed, we observed that lack of trpa-1 reduces the upregulation of PSME-3 protein levels at low temperature. Likewise, loss of trpa-1 also attenuated the induction of psme-3 mRNA amounts at 15 °C, suggesting that TRPA-1 modulates PSME-3 at the transcriptional level. As a sensor of cold temperature, TRPA-1 cannot promote transcriptional expression on its own and requires the activation of downstream transcription factors such as DAF-16/FOXO^(11). However, DAF-16 was not required for induction of psme-3 expression and trypsin-like activity. Besides DAF-16, other transcription factors are also involved in cold-induced longevity^(3). Among them, knockdown of the nuclear receptor daf-12 ^(23) partially reduced cold-induced psme-3 levels. However, we found the strongest inhibitory effects upon loss of the nuclear hormone receptor-49. Subsequently, loss of nhr-39 prevented cold-induced trypsin-like proteasome activity. Knockdown of nhr-49 did not affect the expression of the catalytic proteasome subunit pbs-2 , further supporting that nhr-49 induces trypsin-like activity through transcriptional regulation of psme-3 . Notably, loss of nhr-49 did not further decrease psme-3 expression in mutant worms lacking trpa-1 . Thus, TRPA-1 channels induce psme-3 levels at cold temperature through NHR-49 transcription factor.",
"Notably, knockdown of PA28γ/ psme-3 after development reduced the long lifespan phenotype induced by cold temperature. In contrast, knockdown of rpn-6.1 , a specific activator of 26S proteasomes^(33 , 37), shortened lifespan at all the temperatures tested. These data indicate that 26S proteasomes are essential for viability at different temperatures^(33 , 38), whereas PA28γ/PSME-3 is particularly required for cold-induced longevity.",
"Intrigued by these findings, we asked in which tissues PSME-3 acts to regulate organismal lifespan. Although TRPA-1 is expressed in multiple tissues, its activation in the intestine and neurons is particularly important to promote longevity^(11). However, activation of TRPA-1 in neurons also signals distal tissues such as the germline to delay reproductive aging^(9). In turn, the germline releases factors to induce pro-longevity genes in somatic tissues, including the intestine and muscle^(9). According to its key role in cell non-autonomous regulation of cold-induced longevity^(9), knockdown of psme-3 in the germline alone resulted in the strongest decrease of lifespan at 15 °C. In addition, tissue-specific knockdown of psme-3 in neurons, intestine or muscle also significantly decreased lifespan at 15 °C. Thus, PSME-3 has a pro-longevity role in all the tissues which are known to influence cold-induced lifespan extension. Because cold temperature only induces a moderate increase in PSME-3 levels, we could not use the reporter strain to assess whether PSME-3 is upregulated in a particular tissue at 15 °C. Nevertheless, we confirmed that PSME-3 is highly expressed not only in the germline and intestine but also in muscle and neurons, although to a lesser extent. Importantly, specific knockdown of psme-3 in the aforementioned tissues decreased trypsin-like activity, further supporting a functional role of PSME-3 in the germline, intestine, muscle and neurons.",
"We then assessed whether PSME-3 overexpression in somatic tissues is sufficient to promote longevity. Interestingly, PA28γ/ psme-3 overexpression slightly decreased lifespan at standard temperature. On the contrary, PA28γ/ psme-3 overexpression further extends longevity at 15 °C. Whereas moderate cold temperature. Thus, our data indicate that PA28γ/PSME-3 does not protect from extreme low temperatures but contributes to the longevity effects induced by moderate cold temperature. However, PSME-3 overexpression can have negative effects on lifespan at higher temperatures.",
"Given that activation of TRPA-1 promotes cold-induced longevity, we performed epistasis experiments to assess its functional links with PSME-3 in lifespan regulation. Similar to wild-type animals, knockdown of psme-3 did not shorten lifespan of trpa-1 -lacking worms at standard. Whereas loss of psme-3 shortened the cold-induced long lifespan of wild-type animals, it did not further decrease the short lifespan of trpa-1 mutant worms at cold temperature. Moreover, overexpression of psme-3 also shortened the lifespan of trpa-1 mutant animals at both standard and warm temperatures, but not at cold temperature. Although psme-3 overexpression slightly increased the mean lifespan of trpa-1 mutant worms at 15 °C, this extension was not significant. Together, our results suggest that TRPA-1 acts upstream of PSME-3 and is required for its longevity effects in C. elegans at moderate low temperature.",
"In contrast to 26S proteasomes, activation of the 20S proteasome through PA28γ induces protein degradation in a ubiquitin-independent manner^(31). Aging triggers a global loss of ubiquitination through the proteome in C. elegans , reducing the degradation of multiple proteins by the 26S proteasome^(26). Subsequently, these dysregulated proteasome targets accumulate during aging and impair cellular function^(26). For instance, the intermediate filament IFB-2 escapes the clean-up by the 26S proteasome with age, leading to its aggregation within intestinal cells. Conversely, knockdown of IFB-2 during adulthood delays the decline in intestinal integrity characteristic of aging animals and extends lifespan at standard temperature^(26). Notably, we found that cold temperature prevents the accumulation of IFB-2 and its subsequent aggregation in adult wild-type animals with age. However, knockdown of PA28γ/ psme-3 reduces the degradation of IFB-2, suppressing the ameliorative effects of low temperature on IFB-2 aggregation. Thus, these results suggest that cold-induced PA28γ/PSME-3 can ameliorate age-related deficits in protein degradation.",
"In vitro, PA28γ preferentially promotes the degradation of unstructured proteins over their native/folded counterparts, including unfolded variants of β-casein and insulin-like growth factor 1. Notably, cold temperature. On the contrary, low temperature did not decrease the protein levels of control polyQ19 when compared with standard temperature.",
"Knockdown of PA28γ/ psme-3 diminished the cold-induced degradation of polyQ67, increasing its aggregation at 15 °C. The aggregation of polyQ67 in neurons causes neurotoxicity and subsequently impairs motility, a disease-like phenotype^(42 , 43). We found that loss of PA28γ/ psme-3 reduces the motility of neuronal polyQ67-expressing worms at cold temperature, but does not affect control polyQ19 worms. We then asked whether PSME-3 influences neuronal aggregation of polyQ67 through its intracellular activity in neurons or via cell non-autonomous effects triggered by its function in other tissues. Notably, neuronal-specific knockdown of psme-3 was sufficient to induce aggregation of polyQ67 protein in neurons. Thus, these results indicate that intracellular levels of PSME-3 can directly regulate proteostasis of polyQ-expanded proteins in neurons. Because overexpression of psme-3 induces trypsin-like activity at both 15 °C and 25 °C, we assessed the effects of psme-3 overexpression in polyQ67-expressing worms. We found that psme-3 overexpression reduces the total levels of neuronal polyQ67 at both cold and warm temperatures. Concomitantly, psme-3 overexpression diminished the accumulation of aggregated polyQ67 peptides as well as motility defects at 25 °C. Given the low levels of aggregated polyQ67 at cold temperature, we could not detect a further decrease upon psme-3 overexpression at 15 °C. Nevertheless, psme-3 overexpression was sufficient to further ameliorate motility defects at 15 °C. In contrast, psme-3 overexpression did not influence the levels, aggregation and neurotoxicity of polyQ67 at 20 °C, according to its lack of effects on proteasome activity at standard temperature.",
"In addition to neurons, low temperature also decreased polyQ levels and aggregation in C. elegans that specifically express expanded polyQ peptides in the muscle. Moreover, knockdown of PA28γ/ psme-3 reduced the degradation of muscle polyQ peptides. Conversely, loss of psme-3 suppressed the inhibitory effects of cold temperature over polyQ aggregation in the muscle. The aggregation of expanded polyQ within muscle cells has intracellular detrimental effects in C. elegans , reducing muscle function and organismal motility^(46). In correlation with polyQ aggregates levels in the muscle, cold temperature ameliorated the deficits in coordinated movement whereas loss of psme-3 suppressed these beneficial effects. Therefore, cold-induced PA28γ/PSME-3 can prevent the aggregation of expanded polyQ proteins in distinct tissues, alleviating their pathological effects.",
"Besides expanded polyQ proteins, we asked whether cold-induced PA28γ/PSME-3 can also diminish aggregation of other disease-related proteins. To this end, we examined C. elegans that express an ALS-related mutant variant of FUS protein. However, knockdown of PA28γ/ psme-3 diminished the cold-induced degradation of mutant FUS, triggering the accumulation of FUS aggregates at 15 °C. Subsequently, knockdown of psme-3 suppressed the beneficial effects of cold temperature on ALS-related motility deficits. In addition to mutant FUS, cold temperature also decreased the protein levels and aggregation of ALS-related TDP-43^(M331V) variant, another mutant protein which is prone to aggregation^(48). Conversely, knockdown of PA28γ/ psme-3 reduced the cold-induced degradation of mutant TDP-43, promoting its aggregation at 15 °C. Collectively, our data indicate that cold-induced PA28γ/PSME-3 can attenuate the pathological aggregation of distinct disease-related proteins in C. elegans models.",
"The human body can physiologically reach moderate cold temperatures. However, a further decrease in temperature to 35 °C not only downregulated trypsin-like activity but also caspase-like activity when compared with 37 °C. Thus, these results indicate that moderate cold temperature, we asked whether this cold-sensitive channel also regulates the induction of trypsin-like activity in human cells at moderate cold temperature. Indeed, either knockdown of TRPA1 or treatment with HC-030031, a selective antagonist of TRPA1^(49 , 50), blocked the trypsin-like activity induced by cold temperature in HEK293 cells.",
"Moderate cold temperature. Moreover, we found increased assembly of PSME3 subunits into proteasome-activator 11S/PA28γ_(7) complexes at 36 °C. To further determine whether PSME3 underlies the upregulation of trypsin-like activity triggered by moderate cold temperature, we generated stable PSME3 -shRNA expressing HEK293 lines. These cells exhibited robust knockdown of PSME3 at either standard or cold temperatures. Remarkably, loss of PSME3 prevented the upregulation of trypsin-like activity induced by moderate cold temperature, but did not have strong effects at standard temperature. Moreover, PSME3 overexpression further increased trypsin-like activity at moderate cold temperature. In contrast to C. elegans , PSME3 overexpression was also sufficient to induce trypsin-like activity at 37 °C, raising the possibility that PSME3 can have valuable effects in human cells even at normal temperature.",
"Given the beneficial impact of cold temperature in C. elegans , we asked whether low temperature also prevents disease-related protein aggregation in human cells. To this end, we generated HEK293 cell models that express either control. Moderate cold temperature. We found that either the knockdown or inhibition of TRPA1 channels is sufficient to block the cold-induced degradation of mutant HTT, leading to its aggregation at 36 °C. Likewise, stable PSME3 -knockdown HEK293 cells lost their cold-induced ability to promote degradation of mutant HTT, resulting in similar levels of polyQ-expanded aggregates at cold and standard temperatures. In contrast, loss of PSME3 did not further increase the protein levels and aggregation of mutant HTT at standard temperature. Moreover, knockdown of PSME3 did not affect control Q23-HTT levels at either standard or low temperature, supporting that cold-induced PA28γ/PSME3 preferentially promotes the degradation of mutant HTT. Given that PSME3 overexpression induces trypsin-like activity even at normal temperature, we assessed whether increasing PSME3 levels prevents mutant HTT aggregation at 37 °C. Indeed, PSME3 overexpression was sufficient to promote the degradation of mutant HTT, reducing its aggregation at normal temperature. Because the aggregated amounts of mutant HTT were very low at 36 °C, it was difficult to interpret whether PSME3 overexpression further decreases its aggregation at cold temperature.",
"Besides polyQ-expanded HTT, cold temperature also diminished the levels and aggregation of the ALS-related mutant FUS^(P525L) variant in HEK293 human cells. Knockdown of PSME3 suppressed the cold-induced degradation of aggregation-prone FUS^(P525L), resulting in the accumulation of FUS aggregates in HEK293 cells at cold temperature. In contrast, cold-induced PA28γ/PSME3 did not change wild-type FUS levels. Importantly, either knockdown or pharmacological inhibition of TRPA1 also triggered mutant FUS aggregation at cold temperature. Because TRPA1 inhibition did not further increase mutant FUS aggregation in PSME3 -knockdown HEK293 cells, these results further support a role of TRPA1 on PSME3 effects at cold temperature. However, PSME3 overexpression could circumvent the requirement for TRPA1 and promote degradation of FUS^(P525L) at 37 °C, reducing mutant FUS aggregates in human cells at normal temperature.",
"Prompted by these findings, we asked whether cold temperature can ameliorate disease-related neurodegeneration. ALS is characterized by the selective degeneration of motor neurons^(53). Accordingly, motor neurons differentiated from patient-derived induced pluripotent stem cells. Notably, cold temperature. To assess whether these effects are mediated by PA28γ/PSME3, we generated stable PSME3 -shRNA ALS-iPSCs and differentiated them into motor neurons. The nervous system express the highest levels of PA28γ/PSME3 compared with other tissues^(32). Consistently, we found that iPSC-derived motor neurons have higher. Although iPSC-derived motor neurons already displayed elevated trypsin-like activity at standard conditions, cold temperature could further increase this specific activity without affecting chymotrypsin-like and caspase-like activities. Knockdown of PA28γ/PSME3 decreased trypsin-like activity in motor neurons at both standard and cold temperature, but the reduction was significantly stronger at cold temperature. In correlation with this decline in trypsin-like activity, knockdown of PSME3 reduced the ameliorative effects of cold temperature in the neurodegeneration phenotype of ALS motor neurons. Together, our results indicate that cold temperature prevents pathological phenotypes such as protein aggregation and neurodegeneration, a process mediated by the induction of trypsin-like activity in a PA28γ-dependent manner.",
"Because proteasomes are active in both the cytoplasm and nucleus^(59), we asked in which subcellular compartment PA28γ/PSME3 promotes degradation of disease-related proteins. Although PA28γ/PSME3 is mostly located in the nucleus of distinct human cell lines^(60 , 61), cumulative evidence demonstrates that PSME3 also becomes more prominent in the cytoplasm depending on the conditions and cell type^(62 , 63). Indeed, we found that the subcellular distribution varies depending on the cellular type. In the C. elegans germline and muscle, PSME-3 mostly accumulated in the nucleus. In intestinal cells, PSME-3 was mostly present in the cytoplasm but also detected in the nucleus. Likewise, PSME-3 was present in both the soma and nucleus of C. elegans neurons, but we did not detect PSME-3 in neuronal extensions. We observed a similar distribution of PSME3 in the soma and nucleus of human iPSC-derived motor neurons. In contrast, PSME3 was mostly accumulated in the nucleus of HEK293 cells, although we also observed cytoplasmic PSME3 to a lesser extent. Importantly, cold temperature did not change the subcellular distribution of PSME3 in C. elegans or human cells.",
"TDP-43 and FUS shuttle between the nucleus and the cytoplasm, but mostly localize in the nucleus^(64 – 66). However, familial ALS mutations in TDP-43 and FUS increase their cytosolic localization^(67 , 68). Accordingly, ALS-linked FUS^(P525L) mutant variant is located in both the nucleus and cytoplasm of C. elegans and human cells, whereas wild-type FUS is essentially located in the nucleus^(44 , 47 , 58). Accordingly, we observed increased cytoplasmic localization of mutant FUS^(P525L) in both human motor neurons and HEK293 cells, but a fraction of mutant FUS remained in the nucleus. We found that cold temperature does not change the subcellular distribution of mutant FUS^(P525L) in human HEK293 cells. Likewise, cold temperature did not alter the subcellular distribution of PSME3, which remained mostly located in the nucleus. Thus, we assessed whether cold-induced PSME3 prevents aggregation of mutant FUS by inducing its degradation in the cytoplasm or nucleus. To this end, we treated HEK293 cells with leptomycin B, an inhibitor of nuclear export^(69). Notably, leptomycin B treatment for 6 hours was sufficient to induce the accumulation of mutant FUS^(P525L) in the nucleus. Subsequently, leptomycin B treatment further increased the cold-induced degradation of mutant FUS^(P525L) protein. Although leptomycin B also accumulated FUS^(P525L) in the nucleus at normal temperature. Thus, PSME3 preferentially promotes cold-induced degradation of FUS^(P525L) in the nucleus, a process that could eventually reduce the loading of mutant FUS into the cytoplasm and subsequent aggregation. In contrast to FUS, mutant HTT is mainly cytoplasmic^(70) and remained in the cytoplasm upon leptomycin B treatment. Concomitantly, leptomycin B did not further increase the cold-induced degradation of mutant HTT. Because cold temperature was sufficient to promote HTT degradation without leptomycin B treatment, these data suggest that even the relative low amounts of PSME3 in the cytoplasm of HEK293 cells can scavenge HTT. Thus, cold-induced PSME3 may promote degradation of aggregation-prone proteins in either the nucleus or cytoplasm, depending on the main subcellular localization of the disease-related proteins."
] |
PMC10227795
|
Stem Cell Research & Therapy
|
MiR-146a-5p delivered by hucMSC extracellular vesicles modulates the inflammatory response to sulfur mustard-induced acute lung injury
|
30-05-2023
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Background Sulfur mustard (SM) is a highly toxic chemical warfare agent that has caused numerous casualties during wars and conflicts in the past century. Specific antidotes or therapeutic strategies are rare due to the complicated mechanism of toxicity, which still awaits elucidation. Clinical data show that acute lung injury (ALI) is responsible for most mortality and morbidity after SM exposure. Extracellular vesicles are natural materials that participate in intercellular communication by delivering various substances and can be modified. In this study, we aim to show that extracellular vesicles derived from human umbilical cord mesenchymal stromal cells (hucMSC-EVs) could exert therapeutic effects on SM-induced ALI, and to explain the underlying mechanism of effects. Methods MiR-146a-5p contained in hucMSC-EVs may be involved in the process of hucMSC-EVs modulating the inflammatory response to SM-induced ALI. We utilized miR-146a-5p delivered by extracellular vesicles and further modified hucMSCs with a miR-146a-5p mimic or inhibitor to collect miR-146a-5p-overexpressing extracellular vesicles (miR-146a-5p + -EVs) or miR-146a-5p-underexpressing extracellular vesicles (miR-146a-5p − -EVs), respectively. Through in vivo and in vitro experiments, we investigated the mechanism. Results The effect of miR-146a-5p + -EVs on improving the inflammatory reaction tied to SM injury was better than that of hucMSC-EVs. We demonstrated that miR-146a-5p delivered by hucMSC-EVs targeted TRAF6 to negatively regulate inflammation in SM-induced ALI models in vitro and in vivo. Conclusion In summary, miR-146a-5p delivered by hucMSC-EVs targeted TRAF6, causing hucMSC-EVs to exert anti-inflammatory effects in SM-induced ALI; thus, hucMSC-EVs treatment may be a promising clinical therapeutic after SM exposure. Graphical Abstract Supplementary Information The online version contains supplementary material available at 10.1186/s13287-023-03375-8.
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[
"With its characteristic simple structure, easy availability and convenience in creating stockpiles, sulfur mustard in China [ , ]. According to clinical data on SM victims, acute lung injury and their extracellular vesicles [ , ]. We previously found that bone marrow mesenchymal stem cells have the advantages of being less ethically controversial, having abundant tissue sources, and having low immunogenicity compared with BMSCs from mice [ , ]. HucMSCs have become the dominant type of stem cell used for allogeneic cell therapy and may be more suitable for the clinical treatment of SM-induced lung injury. HucMSC extracellular vesicles and mRNAs that can be transmitted to target cells and participate in cell-to-cell communication [ ]. Given the growing evidence that hucMSCs primarily rely on the release of extracellular vesicles to demonstrate therapeutic effects, extracellular vesicles may be a better choice for treating SM poisoning by avoiding the administration of live cells, which arouses concern related to tumor formation and long-term safety [ ]. In addition, the treatment ability of the extracellular vesicles could be further improved by modifying hucMSCs [ ].",
"In the present paper, we researched the therapeutic quality of hucMSC-EVs on ALI induced by SM and explored the mechanism of action. HucMSC-EVs exhibited strong therapeutic effects, as revealed by the improved survival rate and functional indicators, especially the reduced pulmonary inflammatory response of mice after SM injury. Furthermore, we examined the anti-inflammatory effects and mechanisms in SM-induced lung injury in vitro and in vivo. We found that hucMSC-EVs exerted anti-inflammatory effects in SM-induced ALI at least partly through miR-146a-5p delivered by hucMSC-EVs, which targeted TRAF6.",
"All mouse studies complied with the United States National Research Council’s Guide for the Care and Use of Laboratory Animals and the Committee on Ethics of Medical Research of the Naval Medical University’s with propylene glycol for 30 min, the sections were incubated with the NF-κB, TRAF6. HucMSC-EVs were isolated from the cell supernatant of passage 3–7 hucMSCs. The identity and purity of the extracellular vesicles were characterized by several methods, such as nanoparticle tracking analysis, transmission electron microscopy, and western blotting. To study the therapeutic effects of hucMSC-EVs on mice after SM injury, a stable and optimized mouse model of ALI was established. Detailed information about the general health of the mice in each group was recorded for 14 days, and the survival rate was calculated. At the end of the observation, all mice were euthanized by overdose of anesthetic. Compared to the control group, the dietary intake and physical activity of the mice were significantly reduced twenty-four hours after SM injection. The mice began to lose weight significantly on the third day, and some of them died on the sixth day, which is the reason that subsequent experiments examined tissues from mice after SM injury for 5 days. These SM-induced effects were alleviated by the administration of hucMSC-EVs. HucMSC-EVs administration significantly improved the general health condition and survival rates. HFL-1-EVs as the negative control had no effects on the general health and survival rates of the mice.",
"In the histopathological study, the presence of alveolar septum thickening, pulmonary edema, massive inflammatory cell and exudate infiltration, and hemorrhage after SM injury were confirmed by H&E staining. These effects could be improved by hucMSC-EVs injection, while the negative control HFL-1-EVs showed no benefit. In addition, BALF protein and the wet/dry weight ratio were important indicators of the exudation associated with pulmonary edema, confirming that SM injury could be ameliorated by hucMSC-EVs.",
"ELISA was used to measure inflammatory factors in mouse lung tissues. The levels of TNF-α and IL-1β were markedly augmented after SM injury compared to those in the control group, and their levels were successfully reduced by hucMSC-EVs administration, whereas HFL-1-EVs could not reduce their levels. The level of IL-10, an anti-inflammatory factor, was significantly augmented with hucMSC-EVs treatment. In general, hucMSC-EVs administration markedly reduced the inflammatory response in mice after SM injury.",
"Many studies have reported that miRNAs play an important role in the therapeutic effects of extracellular vesicles, although extracellular vesicles also contain proteins, lipids, metabolites and other components of extracellular vesicles that demonstrate therapeutic effects [ ]. We therefore sought to determine the mechanisms by which the miRNAs contained in hucMSC-EVs exert anti-inflammatory effects. According to the functions of some miRNAs already reported and the miRNA components of hucMSC-EVs [ , ], several miRNA molecules involved in hucMSC-EVs that might be relevant to our study were screened out, including miR-100-5p, miR-146a-5p, miR-23a-3p, let-7a-5p, miR-22-3p, miR-21, miR-221-3p, miR-15a-5p, miR-145-5p and miR-16-5p. We found that the protective effect of hucMSC-EVs on cell viability was significantly reduced when the miR-146a-5p was inhibited, while other miRNA molecules had no significant effects.",
"Many papers have shown that miR-146a-5p is more closely correlated with inflammation [ – ]. Therefore, we believe that miR-146a-5p may be involved in the process by which hucMSC-EVs modulate the inflammatory response to SM-induced ALI. An analysis of miR-146a-5p expression in mouse lung tissues and cells revealed that the levels of miR-146a-5p expression were markedly mitigated after SM injury compared to the control group, and their levels were successfully increased by hucMSC-EVs administration. MiR-146a-5p is an important immunoregulatory miRNA that is reportedly expressed in both MSCs and MSC-derived extracellular vesicles [ ]. Therefore, we explored the mechanisms of miR-146a-5p delivered by hucMSC-EVs involvement in the hucMSC-EV-mediated anti-inflammatory effects in SM-induced lung injury.",
"To identify the mechanisms of the anti-inflammatory effects of miR-146a-5p, an inflammatory cell model of SM injury was established using RAW264.7 cells, which is a murine lung macrophage cell line widely used in the study of ALI and inflammation [ ]. MiR-146a-5p was overexpressed or underexpressed in RAW264.7 cells by transfection of a miR-146a-5p mimic or inhibitor, respectively. Following transfection for twelve hours, the cells were exposed to SM for 30 min. As shown in Fig. C, miR-146a-5p was significantly downregulated twenty-four hours after SM injury. Cell viability was reduced after SM exposure and was significantly increased or reduced in miR-146a-5p-overexpressing or miR-146a-5p-underexpressing cells, respectively, while the negative controls showed no significant effects. These results suggested that miR-146a-5p attenuated SM-induced cytotoxicity and promoted recovery in RAW264.7 cells.",
"Compared to the NC group, ELISA revealed that the levels of TNF-α, IL-1β, and IL-6 secreted by RAW264.7 cells were successfully decreased by miR-146a-5p mimic administration, and miR-146a-5p inhibitor administration notably increased their levels after SM injury. The level of the anti-inflammatory factor IL-10 was significantly enhanced with miR-146a-5p mimic treatment. In addition, RT–PCR analysis also showed that the trend in these factors in cells was the same as the ELISA results. These results showed that miR-146a-5p significantly suppressed inflammation after SM injury.",
"One of the most important regulators of inflammation is the TLR4/NF-κB signaling pathway, and we found that in the miR-146a-5p-overexpressing group, the TLR4, TRAF6, IRAK1, NF-κB, and pNF-κB levels all decreased, while those levels were augmented in the miR-146a-5p-underexpressing group compared to those in the NC group. In general, miR-146a-5p negatively regulates inflammation induced by SM and is related to the regulation of the TLR4 signaling pathway.",
"We examined potential mediators of the effect exhibited by miR-146a-5p delivered by hucMSC-EVs. MiR-146a-5p could bind to the TRAF6 mRNA 3′-untranslated region. The combination of seven complementary nucleotides was altered to construct a mutated version of the TRAF6 3′-UTR. This mutated TRAF6 3′-UTR was added to the luciferase coding region and cotransfected into HEK293T cells with miR-146a-5p mimic. The luciferase activity was significantly lower when the TRAF6 3′-UTR was cotransfected with miR-146a-5p mimic than that cotransfected with the control. However, it was obvious that the mutant TRAF6 3′-UTR reduced this effect. These results confirmed that miR-146a-5p specifically targeted and suppressed the 3′-UTR of TRAF6.",
"To explore the mechanism of suppressed inflammation by miR-146a-5p in hucMSC-EVs, miR-146a-5p-overexpressing extracellular vesicles. We treated RAW264.7 cells with extracellular vesicles or miR-146a-5p^(+)/miR-146a-5p^(−)-EVs after SM injury. The expression of miR-146a-5p and the cell viability were increased after hucMSC-EVs treatment and were significantly increased or reduced in the miR-146a-5p^(+)-EV group or miR-146a-5p^(−)-EV group in comparison with the hucMSC-EV group, respectively. However, comparing the HFL-1-EV group with the SM group, no significant difference was found. The same results were detected in lung epithelial cells. These results suggested that the alleviation of SM-induced cytotoxicity and promotion of recovery in RAW264.7 cells by hucMSC-EVs were mediated through miR-146a-5p delivered by hucMSC-EVs.",
"To identify whether the abovementioned effect of miR-146a-5p is TRAF6 dependent, RAW264.7 cells were treated with hucMSC-EVs, miR-146a-5p^(+)-EVs, or miR-146a-5p^(−)-EVs or were transfected with siTRAF6. The ELISA results showed that miR-146a-5p^(+)-EVs administration successfully diminished the secretion of TNF-α, IL-1β, and IL-6 in RAW264.7 cells after SM exposure. The level of the anti-inflammatory factor IL-10 was significantly augmented in the miR-146a-5p^(+)-EVs group. The effect of miR-146a-5p^(+)-EVs was the same as transfection with siTRAF6 but was more obvious than that of hucMSC-EVs administration. MiR-146a-5p^(−)-EVs aggravated the inflammatory response, as opposed to miR-146a-5p^(+)-EVs. These data suggested that miR-146a-5p delivered by hucMSC-EVs mediated the anti-inflammatory effect of hucMSC-EVs. We further explored the mechanism. As shown in Fig. J, TLR4, TRAF6, IRAK1, NF-κB, and pNF-κB protein expression was reduced after hucMSC-EVs treatment and was further significantly downregulated in the miR-146a-5p^(+)-EVs group compared to hucMSC-EVs administration. In addition, comparing the miR-146a-5p^(+)-EV group with the siTRAF6 group, no significant difference was found. The same results have been shown in lung epithelial cells. To observe the influence of extracellular vesicles and siRNA on TRAF6 and NF-κB expression, we detected these proteins in RAW264.7 cells by immunofluorescent staining after multiple treatments. MiR-146a-5p^(+)-EV administration significantly downregulated TRAF6 expression and NF-κB nuclear translocation compared to hucMSC-EVs administration, and the effect was the same as that of the siTRAF6 group. MiR-146a-5p^(−)-EVs showed the opposite effect relative to miR-146a-5p^(+)-EVs. The above results demonstrated that miR-146a-5p delivered by hucMSC-EVs targeted TRAF6 and mediated the anti-inflammatory effect of hucMSC-EVs in vitro.",
"To explore the mechanism of the therapeutic effects of hucMSC-EVs on SM injury in vivo, the mice were treated with different types of extracellular vesicles via tail vein injection on the first and third days after SM exposure. Compared with the therapeutic effects of miR-146a-5p^(+)-EVs, miR-146a-5p^(−)-EVs, and hucMSC-EVs, we found that miR-146a-5p was significantly increased or reduced in the miR-146a-5p^(+)-EV group or the miR-146a-5p^(−)-EV group compared with the hucMSC-EV group, respectively. MiR-146a-5p^(+)-EVs dramatically decreased ALI induced by SM, as shown by H&E staining, BALF protein, the wet/dry weight ratio, and the expression of Ki67, compared to those of the hucMSC-EV group. The proinflammatory factors present in mouse lung tissues and serum samples were examined using ELISA. Compared with the levels in the hucMSC-EV group, the levels of TNF-α, IL-1β, and IL-6 in the miR-146a-5p^(+)-EV group were markedly reduced, while the level of the anti-inflammatory factor IL-10 was significantly increased. MiR-146a-5^(−)-EVs showed the opposite effect compared to that of miR-146a-5p^(+)-EVs. These results suggested that miR-146a-5p delivered by hucMSC-EVs mediated the anti-inflammatory effect of hucMSC-EVs, which was the same as the results of in vitro experiments.",
"The mechanism was further explored. As shown in Fig. I, TLR4, TRAF6, IRAK1, NF-κB, and pNF-κB protein expression was significantly downregulated in the miR-146a-5p^(+)-EV group compared to the hucMSC-EV group. The influence of different types of extracellular vesicles on TRAF6 and NF-κB expression was evaluated by immunohistochemical staining. MiR-146a-5p^(+)-EV administration significantly downregulated TRAF6 expression and NF-κB nuclear translocation compared to hucMSC-EVs administration. MiR-146a-5p^(−)-EVs showed the opposite effect to that of miR-146a-5p^(+)-EVs.",
"These results were also the same as the in vitro results described above, suggesting that miR-146a-5p delivered by hucMSC-EVs targeted TRAF6 and mediated the anti-inflammatory effect of hucMSC-EVs in vivo.",
"In the current research, we found a therapeutic effect of hucMSC-EVs on ALI caused by SM, especially in terms of improving the inflammatory response. Treatment with hucMSC-EVs increased the survival rate, attenuated ALI, reduced BALF protein and the wet/dry weight ratio, and suppressed proinflammatory cytokine levels. Through an analysis of the function and contents of extracellular vesicles, the delivery of bioactive miRNAs by extracellular vesicles to cells is regarded as the potential mechanism of these effects. We found that the miR-146a-5p expression levels markedly decreased after SM injury, and their expression could be augmented in lung tissue or cells by treatment with hucMSC-EVs. Moreover, by transfecting miR-146a-5p mimic or inhibitor to enhance or mitigate its expression in RAW264.7 cells, respectively, we demonstrated that miR-146a-5p alleviated SM-induced cytotoxicity and significantly suppressed inflammation by regulating the TLR4 signaling pathway. Finally, miR-146a-5p^(+)/miR-146a-5p^(−)-EVs were isolated and collected by modifying hucMSCs. We discovered that miR-146a-5p^(+)-EVs administration significantly attenuated TRAF6 expression, which negatively regulated SM-induced inflammation in vitro and in vivo. Taken together, these accumulated data indicate that hucMSC-EVs could prevent inflammation and improve ALI induced by SM through the delivery of miR-146a-5p.",
"In recent years, the potential role of stem cells as a therapy has attracted considerable attention. MSCs are non-hematopoietic cells which can be isolated from various sources, including umbilical cord, adipose tissue, bone marrow, and human dental pulp [ , ]. The therapeutic efficacy of mouse BMSCs and their extracellular vesicles in SM-induced lung injury has been reported by our group [ , ]. Due to limited tissue sources, immunogenicity, and ethical restrictions on studying BMSCs, we explored the utility of hucMSCs in treating SM-ALI. HucMSC surface antigens are not prominent, the rejection reactions of transplanted cells are insignificant, and the matching requirements are not strict, which makes them convenient for use in allotransplantation. Numerous studies have confirmed that hucMSCs possess potential effects in treating pulmonary disease including COVID-19 [ , ]. In addition, positive outcomes from hucMSCs in treating diseases have been found in several clinical trials evaluating their therapeutic efficacy [ – ]. It has been suggested that MSCs derived from bone marrow are potentially good candidates for brain and spinal cord injury treatment, MSCs derived from adipose tissue are potentially good candidates for reproductive disorder treatment and skin regeneration, MSCs derived from the umbilical cord are potentially good candidates for pulmonary disease and acute respiratory distress syndrome treatment [ ]. However, the clinical application of hucMSCs is limited because of their differentiation and proliferation abilities, which are related to long-term culture and donor age [ ]. Therefore, we focused on hucMSC-EVs as an alternative strategy that could have the same therapeutic ability as hucMSCs while eliminating the complications of cell transplantation [ ]. In our study, the therapeutic effect of hucMSCs-EVs was evaluated by injecting extracellular vesicles into the tail veins of mice with ALI caused by SM. Compared with the control groups, we discovered that extracellular vesicles derived from hucMSCs protected against SM-induced ALI by attenuating inflammation.",
"HucMSCs-EVs are natural materials and serve as a vehicle that could alter the gene expression of the recipient cells by transferring protein, mRNA, and miRNA to distant recipient cells [ , ]. Recent reports have suggested that extracellular vesicles have diverse potential applications in therapeutics by delivering miRNAs and could be modified by manipulating hucMSCs [ ]. In the nucleus of hucMSCs, a primary transcript-EVs) has the similar effects, which is similar to the effects of siTRAF6. These results demonstrated that miR-146a-5p delivered by hucMSC-EVs targeted TRAF6 and mitigated inflammation induced by SM.",
"ALI is an overactivated inflammation caused by direct or indirect injuries, which can destroy lung parenchymal cells and significantly reduce lung function. We established the mouse model of ALI by sulfur mustard. After sulfur mustard injury, immune cells will be activated, and the activated immune cells will release excessive proinflammatory factors, chemokines and proteases, resulting in the damage of lung parenchymal cells such as vascular endothelial cells and alveolar epithelial cells [ , ]. Since inflammation plays an important role in the pathogenesis of ALI, we are more concerned about the effect and mechanism of extracellular vesicles on the inflammation of SM-induced ALI. Due to heterogeneity and etiology, the pathogenesis of ALI remains unclear. With the progress of research, several inflammation-related mechanisms in ALI have been discovered. In addition to the TLRs mediate NF-κB signaling pathway involved in our study, there are also JAK2/STAT3, NLRP3 inflammasome, PI3K/AKT, p38 MAPK and so on [ ]. Whether there are other miR-146a-5p related pathways or other components involved in the hucMSC-EV-induced improvement in ALI caused by SM remains to be further studied because the components of extracellular vesicles are very diverse, and the injury mechanism of SM is complicated and has not been clearly elaborated. We will continue to perform related studies in the future to explain the mechanism of hucMSC-EVs in improving lung injury caused by SM.",
"We demonstrated that hucMSC-EVs can effectively ameliorate SM-induced inflammation and ALI. Further studies demonstrated the importance of miR-146a-5p in the regulation of inflammation by hucMSC-EVs. Thus, we elucidated the key role of miR-146a-5p delivered by hucMSC-EVs in the amelioration of SM-induced inflammation, which might provide a therapeutic approach for the clinical rescue of SM victims."
] |
PMC10381223
|
Turkish Journal of Medical Sciences
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The effectiveness of anti-interleukin-1 therapy on subclinical inflammation parameters during the attack-free period in familial Mediterranean fever patients: A case-control study
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0-0-2022
|
Background/aim Anti IL-1 therapy is useful in suppressing attacks in FMF patients with colchicine resistance, however, it is not certain whether subclinical inflammation can sufficiently be inhibited with anti-IL-1 therapy in FMF patients with amyloidosis. Materials and methods Forty-six FMF patients receiving anti-interleukin-1 therapy and 36 healthy control patients were compared in terms of laboratory parameters. Also, FMF patients were further divided into two groups; those with amyloidosis and those without it, and these subgroups were compared to each other in terms of clinical and laboratory findings. Results In comparison between the FMF and healthy control groups, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, and red cell distribution width (RDW) level were detected to be higher and hemoglobin level lower in the patient group. Within the FMF patient group, the ESR, CRP, fibrinogen, RDW, and NLR values were significantly higher in the subgroup with amyloidosis in comparison to the subgroup without amyloidosis. Conclusion Anti-interleukin-1 therapy could not fully suppress the subclinical inflammatory parameters when compared to healthy individuals.
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[
"Familial Mediterranean fever, C-reactive protein is an index obtained from the proportion of neutrophils to lymphocytes. In recent studies, NLR has been a useful indicator of inflammation [ , ].",
"Red cell distribution width may also be an indicator of subclinical inflammation. However, contradictory results between MPV and subclinical inflammation have been reported [ – ].",
"The MEFV gene encodes the protein pyrin, essential in the innate immune system and inflammasome. Mutations in the MEFV and thus in the induction of inflammation, and when inflammasome activity is abnormally stimulated through a mutation, IL-1 may be involved in the pathogenesis of FMF [ , ]. Anti-interleukin-1 receiving IL-1 antagonist therapy.",
"This study was planned as a case-control study. The study group consisted of patients diagnosed with FMF according to the Tel-Hashomer criteria [ ] who were on follow-up at our clinic and were in the attack-free period. All patients had classical, and it was determined that a total of 50 people in the comparison of categorical data. The risk factors and estimated relative risk.",
"In FMF patients, a statistically significant, moderate/strong positive correlation was detected between the mean CRP and RDW values.",
"A statistically significant, moderate positive correlation was detected between the mean CRP and fibrinogen means in FMF patients.",
"The duration of IL-1 antagonist therapy in FMF patients with amyloidosis was significantly higher than that in FMF patients without amyloidosis.",
"In FMF patients with amyloidosis, the mean/median values of fibrinogen, ESR, CRP, WBC, neutrophil, NLR, and RDW were significantly higher than those without amyloidosis.",
"According to the multivariate binary logistic regression analysis performed to determine the factors that increase the risk of amyloidosis in FMF patients, age, gender, fibrinogen, ESR, CRP, NLR, RDW, and the presence of arthralgia/arthritis variables, which were found to be clinically and/or statistically significant, were included in the model, while the ESR, male gender, and the presence of arthralgia/arthritis variables remained significant in the model.",
"The ROC curve analysis was done to see if fibrinogen, NLR, and RDW values could be used as a diagnostic marker for amyloidosis positivity in FMF patients. For fibrinogen, we found a cut-off value of ≥2.97, sensitivity of 75.00%, and specificity of 65.40%, while the positive predictive value was 52.20% and the negative predictive value was 47.80%. The area under the curve was calculated as 0.705, with a standard error of 0.080.",
"Our results demonstrated, ESR, CRP and RDW levels were higher and hemoglobin levels were lower in FMF patients under anti IL 1 therapy when compared to healthy subjects. Within the FMF patient group, the ESR, CRP, fibrinogen, RDW, and NLR values were significantly higher in the subgroup with amyloidosis in comparison to the subgroup without amyloidosis.",
"Fibrinogen, ESR, CRP, SAA protein, and WBC values are used as laboratory parameters of APR in FMF. These laboratory parameters increase during the FMF attack and generally return to normal limits during the attack-free periods [ , ]. Some studies show that inflammation may continue during the attack-free periods in patients with FMF [ , ]. A permanent increase in acute-phase proteins during the attack-free periods is important because it reflects inflammation even in the absence of clinical findings. Persistent subclinical inflammation in FMF patients may increase the risk of amyloidosis, which can be fatal [ , ]. Amyloidosis is the accumulation of proteins called amyloid protein in various tissues and organs in the body. There are different types of amyloidosis. Secondary, naturally present in the body, controls the activity of IL-1 by competing with IL-1 to bind to the IL-1 receptor. Anakinra is a recombinant form of human IL-1 receptor antagonist that competitively inhibits the binding of IL-1α and IL-1β to the endogenous IL-1 receptor [ ]. The other drug used in therapy, canakinumab, is a monoclonal antibody that is created against IL-1β and neutralizes its bioactivity [ , ]. These drugs, which are costly and require high technology, are used in the treatment of autoinflammatory diseases. If there is no response to treatment with other drugs in FMF patients, it is necessary to use these drugs [ ].",
"In our study, the ESR, CRP, and RDW values in FMF patients were found to be significantly higher compared to the healthy population. We believe that these findings are related to inflammation [ ]. On the other hand, Hb values were low. We can argue that anti-IL-1 therapy did not display sufficient impact on suppressing these parameters that indicated an inflammation during the attack-free periods. However, because our study is a case-control study and we have not followed up these parameters before and after IL-1 antagonist therapy, we did not have the opportunity to assess the efficacy of the drugs on this subject objectively.",
"Platelets are multifunctional blood cells and are considered to be effective in initiating inflammation and fibrosis, which are associated with a variety of prothrombotic and proinflammatory diseases [ ]. Mean platelet volume is a marker of platelet function and activation [ ]. A high level of MPV is considered a risk factor for myocardial infarction and ischemic cardiovascular disease [ , ]. The increased platelet count and function in inflammatory diseases can be explained by the stimulation of platelet release by proinflammatory cytokines, especially the IL-6. The course of the inflammatory response is also associated with the percentage of large platelets. The large platelets migrate to the inflamed area. Accordingly, MPV is expected to be low in ongoing inflammation [ ]. Gasparyan et al. demonstrated that high-grade inflammatory diseases, such as attacks of FMF, present with low levels of MPV, which have increased due to the administration of antiinflammatory drugs [ , ]. On the contrary, according to Yazıcı et al., it has been asserted that high MPV values in rheumatoid arthritis patients are associated with disease activity [ ]. In our study group, no difference could be found between the patients with FMF and healthy individuals in terms of platelet and MPV levels. Similarly, these two laboratory parameters were not different in FMF patients with amyloidosis and without amyloidosis.",
"Red cell distribution width is part of the hemogram and is accepted as the variability in the size of circulating erythrocytes [ ]. Higher RDW values are accepted as a strong predictor of mortality in patients with heart failure and in adults 45 years or older [ , ]. Inflammation is considered to play a role in the etiopathogenesis of cardiovascular diseases [ , ]. According to the hypothesis of Tonelli et al., the relationship between high RDW and mortality in cardiovascular diseases may be related to the underlying inflammation [ ]. In a cross-sectional study in which the authors examined the laboratory parameters of 3,845 adult patients, Lippi et al. showed that high RDW values were associated with ESR and high-sensitivity CRP, which are inflammatory markers [ ]. In our study group, we found a correlation between the CRP and RDW values.",
"Fibrinogen is also one of the acute phase reactants that increases during the FMF attacks and is expected to return to normal values during the attack-free periods [ , ]. Similarly, we detected a correlation between CRP and fibrinogen levels in FMF patients.",
"In the literature, there are studies showing that the NLR is important in determining the risk of developing amyloidosis and ongoing inflammation in patients with FMF during attack free-periods [ , , ]. In our study, NLR was found to be the same in the healthy and FMF patient groups. However, NLR was higher in patients with amyloidosis than those without it.",
"When only the FMF patients with or without amyloidosis were considered, in patients who received anti-IL-1 therapy, the fibrinogen level, RDW, and NLR, as well as inflammatory parameters such as ESR and CRP, were higher in patients who had amyloidosis than those who had not. Besides, when we evaluated whether the fibrinogen, NLR, and RDW values could be used as a diagnostic marker for amyloidosis positivity, we found a cut-off value of ≥2.97, sensitivity of 75.00%, and specificity of 65.40% for fibrinogen, a cut-off value of ≥2.16, sensitivity of 70.00%, and specificity of 43% for NLR, and a cut-off value of for ≥15.40, sensitivity of 75.00%, and specificity of 76.90% for RDW. These findings demonstrate that a fibrinogen value ≥2.97, an NLR value ≥2.16, and a RDW value ≥15.40 may be used in determining the amyloidosis risk in FMF patients.",
"Although there are studies in the literature that state that anti-IL-1 therapy controls the acute phase reactants in FMF patients with amyloidosis [ , ], we could not observe a similar effect in our study.",
"It has been reported that the male gender is a risk factor in the development of amyloidosis [ , ]. In accordance with the literature, in the present study, we found that most FMF patients with amyloidosis were males and most FMF patients without amyloidosis were females.",
"Arthralgia/arthritis was more frequent in the nonamyloidosis group this may be related to the longer duration of anti-IL-1 therapy which may suppress joint findings in the amyloidosis-positive group.",
"Mutations in the MEFV gene, which encode a protein called pyrin which is essential in the innate immune system, may be associated with FMF [ , ]. A more severe course of the disease in patients with a homozygous gene mutation is well known [ ]. In our study group, while the M694V homozygous gene mutation ratio was about 60% for the patients with amyloidosis, this ratio was decreased to about 40% in those without amyloidosis; a finding consistent with the literature.",
"The fact that our study was not a prospective, controlled study in which the drug effect was demonstrated is our main limitation. Another limitation is that we compared FMF patients receiving anti-IL-1 therapy with only healthy individuals; FMF patients who did not receive anti IL-1 therapy were not included in the study.",
"Among FMF patients who received anti-IL-1 therapy, fibrinogen, NLR, and RDW, as well as inflammatory parameters such as ESR and CRP levels, were higher in patients with amyloidosis than those without amyloidosis. Anti-interleukin-1 therapy may not sufficiently control the subclinical inflammation parameters in the amyloidosis group. Multicenter prospective controlled studies are needed to demonstrate the effects of these drugs on preventing the development of amyloidosis in FMF patients."
] |
PMC10061370
|
Analytical Chemistry
|
Dense and Acidic
Organelle-Targeted Visualization
in Living Cells: Application of Viscosity-Responsive Fluorescence
Utilizing Restricted Access to Minimum Energy Conical Intersection
|
17-03-2023
|
Cell-imaging methods
with functional fluorescent probes are an
indispensable technique to evaluate physical parameters in cellular
microenvironments. In particular, molecular rotors, which take advantage
of the twisted intramolecular charge transfer (TICT) process, have
helped evaluate microviscosity. However, the involvement of charge-separated
species in the fluorescence process potentially limits the quantitative
evaluation of viscosity. Herein, we developed viscosity-responsive
fluorescent probes for cell imaging that are not dependent on the
TICT process. We synthesized AnP 2 -H and AnP 2 -OEG , both of which contain 9,10-di(piperazinyl)anthracene,
based on 9,10-bis( N , N -dialkylamino)anthracene
that adopts a nonflat geometry at minimum energy conical intersection. AnP 2 -H and AnP 2 -OEG exhibited enhanced fluorescence
as the viscosity increased, with sensitivities comparable to those
of conventional molecular rotors. In living cell systems, AnP 2 -OEG showed low cytotoxicity
and, reflecting its viscosity-responsive property, allowed specific
visualization of dense and acidic organelles such as lysosomes, secretory
granules, and melanosomes under washout-free conditions. These results
provide a new direction for developing functional fluorescent probes
targeting dense organelles.
|
[
"Biological events involve various\ntypes of molecules in diverse environments, but these events are generally\nunobservable unless a combination of spectroscopic and microscopic\ntechniques is used.^(1 , 2) Cell-imaging methods with fluorescent\nmolecular probes are indispensable for observing biological molecular\nbehavior and have provided a better understanding of molecular cell\nbiology. Of the various fluorescent probes. Indeed, AnP _(2) -OEG showed high water solubility,\nlow cytotoxicity, efficient cellular uptake, and specific visualization\nof dense and acidic organelles -H and AnP _(2) -OEG used in this\nwork. First, we synthesized bispiperazine-substituted\nanthracene AnP _(2) -H by Buchwald–Hartwig amination^(64) of 9,10-dibromoanthracene in the presence of an excess amount of\npiperazine. We anticipated that AnP_(2)-H could\nbe converted into various derivatives due to the free secondary amino\ngroups, which can be easily functionalized without loss of fluorescence\nproperties. AnP _(2) -H was treated with mono-tosylated octa(ethylene glycol) in CH_(3)CN in the presence of K_(2)CO_(3), yielding AnP _(2) -OEG .^(65) For details of the synthesis and characterization\nof AnP _(2) -H and AnP _(2) -OEG , see the Supporting Information."
] |
PMC10007047
|
Sensors (Basel, Switzerland)
|
Comparing Direct Measurements and Three-Dimensional (3D) Scans for Evaluating Facial Soft Tissue
|
22-02-2023
|
The inspection of patients’ soft tissues and the effects of various dental procedures on their facial physiognomy are quite challenging. To minimise discomfort and simplify the process of manual measuring, we performed facial scanning and computer measurement of experimentally determined demarcation lines. Images were acquired using a low-cost 3D scanner. Two consecutive scans were obtained from 39 participants, to test the scanner repeatability. An additional ten persons were scanned before and after forward movement of the mandible (predicted treatment outcome). Sensor technology that combines red, green, and blue (RGB) data with depth information (RGBD) integration was used for merging frames into a 3D object. For proper comparison, the resulting images were registered together, which was performed with ICP (Iterative Closest Point)-based techniques. Measurements on 3D images were performed using the exact distance algorithm. One operator measured the same demarcation lines directly on participants; repeatability was tested (intra-class correlations). The results showed that the 3D face scans were reproducible with high accuracy (mean difference between repeated scans <1%); the actual measurements were repeatable to some extent (excellent only for the tragus-pogonion demarcation line); computational measurements were accurate, repeatable, and comparable to the actual measurements. Three dimensional (3D) facial scans can be used as a faster, more comfortable for patients, and more accurate technique to detect and quantify changes in facial soft tissue resulting from various dental procedures.
|
[
"Researchers [ , , ] have been employing various two-dimensional scans in various areas of dental medicine. These improvements include high-quality motion-fixed image capture to provide better sequential frames with landmark detection. Three-dimensional surface scanning can generate a 3D soft tissue model of the face. The scanning equipment, such as infrared laser digitisers, stereophotogrammetric cameras, or structured-light scanners, is non-invasive [ , ]. At the same time, some researchers employ computed tomography. Each landmark is defined by three coordinates in the x, y and z spatial dimensions. The set of all landmarks representing a 3D model of the face is known as a landmark configuration or a shape, and such configurations are further analysed using the methods of geometric morphometrics. The development of software to study 3D images tends to create subgroups based on soft tissue shape differences, as opposed to traditional predefined facial characteristics used in 2D studies [ ]. The accuracy of the non-invasive facial scanners, usually 0.2 to 1 mm, is satisfactory for clinical purposes [ ]. However, there are differences between various scanning techniques and manufacturers [ , ]. Nevertheless, the advancement in scanning technology and computational methods have made non-invasive scanners available at affordable prices, which could facilitate and further promote research and clinical application of 3D models. Additionally, independent initiatives in software development help verify the application of commercially available low-cost equipment. Analysing patients’ soft tissues and the effect of various dental procedures on their facial physiognomy is quite demanding. The operator performing manual physical measurements must possess sufficient knowledge and exhibit considerable caution to the patient. Because there is direct contact between the soft tissue and the instrument, the process can cause discomfort for the patient, especially after certain procedures that may result in swelling and pain. In addition, it is time-consuming for both the patient and the examiner.",
"To minimise discomfort and simplify the process, we performed facial scanning and computer measurement of experimentally determined demarcation lines. Demarcation lines are virtual boundaries or lines that separate different areas or connect two different anatomical points on the face. Demarcation lines used in this research are chosen based on previous research for the assessment of the post-surgery oedema [ , , ]. The image acquisition was carried out with a low-cost 3D scanner which requires many consecutive recordings of the object for the best results. RGBD integration was used for merging frames into a 3D object [ ]. For correct comparison, the resulting images need to be registered together, which is usually performed with Ransac [ ] and ICP [ ] based techniques. We used the slower but more precise ICP method [ ]. The measurements on 3D images can be performed using exact or approximate distances. With approximate distances, it is assumed that the path between two close points can be approximated by Euclidian distance.",
"This study aimed to evaluate the accuracy and repeatability of facial scans obtained with a low-cost 3D camera and compare the direct measurements from patients’ faces with measurements from 3D facial images for use in dental medicine research.",
"Hypotheses are: (1) Three dimensional. Ethical approval was obtained from the local ethical committee had different set of scans. The first scan was taken in a habitual occlusion index was calculated. Values above 0.9 indicate excellent reliability, values between 0.75 and 0.9 indicate good reliability, between 0.5 and 0.75 indicate moderate reliability, and below 0.5 indicate poor reliability [ ]. Correlation calculation were performed for the results of the two measurement methods. The t-tests for samples to indicate whether the two samples were comparable in terms of means was conducted, statistical significance was set to p < 0.05 . The first step after data collection and rgbd integration was visualization. High quality visualization is required to determine the differences in the obtained 3D models, but this process requires optimal alignment. The process of optimal alignment of two three-dimensional models in the initial position is called global registration. Global registration is a fundamental problem in shape registration and modeling. Such registration methods do not require information about the initial positions of the observed models. They usually lead to less accurate alignment results and are often used as initialization for local refinement methods. Among local methods, the popular point-to-point Iterative Closest Point is denoted in Equation, where S represents a set of related points s n : The target point cloud is defined as in Equation, where T represents a set of associated points t n : Given two points set, the ICP method computes the rigid transformation between them by determining the optimal translation and rotation to minimize the sum of squared errors. It finds the missing pairing between each corresponding point with minimizing distances E , see Equation where R is the rotation, N t is the number of target points T , t ′ is the translation, s i and t i are the corresponding points from the point clouds S and T . The ICP method is commonly used for matching 2D and 3D laser scans, a challenge known as “scan matching”. It has been used in robotics to match scans from 2D laser range scanners [ ]. The motion of the robot is proportional to a function that minimizes the difference between two successive snapshots of the environment. Theoretically, it is possible to create a 2D map of the environment by stitching together a series of snapshots. This method can also be used to create 3D maps, but with the disadvantage that errors accumulate between each snapshot. We did not use the ICP algorithm for mapping, but for alignment. We focused on the ICP algorithm to match two repeated head scans of the same object without any changes to it. Although our point clouds consisted of a considerable number of points, it might be useful to use only a few selected points to compute the optimal transformation between two point clouds. It turns out that depending on the data source, some points are more suitable than others because it is easier to find matches for them. For example, if we look at a frontal view of a 3D scanned head model and select known facial landmarks of the face image represents the face before the medical intervention, and do not contribute to the function that minimizes the difference. For more information on the code workflow, see the in . The faces of all subjects were scanned twice to measure the overlap of the scans. Measurements of the demarcation lines of the face C and D , we first determine the minimum distance d c between each point c on contour C and all points s on contour D , d p s is distance between points, see Equation. The second step was to calculate the minimal distance for each boundary point and use the minimal distance with the largest value as the worst-case scenario. See Equation, where d c is distance between c points and D contour points. This metric is not symmetric and h c ( C , D ) ≠ h c ( D , C ) , considering that statement. The Hausdorff distance was calculated as in Equation, where H C stands for Hausdorff distance, and h C for the worst-case scenario between was chosen for comparison of difference results obtained with two measurement methods. See Equation, where R M S E stands for Root Mean Square Error Metrics, C o m p u t e r M i for the computed measurement, G r o u n d T i for the physical measurement, and N for the number of measurements. The relatively low value of the RMSE indicates how accurate the model results are.",
"Three dimensional. Ethical approval was obtained from the local ethical committee had different set of scans. The first scan was taken in a habitual occlusion index was calculated. Values above 0.9 indicate excellent reliability, values between 0.75 and 0.9 indicate good reliability, between 0.5 and 0.75 indicate moderate reliability, and below 0.5 indicate poor reliability [ ]. Correlation calculation were performed for the results of the two measurement methods. The t-tests for samples to indicate whether the two samples were comparable in terms of means was conducted, statistical significance was set to p < 0.05 .",
"The first step after data collection and rgbd integration was visualization. High quality visualization is required to determine the differences in the obtained 3D models, but this process requires optimal alignment. The process of optimal alignment of two three-dimensional models in the initial position is called global registration. Global registration is a fundamental problem in shape registration and modeling. Such registration methods do not require information about the initial positions of the observed models. They usually lead to less accurate alignment results and are often used as initialization for local refinement methods. Among local methods, the popular point-to-point Iterative Closest Point is denoted in Equation, where S represents a set of related points s n :",
"The target point cloud is defined as in Equation, where T represents a set of associated points t n :",
"Given two points set, the ICP method computes the rigid transformation between them by determining the optimal translation and rotation to minimize the sum of squared errors. It finds the missing pairing between each corresponding point with minimizing distances E , see Equation where R is the rotation, N t is the number of target points T , t ′ is the translation, s i and t i are the corresponding points from the point clouds S and T .",
"The ICP method is commonly used for matching 2D and 3D laser scans, a challenge known as “scan matching”. It has been used in robotics to match scans from 2D laser range scanners [ ]. The motion of the robot is proportional to a function that minimizes the difference between two successive snapshots of the environment. Theoretically, it is possible to create a 2D map of the environment by stitching together a series of snapshots. This method can also be used to create 3D maps, but with the disadvantage that errors accumulate between each snapshot. We did not use the ICP algorithm for mapping, but for alignment. We focused on the ICP algorithm to match two repeated head scans of the same object without any changes to it. Although our point clouds consisted of a considerable number of points, it might be useful to use only a few selected points to compute the optimal transformation between two point clouds. It turns out that depending on the data source, some points are more suitable than others because it is easier to find matches for them. For example, if we look at a frontal view of a 3D scanned head model and select known facial landmarks of the face image represents the face before the medical intervention, and do not contribute to the function that minimizes the difference. For more information on the code workflow, see the in .",
"The faces of all subjects were scanned twice to measure the overlap of the scans. Measurements of the demarcation lines of the face C and D , we first determine the minimum distance d c between each point c on contour C and all points s on contour D , d p s is distance between points, see Equation.",
"The second step was to calculate the minimal distance for each boundary point and use the minimal distance with the largest value as the worst-case scenario. See Equation, where d c is distance between c points and D contour points. This metric is not symmetric and h c ( C , D ) ≠ h c ( D , C ) , considering that statement. The Hausdorff distance was calculated as in Equation, where H C stands for Hausdorff distance, and h C for the worst-case scenario between was chosen for comparison of difference results obtained with two measurement methods. See Equation, where R M S E stands for Root Mean Square Error Metrics, C o m p u t e r M i for the computed measurement, G r o u n d T i for the physical measurement, and N for the number of measurements. The relatively low value of the RMSE indicates how accurate the model results are.",
"Before overlapping and visualizing different head scans, we used an overlap of the repeated same head scan to determine the reproducibility and influence of the scanner. The matching of 39 different pairs of repeated head scans shows results for the Hausdorff distance and computational measurements. The calculation of the difference for each pair was performed as in Equation where c m is the computed measurement and o m is the ground truth. The other demarcation lines on the right side fall into good. The result for p value is 0.31 , so we conclude that there is no statistical significance difference between the two groups. Additionally, the correlation between the two measurement groups shows results of 0.973, which shows a strong relationship between the two independent measurement results. To determine the agreement between two measurements, we used the Bland–Altman plot. Ideally, two of our different measurement methods would give the same result, with all differences equal to zero. In a real scenario, there is always some degree of error in any measurement of variables. This approach does not say whether the agreement is sufficient or suitable to use the method. It simply quantifies bias and a range of agreement. The best way to use such a plot would be to define a priori the limits of the maximum acceptable differences, based on biologically and analytically relevant criteria [ ]. The limits of agreement are given in the . Bias is defined as the average value between two measurement methods for each sample. The minimum and maximum limits are a 95% confidence interval for the average difference. represents limits of agreement of two paired measurement methods for every demarcation line. Results from and indicate acceptable agreement between the two measurement methods, since the differences are in range [−1.336,3.779] [mm], which is acceptable for the aforementioned clinical research on post-surgery oedema. An example of the results of a computer measurement can be found in the in .",
"Additional analyses of the forward movement of the mandible were performed. After overlapping and matching, the Hausdorff distance was calculated and is presented in . Examples of scan matching is an area viewed at a distance of 0 mm, an aligned domain.",
"Our research has shown that 3D facial scans from low-cost scanners are reproducible with high accuracy, but comparison of the volumes obtained was considered unsatisfactory. In all the aforementioned articles, the scans were manually or semi-manually adjusted before analysis. Usually, the part of the scan that contained the hair was cut off, and landmarks were manually placed on each scan or on each subject before scanning [ , ]. Because these procedures can be time consuming, we attempted to analyse the scans with automated landmark tracking. Automated landmark tracking saves significant time. The tested 3D Bellus software sets a total of over 100 landmarks; tragus — pogonion [ , ]. Additionally, discomfort due to physical contact between the subject’s skin. For the exact computational measurement over a triangular mesh, we used the “continuous” Dijsktra method proposed in [ ].",
"Our results for the computational measurement show a difference of 1 cm for demarcation lines A, B, and C. The largest deviation of 1cm from the ground truth measurement is for the D line. The lowest accuracy is limited not only by reflex movement of the lips, but also due to a lower quality selection of the gonion location; rather than a computer measurement error. The gonial angle is a location where the lower mandibular body meets the posterior border of the ramus [ ]. Due to the influence of the shape of the face and the amount of fat tissue, it can be challenging to choose an exact gonion position. Considering the experimental results obtained and taking into account the more demanding selection of the gonion location, we can conclude that the computer-based method provides reasonable accuracy. Furthermore, a big part of the measurement error is caused by initial settings. Initial measurement errors are represented by the number of triangles that build a 3D polygonal structure. If the mesh model is created from a smaller number of polygons, the lines that builds the surface area do not describe the real surface curvature. Therefore, it is desirable to have 3D meshes made of a greater number of polygons. Additionally, the precise selection of the source and destination points is also crucial step for computational measurement accuracy. To determine differences between the computational and physical measurements, we performed a two-tailed t-test. The result for the p value of 0.31 shows that there is no statistical difference between the two groups and correlation of 0.973 strong association between two measurements. The limits of the agreements are determined for each of the four demarcation lines of the computational measurement. The visualization of such boundaries, here presented with the Bland–Altman diagram, brings us to conclusion that computer-aided measurement provides sufficient accuracy to provide clinically relevant results. The graph shows the less stringent limits for measuring the D line, it is advisable to try to gain, as much as possible, forward growth of the mandible with functional orthodontic appliances during the peak pubertal growth [ ]. Recording the initial state and comparing it to the projected goal of different scans of the same individual subjected to FM show a significant change in the forward movement of the mandible, allowing further comparison and tracking of treatment progress, which would not be possible if we were limited to visualization with X-rays. At each follow-up of different dental procedures and for monitoring the changes, the 3D facial scans could be used and measurements could be taken with a minimum of additional time and discomfort for the patients, as the physical contact of the measuring tape with sensitive, prone to reflex contractions and potentially painful parts of the facial soft tissue is reduced.",
"The low-cost 3D facial scans are reproducible with high accuracy (mean difference between repeated scans 1%).",
"The physical measurements are dependent on landmark positioning, sensitivity of the measured area of skin, the measured length and the skill of the operator, but are still considered to be the ground truth; a comparison of computer and physical measurement results shows reasonable accuracy. Facial scans and computed measurements can be used instead of physical measurements.",
"Further advances for the future use of 3D facial scans are: contactless data acquisition and measuring, better non-invasive visualization in multiple time-points for various dental procedures influencing changes of the facial soft tissues."
] |
PMC10058173
|
Pharmaceutics
|
Platinum-Nucleos(t)ide Compounds as Possible Antimetabolites for Antitumor/Antiviral Therapy: Properties and Perspectives
|
14-03-2023
|
Nucleoside analogues (NAs) are a family of compounds which include a variety of purine and pyrimidine derivatives, widely used as anticancer and antiviral agents. For their ability to compete with physiological nucleosides, NAs act as antimetabolites exerting their activity by interfering with the synthesis of nucleic acids. Much progress in the comprehension of their molecular mechanisms has been made, including providing new strategies for potentiating anticancer/antiviral activity. Among these strategies, new platinum-NAs showing a good potential to improve the therapeutic indices of NAs have been synthesized and studied. This short review aims to describe the properties and future perspectives of platinum-NAs, proposing these complexes as a new class of antimetabolites.
|
[
"Nucleos(t)ide analoguesides analoguesides, the NAs can maintain the ability to enter cells by exploiting specific plasma membrane nucleoside transporters [ , ]. Organic cation and/or anion transporters, not specific for nucleosides, can also be involved in the cellular uptake of some NAs [ ]. These classes of antitumor and/or antiviral compounds can differ for the types of transporters used and for their preferential interaction with specific targets. This can explain the effectiveness differences observed for these compounds in the treatment of neoplasia with protracted evolution, rapidly proliferating tumors, and viral diseases [ ]. A major difference of the NAs used as antiviral drugs, with respect to those used as antitumor agents, consists in a generally lower affinity for the mammalian enzymatic systems. Another, but not secondary, aspect is the lower dosages generally required to produce an effective antiviral activity compared to those necessary for a relevant antitumor activity. Both these characteristics concur in determining a generally better tolerance profile when the NAs are used as antiviral drugs rather than as antitumors.",
"All NAs use similar mechanisms of action to exert their activity. They enter the cells through an active transport across the cell membrane by using specific membrane transporters. After entering the cells, NAs use the same metabolic pathways of the endogenous nucleos(t)ides [ ]. Their mechanism of action includes a first step of phosphorylation, catalyzed from the nucleoside kinase, undergoing production of the nucleoside monophosphate analogue. Two further phosphorylation steps, performed, respectively, by nucleoside monophosphate kinases and nucleoside diphosphate kinases, produce the active triphosphate form [ ]. Cellular or viral nucleic acids can incorporate the triphosphate forms of nucleoside analogues which compete with their counterparts, eventually inhibiting essential enzymes such as human and viral polymerases, therefore interfering with cancer cell growth or viral replication [ ].",
"As for most of the anticancer drugs used in chemotherapy, and also for NAs, some mechanisms of resistance may occur. The main causes of resistance to NAs in both cell lines and clinical samples are is still highly desired. One of the employed therapeutic approaches consists in combining the NAs therapy with other agents modulating the apoptotic responses. An example is combination chemotherapy. This approach, adopted for high rate malignant tumors, takes advantage of the combined use of different therapeutic agents, providing additional benefits to the treatments [ ]. A multifactorial approach may allow significant progress in the treatment of cancer and viral diseases. In 1997, Mosconi et al. reported the effectiveness of combining gemcitabine and cisplatin in non-small cell lung cancer. By combining gemcitabine, a pyrimidine analogue, with cisplatin, one of the most potent anticancer agents used in the treatment of various solid tumors, the response rates significantly increased with respect to either drug used alone [ ]. Nowadays, this combined treatment and thanks to their ability to bind and inhibit key enzymes such as metallo-β-lactamase or ranitidine bismuth citrate cyanide and thiosulfates, were introduced and approved for rheumatoid arthritis treatment. Among these, we might mention sodium aurothiomalate, aurothioglucose, sodium aurothiopropanol sulfonate, sodium aurothiosulfate, and the much newer gold(I) compound, auranofin is a promising manganese(II) metallodrug candidate for the treatment of cardiovascular disorders [ ]. Again, lithium-based drugs represent modern psychopharmacological agents and are the gold standard in the treatment of bipolar disorders and mania [ , ]; a lithium carbonate formulation was first approved in 1979, while a lithium citrate tetrahydrate is currently undergoing clinical trials for the treatment of Huntington’s disease [ ].",
"An important step in the development of metallodrugs was the discovery of cisplatin and its clinical debut in 1978 [ ]. Platinum drugs are used in 50% of cancer chemotherapies. Together with cisplatin, carboplatin and oxaliplatin are the only FDA-approved platinum drugs, but there are other platinum complexes which have been approved in single nations, such as nedaplatin, heptaplatin, lobaplatin, miriplatin, and dicycloplatin [ , ]. The mechanism of platinum-based anticancer drugs involves the formation of platinum-DNA adduct and inter- and intra-DNA strand cross-links, which interfere with DNA replication and DNA transcription, causing cell cycle arrest and cell apoptosis/necrosis [ ]. Furthermore, platinum complexes have also demonstrated to be good antiviral and antibiotic agents and protect cells from different types of viruses and bacteria [ , ].",
"Focusing on their applications as anticancer or antiviral, antivirals metal-based drugs can block viral infections, relieve symptoms, regulate the human immune system, and inhibit virus replication enzymes [ ]. When used as adjuvants, they can also improve the effectiveness of antiviral drugs and vaccines [ ]. Anticancer metal-based drugs can act via metal–DNA or metal–protein adducts formationides-based compounds, which may represent a new promising class of antimetabolites with merged properties between those of platinum compounds and those of nucleoside analogues. The perspectives in the treatment of cancer and viral diseases are discussed here.",
"Metal-based antitumor drugs constitute a very successful class of drugs. In this class, the main clinical and therapeutic successes can be referred to the wide family of platinum-based antitumor drugs, starting from the first discovered platinum-based drug named cisplatin [ ]. After cisplatin discovery, several platinum complexes have been synthesized but only few of them have been successfully marketed worldwide.",
"Platinum compounds act as antiviral agents by interfering with DNA or RNA synthesis to exploit their mechanism of action. Moreover, it has recently been demonstrated that they are able to induce the virus’s death without affecting the host cell [ ].",
"Starting from the wide research interest on platinum drugs as chemotherapeutic agents, thousands of new platinum compounds were synthesized [ , , , , ]. Considering the high reactivity of platinum complexes with the DNA nucleobases, some new platinum-nucleoside analogues were synthesized [ ]. These can be considered as special nucleobase analogues, where the modification of the nucleoside mainly consists of a coordination to a metal complex.",
"Here, we highlight the demonstrated antitumor and antiviral activities of platinated nucleos(t)ides, confirming the adaptability of this class of complexes to the different fields of application complexes with three coordinated N -donor ligands, as reported in . Among these compounds, some platinum(II)-nucleoside complexes of the type cis -[Pt(NH_(3))_(2)(Am)Cl]^(+) demonstrated high stability and solubility in aqueous media and an interesting antitumor potential against different tumors, including Sl80a, P388, and L1210 in mice [ ].",
"In detail, cis -[Pt(NH_(3))_(2)( N3 -cytosine)Cl]Cl and cis -[Pt(NH_(3))_(2)( N7 -2′-deoxyguanosine)Cl]Cl complexes showed the best combination of activity and potency in the S180a screen. In the L1210 leukemia screen, cis -[Pt(NH_(3))_(2)( N3 -cytosine)Cl]Cl and cis -[Pt(NH_(3))_(2)( N3 -cytosine)Cl]Cl demonstrated good antitumor activity. Cis -[Pt(NH_(3))_(2)( N3 -cytosine)Cl]Cl was also found active against P388 leukemia.",
"Other cis -dichloridoplatinum(II)- N -aminated nucleoside complexes were synthesized and tested for their antitumor effect against L1210 in vivo and 3-amino-2′-deoxycytidine-dichloridoplatinum(II), which possess high antitumor activity against L1210 cells in vivo in a wide dose range from 10 to 200 mg/kg. The in vitro cytotoxic effects in L1210 cells demonstrated higher cytocidal effects than the parent not-platinated N -aminated nucleosides. The IC_(50) values of the complexes were higher than that of cis -DDP by factors of 10 to 10^(3).",
"Extending the study on this class of cis -dichloridoplatinum(II)- N -aminated nucleoside complexes, researchers also established that their mechanism of action caused the inhibition of DNA and RNA synthesis, as occurs for widely used anticancer/antiviral antimetabolites. Maeda et al. demonstrated the role of sugar moiety in the action mechanism of the considered complexes: the Pt-nucleoside complexes having ribose inhibited RNA synthesis and those having deoxyribose or arabinose inhibited DNA synthesis [ ].",
"Recently, Štarha et al. offered an overview of platinum(II) and platinum(IV) complexes containing adenine as ligands or its derivatives coordinated to platinum through N - or C -donor atom(s) of the adenine moiety [ ]. Many complexes of this type have been synthesized, demonstrating the interest of researchers in this new class of nucleoside analogues [ , ]. Complexes containing monodentate N 7 coordinating adenine-based ligand(s) are the most numerous with respect to the N6 , N9 , C8, or bidentate N1,N6, which are relatively rare.",
"Summaries of the known biological activities of tested complexes were also reported. For the [PtCl_(2)(Ado- N6 , N7 )] complex, in vivo tests against mice Sarcoma 180 cells were performed by Cleare and Hoeschele in 1973. Unfortunately, for the mentioned compound, low activity was showed [ ].",
"Baranowska-Kortylewicz et al. studied the in vitro cytotoxicity of new complexes of the type dichlorido(6-aminoethylaminopurine)platinum(II) and dichlorido(6-hydroxyethylaminopurine)platinum(II) against different carcinoma cancer cells, while also investigating nephrotoxicity in the mouse kidney [ ]. Despite the lower cytotoxicity on tumor cells, an interesting, relatively lower renal toxicity was also observed compared to cisplatin.",
"Other synthesized platinum complexes containing adenosine showed anticancer activity in in vitro assays. An example is the antineoplastic agent cis -K_(4)[PtCl_(2)ATP] synthesized by Nayak et al., which demonstrated active against Dalton’s lymphoma cells [ ].",
"Kirschner et al. reported that platinum(IV) complex of the antimetabolite 6-mercaptopurine, is an antimetabolite with known antineoplastic and immunosuppressant properties [ ]. It is generally used in combination with other drugs, inhibiting purine metabolism and, as consequence, the nucleic acid synthesis.",
"Other thio and selenoguanine–platinum complexes were reported from Maeda et al. [ , ], as shown in . In detail, aquated cis -diamminoplatinum(II) reacted in slightly acidic conditions with stoichiometric amounts of selenopurine or thiopurine and the resulting complexes were studied for their antitumor activity against L1210 cells in mice. These compounds exhibited a satisfying antitumor activity and very low toxicity. Although their mechanisms of action were not fully understood, the antitumor activity of these complexes seem to also be due to a slow release of the ligands, therefore resulting in a merged action of both the residual platinum complex moiety and the purine analogues.",
"One of the reasons for the continued study of platinum complexes is the search for new drugs able to circumvent the resistance phenomena that often occurs during cisplatin treatment. In addition to Pt(II) complexes, Pt(IV) complexes also showed high potential as anticancer drugs, even for their ability to work as prodrugs.",
"Model platinum-nucleobase and -nucleoside complexes were synthesized and studied for their antitumor activity by Ali et al. The mentioned study concerns a series of platinum(II) and, were synthesized.",
"These platinum-nucleoside monoadducts may also have the ability to further interact with DNA. The cytotoxicity for some of the synthesized compounds against A2780 and A2780CP human ovarian cell lines that were, respectively, sensitive and resistant to cisplatin was also evaluated in comparison with the latter.",
"Although able to show cytotoxicity on cisplatin-resistant A2780CP cells, also in a low concentration range, the nucleobase adducts proved less effective against A2780 cells then cisplatinides, creating interferences and alterations of the normal metabolic pathways [ , , , , , ]. In fact, they are widely used for the treatment of both acute and chronic viral infections since they may inhibit virus replication, by interfering with the synthesis of DNA and/or RNA in infected cells. Nucleos(t)ide analogues drugs generally cause the inhibition of specific intracellular enzymesides, in the nucleobase and/or sugar moieties, with the aim to enhance the biological interactions able to generate antiviral activity [ ]. In this optic, AcyclovirCl(NH_(3))_(2)]NO_(3) or neocuproine and HSV-1phen-containing complexes were generally more active with respect to the phen-containing analogues. These results could be ascribed to a different stability in the biological medium of phen and neocuproine derivatives [ ].",
"The nucleoside tubercidinB_(3-m)](NH_(3))_(2)]NO_(3) and trans -[PtCl( N7 -9-ethylguanine)(NH_(3))(quinoline)]NO_(3) demonstrated protective capabilities in the host cells against HIV infection, after administration [ , ]. The affinity towards S -donor ligands of trans -[PtCl( N7 -9-ethylguanine)(NH_(3))(quinoline)]NO_(3) complex was exploited to eject zinc from the zinc finger site of the C -terminal finger of the HIV-nucleocapsid protein(NH_(3))_(2)]NO_(3) showed good viral inhibition at subtoxic concentration against other type of viruses, such as HCMV, VCV, HSV-1 and 2, EBV, and VZV [ ].",
"Among nucleotide analogues directed against the RNA polymerases of RNA-dependent viruses and positive-sense, including MERS-Cov and SARS-CoV-2 [ , , , , , , , , , ]. Abacavir, zidovudine, lamivudine, tenofovir, stavudine, didanosine, zalcitabine, and emtricitabine are nucleoside/nucleotide analogues approved by the FDA for the treatment of HIV infections. Each of these analogues)_(2)(ddI)] complex), with the purpose of designing a new nucleoside analogue with improved clinical efficacy. The application of spectroscopic techniques such as UV absorption, fluorescence spectroscopy, and dynamic viscosity measurements allowed the study of the interaction of K[PtCl(OCH_(3))_(2)(ddI)] complex with calf thymus DNASO_(4) with [Pt(CH_(3)CN)_(2)Cl_(2)] and isolated deep blue complexes. Interest in these platinum complexes derived from their antitumor activity, radio-sensitizing action, high water solubility, and low levels of renal toxicity [ , ]. In 1975, Rosenberg and collaborators reported on a new class of “platinum blues”ide analogues, the study of the ligand properties of modified nucleos(t)ides towards metal centers is an interesting promising field in the design of novel antivirals [ , ]. DNA is a primary target for many antiviral drugs because inhibition of DNA and/or RNA synthesis during viral replication is an important step, sometimes necessary, for the design of new antiviral drugs. For these reasons, the ability of some nucleos(t)ides-based platinum(II) compounds to interfere with the production, function, and/or metabolism of nucleic acids, even at low dosages, could enhance the efficacy and tolerance profiles of antiviral drugs based on modified nucleos(t)ides [ , , ]."
] |
PMC10787678
|
Mycopathologia
|
COVID-19 associated Pulmonary Aspergillosis in Patients Admitted to the Intensive Care Unit: Impact of Antifungal Prophylaxis
|
13-01-2024
|
Early after the beginning of the coronavirus disease 2019 (COVID-19)-pandemic, it was observed that critically ill patients in the intensive care unit (ICU) were susceptible to developing secondary fungal infections, particularly COVID-19 associated pulmonary aspergillosis (CAPA). Here we report our local experience on the impact of mold active antifungal prophylaxis on CAPA occurrence in critically ill COVID-19 patients. This is a monocentric, prospective cohort study including all consecutive patients with COVID-19 associated acute respiratory failure who were admitted to our local medical ICU. Based on the treating physician’s discretion, patients may have received antifungal prophylaxis or not. All patients were retrospectively characterized as having CAPA according to the 2020 ECMM/ISHAM consensus definitions. Seventy-seven patients were admitted to our medical ICU during April 2020 and May 2021 and included in the study. The majority of patients received invasive-mechanical ventilation (61%). Fifty-three patients (68.8%) received posaconazole prophylaxis. Six cases of probable CAPA were diagnosed within clinical routine management. All six cases were diagnosed in the non-prophylaxis group. The incidence of CAPA in the overall study cohort was 0.57 events per 100 ICU days and 2.20 events per 100 ICU days in the non-prophylaxis group. No difference of cumulative 84-days survival could be observed between the two groups ( p = 0.115). In this monocentric cohort, application of posaconazole prophylaxis in patients with COVID-19 associated respiratory failure did significantly reduce the rate of CAPA. Supplementary Information The online version contains supplementary material available at 10.1007/s11046-023-00809-y.
|
[
"Recent studies have highlighted that severe respiratory viral infections such as influenza or coronavirus disease 2019 has been recognized as a new entity that affects immunocompromised as well as non-immunocompromised critically ill patients [ ]. In line, a severe course of COVID-19, caused by severe acute respiratory syndrome coronavirus 2, and thereby allowing the fungus to remain concealed from recruited lung neutrophils [ , ]. In addition to the direct effects caused by viral infection, adjunctive immunosuppressive/immunomodulatory treatment for the treatment of moderate to severe COVID-19 may exacerbate the risk of developing CAPA [ , ].",
"The overall burden of CAPA in critically ill COVID-19 patients is challenging to assess and wide variability of CAPA prevalence has been reported [ ]. In a pan-European multicenter study, inter-center CAPA prevalence rate varied between 1.7 to 26.8%, with a median prevalence of 11% [ ]. This variance in incidence rates was also observed among many other studies [ ] and has several potential reasons including availability of fungal diagnostics, local epidemiology, demographics and socio-economic factors. High prevalence and mortality rates [ ] of CAPA raised the question whether critically ill COVID-19 patients may benefit from application of mold-active antifungal prophylaxis, similar to other high-risk groups [ – ]. Additionally, diagnosis of invasive aspergillosis in the ICU is often challenging, given the often unspecific clinical and radiological presentation as well as the risks associated with invasive diagnostic procedures, even though bronchoscopy is a well-tolerated procedure in ventilated COVID-19 patients [ ].",
"In a recently published observational data obtained from several ICUs from our center, it could be shown, that CAPA prevalence rate may significantly be reduced by application of antifungal prophylaxis [ ]. However, antifungal prophylaxis was not associated with survival benefits in critical ill COVID-19 patients. Here we report our local experience with CAPA in a medical ICU, and the impact of systemic mold active prophylaxis in critically ill COVID-19 patients on CAPA development. We report this data in addition to the data reported earlier [ ], as we have observed that the baseline characteristics of critically ill COVID-19 patients have changed over the time of the pandemic. We now observe a higher number of immunocompromised patients in the ICU and who received antifungal prophylaxis versus those who did not receive prophylaxis. Secondary objectives were the comparison of demographic data and outcome between the two groups.",
"At our institution, systemic antifungal prophylaxis with posaconazole [intravenous.",
"For statistical analysis IBM SPSS 27 were female and 50. Median survival time was estimated with 42 days, but failed to prove statistical significance, because of lack of power and due to the fact that the rate of early IAPA after ICU admission levels of > 1000 mg/L are achieved approximately 3 days after start of intravenous posaconazole [ ]. Even though, it may take several more days to reach a solid steady state of subjects that received tocilizumab, however, majority of these patients where there was no local recommendation for antifungal prophylaxis in critically ill COVID-19 patients. Whether future variants of SARS-CoV-2 or adaptions in the COVID-19 management will affect the epidemiology of CAPA needs to be closely observed, as this may also affect the strategies for CAPA management and prevention.",
"Based on currently available data, no recommendation can be given for or against the general use of antifungal prophylaxis in critically ill COVID-19 patients. This is also influenced by several factors like the wide variation on local epidemiology, the use of (combination) immunomodulatory treatment, individual risk factors like underlying immunosuppressive disease, potential transient risk factor like construction work, and draw backs of azole usage in the ICU like drug-drug interactions or toxicities. Besides antifungal prophylaxis, however, fungal awareness is key for early diagnosis and treatment. This is critical, as it is well-known, that true fungal infections in COVID-19 patients are associated with reduced probability of survival [ , ].",
"This report highlighted the local experience with application of antifungal prophylaxis in critically ill COVID-19 patients. As this was a non-interventional observational trial, it does come with some important limitations that should be considered: First, the uncontrolled study design does not allow for equal distribution of risk factors for CAPA development or poor outcome among the two groups. As some variables including APACHE-II score, SOFA score or details on EORTC/MSGERC risk factors for fungal infections were not available, it cannot be excluded, that baseline characteristics were distributed unequally among the two groups. Second, as no systemic antifungal screening protocol was implemented at our center, the decision whether or not to perform antifungal diagnostics was solely based on the treating physician’s discretion. This may cause over- or underdiagnoses of CAPA in one of the groups. Third, we did not observe a biopsy proven CAPA case, which is due to the fact, that lung biopsy in critically ill COVID-19 patients is usually not possible. Lastly, the study was not designed to investigate a survival benefit of antifungal prophylaxis in this cohort. In addition, a cox regression model couldn’t be performed to implement CAPA as a time-dependent variable and avoid immortality bias due to the small sample size of CAPA cases and not fulfilling the assumption of proportional hazards.",
"In conclusion, in this observational cohort we found that the application of mold active antifungal prophylaxis in critically ill COVID-19 patients was associated with significantly reduced number of CAPA cases, while we could not observe an effect on overall survival."
] |
PMC10264378
|
Scientific Reports
|
Altered functional brain network patterns in patients with migraine without aura after transcutaneous auricular vagus nerve stimulation
|
13-06-2023
|
Transcutaneous auricular vagus nerve stimulation (taVNS) shows excellent effects on relieving clinical symptoms in migraine patients. Nevertheless, the neurological mechanisms of taVNS for migraineurs remain unclear. In recent years, voxel-wise degree centrality (DC) and functional connectivity (FC) methods were extensively utilized for exploring alterations in patterns of FC in the resting-state brain. In the present study, thirty-five migraine patients without aura and thirty-eight healthy controls (HCs) were recruited for magnetic resonance imaging scans. Firstly, this study used voxel-wise DC analysis to explore brain regions where abnormalities were present in migraine patients. Secondly, for elucidating neurological mechanisms underlying taVNS in migraine, seed-based resting-state functional connectivity analysis was employed to the taVNS treatment group. Finally, correlation analysis was performed to explore the relationship between alterations in neurological mechanisms and clinical symptoms. Our findings indicated that migraineurs have lower DC values in the inferior temporal gyrus (ITG) and paracentral lobule than in healthy controls (HCs). In addition, migraineurs have higher DC values in the cerebellar lobule VIII and the fusiform gyrus than HCs. Moreover, after taVNS treatment (post-taVNS), patients displayed increased FC between the ITG with the inferior parietal lobule (IPL), orbitofrontal gyrus, angular gyrus, and posterior cingulate gyrus than before taVNS treatment (pre-taVNS). Besides, the post-taVNS patients showed decreased FC between the cerebellar lobule VIII with the supplementary motor area and postcentral gyrus compared with the pre-taVNS patients. The changed FC of ITG-IPL was significantly related to changes in headache intensity. Our study suggested that migraine patients without aura have altered brain connectivity patterns in several hub regions involving multisensory integration, pain perception, and cognitive function. More importantly, taVNS modulated the default mode network and the vestibular cortical network related to the dysfunctions in migraineurs. This paper provides a new perspective on the potential neurological mechanisms and therapeutic targets of taVNS for treating migraine.
|
[
"Migraine is defined as a severe throbbing headache accompanied by sensitivity to light and sound, decreased executive ability, memory and attention, which is persistent and has severe negative impacts on sufferers' life. Each patient received a 4-week treatment period which included 12 sessions, with 30 min per session. Based on previous taVNS studies, patients were treated with therapy intensity of 0.2 ms and frequency setting of 1 Hz^(28 , 47 , 56). The intensity level of somatosensory stimulus was slowly adjusted to the strongest painless stimulus the patient could receive; HCs did not do any treatment.",
"Patients underwent functional and structural MRI scans before and after treatment. The time window between the MRI scan and treatment visit is one day, i.e. the pre-treatment MRI scan was completed first, and then the first treatment visit was performed on the next day; at the end of treatment, the last treatment visit was performed first, and then the post-treatment MRI scan was completed on the next day. The experiment for migraineurs is shown in Supplementary Fig. . The HCs underwent only one scan. The same MRI scanner compared to the HCs. In the meantime, the pre-taVNS patients had reduced DC values at the right inferior temporal gyrus.",
"In the FC analysis, we used the right cerebellar lobule VIII, right FFG, right ITG, and left PCL as ROIs to analyze the changes in the whole-brain FC in these brain regions in the post-taVNS patients. Compared to the pre-taVNS patients, the post-taVNS patients had enhanced FC in the right ITG with the bilateral orbitofrontal gyrus. Meanwhile, compared to the pre-taVNS patients, the post-taVNS patients had reduced FC of the right cerebellar lobule VIII with the bilateral supplementary motor area. The correlation analysis revealed that the changed FC of ITG-IPL was significantly and positively correlated with the changes in headache intensity."
] |
PMC10464105
|
BMC Public Health
|
Challenges and successes in the sustainment of Dutch community-level smoking cessation interventions for residents with a low socioeconomic position
|
23-08-2023
|
Background When health promotion interventions are implemented, the gains are often short-lived, as interventions are seldom successfully sustained. The current study explores how and under what conditions community-level smoking cessation interventions for people with a lower socioeconomic position can be sustained, drawing upon interventions delivered in Dutch neighbourhoods with a predominantly low socioeconomic position. Methods We conducted 15 semi-structured interviews with key stakeholders from three Dutch community-level smoking cessation interventions implemented at least three years prior. The topic guide was developed based on the Determinants of Innovation framework and transcripts were analysed thematically. Results We identified several factors that promote the sustainment of smoking cessation community-level interventions: 1) structural, long-term funding through the commitment of health insurers and policy makers; 2) continued stakeholder enthusiasm and involvement; 3) training and time for professionals to discuss smoking cessation, thereby also increasing the visibility of the intervention for professionals and residents; 4) integrating the intervention with existing initiatives and adapting it to be compatible with current working practices of executive staff; and 5) planning for sustainment as a team from the outset. Conclusions The current study highlights challenges and successes in intervention sustainment for people with a lower socioeconomic position. Lack of structural funding was one of the most challenging aspects for intervention sustainment in which health insurers and policy makers can play an important role. Planning for sustainment from the outset would enable intervention coordinators to consider the abovementioned factors early on. This need not be done alone but can best be discussed within a team of stakeholders. Supplementary Information The online version contains supplementary material available at 10.1186/s12889-023-16529-3.
|
[
"Health promotion interventions at the community level are regularly utilised for underserved or disadvantaged groups [ ], such as those with a lower socioeconomic position impact of the intervention and may also reduce trust and support in the community for new interventions [ , ]. Furthermore, the initial development and implementation of an intervention often involves considerable start-up costs, which are potentially a poor investment and use of finite resources if the intervention is not sustained [ ]. A review of the sustainment of interventions in disadvantaged communities found that only 43% of studies reported interventions that were successfully sustained at least 2 years after the initial training/implementation amongst stakeholders of the three community-level smoking cessation interventions in Haarlem, The Hague, and Utrecht. The three projects were chosen because they were all carried out in districts with neighbourhoods with a predominantly low SEP. The projects were varied in the type of intervention provided and degree of sustainment. Interviews were performed between March and May of 2022.",
"In Haarlem, the project ‘Rookvrij Opgroeien’, developed by smoking cessation company SineFuma, was given [ ] as part of a neighbourhood challenge. All stakeholders were involved in advising, the delivery of, and/or the coordination of the community-level interventions. Of the 25 stakeholders that we approached to interview, ten declined because of time constraints or because they felt insufficiently involved in the recruitment and coordination of the intervention.",
"Interviews were conducted by author NP with video conferencing or via telephone and lasted 48 minutes on average. The framework depicts four processes of innovation [ , ]. For our topic list, we made a selection of determinants within the five determinant categories, based on the emerging factors associated with sustainability of interventions at the community level, as identified by Shelton, Rhoades Cooper and Wiltsey Stirman [ ]. We paid particular attention to the factor recruitment in our topic list because there is still little known about how recruitment activities can be sustained.",
"The interviewer and/or the research assistant made notes during the interviews and kept a reflection log to facilitate the analysis. These notes were regularly shared with the rest of the project team. All interviews were transcribed verbatim and returned to the interviewee to be checked and approved without adjustments. Transcripts were subsequently imported into NVivo 12. For instance, the theme ‘ ’ contained sub-themes directly from the model, such as ‘compatibility with current way of working’, and new themes, such as ‘scope of the intervention’. Themes relating to the sustainment of recruitment of participants were included under the themes ‘ ’, ‘ ’ and ‘ ’. Saturation of all sub-themes was reached, as no new codes were added to the coding tree in the final four interviews coded."
] |
PMC10988786
|
ACS Sustainable Chemistry & Engineering
|
Reusable,
Recyclable, and Biodegradable Heat-Shrinkable
Melt Cross-Linked Poly(butylene adipate-co-terephthalate)/Pulp
Biocomposites for Polyvinyl Chloride Replacement
|
15-03-2024
|
Heat-shrinkable films are widely used as disposable secondary
packaging
but are conventionally made from fossil-based and nonbiodegradable
polyvinyl chloride or polyethylene. To lower the environmental impact
of such products, this work reports the development of recyclable,
biodegradable, and partially biosourced heat-shrinkable biocomposites
that are cost-competitive with existing shrink wraps. Poly(butylene
adipate- co -terephthalate), a growing biodegradable
thermoplastic, was simultaneously reinforced with pulp fibers and
partially cross-linked in a single-step reactive melt processing.
The designed peroxide-initiated reaction led to a 55 wt % cocontinuous
insoluble gel incorporating all the pulp fibers into a cross-linked
polymer network. In the solid state, the cross-linked biocomposite
shows 60% elongation at break with a 200% increase in Young’s
modulus, while the only addition of pulp fibers stiffens and embrittles
the matrix. Creep tests in the melt state indicated that the cross-linked
network induces homogeneous shrinking even during the loading phase,
demonstrating the potential use of the biocomposites as heat-shrinkable
films. The shrinking also promotes the shape-memory of the biocomposite,
which retains its dimensions after four cycles. The circularity of
the materials was assessed by mechanical recycling and industrial
composting, which have proven feasible end-of-life options for heat-shrinkable
biocomposites.
|
[
"Heat-shrinkable films are a common and\nindispensable single-use\npackaging solution for the stabilization and protection of goods during\nsale and transportation. Usually, they are based on thermoplastic\nthat is stretched and oriented during production and can shrink and\nwrap around a product upon heating. When the films are produced, cooling\nis used to fix the polymer chains in reversible oriented configurations,\nand when they are reheated, the configurations return to their random\nstate more thermodynamically stable. This entropy-driven phenomenon\nallows the films to shrink upon heating.^(1) The shrink films are characterized by high puncture resistance,\ngood shrinkage, and shrinkage stress related to certain mechanical\nand rheological performances.",
"Common applications of heat-shrinkable\nfilms include wrapping packs\nof bottles or cans, books, magazines, and vegetables, sealing caps,\nand shrinkable labels. As for most single-use plastics, heat-shrinkable\nfilms are disposable and have a short service life. Nevertheless,\nthe most common polymers employed are fossil-based not biodegradable\ndurables such as polyvinyl chloride and 1.6 phr of benzoyl peroxide is the\ndry weight of the insoluble fraction and w _(0) is the initial weight of the sample. To separate possible pulp physically\nentrapped in the gel, the extracted insoluble fraction of X-P-PBAT\nwas redispersed in DCM and centrifuged in a Heraeus Labofuge 200 Centrifuge\n(Thermo Scientific) at 5000 rpm for 5 min.",
"Attenuated Total\nReflectance Fourier-Transform Infrared Spectroscopy\n(ATR-FTIR) was performed with a PerkinElmer FT-IR Spectrometer Frontier\nin ATR mode. Twenty scans were acquired from 4000 to 400 cm^(–1) with a resolution of 4 cm^(–1). All data were recorded\nusing the PerkinElmer Spectrum software.",
"Size-exclusion chromatography\n(SEC) was carried out in CHCl_(3) at 30 °C by using an\nAgilent The R _(r) quantifies the ability of the\nmaterial to recover its shape and is calculated as the ratio between\nthe strain recovered and the maximum strain is the specific melting enthalpy, Δ H _(0) is the melting enthalpy of 100% crystalline PBAT. The fibers\nwere fed in the never-dried state to reduce their agglomeration during\nmelt processing and to exploit the water for boosting the radical\nreactions.^(18 , 20)",
"Three references were processed to explore the\ninfluence of the\nfibers and cross-linking on the biocomposite properties: PBAT in the\npresence of water, PBAT cross-linked with the same amount of peroxide\nin the presence of water, indicating negligible hydrolysis. To\nenable melt processing.^(29 , 30) The radicals on PBAT chains can\npreferentially form on aliphatic carbons^(31 − 33) while some\nstudies hypothesize radical formation on the aromatic ring.^(34 , 35) PBAT radicals can further react forming covalent bonds with other\nPBAT chains or pulp, or can break the chains by β-scission.^(31) The intermolecular bonds increase the molecular\nweight. The similarity is ascribed to the same reactivity\nof benzoyl peroxide in both systems. In the cross-linked biocomposite,\nradicals could have formed both on PBAT chains and on pulp fibers\n( b),^(29) leading to an insoluble fraction containing\nPBAT and fibers. The elution curves showed a reduction\nof PBAT molar mass and larger polydispersity after cross-linking.\nThe lower molecular weight can be a consequence of both the promotion\nof branched chains to the cross-linked insoluble network and β-scission.\nA small shoulder at higher molar mass is also detected, confirming\nthe branched structure.",
"The as-processed materials\nwere characterized by SEM to observe how the reactive processing influences\ntheir morphology and if cross-linking has an effect on the pulp dispersion\nand interaction with PBAT. The micrographs of PBAT cryo-fracture show\na typical brittle surface fracture of a ductile polymer in its glassy\nstate, and it is not influenced by cross-linking. Few micrometrical fibers\nin bundles are detected in both biocomposites but the majority\nof cellulosic fibers appears fibrillated,^(38 − 40) as a consequence\nof shear forces induced during melt processing and the beneficial\nwet-feeding approach, which prevents fibers agglomeration. The fracture\nsurface of the P-PBAT biocomposite is characterized by numerous voids,\nwhich are correlated to the pull-out of the fibers, indicating poor adhesion\nat the interface pulp/PBAT. In the cross-linked X-P-PBAT biocomposite\n( d), the number\nand size of the voids decrease, indicating that cross-linking reduces\nthe agglomeration of the fibers and improves the interface with PBAT.\nThe discrepancy between the number of voids, aggregates, and pull-outs\ncan be ascribed only to the formation of pulp/PBAT hybrids during\ncross-linking.",
"Creep tests at 160 °C were carried out to\nverify whether the\nmaterials shrink when heated above the PBAT melting temperature. The only addition of pulp avoids PBAT\nfracture, and it limits the creep strain to less than 2% after half\nan hour of loading; however, the biocomposite is not able to recover\nthe deformation. This result indicates a large elasticity in the melt\nstate provided by the fibers. Both X-PBAT and X-P-PBAT uniformly shrink\nwhen exposed to tensile load and high temperature, i.e., the creep\nstrain is negative. The uniformity of the shrinkage indicates a cocontinuity\nof the cross-linked network in the materials. During compression molding,\nthe network is fixed into a stretched state at low entropy and at\nhigh temperature it coils to a high entropy state.^(18) The creep curve of the cross-linked biocomposite reaches\na plateau during both load and recovery steps. Instead, the cross-linked\nPBAT first shrinks and then relaxes, i.e., the strain increases with\ntime during both load and recovery. This difference in the cross-linked\nmaterials is ascribed to the elasticity provided by the pulp fibers,\nwhich limits the shrinkage of X-P-PBAT compared to X-PBAT but ensures\nhigher dimensional stability.",
"The heat-shrinking observed in the cross-linked\nmaterials was also\ntested by simulating their potential application as shrink films.\nA pin was wrapped with a thin film. The shrinkage was achieved in around 15 s, demonstrating the\nfeasibility of both cross-linked materials to be applied as alternatives\nto currently commercially available shrink films. If the films are\nleft free to shrink under no stress in an oven at 160 °C, their\ndeformation is isotropic and the shrinkage is 40 and 60% of their\ninitial shape for X-P-PBAT and X-PBAT, respectively, given the elasticity\nprovided by the pulp fibers in the network. The level of stress and\nmaximum strain of X-P-PBAT remain similar during the cycles, indicating\na more homogeneous response of the cross-linked network in the biocomposite\ncompared to one in X-PBAT, which shows more oscillating values of\nstress and strain. This variation in the strain values observed for\nX-PBAT can be ascribed to the lower elasticity of the cross-linked\npolymer without the pulp fibers, and it is consistent with the higher\nshrinkage and relaxation observed in the creep analysis. The shape-memory\nbehavior was quantified by the shape-recovery. The addition of pulp fibers increases the moduli and reduces\nthe gap between the loss and storage moduli, especially in the low-frequency\nregion, confirming a higher elasticity of the biocomposite in the\nmelt state. The effect of the pulp on the rheological properties of\nPBAT is greater than the neat effect of cross-linking. The not-reacted\ncomposite has overlapping G ′ and G ″ up to 1–2 rad/s and increasing the frequency the\ndissipative part prevails, indicating a disruption of the pulp fibers\nnetwork. In contrast, the cross-linked biocomposite shows a prevalent\nsolid-like behavior in all the frequency range observed displays the phase angles\nas a function\nof the absolute value of the complex shear modulus, where phase angles\nbelow 45° indicate predominant melt elasticity.^(44) PBAT liquid-like behavior is confirmed by angles above\n60°, while the elastic cross-linked materials have phase angles\nbelow 30°. The complex viscosity of PBAT follows a linear Newtonian\nbehavior until 10 rad/s, followed by shear thinning. The addition of pulp increases\nthe complex melt viscosity, and anticipates the shear thinning because\nof its solid structure and its networking disruption at increasing\nfrequencies.^(17) Also the only cross-linking\ninduces shear thinning over the entire frequency range and increases\nthe viscosity of PBAT as a consequence of the larger molecular weight\nand chain entanglement.^(31 , 45) The two contributions\nare combined in X-P-PBAT, which is characterized by the largest complex\nviscosities over the entire range of frequencies.",
"The mechanical\nproperties of the materials were evaluated by tensile\ntests at room temperature. Cross-linking slightly reduces the mechanical\nproperties of PBAT, while pulp increases the stiffness of the matrix\nby 340% but significantly reduces its deformability. The cross-linked biocomposite shows a\n200% increase in PBAT Young’s modulus and retains some deformability\n(≈80%), almost 4 times the values registered for the P-PBAT\nbiocomposites. This result is consistent with the observed morphology\n( c,d), indicating\nthat cross-linking reduces the pulp agglomeration and improves its\ndispersion thanks to an increased PBAT/pulp interaction.",
"Neat PBAT has low crystallinity.^(32) The presence\nof pulp is reflected in an earlier onset of degradation in the biocomposites\ncompared to that of PBAT, as expected after the addition of a lower\nthermostable component. However, PBAT protects pulp fibers from thermal\ndegradation increasing their onset of about 30 °C. The effect\nof cross-linking in the biocomposite results in a slight improvement\nof the onset of P-PBAT, in line with the creation of a hybrid network.",
"To evaluate whether the produced\nmaterials could replace the shrink films on the market, their mechanical\nproperties and price were compared with commercial heat-shrinkable\nPVC wrap and cross-linked polyethylene, and with other biobased/biodegradable\ncommercial polymers. The Ashby plot in reports the specific elongation as a function\nof the price of selected materials. Compared to the targeted PVC shrink\nwrap, the cross-linked PBAT and biocomposite are cheaper and have\nhigher specific elongation, in addition to their biodegradability,\nnontoxicity and higher renewable content. The properties of X-PBAT\nand X-P-PBAT lie in the same range of cross-linked polyethylene. The\nreactive processing strategy adopted in this study is therefore economically\nviable to produce sustainable heat-shrinkable biocomposites that can\nreplace fossil-based and nonbiodegradable packaging.",
"To further investigate the economical/environmental\nbenefits of\nmore valuable end-of-life options than incineration and landfilling,\nmechanical recycling and biodegradation of the materials have been\nevaluated, which are not taken into account in the Ashby economical\nassessment.",
"The mechanical recycling of the cross-linked materials\nwas carried\nout by extrusion of shredded compression-molded films. This test was a simulation\nof postindustrial waste recycling as it did not take into account\nthe effects of consumers use of the films. The gel content of the\ncross-linked materials. The increase\nin the stiffness, not registered in the recycled X-PBAT, can be ascribed\nto further dispersion/fibrillation of the pulp fibers within the matrix\nachieved by reprocessing.^(46) This hypothesis\nfound confirmation in the morphological analysis performed on the\ncryo-fractured recycled X-P-PBAT, which showed individualized fibers, fewer\nfiber bundles, and fewer pull-outs. The cross-linked materials developed\nin this study can be therefore recycled, highlighting the advantage\nof their use as a replacement for PVC heat-shrinkable films. Indeed,\nPVC is difficult to mechanically recycle because its degradation generates\nchlorinated products that are toxic and corrosive to melt processing\nequipment.^(3)",
"A further advantage of PBAT over other fossil-based\npolymers, such\nas polyethylene and PVC is its biodegradability. To assess whether\nthe reactive melt processing and pulp fibers influence PBAT biodegradation,\ndisintegration under composting conditions was carried out following\nthe ISO 20200:2015 standard.\nThe weight loss over 90 days of industrial composting shows that cross-linking\nincreases PBAT disintegration rate, as a consequence of the larger\npolydispersity, as low molecular weight polyester chains are more\nreadily available for microorganisms to biodegrade^(47) thus catalyzing the PBAT disintegration. Similar results have been\nreported for PCL biodegradation, enhanced by radiation cross-linking.^(48) However, after 40 days, the biodegradation rate\nremarkably decreases. This result can be explained by the biodegradation\npath for synthetic polyesters, which progresses via hydrolytic degradation\nstarting from the amorphous to the crystalline domains and continue\nwith bacterial attack only when the molecular chains become oligomers.^(11 , 49 , 50) Pulp also increases the PBAT\nweight loss under composting, due to its faster biodegradation compared\nto the matrix,^(51) offering hydrophilic surfaces\nand not perfectly adherent interface with the matrix which promotes\nwater and microorganisms penetration within the biocomposite bulk.^(52 , 53) After 90 days the weight loss of both P-PBAT and the cross-linked\nX-P-PBAT films is around 85% compared to 55% of neat PBAT, indicating\na positive influence of the pulp fibers on the PBAT biodegradation."
] |
PMC10102360
|
Frontiers in Neurology
|
Association betweenCORINpromoter methylation and stroke: Results from two independent samples of Chinese adults
|
31-03-2023
|
Objective As the physical activator of natriuretic peptides, corin has been associated with stroke, but the underlying mechanism is not very clear. Here, we examined whether the CORIN promoter’s methylation, an epigenetic DNA modification, was associated with the risk of stroke in two independent samples. Methods A total of 1771 participants including 853 stroke cases and 918 healthy controls were included as a discovery sample and 2,498 community members with 10 years of follow-up were included as a replication sample. DNA methylation of the CORIN promoter was quantified by target bisulfite sequencing in both samples. We first examined the single CpG association, followed by a gene-based analysis of the joint association between multiple CpG methylation and stroke, adjusting for conventional risk factors. Results The single CpG association analysis found that hypermethylation at all of the 9 CpG sites assayed was significantly associated with lower odds of prevalent stroke in the discovery sample (all p < 0.05), and three of them located at Chr4:47840038 (HR = 0.74, p = 0.015), Chr4:47839941 (HR = 0.80, p = 0.047), and Chr4:47839933 (HR = 0.82, p = 0.050) were also significantly associated with incident stroke in the replication sample. The gene-based association analysis found that DNA methylation of the 9 CpG sites at the CORIN promoter was jointly associated with stroke in both samples (all p < 0.05). Conclusion DNA methylation levels of the CORIN gene promoter were lower in stroke patients and predicted a higher risk of incident stroke in Chinese adults. The underlying causality warranted further investigation.
|
[
"Cardiac natriuretic peptides. Their circulating levels have been associated with the risk of stroke which is the leading cause of long-term disability and mortality all over the world, China in particular, in various prospective studies. Corin, a trypsin-like protease highly expressed in the heart, is the physiological activator of ANP and could also activate BNP. It may be a switching regulator of the NP system and thereby contributing to the development of stroke. Indeed, the cardiovascular effect of corin has been suggested by basic and population studies. For example, the expression of corin was upregulated in atherosclerotic aorta intima and vascular endothelial cells stimulated by oxidative stress. Blood pressure was elevated in mice with corin gene knockout. In humans, single nucleotide variations, cardiac hypertrophy, and hypertension. Circulating levels of corin have been associated with various cardiovascular disorders such as heart failure, atrial fibrillation, and myocardial infarction. Furthermore, our group previously found that decreased serum corin was significantly associated with prevalent stroke and unfavorable poststroke outcomes. These findings suggest that corin could be a risk factor or drug candidate for the prevention and control of stroke. However, no inhibitor of corin function has been found in human plasma, which may increase the unsafety of its clinical translation. Therefore, a better understanding of the molecular mechanisms underlying the association between corin and stroke is urgent for clinical translation. As a mediator between the dynamic environment and fixed genome, DNA methylation may affect gene expression and function and thereby representing one of the candidate molecular mechanisms that we are seeking. To date, many DNA methylation markers of stroke have been identified by epigenome-wide association studies. DNA methylation levels of the global genome and some candidate genes, such as ATP-binding cassette G1, matrix metalloproteinase-2, estrogen receptor alpha, thrombomodulin, and tumor protein p53 have been associated with stroke. As suggested above, we hypothesized that DNA methylation of the CORIN gene may also play a considerable role in stroke development, but lacking epidemiological evidence. Therefore, we aimed to examine the association between CORIN gene promoter methylation and the risk of stroke in two independent samples of Chinese adults. The identified methylation markers might be useful targets for the prevention and treatment of stroke because DNA methylation is a modifiable molecular modification.",
"Methods of selection of study participants and data collection were described in the . By frequency matching, 1,000 age-and sex-matched controls were selected from the 3,999 community individuals free of cardiovascular diseases. After excluding 229. In brief, as illustrated in , after bisulfite treatment, amplification by polymerase chain reaction. Hypertension was defined as SBP ≥140 mmHg and/or DBP ≥90 mmHg or under antihypertensive treatment in the last 2 weeks.",
"The clinical characteristics of study participants were presented according to the status of stroke. Log2-transformation was applied to maximize the normality of data distribution for methylation levels at single CpG sites. The transformed data were used in downstream analyses. Both single CpG and joint associations between CORIN promoter methylation and stroke were repeatedly examined in both samples. All statistical analyses were performed using R Studio.",
"The median levels of DNA methylation at single CpG sites were compared between patients with ischemic stroke and their healthy controls using the Wilcoxon rank-sum test. To examine the association between DNA methylation at a single CpG and stroke, we constructed a logistic regression model in which ischemic stroke.",
"To replicate and further examine whether CORIN promoter methylation at baseline predicted the risk of stroke incidence, we similarly examined the single CpG and gene-based associations between CORIN promoter methylation and stroke by constructing a competing-risks survival regression model. In this model, time. In the replication sample, 88 participants developed stroke during follow-up. At baseline, they also had more risk factors listed above than those who remained free of stroke by the end of follow-up. After adjusting for confounding factors, DNA methylation levels at these CpG sites were also negatively associated with prevalent ischemic stroke. These single CpG associations persisted after correction for multiple testing. After multivariate adjustment for conventional risk factors, it was also significantly associated with a lower risk of prevalent ischemic stroke. Similarly, the wTPM also found that DNA methylation of the 9 CpG sites in the CORIN promoter as a whole was significantly associated with ischemic stroke. After adjusting for the same risk factors as the discovery sample, hypermethylation of these CpG sites seemed to be associated with a decreased risk of incident stroke during follow-up. They were CpG3 located at Chr4:47840038, the wTPM found that DNA methylation at the 9 CpG sites was still jointly associated with the risk of future stroke in the replication sample."
] |
PMC10346566
|
Nutrients
|
Synergistic Effects of Heat-Treated Green Tea Extract and Enzymatically-Modified Isoquercitrin in Preventing Obesity
|
28-06-2023
|
Previous research has shown that both heat-treated green tea extract (HTGT) and enzymatically modified isoquercitrin (EMIQ) have anti-obesity effects. Given the absence of in vivo evidence demonstrating their synergistic effects, our study aimed to elucidate the combined obesity prevention potential of HTGT and EMIQ in mice. Mice were treated with these compounds for 8 weeks, while being fed a high-fat diet, to investigate their preventive anti-obesity effects. We demonstrated that the co-treatment of HTGT and EMIQ results in a synergistic anti-obesity effect, as determined by a Kruskal–Wallis test. Furthermore, the combined treatment of HTGT and EMIQ was more effective than orlistat in reducing body weight gain and adipocyte hypertrophy induced by high-fat diet. The co-treatment also significantly reduced total body fat mass and abdominal fat volume. Additionally, the group receiving the co-treatment exhibited increased energy expenditure and higher glucose intolerance. We observed a dose-dependent upregulation of genes associated with mitochondrial oxidative metabolism and PKA signaling, which is linked to lipolysis, in response to the co-treatment. The co-treatment group displayed elevated cAMP levels and AMPK activation in adipose tissue and increased excretion of fecal lipids. The results indicate that the co-treatment of HTGT and EMIQ holds the potential to be a promising combination therapy for combating obesity. To further validate the anti-obesity effect of the combined treatment of HTGT and EMIQ in human subjects, additional clinical studies are warranted.
|
[
"Obesity poses substantial implications for public health, as it is associated with an elevated risk of chronic diseases, including diabetes and cardiovascular disorders [ ]. Obesity is primarily caused by an imbalance between the intake and expenditure of energy, where excess calories are stored in the body as fat [ ]. The existing treatments for obesity encounter challenges regarding long-term effectiveness and sustainability, making it difficult for individuals to achieve and maintain weight loss [ ]. Considering the potential adverse effects associated with current pharmaceutical interventions for obesity treatment, our study focuses on investigating the potential of phytochemicals as dietary supplements, offering promising alternatives for obesity prevention. The prevalence of obesity has been steadily rising in the recent few years, highlighting the need for effective strategies to prevent and treat this public health problem.",
"Adipose tissue exerts a crucial function in energy metabolism and is composed of adipocytes, which are specialized cells that store energy in lipid droplets [ ]. Adipose tissue is generally classified into two major categories: brown adipose tissue expression, which is important for non-shivering thermogenesis [ ]. Conversely, WAT serves as a site for lipid storage in the form of triglycerides signaling pathway is a key player in BAT activation and WAT browning, as it serves as a major regulator of cytosolic lipolysis by activating hormone-sensitive lipase is a prominent phytochemical found in green tea extract, and approximately half of EGCG undergoes epimerization to form gallocatechin gallate on visceral fat and hepatic triacylglycerol in rats [ ], while our group confirmed that HTGT induces significantly higher expression of UCP1 in brown adipocytes, compared to green tea extract refers to the enzymatic derivatives of rutin, where glucose-rhamnose is attached to the position 3 of the quercetin glycosides [ , ]. This modification enhances the bioavailability of EMIQ, making it more effective compared to quercetin alone [ ]. EMIQ treatment enhanced energy metabolism mainly by phosphorylating 5′ adenosine monophosphate-activated protein kinase feeding regiment, in contrast to our previous study where obese mice were treated with the compounds after 8 weeks of HFD feeding. During the course of the study, HTGT and EMIQ were administered orally, either individually or in combination, at different doses was made by hydrolyzing rutin and then treating with glycosyltransferase to transglycosylation [ ]. HTGT and EMIQ were supplied by Amorepacific Corp. was 45mm, and the size of pixel was 90μm. The scan mode was set to 4 min with high resolution. The volumes of abdominal fat regions between the proximal end of the L1 vertebrae and the distal end of the L5 vertebrae were calculated using AnalyzeDirect software was used to stain deparaffinized tissues at 4 °C overnight. Goat anti-rabbit Alexa Flour 488 after 12-h fasting. The glucose levels in the blood were measured at 0, 15, 30, 45, 60, 90, 120, and 150 min using test strips and a Gluco Dr.Top blood glucose meter. After evaporating the solution of the lipid phase for 3 days, the dried lipid was weighed and calculated.",
"Adiponectin, leptin, and cAMP were quantified by ELISA kit. Reverse transcription of RNA into cDNA was carried out using cDNA Reverse Transcription kit, with PhosSTOP phosphate inhibitor for statistical analysis. The data are presented as mean ± SEM. Vehicle controls of HFD-fed mice showed significant body weight gains, compared to mice on an NCD. Interestingly, the co-treatment of HTGT and EMIQ resulted in a dose-dependent reduction in body weight gain that compared to individual treatments of HTGT or EMIQ throughout the 8 weeks, and surpassed the effectiveness of orlistat.. Histological analysis of iWAT and gWAT revealed a dose-dependent decrease in the cross-sectional diameters of adipocytes in the mixture groups compared to the single compound groups.",
"To evaluate the effects of co-treatment of HTGT and EMIQ against obesity, we conducted a body composition analysis. The results demonstrated a significant decrease in the percentage of fat mass and an increase in the percentage of lean mass in a synergistic and dose-dependent manner following the co-treatment. Furthermore, micro-CT was utilized to assess the impact of the combination treatment on abdominal adiposity by calculating abdominal fat volume. As shown in B, the co-treatment groups exhibited a significant reduction in both abdominal subcutaneous and visceral fat volumes in synergistic and dose-dependent manner.",
"Next, we evaluated the impact of the treatment on glucose tolerance by conducting an IP-glucose tolerance test. The results revealed that the co-treatment, synergistically and in a dose-dependent manner, improved glucose tolerance induced by HFD. Furthermore, indirect calorimetry analysis showed that all co-treatment groups increased energy expenditure.",
"Reduction of dietary lipid absorption by the inhibition of pancreatic lipase in the gastrointestinal tract is one of the potential mechanisms for preventing obesity. Previous studies have demonstrated the inhibitory effects of green tea and quercetin on pancreatic lipase activity [ , ]. As shown in C, co-treatment of HTGT and EMIQ exhibited a dose-dependent inhibition of the pancreatic lipase activity with an IC_(50) of 46.02 μg/mL. In addition, we measured fecal lipid excretion in mice over the 8-week period. After 4 weeks, we observed increased lipid content in the feces of the co-treatment groups, especially in the high-dose co-treatment group.",
"Next, we assessed the effects of the co-treatment of HTGT and EMIQ on serum adiponectin and leptin levels. Compared to the HFD CTL group, all co-treatment groups exhibited increased serum adiponectin levels and decreased leptin levels. Collectively, co-treatment of HTGT and EMIQ has a synergistic effect of preventing obesity and related diseases compared to administration of the individual phytochemicals.",
"To explore the potential synergism of HTGT and EMIQ on thermogenesis in adipose tissues, we confirmed the expression of UCP1, a marker of thermogenesis. The mRNA level of UCP1 in BAT tended to be higher in all treatment groups than in the HFD CTL group, but there was no statistically significant difference between administration groups. Furthermore, UCP1 mRNA expression in iWAT was higher in the co-treatment group than in other groups, but the difference in the high-dose of the co-treatment group was the only statistically significant difference. As shown in B,C, the intensity of immunofluorescence in BAT showed synergistic and dose-dependent upregulation of UCP1.",
"The process of adipocyte browning is tightly linked to the regulation of mitochondrial activity and oxidative capacity [ ]. Therefore, protein markers related to mitochondrial metabolic activity were examined by western blot analysis. Co-treatment of HTGT and EMIQ upregulated UCP1 and several protein markers involved in mitochondrial oxidative phosphorylation in both BAT and iWAT. These results indicate that co-treatment of HTGT and EMIQ stimulates adipocyte browning and regulation of mitochondrial activity.",
"A previous study has reported that the combination of HTGT and EMIQ increased the phosphorylation of HSL in vitro [ ], suggesting that the cAMP/PKA signaling pathway may be involved in the observed effects of HTGT and EMIQ. Thus, we hypothesized that the combination of HTGT and EMIQ has a synergism on PKA-dependent lipolysis and mitochondrial metabolism in HFD-fed mice. As expected, the phosphorylation of PKA-downstream proteins was higher following co-treatment, compared to treatment with the individual phytochemicals, in both BAT and iWAT. In addition, we estimated the cAMP levels in iWAT, and found that co-treatment of HTGT and EMIQ significantly increased the cAMP in a dose-dependent manner compared to single treatments.",
"To determine if the expression levels of these proteins exhibited dose-dependent changes, western blotting was performed on two different doses of co-treatment groups. Consistent with the earlier findings, the high-dose group. These results support the hypothesis that the combination of HTGT and EMIQ activates PKA signaling, which, in turn, promotes lipolysis and thermogenesis in adipose tissues.",
"Our results revealed that the combined administration of HTGT and EMIQ led to an increase in AMPKα phosphorylation in both BAT and iWAT. Furthermore, we observed a downregulation of p-mTOR levels in iWAT, while no significant changes were observed in BAT, suggesting a depot-specific response of mTOR signaling to the treatment in adipose tissue. To elucidate the role of PKA signaling and AMPK activation in the effects mediated by HTGT and EMIQ, we employed pharmacological inhibitors, specifically H89. These results strongly suggest that the co-treatment exerts its anti-obesity effects through PKA signaling and AMPK activation."
] |
PMC10541821
|
Environmental Science and Pollution Research International
|
Seasonal characterization of mercury contamination along the Portuguese coast: human health and environmental risk assessment
|
30-08-2023
|
A seasonal characterization of mercury (Hg) accumulation in three different estuaries along the Portuguese coast (i.e. Ria de Aveiro, Tagus estuary and Ria Formosa) was done. For that, it was evaluated: (1) Hg concentrations in abiotic (water) and biotic matrices (flora and fauna); (2) the risk of consumption of local seafood species (e.g. bivalves) to human health; and (3) the environmental risk to Hg exposure. During 1 year, water and biological samples were collected during low tide, in each system for Hg quantification. Our findings revealed that total Hg concentrations in surface waters were higher in Ria de Aveiro and Tagus estuary than in Ria Formosa. In Ria de Aveiro, a particular attention should be given in autumn periods, where Hg levels (≈ 100 µg L −1 ) were considered quite high according to European quality parameters. The same was observed for the Tagus estuary during spring time. Regarding macrofauna Hg levels, no clear seasonal trend was observed. Also, total Hg concentrations in edible species (< 0.5 µg. g −1 ww) represent no risk for consumption. However, considering the environmental risk, in Ria de Aveiro, there is a moderate risk (RQ > 0.1) in autumn periods, which can be a matter of concern. Supplementary Information The online version contains supplementary material available at 10.1007/s11356-023-29495-5.
|
[
"Mercury. Both inorganic and organic Hg, especially the bivalves, among others.",
"Hg is subject to complexation and reduction with dissolved organic matter and suspended particulate matter in the water column, affecting its speciation, bioavailability and mobility in aquatic systems. All these processes may vary seasonally due to modifications in physical and biological factors, which can affect the methylmercury bioaccumulation.",
"Along the Portuguese coast, Ria de Aveiro and confined areas of the Tagus estuary are historically contaminated with mercury from industrial. Currently, despite the efforts to minimize Hg sources having the potential to affect the respective trophic webs and ultimately the human health.",
"In the south coast of Portugal, Ria Formosa is not a heavily industrialized area, and according to previous records, there is indication that Hg contamination in surface waters has become stable since the 1970s. However, there are few recent records on the system.",
"The characterization of Hg contamination and bioaccumulation in specific coastal areas/estuaries and/or biotic groups is a common topic in the literature. Nevertheless, there is a lack of information regarding a broader scenario, comparing distinct systems and food webs in a joint work. So, the main goal of the present work was to do a general temporal characterization of Hg levels in three different estuarine ecosystems. The lack of data in some temporal points in Ria de Aveiro and Ria Formosa was due to some logistic issues related with COVID-19 constraints.",
"Ria de Aveiro is a shallow coastal lagoon located in the northwestern coast of Portugal. It is considered one of the most Hg-contaminated systems in Europe due to continuous discharges of Hg from a chlor-alkali industry between 1950 and 1994 related the observed high suspended particulate Hg concentrations with the resuspension of most contaminated sediment layers.",
"Five sampling stations.",
"Tagus estuary is the largest estuary in Portugal, and one of the biggest in Europe, covering an area of approximately 350 km^(2). It experienced high levels of Hg contamination as consequence of past industrial activity mainly related with pyrite processing.",
"Five sampling stations were selected along the estuary, two in the North Margin.",
"Ria Formosa is a mesotidal coastal lagoon with 180 km^(2) of area, in permanent connection with the sea through six channels. Located in the South of Portugal, it represents the largest lagoon of the Portuguese coast.",
"Five sampling stations were selected.",
"At each coastal system, 5 sampling stations were selected. Samples were stored in borosilicate glass bottles and maintained in a refrigerated room at 4 °C. Total dissolved Hg analysis in water samples was performed by cold vapour atomic fluorescence spectroscopy.",
"For total mercury quantification in plants and fauna, freeze-dried samples were analysed in triplicate by thermal decomposition atomic absorption spectrometry with gold amalgamation, using a LECO AMA-254."
] |
PMC10576158
|
Journal of Occupational Health
|
Inequality in workplace support for various types of precarious workers compared with permanent workers in Japan: Across‐sectionalstudy
|
13-10-2023
|
Abstract Objectives The purpose of this study was to examine, by sex, whether precarious workers in Japan receive less support in the workplace than permanent workers. Methods We conducted a cross‐sectional study using an online questionnaire in 2022. We stratified participants by sex and performed modified Poisson regression analysis. The outcomes were support from supervisors, co‐workers, occupational health professionals, and no one. Adjusted prevalence ratios (aPR) were calculated for contract workers, part‐time workers, and dispatched workers, using permanent workers as reference. Results This study had 21 047 participants. For men, 87.9% were permanent workers; for women, 50.7% were permanent workers and 37.3% were part‐time workers. For workplace support, 47.5% of men and 45.2% of women selected superiors; 41.8% of men and 50.5% of women selected colleagues; 16.8% of men and 6.2% of women selected occupational health professionals. Female contract workers were less likely to receive support from their supervisors (aPR 0.88) or co‐workers (aPR 0.89). Male part‐time workers were less likely to be supported by their co‐workers (aPR 0.86). Dispatched workers were less likely to be supported by their supervisors (men aPR 0.71, women aPR 0.84) and co‐workers (men aPR 0.73, women aPR 0.77). Part‐time and dispatched workers were less likely to receive support from occupational health professionals. Conclusions Precarious workers could get less workplace support than permanent workers. This may contribute to occupational health problems with precarious workers.
|
[
"The number of precarious workers is increasing in countries all over the world. This trend has been reported in the United States and European countries, , and also in Japan, where approximately 40% of workers are currently in precarious employment. ,",
"Previous studies in Japan have identified three types of precarious workers: contract workers, part‐time workers, and dispatched workers. , Contract workers are defined as workers working under fixed‐term contracts for professional employment or reemployment after retirement. Part‐time workers are defined as workers whose working hours are shorter than those of permanent workers, who work more than 40 hours per week. Dispatched workers have two contractual arrangements. First, they have an employment contract with one company",
"In many workplaces, as the number of precarious workers increases, workers with various types of employment status are required to work with permanent workers, who are directly employed and have no limitation on their contract period. There may also be obvious disparities in pay and treatment among workers with different types of employment contract. It is therefore likely that precarious workers will face a variety of difficulties in working with permanent workers in the same workplace. ,",
"Previous studies have shown that it is beneficial for workers' long‐term health and safety to receive support in the workplace from supervisors, co‐workers, and occupational physicians. Supervisory coaching and support from co‐workers were reported to increase work engagement, characterized by vigor, dedication, and absorption in work. Higher workplace social capital"
] |
PMC10905999
|
Nano Letters
|
Fluorescence
Enhancement in Topologically Optimized
Gallium Phosphide All-Dielectric Nanoantennas
|
14-02-2024
|
Nanoantennas capable of large fluorescence enhancement
with minimal
absorption are crucial for future optical technologies from single-photon
sources to biosensing. Efficient dielectric nanoantennas have been
designed, however, evaluating their performance at the individual
emitter level is challenging due to the complexity of combining high-resolution
nanofabrication, spectroscopy and nanoscale positioning of the emitter.
Here, we study the fluorescence enhancement in infinity-shaped gallium
phosphide (GaP) nanoantennas based on a topologically optimized design.
Using fluorescence correlation spectroscopy (FCS), we probe the nanoantennas
enhancement factor and observe an average of 63-fold fluorescence
brightness enhancement with a maximum of 93-fold for dye molecules
in nanogaps between 20 and 50 nm. The experimentally determined fluorescence
enhancement of the nanoantennas is confirmed by numerical simulations
of the local density of optical states (LDOS). Furthermore, we show
that beyond design optimization of dielectric nanoantennas, increased
performances can be achieved via tailoring of nanoantenna fabrication.
|
[
"Light-matter interaction can\nbe controlled by the use of optical nanoantennas which confine light\nat the nanoscale, resulting in high local fields.^(1) While plasmonic nanoantennas have long been used for their\nlarge Purcell enhancement factor, they suffer from strong absorption\nand nonradiative quenching losses. Instead, dielectric nanostructures\noffer moderate Purcell factor combined with close to no losses^(2 , 3) by exploiting both electric and magnetic resonances.^(4 , 5) Thus, dielectric nanocavities have recently been the focus of intense\nresearch in the field of nanophotonics^(6 , 7) with applications\nin lasing,^(8) integrated photonics,^(9) nonlinear optics,^(10 , 11) and biosensing.^(12 − 14) In particular, gallium phosphide is strategically crafted to enhance local electromagnetic\neffects through the precise tuning of constructive interference. Fluorescence\ncorrelation spectroscopy, and the\nerror is the standard deviation of three measurements. Due to proximity effects,\nthe gap is often bridged below 15 ± 2.5 nm and is difficult to\nconsistently replicate with a standard EBL setup.^(35)",
"Numerical simulations predict an intense LDOS enhancement\nfor the\ntopologically optimized GaP antenna, as shown in d–f. At resonance, the\nfield is confined in the nanoantenna due to constructive interferences,\nleading to strong LDOS enhancement in the nanogap region between the\ntwo bowtie tips. In addition, according to Maxwell’s equations, the normal\ncomponent of the electric displacement field remains continuous at\nthe boundaries between two dielectrics.^(16) Therefore, the size of the nanogap being much smaller than the wavelength,\na strong, frequency-independent electrostatic enhancement, can be\nachieved for emitters aligned along the gap direction, so the LDOS\nenhancement effectively covers a broad spectral range. LDOS enhancement factors\nexceeding 40-fold are predicted for nanogap sizes below 10 nm.",
"We use\nfluorescence correlation spectroscopy. 200 mM\nof methyl viologen is added to the buffer solution in order to quench\nthe fluorescence quantum yield of Alexa Fluor 647 from 33% to 8% and\nincrease the magnitude of the fluorescence enhancement factor.^(41 , 42) This experimental configuration also enables a straightforward comparison\nwith our earlier works using different dielectric and plasmonic antenna\ndesigns.^(14 , 41)",
"a,b displays\ntypical experimental results on a 30 nm gap antenna probed with two\ndifferent excitation polarizations parallel or perpendicular to the\nnanogap. We have checked that our microscope setup is polarization-insensitive\nso that the difference seen on the fluorescence intensity–time\ntraces\nand ACFs\ncan be directly related to the excitation of the nanogap mode which\nin turns leads to the fluorescence enhancement. We apply a similar\nanalysis of the FCS fit as in our earlier studies^(14 , 41) to extract for each antenna the average number of molecules N * in the effective volume defined by the nanogap together\nwith the average fluorescence brightness per emitter Q *. From the knowledge of N * and the fluorescent\ndye concentration, we can then compute the effective detection volume\nof the nanogap region. The fluorescence brightness enhancement is\nobtained by dividing the brightness per emitter in the nanogap Q * by the reference brightness per molecule Q _(0) found with the diffraction-limited confocal configuration.\nAll the fit results for the data in a,b are summarized in the SI Table S2. We find a linear dependence between the number\nof molecules measured in the nanogap N * and the Alexa\n647 concentration used in the experiments. This provides an important confirmation\nof the validity of our results and demonstrates a good reusability\nof our GaP nanoantennas.",
"Ideally one would like to directly record the fluorescence\nlifetime\nreduction and Purcell enhancement on each GaP nanoantenna. However,\nthis is not currently possible in our setup for two main reasons.\nFirst, because we rely on diffusing molecules to probe the nanogap,\nwe have to work at high micromolar concentrations and thus there is\na significant number. Our results show a clear\nincrease in brightness enhancement for smaller gap sizes consistent\nwith the enhancement stemming from the hotspot in the nanogaps. Enhancement\nfactors exceeding 60-fold are readily observed for nanogaps below\n30 nm. To support our findings, we simulated the brightness enhancement\nusing Lumerical for a dipole emitter with 8% quantum yield aligned\nin the center of the nanogap and an excitation intensity well below\nthe saturation as in the experiment. The solid line in d deduced from the numerical simulations\nwithout any free parameter shows a remarkable agreement with the experimental\ndata.",
"Along with the brightness enhancement per molecule, our\nFCS measurements\nsimultaneously monitor the evolution of the nanoantenna detection\nvolume with the gap size. Detection volumes below 300 zL are achieved with\nnanogaps below 30 nm. By integrating the Purcell factor P over the gap volume Hdxdy , , in the numerical simulations in d, we can estimate\na detection volume around 400 zL which comes close to the 215 ±\n50 zL measured for 30 nm gap antennas with FCS. The nanogap volume\nscales linearly with the gap size while the LDOS enhancement in the gap\ndecays inversely proportional to the gap size as seen from simulations\n( d). Since\nthe brightness enhancement is proportional to the square of LDOS enhancement\nfor low-quantum yield emitters, we expect the brightness enhancement\nto decay slightly sublinearly with the mode volume when accounting\nfor the background enhancement contribution from the antenna. This\nobserved correlation echoes findings from previous studies on gold\ndimer nanoantennas,^(40) reaffirming the credibility\nof our results.",
"The nanoantenna with a 15 nm gap does not follow\nthis trend. This\nmay be the consequence of fabrication imperfections such as reduced\nhotspot efficiency due to a nonsmooth nanogap, or high losses due\nto an increase in the imaginary part of the refractive index.^(21) Alternatively, individual molecules might be\nunable to access the center of the smaller nanogap due to reduced\nBrownian motion and/or blockage from nonfluorescent buffer molecules\nadsorbed onto the GaP. However, as the only antenna with such a small\ngap, we must be careful about generalizing the deteriorated performance.",
"The optical performance of these topologically optimized GaP nanoantennas\nsignificantly outperforms the values achieved using silicon nanodisk\ndimers^(14) or gold antenna-in-box^(41) with similar gap sizes. To ensure a fair comparison,\nwe focus on nanoantennas with similar 30 nm gap sizes probed under\nsimilar experimental conditions with the same fluorescent dye. a shows a bidimensional\nmap allowing to compare at a glance between the brightness enhancement\nand the detection volume achieved with different nanogap antennas.\nImportantly, our topologically optimized nanoantenna outperforms its\ncompetitors on both the brightness enhancement and the optical confinement,\ndemonstrating the superiority of its rational phase optimization design.^(29)",
"The excellent agreement found between the experimental\ndata and\nthe numerical simulations in d allows us to elaborate on the simulations to predict\nthe conditions leading to maximum brightness enhancement. The results\nsummarized in b, c predict enhancement factors exceeding 1000-fold for all-dielectric\nGaP nanoantennas, albeit for emitters with quantum yields below 2%\nand gap sizes below 10 nm. This positive insight holds promising implications\nfor the realm of all-dielectric nanophotonics, providing an added\nincentive to enhance nanofabrication technology and attain sub-10\nnm gaps. A narrowing of the nanogap is clearly one of the best ways\nto improve a nanoantenna’s performance, however it remains\nextremely challenging to consistently control on multiple structures.^(43 − 45)",
"In conclusion, we have successfully demonstrated the superior\noptical\nperformance of all-dielectric GaP nanoantennas designed according\nto a topologically optimized approach. Thanks to a precise tuning\nof interferences occurring in the near field of the emitter,^(29) the LDOS enhancement is maximized, leading to\nintense brightness enhancement of single quantum emitters. Nanoantennas\ncapable of large fluorescence enhancement with minimal absorption\nlosses are key elements to advance optical technologies from single-photon\nsources to biosensing. Therefore, this experimental demonstration\nof all-dielectric topologically optimized nanoantennas in the visible\nspectral range holds profound significance for the realms of future\nsensing and quantum technologies. Beyond the design optimization using\na rational approach, increased antenna performances can be achieved\nvia tailoring the nanofabrication to reach smaller gaps. Localizing\nthe emitter into the nanogap, controlling its orientation or using\nnew high refractive index materials like transition metal dichalcogenides\nare other future optimization directions.",
"Here, we base the nanoantenna design\non the one from ref, i.e., 50 nm thick, 550 nm long, and 10 nm gap size. For this, a\nGaP film is deposited on a glass substrate using sputter deposition\nat 350 °C. Next, the nanofabrication is carried out using EBL\nand subsequent RIE, as sketched in Figure S1 in the Supporting Information. Poly(methyl methacrylate) and the built-in function\nin Symphotime64 (Picoquant).",
"FCS\ncomputes the temporal correlation of the fluorescence signal ⟨ I ( t )· I ( t + τ)⟩/⟨ I ( t )⟩^(2), where τ is the delay (lag) time, and\n⟨ ⟩ indicates time averaging. Our analysis approach\nbuilds on the similar methodology used for our earlier studies on\nplasmonic^(39 − 41) and dielectric nanoantennas.^(14) The total fluorescence signal is considered to be composed to two\nparts: the enhanced fluorescence from molecules within the nanogap\nand the fluorescence from the molecules away from the nanogap yet\nstill present within diffraction-limited confocal volume. An essential\nfeature in FCS is that the molecules contribute to G in proportion to the square of their fluorescence brightness, so\nthat the fluorescence from molecules in the nanogap region experiencing\nthe maximum enhancement will have a major contribution in the FCS\ncorrelation. See SI for details on the\nfit analysis.",
"We performed electrodynamic simulations\nusing Lumerical, a commercial finite difference time domain (FDTD)\nsolver.^(47) For details on the numerical\nsimulations, see SI."
] |
PMC10242231
|
Scientific Reports
|
Effect of situation similarity on younger and older adults’ episodic simulation of helping behaviours
|
06-06-2023
|
Similar cognitive processes enable us to remember the past (i.e., episodic memory) and simulate future events (i.e., episodic simulation). In the current study, we demonstrate an important role for previous experience when younger and older adults simulate future behaviours. Participants read short descriptions of a person in need of help in scenarios that were more familiar to either younger or older adults (e.g., dealing with dating apps vs writing a cheque). Participants either imagined helping the person or thought about the style of the story (control task), and then rated their willingness to help, scene vividness, emotional concern, and subjective use of theory of mind. Hierarchical mixed effect modelling revealed that both episodic simulation and one’s previous experience increased willingness to help, in that participants were more willing to help if they imagined helping and the situation was more familiar to them. Further, in simulated scenarios the relationship between previous experience and willingness to help was mediated by scene vividness and perspective-taking in younger adults, but only by perspective-taking in older adults. Taken together, these findings suggest that situation similarity and episodic simulation increase willingness to help, possibly via different mechanisms in younger and older adults.
|
[
"As we engage with the world around us, we spend a considerable amount of time thinking about hypothetical scenarios. These would-be scenarios. The selected stories were then divided into lists of young-familiar and old-familiar stimuli that differed significantly between age groups in terms of similarity, t _(older-familiar). Raw participant ratings of all 40 scenarios as well as their demographics are available at. The best fit model also revealed a positive effect of similarity, such that higher levels of situation similarity were related to a greater willingness to help overall.",
"Scene vividness was calculated by averaging participants’ ratings of coherence and detail on each trial^(23). In terms of predicting scene vividness ratings, both participant id. There was also an effect of similarity, such that higher similarity ratings were related to increased scene vividness ratings. The similarity by age interaction was due to the relationship between similarity and scene vividness being attenuated in older adults. The best fit model also revealed a positive effect of similarity, such that higher levels of situation similarity ratings related to greater perspective-taking. However, the interaction between similarity and condition revealed that the relationship between similarity and perspective-taking was significantly attenuated in the imagined condition, B = − 0.06, SE = 0.03, t (1700.60) = 2.03, 95% CI [− 0.11, − 0.00].",
"In keeping with previous research, emotional concern was calculated by averaging participants’ ratings of emotions felt on each trial^(19 , 23). The best fit model also revealed a positive effect of similarity, such that higher levels of situation similarity ratings were related to greater emotional concern."
] |
PMC10814099
|
Entropy
|
Radio Frequency Fingerprint Identification for 5G Mobile Devices Using DCTF and Deep Learning
|
29-12-2023
|
The fifth-generation (5G) mobile cellular network is vulnerable to various security threats. Radio frequency fingerprint (RFF) identification is an emerging physical layer authentication technique which can be used to detect spoofing and distributed denial of service attacks. In this paper, the performance of RFF identification is studied for 5G mobile phones. The differential constellation trace figure (DCTF) is extracted from the physical random access channel (PRACH) preamble. When the database of all 64 PRACH preambles is available at the gNodeB (gNB), an index-based DCTF identification scheme is proposed, and the classification accuracy reaches 92.78% with a signal-to-noise ratio of 25 dB. Moreover, due to the randomness in the selection of preamble sequences in the random access procedure, when only a portion of the preamble sequences can be trained, a group-based DCTF identification scheme is proposed. The preamble sequences generated from the same root value are grouped together, and the untrained sequences can be identified based on the trained sequences within the same group. The classification accuracy of the group-based scheme is 89.59%. An experimental system has been set up using six 5G mobile phones of three models. The 5G gNB is implemented on the OpenAirInterface platform.
|
[
"The fifth generation address, subscriber identity module-based device identification is an emerging physical layer [ ], in-phase/quadrature was proposed in [ ], where raw I/Q samples could be transformed into a stable two-dimensional DCTF even with the presence of a CFO. The DCTF provides a visualization of the statistical distribution of the I/Q samples after differential operation, which reflects the influence of the RFF features [ ]. A convolutional neural network phones using a CNN. The DCTF of a long-term evolution preamble was identified. In this work, the DCTF is divided into transient parts and steady state parts, and then a multi-channel CNN is used with each channel treated a part of the DCTF.",
"In this paper, the DCTF features of a 5G mobile phone are studied based on the PRACH preamble. The PRACH preamble is the first signal transmitted by the user terminal for random access procedures. Device identification through PRACH signals can effectively prevent malicious devices from accessing the network and can also detect distributed denial of service platform and universal software radio peripheral, which consists of the primary synchronization signal and several repeated preamble sequences generated using the Zadoff–Chu, possesses desirable properties, such as a constant envelope and ideal periodic autocorrelation and cross-correlation characteristics [ , ]. Moreover, the Fourier transformation does not alter the characteristics of the ZC sequence. The ZC sequence can be generated using the following equation:\nwhere L Z C is the length of the ZC sequence. Referring to 3GPP technical specification, then we have ⌊ L Z C / N C S ⌋ = 4 , indicating that only 4 ZC sequences can be generated based on one root value. In this case, 16 root values are required to generate all 64 preamble sequences. The first root is determined by the base station parameter “prach_RootSequenceIndex”, and the other roots are the natural numbers following the first root. We note that these root values are logical roots, and the corresponding physical roots can be found in Table 6.3.3.1-4 in TS 38.211 [ ], denoted as μ in the formula. To launch the access requirement, the UE randomly selects one of the 64 preamble sequences. Examples of the different PRACH preambles for one cell are illustrated in , where the periodic structure can be observed. Moreover, the preamble sequences generated from the same root value exhibited high similarity on the waveform.",
"In this paper, we use the term “ group ” to refer to the preamble sequences generated from the same root value. In our experiment, each group consisted of four preamble sequences estimation and compensation, channel estimation and channel equalization, as shown in .",
"Time synchronization . The starting point of the received baseband signal y must be well located to extract the PRACH signal properly. In this paper, we determine the starting point through the repeatability of CP in the signal such that\n\nwhere L C P and L i n t e r represent the theoretical CP length and the signal length without CP, respectively, and L is the difference between the received signal length and the theoretical signal length.",
"CFO estimation and compensation . CFO is caused by the difference between oscillator frequencies at the transmitter and receiver. It is also estimated based on the CP of the PRACH signal such that\n\nwhere a n g l e ( · ) refers to the phase angle and R s is the sampling frequency of the received signal. The CFO-compensated signal is given by",
"PHO estimation and compensation . The phase offset can be estimated as follows:\n\nwhere x l ( k ) represents the corresponding standard PRACH signal. The PHO can be compensated by",
"Channel estimation and equalization . In our experiment, the UE worked in the 5G NR n78 frequency band, and hence the PRACH signals were affected by multipath channel fading. Least squares"
] |
PMC10633951
|
Journal of Intensive Care
|
Lacosamide dosing in patients receiving continuous renal replacement therapy
|
09-11-2023
|
Background Lacosamide is one of the anticonvulsants used in critically ill patients. This study aimed to suggest appropriate lacosamide dosing regimens in critically ill patients receiving continuous renal replacement therapy (CRRT) via Monte Carlo simulations. Methods Mathematical models were created using published demographic and pharmacokinetics in adult critically ill patients. CRRT modalities with different effluent rates were added into the models. Lacosamide regimens were evaluated on the probability of target attainment (PTA) using pharmacodynamic targets of trough concentrations and area under the curve within a range of 5–10 mg/L and 80.25–143 and 143–231 mg*h/L for the initial 72 h-therapy, respectively. Optimal regimens were defined from regimens that yielded the highest PTA. Each dosing regimen was tested in a group of different 10,000 virtual patients. Results Our results revealed the optimal lacosamide dosing regimen of 300–450 mg/day is recommended for adult patients receiving both CRRT modalities with 20–25 effluent rates. The dose of 600 mg/day was suggested in higher effluent rate of 35 mL/kg/h. Moreover, a patient with body weight > 100 kg was less likely to attain the targets. Conclusions Volume of distribution, total clearance, CRRT clearance and body weight were significantly contributed to lacosamide dosing. Clinical validation of the finding is strongly indicated.
|
[
"Lacosamide is one of the newer antiepileptic agents. It has been widely used in clinical practice for focal is one of the renal replacement therapies and has been chosen for the treatment of acute kidney injury in hemodynamically unstable critically ill patients [ ]. Nearly, 50% of critically ill patients with sepsis develop acute kidney injury and subsequently require CRRT for fluid and waste product removal [ ]. Most common modalities of CRRT used in ICU settings include continuous venovenous hemofiltration were prescribed, the lacosamide dose of 600–800 mg/day were recommended.",
"Furthermore, several lacosamide doses were suggested based on only pharmacokinetic calculation using equations for which most of them were not included the pharmacodynamic calculated from PK parameters to be at least 94 mg × h/L [ ]. Currently, there is no suggested lacosamide dosing regimens incorporating both PK and PD evaluation among critically ill patients undergoing CRRT.",
"Our study was aimed to predict the probability of target attainment) between pharmacokinetic parameters as patient’s body weight, non-renal clearance, and volume of distribution into the models to reflect virtual critically ill patients with CRRT in real clinical scenarios. The body weight > 40 kgs was set as a lower limit assuming that all virtual patients are adult.",
"We included both modalities of continuous venovenous hemofiltration and continuous venovenous hemodialysis in our models. Transmembrane drug clearance [ ] was calculated by multiplying effluent flow rate, we decided to apply sieving coefficient); hematocrit is 30%; Qreplacement is replacement fluid flow rate to generate lacosamide deposition of a group of 10,000 virtual patients for each dose to evaluate the probability of target attainment. Pharmacodynamic target of the minimum concentrations of 5–10 mg/L [ , ]and both area under the concentration–time profile curve targets gathered from published PK studies in a range of 80.25–143 and 143–231 mg × h/L [ , ] was used to predict the PTA of each lacosamide dosing regimen. The optimal doses were defined as occurring the highest number of virtual patients achieved the pharmacodynamic target with the lowest daily dose to maximize lacosamide efficacy and minimize toxicity. As mentioned earlier, the therapeutic goals for lacosamide in our study were the concentration of 5–10 mg/L or the AUCs of 80.25–143 and 143–231 mg*h/L. Therefore, the PTA is calculated and counted only the concentrations that are within the given therapeutic ranges. For a lower effluent rate of CRRT, the clearance is lower, this provided the higher concentrations of lacosamide that could be above the upper therapeutic goal ranges, resulting in lower % of PTA. Similarly, the higher effluent rate of CRRT, the clearance is higher, the resulted in the lower concentrations of lacosamide, for this reason, the concentrations fell within the therapeutic ranges, which explains the higher % of PTA.",
"All statistical analyses were performed using SPSS statistical software, version 20 in critically ill patients receiving CRRT are presented in Tables and .",
"From the three PD targets used in this study, the optimal lacosamide dosing regimens for critically ill patients undergoing CRRT with two commonly used modalities and different effluent rates of 20–25 mL/kg/h and higher effluent rate of 35 mL/kg/h for high volume CRRT were summarized in Table .",
"Regarding the effect of body weights on the attainment of PTA targets, it showed that the percentages of attaining the PK/PD targets unidirectionally increased when the body weight is higher in a range of 60–100 kg with p value < 0.05. However, the body weight above 100 kg gradually reduced the probability to attain the PK/PD targets in critically ill patients undergoing CRRT compared with those who weigh less than 100 kg. Interestingly, the PTA considerably declined to 70% in the body weight more than 140 kg.",
"This is the first simulation study applying MCS technique to evaluate dosing of lacosamide for seizure management in critically ill patients. We gathered all necessary PK parameters from previous published PK studies conducted in adult critically ill patients receiving CRRT, including body weight, Vd, non-renal clearance, and SC/SA to evaluate and establish dosing regimens [ – ]. We modeled our simulation using KDIGO recommended effluent rates of 20–25 mL/kg/h, and also applied the higher intensive effluent flow rate of 35 mL/kg/h into the model [ , ]. All necessary parameters were incorporated into pharmacokinetic models to predict lacosamide disposition in critically ill patients receiving CRRT for 72 h. The correlations between pharmacokinetic parameters were applied in the models to create population-specific virtual patients.",
"As mentioned, critically illness have an impact on drug dosing in these patients. Volume of distribution of hydrophilic agents tends to be increased due to fluid accumulation and hypoalbuminemia [ , ]. Larger Vd causes subtherapeutic drug concentrations and may lead to treatment failure. Giving higher doses can be suggested to achieve PK/PD targets. However, the Vd values gathered from the previous studies in our model was 0.61 ± 0.12 L/kg [ – ] which was similar to the healthy volunteers of 0.6 L/kg [ , ]. Therefore, lacosamide dosing regimens may not be greatly affected in critically ill patients due to the comparable Vd between critically ill and normal population.",
"We assumed that the critically ill patients with CRRT have a renal clearance of 0 mL/min in our model. Therefore, total lacosamide clearance was derived from two major factors, including CRRT and non-renal clearance. CRRT clearances samples from 21 patients receiving lacosamide for epilepsy management. The optimal correlation was described as the mean CSF-to-serum ratio of 0.897 ± 0.193 in the daily dose range of 50–600 mg. They suggested the serum concentration of lacosamide may be an important indicator of central nervous system concentration to estimate therapeutic efficacy [ ]. Therapeutic drug monitoring of lacosamide was proposed by some experts with the lacosamide concentration ranging from 5 to 10 mg/L [ , ]. Laveille and colleagues proposed that the trough concentration producing half the maximum seizure frequency reduction [ ]. Direct conversion from oral to IV lacosamide, or vice versa, is possible. However, pharmacokinetic changes in critically ill patients are challenging for drug dosing especially in absorption process [ ]. Changes in gastric pH, delayed gastric emptying, drug–food interactions, and/or altered efflux transporter activity play major contributions to unreliable absorption. Therefore, the IV route of administration is strongly recommended [ ].",
"Presently, the recommended dosing regimens of lacosamide for patients receiving CRRT are only based on two case reports [ , ]. Franquiz and colleagues [ ] presented a case study of the patient with status epilepticus and multiorgan failure undergoing CRRT with the effluent rate of 2.3 L/h who was prescribed 400 mg/day of lacosamide. Lacosamide was effectively removed via CRRT with the sieving coefficient was 0.8 ± 0.06. Vd and non-renal clearance were identified as 0.7 L/kg and 13.42 mL/min [ ]. The second case report was published by Wieruszewski and colleagues [ ]. The patient developed nonconvulsive status epilepticus and received CRRT with the same effluent rate and was prescribed lacosamide 400 mg intravenously daily. The Vd, non-renal clearance and sieving coefficient were reported as 0.69 L/kg, 25.20 mL/min and 0.69 for which they were similar compared to the first case report [ , ]. Notably, their dosing recommendations were done based on only PK parameters without utilizing pharmacodynamics outcomes, while in our study, we applied both PK and PD, and combined the MCS technique to amplify the outcomes of efficacy and toxicity. Consequently, our recommended maintenance doses of 100–150 mg every 8 h with the standard KDIGO-recommended flow rates were different to the regimen from both case reports of 200 mg twice daily.",
"Recently, Kalaria and colleagues [ ] conducted a pharmacokinetic study of lacosamide use in critically ill patient receiving CRRT to establish a lacosamide dosing protocols from PK parameters in 7 critically ill patients undergoing CVVH. The average of SC, Vd and non-renal clearance were 0.79, 0.58 L/kg and 15.50 mL/min, respectively [ ]. They proposed the protocol of lacosamide dosing regimens for patients receiving CRRT depending on effluent flow rates and lower or higher exposure dosing regimen [ ]. The dosing protocol was based on PK parameters and a PD target of 94 mg × hour/L. In our study, we included both PD targets we defined the optimal dosing regimens using available published PK studies, such as body weights, non-renal clearance, sieving coefficient and volume of distribution. All combined pharmacokinetic data were only from adult patients. Therefore, our recommendation should be applied for the patients who match our assumptions. (2) our dosing recommendations are suggested in anuric patients. If lacosamide is used in patients with higher renal clearance, the dose should be adjusted. (3) the pharmacokinetic changes in critically ill patients are dynamic and depends on individual patient conditions, we recommend closely monitoring of lacosamide concentrations. (4) To our knowledge, there is no standard guideline for lacosamide therapeutic drug monitoring and desired target lacosamide concentrations. However, the trough concentration producing half the maximum seizure frequency reduction was 4.6 mg/L as presented by Laveille and colleagues [ ]. In addition, Svendsen and colleagues [ ] conducted a pharmacokinetic study using therapeutic drug monitoring data of lacosamide from The Norwegian Prescription Database. They revealed that the average lacosamide concentration in patients with modest and good efficacy should be at least 5.71 mg/L, while non-responders had an average lacosamide concentration as 4.65 mg/L [ ]. This concentration is aligned with our lacosamide target range of 5–10 mg/L. Hence, monitoring of clinical conditions would be required to assure lacosamide efficacy and toxicity. Clinical validation of this finding is needed.",
"In conclusion, we suggested optimal lacosamide dosing in critically ill patients undergoing CRRT depending on different modalities and the pharmacodynamic targets in Table . The effluent rate as 35 mL/kg/h required higher lacosamide doses. Three main factors as total clearance, volume of distribution, and body weight are responsible for lacosamide dosing modification to achieve the pharmacokinetic and pharmacodynamic targets. Pharmacokinetic changes in critically ill patients owing to pathophysiologic variability need to be aware for lacosamide prescription to avoid treatment failure or drug toxicity. Moreover, larger doses than our recommendations with closely drug monitoring would be considered in the patients with body weight more than 100 kg."
] |
PMC10470377
|
Journal of Public Health (Oxford, England)
|
Does antenatal cholecalciferol supplementation affect the mode or timing of delivery? Post hoc analyses of the MAVIDOS randomized controlled trial
|
28-12-2022
|
Abstract Background Observational studies relating maternal 25-hydroxyvitamin D status to timing and mode of delivery have reported inconsistent results. We assessed the effect of antenatal cholecalciferol supplementation on the incidence of preterm birth, delivery mode and post-partum haemorrhage (PPH). Methods MAVIDOS was a randomized, double-blind, placebo-controlled trial of 1000 IU/day cholecalciferol from 14 weeks’ gestation until delivery. Gestational age, mode of delivery [categorized as spontaneous vaginal delivery (SVD), instrumental (including forceps and vacuum extraction) or Caesarean section] and PPH (>500 ml estimated blood loss) were determined from medical records. Results A total of 965 women participated in the study until delivery. Gestation at birth and incidence of preterm birth (cholecalciferol 5.7%, placebo 4.5%, P = 0.43) were similar between the two treatment groups. SVD (versus instrumental or Caesarean delivery) was more likely in women randomized to cholecalciferol [Relative Risk (RR) 1.13, 95% confidence interval (CI) 1.02,1.25] due to lower instrumental (RR 0.68, 95%CI 0.51,0.91) but similar risk of Caesarean delivery (RR 0.94, 95%CI 0.74,1.19). PPH was less common in women randomized to cholecalciferol [32.1% compared with placebo (38.1%, P = 0.054) overall], but similar when stratified by delivery mode. Conclusions Antenatal cholecalciferol supplementation did not alter timing of birth or prevalence of preterm birth but demonstrated a possible effect on the likelihood of SVD.
|
[
"Vitamin D deficiency in pregnancy is common. In a study of predominately White women in the south of the UK, 31% had a serum 25(OH)D < 50 nmol/l and 18% < 25 nmol/l in late pregnancy. In a more ethnically diverse population in London, 36% women had 25(OH)D < 25 nmol/l in early pregnancy. Reports of similarly high prevalence of vitamin D deficiency in pregnancy have also been reported in other countries across Europe, although in Nordic countries where ultraviolet B",
"Vitamin D deficiency has been associated with obstetric outcomes in numerous observational studies, including timing and mode of delivery and incidence of post-partum haemorrhage but the study findings are inconsistent. ^(,) For example, maternal vitamin D deficiency has been associated with an increased risk, no difference in risk and reduced risk of preterm birth. ^(,) Furthermore, a recent meta-analysis of observational studies suggested that the timing of vitamin D deficiency may be important to the risk of preterm birth, with only deficiency in the second, and not the third, trimester being of potential importance to this outcome. Several recent observational studies have also shown lower maternal 25(OH)D levels in those requiring Caesarean section compared with vaginal delivery, but observational studies can be confounded by factors that affect both maternal 25(OH)D and risk of needing an operative delivery, such as maternal obesity, gestational weight gain and ethnicity. Christoph et al. found vitamin D deficiency reduced the incidence of PPH in an observational study. In contrast, women in China with gestational diabetes"
] |
PMC10581746
|
Journal of Law and the Biosciences
|
Implementing the human right to science in the regulatory governance of artificial intelligence in healthcare
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14-10-2023
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Abstract Artificial intelligence (AI) enables a medical device to optimize its performance through machine learning (ML), including the ability to learn from past experiences. In healthcare, ML is currently applied within controlled settings in devices to diagnose conditions like diabetic retinopathy without clinician input, for instance. In order to allow AI-based medical devices (AIMDs) to adapt actively to its data environment through ML, the current risk-based regulatory approaches are inadequate in facilitating this technological progression. Recent and innovative regulatory changes introduced to regulate AIMDs as a software, or ‘software as a medical device’ (SaMD), and the adoption of a total device/product-specific lifecycle approach (rather than one that is point-in-time) reflect a shift away from the strictly risk-based approach to one that is more collaborative and participatory in nature, and anticipatory in character. These features are better explained by a rights-based approach and consistent with the human right to science (HRS). With reference to the recent explication of the normative content of HRS by the Committee on Economic, Social and Cultural Rights of the United Nations, this paper explains why a rights-based approach that is centred on HRS could be a more effective response to the regulatory challenges posed by AIMDs. The paper also considers how such a rights-based approach could be implemented in the form of a regulatory network that draws on a ‘common fund of knowledges’ to formulate anticipatory responses to adaptive AIMDs. In essence, the HRS provides both the mandate and the obligation for states to ensure that regulatory governance of high connectivity AIMDs become increasingly collaborative and participatory in approach and pluralistic in substance.
|
[
"In April 2018, the Food and Drug Administration diagnostic system that does not require clinician interpretation to detect greater than a mild level of diabetic retinopathy in adults diagnosed with diabetes. In essence, this fully autonomous prescription software device incorporates an adaptive algorithm to evaluate images of the eye taken with a retinal camera that are uploaded to a cloud server. A screening decision is made by the device as to whether the individual concerned is detected with ‘more than mild diabetic retinopathy’. If so, this individual is referred to an eye care professional for medical attention. From a regulatory standpoint, software intended for use by healthcare professionals and patients in the USA must comply with basic regulatory requirements, including medical device listing and labeling, premarket notification for the remote diagnosis of diabetic retinopathy developed by Shenzhen Guiji and Shanghai Yingtong have received regulatory approval from the National Medical Products Administration in China.",
"Like conventional medical devices, the regulation of AIMDs is risk-based, context-specific, and case-sensitive. Unlike the former however, the risk profiles of technically sophisticated AIMDs can significantly deviate from the versions that secured regulatory approval since some of these devices have the capability of adapting to new conditions through ‘unsupervised’ learning, and thereby present concerns over patient safety and effectiveness. Recognizing that the conventional point-in-time regulatory approach is not well suited for AIMDs that undergo fast-paced cycles of iterative modifications, regulators from major AIMD jurisdictions have, working singly and collaboratively through the International Medical Device Regulators Forum"
] |
PMC10532939
|
Life
|
Comparison of the Ocular Surface Disease Index and the Symptom Assessment in Dry Eye Questionnaires for Dry Eye Symptom Assessment
|
21-09-2023
|
Background: Patient-reported dry eye symptoms (DESs), assessed using the Ocular Surface Disease Index (OSDI) and the Symptom Assessment iN Dry Eye (SANDE) questionnaires, were compared in a large sample of patients. Methods: The correlation (Spearman coefficient) and agreement (Bland-Altman analysis) between the OSDI and SANDE questionnaire scores (with and without score normalization) were assessed in 1033 patients and classified according to the OSDI score as non-DES and DES in a cross-sectional analysis. Results: The normalized and non-normalized SANDE results were higher than the OSDI results in all samples (2.83 ± 12.40 ( p = 0.063) and 2.85 ± 15.95 ( p = 0.016), respectively) and in non-DES ( p > 0.063) and DES ( p < 0.001) with both OSDI cutoff values. Weak correlations were found (Spearman coefficient < 0.53; p < 0.001) in all cases except DES (0.12, p = 0.126). Weak agreement was found with a Bland-Altman analysis of the normalized and non-normalized scores of both questionnaires (mean difference from −7.67 ± 29.17 (DES patients) to −1.33 ± 8.99 (non-DES patients) without score normalization, and from −9.21 ± 26.37 (DES patients) to −0.85 ± 4.01 (non-DES) with data normalization), with a statistically significant linear relationship (R 2 > 0.32, p < 0.001). The SANDE questionnaire did not yield the same patient classification as OSDI. The same operative curves (ROC) of the SANDE normalized and non-normalized scores were used to differentiate among patients with DES using OSDI < 12 (0.836 ± 0.015) or OSDI < 22 (0.880 ± 0.015) cutoff values. Conclusions: Normalized and non-normalized data collected from the SANDE questionnaire showed relevant differences from those of the OSDI, which suggests that the results of the SANDE visual analog scale-based questionnaire provide different patient classifications than the OSDI score.
|
[
"Dry eye disease, topical eye medication use, systemic disease, and living region and Symptom Assessment in Dry Eye [ , ]. The OSDI questionnaire was developed by Allergan Inc., mild symptoms, [ , , , , ], and is commonly used in epidemiological studies [ , ]. Although the development process of the OSDI questionnaire was not reported, [ ], it is one the most widely used questionnaires to discriminate between patients, with adequate psychometric properties and reliability. The measurement of symptom frequency ranges from “rarely” to “all of the time”, and the measurement of symptom severity ranges from “very mild” to “very severe” [ , ]. The SANDE questionnaire has a weak correlation with clinical tests has been observed in patients with mild to severe DED [ ].",
"Some reports have compared OSDI and SANDE results in dry eye patients [ , ] and proposed the use of the SANDE questionnaire to allow clinicians to quickly and reliably measure DES [ ] to conduct the disease diagnosis and to assess the effect of different treatments [ , ]. However, there is a lack of studies comparing OSDI and SANDE results in a large sample of patients with and without DES.",
"This study aimed to compare assessments of DES using the OSDI and SANDE questionnaires in a large sample of patients with and without DES while also exploring the potential of the SANDE questionnaire to differentiate between patients with and without DES.",
"The OSDI and SANDE scores from patients who attended a routine eye exam in 12 primary eye care centers of the EMO research group in Spain in a diverse range of geographical locations were compared and analyzed. All patients were evaluated in a single visit, and both questionnaires were conducted via interviews by the investigators; the same application protocol was followed in all centers. A comprehensive eye examination was performed, including visual acuity measurement, active anterior eye inflammation, vision-related daily function and DES was used. Normal distribution of the variables was assessed with the Kolmogorov-Smirnov test, because the two questionnaires do not measure symptoms in the same way. Therefore, a statistical comparison correlation coefficient was calculated. Exact 95% confidence intervals were conducted for all samples and in non-DES and DES patients classified with OSDI scores. Additionally, differences between non-DES and DES classified with OSDI cutoff values of 12 or 22 were assessed with the Mann-Whitney U test. Finally, to explore the use of the SANDE questionnaire to classify DES patients, a receiver operating characteristic for all samples and DES patients.",
"Bland-Altman analysis for clinical agreement between non-normalized OSDI and SANDE scores revealed a clinical difference, where agreement ranged from −9.21.",
"The SANDE score showed a significantly different value. However, a pairwise comparison showed statistically non-significant differences between SANDE scores in moderate and severe DES patients.",
"ROC analysis was used to assess the SANDE scores to differentiate between patients with and without DES; it showed a similar area under the curve with both OSDI cutoff values, both questionnaires showed significantly different values with and without score normalization in patients with DES. Additionally, a weak correlation was found between both questionnaire results. Previous reports found correlation coefficients of 0.64 [ ] and 0.67 [ ] between both questionnaires in dry eye patients, i.e., slightly higher than our results.",
"The differences between both questionnaires suggest that normalized and non-normalized SANDE scores are slightly higher than OSDI results in all of the compared samples and subgroups. Chen et al. found [ ] significantly higher SANDE scores in a sample of young women, mostly without dry eyes, and Kheirkhah et al. [ ] also found higher SANDE compared with previous reports of 16 units [ ] was found, albeit with similar differences between OSDI and SANDE scores with and without score normalization. This suggests that score normalization does not provide a great advantage in data comparisons. In contrast to previous reports, a linear tendency between the difference and mean value of the OSDI and SANDE questionnaires was found; as such, we do not recommend their interchangeable use.",
"Although both questionnaires showed small differences and the SANDE score was significantly different between patients with and without DES with the SANDE questionnaire compared to OSDI when classifying DES patients. Wang et al. [ ]. found a similar area under the curve who attended a routine eye exam in an eye care center were asked to complete the OSDI and SANDE questionnaires; it was therefore to be expected that most of them had not previously completed this type of questionnaire. The effect of patients or subjects who answer questionnaires could be related to the psychometric properties of the OSDI and SANDE questionnaires. A recent report [ ] reviewed the properties of questionnaires designed to explore DES according to the COnsensus-based Standards for the selection of health Measurement Instruments. However, both questionnaires than the OSDI score. Recommendations in future reports to improve the psychometric validation of DES questionnaires and to standardize the procedure to describe patient symptomatology for dry eyes could help provide useful research results and improve the management of DES patients."
] |
PMC10141467
|
Pharmaceuticals
|
A Treat-and-Extend Regimen of Intravitreal Brolucizumab for Exudative Age-Related Macular Degeneration Refractory to Aflibercept: A 12-Month Result
|
07-04-2023
|
We aimed to investigate whether a treat-and-extend regimen of intravitreal brolucizumab (6.0 mg/0.05 mL) is effective for eyes with exudative age-related macular degeneration (AMD) refractory to aflibercept for 12 months. Sixty eyes from 56 patients receiving brolucizumab for exudative AMD refractory to aflibercept were included. Patients received a mean of 30.1 aflibercept administrations for a mean 67.9-month follow-up. All patients exhibited exudation on optical coherence tomography (OCT) despite regular 4–8 weeks of aflibercept administration. Visit 1 was scheduled at the same interval from the last aflibercept injection to the baseline. The treatment interval was extended or shortened by 1–2 weeks depending on the presence or absence of exudation on OCT. After switching to brolucizumab, the follow-up interval significantly extended at 12 months (before switching: 7.6 ± 3.8 weeks vs. at 12 months: 12.1 ± 6.2 weeks, p = 1.3 × 10 −7 ). Forty-three percent of the eyes achieved a dry macula at 12 months after switching. However, the best-corrected visual acuity did not improve at any visit. Morphologically, the central retinal thickness and subfoveal choroidal thickness significantly decreased from baseline at 12 months ( p = 3.6 × 10 −3 and 1.0 × 10 −3 , respectively). Switching to brolucizumab can be considered to extend the treatment interval in eyes with exudative AMD refractory to aflibercept.
|
[
"Age-related macular degeneration, and geographic atrophy, also known by the recent term “complete retinal pigment epithelium [ ]. Among these cytokines, VEGF is a key factor in the development and progression of neovascular AMD [ , , ]. The advent of VEGF inhibitors has revolutionized the treatment of exudative AMD, and intravitreal injection of VEGF inhibitors is currently an established treatment for exudative AMD [ , , ]. Pegaptanib, the first commercially available VEGF inhibitor, was designed to bind and block the extracellular VEGF, VEGF_(165) [ ]. However, in the VISION study using 1186 participants with neovascular AMD, all three dosing in 2006 [ ]. In large-scale randomized clinical trials. Therefore, aflibercept aflibercept at an 8-week interval [ ]. However, as reported in this clinical trial, several eyes show residual exudation including subretinal fluid, and doses of brolucizumab taken every 6 weeks brolucizumab demonstrated similar visual gains to and better morphological improvement than the intravitreal administration of, retinal vasculitis, and retinal vascular occlusion after intravitreal administration of brolucizumab, there is mounting evidence regarding incidence, treatment, and prophylaxis of intraocular inflammation [ , , , , , , , , , ]. Though these data from animal experiments and clinical trials suggest the possible advantage of brolucizumab over other anti-VEGF agents, few data reveal the efficacy of switching to brolucizumab from other anti-VEGF agents for neovascular AMD with persistent exudation, including SRF and IRF, despite multiple intravitreal injections.",
"In the present study, we investigated one-year efficacy of switching to intravitreal administration of 6.0 mg brolucizumab for exudative age-related macular degeneration refractory to aflibercept using a treat-and-extend regimen.",
"Sixty eyes from 56 patients were included in this study. The mean age was 76.2 ± 7.4, and 51 patients were male and none of eyes with neovascular AMD had a history receiving PDT.",
"shows the mean treatment interval before and after switching to brolucizumab. After switching to brolucizumab, the mean treatment interval at 12 months was significantly longer than that before switching before and after switching. Mean logarithm of the minimal angle resolution. The mean central retinal thickness. The mean subfoveal choroidal thickness. and show the mean change of CRT/SCT on SS-OCT according to the length of the extended treatment intervals. Mean CRT significantly decreased from baseline to 12 months in the patients with extended intervals of ≥4 weeks. Mean SCT significantly decreased in the patients with extended intervals of 0 weeks and ≥4 weeks.",
"shows the number of patients showing exudation on SS-OCT before and after switching. At 12 months, 26 out of 60 eyes. Among 12 eyes, 2 eyes showed mild anterior chamber cells and keratic precipitates, and 7 eyes showed mild posterior IOI including vitreous opacity and anterior vitreous cells. Topical steroids were administered to these patients with mild anterior or posterior IOI, and the IOIs were immediately resolved. Intravitreal brolucizumab injection was discontinued, and the patient was switched to aflibercept again from the next visit. Floaters were seen in 3 eyes of study eyes. Similarly, the results in this study showed the significant extension of treatment intervals from 7.6 ± 3.8 weeks to 12.1 ± 6.2 weeks at 12 months, and IOIs occurred in 15.0% and aflibercept. Several studies have reported the efficacy of brolucizumab for refractory exudative AMD in short-term results in the real-world [ , , , , , , , , ]. In the present study, 45.7%. Therefore, assuming a long-standing visual prognosis in eyes with exudative AMD, complete resolution of SRF is preferable when treated with anti-VEGF agents. Further studies are needed to confirm these questions.",
"About SCT after treatment for exudative age-related macular degeneration, three monthly ranibizumab administrations induced a decrease in SCT by 6%, three monthly aflibercept administrations induced a decrease in SCT by 12–16% and photodynamic therapy and was conducted in accordance with the tenets of the Declaration of Helsinki. Written informed consent for treatment was obtained from all patients.",
"The inclusion criteria were as follows: was administered in all eyes. The first visit (visit 1) was scheduled at the same interval between the last aflibercept injection and the baseline. The second visit (visit 2) was extended by 1–2 weeks based on one (Y.S) of the doctors’ discretion if there was no exudation including subretinal fluid and intraretinal fluid on SS-OCT during the first visit. If exudation was observed on SS-OCT, the interval between visits 1 and 2 was retained. Similarly, the next visits were extended by 1–2 weeks if there were no exudations including subretinal and intraretinal fluid on SS-OCT during the previous visits. If exudation was observed on SS-OCT, the next interval was shortened by 1–2 weeks, as the interval was extended at the previous visit. None of the intervals were designed to be shortened to less than the first interval. A “12-month visit” is defined as a 52-week visit or the visit first exceeding 52 weeks. All of the patients were instructed to make an immediate call in case of any abnormal symptoms after injection. Patients who reported symptoms of floater or blurred vision after the intravitreal injection were immediately seen in our hospital.",
"At every visit, all patients underwent BCVA measurement using a Landolt chart, intraocular pressure measurement, slit-lamp biomicroscopy with or without 78D lens, color fundus photography, and SS-OCT using DR-1/Atlantis. Scan signal strength equal to or more than 6 was applied to all.",
"Statistical analyses were performed using the Statflex 7 software (Artec Co., Ltd., Osaka, Japan). BCVA measured on a Landolt chart was converted into logMAR for statistical analyses. The paired t -test was used to determine the significance of the difference between the values before and after treatment. Statistical significance was set at p -value less than 0.05."
] |
PMC10350255
|
BMC Women's Health
|
The global prevalence of sexual dysfunction in obese and overweight women: a systematic review and meta-analysis
|
15-07-2023
|
Background Obesity is a pressing public health risk issue worldwide. Women, in particular, face a higher risk of obesity. Recent research has highlighted the association between obesity and female sexual dysfunction. Therefore, the objective of this study is to investigate the global prevalence of sexual dysfunction in obese and overweight women through a systematic review and meta-analysis. Methods In this study, a systematic search was conducted across electronic databases, including PubMed, Scopus, Web of Science, Embase, ScienceDirect, and Google Scholar. The search aimed to identify studies published between December 2000 and August 2022 that reported metabolic syndrome's impact on female sexual dysfunction. Results The review included nine studies with a sample size of 1508 obese women. The I 2 heterogeneity index indicated high heterogeneity (I 2 : 97.5). As a result, the random effects method was used to analyze the data. Based on this meta-analysis, the prevalence of sexual dysfunction in women with obesity was reported as 49.7% (95%CI: 35.8–63.5). Furthermore, the review comprised five studies involving 1411 overweight women. The I 2 heterogeneity test demonstrated high heterogeneity (I 2 : 96.6). Consequently, the random effects model was used to analyze the results. According to the meta-analysis, the prevalence of sexual dysfunction in overweight women was 26.9% (95% CI: 13.5–46.5). Conclusion Based on the results of this study, it has been reported that being overweight and particularly obese is an important factor affecting women's sexual dysfunction. Therefore, health policymakers must acknowledge the significance of this issue in order to raise awareness in society about its detrimental effect on the female population.
|
[
"Obesity and overweight refer to the excessive and abnormal accumulation of body fat, which leads to adverse health effects [ ]. This condition represents a significant public health concern worldwide [ ] and has detrimental health effects on individual well-being and society’s financial burden [ ].",
"The increasing prevalence of high body mass index and behavioural characteristics compared to men [ ]. Additionally, certain treatments for these conditions, such as the use of certain anti-hypertensive drugs or antidepressants, can have negative effects on sexual performance [ ].",
"Sexual dysfunction refers to any condition that hinders a person's ability to derive satisfaction from sexual activity [ ]. In particular, female sexual dysfunction. Initially, duplicate studies found across different databases were excluded. To mitigate bias, two researchers independently conducted the review process and data extraction. In total, 505 articles were screened through database searches, and two potentially relevant articles were identified through manual searches. The selected articles were then imported into the information management software EndNote for further analysis. Following the PRISMA steps, the articles underwent thorough evaluation, resulting in the inclusion of 10 studies for the final review. The findings and relevant information from these 10 studies are presented in Table and Fig. .",
"To validate and assess the quality of articles, a STROBE checklist, designed for observational studies, was utilized. This checklist comprises 32 items. Articles that achieved a score of 16 or higher were categorized as having good or moderate methodological quality, whereas those scoring below 16 were deemed to exhibit poor methodological quality. As a result, articles characterized by poor methodological quality were excluded from the study. The extracted results of the selected studies were entered into Comprehensive Meta-Analysis, version 2 questionnaire to assess the presence of sexual dysfunction. One study employed a self-administered version of the FSFI questionnaire [ ], while another study used face-to-face interviews [ ].",
"Regarding the studies presented in Table , the highest reported prevalence of sexual dysfunction among obese women was 86% in a study conducted by Yaylali et al. in 2010 in Turkey [ ]. In overweight women, the highest prevalence was reported as 57.1% in a study conducted by Silva et al. in 2019 in Brazil [ ]. Conversely, the lowest prevalence of sexual dysfunction among obese women was reported as 12.8% in a study conducted by Erenel et al. in 2013 in Turkey [ ]. For overweight women, the lowest prevalence was reported as 10.0% in a survey conducted by Karadag et al. in 2014 in Turkey [ ].",
"In the review of 9 studies with a total sample size of 1508 obese women, a high level of heterogeneity was observed according to the I^(2) heterogeneity test. Additionally, a check for publication bias in the included studies was conducted using the Egger, which indicated the absence of publication bias in the studies.",
"In the review of 5 studies involving a total sample size of 1411 overweight women, the I^(2) heterogeneity test revealed a high-level heterogeneity. Furthermore, an assessment of publication bias in the included studies was conducted using the Egger test, which indicated the absence of publication bias in the studies.",
"This study represents the first systematic review and meta-analysis focusing on the global prevalence of sexual dysfunction in obese and overweight women. To the best of our knowledge, no previous systematic review study has specifically examined this topic globally. The study employed rigorous secondary analysis methods, selecting and analyzing data from 10 high-quality primary studies.",
"Given that the prevalence of obesity is higher than that of underweight individuals, except in certain regions of sub-Saharan Africa and Asia, the issue of obesity has emerged as a significant social threat in contemporary times [ ]. Female sexual dysfunction scores of ≥ 23. Their findings revealed that age and BMI were the only factors associated with FSD [ ]. Similarly, Kirchengast et al. scores of 52 women with abnormal names? to those of 66 women in the control group. The study found a significant association between FSFI scores and BMI but not the waist-to-age ratio [ ]. Similarly, another study found a negative correlation between BMI and female sexual dysfunction. The researcher suggested that individuals with higher BMI might face difficulties with body positioning during sexual activity, emphasizing the importance of early interventions to reduce BMI in healthcare settings [ ].",
"Contrary to our study findings, one study reported no significant relationship between BMI and the improvement of FSFI scores following non-surgical weight loss interventions for obese women. In contrast, non-surgical weight loss in obese men demonstrated more pronounced improvements in sexual dysfunction [ ]. Another study found no statistically significant difference in FSFI scores between obese and control groups. The prevalence of female sexual dysfunction was reported to be 50% and 41% in the obese and control groups, respectively [ ]. Elofsson et al. also conducted a study involving a Swedish population that included 840 young women (18% overweight, 6% obese) and 426 older women (32% overweight and 11% obese). Their findings indicated no difference in sexual life satisfaction between obese and normal-weight women, contradicting the results of our study [ ].",
"This meta-analysis had certain limitations that should be acknowledged. Firstly, the number of studies available from different countries was unequal, and the participants’ age distributions varied, which could contribute to the differences in the prevalence of obesity and overweight across countries. Additionally, the inclusion of studies was limited to those published in English, potentially leading to the oversight of studies published in other languages. It is important to consider these limitations when interpreting the findings of this meta-analysis.",
"The findings of this study reveal the significant prevalence of sexual dysfunction in overweight and obese women. It is crucial to recognize that sexual dysfunction adversely affects the quality of marital relationships and overall life satisfaction for women. Policymakers can use the outcomes of this meta-analysis to emphasize the importance of screening for obesity and overweight among women, as well as raising awareness within society about the detrimental effects of these conditions, including their impact on sexual performance. The results of this research can serve as a valuable research priority and guide interventions aimed at addressing the issue effectively."
] |
PMC10668436
|
BMC Public Health
|
A scoping review of the self-reported compassion measurement tools
|
24-11-2023
|
Background Compassion is closely linked to psychological well-being, and several assessment tools have been developed and studied to assess the level of compassion in different populations and for more precise measurement. There is currently a scarcity of comprehensive knowledge about compassion-related assessment tools, and our research provides an overview of these tools. Aims To identify scales used to measure compassion from different flows, and to assess their measurement properties and quality. Methods Focusing on compassion assessment tools, the authors conducted a thorough search of 10 Chinese and English databases from their establishment until August 14, 2022. Data extracted included the author, year, country, objectives, target population, as well as the primary evaluation content. Using the COSMIN checklist, the methodological quality and measurement properties of the included studies were appraised. This scoping review was registered with the Open Science Framework and followed the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) checklist. Results There were 15,965 papers searched, and 36 compassion-related measurement tools were identified in this study. None of the 36 studies provided possessed all nine psychometric properties, as outlined by the COSMIN criteria. On the basis of a systematic evaluation of quality, measurement qualities were ranked. The results for internal consistency and content validity were relatively favorable, whereas the results for structural validity were variable and the results for the remaining attributes were either uncertain or negative. A Venn diagram was used to illustrate the overlapping groups of compassion measurement tools based on the three-way flow of compassion. An overview of the reference instrument and theoretical basis for the included studies was provided, and half of them did not contain any theoretical or scale-based evidence. Conclusion In this study, 36 compassion-related measuring instruments were identified, and the methodological quality and measurement properties of the included studies were acceptable. The included measurements were consistent with flows of compassion. A further focus of further research should be on developing theories in the compassion domain and developing instruments for measuring compassion that are multidimensional, multi-populations, and culturally relevant. Supplementary Information The online version contains supplementary material available at 10.1186/s12889-023-17178-2.
|
[
"In recent decades, positive psychology has received increasing interest from researchers. The term “positive psychology” is generally defined as the use of psychological theory, research, and intervention techniques to investigate the positive, adaptive, creative, and emotionally fulfilling aspects of human behavior [ ]. Positive psychology focuses on human strengths and good emotions, and compassion is acknowledged as a viable and useful study topic in this field. Compassion is a key part of human emotional interactions and it contributes to the mental health of individuals as well as harmonious community coexistence. The intellectual development of compassion has a lengthy history. Compassion emerged from a key component of Buddhist philosophy and Christian traditions [ ].",
"Commonly, compassion is described as the awareness and sensitivity to the experience of pain, as well as the desire to alleviate that suffering [ ]. Based on evolutionary theory, Paul Gilbert [ ] stated that compassion is a profound awareness of another’s suffering paired with the desire to alleviate it. Compassion, as defined by Gu, et al. [ ] and Strauss, et al. [ ], consists of five elements: the emotional perception and recognition of the suffering of others and the desire to alleviate it, understanding the universality of suffering, feeling moved by the person suffering and emotionally connecting with their distress, and tolerating uncomfortable feelings so that we remain open and accepting of the person suffering.",
"Existing research indicates that compassion may be measured in three ways: compassion toward others, compassion from others, and self-compassion [ , , ]. Compassion for others and self-compassion have received greater attention and investigation, but compassion from others is a young and rising field of study.",
"Compassion for others needs a desire to be helpful, the ability to recognize and respond to distress signals [ ] were developed that measured self-compassion and compassion for others. Research is needed to validate whether existing compassion-related scales are consistent with the flow of compassion, regardless of the general applicability of these scales across populations.",
"There is a growing interest in developing patient-reported outcome measures checklist [ ]. The protocol was registered on the Open Science Framework COSMIN checklist, methodological quality and measurement properties of the included studies were assessed [ ]. The COSMIN checklist includes 9 boxes for classical test theory, uncertain of the scales came from the United States, 6 from the United Kingdom, and the rest came from Canada, South Korea, Spain, New Zealand, China, and other countries. 13 scales were initially developed and administered to undergraduate students, 6 scales to students and other populations, 4 scales to children and adolescents, 5 scales to patients in clinical practice, 4 scales to healthcare professionals, and 4 scales to others. Table provides an overview of the studies.",
"Table summarizes the psychometric features of the 36 studies. None of the 36 studies included all nine psychometric features in this review. In terms of reliability, content validity, structural validity, and responsiveness, these measures appear to be valid. The majority of measurements, however, did not report assumptions, measurement error, and cross-cultural validity, which implied that methodological weaknesses existed in these studies, it may affect the reliability and validity of the scales. The applicability of scales to different cultures needs to be strengthened, and more cross-cultural validation of these measures would be a significant advancement. In the majority of cases, these measures retained adequate psychometric properties. In practical terms, it is crucial to seek out and consider various perspectives, so as to ensure the scale is more comprehensive and applicable across different contexts. This approach not only compensates for any shortcomings in the scale’s pre-design but also contributes to its overall effectiveness and validity.",
"Population and age have led to a diversification of tools for measuring compassion. Children and college students have been the majority of these studies’ target populations to date. Researchers sought to construct universal compassion assessment scales or a single orientation of compassion. The scale was initially designed and validated among college students in order to test one’s compassion level. It was then primarily used to examine self-compassion among teenagers [ ]. Several research shown that self-compassion may be acquired from childhood; thus, a number of measures were established for the young population [ , ]. In clinical practice, patients’ psychological wellbeing is of great concern, caregivers may simultaneously face a variety of stressful and complex situations, the care provided to patients should be compassionate, and caregivers themselves require self-compassion, as measured by scales such as the Compassionate Leadership Self-reported Scale [ ], the Bolton Compassion Strengths Indicators [ ] and the Sussex-Oxford Compassion Scales [ ] and the Compassion Motivation and Action Scales (CMAS) [ ] were the only two scales that measured self-compassion and compassion for others. This shift in focus reflects a growing recognition of the importance of understanding and exploring the interplay between different aspects of compassion. Consequently, there is a pressing need to develop multidimensional compassion scales that can capture the complexity and nuances of compassion across various dimensions. This will enable researchers to gain a more comprehensive understanding of compassion and its multifaceted nature. In particular, it explores the interrelationships and internal mechanisms underlying the different compassion flows of individuals, as previous research has indicated that individuals may have inconsistent levels of self-compassion and compassion for others [ ].",
"In the included studies, different methodologies were employed, or developed from various scales. To measure the self-compassion, the Self-Compassion Scale and Short-Form Self-Compassion Scale were most popularly used, and most of self-compassion related scales such as SCS-SF, SCS-Y, S-SCS-A, and SCS-D were derived from them. Further development of research on cultural adjustment and population adjustment in other flows of compassion is necessary to enhance the breadth and depth of studies in this field. Exploring how compassion expresses and adapts across cultures and groups will provide vital insights into the complex dynamics of human compassion, eventually leading to a more inclusive and holistic view of compassion.",
"To date, there is no consensus about the theory of compassion. Our results showed that the scales developed from different theoretical foundations. Self-compassion was defined by Kristin Neff [ ] based on Buddhist perspectives, which is not a theory in the traditional sense. Paul Gilbert [ ] developed compassion from evolutionary theory and developed the Compassion Mind model as a result. Moreover, Paul Gilbert, et al. [ ] developed fears of compassion scales on the basis of attachment theory. In terms of compassion-related theories, there are relatively few and underdeveloped. M. Durkin, et al. [ ] developed the compassion strengths model as the foundation of the Bolton compassion strengths indicators. S. Sinclair, et al. [ ] also developed a compassion model to guide the construction of the Sinclair compassion questionnaire. Fernando, et al. [ ] did similar work as previous researchers. In light of this, it is evident that there is a dearth of comprehensive theoretical models in the field of compassion. Particularly, the absence of well-established and applicable theories is notable. Therefore, it is imperative to prioritize the development of theories and compassionate assessment tools that are grounded in these theories. Future research should focus on bridging this gap and advancing our understanding of compassion through the development and application of robust theoretical frameworks.",
"This review has significant implications for future practice and research. From a public health perspective, this study critically examines existing assessment instruments related to compassion and evaluates their quality. The findings of this study can be valuable for psychology researchers, practitioners, educators, and healthcare professionals, providing them with insights and benefits for their respective fields. It is crucial to consider factors such as the target population, age characteristics, and purpose, in order to choose the most suitable compassion assessment tool. In particular, in the context of positive psychology, our study may serve as an inspiration for the design of compassion measurement approaches that can be selected and used by researchers across three different flows, and which can avoid the measurement of a single flow. Our study also offers a theoretical foundation for the development and refinement of scales in future research. Lastly, it is essential to develop compassion scales that are culturally adapted, multidimensional, and encompass a broader range of populations in the future.",
"Our research has several limitations. To begin, only English and Chinese databases were searched, and non-English and non-Chinese journals were excluded from this study, other potentially relevant literature could have been omitted. In addition, we concentrated on scales that could be used to quantify the three flows of compassion, other measurements such as compassion fatigue and compassion satisfaction were left out of this study, we believe that such a design would allow this study to be more focused. Finally, our analysis focused only on the basic information about the scales rather than exploring in depth their implementation, outcomes, and other indicators, which will limit the generalizability of this study as a result.",
"We identified 36 compassion-related measuring instruments, and the included studies’ methodological quality and measurement properties were acceptable. This study also revealed that the included measurements are consistent with three-way compassion flows. Since compassion is such a broad concept, we propose that researchers select appropriate measurement tools based on the needs of measurement and intervention, and that they can also develop more compassion measurement tools suitable for specific populations through further adaptation and validity. Furthermore, future research should concentrate on the development of compassion-related theories to guide and facilitate the application of the scale as well as to promote the field of compassion within a positive psychology perspective."
] |
PMC10291253
|
Cureus
|
Perspectives on Current Attitudes, Enablers, and Barriers to Obtaining Surgical Informed Consent for Doctors-in-Training
|
26-06-2023
|
Background Surgical informed consent (SIC) is paramount in modern-day litigious surgical practice, yet numerous complaints remain about the consenting process. This paper investigated current attitudes, enablers, and barriers to obtaining SIC in clinical practice for doctors-in-training (DiT). Methodology Self-reported SIC practice among DiT (N=1,652) across three metropolitan health service regions in Western Australia (WA) was surveyed using a de-identified 20-item multiple response ranking, dichotomous quantitative and qualitative online survey. Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 27 (IBM Corp., Armonk, NY, USA). Results The response rate was 23% (n=380). There was an even distribution of key demographics across all three health regions; the median postgraduate year (PGY) was two. Only 57.4% of DiT strongly felt comfortable and confident obtaining a SIC. Of the responders, 67.4% correctly identified key SIC components. There were significant positive associations between comfort and confidence with obtaining SIC and the seniority level of the DiT (p<0.001), identification of SIC components (p<0.001), and prior training in SIC (p<0.001). Most DiTs highlighted the necessity for formal SIC training with a preference for interactive workshops supported by e-learning modules. Conclusions Most DiTs can identify the key factors that constitute a valid SIC; however, the practical conversion of this skill could be better. The key enablers to improved SIC techniques were well-supported departments, with further training and clear guidelines within the institutions. The identified barriers were time constraints, inexperience, and a lack of senior support. Future practices and interventions should address these key barriers while promoting the enablers of sustainable and efficient SIC practice.
|
[
"Surgical informed consent to the current model of SIC description of the disease process, need for surgical intervention, and proposed operation, on May 11th, 2021, in Melbourne and May 6th, 2019, in Bangkok.",
"Study population",
"In Australia, the natural progression of the medical career begins as an intern, then a resident, registrar, fellow of a specialty college, and finally, a consultant. An intern is a postgraduate year 1.",
"Components of SIC",
"Most respondents.",
"SIC practice",
"This survey shows that DiTs have good self-reported practices in obtaining SIC. Most routinely check for competency and discuss key tenants such as diagnosis, indications, risks, benefits, potential complications, and alternative management options. However, only 57.4% of the respondents felt comfortable or confident obtaining SIC.",
"Univariate analysis",
"Univariate analysis showed significant positive associations between comfort/confidence with getting SIC and seniority.",
"Furthermore, the univariate analysis also showed significant positive associations between the correct identification of SIC components and seniority.",
"Barriers and enablers",
"The critical enablers identified in the qualitative informants’ analysis included having previous training in SIC and working in well-supported departments with clear guidelines on SIC. The barriers highlighted were inexperience with SIC.",
"Thematic analysis",
"A comprehensive logarithmic qualitative thematic analysis of free text item perspective responses was conducted. A pictorial representation of the key informants on enablers and barriers is demonstrated in Figure .",
"Obtaining an adequate SIC can be a complex and detailed process, the responsibility of which often befalls junior doctors in busy hospital settings, a homogenous observation between studies [ ]. All clinicians have a moral and ethical obligation to engage fully in the SIC process, a conversation they ought to have with patients to ensure consistent delivery of individualized, safe, culturally sensitive, and appropriate healthcare. Poor SIC practices may expose the DiT to medicolegal risk, potentially causing patient harm. All stakeholders must actively engage in the SIC process to achieve appropriate shared decision-making.",
"This study shows that a significant proportion of SIC needs to be executed to the required legal standard offered by the Royal Australasian College of Surgeons or hospital-based simulation skills workshops that allow for formal constructive feedback after observing DiTs performing these tasks. These opportunities should not be administrative-mandated learning modules as these tend to disengage learners [ ]. There is a pressing need for a global initiative to standardize the education and training instruction of the SIC process as we move away from a paternalistic model to autonomous patient care, bearing in mind local cultural differences worldwide.",
"There are certain limitations to this study. Overall, the response rate for the survey was low at 23%. At the same time, low survey response rates are not uncommon, especially in surveys involving healthcare professionals [ - ]. This may reflect a level of response bias in our results. DiTs who felt strongly about SIC were likelier to participate, resulting in an over-representation of the cohort. An important observation from the study is that most respondents were comprised of junior doctors, i.e., interns and residents. Despite the low response rate, the study captured responses from the most susceptible group of junior doctors, early in their careers and often tasked with a realm of responsibilities, including obtaining consent.",
"To improve response rates, reminders at various periods could be sent out to prompt responses or provide small incentives for completing the surveys. Another option is to liaise with the institutions’ education officers to promote completing such surveys at the start of continuous professional development sessions. The study also included self-reported clinical practice, as assessing each documented consenting process for each respondent in the survey would be impractical. As such, the study would not be able to determine the competence of the DiT, with potential gaps between the DiTs’ confidence/comfort/skill with SIC and their basic skills in SIC.",
"Qualitative studies such as surveys are inherently prone to recall bias; for example, in this study, many DiTs reported not receiving formal training in obtaining SIC, which could be true. On the contrary, possibilities may include simply not remembering prior education in this area, particularly in cases of significant time lapse between education and undertaking the survey or where education received was considered inadequate. Lastly, this study did not analyze nor identify where respondents initially trained, with overseas trainees unlikely to be familiar with the nuances of the Australian medicolegal system compared to their domestic counterparts. In addition, different medical schools may vary in their approaches and emphasis on SIC training, leading to differences observed in the regions. This necessitates the pressing need for a global initiative to standardize the education and training instruction of the SIC process as we move from a paternalistic model to autonomous patient care.",
"This study highlights the need for ongoing support and education for DiTs performing SIC. There is a greater need to emphasize SIC training, education, and practice beginning in medical school and then reinforced in clinical practice. Health institutions play an integral role in supporting DiTs in developing good SIC practices through regular training and providing access to clear guidelines. When clinicians and patients engage well in SIC, shared decision-making occurs, leading to individualized, safe, culturally sensitive, and appropriate healthcare delivery. A workforce well versed in the intricacies of the SIC process in tandem with a well-informed patient population will contribute to a sustainable healthcare system with consistent good health outcomes."
] |
PMC10377621
|
Biomolecules
|
The Metallodrug BOLD-100 Is a Potent Inhibitor of SARS-CoV-2 Replication and Has Broad-Acting Antiviral Activity
|
08-07-2023
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The COVID-19 pandemic has highlighted an urgent need to discover and test new drugs to treat patients. Metal-based drugs are known to interact with DNA and/or a variety of proteins such as enzymes and transcription factors, some of which have been shown to exhibit anticancer and antimicrobial effects. BOLD-100 (sodium trans -[tetrachlorobis(1 H -indazole)ruthenate(III)]dihydrate) is a novel ruthenium-based drug currently being evaluated in a Phase 1b/2a clinical trial for the treatment of advanced gastrointestinal cancer. Given that metal-based drugs are known to exhibit antimicrobial activities, we asked if BOLD-100 exhibits antiviral activity towards SARS-CoV-2. We demonstrated that BOLD-100 potently inhibits SARS-CoV-2 replication and cytopathic effects in vitro. An RNA sequencing analysis showed that BOLD-100 inhibits virus-induced transcriptional changes in infected cells. In addition, we showed that the antiviral activity of BOLD-100 is not specific for SARS-CoV-2, but also inhibits the replication of the evolutionarily divergent viruses Human Immunodeficiency Virus type 1 and Human Adenovirus type 5. This study identifies BOLD-100 as a potentially novel broad-acting antiviral drug.
|
[
"Vaccination is widely recognized to be the most important component of severe COVID-19 prevention. Several mAb-based therapies have received Emergency Use Authorization, such as bamlanivimab/etesevimab, casirivimab/imdevimab, sotrovimab, and bebtelovimab. These mAbs recognize and bind a specific epitope present on the receptor-binding domain, Paxlovid is the oral prodrug of the ribonucleoside analog beta-D-N4-hydroxycytidine. Recently, Gil-Moles and colleagues and M^(pro) [ , , ]. Their antiviral activity against other viruses, such as Chikungunya virus, also highlights the potential of ruthenium-based compounds as broad-acting antivirals [ ].",
"BOLD-100 is a clinical-stage ruthenium-based compound that is composed of sodium trans -[tetrachlorobis(1 H -indazole)ruthenate(III)]dihydrate [ ]. Its predecessor molecules include KP1339, induce reactive oxygen species generation, induce a DNA damage response, interact and be impacted by ribosomal biogenesis, and alter cellular metabolism [ , , , ].",
"Prior to the COVID-19 pandemic, BOLD-100 had never been tested as an antiviral. Accordingly, the existing body of literature focuses almost exclusively on the drug’s anticancer properties. Although not fully characterized, multiple components of BOLD-100′s mechanism of action have the potential to cause viral inhibition. Additionally, clinical trials in oncology patients have suggested that BOLD-100 is well tolerated with limited severe adverse events, even at high dose levels [ ]. The need for novel therapeutics for the treatment of COVID-19 and other viral pathogens warrants expanded research into novel therapeutic approaches. Here, we investigated the potential of BOLD-100 as an antiviral inhibitor and demonstrated that it not only potently inhibits SARS-CoV-2 replication, but the replication of other evolutionarily diverse viruses, HIV-1 and adenovirus.",
"Vero E6 cells Vero E6 cells were seeded in 96-well plates 24 h prior to infection. On the day of infection, the cell culture medium was removed and the cells were washed 1x with PBS. Ten-fold serial dilutions of stock SARS-CoV-2 were prepared in DMEM + 2% FBS. The cells were infected in triplicate with 90 µL of either undiluted virus, one of the serial dilutions of virus, or media only as a negative control. The cells were incubated for 72 h at 37 °C with 5% CO_(2) and visually evaluated for cytopathogenicity to determine infection. TCID50/mL was calculated using the Reed–Muench method.",
"HIV-1 AD.MDR01 was propagated in U87.R5 cells. Briefly, the U87.R5 cells were seeded in T-150 cell culture flasks. Once the cells reached 80% confluency, the cell culture medium was removed. A 1 mL aliquot of stock virus was diluted in 30 mL of DMEM + 2% FBS and added to the flask. The cells were incubated at 37 °C with 5% CO_(2) for 7 days. The virus-containing supernatant was harvested from the flask and centrifuged at 500× g for 10 min to pellet the cell debris. The resulting supernatant was aliquoted into cryovials and stored at -80 °C. The virus titer was determined by a TCID50 assay on TZM-bl cells. Specifically, 1.5 × 10^(4) TZM-bl cells were seeded in 96-well plates 24 h prior to infection. On the day of infection, the cell culture medium was removed. Ten-fold serial dilutions of propagated HIV-1 AD.MDR01 were prepared in DMEM + 2% FBS. The cells were infected in triplicate with 90 µL of either undiluted virus, one of the serial dilutions of virus, or media only as a negative control. The cells were incubated for 48 h at 37 °C with 5% CO_(2) and the infection in each well was determined using the Galacto-Star™ β-Galactosidase Reporter Gene Assay System.",
"The A549 cells were seeded in 12-well plates. To quantitatively assess the impact of BOLD-100 on cell survival following a SARS-CoV-2 infection, we repeated this experiment and measured the ATP levels in the infected cells using a CellTiter-Glo assay = 8.6 nM).",
"In parallel, we used the same assay to measure the cytotoxicity of BOLD-100 in the absence of infection. At 72 h post-treatment, the cells treated with ≤100 µM of BOLD-100 remained viable at similar levels to the mock-treated cells. At 200 µM of BOLD-100, approximately 51.9% of the cells remained viable after 72 h, while at ≥400 µM of BOLD-100, no viable cells were detected. Thus, the inhibitory effects of BOLD-100 against SARS-CoV-2 occur well below the drug’s toxic range. Taken together, these data show that BOLD-100 treatment protected the cells from SARS-CoV-2 cytopathogenicity at nanomolar concentrations, indicating antiviral activity in vitro.",
"Given that BOLD-100 inhibited SARS-CoV-2-induced cytopathic effects, we next asked whether BOLD-100 treatment would inhibit SARS-CoV-2 replication in cell culture. While Vero E6 is a practical cell line for propagation and antiviral assays with SARS-CoV-2, it is not human in origin. To strengthen the relevance of our data to future clinical applications, we chose to use human cells for the subsequent experiments. We obtained human embryonic kidney 293T protein and RNA at each BOLD-100 concentration were measured to determine the effect of BOLD-100 on SARS-CoV-2 replication. A quantitative Western blot analysis using a monoclonal antibody directed towards SARS-CoV-2 N protein demonstrated that BOLD-100 treatment inhibited the intracellular accumulation of the N protein in a dose-dependent manner. N protein is highly abundant and is a critical factor for the production of infectious virions, owing to its role in packaging the viral genome [ , ]. Likewise, RT-qPCRs indicated a dose-dependent reduction in N RNA following BOLD-100 treatment. At the highest BOLD-100 concentration tested.",
"To measure the BOLD-100 cytotoxicity in these cells, we treated them with cell culture media containing varying concentrations of BOLD-100 or cell culture media with 0.1% DMSO as a mock-treated control. Forty-eight hours post-treatment, we measured the relative cell viability at each BOLD-100 concentration via the CCK8 assay. This analysis revealed that the 50% cytotoxic concentration. In concordance with our cytopathic protection assays, these inhibitory effects occurred at relatively non-toxic concentrations of BOLD-100. The selectivity index = 35.9 µM, SI = 10.2), while the delta variant was inhibited at concentrations slightly higher than the ancestral strain. Together, these results show that BOLD-100 differentially inhibited the accumulation of viral RNA in cells infected with SARS-CoV-2 variants.",
"Next, we asked if BOLD-100 affected the cellular transcription profile of SARS-CoV-2-infected cells. The 293T-ACE2 cells were mock-infected or infected with SARS-CoV-2. Notably, the SARS-CoV-2-infected cells that were subsequently treated with BOLD-100 exhibited a significant decrease in the percentage of viral reads detected. These data correlate with our previous findings that BOLD-100 inhibits the replication of SARS-CoV-2.",
"To determine the specific transcriptional effects of the BOLD-100 treatment and SARS-CoV-2 infections on the 293T-ACE2 cells, we performed a differential gene analysis. Here, we defined genes as differentially expressed compared to the control. For the cells treated with BOLD-100 in the absence of SARS-CoV-2 infection, the only upregulated genes that met the applied cutoffs of p -adjusted ≥ 0.05 and a fold-change ≥ 1.5 were RP11-433J8.1 , ZNF439 , KIAA1755 , and CABP4 . The only downregulated gene was DHRS2 .. In contrast, SARS-CoV-2 infection induced large changes in the cellular transcriptome, with 46.87% of the total genes detected being differentially expressed. Among the genes with the highest magnitude of upregulation after infection were ZNF334 , FUT6 , KLRK1 , IRGM , FCAMR , PPP1R1B , GPR111 , CABP4 , and PIGR . Conversely, among the genes most downregulated by SARS-CoV-2 infection were PDF , HBQ1 , LMP3 , and SPINK2 .",
"In stark contrast to the cells infected with SARS-CoV-2 alone, the percentage of genes differentially expressed in the cells infected with SARS-CoV-2 and treated with BOLD-100 was reduced to 1.02%. The differentially expressed genes in the cells treated with BOLD-100 and infected with SARS-CoV-2 were largely shared with those observed in the cells infected with SARS-CoV-2 alone. While none of these shared protein-coding genes were downregulated to a large extent, several were highly upregulated, including GOLGA6B , FUT6 , KLRK1 , FCAMR , CABP4 , and LTA .",
"We then analyzed the enriched Gene Ontology. Within this category, SARS-CoV-2 infection enriched terms related to leukocyte migration and activation, as well as the broader immune response. To explore the specific impact of infection and drug treatment on these gene categories, we analyzed the expressions of the genes involved in the Type 1 IFN response, cytokine signaling, and chemotaxis. Consistent with previous reports on human primary bronchial epithelial cells, the gene enrichment analyses illustrated a generally diminished IFN-I signaling biology for SARS-CoV-2 overall, though certain IFN-induced factors were nonetheless highly upregulated [ ]. Several key IFN-induced host restriction factors, including BST2/tetherin , interferon-induced transmembrane proteins . Likewise, various cytokines and chemokines involved in immune response were downregulated by SARS-CoV-2 infection, including CXCL12 and CXCL16 , which activate and attract leukocytes, respectively, and the pro-inflammatory cytokine MIF . However, this converse pattern was also observed in some cases, in which pro-immune cytokines and effector genes such as CXCL11 , IL16 , GBP2 , TNFSF11 , and LTA were strongly upregulated by SARS-CoV-2 infection. Similar to the Type I IFN-induced genes, the expressions of these cytokine and chemokine genes were at the control levels in the presence of BOLD-100, except LTA, whose expression remained high after the BOLD-100 treatment. Taken together, BOLD-100 treatment of SARS-CoV-2-infected cells counteracts virus-induced cellular transcriptional changes.",
"Human Immunodeficiency Virus type 1 value of 8.9 µM and an SI of 39.3. Concurrently, we measured the cytotoxicity of BOLD-100 treatment alone in the HOS-CD4/CXCR4 cells, which yielded a CC_(50) value of 349.7 µM.",
"We then asked whether BOLD-100 could inhibit the replication of a clinically relevant drug-resistant HIV-1 isolate, AD.MDR01. AD.MDR01 is an HIV-1 subtype B clone associated with rapid disease progression and resistance to existing HIV therapeutics. Since cells infected with HIV-1 produce both infectious and non-infectious viral particles [ , ], we utilized the infectious HIV-1 indicator cell line TZM-bl, which is a HeLa derivative that expresses the HIV-1 receptor CD4 and CCR5 co-receptor. In addition, TZM-bl cells contain a β-galactosidase and firefly luciferase reporter cassette under the transcriptional control of an HIV-1 Tat-responsive long terminal repeat promoter of 29.7 µM and an SI of 7.9. In parallel, we measured the cytotoxicity of BOLD-100 treatment alone in the TZM-bl cells, which yielded a CC_(50) value of 235.6 µM.",
"Adenoviruses are non-enveloped viruses with double-stranded DNA genomes that infect a wide range of vertebrates. Depending on their species and type, human adenoviruses have various tropisms, where, most commonly, the respiratory tract, gut, and eye are targeted [ ]. Human adenovirus serotype 5. At 200 µM of BOLD-100, this effect corresponded to a 0.6-log10 reduction in the viral titer. In parallel, we measured the cytotoxicity of BOLD-100 treatment alone in the A549 cells, which yielded a CC_(50) value of 396.4 µM.",
"The COVID-19 pandemic prompted an unprecedented effort to discover and repurpose therapeutics for the treatment of COVID-19. In this study, we identified BOLD-100 as a novel antiviral agent that inhibits SARS-CoV-2 replication, in addition to virus-induced cytopathogenicity and transcriptional effects. BOLD-100 retained its antiviral efficacy against major SARS-CoV-2 variants of concern and the evolutionarily diverse viruses HIV-1 and HAdV-C5, indicating the potential for its broad-spectrum antiviral activity.",
"The cytopathic effects, a secreted cytokine that mediates inflammatory and antiviral responses [ ]. We observed a similar pattern with KLRK1 and FCAMR , which were also induced by SARS-CoV-2 infection and remained highly expressed after BOLD-100 treatment. KLRK1 encodes NKG2D, an activating receptor for natural killer cells and other cytotoxic cells, which recognizes “induced-self” peptides presented by virus-infected cells [ ]. FCAMR encodes an Fc receptor that binds immunoglobulin M and immunoglobulin A and is predicted to contribute to adaptive immune responses [ , ]. Overall, though BOLD-100 generally reversed the changes in the immune-related genes induced by SARS-CoV-2, it is intriguing that certain genes important in immune response were still highly expressed, which could be beneficial in a therapeutic context. The cellular response to SARS-CoV-2 is highly dynamic over the course of an infection [ ]. A limitation of our study is that we analyzed the cellular transcriptional changes at one timepoint during infection. The cellular response to SARS-CoV-2 is highly dynamic over the course of an infection [ ]; therefore, we only provided an analysis of the transcriptional changes during the early course of infection and the corresponding effects of BOLD-100.",
"To better understand the mechanism of the anti-cancer activity of BOLD-100, Schoenhacker-Alte and colleagues”, and “chromatin organization,” whereas the low-responsive cells preferentially activated the pathways controlling the cell cycle, DNA repair, and metabolism. Although their screen did not include HEK293T cells and we treated cells for 24 h as opposed to 6 h, the related GO pathways of the genes affected by BOLD-100 treatment only were consistent with the category of low-responsive. For example, ZNF439 is involved in DNA transcription, CABP4 is involved in calcium binding, and DHRS2 is involved in metabolic processes, responses to stress, cell differentiation, and the negative regulation of apoptosis. A recent gene expression profiling study by Baier and colleagues. It was recently shown that the inhibition of glycolysis abolishes SARS-CoV-2 replication and the cytokine response, placing glycolysis as a key upstream event during SARS-CoV-2 pathogenesis [ , ]. It will be interesting to learn if the effects of BOLD-100 on glycolysis are also key contributors to its antiviral effects.",
"We determined that the antiviral activity of BOLD-100 was not specific to SARS-CoV-2 and that the drug also inhibits HIV-1 and HAdV-C5. Although the mechanism of this antiviral activity in these viruses remains to be characterized, our findings highlight the potential of BOLD-100 as a broad-acting antiviral. Previous research into ruthenium drugs as antimicrobials has predominantly focused on their antibacterial or antiparasitic properties [ ]. However, the COVID-19 pandemic prompted a renewed effort to repurpose diverse classes of therapeutic agents for the treatment of COVID-19. In this context, several metallodrugs, including ruthenium-based compounds, were also evaluated for their antiviral potential. For instance, the BOLD-100 precursor KP1019 (indazole trans -[tetrachlorobis(1 H -indazole)ruthenate(III)]) demonstrated anti-SARS-CoV-2 activity in Calu-3 human lung cancer cells [ ]. Other ruthenium drugs have shown promise in an antiviral context. Several test compounds have been shown to inhibit the replication of diverse viruses, such as HIV-1 and Polio virus [ ]. An identification of the other viruses that BOLD-100 does or does not inhibit will help to elucidate the specific factors or pathways targeted by the drug mechanistically.",
"We have described the antiviral potential of the ruthenium-based small molecule BOLD-100 against SARS-CoV-2 and evolutionarily divergent viruses. We used a variety of molecular techniques to show that SARS-CoV-2 replication and its cytopathic effects were inhibited in a dose-dependent manner by BOLD-100. Moreover, we showed that BOLD-100 largely reversed the transcriptional signature of SARS-CoV-2 infection in cell culture. Finally, we determined that BOLD-100 inhibited the production of infectious HIV-1 and HAdV-C5. Further studies are required to better understand the potential of BOLD-100 as a novel antiviral therapeutic to alleviate the burden of current and future viral epidemic and/or pandemics."
] |
PMC10361491
|
PLOS ONE
|
Economic policy uncertainty and stock market in G7 Countries: A panel threshold effect perspective
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21-07-2023
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Based on the literature, it is commonly understood that stock prices (SP) are influenced by economic policy uncertainty (PU), with a rise in PU typically having a negative impact on SP. However, the relationship between PU and SP may not always be linear due to the varying risk preferences of individuals. Risk preference theory posits that individuals respond differently to different levels of risk. Therefore, this study aims to investigate whether PU determines SP asymmetrically (i.e., in a non-linear manner) by considering risk preferences and addressing a gap in the literature. To answer this question, the study employs a panel threshold approach to examine the effect of PU on SP in the Group of Seven (G7) countries, namely Canada, France, Germany, Italy, Japan, UK, and the US. In contrast to previous research, this study finds evidence of an asymmetric effect of PU on SP in the G7 countries. Specifically, the panel threshold results reveal that the impact of increased PU on SP is positive up to a certain level (Threshold1), beyond which it becomes negative (Threshold2). These findings are in line with information asymmetry hypothesis, prospect theory, behavioural finance hypothesis, and market liquidity hypothesis and shed light on the asymmetric behaviour of SP in response to varying levels of PU. The implications of these findings are significant for understanding how to manage risks effectively in the financial markets.
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[
"The study is motivated by the conflicting and inconclusive empirical literature on economic policy uncertainty countries.",
"The G7 countries, including Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States, are major global economies with substantial financial markets. These countries play a significant role in shaping global economic policies and have a substantial impact on international financial markets. Findings derived from studying the G7 countries have broader implications due to their global economic significance. As these countries are influential players in the international financial system, their financial market dynamics and policy implications can often be generalized to other countries or regions. Consequently, empirical research conducted on G7 countries can provide insights that are relevant and applicable to a wider range of economies and financial markets. Therefore, the use of the G7 countries as a sample in empirical research within the finance field is driven by their economic significance, diverse policy frameworks, availability of data, generalizability of findings, benchmarking value, and policy relevance.",
"Since the introduction of the measure for PU [ ], scholars, businessmen, and policymakers closely track PU and its impacts on the economy and stock markets [ ]. PU is defined as \"a non-zero probability of changes in existing economic policies that determines the rules of the game for economic agents.\" PU has many implications for the economy. Companies and other important economic actors change and delay their decisions regarding investment, employment, consumption, and saving due to PU [ – ]. Existing literature suggests that there is a generally accepted understanding that stock prices), after which the effect is negative effect of EPU on G7 Stock Prices.",
"The information asymmetry hypothesis by Akerlof [ ] can be used to explain the asymmetric effect of EPU on stock prices in G7 countries. When EPU is high, investors have less information about the future direction of the economy and the policies that will be implemented. This can lead to market volatility, as investors become more risk-averse and are less willing to buy stocks. The information asymmetry hypothesis suggests that the asymmetric effect of EPU on stock prices is due to the fact that investors have more information about the negative consequences of EPU than the positive consequences. For example, investors know that EPU can lead to lower economic growth, higher unemployment, and a decline in corporate profits. However, they may not be as aware of the positive consequences of EPU, such as increased government spending and investment. As a result, investors are more likely to sell stocks when EPU increases, leading to a decline in stock prices. However, they are less likely to buy stocks when EPU decreases, leading to a slower recovery in stock prices. The information asymmetry hypothesis can also help to explain why the asymmetric effect of EPU is more pronounced in bear markets than in bull markets. In bear markets, investors are already pessimistic about the future direction of the economy. As a result, they are more likely to sell stocks even when EPU decreases, which can lead to a sharper decline in stock prices. In bull markets, investors are more optimistic about the future direction of the economy. As a result, they are less likely to sell stocks even when EPU increases, which can lead to a slower recovery in stock prices.",
"Prospect theory, developed by Kahneman and Tversky [ ], is a behavioral economic theory that seeks to explain how individuals make decisions under risk and uncertainty. The theory provides insights into how people perceive and evaluate potential gains and losses, and how these perceptions influence their decision-making. In the context of the asymmetric impact of EPU on stock prices, prospect theory helps explain why individuals may react differently to positive and negative changes in policy uncertainty. According to prospect theory, individuals evaluate potential gains and losses relative to a reference point, typically their current wealth or the status quo. The theory posits that people are generally loss-averse, meaning the pain of potential losses is felt more strongly than the pleasure of equivalent gains. This leads to a bias where individuals are more motivated to avoid losses rather than maximize gains. Applying prospect theory to the asymmetric impact of EPU on stock prices, we can expect to observe a stronger negative reaction to increases in policy uncertainty compared to positive reactions to decreases in uncertainty. When policy uncertainty rises, it creates an environment of increased risk and ambiguity. Loss-averse investors, concerned about potential downside risks, may become more risk-averse and sell their holdings or reduce their exposure to the stock market. This selling pressure can lead to larger declines in stock prices.",
"Conversely, when policy uncertainty decreases, it can provide a sense of relief and reduce perceived risks. However, the positive impact on stock prices may not be as pronounced as the negative impact because of loss aversion. Investors may be less motivated to take on additional risk and increase their stock holdings to capitalize on the decrease in uncertainty, leading to a smaller or more muted positive effect on stock prices. To summarize, prospect theory suggests that individuals’ responses to changes in policy uncertainty are asymmetric due to their loss aversion. Negative changes or increases in uncertainty are likely to result in stronger negative reactions and larger declines in stock prices, while positive changes or decreases in uncertainty may have a smaller or more muted positive impact on stock prices.",
"Behavioral finance hypothesis [ ] states that investors are not always rational and may make decisions based on emotions, such as fear and greed. When EPU is high, investors may become more fearful and sell stocks, even if there is no fundamental reason to do so. This can lead to a sharp decline in stock prices. However, when EPU is low, investors may become greedier and buy stocks, even if there is no fundamental reason to do so. This can lead to a slower recovery in stock prices.",
"The market liquidity hypothesis [ ] states that EPU can lead to a decrease in market liquidity, which makes it more difficult for investors to buy and sell stocks. This can lead to a sharp decline in stock prices, as investors are less able to adjust their positions in response to changes in EPU. However, when EPU is low, market liquidity is restored, which can lead to a slower recovery in stock prices.",
"It is important to note that the asymmetric effect of EPU on stock prices is not always straightforward. The effect may depend on a number of factors, including the specific context. The study employs a GARCH-M model and finds that both the national and global PU shocks have significant and negative impacts on the time-varying risk–return relationship, and that these negative impacts increase and intensify during the GFC.",
"Liu and Zhang [ ] uses S&500 index data from January 1996 to June 2013 and finds that PU impacts stock market volatility and holds significant predictive power on stock market volatility. Asgharian and Christiansen [ ] examines the relationship between the US, with both negative and positive findings, and most of the literature is devoted to linear impact. These divergent outcomes suggest that the relationship between PU and stock markets is inconclusive and dependent on the specific context or conditions under investigation. In other words, the impact of PU on stock market dynamics may vary in different countries, time periods, or economic environments. The behavior of stock markets in response to changes in PU is not necessarily linear, as market reactions can vary depending on the level of risk. This asymmetric response may be influenced by investors’ risk preferences, leading to the need for empirical testing of this hypothesis. In this study, a fixed effect panel threshold modeling approach is employed to examine the threshold effect of PU on SP in the G7 countries. By utilizing this methodology and sample, the study aims to fill the knowledge gap in assets pricing literature.",
"shows the average monthly SP of G7 countries for sample period, while depicts the average monthly PU.",
"illustrates the Theoretical Framework Drawn on Risk Preference theory and empirical literature.",
"According to literature [ ], threshold models are visionary innovation, and advancements in the fields of economics and econometrics are greatly influenced by this model. Threshold regression can capture the threshold(s) point where the magnitude and direction of the impact of PU on stock prices changes. Most of the literature on PU and the stock market uses linear modeling, while the Threshold models are increasingly used to capture nonlinear behavior in economics. In panel dataset, researchers often used traditional fixed effect or random effect models guided by Hausman test. Panel data is plagued by the problem of heterogeneity. To put it another way, each unit in a study is unique, and the structure of their interactions may differ. Only the variability in intercepts is reflected by the standard fixed or random effect. That is the reason present study uses panel threshold regression to examine the threshold effect of PU on stock prices of G7 countries. In panel threshold regression, there is one effect may be extended as;",
"In this case, γ _(1) and γ _(2) represent the thresholds that separate the equation into its three distinct regimes, which are denoted by the coefficients β _(1), β _(2), and β _(3). The sequential estimator is consistent, as stated by Bai [ ] and Bai and Perron [ ], hence the thresholds are estimated as follows:",
"In order to derive the threshold estimator γ _(1) and the RSS S 1 ( γ ^ 1 ) , it is necessary to fit the single-threshold model.",
"In the presence of γ ^ 1 , estimating the second threshold and its confidence interval.",
"Similarly, if the null hypothesis is rejected for the single-threshold model, we must then test the double-threshold model. There is a single-threshold null hypothesis and a double-threshold alternative hypothesis. In order to calculate the F statistic, the bootstrapping design is quite comparable to the one used in the model with a single threshold. The procedure is essentially the same for models with more than two threshold parameters [ , ].",
"To examine the threshold effect of PU on SP of G7 countries. A second component indicates the amount of elements of tax legislation that will expire in the next years. The third component uses economic meteorologists’ disagreement as an indicator of uncertainty. First, each component is normalized by its own standard deviation to produce overall index of policy-related economic uncertainty. After that, an average is taken, giving the tax expirations index, the CPI prediction disagreement measure, and the federal/state/local purchases disagreement measure each a weight of 1/6 and giving the broad news-based policy uncertainty index a weight of 1/2. Similarly, the index construction relies on alike methodology with different count of number of newspapers.",
"This study makes use of monthly data spanning from January 1998 all the way through August 2020. For this time period, data on PU were obtained by downloading them from the PU website, which can be found at http://www.policyuncertainty.com/. This website is an open source and is frequently referenced in the relevant research, and for each of the G7 member country the respective details may be accessed at https://www.policyuncertainty.com/. The SP, industrial production where standard deviation is reportedly higher. With regard to Unemployment Rate witnessing that until a certain level, the PU positively explains the SP with a coefficient of 0.492. The results of first model confirm that a certain level of PU where PU exceeds TH2, the coefficient becomes positive but insignificant. The situation shows that during the period between TH1 to TH2, majority of the pessimistic investors might have shifted the investment to bond market where the return has increased due to increase in PU and remain risk seeking investors are involved in trading but due to low volume of trading the stock markets are not gaining considerable momentum. The findings of threshold analysis are aligned with the intuition and philosophy of risk return theorem, and effect of risk aptitude of investors.",
"In order to examine the long-term relationship between variables, we used fixed effects with Driscoll-Kraay standard errors and panel corrected regression due to an estimated potential for errors as robustness check [ ]. represents the simulation results of panel data model with fixed effect where Driscoll-Kraay method was used to calculate error. Overall results reported in the confirms that findings are robust in terms of the sign and significance of various threshold of PU. In general, the results reported in are consistent with those reported in the baseline regressions, suggesting that the results are not driven by potential heteroscedasticity and serial correlation.",
"In this section the findings of present study are discussed in the light of related theoretical and empirical literature.",
"The empirical findings show that PU boosts SP up to a certain level, above which it follows the traditional path to negatively drive the SP for G7 countries. The varying attitudes that investors have toward risk are a contributory factor that plays a role in the ups and downs in asset values as well as the momentum of the market. Monitoring the trends of investors’ risk attitudes would improve academics’ comprehension of financial markets, make risk management more efficient for practitioners, and strengthen policymakers’ ability to keep an eye on markets.",
"The empirical findings of panel threshold regression show two significant thresholds in the context of PU and SP for G7 countries. Specifically, the panel threshold results indicate that the increased PU has a significant positive effect on stock prices in G7 countries up to a certain level may reduce the investors’ confidence and risk appetite, leading to a decline in stock prices. However, a negative PU shock using monthly data from January 1998 to August 2020. In order to account for the possible asymmetric effect of policy uncertainty on stock prices, the study employs panel threshold model. The empirical results reveal an asymmetric effect of policy uncertainty on stock prices in the G7 countries. Specifically, policy uncertainty has a positive impact on stock prices up to a certain level (Threshold1), beyond which the effect turns negative up to another certain level (Threshold2). The findings above Threshold1 are consistent with the general expectation that the stock market dislikes rising risk. However, the positive effect of policy uncertainty on stock prices is an interesting addition to the financial market literature. The results are consistent with information asymmetry hypothesis, prospect theory, behavioral finance hypothesis, and market liquidity hypothesis and have implications for understanding the asymmetric behavior of stock prices in response to different levels of policy uncertainty. Understanding the risk preferences of investors, whether individual or institutional, is crucial in financial market decision-making. The study’s findings demonstrate the nonlinear response of stock prices to changes in policy uncertainty in G7 countries and underscore the importance of considering risk preferences when managing investments. Future research could expand the scope of analysis beyond the G7 countries to explore whether the observed effect of policy uncertainty on stock prices holds true in other countries as well. Comparing emerging and developed markets could also provide valuable insights for policymakers and investors. This would enable a more comprehensive understanding of the relationship between policy uncertainty and stock prices across a range of economic contexts and regions, and could provide important policy inputs for managing investments in different parts of the world."
] |
PMC10820995
|
Micromachines
|
Micro-Raman for Local Strain Evaluation of GaN LEDs and Si Chips Assembled on Cu Substrates
|
22-12-2023
|
Integrated circuits are created by interfacing different materials, semiconductors, and metals, which are appropriately deposited or grown on substrates and layers soldered together. Therefore, the characteristics of starting materials and process temperatures are of great importance, as they can induce residual strains in the final assembly. Identifying and quantifying strain becomes strategically important in optimizing processes to enhance the performance, duration, and reliability of final devices. This work analyzes the thermomechanical local strain of semiconductor materials used to realize LED modules for lighting applications. Gallium Nitride active layers grown on sapphire substrates and Si chips are assembled by soldering with eutectic AuSn on copper substrates and investigated by Raman spectroscopy in a temperature range of −50 to 180 °C. From the Raman mapping of many different samples, it is concluded that one of the leading causes of strain in the GaN layer can be attributed to the differences in the thermal expansion coefficient among the various materials and, above all, among the chip, interconnection material, and substrate. These differences are responsible for forces that slightly bend the chip, causing strain in the GaN layer, which is most compressed in the central region of the chip and slightly stretched in the outer areas.
|
[
"Light-emitting devices, or LEDs, are extensively studied in terms of emission efficiency, wavelength modulation, stability, and duration, as they are widely used for applications in various fields, such as interior and exterior lighting, computer, and smartphone screens, and for the automotive industry [ , ]. For applications in diverse environments, where they are often subjected to high temperatures and thermal cycling, one critical aspect that influences the widespread use of LEDs is their reliability and resistance, particularly in the face of extreme temperature conditions. Ensuring the reliability of LED devices under such challenging conditions has become a focal point in the pursuit of sustainable and efficient lighting solutions.",
"Gallium nitride examines residual strains at different depths of the film structure due to the penetration capacity of the X-ray, but it does not satisfy the requirement for mechanical measurement in microelectronic devices due to its inherent limitations in spatial resolution and accuracy [ ]. Cross-sectional transmission electron microscopy [ ] can provide information on strain on a very high resolution scale. The interconnection layers comprised a tin–gold eutectic alloy were characterized in their pristine state before the assembly procedure. Using an eutectic layer of gold tin. The 488 nm radiation was filtered out, and a half-wave plate was used to control the polarization of the incident light. Optical density filters were arranged on a remotely controlled reel to regulate the light intensity hitting the sample. The laser beam is coupled to a microscope in 10 × 10 positions and the surface of the LED in 20 × 20 positions at −50, 20, and 180 °C. Each point was recorded using the 20× microscope objective, and the spectrograph slit was set at 40 μm. The spectra were obtained by averaging five repeated measurements with an acquisition time of 5 s for each spectrum or lower shift of the E 2 H Raman mode are represented by the following simplified equation, which allows the calculation of the induced strain of the experimental Raman shift [ ]:\nwhere σ x x + σ y y is the average value of the total induced “in-plane strain”, i.e., the sum of the inverse piezoelectric through the elastic compliance tensor elements of silicon, the biaxial stress along the [100] and [010] directions at 20 °C, associated with two transverse and one longitudinal branch, an LTO branch, and a small broad peak at 950 cm^(−1), corresponding to the second-order Raman signal. These signals are comparable to those reported in the literature [ ]. The peak is shifted to 521 cm^(−1) at −50 °C; at 180 °C, the peak is shifted to 515.5 cm^(−1). The peaks at 116, E 2 H centered at 568 cm^(−1), and an LO phonon peak, A 1 ( L O ) centered at 736 cm^(−1), and a TO phonon peak, A 1 ( T O ) centered at 560 cm^(−1), while E 1 can be observed as a small shoulder of the E 2 H peak. These are typical phonon spectra of a hexagonal GaN layer grown on a sapphire^(1)), compared to the other samples, b–d assembled on a thinner copper substrate or with pressure^(1) for Si and 0.46 cm^(−)^(1) for GaN, while the Si chip shows ∆ ω S i = 1.88 cm^(−)^(1), a value in the middle in between those observed for S1 and S2–S4 LED samples.",
"The Si chip and GaN LED samples, unmounted, at different temperatures: −50, 20, and 180 °C. The values of the Raman shift of the LO peak of Si and E 2 H peak of GaN Raman shifts, collected on the samples, are reported in for Si and S1 and on high values at 180 °C.",
"Finally, it is possible to outline that the Raman shift of both Si and GaN samples, measured at room temperature before and after the thermal treatments, is unchanged.",
"To calculate the strain for the Si and GaN layers, a reference value is necessary: the best possible reference would be a layer of strain-free Si and GaN, respectively; it can be found by taking either a literature value or an internal value from measurements, such as the unmounted samples. For these considerations, the Raman frequency of the unmounted sample was assumed as a reference value to evaluate the strain values of the assembled samples. Therefore, positive and negative values were observed; positive strain values correspond to tensile strain, while negative strain values correspond to compressive strain.",
"The strain distribution of the different samples was determined from the Raman mapping data; color maps in report the strain values of the Si and GaN samples, determined on the entire surface of the samples at 20 °C. The maps have an almost symmetric distribution with tensile strains at the corners and compressive strains at the central part of the samples.",
"Data calculated at the different set temperatures are reported in for the Si chip and for the GaN LED, where the maximum and minimum stress values are reported, together with the average values and the maximum variation along the sample. At 20 °C, Si shows an evident prevalence of contractile deformation with a minimum value slightly higher than that obtained for GaN. At the same temperature, GaN shows both tensile and compressive stress values, with high intensity in both directions and comparable to each other. Tensile stresses are recorded in the peripheral areas of the device, and compressive stresses are recorded in the central area.",
"At low temperatures and maximum compared to silicon (around 2.4 ppm/°C) and GaN (around 4 ppm/°C).",
"The results at different temperatures clearly show that the strain variation in the GaN layer is characterized by much lower values when measured at 180 °C. On the contrary, the highest strain variations were recorded at −50 °C. A possible explanation is suggested by considering the sample assembly processes: for soldered samples, the temperature is mainly between 220 °C and 250 °C. This means that liquid solder connects an expanded chip to an expanded substrate at these temperatures. As the cooling ramp begins, all materials shrink according to their thermal expansion coefficient, which differs between the chip components, between the chip and the interconnect, and between the interconnect and the substrate. Even if the existence of a temperature range for the solder with a still soft interconnect that can plastically adapt to the shrinking sizes of the sample components is assumed, mechanical rigidity is achieved, and elastic strain is built into the chip.",
"At 180 °C, where the temperatures are very close to the assembly process temperature, the dimensions of the sample’s components are closer to the size they had during the soldering process; therefore, most of the elastic strain is relaxed, resulting in the lower strain values registered. On the opposite side of the range, the −50 °C experiment represents a situation in which the sample components have a very different size than the one they had during the assembly process and, therefore, the resulting measured strains are higher.",
"The assembled LED will likely be slightly curved due to the forces built in due to thermal expansion coefficient mismatch. This is consistent with the strain results obtained, which can be interpreted as a slight concave curving of the GaN surface.",
"The comparison between the Si sample and the GaN LED, reported in , allows us to make some interesting final considerations. The thicknesses and number of interfaced layers influence their deformation. The Si sample represents the substrate on which the active GaN layer is deposited. From the comparison between the maximum stress values developed within the two assemblies, it is possible to observe that both, at low and room temperature, present a difference equal to approximately 450 MPa, which becomes approximately 50 MPa at 180 °C. This fact indicates that the main component of stress is attributable to the Si substrate, which is thicker than that of GaN.",
"It has already been demonstrated that most LED products with high local strain have poor photoelectric performance and decrease in a short time [ ], and in addition, the reliability also mainly includes the lifetime [ ]. Recently, many articles have mentioned that the most important factor in affecting reliability is the thermal management problem of the LED packaging structure [ , ]. Therefore, the reliability of LED products depends on the cooling channels with reasonable design and on the materials with high heat conduction performance. Moreover, the local strain in the chip affects the emission characteristics of LEDs, the operational stability is reduced, and the strained interfaces cause an increased defect density. Power conversion efficiency can be strongly affected by local strain. In the current study, the distribution of strain inside the device has been systematically investigated by testing the effect of different assembly parameters and the temperature dependence of the Raman signal. Therefore, the characteristics of the substrates and assembly parameters that induce the least stress development have been identified in this work, from a comparison between the various samples.",
"One of the particularly interesting results to underline is related to the position of the Si and Gan Raman peaks recorded before and after thermal treatments: since they remain unchanged, it indicates reversibility of the process and, therefore, a good thermal resistance of the samples. This is a good result, since many electronic devices have to operate at high temperatures and are exposed to temperature cycles with large temperature differences; thus, they have to withstand strong cyclic thermo-mechanical stress. Several failure modes are possible up to intense cracking of the solder joints. Further advanced testing is required to verify the formation of defects in welded components and interconnection materials when a large number of thermal cycles occur. As an example, crack propagation in solder joints has already been identified by measuring the relative thermal resistance using transient thermal analysis [ , ].",
"Therefore, we can conclude that the choice of the type of material used as a substrate for the assembly of the samples and the determination of its thickness, together with the definition of the experimental parameters used in the assembly phase, are vital in determining the strains developed. Furthermore, the possibility of using micro-Raman for process control is beneficial for optimizing assembly processes."
] |
PMC10788531
|
The Journal of Biological Chemistry
|
A regulatory role for the unstructured C-terminal domain of the CtBP transcriptional corepressor
|
23-11-2023
|
The C-terminal binding protein (CtBP) is a transcriptional corepressor that plays critical roles in development, tumorigenesis, and cell fate. CtBP proteins are structurally similar to alpha hydroxyacid dehydrogenases and feature a prominent intrinsically disordered region in the C terminus. In the mammalian system, CtBP proteins lacking the C-terminal domain (CTD) are able to function as transcriptional regulators and oligomerize, putting into question the significance of this unstructured domain for gene regulation. Yet, the presence of an unstructured CTD of ∼100 residues, including some short motifs, is conserved across Bilateria, indicating the importance of maintaining this domain over evolutionary time. To uncover the significance of the CtBP CTD, we functionally tested naturally occurring Drosophila isoforms of CtBP that possess or lack the CTD, namely CtBP(L) and CtBP(S). We used the CRISPRi system to recruit dCas9-CtBP(L) and dCas9-CtBP(S) to endogenous promoters to directly compare their transcriptional impacts in vivo . Interestingly, CtBP(S) was able to significantly repress transcription of the Mpp6 promoter, while CtBP(L) was much weaker, suggesting that the long CTD may modulate CtBP’s repression activity. In contrast, in cell culture, the isoforms behaved similarly on a transfected Mpp6 reporter gene. The context-specific differences in activity of these two developmentally regulated isoforms suggests that the CTD may help provide a spectrum of repression activity suitable for developmental programs.
|
[
"Eukaryotic transcription factors and cofactors are rich in unstructured domains; these proteins have a higher percentage of predicted intrinsically disordered regions. Some of these IDRs have been shown to participate in specific transcriptional processes, sometimes through promoting the formation of phase separated condensates. For example, the C-terminal domain. The N-terminal IDR of the androgen receptor has also recently been found to be necessary for condensate formation and transcriptional activity on enhancers. IDRs in a plethora of other transcriptional regulators are thought to similarly play roles related to gene regulation, although most remain understudied. Recent high-throughput analyses to determine the function of IDRs across the eukaryotic proteome have uncovered important motifs, interacting partners, and putative gene regulatory functions of some of these uncharacterized IDRs. However, the specific roles of many IDRs present in these factors are still unknown. Tools to probe the function of certain IDRs and examine their gene regulatory roles in a physiologically relevant context and in a developing organism are necessary to delineate mechanisms of gene regulation by these IDRs and start to assign in vivo functions to them.",
"A prominent IDR that has not been well-studied is the CTD of the C-terminal binding protein. This IDR of approximately 100 amino acids is not necessary for oligomerization of CtBP and may not be necessary for gene regulation, putting into question the significance of the CtBP CTD. Yet, our recent study shows that the CtBP CTD is highly conserved across Bilateria, and despite possessing overall lower sequence conservation than other parts of the protein, it features conserved short linear motifs within this predicted unstructured domain. A few lineages such as roundworms and flatworms have novel, derived CTD sequences that are predicted to form intrinsic structures of unknown function. However, the deep conservation in primary sequence, length, and unstructured property of the CtBP CTD in bilaterians suggests that this IDR plays an important role, perhaps in gene regulation.",
"Mammalian genomes encode the CtBP1 and CtBP2 paralogs, which play overlapping and nonredundant roles in regulating expression of genes involved in apoptosis, the epithelial to mesenchymal transition, and cell differentiation. The CtBP1 and CtBP2 CTDs exhibit 50% sequence conservation, which is much lower than that of the central core dehydrogenase domain, which is used for oligomerization, NADH binding, and in vitro dehydrogenase activity. Interestingly, CtBP isoforms without the CTD exist in certain tetrapods such as birds and amphibians. Likewise, in Drosophila , the single CtBP gene encodes multiple splice forms, including short isoforms that lack the CTD. These two major isoforms differing in the retention or loss of the IDR are coexpressed in fly development. Thus, Drosophila is an appropriate model system to test a possible role of the CtBP CTD in gene regulation and assign a function to this elusive IDR.",
"Previous work using GAL4-CtBP fusions in the Drosophila embryo demonstrated that the two isoforms have similar repressive effects on an even-skipped -lacZ reporter, and both isoforms individually rescue a CtBP null fly, albeit with some different phenotypes in the wing. Thus, the CtBP CTD does not seem to play an essential role for completion of developmental programs under laboratory conditions. The expression pattern of the two isoforms exhibit developmentally distinct profiles; CtBP(S) is expressed throughout development, while CtBP(L) is highly expressed in the embryonic stage. The fact that short isoforms have been independently derived in other insects, such as Hymenoptera, and in other lineages in Bilateria suggests that expression of both isoforms is somehow important. The strict evolutionary conservation in these lineages of CtBP isoforms with and without the CTD indicates that both are functional, but a role in gene expression has remained unclear, compelling us to directly compare the activity of CtBP isoforms in vivo .",
"Here, we have made use of precise genetic tools in Drosophila to probe the function of the fly CtBP isoforms, CtBP(L) and CtBP(S), to uncover the role of the C-terminal IDR in regulating gene expression. Specifically, we used the CRISPRi system in the developing fly to assess the function of chimeric dCas9-CtBP proteins targeted to diverse gene promoters in vivo . This method allowed us to compare the activity of the long and short isoforms on the same loci in fly wing tissue and compare the results to those targeted to transfected reporters in cell culture. We found that when assessed on endogenous targets, CtBP(S) is a more potent repressor of the Mpp6 promoter than CtBP(L) but that this difference in repression ability is not observed on a transiently transfected Mpp6 -luciferase reporter. Thus, in some contexts, the disordered CTD seems to provide a regulatory function, but the difference observed between endogenous gene regulation and transient transfections raises the possibility that the effect may be chromatin dependent. Additionally, gene promoters targeted here had differential sensitivity to CtBP recruitment, indicating a further level of regulatory specificity, in accord with recent high-throughput assays.",
"To investigate the function of the CtBP C-terminal IDR and differences in gene regulation by the CtBP(L) and CtBP(S) isoforms in Drosophila , we employed CRISPRi. These two isoforms are created through alternative splicing, with CtBP(L) having a ∼130 amino acid domain and CtBP(S) a ∼30 amino acid domain, which only share the first 20 residues with one another. We fused the coding sequence of each CtBP isoform to a nuclease dead Cas9. dCas9-CtBP(L) and dCas9-CtBP(S) are expressed in S2 cells, according to Western blot.",
"We expressed the chimeric proteins in the wing discs of third instar larvae. These gRNAs were obtained as fly lines from the Bloomington Drosophila Stock Center. We previously tested dCas9-Rb chimeras in L3 discs, where we observed gene-specific effects after targeting ∼30 different gene promoters; here, we targeted many of the same promoters with the CtBP isoforms.",
"The epithelial cells of the developing wing are a highly sensitive tissue that has been used to measure developmental perturbation of a number of regulatory pathways. To screen for genetic effects after targeting chimeras in cells of the L3 wing discs, we allowed the flies expressing the three transgenes to grow to adulthood and then assessed adult wing phenotypes from targeting each promoter, as has been previously done in Drosophila CRISPR activation screens. We note that the nubbin - GAL4 >UAS:dCas9-CtBP flies crossed to a nontargeting gRNA control fly line. We presume that ectopic CtBP, even when fused to dCas9, may interact with diverse endogenous CtBP binding sites on the genome, leading to these mild phenotypes. The QUAS control gRNAs used here did not produce phenotypes with dCas9-Rb corepressor fusions tested previously, so the phenotypic effect is CtBP-specific.",
"We recruited CtBP(L) and CtBP(S) to a number of promoters, with specific effects observed only on a few promoters. Here, we detail the effects of targeting the E2F2/Mpp6 bidirectional promoter, the insulin receptor. Targeting CtBP(S) to the divergent E2F2/Mpp6 promoter produced small wings with severe morphological defects, similar to that seen with dCas9-Rb fusions. Intriguingly, CtBP(L) did not produce this phenotype but instead produced much milder effects, including wings with ectopic veins and supernumerary bristles. dCas9 alone did not produce any phenotypic effect, indicating that the observed phenotypes are CtBP specific. The clear difference between targeting the long and short isoforms on this promoter suggests that the long CTD may inhibit CtBP’s gene regulatory activities.",
"The strong CtBP(S) effect is only seen when using two gRNAs; recruitment using the individual gRNAs at the same locus produced milder effects, such as ectopic veins seen with the CtBP(L) isoform when both gRNA were used. Interestingly, the number of wings with supernumerary bristles was less than that observed for the nontargeting control QUAS gRNA. We speculate that nonspecific CtBP overexpression effects are suppressed by targeting the chimeric protein to specific DNA locations using these single gRNAs.",
"Targeting the InR promoter produced adult wings with mild phenotypes, similar to those produced with the nontargeting QUAS gRNA control, so this effect is difficult to distinguish from a mild overexpression phenotype rather than specific InR targeting. Clearly, positioning the CtBP chimeras near the InR transcriptional start site does not strongly affect the wing, although we know that positioning dCas9-Rb chimeras at this promoter does impact development and transcription. This distinct effect is consistent with CtBP promoter selectivity, a property illustrated from recent high-throughput assays.",
"Recruitment to the Acf promoter region generated a different spectrum of phenotypes. In this case, a significant proportion of wings from the dCas9 control cross showed supernumerary bristles—evidence that dCas9 alone can disrupt gene function in certain locations. Notably, the position of one of the gRNAs used here is 3′ of the initiation site for the divergently transcribed Mccc1 gene, a position from which transcriptional inhibition is possible by dCas9. Over and above the background of this dCas9 effect, the CtBP fusions had unique, specific effects, with CtBP(S) causing a larger proportion of wings to be affected. Results from these targeted promoters indicate that CtBP exhibits gene-specific effects, and that in some cases, CtBP(S) has a more pronounced effect than CtBP(L).",
"Given the noticeable difference in wing phenotype as a result of targeting the two CtBP isoforms to the E2F2/Mpp6 shared promoter, we measured transcript levels of both of these genes in the L3 wing disc using RT-qPCR. The two gRNAs targeting E2F2/Mpp6 bind at −577 and −672 relative to the E2F2 TSS, and at −18 and +57 relative to the Mpp6 TSS. CtBP(S) targeting led to ∼50% repression of the Mpp6 gene, whereas CtBP(L) effects were significantly weaker. Effects on E2F2 were more modest, with only ∼10% decrease in E2F2 expression resulting from targeting by dCas9 and dCas9-CtBP(L), and no statistically significant change after targeting with dCas9-CtBP(S). The greater impact on Mpp6 is likely a reflection of the inherent short-range of action of many transcriptional repressors and corepressors, which may influence chromatin structure over a span of a nucleosome.",
"In this system, we did not find complete suppression of gene expression as noted in other transcriptional assays. However, an important caveat is that the level of repression measured may be an underestimate because the nubbin driver is expressed only in the wing pouch, while we used the entire wing disc for RT-qPCR analysis. Interestingly, although CtBP(L) repressed E2F2 and Mpp6 to the same extent as dCas9 alone, it clearly showed more pronounced phenotypic effects in the adult stage. It may be that the CtBP(L) does have some specific activity in this setting. Here, we employed seven individual gRNAs to test for possible position effects on this 1 kb promoter region. Both CtBP(S) and CtBP(L) showed strongest effects with gRNA 2 and 5; dCas9 alone did not mediate significant repression from the gRNA 2 position but did from gRNA 5, likely due to steric effects. The dCas9 control did not mediate repression from any other site, clearly different from the CtBP effects with gRNAs 1, 2, and 3. A simple distance effect, with stronger repression proximal to the transcriptional start site, was not evident. Additionally, CtBP(S) appeared to be more effective at the more distal gRNA 1 and B positions than near the TSS, at 4. Overall, it is striking that CtBP(L) performed similarly to CtBP(S) on this reporter, given the clear differences noted for activity in the native chromosomal context.",
"Here, we created novel dCas9-chimeras to CtBP corepressor proteins to compare their impact on gene expression in an in vivo system. Our study of Drosophila CtBP(L) and CtBP(S) isoforms using this CRISPRi approach has revealed that the two isoforms of this corepressor do exhibit different functional potential. Additionally, CtBP itself shows promoter selectivity, consistent with the findings of the Stark laboratory, where CtBP(S) was assayed against a wide spectrum of putative enhancers. Our data suggest that CtBP proteins are involved in selective modulation of their gene targets, consistent with a “soft repression” form of regulation that may characterize many repressive interactions in the cell.",
"Evolutionary conservation of the CTD of CtBP indicates that this portion of the corepressor must be of importance; yet, most assays employed in previous studies have not identified a difference in function at the transcriptional level. One possible explanation is that the domain is involved in other aspects of CtBP biology, such as turnover or intracellular targeting, which may be overlooked in overexpression assays. Alternatively, its function in gene regulation may not have been identified yet, as the context in which CtBP has been assayed is limited; even the recent high-throughput assessment of GAL4-CtBP(S) using STARR-seq was carried out with transient transfections, and the significance of the CTD were not assessed. There may be diverse roles for this IDR; however, our results strongly point to a transcriptional regulatory potential for the unstructured CtBP CTD.",
"Few studies have tested the impact of CtBP proteins with or without the conserved, long CTD on expression of endogenous genes, with the exception of genomic rescue experiments that demonstrated that viability is possible with either a CtBP(S) or CtBP(L) rescue construct. However, the survivors from genomic rescues employing single isoforms showed a variety of phenotypes, including elevated embryonic lethality and aberrant wing development, indicating that limiting expression to one isoform alone does not fully satisfy developmental demands. Here, by directly testing CtBP isoforms using CRISPRi on endogenous genes in Drosophila , we uncovered a striking difference between CtBP(L) and CtBP(S). On the Mpp6 promoter, CtBP(S) was a potent repressor of gene expression and caused a severe wing phenotype, while CtBP(L) was much milder in its transcriptional and phenotypic effects.",
"Many studies probing IDR functions have relied on high-throughput assays to characterize IDRs en masse, and those focused on specific IDRs and proteins with disordered domains often use cell culture assays to uncover function. Therefore, it is important that with a direct comparison of our transcriptional effectors using transiently transfected reporters in S2 cells, we are unable to recapitulate the clear difference between CtBP(S) and CtBP(L) observed when targeting genes in a chromosomal context in the developing organism. Our finding that the CtBP(L) isoform is less active only on the chromatinized endogenous E2F2/Mpp6 regulatory region provides support for the notion that the CTD regulation is chromatin related. By combining an in vivo approach with CRISPRi, which is rarely done for dissecting mechanisms of gene regulation, we uncovered that the unstructured and highly conserved CTD of CtBP does in fact play a role in gene regulation. Additionally, our CRISPRi system ensures targeting to the promoter; thus, the CTD regulatory impact is likely to be at the level of transcriptional action, rather than promoter binding.",
"What might be the molecular action of this IDR on CtBP itself? Biochemical assays have shown that this intrinsically disordered domain is not required for NAD(H) binding or oligomerization—properties which are necessary for in vivo functionality. The CTD of mammalian CtBP has been shown to be a target of posttranslational modifications, including phosphorylation and sumoylation, which may affect conformation or protein–protein interactions of this domain. It is interesting that a different eukaryotic dehydrogenase-like corepressor, NPAC/GLYR1, similar to CtBP, forms tetramers and possesses an IDR that is involved in functional contacts with histone-modifying lysine demethylases. A similar function for the CtBP CTD may be uncovered in the future, but deeper understanding will require further biochemical and molecular genetic studies.",
"To create UAS:dCas9-CtBP constructs, the FLAG-tagged. These coding sequences were amplified from their parent vector using 5′ Pac I and 3′ Xba I sites and inserted in place of Rbf1 in the UAS:dCas9-Rbf1 plasmid described previously. CtBP(L) is isoform F, and CtBP(S) is a combination of isoform E and J, based on Flybase nomenclature. The Mpp6 -luciferase reporter construct uses the Mpp6 promoter, which includes the Mpp6 5′UTR, to drive luciferase expression, as was described previously. The gRNA plasmids used in transfections were described previously and target different sites of the E2F2/Mpp6 bidirectional promoter.",
"Flies were fed on standard lab food. Homozygous nubbin-GAL4 >UAS:dCas9-CtBP flies were crossed to homozygous gRNA flies to generate triple heterozygotes was used to measure statistical significance. Error bars indicate SD",
"Reporter assays were performed as described previously but with dCas9-CtBP(L) and dCas9-CtBP(S) effectors used here.",
"Drosophila S2 cells were grown in 25 °C in Schneider Drosophila medium with glutamine). Blocking with both primary and secondary antibodies was performed in 5% milk-TBST (500 mM Tris-HCl, pH 7.4, 150 mM NaCl, 0.1% Tween 20). Blots were developed using HRP-conjugated GaM and GaR secondary antibodies (Pierce) and imaged using SuperSignal West Pico chemiluminescent substrate.",
"The data supporting the findings of this study are available within the article and in the .",
"The authors declare that they have no conflicts of interest with the contents of this article."
] |
PMC10318683
|
Journal of Eating Disorders
|
Chinese TikTok (Douyin) challenges and body image concerns: a pilot study
|
03-07-2023
|
Background Social media content on Western platforms promoting thinness, or thinspiration , has been found to negatively affect body image perception of users. Less is known about non-Western social media use and its effects on body image concerns. Chinese TikTok, known as Douyin, is a popular short video platform with 600 million daily active users. Recent trends on Douyin encourage users to demonstrate thinness through participation in ‘body challenges’. This paper argues that such content is comparable to thinspiration, however, to date hardly any research has been undertaken on these challenges. Thus, this pilot study aimed to analyse the content of three viral challenges and investigate their impact on Douyin users. Methods Thirty most viewed videos were collected for three challenges (N = 90): the Coin challenge, the A4 Waist challenge, and the Spider leg challenge. Videos were coded for variables relating to thin idealisation, including thin praise, sexualisation and objectification, and analysed through content analytic methods. Video comments (N ≈ 5500) were analysed through thematic analysis, and main themes were identified. Results Preliminary findings showed that participants who objectified their bodies to a greater extent expressed more negative body image concerns. In addition, comments on the videos had themes of thin praise, self-comparison, and promotion of dieting behaviours. In particular, videos of the A4 Waist challenge were found to incite more negative self-comparison in viewers. Conclusion Preliminary findings suggest all three challenges promote the thin ideal and encourage body image concerns. Further research about the broader impact of body challenges is needed.
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[
"Social media plays an important role in shaping public perceptions of body ideals. Short-video platforms, such as TikTok, have further facilitated the dissemination and consumption of media content and popularised challenge videos that involve wide user participation. The aim of our study was to analyse the content of three viral Chinese TikTok with both peers and celebrities compared to the previous mass media that mainly focused on celebrities [ , ]. The predominance of visual media on video- and image-sharing platforms such as TikTok or Instagram combined with 'thin ideal' stereotypes by users who engage in interactive comment exchanges for the different images and videos, presents a potential explanation for the strong association between social media use and eating concerns [ ].",
"Importantly, following the outbreak of COVID-19, researchers have theorised that an increased use of social media during the pandemic and concerns about health and fitness during COVID-19-related isolation may have increased the risk of developing eating disorders in vulnerable individuals [ , ]. In particular, symptom escalation correlated with the pandemic was most commonly reported in individuals with confirmed eating disorder cases, young women, athletes and parents or carers [ ].",
"Given the prevalence of social media use globally, with an estimated 4.26 billion users in 2021 [ ], it is important to examine the effect of social media on body image in other countries. With 926.8 million users alone, China is the largest national social media market in the world, despite government censorship of Western social media sites such as Facebook and Instagram [ ]. Despite this high number of social media users in China, limited attention has been given to the impact of local social media in Asian countries [ ]. This points to a gap in the literature on the impact of social media on body image in China, which is especially concerning given that rates of clinical eating disorders among female undergraduate students in China have been found to be on par with equivalent populations in the US [ ]. Furthermore, while regional comparisons show that the prevalence of eating disorders have historically been lower in non-Western countries, they are gradually catching up [ – ].",
"Studies focusing on a Chinese population have found that traditional mass media reflects societal expectations to be thin, which creates perceived appearance pressure that is linked to body dissatisfaction and other risk factors were more likely to judge themselves as larger-bodied [ ]. However, the impact of media may be affected by the cultural context, as well as factors such as socioeconomic status, modernisation, and urbanisation, all of which may influence body ideals in non-Western cultures [ , , ].",
"In the past decade, the rising trend of online videos encouraging viewers to undertake or participate in ‘body challenges’ showcasing users' thinness has drawn concern about their contribution to increased disordered eating behaviours [ ]. These videos have been popularised on Douyin, known as TikTok outside of mainland China, a social media platform with 689 million monthly active Chinese users, the Coin challenge, #锁骨放硬币 coded the videos individually, and discussed the results.",
"Variables were coded as present or absent. Two coders analysed each challenge, and the percentage of agreement and Cohen’s Kappa were calculated to assess the reliability of the coding. A third coder then resolved any discrepancies to create a final code. The frequencies of present variables were then used for quantitative analyses and comparison of video content, based on a method employed by Alberga et al. [ ]. Differences in the frequencies of variables of interest across the challenges were not assessed using Chi-square analyses, or Fisher’s exact tests given that many of the counts were 0 for some of the challenges. Finally, descriptive statistics about the videos were collected, for example the percentage of videos with the challenge music, or the percentage of videos in which the subject themselves are speaking.",
"Thematic analysis methods were chosen to show the impact of challenge videos on viewers who commented on the videos, as well as the video creators themselves and sample comments were selected to demonstrate the themes who were fluent in Chinese and English coded the extracted comments.",
"A main purpose of this study was to inductively examine the prevalent themes within the viewers; thus, refined nuances were included in the map in the branched tiers to provide a more detailed picture of the viewers’ responses to the challenges. This also allowed contemplation of possible relationships between content dataset and shows that more video subjects had female or feminine appearances. More commenters also identified as female, as indicated by their gender identity listed on their profiles with other personal information, arms. All Spider leg challenge videos featured the subject participating in the challenge, 96.67% of the Coin challenge subjects participated, and none of the A4 Waist challenge videos featured the subject participating in the challenge. Similarly, subjects in most of the Coin and Spider leg challenge videos displayed a positive attitude towards the challenge, feeling happy at having succeeded - C1, C14, C17",
"哇哦!居然成功了 - C8",
"挑战一下看看能不能放更多的硬币。加油好好瘦! - A1",
"你是不是像这样侧躺的时候呢, 发现腰线出来了, 但是肚子前面的肉呢, 却流到床上。, and sexualisation comments. The Physical Trait subtheme under Criticism of Video Subject included commenting that subjects are not thin enough or too thin, comparison with other people, and personal insults such as “you disgust me”. The themes Criticism of Video Subjects and Criticism of the Challenge shared one common theme, which is Demeaning Comments. Demeaning Comments could present themselves as personal insults, gender comparison, or commenter being unimpressed about the challenge that the video subject is doing.",
"Many comments expressed their approval of the challenge itself, seeing it as an instrument worthy of being spread and popularised. The most common type of comment was a user tagging another user. @user 我想看你拍个这个 - A1.1 瘦下来的你, 更好看了【666】 . The overall predominance of thin bodies in the videos aligns with findings from studies which performed content analysis on fitspiration and thinspiration content on Western social media sites and suggested that the Western female body ideal is one of thinness [ , , ]. Our current findings therefore confirm the findings of other studies, which theorise that the contemporary Chinese female body ideal also incorporates thinness as a key attribute [ – ]. This suggests that the Douyin body challenge videos, as a form of social media designed to show off video subjects’ physical appearances, may enable appearance comparison in a similar manner to thinspiration and fitspiration content. Social comparison has been theorised as the major mechanism for media exposure to lead to body dissatisfaction and disordered eating through sociocultural exposures [ ]. The most notable of these models is the Tripartite Influence Model [ ] which proposes that the main influences for body image are peers, parents. Hence, our findings suggest that people with existing body dissatisfaction who then engage in body-focused Douyin challenges as either a subject or a viewer would be more likely to report greater body dissatisfaction. Some proportion of the body challenge videos contained thin praise. Thin praise was found in 50% of the A4 Waist, 16.67% of the Coin and 3.33% of the Spider leg challenge videos. As above, this draws similarities with thinspiration and fitspiration images of women on Western social media sites. In particular, Tiggemann and Zaccardo [ ] found that a majority were of men of an average body type, with 0% of a thin body type. However, in our current study, there were very few videos extracted featuring men. Objectification can influence the degree of sexualisation, which ultimately affects body image concerns. We theorised that body focused Douyin challenges would have greater objectification elements, and objectification of video subjects was approximated by the incidences of videos which did not show the full body of the subject. While the Spider leg challenge videos tended to be less objectifying in the sense that more of the body was shown. Besides eating restriction, the mention of mental illness was also absent in all of the videos collected. The lack of mention for mental illness may be the result of cultural differences. Mental health is highly stigmatised in Chinese culture, and it is closely correlated with moral values and societal expectations [ , ]. A person with mental health issues is more likely to face stigma and discrimination in China compared to other Western countries, and often result in more negative life outcomes, such as less social/familial support [ ]. Therefore, not mentioning mental illness may be protective for both the video subjects and commenters to avoid unnecessary negative feedback. Mention of celebrities was coded in 6.67% of the A4 Waist, 6.67% of the Coin, and 3.33% of the Spider leg challenge videos. Even though mention of celebrity was not coded in many of the challenge videos, it was still important to include this variable because of Douyin’s unique operation system linking video subjects’ profit or other positive outcomes, such as fame, exposure, sponsorships, etc., with the popularity of their videos. By mentioning trendy celebrities, the video subjects are not only bringing the attention of celebrities’ fans to the videos but also garner views through relevant trends and potentially increasing their own fans [ ]. For example, a famous singer in China, Hua Chenyu, was often mentioned in the Coin challenge videos because he participated in the challenge on multiple TV channels and TV shows. His participation video clips from these TV shows were then uploaded to Douyin, where the challenge became viral among his fans. From there, this challenge was able to reach a broader population not limited to Hua’s fans and became a national challenge. The participation of big-name singers and actors in these Douyin challenges was different from the participation of influencers or YouTubers in other studies [ ]. The big-name singers and actors tend to have more fans and better reputations compared to individual influences that may only be known for certain populations. Therefore, mentioning or including big-name celebrities would help increase more engagement of the viewers, which promotes the videos and video subjects naturally. In addition, YouTube videos tend to be longer and allow the subjects to use disclaimers when engaging in potentially dangerous behaviours to protect the viewers and minimise the harm. Douyin is a short video platform, therefore, video subjects tend to jump right into the topic without disclaimers, which could potentially be more dangerous. Challenging others was the other new variable for this study and was coded in 26.67% of the Coin, 6.67% of the Spider leg, and none of the A4 Waist challenge videos. Although not all of the challenge videos collected had challenged others, it was included as it is also unique to the nature of a Douyin Challenge. Video subjects use challenging others as a strategy to encourage engagements from the viewers and interact with the viewers in the hope to gain more impact on the Douyin platform. The operation system of Douyin allows the video subjects and viewers to interact in a way where viewers are presented with content that they are interested in, and video subjects are gaining profit or popularity through the engagement the age groups or populations that a challenge is targeted to, is a motivating factor to exercise [ , , ]. In accordance with our finding, Alberga, Withnell [ ] noted that the encouragement to exercise for appearance-related reasons has been previously linked to negative body image [ , ], disordered eating [ ] and depressive symptoms [ ]. To conclude, the content analysis described above demonstrated that most subjects were coded as thin, a small number were coded as average, but none had larger bodies or were coded as overweight. Combined with their themes of encouraging everyone to complete exercises together and lose weight were different from the newer challenges are of Chinese heritage and have competency in the Chinese language, they are not currently located in China and received some parts of their education in Australia and the United States. Every effort was made to interpret meaning through a Chinese cultural lens; however, it must still be noted that the thematic and content analyses were conducted by coders with a Western-biased understanding of social media use, landscape, and lifestyle integration. Second, the relatively small sample size of videos meant that videos which were once popular a few years ago at the height of the challenge’s popularity may have since been deleted. Furthermore, the temporal difference between the video’s creation and the present study may be enough to shift the sociocultural context within which the challenges were viewed. Lastly, a final limitation was potential errors in extracting the comments. Python was used to extract the comments into an Excel file format, the visual impact of some emojis were limited. The challenge in both cases was to accurately extract meaning from a visual symbol or a description of one. Despite these limitations, the study also had several notable strengths. Its primary strength was the application of an inductive, mixed methods approach to the analysis of a novel set of data (Chinese social media, or Douyin videos specifically). Specifically, where literature is scarce, the use of inductive research methods allowed the data to guide research hypotheses without preconceived biases. In addition, the study was able to consider both Chinese and Western cultural contexts comparatively due to the coders’ language competencies in both English and Chinese. Furthermore, analysis of comments demonstrated it can be a rich source for investigating the impacts of social media content on viewers.",
"@user 我想看你拍个这个 - A1.1",
"瘦下来的你, 更好看了【666】 . The overall predominance of thin bodies in the videos aligns with findings from studies which performed content analysis on fitspiration and thinspiration content on Western social media sites and suggested that the Western female body ideal is one of thinness [ , , ]. Our current findings therefore confirm the findings of other studies, which theorise that the contemporary Chinese female body ideal also incorporates thinness as a key attribute [ – ].",
"This suggests that the Douyin body challenge videos, as a form of social media designed to show off video subjects’ physical appearances, may enable appearance comparison in a similar manner to thinspiration and fitspiration content. Social comparison has been theorised as the major mechanism for media exposure to lead to body dissatisfaction and disordered eating through sociocultural exposures [ ]. The most notable of these models is the Tripartite Influence Model [ ] which proposes that the main influences for body image are peers, parents. Hence, our findings suggest that people with existing body dissatisfaction who then engage in body-focused Douyin challenges as either a subject or a viewer would be more likely to report greater body dissatisfaction.",
"Some proportion of the body challenge videos contained thin praise. Thin praise was found in 50% of the A4 Waist, 16.67% of the Coin and 3.33% of the Spider leg challenge videos. As above, this draws similarities with thinspiration and fitspiration images of women on Western social media sites. In particular, Tiggemann and Zaccardo [ ] found that a majority were of men of an average body type, with 0% of a thin body type. However, in our current study, there were very few videos extracted featuring men.",
"Objectification can influence the degree of sexualisation, which ultimately affects body image concerns. We theorised that body focused Douyin challenges would have greater objectification elements, and objectification of video subjects was approximated by the incidences of videos which did not show the full body of the subject. While the Spider leg challenge videos tended to be less objectifying in the sense that more of the body was shown.",
"Besides eating restriction, the mention of mental illness was also absent in all of the videos collected. The lack of mention for mental illness may be the result of cultural differences. Mental health is highly stigmatised in Chinese culture, and it is closely correlated with moral values and societal expectations [ , ]. A person with mental health issues is more likely to face stigma and discrimination in China compared to other Western countries, and often result in more negative life outcomes, such as less social/familial support [ ]. Therefore, not mentioning mental illness may be protective for both the video subjects and commenters to avoid unnecessary negative feedback.",
"Mention of celebrities was coded in 6.67% of the A4 Waist, 6.67% of the Coin, and 3.33% of the Spider leg challenge videos. Even though mention of celebrity was not coded in many of the challenge videos, it was still important to include this variable because of Douyin’s unique operation system linking video subjects’ profit or other positive outcomes, such as fame, exposure, sponsorships, etc., with the popularity of their videos. By mentioning trendy celebrities, the video subjects are not only bringing the attention of celebrities’ fans to the videos but also garner views through relevant trends and potentially increasing their own fans [ ]. For example, a famous singer in China, Hua Chenyu, was often mentioned in the Coin challenge videos because he participated in the challenge on multiple TV channels and TV shows. His participation video clips from these TV shows were then uploaded to Douyin, where the challenge became viral among his fans. From there, this challenge was able to reach a broader population not limited to Hua’s fans and became a national challenge. The participation of big-name singers and actors in these Douyin challenges was different from the participation of influencers or YouTubers in other studies [ ]. The big-name singers and actors tend to have more fans and better reputations compared to individual influences that may only be known for certain populations. Therefore, mentioning or including big-name celebrities would help increase more engagement of the viewers, which promotes the videos and video subjects naturally. In addition, YouTube videos tend to be longer and allow the subjects to use disclaimers when engaging in potentially dangerous behaviours to protect the viewers and minimise the harm. Douyin is a short video platform, therefore, video subjects tend to jump right into the topic without disclaimers, which could potentially be more dangerous.",
"Challenging others was the other new variable for this study and was coded in 26.67% of the Coin, 6.67% of the Spider leg, and none of the A4 Waist challenge videos. Although not all of the challenge videos collected had challenged others, it was included as it is also unique to the nature of a Douyin Challenge. Video subjects use challenging others as a strategy to encourage engagements from the viewers and interact with the viewers in the hope to gain more impact on the Douyin platform. The operation system of Douyin allows the video subjects and viewers to interact in a way where viewers are presented with content that they are interested in, and video subjects are gaining profit or popularity through the engagement the age groups or populations that a challenge is targeted to, is a motivating factor to exercise [ , , ]. In accordance with our finding, Alberga, Withnell [ ] noted that the encouragement to exercise for appearance-related reasons has been previously linked to negative body image [ , ], disordered eating [ ] and depressive symptoms [ ].",
"To conclude, the content analysis described above demonstrated that most subjects were coded as thin, a small number were coded as average, but none had larger bodies or were coded as overweight. Combined with their themes of encouraging everyone to complete exercises together and lose weight were different from the newer challenges are of Chinese heritage and have competency in the Chinese language, they are not currently located in China and received some parts of their education in Australia and the United States. Every effort was made to interpret meaning through a Chinese cultural lens; however, it must still be noted that the thematic and content analyses were conducted by coders with a Western-biased understanding of social media use, landscape, and lifestyle integration.",
"Second, the relatively small sample size of videos meant that videos which were once popular a few years ago at the height of the challenge’s popularity may have since been deleted. Furthermore, the temporal difference between the video’s creation and the present study may be enough to shift the sociocultural context within which the challenges were viewed.",
"Lastly, a final limitation was potential errors in extracting the comments. Python was used to extract the comments into an Excel file format, the visual impact of some emojis were limited. The challenge in both cases was to accurately extract meaning from a visual symbol or a description of one.",
"Despite these limitations, the study also had several notable strengths. Its primary strength was the application of an inductive, mixed methods approach to the analysis of a novel set of data (Chinese social media, or Douyin videos specifically). Specifically, where literature is scarce, the use of inductive research methods allowed the data to guide research hypotheses without preconceived biases. In addition, the study was able to consider both Chinese and Western cultural contexts comparatively due to the coders’ language competencies in both English and Chinese. Furthermore, analysis of comments demonstrated it can be a rich source for investigating the impacts of social media content on viewers.",
"This study aimed to explore the relationships between Douyin body challenge videos and body dissatisfaction in both video creators and viewers. Overall, the trending challenges contain content of concern with regards to body image and risks for disordered eating. The nature of the challenges, elements of objectification and sexualisation, thin-ideal messaging and unnatural filtered appearances contribute to negative and problematic attitudes towards body image. Thematic analysis of users’ comments revealed that viewing challenges can lead to greater body dissatisfaction, in addition, viewers can participate and objectively compare themselves. Moreover, the widespread nature of challenge through users’ participation and tagging, or digitally by the Douyin platform itself, means the risk of body dissatisfaction or disordered eating may be greater than other social media trends with similar risks. The study hopes to inform further research on short-video platforms similar to Douyin, including TikTok or YouTube Shorts or Instagram Reels, or Chinese social media, or challenge videos specifically."
] |
PMC10946784
|
Angewandte Chemie (Weinheim an Der Bergstrasse, Germany)
|
Enzyme‐Activatable Chemokine Conjugates for In Vivo Targeting of Tumor‐Associated Macrophages
|
05-09-2022
|
Abstract Increased levels of tumor‐associated macrophages (TAMs) are indicators of poor prognosis in most cancers. Although antibodies and small molecules blocking the recruitment of macrophages to tumors are under evaluation as anticancer therapies, these strategies are not specific for macrophage subpopulations. Herein we report the first enzyme‐activatable chemokine conjugates for effective targeting of defined macrophage subsets in live tumors. Our constructs exploit the high expression of chemokine receptors (e.g., CCR2) and the activity of cysteine cathepsins in TAMs to target these cells selectively over other macrophages and immune cells (e.g., neutrophils, T cells, B cells). Furthermore, we demonstrate that cathepsin‐activatable chemokines are compatible with both fluorescent and therapeutic cargos, opening new avenues in the design of targeted theranostic probes for immune cells in the tumor microenvironment.
|
[
"Macrophages are critical regulators of tissue homeostasis, but some subpopulations",
"Antibody‐drug conjugates, which use monoclonal antibodies for cell targeting, have been successfully translated to the clinic; however, antibodies for some proteins"
] |
PMC10531928
|
Insects
|
Differential Spreading of Microsatellites in Holocentric Chromosomes of Chagas Disease Vectors: Genomic and Evolutionary Implications
|
19-09-2023
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Simple Summary This study analyzed microsatellite distribution in the holocentric chromosomes of Triatominae, Chagas disease vectors. Using a non-denaturing FISH technique, 16 microsatellites were examined across 25 species from the Triatomini and Rhodniini tribes. Three hybridization patterns emerged: strong signals in specific regions, dispersed signals based on microsatellite abundance and the absence of signals in certain regions or chromosomes. Rhodniini had weak and scattered signals, indicating low microsatellite abundance, while Triatomini showed diverse and abundant patterns, suggesting their significance in genomes. Particularly, all Triatomini species exhibited a high abundance of GATA repeats in the Y chromosome, unlike Rhodniini. This suggests the ancestral trait is specific to Triatomini. The study provides insights into microsatellite composition and distribution in Triatominae genomes, shedding light on their evolutionary processes and relationships with other reduviid groups. Abstract This study focused on analyzing the distribution of microsatellites in holocentric chromosomes of the Triatominae subfamily, insect vectors of Chagas disease. We employed a non-denaturing FISH technique to determine the chromosomal distribution of sixteen microsatellites across twenty-five triatomine species, involving five genera from the two principal tribes: Triatomini and Rhodniini. Three main hybridization patterns were identified: strong signals in specific chromosomal regions, dispersed signals dependent on microsatellite abundance and the absence of signals in certain chromosomal regions or entire chromosomes. Significant variations in hybridization patterns were observed between Rhodniini and Triatomini species. Rhodniini species displayed weak and scattered hybridization signals, indicating a low abundance of microsatellites in their genomes. In contrast, Triatomini species exhibited diverse and abundant hybridization patterns, suggesting that microsatellites are a significant repetitive component in their genomes. One particularly interesting finding was the high abundance of GATA repeats, and to a lesser extent AG repeats, in the Y chromosome of all analyzed Triatomini species. In contrast, the Y chromosome of Rhodniini species did not show enrichment in GATA and AG repeats. This suggests that the richness of GATA repeats on the Y chromosome likely represents an ancestral trait specific to the Triatomini tribe. Furthermore, this information can be used to elucidate the evolutionary relationships between Triatomini and other groups of reduviids, contributing to the understanding of the subfamily’s origin. Overall, this study provides a comprehensive understanding of the composition and distribution of microsatellites within Triatominae genomes, shedding light on their significance in the evolutionary processes of these species.
|
[
"Microsatellites, also known as short tandem repeats, these loci are usually no longer than 100 nucleotides. These short microsatellite arrays, despite their presence at many genomic locations, can only be detected in specific situations in the chromosomes by fluorescence in situ hybridization can be an alternative to conventional FISH techniques when oligonucleotides are used as probes [ ]. The implementation of ND-FISH using single-sequence oligonucleotides as probes has been a breakthrough in determining the presence and distribution of microsatellites in both plants and animals, facilitating the knowledge of the chromosomal origin, organization, function and evolution of these repeats’ sequences [ , , ].",
"In insects, bioinformatic analyses conducted on 136 species, including 12 hemipteran species, have revealed that microsatellites represent only a small fraction of the whole genome, ranging from 0.02% to 3.1% [ ]. However, in two Triatoma species, T. infestans and T. delpontei , our genome analyses from low-coverage sequencing using RepeatExplorer2, RepeatMasker v.4.1.1 and RepeatProfiler software programs have identified two highly amplified microsatellites comprises over 150 species of blood-sucking insects commonly known as kissing bugs. Many of these species are vectors of Chagas disease [ ], which is recognized as the most severe parasitic disease in Latin America. It is caused by the protozoan Trypanosoma cruzi and affects approximately six to seven million people worldwide [ ]. Triatomines, like other hemipteran insects, possess chromosomes with diffuse or non-localized centromeres, known as holocentric chromosomes [ ]. Triatomines exhibit high uniformity in their diploid chromosome numbers, ranging from 2n = 21 to 2n = 25 chromosomes in males [ ]. The number of autosomes remains remarkably constant, with almost all of the 102 studied species having 20 autosomesX_(2)Y and X_(1)X_(2)X_(3)Y, the first one considered the ancestral system [ ]. Despite the overall stability in chromosome number, triatomines exhibit significant karyotypic variation in terms of the quantity, distribution and base pair composition of heterochromatin, as evidenced by C-banding and fluorochrome staining techniques [ , ]. Additionally, there is considerable variability in the chromosomal location of the major ribosomal clusters among these insects [ ].",
"To gain a deeper understanding of the microsatellite composition of heterochromatin and the sex chromosome evolution in the subfamily Triatominae and male sex chromosome systems.",
"Chromosome preparations were obtained from males. Testes were removed from adult insects alive and fixed in an ethanol:glacial acetic acid mixture_(20) and and streptavidin-Cy3, populations and individuals from the same population [ ]. A shows the C-banding pattern obtained in one of the Andean individuals used in this study, with heterochromatic blocks on nine of the ten bivalents; only the smallest bivalent seems to lack C-heterochromatic blocks.",
"In T. infestans , three microsatellite probes,. As commented above, the number of autosomes with heterochromatic blocks is variable. Anyway, the distribution and intensity of the. The presence of GATA repeats in the heterochromatic regions of Andean T. infestans was previously shown using conventional FISH [ ]. Two probes,. On the contrary, four motifs,. For these four probes, hybridization signals appeared scattered over euchromatin regions of all autosomes and the X chromosome, covering almost the entire chromosomal length, except for the distal regions where heterochromatin was localized. It is noticeable that the hybridization patterns of the motifs, while appearing free of labeling with GACA, AC, C, A and AAG repeats. No hybridization signals were observed with the remaining analyzed trinucleotides.",
"The heterochromatic Y chromosome of all analyzed Triatomini species. In addition, and similar to the T. infestans Andean group, some species of Triatoma , Panstrongylus and Mepraia showed hybridization with. The presence of GATA repeats in the heterochromatin was previously described in Andean and non-Andean T. infestans , as well as in T. delpontei , using conventional FISH [ , ]. Interestingly, in other Triatomini species, the heterochromatic autosomal regions appear free of the GATA label, such as T. sordida , all North American Triatoma , Paratriatoma lecticularia and several Panstrongylus species. However, T. nitida presents a euchromatic bivalent with strong GATA signals. The remaining eight bivalents, including the two heterochromatic ones, do not have any GATA signals. In most species, the X chromosomes appear without hybridization signals, excepting some species with a GATA dot, such as the T. infestans Andean group, T. delpontei , T. patagonica , and M. spinolai . Nevertheless, in T. barberi , the hybridization signals cover the entire length of the X_(2) chromosome. In these species, the X chromosomes also have a heterochromatic region revealed by C-banding. No.",
"This microsatellite generates three main hybridization patterns:. In this species, AG repeats generate strong hybridization signals on heterochromatic regions of four autosomes and the Y chromosome, similar to those observed with GATA repeats. In addition, dispersed AG repeats are also observed in most euchromatic autosomal regions, while other euchromatic regions and the X chromosome did not show a label.",
"In the other Triatomini species, the accumulated pattern of AG is also very similar to that observed with GATA repeats. The heterochromatic Y chromosome is also intensely labeled with the AG probes, indicating the high number of these repeats. In autosomal chromosomes, in some species, such as T. infestans , T. delpontei and T. patagonica , AG repeats colocalize in the same heterochromatic blocks with GATA repeats. However, in T. sordida and all North American Triatoma , Panstrongylus , Paratriatoma and Mepraia species, the heterochromatic autosomal regions appear free of labeling with the and T. nitida do not show AG repeats. Two species, T. sanguisuga and T. recurva show a strong dot signal in only one bivalent. The X chromosomes appear without hybridization signals in all species except for T. barberi , where the smallest X_(2) chromosome is almost entirely labeled. No. The richness of AC repeats over most of the length of the autosomes could be observed in species lacking autosomal heterochromatin, such as P. lutzi and T. carrioni . E–G show the same spermatogonial metaphase of T. rubrofasciata , wherein the terminal C-heterochromatic regions of all autosomes and Y chromosomes showed an exact inverse pattern compared to the GATA pattern. Finally, no signals with. Triatoma delpontei , T. nitida and M. spinolai show a dot region on one autosome pair. In T. nitida , the half-bivalent with, the euchromatic regions of all autosomes and both X chromosomes presented terminal AAG regions, while the Y chromosome was free of label. The double hybridization of AAG + GATA clearly shows the reverse distribution of both microsatellites, with euchromatin labeled with AAG and heterochromatin labeled with GATA."
] |
PMC10474031
|
Scientific Reports
|
Building capacity for estimating fire emissions from tropical peatlands; a worked example from Indonesia
|
01-09-2023
|
Tropical peatlands are globally significant in the terrestrial carbon cycle as they are comprised of a large forest carbon sink and a large peat carbon store—both of which can potentially be exchanged with the atmosphere on decadal time frames. Greenhouse gas emissions from fire-disturbance and development of tropical peatlands over the last few decades, and the potential for ongoing emissions, highlights the need for policy to slow or halt emissions and to activate mechanisms to sequester carbon through restoration of degraded peatlands. The UN REDD + scheme provides a means for developing countries to receive payments for avoided deforestation and forest degradation, but the steps to achieve REDD+ compliance are rigorous and the details required can be a barrier to activating benefits—especially for peatlands where repeated cycles of fire interrupt forest recovery and create a range of recovery classes. Therefore, to improve estimates of peat fire emissions and of carbon balance of tropical peatlands, the biomass and combustion factor parameters need to be developed and applied according to forest recovery stage. In this study we use published activity data from the extensive 1997 fires in the peatlands of Indonesian Borneo to detail a transparent and accountable way to estimate and report emissions from tropical peatland fires. This example for estimating and reporting emissions is provided to assist REDD+ countries to efficiently develop their capacity for improving emissions estimates from fire-impacted tropical peatlands.
|
[
"Greenhouse gas, where the latter are generally dominated by shrubs and grasses and have a shallower peat layer than less disturbed forests^(12).",
"Recognizing the varying outcomes of either recovery or continued degradation of peatland landscapes following disturbance is important for carbon and emission accounting, as forest condition sets the starting point for selecting the most appropriate parameters for emissions calculations. However most published studies rely on the default parameters provided in the Guideline of the Intergovernmental Panel on Climate Change IPCC^(13) that apply to primary forests, and rarely adopt parameters that are more appropriate to the burning of already degraded peat swamp forests. Moreover, as we mentioned above, highly cited publications on the amount of emissions released from peat fires in Indonesia have applied simplified, non-IPCC methods for estimating emissions, and have also not distinguished between primary and already degraded peatlands in making their emissions estimates^(7 , 14).",
"Initial methodologies for estimating emissions from biomass burning were published by the IPCC in 1996^(15). The parameters required for estimating emissions are the activity data.",
"The EF is estimated as the mass of the fuel available for combustion.",
"In the case of peatlands, separate EFs are required for aboveground and peat layers—as both are combusted in fires, thus information on mass of peat.",
"Emissions are reported in CO_(2)-equivalent and global warming potential:",
"As we mentioned above, using the same M for primary or intact forests and for degraded peatlands will either over or underestimate emissions. Therefore, emissions estimates should be stratified by peatland cover classes.",
"As research advances and as technologies progress revision of Eq. ( ) and parameters i.e., AGB, BD, h, Gi, Cf, acts to improve emissions estimates and reduce uncertainties. One good example of continuous updates in the emission equation parameters is for peat combustion factor. The widely used IPCC 2014 Supplement^(13) states on page 2.39: “For all organic soil fires, the default combustion factor is 1.0, since the assumption is that all fuel is combusted. We also chose the 1997 fires because of their wide coverage in the scientific literature, including fire emissions estimates equivalent to between 13 and 40% of the mean annual global carbon emissions accounted from fossil fuels^(7).",
"The methodology applied in this study estimated emissions separately for peat, and for the aboveground biomass, using the emissions equations as described above.",
"As described above in Eq. ( ), peat mass and.",
"AGB was estimated as the sum of biomass components—trees, litter, deadwood and pyrogenic carbon, pending data availability.",
"A fire area map for the 1997 fires in Kalimantan was developed using QGIS 3.3. Total emissions decreased with increased fire frequency as the depth of peat burnt decreased.",
"Emissions from AGB followed the same pattern as for peat layer with the highest emissions from long unburnt forests.",
"As mentioned in the introduction, the total burnt area for Kalimantan from the study of^(7) was applied to each of the peatland cover class reported, and emission equation parameters derived in this study were applied to estimate total emissions for the peat layer and for AGB.",
"Our emissions results for the study area are 0.14 Gt C, half the reported 0.24–0.28 Gt C in^(7). The 50% lower emissions estimate can be attributed to the following factors:.",
"The average emission estimates in our study of 1.92 × 10^(−7) Gt C ha^(−1) (i.e., the total emission of 0.14 Gt C divided by the total area burnt of 726,782.1 ha), demonstrates that the 1997 fires released between 0.47 Gt C, an intermediate estimate (1.92 × 10^(−7) Gt C ha^(−1) × 2,441,000 ha) and an upper estimate 1.31 Gt C (1.92 × 10^(−7) Gt C ha^(−1) × 6,804,668 ha), where 2,441,000 ha and 6,804,668 ha are the peat area burnt over the entire Indonesia extracted from^(7). This is a half of the 0.81–2.57 Gt C emissions previously reported. Our estimates match well with the top–down estimates of GFEDv4 of 0.5 Gt C released from the 1997 fires. While GFEDv4 estimates produced a reasonable assessment of Indonesian 1997 peat fires emissions, it may be technically challenging for some countries to use GFEDv4. The example emissions calculations shown in this study are relatively simple, can be completed in an excel spreadsheet, and also do not require an in depth knowledge of rather complex and lengthy IPCC methodologies.",
"To better enable the development of climate change mitigation actions we believe that building the capacity of countries that aspire to REDD+ payments, through international collaborations with countries more experienced in emission reporting, is a priority for the UNFCCC COP meetings to address. This study can help to guide communities from REDD+ countries, and anyone interested more generally in emissions reporting, to make informed IPCC-method compliant estimates."
] |
PMC10049479
|
International Journal of Molecular Sciences
|
Developing New Cyclodextrin-Based Nanosponges Complexes to Improve Vitamin D Absorption in an In Vitro Study
|
10-03-2023
|
Vitamin D plays an important role in numerous cellular functions due to the ability to bind the Vitamin D receptor (VDR), which is present in different tissues. Several human diseases depend on low vitamin D3 (human isoform) serum level, and supplementation is necessary. However, vitamin D3 has poor bioavailability, and several strategies are tested to increase its absorption. In this work, the complexation of vitamin D3 in Cyclodextrin-based nanosponge (CD-NS, in particular, βNS-CDI 1:4) was carried out to study the possible enhancement of bioactivity. The βNS-CDI 1:4 was synthesized by mechanochemistry, and the complex was confirmed using FTIR-ATR and TGA. TGA demonstrated higher thermostability of the complexed form. Subsequently, in vitro experiments were performed to evaluate the biological activity of Vitamin D3 complexed in the nanosponges on intestinal cells and assess its bioavailability without cytotoxic effect. The Vitamin D3 complexes enhance cellular activity at the intestinal level and improve its bioavailability. In conclusion, this study demonstrates for the first time the ability of CD-NS complexes to improve the chemical and biological function of Vitamin D3.
|
[
"Vitamin D comprises the isoforms D3. CDs are truncated cone-shaped oligosaccharides made up of α-(1,4) linked glucose units, obtained from the degradation of starch by the enzyme Cyclodextrin Glucosyltransferase is an innovative cross-linked polymer possessing good swelling properties and with a three-dimensional network and modulable tunable structure such as crystalline, amorphous or spherical structure [ ]. In recent years, it has been proposed as a possible drug carrier to be considered in pharmaceutical applications [ ], as it is stable, insoluble, biocompatible and capable of encapsulating drugs through the formation of inclusion and non-inclusion complexes. In addition, nanosponges have been reported to be able to increase the stability of drugs and reduce their degradation [ ]. Recent reviews [ , ] point to their wide potential and minimal negligible toxicity [ , ], increasing their bio-capacities in several applications including the ability to. The kneading process presents some advantages because it is scalable, easy and efficient [ ]. The 5% of loading that all the VitD3 will enter completely in the cavities and, physical mixture and inclusion complex. VitD3 showed the typical peaks around 2850–3000 cm^(−1) in the FTIR spectrum is the characteristic feature of NS [ ] An interesting change in the peak appearance was found around 850 cm^(−1). To better understand the complex formation and the stability of the complex, an isothermal TGA was performed at 200 °C is kept practically intact. A higher decrease in the mass of the physical mixture was shown in comparison with the complex, demonstrating that the beneficial effects were maintained during all periods of treatment excluding any cytotoxic effect. Concurrently, a small amount of ROS production from nanosponges and VitD3 Sigma solvent, although within physiological values, thus suggesting the absence of oxidative stress. Finally, to confirm the correct cellular function and avoid mitochondrial dysfunction at the end of the treatment, further experiments were carried out by analyzing the reduction in malonaldehyde.",
"Further experiments were performed using a 3D in vitro model to mimic the in vivo intestinal barrier complexity to assess permeability and obtain additional information about the VitD3 NS intestinal absorption. In this context, the VitD3 NS, VitD3 Physical Mix and VitD3 Sigma at the same concentration were tested from 1 to 6 h in order to evaluate transepithelial electrical resistance. Indeed, VitD3 NS 100 nM demonstrates a better effect than VitD3 Physical Mix 100 nM and VitD3 Sigma 100 nM during all treatment times confirmed our previous findings, as the amount of VitD3 NS 100 nM was able to release a huge amount of VitD3 with more efficiency over time than VitD3 Physical Mix 100 nM and VitD3 Sigma 100 nM showed that VitD3 NS was able to cross the barrier and reach the plasma level in greater amounts than the control; in particular, the major activity was shown in the cells treated with VitD3 NS with an increase of 35% and 25% compared to VitD3 Sigma and VitD3 physical, respectively. In addition, VitD3 treatment exerts a role in improving permeability by enhancing tight junction proteins; actually, in epithelial cells, tight junction formation plays a key role in the intestinal barrier, and this is mediated by proteins such as claudin, occludin, and ZO-1 that are necessary for epithelial barrier activity. As expected, VitD3 NS has been shown to maintain epithelial integrity and ion exchanges across the intestinal barrier, suggesting that this complex is able to cross the cell monolayer without negatively altering the epithelium. Summarizing, these results support the idea that nanosponges are the best choice to improve the bioavailability of molecules with poor bioavailability, including VitD3. Therefore, the application of this novel form of a vehicle could be an excellent strategy to ameliorate pharmaceutical applications for poorly soluble active ingredients.",
"The following procedure is already reported in the literature [ ], with slight modifications. The cross-linked βCD Nanosponges were prepared using the ball mill is called BCDI 1:4) was prepared weighting 1 mg and dissolving it in 2 mL of medium and diluting it to obtain the final concentration to be tested in the well was prepared by weighing 1 mg and dissolving it in 2 mL of ethanol 100% cells in 96-well plates to study cell viability by MTT; 1 × 10^(6) cells in 6-well plates to study the intracellular mechanisms involved by kit ELISA analysis and 1.8 × 10^(4) cells in a 24-well plate on 6.5 mm Transwell^(®) with 0.4 μm pore polycarbonate membrane insert cells in a 96-well plate to verify the cell viability by MTT test; 1 × 10^(6) cells in 6-well plates to study the intracellular mechanisms involved and 2 × 10^(3) cells on 6.5 mm Transwell^(®) with 0.4 μm pore polycarbonate membrane insert [ ], following the manufacturer’s instructions. Indeed, at the end of treatment, the cells were incubated with 1% MTT dye for 2 h in an incubator at 37 °C, 5% CO_(2), and 95% humidity, and then the purple formazan crystals were dissolved in an equal volume of MTT Solubilization Solution. The absorbance was analyzed by spectrophotometer was made to analyze the passage through the intestinal barrier of the three different VitD3 formulations. For this reason, the transepithelial electrical resistance and pH around 7.4 at the basolateral level, after that, the TEER values were measured again before the start of the experiment to verify the stabilization of the values. The cells were treated with three different VitD3 formulations for 2 h to 6 h before the successive analysis, including the permeability assay measured by Papp analysis [ ]. Briefly, the Papp. Specifically, 100 μL of cytochrome C. In addition, it was necessary to plot a standard curve [ ]. Briefly, 100 μL of SDS solution was added to 100 μL of sample or standard. Then, 4 mL of Dye Reagent was added to each vial before boiling them for 1 h. After cooling down the samples for 10 min, the vials were centrifuged for 10 min at 1600× g at 4 °C and then 150 μL of samples or standard were added to the wells of a 96 multi well; the absorbance of all samples was measured through a spectrometer 1× and centrifuged at 1500× g for 10 min at 4 °C. A quantity of 100 μL of each sample was added to a strip well and incubated at 37 °C for 90 min; then, the supernatants were removed and 100 μL of Detection Solution A was added to each of them and incubated for 45 min at 37 °C. After this time, the wells were washed with Wash Solution and incubated with 100 μL of Detection Solution B for 45 min, and then 90 μL of Substrate Solution was added, incubating for 20 min at 37 °C in the dark. Finally, after adding 50 μL of Stop Solution, the plate was analyzed by a spectrometer at 450 nm. The concentration was compared to the standard curve at 450 nm. The concentration was compared to the standard curve (range from 0 to 1000 pg/mL) and the results were then compared to the control (0% line), which represented untreated cells.",
"The Human Vitamin D Receptor (VDR) ELISA kit (MyBiosource, San Diego, CA, USA) was used to measure the presence of VDR in cell lysates of the coculture, following the manufacturer’s instructions. Briefly, the cells were lysed using trypsin and then collected by centrifugation. Then, cells were washed three times with cold PBS 1× and then resuspended in PBS 1×; subsequently, the cells were subjected to ultrasonication four times and then they were centrifuged at 1500× g for 10 min at 4 °C to remove cellular debris. A quantity of 100 μL of each sample was added to a well and incubated at 37 °C for 90 min; then, the materials were removed, and to each well was added 100μL of Detection Solution A and incubated for 45 min at 37 °C. Wells were washed with Wash Solution and after 100 μL Detection Solution B was added to each well. After incubation of 45 min, the wells were washed again and 90 μL of Substrate Solution was added in each well and then incubated for 20 min at 37 °C in the dark. Finally, 50 μL of Stop Solution was added and then the plates were read by a spectrometer (Infinite 200 Pro MPlex, Tecan, Männedorf, Switzerland) at 450 nm. The concentration was expressed as ng/mL and the data were compared with the standard curve (range 0.625 ng/mL–40 ng/mL).",
"For each experimental protocol, at least four independent experiments have been carried out; the results are expressed as means ± SD of independent experiments performed on four technical replicates. One-way ANOVA followed by the Bonferroni post hoc test was used for statistical analysis, and pairwise differences were compared by Mann–Whitney U tests followed by Welch’s test. p values < 0.05 were considered statistically significant.",
"In conclusion, this study demonstrates for the first time the ability of CD-NS complexes to improve the thermostability, chemical and biological function of VitD3. In particular, the chemical stability confirms the security of in vitro study in intestinal cells. This supports the potential of the VitD3 complex to be a new dietary supplementation. Although the in vitro data are very clear and promising, in vivo or even human studies would be needed to confirm these observations before assuming an absolute efficacy of this Vitamin D CD-NS. Thus, the results of the present study about the effectiveness in improving VitD3 absorption may support the hypothesis that oral administration in humans can be considered a valid therapeutic strategy to obtain beneficial therapeutic effects under low VitD3 conditions."
] |
PMC10212672
|
Journal of Parasitology Research
|
Prevalence and Associated Factors of Intestinal Parasites among Food Handlers Working in Food Service Establishments in Northwest Ethiopia, 2022
|
0-0-2023
|
Background As in most of African countries, intestinal parasites have been widely distributed in Ethiopia and are among the 10 top causes of morbidity and mortality nationwide. Statistics for food-borne illness in various industrialized countries show that up to 60% of cases may be caused by poor food handling techniques and by contaminated food served in food service establishments. Epidemiological information on the prevalence of various intestinal parasitic infections in different regions/localities is a prerequisite to develop appropriate strategies. Objective This study aimed to determine the magnitude of intestinal parasites among food handlers working in different food service establishments in Gondar city. Methods A cross-sectional study was conducted with food handlers working in different food service establishments in Gondar city. Stool samples were collected from 350 food handlers and processed using the formol-ether concentration method and then microscopically examined for intestinal parasitic infections. Pre-tested and structured questionnaire was used to study the socio-demographic characteristics of food handlers. Chi-square test and p -value were used to assess the associations between risk factors and the parasite isolation rate. The p -value ≤0.05 was considered as statistically significant. Results Of the 350 food handlers, 160 (45.71%) had parasites. Among the isolated parasites, Ascaris lumbricoides was found to be the most prevalent parasite 35.63%, followed by hookworm 19.38%, Entamoeba histolytica/dispar 16.25%, Trichuris trichiura 10.00%, Strongyloides stercoralis 8.13%, Schistosoma mansoni 6.88%, and Cystoisospora belli, Hymenolepis nana , and Taenia species each accounting 1.25%. Conclusion The result of the study indicated that the magnitude of intestinal parasitosis among food handlers working at different levels of food establishments in Gondar, Ethiopia, was found to be high. Being at lower educational level and inactive role of the town's municipality are determined as a risk factor for parasitic positivity of food handlers.
|
[
"Food-borne diseases are caused by bacteria, viruses, fungi, and parasites. Intestinal parasitosis refers to a group of diseases caused by one or more species of protozoa and helminths. These parasites are responsible for the major share of morbidity and mortality in a community where there is overcrowding, poor environmental sanitation, and poor personal hygienic practices, economic and social conditions also affect the distribution of human parasites [ – ].",
"Globally, due to intestinal parasitic infections, around 3.5 billion people are affected and more than 200,000 deaths are reported annually. Around 50,000 deaths yearly are caused by intestinal parasites in Ethiopia [ , ].",
"As in most of African countries, intestinal parasites have been widely distributed in Ethiopia and are among the 10 top causes of morbidity and mortality nationwide [ ]. According to the Ministry of Health of Ethiopia, intestinal parasitism accounts for 8.5% of all male and 10.4% of all female outpatient infections. Prevalence rates higher than 70% and high rate of multiple infections in those infected individuals have been reported from many parts of the country [ ]. Although the prevalence rates of individual parasites vary considerably latitudinal in different parts of the country, several studies show that Ascaris lumbricoides is the most prevalent intestinal parasite, followed by Trichuris trichiura , a hookworm, and Strongyloides stercoralis [ ]. The prevalence of A. lumbricoides infection was 29% in the highlands, 35% in the temperate areas, and 38% in the lowlands. The prevalence of hookworm infection was highest in the lowlands 24%, followed by highlands 17% and temperate 15% areas, and the differences were significant. T. trichiura infection exhibited similar prevalence in all altitudinal regions with undulating mountainous topography. According to the Central Statistics Agency = 0.05), the actual sample size for the study is computed using one sample population proportion formula as indicated below:",
"where: n = sample size, p = proportion of women who knew about obstetric danger signs, q = proportion of failure for 5 minutes. The supernatant was poured off, and a smear on a clean slide was prepared from the sediment and covered with a clean cover slip. The preparation was examined in the same way as that of the direct saline method. Negative results were reported after assessing the whole smear under the 10× objective [ ]. Investigators supervised all aspects of data collection and laboratory procedures.",
"Data were analyzed using SPSS version 21. Chi-square test and p -value were used to assess the association between risk factors and the parasite isolation rate. The p -value ≤0.05 was considered as statistically significant.",
"Ethical approval of the research was obtained from Ethical Review Committee of School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, and an official letter was directed to Gondar town municipality. Written informed consent was obtained from the study participants. Food handlers with parasitic infections were treated in accordance with the Ethiopian national treatment guideline. Information obtained in any course of the study was kept confidential."
] |
PMC10616234
|
Frontiers in Endocrinology
|
Associations between genetically predicted sex and growth hormones and facial aging in the UK Biobank: a two−sample Mendelian randomization study
|
17-10-2023
|
Background Aging is an inescapable process, but it can be slowed down, particularly facial aging. Sex and growth hormones have been shown to play an important role in the process of facial aging. We investigated this association further, using a two-sample Mendelian randomization study. Methods We analyzed genome-wide association study (GWAS) data from the UK Biobank database comprising facial aging data from 432,999 samples, using two-sample Mendelian randomization. In addition, single-nucleotide polymorphism (SNP) data on sex hormone-binding globulin (SHBG) and sex steroid hormones were obtained from a GWAS in the UK Biobank [SHBG, N = 189,473; total testosterone (TT), N = 230,454; bioavailable testosterone (BT), N = 188,507; and estradiol (E2), N = 2,607)]. The inverse-variance weighted (IVW) method was the major algorithm used in this study, and random-effects models were used in cases of heterogeneity. To avoid errors caused by a single algorithm, we selected MR-Egger, weighted median, and weighted mode as supplementary algorithms. Horizontal pleiotropy was detected based on the intercept in the MR-Egger regression. The leave-one-out method was used for sensitivity analysis. Results SHBG plays a promoting role, whereas sex steroid hormones (TT, BT, and E2) play an inhibitory role in facial aging. Growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels had no significant effect on facial aging, which is inconsistent with previous findings in vitro . Conclusion Regulating the levels of SHBG, BT, TT, and E2 may be an important means to delay facial aging.
|
[
"Facial aging is a multifactorial process governed by intrinsic and extrinsic factors that involves all tissues of the face, including the skin, muscles, fat, ligaments, and bone. Accordingly, exploring the mechanisms involved in facial aging, particularly facial skin aging, has been an area of interest, not only for aesthetic purposes but also because they may provide mechanistic insights into diseases with similar mechanisms. In the current society, the greatest efforts are made to camouflage signs of facial aging. While our understanding of aging has evolved over the years, a comprehensive understanding of all contributing factors is still lacking.",
"Different molecular mechanisms have been suggested to explain facial aging. In recent years, the relationship between sex hormone-binding globulin. Studies have shown that keratinocytes, Langerhans cells, melanocytes, sebaceous glands, and fibroblasts are affected by hormones. A pilot observational study of subjects who were 5 years into menopause revealed that long-term hormone therapy users had less severe wrinkling. During menopause, collagen loss accelerates due to the decrease in estrogen levels, with an average decline of 2.1% in skin collagen per postmenopausal year. In women on hormone therapy, collagen levels increase, and estradiol.",
"Mendelian randomization. In this study, we aimed to examine the potential causal associations between SHBG, total testosterone of data collected from the UK Biobank. MR is an ideal tool for investigating aging-related processes because genetic variables can affect lifetime when exposed to external environmental factors. We employed several MR methods to estimate the causal effects of sex hormones on the risk of facial aging and we used summary data-based Mendelian randomization and comprised 370,125, 194,453, and 178,782 samples, and 161,317,172, 16,131,612, and 16,131,701 SNPs under study accessions ebi-a-GCST90012111, ebi-a-GCST90012113, and ebi-a-GCST90012103. The E2 data were generated by Schmitz et al. and comprised 163,985 samples and 748,8193 SNPs under study accession ebi-a-GCST90020092. The IGF1 and GH data were generated by Prins et al. and Folkersen et al. and comprised 9,732 and 21,758 samples under study accessions ebi-a-GCST005071 and ebi-a-GCST90012032.",
"Data on facial aging were obtained from a publicly available GWAS database and included phenotypes and biological samples from 432,999 participants in Great Britain. The facial aging data in the UK Biobank were obtained via a questionnaire and can be accessed on the Integrative Epidemiology Unit GWAS database web site via accession ukb-b-2148.",
"Sex hormone-related drugs with a screening threshold of 5E10^(–8) for SNPs and using default software parameters, with Bonferroni correction for multiple p -values.",
"All statistical analyses were performed using R software. Fixed/random-effects models were selected for the IVW test according to the existence of heterogeneity. In general, the IVW method assumes that all SNPs are valid instrumental variables. It is the most recognized method, and has high statistical power. The weighted median, MR-Egger regression, and simple and weighted mode methods were used for complementary analysis. Odds ratios. The other methods corroborated that SNPs are positively correlated with facial aging. Pleiotropy, heterogeneity, and sensitivity tests were used for quality control. The results showed that a high level of heterogeneity existed, whereas pleiotropy was absent. Leave-one-out sensitivity analysis showed that all points were on the same side of zero, indicating that individual SNPs did not affect model selection.",
"Through threshold filtering, we identified 142, 73, and 19 SNPs in TT , BT , and E2 , respectively. The accumulation effect model of IVW was applied for model analysis. The IVW results were TT. Pleiotropy, heterogeneity, and sensitivity tests were used for quality control.",
"We obtained 13 SNPs in GH and 10 SNPs in IGF1 . The analytical results showed that the levels of GH and IGF-1 have no effect on facial aging.",
"Fifteen genes."
] |
PMC10058020
|
Toxins
|
Differential Role of Active Compounds in Mitophagy and Related Neurodegenerative Diseases
|
06-03-2023
|
Neurodegenerative diseases, such as Alzheimer’s disease or Parkinson’s disease, significantly reduce the quality of life of patients and eventually result in complete maladjustment. Disruption of the synapses leads to a deterioration in the communication of nerve cells and decreased plasticity, which is associated with a loss of cognitive functions and neurodegeneration. Maintaining proper synaptic activity depends on the qualitative composition of mitochondria, because synaptic processes require sufficient energy supply and fine calcium regulation. The maintenance of the qualitative composition of mitochondria occurs due to mitophagy. The regulation of mitophagy is usually based on several internal mechanisms, as well as on signals and substances coming from outside the cell. These substances may directly or indirectly enhance or weaken mitophagy. In this review, we have considered the role of some compounds in process of mitophagy and neurodegeneration. Some of them have a beneficial effect on the functions of mitochondria and enhance mitophagy, showing promise as novel drugs for the treatment of neurodegenerative pathologies, while others contribute to a decrease in mitophagy.
|
[
"For adequate interaction with the environment, adaptive behavior in society, and the realization of creative potential, every person needs a properly functioning nervous system production, an increase in oxidative stress products, and an increase in the level of Ca^(2+) in the cytosol. These undesirable consequences can be prevented through the processes of mitophagy. Mitophagy is a specific type of autophagy in which the maintenance of cellular structure and function is carried out via elimination of unhealthy mitochondria [ , ]. The term mitophagy first appeared in 2005; since then, the popularity of this topic has grown exponentially [ , ]. Due to the role played by mitochondria in the cell, the topic of mitophagy has attracted researchers in anti-aging medicine [ , ], cardiology [ , ], endocrinology [ , , ], nephrology [ , ], and neuroscience [ , , , ].",
"Mitochondrial damage can occur by various agents associated with drug intervention, such as during anesthesia by sevoflurane [ , , , ], when using anticancer drugs [ , ], after ischemic brain damage [ , ], and in neurodegenerative diseases [ , ]. In all these cases, the mitophagy process is disturbed, and therefore it should be a target for therapeutic intervention in order to enhance the effectiveness of a rehabilitation or preventive program. This circumstance promotes an investigation of compounds that may accelerate mitophagy.",
"In this review, we have collected the latest data on the study of the effect of different molecules on mitophagy and neurodegenerative processes. We will take a detailed look at exactly how damage to mitochondria contributes to neurodegeneration and how some compounds can influence this through mitophagy. Not being able to cover all possible substances that affect mitophagy, we focused on such compounds that:, excitatory amino acid transporter signaling [ ].",
"Damaged mitochondria contribute to the production of reactive oxygen species that disrupt the structure of macromolecules such as DNA, lipids, and proteins, which ultimately leads to necrosis and/or apoptotic death of the nerve cell [ , ].",
"The number of processes that depend on mitochondria in synapse is equal to all currently known molecular mechanisms in this area and requires a separate review. We have previously reported in more detail on the role of mitochondria in this area [ ]. Thus, a functional deficiency of synaptic mitochondria leads to negative changes in this area. That is why mitochondria and the processes of maintaining their quality have become such an important target for therapeutic intervention.",
"To understand how various compounds can determine the course of neurodegenerative pathologies through mitophagy, it is necessary to understand the role of mitophagy in neurodegeneration. If the violation of mitophagy occurs because of pathological processes of neurodegenerative pathology, then these compounds are cofactors that can change the course of pathology through mitophagy. If the disruption of mitophagy is primary in relation to neurodegenerative processes, then these compounds are toxins that may receive a status of etiological factors. This provision will significantly change the understanding of neurodegenerative pathologies and the role of surrounding compounds.",
"Alzheimer’s disease is one of the most common neurodegenerative diseases characterized by a progressive impairment in cognitive functions and episodic memory, changes in behavior and personality, followed by social and everyday maladaptation. Genetic variants of AD occur only in 1–2% of cases and are associated with mutations in the APP, PS1, and PS2 genes [ , ]. At the tissue and cellular level, the disease is characterized by extracellular deposits of Amyloid beta, the respiratory chain, a decrease in cytochrome oxidase activity, damage to proteins responsible for the transportation of mitochondria along the neuron, and proteins responsible for normal fission–fusion of mitochondria. As a result, the mitochondrion ceases to provide the cell with a sufficient supply of ATP, the production of reactive oxygen species is characterized by typical motor disturbances, including bradykinesia, tremor, rigidity, and postural unsteadiness, as well as a range of non-motor symptoms. The pathological picture of PD is associated with progressive loss of dopaminergic neurons and aberrant accumulation of α-synuclein or mitochondria-associated membrane and PARK2 [ , ]. The cell needs to maintain a balance between the number of mitochondria and mitochondrial health in order to provide enough energy on the one hand, and on the other hand to maintain other homeostatic parameters.",
"Thus, mitophagy in neurodegenerative processes is an important link in the self-sustaining feedback loop of neurodegeneration, which is why the search for and study of compounds that contribute to the proper course of mitophagy is so important.",
"Mitophagy is provided by mitochondria-specific mechanisms for the elimination of damaged mitochondria. The purpose of mitophagy is to isolate the cell from damaged mitochondria and to create space for new healthy ones. This process is carried out with the help of phagophore formation and utilization by lysosomal enzymes. There are different signaling pathways that enable the formation of phagophores. Traditionally, these pathways are divided into those that are Parkin-dependent and Parkin-independent. The Parkin-dependent mitophagy signaling pathway initiates the appearance of PTEN-induced putative kinase 1, which is thought to phosphorylate PINK1. Knockdown of the genes responsible for ATM synthesis leads to disruption of mitophagy stimulated by lead plays an important role in mitochondrial division. In the region of the mitochondrial fission ring, Drp1 attaches to fission 1, adenosine monophosphate, which phosphorylates various proteins necessary for normal mitophagy, such as Parkin, TANK-binding kinase 1 on the one hand, and mitophagy factors, Diphyllobothrium latum and non-viral; therefore, research is underway on chemical modifications of niclosamide to increase bioavailability and therapeutic efficacy [ ].",
"Barini et al. found that niclosamide and its analogues activate PINK1 in cells due to reversible alterations to the mitochondrial membrane potential, including neurons taken from E16.5 mouse embryos, in cells of pathological relevance to PD [ ]. Since then, results have appeared on the effect of the drug on the cells of the nervous system during stress induction. Kato, Y., and Sakamoto, K. conducted a study on cultured microglial cells. Microglial cells are actively involved in maintaining homeostasis in brain tissue, but can also cause neuroinflammation, contributing to the emergence of neurodegenerative pathologies [ , ]. During the experiments, it was possible to determine that T-2 toxin causes neurotoxic effects, as well as induces a loss of mitochondrial membrane potential in BV2 microglial cells. Exposure to T-2 toxin activates autophagy in the cell, and this autophagy plays a protective role, accompanied by increased expression of Beclin1 and LC3II proteins [ ]. Yet, to date, there are no published articles on the role of T-2 toxin in relation to mitophagy in neurons or astrocytes.",
"Urolithin A belongs to a class of substances with α-benzocoumarin in base. Urolithins are formed in the gut microbiota from naturally occurring polyphenols such as ellagitannin or ellagic acid [ , , ]. The bacteria responsible for the conversion of polyphenols to urolithins in the human intestine is still unknown [ , ]. It is assumed that Gordonibacter urolithinfaciens and Gordonibacter pamelaeae are responsible for the synthesis of urolithin in the intestine [ , ]. Foods rich in metabolic precursors of urolithins are pomegranate, strawberries, walnuts, almonds, persimmons, raspberries, black raspberries, peaches, and plums [ , , ].",
"Urolithin A activates Nrf2, contributing to the regularization of mitophagy and mitochondrial biogenesis [ , , , ]. There is evidence that urolithin A promotes the activation of the AMPK pathway, which prevents apoptosis of cells with damaged mitochondria and directs biochemical processes towards mitophagy [ , ]. In SH-SY5Y neuroblastoma AD model cells with glucose-induced amyloidogenesis, the destruction of the AIP-AhR complex leads to the expression of type 2 transglutaminase family pyrin domain containing 3.",
"Resveratrol. There are two isomeric forms of resveratrol: cis and trans. It is trans-resveratrol that has greater biological activity [ , , , ]. Trans-resveratrol is a photosensitive compound and converts to cis-resveratrol under irradiation [ , ]. This compound is found in grapes, peanuts, berries, in the bark of some plants, seeds, nuts, flowers, and in the plant Polygonum cuspidatum, used in Japanese folk medicine [ , ]. Polyphenols accumulate in plants in response to exogenous stress factors such as trauma, fungal infections, or UV exposure [ , ].",
"It is known that resveratrol reduces oxidative stress by suppressing the formation of reactive oxygen species, derivatives of NADPH oxidase, and the activation of Nrf2 to maintain endogenous antioxidant protection [ ]. By activating Nrf2, resveratrol more likely exhibits cyto- and mitoprotective properties than the properties of a pure mitophagial inducer, since in experiments with the induction of mitophagy using cadmium, resveratrol attenuated the overexpression of p62 and PINK1/Parkin, which suppressed mitophagy and ultimately restored mitochondrial homeostasis [ ]. In other situations, resveratrol stimulated mitophagy; for example, in an experiment on a model of Alzheimer’s disease, it was demonstrated that resveratrol promotes mitophagy in Aβ-induced PC12 cells, thereby attenuating oxidative damage to neurons caused by Aβ-peptide [ ]. In metabolic disorders, as in the experiment with the induction of endothelial dysfunction, resveratrol activated mitophagy through Bnip3 [ ].",
"Quercetin is a flavonoid compound found in fruits, vegetables, berries, grapes, wine, various seeds, and nuts. Quercetin has a hydrophobic structure, and the presence of a hydroxyl group contributes to its reducing activity and, accordingly, antioxidant properties [ , , ]. In addition to antioxidant properties, quercetin is characterized by anti-inflammatory, antibacterial, antiviral, hepatoprotective, and immunomodulatory activity [ , ].",
"Quercetin affects many signaling pathways in the cell; in applying to mitophagy, it is able to modulate the process by influencing AMPK and Nrf2, contributing to the modulation of the expression and activity of PINK1/Parkin-mediated mitophagy [ , ].",
"There are many studies on the positive effects of quercetin in models of neurodegenerative pathologies. Among these effects, a decrease in the level of hyperphosphorylated Tau and amyloid plaques in AD models, a decrease in neuroinflammation with a decrease in microglia and astrocyte activation, and a mitoprotective effect with an increase in ATP production and a decrease in ROS levels were found [ , ]. In studies of mitophagy in PD rat models affected by 6-hydroxydopamine.",
"Haloperidol is a typical first-generation antipsychotic drug belonging to the butyrophenone group. Butyrophenones are prescribed to patients with positive symptoms: delusions, mania, psychosis, and schizophrenia. In addition to antagonistic activity against dopamine D2 receptors, butyrophenones also have activity against several other central nervous system receptors, including other dopamine receptor subtypes, serotonin showed that in in vivo MS models, demyelination is associated with excessive mitophagy, and inhibition of autophagy and mitophagy by haloperidol and clozapine leads to the restoration of myelin production and axonal myelination. Treatment of mouse models with these drugs contributed to the improvement of motor activity up to the complete elimination of behavioral disorders [ ].",
"Sevoflurane is an ether drug used for inhalation anesthesia. The low solubility facilitates a rapid onset of action, and low blood solubility also promotes rapid recovery from anesthesia. Sevoflurane has a dose-dependent inhibitory effect on the central nervous system, cardiovascular system, and respiratory tract [ ]. It has been used in medical practice since 1990 [ ]. The use of anesthetics is known to be accompanied by postoperative complications from the nervous system, such as decreased concentration and attention, cognitive decline, and mental and behavioral disorders [ , , ]. The issue of the consequences of the use of general anesthetics in children is especially acute, since the developing brain is most susceptible to the toxicity of this group of drugs [ , ]. These disturbances may be related not only to the consequences of the drug’s overall effect on the nervous system, but also to the effect of the drug on mitochondrial dynamics. In studies of the effect of the drug on the cells of the nervous system, it was repeatedly confirmed that sevoflurane stimulates the apoptosis pathway, thereby providing a neurodegenerative effect [ , , , ].",
"The use of various mitophagy inducers contributed to a decrease in the toxic effect of sevoflurane. Experiments have shown that the use of methylene blue [ ], honokiol [ ], and dexmedetomidine [ , ] contributes to the activation of mitophagy factors and mitigation of sevoflurane’s toxic effect. These data are indirectly supported by studies of the protective effect of sevoflurane in the late phase of reperfusion injury of the heart. The protective effect was provided by the inhibition of mitophagy and the reduction of excessive production of Drp1 and Parkin [ , ]. Therefore, it can be said with certainty that some of the causes of the neurotoxic and neurogenerative effect of sevoflurane are related to mitophagy disorders.",
"Spermidine is a natural polyamine found in wheat germ, soybeans, mushrooms, nuts, vegetables such as fresh green peppers, cauliflower, broccoli, and enzymatic products such as cheese and red wine. The Mediterranean diet is especially rich in spermidine [ , , ]. Despite the fact that the replenishment of spermidine reserves occurs not only due to external sources, but also due to synthesis in cells of the body and intestinal microbiota, with age, the amount of spermidine in the human body decreases, so a person needs a diet with a sufficient amount of spermidine [ , ].",
"Spermidine has three positively charged amino groups, which are very important for its different positive effects [ ]. At the cellular and molecular levels, spermidine protects proteins from glycation [ , ]; exhibits antioxidant properties [ , , ]; is involved in a number of biological processes such as cell proliferation, cell cycle, and apoptosis [ , ]; has an anti-inflammatory effect by suppressing NFκB-dependent pro-inflammatory cytokines [ ]; and promotes autophagy induction by inhibiting EP300 acetyltransferase, leading to deacetylation of a cytosolic autophagy-associated protein [ ]. At the level of organs and the organism, the above effects contribute to the cardioprotective effect [ ], reducing the risk of tumor formation [ , ], prevention of neurodegeneration through demyelination [ , ], and increased lifespan in yeast, flies, human cells [ ], and mice [ , ].",
"In addition to the induction of autophagy pathways, spermidine can stimulate mitophagy. As a mitophagy inducer, spermidine activates ataxia-telangiectasia mutated protein kinase ATM and induces mitochondrial membrane depolarization, thereby promoting the PINK1/Parkin-dependent mitophagy pathway [ , , ]. The nonspecific effect on mitophagy of spermidine is manifested by mTOR inhibition and AMPK activation [ , ].",
"The positive effects of spermidine on cognitive processes have been well studied. Spermidine improved olfactory memory in models with age-related memory impairment drosophila flies [ ]. In a recent study on the effect of spermidine in C. elegans models of AD and PD, spermidine was shown to inhibit memory loss in AD models and improve behavioral performance in PD models [ ]. In experiments in mice with accelerated aging SAMP8, spermidine increased the expression of neurotrophic in neurons, reduced memory loss in the object recognition test in older adults with subjective cognitive decline [ , ]. Thus, spermidine, as a natural compound, along with urolithin A, has excellent potential for implementation as a drug for the treatment and prevention of neurodegenerative pathologies."
] |
PMC10831082
|
Nature Communications
|
Toripalimab plus capecitabine in the treatment of patients with residual nasopharyngeal carcinoma: a single-arm phase 2 trial
|
31-01-2024
|
Patients with residual nasopharyngeal carcinoma after receiving definitive treatment have poor prognoses. Although immune checkpoint therapies have achieved breakthroughs for treating recurrent and metastatic nasopharyngeal carcinoma, none of these strategies have been assessed for treating residual nasopharyngeal carcinoma. In this single-arm, phase 2 trial, we aimed to evaluate the antitumor efficacy and safety of toripalimab (anti-PD1 antibody) plus capecitabine in patients with residual nasopharyngeal carcinoma after definitive treatment (ChiCTR1900023710). Primary endpoint of this trial was the objective response rate assessed according to RECIST (version 1.1). Secondary endpoints included complete response rate, disease control rate, duration of response, progression-free survival, safety profile, and treatment compliance. Between June 1, 2020, and May 31, 2021, 23 patients were recruited and received six cycles of toripalimab plus capecitabine every 3 weeks. In efficacy analyses, 13 patients (56.5%) had complete response, and 9 patients (39.1%) had partial response, with an objective response rate of 95.7% (95% CI 78.1-99.9). The trial met its prespecified primary endpoint. In safety analyses, 21 of (91.3%) 23 patients had treatment-related adverse events. The most frequently reported adverse event was hand-foot syndrome (11 patients [47.8%]). The most common grade 3 adverse event was hand-foot syndrome (two patients [8.7%]). No grades 4-5 treatment-related adverse events were recorded. This phase 2 trial shows that combining toripalimab with capecitabine has promising antitumour activity and a manageable safety profile for patients with residual nasopharyngeal carcinoma.
|
[
"Nasopharyngeal carcinoma is an epithelial cancer that develops from the mucosal lining of the nasopharynx^(1 , 2). The geographic distribution of nasopharyngeal carcinoma is markedly uneven; over 70% of new cases occur in southern China, southeast Asia, and north Africa^(1 , 2). More than 70% of patients with nasopharyngeal carcinoma are classified as having locoregionally advanced disease, which is associated with unfavourable survival outcomes^(3). Over the past few decades, much efforts have been made to improve the locoregional and distant control of this disease through photon-based radiotherapy techniques and the combination of chemotherapy and radiotherapy^(1). Nevertheless, although most patients achieve complete response after standard-of-care treatment, residual disease occurs in approximately 6.8–13% of patients, in either the nasopharynx or regional lymph nodes or both^(4 – 7). Previous studies found that residual disease was a negative prognostic factor, contributing to poor survival^(4 , 8 , 9). Thus, aggressive treatments of patients with residual nasopharyngeal carcinoma are crucial. The most common therapy for residual nasopharyngeal carcinoma is re-irradiation because the precise radiation dose can be conveniently applied to the nasopharynx and/or regional lymph nodes^(1 , 10 , 11). However, the overall incidence of re-irradiation-related grade 3–5 toxicities were reported in the range of 16.7–33%^(1 , 7 , 12). Surgery, another treatment approach, can be used to radically remove the residual tumour and/or regional lymph nodes^(1 , 13). However, surgery can potentially result in severe trauma and grave complications^(14 – 16). Thus, novel strategies for treating residual nasopharyngeal carcinoma are urgently needed, particularly for treating candidates that is neither resectable nor suitable for reirradiation.",
"Immune checkpoint blockade therapy is a breakthrough in cancer treatment that can prevent tumour spread and metastasis^(1 , 17). The high expression of programmed death-ligand 1. The median age of the 23 patients was 52 years had complete response, 17 patients. After the completion of six cycles of scheduled study treatment, 13 patients. Median time to the best response from the treatment initiation was 4.5 months did not achieve complete response. Overall, five patients. The median duration of response was not reached. No deaths occurred during the study treatment and follow-up phase.",
"In the safety population, any grade treatment-related adverse events occurred in 21 of 23 patients completed the six cycles of toripalimab plus capecitabine combination treatment. Overall, three of 23 patients. Management of residual nasopharyngeal carcinoma is a challenge. Treatments usually consist of re-irradiation, surgery, or chemotherapy. Thus, optimisation of treatment according to the patterns of residual disease has naturally attracted the most attention.",
"In recent years, immune checkpoint inhibitors have been extensively studied for treating nasopharyngeal carcinoma. In the POLARIS-02 study, Wang and colleagues found that toripalimab provided a durable clinical response and manageable safety profile in patients with previously treated recurrent or metastatic nasopharyngeal carcinoma^(22). A 2021 phase 3 trial. Other inclusion criteria were as follows: not suitable for local treatment.",
"The Institutional Ethics Review Board of Sun Yat-sen University Cancer Centre approved the trial protocol. This study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines defined by the International Conference on Harmonization. All patients provided written informed consent.",
"The first patient was enrolled on June 27, 2020, and the last patient on May 28, 2021. Essential assessments of residual nasopharyngeal carcinoma were performed within a span of two weeks before treatment initiation. These assessments included the collection of a complete medical history; physical examination; haematological and biochemical tests; urine and stool tests; thyroid function test; nasal endoscopy or rhino-sinusal endoscopy; electrocardiograms; enhanced MRI of the nasopharynx and neck; computed tomography and capecitabine. During the treatment, dose modification of toripalimab was not permitted. If grade 2 or 3 adverse events occurred, capecitabine was delayed until recovery to grade 1 or better and then resumed at the original dose or at a reduced dose (75% or 50% of the original dose). Upon the fourth occurrence of grade 2 adverse events or the third occurrence of grade 3 adverse event, capecitabine was permanently discontinued. If grade 4 adverse event occurred, capecitabine was discontinued permanently or delayed until recovery to grade 1 or better; then, it was resumed at a reduced dose (50% of the original dose). Dose modification or interruption of capecitabine due to adverse events was performed according to the protocol.",
"The response of residual nasopharyngeal carcinoma to the treatment was evaluated at the end of three cycles of scheduled treatment and three weeks after the completion of six cycles of the scheduled treatment. According to the Response Evaluation Criteria in Solid Tumours (RECIST; version 1.1), an independent review team evaluated the response by physical examination, nasal endoscopy or rhino-sinusal endoscopy, enhanced MRI of the nasopharynx and neck, and ^(18)Ffluorodeoxyglucose PET-CT (if necessary). Adverse events reported by the patients were assessed, and physical examination and haematological tests were carried out on days 1 and 8 of every cycle. Biochemical tests, urine and faecal tests, thyroid function tests, electrocardiograms, and nasal endoscopy or rhino-sinusal endoscopy were performed on day 1 of every cycle. Adverse events were monitored continuously throughout the treatment period and until 60 days after the last dose of the study drugs. Adverse events were graded in accordance with the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTC-AE; version 5.0).",
"One month after patients had completed or discontinued the study treatment, a follow-up visit was conducted. Then, the patients were followed up every 3 months for the first 3 years, every 6 months for the next 4–5 years, and annually thereafter. The follow-up details are specified in the protocol.",
"The efficacy and safety were assessed by an independent review team according to RECIST (version 1.1) and NCI CTC-AE (version 5.0).",
"The primary endpoint of this trial was the objective response rate (three weeks after completion of six cycles of scheduled treatment), which was defined as the proportion of patients with confirmed complete or partial response according to RECIST version 1.1. The following secondary endpoints were also analysed: complete response rate (defined as the proportion of patients who had complete response); disease control rate (defined as the proportion of patients who achieved an objective response or stable disease); duration of response (defined as the time from the first documented objective response to disease progression or death from any cause, whichever occurred first); progression-free survival (defined as the time from treatment initiation to disease progression or death from any cause, whichever occurred first); safety profile; and treatment compliance. Data for patients who had no observed events were censored at the date of the last follow-up.",
"The data cut-off date for the present analysis was September 1, 2023.",
"The sample size was estimated according to Simon’s two-stage design with a one-sided α error of 0.025 and a power of 80%^(45 , 46). A previous trial reported that the highest objective response rate of capecitabine monotherapy for recurrent nasopharyngeal carcinoma was 47.8%^(28). The objective response rate to the combination regimen (toripalimab plus capecitabine) was initially expected to be 80%. Under these assumptions, the stages were as follows: in stage one, among six evaluable patients, if the responders were three or fewer, the trial would be terminated. Otherwise, an additional 15 patients would be enrolled for stage two. In stage two, if 15 responders or more were observed (including those from stage one), the trial would be considered a success. Assuming a 10% dropout rate, a total of 23 patients were required for this trial.",
"Efficacy analyses were conducted for all assigned patients who received at least one dose of the study medications (the efficacy population). Patients who did not have at least one post-baseline efficacy assessment were excluded from the efficacy population. Safety was assessed in all assigned patients who received at least one dose of the medications in our study (the safety population). The safety population excluded patients without any safety data.",
"Continuous and categorical variables were expressed as the median (interquartile range [IQR]) and number (percentage [%]), respectively. We calculated the objective response rate, complete response rate, and disease control rate; and the accompanying 95% confidence intervals (95% CIs) were calculated based on the Clopper-Pearson method. The median duration of response and median progression-free survival were estimated using the Kaplan–Meier method, and the corresponding 95% CIs were estimated using the BrookmeyerCrowley method.",
"An independent data monitoring committee monitored the trial. The interim analyses were planned. Statistical analyses were conducted using SPSS (version 26.0), R (version 4.0.2). The trial is registered with the Chinese Clinical Trial Registry (number: ChiCTR1900023710).",
"Further information on research design is available in the linked to this article."
] |
PMC10051123
|
Nutrients
|
Maternal Vitamin B12 Status during Pregnancy and Early Infant Neurodevelopment: The ECLIPSES Study
|
22-03-2023
|
In this prospective cohort study of 434 mother–infant pairs from the ECLIPSES study, we examine the association between maternal vitamin B12 status at the beginning and end of pregnancy and the neurodevelopmental outcomes of infants 40 days after birth in a pregnant population from a Mediterranean region of northern Spain. Maternal vitamin B12 concentrations were determined in the first and third trimesters, and sociodemographic, nutritional, and psychological data were collected. At 40 days postpartum, the Bayley Scales of Infant Development-III (BSID-III, cognitive, language, and motor skills) were administered to the infants and several obstetrical data were recorded. In the multivariable models, medium maternal first-trimester vitamin B12 levels (312 to 408 pg/mL, tertile 2) were associated with better neonatal performance in the motor, gross motor, language, and cognitive skills with respect to tertile 1 (<312 pg/mL). The probability of obtaining a neonatal motor, gross motor, and receptive language score >75th percentile was significantly higher also in the tertile 2 group. In summary, good maternal vitamin B12 status in the early stage of pregnancy appears to be associated with better infant motor, language, and cognitive performance at 40 days postpartum.
|
[
"Maternal nutrition before and during pregnancy is essential for maintaining normal fetal growth and adequate neurodevelopment because the nutritional supply and nutritional reserves from the mother are the only sources of nutrients for the fetus [ , ].",
"Several epidemiological studies have reported associations between lower maternal circulating nutrient concentrations during pregnancy and greater neurodevelopmental impairment in infants. Like nutrients such as folate, iron, vitamin D, and polyunsaturated fatty acids [ , , ], maternal vitamin B12 has a clear effect on the neurodevelopment of children [ , ] and affects a high percentage of the population, even in developed countries. In Europe, prevalence from 18% to 43% has been observed. Moreover, this prevalence is higher in, for example, environments with lower socioeconomic levels [ , , , ].",
"Numerous studies have reported environmental risk factors associated with vitamin B12 deficiency, including diet, smoking, and physical activity [ , , , ]. The main causes of vitamin B12 deficiency worldwide are the low consumption of foods of animal origin and absorption problems. It has been reported, for example, that pregnant women who have been strict vegetarians for several years, and even omnivores who consume low amounts of animal foods, are prone to developing vitamin B12 deficiency during pregnancy [ , , ]. Smoking is another associated factor because vitamin B12 in hydroxycobala-mine form binds to the cyanide present in cigarettes to form a non-toxic compound associated with vitamin B12 metabolism have been described, though their impact on the vitamin’s serum levels has not yet been determined [ , , ]. This hereditary disorder has been related to cardiometabolic, hematological, and neurological alterations [ ].",
"Vitamin B12 is involved in several metabolic mechanisms, and its deficiency in pregnant women can cause hyperglycemia, insulin resistance, obesity, and dyslipidemia, which affect the health of the mother and directly and indirectly influence the development of the baby [ , ]. Moreover, along with folate, vitamin B12 is a required cofactor in one-carbon metabolism, a deficiency of which leads to elevated levels of homocysteine during certain periods of gestation can therefore have early postnatal consequences for cognitive development, thus affecting memory, language, and visual and auditory processing in the offspring [ , , , ]. This latter aspect affects perceptual–motor integration and, consequently, motor skills [ , ].",
"As far as we know, only seven observational studies have focused on these topics, and their findings are not conclusive. Five studies were conducted in Asian countries [ , , , , ], one was conducted in Canada [ ], and one in the Netherlands [ ]. Of the five Asian studies, the research conducted by Keskin et al. [ ] reported that low maternal vitamin B12 status in the first trimester was associated with impaired motor, language, and social skills in four-month-old infants who were also found to have vitamin B12 deficiency [ ]. Two other studies found that low maternal vitamin B12 levels during the third trimester were associated with lower cognition [ , ] and social development [ ] in offspring at two years of age. Bhate et al. [ ] reported a lower performance on a working-memory task completed by the 9- to 10-year-old children of mothers in the lowest decile of vitamin B12 concentrations during the third trimester of pregnancy. However, children of mothers in the highest vitamin B12 decile performed better on the same task [ ]. Vaena et al. [ ], on the other hand, found no association with cognitive development in children of the same age [ ]. Similarly, in the studies conducted in Canada by Wu et al. [ ] in children aged 1.5 years and in the Netherlands by Ars et al. [ ] with children aged 6 to 8 years, no evidence was found of an association between maternal vitamin B12 status during the second trimester of pregnancy and offspring neurodevelopment.",
"In addition, two randomized controlled trials.",
"We conducted a prospective follow-up study to analyze data from pregnant women as well and their children 40 days after delivery. This work is part of the ECLIPSES Study [ ]. A total of 791 participants were recruited during the first prenatal visit from 12 sexual- and reproductive-health-care services and the Institut d’Investigació Sanitària Pere Virgili [ ] was used to assess smoking, and the women were classified as smokers or non-smokers. Smoking was evaluated in the three pregnancy trimesters. Women who smoked during at least one trimester were considered smokers, whereas those who did not smoke during the three trimesters of pregnancy were considered non-smokers.",
"Eating habits were assessed using a self-administered food-frequency questionnaire [ ] to extract daily energy intake score based on the intake of nine components was measured using the short version of the International Physical Activity Questionnaire, frequency and height) or overweight/obese and state anxiety were divided into tertiles, with the pregnant woman categorized as having low, medium, or high vitamin B12 levels for continuous variables and as a number. For each analysis, we created 20 imputed data sets and pooled the results using the MI command in Stata. Estimates were presented as a β coefficient values and variance-inflation factors and >75th percentile). Separate multivariable logistic-regression models were similarly applied to examine the odds and a mean gestational weight gain of 10.3 ± 3.6 kg. According to the Institute of Medicine. There were no significant differences in most baseline characteristics between the pregnant women who were included in the analysis and those who were not.",
"The anthropometric measurements of the babies at birth were normal.",
"The BSID-III scores of children according to maternal vitamin B12 tertiles during the first and third trimesters showed no statistically significant differences. However, the children of mothers with medium vitamin B12 levels.",
"Multiple linear-regression models adjusted for various environmental factors show that medium maternal vitamin B12 levels during the first trimester of pregnancy. No other significant associations were observed for the motor scale in the first trimester. Similarly, no significant associations were observed between serum vitamin B12 levels and BSID-III scores in the third trimester.",
"To evaluate what appeared to be better neurodevelopment, we therefore divided the children into quartiles according to their Bayley III assessment and, taking into account statistical power, used the top 75th percentile of the study sample to define elevated neurodevelopment. According to the BSID-III scores from the first trimester of pregnancy, above the 75th percentile were 27.2% of the babies on the cognitive scale, 26.3% of the babies on the language scale, 40.8% on the receptive-language subscale, 54.8% on the expressive-language subscale, 31.4% on the motor scale, 37.1% on the fine motor subscale, and 27.5% on the gross motor subscale. Multiple logistic-regression models showed that the children of mothers with medium vitamin B12 levels, than the children of mothers with lower vitamin B12 levels.",
"In this study we found that medium vitamin B12 levels at the beginning of pregnancy in healthy pregnant women from the Spanish Mediterranean area affected the neurodevelopment of their children at 40 days postpartum in the motor area, gross motor skills, and language and cognitive development. Although the BSID-III scores of children were within the normal range, a sufficient maternal vitamin B12 status was associated with a greater probability of children having better motor, gross motor, and receptive-language skills was therefore similar to the WHO’s marginal-deficiency value values and lower scores on the motor, language, and cognitive scales, whereas a slighter, insignificant improvement was observed in tertile 3. This suggests that the effect of maternal vitamin B12 on the infant’s neurodevelopment is not completely linear.",
"The findings of scarce studies with regard to maternal vitamin B12 status during pregnancy and its effects on child neurodevelopment [ , , , , , , ] have been heterogeneous. The methodological characteristics of the studies, including the different design and B12-deficiency cutoff values, as well as the socio-demographic factors of each population, may be behind this diversity in results. Those conduced in developing Asian countries [ , , ] reported a negative effect on neurodevelopment; however, neither of the two studies realized in developed countries, such as Canada [ ] and the Netherlands [ ], found any effect of low B12 levels.",
"With regard to age in evaluations of infant neurodevelopment, only a recent prospective cohort study by Keskin et al. [ ] in Turkey was conducted at a very early age, specifically, four months that are more related to the prenatal maturation of the CNS and may be more easily observed at this neonatal age that are more related to the prenatal maturation of the CNS and may be more easily observed at this neonatal age, support the effect of B12 on prenatal brain maturation. In contrast, none of the other previous observational studies [ , , , , , ] found an association between language in children from two years of age or when maternal vitamin B12 levels were evaluated in the second or third trimester of pregnancy. It is likely that at this age the effect of B12 deficiency on language is offset by stimulation from the postnatal environment or is related to the later period of pregnancy. However, RCTs [ , ] reported that the children of mothers supplemented with and presenting higher serum concentrations of vitamin B12 during the first [ ] and third [ , ] trimesters of pregnancy had higher expressive-language scores at 2 [ ] and 2.5 [ ] years of age than the children of mothers who did not receive supplements.",
"In the present study, we found an association between maternal serum vitamin B12 levels in early or late pregnancy and cognitive development. Other studies observed a similar effect in 2-year-olds from Singapore [ ] and 2- [ ] and 9year-olds [ ] from India in the third trimester, though they were also deficient in other micronutrients, such as vitamin B6, [ ] folate, and iron [ , ], that are important to the neurodevelopment of children [ ]. However, in our study, besides the fact that maternal folate deficiency was very low mechanisms [ ].",
"It has been reported that intrauterine exposure to tobacco can generate cognitive improvements in response to greater cholinergic activation and cortical arousal derived from nicotine stimulation [ , , ]. Many studies have observed an association between fetal-growth restriction and poorer neurodevelopmental outcomes [ , ].",
"Previous studies have assessed maternal vitamin B12 concentrations at the beginning [ ] and end [ , , , ] of pregnancy. However, we only found effects of vitamin B12 deficiency in the first trimester of pregnancy, even though vitamin B12 levels were lower in the final period of gestation. This suggests that the alteration in neurodevelopment has more to do with the time in which fetal development is more vulnerable to vitamin B12 deficiency than with the serum levels of the vitamin. Indeed, vitamin B12 participates in a wide range of critical processes that are important to the development of the CNS, and some of these, allied to the relatively large sample size, enabled us to find significant results.",
"The strengths of this study lie In the fact that, to the best of our knowledge, it is the first to assess the effect of maternal vitamin B12 levels at two stages of pregnancy on neurodevelopment at 40 days postpartum while adjusting for a wide range of confounding factors, such as diet and maternal psychological aspects. Moreover, different ethnic groups, social classes, and educational levels were represented in the sample and the data were collected using validated questionnaires and standardized techniques.",
"In a sample of healthy women from a Spanish Mediterranean region, a sufficient maternal vitamin B12 status in the first trimester of pregnancy, adjusted for various environmental and lifestyle factors, was associated with better motor, language, and cognitive performance in their offspring 40 days after birth. Our findings support the need to assess vitamin B12 levels from the beginning of pregnancy to promote an adequate course of pregnancy and ensure optimal infant neurodevelopment."
] |
PMC10372109
|
Journal of Youth and Adolescence
|
Sexting Among Australian Adolescents: Risk and Protective Factors
|
22-07-2023
|
Although consensual sending of sexts between adolescents is considered developmentally appropriate, it may also entail a range of negative consequences. Current sexting research lacks a comprehensive theoretical framework identifying a range of risk and protective factors underpinning adolescent consensual sending of sexts across individual, interpersonal, and distal levels. Further, there is a lack of systematic evaluation of how the importance of these factors may vary across adolescent age. This study investigated the utility of the Social Development Model to predict a range of risk and protective factors across individual, family, peer, school, and community-level factors. The sample included 1302 teenagers from Victoria, Australia ( M age = 14.54, SD = 1.14, 50.8% girls). Results indicated that 146 (11.7%) participants sent a sext (76 boys and 70 girls). Logistic regression analyses revealed that the Social Development Model accounted for 45.8% of variance in sexting, with greater likelihood of sending sexts being associated with older age, prior sexual activity, school sector, physical activity, lifetime substance use, greater depressive symptoms, sensation seeking, and perceived substance availability in the community. Multigroup analyses revealed that lifetime substance use was associated with a greater likelihood of sending sexts among younger teens. Among older adolescents, adaptive coping was associated with reduced engagement in sexting, while higher parental overcontrol and family conflict increased the odds of sending sexts. Overall, sexting is associated with a range of modifiable factors potentially amenable to intervention.
|
[
"Consensual sending of sexts among adolescents is considered normative. However, this behavior may also entail adverse consequences including poor mental health, reputational damage, in-person and online victimization, and potentially even legal ramifications. As adolescents may not be well-equipped to deal with the psychological, social, and legal sequelae associated with sending image-based sexts, an understanding of the risk and protective factors linked to this behavior is needed to identify areas for sexting prevention and intervention measures. Current research on sexting lacks a theoretical model that would comprehensively examine a range of risk and protective factors associated with consensual sexting, and how the importance of these factors may vary across adolescent age. The present study will address these gaps by adopting the Social Development Model to examine the correlates of sending sexts across individual, family, peer, school, and community levels among younger and older Australian adolescents.",
"Sexting constitutes a common form of online sexual communication. The behavior can entail sending, receiving, and forwarding of sexual content. While consensual sexting is perceived to be a normative expression of young persons’ sexual repertoire and a need for intimacy or validation, non-consensual sexting can be considered potentially harmful. The latter encompasses sexting behaviors performed under pressure, coercion, or threat, instances when a person is exposed to sexual material unwillingly/without their consent, or when their sexual image or text is distributed to the audiences beyond the intended recipients.",
"A recent meta-analysis revealed that 19.3% of young persons under the age of 18 reported sending sexts. Sending sexts among adolescents was found to increase with the age of respondents and more recent time of publication/data collection, with no differences noted across gender. A review examining the characteristics of consensual and non-consensual sexting among persons aged 10–24 years revealed a similar trend, in that participation in both forms of sexting increased with age but tended to be more prevalent among males. These findings suggest that engagement in sexting among young people is likely to continue and potentially increase.",
"Research on sexting among young persons has revealed that the behavior can be problematic, even in instances when it is consensual. The consensual sending of sexts has been linked to increased symptoms of stress, depression, anxiety, reports of suicidal ideation, and suicide attempts among adolescents aged between 10 and 19 years, with the effects for anxiety and depression being more pronounced among younger respondents. Some adolescent girls reported greater body image self-consciousness as a result of sending sexts, getting in trouble with their teacher, and more frequent negative consequences when sexts were sent to multiple boys or men, or outside a romantic relationship. Young people depicted in sexts, especially girls, were subjected to harsh judgment, derogatory labeling, and suffered reputational damage. Further, sending image-based sexts among adolescents was significantly associated with higher odds of experiencing emotional and physical dating and relationship violence, in-person sexual assault, bullying, cyberbullying, sextortion, and grooming. Sextortion pertains to a situation in which a person is blackmailed, threatened, or forced, by means of their sexually explicit material, to provide more sexual images, engage in sexual activity, or comply with other demands made by a perpetrator. Grooming refers to building rapport and “befriending” a victim to exploit them sexually.",
"Legal consequences may also ensue. In some United States jurisdictions, even consensual sexting between young people under the age of 18 may result in legal charges and sex offender registration, as sexting may fall under the category of the possession and/or distribution of child pornography. Similarly, in Australia, an underage person who produces, possesses, or shares sexually explicit images of a minor may incur criminal charges under the Commonwealth laws.",
"While the sending of sexts is not always associated with negative consequences, especially if the behavior is consensual and occurs in the context of a romantic relationship, some researchers consider it inherently risky. This is because even consensual sexting can ultimately lead to the non-consensual forwarding of sexts or sexting due to pressure. To develop appropriate intervention and prevention measures addressing sexting behaviors among adolescents, a thorough understanding of the cross-section of risk and protective factors associated with sexting is needed. While risk factors increase one’s proclivity to engage in health-compromising behaviors, protective factors buffer against such actions and predict healthy development.",
"According to the Social Development Model, an individual’s behavior, in addition to intrapersonal characteristics, is shaped by transactional. Both models can be used to investigate a range of person-context factors to explain adolescent behavior. However, the Social Development Model offers a measurable framework to test a range of risk and protective factors underpinning potentially problematic behaviors, including sexting. The model also explains how certain aspects of one’s environment may determine youth’s engagement in prosocial versus problematic actions. That is, the Social Development Model focuses on strong social bonds as a mechanism through which problem adolescent behaviors could be prevented. Therefore, positive relationships between adolescents and their parents, peers, school, and the broader community may constitute protective factors against behaviors such as sexting and could be targeted in sexting prevention and intervention measures.",
"In line with the Social Development Model, research to date has identified several risk and protective factors associated with sending sexts among adolescents. On an individual, intrapersonal level, ethnic background. Engagement in sexting was also related to higher levels of sensation seeking, impulsivity, and substance use,, lower religiosity, deviant behavior, and poorer mental health. Experiences of relational aggression, bullying, and cyberbullying have also been linked to sending sexts. Personal qualities such as fairness and authenticity, on the other hand, were protective against sending sexts, suggesting that these character strengths constitute the basis for more measured technology use among young persons and hence should be targeted and enhanced in sexting prevention and intervention programs. However, it is noteworthy that the aforementioned research encompasses samples of adolescents across a broad age range from 10 to 19 years. Therefore, whether the significance of these risk and protective factors varies across adolescent age requires further investigation.",
"Research regarding parenting and family functioning among adolescents aged 12–20 years revealed several correlates significantly associated with sending sexts. Poorer attachment to parents and overly restrictive parenting practices have been identified as risk factors for greater willingness to send sexts. Lower family cohesion reported by adolescents constituted a risk factor for sending partially naked photos or images to someone online. Conversely, good family communication was a protective factor against engagement in sexting, including the number of people to whom sexts were sent and sending sexts to regulate one’s emotions. Greater parental love and support characterized by clear rules and interest in and encouragement of young persons’ future, higher quality of parent-youth communication, parental knowledge, and monitoring of adolescent online and offline behaviors have been associated with the reduced engagement in sexting among adolescents.",
"Some research, however, has revealed that not all family variables are associated with sexting. Perceived parental attitudes towards sexting were not significantly related to young persons’ sending of sexts to a romantic partner or others. Parental supervision of youth’s online activities or mobile phones was not related to teens’ willingness to send sexts and sending of sexts. Some of these studies included samples of older adolescents, e.g., aged 15–21 years, suggesting that parental influence on teens’ sexting behaviors may reduce as the latter mature and individuate. However, this potential effect, especially in the context of Australian families, needs to be examined further.",
"Considering more distal factors, research examining peer, school, and community factors revealed that older teens, and if their peers held favorable attitudes towards the engagement in sexting. These findings are not surprising as the influence of peer group on adolescent behavior increases with age. Further, students under the age of 16 with lower academic performance were more likely to send sexts, while those who reported greater school connectedness were at a lower risk of sending sexts. Adolescents aged 13–14 years from low-income families were less likely to send sexts relative to teens from high-income families. One study examined perceived social support. However, this study focused on sexting perpetration, such as coercing someone into sexting or sending a sext to the recipient who did not consent to receive it. Overall, the importance of community variables and the potential interaction of age with peer, school, and community factors on the consensual sending of sexts is poorly understood.",
"Research regarding consensual sexting behaviors is lacking a comprehensive theoretical model examining a range of potentially modifiable risk and protective factors associated with the consensual sending of sexts. It also encompasses samples of adolescents with broad age ranges, thereby lacking a systematic investigation of the significance of these factors across adolescent developmental stage. Engagement in any problem behavior, for example substance use, is often influenced by a variety of intrapersonal and environmental characteristics operating at various levels. Therefore, the current study adopted the Social Development Model to examine a range of factors that may account for young people’s participation in sending sexts. The current study’s aims were two-fold. First, this study examined the utility of the Social Development Model in identifying a range of individual, family, peer, school, and community risk and protective factors associated with consensual sending of sexts. Communities that Care is an international intervention program, the purpose of which is to modify problem behaviors among adolescents in the United States, the Netherlands, and Australia. Delivered in five stages.",
"The current study included adolescents from schools in Victoria, Australia. In total, 1311 participants took part in the study at baseline. A small proportion of respondents, the Victorian Department of Education and Training were approached, followed by additional schools within each community to ensure balance across school types. For sending sexts, participants were asked whether they “have ever sent a nude examining several risk and protective factors at individual, family, peer, school, and community levels that may underpin a range of young persons’ problematic behaviors. The survey has demonstrated validity and reliability among adolescent respondents, with reliability overall averaging .76–.78 in prior studies. After recoding relevant items, scale scores were calculated as a mean of all responses, with higher values indicating higher levels of risk or protection. Responses for the Short Mood and Feeling Questionnaire were summed, with higher values reflecting more depressive symptoms. Table lists all scales along with their means, standard deviations, and measures of internal consistency."
] |
PMC10486576
|
Animals : an Open Access Journal from MDPI
|
Prevalence and Diversity of Blood Parasites (Plasmodium,LeucocytozoonandTrypanosoma) in Backyard Chickens (Gallus gallus domesticus) Raised in Southern Thailand
|
03-09-2023
|
Simple Summary Chickens can be infected by several avian blood parasites ( Plasmodium , Haemoproteus , Trypanosoma and microfilaria) that can cause a big impact on poultry production. However, some of them are known to cause a high impact on poultry production ( Plasmodium and Leucocytozoon ), while others still require further investigation. Raising backyard chickens is a common practice in Thailand, and the low-biosecurity system in which they are kept favors the transmission of vector-borne diseases, which include several blood parasites. The spread of such infections can compromise production, resulting in economic impact. This study aimed to report the molecular prevalence, lineage diversity and morphology of blood parasites infecting backyard chickens in three different provinces in Thailand. We found a high prevalence of Plasmodium sp. and Leucocytozoon sp. infections, while Trypanosoma and microfilaria had a lower prevalence. Plasmodium gallinaceum and Leucocytozoon macleani were present in the studied individuals as well as Trypanosoma, which resembles T. calmettei . The buffy-coat method and molecular analysis were shown to be valuable diagnostic tools for blood parasites in chickens. These results can be used to promote awareness of parasite infections in the study area. Abstract Avian malaria and leucocytozoonosis can cause fatal diseases, whereas avian trypanosomiasis is reported to be harmless in chickens. Backyard chickens can be infected by several pathogens, including blood parasites, that may shed to industrial poultry production, with a consequently higher economic impact. This study aimed to investigate the presence of several blood parasites ( Plasmodium , Leucocytozoon and Trypanosoma ) in backyard chickens raised in Southern Thailand, using PCR-based detection and microscopic methods. From June 2021 to June 2022, 57 backyard chickens were sampled. Fresh thin blood smears were prepared from 11 individuals, and buffy coat smears were prepared from 55 of them. Both thin blood smears and buffy coat smears were used for microscopic analysis. Two nested PCR protocols that amplify a fragment of cytochrome b ( cytb ) and small subunit rRNA ( SSU rRNA) genes were used to identify Haemosporida and Trypanosoma parasites, respectively. The number of positive samples was higher with the application of nested PCR than when buffy coat smears were used. Three new Plasmodium lineages (GALLUS47-49) and thirteen Leucocytozoon lineages (GALLUS50-62) were found. Trophozoites, meronts and gametocytes of Plasmodium gallinaceum (GALLUS01) were present in one thin blood smear. All thin blood smears revealed Leucocytozoon infections, but only three samples were a single infection. These three samples revealed the presence of fusiform host cell–parasite complexes, of which the morphological features resembled those of Leucocytozoon macleani (possible synonym is Leucocytozoon sabrazesi ), while the cytb showed that this parasite is closely related to the lineage GALLUS06-07, described as Leucocytozoon schouteni . The Trypanosoma prevalence was 33.33%; it was present in only one of the thin blood smears, and it resembles Trypanosoma calmettei . This study showed the prevalence of a high diversity of Plasmodium (64.91%) and Leucocytozoon (89.47%) in Thai chickens. Both nested-PCR and buffy coat smear can be used as the diagnostic tool for the testing of Plasmodium , Leucocytozoon and Trypanosoma for parasitic control in backyard chickens and poultry farms. The information on the parasite species that can be found in chickens raised in Southern Thailand was also considered as the baseline information for further study.
|
[
"Avian haemosporidian, two Plasmodium species were described: Plasmodium gallinaceum , likely endemic in Asia, and Plasmodium juxtanucleare [ ], which has a global distribution [ ]. Three Leucocytozoon species were reported in domestic chickens: Leucocytozoon macleani , with P. gallinaceum being transmitted mainly by Mansonia crassipes and Culex quinquefasciatus [ , ], while P. juxtanucleare is mainly transmitted by several species of Culex mosquitoes [ ]. Leucocytozoon spp. are transmitted by several species of back flies and Dermanyssidae are greenish feces, anemia, depression, reduced weight gain, fluffed-out feathers and often death [ ]. Leucocytozoon causes a malaria-like disease called leucocytozoonosis [ , ], and its pathogenicity can vary according to the vertebrate host, parasite species and lineage [ , , , ]. This important disease was first reported in Vietnam in 1909 [ ]. Leucocytozoon caulleryi can cause a lethal hemorrhagic disease [ , ], and infected chickens frequently exhibit anemia, anorexia, ataxia, lethargy, green diarrhea, pallor, decreased egg production and eventually death [ , ]. Leucocytozoon macleani and L. schouteni are less pathogenic but can still cause anemia and greenish droppings, slight emaciation and reduced egg production [ , ]. Avian trypanosomes have been reported as non-pathogenic for domestic chickens, due to their impact in wild birds being rarely reported and understudied [ , ]. Even though about 100 species of avian trypanosomes have been described, they are poorly known [ , , ].",
"Backyard chickens is one of the common low biosecurity poultry production systems in Thailand [ ]. The animals raised in this system are not kept in areas protected from blood-sucking insects that can transmit these parasites. They can easily be bitten by those insects that can be infected by blood parasites but also the species and lineages and dry season and fresh thin blood smears equipped with a Nikon DS-F i 3 digital camera Ultra, Bio-Helix, New Taipei City, Taiwan), 1 µL of each primer. The amplicons were then submitted to the U2Bio Thailand. If such co-infections were seen, they were excluded from the analysis [ , ]. Plasmodium and Leucocytozoon sequences from single infections were compared with the sequence deposited on the MalAvi database [ ], using BLAST tool. The sequences showing at least one nucleotide of difference were considered as a new lineage [ , ], and it was named according to MalAvi database [ ]; all sequences were deposited in MalAvi and GenBank databases was selected with the mrModeltest 2.3 program [ ], based on hierarchical likelihood ratio test, which was selected based on lowest Bayesian information criterion between areas blood samples were investigated for the presence of Plasmodium , Leucocytozoon and Trypanosoma infections. This included native chickens. In a comparison of the prevalence of blood parasite infections between areas, the prevalence of Plasmodium in NST.",
"Microscopic analysis of the buffy coat smears revealed the presence of Plasmodium in 5 individuals, Leucocytozoon in 48, and Trypanosoma in 4. Unfortunately, the PCR-protocol used in the study failed to amplify a few microscopically positive samples: two positives for Plasmodium and Trypanosoma and one sample for Leucocytozoon . In the buffy coat smear analyses, we could also observe that a small number of individuals were infected by microfilaria of filarial nematodes.",
"Of the eleven fresh thin blood smear analyses, in one individual were verified, the lineage of which was molecularly identified as GALLUS01. The morphological identification was possible due to the presence of the following characteristics: trophozoites were located anywhere in the infected cell; fully grown erythrocytic meronts markedly displacing the nuclei of erythrocytes occupied more than half of the cytoplasmic space of infected erythrocytes; growing gametocytes were found in mature erythrocytes, displacing the nuclei of host cells; and mature gametocytes were varying in shape and markedly deformed host cells and displaced their nuclei laterally. Parasitemia was lower than 0.01%.",
"In the Bayesian phylogenetic analysis, the five Plasmodium lineages identified in the present study were grouped in the P. juxtanucleare clade, and they were separated from P. gallinaceum clade. In these two clades, Plasmodium parasites of Phasianidae birds were separated from avian Plasmodium lineages from other host families. The homology in the P. juxtanucleare clade was 99.33–100%, whereas in the P. gallinaceum it was 100%. Plasmodium lineages GALLUS48 and GALLUS49 were closely related to P. juxtanucleare GALLUS02, with 99.78% and 99.55% similarity. In contrast, the Plasmodium lineage GALLUS47 showed 100% similarity to Plasmodium lineage TSUB01.",
"All eleven fresh blood smears were positive for Leucocytozoon parasites that developed into fusiform host cells–parasite complexes. Of these eleven samples, seven samples were found with only fusiform host cells–parasite complexes, whereas the other four samples were found with both fusiform host cells–parasite complexes and roundish host cells–parasite complexes. Three different genetic lineages were present in the studied samples: GALLUS55, GALLUS61 and GALLUS62. Based on the microscopic analysis of the thin blood smears, the gametocytes of GALLUS55 and GALLUS62 showed fusiform host cells–parasite complexes and roundish host cells–parasite complexes in, whereas GALLUS61 developed only in fusiform host cells. These three parasites were suspected to be L. macleani . However, the Bayesian phylogenetic inference revealed that these three parasites were grouped in the Leucocytozoon schouteni clade, which had the homology ranging between 91.02 and 100%.",
"One out of eleven fresh thin blood smears showed the presence of tiny trypomastigotes of Trypanosoma sp.. However, due to the presence of only a few trypomastigotes in the sample, it was not possible to morphologically identify it. Unfortunately, the PCR-protocol used failed to amplify the SSU rRNA of this parasite. However, some morphometric parameters were measured from five trypomastigotes. Detailed information can be found in .",
"It was possible to amplify two SSU rRNA sequences of Trypanosoma from native chickens. The homology of this clade was 99.74–100%. Trypanosoma GGD-AVC56 and Trypanosoma GGD-AVC57 had 99.74% similarity to others in this clade. However, our two sequences do not belong to any of the described lineages.",
"The prevalence of Plasmodium spp. and Leucocytozoon spp. in backyard chickens in Southern Thailand was high, PHL might be the suitable area for sample collection.",
"This study described new genetic lineages of Plasmodium and Leucocytozoon , indicating that the diversity of parasites in this area was high and even new species can be involved in the infections. Especially for Leucocytozoon, many of their lineages were found, and some samples in Brazil [ ], which showed that P. juxtanucleare can spillover from domestic chicken to wild animals. Since P. juxtanucleare has a global distribution, when a suitable temperature is present, not only can the vectors develop but also the parasite can complete its life cycle and be transmitted to the next host, which can be domestic and wild birds [ , , ]. Southern Thailand may be an excellent environment for the development and transmission of P. juxtanucleare and other vector-borne diseases between wild passerine birds and backyard chickens. The other seven individuals were PCR-positive to P. gallinaceum GALLUS01. This lineage was isolated from chickens, which resembled T. calmettei [ ]. The Trypanosoma sp. present in our samples can be readily differentiated from T. gallinarum and T. numidae by its smaller size. However, these two sequences were different from the avian trypanosomes lineages described in the literature [ ]. It is noteworthy that the previous article [ ] described avian trypanosomes lineages based on the RAPD method. Thus, to define whether our sequences were new lineages, the RAPD analysis might be needed. The result of nested PCR indicates the existence of this parasite in Southern Thailand. Three trypomastigotes of trypanosomes found in buffy coat smears showed variation in their sizes and shapes. Although this method was not recommended for describing morphospecies, this information may be evidence that domestic chickens can be infected by different species of Trypanosoma parasites. Therefore, the present study reinforces the importance of further studies addressing Trypanosoma parasites in the study area.",
"The rapid development of DNA-based molecular methods allowed us to understand the genetic diversity [ ], population genetic structure [ ] and parasite taxonomy [ ]. The nested-PCR used in this study detected a higher number of Plasmodium spp., Leucocytozoon spp. and Trypanosoma spp. than the buffy-coat smear, indicating low sensitivity of buffy-coat smear. However, the observation of Giemsa-stained buffy coat smears was the evidence that this method can be used for the diagnosis of an infection of Plasmodium sp., Leucocytozoon sp. or Trypanosoma sp. Nevertheless, due to the initiation of the exflagellation process when mature Leucocytozoon gametocytes are in contact with air and the modifications that can be seen in the stained slides, this material is not recommended for descriptions of species—even though it can be used for avian blood parasite diagnosis [ ]. On the other hand, the resources and facilities to perform molecular analysis might not be present and/or available in all veterinarian laboratories, and molecular-based diagnosis is more expensive than using microscopy. Therefore, even though molecular techniques were more specific and sensitive for avian haemosporidian diagnosis [ , ], the Giemsa-stained buffy-coat method can be recommended as a useful tool in the diagnosis of such infections.",
"The buffy coat smear was prepared by breaking the glass capillary tube right below the buffy coat layer, which results in a small portion of red blood cells being transferred to the glass slide [ ]. This is a well-known methodology to investigate blood parasites, widely applied in the diagnosis of parasites of medical and veterinary importance [ , , , ], for both extra- and intracellular parasites, such as microfilaria, Trypanosoma , Erlichia canis , Haemoproteus and Lankesterella . However, different parasites might require some modification in the protocol to facilitate their diagnosis. For instance, human Plasmodium can be diagnosed with the application of the buffy coat method when blood samples are collected in capillary tubes containing orange acridine [ , , , ]. Previously, it was reported that the buffy coat method was not appropriate for the diagnosis of Plasmodium and Leucocytozoon . Here, we modified the proposed methodology that consisted of the preparation of smears and staining them with Giemsa. This improved the detection of these two parasites, making this methodology useful for the diagnosis of blood parasites in chickens. Additionally, this is a cheap and quick methodology, that can be easily applied in veterinary diagnosis.",
"This study aimed to investigate molecular prevalence and diversity of blood parasites infecting backyard chickens raised in Southern Thailand. This study showed a high molecular prevalence of Plasmodium spp. (64.91%) and Leucocytozoon spp. (89.47%). Trypanossoma parasites were also identified but in a lower prevalence (33.33%). Here we identified three new lineages of Plasmodium sp. (GALLUS47-49) and 13 new lineages of Leucocytozoon spp. (GALLUS50-62), confirming a high diversity of parasites infecting chickens in the study area. This prevalence and diversity might be due to the low biosecurity production system in which these chickens are raised. Plasmodium gallinaceum was identified in the few thin blood smears that were collected. These results highlight the importance of raising awareness to the livestock authorities and local farmers about the presence of these parasites, how they can compromise their production and the influence of poultry production on a bigger scale. Even though it is not recommended for detailed morphological analysis, buffy coat smears can be a useful tool for the diagnosis of avian blood parasites in veterinary clinics and laboratories, being cheap and easy to be performed. If more detailed information about parasite genetic diversity is necessary, then PCR-based methods should be employed. Further studies are necessary to better understand the pathogenicity and patterns of transmission of these parasites in backyard chickens. Additionally, potential vectors should be investigated in the area in order to elaborate and to test prophylactic methods to reduce the impact of infections."
] |
PMC10483257
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Cureus
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Lyme Disease and Post-treatment Lyme Disease Syndrome: Current and Developing Treatment Options
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08-08-2023
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Lyme disease and its treatment implications have become an ever-increasing area of concern within the United States related to the markedly increased prevalence of infection within the last two decades. The presentation, pathophysiology, and epidemiology of Lyme disease have been well studied, and thus treatments for this disease are widely available. While the treatment of its early and late stages is relatively simple with 10-14 day and four-week courses of doxycycline, respectively, the main problem rests in the understanding of the etiology and pathology of post-treatment Lyme disease syndrome (PTLDS). With the time of symptoms onsetting approximately six months after treatment and potentially lasting indefinitely, this syndrome's effect on patients' quality of life could be devastating. Searching on PubMed, Google Scholar, MEDLINE, and ScienceDirect using keywords including Lyme disease, PTLDS, doxycycline, erythema migrans, azlocillin, and treatment, the authors have tried to make clear the different aspects. The authors have reviewed and discussed clinical studies of Lyme disease and its treatments/potential therapeutics as well as PTLDS and its sparse treatments/potential therapeutics.
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[
"Lyme disease is one of the most prevalent vector-borne diseases in the United States [ ]. Originating from the spirochete family of bacteria, specifically the genus Borrelia , Lyme disease can be caused by different strains depending on geographical location. Borrelia burgdorferi is found in the western hemisphere, and B. afzelii and B. garinii , in addition to B. burgdorferi , can be found in Europe and Asia [ ]. B. burgdorferi often causes arthritic symptoms while B. afzelii and B. garinii commonly cause skin and neurological manifestations [ ]. Commonly, the cases of Lyme disease in the United States have increased in the northeastern portion of the country as well as the mid-Atlantic and upper Midwest [ ]. European cases are seen in the Scandinavian and Baltic states, in Northern Europe, Germany, Austria, Czech Republic, and Slovenia in Central Europe [ ]. Furthermore, a new species, B. mayonii , was discovered as rarely appearing in the upper Midwest and is not known to exist in Europe [ ]. The specific vector is primarily the Ixodes species of ticks, which acquire the spirochete from smaller animals such as birds and mice by taking a blood meal to molt. From this point, the ticks utilize the blood meal to transition from larva to nymph or nymph to adult tick. If the bacteria survive this developmental stage, they can remain in the nymph or adult tick stage and be transferred in the next blood meal, which can commonly involve deer and humans [ ].",
"Approximately 476,000 people are treated for Lyme disease each year in the United States [ ]. Since 2004, Lyme disease has accounted for 63% of all reportable tick, flea, or mosquito-borne illnesses nationwide [ ]. The major health concerns of Lyme disease begin with characteristic skin rashes and can eventually lead to dermatological, cardiological, musculoskeletal, and neurological manifestations [ ]. Furthermore, the consequences of infection with Lyme disease can lead to continuing symptoms and also develop into post-treatment Lyme disease syndrome [ ]. This procedure is promptly followed with a more specific western immunoblot where a positive test only occurs if both the ELISA and western immunoblot are positive [ ].",
"There is some slight variation in what level of antibody binding is considered positive, so it is imperative that labs follow the CDC guidelines on immunoblot interpretation [ ]. Specifically, the western blot requires five bands to be positive. The stages of Lyme disease can have significant symptom overlap, which physicians must identify to order the correct diagnostic tests. The typical erythema migrans rash, often referred to as a localized disease, does not always follow the typical pattern or progression. If a patient were to present after the initial rash resolves but still has similar symptoms, some physicians could completely dismiss the possibility of Lyme disease. As a result, this dismissal can cause both overdiagnosing or misdiagnosing patients with post-treatment Lyme disease. For example, if a patient presenting with lethargy, low energy, and low appetite had a history of Lyme disease in the past, there can be an overdiagnosis of post-treatment Lyme disease. Conversely, if a patient previously had undiagnosed Lyme disease and presented with the same symptoms, there could be a misdiagnosis of various mental health issues, including depression [ ]. Without appropriate serological testing or in the event of poor interpretation, the combination of the variability of the timeline of symptom presentation and the different array of symptoms that can be involved make this disease a challenging condition to diagnose accurately and subsequently presents increased difficulty in treating [ ].",
"Post-treatment Lyme disease syndrome pathogenesis",
"One of the most concerning aspects of Lyme disease is the presence of symptoms after treatment. This trait is characteristic of an aptly named post-treatment Lyme disease syndrome, and esophageal perforation [ ]. The effectiveness of cefuroxime vs. doxycycline as a treatment in adult erythema migrans infections was evaluated in a study that found satisfactory remission of symptoms in 51 of 55 patients treated with cefuroxime and 45 of 51 patients treated with doxycycline [ ]. Another study was performed concerning the effectiveness of cefuroxime as an alternative to doxycycline as a treatment option for children with erythema migrans [ ]. This study found total resolution of symptoms in 92% and 67% of groups treated with cefuroxime and doxycycline, respectively [ ].",
"PTLDS has proven to be more difficult to remediate as the specific nature of its pathology and etiology is poorly understood. Many patients experience symptoms that include fatigue, pain, arthralgia, and neurocognitive involvement [ ]. There is very little literature referencing specific therapies for symptoms of PTLDS, but in recent times, the topic has been extensively reviewed [ ]. Treatments for symptoms of arthralgia and pain are generally done so in a stepwise manner, from heating pads and nonsteroidal anti-inflammatory drugs to physical therapy and narcotics. The treatment for neurocognitive involvement depends heavily on the specificity of the deficits that the patients present with. According to the Mayo Clinic, the cessation of some drugs that may be involved with exacerbating neurocognitive symptoms has been indicated in patients suffering from mild cognitive impairment [ ]. Medications that can exacerbate neurocognitive symptoms include drugs such as benzodiazepines, anticholinergics, antihistamines, opioids, and proton pump inhibitors [ ]. The length of this syndromic condition appears to have a wide range as one study by Rebman et al. [ ] had a cohort of patients whose range of PTLDS onset was from 8.3 months to 27.7 years. For patients on medications for comorbid or chronic conditions, this can present difficulties in their treatment and lead to overall reductions in quality of life.",
"While potential therapeutics for PTLDS are currently being investigated, several contraindicated therapeutics have been thoroughly reviewed and are recommended to be avoided by institutions such as the CDC. The risk of infection or electrolyte imbalances in patients with PTLDS treated with oral or intravenous (IV) antibiotics was more prevalent than in those not on antibiotic therapy [ ]. Another study of the repeated use of IV and oral antibiotics in five patients found an increased risk of infection accompanied by no improvement in symptoms associated with chronic Lyme disease [ ]. A case study, in 2017, evaluated the use of ceftriaxone in a patient with PTLDS that caused acute kidney injury and associated hemolytic anemia [ ]. The above studies have not seen significant symptom relief upon administration of antibiotics; thus, it is unlikely that the causative agent of PTLDS is a latent infection of Borrelia burgdorferi . Due to the lack of a definitive standard of treatment for PTLDS outside of supportive care, these studies are imperative in improving our ability to set a better standard of care [ ]. With current treatments for PTLDS being exclusively supportive, new therapies must be developed to curb the unclear course of this syndrome.",
"Lyme disease potential therapeutics and prevention options",
"Vaccination Developments",
"A previous vaccine, LYMErix, was originally on the market from 1998 to 2002 in which the lipoprotein OspA was targeted with antibodies [ , ]. These antibodies would target the spirochete in the midgut of the tick while feeding; therefore, inhibiting transmission. However, the vaccine received scrutiny due to unsubstantiated claims that correlated the vaccine with arthritis [ ]. Despite the FDA stating these claims were unsupported by concrete evidence, the vaccine was pulled from the market in 2002 because of decreased sale revenue [ ]. Recent research on the OspA vaccine has served to further remove these connections and show its efficacy in preventing Lyme disease [ ].",
"Some methods of antibiotics tend to work as discussed before; however, with 10-20% of people later presenting with PTLDS and the incidence rate steadily increasing, preventative measures and treatments are necessary to prevent long-term effects [ ]. While LYMErix was attempted in the early 2000s, the development of new vaccines has been limited, despite increased rates of Lyme disease [ ]. There is no Lyme disease vaccine that has full FDA approval and is currently disseminated in the United States [ ]. However, recently, a new vaccine, the VLA15 vaccine, has proven efficacious thus far in mice. The target in mind is once again the OspA protein that exists on the outer side of the spirochete before transmission while it is in the tick’s gut [ ]. As the tick feeds, the OspA protein will be downregulated as OspC is upregulated and subsequent infection of the host occurs. The new VLA15 vaccine creates anti-OspA-specific antibodies, preventing tick transmission before OspC can be expressed [ ]. Proven by earlier data and experimental studies, the vaccine successfully prevented infection with Lyme disease in mice [ ]. Moreover, the vaccine showed the potential to work against many clinically relevant strains of Lyme disease, providing protection in the United States, Europe, and potentially worldwide [ ]. The vaccine has progressed to a phase 3 clinical trial, starting in 2022, and is one of the most promising Lyme disease vaccine trials in the past 20 years [ ].",
"Furthermore, studies have been conducted in recent years to discuss the willingness of people to receive a safe Lyme disease vaccine. Recent data of 3313 respondents from northeastern parts of the United States, including Connecticut, Maryland, Minnesota, and New York, showed that 64% of participants were willing to receive a potential vaccine. In contrast, 30% were uncertain and 7% were unwilling [ ]. Importantly, those who were unwilling tended to be generally dissatisfied with vaccines and were not correlated to a Lyme disease vaccine specifically [ ]. Ultimately the VLA15 vaccine shows the potential to work as a clinically useful vaccine and has public support to be utilized.",
"Pharmacologic Developments",
"While the development of a new vaccine and current antibiotics for Lyme disease exist, the prevalence of PTLDS has continued to fester without any treatment for the ambiguous pathology of the disease. Due to the limited understanding of the underlying etiology of PTLDS, current and developing treatments for this condition are centered on preventative rather than curative measures. One theory, mentioned earlier, suggests that PTLDS can arise from persistent and drug-tolerant Borrelia infection [ ]. Promisingly, a recent study showed the efficacy of azlocillin as a potential candidate for the prevention of PTLDS [ ]. However, a large dilemma concerning this potential therapeutic is azlocillin’s broad range of action that commonly creates a more rapid resistance profile among the bacteria it treats [ ]. Unfortunately, the potential therapeutics for PTLDS are largely based on theory without convincing evidence. For example, persistent bacteria, dormant and undetectable infections, and triggering an auto-immune response are potential theories for the cause of PTLDS [ ]. As a result, azlocillin would have the potential to work only if the theory concerning persistent Borrelia as the cause of PTLDS is true. Azlocillin’s current trials in mice studies show curative potential and at least a possible step in the right direction for treatment [ ].",
"To answer the problem of wide-ranged antibiotics, a new drug, hygromycin A, has been found to kill spirochetes selectively [ ]. While the current data has only been shown in mice, the low-scale production of Lyme disease treatment presents hygromycin A as one of the more promising developments. Furthermore, the benefits of hygromycin A include sparing the microbiome, low level of resistance development, and no detectable cytotoxicity against human cells [ ]. Although the drug was capable of clearing B. burgdorferi infection, the current trials only saw this result in mice, so any future use in humans will need extensive testing and research. On the other hand, hygromycin A has been shown to work as a bait for mice and could serve as a method to start lowering the levels of Lyme disease in nature [ ]. Moreover, a potential cause of PTLDS has been theorized to be a characteristic shift in the microbiome composition, which hygromycin A has been shown to not affect [ ]. While the potential results are promising, extensive research and trials are required before use in people.",
"Clinical Studies of Lyme Disease Treatments",
"One challenging aspect of treating Lyme disease is the emergence of antimicrobial-resistant Borrelia burgdorferi infections. While the exact cause of PTLDS is unknown, current research postulates that antimicrobial-resistant Borrelia burgdorferi infections may be integral in its pathophysiology [ , ].",
"Several in vitro studies have demonstrated that B. burgdorferi forms drug-tolerant \"persister cells\" when treated with traditional antibiotic therapy and infections by these drug-tolerant forms cannot be eradicated by ceftriaxone and doxycycline [ - ]. In an in vitro study using a semisolid plating method, Pothineni et al. [ ] demonstrated that when used alone, the antibiotic azlocillin can completely eradicate late log phase and seven to 10 days old stationary B. burgdorferi . The combination of azlocillin and cefotaxime can effectively kill doxycycline-tolerant B. burgdorferi . Additionally, the authors found that azlocillin has shown significant efficacy in treating B. burgdorferi in mice through in vivo testing. The authors concluded that more in-depth research is necessary to evaluate the potential use of azlocillin in treating Lyme disease and its associated disorders.",
"In 2020, Wormser et al. [ ] described the aggregation of data from four clinical studies focusing on single-dose doxycycline as postexposure prophylaxis for three spirochetal infections: Lyme disease, syphilis, and tick-borne relapsing fever. In all the studies, a single dose of doxycycline was administered within 72 hours of participants’ exposure to one of the spirochetal pathogens. The authors detail a double-blind, placebo-controlled trial in which a single 200 mg dose of doxycycline was administered within 72 hours after detaching an Ixodes scapularis tick from the skin; this study found that the postexposure doxycycline administration was 87% effective in preventing the development of Lyme disease [ ]. Another open-label, randomized clinical trial performed in 2020 administered a single dose of doxycycline to study participants within 72 hours of an Ixodes ricinus tick bite; this study found the efficacy rate of doxycycline was 67% [ ]. Through analysis using the DerSimonian-Laird method for variance estimation, the four studies in combination demonstrated an overall efficacy of doxycycline use of postexposure prophylaxis for prevention of the three spirochetal infections as 78% [ ]. Another focus of Lyme disease treatment has been the early treatment of the disease to prevent the development of PLTDS. In a longitudinal prospective cohort study, the authors set out to determine if study participants with a prior history of Lyme disease were more likely to meet the criteria for PTLDS than those without a history of Lyme disease [ ]. Study participants completed surveys to evaluate their pain, fatigue, depression, and quality of life and afterward, the distribution of clinical outcomes was examined. After the study, the authors found that 13.7% of participants with a history of Lyme disease met the criteria for PTLDS as opposed to the 4.1% of participants without a history of Lyme disease who met the criteria for PTLDS. Overall, patients with prior Lyme disease were about 5.28 times more likely to meet PTLDS criteria when compared to the group without a prior history of Lyme disease.",
"Kundalini yoga has also been examined as a potential treatment for PTLDS; yoga has been shown to alleviate fatigue, pain, sleep disturbance, and cognitive impairment [ ]. Additionally, contemplative practices have been theorized to mediate these symptoms due to their effects on the autonomic nervous system and attenuation of the stress response. Stress is a common occurrence in patients suffering from any type of chronic disease [ ].",
"In 2022, Murray et al. [ ] conducted a preliminary randomized study to determine the adherence to and potential benefit of Kundalini yoga for PTLDS. A total of 29 participants were randomly assigned to either eight weeks of Kundalini yoga in group sessions or a “waitlist” control group. Participants were invited to participate in the study if they were 18 years of age or older, had received a clinical diagnosis of Lyme disease at least six months before the start of the study, and had a primary complaint of pain or fatigue that met the required severity criteria. The primary outcomes measured were pain, fatigue, and global health; secondary outcomes included symptom burden, cognition, mood, sleep, and mindfulness. Outcomes were measured using group discussion, the Neuro-QoL Cognitive General Concerns questionnaire, and documentation of independent yoga practice each day. After the study ended, there were no differences in primary outcomes between the two groups. Still, Kundalini yoga was associated with improvement in two of the secondary outcomes: symptom burden and cognition. The authors concluded that Kundalini yoga is safe and cost-effective and may effectively decrease some of the symptoms associated with PTLDS [ ].",
"Investigation into vaccines for the prevention of Lyme disease has become more prominent in recent years. LYMErix is a vaccine for Lyme disease that was developed in the 1990s and was found to reduce infections in vaccinated adults by 80%. However, it was discontinued by the manufacturer due to the low use of the vaccine by the general population [ ]. Because Lyme disease is challenging to diagnose and is debilitating when not treated promptly, prevention is key in protecting both children and adults from the disease. Kamp et al. [ ] designed a six-component vaccine targeting OspA that can elicit antibody response against all Borrelia strains that cause Lyme disease. OspA is a lipoprotein located on the outer membrane of B. burgdorferi , and antibodies against this lipoprotein can kill the organism in the midgut of the Ixodes tick before transmission occurs. The previously available vaccine, LYMErix, also targeted this lipoprotein but was only effective against one strain of Borrelia . They designed the vaccine by fusing OspA to the N-terminus of Helicobacter pylori ferritin and was tested in a mouse model. Ixodes tick-fed mice that received the vaccine demonstrated immunity from both B. burgdorferi and the response was sustained for more than six months. The clinical studies related to the treatment of Lyme disease are outlined in Table [ ].",
"The growing prevalence and exposure to Lyme disease have created an increased necessity for newer treatments and medicines to combat the rise in cases. Furthermore, since the rise in Lyme disease is paired with difficulty in diagnosis, long-term complications have also increased. As a result, the need for clear and concise treatment options and methods has become more important as well as an emphasis on research for new medications. The consensus shows that current treatments, including the use of antibiotics such as doxycycline, cefuroxime, and others, are the most clear-cut choices. However, with PTLDS affecting up to 20% of those with Lyme disease, more options are needed to prevent Lyme disease or treat PTLDS to help patients. The most promising options include actively developing vaccinations such as VLA15 and antibiotics such as hygromycin A and azlocillin, which are being investigated for safety and efficacy. Moreover, each of these options allows researchers to explore better options for Lyme disease treatment and also more insight into the true root cause of PTLDS. The current literature suggests the prevention of Lyme disease symptoms and infection to prevent PTLDS, and more research and investigation are required to find direct treatments and causes for PTLDS. Currently, no treatment option exists that will directly treat PTLDS, and the first step appears to be discovering the pathology of the disease. While certain theories exist, the leading hypotheses pertain to lingering or drug-resistant B. burgdorferi , autoimmune attacks, remaining peptidoglycans, and central sensitization. Despite the array of theories, more in-depth research is certainly required in each area to help find a suitable treatment for PTLDS.",
"Additionally, the creation of Lyme disease-specific treatments and procedures is in the works. Still, more research directed to this field is essential to combat the growing number of cases and the severity of PTLDS or any other lingering symptoms. Currently, studies on PTLDS are lacking and more research is required to meet the growing demand for treatment. Lyme disease, which was primarily centralized in the northeast on the coast, has expanded to affect more inland areas, including expansion into the Midwest. Current treatment includes antibiotics such as doxycycline, cefuroxime, and amoxicillin, as well as any relevant supportive treatment. Goals of developing treatment hope to prevent or treat Lyme disease effectively to stop the development of PTLDS. Current PTLDS treatment is mostly supportive with a need for more research into direct treatments. New ongoing developments include the VLA15 vaccine and new antibiotics such as hygromycin A and azlocillin."
] |
PMC10509242
|
Scientific Reports
|
Mechanistic investigation into the binding property of Yohimbe towards natural polymeric DNAs
|
19-09-2023
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DNA interactions with multivalent ligand(s) have increasingly become the subject of substantial research. For several small molecules with therapeutic potential, nucleic acids serve as their primary molecular target. Such interaction has been shown to affect transcription or replication, ultimately leading to apoptotic cell death. As a result, researchers are becoming increasingly interested in understanding how small molecules interact with DNA making it possible to develop new, DNA-specific drugs. The bioactive indole alkaloid, Yohimbe (Yohimbine; Yh) has been broadly studied in pharmacological properties while its binding mode to DNA has not been explicated so far. This study adopted molecular modelling and multi-spectroscopic methods to investigate the interaction between Yohimbine and herring testes (HT DNA) in physiological conditions. Minor hypochromic and bathochromic shifts of fluorescence intensity were observed, suggesting the binding of Yh to HT DNA. The Scatchard plot analyses using the McGhee-von Hipple method revealed non-cooperative binding and affinities in the range of 10 5 M −1 . The thermodynamic parameters suggested exothermic binding, which was favoured by negative enthalpy and positive entropy changes from temperature-dependent fluorescence experiments. Salt-dependent fluorescence suggested that the interaction between the ligand and DNA was governed by non-polyelectrolytic forces. The results of iodide quenching, urea denaturation assay, dye displacement, and in silico molecular docking, suggested groove binding of Yh to HT DNA. Thus, the groove binding mechanism of interaction was validated by both biophysical and computational techniques. The structural elucidation and energetic profiling of Yh's interaction with naturally occurring polymeric DNA can be useful to the development of DNA-targeted therapeutics.
|
[
"Phytochemicals, over the years, have been receiving plenty of attention due to their pharmacological effects. One such phytochemical is yohimbine which has been mostly used as a stimulant and aphrodisiac for erectile dysfunction. Yohimbine is a plant alkaloid that is located in the bark of Pausinystalia yohimbe ^(1) and has been used to treat various ailments. Symptoms that it has successfully treated include marijuana abuse, male erectile dysfunction, diabetes mellitus type II, orthostatic hypotension. Only the hypochromic effect with no or a very slight bathochromic shift can be observed when electrostatic and groove binding interactions occur^(37).",
"In UV–Vis spectroscopy at a fixed temperature, a continual variation approach. The numbers of excluded sites derived from the McGhee–Von Hipple analysis of the fluorescence data and the values of stoichiometry are in close agreement.",
"An important method for determining how biomacromolecules and ligands interact is fluorescence spectroscopy^(41 , 42). Fluorescence experiments can be used to determine parameters like binding sites, dynamics, binding affinity, and conformational changes. Since DNA has relatively weak fluorescence, Yh was chosen as the fluorescence probe to analyze its interaction with DNA. The emission spectrum of Yh exhibits a strong intrinsic fluorescence and ranges from 300 to 440 nm, with maxima at 352 nm if excited at 250 nm. Fluorescence was quenched by interaction with HT DNA, which eventually caused the binding sites to be more saturated. Figure depicts the complexation of Yh with HT DNA in comparison to other fluorescence characteristics. The fluorescence quenching was approximately about 60%, which indicates that the ligand has a strong affinity for these natural polymeric DNA structures. Following the application of McGhee-von Hippel analysis, this data were utilized to create linear graphs of the Scatchard binding isotherm, which revealed non-cooperative binding^(43). The binding constants determined were at temperatures between 288.15 and 308.15 K is represented in Table . Results revealed that with an increase in temperature from 288.15 to 308.15 K, the binding affinity of such interaction lowered, resulting in a moderately weak binding of Yh with HT DNA. A fall from 2.20 × 10^(5) M^(−1) to 1.59 × 10^(5) M^(−1) at 308.15 K occurred, which determines the ligand–DNA complexation was disrupted due to the increase in temperature. The ' n ' value and.where R can be used to determine the free energy change. Δ H ° and Δ S ° values were determined by calculating the slope based on lnK versus 1/T . Thus variables of Δ G °, Δ H °, and Δ S ° were calculated using Eqs. ( ) and, and the findings are presented in Table . In accordance with the report, the primary force includes electrostatic when Δ H ° < 0 and Δ S ° > 0, the essential factor is hydrogen bonding and Van der Waals when Δ H ° < 0 and Δ S ° < 0, and the major force is hydrophobic association when Δ H ° > 0 and Δ S ° > 0^(49). According to Table , which shows the thermodynamic characterization of such interaction, the complexation favors negative enthalpy, with Δ H ° = – 13.01 kJ mol^(−1)] increased, the values of K . As a result, the quantity of salt in the environment had a significant effect on how strong the interaction is. Their values of ‘ n ’, meanwhile, maintained relatively consistent and indicated a 2:1 complex formation between the possible binding molecules under all salt concentrations.",
"Most ligand–DNA binding interactions depend on electrostatic interactions. Thus, according to Chaires and his coworkers' study, the binding free energy was divided between polyelectrolytic and non-polyelectrolytic portions. Researchers used a fluorescence experiment as well as a Van't Hoff analysis to compare the effects of the salt concentration from the range of [Na^(+)] 10 mM to 100 mM. The binding capacity of such contact decreased as the [Na^(+)] level increased. A greater fall from 2.00 × 10^(5) M^(−1) at 10 mM to 1.10 × 10^(5) M^(−1) at 100 mM occurred, A rise in [Na^(+)] quantity reduces total electrostatic interactions between the phosphate groups with negative charges of consecutive nucleotides of DNA, which may hamper the interaction of such a ligand and cause a reduction in binding affinity levels as seen in Table . Manning's counter ions model-based polyelectrolytic theories just describe the process and provide a framework for interpreting the subsequent findings^(52). The best fit linear slope of such plot of lnK versus ln[Na ^(+) ] is connected to the counter ion liberated based on the polyelectrolytic theory^(53) by the given relation",
"Here Z is the actual value of the ligand-bound per phosphate binding, Ψ is the proportion of [Na^(+)] bound per phosphate group, and SK is the number of counter ions linked to the drug complexation. Figure slope of the lnK versus ln[Na ^(+) ] graph indicates results of 0.31. Significant evidence for this is provided by dividing the observed binding Gibbs free energy into components from polyelectrolytic. The proportion of Δ G° _(pe) towards the overall changes in Gibbs free energy at 10 mM [Na^(+)] was determined to be − 3.54 kcal mol^(−1) and about 25%. Estimated values of Δ G° _(pe) were calculated to be − 1.77 kcal mol^(−1) for salt content at 100 mM [Na^(+)], which is nearly 15% of the total change in Gibbs free energy. Figure and Table show a depiction of the divided Gibbs-free energy change. It is evident that each time, whenever the [Na^(+)] concentration rises, the Δ G° _(t) component stayed constant while the Δ G° _(pe) component is reduced. This complexation by Yh binding to HT DNA is stabilized mainly by non-polyelectrolytic:",
"Where F_(o) and F indicate the emission intensities in the presence and absence of the quencher, respectively, indicating the groove binding mechanism instead of the intercalation mechanism^(58). Figure A depicts the relationship between the emission intensities of the Yh to HT DNA complex in the addition and exclusion of urea, but ethidium bromide had no such impact. K_(sv) values from the Stern–Volmer plot were used to determine the shifts in emission intensity of such dyes after they were attached to HT DNA by Yh. To further confirm the groove binding mode the experiment was also performed with acridine orange which is an intercalator and further no shifts or significant change was observed. Rhodamine-B has substantially higher K_(sv) values than ethidium bromide. Our data corroborate how Yh attaches to HT DNA through a groove binding mode based on the aforementioned results obtained^(63 , 64). This is in agreement with the above mentioned experimental outcomes.",
"Vitamins and minerals found in food items may increase or decrease the drug's pharmacokinetic profile) for the absence and presence of metal ions are presented. It is noticeable that when ions were added, the K_(sv) values were altered. The interaction with both Yh and the metal ion could be responsible for this alteration.",
"Complexation of Yh with a metal ion could be the cause for the increase in K_(sv). Increased K_(sv) values could increase Yh's effect and retention time. Whereas, the interaction of HT DNA with metal ions, results in complextion, leading to decreased K_(sv) values. Such complexation is anticipated to have an influence on the structure of the DNA and the dynamics of Yh interaction. Therefore, the elimination rate of Yh may slightly increase was present. With a separation of 1.77 Å, the indole part of Yh formed an H-bond with the C_(3)-NH of the dihydropurin group of guanine. Researchers have also performed molecular docking of Yh with hemoglobin protein^(33). It is estimated that Yh can attach to HT DNA with a binding energy of − 11.2 kcal mol^(−1). The experimental findings are corroborated by the expected binding energy using molecular modelling. The inhibition constant was 6.81 μM. Thus, the mode of binding was via groove binding which also complements the experimental data."
] |
PMC10190054
|
BMC Health Services Research
|
Adaptation and psychometric testing of the end-of-life professional caregiver survey in Jamaica
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16-05-2023
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Background Using a validated instrument to measure palliative care (PC) educational needs of health professionals is an important step in understanding how best to educate a well-versed PC workforce within a national health system. The End-of-life Professional Caregiver Survey (EPCS) was developed to measure U.S. interprofessional PC educational needs and has been validated for use in Brazil and China. As part of a larger research project, this study aimed to culturally adapt and psychometrically test the EPCS among physicians, nurses, and social workers practicing in Jamaica. Methods Face validation involved expert review of the EPCS with recommendations for linguistic item modifications. Content validation was carried out by six Jamaica-based experts who completed a formal content validity index (CVI) for each EPCS item to ascertain relevancy. Health professionals practicing in Jamaica (n = 180) were recruited using convenience and snowball sampling to complete the updated 25-item EPCS (EPCS-J). Internal consistency reliability was assessed using Cronbach’s \documentclass[12pt]{minimal}
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\begin{document}$$\alpha$$\end{document} coefficient and McDonald’s \documentclass[12pt]{minimal}
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\begin{document}$$\phi$$\end{document} . Construct validity was examined through confirmatory factor analysis (CFA) and exploratory factor analysis (EFA). Results Content validation led to elimination of three EPCS items based on a CVI < 0.78. Cronbach’s \documentclass[12pt]{minimal}
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\begin{document}$$\alpha$$\end{document} ranged from 0.83 to 0.91 and McDonald’s \documentclass[12pt]{minimal}
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\begin{document}$$\phi$$\end{document} ranged from 0.73 to 0.85 across EPCS-J subscales indicating good internal consistency reliability. The corrected item-total correlation for each EPCS-J item was > 0.30 suggesting good reliability. The CFA demonstrated a three-factor model with acceptable fit indices (RMSEA = 0.08, CFI = 0.88, SRMR = 0.06). The EFA determined a three-factor model had the best model fit, with four items moved into the effective patient care subscale from the other two EPCS-J subscales based on factor loading. Conclusions The psychometric properties of the EPCS-J resulted in acceptable levels of reliability and validity indicating that this instrument is suitable for use in measuring interprofessional PC educational needs in Jamaica.
|
[
"The World Health Organization and the WHO include PC as a fundamental human right and a critical component of the Sustainable Development Goals [ ]. These global goals call for equitable access to PC services for all patients and their families facing serious illness. Despite these advanced, only 14% of those in need across the globe have access to PC [ ]. Hence, to make progress towards the goals of UHC and achieving the SDGs, it is imperative to strengthen PC services.",
"Like most low- and middle-income countries was designed to measure PC educational needs across healthcare disciplines. The EPCS was initially developed and validated in the U.S. [ ], and was later adapted for use in Brazil [ ] and China [ ]. The original EPCS has 28 items across three subscales, Patient and Family-Centered Communication, Cultural and Ethical Values , and Effective Care Delivery , rated on a five-point Likert scale. A low EPCS score indicates higher PC educational needs [ ].",
"Given the ECPS’ utility across disciplines, cultural adaptability, and psychometric rigor, this tool was selected to ascertain interprofessional PC educational needs in Jamaica. This study aimed to culturally adapt and psychometrically test the EPCS for use in Jamaica by determining face, content, and construct validity, as well as reliability. It also serves as part of a larger research project that investigates ways to educate a well-versed PC workforce in Jamaica.",
"EPCS validation comprised a three-phase process: Phase I determined face validity, Phase II determined content validity, and Phase III implemented the adapted survey for EPCS items. In Phase III , the modified EPCS-J was distributed to physicians, nurses, and social workers who practice in Jamaica and survey results were statistically analyzed to determine psychometric properties. Findings from all phases are reported based on the Strengthening the Reporting of Observational Studies in Epidemiology. For Phase I , five SERHA-based PC experts, who were also study team members, reviewed the EPCS survey for face validity. For Phase II , study team members identified six Jamaica-based interprofessional PC experts to participate in a content validity process of the EPCS. Inclusion of six experts allowed for use of Lynn’s criteria for retaining survey items with an I-CVI of no lower than 0.78 [ ].",
"For Phase III , we implemented the survey across Jamaica’s four Regional Health Authorities. A convenience sample of participants was identified by a multi-modal recruitment strategy [ ]. Study team members recruited in-person participants across SERHA healthcare settings using a Qualtrics [ ] generated QR code shared to mobile devices, and by posting and distributing recruitment flyers. Additionally, multiple healthcare professional organizations serving all of Jamaica’s health regions were asked to electronically distribute surveys via their email listservs, using a Qualtrics-generated hyperlink. Inclusion criteria were:, and 12 PC educational preferences items were also included on the survey.",
"Two Jamaica-based co-investigators, a PC specialist physician. A four-point scale was used to avoid neutral or ambivalent midpoint scores [ , ]. Our Jamaica-based study team members identified six PC content experts to complete the survey; three physicians, two nurses, and one social worker who represented the target population and had expertise across disciplines. Each of the six respondents rated the items and provided narrative comments pertaining to items requiring changes. After content validation, three items were eliminated leaving a final survey$$\\end{document}",
"",
"Each organization’s administrator was contacted via email using a cover letter outlining the study objectives and rationale. Copies of the Jamaica-based ethics committee approvals were attached to each email. A modified version of Dillman’s method to maximize survey response rates was incorporated for email recruitment [ ].",
"",
"Once agreement to distribute surveys was obtained, subsequent emails to organizational administrators included study information and a Qualtrics-generated hyperlink which allowed survey access. Administrators were asked to distribute this information to their email listservs using the modified Dillman method timeline [ ]. During collection, the primary investigator monitored survey responses and electronically distributed a $25US gift card incentives as part of the agreement for survey completion. The survey was initially distributed, using these methods, between April and June 2022.",
"Due to low survey uptake, we kept the survey open for another ten weeks. During these weeks, those who received the survey link through healthcare professional organization email listserv distribution had additional time to complete the survey. Jamaica-based research assistants continued to recruit participants on-the-ground. We incorporated snowball sampling via email messages to those who completed the survey requesting that they distribute the survey to other eligible participants in their networks. Also, study investigators contacted health professional leaders at Jamaica’s Ministry of Health and Wellness, the University Hospital of the West Indies, and the University of the West Indies requesting that they distribute the survey to eligible health professionals. We compared participants’ demographics and contact information to ensure survey responses were unique. The survey was closed August 14, 2022."
] |
PMC10366312
|
Archives of Dermatological Research
|
Overexpression of hypoxia-inducible factor-1α in hidradenitis suppurativa: the link between deviated immunity and metabolism
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24-03-2023
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Hypoxia-inducible factor-1α (HIF-1α) is the master transcription factor of glycolysis, Th17 cell differentiation and suppression of regulatory T cells. In the skin and serum of patients with psoriasis vulgaris, increased expression of HIF-1α has been reported, whereas HIF-1α expression in the skin and serum of patients with hidradenitis suppurativa (HS) has not yet been studied. The objective of the study is to demonstrate is there a role for HIF-1α in the pathogenesis of hidradenitis suppurativa, and its relation to HS severity. Twenty patients suffering from hidradenitis suppurativa were included in the study. Punch biopsies were taken from lesional skin for the determination of HIF-1α expression by immunohistochemical staining, and HIF-1α gene expression by quantitative reverse transcription real time PCR. Quantification of HIF-1α protein concentration was done by enzyme-linked immunosorbent assay. Twenty socio-demographically cross-matched healthy volunteers served as controls. We found increased serum levels of HIF-1α. Literature-derived evidence indicates that the major clinical triggering factors of HS, obesity, and smoking are associated with hypoxia and enhanced HIF-1α expression. Pro-inflammatory cytokines such as tumor necrosis factor- \documentclass[12pt]{minimal}
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\begin{document}$$\kappa$$\end{document} κ B enhance HIF-1α expression. HIF-1α plays an important role for keratinocyte proliferation, especially for keratinocytes of the anagen hair follicle, which requires abundant glycolysis providing sufficient precursors molecules for biosynthetic pathways. Metformin via inhibition of mTORC1 as well as adalimumab attenuate HIF-1α expression, the key mediator between Th17-driven deviated immunity and keratinocyte hyperproliferation. In accordance with psoriasis, our study identifies HS as an HIF-1α-driven inflammatory skin disease and offers a new rationale for the prevention and treatment of HS by targeting HIF-1 \documentclass[12pt]{minimal}
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\begin{document}$$a$$\end{document} a overexpression.
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[
"Hidradenitis suppurativa has been observed in the skin of HS [ ], psoriatic epidermis [ , ], obesity and diabetes mellitus [ , ], and is regarded as a potential link between deviations of metabolism and immunity in HS [ – ]. Notably, hypoxia-inducible factor-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a [ , ]. The IL-17 pathway plays a key role in the pathogenesis of HS and psoriasis [ – ]. HS is characterized by dysregulation of Th17 and regulatory T, a key transcription factor that drives the differentiation of Th17 cells [ , ]. In contrast, HIF-1α restricts the differentiation and function of Treg cells through binding to FoxP3 targeting it for degradation [ , ]. HIF-1α plays a pivotal role in metabolic reprogramming in inflammation [ ] and controls the activation of macrophages, neutrophils and dendritic cells, creating a pro-inflammatory microenvironment within autoinflammatory lesions [ ].",
"HIF-1α is the master transcription factor of hypoxia and glycolysis [ , ]. Glycolysis is the preferred source of energy and biosynthetic precursor availability for highly proliferating cells including Th17 cells [ ], psoriatic keratinocytes [ , ] and anagen hair follicle cells [ – ]. Perilesional skin of HS shows mild psoriasiform hyperplasia [ ]. Excessive proliferation of outer root sheath keratinocytes has been observed in HS [ , ].",
"Upregulated expression of HIF-1α has been detected in the skin and serum of patients with psoriasis [ , ] and other Th17-mediated inflammatory diseases [ ]. In accordance with HS, obesity and smoking are aggravating factors promoting psoriasis [ , ]. Therefore, we wondered whether HIF-1α is also overexpressed in the skin and serum of patients with HS and whether HIF-1α may link obesity and smoking to Th17 cell-driven dysregulations of immunity and infundibular keratinocyte hyperproliferation.",
"This study included 20 patients suffering from hidradenitis suppurativa and 20 socio-demographically cross-matched healthy controls. All participants were recruited from the Dermatology Outpatient Clinic of the Alexandria Main University Hospital. Approval by ethical committee as well as written informed consent was obtained from all patients and controls. All procedures were in accordance with the ethical standards of the institutional and/or national research committee and the 1964 Declaration of Helsinki and registered with IRB No.: 00012098, FWA No.: 00018699. Patients with other concomitant lesions in the diseased area, patients who were receiving therapy for HS during the last 6 months, pregnant and lactating females were excluded. Patients were subjected to a full history, general medical and dermatological examination. Severity of HS was graded by the Hurley system: stage I: solitary or multiple, isolated abscess formation without scarring or sinus tracts; stage II: recurrent abscesses, single or multiple widely separated lesions, with sinus tract formation; stage III: diffuse or broad involvement, with multiple interconnected sinus tracts and abscesses [ ].",
"The procedure was explained to all patients. One 5 mm punch biopsy, streptavidin–HRP conjugate was for the determination of HIF-1α protein concentrations in serum and tissue. Antibodies labelled with enzyme were added for an incubation time of 60 min at 37 °C. After washing the plates and addition of Chromogen solution A, B, optical density [ ]. The concentration and purity of RNA were measured at 260, 280 and 230 nm using Nano Drop 2000c spectrophotometer using ABI 7900 sequence detector, while BMI in the control group was 26.74 ± 3.10 kg/m^(2). With regard to Hurley stage, 25%.",
"Stain intensity in the HS group. Figure and Table show the representative of immunohistochemical expression of HIF-1α in relation to Hurley staging. An increased HIF-1α immune staining of the inflammatory infiltrate could be observed in relation to Hurley stage, while Fig. f represents immunohistochemical expression of HIF-1α in controls.",
"The cutaneous HIF-1α protein in lesional skin of HS patients. There was a statistically significant correlation between grading of the stain intensity and Hurley staging of HS and HIF-1α serum level.",
"The mean serum HIF-1α levels in HS patients. There was also a positive correlation between HIF-1α serum levels with Hurley staging of HS as well as HIF-1α protein expression and immunohistochemical expression in skin biopsies.",
"Relative gene expression of HIF1A was lower in the HS group. Notably, HIF1A gene expression showed a negative correlation to both HIF-1α protein expression in the skin and HIF-1α serum levels.",
"Our study is the first investigation showing increased expression of HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a in lesional skin of HS patients. In normal human skin, HIF-1a protein expression is low and focal in the epidermis in contrast to hair follicles, sebaceous glands, and sweat glands, where HIF-1α is abundantly expressed [ ]. Upregulated expressions of HIF-1α has been detected in psoriasis vulgaris [ , , – ] and other autoinflammatory diseases related to Th17-mediated inflammation [ , – ]. HIF-1α plays a pivotal role in Th17 cell differentiation [ , ]. HS exhibits hyperproliferation of ORS keratinocytes [ , ] and is associated with Th17-mediated autoimmunity [ – , , ].",
"HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a is the key transcription factor of glycolysis [ , ], which is required for accelerated cell proliferation [ ]. HIF - 1α-induced glycolysis has been associated with keratinocyte proliferation in psoriasis vulgaris [ , , ]. Notably, the human hair follicle is intensively engaged in aerobic glycolysis [ , ] and exhibits high expression of HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a [ ]. The pathogenic role of HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a in HS is supported by our observation of increased expression of HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a in lesional skin of HS associated with a positive correlation with Hurley staging. In analogy to psoriasis [ ], we found also significantly elevated serum levels of HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a in our HS patients compared to healthy controls. In psoriasis, high serum levels of HIF-1α showed a correlation with overexpression of IL-6 [ ]. IL-6 via STAT3 signaling enhances HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a expression [ ].",
"In psoriasis, human dermal microvascular endothelial cells display increased angiogenesis and migration [ ]. In the dermis of lesional HS areas with chronic inflammation, increased neovascularization has also been observed [ , ]. Enhanced vascular endothelial growth factor is upregulated in adipose tissue of obese and diabetic subjects [ – ]. A significant overexpression of miR-21, miR-155, miR-223, miR-31, miR-125b, and miR-146a has been observed in lesional HS skin compared to healthy controls [ ]. Intriguingly, miR-21 targets and thus attenuates the expression of VHL mRNA [ – ]. MiR-146a is upregulated by NF \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\upkappa$$\\end{document} κ B and targets 3´UTRs of signaling proteins of innate immune responses [ ] as well as HIF-1α mRNA [ ]. MiR-148a is another upregulated miR related to obesity and diabetes [ – ]. Notably, HIF1AN, the gene encoding FIH-1, is a direct target of miR-148a, miR-31 and miR-125 that all inhibit HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a transactivation cells [ ]. HBE cells release miR-21-enriched exosomes after CS exposure enhancing HIF-1α signaling via targeting pVHL [ , ]. Further evidence confirms that CS activates HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a [ , ]. Nicotine increased HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a expression in non-small cell lung cancer cells [ ]. Benzo(a)pyrene, a component of CS extract [ ], enhances the binding ability of HIF-1α to HIF-1β protein [ ]. CS and hypoxia both increase oxidative stress and produce reactive oxygen species, which induce autoreactive pro-inflammatory T cells and reduce Treg cell activity [ ].",
"Interestingly, vitamin D deficiency has been repeatedly confirmed in HS patients and has been related to disease severity [ – ]. Vitamin D has inhibitory effects on mTORC1 [ , ] which promotes the synthesis of HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a [ ]. Vitamin D supplementation downregulated mTORC1 activity and lowered HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a mRNA levels in CD4 + T cell subsets of high-fat-diet-induced obese mice [ ]. Of note, vitamin D/VDR signaling enhances the transcription of VHL [ ].",
"Pro-inflammatory cytokines, such as IL-17A, tumor necrosis factor- \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a that IL-17A recruits IL-1β-secreting myeloid cells that prime pathogenic γδT17 and Th17 cells [ ], whereas mice with HIF-1α-deficient T cells are resistant to induction of Th17-dependent EAE [ ]. These data underline an intimate crosstalk between pro-inflammatory cytokines and HIF-1 signaling, which may also have an impact on HS pathogenesis.",
"Single-cell RNA sequencing reveals cellular and transcriptional changes associated with M1 macrophage polarization in HS related to increased expression of HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a [ ]. HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a plays a key role in the induction of macrophage glycolysis and activation of pro-inflammatory M1 polarization [ ]. In M1 polarized macrophages, HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a is responsible for sustanined production of IL-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\upbeta$$\\end{document} β [ ].",
"Recent evidence indicates that glycolysis is coordinated by both Notch and HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a signaling [ ]. Notch intracellular domain improves HS and enhances the efficacy of adalimumab and ustekinumab [ – ]. In selected experimental models, HBOT decreased the expression of HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a [ – ].",
"There is recent interest in the antidiabetic drug metformin for the treatment of HS [ – ]. Metformin not only attenuates the activity of mTORC1 [ ] but downregulates the expression of HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a [ – ]. Inhibition of mTORC1 by rapamycin. In accordance with the autoimmune pathogenesis of psoriasis [ ], we observed increased HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a protein expression in HS, which both share enhanced HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a and IL-17 signaling. There is compelling evidence that HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a is a dysregulated master transcription factor of HS pathogenesis explaining (1) enhanced HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a -driven glycolysis with keratinocyte hyperproliferation, (2) increased HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a /ROR \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\upgamma$$\\end{document} γ t-mediated Th17 cell differentiation with increased IL-17 production, (3) reduced Treg cell differentiation by HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a -mediated degradation of FoxP3, (4) HS aggravation by obesity and smoking, key trigger factors of HS that increase HIF signaling. Apparently, lesional imbalances HIF-1 signaling are at the center of disturbed infundibular keratinocyte and Th17 cell proliferation in the pathogenesis of HS. Pharmacological targeting of HIF-1 \\documentclass[12pt]{minimal}\n\t\t\t\t\\usepackage{amsmath}\n\t\t\t\t\\usepackage{wasysym} \n\t\t\t\t\\usepackage{amsfonts} \n\t\t\t\t\\usepackage{amssymb} \n\t\t\t\t\\usepackage{amsbsy}\n\t\t\t\t\\usepackage{mathrsfs}\n\t\t\t\t\\usepackage{upgreek}\n\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\n\t\t\t\t\\begin{document}$$\\mathrm{a}$$\\end{document} a may be a promising approach to manage HS as already suggested for psoriasis and other autoimmune disorders [ , , , ]."
] |
PMC10944409
|
Forensic Science, Medicine, and Pathology
|
Fatal cardiac air embolism after CT-guided percutaneous needle lung biopsy: medical complication or medical malpractice?
|
09-05-2023
|
Computed tomography (CT)-guided percutaneous needle biopsy of the lung is a well-recognized and relatively safe diagnostic procedure for suspicious lung masses. Systemic air embolism (SAE) is a rare complication of transthoracic percutaneous lung biopsies. Herein, we present a case of an 81-year-old man who underwent CT-guided percutaneous needle biopsy of a suspicious nodule in the lower lobe of the right lung. Shortly after the procedure, the patient coughed up blood which prompted repeat CT imaging. He was found to have a massive cardiac air embolism. The patient became unresponsive and, despite resuscitation efforts, was pronounced dead. The pathophysiology, risk factors, clinical features, radiological evidence, and autopsy findings associated with SAE are discussed, which may, in light of the current literature, assist with the dilemma between assessing procedural complications and medical liability. Given the instances of SAE in the setting of long operative procedures despite careful technical execution, providing accurate and in-depth information, including procedure-related risks, even the rarest but potentially fatal ones, is recommended for informed consent to reduce medicolegal litigation issues.
|
[
"Computed tomography, which occurs when air is introduced into the coronary and/or cerebral arterial vasculature, is a rare but potentially fatal complication. The reported incidence of SAE is 0.08% [ ], although the incidence may be higher, which showed hypercaptation. This needle remained in this position until the end of the procedure, as confirmed with multiple consecutive scans. A coaxial 18-gauge needle was then inserted through the 17-gauge needle to obtain multiple “cutting-type” biopsy samples of the lesion. The insertion of the needle and the biopsies were performed only during inspiratory breath-holding. At the conclusion of the procedure, the 17-gauge needle was removed.",
"",
"At the end of the procedure, the patient coughed, and bright red blood was expectorated. Of note, the patient did not cough or breathe improperly during the procedure while the needles were inserted. Repeat CT imaging of the chest showed slight hemorrhage around the lesion and a massive air embolism within the left ventricular chamber with extension into the aortic root and right coronary artery. Unfortunately, the patient suddenly became unresponsive shortly after the CT imaging was obtained and experienced cardiac arrest. After 40 min of adequate resuscitation efforts, the patient was pronounced dead in the radiology suite.",
"Given the circumstances surrounding the death and the necessity to exclude the possibility of medical malpractice, a medicolegal autopsy was performed the following day. Evidence of previous surgical procedures was noted during the examination, including surgical scars and the absence of the upper lobe of the right lung as well as the spleen and distal pancreas. Examination of the abdominal organs did not yield evidence of further natural disease processes. There were also no noteworthy intracranial findings. Examination of the right lung confirmed evidence of the needle-guided procedure along the pleural surface of the posterior aspect of the lower lobe. Further sectioning of the lung lobe revealed a white-tan ill-defined mass measuring approximately 3 cm within an area of hemorrhage. Sections were obtained for microscopic examination, which showed areas of hemorrhage and pneumatosis foci within the lung parenchyma.",
"",
"A specific procedure was utilized to confirm the presence of an air embolism within the heart and coronary arteries as indicated on the post-procedure CT scan. The procedure is well documented by Richter [ ] and Zolotarov and Fraser [ ] and includes filling the pericardial sac with water and inserting a large bore needle with attached water-filled syringe into each chamber of the heart and the great vessels while watching for bubbles to enter the syringe. In the present case, bubbles appeared in the syringe barrel when the needle tip was inserted into the left ventricle and the ascending aorta. Further examination of the heart did not reveal any significant structural pathological findings. Based on the available clinical data and autopsy findings, the death was attributed to a massive left cardiac and coronary air embolism in the cerebral vascular system, ascending aorta, the left side of the heart, and pulmonary veins [ ]. Early treatment of a SAE consists of prompt administration of 100% oxygen and placing the patient in the left lateral decubitus position with lowering of the head in an effort to increase the intracavitary pressure of the left atrium and avoid cerebral embolization of air [ ].",
"",
"From a pathophysiological point of view, arterial air embolism stems from air entering the pulmonary veins during percutaneous needle biopsy of the lung. According to the literature, several different mechanisms may be responsible for air entry into the pulmonary venous system, firstly, through a hole in the pulmonary vein caused by the needle and an adjacent pulmonary venous vessel created during the needle penetration likely occurred. It is likely that the Valsalva maneuver related to the cough of the patient at the end of the procedure facilitated air penetration into the vascular system. Air reached the left heart and coronary arteries through the pulmonary vein causing heart and coronary embolism with resulting myocardial ischemia, decreased myocardial function, and death.",
"Despite the unfavorable outcome, the multidisciplinary review of the procedure indicated that in the absence of any known risk factors, alternatives such as conservative surveillance through imaging and invasive surgical options both shared significant risks when compared to CT-guided percutaneous needle biopsy. Furthermore, the consent procedure was adequate, and ultimately, the patient was able to make an informed decision regarding his care plan, correctly carried out, giving to the patient all the information needed for his choice.",
"The medicolegal point of view proposed herein for analyzing fatal SAE cases is important because air embolism following CT-guided percutaneous needle lung biopsy is a complication that is difficult to prevent and could serve as a possible source of litigation. Although several recommendations and precautions have been suggested to reduce the risk of SAE following CT-guided percutaneous needle biopsy of the lung, this complication can occur particularly in cases with long operative exposure and despite careful technical execution. It is often worth acknowledging that in the context of personalized treatment, this diagnostic procedure represents a major trend in the future [ ]. On this basis, a thorough disclosure of the procedure given preferably by the operator during the consent process, including all procedure-associated risks, even the rarest but potentially fatal ones, is recommended. In fact, to ensure adequate informed consent, providing accurate and in-depth information, including alternative invasive and conservative approaches, is essential to reduce medicolegal litigation issues.",
"Computed tomography (CT)-guided percutaneous needle\nbiopsy of the lung is a safe diagnostic procedure for suspicious lung lesions. Systemic air embolism (SAE) is a rare and potentially fatal procedure-related\ncomplication. An 81-year-old man died after SAE development during a\nCT-guided needle biopsy of the lung. The thorough medicolegal investigation identified SAE\nas a procedure-related complication excluding medical malpractice. Thorough disclosure of the procedure given, preferably\nby the operator during the consent process, is recommended in order to avoid\nmedicolegal litigation issues.",
"Computed tomography (CT)-guided percutaneous needle\nbiopsy of the lung is a safe diagnostic procedure for suspicious lung lesions.",
"Systemic air embolism (SAE) is a rare and potentially fatal procedure-related\ncomplication.",
"An 81-year-old man died after SAE development during a\nCT-guided needle biopsy of the lung.",
"The thorough medicolegal investigation identified SAE\nas a procedure-related complication excluding medical malpractice.",
"Thorough disclosure of the procedure given, preferably\nby the operator during the consent process, is recommended in order to avoid\nmedicolegal litigation issues."
] |
PMC10752984
|
Frontiers in Pharmacology
|
Boswellia carteriioleoresin extracts induce caspase-mediated apoptosis and G1cell cycle arrest in human leukaemia subtypes
|
14-12-2023
|
Background: Leukemias are a common cancer in adults and children. While existing treatments are effective, they are associated with severe side-effects compounded by the emergence of drug resistance. This necessitates the need to develop new drugs and phytopharmaceuticals offer a largely untapped source. Oleoresins produced by plants in the genus Boswellia have been used for centuries in traditional medicine and recent work suggests they may exhibit anti-cancer activity. However, the underlying mechanisms remain unclear and most existing research focusses on Boswellia serrata ; just one of many species in the Boswellia genus. To address these limitations, we elucidated the anti-cancer potential and associated mechanisms of action of Boswellia carterii . Methods: A methanolic solvent extraction method was optimised. The effect of methanolic extracts of B. carterii on leukaemia (K562, MOLT-4 and CCRF-CEM) and normal (PBMC) cell line viability was assessed using MTT assay and flow cytometry. Cell morphology, apoptosis (Annexin-V/propidium iodide), mitochondrial membrane potential (Rhodamine-123) and the cell cycle (propidium iodide) were evaluated using flow cytometry. Regulatory protein expression was quantified using Western Blot. Results: Methanolic extracts of B. carterii oleoresin reduced the viability of K562, MOLT-4 and CCRF-CEM cell lines with selectivity indexes of between 1.75 and 2.68. Extracts increased the proportion of cells in late apoptosis by 285.4% ± 51.6%. Mitochondrial membrane potential was decreased by 41% ± 2% and the expression of cleaved caspase-3, -7, and -9 was increased by 5.7, 3.3, and 1.5-fold respectively. Extracts increased the proportion of cells in sub G 1 and G 1 phase by 867.8% ± 122.9% and 14.0 ± 5.5 and decreased those in S phase and G 2 /M by 63.4% ± 2.0% and 57.6% ± 5.3%. Expression of CDK2, CDK6, cyclin D1, and cyclin D3 were decreased by 2.8, 4.9, 3.9, and 2.5-fold. Conclusion: We are the first to report that methanolic extracts of B. carterii are selectively cytotoxic against three leukemia cell lines. Cytotoxic mechanisms likely include activation of the intrinsic apoptotic pathway and cell cycle arrest through downregulation of CDK2, CDK6, cyclin D1, and cyclin D3. Our findings suggest that B. carterii may be an important source of novel chemotherapeutic drugs and justifies further investigation.
|
[
"Leukaemia is a common cancer that presents as increased blood leucocyte count and remains a considerable global health burden. In children and young adults, the incidence of leukaemia increases each year and now accounts for one-third of all cancer diagnoses. Despite this, improvements in chemotherapeutics—which remain at the forefront of treatment regimens—have produced net 5-year survival rates of between 37% and 89% dependent on leukaemia subtype. Drugs commonly used to treat leukaemia include anthracyclines, topoisomerase inhibitors, mitotic inhibitors, alkylating agents and antimetabolites which produce cell cycle arrest and apoptosis via various mechanisms. However, despite their effectivity against leukaemia, many produce severe short and long-term off-target effects in multiple organ systems which are particularly severe in developing children and adolescents. Therefore, there remains a need to develop novel effective chemotherapeutics with fewer off-target effects.",
"Many anti-cancer drugs are derivatives of plant-based compounds. Yet, phytopharmaceuticals offer a largely untapped source for the development of novel anti-cancer drugs despite a tendency to exhibit fewer and less severe side-effects. Plants in the genus Boswellia provide a notable example.",
"Boswellia species are shrub-like trees, widely distributed from the Horn of Africa, throughout the Middle East and into India and China. These plants produce oleoresins—commonly known as Frankincense—which have been used for centuries as a part of Ayurvedic and traditional medicine practices. However, recent evidence suggests that Boswellia oleoresins and oleoresin-derived compounds may be effective in the treatment of a variety of diseases. For example, previous work highlights that extracts of Boswellia oleoresins show anti-inflammatory and anti-microbial activity. Furthermore, several studies show that extracts of the Boswellia oleoresins exhibit anti-cancer activity against multiple cancer cell types in vitro through mechanisms such as apoptosis, and cell cycle arrest.",
"However, studies that seek to elucidate the mechanistic actions of Boswellia are limited, use a variety of cancer cell types and tend to focus on one particular mechanistic element. As such, a cohesive description of the mechanistic effects of Boswellia remains unreported. Furthermore, the majority of existing research focusses on Boswellia serrata which is one of many species in the Boswellia genus. As a result, much less is known about the biological activity of other accessible Boswellia species such as Boswellia carterii .",
"To address these limitations, we sought to investigate the anti-cancer effects of B . carterii oleoresin extracts against leukemia cell lines. We then took an integrative methodological approach to reveal the associated mechanisms of action thus producing a unified description of the anti-cancer activity of B . carterii .",
"All chemicals and reagents were purchased from Fisher scientific, United States, unless otherwise stated.",
"The B. carterii Birdw oleoresin samples used for this study was provided by United Kingdom Essential oils and authenticated by Steven Holmes as a part of industrial procurement quality control. Voucher specimens are stored at The University of Salford, United Kingdom.",
"B. carterii oleoresin was macerated to a fine powder and then extracted using either acetonitrile and MOLT-4 and CCRF-CEM, which are both acute lymphoblastic leukaemias",
"Peripheral blood mononuclear cells atmosphere.",
"The cytotoxic effects of the B. carterii oleoresin extracts were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide values were calculated using SigmaPlot 12.3.",
"Cell densities of 50,000 cells were treated for 24–72 h with 25–100 μg/ml B. carterii oleoresin methanolic extract then washed with 1x PBS. A minimum of 10,000 cells were measured using flow cytometry alone.",
"Cell densities of 100,000 cells were incubated for 48 h with 25–100 μg/ml B. carterii oleoresin methanolic extract or a vehicle control or a positive control. Cells were then washed with 1x PBS and fixed with ice-cold 70% v/v ethanol. Following fixation cells were treated with 100 μg/mL RNase A substrate and significantly greater than those produced by acetonitrile and water; 14% ± 5% and 8% ± 2% respectively and ALL values. In K562 cells, the IC_(50) of methanol, the IC_(50) of acetonitrile, methanol, and propanol IC_(50) values for acetonitrile. The independent experiment shown in was designed to evaluate the time-dependent effect of B. carterii in K562 cells. The effect of each concentration tested on viability increases with incubation time. This is quantified in which compares the IC_(50) values of equivalent dose response curves following 24-, 72- and 120-h incubation periods. This reveals a significant time-dependent effect.",
"We next evaluated the specificity of effect of B. carterii by comparing dose response curves in leukemia cells to that in an equivalent normal cell-line. The average IC_(50) value in PBMC cells and 9.6% ± 3.2% decrease B. carterii oleoresin decreased the proportion of viable cells by 95.1% ± 3.8% shows a leftward shift in rhodamine-123 fluorescence indicating a decrease in mitochondrial membrane potential. The mean data shown in demonstrates this effect is concentration, but not incubation time dependent. For example, incubation with the highest concentration tested. For example, 100 μg/ml B. carterii oleoresin decreased relative PARP expression by 3.3-fold reveals a concentration-dependent effect on the proportion of cells in sub G_(1), G_(1), S phase and G_(2). 100 μg/mL increased the proportion of cells in sub G_(1) and G_(1) by 867.8% ± 122.9%. 100 μg/ml B. carterii oleoresin significantly decreased CDK2, CDK6, cyclin D1 and cyclin D3 expression by 2.8-fold. Furthermore, it remains the case that many existing chemotherapeutic strategies are associated and the severe side-effects, which is especially the case in children. For both reasons, the discovery and development of novel chemotherapeutics remains a priority.",
"Natural products are an important source given 1) the richness and diversity of potentially therapeutic species, many of which remain unexplored and 2) that compounds isolated from natural sources frequently produce fewer or attenuated side-effects. One plant genus of interest is Boswellia , which has been used in traditional Chinese and Indian medicine for centuries. More recently, several studies show B. serrata to be an effective anti-cancer chemotherapeutic in vitro . However, a cohesive description of the mechanistic effects of Boswellia remains unreported. Furthermore, the majority of existing research focusses on B. serrata which is one of many species in the Boswellia genus. To address these limitations, we used an integrated approach to elucidate the anti-leukemic potential and mechanisms of effect of B. carterii.",
"Previous investigators predominantly use alcoholic extractions to evaluate the biological activity of Boswellia oleoresins. However, it wasn’t clear if alcoholic solvents are optimal given that no previous studies have directly compared the extraction yield and biological activity of alternative solvent extracts. Our findings revealed that alcohol-based solvents 1) produce the highest yield and 2) appear to effectively isolate potentially biologically active compounds. Given the high proportion of alcohol soluble material within Boswellia oleoresins, this observation may not surprise. However, we deemed it important to rule out the potential superiority of non-alcoholic solvents.",
"Integrating the data of and 1 reveals that of the alcohols tested, methanol produces the highest yield and extracts with the greatest potency and diversity of effect against leukemia cell lines. For this reason, methanolic extracts were used in all further experiments. Methanol is a commonly used as a Boswellia extraction solvent, though our study is the first to empirically demonstrate it is indeed most effective.",
"B. carterii oleoresin methanolic extract was cytotoxic against CML and concentration manner. This contributes to a more complete understanding of the B. carterii cytotoxic profile, and we are the first to report cytotoxic effects in leukemia.",
"Clinically used chemotherapeutic agents are associated with severe and long-term side effects. While it is encouraging that clinical trials using other Boswellia species report few off target effects, similar evidence does not exist for B. carterii specifically. As such, we also began to investigate the anti-cancer selectivity of the B. carterii oleoresin methanolic extract. show minimal cytotoxic activity against human PBMC’s over anti-leukemic concentration ranges. Here, the IC_(50) value of 90.8 ± 1.3 μg/mL was around 2–3 times that against K562, MOLT-4 and CCRF cell lines. Measured IC_(50) values were used to calculate selectivity indexes. This is important, as selectivity indexes calculated during in vitro studies predict the likelihood of side effects when compounds are administered in vivo . The selectivity indexes for K562, MOLT-4 and CCRF-CEM were 1.75, 2.68 and 2.39 respectively which are considered mildly selective according to the recognised standard scale. However, it should be noted that the methanolic extract of B. carterii oleoresin is more selective than clinically employed chemotherapeutic agents such as anthracyclines, which have selectivity indexes in the region of 0.2–1.5.",
"Previous studies show oleoresin extracts from other Boswellia species induce apoptotic cell death in colorectal breast and oral squamous cell carcinomas. However, the precise pathways and molecular mechanisms remain ambiguous.",
"Visual review of cells revealed concentration and time-dependent morphological changes. These included increased granularity and are consistent with apoptosis. Further evidence for a pro-apoptotic action is provided by annexin V/propidium iodide co-staining thus molecular investigation of flippase phosphatidylserine translocation; a phenomenon commonly associated with apoptosis. The mean data shown in 1) confirms the effect on cell viability reported in and 2) reveals that apoptosis but not necrosis is responsible.",
"Our next experiments sought to establish whether apoptosis resulted from activation of the intrinsic or extrinsic pathway. show that B. carterii oleoresin methanolic extract decreases mitochondrial membrane potential. In apoptotic cells, mitochondrial membrane potential is decreased by the BCL-2 family of proteins. This mitochondrial deplolarisation is a key factor in the development of the apoptosome in conjunction with caspase 9 and more strongly associated with the intrinsic pathway.",
"Western blotting revealed increased cleavage of the DNA repair enzyme PARP, the loss of which is associated with caspase activation to prevent depletion of adenosine triphosphate pools. Furthermore, we observed increased cleavage of the cysteinyl proteases caspases-3, -7 and 9. Cleavage of caspase-3 and -7 coverts them to their active isoforms; a process vital for the effector pathways of apoptosis. That we see an upregulation of cleaved caspase-9 strongly suggests it is activation of the intrinsic pathway that leads to activation of effector pathway.",
"The induction of apoptosis without necrosis is an important consideration for prospective cytotoxic agents. Cells killed via apoptosis can be removed by the immune system. This prevents leakage of intracellular components into the extracellular space thus reduces inflammation further decreasing the likelihood of side effects if translated to an in vivo model.",
"Many cancer cells overexpress cell division promoting proteins. As such, another target of chemotherapeutic agents is the cell cycle thus prevention of uncontrolled, indefinite cancer cell division. Previous work suggests that B. serrata extracts can induce _(sub)G_(1) and G_(1) cell cycle arrests in vitro though the underlying mechanisms remain unclear. Therefore, we determined whether B. carterii oleoresin methanolic extract impacted cell cycle regulation. show that extracts increase the proportion of cells in _(sub)G_(1) which is indicative of DNA damage. Furthermore, the accumulation of cells in G_(1) and decrease of cells in S phase suggests inhibition of transition which ought to prevent, or at least slow division.",
"To better understand the molecular mechanisms underlying cell cycle dysregulation we measured the expression of key regulatory proteins. B. carterii oleoresin methanolic extract did not significantly alter the expression of p18; a protein that inhibits transition from G_(1) to S phase of the cell cycle. However, the extract reduced the expression of cyclins D1 and D3, and CDK2 and CDK6; proteins that facilitate the transition from G_(1) to S phase of the cell cycle.",
"Our data suggests it is the downregulation of transition-promoting proteins, rather than upregulation of inhibitory proteins that is primarily responsible for the proportional changes reported in . However, we cannot rule out a role for other inhibitory proteins such as p21 and p27. For this, further work is required.",
"There remains a global need to develop new anti-cancer drugs given the ever present off-target effects and increasing incidence of drug resistance associated with existing compounds. Our data suggests that B. carterii may be a promising source of novel anti-cancer agents. The cytotoxic effects were specific and produced by the controlled mechanisms of apoptosis and cell-cycle arrest; common targets for other chemotherapeutics. Furthermore, we know that oleresins from other Bosweillia species are well tolerated in animal models and clinical trials. The therapeutic potential of B. carterii may be of value in low-income and developing countries. Here, mainstream chemotherapeutics are frequently inaccessible so plant-based and traditional medicines are used widely. However, further research into the pharmacodynamics and pharmacokinetics of B. carterii oleoresin methanolic extracts is required.",
"We are the first to report that methanolic extracts of B. carterii are selectively cytotoxic against three leukemia cell lines. Cytotoxicity results from 1) activation of the intrinsic apoptotic pathway and 2) cell cycle arrest through downregulation of CDK2, CDK6, cyclin D1 and cyclin D3. These data suggest that B. carterii may be an important source of potential novel chemotherapeutic drugs. This warrants further investigation to elucidate and purify the precise compounds responsible for the reported effects."
] |
PMC10604885
|
Antioxidants
|
Multi-Organ Nutrigenomic Effects of Dietary Grapes in a Mouse Model
|
01-10-2023
|
As a whole food, the potential health benefits of table grapes have been widely studied. Some individual constituents have garnered great attention, particularly resveratrol, but normal quantities in the diet are meniscal. On the other hand, the grape contains hundreds of compounds, many of which have antioxidant potential. Nonetheless, the achievement of serum or tissue concentrations of grape antioxidants sufficient to mediate a direct quenching effect is not likely, which supports the idea of biological responses being mediated by an indirect catalytic-type response. We demonstrate herein with Hsd:ICR (CD-1 ® Outbred, 18–24 g, 3–4 weeks old, female) mice that supplementation of a semi-synthetic diet with a grape surrogate, equivalent to the human consumption of 2.5 servings per day for 12 months, modulates gene expression in the liver, kidney, colon, and ovary. As might be expected when sampling changes in a pool of over 35,000 genes, there are numerous functional implications. Analysis of some specific differentially expressed genes suggests the potential of grape consumption to bolster metabolic detoxification and regulation of reactive oxygen species in the liver, cellular metabolism, and anti-inflammatory activity in the ovary and kidney. In the colon, the data suggest anti-inflammatory activity, suppression of mitochondrial dysfunction, and maintaining homeostasis. Pathway analysis reveals a combination of up- and down-regulation in the target tissues, primarily up-regulated in the kidney and down-regulated in the ovary. More broadly, based on these data, it seems logical to conclude that grape consumption leads to modulation of gene expression throughout the body, the consequence of which may help to explain the broad array of activities demonstrated in diverse tissues such as the brain, heart, eye, bladder, and colon. In addition, this work further supports the profound impact of nutrigenomics on mammalian phenotypic expression.
|
[
"The influence of diet on human health has been recognized over the millennia. From the time of Hippocrates Outbred, 18–24 g, 3–4 weeks old, female) mice were obtained from Envigo RMS, LLC and an isocaloric control diet supplemented with 5% were manufactured by Envigo.",
"To understand the multi-organ effect of grape consumption, we conducted RNA seq analysis from samples derived from the liver, colon, kidney, and ovary, as described in . Differential expression analysis was performed for each organ, with the criteria of q < 0.05 and Log2(Fold-change) > 1 for gene selection. A list of genes from the differentially expressed gene. The colon exhibited a higher number of DEGs, with 84 being differentially expressed. The entire gene list is comprised of 35,275 genes, and the volcano plots show gene distribution for the liver, colon, kidney, and ovary. The plots further differentiate the genes based on their fold-change threshold Log2(Fold-change) > 1 and the significance value, was used to generate MA plots. These plots illustrate the expression levels of the DEGs for each organ, namely, the liver, colon, kidney, and ovary. The distinct populations of genes on the MA plot represent the influence of grapes on the genes; some genes are clustered closely while others are uniquely positioned, suggesting varying magnitude of expression changes.",
"As an attempt to gain functional insight into the changes observed in various organs resulting from grape consumption, we conducted pathway analysis on the entire gene set. The pathways were analyzed for each subject organ: liver, colon, kidney, and ovary. Functional annotations of these pathways were derived from cancer gene pathways, Reactome pathways, PID pathways, and Biocarta. The data set used for the analysis was generated by comparing STD5GP vs. STD diet groups, and each specific gene set corresponding to a particular pathway was identified based on the ontology domain. The analysis provides the enrichment score and the statistical values, which were utilized to generate bar plots for the significantly enriched pathways with q < 0.05. The pathways for each organ suggest the magnitude of enrichment influenced by grape consumption.",
"Pathway analysis",
"In the liver, pathways such as the citric acid cycle [ ], protection through sulfation of benzene metabolites [ ], tumor suppressor gene [ ]. Down-regulation of the biosynthesis of monounsaturated fatty acids pathway, which functions as a tumor suppressor and acts as a negative regulator of the ERBB2 receptor tyrosine kinase [ ]. Additionally, the enrichment of the NO2IL12 pathway indicated the potential role of grapes in promoting host defense against intracellular microbial infections and controlling malignancy [ ]. Furthermore, we observed enrichment of the CTLA4 pathway, highlighting the effect of grapes in preventing autoimmune diseases by inhibiting T cell activation [ ].",
"Genes enriched",
"In the kidney, we observed that grape consumption up-regulated genes associated with the production of the immunoglobulin kappa light chain [ ]. Moreover, TGF-beta signaling mediated ovarian cancer was attenuated by decreased expression of igkc [ ]. Intriguingly, inhibition of genes such as krt7 [ ], krt8 [ ], ehf [ ], s100p [ ], cbs [ ], wfdc2 [ ], pdxk [ ], fxyd [ ], igj [ ], snhg11 [ ], and calb1 [ ] provides evidence of suppressive impact of the grape diet on progression of tumors in the ovary.",
"As described above, the addition of grapes to the diet of mice influences gene expression in the liver, colon, kidney, and ovary, and presumably other organs as well. In related work, we have demonstrated physiological responses likely resulting from grape consumption related to the liver [ ], brain [ ], and longevity [ ]. More broadly, dietary grapes have been demonstrated to mollify various disease states [ ] in clinical trials and animal models.",
"In general, based on the alteration of gene expression modulated by grapes, it is logical to anticipate some cause-and-effect relationship. The main objective of this work was to examine the multi-organ nutrigenomic potential of grapes. Direct assessment of physiological responses was beyond the scope of the study. However, based on the accumulated data, it is possible to analyze the influence of grapes on metabolic pathways established as relevant to illness. Although additional investigations are required to prove such cause/effect relationships, some examples follow that provide suggestive evidence and a rationale for additional work.",
"In the liver, several facets of grape-related effects have emerged. First, grapes up-regulated the expression of sult3a1 , which is associated with drug metabolism and pharmacokinetics holds the potential for preventing hepatocellular carcinoma, particularly through the Wnt/β-catenin pathway [ ]. This function is tied to the spatial organization within the portocentral axis, highlighting the significance of grapes in orchestrating metabolic and biotransformation processes within specific hepatic zones [ ]. These multifaceted effects emphasize the interplay between metabolism and regulation of pathogenesis.",
"In the colon, grapes play a role in maintaining homeostasis through regulatory actions on ctrb1 and clps . As discussed previously regarding involvement in food breakdown and nutrient absorption, it is established that ctrb1 is a mediator of epithelial homeostasis, leading to amelioration of T cell-mediated colitis [ ]. This protective effect is attributed to the nuclear receptor LRH-1, which binds to the proximal promoter of ctrb1 , initiating downstream effects that promote cell survival and maintain epithelial homeostasis [ ]. This function is further substantiated by the up-regulation of reg1 , a downstream effector of IL-22 [ ], and down-regulation of ceacam2 , which is shown to be modified in inflammatory bowel disease, it has been observed that IL-4 orchestrates the process of recovery, particularly within tubule-interstitial injury [ ]. Extending the scope of inquiry, we found down-regulation of genes such as gbp2 , snhg11 , irgm1 , and irgm2 with the grape diet. Specifically, gbp2 has been observed to modulate the expression of programmed death-ligand 1 ubiquitination, thereby contributing to the activation of the Wnt/β-catenin pathway [ ]. Additionally, enrichment of the transforming growth factor beta-1, which is expressed via tumor-associated macrophages. This suppression is significant in the context of cancer immunotherapy [ ]. Furthermore, cdh1 is known to be involved in DNA methylation [ ], which was down-regulated by the grape diet. Additionally, genes igkc , krt7 , and krt8 play crucial roles in regulating the epithelial–mesenchymal transition. Some ramifications of these phenotypic changes are suggested through pathway analysis and consideration of the specific gene function. However, the implications are much broader. From a holistic point of view, the potential of dietary grapes to alter gene expression and corresponding downstream responses signifies a broad-based mechanism that may contribute to the pleiotropic activities mediated by grapes. Naturally, any influence of diet on genetic homeostasis depends on the diet as a whole. Nonetheless, the utilization of grapes in this capacity may be viewed as a prototype that exemplifies the power of dietary nutrigenomics."
] |
PMC10361452
|
Discover. Oncology
|
PTEN-related risk classification models for predicting prognosis and immunotherapy response of hepatocellular carcinoma
|
20-07-2023
|
Introduction PTEN often mutates in tumors, and its manipulation is suggested to be used in the development of preclinical tools in cancer research. This study aims to explore the biological impact of gene expression related to PTEN mutations and to develop a prognostic classification model based on the heterogeneity of PTEN expression, and to explore its sensitivity as an indicator of prognosis and molecular and biologic features in hepatocellular carcinoma (HCC). Material and methods RNA-seq data and mutation data of the LIHC cohort sample downloaded from The Cancer Genome Atlas (TCGA). The HCC samples were grouped according to the mean expression of PTEN, and the tumor microenvironment (TME) was evaluated by ESTIMATE and ssGSEA. The prognostic classification model related to PTEN were constructed by COX and LASSO regression analysis of differentially expressed genes (DEGs) between PTEN-high and -low expressed group. Results The expression of PTEN was affected by copy number variation (CNV) and negatively correlated with immune score, IFNγ score and immune cell infiltration. 1281 DEGs were detected between PTEN-high and PTEN-low expressed group, 8 of the DEGs were finally filtered for developing a prognosis classification model. This model showed better prognostic value than other clinicopathological parameters, and the prediction accuracy of prognosis and ICB treatment for immunotherapy cohorts was better than that of TIDE model. Conclusions This study demonstrated the effect of CNV on PTEN expression and the negative immune correlation of PTEN, and constructed a classification model related to the expression of PTEN, which was of guiding significance for evaluating prognostic results of HCC patients and ICB treatment response of cancer immunotherapy cohorts. Supplementary Information The online version contains supplementary material available at 10.1007/s12672-023-00743-x.
|
[
"Hepatocellular carcinoma, which a tumor suppressor gene located in the long arm of chromosome 10 at position 23.3 that often manifests mutation in cancer, could suppress tumorigenesis via a variety of mechanisms, for example, subcellular localization and protein–protein interaction, phosphatase-dependent and independent activities, and it regulates many cellular functions including DNA repair and cell movement, cell growth, proliferation, and survival [ , ]. The mutation and deletion of PTEN are related to a series of clinical results of the tumor. PTEN gene mutation in advanced cervical cancer is associated with tumor progression and adverse outcome after radiotherapy [ ]. PTEN loss is identified as a clinically related genetic change that drives the molecular and histopathological heterogeneity of lung tumors caused by Rb1/Trp53 mutations [ ]. Mutations, decreased promoter activity and decreased expression in PTEN were also reported in patients with HCC [ ], their dysregulation has a critical pathogenic role in HCC development. Future studied are encouraged to probe into the regulation of PTEN expression level and its downstream signaling to facilitate the design of therapeutic strategies for treating HCC as well as some other cancers [ ].",
"The current study used bioinformatics analysis to evaluate the biological effects of PTEN mutation-regulated expression, including cancer stem cell obtained by one-class logistic regression machine-learning algorithm, as one of the immune indicators evaluated in this study. Meanwhile, using the strategy proposed by Charoentongm [ ], 28 subpopulations of tumor-infiltrating lymphocytes, in which the selected gene set was “h.all.v7.5.1.symbols.gmt” and the threshold of significance was defined as p.adj < 0.25.",
"The gene expression profiles of PTEN high expression group and PTEN low expression group were uploaded to “Limma” to calculate the difference of gene expression profile between the two groups. The differentially expressed genes is often used to evaluate responses to ICB treatment [ ]. TIDE and prognostic classification models were introduced into the two ICB treatment data sets to calculate risk score and evaluate OS. The prediction accuracy of the two models for immunotherapy response was also evaluated and compared by AUC.",
"Univariate and multivariate Cox regression analysis were used to identify independent prognostic variables in age, gender, tumor stage and grade and risk score, which were integrated into a nomogram by the “RMS” package. The calibration chart was used to compare the 1-year, 3-year and 5-year OS predicted by nomogram and actually observed. The accuracy of nomogram in predicting OS was evaluated by decision curve analysis. The mutation information of PTEN gene was sorted out by using the maf data of TCGA, and 8 samples with PTEN mutation and 334 samples without PTEN mutation were found. We observed that the expression of PTEN in PTEN mutant samples was lower than that in wild type samples, but there was no significant difference in PTEN expression between the two types of samples. In comparison to the wild-type samples, mitotic spindle, MYC targets, DNA repair, G2M checkpoint, E2F targets, and other signal pathways were significantly enriched in PTEN mutant samples. In the aspect of CNV, the PTEN CNV type of 2 samples in TCGA-LIHC cohort was copy number amplification, the CNV type of PTEN in 22 samples was copy number deletion, and the CNV of PTEN does not exist in 329 samples. Significant differences in PTEN expression were detected among the three types of samples, and PTEN expression was significantly inhibited in samples with copy number deletion compared with samples with copy number amplification and CNV without PTEN. The results here indicated that CNV affects the expression of PTEN. Therefore, we went on to analyze the biological effects of PTEN expression. The correlation of cancer stem cell. The expression of PTEN was also positively correlated with carcinogenic signal pathways including PI3K, TGF- β, NOTCH, TP53 and WNT, HIPPO, NRF1, and RAS. Patients with HCC were divided into groups according to the average amount of PTEN expression in the TCGA-LIHC cohort. Twelve pathways were identified that were significantly more highly enriched in PTEN-High group than PTEN-low group, including mitotic spindle, protein secretion, TGF-β signaling, UV response, WNT β catenin signaling, etc..",
"Patients with HCC were divided into groups according to the average amount of PTEN expression in the TCGA-LIHC cohort. The abundance of immune score, immune cells and 29 gene signatures representing the main functional components, immunity, matrix and other cell groups of tumor were evaluated in two different PTEN expression groups. Compared with cases with low PTEN expression, the immune score and IFN-γ score were significantly reduced in cases with high PTEN expression. We detected a significant difference in the abundance of 16 TILs between the cases with high expressed PTEN and the cases with low expressed PTEN. Compared with the patients with low expression of PTEN, patients with high expression of PTEN had significantly elevated abundance of type 2T helper cell and significantly decreased abundance of activated B cell, macrophage, effector memory CD4 T cell, regulatory T cell, effector memory CD8 T cell, activated CD8 T cell, type 17T helper cell, type 1T helper cell, myeloid-derived suppressor cell. The results calculated by gene signatures indicating 29 TME components showed that the enrichment of 17 TME-related components was significantly lower in cases with high expression of PTEN than in cases with low expression of PTEN.",
"Prognosis of TCGA-LIHC cohort cannot be significantly stratified based on PTEN expression: risk score = 0.136 × BMI1 + 0.088 × AGPS + 0.076 × RAP2A + 0.162 × FAM83D + 0.085 × SKP2 + (− 0.122 × SLC2A2) + 0.109 × SGCB + (− 0.064 × SPP2). Based on the median of risk score in the TCGA-LIHC cohort. The 1-year AUC of the prognosis classification model in the TCGA-LIHC cohort and the GSE14520 cohort were 0.79 and 0.71, respectively; the 3-year AUC were 0.73 and 0.7, respectively; And the 5-year AUC were 0.73 and 0.67, respectively.",
"The prognostic classification model and TIDE were introduced into two ICB treatment cohorts to evaluate the OS of the samples. The prognostic classification model was statistically significant in predicting the OS of IMvigor210 cohort samples, and its AUC reached 0.62 at 1 year and 1.5 years. TIDE had no statistical significance in predicting the OS of IMvigor210 cohort samples, and the AUC of predicting 1-year and 1.5-year OS did not reach 0.6. In terms of the accuracy of predicting the treatment response of ICB, the efficiency of prognostic classification model was higher than that of TIDE. The prognostic classification model also significantly distinguished the OS of patients in different risk groups in the GSE78220 cohort, and the AUC of 1 year, 2 years and 2.5 years were 0.76, 0.85 and 0.82, respectively. There was no significant correlation between TIDE score and OS calculated by TIDE in the GSE78220 cohort, and the AUC in 1 year, 2 years and 3 years was much lower than that in the prognostic classification model. In this cohort, the prognostic classification model also had more potential to predict ICB than TIDE. Moreover, no matter which clinical stage case is in, the prognostic classification model could significantly distinguish different survival outcomes. In the IMvigor210 cohort, 348 patients showed varying degrees of response to PD-L1 receptor blockers, including stable disease. Among the two risk groups, the proportion of CR/PR in the low-risk group was significantly higher than that in the high-risk group, so it was judged that the response of low-risk cases to ICB was better than that of high-risk cases.",
"By univariate Cox regression analysis of clinical variables and risk score, the significant variable clinical stage and risk score was introduced into the multivariate COX regression model, and the significant variables in the univariate model were also significant in the multivariate model, indicating that clinical stage and risk score was an independent variable related to the prognosis of HCC. Thus, clinical and risk score were combined into a nomogram. The calibration curve showed that the 2-year and 3-year OS of HCC predicted by nomogram almost coincided with the 45° dotted line, indicating that nomogram could accurately predict the prognosis of HCC. The net benefit of nomogram and risk score in predicting the prognosis of HCC was observed in the DCA curve. In the 1-year, 3-year and 5-year OS forecasts for HCC, the AUC of nomogram and risk score was significantly higher than that of age, gender and clinical stage and grade.",
"The clinical correlation of prognostic classification model was explored. We found that risk score had different levels in different T stages, different clinical stages and different grades groups. The risk score of T2–T4 was significantly higher than that of T1. Similarly, the sample at the later clinical stage exhibited a higher risk score than the sample at the earlier clinical stage. High-grade HCC cases showed higher risk score than low-grade HCC cases. Compared with low-risk cases, the mutation rate of high-risk cases increased significantly, especially TP53, with a mutation rate of 41% in high-risk cases and 17% in low-risk cases. The mutation pattern of this gene was also different in different risk cases. Compared with low-risk cases, the activity of 18 pathways in high-risk cases was significantly increased, among which the pathways with the greatest difference in activity between risk groups were those regulating the cell cycle, such as mitotic spindle, E2F targets and G2M checkpoint. These results indicate that the prognostic classification model is beneficial to the identification of different mutation characteristics and biological functions in HCC cases."
] |
PMC10927983
|
Frontiers in Endocrinology
|
A comparative analysis of energy expenditure and substrate metabolism in male university students with overweight/obesity: Tabata vs HIIT and MICT
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27-02-2024
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Introduction Exploring the energy expenditure and substrate metabolism data during exercise, 10-minute recovery, and 20-minute recovery phases in Tabata, HIIT(High-Intensity Interval Training), and MICT(Moderate-Intensity Continuous Training). This study explores the scientific aspects of weight reduction strategies, examining energy expenditure and substrate metabolism from various training perspectives. The aim is to establish a theoretical foundation for tailoring targeted exercise plans for individuals within the population with overweight/obesity. Methods This study used an experimental design with fifteen male university students with overweight/obesity. Participants underwent random testing with Tabata, HIIT, and MICT. Tabata involved eight sets of 20 seconds exercise and 10 seconds rest, totaling 4 minutes. HIIT included four sets of power cycling: 3 minutes at 80% VO 2max intensity followed by 2 minutes at 20% VO 2max . MICT comprised 30 minutes of exercise at 50% VO 2max intensity. Gas metabolism indices were continuously measured. Subsequently, fat and glucose oxidation rates, along with energy expenditure, were calculated for each exercise type. Results During both the exercise and recovery phases, the Tabata group exhibited a significantly higher fat oxidation rate of (0.27 ± 0.03 g/min) compared to the HIIT group (0.20 ± 0.04 g/min, p<0.05) and the MICT group (0.20 ± 0.03g/min, p<0.001). No significant difference was observed between the HIIT and MICT groups (p=0.854). In terms of energy expenditure rate, the Tabata group maintained a substantially elevated level at 5.76 ± 0.74kcal/min compared to the HIIT group (4.81 ± 0.25kcal/min, p<0.01) and the MICT group (3.45 ± 0.25kcal/min, p<0.001). Additionally, the energy expenditure rate of the HIIT group surpassed that of the MICT group significantly (p<0.001). Conclusion The study finds that male college students with overweight/obesity in both exercise and recovery, Tabata group has lower fat and glucose oxidation rates, and energy expenditure compared to HIIT and MICT groups. However, over the entire process, Tabata still exhibits significantly higher rates in these aspects than HIIT and MICT. Despite a shorter exercise duration, Tabata shows a noticeable “time-efficiency” advantage. Tabata can be used as an efficient short-term weight loss exercise program for male college students with overweight/obesity.
|
[
"In recent years, the improvement of living standards has brought about various health issues, with obesity being a global public health concern. The sedentary lifestyle and changes in dietary habits associated with socio-economic development have contributed to a rapid increase in global obesity rates. According to the World Obesity Federation’s “World Obesity Atlas 2023” report, it is projected that over the next 12 years, more than 51% of the global population—exceeding 4 billion people—will be either obese or overweight. Research indicates that obesity is a significant risk factor for chronic diseases such as cardiovascular diseases, diabetes, and musculoskeletal disorders. The high prevalence of obesity significantly affects the health and societal development in China, making the scientific and efficient approach to weight loss a critical issue.",
"Traditional weight loss exercises often involve MICT(Moderate-Intensity Continuous Training), such as walking, brisk walking, running, and cycling, which has proven to be effective. However, the lengthy and monotonous nature of the exercise makes it challenging for many individuals with obesity to adhere to. In recent years, HIIT(High-Intensity Interval Training) has gained attention. Initially proposed by Reindell and Roskamm, HIIT has become popular among fitness enthusiasts. HIIT involves repeated cycles of high-intensity exercise interspersed with low-intensity exercise or rest periods with varying recovery times. Compared to traditional long-duration continuous exercise, HIIT has a relatively short exercise duration but higher intensity. HIIT is considered an exercise method that increases the metabolic rate and promotes fat consumption. The primary energy systems during HIIT are the phosphagen and glycolytic systems, with glucose being the main metabolic substrate. Therefore, the efficacy of HIIT in reducing fat is not solely due to the energy expenditure during exercise but also the significant aerobic demand fluctuations that enhance post-exercise metabolic rate and fat utilization.",
"However, traditional HIIT training still requires more than 20 minutes. This is where Tabata comes into play. Originating in Japan, Tabata involves 20 seconds of exercise, 10 seconds of rest, repeated for eight sets, totaling a 4-minute interval training session. Compared to HIIT and MICT, Tabata offers advantages such as a relatively short exercise duration, high enjoyment, unrestricted space requirements, and easy implementation, making it more accessible for individuals with overweight/obesity to adhere to.",
"Current research primarily focuses on the effects of different exercise modalities on body composition, body components, and weight loss. Many scholars have conducted comparative studies on the fitness effects of HIIT and MICT, finding that for the same energy expenditure, HIIT yields a greater increase in VO_(2max) [23.8% vs 19.3%, 15.8% vs 8.0%, 14% vs 7%]. Moreover, HIIT has been shown to reduce insulin and blood sugar levels, improve insulin sensitivity, and enhance the mechanisms of blood dynamics, metabolism, and endocrine factors involved in the pathogenesis of hypertension in healthy populations. The effects of HIIT are also superior to those of MICT for reducing total fat mass and abdominal fat mass, even with the same energy expenditure.",
"Physical exercise promotes browning of adipocytes, which is a transition from white adipose tissue to metabolically active brown adipose tissue. The characteristic of browning is an increase in the number of mitochondria and the dissipation of energy through heat generation, namely non shivering heat generation. Due to the large amount of energy consumed by brown adipose tissue in non shivering heat generation, this can lead to an overall increase in energy consumption. Physical exercise can promote more effective energy consumption in the body by activating these physiological processes. This is precisely why this study aims to provide new insights into the field of exercise and weight loss for obese individuals from the perspectives of energy expenditure and substrate metabolism through different exercise methods.",
"The debate over the superiority of weight loss effects between HIIT and MICT is a current hotspot. Although some studies suggest that HIIT is more effective for weight loss than MICT, due to differences in research methods and training programs, it is premature to conclude that HIIT is superior to MICT for weight loss. With the emergence of Tabata, a form of exercise with shorter duration and higher intensity compared to HIIT and MICT, further research is needed to determine its potential superior effects on weight loss. Therefore, this study aims to conduct experimental research on randomly selected individuals with overweight/obesity undergoing Tabata, HIIT, and MICT. The analysis will focus on substrate metabolism and energy expenditure data during the exercise and recovery phases of 10 and 20 minutes, comparing the fat oxidation rate, glucose oxidation rate, and energy expenditure rate of the three exercise modalities. The findings aim to provide a theoretical basis for the tailored development of training plans for overweight/obese individuals.",
"This study employed an experimental research design involving a cohort of randomly selected fifteen male university students with overweight/obesity. Initial assessments included maximal oxygen consumption tests to determine the power corresponding to 20% VO_(2max), 50% VO_(2max), and 80% VO_(2max) intensities on a stationary bicycle. Subsequently, participants underwent random Tabata, HIIT and MICT exercise tests, each separated by a 7-day interval. Continuous measurements of gas metabolism parameters were conducted during exercise and the 10-minute and 20-minute recovery periods. This data was then utilized to calculate the fat oxidation rate, glucose oxidation rate, and energy expenditure rate for each of the three exercise modalities.",
"Fifteen male university students with overweight/obesity were randomly selected for this study for the experimental protocol.",
"BMI was determined as weight/height squared: ① Oxidation rate of sugar.",
"G*power3.1.9.7, with an effect size of 0.25, an alpha value of 0.05, and a power of 0.80, was used to estimate the sample size.Based on the calculation, the minimum sample size necessary to satisfy the test requirements was 8. All data were statistically analyzed using SPSS 26.0 software Significant differences were considered at p<0.05.",
"Energy consumption and substrate metabolism are important indicators for evaluating exercise effectiveness. Glucose and fat are important indicators of substrate metabolism, and this study mainly monitors fat oxidation rate. Glucose oxidation rate, glucose oxidation. For energy consumption, the main monitoring is the energy expenditure rate. We monitor the energy consumption and substrate metabolism analysis data of three different exercise modes at three time points: exercise period, recovery period, exercise and the entire recovery process. The purpose is to provide theoretical basis for developing targeted training plans for overweight/obese populations from the perspectives of energy consumption and substrate metabolism.",
"During the exercise phase, there was a statistically significant difference in the fat oxidation rate among the three exercise modes.",
"There was a statistically significant difference in the glucose oxidation rate among the three exercise modes during the exercise phase.",
"The energy expenditure rate during the exercise phase showed a statistically significant difference among the three exercise modes.",
"The fat oxidation amount during the exercise phase exhibited a statistically significant difference among the three exercise modes.",
"The glucose oxidation amount during the exercise phase demonstrated a statistically significant difference among the three exercise modes.",
"The energy expenditure during the exercise phase displayed a statistically significant difference among the three exercise modes.",
"During the 10-minute recovery period, there was a statistically significant difference in fat oxidation rates among the three exercise modes.",
"There was a statistically significant difference in glucose oxidation rates among the three exercise modes during the 10-minute recovery period.",
"The energy expenditure rate during the 10-minute recovery period showed a statistically significant difference among the three exercise modes.",
"The fat oxidation amount during the 10-minute recovery period exhibited a statistically significant difference among the three exercise modes.",
"There was a statistically significant difference in glucose oxidation amounts among the three exercise modes during the 10-minute recovery period.",
"The energy expenditure during the 10-minute recovery period showed a statistically significant difference among the three exercise modes.",
"During the 20-minute recovery period, there was a statistically significant difference in fat oxidation rates among the three exercise modes.",
"During the 20-minute recovery period, there was no significant difference in glucose oxidation rates among the three exercise modes.",
"The energy expenditure rate during the 20-minute recovery period showed a statistically significant difference among the three exercise modes.",
"The fat oxidation amount during the 20-minute recovery period exhibited a statistically significant difference among the three exercise modes.",
"During the 20-minute recovery period, there was no significant difference in glucose oxidation amounts among the three exercise modes.",
"The energy expenditure during the 20-minute recovery period showed a statistically significant difference among the three exercise modes.",
"Throughout the exercise and recovery period, there was a statistically significant difference in fat oxidation rates.",
"The glucose oxidation rates throughout the exercise and recovery period showed a statistically significant difference.",
"Throughout the exercise and recovery period, there was a statistically significant difference in energy expenditure rates.",
"Throughout the exercise and recovery period, there was a statistically significant difference in fat oxidation amounts.",
"Throughout the exercise and recovery period, there was a statistically significant difference in glucose oxidation amounts.",
"Throughout the exercise and recovery period, there was a statistically significant difference in overall energy expenditure.",
"During the exercise period, there was a statistically significant difference in heart rate among the three exercise modes.",
"Throughout the exercise period, there was a statistically significant difference RPE among the three exercise modes.",
"The findings of this study reveal that, during exercise, the MICT group exhibits a significantly higher fat oxidation quantity compared to the Tabata and HIIT groups. However, the fat oxidation rate of the MICT group only surpasses that of the HIIT group, and there is no significant difference in fat oxidation rates between the Tabata and MICT groups. The study suggests that the duration of exercise significantly influences the body’s ratio of glucose to lipid energy provisioning. The possible explanation lies in the relatively stable state of the body during MICT exercise at 50% VO_(2max) intensity. This steadiness allows the body’s oxygen intake to precisely match the required oxygen quantity, gradually promoting energy conservation primarily through the utilization of fat. It is speculated that this phenomenon signifies the initiation of the body’s energy-saving function. The reasons behind this may be linked to the gradual depletion of muscle glycogen, reduced glucose stores, leading to decreased levels of adrenaline and insulin, consequently enhancing the rate of fat consumption.",
"In terms of sugar metabolism, the HIIT group demonstrates a significantly higher glucose oxidation quantity than the Tabata and MICT groups. However, the sugar consumption rate in Tabata is notably higher than in the other two groups. Exercise intensity influences the efficiency of sugar oxidation during exercise, and as the intensity increases, so does the efficiency of sugar oxidation metabolism. High-intensity exercise results in rapid glycogen consumption. For instance, in 1 minute of exercise at 150% VO_(2max) intensity, muscle glycogen levels can decrease by 20%. Conversely, a set of high-intensity intermittent exercises can reduce glycogen levels to 28%-37% of pre-exercise levels. The energy consumption during exercise is significantly higher in the MICT group compared to the Tabata and HIIT groups. However, Tabata’s energy consumption rate is also significantly higher than the other two groups. Moderate-intensity continuous exercise, due to its lower intensity, is easier for subjects to sustain, resulting in higher energy consumption and fat oxidation rates. This proves beneficial in preventing cardiovascular diseases, obesity, diabetes, and reducing overall mortality rates.",
"At the same time, body composition has a significant impact on energy expenditure and substrate metabolism. Research has found that body weight has a significant impact on sugar and total energy expenditure, but has no significant effect on the proportion of fat and substrate metabolism energy supply. The reason may be that different body fat levels and body weight have a certain impact on exercise ability, with the greatest impact on defatted weight. Defatted weight is highly correlated with the aerobic and anaerobic capacity of the human body, and there is a significant difference in defatted weight between weights. Therefore, when sugar is needed for rapid oxidation energy supply, there is a significant difference in weight between weights. Gao Binghong’s research found that there is a high correlation between the defatted weight, muscle weight, and anaerobic capacity of judo athletes, with a correlation coefficient between 0.66 and 0.9. It can be considered that differences in body fat levels seriously affect substrate metabolism and energy consumption.",
"At the 10-minute recovery mark, the HIIT group exhibits a significantly higher fat oxidation rate and quantity than the MICT group, with no significant difference compared to the Tabata group. Regarding sugar metabolism, the Tabata group shows a significantly higher sugar oxidation rate and quantity than both the HIIT and MICT groups. The MICT group demonstrates significantly lower energy consumption and energy consumption rates compared to the other two groups. At the 20-minute recovery stage, the Tabata group’s fat oxidation rate and quantity are significantly higher than the other two groups. In terms of sugar metabolism, there are no significant differences among the three groups. Energy consumption induced by exercise includes not only during but also post-exercise excess post-exercise energy expenditure. With increasing exercise intensity, post-exercise sugar oxidation rates and quantities gradually decrease, while fat oxidation rates, quantities, and overall energy consumption increase. This is primarily due to the maintenance of high levels of endocrine hormones, body temperature, and pulmonary ventilation after high-intensity exercise. Oxygen reserves need rapid replenishment, the ATP-CP system requires quick supplementation, and lactate needs swift clearance. At this stage, the primary energy supply shifts from anaerobic to aerobic, with the main substance for aerobic energy supply transitioning from sugar to fat. post-exercise blood levels of free fatty acids significantly increase. Research demonstrates a correlation between the percentage of fat energy supply after exercise and exercise intensity and duration. Exercise intensity affects the amount of excess post-exercise oxygen consumption, while exercise duration extends the time of excess post-exercise oxygen consumption. There is currently limited research on the recovery to resting state after high-intensity intermittent exercise, and changes in substrate levels can reflect changes in fat metabolism. Studies show that completing high-intensity intermittent exercise before eating results in a significantly greater decrease in total cholesterol and very low-density lipoprotein levels compared to the MICT group, demonstrating the superior effect of high-intensity intermittent exercise in enhancing post-exercise fat metabolism. This study confirms that Tabata significantly enhances post-exercise fat metabolism during the recovery period, surpassing both HIIT and MICT.",
"The fat mass of male college students with overweight/obesity is relatively higher than that of ordinary college students. Due to the higher oxidation and energy supply ratio of fat after high-intensity interval exercise, and the increase in exercise intensity, male college students with overweight/obesity can use high-intensity interval exercise as a supplement to play the role of excessive oxygen consumption after exercise.",
"The results of this study indicate that throughout the exercise and recovery period, the fat oxidation rate of the Tabata group is significantly higher than that of the HIIT and MICT groups, with no significant difference between the HIIT and MICT groups. However, the fat oxidation quantity of the MICT group is significantly higher than the other two groups during the entire process. This is attributed to the short duration of Tabata exercises, lasting only 4 minutes. Considering that Tabata is 16 minutes shorter than HIIT and 26 minutes shorter than MICT, there is also a corresponding resting fat oxidation during this period, and the fat oxidation rate of Tabata is higher than the other two groups. Therefore, in reality, the difference in fat oxidation quantity of the Tabata group should be less. Combining the entire exercise and recovery period, it is found that, in terms of fat burning effectiveness, Tabata outperforms the MICT group, and the MICT group surpasses the HIIT group. In terms of overall sugar metabolism during the exercise and recovery period, both Tabata and HIIT show significantly higher sugar oxidation rates than MICT. Although the MICT exercise duration is 10 minutes longer than HIIT, the sugar oxidation quantity of HIIT is still significantly higher than MICT. The conversion of energy supply from anaerobic to aerobic in HIIT, characterized by the continuous repetition of cycles, may lead to a high dependence on sugar oxidation energy supply and a high proportion of aerobic oxidation energy of glycogen in HIIT. The changes in substrate metabolism during Tabata exercises and the recovery period may be related to changes in the quantity and activity of skeletal muscle fat metabolism-related enzymes induced by HIIT, enhancing fat metabolism efficiency. Additionally, HIIT can rapidly deplete glycogen in a short period. The post-exercise glycogen compensation mechanism may induce a tendency for glycogen to be resynthesized after exercise and fat metabolism to be characterized by decomposition, oxidation, and energy supply. This study also found that, although the exercise duration of HIIT is shorter than MICT, the total energy consumption during the “exercise + recovery period” induced by exercise is not significantly different between HIIT and MICT. Although the energy consumption of the Tabata group is significantly lower than the other two groups, this is because of the shorter exercise duration compared to the other two groups. However, the energy consumption rate is still significantly higher than the HIIT and MICT groups. The direct reason for this phenomenon may be that Tabata and HIIT have a deeper impact on EPEE, and Tabata has a shorter time compared to HIIT and MICT, with higher fat oxidation rates and energy consumption rates. It may be more suitable for individuals who don’t have time for long-duration low-intensity aerobic exercise.",
"This study found that male college students with overweight/obesity in the Tabata group had lower levels of fat oxidation, sugar oxidation, and energy expenditure throughout the exercise and recovery periods compared to the HIIT and MICT groups. However, during the entire process, the rates of fat oxidation, sugar oxidation, and energy consumption were significantly higher in the HIIT and MICT groups, and Tabata exercise time was significantly shorter than the other two groups, demonstrating a certain “time efficiency” advantage. Tabata can be used as an efficient short-term weight loss exercise program for male college students with overweight/obesity.",
"The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.",
"The studies involving humans were approved by ethical review of the Human Ethics Committee of Guangxi Normal University. Ethical review number: 20231129001. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study.",
"YBW: Writing – original draft. MCF: Writing – review & editing. LC: Writing – review & editing. YFW: Writing – review & editing. XDP: Writing – review & editing. CFL: Writing – review & editing. BYH: Writing – review & editing. LHW: Writing – review & editing."
] |
PMC10302579
|
Pathogens
|
Low Prevalence ofToxoplasma gondiiin Sheep and Isolation of a Viable Strain from Edible Mutton from Central China
|
14-06-2023
|
Sheep are highly susceptible to Toxoplasma gondii , and miscarriage is the main clinical feature. This study investigated 227 sheep samples (210 myocardial tissues from slaughterhouses, 6 ewe serum samples, 3 aborted fetuses, and 8 dead lambs from veterinary clinics) from central China for T. gondii infection. Antibodies against T. gondii were detected using the modified agglutination test (MAT). PCR was performed to detect T. gondii DNA in the tissue samples. The results showed that four samples were seropositive (MAT titer ≥ 1:100), with a seroprevalence of 1.8% (4/227). The seropositive samples included two myocardial samples from a slaughterhouse, one ewe and its aborted fetus from a veterinary clinic. The results revealed that 7 out of 207 (3.4%) sheep tissue samples were PCR-positive, including two myocardial tissue samples from slaughterhouses, three aborted fetuses, and two lambs from veterinary clinics. Toxoplasma gondii vertical transmission had occurred in two of three pairs of ewes and her pups. One viable T. gondii strain (TgSheepCHn14) was isolated from the myocardial tissues of sheep from a slaughterhouse. Tachyzoites were obtained from cell cultures at 70 days following seeding in the brains and lungs of mice. This strain was non-lethal to Swiss mice. The number of parasite brain cysts in mice decreased with time post-infection ( p < 0.05). Overall, the prevalence of T. gondii in the sheep samples was low. Although the samples were scattered, and not from planned collections, the current study detected T. gondii antibodies and DNA in aborted fetuses, indicating that vertical transmission could occur and maintain the parasites in sheep herds without exogenous infection.
|
[
"Toxoplasma gondii is an intracellular protozoan that infects all warm-blooded animals, including humans and livestock. Members of the felid family are the definitive hosts of T. gondii , while other warm-blooded animals may be intermediate hosts. Over the last decade, the prevalence of T. gondii in humans has decreased [ ]. Toxoplasma gondii infection is usually asymptomatic or subclinical in immune-competent patients and animals. However, T. gondii infection during gestation may cause miscarriage, fetal death, and eye or brain disorders [ , ]. Sheep are highly susceptible to T. gondii infection. Studies have found that the mutton, viscera, blood, and milk of sheep or goats with acute toxoplasmosis can transmit the parasite to other animals and humans [ , , ]. The seroprevalence of T. gondii in sheep of sheep globally: 97% of strains from sheep in Europe and Africa are Type II, ToxoDB #9 were collected from Henan and Shandong provinces. All the samples were collected and transported to the Laboratory of Veterinary Pathology, Henan Agricultural University. Serum from T. gondii VEG-infected mice was provided by Dr. J. P. Dubey were used.",
"Tissue samples, according to published methods [ ]. In brief, every myocardial tissue, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico [ ]. The virulence genes ROP5 and ROP18 were also typed, as reported previously [ ]. Reference T. gondii DNA.",
"Molecular diagnostic results showed that 7 of 207 samples were positive for PCR of T. gondii DNA.",
"Mouse bioassay was performed on four sheep myocardial tissue samples, two of which were seropositive to T. gondii . The results showed that using MAT in the Tox35-4 group, 4/5 mice were seropositive for T. gondii . The brain and lungs of mouse M#1216, and T. gondii parasites in the brain were verified using hematoxylin and eosin. The brain and lungs of mouse M#764, and parasites from the liver tissues were verified using IHC.",
"The growth times of the TgSheepCHn14 strain in Vero cells are summarized in . The T. gondii strain from the brain and lungs of M#764. Unfortunately, no viable T. gondii strains were isolated from other sheep myocardial tissues.",
"TEM showed the presence of T. gondii TgSheepCHn14 tachyzoites with parasitophorous vacuoles in Vero cells. The tachyzoites of the TgSheepCHn14 strain were oval or crescent-shaped, 2.6 × 1.8 µm in size. However, they were deficient in amylopectin granules and lipids.",
"The genotype of TgSheepCHn14 was determined using PCR-RFLP with 10 markers, and the results indicated that it belonged to the ToxoDB genotype #3. The ROP18/ROP5 allele combination provides a strong prediction of T. gondii strain virulence in mice. The ROP18 and ROP5 loci of the strain were detected, and the allele types were 2/2. The positive rate and mortality of mice infected with T. gondii tachyzoites at different doses are shown in . None of the mice died of acute infection, but when 10^(4) tachyzoites were inoculated, one mouse died at 37 DPI, and the number of brain cysts from this group of mice was 295.0 ± 285.0. The results showed that this strain was non-lethal to Swiss mice. The numbers ranged from 10 to 1270 cysts per mouse brain, and the number of cysts in the brain tissues of mice increased with an increase in tachyzoite doses, but the difference was not significant."
] |
PMC10194890
|
PLOS ONE
|
An external validation of the QCOVID3 risk prediction algorithm for risk of hospitalisation and death from COVID-19: An observational, prospective cohort study of 1.66m vaccinated adults in Wales, UK
|
18-05-2023
|
Introduction At the start of the COVID-19 pandemic there was an urgent need to identify individuals at highest risk of severe outcomes, such as hospitalisation and death following infection. The QCOVID risk prediction algorithms emerged as key tools in facilitating this which were further developed during the second wave of the COVID-19 pandemic to identify groups of people at highest risk of severe COVID-19 related outcomes following one or two doses of vaccine. Objectives To externally validate the QCOVID3 algorithm based on primary and secondary care records for Wales, UK. Methods We conducted an observational, prospective cohort based on electronic health care records for 1.66m vaccinated adults living in Wales on 8 th December 2020, with follow-up until 15 th June 2021. Follow-up started from day 14 post vaccination to allow the full effect of the vaccine. Results The scores produced by the QCOVID3 risk algorithm showed high levels of discrimination for both COVID-19 related deaths and hospital admissions and good calibration (Harrell C statistic: ≥ 0.828). Conclusion This validation of the updated QCOVID3 risk algorithms in the adult vaccinated Welsh population has shown that the algorithms are valid for use in the Welsh population, and applicable on a population independent of the original study, which has not been previously reported. This study provides further evidence that the QCOVID algorithms can help inform public health risk management on the ongoing surveillance and intervention to manage COVID-19 related risks.
|
[
"Following the emergence of the SARS-CoV-2 infection and at the start of the COVID-19 pandemic, there was an urgent public health need to identify individuals at highest risk of severe outcomes, in particular hospitalisation and death following infection. To support the National Health Service, extending the categorisation of severity of diabetes to include glycated haemoglobin levels, bipolar disorder, schizophrenia, and a seven-day moving average of the background rates of positive SARS-CoV-2 tests per 100,000 people to account for changing infection rates. The risk scores from these algorithms provide further evidence to prioritise high-risk individuals who may need further interventions, such as additional booster vaccinations or treatment with monoclonal antibodies, antivirals or pre-exposure prophylaxis June 2021 in Wales, UK.",
"We conducted an observational, longitudinal, cohort study of vaccinated adults living in Wales from 8^(th) December 2020, with follow-up until 15^(th) June 2021. The outcomes of interest were time to COVID-19 related death and hospitalisation. We assessed the performance of the QCOVID3 algorithms using measures of discrimination and calibration. This paper mirrors the published English study and follows the STROBE and TRIPOD reporting guidelines [ , , ].",
"This study used routinely collected anonymised, individual-level, population-scale health and demographic data held in the Secure Anonymised Information Linkage, Welsh Longitudinal General Practice December 2020 with follow-up until 15^(th) June 2021. Individuals included were aged between 19 and 100 on the 8^(th) December 2020, registered with a SAIL-providing general practice. Follow-up started from 14 days after receiving each vaccine dose until they had the outcome of interest to validate the updated algorithms were based on the original QCOVID studies [ – ], which includes the clinical vulnerability group criteria used to identify those advised to shield at the start of the pandemic and risk factors associated with adverse outcomes for respiratory diseases [ , ].",
"Demographic",
"• Age in years on 8^(th) December 2020",
"• Biological sex at birth",
"• Townsend Deprivation Score",
"• Ethnicity",
"• What is your housing category—care home, homeless or neither?",
"Have you had a 1^(st) or 2^(nd) dose of Oxford-AstraZeneca or Pfizer-BioNTech COVID-19 vaccination?",
"• What is the background daily rate per 100,000 for SARS-CoV-2 infection in the last 7 days?",
"Lifestyle",
"Body Mass Index",
"Conditions",
"• Have you had chemotherapy in the last 12 months?",
"• Have you had radiotherapy in the last 6 months?",
"• Do you have sickle cell disease?",
"• Have you a cancer of the blood or bone marrow such as leukaemia, myelodysplastic syndromes, lymphoma or myeloma and are at any stage of treatment?",
"• Do you have lung or oral cancer?",
"Do you have a learning disability or Down’s syndrome?",
"• Do you have Chronic Kidney Disease is linked to the cohort in order to derive ethnic groups. To adjust for changing infection rates over the study period, a seven-day moving average of the background rates of positive SARS-CoV-2 tests per 100,000 people using published data was added to the algorithms [ ].",
"The majority of pre-existing conditions were identified in the WLGP primary care data source using Read codes version 2 were assigned the chemotherapy group B values, D statistic, and Harrell’s C statistic with corresponding 95% intervals were calculated for the total cohort and by age, sex, and vaccination number [ – ]. The R^(2) values refer to the proportion of variation in survival time explained by the model. The D statistic and Harrell’s C statistic are discrimination measures that quantify the separation in survival between patients with different levels of predicted risks and the extent to which people with higher risk scores have earlier events respectively. To measure calibration, we compared the mean predicted risks with observed risks, by 20ths of predicted risk.",
"The use of de-identified data in SAIL complies with National Research Ethics Service. Of these, 787,878.",
"Individuals with a COVID-19-related admission were more likely to be female.",
"shows the performance metrics of the QCOVID3 algorithm in the Welsh cohort. The metrics have been provided for the total cohort and by age, sex, and the number of vaccinations. For COVID-19 related deaths, the algorithm explained 72.5% and under-prediction of COVID-19-related hospitalisations, with the largest difference seen in the highest risk group.",
"presents the percentage of COVID-19 related deaths at different thresholds based on centiles of predicted absolute risk. 71.4% of deaths occurred in those in the top 5% for predicted absolute risk of COVID-19 related deaths which increases to 95.2% of deaths occurring in the top 30% for predicted absolute risk of COVID-19 related deaths.",
"The results from this validation study demonstrate that the performance of the algorithms was good and yielded similar results to the original study in England [ ]. In general, the risk algorithms showed high levels of discrimination or higher risk of severe COVID-19 related outcomes [ ].",
"We found higher observed to predicted risks for hospitalisation and lower observed to predicted risk of death in the highest risk groups in Wales. For COVID-19-related hospital admissions, both studies demonstrated similar trends of observed versus predicted risk, with observed admissions higher than predicted in the Welsh data in general compared to England. Overall, there was a slightly larger proportion of COVID-19 related hospital admission in the Welsh study which was similar to the English study. Due to SAIL’s information governance and disclosure control policies, we were unable to include information that is deemed too sensitive and therefore could not include HIV status. Some 41.6% of our cohort did not have a BMI recorded in the previous five years, therefore, missing observations were imputed. OPCS codes in hospital admissions data were used to define chemotherapy status with anyone with a record of receiving chemotherapy is assigned the coefficients for the middle severity chemotherapy group.",
"Also, this study replicates the original English study and so has similar stated limitations such as a relatively short follow-up, a partially vaccinated population including the Oxford-AstraZeneca or Pfizer-BioNTech COVID-19 vaccinations only, and small numbers of events in some subgroups. Consequently, it was not possible to calculate metrics by ethnic groups, or for narrowly defined age groups. Additionally, the study does not account for the interval between completion of the first and second vaccination, any changes that may have occurred in COVID-19 transmission rate within the study follow-up that might have impacted the prediction model temporally, or the different emerging variants during the study period [ ]. Finally, whilst many risk factors for serious COVID-19 related outcomes have been included, additional risk factors such as occupational exposure to infection are not accounted for in this model.",
"This study presents an independent external validation of the updated QCOVID3 risk algorithms in the adult vaccinated Welsh population and has shown that the algorithms are valid for use in the Welsh population, and applicable on a population independent of the original study, which has not been previously reported. This study provides further evidence that the QCOVID3 algorithms can help inform public health risk management on the ongoing surveillance and intervention to manage COVID-19 related risks following vaccination. The outputs from the QCOVID algorithms can be used to support the prioritisation of vaccine boosters, invitation onto clinical trials, personalised interventions for prevention of patient care with both clinicians and patients being able to calculate their own risk through the online QCOVID calculator, and support allocation planning for possible future pandemics and improve global preparedness [ ]."
] |
PMC10928718
|
ACS Infectious Diseases
|
Ubiquitin Ligase Parkin Regulates the Stability of
SARS-CoV-2 Main Protease and Suppresses Viral Replication
|
22-02-2024
|
The highly infectious
coronavirus SARS-CoV-2 relies on the viral
main protease (M pro , also known as 3CLpro or Nsp5) to proteolytically
process the polyproteins encoded by the viral genome for the release
of functional units in the host cells to initiate viral replication.
M pro also interacts with host proteins of the innate immune
pathways, such as IRF3 and STAT1, to suppress their activities and
facilitate virus survival and proliferation. To identify the host
mechanism for regulating M pro , we screened various classes
of E3 ubiquitin ligases and found that Parkin of the RING-between-RING
family can induce the ubiquitination and degradation of M pro in the cell. Furthermore, when the cells undergo mitophagy, the
PINK1 kinase activates Parkin and enhances the ubiquitination of M pro . We also found that elevated expression of Parkin in the
cells significantly decreased the replication of SARS-CoV-2 virus.
Interestingly, SARS-CoV-2 infection downregulates Parkin expression
in the mouse lung tissues compared to healthy controls. These results
suggest an antiviral role of Parkin as a ubiquitin ligase targeting
M pro and the potential for exploiting the virus–host
interaction mediated by Parkin to treat SARS-CoV-2 infection.
|
[
"The ongoing coronavirus disease\n2019.\nIn contrast, CHIP E3 did not generate any ubiquitinated M^(pro). Since\nPINK1 can phosphorylate Parkin to stimulate its UB ligase activity,^(34) we set up in vitro ubiquitination of M^(pro) by Parkin with and without the addition of PINK1. We found that\nPINK1 enhanced the level of monoubiquitinated M^(pro) species\nand promoted the formation of polyubiquitinated M^(pro) of\nhigher molecular weight. These results suggest that M^(pro) is recognized\nas a ubiquitination target of various E3s, such as E6AP, Parkin, and\nHHARI, and PINK1 activation of Parkin enhances M^(pro) ubiquitination\nby Parkin. Since the UB we used in the reconstituted reaction had\nan HA tag appended to its N-terminus, we also used an anti-HA antibody\nto detect the polyubiquitination of M^(pro) and the E3 enzymes\nin the reconstituted reactions and showed the results in Figure S1."
] |
PMC10843955
|
The European Journal of Public Health
|
An investment case analysis for the prevention and treatment of adolescent mental disorders and suicide in England
|
24-11-2023
|
Abstract Background Adolescent mental health (AMH) needs in England have increased dramatically and needs exceed treatment availability. This study undertook a comparative assessment of the health and economic return on investment (ROI) of interventions to prevent and treat mental disorders among adolescents (10–19 years) and examined intervention affordability and readiness. Methods Interventions were identified following a review of published and grey literature. A Markov model followed a simulated adolescent cohort to estimate implementation costs and health, education, and economic benefits. Intervention affordability was assessed, comparing annual cost per adolescent with NHS England per capita spending, and an expert panel assessed intervention readiness using a validated framework. Results Over 10- and 80-year horizons, interventions to treat mild anxiety and mild depression were most cost-effective, with the highest individual lifetime ROI (GBP 5822 GBP 1 and GBP 257: GBP 1). Preventing anxiety and depression was most affordable and ‘implementation ready’ and offered the highest health and economic benefits. A priority package (anxiety and depression prevention; mild anxiety and mild depression treatment) would avert 5 million disability-adjusted life-years (DALYS) and achieve an ROI of GBP 15: GBP 1 over 10 years or 11.5 million DALYs (ROI of GBP 55: GBP 1) over 80 years. Conclusion The economic benefits from preventing and treating common adolescent mental disorders equivalent to 25% of NHS England’s annual spending in 2021 over 10 years and 91% over 80 years. Preventing and early treatment for anxiety and depression had the highest ROIs and strong implementation readiness.
|
[
"Adolescent mental health",
"In 2017, one in eight young people aged 5–19 in England experienced a mental disorder. UK hospital admissions for self-harm for ages 9–17 increased 22% between 2020 and 2022. Reports indicate extensive waiting times for diagnosis and starting treatment, insufficient capacity to assess all adolescents experiencing mental disorders, and an urgent need for greater prevention. ^(,) Government funding commitments and plans included a 1.4 billion commitment to transform child and AMH services in 2015, a 2017 green paper, and the 2019 NHS Long-Term Plan set out an intention to develop school and college support services. However, the COVID-19 pandemic and lockdowns, school and youth facility closures, and reduced mental health service capacity have squeezed resources. ^(,)",
"The National Institute of Health and Care Excellence produces evidence-based guidelines, including consideration of costs and benefits; however, guidelines focus on selected, specific mental disorders and use existing economic evidence rather than de novo analyses. To date no comparative assessment of cost-effectiveness across interventions to prevent and treat a range of high-impact adolescent mental disorders has been conducted. In a high-inflation fiscal context where government and civil society expenditure is constrained, this study quantified the costs and benefits of interventions to prevent or treat anxiety, depression, bipolar disorder and suicidal behaviour among adolescents in England and to identify the interventions that will produce the strongest return on investment, quantified the costs and expected benefits of interventions to prevent and/or treat anxiety, bipolar disorder, depression and suicide among adolescents and expressed in 2021 GBP."
] |
PMC10318158
|
Frontiers in Physiology
|
Variability of extracellular vesicle release during storage of red blood cell concentrates is associated with differential membrane alterations, including loss of cholesterol-enriched domains
|
20-06-2023
|
Transfusion of red blood cell concentrates is the most common medical procedure to treat anaemia. However, their storage is associated with development of storage lesions, including the release of extracellular vesicles. These vesicles affect in vivo viability and functionality of transfused red blood cells and appear responsible for adverse post-transfusional complications. However, the biogenesis and release mechanisms are not fully understood. We here addressed this issue by comparing the kinetics and extents of extracellular vesicle release as well as red blood cell metabolic, oxidative and membrane alterations upon storage in 38 concentrates. We showed that extracellular vesicle abundance increased exponentially during storage. The 38 concentrates contained on average 7 × 10 12 extracellular vesicles at 6 weeks (w) but displayed a ∼40-fold variability. These concentrates were subsequently classified into 3 cohorts based on their vesiculation rate. The variability in extracellular vesicle release was not associated with a differential red blood cell ATP content or with increased oxidative stress (in the form of reactive oxygen species, methaemoglobin and band3 integrity) but rather with red blood cell membrane modifications, i.e., cytoskeleton membrane occupancy, lateral heterogeneity in lipid domains and transversal asymmetry. Indeed, no changes were noticed in the low vesiculation group until 6w while the medium and the high vesiculation groups exhibited a decrease in spectrin membrane occupancy between 3 and 6w and an increase of sphingomyelin-enriched domain abundance from 5w and of phosphatidylserine surface exposure from 8w. Moreover, each vesiculation group showed a decrease of cholesterol-enriched domains associated with a cholesterol content increase in extracellular vesicles but at different storage time points. This observation suggested that cholesterol-enriched domains could represent a starting point for vesiculation. Altogether, our data reveal for the first time that the differential extent of extracellular vesicle release in red blood cell concentrates did not simply result from preparation method, storage conditions or technical issues but was linked to membrane alterations.
|
[
"Blood conservation outside the bloodstream started a century ago with the discovery of citrate as anticoagulant and the addition of dextrose. From that time, scientists have been trying to improve continuously blood storage conditions and the transfusion efficacy. Nowadays, thanks to leukoreduction and additive solutions such as Saline-Adenine-Glucose-Mannitol. Among those lesions, the irreversible loss of plasma membrane through the formation and the release of extracellular vesicles. In addition, EVs seem to be responsible for adverse post-transfusional complications such as thromboembolic and immunomodulatory events as suggested by in vitro studies. Therefore, it appears essential to carefully investigate EV biogenesis and release mechanisms in RCCs in order to improve RBC quality maintenance and to reduce risks of potential adverse effects upon transfusion.",
"Vesiculation seems to be the consequence of a series of lesions, supposed to be mainly induced by the development of oxidative stress. Throughout storage, the glycolysis pathway is reduced by the accumulation of lactate as well as the hypothermic and acidic storage conditions. As a result, high energy,, and. In consequence, oxidative stress-related damage might finally lead to plasma membrane loss through vesiculation.",
"Nevertheless, literature data on vesiculation are difficult to compare due to differential RCC preparation and storage conditions.",
"Among the alternative mechanisms, one could propose the budding of EVs from specific regions of the plasma membrane such as submicrometric lipid domains. We previously showed the coexistence of 3 types of lipid domains at the outer plasma membrane leaflet of resting RBCs:. During RBC deformation, GM1-enriched domain abundance increases in the LC area concomitantly with calcium influx while chol-enriched domains gather to increase the HC area needed for RBC deformation. After deformation, the SM-enriched domain number rises in parallel to calcium efflux in order to restore the initial discoid shape.",
"During the storage of RBCs in K^(+)/EDTA-coated tubes at 4°C, we observed that, among the 3 types of lipid domains at the RBC area, only those enriched in chol are reduced in abundance, suggesting a fine tuning of lipid domain dynamics during storage. This decrease occurs concomitantly with the increase of EV release and is preceded by a transient increase in the membrane microviscosity which could create a line tension between the bulk membrane and lipid domains and lead to their loss by vesiculation. Although storage of RBCs in K^(+)/EDTA tubes accelerates and exacerbates the accumulation of lesions, this phenomenon could also occur during storage of RCCs as the chol-binding protein stomatin was found to decrease from RBC membranes and to be enriched in EVs during storage of RCCs.",
"The present study aimed at determining the mechanisms behind EV release in 38 RCCs by deciphering the time courses and extents of RBC metabolic. Dulbecco’s Modified Eagle Medium. Briefly, RBCs were centrifuged 2 times at 2,000 g for 15 min at room temperature. Briefly, particles were immobilized on poly-L-Lysine. Data were normalised by the Hb content evaluated spectrophotometrically and expressed as % of fresh citrate-coated blood tubes.",
"Intracellular ROS levels were detected by using the 2,7-dichlorodihydrofluoresceindiacetate, except that the experiment was performed in calcium-free HBSS. The median fluorescence intensity. Since Annexin-V labelling requires the presence of calcium ions, calcium-containing DMEM was used for this experiment. The % of PS-exposing RBCs in fresh citrate-coated blood tubes was subtracted from the % of PS-exposing RBCs in concentrates.",
"Immunolabelling of α,β-spectrin was performed as in, except that RBCs were blocked with 3% bovine serum albumin. The mCherry-Theta toxin fragment concentrations ranged from 0.55 to 1.75 µM, due to several productions and purifications during the study. Lipid domain abundance was assessed through manual counting, normalised by the average hemi-RBC area calculated with the Fiji software and finally expressed as % of lipid domain abundance in fresh citrate-coated tubes or K^(+)/EDTA-coated tubes. The HC area corresponds to the periphery of spread RBCs while the LC area represents the centre of spread RBCs.",
"Chol content was assessed using the Amplex Red cholesterol assay kit. Washed RBCs were lysed in 1 mL of distilled water and diluted 8-fold in the kit reaction buffer while PBS-resuspended EVs were diluted 2-fold. Data on RBCs were normalised by the Hb content evaluated spectrophotometrically and expressed as % of fresh citrate blood tubes while data on EVs were expressed as a chol content respectively. Equal protein amounts. The end of the legal storage period is indicated by a vertical blue dotted line. Horizontal black dotted line indicates reference values obtained from fresh blood tubes, mainly citrate-coated tubes except otherwise stated. The physiological range for metHb and K^(+) content in blood is represented by a grey frame while the maximal percentage of hemolysis authorized by the Council of Europe guidelines and the glucose concentration in SAGM and plasma are indicated by horizontal red full and dotted lines. Whenever data for a specific parameter was collected within one storage week from more than one RCC, the mean ± SEM. The ‘high’ vesiculation group contains RCCs with a vesiculation rate ≥7.5 EVs/RBC at 42 days of storage or a Mann-Whitney test was performed. Graphically, statistical significance is indicated above a horizontal full line connecting 2 time intervals. Statistical comparison was mainly performed between 3w.",
"Particles in RCC supernatants were concentrated by differential ultracentrifugation and measured by NTA for their abundance and size. As previously shown, the number of particles, expressed in relation to the number of RBCs present in RCCs, increased exponentially during storage, revealing significant differences between 3 and 6w and between 3 and 9w. However, the size remained stable over storage, at around 180 nm. At 6w, a mean of 4 particles for one RBC was measured, corresponding to ∼7 × 10^(12) particles in a 250 mL bag. In reality, this number showed a ∼40-fold variability. A potential contamination of samples was also excluded, as shown by very few amounts of lipoproteins and platelets. Inversely, particles appeared to have an erythrocytic origin, as revealed by the detection of the RBC marker GPA, and exhibited the raft marker flotillin-1, known to be associated with EVs. Further analysis with electron microscopy showed vesicle-like structures with a spherical morphology and no aggregates. Altogether these data indicated that particles were mainly, if not exclusively, EVs and that RCCs released a variable quantity of vesicles upon storage which cannot be explained by technical issues.",
"To further determine the origin of this variability, RCCs were separated into 3 groups based on their vesiculation rate at the legal storage period of 6w: ‘low’ rate. These groups consisted of 9, 20 and 9 RCCs respectively. Each cohort showed an exponential and significant increase of EVs between 3 and 9w but was significantly different from each other in terms of amounts of EVs released. This variability could not be attributed to basic quality measures such as hemolysis and extracellular K^(+) and glucose contents, since these parameters were in the expected range and were not different from one cohort to another.",
"Since vesiculation is usually associated with RBC morphological modifications, we next evaluated the relative proportion of discocytes, echinocytes and spherocytes upon time. The abundance of discocytes was already less important than in fresh blood tubes at 1w and further decreased upon storage in favour of echinocytes and a minority of spherocytes. The decrease of discocytes and the increase of spherocytes both correlated with the rise of released EVs for all vesiculation cohorts, suggesting that the relatively late appearance of spherocytes from 6w of storage could be attributed to vesiculation.",
"We next wondered whether the high variability in EV abundance between groups could be explained by a differential intracellular ATP concentration. Indeed, ATP levels are known to decrease during storage leading to reorganisation of cytoskeleton, reduction of the antioxidant system activities and EV formation. In the overall RCC population, intracellular ATP levels first increased, showing a peak between 1 and 4w of storage, and then decreased progressively, as observed by Gevi et al.. Despite differential kinetics, no significant difference in ATP level could be detected at 6w between groups. Compared with fresh tubes. This could be due to the fact that, despite a constant decrease, the glucose content in SAGM never dropped to the plasma level during the whole storage period in each cohort. Taken together, these data indicated that the EV abundance variability between the 3 cohorts at 6w could not be explained by a differential intracellular ATP content.",
"As oxidative stress is proposed to be a key player in the development of storage lesions, we next measured intracellular ROS and metHb contents. Surprisingly, the ROS content was similar in fresh concentrates and in blood tubes and was not modified upon storage. MetHb levels showed a tendency of constant increase upon storage but stayed in the normal range for fresh blood tubes as defined by the manufacturer of the automated blood gas analyser ABL-90. A technical issue was excluded as ROS and metHb highly increased under H_(2)O_(2) treatment and during the storage of K^(+)/EDTA blood tubes. Moreover, even after cohort division, we were not able to detect accumulation of ROS or metHb in RCCs. Overall, oxidative stress did not appear to develop in RCCs at least in the form of ROS and metHb and can therefore not reflect the differences in vesiculation between the 3 groups.",
"Intrigued by the absence of ROS accumulation, we next wondered whether these reactive species could have attacked other targets than Hb, i.e., the anchorage complex-associated anion transporter band3 and the cytoskeletal protein spectrin, thereby preventing their accumulation and detection. We started by evaluating the presence of band3 in EVs at 3 and 6w of storage by Western blotting in reducing conditions for the 3 vesiculation cohorts. Band3 was found in EVs mainly in the form of monomers but also in dimers at both 3 and 6w whereas no degradation products were detected. However, no obvious differences were visible between 3 and 6w of storage or between the 3 vesiculation cohorts. We then determined whether band3 dimers were also present in RBC ghosts for each vesiculation cohort. We observed that dimers detected in EVs are present in considerably lower proportions in RBC ghosts when compared with the monomeric form. However, degradation products at approximately 60, 40, 35 and 25 kDa could be visualised. These band3 fragments were previously reported by Rinalducci et al. and were attributed to oxidative lesions. Once again, no obvious changes in the profile of band3 could be noticed in the RBC ghosts regarding storage time or according to the vesiculation cohort. The spectrin network was then immunolabelled, visualised by confocal microscopy and quantified for membrane surface occupancy. In the overall RCC population, spectrin occupancy was significantly 2-fold lower than in blood tubes and did not considerably evolve over time. Once cohorts were separated, spectrin occupancy tended to decrease between 2–3 and 5w in the medium and high vesiculation cohorts. In contrast, the low vesiculation cohort showed a stable spectrin occupancy until 6w and then started to decrease. Altogether, these data suggested that the membrane:cytoskeleton interactions were impaired early during storage which could in part be attributed to oxidative stress. However, whereas spectrin occupancy was differentially altered in the 3 vesiculation groups and evolved over time, it was not the case for band3 alterations.",
"To explore whether cytoskeleton alterations were associated with impairments of membrane transversal asymmetry, PS externalisation was determined by flow cytometry using Annexin-V labelling. Although PS exposure remained similar to that of fresh blood tubes until 6w of storage, a significant increase was noticed between 6 and 9w with ∼2% of PS-exposing RBCs at 9w. This parameter correlated positively with EV release by RBCs. More importantly, the 3 cohorts could be discriminated with this parameter. Indeed, the low vesiculation group did not expose PS whatever the storage duration while the medium and high vesiculation groups showed an increase from 8w of storage reaching ∼1.5% and ∼3% PS exposure at 10w, respectively. Moreover, significant differences were obtained between the low and high groups at 9w of storage. Taken together, our data revealed that the 3 cohorts could be distinguished by the extent of PS surface exposure. Nevertheless, the kinetics of changes were quite late, occurring during 7–10w. As PS-cytoskeleton interactions are known to modulate membrane stability, we next wondered whether lateral membrane heterogeneity in domains at the RBC surface could also be altered and contribute to the variability in EV release between groups.",
"We therefore analysed the abundance of SM-enriched domains, mostly if not exclusively associated with the LC areas of RBCs. Until 4w of storage in the overall RCC population, this abundance remained stable and was relatively similar to fresh blood tubes. From 5w, SM-enriched domains started to significantly and exponentially increase and correlated positively with the amount of EVs released. As for PS exposure, the low vesiculation cohort was protected from this membrane change and showed no correlation between the number of SM-enriched domains and EVs. Conversely, the medium and high vesiculation groups showed a significant exponential increase of SM-enriched domains which correlated with the amount of EVs released. Nevertheless, no significant difference between the 3 groups could be detected at 9w.",
"Next, we evaluated the abundance of chol-enriched domains at the RBC surface in RCCs by fluorescence microscopy. We observed a complex non-significant kinetics with a first transient increase around 2w of storage followed by a decrease between 2 and 5w and a re-increase from 6w of storage. Of note, the number of chol-enriched domains remained lower than in fresh RBCs from blood tubes for the whole storage period. As no statistical difference during storage could be evidenced, we tried to determine from which membrane region the decrease of chol-enriched domains between 2 and 5w could occur. Indeed, we previously showed that lipid domains are preferentially lost from HC areas in K^(+)/EDTA tubes upon storage. We therefore differentiated and quantified the domain abundance in HC, supporting our previous data in K^(+)/EDTA tubes upon storage and suggesting that chol-enriched domains could be lost by vesiculation from HC areas.",
"An alternative explanation behind the absence of statistical differences during storage is that the 3 vesiculation cohorts could exhibit differential kinetics of chol-enriched domain alteration. We therefore analysed separately the evolution of chol-enriched domains in the 3 cohorts. Despite different behaviours, the 3 vesiculation groups exhibited a decrease in domain abundance at some time points. To address whether this decrease could be associated with an increase of chol content in EVs, we first evaluated by Western blotting the EV content in stomatin, a chol-binding protein. We showed that stomatin was the only protein enriched in EVs compared with RBC ghosts regardless of the storage time. GPA and spectrin were also present in EVs but not enriched compared with RBC ghosts and ankyrin could not be detected. Additionally, stomatin was more enriched in EVs than the raft marker flotillin-1 at 6w except for one RCC from the high vesiculation group. Second, we measured the chol content in EVs during storage in the 3 vesiculation groups. A mirror image between the evolution of chol-enriched domains and EV chol content was evident for the 3 groups and was reflected in the correlations between these two parameters suggesting that chol-enriched domains could contribute to vesiculation. However, while a negative correlation was observed for the low and medium vesiculation groups as expected, a positive correlation was seen in the high vesiculation group, indicating that lower the abundance of chol-enriched domains, lower the chol content in EVs. Combined with the observations that this high vesiculation cohort presented the highest EV number released, the strongest chol level in EVs at 3w and a loss of chol content from the RBC membrane, this positive correlation suggested that other membrane regions than chol-enriched domains are lost from RBCs in this group.",
"To confirm the potential contribution of the loss of chol-enriched domains to the vesiculation process whatever the cohort, we looked at the chol content in EVs of the 3 groups for a same chol-enriched domain loss of ∼30%. Such domain decrease was associated with a similar chol content of ∼1.9 µg per 10^(9) EVs in all 3 groups and was reached only after 6w of storage for the low vesiculation group, between 3 and 4w for the medium vesiculation group and as early as 2w for the high vesiculation group. Altogether, these data indicated that the decrease of chol-enriched domains was accompanied by an increase of chol in EVs, suggesting that chol-enriched domains were lost by vesiculation. Moreover, this decrease occurred at differential time points during the storage in the 3 vesiculation cohorts, providing an additional explanation for the non-significant kinetics of chol-enriched domains in the overall cohort besides the differential domain decrease from HC and LC areas.",
"To then gain insight on the mechanism behind the decrease of chol-enriched domains in the 3 vesiculation groups while addressing the possibility of additional RBC membrane alterations in the high vesiculation group, we measured the RBC membrane microviscosity. For this purpose, fluorescence lifetime of BODIPY-C10 was monitored at 1, 4 and 7w of storage of RBCs from 1 medium and 2 high vesiculation RCCs. The lifetime of this probe correlates with the viscosity of its environment, a longer lifetime indicating a higher microviscosity of the membrane. After labelling, RCCs were observed by multiphoton microscopy and analysed for the BODIPY-C10 lifetime. Data were expressed as a difference of BODIPY-C10 lifetime versus fresh blood tubes. The increase in membrane microviscosity as compared with RBCs from fresh tubes was already present after 1w in the RCC exhibiting the highest vesiculation rate. It then continued to increase up to 4w and was followed by a decrease in the 3 RCCs. This suggested a transient increase in RBC membrane microviscosity which was reminiscent to the transient rise of ATP concentration. Accordingly, both parameters correlated positively. Correlation with the EV number was also observed, but was negative between BODIPY-C10 lifetimes and the EV number at the same storage time. Correlation became positive if the lifetimes at 1 and 4w were correlated with EVs released at 4 and 7w respectively. Altogether, these data suggested that the transient increase in membrane microviscosity preceded the release of EVs, at least in the 3 RCCs analysed. The release of EVs and chol from the RBC membrane could in turn affect the RBC membrane in such a way that other membrane regions could be affected."
] |
PMC10164451
|
BMC Pregnancy and Childbirth
|
Inequity of antenatal influenza and pertussis vaccine coverage in Australia: the Links2HealthierBubs record linkage cohort study, 2012–2017
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08-05-2023
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Background Pregnancy and early infancy are increased risk periods for severe adverse effects of respiratory infections. Aboriginal and/or Torres Strait Islander (respectfully referred to as First Nations) women and children in Australia bear a disproportionately higher burden of respiratory diseases compared to non-Indigenous women and infants. Influenza vaccines and whooping cough (pertussis) vaccines are recommended and free in every Australian pregnancy to combat these infections. We aimed to assess the equity of influenza and/or pertussis vaccination in pregnancy for three priority groups in Australia: First Nations women; women from culturally and linguistically diverse (CALD) backgrounds; and women living in remote areas or socio-economic disadvantage. Methods We conducted individual record linkage of Perinatal Data Collections with immunisation registers/databases between 2012 and 2017. Analysis included generalised linear mixed model, log-binomial regression with a random intercept for the unique maternal identifier to account for clustering, presented as prevalence ratios (PR) and 95% compatibility intervals (95%CI). Results There were 445,590 individual women in the final cohort. Compared with other Australian women (n = 322,848), First Nations women (n = 29,181) were less likely to have received both recommended antenatal vaccines (PR 0.69, 95% CI 0.67–0.71) whereas women from CALD backgrounds (n = 93,561) were more likely to have (PR 1.16, 95% CI 1.10–1.13). Women living in remote areas were less likely to have received both vaccines (PR 0.75, 95% CI 0.72–0.78), and women living in the highest areas of advantage were more likely to have received both vaccines (PR 1.44, 95% CI 1.40–1.48). Conclusions Compared to other groups, First Nations Australian families, those living in remote areas and/or families from lower socio-economic backgrounds did not receive recommended vaccinations during pregnancy that are the benchmark of equitable healthcare. Addressing these barriers must remain a core priority for Australian health care systems and vaccine providers. An extension of this cohort is necessary to reassess these study findings. Supplementary Information The online version contains supplementary material available at 10.1186/s12884-023-05574-w.
|
[
"Pregnancy and early infancy are increased risk periods for severe adverse effects of respiratory infections [ , ]. A decrease in immunity from physiological effects of pregnancy, [ ] and age-associated immune immaturity in infants, exacerbated in infants born preterm, are among the reasons for these heightened infection risks [ ]. Other risk factors include co-morbidities, living in remote regions, lower socio-economic status, inadequate housing, decreasing rates of exclusive breastfeeding, and limited access to culturally safe and appropriate, affordable health care [ ]. To combat respiratory infections among these groups, inactivated influenza vaccines women and children in Australia bear a disproportionately high burden of respiratory diseases compared to non-Indigenous women and infants [ ]. As such, First Nations women are a priority for antenatal vaccination. Several Australian studies incorporating First Nations women have suggested the coverage of IIV in pregnancy is low are scarce. One Australian survey conducted over a three-month period examined IIV and dTpa vaccination coverage in pregnant women from CALD backgrounds in Victoria [ ]. Although these results are important, the small sample size, and CALD pregnant women.",
"The primary aim of this study was to provide robust estimates of antenatal IIV and/or dTpa vaccine coverage across three Australian jurisdictions over six years, among, Queensland [ ].",
"Women were excluded from the study if: they recorded a birth before 20 weeks gestation; had missing data related to gestation at birth; or birthed outside the study period.",
"The cohort was created through the linkage of Perinatal Data Collections whereas dTpa was analysed from 2015 onwards following implementation of funded vaccination programs [ ].",
"The key variables used to estimate vaccination coverage were; infant date of birth, gestation in weeks at the time of infant birth, gestation in weeks at the time of vaccination, and trimester of pregnancy in which maternal vaccination occurred. Vaccination in pregnancy, 2016 Australian Bureau of Statistics [ ]. A composite variable was created to classify women as.",
"The Index of Relative Socio-economic Advantage and Disadvantage with a random intercept for the mother’s ID was used to account for clustering of participants who were in the cohort more than once over the study period. To determine the relative influence of socio-economic disadvantage or speculatively associated with maternal vaccination coverage were then included in a multivariable GLMM and reported as adjusted prevalence ratios, there were 445,590 individual women out of 591,867 unique pregnancies; comprising 29,181 First Nations, 322,848 Other Australian and 93,561 women from CALD backgrounds.",
"",
"",
"Overall, 69,670. Compared to other Australians, First Nations women were less likely to have received any of the recommended vaccines during pregnancy: dTpa; PR 0.70, 95%CI 0.69–0.71) and both vaccines; PR 0.69, 95%CI 0.67–0.71, and women from CALD backgrounds were more likely to have received IIV. Factors positively associated with vaccine coverage within the population groups were similar to those overall, apart from increasing maternal age among First Nations women.",
"Coverage of antenatal IIV was similar. This trend was consistent across each jurisdiction. Univariable and multivariable models confirmed statistically that overall, living remotely detracted from antenatal vaccination coverage: IIV PR 0.88. This trend remained consistent among all groups.",
"Antenatal vaccine coverage increased with socio-economic advantage. The highest proportions of vaccine coverage were in the SEIFA 10 decile compared to women from areas of highest disadvantage; dTpa,, and each jurisdiction.",
"We identified overarching inequity in coverage of antenatal vaccinations among First Nations women, and in women who lived in remote areas, and women who lived in areas of higher socio-economic disadvantage. Other Australian women and CALD women living in major cities were more likely to have received the recommended and funded vaccines in pregnancy, and women from lower socio-economic backgrounds were less likely to have received vaccines. We also confirmed that younger women who birthed in public hospitals and who attended antenatal care later during pregnancy were less likely to have received antenatal vaccines. These geographic, social and financial access issues demonstrate shortcomings in our current health systems and NIP, and highlight the need for more dedicated resources and training to address the inequity.",
"As with other studies, we saw vaccination coverage improve over the years of the study, [ ] particularly following the implementation of the antenatal dTpa program, but despite surveys indicating a high willingness of First Nations women to be vaccinated in pregnancy if offered, [ , ] coverage of antenatal IIV and dTpa vaccination remained low. The gap between willingness and coverage is a potential physical and financial health systems access issue. Designing antenatal services specifically for younger mothers and promoting young parent programmes similar to some existing models may be one way to increase antenatal vaccination coverage among both younger and First Nations mothers [ ]. Midwifery group practices co-designed with First Nations peoples for First Nations families, and antenatal care provided by First Nations health workers and midwives have demonstrated improved antenatal care attendance and equitable or better outcomes among First Nations mothers and infants compared to other Australians in mainstream care [ , ]. However, this has not translated into practice for antenatal vaccination coverage in all jurisdictions as yet. Although our data relate to the years 2012–2017, data from a 2021 clinical audit within a major Qld public hospital showed both antenatal IIV and dTpa coverage remained considerably low among First Nations mothers, with overall uptake ~ 48% in South Australia and Victoria, higher for dTpa (~ 79–83%), [ , ] however, our data are the most comprehensive and contemporary for comparison thus far. An updated analysis of national data are warranted, particularly now that COVID-19 vaccination in pregnancy has been recommended since 2021 [ ]. This recommendation may have influenced the priority of antenatal COVID-19 vaccination over antenatal IIV and dTpa administration during this time period, or pandemic restrictions may have affected access to antenatal IIV and dTpa.",
"Where First Nations or CALD focused midwifery models of care are not in place, more attention should be given to developing culturally safe clinical practice, and improving vaccine education and service delivery to avoid systemic barriers to equity such as racism and discrimination [ ]. Strategies to increase antenatal vaccination coverage could include the use of appropriate language and interpreters in healthcare provider service settings.",
"Our data include the largest linked cohort of First Nations mother-infant pairs across three Australian jurisdictions, and includes urban, rural and remote-living representation. The WA validated algorithm used to identify maternal First Nations status across multiple datasets strengthens the accuracy of these data. Our data are also the first to describe antenatal vaccination status by areas of accessibility to services and socio-economic advantage and disadvantage based on individual postcode level data. Our antenatal vaccination coverage results are consistent with international studies conducted during similar time periods, with similar Indigenous and ethnic population proportions [ – ]. These studies have also suggested that sub-optimal antenatal IIV and dTpa vaccination will persist if strategies to address ongoing inequity are not met.",
"Our data did not include First Nations status or ethnicity of infants. We acknowledge that including Indigeneity only of the mother underrepresents First Nations infants of First Nations fathers, and that the mother may choose to not identify as First Nations due to risks of receiving poorer care [ ]. Our large sample size of First Nations mothers however, affords good generalisability for the three jurisdictions included in our study. We also acknowledge potential limitations around using the variables ‘country of birth’ and ‘ethnicity’ as an imperfect way of assessing English language capacity and health literacy. We also acknowledge potential unknown errors of vaccine reporting.",
"Our data demonstrated significant inequity in antenatal vaccination among First Nations Australian families, and families who live remotely and/or from lower socio-economic backgrounds. Given that the known increased risk factors for acquiring influenza or pertussis infections are living in remote regions, lower socio-economic status, inadequate housing, and limited access to culturally safe and appropriate, affordable health care, vaccination against these infections remains a key public health strategy in preventing severe disease in pregnancy and early infancy. Systematically monitoring vaccine coverage, and strategies that ensure vaccines are offered and provided to women equitably alongside other quality healthcare during pregnancy are required. This is a core responsibility of Australian health care systems and vaccine providers."
] |
PMC10457954
|
Pharmaceuticals
|
Impact of Sirolimus versus Mycophenolate Mofetil on Kidney Function after Calcineurin Inhibitor Dose Reduction in Liver Transplant Recipients
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31-07-2023
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Impaired kidney function is associated with increased morbidity and mortality in patients undergoing liver transplantation. Although immunosuppressants are essential in these patients, they impair kidney function. This study aimed to compare adverse kidney outcomes between patients treated with a reduced dose of tacrolimus (calcineurin inhibitor) plus sirolimus or mycophenolate mofetil (MMF) in the liver transplant center at Kaohsiung Chang Gung Memorial Hospital between April 2011 and December 2017. Propensity score matching was used to identify 232 patients. The risk of adverse kidney outcomes was estimated using Cox proportional hazards regression, and changes in kidney function over time were analyzed using linear mixed modeling. Acute kidney disease risks in this study cohort were not significantly different for the two immunosuppressants (aHR 1.04; 95% CI: 0.70–1.55, p = 0.8328). However, sirolimus use was significantly associated with a higher risk of estimated glomerular filtration rate decline > 30% than MMF (aHR, 2.09; 95% CI: 1.33–3.28; p = 0.0014). Our results demonstrate that sirolimus use may have worsened long-term kidney outcomes compared to MMF. Close monitoring of kidney function, dose adjustment, and timely transition to MMF is necessary for LT patients receiving sirolimus.
|
[
"Liver transplantation, including cyclosporine and tacrolimus, has revolutionized the long-term prognosis of organ transplants by preventing graft rejection [ ]. However, these agents can have significant side effects, of which acute or chronic nephrotoxicity are considered major contributors to chronic kidney disease and CKD, which are associated with short- and long-term risks, develop after LT. AKI is a condition defined by a sudden loss of kidney function on the basis of increased serum creatinine levels or reduced urinary output within a duration of 7 days [ ]. CKD is defined as an abnormality of kidney structure or function for more than 3 months [ ]. The development of post-LT AKI is associated with an increased risk of CKD [ ], prolonged hospital stay [ ], higher incidence of graft failure [ ], and even higher mortality rates [ , , ]. CKD is the final manifestation of persistent intrinsic renal damage, particularly after several AKI events. Further, CKD after LT is associated with an increased risk of death [ , , ], graft failure [ ], and other adverse outcomes, such as cardiovascular diseases [ , ]. Acute kidney disease or mycophenolic acid, a semi-synthetic 2-morpholinoethyl ester of MPA, is a selective and reversible noncompetitive inhibitor of inosine monophosphate dehydrogenase, a crucial enzyme in DNA formation [ ]. MMF is often used in combination with other immunosuppressive medications to prevent the rejection of transplanted organs and reived FDA approval for use in LT in 2000 [ ]. Many studies have shown that MMF is a safe immunosuppressant that offers metabolic and renal benefits over the standard dose of CNIs [ ]. In a multicenter, randomized controlled study, Boudjema et al. showed that reduced-dose tacrolimus with MMF decreased the incidence of renal dysfunction compared with standard-dose tacrolimus [ ]. Another prospective multicenter randomized study showed that the introduction of MMF combined with a reduced CNI dose of at least 50% resulted in a significant improvement in renal function [ ].",
"Previous studies have demonstrated that CNI dose reduction combined with sirolimus or MMF contributes to the preservation of kidney function and is a useful strategy for reducing the risk of nephrotoxicity in LT recipients. However, kidney function deterioration still occurs in these patients; therefore, a head-to-head comparison between sirolimus and MMF combined with a CNI is warranted. Consequently, this study aimed to examine the effects of sirolimus and MMF on kidney outcomes in patients undergoing LT.",
"Between April 2011 and December 2017, 789 patients underwent liver transplantation. Prior to propensity score.",
"The baseline characteristics of the study cohort are presented in . The PS-matched groups each consisted of 116 patients with an average age of 52.3 years. The demographic and clinical characteristics of sirolimus and MMF users were well balanced, warm ischemia time.",
"At 6 months after initiation, the doses of tacrolimus were higher in the MMF group than in the sirolimus group and 50%.",
"As shown in a, there was no significant difference in the incidence of AKD between the two treatment groups.",
"Decreases in estimated GFR smaller than a doubling of serum creatinine concentration are strongly linked to the risk of End-Stage Renal Disease. A more prominent difference was evident between the two groups in the cumulative events of eGFR decline of over 50%. Further, the Cox regression analysis showed a notable association between the use of sirolimus and a higher risk of a 30% reduction in eGFR, compared to the use of MMF.",
"As shown in , the median follow-up [ , ]. Pre-transplant renal dysfunction is an important risk factor for post-LT AKI [ , ]. As the baseline renal function in our cohort was relatively preserved.",
"CKD, defined as a reduced eGFR for ≥3 months, is a common complication that has a major impact on graft and patient survival in LT [ , ]. A decline in eGFR of 30% has been proven to correlate well with the development of CKD and can be used to predict death and advanced CKD requiring dialysis in patients who undergo LT [ , , ]. Many studies have indicated CNIs as the main cause of CKD in LT recipients [ ]. MMF and mTORi are used as strategies for renal protection to minimize the requirement for high CNI doses [ ]. However, head-to-head comparisons between MMF and sirolimus are scarce. Our study showed that MMF had a lower incidence of eGFR decline of >30% than sirolimus. Although tacrolimus exposure is an important factor in nephrotoxicity after LT, tacrolimus trough levels change dynamically and are difficult to record. The tacrolimus trough at the index date and 6 months after were used as confounders for EGFR decline > 30%. The reason why the initial dose and trough of tacrolimus in the sirolimus group at the index date were lower than those in the MMF group may be because sirolimus was given later than MMF. The mechanisms by which sirolimus is associated with poor renal outcomes remain unclear. DuBay et al. illustrated that LT patients with an initial creatinine clearance < 30 mL/min who were switched to sirolimus were worse off than patients maintained on low-dose CNI [ ]. Li et al. reported that LT patients with proteinuria and poor baseline renal function had poor renal outcomes and survival [ ]. It has also been reported that sirolimus may be associated with worse allograft survival in patients undergoing kidney transplants [ ]. In this study, patients who received sirolimus exhibited a higher >30% decrease in eGFR. Although no significant differences were observed in some subgroup analyses, this could be due to the small numbers in certain subgroups. Nevertheless, most subgroup analyses showed a protective effect against MMF. Notably, the protective effects of MMF were most pronounced in older male patients who experienced AKD during the follow-up period.",
"Some limitations of our study should be acknowledged. First, this was a retrospective study conducted at a single medical center. Second, we selected patients who underwent follow up for at least 3 years until Geissler et al. published in 2016 that sirolimus in LT recipients with HCC did not improve long-term recurrence-free survival beyond 5 years [ ]. Sirolimus was initiated at 1 mg once daily for 3–7 days and then titrated to main a trough level of 4–10 ng/m [ ]. The dose of MMF used was initiated at 1–2 gm/day. Methylprednisolone, and adhered to the principles of the Declaration of Helsinki and Declaration of Istanbul.",
"The outcomes of interest were AKD, advanced AKD was defined as an increase in serum creatinine level to ≥2.0 times that occurred or persisted within 90 days after renal injury [ ]. The reason for using AKD instead of AKI was that most LT patients were followed up at the outpatient clinic with renal function monitoring intervals ranging from 7 to 90 days. Furthermore, there is currently limited research on the potential occurrence of AKD in LT patients due to these two medications and the impact of AKD occurrence on the prognosis of LT patients.",
"The eGFR was calculated using the Taiwan version of the abbreviated Modification of Diet in Renal Disease were used to assess the change in eGFR over time.",
"To level the baseline demographic and clinical discrepancies between the sirolimus and MMF groups, PS matching was used. The individual propensity scores of patients treated with either sirolimus or MMF were approximated via logistic regression. We matched new users of sirolimus and MMF on a 1:1 basis using the greedy technique in the PS-matching method. Before and after PS matching, we evaluated baseline traits and comorbidities between the two treatment groups. The standardized mean difference (SMD) was used to gauge comparability in baseline traits between groups, with an SMD < 0.1 considered as no meaningful difference.",
"We utilized the chi-squared test to calculate adverse kidney outcomes (AKD and eGFR decline). The time-to-adverse kidney outcome endpoint was probed using the Kaplan–Meier approach with log-rank tests. We employed the Cox proportional hazard regression model to scrutinize the independent correlation between the selection of MMF (or sirolimus) and the occurrence of individual adverse kidney diseases. A linear mixed-effects model was employed to estimate the discrepancy in the average eGFR changes over time between sirolimus and MMF users. To evaluate the heterogeneous impacts of sirolimus and MMF by varying baseline characteristics, we conducted stratified analyses in the matched cohorts considering sex, age (<55 years vs. >55 years), and baseline eGFR groups (<90, and ≥90 mL/min/1.73 m^(2)), HBV, HCV, HCC, DM, and AKD in eGFR decline. A two-tailed test result of p < 0.05 was considered statistically significant. All statistical analyses were performed using SAS 9.4 (SAS Institute, Cary, NC, USA).",
"In conclusion, our study showed that among LT patients, the use of sirolimus plus tacrolimus may carry a higher risk of long-term kidney function deterioration than the use of MMF plus tacrolimus. These findings highlight the need for periodical monitoring of kidney function and early detection of kidney injury at least every 1–3 months and other reno-protective strategies, such as dose optimization of immunosuppression and early transition to MMF in LT patients using sirolimus."
] |
PMC10684871
|
Scientific Reports
|
Maternal early mid-pregnancy adiponectin in relation to infant birth weight and the likelihood of being born large-for-gestational-age
|
27-11-2023
|
This study aimed to evaluate the association of maternal adiponectin with infant birth size in 1349 pregnant women at Uppsala University Hospital, Sweden. The mean age of the women was 31.0 years, and 40.9% were nulliparous. Maternal early mid-pregnancy adiponectin was measured in microgram/mL. Linear regression models were performed to evaluate the association between adiponectin and infant birth weight. Logistic regression models were used to evaluate adiponectin in relation to the odds of giving birth to an infant large-for-gestational-age (LGA, infant birth weight standard deviation score > 90th percentile). Adjustments were made for early pregnancy BMI and diabetes mellitus. Prior adjustments, adiponectin was inversely associated with infant birth weight (β − 17.1, 95% confidence interval (CI) − 26.8 to − 7.4 g, P < 0.001), and one microgram/mL increase in adiponectin was associated with a 9% decrease in the odds of giving birth to an LGA infant (odds ratio 0.91, CI 0.85–0.97, P = 0.006). The associations did not withstand in the adjusted models. We found a significant interaction between adiponectin and infant sex on birth size. This interaction was driven by an inverse association between maternal adiponectin and birth size in female infants, whereas no such association was found in males.
|
[
"The intrauterine milieu has a considerable impact on fetal growth and later on the birth weight of the infant^(1). Excessive fetal growth is observed among women with obesity^(2) and diabetes mellitus^(3). Increased nutrient availability and elevated insulin levels promoting fetal growth are proposed as mechanisms behind these observations^(4).",
"A high birth weight is associated with infant morbidity and mortality, and prediction of a high birth weight is therefore of clinical importance. High birth weight infants^(29). Variables were included in the DAG if they were known to be associated with the exposure and outcome, or if they were considered clinically relevant. We also performed sensitivity analyses including only women without pregestational or gestational diabetes mellitus. In the sensitivity analyses, adjustment were made for early pregnancy BMI. To investigate any sex-specific differences, we performed an interaction analysis on the interaction between adiponectin and infant sex on birth weight. The interaction analysis was adjusted for early pregnancy BMI and diabetes mellitus. Early pregnancy adiponectin levels correlated negatively with BMI. There was no correlation between adiponectin and maternal age.",
"For every microgram/mL increase in adiponectin there was an associated decrease in birth weight of 17.1 g. However, no association was seen in the model adjusted for early pregnancy BMI and diabetes mellitus. The results were similar in the analysis evaluating BWSDS.",
"An increase of adiponectin by one microgram/mL was associated with a 9% decrease in the odds of having an LGA infant.",
"In the sensitivity analyses including only women without diabetes mellitus, the results were similar.",
"An interaction between adiponectin and infant sex on birth weight was demonstrated; the effect on birth weight of one microgram/mL increase in adiponectin was 20.2 g lower for females versus males.",
"Stratified analyses in each sex revealed an inverse association between adiponectin and birth size prior to adjustments in female infants. One microgram/mL increase in adiponectin was associated with a decrease in birth weight of 29.2 g. The association did not withstand after adjustments. An increase of adiponectin by one microgram/mL was also associated with a 12% decrease in the odds of having an LGA infant. In male infants, there was no association between adiponectin and birth size."
] |
PMC10366197
|
Scientific Reports
|
LAMP (Loop-mediated isothermal amplification) assay for rapid identification of Varroa mites
|
24-07-2023
|
Varroa mites are serious pests of European honeybees ( Apis mellifera). For detection of Varroa mite, a new molecular LAMP-based assay has been developed, which retains the body of the mite intact for morphological identification. Six novel Varroa LAMP primers were designed from existing DNA sequences of the COI locus to target V. destructor and V. jacobsoni, providing the ability to tell them apart from other non-target beehive associated mite and insect species. This LAMP assay is specific in detecting these Varroa species and has been tested on specimens originating from multiple countries. It produces amplification of V. destructor and V. jacobsoni in 16 ± 3.4 min with an anneal derivative of 78 ± 0.5 °C whilst another Varroa species, V. underwoodi, showed late amplification. A gBlock gene fragment, used here as a positive control has a different anneal derivative of 80 °C. Three non-destructive DNA extraction methods (HotShot, QuickExtract and Xtract) were tested and found to be suitable for use in the field. The LAMP assay was sensitive to very low levels of Varroa DNA, down to 0.24 picogram (~ 1 × 10 copies/µL of Varroa gBlock). This is a new molecular tool for rapid and accurate detection and identification of Varroa mites for pest management, in areas where these mites do not occur.
|
[
"Varroa mites were developed to target a 259 bp portion of the Varroa COI locus. Ambiguous bases were added to the primers to account for common genetic variation present in the wider COI dataset of V. destructor and V. jacobsoni individuals available on GenBank. Six primers are used in the Varroa LAMP assay, two inner primers. The DNA sequence difference between the Varroa species and the non-target mites was > 24%. The new DNA barcode reference sequences generated in this study have been submitted to GenBank, accession numbers OQ205274—OQ205287.",
"All 22 specimens of Varroa species tested produced positive amplification for the Varroa LAMP assay while the eight non-target mite species did not amplify. The seventeen V. destructor specimens amplified in 15.4 ± 3.3 min, while the four V. jacobsoni amplified in 19.4 ± 2 min, and the single V. underwoodi amplified very late at 24 min. The anneal derivative temperatures appear very similar between all three Varroa species, at 78 ± 0.5 °C. The 18S LAMP assay confirmed the quality of DNA samples to be high for all the DNA samples, producing positive amplification except for Acarapis woodi which failed to amplify for the 18S assay. None of the negative non-template controls amplified in any of the LAMP runs performed while optimising the new Varroa assay, confirming the absence of primer dimers and that there was no reagent contamination.",
"Different DNA extraction methods, both destructive and non-destructive, were tested using specimens of V. destructor . All four non-destructive DNA extraction methods yielded good quality and quantity of DNA as assessed with both Varroa and 18S LAMP assays. Three of these non-destructive DNA extraction methods – HotShot, QuickExtract and Xtract–are suitable for use in the field, as they both yielded V. destructor DNA which could be amplified in 12 to 17 min. Amplification was quicker using 25 µL of Xtract buffer.",
"Sensitivity of the LAMP assay was tested using a four-fold serial dilution of V. destructor DNA which produced positive LAMP amplifications for all eight DNA concentrations. The highest DNA concentration 4 ng/µL produced amplification in 10 min and the lowest DNA concentration 2.44 × 10^(–4) ng/µL amplified in 25 min. The LAMP assay is very sensitive and amplified very low levels of targeted DNA equal to 0.24 picograms of Varroa DNA, with decreasing amounts of DNA resulting in longer amplification times.",
"The 256 bp Varroa gBlock was very sensitive, being detected as low as ~ 1 × 10 copies/µL of Varroa gBlock within 30 min with an anneal derivative of 80 °C. One million copies. Based on this amplification time, 1 × 10^(6) copies/µL of Varroa gBlock was found to be suitable for use as synthetic positive in Varroa LAMP assay. The anneal derivative of LAMP amplicons produced two distinct peaks, 78 °C for Varroa DNA and 80 °C for the gBlock which are easily distinguishable from each other.",
"Our optimised Varroa LAMP assay was tested in the laboratory, with the performance of the assay compared using three commercially available master mixes. All three Varroa species amplified as expected using the three master mixes, with minimal difference in amplification times between them. The non-target species did not amplify in all three tests and the two positive control Varroa gBlocks 1 × 10^(6), which are the two primers required to initiate the LAMP amplification process. Interestingly, given that all three species amplified with our new assay it suggests that the LAMP assay will likely not be affected by minor intraspecific haplotypic variation in V. destructor or V. jacobsoni. To further evaluate the specificity of the Varroa LAMP assay, we tested other relevant mite species closely associated with the bee colonies.",
"Identification of specimens representing each Varroa species and the two non-target mite species— Melittiphis alvearius and Machrochelidae sp.. The Varroa COI regions of homology were identified manually, and this alignment was used to design a Varroa mite specific LAMP assay. Six novel LAMP assay primers were designed in the present study. For all primers the GC content. To evaluate detection sensitivity, the copy number and a ten-fold serial dilution (1:10) of the gBlock was prepared as outlined in Agarwal (2022). Sensitivity of the gBlock was tested using 1 × 10^(8) copies/µL to 1 × 10 copies/µL of gBlock in the Genie III, following the Varroa LAMP assay conditions mentioned above (with run time being increased from 25 to 35 min). Following this test, another LAMP run was conducted to determine the best dilution for gBlock to be used as a positive control in LAMP assays. The same four-fold serial dilution of Varroa DNA (VAITC 9797a) (4 ng/µL to 0.0039 ng/µL) was used as template to compare amplification time with one million copies (1 × 10^(6) copies/µL) of gBlock.",
"The performance of the new Varroa LAMP assay was tested using two commercially available isothermal master mixes (ISO-001 and ISO-004, OptiGene, UK) and a commercially produced lyophilised kit (GWS-K-VDES-08, Geneworks, Australia). Each LAMP reaction mix was made by adding 24 µL of master mix and 1 µL of template DNA. Each run included one of each Varroa species – V. destructor , V jacobsoni and V. underwoodi , and the non-target species Melittiphis alvearius, 1 × 10^(6) copies/µL of Varroa gBlock, 3.8 × 10^(8) copies/µL VDES synthetic positive control (GWS-K-VDES-08, Geneworks, Australia) and a no-template negative control. All LAMP assays were run in the Genie III at 65 °C for 35 min followed by an annealing curve analysis from 98 °C to 73 °C with ramping at 0.05 °C/s and results analysed on the blue channel."
] |
PMC10663215
|
Frontiers in Plant Science
|
Detection of breakage and impurity ratios for raw sugarcane based on estimation model and MDSC-DeepLabv3+
|
08-11-2023
|
Broken cane and impurities such as top, leaf in harvested raw sugarcane significantly influence the yield of the sugar manufacturing process. It is crucial to determine the breakage and impurity ratios for assessing the quality and price of raw sugarcane in sugar refineries. However, the traditional manual sampling approach for detecting breakage and impurity ratios suffers from subjectivity, low efficiency, and result discrepancies. To address this problem, a novel approach combining an estimation model and semantic segmentation method for breakage and impurity ratios detection was developed. A machine vision-based image acquisition platform was designed, and custom image and mass datasets of cane, broken cane, top, and leaf were created. For cane, broken cane, top, and leaf, normal fitting of mean surface densities based on pixel information and measured mass was conducted. An estimation model for the mass of each class and the breakage and impurity ratios was established using the mean surface density and pixels. Furthermore, the MDSC-DeepLabv3+ model was developed to accurately and efficiently segment pixels of the four classes of objects. This model integrates improved MobileNetv2, atrous spatial pyramid pooling with deepwise separable convolution and strip pooling module, and coordinate attention mechanism to achieve high segmentation accuracy, deployability, and efficiency simultaneously. Experimental results based on the custom image and mass datasets showed that the estimation model achieved high accuracy for breakage and impurity ratios between estimated and measured value with R 2 values of 0.976 and 0.968, respectively. MDSC-DeepLabv3+ outperformed the compared models with mPA and mIoU of 97.55% and 94.84%, respectively. Compared to the baseline DeepLabv3+, MDSC-DeepLabv3+ demonstrated significant improvements in mPA and mIoU and reduced Params, FLOPs, and inference time, making it suitable for deployment on edge devices and real-time inference. The average relative errors of breakage and impurity ratios between estimated and measured values were 11.3% and 6.5%, respectively. Overall, this novel approach enables high-precision, efficient, and intelligent detection of breakage and impurity ratios for raw sugarcane.
|
[
"Sugarcane is an important raw material for the sugar industry worldwide. In China, sugarcane-based sugar production reached 4.6 million tons in 2022, which is 4.3 times that of beet sugar. In recent years, the use of machine-harvested sugarcane has been steadily increasing, with plans to reach 30% of total sugarcane harvest in China by 2025. Machine harvesting significantly improves efficiency and reduces labor intensity; however, it also leads to higher ratios of broken cane and impurities such as top, leaf, which can negatively impact the yield of the sugar manufacturing process. As a result, the breakage and impurity ratios are crucial indicators for assessing the quality and pricing of raw sugarcane in practice, and determining these two ratios is indispensable for sugar refineries. Unfortunately, the commonly used manual sampling approach for detecting breakage and impurity ratios brings several issues, including strong subjectivity, low efficiency, and significant result discrepancies.",
"To address the aforementioned problem, an estimation model was established, and machine vision technology was employed to provide a more objective, efficient, accurate, and intelligent approach for quantifying the cane, broken cane, and impurities, as well as the ratios of breakage and impurity. This enables seamless integration with the sugarcane harvesting and sugar processing stages. Both cane and broken cane can be used as raw materials, but broken cane is considered in mass deduction by sugar refineries because it results in the loss of sugar content and impacts the quality of the final sugar product. The sugarcane top, leaf, root, sand, gravel, and soil and so forth are collectively referred to as impurities. Adjusting the height between the harvester’s cutting device and the ridge surface will reduce the introduction of sand, gravel, and soil during sugarcane harvesting. Furthermore, when the mechanical harvester operates smoothly and adheres to specifications, it noticeably decreases the levels of mud, stone, and cane root. Mechanical removal methods, such as vibration, can often be used to screen out the sand, gravel, and soil. However, the top, leaf and cane root are unavoidable impurities as they are naturally part of each sugarcane stem. Regarding cane root, object detection can be utilized to count its quantities. Combining this with the average weight of the cane root helps predict the mass of root impurity after excluding sand, gravel and soil. Based on the quality detection practice of sugar refineries, the four categories of cane, broken cane, top, and leaf are selected as the detection objects in this study.",
"Estimation models and machine vision technology have been widely used for the detection and monitoring of impurities in grain crops such as rice, wheat, and corn. For example, proposed a NAM-EfficientNetv2 lightweight segmentation approach for rapid online detection of rice seed and impurities in harvesters, achieving high evaluation index F1 scores of 95.26% and 93.27% for rice grain and impurities, respectively. To improve accuracy in wheat and impurity recognition, designed a vision system based on DeepLabv3+ to identify seeds and impurities in wheat, obtaining mean pixel accuracy"
] |
PMC10661729
|
Journal of Gastrointestinal Surgery
|
Duodenum-Preserving Pancreatic Head Resection for Benign and Premalignant Tumors—a Systematic Review and Meta-analysis of Surgery-Associated Morbidity
|
05-09-2023
|
Background Pancreatic benign, cystic, and neuroendocrine neoplasms are increasingly detected and recommended for surgical treatment. In multiorgan resection pancreatoduodenectomy or parenchyma-sparing, local extirpation is a challenge for decision-making regarding surgery-related early and late postoperative morbidity. Methods PubMed, Embase, and Cochrane Libraries were searched for studies reporting early surgery-related complications following pancreatoduodenectomy (PD) and duodenum-preserving total (DPPHRt) or partial (DPPHRp) pancreatic head resection for benign tumors. Thirty-four cohort studies comprising data from 1099 patients were analyzed. In total, 654 patients underwent DPPHR and 445 patients PD for benign tumors. This review and meta-analysis does not need ethical approval. Results Comparing DPPHRt and PD, the need for blood transfusion (OR 0.20, 95% CI 0.10–0.41, p <0.01), re-intervention for serious surgery-related complications (OR 0.48, 95% CI 0.31–0.73, p <0.001), and re-operation for severe complications (OR 0.50, 95% CI 0.26–0.95, p =0.04) were significantly less frequent following DPPHRt. Pancreatic fistula B+C (19.0 to 15.3%, p =0.99) and biliary fistula (6.3 to 4.3%; p =0.33) were in the same range following PD and DPPHRt. In-hospital mortality after DPPHRt was one of 350 patients (0.28%) and after PD eight of 445 patients (1.79%) (OR 0.32, 95% CI 0.10–1.09, p =0.07). Following DPPHRp, there was no mortality among the 192 patients. Conclusion DPPHR for benign pancreatic tumors is associated with significantly fewer surgery-related, serious, and severe postoperative complications and lower in-hospital mortality compared to PD. Tailored use of DPPHRt or DPPHRp contributes to a reduction of surgery-related complications. DPPHR has the potential to replace PD for benign tumors and premalignant cystic and neuroendocrine neoplasms of the pancreatic head. Supplementary Information The online version contains supplementary material available at 10.1007/s11605-023-05789-4.
|
[
"Pancreatoduodenectomy The publications were checked for cross-references to identify eligible additional reports that were not identified by the primary search items. Differences were resolved by mutual agreement between two authors.",
"Partial pancreatic head resection DPPHRp.",
"DPPHRt involves resection of the pancreatic head with the tumor, while conserving the pancreatic neck, intrapancreatic CBD, and duodenum. A subgroup of DPPHRt comprises patients who underwent resection of the peripapillary segment of the duodenum. A few patients are included in the DPPHRt group, who underwent near total pancreatic head resection by conserving, after resection of the uncinate process, some suprapapillary pancreatic tissue of the groove of the pancreas. Reconstruction technique was predominantly pancreaticojejunostomy. A total of 445 patients included in the meta-analysis underwent PD for benign tumors, premalignant neoplasms, or low-risk malignant periampullary tumors. The systematic review was performed by analyzing the DPPHR-related data of all patients of the 34 cohort studies. DPPHRt was reported for 462 patients and DPPHRp for 192 patients. The meta-analysis was based on data from 13 controlled studies, including the control group of patients who underwent PD. The results of 350 patients following DPPHR and 13 studies in the meta-analysis group. In total, 19 studies were controlled cohort studies, of which 13 were prospective and 6 retrospective reports. Fifteen reports were without a control group, nine of them prospective studies. The critical appraisal for methodology revealed 24 studies with evidence level 2 and ten studies with evidence level 3. Evidence level 2 certifies a good quality cohort study. Additionally, the NOS score was used to assess the quality of all cohort studies which enabled an objective evaluation of the most basic quality aspects of non-randomized studies. Twenty-seven cohort studies elicited a score of ≥ 8; the mean NOS score was 8.1, which indicated a good quality of the cohort studies.",
"The baseline data of the 34 cohort studies comprising 1099 patients are presented in Tables and . The 34 studies comprised data of 654 patients following DPPHR and 445 patients following PD. Twenty-three studies were published between 2010 and 2021. In the review group, the mean age of the patients was 50.1 years. The gender relationship M/F was 1.5 across all studies. In two studies, results were reported after the use of DPPHR in adolescents and children, predominantly for SPN.^(33 , 52)",
"In total, 462 patients. Tumor size of the DPPHRt group of 3.7 cm was significantly larger. Gastrointestinal.",
"Of the 445 patients, who underwent PD for benign tumors of the pancreatic head, Whipple resection was performed in three studies. Of those undergoing PD, pancreatico-jejunostomosis was performed in 280 patients and pancreatico-gastrostomosis in 128 patients; two studies reported PPPD but not the type of pancreatic anastomosis.^(53 , 57) The final histopathologic diagnosis revealed 420 patients with cystic neoplasm and 83 patients with PNET. Thirty-four patients displayed tumors of the papilla/ampulla or peripapillary duodenum or peripapillary CBD and/or maljunction of the pancreatic and biliary ducts. “Other” tumors were reported for 111 patients. Under “other” tumors, which were operated with the diagnosis of a benign neoplasm, 15 patients presented with the histopathology of advanced adenocarcinoma intraoperatively by frozen section and/or by the final histopathology. These patients were listed in the section “others”; nine of them experienced conversion to classical PD or resurgery PD during the index hospitalization or DPPHRt plus adjuvant chemotherapy.",
"The overall morbidity rates following DPPHRt and DPPHRp were 40.7% and 39.5% respectively. The frequencies of pancreatic fistula, biliary fistula, DGE, and reoperation were on the same level comparing total and partial pancreatic head resection. In 115 patients.",
"DPPHRt was more frequently used for surgical treatment of IPMN and SPN. For functional PNETs, DPPHRt was more frequently applied for patients with sporadic insulinoma. Non-functional PNETs were predominantly treated with DPPHRp. Of the 233 patients with the final diagnosis of IPMN, predominantly BD-IPMN was histologically verified, when the guidelines for IPMN subgrouping were applied. Almost all patients with periampullary tumor underwent a total DPPHR included 15 of 25 patients who in the final histopathology displayed advanced cancer. The in-hospital mortality rate following DPPHRt compared to PD was 1 of 350 patients. Following DPPHRt, pancreatic fistula B + C was observed in 62 of 326 patients. DGE following DPPHRt and PD was observed in 28 of 273 patients. Biliary fistula was observed following DPPHRt and PD in 14 of 221 patients and in 15 of 352 patients, respectively.",
"Comparing baseline data after DPPHR and PD analyzed in the meta-analysis, age. Reoperation was less frequent following DPPHR.",
"Reinterventions for serious, local complications necessitating radiologic, angiographic, endoscopic, transgastric, transabdominal, ERC, or transhepatic bile duct interventions were significantly more frequently observed following PD. Comparing 350 DPPHR and 445 PD patients, the frequency of adverse events was for PPH 13 vs. 28 and a low level of heterogeneity in Fig. B and E. There was no reference for publication bias as demonstrated by funnel plots)."
] |
PMC10458721
|
Molecular & Cellular Proteomics : MCP
|
Monitoring Both Extended and Tryptic Forms of Stable Isotope-Labeled Standard Peptides Provides an Internal Quality Control of Proteolytic Digestion in Targeted Mass Spectrometry-Based Assays
|
20-07-2023
|
Targeted mass spectrometry (MS)-based proteomic assays, such as multiplexed multiple reaction monitoring (MRM)-MS assays, enable sensitive and specific quantification of proteotypic peptides as stoichiometric surrogates for proteins. Efforts are underway to expand the use of MRM-MS assays in clinical environments, which requires a reliable strategy to monitor proteolytic digestion efficiency within individual samples. Towards this goal, extended stable isotope-labeled standard (SIS) peptides (hE), which incorporate native proteolytic cleavage sites, can be spiked into protein lysates prior to proteolytic (trypsin) digestion, and release of the tryptic SIS peptide (hT) can be monitored. However, hT measurements alone cannot monitor the extent of digestion and may be confounded by matrix effects specific to individual patient samples; therefore, they are not sufficient to monitor sample-to-sample digestion variability. We hypothesized that measuring undigested hE, along with its paired hT, would improve detection of digestion issues compared to only measuring hT. We tested the ratio of the SIS pair measurements, or hE/hT, as a quality control (QC) metric of trypsin digestion for two MRM assays: a direct-MRM (398 targets) and an immuno-MRM (126 targets requiring immunoaffinity peptide enrichment) assay, with extended SIS peptides observable for 54% (216) and 62% (78) of the targets, respectively. We evaluated the quantitative bias for each target in a series of experiments that adversely affected proteolytic digestion ( e.g. , variable digestion times, pH, and temperature). We identified a subset of SIS pairs (36 for the direct-MRM, 7 for the immuno-MRM assay) for which the hE/hT ratio reliably detected inefficient digestion that resulted in decreased assay sensitivity and unreliable endogenous quantification. The hE/hT ratio was more responsive to a decrease in digestion efficiency than a metric based on hT measurements alone. For clinical-grade MRM-MS assays, this study describes a ready-to-use QC panel and also provides a road map for designing custom QC panels.
|
[
"Over the past decade, targeted mass spectrometry. Quantitative measurements in MRM-MS assays are typically made using stable isotope dilution in a “bottom-up” fashion, in which proteolytic digestion.",
"For clinical implementation of targeted MS-based measurements, robust quality control. In particular, proteolytic digestion efficiency, which is widely regarded as the largest source of variation in quantitative measurements, should ideally be monitored within individual clinical biospecimens. External QC, performed by analyzing QC materials in parallel with each batch of unknowns, can be useful for monitoring digestion in targeted MS-based proteomic assays, but the complexity of the digestion step and the potential for matrix effects within samples to affect quantitative measurements warrants additional internal QC metrics, especially in the clinical setting.",
"Several approaches using an internal QC for digestion have been developed, including, to monitor its products, and or extended SIS peptides, which recapitulate the tryptic cleavage sites on both the C- and N-termini of the target proteotypic peptide sequence.",
"While these internal QC approaches can provide some quality assurance, there are some drawbacks to their use. For instance, QC metrics based on tryptic SIS peptides are insufficient to describe the extent of digestion. Furthermore, spiking in additional proteins prior to proteolytic digestion may be undesirable for some samples due to ionization suppression and may not cover all the range of problems with digestion.",
"To address the need for a robust internal QC of proteolytic digestion in targeted MS-based assays, we hypothesized that MRM-MS measurements of undigested extended SIS. For peptide targets of interest that contained PTMs or modified residues, extended SIS peptides were synthesized with the corresponding chemical modifications, including carbamidomethylation of cysteine were generated and used as previously described; many of these are available from the National Cancer Institute’s Antibody Portal search parameters included trypsin enzyme specificity, up to three missed cleavage sites, and variable clipping of N-terminal methionine. Carbamidomethylation of cysteine residues and ProteinProphet, with a false discovery rate set to less than 1% based on the decoy database search. Skyline was used to generate a spectral library for peptides with >90% probability."
] |
PMC10902380
|
Nature Communications
|
A spatial map of hepatic mitochondria uncovers functional heterogeneity shaped by nutrient-sensing signaling
|
28-02-2024
|
In the liver, mitochondria are exposed to different concentrations of nutrients due to their spatial positioning across the periportal and pericentral axis. How the mitochondria sense and integrate these signals to respond and maintain homeostasis is not known. Here, we combine intravital microscopy, spatial proteomics, and functional assessment to investigate mitochondrial heterogeneity in the context of liver zonation. We find that periportal and pericentral mitochondria are morphologically and functionally distinct; beta-oxidation is elevated in periportal regions, while lipid synthesis is predominant in the pericentral mitochondria. In addition, comparative phosphoproteomics reveals spatially distinct patterns of mitochondrial composition and potential regulation via phosphorylation. Acute pharmacological modulation of nutrient sensing through AMPK and mTOR shifts mitochondrial phenotypes in the periportal and pericentral regions, linking nutrient gradients across the lobule and mitochondrial heterogeneity. This study highlights the role of protein phosphorylation in mitochondrial structure, function, and overall homeostasis in hepatic metabolic zonation. These findings have important implications for liver physiology and disease.
|
[
"Mitochondria are highly dynamic organelles that play critical roles in cell physiology, including energy production through oxidative phosphorylation. E-cadherin and CD73 antibodies were used to enrich PP and PC hepatocytes, respectively, and Western blots were performed for validation.",
"Next, PP and PC hepatocytes were subjected to tandem mass tag. Of 5018 proteins identified, 46% were zonated, meaning they had a biased expression toward PP or PC hepatocytes. Pathway analysis highlighted PP and PC-restricted processes consistent with a previous study describing gene expression^(16).",
"The list of quantified proteins was compared with the murine MitoCarta 3.0 database, which consists of 1,140 proteins. We identified 829 mitochondrial proteins, 422 of which were enriched in PP mitochondria and 113 in PC mitochondria. To gain insight into the functions of PP and PC mitochondria, the top 25 unique proteins were selected, and their location and pathway within the mitochondria were determined using MitoCarta 3.0 database. Selected mitochondrial proteins were also validated by immunofluorescence.",
"Proteins enriched in PP mitochondria were primarily localized to the inner membrane or the mitochondrial matrix and were involved in amino acid metabolism or OXPHOS. Thus, we examined the spatial expression of selected OXPHOS proteins and found that PP mitochondria expressed higher levels of nuclear and mitochondrial-encoded OXPHOS components. In contrast, proteins enriched in PC mitochondria localized to the outer and inner mitochondrial membranes and matrix. In addition to regulating mitochondrial structure, dynamics, and contact with other organelles, many of the identified PC proteins are involved in lipid metabolism, detoxification, and carbohydrate metabolism. Notably, citrate synthase.",
"We next performed a functional evaluation of the PP and PC mitochondria to determine their bioenergetic capacity. Intravital microscopy^(21) was used to examine mitochondrial membrane potential in the intact liver of anesthetized mice. Mitochondria were labeled with MitoTracker green and TMRE, with the former labeling mitochondria matrix and the latter indicating membrane potential. TMRE labeled mitochondria in PP regions more intensely, indicating higher membrane potential. Isolated hepatocytes were labeled with Anti-CD73, Anti-E-cadherin antibodies, and JC1, a ratiometric fluorescent reporter of mitochondrial membrane potential. Consistent with the in vivo data, PP cells labeled in suspension had higher mitochondrial membrane potential than PC cells. Together, these data show that PP mitochondria have a higher membrane potential that is not disrupted by spatial sorting, allowing the use of these cells for further physiological evaluation.",
"Subsequently, mitochondrial oxygen consumption rate and substrate preferences were evaluated using the Seahorse XF Analyzer in spatially sorted hepatocytes. PP hepatocytes consumed up to double the amount of oxygen compared to PC cells and had higher maximal respiration. Next, substrate preference was determined by measuring the rate of ATP production in the presence of inhibitors. The capacity of PP mitochondria to produce ATP was significantly decreased by etomoxir, an irreversible inhibitor of fatty acid oxidation, whereas, in PC mitochondria, UK5099, an inhibitor of the mitochondrial pyruvate carrier that inhibits pyruvate-dependent oxygen consumption, negatively impacted ATP production.",
"ATP levels in PP hepatocytes were significantly higher as measured by a luminescent ATP Detection Kit. On the other hand, citrate synthase expression and activity as well as triglyceride. Likewise, lipid droplets. Higher TG levels in PC cells could be the result of lower lipid oxidation, increased lipid uptake, or decreased lipophagy. Alternatively, since high ATP levels inhibit citrate synthase activity^(22 , 23), the lower ATP levels in PC hepatocytes may permit citrate synthase activity and lipogenesis.",
"Consistent with a previous report^(24), mRNA and protein abundance of the lipogenesis-related enzymes Fasn. However, PP hepatocytes displayed higher levels of serine 79 phosphorylation, on acetyl-CoA carboxylase. This implies that the functional specialization of hepatocytes is not only regulated by differential expression but also via phosphorylation.",
"To better understand the spatial organization of mitochondria in the hepatic lobule, we used confocal microscopy to visualize mitochondria in liver sections from mito-Dendra2 mice^(25). Consistent with previous reports^(17 – 20), an apparent dichotomy in mitochondrial architecture was observed along the PP–PC axis, with short, round mitochondria in PP and tubulated mitochondria in PC hepatocytes. The transition between these two phenotypes occurred in the mid-lobular area, with a limited number of cells containing both phenotypes within a single cell.",
"Mitochondrial topology was visualized in 3D and at nanometer resolution with Focused Ion Beam Scanning Electron Microscopy. Next, FIB-SEM volumes of the selected cells were acquired, individual mitochondria segmented, and mitochondrial volumetric models generated. Distinct subcellular organization of the mitochondrial network in different parts of the lobule was apparent. Mitochondria volume and surface area in PP cells were approximately 2-fold greater than those measured in PC cells. The sphericity index also significantly differed between PP and PC, with mean values of 0.93 and 0.74, respectively. The higher mean values in PP hepatocytes indicate a shape closer to a sphere as demonstrated by the round surfaces rendered.",
"Larger mitochondrial volume in PP hepatocytes, together with higher bioenergetic capacity suggests that overall mitochondrial mass is higher in PP regions of the lobule. Lending further support to this idea, mitochondrial DNA copy number, a commonly used method to evaluate mitochondrial mass, was also higher in PP hepatocytes. Mitochondrial structural diversity, including the typical PP and PC morphologies described above, was conserved in the human liver, suggesting a similar structure-function relationship may apply. Taken together, mitochondrial structural variations across the lobule strongly correlate with the functional diversity in lipid oxidation and biosynthesis under normal physiological conditions.",
"Mitophagy, the selective degradation of mitochondria via autophagy, is stimulated in response to various signals, including hypoxia, nutrient deprivation, and glucagon signaling^(28 , 29). In the liver, basal mitophagy is also activated by the daily feeding and fasting cycle^(30 , 31). To evaluate if mitophagy is differentially regulated across the liver lobule, we applied intravital microscopy of mitochondria-targeted Keima in ad-lib-fed mice. The ratio of acidic-to-neutral excitation is a measure of mitophagy and the relative difference between mitophagy in the presence or absence of the protease inhibitor leupeptin, is used to determine mitophagy flux. Tile scans of entire lobules were acquired and ratios of acidic-to-neutral excitation were calculated in selected regions. While in saline-treated mice, mitophagy was consistently higher in PP regions, leupeptin significantly increased mitophagy only in PC hepatocytes, suggesting a higher mitophagy flux in PC regions.. Notably, the increase in mtKeima fluorescence in PP regions was driven by a higher signal in both the neutral and acidic compartments, while in PC regions it was mainly due to an increase in the acidic compartments. Similar trends were obtained with another mitophagy reporter Cox8-EGFP-mCherry^(33). The spatial differences in mtKeima fluorescence intensities in PP and PC regions were not due to variations in mtKeima expression levels.",
"We further tested the spatial differences in mitophagy by evaluating the levels of the mitophagy receptor Bnip3 and the autophagy marker LC3A/B using Western blots. In saline-treated mice, there were higher levels of Bnip3 in PC hepatocytes, and significantly higher levels in mice treated with leupeptin, consistent with higher mitophagy flux in PC regions. On the other hand, the proportion of LC3A/B. Other mitophagy-related proteins were enriched in PC hepatocytes, as previously reported^(34 , 35). Likewise, the lysosomal marker LAMP1 was distributed uniformly across the lobule, while LAMP1-positive lysosomes containing mitochondria were more abundant in PC hepatocytes. Thus, basal mitophagy is higher in PC hepatocytes, which may be driven by the higher expression of mitophagy-related proteins and contribute to the lower mitochondrial mass.",
"Reversible protein phosphorylation has been linked to cellular and mitochondrial metabolism^(6 – 8 , 36 , 37). To examine the role of phosphorylation in regulating mitochondrial spatial heterogeneity and identify signaling pathways that may be involved, we profiled the phosphoproteomes of PP and PC hepatocytes. We identified 7278 phosphopeptides corresponding to 3686 phosphosites in 1623 proteins. The majority of phosphorylation sites were on serine residues. More than half of the proteins had a single phosphorylation site. Interestingly, the overall number of phosphosites with PP or PC zonation was similar, suggesting that ATP availability across the lobule is not limiting in homeostasis.",
"Next, we performed a pathway analysis on zonated phosphopeptides to determine the processes that may be influenced by phosphorylation. In PP hepatocytes, protein translation, metabolism, and positive regulation of autophagy were most notably regulated via phosphorylation. On the other hand, multiple pathways related to lipid and phospholipid synthesis were represented in PC cells. Sequence analysis of phosphorylated peptides using the online tool Momo.",
"We also examined the phosphorylation of mitochondrial proteins, with mitochondrial phosphoproteome shown in the volcano plot and the zonated phosphoproteins for each hepatocyte group summarized in the table. Assessment of upstream regulators/kinases using PhosphoSitePlus highlighted factors such as leptin, insulin, mTOR, and AMPK as major drivers of the zonated phosphorylation. To further examine the role of nutrient sensing in shaping the zonated phosphoproteome, we surveyed all zonated phosphopeptides for putative AMPK and mTOR consensus sites using Group-based Prediction System. However, there was very little overlap in AMPK or mTOR substrates within PP and PC cells. This suggests that although active throughout the lobule, AMPK and mTOR act on different substrates in PP and PC hepatocytes. To further substantiate this, we examined the phosphorylation status of two well-characterized mTOR substrates. Whereas phosphorylation on T389 of Ribosomal protein S6 kinase. Together, these results highlight a potential role for nutrient-sensing signaling in shaping zonated phosphoproteomes.",
"Given the spatial variation in mitochondrial phosphosites, their potential regulation by the nutritional state, and the capacity of mitochondria to respond to nutrient fluctuations^(1 , 8), we hypothesized that nutrient-sensing signaling governs mitochondrial remodeling in hepatocytes. To test this, and decouple protein phosphorylation from transcription, we pharmacologically modulated AMPK or mTOR signaling in vivo and evaluated mitochondrial membrane potential. Drug concentrations for acute response were determined by Western blotting of known downstream effectors. Activation of AMPK. The inhibition of AMPK. On the other hand, the activation of mTOR, significantly increased lipid content in both PP and PC cells, highlighting the spatial coordination of these pathways in lipid homeostasis. Notably, the drugs had an acute effect on the mitochondria, largely independent of cell size underscoring the complex spatial regulation of nutrient-sensitive signaling in the intact liver.",
"Finally, we performed microscopy studies in liver sections to examine if acute modulation of AMPK or mTOR impacted mitochondrial morphology. PC mitochondria from AICAR-treated mice had a round morphology with a higher sphericity index, similar to PP mitochondria in vehicle-treated cells. Conversely, mTOR activation induced dense, elongated mitochondria in PP hepatocytes, with a lower sphericity index resembling the phenotypes observed in PC hepatocytes. These effects were observed in multiple cells in the PP and PC regions as shown in z-stacks. Taken together, the results show that mitochondrial zonation is acutely remodeled in vivo by nutrient-sensing signaling suggesting the nutrient gradient fine-tune mitochondrial metabolic output.",
"Mitochondrial heterogeneity can be established through various mechanisms, including differential gene expression. Overall, these experiments show that acute modulation of nutrient-sensing pathways shifts mitochondrial functions to impact mitochondrial functional diversity. These pathways work in concert with Wnt/β-catenin-regulated genes in determining the mitochondrial proteomes of both PP and PC."
] |
PMC10691617
|
Journal of Applied Clinical Medical Physics
|
Predicting successful clinical candidates for fiducial‐free lung tumor tracking with a deep learning binary classification model
|
11-09-2023
|
Abstract Objectives The CyberKnife system is a robotic radiosurgery platform that allows the delivery of lung SBRT treatments using fiducial‐free soft‐tissue tracking. However, not all lung cancer patients are eligible for lung tumor tracking. Tumor size, density, and location impact the ability to successfully detect and track a lung lesion in 2D orthogonal X‐ray images. The standard workflow to identify successful candidates for lung tumor tracking is called Lung Optimized Treatment (LOT) simulation, and involves multiple steps from CT acquisition to the execution of the simulation plan on CyberKnife. The aim of the study is to develop a deep learning classification model to predict which patients can be successfully treated with lung tumor tracking, thus circumventing the LOT simulation process. Methods Target tracking is achieved by matching orthogonal X‐ray images with a library of digital radiographs reconstructed from the simulation CT scan (DRRs). We developed a deep learning model to create a binary classification of lung lesions as being trackable or untrackable based on tumor template DRR extracted from the CyberKnife system, and tested five different network architectures. The study included a total of 271 images (230 trackable, 41 untrackable) from 129 patients with one or multiple lung lesions. Eighty percent of the images were used for training, 10% for validation, and the remaining 10% for testing. Results For all five convolutional neural networks, the binary classification accuracy reached 100% after training, both in the validation and the test set, without any false classifications. Conclusions A deep learning model can distinguish features of trackable and untrackable lesions in DRR images, and can predict successful candidates for fiducial‐free lung tumor tracking.
|
[
"The CyberKnife robotic radiosurgery system to pregenerated DRRs obtained from the patient CT scan. The target can be localized based on density difference between the tumor and the surrounding lung tissue",
"Lung tumor tracking is clinically desirable to keep target margins to a minimum, while avoiding the risks associated with the fiducial implantation procedure. , However, not all lung tumors can be directly visualized on planar radiographs, and prospectively identifying candidates for fiducial‐free lung tumor tracking is challenging.",
"The visibility of a lung lesion on 2D projection images depends on its size, density, shape, and position relative to the spine or mediastinum. Typically, lung tumor tracking is successful for lesions greater than 1.0–1.5 cm in all dimensions, located in the peripheral region of the lung, and not obstructed by the spine or the heart in the 45º view. Figure shows axial, sagittal, and coronal CT slices of a patient with an upper left lung lesion. The TTV is projected on the DRR to perform the registration based on the tumor intensity, and it is used to visually assess proper target identification. The tumor template DRR is generated by limiting the ray‐tracing projections through a volume of the planning CT around the TTV, thus enhancing the visibility of the tumor, and the ability of the tracking algorithm to identify its location. Registration between tumor template DRR and X‐ray image is performed separately for each view, therefore image A and image B can be analyzed independently. Figure shows, for the same patient, the DRR visible at the treatment console solver was found to perform better than both the adaptive moment estimation"
] |
PMC10949921
|
Frontiers in Microbiology
|
Rhizosphere microbial community enrichment processes in healthy and diseased plants: implications of soil properties on biomarkers
|
29-02-2024
|
Plant health states may influence the distribution of rhizosphere microorganisms, which regulate plant growth and development. In this study, the response of rhizosphere bacteria and fungi of healthy and diseased plants compared to bulk microbes was analyzed using high-throughput sequencing. Plant adaptation strategies of plants under potato virus Y (PVY) infection have been studied from a microbial perspective. The diversity and community structure of bacteria and fungi varied between bulk and rhizosphere soils, but not between healthy and diseased rhizosphere soils. A LEfSe analysis revealed the significant differences between different treatments on bacterial and fungal community compositions and identified Roseiflexaceae, Sphingomonas , and Sphingobium as the bacterial biomarkers of bulk (BCK), healthy rhizosphere (BHS), and diseased rhizosphere (BIS) soils, respectively; Rhodotorula and Ascomycota_unidentified_1_1 were identified as the fungal biomarkers of bulk (FCK) and healthy rhizosphere (FHS) soils. Bacterial networks were found to be more complex and compact than fungal networks and revealed the roles of biomarkers as network keystone taxa. PVY infection further increased the connectedness among microbial taxa to improve rhizosphere microbial community stability and resistance to environmental stress. Additionally, water content (WC) played an apparent influence on bacterial community structure and diversity, and pH showed significant effects on fungal community diversity. WC and pH greatly affected the biomarkers of bacterial rhizosphere communities, whereas the biomarkers of bulk bacterial communities were significantly affected by soil nutrients, especially for Sphingobium . Overall, the rhizosphere microbial community enrichment processes were different between healthy and diseased plants by changing the community compositions and identifying different biomarkers. These findings provide insight into the assemblage of rhizosphere microbial communities and soil physicochemical properties, which contributes to a deeper understanding of the establishment of an artificial core root microbiota to facilitate plant growth and bolstering resistance mechanisms. This knowledge contributes to a deeper understanding of the establishment of an artificial core root microbiota, thereby facilitating plant growth and bolstering resistance mechanisms.
|
[
"Potato virus Y. Upon infection, plants activate their defense mechanisms by producing various resistant substances, including phytoalexin chitinase, peroxidase, and plant antitoxin to enhance their tolerance. Furthermore, the presence of PVY in a host organism leads to the observation of numerous morphological, physiological, and histological alterations. However, the extent to which PVY infection affects the rhizosphere, a critical component of soil-plant interaction, is constrained. Prior studies have provided evidence of the impact of plant diseases or pests on the composition of rhizosphere microbiomes. For instance, the introduction of the downy mildew pathogen to Arabidopsis thaliana leaves induces changes in the microbial communities within the rhizosphere. Similarly, the presence of the western corn rootworm, a pest that inflicts damage on maize plants, results in the proliferation of distinct microbial taxa in the rhizosphere, such as Acinetobacter, Smaragdicoccus , and Aeromicrobium .",
"Plants establish direct contact with numerous microorganisms in the soil through the roots, leading to the observable differentiation between bulk and rhizosphere soils. The rhizosphere effect, a phenomenon in which plant roots attract and accumulate certain microorganisms from the bulk soil, plays a vital role in governing rhizosphere microbial communities. The rhizosphere, functioning as the primary site of soil-plant interaction, typically demonstrates a higher frequency of nutrient exchange and increased microbial activities in comparison to the bulk soil. The observed dissimilarity in microbial communities between the rhizosphere and bulk soil can be ascribed to root exudates, rhizosphere metabolism, and the root system's heightened selectivity. Consequently, the disparities in microbial communities are expected to result in variations in nutrient preferences and metabolic patterns of microbial communities, thereby facilitating the suppression of phytopathogens and bolstering tolerance to environmental stress. Increasing evidence demonstrated the effect of numerous factors on the shifts in microbiomes of rhizosphere and bulk soil, including abiotic factors such as disease and insect pests, soil types, plant species, and climate factors. However, root-rot disease of Zanthoxylum bungeanum trees showed significant changes in the KEGG and CAZy functional profiles of microbiomes between the rhizosphere and bulk soils, rather than microbial diversity and community composition. These feedback explorations about the recruitment of rhizosphere microbes from bulk soil are vital to the ecological functions of terrestrial ecosystems.",
"Limited investigations have been observed regarding the impacts of PVY invasion on the plant microbiome, especially for microbial interactions and community assembly.",
"Recent research has demonstrated that environmental factors, encompassing both biotic and abiotic factors, conventionally govern the equilibrium between stochastic and deterministic assembly processes. It has been ascertained that a harmonized stochastic and deterministic assembly process confers benefits in upholding a diverse ecosystem. Modifications in soil physicochemical properties, such as heightened soil salinity and pH levels, may exert a deterministic impact on the composition of soil bacterial communities. Conversely, optimal soil pH values and diminished salinity content may contribute to the stochastic nature of soil formation. Additionally, it has been observed that disease-induced modifications in plant performance can trigger a series of consequential changes in the rhizosphere environment, thereby significantly impacting the equilibrium between deterministic and stochastic factors within the rhizosphere microbiome. Despite the apparent recognition of this phenomenon, comprehensive testing and examination of its intricacies have been infrequently conducted. It is possible to propose the hypothesis that the invasion of pathogens in the rhizosphere microbiome has a deterministic impact on the compositional variability of said microbiome by altering plant performance. The occurrence of pathogen invasion is frequently accompanied by alterations in the diversity of rhizosphere microorganisms. As a result, it can be deduced that the invasion of pathogens affects the microbial interactions that depend on the particular types and quantities of microorganisms that exist. Moreover, the evaluation of whether the bacterial microbiome of plant roots demonstrates dynamic universality, characterized by consistent interactions between microbes and their surroundings across hosts, or if each individual's microbiota adheres to its own distinct set of principles, is yet to be determined.",
"This study aimed to investigate the response of rhizosphere bacteria and fungi in healthy and diseased plants, as well as the bulk microbe, in relation to microbial diversity, structure, composition, co-occurrence network, and their correlation with soil physicochemical properties. Specifically, this research examined the disparities in.",
"Total DNA of rhizosphere and bulk soil samples. The polymerase chain reaction. In summary, after the elimination of adaptors and primer sequences, the raw sequences were assembled for each sample based on the distinctive barcode. The clean sequences, exhibiting a similarity of 97%, were then allocated to amplicon sequence variants, and their representative sequences were classified using the SILVA reference database. After discarding singletons, the ASVs table was resampled for downstream analysis.",
"The linear discriminate analysis effect size. Initially, a non-factorial parametric Kruskal-Wallis. The network was visualized using Gephi.",
"The community alpha diversity indices, including the Shannon index, species richness, and Pielou's evenness index, were calculated using the vegan package. The differences in alpha diversity indices and soil properties among bulk, healthy rhizosphere, and diseased rhizosphere soils were tested using ANOVA. Principal coordinate analysis. All the plots were visualized using the “ ggplot ” package."
] |
PMC10334940
|
JMIR Dermatology
|
Medicare Opt-Out Trends Among Dermatologists May Reflect Systemic Health Policy: Cross-sectional Analysis
|
0-0-2022
|
Background Provider opt-out of accepting Medicare insurance is a nationally tracked metric by the Centers for Medicare & Medicaid Services (CMS) for all physicians, including dermatologists. Although this usually only consists of a small number of providers, the magnitude of opting out has varied historically, often tracing changes in systemic health care policy. Objective In this paper, we explored dermatologist opt-out data since 2001, as reported by the CMS, to characterize trends and provide evidence that shifts in provider opt-out may represent a potential indicator of the state of health policy and possible needs for reform as it pertains to Medicare. Methods The publicly available Opt Out Affidavits data set, available from the CMS, was evaluated for providers in all dermatologic specialties from January 1, 2001, to May 27, 2022. Results There were a total of 196 dermatology opt-outs in the overall period, with the largest spike being 33 providers in 2016, followed by generally consistent decreases through 2021. In the most recent 12 months of data, the number of new monthly opt-outs from January 2022 to May 2022 was significantly higher than that of the trailing 7 months of 2021 ( P =.03). Conclusions Despite decreasing numbers of dermatologist opt-outs in the late-2010s, 2022 was marked by a significant increase in opt-outs. The reduced acceptance of Medicare by dermatologists may present risks to care access, so it is important to frequently assess physician opt-out data and changes over time.
|
[
"Private contracting with Medicare patients is a practice associated with provider “opt-out” from the federal program, where billing and collecting from Medicare is precluded; although the impact of dermatologist opt-out likely varies based on factors such as practice type, provider density, and population composition, fewer physicians accepting Medicare inherently presents greater risks for care access, especially in remote, low-income, or population-sparse areas [ ].",
"Due to the Medicare program’s role in providing broad access to care, it is important to explore characteristics associated with provider Medicare opt-out and trends over time to assess potential impacts on aspects of care delivery. Although literature on opting out is limited and the practice is infrequent [ , ], trends among provider opt-out may be revelatory of systemic issues such as complex Medicare reimbursement [ ], bureaucratic intricacies, and prolonged accounts receivable periods, which can strain practitioners [ ]. Therefore, assessing national metrics such as Medicare opt-out may also provide insights into health policy and systemic changes that shape Medicare provider participation.",
"This cross-sectional analysis evaluates publicly available data from the Opt Out Affidavits data set available from the Centers for Medicare & Medicaid Services, comprehensive of all 50 states and the District of Columbia. We included all entries for physicians indicating dermatologic specialties over the total available period. In 2021, there were 9 new opt-outs, and there were 10 in the first 5 months of 2022. Considering the most recent 12 months, the number of new monthly opt-outs for the first 5 months of 2022 Reauthorization Act of 2015; although beneficial in promoting patient-centric care, it may be accompanied by a higher risk exposure for providers and additional administrative strain [ ]. Further investigation and provider surveying are needed to determine which specific issues are driving the described patterns in provider opt-out, since it is unclear whether the primary catalyst for provider opt-out is economic, logistic, or administrative factors. Although the reduction in dermatology opt-outs during the late-2010s likely represents a positive shift for patients and providers, the latest data show a significant monthly increase in opt-out providers, which should be monitored to ensure optimal care access for communities. Limitations of this analysis include the lack of commercial insurance opt-out data, absent information on nonphysician provider statuses, and unavailable information around reopting into Medicare or those who retired with opt-out status.",
"In an indirect manner, Medicare opt-out has been previously proposed as a figurative voice for providers to express sentiments about reimbursement policy [ ] and may implicitly represent the impacts of other policy challenges on the state of practice. Additionally, the implications of physician opt-out can be broad, where individuals served by Medicare in certain localities may experience inadequate access to care and poorer health outcomes with increasing provider opt-out. As a result, trends in Medicare opt-out should be followed closely to evaluate possible needs to review or refine systemic dermatologic health policy in favor of both patients and providers."
] |
PMC10629663
|
PLOS Computational Biology
|
Bayesian modeling of the impact of antibiotic resistance on the efficiency of MRSA decolonization
|
0-10-2023
|
Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of morbidity and mortality. Colonization by MRSA increases the risk of infection and transmission, underscoring the importance of decolonization efforts. However, success of these decolonization protocols varies, raising the possibility that some MRSA strains may be more persistent than others. Here, we studied how the persistence of MRSA colonization correlates with genomic presence of antibiotic resistance genes. Our analysis using a Bayesian mixed effects survival model found that genetic determinants of high-level resistance to mupirocin was strongly associated with failure of the decolonization protocol. However, we did not see a similar effect with genetic resistance to chlorhexidine or other antibiotics. Including strain-specific random effects improved the predictive performance, indicating that some strain characteristics other than resistance also contributed to persistence. Study subject-specific random effects did not improve the model. Our results highlight the need to consider the properties of the colonizing MRSA strain when deciding which treatments to include in the decolonization protocol.
|
[
"Staphylococcus aureus colonizes approximately 30% of the population [ ] and is a leading cause of healthcare and community associated infections [ ]. Healthcare-associated infections with MRSA are associated with higher mortality rates as well as increased cost and hospitalization duration compared to infection with methicillin-susceptible S. aureus . MRSA carriers have a higher predisposition for infection with a 35% risk of MRSA infection within one year following colonization [ – ]. The anterior nares are the main reservoir of S. aureus , and the skin, particularly the axilla and groin, and pharynx are also often colonized. The risk of infection is correlated with the extent of colonization, as determined by the number of body sites found to be colonized [ ]. MRSA infections are most often caused by the colonizing strain [ ]. Infection prevention and control strategies include reducing spread by preventing colonization of new individuals as well as decolonization of MRSA carriers.",
"Decolonization reduces carriage rates and subsequent infection by 30% [ – ]. However, the effectiveness of decolonization protocols varies. The extent to which this variation is due to the protocol, the features of the MRSA strains colonizing the study subjects, characteristics of the colonized individuals, and the interaction among these factors has been unclear. Moreover, most studies have lacked appropriate controls and/or have had limited sample sizes [ ]; additionally, most studies of decolonization protocols have had limited if any analysis of the colonizing MRSA strains [ ].",
"The CLEAR to define persistent strains [ ] and formulated a Bayesian mixed effects survival model [ ], where the survival outcome was the clearance of MRSA during a given study interval, and the lack of clearance represented persistent colonization. Resistance to different antibiotics as predicted by Mykrobe predictor [ ] were the covariates in the fixed effects, and the study subject- and strain-specific random effects were included to quantify the impact of other subject and strain related factors on clearance. Our approach was fully Bayesian, which allowed characterization of uncertainty of all quantities of interest and incorporation of prior knowledge [ ].",
"See [ ] for the details of the study protocol. In brief, subjects were selected for the study based on an MRSA positive culture within the hospitalization prior to enrollment, grouping samples by sequence type CHG solution distance and time between consecutive visits to estimate the probability that a pair of isolates collected from a study subject represent the same strain. The SNP distance of 45, estimated by BaeMBac using 10 percent of the education arm data, was used as a threshold to divide the isolates from each subject into strains. The MRSA isolates were primarily from ST5 were excluded because of the small number of samples. Most subjects were colonized with only one strain over the course of the study, but some were colonized with multiple strains.",
"Our goal was to study the clearance of MRSA using survival models. For this purpose, we defined observations the subject was not colonized by the strain at any site. Furthermore, in the strain-specific analysis there may have been multiple colonizing isolates at v _(0) belonging to the same strain, and the covariate corresponding to a certain resistance was defined as present if at least one of these isolates was resistant; in practice, the isolates of the same strain were so closely related that their predicted full resistance profiles were identical in 86% of cases. Second, in a site-specific analysis, clearance of a strain was defined as the absence of the strain at v _(1) on a body site of interest to v _(1) when the strain was known to be resistant to some antibiotics at v _(0). Consequently, an estimated hazard ratio exp ( β ) of 1.5, for example, indicated that a unit increase in the corresponding covariate resulted in a 1.5-fold risk of the clearance.",
"Our observations were either interval- or right censored: observations corresponding to study intervals where the clearance occurred, s = 1, …, S , and ρ _(h), h = 1, …, H , were the the strain- and subject-specific random effects and S and H were the numbers of strains and study subjects, respectively. Functions h ( i ) and s ( i ) specified the subject [ ] for 7500 iterations for the strain-specific models and for 10000 iterations for the site-specific models over four chains. We increased the target average acceptance probability in the presence of divergent transitions as suggested by rstanarm documentation [ ]. We assessed the convergence with R ^ values and by visual inspection of traceplots. The full model included all antibiotics and both strain and study subject random effects. We compared the full model with different random effect configurations using the 10-fold cross-validation. The difference was significant with non-overlapping 95% confidence intervals. In the education arm, there was no difference in the clearance probability between resistant and non-resistant strains. Further, the clearance probability of the non-resistant strains is considerably larger in the decolonization arm than in the education arm, reflecting the overall efficiency of the protocol [ ].",
"We used the 10-fold cross-validation to compare the prediction accuracy of the different random effect combinations. In contrast, including the subject-specific random effects did not improve the model, but instead slightly decreased the elpd value in the education arm. Because this decrease was minor and not significant, we decided to use the complete model to characterize both the strain and study subject random effects in the following section. The estimates for the fixed effects representing the impact of antibiotic resistance types on clearance were approximately the same regardless of whether the study subject random effects were included in the model.",
"In the decolonization arm, the mupirocin resistance coefficient was -2.6. Mupirocin resistance thus was correlated with greater MRSA persistence in the decolonization arm. However, this effect was not observed in the education arm, leading to wide credible intervals.",
"In addition to using the genetic resistance determinants, we analysed phenotypic resistance based on MIC thresholds. We include the comparison of genotypic and phenotypic resistance as a supplementary table. The model is otherwise the same except that a distinction is made between high-level show that increased persistence is associated with high-level mupirocin resistance, but not with low-level resistance in the decolonization arm.",
"There was more variation in the strain random effects than in the study subject random effects in both the decolonization and education arms, which means that antibiotic resistance alone does not fully explain the variability in persistence. Furthermore, the variation in the strain random effects was larger in the education arm than in the decolonization arm. The study subject random effects were small in both arms. However, we note that many subjects were colonized by one strain only and for those cases the effects of the strain and subject are statistically indistinguishable. Sequence type did not correlate with strain random effects.",
"In the decolonization arm, mupirocin resistance was again strongly associated with a reduced rate of clearance. Ciprofloxacin resistance and gentamicin resistance were weakly associated with increased persistence. The variation in the strain random effects was again greater than in the subject random effects. Furthermore, this effect was clearest in the nares, from which most of the samples were obtained.",
"As a sensitivity analysis, we conducted Bayesian logistic regression and Cox porportional hazards, indicating robustness of our approach. We observed some correlation between mupirocin and gentamicin resistance. To account for this correlation, we ran the survival model separately for each antimicrobial, observing that the effect of gentamicin resistance shifted towards zero.",
"We applied Bayesian survival analysis on a dataset of sequenced MRSA samples collected from colonized patients after hospital discharge at given intervals during a follow-up period. Our results showed that mupirocin-resistant MRSA strains were more persistent than non-resistant strains in the decolonization arm, but not in the education only arm. We additionally analyzed the data using high- and low-level phenotypic mupirocin resistance based on MIC values. The results on high-level mupirocin resistance confirmed the findings based on genetic resistance determinants. When we looked at each body site separately, the effect of mupirocin was detected only in the nares, and not in the skin, throat, or wound. Since mupirocin is administered intranasally as part of the decolonization protocol and nares is the most prominent site of MRSA colonization [ ], this result seems expected. However, despite chlorhexidine also being part of the decolonization protocol, chlorhexidine resistance did not seem to be associated with decolonization failure. This could be because chlorhexidine is applied to the throat of the MRSA strain did not seem to be associated with persistence . Including the study subject-specific random effects in addition to the strain-specific effects did not improve the model, in contrast with reports that study subject related factors affect MRSA colonization. However, we note that some strain and subject-specific effects were overlapping (when there was only one strain from one subject), and consequently some subject effects might be explained as part of the strain effects.",
"In future studies, a larger dataset could confirm associations between resistance and persistence that did not reach statistical significance in this study. This could also help to identify in more detail the genetic determinants of persistence that were represented here by the strain-specific random effects. While the random effects for study subjects were not significant in our study, including explicit characteristics of the subjects might add power to find some features that affect persistence. In addition, the use of antibiotics other than those that were part of the protocol during the study period was not considered in this study, but including them as covariates might reveal further insights about the relationship between resistance and persistence.",
"We showed that genetic variants for mupirocin-resistance in MRSA were associated with a large drop in the efficiency of a decolonization protocol that includes intranasal mupirocin. Therefore, alternative decolonization protocols for patients with mupirocin-resistant MRSA colonization should be considered, such as nasal iodophor in place of mupirocin, although mupirocin is a superior treatment of the two in general [ ]. However, we did not see a similar effect for chlorhexidine body and mouth wash, another part of the decolonization protocol, nor for any other antibiotic, which supports chlorhexidine as a reliable component of a skin decontamination protocol even when genetic correlates of chlorhexidine resistance are identified. In general, these findings point to the potential utility of improving the efficiency of decolonization protocols by characterizing an individual’s colonizing strain to determine its resistance profile."
] |
PMC10695375
|
PLOS ONE
|
Effect of pueraria on left ventricular remodelling in HFrEF: A systematic review and meta-analysis
|
04-12-2023
|
Background Heart failure with reduced ejection fraction (HFrEF) is a prevalent cardiovascular disease globally, posing a significant burden on healthcare and society. Left ventricular remodelling is the primary pathology responsible for HFrEF development and progression, leading to increased morbidity and mortality. Pueraria, a traditional Chinese herbal medicine and food, is commonly used in China to treat HFrEF. Accumulating evidence suggests that pueraria can effectively reverse left ventricular remodelling in HFrEF patients. This meta-analysis aims to assess the impact of pueraria on left ventricular remodelling in HFrEF patients. Methods Eight electronic databases, including PubMed, EMBASE, Clinicaltrials.gov, Cochrane Library, Wanfang, CNKI, CQVIP, and CBM were searched for literature from inception to June 2023. All randomized controlled trials (RCTs) using pueraria in the treatment of HFrEF were included. The Cochrane Risk of Bias tool was utilized for RCTs’ methodological evaluation, while Review Manager 5.4.1 was used to analyze the data. Results Nineteen RCTs with a total of 1,911 patients (1,077 males and 834 females) were identified. Meta-analysis indicated that combination medication of pueraria and conventional medicine (CM) was superior to the CM alone in raising left ventricular ejection fraction (LVEF; MD = 6.46, 95% CI , 4.88 to 8.04, P < 0.00001), and decreasing left ventricular end-diastolic diameter (LVEDD; MD = -4.78, 95% CI , -6.55 to -3.01, P < 0.00001), left ventricular end-Systolic diameter (LVESD; MD = -3.98, 95% CI , -5.98 to -1.99, P < 0.00001) and N-terminal pro-brain natriuretic peptide (NT-proBNP; MD = -126.16, 95% CI , -185.30 to -67.03, P < 0.0001). Besides, combination medication improved clinical efficacy rate (RR = 3.42, 95% CI , 2.54 to 4.59, P < 0.00001), 6-min walk test (6-MWT; MD = 65.54, 95% CI , 41.77 to 89.31, P < 0.00001), and TCM syndrome score efficacy (RR = 3.03, 95% CI , 1.57 to 5.83, P = 0.0009). Regarding safety, no difference was observed for adverse events (RR = 0.59, 95% CI , 0.22 to 1.54, P = 0.28). Conclusion The use of pueraria combined with conventional medicine in HFrEF patients has superiority over conventional medicine alone in ameliorating cardiac function and reversing left ventricular remodeling. Moreover, combination medication has no increase in adverse drug events. Given some limitations, more prudence and high-quality clinical trials are needed in the future to verify the conclusions.
|
[
"Heart failure, has gradually increased over the past 30 years. This has placed a significant burden on healthcare and social systems [ ]. Left ventricular is widely used as an adjunctive therapy for the treatment of HFrEF, and it has been verified to enhance efficacy and reduce side effects [ , ]. Of particular research interest is the herb pueraria Ohwi, has been recognized as a homologous medicine and food and is widely used to treat HFrEF in China. It is reported that pueraria and its main bioactive component puerarin can effectively ameliorate cardiac function and reverse LV remodeling [ , ]. Currently, there are only a few clinical trials conducted solely on pueraria for HFrEF [ – ], but there are several trials on CHM compound including pueraria as the main components for HFrEF [ – ]. These trials indicate that pueraria has exhibited positive therapeutic effects on LV remodeling in HFrEF patients. To date, no systematic studies have been conducted on the impact of pueraria on LV remodeling in HFrEF patients. Based on the available trials, we performed this meta-analysis to thoroughly evaluate the clinical efficacy and adverse drug events of pueraria in treating LV remodeling in HFrEF patients.",
"The preferred reporting items for systematic reviews and meta-analysis.",
"Eight electronic databases were systematically searched for literature from inception to June 2023: PubMed, EMBASE, Clinicaltrials.gov, Cochrane Library, Wanfang Database, China National Knowledge Infrastructure Left ventricular ejection fraction random sequence generation method; 2) distribution concealment of randomization scheme; 3) blinding; 4) integrity of outcomes; 5) reporting bias; 6) other bias. After that, the bias risk assessment chart drawn was assessed and graphed using Review Manager 5.4.1 software.",
"Review Manager software, EMBASE participated in the study, and sample sizes ranged from 30 to 100. The control group was given conventional medicine for HFrEF, including diuretics, ACEI, ARB, beta-blockers, spironolactone, and myocardial metabolism-improving drugs, etc. The treatment group received pueraria combined with conventional medicine. Pueraria CHM compounds used in the included studies were Yangxinshi tablets, Getong Tongluo capsules, Dange Wuling powder, Tongyang Lishui decoction, Yiqi Yangyin Tongmai decoction, Xinshuning capsules, Linggui Zhugan decoction, and, Yixintong capsules. The intervention duration ranged from 10 days to 12 months. 18 studies [ – , – ] reported LVEF, 9 studies [ , , , , , , , , ] reported LVEDD, 7 studies [ , , , , , , ] reported LVESD, 15 studies [ – , , , – ]reported clinical efficacy rate, 4 studies [ , – ] reported NT-proBNP, 8 studies [ , , – ] reported 6-MWT, and 4 studies [ , , , ] reported TCM syndrome score efficacy. Among the included studies, 10 studies [ – , , , , – ] reported adverse events, 4 studies [ – , ] of them reported no adverse events occurred. Only 1 study [ ] described the follow-up period.",
"showed the quality assessment result. Only 13 studies [ , – , , – ] reported the randomization method and their random sequences were generated by random number tables. However, 6 studies [ – , , ] did not report the randomization method, so their risk levels were unclear. Blinding and allocation concealment procedures were not described in any of the 19 studies. The risk of other biases was unclear.",
"18 studies [ – , – ] that included 1,811 patients reported LVEF. Due to the high heterogeneity. Subgroup analysis indicated that pueraria oral administration and injection could better elevate LVEF than conventional medicine.",
"9 studies [ , , , , , , , , ] that included 807 patients reported LVEDD. Due to the high heterogeneity. Subgroup analysis indicated that pueraria oral administration could better improve LVEDD.",
"7 studies [ , , , , , , ] that included 597 patients reported LVESD. Due to the high heterogeneity. Subgroup analysis indicated that pueraria oral consumption could better improve LVESD.",
"15 studies [ – , , , – ] that included 1,519 patients reported clinical efficacy rate. Due to the low heterogeneity.",
"4 studies [ , – ] that included 363 patients reported NT-proBNP. Due to the high heterogeneity.",
"8 studies [ , , – ] that included 872 patients reported 6-MWT. Due to the high heterogeneity.",
"4 studies [ , , , ] that included 371 patients reported the TCM syndrome score efficacy. Due to low heterogeneity.",
"Adverse drug events were reported in 10 studies [ – , , , , – ], 4 [ – , ] of which reported no adverse events occurred. 7 studies [ , , , , , ] that included 577 patients reported a total of 6.51%. We analyzed the sources of publication bias by excluding studies one by one. Nevertheless, this method could not completely eliminate publication bias. Thus, we supposed that publication bias rooted in the fact that all included studies were conducted in China.",
"HFrEF remains a major global public health issue and is a leading cause of medical hospital admissions for individuals over the age of 60 [ – ]. While various medications aimed at improving ventricular remodeling and heart failure have been developed, they have not yielded entirely satisfactory results [ – ]. Currently, several drugs have been used clinically to treat LV remodeling, including diuretics, beta-blockers, spironolactone, angiotensin receptor blockers. Subgroup analysis indicated that pueraria combination therapy improved LVEF, regardless of whether puerarin is taken orally or injected. The benefit of pueraria combination therapy in LV remodeling in HFrEF patients was evident regardless of subgroup analysis. This is attributed to pueraria’s active components that can reverse ventricular remodeling [ ]. In addition, we also observed that pueraria combination therapy had betterments in cardiac function [ , , , , , ], more studies would be required to validate the safety of pueraria combination therapy in the treatment of HFrEF in future.",
"This study is the first meta-analysis to evaluate the effect of pueraria on left ventricular remodelling in HFrEF patients. It contributes to guiding clinical medication to ameliorate cardiac function and reverse left ventricular remodeling in HFrEF. By adhering to the PRISMA checklist and Cochrane Handbook, our study draws quantitative conclusions based on scientific and rigorous research. Ultimately, our combined results suggest that pueraria combination therapy can more effectively improve left ventricular remodeling and enhance clinical efficacy in patients with HFrEF.",
"However, several limitations existed in our review. Firstly, not all of the included RCTs described the allocation concealment and blinding methods. This may have resulted in potential selective bias. Secondly, despite our comprehensive search, all the included RCTs in our study were carried out in China. Thus, the findings may not be generalizable. Thirdly, none of the included RCTs used placebos, which is a potential limitation. Therefore, our findings need to be supported by more well-designed RCTs. Fourthly, most of the included studies did not describe the follow-up periods, which may have inadequately evaluated the results. Fifthly, due to the included RCTs were conducted between 2000 and 2022, the diagnostic criteria of different periods were inconsistent, which is a possible limitation. Despite these limitations, our manuscript is the first meta-analysis to assess pueraria combination therapy for left ventricular remodeling in HFrEF patients. It will draw great attention from researchers and doctors to the potential benefits of pueraria combination therapy for HFrEF.",
"According to current evidence, pueraria combined with conventional medicine has superiority over conventional medicine alone in reversing LV remodeling (LVEF, LVEDD, and LVESD), ameliorating cardiac function (6-MWT and NT-proBNP), improving clinical efficacy rate and TCM syndrome score efficacy, as well as good safety in treating HFrEF. However, given some limitations, our conclusion needs to be verified by more high-quality, more prudent clinical studies in the future."
] |
PMC10310041
|
PLOS Computational Biology
|
coiaf: Directly estimating complexity of infection with allele frequencies
|
0-06-2023
|
In malaria, individuals are often infected with different parasite strains. The complexity of infection (COI) is defined as the number of genetically distinct parasite strains in an individual. Changes in the mean COI in a population have been shown to be informative of changes in transmission intensity with a number of probabilistic likelihood and Bayesian models now developed to estimate the COI. However, rapid, direct measures based on heterozygosity or FwS do not properly represent the COI. In this work, we present two new methods that use easily calculated measures to directly estimate the COI from allele frequency data. Using a simulation framework, we show that our methods are computationally efficient and comparably accurate to current approaches in the literature. Through a sensitivity analysis, we characterize how the distribution of parasite densities, the assumed sequencing depth, and the number of sampled loci impact the bias and accuracy of our two methods. Using our developed methods, we further estimate the COI globally from Plasmodium falciparum sequencing data and compare the results against the literature. We show significant differences in the estimated COI globally between continents and a weak relationship between malaria prevalence and COI.
|
[
"This is a PLOS Computational Biology Methods paper.",
"Malaria remains a leading cause of death worldwide—in 2021, there were an estimated 247 million cases and 619,000 deaths around the globe [ ]. Despite the considerable burden of malaria, these numbers represent the substantial global progress made to control malaria in the last two decades. The WHO reports that 2 billion malaria cases and 11.7 million malaria deaths were averted globally from 2000 to 2021 [ ]. The majority of these gains reflect an increase in vector control initiatives [ – ], the development of highly efficacious antimalarial combination therapies [ – ], and improved case management through the deployment of rapid diagnostic tests. Sometimes referred to as multiplicity of infection, although this is generally reserved for infections within the same cell, the COI represents the number of genetically distinct malaria genomes or strains that can be identified in a particular individual. These polyclonal infections may arise from one or both of the following: or. Measures of genetic diversity and the COI are increasingly used for inferring malaria transmission intensity and evaluating malaria control interventions [ ]. Transmission intensity has been shown to impact the contribution of each event towards the generation of within-host parasite genetic diversity [ ]. Superinfection is modulated by the host’s current infections [ ], age, and exposure-acquired immunity [ ]. Additionally, the COI provides a practical approach for identifying monoclonal infections to simplify genomic analyses.",
"Traditionally, the COI was measured in one or a few regions of the genome, relying on the enumeration of the maximal number of haplotypes detected through PCR amplification at genes or markers encoding highly diverse length polymorphisms. Two of the most common markers are the merozoite surface proteins 1 and 2, all sequence reads should be identical, originating from the same parasite strain. However, a combination of each parasite strain, proportional to the strain’s abundance, will contribute to the observed sequence reads in mixed infections. At genetic loci containing variation, there is an increased chance of observing multiple alleles as the number of unrelated parasite strains within an infection increases. Therefore, the likelihood of observing multiple alleles at any locus depends on the number of parasite strains in an infection and the prevalence of genetic polymorphisms in the population.",
"We focus on only biallelic SNPs—the vast majority of loci—and define the major allele as the most prevalent allele in a population. We note that any multiallelic site can be collapsed into a biallelic site, although some information will be lost. Assuming for any individual there are l biallelic loci, we define the population-level allele frequency. We thus write,",
"As the COI increases, the probability of observing a heterozygous locus within an infection also increases. We note that this is the same expression used within the categorical method of THE REAL McCOIL . This is the same outcome as for the THE REAL McCOIL categorical method [ ], and first described in the earlier COIL method [ ].",
"In the Frequency Method, we focus on the expected value of the within-sample minor allele frequency. For the sake of simplicity, the complete derivation has been left to Appendix B in . Briefly, we determine the probability of a particular strain carrying the minor allele and then determine the expected WSMAF by summing over the expected contribution of each strain. We represent the expected value of the within-sample minor allele frequency given that a site is heterozygous as follows:"
] |
PMC10505267
|
Cureus
|
Dengue Infection Triggering Concurrent Thrombotic Thrombocytopenic Purpura in a Case of Chronic Idiopathic Thrombocytopenic Purpura
|
18-08-2023
|
We present a case report detailing the medical history of a 53-year-old female who had a well-established 10-year history of idiopathic thrombocytopenic purpura (ITP). The patient presented with fever and gum bleeding, prompting a series of laboratory investigations. These examinations revealed concurrent thrombocytopenia and hemolytic anemia, alongside a positive test result for serum dengue IgM antibodies. Initial treatment for the patient involved intravenous administration of glucocorticoids and intravenous immunoglobulin. Regrettably, this therapeutic intervention did not yield a favorable response. Subsequent clinical developments, including the onset of generalized tonic-clonic seizures, raised suspicions of thrombotic thrombocytopenic purpura (TTP). A notable diagnostic indicator was the elevated PLASMIC score (platelet count; combined hemolysis variable; absence of active cancer; absence of stem-cell or solid-organ transplant; mean corpuscular volume; international normalized ratio; creatinine), reinforcing the consideration of TTP. To confirm the diagnosis, ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin motifs 13) enzyme levels were assessed and found to be low. Consequently, the patient was diagnosed with TTP. Plasmapheresis was administered, resulting in a positive clinical response after two cycles. Notably, the patient experienced a resolution of thrombocytopenia and hemolytic anemia. Following successful treatment, the patient was discharged with a prescription for immunosuppressants. This case underscores the critical importance of including TTP as a potential differential diagnosis when encountering patients with chronic ITP. TTP is characterized by its acute and life-threatening nature, often deviating from the typical clinical presentation. The application of the PLASMIC score serves as a valuable tool in guiding decision-making processes when TTP is suspected.
|
[
"Thrombocytopenia represents a frequently encountered condition in clinical practice, with a diverse array of underlying causes, encompassing infections, malignancies, and autoimmune disorders. Among the conditions leading to thrombocytopenia, thrombotic thrombocytopenic purpura are categorized as primary ITP, while secondary ITP stems from an array of underlying factors, including infections, autoimmune disorders, primary immune deficiencies, or malignancies [ ]. In contrast, TTP represents a relatively uncommon yet gravely perilous disorder. It arises from an insufficiency of the metalloproteinase ADAMTS13, whereas glucocorticoids assume the foremost role in treating ITP [ ]. Although rituximab finds utility in the management of both ITP and TTP, it does not stand as the initial treatment of choice [ ]. Albeit the co-occurrence of TTP and ITP in a single patient is an infrequent phenomenon, documented occurrences exist within select groups, including pregnancies, acquired immune deficiency syndrome presented with a fever persisting for one week, accompanied by documented temperatures reaching up to 102°F. The patient encountered three episodes of gum bleeding and sought medical attention at a local hospital, where she received a diagnosis of severe anemia and thrombocytopenia. Subsequently, she was admitted, and a routine workup was conducted.",
"Upon physical examination, pallor and an ecchymosis patch on the left shin area were observed. The patient had clear lung sounds, normal jugular venous pressure level was elevated at 2068 IU/L, while plasma and urine hemoglobin tests yielded negative results. Serological tests for HIV, hepatitis B, and hepatitis C were negative, and anti-nuclear antibodies.",
"In consideration of the concurrent dengue infection and previous research indicating instances of dengue-mimicking relapse or progression of underlying hematological disorders, ADAMTS13 enzyme levels were subsequently measured [ ]. These levels indicated 8% of normal activity, thereby confirming the diagnosis of TTP through the revelation of decreased ADAMTS13 enzyme activity. Following the confirmation of the TTP diagnosis, the patient underwent two cycles of plasmapheresis, leading to an improvement in her overall condition as well as positive changes in laboratory parameters such as hemoglobin, platelet count, and ADAMTS13 enzyme levels. Upon resolution of the hemolysis and thrombocytopenia, the patient was discharged and prescribed immunosuppressants along with oral steroids. A subsequent blood count assessment after one month showed a hemoglobin level of 10.9 g/dL and a platelet count of 200,000/mm3, with no recurrence of symptoms.",
"The management of ITP typically involves initiating treatment with high-dose steroids, followed by a tapering dose. Additional treatment options include rituximab, IVIG, or thrombopoietin receptor agonists. In some cases, splenectomy or the use of immunosuppressive agents or antibodies targeting CD40-CD154 may be considered [ ]. Our patient also initially responded well to steroid treatment upon the first diagnosis of ITP.",
"However, when the patient did not exhibit improvement with steroid and IVIG therapy and developed new central nervous system is the recommended first-line therapy for TTP, as it replenishes deficient ADAMTS13 enzyme levels [ ]. Steroids can be used as immunomodulators alongside PEX, targeting ADAMTS13 enzyme autoantibodies [ ]. Plasmapheresis effectively corrected our patient's hemolysis and thrombocytopenia. PEX functions by removing ADAMTS13 enzyme inhibitors, unusually large von Willebrand factor multimers (UL-VWFM), and inflammatory cytokines responsible for the release of UL-VWFM from vascular endothelial cells. Additionally, PEX replenishes ADAMTS13 enzyme and normal-sized vWF multimers, which are crucial for normal hemostasis.",
"Glucocorticoids are commonly included as an adjunct therapy in the management of TTP, expediting recovery by reducing the production of ADAMTS13 enzyme inhibitors, decreasing cytokine production, and mitigating autoantibody-mediated clearance of ADAMTS13 enzyme. According to the 2020 guidelines of the International Society on Thrombosis and Haemostasis (ISTH), glucocorticoids are recommended in combination with PEX as the initial treatment for TTP [ ]. However, it should be noted that glucocorticoid monotherapy is ineffective in managing TTP, as demonstrated by a study where approximately half of the patients who received glucocorticoid monotherapy did not show improvement [ ]. Another study comparing prednisone to cyclosporine in terms of increasing ADAMTS13 enzyme activity and suppressing anti-ADAMTS13 antibodies found that prednisone was superior to cyclosporine [ ]. While glucocorticoid monotherapy is not effective in TTP, it is the first-line treatment for ITP, with ITP patients generally responding favorably to glucocorticoid therapy, as our patient did initially upon being diagnosed with ITP. The addition of rituximab to corticosteroid and PEX therapy has been shown to improve outcomes in refractory TTP [ ].",
"Caplacizumab, an anti-vWF immunoglobulin targeting the A1 domain of vWF, prevents the interaction of vWF with the platelet glycoprotein Ib-IX-V receptor [ ]. The use of caplacizumab in conjunction with standard treatment for acquired TTP has demonstrated promising results, including early recovery of platelet count to normal levels and decreased recurrence rates [ ]. The recombinant ADAMTS13 enzyme is an emerging treatment for congenital TTP and has also been explored for acquired TTP [ ].",
"In our patient's case, she responded well to plasmapheresis, undergoing two cycles, which resulted in improvements in hemoglobin and platelet count, as well as clinical recovery.",
"This case report underscores the significance of considering TTP in patients presenting with thrombocytopenia and microangiopathic hemolytic anemia, particularly when standard ITP treatment proves ineffective, especially in the presence of known triggers like dengue infection, as observed in our case. Timely diagnosis and treatment involving PLEX and immunomodulators can substantially enhance patient outcomes for TTP. Clinicians need to be attentive to the diagnostic complexities associated with TTP, and the possibility of TTP should be contemplated in instances of unexplained thrombocytopenia and microangiopathic hemolytic anemia.",
"It is worth noting that the classic pentad of TTP may not manifest in all patients, thus maintaining a heightened level of suspicion is crucial for those with thrombotic microangiopathy. The use of the PLASMIC score can serve as an adjunct to strengthen the diagnostic consideration of TTP. Moreover, given the heightened association between dengue infection and increased TTP incidence, physicians should remain vigilant about this potential complication. Since TTP is an acute, life-threatening condition, early treatment is imperative, necessitating a high index of suspicion even in rare scenarios."
] |
PMC10674246
|
Sensors (Basel, Switzerland)
|
Aberration Theory of a Flat, Aplanatic Metalens Doublet and the Design of a Meta-Microscope Objective Lens
|
19-11-2023
|
A theoretical approach for reducing multiple monochromatic aberrations using a flat metalens doublet is proposed and verified through ray tracing simulations. The theoretical relation between the Abbe sine condition and the generalized Snell’s law is revealed in the doublet system. Starting from the Abbe aplanat design, minimization conditions of astigmatism and field curvature are derived. Based on the theory, a metalens doublet is semi-analytically optimized as a compact, practical-level meta-microscope objective lens working for a target wavelength. The proposed approach also reveals how to reduce lateral chromatism for an additional wavelength. The design degree of freedom and fundamental limits of the system are both rigorously analyzed in theory and verified through ray tracing simulations. It is expected that the proposed method will provide unprecedented practical opportunities for the design of advanced compact microscopic imaging or sensing systems.
|
[
"Recently, with the rise of the metasurface optics. However, it shows poor non-paraxial imaging performance owing to severe off-axis aberrations. Many studies about compensating longitudinal chromatic aberrations imply that a large chromatic dispersion of high-index dielectric meta-atoms is inherently harmful for the suppression of chromatic aberrations [ , ].",
"On the other hand, several breakthroughs in singlet or doublet metalenses have been proposed to deal with monochromatic aberrations. In a singlet scheme, multiple primary aberrations can be reduced over wide field angles only by introducing a quadratic phase profile rather than a hyperbolic one [ , , ]. It was revealed that the quadratic phase method enables good performance for a low-NA design, and it can be also explained via the Fourier transform property of a paraxial lens in Fourier optics [ , , ]. A few decades ago, D. A. Buralli and G. M. Morris proposed a similar idea of monochromatic imaging using an external front stop and a quadratic phase lens [ ]. However, the application of these methods is restricted to wide-angle photographic lenses rather than high-resolution microscopy. For a greater design degree of freedom and a multi-objective design, metalens doublets combined with additional front stops have been successfully demonstrated for a miniature camera with a near-diffraction limited modulation transfer function and largely suppressed primary aberrations [ , , , , , ]. Since the two seminal papers on metalens doublets by A. Faraon’s and F. Capasso’s groups [ , ], numerous studies on parameter optimizations of the doublet profiles of nanoantenna arrays for various objectives such as achromatism have been successfully achieved [ , , , ].",
"A physical understanding of cascaded metalens systems is lacking despite their significance in potential complex imaging systems designed as hybrid refractive–meta-optics systems. Despite rapid advances in the numerical optimization of optical metalenses, the practical benefits of a profound theoretical understanding of aberration control cannot be neglected. The theoretical design of a meta-optic system can facilitate multi-objective optimization as well as better error management considering manufacturing and mass production compared to brute force optimization with many parameters. It is obvious that cascading additional metalenses to a doublet system would be harmful for optical efficiency, the operation bandwidth, and the manufacturing cost. On the other hand, a singlet provides limited design capability for reducing multiple aberrations. In this context, we conducted a rigorous study on a doublet platform which can not only provide a moderate design degree of freedom but may also have more advantages when hybridized with refractive lenses for high-performance imaging systems [ ].",
"In this paper, the basic design theory of an Abbe aplanat for a flat metalens doublet is proposed and verified. Compared to previous papers suggesting numerical optimization examples of doublets [ , , , , , ], a rigorous theoretical study on ray aberrations is proposed, and a semi-analytical design example of a monochromatic microscope objective lens is suggested. The systematic design enables the compensation of multiple monochromatic aberrations simultaneously, without the help of ray tracing optimization simulations. Moreover, we investigate the achievable lateral achromatic performance of our aplanatic doublet method and the theoretical limit.",
"In the field of classical lens design, Abbe found that in a spherical, aberration-free system, when a parallel ray incident along the optical axis has the same effective focal length regardless of its height, coma is also removed. This condition can be described as ρ 1 / sin u 2 ′ = − f , where ρ 1 is the height of the incident ray, u 2 ′ is the converging angle at the image plane, and f is the effective focal length [ ]. This is known as an Abbe aplanat, and it is required that the principal plane must be a spherical surface of a radius f for a very far object. F. Aieta et al. proposed the theory and design of a spherically curved metalens singlet which has a radius equal to its focal length [ ], but the fact that it must be curved is an obstacle to its practical use. Chen et al. demonstrated a 1× magnification system with a special case in which the intersecting plane is flat [ ]. However, this case of unity magnification is the only exception when the principal plane is flat.",
"In this context, for a more general and practical design, we propose a method using a flat metalens doublet separated by a substrate. It can be used to satisfy the aplanatic condition when the focal length of the system is determined. The phase profiles of two different metalenses are analytically derived via the geometrical ray tracing of the on-axis field in the meridional plane. For simplicity, we adopted a bi-facial doublet scheme on a single quartz wafer substrate [ ]. The metalenses were set to be separated by the substrate, and the first metalens was chosen to be the aperture stop. The proposed theory can also be extended to a cascaded system of two singlets on different substrates. To implement the proposed aplanatic doublet, the relationships between the two phase profiles of the surfaces should be determined. As illustrated in , a ray incident on the first surface with a height ρ1 must intersect with the optical axis at the back focal point with an angle of u _(2′) = sin^(−1)( n _(1) ρ _(1)/ n _(2′) f ) after passing through the two surfaces. Consequently, the height ρ _(2) = L ’tan u _(2′) at the second surface is dependent on both ρ _(1) and L ’ after the first surface can be written with respect to u _(1), and by applying this to the generalized Snell’s law, the phase gradients of each surface can be obtained as follows.",
"A flat metalens doublet consisting of the two correlated phase gradients according to the above equations completely satisfies the Abbe sine condition. Hence, the spherical and coma aberrations of all orders are removed at a design wavelength.",
"The metalens doublet meeting the aplanatic condition suggested in the previous section has aberration-free performance for on-axis objects but still has other off-axis aberrations. In this chapter, we present a method to minimize image blur due to astigmatism and field curvature, which degrade image quality seriously. If astigmatism and field curvature are additionally reduced, the designed doublet can be used for monochromatic microscopy since it is an aberration-corrected objective lens with large magnification. In a doublet satisfying the aplanatic condition, it is possible to calculate the third-order tangential astigmatism by tracing off-axis rays at various angles. The refraction angle of an off-axis ray passing through the r point on the first surface can be determined using Equation, it is necessary to trace the on-axis ray passing through this point and calculate the phase gradient. Following this series of processes, it is possible to determine the height of the off-axis ray on the image surface.",
"The detailed derivation processes can be found in . The height difference of the two marginal rays passing through the edges of the front stop. The optimized phase gradients when the thickness of substrate and back focal length are 15.470 and 8.681 mm, respectively, are fitted as less than an MSE. The resultant design layout is suggested as shown in d. With an effective focal length of 10 mm, the system has diffraction limited performance and an RMS wavefront error of less than λ/30 for entire fields. The field curvature is less than the depth of focus.",
"To the best of our knowledge, this is the first time a doublet phase gradient theory that satisfies both the aplanatic condition and lateral achromatism, the condition between the substrate thickness and back focal length is derived to have the same effective focal length of 10 mm at two different wavelengths"
] |
PMC10689747
|
Scientific Reports
|
Endoscopic gallbladder inside-stenting combined with aspirated lavage for calculous cholecystitis in poor surgical candidates: a prospective pilot study
|
30-11-2023
|
Although long-term stent placement via endoscopic gallbladder stenting (EGBS) reportedly reduces cholecystitis recurrence in patients unfit to undergo cholecystectomy, it can increase the frequency of other late adverse events (AEs) such as cholangitis. This study aimed to examine the feasibility of endoscopic gallbladder inside-stenting (EGB-IS) with lavage and aspiration. This prospective, single-center, pilot study enrolled 83 patients with acute calculous cholecystitis who were poor candidates for surgery. A dedicated catheter with eight side holes was used for lavage and aspiration, and a dedicated single-pigtail stent equipped with a thread was used for EGB-IS. Outcomes such as technical success, clinical success, early AEs, recurrence of cholecystitis, and other symptomatic late AEs associated with EGB-IS with lavage and aspiration were evaluated. The technical and clinical success rates were 80.7% (67/83) and 98.5% (66/67), respectively. The rate of early AEs was 3.6% (3/83). The rate of recurrent cholecystitis was 4.5% (3/66) and that of symptomatic late AEs (besides cholecystitis) was 6.1% (4/66). Consequently, the rate of overall late AEs (cholecystitis plus other events) was 10.6% (7/66). The 1-, 2-, and 3-year cumulative incidence rates of all late AEs were 3.2%, 11.2%, and 18.9%, respectively. EGB-IS with lavage and aspiration for calculous cholecystitis showed promising results in poor surgical candidates. EGB-IS may be useful when EGBS with long-term stent placement is planned, since prevention of cholecystitis recurrence, without a rise in the incidence of other AEs, is anticipated.
|
[
"Calculous cholecystitis is a common disease, for which early surgical cholecystectomy is the standard treatment^(1). However, either percutaneous or endoscopic gallbladder drainage is indicated when emergent surgery cannot be performed in the acute phase due to the patient’s general condition^(2). Even in such cases, the recurrence rate is high if cholecystectomy is not performed after drainage; thus, elective surgery is recommended after improvement in infection, inflammation, and the patient’s general condition^(3 – 8). However, owing to advanced age and/or significant underlying diseases, cholecystectomy may be difficult in some cases, even in the elective setting^(9 , 10).",
"Endoscopic gallbladder stenting. The tip of the catheter is highly tapered to reduce the gap between the catheter and guidewire. Eight side holes with a diameter of 1 mm were created within a length of 25 mm from the tip, allowing aspiration and lavage with high flow.",
"A dedicated 7-Fr, single-pigtail, plastic stent. This stent can be used with both 0.025- and 0.035-inch guidewires, and the tip is highly tapered for good insertability. The stent length, which is the distance from the base of the pigtail part to the distal end, can be set to 90, 110, or 130 mm. A 90-mm long Nylon retrieval thread was attached to the distal end of the stent, so that the stent could be retrieved easily by pulling this thread.",
"A standard duodenoscope. The procedure was performed urgently days.",
"Table depicts the outcomes of EGB-IS with lavage and aspiration. The technical success rate was 80.7%. The frequency of early AEs was 3.6%."
] |
PMC10389688
|
FEMS Microbiology Letters
|
Effect of Holder pasteurization and UV-C irradiation on bacteriophage titres in human milk
|
16-06-2023
|
Abstract Human milk is the optimal nutrition source for infants and contains a complex mix of bioactive compounds and microorganisms. When unavailable, pasteurized donor milk may be provided, particularly to preterm infants. Holder pasteurization (HP) is typically implemented in human milk banks to prevent pathogen transmission. Given the impact of heat on milk bioactives, ultraviolet-C irradiation (UV-C) is an alternative being explored and has demonstrated effective bactericidal activity. In addition to bacteria, milk contains viruses, including primarily bacteriophages (phages) and which likely influence the developing bacterial microbiome of infants. However, the effect of pasteurization on human milk phages is unknown. This study assessed the effect of HP and UV-C on titres of exogenous bacteriophages inoculated into human milk. Ten donor human milk samples were tested in parallel with water controls. Milk samples or water controls were inoculated to a final concentration of 1 × 10 4 PFU/mL (±1 log) each of a thermotolerant Escherichia coli phage (T4) and a thermosensitive Staphylococcus aureus phage (BYJ20) and subjected to HP and UV-C treatments. UV-C inactivated both phages within milk and water controls, however, HP was ineffective against the thermotolerant T4 phages. Initial data suggest that UV-C treatment may eliminate phage with potential to affect preterm infant gut colonization. Further studies should extend this to other phages.
|
[
"Holder pasteurization. While the ability of HP to reduce bacterial numbers in human milk is well characterized, the effect of this treatment on non-bacterial microbes in milk remains understudied with research focused on human pathogens. The effect of HP on milk bacteriophages, with phage diversity being highest in early life. The infant gut phage-ome is initially dominated by prophage, which is derived from maternal sources. Phages modulate human health largely via their effects on the bacterial microbiota. However, despite the role of phages in human health, there is only limited data describing phage dynamics in early life. This is a critical gap, given that early life is a key window for assembly and maturation of gut bacterial populations, with life-long consequences for host health. The study of the infant gut phage-ome is limited by the large portion of uncharacterized viral diversity within infant gut samples, with 70% of infant viral taxa unable to be matched to gut viral databases. Given the predatory relationships between lytic phages and their bacterial hosts, phages may influence early life bacterial colonization patterns.",
"It is not known whether pasteurization of donor milk affects the viability of phages. Importantly, given that phages can be thermotolerant or thermosensitive, HP may have variable effects on different phage populations. Interestingly, data from the dairy industry suggest that milk itself may intrinsically provide thermal protection to phages. In one study of Leuconostoc phages, a 1-minute heat treatment at 70°C on the test phage P808 resulted in a low phage reduction. These data suggest that milk provides thermal protection to some phages, which may indicate that HP may be ineffective against phage.",
"In addition to HP, ultraviolet C. UV-C treatment reduces milk bacterial numbers to a similar extent as HP, but has the additional benefit of preserving many bioactive components of milk, which are destroyed by heating. While the impact of UV-C irradiation on phage titres in human milk is currently unknown, evidence from the dairy industry suggests that UV-C light treatment may be more effective at destroying phages in bovine milk than heat pasteurization.",
"Here, we aimed to characterize the effect of HP and UV-C irradiation on titres of thermosensitive and thermotolerant exogenous phages in human milk.",
"Mothers of infants aged 0–12 months were invited to donate milk samples. Total protein was measured in skim milk in duplicate using the Bradford method. Total solids content was measured by pre-drying samples on a boiling water bath, followed by evaporation and in a drying oven at a temperature of 102°C.",
"Two phages were selected based on their thermostability characteristics and included thermo-resistant dsDNA phage Escherichia coli phage T4 and purified using centrifugal filtration.",
"For each experiment.",
"To assess any potential thermal/UV-C protection that milk may provide for phages, a water control was included alongside each experimental batch. A volume of 800 mL of MilliQ water was inoculated with phages as above and processed in an identical manner to the milk samples.",
"Each milk sample. Briefly, samples were placed into a sterile 500-mL beaker in a sterile laminar flow hood. A germicidal UV-C lamp. Samples were stirred with a magnetic stir bar, there was the possibility that phage titres may be affected by the milk per se , regardless of pasteurization method. To account for this, phage inoculated untreated aliquots of milk and water were stored at room temperature for the duration of each experiment and then titred to assess surviving number of phages. Briefly, double agar overlays were prepared using Tryptic soy agar.",
"HP had little impact on the thermo-resistant phage T4 with titres within 1 log of the inoculated untreated milk and minimal difference in T4 titre was observed between the non-treatment control and HP-treated water samples, noting T4 phage withstood UV-C inactivation in two human milk samples, demonstrating the need for assessment of the impact that pasteurization techniques have on these types of viruses. Here, we demonstrate that phage are differentially impacted by UV-C irradiation and HP of human milk. HP was able to eradicate thermosensitive S. aureus phage; however, the importance of bacteriophages in the early life microbiome is not well understood. A recent analysis of the human milk virome found that 92% of all human milk samples tested had viruses detected and further observed differences in bacteriophages predominance with respect to lactation period, preterm birth, mode of delivery, and infant birth weight. For the safety of preparing donor milk, UV-C treatment is a promising method for inactivation of viruses such as bacteriophages, however, given their abundance in healthy human milk, one might speculate of their role in the early stages of microbiome development. Indeed, vertical transmission of Bifidobacteria phages has been demonstrated from mother to infant via human milk. If bacteriophages play a role in shaping the early life bacterial microbiome, their inactivation by commonly used milk bank pasteurization methods may impact early microbiome establishment in donor milk fed infants. In particular, donor milk is frequently fed to preterm infants, whose gut microbiomes are known to vary from those of full term infants. These infants are particularly vulnerable to bacterial infections, such as E. coli , leading to necrotizing enterocolitis. Faecal filtrate transplants suggest that bacteriophages may play a role in protection from gut bacterial infections. However, the current evidence on bacteriophage populations in human milk and the early life gut is sparse. More work is needed to understand phage–bacteria dynamics in infants.",
"Given that infant gut phage profiles are determined by breastfeeding, and that gut phages modulate the bacterial microbiota and exert direct host effects, we suggest that destruction of milk phages by pasteurization may impact infant health. Indeed, eradication of thermo-sensitive phages in Holder pasteurized donor milk may contribute to the differences seen in the gut microbiome and health outcomes of donor milk fed and mother’s own milk fed infants. The present study highlights that different milk processing techniques can have effects on phage populations. Understanding these effects is an important first step towards examining endogenous milk phages in future studies to further contextualize our findings.",
"While milk phages may act to maintain a balanced infant gut microbiome, phages may also pose a risk to vulnerable preterm infants. In fact, transfer of antimicrobial genes via human milk has been acknowledged, potentially implicating milk phages as mobile genetic elements and a potential source of gene transfer among milk taxa such as Staphylococcus aureus . Therefore, the effects of UV treatment on endogenous bacteria and subsequent prophage induction in human milk is an important topic for future study. Our study provides vital information to enable the field to assess the various parameters that impact the milk microbiome and the potential effects of processing techniques on bacteriophage activity.",
"While previous work in bovine milk suggested that milk provides thermal protection to certain phage, this did not appear to be the case here, potentially due to differences in the physiochemical composition of human and bovine milk. Overall, human milk did not appear to influence the stability of the phages against each treatment as the results from the water controls were not statistically different to those of milk. Milk derivatives such as skim milk have been assessed as microbial cryopreservation agents previously, however, with variable outcomes. It has been suggested that skim milk may affect the fatty acid content of the bacterial cell membranes, which may, in turn, change the viscosity of membranes and help to stabilize cell enzymes. However, in the present study, where whole milk was used, this did not appear to be the case in stress conditions such as heat. Our study further supports this result, with UV-C treatment observed to inactivate both phages used, while HP was only able to inactivate the thermosensitive phage have demonstrated minimal impact of UV-C on milk proteins and bioactive components, including secretory IgA, lactoferrin, and lysozyme. As a result, UV-C treated milk has been shown to induce better weight gain and intestinal health in preterm piglets. This makes UV-C treatment a promising novel pasteurization technique for donor human milk. However, we note that data from studies of human and animal milk suggest that UV-C irradiation may result in lipid oxidation, which may produce undesirable organoleptic effects. Further optimization of UV-C radiance and treatment time may identify a UV-C treatment protocol that eliminates microorganisms while minimizing oxidation and other unwanted effects.",
"The impact of UV-C on bacteriophages has been well studied in general, with early reports of effective use of UV-C to remove Streptococcus lactis bacteriophages from commercial dairy plants. Using a lamp source above rather than submerged within the filtrate, they found that the wattage of the lamp, distance from the sample, and concentration of bacteriophages influenced the time required to inactivate the bacteriophages. In comparison to our methods, the recommended time to destroy all bacteriophages at a titre of 10^(3) PFU/mL of phages, 3 inches from the lamp source. Our study has the benefit of the UV-C lamp being submerged and the steady flow of the solution allowing the entire sample to be directly exposed to the UV-C irradiation, which has resulted in complete inactivation in 18 minutes (average UV-C dosage 1879.2 J/m^(2)). The titre of phages used in the current study was moderate (10^(4) PFU/mL); however, despite the high likelihood of other endogenous phages present naturally within the milk (targeting different hosts), we still observed inactivation of the phages present. To assess the scalability of this approach, future studies may require assessment of various titres.",
"Here, we describe the impact of UV-C compared to HP on phages in human milk. We show that while UV-C irradiation efficiently destroys both thermotolerant and thermosensitive phage, HP is only effective against thermosensitive phage. Our results have broad implications given the potentially beneficial role phages may play in the infant gut microbiome. While exogenous phage were tested in this proof-of-concept study, the effect of UV-C and HP treatment on the endogenous human milk ‘phageome’ should be assessed to better understand the impact of donor milk treatment on the developing infant gut microbiome. In particular, if human milk phage play a role in protecting preterm infants from neonatal necrotizing enterocolitis and other bacterial infections, the impact of donor milk pasteurization techniques on milk phage must be considered."
] |
PMC10856728
|
Molecules
|
Early Diagnosis of Neurodegenerative Diseases: What Has Been Undertaken to Promote the Transition from PET to Fluorescence Tracers
|
04-02-2024
|
Alzheimer’s Disease (AD) and Parkinson’s Disease (PD) represent two among the most frequent neurodegenerative diseases worldwide. A common hallmark of these pathologies is the misfolding and consequent aggregation of amyloid proteins into soluble oligomers and insoluble β-sheet-rich fibrils, which ultimately lead to neurotoxicity and cell death. After a hundred years of research on the subject, this is the only reliable histopathological feature in our hands. Since AD and PD are diagnosed only once neuronal death and the first symptoms have appeared, the early detection of these diseases is currently impossible. At present, there is no effective drug available, and patients are left with symptomatic and inconclusive therapies. Several reasons could be associated with the lack of effective therapeutic treatments. One of the most important factors is the lack of selective probes capable of detecting, as early as possible, the most toxic amyloid species involved in the onset of these pathologies. In this regard, chemical probes able to detect and distinguish among different amyloid aggregates are urgently needed. In this article, we will review and put into perspective results from ex vivo and in vivo studies performed on compounds specifically interacting with such early species. Following a general overview on the three different amyloid proteins leading to insoluble β-sheet-rich amyloid deposits (amyloid β 1–42 peptide, Tau, and α-synuclein), a list of the advantages and disadvantages of the approaches employed to date is discussed, with particular attention paid to the translation of fluorescence imaging into clinical applications. Furthermore, we also discuss how the progress achieved in detecting the amyloids of one neurodegenerative disease could be leveraged for research into another amyloidosis. As evidenced by a critical analysis of the state of the art, substantial work still needs to be conducted. Indeed, the early diagnosis of neurodegenerative diseases is a priority, and we believe that this review could be a useful tool for better investigating this field.
|
[
"Neurodegenerative diseases represent one of the main causes of public health concerns to date, affecting almost 179 million people worldwide and costing more than EUR 800 billion only in Europe [ ]. Alzheimer’s Disease and Aβ_(1–42), while in PD, α-synuclein, while a definitive diagnosis is confirmed only upon a post mortem examination of the patients’ brain. The diagnosis requires the detection of dopaminergic neuron loss, together with the presence of LB and Lewy neurites for PD. NFT and amyloid plaques are instead required to validate the diagnosis of AD [ ]. The diagnostic criteria and methods for other neurodegenerative diseases are even less reliable. CT, as well as in blood vessels in cerebral amyloid angiopathy. Therefore, patients with these conditions show high signals on amyloid PET scans that are similar in pattern to those seen in AD [ , ].",
"Significant advances have been made in amyloidosis imaging so far; however, methods that can help to diagnose and differentiate among patients with neurodegenerative disorders, ideally pre-symptomatically, are still missing. The identification of novel strategies for diagnosis at the incipient stages of Alzheimer’s disease, i.e., before irreversible brain damage or mental decline has emerged, represents one of the most active research areas. Notably, research and clinical findings have highlighted features and biomarkers whose levels significantly change before the onset of early symptoms of these diseases. For example, amyloid beta peptides and protein-misfolding cyclic amplification and phosphorylated Tau technology and mesoscale discovery fluorescent imaging [ ]. Compared to PET and single-photon emission computed tomography.",
"In this review, we aim to provide a general overview of the main achievements in the development of fluorescent probes for the detection of amyloid aggregates in the frame of AD and PD. Since a significant number of reports have already been published for the Aβ_(1–42) peptide [ , , ], this review will firstly show the main advantages and disadvantages of the approaches currently reported for the design of fluorescent probes detecting Aβ_(1–42) toxic oligomers. Afterwards, a discussion in the same regard will be dedicated to the Tau protein, whose detection is still under research investigation, especially for the validation of biomarkers’ outcomes. Finally, a section will be dedicated to α-synuclein, to give the opportunity to the readers interested in fluorescent chemical tools to realize what has been achieved in PD diagnosis to date, and to compare it to that made in AD diagnosis, thus giving the opportunity to take inspiration for future applications in diagnosis. In particular, we focused on three main goals, i.e.,. Fluorescent probes derivatized from styryl scaffold have been proposed [ , , , , ], but even if they were able to cross the blood–brain barrier have allowed for improving the fluorescence properties of NIR probes by increasing the quantum yield possessing the classical push–pull architecture [ , , ]. Despite their high affinity for Aβ aggregates and high metabolic stability, these new probes exhibited a low selectivity between Aβ subspecies, making them unsuitable for monitoring Aβ oligomers at a presymptomatic stage of AD. New natural scaffolds for Aβ imaging agents have been exploited after the observation of their direct interaction with Aβ aggregates. Chalcone derivatives have been reported as PET/SPECT probes for in vivo imaging and proved to specifically stain the Aβ plaques in brain sections from a transgenic AD model mouse. Starting from these results, a series of chalcone derivatives were developed as NIRF probes with improved characteristics, such as plaque affinity and fluorescent properties [ , ]. Despite this, their low micromolar affinity and short excitation/emission wavelength have been presented as a novel scaffold for the future designs of drugs and new diagnostic tools that can target both dense-core and diffuse plaques is one of the most widely used small-molecule organic fluorophores in bioimaging. In the literature, several probes based on BODIPY have been proposed for Aβ imaging, but most of them have not yet been reported to image Aβ in vivo due to a high background signal quenched NIR probe, containing BODIPY as a fluorophore and tetrahydroquinoxaline as a quenching group. This molecule was found to be able to detect both fibrils and oligomers with significant fluorescent switch-on after binding to soluble and insoluble Aβ species. This new quenching strategy allowed for reducing the intrinsic fluorescence of the probe and thus increasing its QY is still now the method of choice for the design of donor–acceptor NIR probes. The strategy for creating larger conjugated systems is based on the hypothesis that this type of molecules could have more potential to bind to Aβ aggregates and plaques. At the same time, this approach has a bad impact on the QY of the probe, because the unbound probe is already highly fluorescent. Therefore, the research in this field is still working on finding a correct balance between the π-conjugation system and the properties of probes [ , , , ]. If the exploitation of diagnostic probes for Aβ fibers and plaques has encountered great research interest in recent years, this is not the case for NIR probes for oligomers binding. A first example is a curcumin-based NIRF imaging probe, which resulted in being unsuitable for in vivo imaging due to its short excitation and emission wavelengths [ ]. Different modifications were designed to have a longer π-conjugation system while preserving the binding affinity [ , ]. Until now, CRANAD-3 is the probe that exhibited the strongest affinity with Aβ monomers, dimers, and oligomers [ ]. However, these curcumin analogs possess a low QY and low selectivity between Aβ subspecies. Specificity was almost achieved after several optimizations of the BODIPY scaffold, which led to the discovery of the BD-Oligo probe. This probe has a high fluorescence enhancement upon incubation with Aβ oligomers, which decreases as more Aβ assembles into fibrils. However, despite its oligomer-sensing ability, this probe suffers from a low binding affinity and short wavelength excitation [ ].",
"The triazole-containing BODIPY-6 and aza-BODIPY are fluorescent dyes showing interactions with soluble and insoluble amyloid aggregates. They have been employed for the co-staining of Aβ in brain tissues and proved to be able to induce a contrasting signal, which can help to monitor the conformational transition of fibrils and oligomers [ , ]. A novel “V-shaped” NIR Aβ oligomer-specific fluorescent probe, PTO-29 [ ], demonstrated good photophysical properties and selective recognition of Aβ oligomers over other Aβs in a solution test and phantom imaging study. PTO-29 also showed good BBB penetration and a low cytotoxicity, and it was successfully employed to image 4-month APP/PS1 mice in vivo. The in vitro fluorescence staining of Aβ oligomers on age-matched Tg mouse APP/PS1 has been also performed with a probe characterized by two electron-donating N,N-diethylaniline recognition groups bonded to a single-boron difluoride bridge azafluvene as the strong electron-withdrawing group [ ]. Finally, a novel fluoro-substituted cyanine probe, F-SLOH, demonstrated a good Aβ oligomer selectivity with a high binding affinity. The selectivity towards the Aβ oligomers in the brain was ascertained by in vitro labelling on tissue sections and in vivo labelling through the systemic administration of F-SLOH in 7-month APP/PS1 double-Tg and APP/PS1/Tau triple-Tg mouse models [ ]. However, to our knowledge, all the listed fluorescent probes have not been studied for their specificity for amyloids associated with specific diseases. Due to their significant aromatic character, it is likely that these types of molecules are not able to discriminate between different amyloid proteins, thus preventing their employment as clinical tools for establishing the early and accurate diagnosis of neurodegeneration in different, but closely related, diseases.",
"Tau is a highly conserved and soluble protein, classified among the so-called “Intrinsically Disordered Proteins” [ ]. Six different Tau isoforms of 352–441 amino acids are currently known, which differ for the presence of zero, Tau can present a reduced affinity for microtubules, resulting in their destabilization [ , , , ]. Moreover, when detached by microtubules, Tau can aberrantly accumulate into the cell cytoplasm, aggregating into toxic multimeric complexes responsible for neuronal cell death [ , ]. Indeed, several clinical and research findings have shown in recent years that aberrant aggregates of Tau participate in the development and progression of a number of neurodegenerative disorders and dementias, collectively named as tauopathies [ , ]. As a consequence, Tau has become a relevant therapeutic target for the development of agents disrupting aberrant aggregates or preventing their formation. However, no drugs have been approved to date for the treatment of tauopathies. Furthermore, Tau PTMs have emerged as potential biomarkers for the early identification and diagnosis of tauopathies, and research endeavors have also been conducted towards their identification in human biofluids, especially by the means of non-invasive techniques [ , , , , , , , ]. Imaging and detection in Tau aggregates is of primary importance, and significant research has also been devoted towards the identification of probes that facilitate the monitoring of different tauopathies; the diagnosis of such diseases is still based on imaging techniques and clinical evaluation is often confirmed only after an examination of patients’ brains [ , , , ]. Several methods are currently available to help in this respect, with positron emission tomography being one of the most employed for neuroimaging deposits of Tau. Indeed, PET presents several advantages for the diagnostic imaging of Tau, including its relatively low invasiveness and a number of already reported molecular probes targeting this protein with a good specificity and affinity, also in vivo [ , ]. Such probes can help to detect abnormal Tau aggregates accumulating in different districts of the human brain, already at the early phases of neurodegeneration. Hence, they represent valuable complementary tools for monitoring tauopathies’ progression [ ]. Moreover, PET imaging might help to differentiate between tauopathies based on different Tau isoforms. One of the first reported Tau tracers is [^(18)F]-FDDNP, which has demonstrated valuable performances in AD monitoring, albeit showing a poor ability to differentiate aggregates of Tau from Aβ-related ones [ ]. In addition, [^(11)C]-PBB3 [ ] has demonstrated being able to differentiate AD patients from healthy controls, and is able to detect Tau aggregates in subjects with dementias not related to Alzheimer’s disease; however, this compound poorly discriminated among Tau/Aβ deposits [ ]. Tau tracers based on a quinoline scaffold, which are also known as “THK compounds”, have also been reported [ , , , , , , , ], demonstrating a significant selectivity for Tau aggregates with respect to Aβ-related ones. Among the first of this class are [^(18)F]-THK-523, [^(18)F]-THK-5105, [^(18)F]-THK-5116, and [^(18)F]-THK-5117. [^(18)F]-THK-523 has also displayed low accumulation in patients’ brains, while [^(18)F]-THK-5105 and [^(18)F]-THK-5117 showed uptakes well correlated with Tau-related disease progression [ , , , , , , ].",
"Later, [^(18)F]-THK5351 demonstrated improved PET imaging performances [ ]. However, it also showed issues related to poor absorption in patients’ brains, concurrently with the administration of monoamine oxidases can be used for diagnosis and monitoring have also been suggested [ , ], as well as its limitations in detecting early-stage Tau pathology [ ]. Notably, FlortaucipirF]-GTP1, [^(18)F]-JNJ069, [^(18)F]-JNJ311, [^(18)F]/[^(3)H]-MK-6240, [^(18)F]/[^(3)H]-PI-2620, [^(18)F]/[^(3)H]-RO-948, with these compounds showing significantly less off-target binding to aggregates and better pharmacokinetic properties. Moreover, several of these compounds showed improved pharmacokinetic properties and the ability to discriminate AD from non-AD tauopathies. Examples in this regard are the compounds [^(18)F]-MK-6240, [^(18)F]-PI-2620, [^(18)F]-RO-948, and [^(18)F]-APN-1607, which showed good performances in discriminating AD from non-AD patients in in vivo PET imaging studies [ , , , ], and also helping to detect low levels of Tau. Altogether, these data can offer insights into the design of compounds targeting Tau aggregates [ , , , ]. The utility of Tau PET tracers for the early diagnosis and monitoring of AD has also been studied in combination with assessments of phosphorylated Tau, providing remarkable results [ ]. However, further research is needed to better assess their utility in clinical settings [ , , ]. In particular, most of the studies reported so far focused on AD and related dementias, and, to a lesser extent, CBD as potential PET tracers have also been conducted [ , ], demonstrating that they might have great potential in radio-labelled neuroimaging for the in vivo early detection of AD. To date, no successful stories focusing on the repositioning of already approved drugs towards Tau PET imaging have been reported. However, these aspects are of particular interest and could suggest novel sources and approaches for rapidly identifying PET tracers for tauopathies investigations. Besides PET, magnetic resonance imaging has also been used to provide insights into AD and tauopathies in different settings [ , ]. Indeed, MRI presents several advantages with respect to PET for Tau imaging. For example, it does not employ ionizing radiation in its assessments. While such techniques show large possibilities of application for studying changes in the brains of patients, approaches and probes based on MRI potentially useful for the molecular imaging of Tau are still under development [ , , , , ]. Indeed, only few studies have reported the use of MRI-based Tau imaging with contrast agents, the majority of them being focused on animal models and employing fluorinated compounds [ ]. One among the first studies reporting the use of a fluorine-19-labeling compound, by the means of fluorine-19 magnetic resonance imaging. Notably, Shiga-X35 showed efficient detection abilities for Tau NFTs, as observed by the means of 19F-MRI imaging in rTg4510 mice, and readily reached the brain after injection, although was gradually excreted with some undesirable accumulation [ ]. However, Shiga-X35 presents a low specificity and selectivity for NFTs and senile plaques, suggesting that further optimization on this scaffold is required. Besides Shiga-X35, an additional MRI probe techniques to analyze MRI-image-related data and other readily available information for predicting the clinical status of patients with neurodegenerative diseases have very recently been proposed and applied for amyloids [ , , , ]. An example of this comes from a very recent study by Lew and colleagues [ ], who reported the development and application of a deep learning approach able to predict the PET-determined amyloid-tau-neurodegeneration, whose fluorescence increases upon binding to Tau aggregates, have been introduced in experimental assays assisting the design of preclinical candidates [ , ]. However, their applicability is restricted only to in vitro experimentations, and they very often require complementary experimental confirmations due to their low binding specificity towards different aggregates. Imaging Tau aggregates in vivo can be challenging due to their structural similarity to the structure of Aβ fibrils; however, fluorescent probes that specifically detect Tau aberrant deposits have been very recently studied [ , , , ]. Among them, we can find the quinoline-based fluorescent probes reported by Elbatrawy et al. [ ], which showed a high selectivity towards Tau aggregates in ex vivo samples from AD brain tissues. Indeed, compounds Q-tau1 and Q-tau4 showed significant binding affinities toward Tau deposits, with selectivity indices of 4.4 and 3.5 over Aβ aggregates, respectively. Moreover, Q-tau4 also showed: that selectively binds to soluble Tau aggregates over mature fibrils [ ]. Of note, this compound was developed starting from the p-FTAA probe reported in 2009 by Åslund and colleagues [ ], which showed a good BBB permeability and different spectral signatures when bound to Aβ or Tau deposits; pTP-TFE was also demonstrated to be cell permeable. As a consequence, this compound represents a promising proof of concept tool for the study of tauopathies’ development and progression [ ]. Later, in 2021, Oh et al. [ ] developed two additional series of thiophene derivatives showing an improved selectivity for Tau aggregates, also in in vitro experiments on SH-SY5Y cells stably expressing GFP-tagged Tau. More recently, in 2022, Soloperto et al. [ ] reported a focused library of eight BODIPY-derived probes, i.e., from BT1 to BT8, inspired by the selective fluorescent probe TAU1. These compounds feature conjugated systems of 13–19 Å length, ending with an electron donor group and characterized by a different polarity. Of note, one of them showed favorable photophysical properties and a high selectivity towards phosphorylated and oligomeric Tau in an in vitro humanized cellular model; the results reported in this study paved the way towards the optimization of compounds potentially aiding in the early diagnosis of neurodegenerative diseases.",
"While the development of fluorescent imaging Tau probes is of primary interest, this field of research is still unfortunately in its infancy. Indeed, most of the fluorescent probes discussed above have been reported only very recently and studied in in vitro assays or ex vivo samples. Therefore, their potential translation into clinical use has yet to be proven. However, considering their potential for the diagnosis and monitoring of tauopathies, future research on fluorescent-based probes of Tau is warranted.",
"In the following paragraph, the current development of fluorescent probes for detecting αSyn aggregation in ex vivo and in vivo systems is presented. A description regarding their selectivity against a specific amyloid or aggregate type is provided in .",
"Anle138b is a pyrazolo bearing 1,3-benzodioxole as a substituent in position 3 and 3-Br-phenyl in position 5. Studies from Fields et al. show that it inhibits the formation and aggregation of αSyn oligomers, without impacting the protein expression and physiological function. Also, the authors demonstrated that it decreases oligomer accumulation, neuronal degeneration, and PD progression in mice [ ]. Interestingly, the anti-aggregation activity of the compound can be correlated to its 1,3-benzodiaxole ring. In cells, the methylene bridge between the oxygens might be disrupted, thus leading to two free hydroxyl groups. Although this could be the basis for the interaction with αSyn, experimental data are needed to prove it. Notably, other experiments showed that its efficacy in disrupting oligomeric aggregates was due to the ability of intercalating among the β-sheets structures, present in the core of these species [ ]. Finally, its efficacy was also proven against Tau and amyloid β aggregates [ ]. In addition to inhibiting αSyn oligomerization, anle138b showed significant fluorescence enhancement at around 345 nm after binding to αSyn oligomers and fibrils. Interestingly, anle138b was able to interact and bind αSyn fibrils with a K_(d) value of 190 ± 120 nM. When the binding with αSyn fibrils took place, an anle138b fluorescence increase occurred around 335 nm and was correlated with the decrease in the red wing fluorescence at λ > 385 nm [ , ]. Due to the promising anti-aggregation activity of the compound, as well as its ability to bind αSyn aggregates and displaying a strong fluorescence shift upon binding, anle138b provided a new possibility for the early diagnosis of PD. In particular, anle138b was proposed as a probe for the in vivo detection of retinal αSyn deposition in combination with confocal scanning laser ophthalmoscopy as a non-invasive technique to spot early αSyn aggregation. However, some limitations have hampered its development as an αSyn fluorescent probe in non-invasive in vivo detection. The main limits are the moderate affinity for αSyn aggregates, together with the lack of affinity regarding amyloid species presented an excitation/emission profile in chloroform of 559/727 nm. Upon binding with αSyn aggregates, PP-BTA-4 presented a considerable fluorescent shift to 682/782 nm. Furthermore, this compound showed a high binding affinity for αSyn aggregates in vitro with a K_(d) value of 48 ± 0.6 nM. As the background autofluorescence was low in the near-infrared region aggregates in vitro and in ex vivo samples, as well as amyloid specificity. First, a good affinity and molecular weight.",
"Ten years ago, Bagchi et al. synthesized phenothiazine derivatives able to selectively bind to αSyn fibrils [ , ]. Among them, SIL23 was the one displaying a moderate affinity for αSyn fibrils, but had a high selectivity versus Aβ and tau. By radio-synthesis, the researchers eventually converted the compound into [^(125)I]SIL23 to create a radiolabeled probe. In vitro binding assays showed that [^(125)I]SIL23 could bind to αSyn aggregates in human PD brain homogenates with a K_(d) value of 143 ± 24 nM. Also, the compound was able to recognize αSyn in transgenic PD miceC]SIL5 and [^(18)F]SIL26 [ ]. Ex vivo biodistribution studies in rats showed that both [^(11)C]SIL5 and [^(18)F]SIL26 could penetrate the BBB and demonstrated appropriate washout kinetics. However, [^(18)F]SIL26 was the compound showing the lowest brain uptake, namely a 0.758 ± 0.013% injected doseF labeled tracer. This molecule, namely [^(18)F]46a, displayed a high affinity for αSyn fibrilsF]46a is one of the probes with the greatest affinity for αSyn fibrils [ ]. However, when authors tested the capacity of the compound to stain αSyn fibrils in PD brain slices, they could not obtain a reliable quantification of the detected aggregates. This is probably due to the high log p valueF]46a was not suitable for serving as a PET radiotracer [ ].",
"Radiolabeled diphenyl derivatives were synthesized a few years ago by Ono et al., with the aim of developing αSyn aggregates ligands [ ]. Among them, [^(125)I]IDP-4 displayed the highest affinity for αSyn aggregates at K_(d) values of 5.4 ± 1.5 nM with a 3-fold selectivity versus Aβ aggregates. Another good hit was [^(125)I]IDP-3, which was able to bind to αSyn with a K_(d) value of 23.3 ± 2.8 nM, as displayed by in vitro binding saturation assays [ ]. Notably, fluorescent staining of PD brain sections showed that both compounds could bind to αSyn aggregates in LBs. However, ex vivo biodistribution in mice showed that [^(125)I]IDP-4 and [^(125)I]IDP-3 were characterized by a low brain intake. Therefore, neither compound was suitable for in vivo αSyn imaging [ ]. Nevertheless, their capacity to bind to LBs αSyn aggregates opened the possibility of further chemical modifications on the diphenyl core, which may lead to an increased brain uptake and possible development as a PET imaging probe.",
"More recently, Verdurand et al. synthesized the benzoxazoles derivatives 2FBox and 4FBox to selectively recognize αSyn fibrils [ ]. The compounds were then radiolabeled with ^(18)F to assess their suitability as radiotracers. As displayed by in vitro saturation filter binding assays, [^(18)F]2FBox displayed the highest affinity for αSyn recombinant fibrils and αSyn aggregates in the other mice models [ , ]. To obtain more insights on the activity of those candidates towards amyloid aggregates’ detection, the authors carried out imaging experiments on post mortem brain sections could detect Aβ_(1–42) and αSyn aggregates, while in vivo PET imaging of rats showed that the compounds could cross the BBB with a good initial brain uptake but failed to detect amyloids fibrils in the fibril-injected rats. Due to these limitations, namely amyloid non-selectivity and a lack of aggregate detection ex vivo and in vivo, [^(18)F]2FBox and [^(18)F]4FBox were not suitable as PET radiotracers for αSyn [ ].",
"Anle253b is a diphenyl pyrazole sharing a similar structure with that of anle138b [ ], identified by Maurer et al. as a possible PET tracer. Bearing an accessible methyl group, the compound was suitable for ^(11)C methylation; thus, it was selected and screened as a PET imaging probe. Interestingly, anle253b bound to αSyn fibrils with an IC_(50) value of 1.6 nM. This very good affinity profile pushed the authors to perform in vivo PET studies in healthy rats [ ]. These experiments showed that [^(11)C]anle253b could cross the BBB with medium brain uptake and was distributed homogeneously in the rat brain. However, data regarding its uptake dynamics, as well as selectivity versus other amyloid aggregates, have yet to be collected and optimized. In particular, the compound displayed a high lipophilicityH and ^(11)C [ ]. Thus, the researchers carried out a series of in vitro and in vivo biological evaluation studies with both [^(11)C]MODAG-001 and [^(3)H]MODAG-001. In particular, [^(3)H]MODAG-001 displayed an impressive high binding affinity for αSyn fibrils in vitro, with a Kd value of 0.6 nM. Furthermore, it showed a 30-fold selectivity over Tau and Aβ_(1–42) aggregates [ ]. Additionally, [^(11)C]MODAG-001 was able to efficiently penetrate the mouse brain-[^(11)C]MODAG-001 as a possible PET tracer, the researchers carried out in vitro autoradiography in LBD showed a high affinity towards αSyn fibrilsF]BQ-2 and performed biodistribution studies in vivoF]BQ-2 was primarily retained in the brainF]BQ-2 was not a suitable PET probe for imaging αSyn aggregates in PD patients’ brains.",
"In comparison with fluorescent probes developed for the imaging of αSyn in ex vivo and in vivo samples, the research on radiolabeled probes has taken several steps forward. In fact, [^(125)I]IDP-3 and [^(125)I]IDP-4 were able to stain αSyn in LB ex vivo samples, while other candidates like [^(3)H]MODAG-001 and [^(18)F]46a were characterized by a potent affinity for αSyn fibrils [ , , ]. Furthermore, most of the compounds discussed in this paragraph were able to cross the BBB and spread homogenously in the brains of in vivo models. However, no suitable radiolabeled probe has yet been obtained for αSyn imaging. The main limits are represented by a low brain uptake, low amyloid selectivity, chemical instability, and low affinity for specific αSyn species [ ]. As a result, more efforts are required to develop a suitable compound able to be exploited as an αSyn imaging probe [ ]."
] |
PMC10168292
|
Frontiers in Bioengineering and Biotechnology
|
Active exoskeleton reduces erector spinae muscle activity during lifting
|
25-04-2023
|
Musculoskeletal disorders (MSD) are a widespread problem, often regarding the lumbar region. Exoskeletons designed to support the lower back could be used in physically demanding professions with the intention of reducing the strain on the musculoskeletal system, e.g., by lowering task-related muscle activation. The present study aims to investigate the effect of an active exoskeleton on back muscle activity when lifting weights. Within the framework of the study, 14 subjects were asked to lift a 15 kg box with and without an active exoskeleton which allows the adjustment of different levels of support, while the activity of their M. erector spinae (MES) was measured using surface electromyography. Additionally, the subjects were asked about their overall rating of perceived exertion (RPE) during lifting under various conditions. Using the exoskeleton with the maximum level of support, the muscle activity was significantly lower than without exoskeleton. A significant correlation was found between the exoskeleton’s support level and the reduction of MES activity. The higher the support level, the lower the observed muscle activity. Furthermore, when lifting with the maximum level of support, RPE was found to be significantly lower than without exoskeleton too. A reduction in the MES activity indicates actual support for the movement task and might indicate lower compression forces in the lumbar region. It is concluded that the active exoskeleton supports people noticeably when lifting heavy weights. Exoskeletons seem to be a powerful tool for reducing load during physically demanding jobs and thus, their use might be helpful in lowering the risk of MSD.
|
[
"Musculoskeletal disorders. Work-related means that they are caused or at least worsened by work or the immediate work environment. More than half of the European workers suffer from some form of MSD. Back pain is the most commonly reported one. The aetiology of MSD seems to be multifactorial. Occupational factors are one relevant element and according to estimates, about 37% of non-traumatic low back pain can be attributed to them. Among others, lifting objects is one of the physical factors at the workplace that is assumed to have a causal relationship with back pain. Still, about a third of the workers in the EU have to carry or move heavy loads during a quarter or more of their working time. In addition to employers’ responsibility towards the health of their employees, MSD result in high costs for companies, which is why preventive actions should not only be in the interest of the workers concerned but also in the interest of the employers. In Germany, for example, MSD and connective tissue disorders were estimated to be responsible for 17.2 billion euros in loss of production only based on labour costs in 2016. The demographic change and the growing shortage of skilled workers exacerbate the situation at the workplace and increase the significance of the challenge to keep employees healthy in the work process for as long as possible.",
"A potential tool to reduce the load in physically demanding jobs might be mechanical structures worn on the human body to support the musculoskeletal system of the user during certain movements and postures, so-called exoskeletons. Exoskeletons can be divided regarding the body segments they support. Possible fields of application are especially where automation is not yet feasible, among others due to the flexibility required within the scope of the tasks which have to be performed.",
"To assure that the use of industrial exoskeletons is in favour of the health and contentment of the workers, the evaluation of exoskeletons is a major step. The research interest in this field is considerably growing, which is evident from the substantial increase in related publications within the last few years. A parameter often considered in common biomechanical investigations is muscle activity measured via electromyography. When using an exoskeleton, a reduction in muscle activity in the intended area is generally interpreted as a relief and thus as a confirmation of the functioning of the respective exoskeleton. Regarding exoskeletons for supporting the lower back, which are mainly designed for dynamic lifting and static holding activities, according to a review from To examine the relationship between the exoskeleton’s support level and the MES activity, percentage differences relative to lifting without exoskeleton were calculated for each subject. For this purpose, the non-normalized RMS values [mV] were used and compared, resulting in relative differences. On average, the use of the exoskeleton yielded a reduction of the MES activity by 8%–22% with increasing support levels compared to lifting without exoskeleton. However, with low levels of support, a few individuals also experienced increased MES activity. Accordingly, only the data of 13 subjects were included for the affected levels as a strong significant correlation can be seen regarding the mean values. A clear downtrend in perceived overall exertion with an increasing level of support can be seen in general. Comparing the results regarding the RPE under the three main lifting conditions using the Friedman test, a main effect can be found and thus confirm their generally supportive effect. As the present work is the first to solely focus on examining the impact of the Cray X exoskeleton. Therefore, the most suitable studies seem to be those considering dynamic lifting movements too. However, unlike the Cray X, it is at a prototype status and not commercially available. Since there are no studies with an active exoskeleton where the effect of changing the level of support has been evaluated, no direct comparison of the current results with the state of research is possible. However, analogies can be found in a study conducted by Furthermore, based on our results, we might assume that the observed reduction in MES activity may lead to a decrease in the MES force required for the lifting movement. We did not perform kinematic measurements of the lifting movement in this study. However, due to the same range of motion, where f _(v) is the parameter for the force-velocity relation, f _(l) is the parameter for the force-length relation and F _(im) is the maximum isometric muscle force. If the parameters F _(im) , f _(l) and f _(v) remain unchanged, a reduction in muscle activation A leads to a reduction in muscle force. We are aware that this is just a first approximation and that further studies are necessary to measure the activation of all the muscles involved in the movement and analyse the kinematics of movement to, among others, make more precise statements about muscle force, e.g., using inverse dynamics in combination with multi-body models. If the necessary muscle strength is reduced by providing a supportive torque when lifting, the mechanical load on the spine might be reduced. Since cumulative mechanical loading of the lower back is associated with low back pain, the exoskeleton could be useful in preventing MSD. Lastly, next to a reduction in MES activity, we generally observed a decrease in the rate of perceived exertion with an increasing support level of the exoskeleton, resulting in a significantly lower RPE when lifting with the active exoskeleton. As the feeling of exertion can have multiple sources, the amount of MES activity does not solely determine the RPE. For example, , examining the perception of exertion during the target-oriented use of multiple different exoskeletons. At this point, it might also be assumed that the muscular relief which was found for the MES in our study is present in other muscle groups too, explaining the perception is that distinct. Even though the MES is the most frequently investigated muscle when looking at the muscular effects of back-supporting exoskeletons, the restriction to only this specific muscle is a limitation of our study. In future studies, other muscles should be taken into account to enable more general statements about the muscular effects of exoskeleton use. At this point, it should also be mentioned that despite the short familiarization period at the beginning of the study, the results only reflect the acute muscular effects of using a back-supporting exoskeleton in rather unexperienced users who had little to no expertise in using an exoskeleton. It might be assumed, for instance, that more experienced participants would have been more engaged with the exoskeleton and its supportive mode of action, which in turn may have manifested in even clearer results. Apart from that, the perception of comfort or discomfort might have influenced the RPE results. Unfortunately, we did not record the parameter comfort. We only can state that none of the subjects actively reported any discomfort resulting from the exoskeleton’s assistance during the conduct of the study on their own. However, this does not necessarily mean that the level with the highest reduction in MES activity or perceived exertion is also the one they would actually prefer for real usage. At the workplace, users would probably select the level of support most suitable for the given conditions (e.g., weight to be lifted, body weight) based on a balance of comfort and reduction of exertion. Thus, subsequent investigations should vary the requirements (e.g., use different loads) and additionally examine how comfortable the assistance resulting from the different support levels is perceived by the subjects. In this study, the effect of the commercially available active exoskeleton Cray X (4th generation) on the MES activity and RPE during lifting has been analysed. As many of the so far evaluated exoskeletons in literature are still at a prototype or early experimental stage, especially regarding active systems, and the exoskeleton market as a whole is still rather young, the results of our study could have an impact on the actual on-site use and acceptance of exoskeletons in commercial companies. We found a significant reduction (approx. 22%) in MES activity when using the exoskeleton with maximum support level compared to lifting without exoskeleton. Regarding the RPE values, a significant reduction could be observed as well. MES activity and subjectively perceived exertion decreased, with an increase in the exoskeleton’s level of support. Thus, the exoskeleton seems to actively support the user noticeably when lifting heavy weights. However, no general recommendations can be made regarding the support level, even though the maximum level of support seems appropriate for the setup we have chosen, as the given conditions (e.g., load to be lifted, body weight, personal preferences) likely play a role here and therefore should always be taken into account. This once again highlights the significance of the control system of exoskeletons and how important the adjustability of the assistance is in order to facilitate versatile application.",
"To examine the relationship between the exoskeleton’s support level and the MES activity, percentage differences relative to lifting without exoskeleton were calculated for each subject. For this purpose, the non-normalized RMS values [mV] were used and compared, resulting in relative differences. On average, the use of the exoskeleton yielded a reduction of the MES activity by 8%–22% with increasing support levels compared to lifting without exoskeleton.",
"However, with low levels of support, a few individuals also experienced increased MES activity. Accordingly, only the data of 13 subjects were included for the affected levels as a strong significant correlation can be seen regarding the mean values.",
"A clear downtrend in perceived overall exertion with an increasing level of support can be seen in general. Comparing the results regarding the RPE under the three main lifting conditions using the Friedman test, a main effect can be found and thus confirm their generally supportive effect.",
"As the present work is the first to solely focus on examining the impact of the Cray X exoskeleton. Therefore, the most suitable studies seem to be those considering dynamic lifting movements too. However, unlike the Cray X, it is at a prototype status and not commercially available. Since there are no studies with an active exoskeleton where the effect of changing the level of support has been evaluated, no direct comparison of the current results with the state of research is possible. However, analogies can be found in a study conducted by Furthermore, based on our results, we might assume that the observed reduction in MES activity may lead to a decrease in the MES force required for the lifting movement. We did not perform kinematic measurements of the lifting movement in this study. However, due to the same range of motion, where f _(v) is the parameter for the force-velocity relation, f _(l) is the parameter for the force-length relation and F _(im) is the maximum isometric muscle force. If the parameters F _(im) , f _(l) and f _(v) remain unchanged, a reduction in muscle activation A leads to a reduction in muscle force. We are aware that this is just a first approximation and that further studies are necessary to measure the activation of all the muscles involved in the movement and analyse the kinematics of movement to, among others, make more precise statements about muscle force, e.g., using inverse dynamics in combination with multi-body models. If the necessary muscle strength is reduced by providing a supportive torque when lifting, the mechanical load on the spine might be reduced. Since cumulative mechanical loading of the lower back is associated with low back pain, the exoskeleton could be useful in preventing MSD. Lastly, next to a reduction in MES activity, we generally observed a decrease in the rate of perceived exertion with an increasing support level of the exoskeleton, resulting in a significantly lower RPE when lifting with the active exoskeleton. As the feeling of exertion can have multiple sources, the amount of MES activity does not solely determine the RPE. For example, , examining the perception of exertion during the target-oriented use of multiple different exoskeletons. At this point, it might also be assumed that the muscular relief which was found for the MES in our study is present in other muscle groups too, explaining the perception is that distinct. Even though the MES is the most frequently investigated muscle when looking at the muscular effects of back-supporting exoskeletons, the restriction to only this specific muscle is a limitation of our study. In future studies, other muscles should be taken into account to enable more general statements about the muscular effects of exoskeleton use. At this point, it should also be mentioned that despite the short familiarization period at the beginning of the study, the results only reflect the acute muscular effects of using a back-supporting exoskeleton in rather unexperienced users who had little to no expertise in using an exoskeleton. It might be assumed, for instance, that more experienced participants would have been more engaged with the exoskeleton and its supportive mode of action, which in turn may have manifested in even clearer results. Apart from that, the perception of comfort or discomfort might have influenced the RPE results. Unfortunately, we did not record the parameter comfort. We only can state that none of the subjects actively reported any discomfort resulting from the exoskeleton’s assistance during the conduct of the study on their own. However, this does not necessarily mean that the level with the highest reduction in MES activity or perceived exertion is also the one they would actually prefer for real usage. At the workplace, users would probably select the level of support most suitable for the given conditions (e.g., weight to be lifted, body weight) based on a balance of comfort and reduction of exertion. Thus, subsequent investigations should vary the requirements (e.g., use different loads) and additionally examine how comfortable the assistance resulting from the different support levels is perceived by the subjects.",
"Since there are no studies with an active exoskeleton where the effect of changing the level of support has been evaluated, no direct comparison of the current results with the state of research is possible. However, analogies can be found in a study conducted by Furthermore, based on our results, we might assume that the observed reduction in MES activity may lead to a decrease in the MES force required for the lifting movement. We did not perform kinematic measurements of the lifting movement in this study. However, due to the same range of motion, where f _(v) is the parameter for the force-velocity relation, f _(l) is the parameter for the force-length relation and F _(im) is the maximum isometric muscle force. If the parameters F _(im) , f _(l) and f _(v) remain unchanged, a reduction in muscle activation A leads to a reduction in muscle force. We are aware that this is just a first approximation and that further studies are necessary to measure the activation of all the muscles involved in the movement and analyse the kinematics of movement to, among others, make more precise statements about muscle force, e.g., using inverse dynamics in combination with multi-body models. If the necessary muscle strength is reduced by providing a supportive torque when lifting, the mechanical load on the spine might be reduced. Since cumulative mechanical loading of the lower back is associated with low back pain, the exoskeleton could be useful in preventing MSD. Lastly, next to a reduction in MES activity, we generally observed a decrease in the rate of perceived exertion with an increasing support level of the exoskeleton, resulting in a significantly lower RPE when lifting with the active exoskeleton. As the feeling of exertion can have multiple sources, the amount of MES activity does not solely determine the RPE. For example, , examining the perception of exertion during the target-oriented use of multiple different exoskeletons. At this point, it might also be assumed that the muscular relief which was found for the MES in our study is present in other muscle groups too, explaining the perception is that distinct.",
"Furthermore, based on our results, we might assume that the observed reduction in MES activity may lead to a decrease in the MES force required for the lifting movement. We did not perform kinematic measurements of the lifting movement in this study. However, due to the same range of motion, where f _(v) is the parameter for the force-velocity relation, f _(l) is the parameter for the force-length relation and F _(im) is the maximum isometric muscle force. If the parameters F _(im) , f _(l) and f _(v) remain unchanged, a reduction in muscle activation A leads to a reduction in muscle force. We are aware that this is just a first approximation and that further studies are necessary to measure the activation of all the muscles involved in the movement and analyse the kinematics of movement to, among others, make more precise statements about muscle force, e.g., using inverse dynamics in combination with multi-body models. If the necessary muscle strength is reduced by providing a supportive torque when lifting, the mechanical load on the spine might be reduced. Since cumulative mechanical loading of the lower back is associated with low back pain, the exoskeleton could be useful in preventing MSD.",
"Lastly, next to a reduction in MES activity, we generally observed a decrease in the rate of perceived exertion with an increasing support level of the exoskeleton, resulting in a significantly lower RPE when lifting with the active exoskeleton. As the feeling of exertion can have multiple sources, the amount of MES activity does not solely determine the RPE. For example, , examining the perception of exertion during the target-oriented use of multiple different exoskeletons. At this point, it might also be assumed that the muscular relief which was found for the MES in our study is present in other muscle groups too, explaining the perception is that distinct.",
"Even though the MES is the most frequently investigated muscle when looking at the muscular effects of back-supporting exoskeletons, the restriction to only this specific muscle is a limitation of our study. In future studies, other muscles should be taken into account to enable more general statements about the muscular effects of exoskeleton use. At this point, it should also be mentioned that despite the short familiarization period at the beginning of the study, the results only reflect the acute muscular effects of using a back-supporting exoskeleton in rather unexperienced users who had little to no expertise in using an exoskeleton. It might be assumed, for instance, that more experienced participants would have been more engaged with the exoskeleton and its supportive mode of action, which in turn may have manifested in even clearer results.",
"Apart from that, the perception of comfort or discomfort might have influenced the RPE results. Unfortunately, we did not record the parameter comfort. We only can state that none of the subjects actively reported any discomfort resulting from the exoskeleton’s assistance during the conduct of the study on their own. However, this does not necessarily mean that the level with the highest reduction in MES activity or perceived exertion is also the one they would actually prefer for real usage. At the workplace, users would probably select the level of support most suitable for the given conditions (e.g., weight to be lifted, body weight) based on a balance of comfort and reduction of exertion. Thus, subsequent investigations should vary the requirements (e.g., use different loads) and additionally examine how comfortable the assistance resulting from the different support levels is perceived by the subjects.",
"In this study, the effect of the commercially available active exoskeleton Cray X (4th generation) on the MES activity and RPE during lifting has been analysed. As many of the so far evaluated exoskeletons in literature are still at a prototype or early experimental stage, especially regarding active systems, and the exoskeleton market as a whole is still rather young, the results of our study could have an impact on the actual on-site use and acceptance of exoskeletons in commercial companies.",
"We found a significant reduction (approx. 22%) in MES activity when using the exoskeleton with maximum support level compared to lifting without exoskeleton. Regarding the RPE values, a significant reduction could be observed as well. MES activity and subjectively perceived exertion decreased, with an increase in the exoskeleton’s level of support. Thus, the exoskeleton seems to actively support the user noticeably when lifting heavy weights. However, no general recommendations can be made regarding the support level, even though the maximum level of support seems appropriate for the setup we have chosen, as the given conditions (e.g., load to be lifted, body weight, personal preferences) likely play a role here and therefore should always be taken into account. This once again highlights the significance of the control system of exoskeletons and how important the adjustability of the assistance is in order to facilitate versatile application."
] |
PMC10384334
|
Molecules
|
Deep Eutectic Solvents: Properties and Applications in CO2Separation
|
08-07-2023
|
Nowadays, many researchers are focused on finding a solution to the problem of global warming. Carbon dioxide is considered to be responsible for the “greenhouse” effect. The largest global emission of industrial CO 2 comes from fossil fuel combustion, which makes power plants the perfect point source targets for immediate CO 2 emission reductions. A state-of-the-art method for capturing carbon dioxide is chemical absorption using an aqueous solution of alkanolamines, most frequently a 30% wt. solution of monoethanolamine (MEA). Unfortunately, the usage of alkanolamines has a number of drawbacks, such as the corrosive nature of the reaction environment, the loss of the solvent due to its volatility, and a high energy demand at the regeneration step. These problems have driven the search for alternatives to that method, and deep eutectic solvents (DESs) might be a very good substitute. Many types of DESs have thus far been investigated for efficient CO 2 capture, and various hydrogen bond donors and acceptors have been used. Deep eutectic solvents that are capable of absorbing carbon dioxide physically and chemically have been reported. Strategies for further CO 2 absorption improvement, such as the addition of water, other co-solvents, or metal salts, have been proposed. Within this review, the physical properties of DESs are presented, and their effects on CO 2 absorption capacity are discussed in conjunction with the types of HBAs and HBDs and their molar ratios. The practical issues of using DESs for CO 2 separation are also described.
|
[
"One of the main objectives of current global research is to develop materials and methods aimed at reducing emissions of acid and toxic gases, especially carbon dioxide. One of the most common technologies used to remove CO_(2) is its absorption with aqueous amine solutions, mainly a 30% aqueous solution of monoethanolamine and hydrogen bond donors separation applications, as well as their CO_(2) absorption capacity.",
"Growing interest in DESs as a new generation of solvents for various practical applications has resulted in the need for accurate and reliable knowledge about their main physical, chemical, and thermodynamic properties. Therefore, numerous scientific articles devoted to the development and characterization of DES properties have recently been added to the literature. This section describes and discusses the main physicochemical and thermodynamic properties of DESs, including those that affect their suitability for gas separation.",
"There are seven types of DESs that can be distinguished. The general formulas and examples of the specific types are presented in . Since most of the research carried out so far has been related to the properties and applications of mixtures of quaternary ammonium salts and HBD, this review is focused mainly on DESs of type III.",
"As mentioned above, a DES is formed by mixing two or three components capable of forming a new liquid phase with a lower freezing point than that for the ideal eutectic mixture [ ]. A significant depression of the freezing point is observed mainly due to the hydrogen bond interactions between the hydrogen bond acceptor and the hydrogen bond donor. Although the number of DESs reported in the literature is huge, the number of DESs with the freezing point lower than room temperature is still limited. In general, the freezing point of a DES is influenced by the nature of its constituents and their molar ratio. However, no clear correlation between the melting points of individual components and the freezing points of the corresponding DESs has been found. Among all the choline chloride-based DESs studied, lower melting points were obtained for DESs consisting of polyols such as glycerol or ethylene glycol [ , ]. However, Shahbaz et al. recorded a very low melting point for 2,2,2-trifluoroacetamide, which confirms a very large contribution of the HBD to lowering the melting point by forming a hydrogen bond [ ]. It has been established that the nature of the HBA anion also affects the DES freezing point. For example, Abbott et al. studied DESs based on urea and they concluded that DESs consisting of urea and a choline salt have freezing points decreasing in the order F − > NO 3 − > Cl − > BF 4 − [ ]. Moreover, in their article, the HBA effect on the freezing point of the DESs was investigated. The researchers found that mixing urea with different salts in the same ratio for modelling the phase behavior of DES systems [ ]. They observed a compatibility with the experimental data, but this method requires a number of molecules and mixing parameters fitted from experimental data. Thus, this model has a limited predictive capability for novel systems. Garcia et al. proposed a quantitative structure–activity relationship applying experimentally independent molecular descriptors has been proposed by Song et al. [ ]. Using 35 choline chloride-based DESs, they found a reliable multilinear relationship between the freezing point depression of DESs and the molecular volume descriptor and their molecular descriptors associated with hydrogen bond interactions.",
"Despite a very limited amount of data on the vapor pressure of DESs, there is general agreement that the vapor pressures of pure deep eutectic solvents at ambient temperatures are low or even negligible, but higher than those of ionic liquids. Recently, Ravula et al. studied the vapor pressure of fluids presenting low-volatility and found that they vary in the following order: short-chain PEGs > long-chain PEGs > DESs > protic ILs > polymeric ILs > aprotic ILs > dicationic ILs [ ].",
"Experimental measurements of the vapor pressures of deep eutectic solvents have so far been taken only at 40–120 °C, considerably above ambient temperatures. Boisset et al. determined the vapor pressure at 40 °C for a DES consisting of N -methylacetamide and lithium bis(trifluoromethylsulfonyl)-imide to be 20 Pa [ ]. Shahbaz et al. found that at 100 °C the vapor pressures of reline, glyceline, diethylethanolammonium chloride:urea, N,N -diethylethanolammonium chloride:glycerol, and methyltriphenylphosphonium bromide:glycerol are equal to 1.33, 11.6, 1.8, 16.9, and 9.9 Pa, respectively [ ]. Recently, Dietz et al. measured the vapor pressures of hydrophobic DESs at 100 °C and obtained values in a range from 55.5 Pa for decanoic acid:lidocaine to 540.9 Pa for decanoic acid:menthol [ ].",
"Most DESs have a density between 1.0 and 1.35 g·cm^(−3) at 25 °C [ ]. However, DESs containing metal salts, such as ZnCl_(2), have slightly higher densities, in the range of 1.3 to 1.6 g·cm^(−3), whereas hydrophobic DESs exhibit a density lower than that of water [ , ]. It is certain, however, that DES densities are higher than those of their individual starting components. According to the principle of the hole theory, mixing DES components reduces the average hole’s radius and thus increases DES density relative to that of the individual constituents.",
"In general, the influence of the amount of HBDs on the density of a DES depends on the molecular characteristics of the HBD used. For most DESs, their density decreases as the amount of HBDs increases [ , , , , ]. However, in the case of DESs, where there is a strong association between HBD molecules, an increase in DES density with the increasing amount of HBDs was observed. Abbott et al. reported the densities of DESs with different molar ratios of choline chloride to glycerol and concluded that as the ratio of HBDs decreased, DES density increased [ ].",
"The increasing number of hydroxyl groups in HBDs, resulting in the formation of additional H-bonds and possibly reducing the available free volume, leads to the higher density of DESs. The results obtained by Basaiahgari et al. showed that ethylene glycol-based DESs have lower densities compared to glycerol-based DESs for both benzyltrimethylammonium and benzyltributylammonium chloride as HBA [ ]. The same effect was observed by Mjalli et al. for similar choline chloride-based DESs [ ].",
"According to the literature, the increase in DES density is also caused by the presence of additional carboxylic groups as well as additional ether bonds in the HBDs. For example, in the case of DESs based on choline chloride, the density of a DES consisting of oxalic acid was higher than that of a DES consisting of glycolic acid [ ]. Basaiahgari et al. reported the densities of DESs consisting of ethylene, diethylene, and triethylene glycol as HBDs and benzyltrimethylammonium chloride as the HBA to be equal to 1.101, 1.110, and 1.117 g·cm^(−3) at 25 °C, respectively [ ].",
"It has been established that the density of DESs decreases with the increasing chain length of the HBDs or HBAs. The results obtained by Florindo et al. show that DESs composed of glutaric acid or levulinic acid have lower density values compared to those observed for DESs based on oxalic or glycolic acids [ ]. Wang et al. reported that the density of ethylene glycol-based DESs consisting of tetraethylammonium bromide, tetrapropylammonium bromide, and tetrabutylammonium bromide were 1.1596, 1.1121, and 1.0762, respectively [ ].",
"Another factor affecting DES density is the type of salt they consist of. Shahbaz et al. observed that ammonium-based DESs have lower densities than phosphonium-based DESs [ ]. Moreover, bromide salts form denser DESs than chloride ones [ ].",
"In general, an increase in temperature causes a linear decrease in density [ ]. However, Yadav et al. found that the decrease in density with increasing temperature of a DES composed of choline chloride and glycerol in a 1:2 mole ratio follows a quadratic expression [ ]. Temperature-dependent density measurements for DESs can be used to estimate their isobaric thermal expansion coefficients, which can quantify DESs’ free volume [ ].",
"Several attempts at predicting deep eutectic solvents’ densities have been reported in the literature so far. Shahbaz et al. applied artificial intelligence and group contribution methods in order to predict the densities of DESs consisting of ethylene glycol and glycerol as HBDs and choline chloride, diethylethanolammonium chloride, and methyltriphenylphosphonium bromide as HBAs [ ]. Mjalii introduced mass connectivity index [ ].",
"Since viscosity is related to the free volume and the probability of finding holes of suitable dimensions for solvent molecules or ions to enter, this property depends on the size of the DES constituents. The high viscosity of DESs also results from the presence of hydrogen bonds as well as electrostatic and van der Waals interactions between the individual components of the DESs. Thus, the viscosity depends on the chemical nature of the components, their molar ratio, water content, and temperature.",
"In general, increasing the amount of HBDs reduces the viscosity of a DES [ ]. However, in the case of DESs based on hydrogen bond donors with a strong cohesive energy, due to the presence of the intermolecular hydrogen bond network, the opposite effect is observed. At 25 °C, the viscosities of choline chloride and glycerol mixtures with molar ratios of 1:4, 1:3, and 1:2 were 350, 320, and 259 mPa·s, respectively [ ].",
"The viscosity of DESs decreases considerably with increasing temperature. For example, for choline chloride:urea equations [ ]. Mjalli and Naser proposed a model for the viscosity of choline chloride-based DESs taking into account not only the temperature, but also the composition of the mixture. According to their results, the model based on the Arrhenius equation is more accurate for less viscous liquids, while the VFT-based viscosity model fits experimental viscosities also for more viscous DESs in a wide temperature range [ ].",
"It has been established that DESs’ viscosity drastically decreases with the water content. This property seems to be the main reason for the differences in the literature values of viscosity for any given deep eutectic solvent, in some cases even within a factor of two. According to Florindo et al., a highly viscous DES such as choline chloride:oxalic acid gives reliable and highly accurate results with respect to the corresponding experimental viscosity values of 27 DESs. Both models also showed good compliance with the temperature trends of viscosity for the investigated DESs. Furthermore, the effect of changing HBD ratios for a fixed HBA was correctly estimated.",
"More recently, Benguerba et al. proposed a new mathematical model for predicting amine-based DESs’ viscosities using the quantitative structure–property relationship for tetrabutylammonium bromide:1-nonanol is equal to 68.0 mN·m^(−1), while for DESs based on the same HBD but with tetrabutylammonium bromide as the HDA, the surface tension is 41.0 mN·m^(−1) at 20 °C [ ]. The results obtained by the same authors further demonstrated that in the case of tetraalkylammonium-based DESs, an increase in the chain length leads to an increase in the surface tension in the following order: tetraethylammonium bromide:pyrogallol < tetrapropylammonium bromide:pyrogallol < tetrabutylammonium bromide:pyrogallol.",
"According to the literature, surface tension increases with a decrease in the molar fraction of the salt due to the strengthening of HBD hydrogen bonding. Thus, the surface tension of DESs consisting of choline chloride and lactic acid decreases with increasing salt concentration, due to the disturbance of the hydrogen bond network of lactic acid [ ]. Hayyan et al. analyzed the effect of increasing the molar amount of choline chloride in DESs containing D-glucose. At 20 °C, with a 1:1 molar ratio of choline chloride to D-glucose, the surface tension at room temperature. The exception is a DES composed of ethylene glycol and choline chloride, the conductivity of which is equal to 7.61 mS·cm^(−1) at 20 °C [ ].",
"The conductivity of DESs generally increases significantly as the temperature increases, and the Arrhenius-like equation or the Vogel–Fulcher–Tammann or is decreasing and the fluidity approach to study the electrical conductivity of ammonium- and phosphonium-based DESs and they obtained an absolute relative deviation of 4.4%, which may be considered satisfactory [ ]. The hole theory was also applied by Abbott et al. to predict DESs’ conductivity, and although good results were obtained in some cases",
"The values that have so far been reported in the literature for these solvatochromic parameters for deep eutectic solvents are generally between those of methanol and water among the common solvents and commensurate with those of ionic liquids [ ]. This means that deep eutectic solvents are highly polar and polarizable, and that they have good hydrogen bond donation and acceptance abilities toward solutes.",
"In general, the number of publications related to DES solvatochromic parameters is limited. Abbott et al. determined the polarities of choline chloride:glycerol DESs of different molar ratios based on several parameters, revealing a linear polarity increase with increasing choline chloride concentration [ ]. Pandey et al. employed solvatochromic probes to examine the polarities of four DESs based on combinations of choline chloride with glycerol, urea, malic acid, and ethylene glycol in 1:2 molar ratios [ ]. They concluded that the high polarity of these DESs was significantly influenced by the HBD nature. Among the above four combinations, choline chloride:glycerol exhibited the highest E_(T) (30) value. Moreover, Pandey et al. investigated the effect of temperature and the addition of water on the DESs’ solvatochromic parameters. These researchers demonstrated that an increase in temperature results in a reduced H-bond donor acidity for the DESs, while no temperature effect was observed for dipolarity/polarizability and H-bond accepting basicity. It was also shown that the addition of water to the DESs caused an increase in their dipolarity/polarizability and a decrease in their H-bond accepting basicity. Teles et al. determined the solvatochromic properties of DESs formed by ammonium-based salts and carboxylic acids and concluded that the studied DESs presented a greater ability to donate and accept protons compared to most ionic liquids or organic molecular solvents [ ]. Moreover, according to these authors, the high acidity of the studied DESs was mainly due to the organic acid present in the mixtures, and an increase in the alkyl side chain of both the HBA and the HBD species leads to a lower ability of the solvent to donate protons. Florindo et al. determined solvatochromic properties for two different types of DESs: those based on salts, such as choline chloride and tetrabutylammonium chloride, and those based on the neutral compound DL-menthol [ ]. They found high values of hydrogen-bonding acidity for all the DESs, probably due to the organic acids present in all the systems. On the other hand, hydrogen-bonding basicity of these DESs did not vary much within the same HBA, but differed slightly in the case of DESs based on choline chloride, tetrabutylammonium chloride, or DL-menthol.",
"Thermal stability . Scarce information is available in the literature on the thermal stability of DESs. Generally, the thermal stability of these solvents is determined by the nature of the hydrogen bond donor and increases with the alkyl chain length on HBDs [ ]. Zhao et al. analyzed the thermal stability of DESs consisting of a choline salt [ ]. The lowest value was observed for the DES containing malonic acid and several HBDs [ ]. Siongco et al. determined the molar heat capacities of DESs based on N , N -diethylethanolammonium chloride and ethylene glycol or glycerol, while Zhang et al. measured the C_(p) of DESs consisting of ethylene glycol and betaine or L-carnitine [ , ]. They found that the molar heat capacity values of these DESs increase with temperature and they used different degrees of polynomials for the expression of the temperature dependence. Moreover, all the authors observed the linear relationship between the molar heat capacity and the molar mass of the DESs, which is similar to that of ILs.",
"In general, three models, based only on knowledge of the molecular structure of the DESs, are available to predict their heat capacities. Taherzadeh et al. developed a correlation to estimate the heat capacity of DESs as a function of temperature, molecular weight, critical pressure, and acentric factor with the resulting AARD% equal to 5.5% [ ]. Haghbakhsh et al. presented group contribution for predicting the heat capacity of ammonium- and phosphonium-based two-component DESs [ ]. The overall average absolute relative deviation of the proposed model from the data was 0.57%.",
"Refractive index. Despite the possibility of using the refractive index as an additional tool to demonstrate hydrogen bonding in DESs, this property has not often been studied [ ]. However, the research carried out thus far has shown that the n_(D) values of deep eutectic solvents are higher than those of ethanol or acetone, but similar to common ILs [ ]. Moreover, for all the studied DESs, a linear decrease in the refractive index with increasing temperature was observed. Murshid et al. investigated DESs based on diethanolamine as HBDs and found that the refractive index of all the systems studied decreases with the increase in the molar ratio of HBAs to HBDs from and varying HBDs, such as propionic acid [ ]. Troter et al. investigated DESs based on choline chloride as HBA and obtained the following order of the refractive index: ChCl:thiourea ChCl:urea ChCl:ethylene glycol ChCl:glycerol ChCl:1,3-dimethylurea ChCl:propylene glycol.",
"Speed of sound. There are only a few reports that describe the speed of sound for DESs, and the information available is mainly limited to deep eutectic solvents based on choline chloride. According to these reports, the speed of sound for DESs decreases with an increase in temperature, and in most cases linear dependence is observed [ , ]. However, in the case of DESs composed of glycerol and benzyltrimethylammonium chloride or benzyltributylammonium chloride, the temperature dependence of the speed of sound was found to be nonlinear, especially in the lower temperature region [ ]. This type of behavior was also observed by Sanchez et al. for L-proline-based DESs [ ]."
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PMC10381519
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Journal of Clinical Medicine
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New Perspective for Drug–Drug Interaction in Perioperative Period
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21-07-2023
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In this review, we aim to discuss current information on drug interactions in the perioperative period. During this period, patients receive several drugs that may interact with each other and affect the efficacy and safety of the treatment. There are three types of drug interactions: pharmacodynamic, pharmacokinetic, and pharmaceutical. It is important to recognize that drug interactions may increase the toxicity of the drug or reduce its efficacy, increasing the risk of complications in the perioperative period. This review describes the most commonly used perioperative drugs approved by the FDA and some of the described interactions between them. Thoroughly reviewing a patient’s medication list and identifying potential interactions are essential steps in minimizing risks. Additionally, vigilant monitoring of patients during and after surgery plays a pivotal role in early detection of any signs of drug interactions. This article emphasizes the significance of addressing DDIs in the perioperative period to ensure patient well-being and advocates for the implementation of careful monitoring protocols to promptly identify and manage potential interactions.
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[
"The perioperative period is the whole period including the preoperative period, the intraoperative phase, and the postoperative phase. This process provides the patient with all integrated care, from emotional and physical preparation and preliminary studies for a good operation, the contemplation of surgery, and the monitoring of recovery to prevent complications. The aim of perioperative care is to provide a healthier environment for patients before, during, and after the operation [ , ].",
"This perioperative management includes the use of drugs and opioids for better pain management. The use of all these drugs and opioids can lead to drug–drug interaction, and infra-additivity.",
"Pharmacodynamic interactions are the most predictable and therefore the most easily avoided. These occur when two or more drugs interact at the same site or receptor in the body, and this type of drug interaction can increase or decrease the effectiveness, increase the toxicity, or reduce its effectiveness. Common examples of pharmacodynamic interactions include the use of opioids and benzodiazepines, which can cause respiratory depression. The other two interactions, in contrast, are more difficult to predict, even with all the knowledge of pharmacokinetics and drug properties already known.",
"On the other hand, pharmaceutical drug interactions usually occur before the drug is administered and occur by chemical or physical reactions. In chemical reactions, there may be salt formation, oxidation-reduction, acid-base, hydrolysis, or epimerization, and in physical reactions there may be adsorption/absorption and emulsion breaking.",
"In pharmacokinetic interactions, one drug alters the absorption, distribution, or elimination of another drug. This type of interaction can affect the efficacy or toxicity of the medicine, as well as the duration of the medicine’s effect, and these interactions occur due to the inhibition or induction of cytochrome P450 enzyme [ ].",
"The different drugs given during the three phases of the perioperative period interact in different ways with each other. They may interact with each other in each phase or interact with the drugs given in the other two phases.",
"Different drugs were administered during the three phases of the perioperative phase [ , , , , , , , , , , , , , , , ]. We investigated about their clinical function, adverse reactions, and possible interactions with other drugs as described in the following parts of this review.",
"Drugs used in the pre-operative phase can have various effects on the body. Those effects can be increased or decreased according to the interaction with other drugs, and a new effect can sometimes occur. There are harmful drug interactions in the pre-operative phase.",
"The most common interactions result from non-steroidal anti-inflammatory drugs during surgery, leading to an increased postoperative morbidity and adverse events.",
"Methadone is a synthetic opioid medication used for the long-term management and treatment of opioid addiction withdrawal symptoms, as well as for chronic pain relief. In the treatment process, other medications may be combined with methadone due to the common occurrence of comorbidities among drug addicts. These additional medications can include psychotropic drugs, antibiotics, anticonvulsants, and antiretroviral drugs. Methadone has a prolonged elimination half-life of 24 to 36 h, and when methadone is coadministered with weak to strong CYP3A inhibitors or a moderate CYP3A4 inducer, its exposure in the body may either decrease or remain unchanged. However, methadone exposure is reduced when combined with CYP2B6 inducers [ , ].",
"Benzodiazepines are a class of drugs that enhance neurotransmission at GABAergic synapses. They are commonly used as anti-anxiety medications and as adjunctive treatment for various neurological and psychiatric disorders [ , ]. However, their misuse is prevalent among individuals taking methadone. Benzodiazepines can amplify the euphoric effects of opioids, alleviate withdrawal symptoms, moderate cocaine highs, potentiate alcohol effects, and modulate withdrawal states. They typically induce a mild to moderate depression of the central nervous system, with deep coma requiring assisted ventilation being rare and suggesting the presence of other toxic substances. The severity of CNS depression depends on factors such as the dosage, the patient’s age, and clinical condition prior to ingestion and the co-ingestion of other central nervous system depressants [ ]. In severe cases of overdose, benzodiazepines can occasionally cause cardiovascular and pulmonary toxicity. While not generally life-threatening, benzodiazepine intoxication can pose a life-threatening risk in certain situations or populations with underlying health conditions [ , ].",
"The combination of methadone and benzodiazepines can lead to pharmacokinetic interactions. Drugs with depressant effects, including benzodiazepines, opioids, alcohol, and antipsychotics, should be closely supervised, and monitored. The interaction between benzodiazepines and methadone can result in severe side effects, such as excessive sedation, respiratory depression, and coma, particularly when both drugs are used together. Since both medications have the potential for physical and psychological dependence, this interaction is of particular concern [ , ].",
"Tramadol is the most commonly prescribed opioid analgesic medication. It acts as a synthetic partial agonist on μ-opioid receptors and inhibits the reuptake of norepinephrine and serotonin. However, the way tramadol is metabolized, and the resulting metabolites depend on interactions with cytochrome P450 enzymes. The half-life of tramadol is approximately 6–8 h, which means that after 6–8 h of taking the drug, the concentration of tramadol in the bloodstream is reduced by half [ , , ].",
"It is available in various formulations, such as drops, capsules, sustained-release tablets for oral use, suppositories for rectal use, and solutions for intramuscular, intravenous, and subcutaneous injection. When taken orally, tramadol is rapidly and almost completely absorbed. Sustained-release tablets gradually release the active ingredient over a period of 12 h, reaching peak concentrations after approximately 4.9 h. They have a bioavailability of 87–95% compared to capsules [ ]. Tramadol is quickly distributed throughout the body, with about 20% of it binding to plasma proteins. The main metabolic pathways of tramadol involve O- and N-demethylation, as well as conjugation reactions forming glucuronides and sulfates. Tramadol and its metabolites are primarily eliminated through the kidneys.",
"Due to its inhibitory effects on serotonin and norepinephrine reuptake, tramadol has unique adverse effects. These can include the potential for serotonin syndrome, seizures, dizziness, nausea, constipation, and headache, and, if left untreated, they can lead to serious health consequences and even mortality [ , ]. Additionally, tramadol can interact with other medications, particularly antidepressants and benzodiazepines. The interaction with benzodiazepines is noteworthy because both drugs act as central nervous system depressants, and when taken together, they can enhance each other’s sedative and depressant effects.",
"Studies have shown that premature deaths in patients who abuse opioids are often associated with the ingestion of other central nervous system depressants, such as benzodiazepines. Cases have been reported involving various medications, including tramadol, when taken concomitantly with different benzodiazepines. The exact reasons for these interactions are not fully understood, but they may be attributed to pharmacodynamics and pharmacokinetics [ ].",
"Paracetamol. Moderate chronic use of approximately 4 g/day may lead to mild and transient liver enzyme elevations in healthy individuals, but in rare cases, it can result in acute liver failure. Chronic alcohol use or the use of certain drugs like barbiturates or isoniazid can increase susceptibility to paracetamol toxicity [ ].",
"In the liver, 52% to 57% of ingested paracetamol is converted to glucuronide conjugates, while 30% to 44% is converted to sulfate conjugates. These conjugates are non-toxic, water-soluble, and rapidly excreted in the urine. Approximately 5% to 10% of ingested paracetamol undergoes metabolism via the cytochrome P-450 system, primarily involving the isoenzyme P450 2E1, with contributions from 1A2, 3A4, and 2A6. P450 2E1 is the same isoenzyme responsible for metabolizing ethanol and can be induced by regular alcohol consumption, leading to increased metabolism of paracetamol through this pathway [ , ]. Metabolism of paracetamol via the cytochrome P450 pathway produces N-acetyl-p-benzoquinone imine painkillers, to relieve the pain, such as opioids, paracetamol, and ibuprofen; and is primarily prescribed for the treatment of pain and inflammation. On the other hand, morphine is an opioid analgesic used to alleviate moderate to severe pain. When celecoxib and morphine are used together, there is an increased risk of side effects such as gastrointestinal bleeding, kidney problems, high blood pressure, and heart failure. Therefore, unless prescribed by a healthcare professional and closely supervised, the combination of these medications should be avoided [ ].",
"Celecoxib is moderately absorbed when taken orally, with peak plasma drug concentration occurring after 2 to 4 h. The extent of absorption is not well known. It binds extensively to plasma albumin and has a volume of distribution of approximately 455 ± 166 L in humans. Celecoxib is eliminated through biotransformation into carboxylic acid and glucuronide metabolites, which are excreted in urine and feces. Only a small percentage of the drug known as 2 arylpropionic acids, or general. Before surgery, everything about the patient medical historic records is taken into consideration, such as comorbidities, adverse reactions to previous anesthetics, current prescriptions, allergies, use of alcohol, smoking, or abuse of drugs.",
"Combined anesthesia is a technique where the general and regional anesthesia are combined and used together to minimize the side effects and maximize both efficacy and safety. To have a more effective and safer anesthesia, there are different types of combinations of combined anesthesia that can be used and made, taking in account their uniqueness in view of the patient and the procedure, such as intravenous general anesthesia with regional anesthesia, intravenous general anesthetic with inhalational anesthesia, intravenous general anesthetic with neuromuscular blockade, and regional anesthesia with conscious sedation [ , ].",
"Isoflurane is an FDA-approved volatile anesthetic used for inducing and maintaining general anesthesia. It works by inhibiting specific receptors in the central nervous system, including GABA, glycine, and NMDA receptors, which helps to achieve the desired sedation and amnesia during surgery. Careful titration is necessary to manage the patient’s hemodynamics because isoflurane can cause significant drops in blood pressure through peripheral vasodilation, particularly in hypovolemic patients [ ]. It is important to note that isoflurane, like other halogenated volatile anesthetics, can trigger malignant hyperthermia in susceptible individuals, especially those with a personal or family history of the condition.",
"Isoflurane has several effects on the cardiovascular system. It reduces the cardiac output by approximately 20% below the control value 15 min after anesthesia. This is primarily due to the dilation of peripheral blood vessels, leading to dose-dependent hypotension. In older patients, isoflurane can have a slight negative impact on heart muscle contractility, which may result in cardiac insufficiency or myocardial hypoxia, particularly in patients with pre-existing cardiac damage. Additionally, exposure to high concentrations of isoflurane can decrease the contractility of the uterus muscle. It is worth noting that respiration is not stimulated by hypoxia during isoflurane anesthesia [ , ].",
"Propofol is an intravenous hypnotic drug used for inducing and maintaining sedation and general anesthesia. It achieves its effects by enhancing the inhibitory neurotransmitter γ-aminobutyric acid, there can be an increased risk of problems associated with central nervous system depression [ ].",
"It is important to be aware that combining propofol and isoflurane can increase the risk and severity of central nervous system depression. Medical professionals should carefully consider this when administering these drugs together [ ].",
"The combination of these two drugs, remifentanil and propofol, is usual. Remifentanil is, just like propofol, a continuous intravenous drug, which provides analgesia and helps to facilitate brief and painful procedures. The stability of these two drugs combined depends on their proportion, time, and the receptor, and if these variables are evaluated, remifentanil and propofol can be used together. Remifentanil can also be used in the postoperative period [ ].",
"Studies demonstrated that propofol pharmacokinetics remains unaffected when this drug is mixed with remifentanil. Studies also show that propofol reduces the central volume of distribution of sevoflurane and propofol is advantageous, but it can be disadvantageous in terms of the occurrence of convulsions and recovery time [ , ]. It is important to note that combining propofol with sevoflurane can increase the risk or severity of central nervous system depression [ ].",
"Fentanyl is an opioid drug that is 100 to 300 times stronger than morphine. It is primarily used for pain management and can also be used in combination with other drugs for anesthesia. Fentanyl can also be administered intravenously, through transdermal patches, or orally. It provides cardiovascular stability in patients and is commonly used as an adjunct to anesthesia. The hepatic metabolism of fentanyl occurs through the CYP450 enzyme system, specifically CYP3A4, and it has a half-life of 3 to 7 h. The drug is excreted through urine, analgesia, constipation, narcotic ileus, muscle rigidity, addiction, loss of consciousness, hypotension, coma, and even death. Concurrent use of alcohol and other drugs such as cocaine or heroin can intensify the side effects of fentanyl, leading to complex clinical situations that can be challenging to manage. These substances, when combined, create undesirable conditions that complicate the patient’s prognosis [ ].",
"Fentanyl is relatively contraindicated in the following situations: patients undergoing biliary tract surgery, as it may impede hepatic drug elimination; patients with respiratory depression or obstructive airway diseases such as asthma, COPD, obstructive sleep apnea, and obesity hypoventilation syndrome interactions between dexmedetomidine and propofol, midazolam, isoflurane, or fentanyl have been seen when taken at indicated target doses. However, a case report suggests that dexmedetomidine infusion may inhibit CYP3A4, causing tacrolimus levels to rise by four times [ ]. Additionally, the concomitant use of antidepressants with dexmedetomidine may impact its pharmacokinetics. Remifentanil was administered intra-operatively to Group H; Remifentanil plus a continuous infusion of dexmedetomidine was administered intra-operatively to Group HD; and Remifentanil, Flurbiprofen Axetil, and Dexmedetomidine were administered intra-operatively to Group HDF. The findings revealed that Group H had much lower mechanical pain thresholds than Groups HD and HDF. Additionally, compared to the other two groups, Group H had a larger area of secondary hyperalgesia at the incision site. Both the total amount of hyanil consumed and the visual analog scale score were lower in the combination group. Sufentanil dosage and analgesia pump pressing intervals were also significantly lower in the combo group. Higher amounts of NK cells, CD3+ T cells, and CD4+/CD8+ ratios were also produced by the combination, indicating enhanced immune function [ ]. In summary, the combination of dexmedetomidine and flurbiprofen axetil shows promising results in preventing hyperalgesia and improving postoperative pain control and immune function in patients undergoing hysterectomy and lung cancer surgery, respectively.",
"The use of benzodiazepines is frequent before the induction of anesthesia, as it helps to relieve anxiety and sedation. However, the concomitant use of benzodiazepines with ketamine may result in a decrease in the effectiveness of ketamine, as benzodiazepines can antagonize its psychedelic and analgesic effects. Despite the positive effect of antagonizing the psychedelic effect, it can antagonize the analgesic effect. Additionally, the use of these two drugs together may result in increased side effects such as respiratory depression and apnea. In elderly or debilitated patients, the situation can be problematic and result in sleep apnea, as these patients may have a less good response to medications. Basically, this interaction can vary according to the type and dose of benzodiazepines and ketamine used. It is a complex interaction and must be adapted to the type of patient [ , , ].",
"The concurrent administration of methadone and ketamine can result in a pharmacological interaction that increases the potential for side effects and toxicity. Ketamine has the ability to enhance the depressant effects of methadone, leading to a decrease in respiratory rate and blood pressure, particularly at higher doses [ ]. Furthermore, the combination of methadone and ketamine may elevate the risk of psychological side effects, including hallucinations, confusion, and delirium. Due to these concerns, it is crucial to exercise caution when using methadone and ketamine together, closely monitoring for signs of adverse reactions. The concurrent use of ketamine and methadone may heighten side effects such as dizziness, drowsiness, confusion, difficulty concentrating, excessive sedation, and respiratory depression. Elderly individuals, in particular, may experience impairment in thinking, judgment, and motor coordination as a result [ , , ].",
"Corticosteroids are commonly prescribed for various medical conditions due to their broad range of effects on the body. While they have therapeutic benefits, corticosteroids are also known for their dose- and duration-dependent toxicities. Common adverse effects observed in patients treated with corticosteroids include hyperglycemia, susceptibility to superinfections, and prolonged hospital stays [ , ].",
"Dexamethasone and betamethasone are long-acting corticosteroids with the highest glucocorticoid efficacy and a biological half-life of 36 to 54 h. Cortisone and cortisol, on the other hand, are short-acting with a half-life of less than 12 h and are less commonly used. Prednisone, prednisolone, methylprednisolone, and triamcinolone fall into the intermediate-acting category with a half-life of 18 to 36 h. Some adverse effects of corticosteroids follow a linear dose–response pattern, where the incidence increases with higher doses, while others exhibit a threshold dose–response pattern, with a higher frequency of events beyond a specific threshold value [ , ].",
"The metabolism of midazolam, a benzodiazepine drug, may potentially be enhanced in patients receiving long-term treatment with corticosteroids. The simultaneous use of these two medications can lead to adverse effects, such as central nervous system depression, resulting in drowsiness, decreased motor coordination, difficulty in speech and reasoning, and impaired motor skills. These effects can be particularly risky for elderly or more vulnerable patients who are more prone to complications and increased risks.",
"Moreover, the interaction between benzodiazepines and corticosteroids can affect the absorption, distribution, and elimination of these drugs as well as other medications the patient may be taking. This can lead to unexpected blood levels, either higher or lower than anticipated, thereby increasing the risk of side effects. Benzodiazepines, phenobarbital, and meprobamate selectively inhibit the rise of plasma corticosteroid levels, whereas other psychotropic drugs such as tricyclic antidepressants, monoamine oxidase inhibitors, neuroleptics, and amphetamines do not have this effect. This impact of benzodiazepines on corticosteroid levels is centrally mediated since diazepam does not block the increase in plasma corticosteroid levels caused by adrenocorticotropic hormone [ , ].",
"Every drug has the potential of interacting with another, and that should be one of the main factors to have in count when deciding and planning surgeries, since these drugs can change the whole dynamics of the perioperative period. It is well established that the perioperative period is incredibly complex and challenging for patients, healthcare teams, anesthetists, and surgeons. Pharmacological treatment plays a vital role in ensuring the safety and effectiveness of surgical procedures, highlighting the significance of DDIs. Recognizing the impact of DDIs on treatment efficacy and safety is crucial.",
"These interactions can affect the efficacy and safety of drugs administered during surgery, potentially resulting in unwanted effects, decreased treatment efficacy, or even risks to the patient. An in-depth understanding of DDIs is essential to avoid potential problems and ensure proper use of medications during the perioperative period. A notable example of drug interactions in the context of anesthesia is propofol, one of the most commonly used anesthetics. Propofol is often administered in combination with other anesthetic drugs such as remifentanil, isoflurane, fentanyl, and sevoflurane; however, these combinations may result in significant drug interactions. Propofol may potentiate the respiratory and cardiovascular depressant effects of remifentanil and may interact with inhaled anesthetic agents such as isoflurane and sevoflurane, which may lead to additive or synergistic effects on central nervous system depression, increasing the risk of excessive sedation and respiratory depression. Another important drug interaction involves fentanyl, an opioid analgesic used in combination with propofol during anesthesia, and coadministration of propofol and fentanyl may result in a potentiation of sedative and analgesic effects.",
"DDIs can affect various several mechanisms in the body, altering absorption, distribution, metabolism, and excretion of the drugs. Therefore, it is important to be aware of possible drug interactions and take steps to minimize their risk. First and foremost, reviewing the patient’s medication list and identifying drugs that may interact based on literature to consider the dosage and duration of medications that will be administered during the perioperative period can be of extreme importance. Thus, it may be necessary to adjust the dosage or change the medication to minimize the risks of interactions. Second, it is important to monitor the patient before, during, and after the surgical procedure to help detect any signs of drug interactions and complications, which include monitoring heart rate, blood pressure, and blood oxygen levels, as well as monitoring plasma levels of medications. Several significant considerations come into play when assessing DDIs in the perioperative period: (1) recognizing the pharmacodynamic effects of commonly used chronic medications during elective surgeries is crucial. These include cardiovascular drugs, lipid-lowering drugs, gastrointestinal medications, pulmonary medications, antibiotics, opioids and non-opioid analgesics, gabapentanoids, erectile dysfunction drugs, and psychotropic drugs. (2) Conducting a risk assessment of the patient population helps identify individuals at higher risk for DDIs based on factors such as age, comorbidities, genetic variations, and polypharmacy. (3) Recognizing the half-life of routinely used medications and adjusting the dosage according to the perioperative schedule is crucial to maintaining therapeutic levels during surgery. (4) Obtaining a comprehensive medical history and involving all clinicians in patient management (e.g., surgeon, anesthesiologist, and medical consultant) ensures a thorough understanding of the patient’s background, enabling the identification of potential DDIs.",
"One of the approaches to take in consideration when discovering and preventing pharmacological interactions in the perioperative period involves reviewing the existing medical literature to identify potential interactions proactively. This includes examining scientific articles, systematic reviews, and meta-analyses that investigate the effects of medications used during this period. However, by applying precision medicine principles, clinicians can better understand the pharmacodynamic effects of commonly used chronic medications during elective surgeries. Conducting pharmacokinetic and pharmacodynamic studies in patients taking multiple medications during surgery can help identify interactions that may impact drug efficacy and safety. Real-time drug interaction alert systems in hospital environments aid in recognizing and avoiding dangerous drug combinations. Collaborative adverse event monitoring, including reviewing reports of adverse events and medication errors, contributes to patient safety.",
"At last, conducting pharmacokinetic and pharmacodynamic simulations in patients undergoing surgery who are taking multiple medications aids in recognizing potential pharmacological interactions that may impact the safety or effectiveness of drugs administered during the perioperative period. To further enhance this process, real-time drug interaction alert systems can be employed during the prescription and administration of medications within the hospital environment. These systems play a vital role in identifying drug interactions and generating alerts for doctors and nurses, allowing them to avoid potentially dangerous drug combinations. Moreover, collaborative adverse event monitoring, encompassing the review of adverse event reports and medication error notifications, serves as an additional method for identifying DDIs and promoting patient safety.",
"Another valuable approach to prevent DDIs is the utilization of pharmacokinetic simulations conducted in laboratory settings. These simulations help predict potential pharmacological interactions beforehand between drugs a patient is taking, assisting in determining appropriate drug dosages during the perioperative period and thereby minimizing the occurrence of undesirable pharmacological interactions.",
"Drug–drug interactions (DDIs) play a crucial role in shaping the dynamics of surgery, underscoring the significance of conducting patient-specific investigations to identify appropriate medications and anticipate potential interactions. By employing the strategies discussed in this review, healthcare professionals can enhance their ability to recognize and manage DDIs during the perioperative period, thereby minimizing risks and optimizing patient outcomes. The use of pharmacokinetic and pharmacodynamic simulations, real-time drug interaction alert systems, collaborative adverse event monitoring, and pharmacokinetic simulations in the laboratory all contribute to the prevention of DDIs. By integrating these methods into clinical practice and considering their findings, healthcare providers can improve patient safety and reduce the occurrence of DDIs in future surgical interventions. This tailored approach to identifying and addressing DDIs ensures a more personalized and effective treatment regimen for each patient, ultimately leading to better surgical outcomes."
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PMC10325054
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PLOS Biology
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Supra-orbital whiskers act as wind-sensing antennae in rats
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06-07-2023
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We know little about mammalian anemotaxis or wind sensing. Recently, however, Hartmann and colleagues showed whisker-based anemotaxis in rats. To investigate how whiskers sense airflow, we first tracked whisker tips in anesthetized rats under low (0.5 m/s) and high (1.5 m/s) airflow. Whisker tips showed increasing movement from low to high airflow conditions, with all whisker tips moving during high airflow. Low airflow conditions—most similar to naturally occurring wind stimuli—engaged whisker tips differentially. Most whiskers moved little, but the long supra-orbital (lSO) whisker showed maximal displacement, followed by the α, β, and A1 whiskers. The lSO whisker differs from other whiskers in its exposed dorsal position, upward bending, length and thin diameter. Ex vivo extracted lSO whiskers also showed exceptional airflow displacement, suggesting whisker-intrinsic biomechanics mediate the unique airflow-sensitivity. Micro computed tomography (micro-CT) revealed that the ring-wulst—the follicle structure receiving the most sensitive afferents—was more complete/closed in the lSO, and other wind-sensitive whiskers, than in non-wind-sensitive whiskers, suggesting specialization of the supra-orbital for omni-directional sensing. We localized and targeted the cortical supra-orbital whisker representation in simultaneous Neuropixels recordings with D/E-row whisker barrels. Responses to wind-stimuli were stronger in the supra-orbital whisker representation than in D/E-row barrel cortex. We assessed the behavioral significance of whiskers in an airflow-sensing paradigm. We observed that rats spontaneously turn towards airflow stimuli in complete darkness. Selective trimming of wind-responsive whiskers diminished airflow turning responses more than trimming of non-wind-responsive whiskers. Lidocaine injections targeted to supra-orbital whisker follicles also diminished airflow turning responses compared to control injections. We conclude that supra-orbital whiskers act as wind antennae.
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[
"Animals can react to airflow stimuli and such wind-sensing abilities are referred to as anemotaxis. The best-studied examples of such behaviors come from insects, where anemotactic turning has been studied, among other species, in crickets [ , ] and in Drosophila [ , ]. Crickets show fast [ ], highly sensitive [ ], and directional escape responses to airflow stimuli. In Drosophila , the antennae are important transducers of anemotactic reactions [ ]. Until recently, little was known about the anemotactic abilities of mammals, but Hartmann and colleagues showed [ ] in a conditioning paradigm that rats can sense airflow. Deficits in airflow sensing after trimming of all whiskers then suggested that this form of airflow sensing is whisker-mediated. The same authors also characterized airflow mechanical responses of mystacial whiskers [ ] and responses of rat trigeminal ganglion cells to airflow stimuli [ ].",
"Our work was inspired by the whisker-anemotaxis shown by Hartmann and colleagues. Rather than focus on the 5 rows of mystacial whiskers, which are represented in the famous posteromedial-barrel-subfield [ ], we decided to assess the role of all facial whiskers in anemotaxis. The decision to look across different whisker subfields was based on our experience that whisker subfields may have very different functional characteristics. The submandibular whisker trident, for example [ ], is a three-whisker array involved in ground sensing. These whiskers appear to possess biomechanical specializations for ground sensing and may provide the animal with ego-motion information about speed and heading direction [ , ]. While the mystacial macrovibrissae have been studied in detail, we know little about the other approximately 300 whiskers on a rat [ ]. These whiskers are organized in arrays Which whiskers react maximally to airflow stimuli?. We labeled the long and short supra-orbital whiskers. We recorded videos of rats under low. We then examined the x- and y- movement of each whisker type and calculated displacement as the positive difference between the whisker end segment positions in the 2D plane and their median. We found that while a large number of whiskers exhibited substantial displacement in the high wind condition, in the low wind condition, only specific whiskers showed marked displacement; these were predominantly the lSO, α, β, A1 whiskers.",
"When grouping the averaged whisker displacement on each rat by whisker type, we observed that the lSO whiskers displayed the highest displacement. To study this pattern quantitatively, we analyzed rats individually. Kruskal–Wallis and post hoc analyses revealed that lSO whiskers moved more than any other whisker apart from α, β, and A1 whiskers. Among this whisker subset, the lSO moved more than the others in most cases. Only in Rats 2 and 4, another whisker. Wilcoxon test indicated that there was a significant increase in the whisker displacement in the high wind condition. A more detailed analysis indicated that this effect was due to a change exhibited by nearly a dozen whiskers, most of them belonging to the supra-orbital region and the top, ocular corner of the whisker pad. While the details of whisker displacements differed across video sequences, two aspects were the same:. Such differences were confirmed when we acquired micrographs of full whiskers and their shafts. Total whisker length and base diameter were measured in wind and non-wind-engaged whiskers. We computed a Pearson correlation to examine the relationship between whisker length and base diameter and found a positive correlation between the two variables [r. lSO whiskers were relatively thin and short among the long whiskers. We grouped the different whisker types according to a semicircular arrangement and compared their fold change for that ratio with respect to the lSO whisker. Semicircles were found to minimize the mean variance of the ratio along the whisker pad when compared to other possible arrangements using shuffling statistics. Further statistical analysis confirmed that lSO exhibits the highest ratio. This result suggests that optimal wind engaging occurs within a length-base diameter range that includes supra-orbital and top semicircle whiskers. To further explore this possibility, we performed Pearson correlations of whisker length, base diameter, and their ratio, against the whiskers displacement under low wind. Results indicated that only the whisker length and the ratio exhibited a significant correlation with displacement. To this end, we inserted the base of a similar sample of wind and non-wind-engaged whiskers in clay on a linear array with similar orientation. We calculated the maximal bending of the whiskers during low wind flow with respect to the curvature at rest and took the bending angle. A Kruskal–Wallis test on whisker type showed a significant effect [H, whereas non-wind-sensitive whiskers tend to have an open ring-wulst. Population data on ring-wulst opening are plotted in . Note the similarity of “ring-wulst-closedness” and wind-induced deflection as shown in . A heatmap of ring-wulst aperture angles indicates the most closed aperture in lSO and sSO follicles, while the most open aperture conformations are found in E-row and arc-4 follicles. We grouped the different whisker types according to a semicircular arrangement and compared their fold change for the ring-wulst aperture with respect to the lSO whisker. Semicircles were found again to minimize the mean variance when compared to other possible arrangements using shuffling statistics, but this time for the ring-wulst aperture. Further statistical analysis confirmed that lSO exhibits the most closed ring-wulst. Interestingly, we found that the ratio between whisker length and base diameter was inversely correlated with the ring-wulst aperture: the more closed the ring-wulst, the higher the ratio. Ring-wulst aperture also showed a correlation with whisker base diameter. Furthermore, ring-wulst aperture did correlate with wind-induced whisker displacement, with lSO whisker displaying the most extreme relation between these variables: the closest ring-wulst and the largest displacement. We conclude that the follicles of wind-sensitive whiskers differ by an unusually closed ring-wulst from non-wind-sensitive whiskers.",
"The differential mechanical airflow responses of whiskers point towards a role of the supra-orbital whiskers in airflow sensing. We therefore mapped the location of cortical barrels representing the supra-orbital whiskers in extracellular receptive field mapping experiments and prepared cytochrome oxidase sections of layer IV of the barrel cortex [ ]. We consistently. Next, we wondered how mechanical airflow responsiveness relates to the cortical barrel field and we color coded it and superimposed it on the barrel map. Quantitative tracking data for whisker displacement was not available for all whiskers the exact position and orientation of putative supra-orbital whisker barrels relative to the posteromedial-barrel-subfield is somewhat variable and more variable relative to the position and orientation of the mystacial barrels to each other... The latter 2 observations support the idea that the short and long supra-orbital whiskers are functionally related.",
"Next, we wondered if the cortical supra-orbital whisker representation differed from barrel cortex neurons in their responses to wind stimuli. We applied wind stimuli to urethane-anesthetized rats, while recording simultaneously with Neuropixel probes from the supra-orbital whisker region at the coordinates identified in our mapping experiments and from the whisker pad region aiming towards E/D-row barrel cortex. We histologically confirmed recording locations to the supra-orbital cortical region and the whisker pad barrel cortex near E/D-row. Judging by the population peristimulus time histogram. Plots of the z-scored responses of individual neurons revealed either no, weak, or inhibitory responses to wind stimuli in E/D-row barrel cortex. In the supra-orbital whisker region instead, we observed strong excitatory responses in single cells. The differences in the firing rate response to either low and were distributed differently in time across response categories. We found that the SO region exhibited the highest percentage of excited neurons, surpassing the 25% of recruitment 1 second after the stimulus onset in both wind conditions. In contrast, pad region neurons displayed a balance between being excited and inhibited during low wind and only recruited 12% of neurons at its peak during high wind. This pattern of response was further explained by an analysis on the response latency, which showed that neurons reached their maximum response 1 second after the stimulus onset. These differences suggest that wind responses map to the supra-orbital whisker barrel. To further confirm this, we calculated for each cell the mutual information of the firing rate given a wind stimulus. Results indicated that only firing rate activity of neurons in the SO region significantly informed about wind stimuli. Moreover, in line with our results regarding the percentage of recruited activity and the response latency, mutual information peaked during second 2. Airflow measurements of hand- and cardboard-flap stimuli were on average ≤0.3 m/s and 0.5 m/s, respectively. The reactions of rats to hand-flap stimuli were assigned by forced choice to one of 3 categories: either no reaction, turning towards the stimulus, or turning away from the stimulus. Even though rats often showed no reaction, when they did, the animals appeared to be able to distinguish the side where the hand-flap was delivered. Accordingly, rats turned significantly more often towards hand-flaps than away from them Test; “Turn to”. Again, the animals consistently showed a higher percentage of responses towards the stimuli side when compared to turning away responses test). When comparing the “Turn to” responses in the 2 wind delivery methods, we observed a stronger reactivity of the animals to cardboard-flap than to hand-flap stimuli. Our results show that rats can not only sense, but also turn towards airflow stimuli. The strength of the reactions differed between weak. A subset of wind-insensitive whiskers. Both sets of individuals were then submitted to cardboard-flap stimuli in complete darkness and were filmed, as described in the previous section. Out of all trials, we counted each individual’s number of turns towards the stimulus. We found that on average, wind-whisker-trimmed individuals turned towards the stimulus 20% of the time, while non-wind-whisker-trimmed individuals turned towards the stimulus 29% of the time. Thus, removal of wind-responsive whiskers resulted in a stronger decrease in turning behavior than the removal of wind-insensitive whiskers.",
"We next asked if the supra-orbital whiskers alone play a role in wind-induced turning. To investigate this, we injected 8 individuals with either lidocaine or Ringer solution. After each injection, we subjected the animals to the cardboard-flap tests, as illustrated in . Therefore, we had 8 paired values for each condition. Seven out of 8 individuals showed a decrease in turning behavior for lidocaine when compared with Ringer solution. The average turns towards the cardboard-flap stimulus were less frequent showing strong movements. We controlled turbulent airflow to reach on average either 0.5 m/s, being the lSO the one showing the largest displacements in most cases. Furthermore, lSO also exhibited the largest change across wind conditions, whiskers with closest ring-wulsts, in the top-ocular corner of the rat’s face, may be more suited to transfer mechanical energy at low wind speeds. Together, the combination of wind-sensitive whiskers mechanical resonances [ ] and the neurons in the supra-orbital region displayed changes that given their described properties could easily be conserved over a broader range of wind speeds. Even if this is not the case, their ring-wulst aperture should always give these whiskers an extra advantage when sensing wind. It remains a matter of future research to determine whether and how the rat’s own movement would affect wind-related sensitivity.",
"Previous work by Yu and colleagues [ ] established the ability of rats to sense wind blown through tunnels. These abilities were diminished by trimming all facial whiskers. Our current work extends our knowledge of rat anemotaxic abilities. We demonstrate that rats show robust turning responses to both weak, future research should be focused on the effect of motor variables in wind sensing, primarily in the top-ocular corner whiskers in Berlin or a 1 μl pipette tip with brightfield or using an AVT Pike f421b camera with a 60 mm Nikon macro lens.",
"For length measurements, we used a Sony alpha 7s camera with an FE 2.8/90 Macro G OSS lens. For the whisker diameter, we used the images taken from the holotomography reconstructions. Whisker diameter was measured in a transverse section close to the ring sinus, once the thickness of the initial segment of the whisker reached a relatively constant thickness.",
"Two whiskers per whisker type from 3 rats. Clusters of neurons were assessed qualitatively in terms of their autocorrelogram. Cell’s firing rate was transformed into z-score and counts for each of 4 time bins using a Zeiss Axioplan microscope fitted with a 10× and 2× objective.",
"Long–Evans rats or Dunn’s test. Data was expressed as the median ± interquartile range. The arrangement with the least mean variance was considered as the optimal and employed as grouping criteria for further analysis.",
"Six possible arrangements were considered: arcs, rows, semicircles (from A1), oblique 45° (from A1), oblique 135° (from A4), and opposite semicircle (from E4). We first calculated the variance inside each arrangement group (e.g., inside each semicircle) and took the mean across them as an estimate of the variance of the whole arrangement. A p -value for that estimation was then calculated by constructing a shuffle distribution of the mean variance for that arrangement. To this aim, data points position on the pad were randomized and the mean variance calculated for that arrangement. This procedure was repeated 10,000 times to create the shuffle distribution. Note that for both variables, the semicircular arrangement exhibited the least mean variance when comparing the observed value against the shuffle distribution for that arrangement."
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