bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chlamydia trachomatisEncodes a Dynamic, Ring-Forming Bactofilin Critical for Maintaining Cell Size and Shape
Authors: Brockett Mary R. , Lee Junghoon , Cox John V. , Liechti George W. , Ouellette Scot P. 
Published: October 2020

ABSTRACTBactofilins are polymer-forming cytoskeletal proteins that are widely conserved in bacteria. Members of this protein family have diverse functional roles such as orienting subcellular molecular processes, establishing cell polarity, and aiding in cell shape maintenance.Chlamydiaspecies are obligate intracellular bacteria that undergo a developmental cycle alternating between an infectious, non-dividing EB and a non-infectious, dividing RB. AsChlamydiadivides by a polarized division process, we hypothesized that BacACTmay function to establish polarity in these unique bacteria. Using sequence alignment to the conserved bactofilin domain, we identified a bactofilin ortholog, BacACT, in the obligate intracellular pathogenChlamydia trachomatis. Utilizing a combination of fusion constructs and high-resolution fluorescence microscopy, we determined that BacACTforms a dynamic, membrane-associated, ring-like structure inChlamydia’sreplicative RB form. Contrary to our hypothesis, this filamentous ring structure is distinct from the microbe’s cell division machinery and does not colocalize with septal peptidoglycan or MreB, the major organizer of the bacterium’s division complex. Bacterial two-hybrid assays demonstrated BacACTinteracts homotypically but does not directly interact with proteins involved in cell division or peptidoglycan biosynthesis. To investigate the function of BacACTin chlamydial development, we constructed a conditional knockdown strain using a newly developed CRISPR interference system. We observed that reducingbacACTexpression significantly impacted chlamydial cell size and morphology. Normal RB morphology was restored when an additional copy of BacACTwas expressedin transduring knockdown. These data reveal a novel function for chlamydial bactofilin in maintaining cell shape in this obligate intracellular bacterium.IMPORTANCEChlamydiais an ancient, obligate intracellular bacterium with a unique biphasic developmental cycle. As a result of its evolution within the osmotically stable environment of a host cell,Chlamydiahas lost its dependence on side-wall peptidoglycan, and maintains only a fraction of the components thought to be required for regulating bacterial cell size and division. As such, very little is known about howChlamydiaspecies carry out these critical processes in the absence of a stabilizing peptidoglycan layer. In the current study, we identify a novel cytoskeletal element, termed a bactofilin, that is critical for maintaining the morphology of the bacteria. Using state-of-the-art genetic techniques for this organism, we demonstrate that chlamydial bactofilin forms a dynamic ring structure independent of the microbe’s division machinery and that abrogating its expression level using CRISPR interference results in abnormal morphologic forms. These findings enhance our understanding of chlamydial biology and bactofilins more generally.
Prevalence of SARS-CoV-2 antibodies in France: results from nationwide serological surveillance
Authors: Vu Stéphane Le , Jones Gabrielle , Anna François , Rose Thierry , Richard Jean-Baptiste , Bernard-Stoecklin Sibylle , Goyard Sophie , Demeret Caroline , Helynck Olivier , Robin Corinne , Monnet Virgile , Facci Louise Perrin de , Ungeheuer Marie-Noelle , Léon Lucie , Guillois Yvonnick , Filleul Laurent , Charneau Pierre , Lévy-Bruhl Daniel , van der Werf Sylvie , Noel Harold 
Published: October 2020

AbstractBackgroundAssessment of cumulative incidence of SARS-CoV-2 infections is critical for monitoring the course and the extent of the epidemic. As asymptomatic or mild cases were typically not captured by surveillance data in France, we implemented nationwide serological surveillance. We present estimates for prevalence of anti-SARS-CoV-2 antibodies in the French population and the proportion of infected individuals who developed potentially protective neutralizing antibodies throughout the first epidemic wave.MethodsWe performed serial cross-sectional sampling of residual sera over three periods: prior to (9-15 March), during (6-12 April) and following (11-17 May) a nationwide lockdown. Each sample was tested for anti-SARS-CoV-2 IgG antibodies targeting the Nucleoprotein and Spike using two Luciferase-Linked ImmunoSorbent Assays, and for neutralising antibodies using a pseudo-neutralisation assay. We fitted a general linear mixed model of seropositivity in a Bayesian framework to derive prevalence estimates stratified by age, sex and region.FindingsIn total, sera from 11 021 individuals were analysed. Nationwide seroprevalence of SARS-CoV-2 antibodies was estimated at 0.41% [0.05−0.88] mid-March, 4.14% [3.31−4.99] mid-April and 4.93% [4.02−5.89] mid-May. Approximately 70% of seropositive individuals had detectable neutralising antibodies. Seroprevalence was higher in regions where circulation occurred earlier and was more intense. Seroprevalence was lowest in children under 10 years of age (2.72% [1.10−4.87]).InterpretationSeroprevalence estimates confirm that the nationwide lockdown substantially curbed transmission and that the vast majority of the French population remains susceptible to SARS-CoV-2. Low seroprevalence in school age children suggests limited susceptibility and/or transmissibility in this age group. Our results show a clear picture of the progression of the first epidemic wave and provide a framework to inform the ongoing public health response as viral transmission is picking up again in France and globally.FundingSanté publique France.
ASSOCIATION BETWEEN VITAMIN D LEVEL AND SERUM LIPID PARAMETERS AMONG INDIAN ADULTS WORKING IN IT SECTOR: A RETROSPECTIVE OBSERVATIONAL STUDY
Authors: Anantharamakrishnan Bhavani , Benansia Jisha 
Published: October 2020

ABSTRACTBackground & objectivesAssociation between serum vitamin D levels and lipid levels has been focus of research in recent times. The relationship of 25(OH)D and Atherogenic Index of Plasma is not well established among Indian population. We investigated the prevalence of vitamin D deficiency, its relation with serum lipids and AIP among IT employees.MethodsA retrospective observational study was conducted among employees of multiple IT firms in Bangalore, India. Participants were selected by convenient sampling from annual comprehensive health screening at work place. Serum lipid levels were assessed auto-analyser (ADVIA1650; Siemens, NY, USA). Serum 25(OH)D was assessed by Chemiluminescent microparticle immunoassay. AIP was calculated as log [Triglycerides/HDL-Cholesterol].ResultsAmong 533 subjects included final analysis, mean of age was 33.18±6.6 with Male: female ratio of 1.8:1. Vitamin D deficiency and AIP > 0.15 was observed in 405 (75.98%) and 450 (84.43%) participants respectively. Median HDL-cholesterol was significantly lower (42 Vs 45.5, P value 0.004) and LDL cholesterol was significantly higher (90 Vs 52, P value <0.001) among people with vitamin-D deficiency. LDL (Spearman Rho=-0.18, P <0.001) had weak negative correlation, Total cholesterol (Spearman Rho=-0.1, P Value <0.01) and VLDL (Spearman Rho=-0.18, P Value <0.001) had weak positive correlation with 25(OH)D. No statistically significant association was observed between AIP and vitamin-D.ConclusionsMore than two thirds of IT employees were deficient in vitamin D. Vitamin D deficiency was associated with significantly higher LDL, lower HDL and VLDL levels. No statistically significant association was observed between vitamin D and AIP.
Changes of evening exposure to electronic devices during the COVID-19 lockdown affect the time course of sleep disturbances
Authors: Salfi Federico , Amicucci Giulia , Corigliano Domenico , D’Atri Aurora , Viselli Lorenzo , Tempesta Daniela , Ferrara Michele 
Published: October 2020

AbstractStudy ObjectivesDuring the COVID-19 lockdown, there was a worldwide increase in electronic devices’ daily usage. The exposure to backlit screens before falling asleep leads to negative consequences on sleep health through its influence on the circadian system. We investigated the relationship between the changes in evening screen exposure and the time course of sleep disturbances during the home confinement period due to COVID-19.Methods2123 Italians were longitudinally tested during the third and the seventh week of lockdown. The web-based survey evaluated sleep quality and insomnia symptoms through the Pittsburgh Sleep Quality Index and the Insomnia Severity Index. During the second assessment, respondents reported the changes in the backlit screen exposure in the two hours before falling asleep.ResultsParticipants who increased electronic device usage showed decreased sleep quality, exacerbated insomnia symptoms, reduced sleep duration, higher sleep onset latency, and delayed bedtime and rising time. In this subgroup, the prevalence of poor sleepers and clinical insomniacs increased. Conversely, respondents reporting decreased screen exposure exhibited improved sleep quality and insomnia symptoms. In this subgroup, the prevalence of poor sleepers and clinical insomniacs decreased. Respondents preserving their screen time habits did not show any change in the sleep parameters.ConclusionsOur investigation demonstrated a strong relationship between the modifications of the evening electronic device usage and the time course of sleep disturbances during the lockdown period. Interventions to raise public awareness about the risks of excessive exposure to backlit screens are necessary to prevent sleep disturbances and foster well-being during the home confinement due to COVID-19.Statement of SignificanceThe present investigation is the first to provide insights about the relationship between the changes in evening electronic device usage and the time course of sleep disturbances during the COVID-19 lockdown. Consistent with the well-known negative effect of backlit screen lights on circadian physiology, we demonstrated a strong relationship between the screen time modifications in the hours before falling asleep, the development and exacerbation of sleep disturbances, and the changes of sleep/wake patterns during the period of home confinement due to COVID-19 pandemic. To date, hundreds of thousands of people are subjected to restraining measures worldwide. Our findings have large scale and broad-spectrum implications, considering the unavoidable increase of electronic device usage during the current period of limited social interactions.
Classification of submandibular salivary stones based on ultrastructural studies
Authors: Tretiakow Dmitry , Skorek Andrzej , Wysocka Joanna , Darowicki Kazimierz , Ryl Jacek 
Published: October 2020

AbstractIntroductionSialolithiasis remains a clinical problem with unclear etiopathogenesis, lack of prevention methods and only surgical treatment.Materials and MethodsAn ultrastructure examination of submandibular sialoliths obtained from patients with chronic sialolithiasis was conducted using a scanning electron microscope and X-ray photoelectron spectroscopy.ResultsBased on the results, we divided sialoliths into three types: calcified (CAL), organic/lipid (LIP) and mixed (MIX). The core structure of the CAL and MIX is very similar. The core of the LIP has a prevalence of organic components. The intermediate layers’ structure of the CAL is different from LIP and MIX. In LIP and MIX, the organic component begins to increase in intermediate layers rapidly. The structure of the superficial layers for all types of sialoliths is similar.ConclusionsWe introduced a new classification of the submandibular salivary gland stones. Based on the results, it can be said that sialoliths type CAL and LIP have their separate path of origin and development, while MIX is formed as CAL stone, and the further pathway of their growth passes as LIP stones. Organic components was much more than inorganic in all layers of salivary gland stones, which highly prevents their dissolution in the patient’s salivary gland duct.
Predicting the efficacy of exenatide in Parkinson’s disease using genetics – a Mendelian randomization study
Authors: Storm Catherine S. , Kia Demis A. , Almramhi Mona , Athauda Dilan ,   International Parkinson’s Disease Genomics Consortium (IPDGC), Burgess Stephen , Foltynie Thomas , Wood Nicholas W. 
Published: October 2020

AbstractBackgroundExenatide is a glucagon-like peptide 1 receptor (GLP1R) agonist used in type 2 diabetes mellitus that has shown promise for Parkinson’s disease in a phase II clinical trial. Drugs with genetic evidence are more likely to be successful in clinical trials. In this study we investigated whether the genetic technique Mendelian randomization (MR) can “rediscover” the effects of exenatide on diabetes and weight, and predict its efficacy for Parkinson’s disease.MethodsWe used genetic variants associated with increased expression ofGLP1Rin blood to proxy exenatide, as well as variants associated with expression ofDPP4, TLR4and 15 genes thought to act downstream of GLP1R or mimicking alternative actions of GLP-1 in blood and brain tissue. Using an MR approach, we predict the effect of exenatide on type 2 diabetes risk, body mass index (BMI), Parkinson’s disease risk and several Parkinson’s disease progression markers.ResultsWe found that genetically-raisedGLP1Rexpression in blood was associated with lower BMI and possibly type 2 diabetes mellitus risk, but not Parkinson’s disease risk, age at onset or progression. ReducedDPP4expression in brain tissue was significantly associated with increased Parkinson’s disease risk.ConclusionsWe demonstrate the usefulness of MR using expression data in predicting the efficacy of a drug and exploring its mechanism of action. Our data suggest that GLP-1 mimetics like exenatide, if ultimately proven to be effective in Parkinson’s disease, will be through a mechanism that is independent of GLP1R in blood.
When governments spread lies, the fight is against two viruses: A study on the novel coronavirus pandemic in Brazil
Authors: Biancovilli Priscila , Jurberg Claudia 
Published: October 2020

AbstractBackgroundOne of the challenges posed by the novel coronavirus pandemic is theinfodemic risk, that is, a huge amount of information being published on the topic, along with misinformation and rumours. Around 100 million people in Brazil (50% of the inhabitants) are users of social media networks, and a substantial amount of false information about the disease circulates in these media.ObjectivesIn this study, we examine the agenda-setting, media frame and content of misinformation published on the topic.MethodsWe analysed all pieces of misinformation published by the Brazilian fact-checking service “Agência Lupa”, during six months of 2020. We used content analysis to classify the texts into categories, and three types of rumours were identified: Misleading content; fabricated content; false context.ResultsWe analysed 232 pieces of misinformation. Most were published on Facebook (76%), followed by Whatsapp, with 10% of total cases. Half of the stories (47%) are classified as “real-life”, that is, the focus is on everyday situations, or circumstances involving people. Regarding the type of misinformation, there is a preponderance of fabricated content, with 53% of total, followed by false context (34%) and misleading content (13%). Wrong information was mostly published in text format (47%). We discuss the influence that misinformation can have on the behaviour of the Brazilian population during the pandemic and how the media’s agenda-setting is influenced by false information published on social media.ConclusionsThis study shows that misinformation about COVID-19 in Brazil seem to help establish an agenda-setting in the country, and the media frame is aligned with President Bolsonaro’s political position.
Mendelian randomization of dyslipidemia on cognitive impairment among older Americans
Authors: Fu Mingzhou , Bakulski Kelly M. , Higgins Cesar , Ware Erin B. 
Published: October 2020

AbstractBackgroundAltered lipid metabolism may be a risk factor for dementia, and blood cholesterol level has a strong genetic component. We tested the hypothesis that dyslipidemia (either low levels of high-density lipoprotein cholesterol (HDL-C) or high total cholesterol) is associated with cognitive status and domains, and assessed inferred causality using genetic predisposition to dyslipidemia as an instrumental variable.MethodsUsing data from European and African genetic ancestry participants in the Health and Retirement Study, we selected observations at the first non-missing biomarker assessment (waves 2006 to 2012). Cognition domains were assessed using episodic memory, mental status, and vocabulary tests. Overall cognitive status was categorized in three levels (normal, cognitive impairment non-dementia, dementia). Based on 2018 clinical guidelines, we compared low HDL-C or high total cholesterol to normal levels. Polygenic scores for dyslipidemia were used as instrumental variables in a Mendelian randomization framework. Multivariable logistic regressions and Wald-type ratio estimators were used to examine associations.ResultsAmong European ancestry participants (n = 8781), at risk HDL-C levels were associated with higher odds of cognitive impairment (OR = 1.20, 95%CI: 1.03, 1.40) and worse episodic memory, specifically. Using cumulative genetic risk for HDL-C levels as a valid instrumental variable, a significant causal estimate was observed between at risk low HDL-C levels and higher odds of dementia (OR = 2.15, 95%CI: 1.16, 3.99). No significant associations were observed between total cholesterol levels and cognitive status. No significant associations were observed in the African ancestry sample (n = 2101).ConclusionOur study demonstrates low blood HDL-C is a potential causal risk factor for impaired cognition during aging in non-Hispanic whites of European ancestry. Dyslipidemia can be modified by changing diets, health behaviors, and therapeutic strategies, which can improve cognitive aging. Studies on low density lipoprotein cholesterol, the timing of cholesterol effects on cognition, and larger studies in non-European ancestries are needed.
Nanotube mediated cell-to-cell communication and cannibalism in Halobacillus sp. GSS1 isolated from Sundarbans, India: A cryptic story of survival under nutrient-limiting condition
Authors: Guria Manas Kumar , Sengupta Sohan , Bhattacharyya Maitree , Karmakar Parimal 
Published: October 2020

AbstractMicroorganisms play a self-protective role by evolving their genetic and metabolic machinery to thrive in extreme environmental habitats. Halophiles are such salt-loving extremophilic microorganisms able to adapt, survive, and tend to grow at high salt concentrations. In this study, we have isolated Halobacillus sp. GSS1 from Sundarbans mangrove, India having a strong salt-tolerant ability (up to 4M) in Zobell Marine 2216 medium. The salt adaptation mechanism of Halobacillus sp. was investigated by Confocal microscopy using [Na+] specific dye, ‘Sodium Green’ indicating the ‘salt-in’ strategy for their osmoadaptation. Electron microscopic studies revealed that a contact-dependent cell-to-cell communication was profound among the Halobacillus sp. under nutrient limiting condition. This communication is mediated by ‘nanotube’, which is highly recommended for the exchange of molecular information between the two individual bacteria. The existence of the ‘ymdB’ gene strongly supports our claim for nanotube formation by Halobacillus sp. GSS1. Surprisingly, Halobacillus sp. not only utilizing the nanotubes for communication, rather they desperately use nanotubes as a survival weapon under nutrient limiting conditions by triggering cannibalism. This is the first-ever report on the existence of nanotube mediated cell-to-cell communication and cannibalism in any halophilic bacteria, isolated from Sundarbans mangrove forest, India.HighlightsThe existence of nanotube mediated cell-to-cell communication was discovered in Halobacillus sp. GSS1, isolated from Sundarbans mangrove, India.The communication of Halobacillus sp. GSS1 was established through single or multiple nanotubes with the neighboring cells.Intercellular nanotube communication was possible only after the participation of two individual bacteria.Halobacillus sp. GSS1 also uses these nanotubes as a survival weapon by triggering the cannibalism to kill their genetically identical siblings.The presence of the ymdB gene in Halobacillus sp. GSS1 strongly confers the evidence of nanotube formation.Graphical Abstract
Ceragenins and antimicrobial peptides kill bacteria through distinct mechanisms
Authors: Mitchell Gabriel , Silvis Melanie R. , Talkington Kelsey C. , Budzik Jonathan M. , Dodd Claire E. , Paluba Justin M. , Oki Erika A. , Trotta Kristine L. , Licht Daniel J. , Jimenez-Morales David , Chou Seemay , Savage Paul B. , Gross Carol A. , Marletta Michael A. , Cox Jeffery S. 
Published: October 2020

ABSTRACTCeragenins are a family of synthetic amphipathic molecules designed to mimic the properties of naturally-occurring cationic antimicrobial peptides (CAMPs). Although ceragenins have potent antimicrobial activity, whether their mode of action is similar to that of CAMPs has remained elusive. Here we report the results of a comparative study of the bacterial responses to two well-studied CAMPs, LL37 and colistin, and two ceragenins with related structures, CSA13 and CSA131. Using transcriptomic and proteomic analyses, we found thatEscherichia coliresponds similarly to both CAMPs and ceragenins by inducing a Cpx envelope stress response. However, whereasE. coliexposed to CAMPs increased expression of genes involved in colanic acid biosynthesis, bacteria exposed to ceragenins specifically modulated functions related to phosphate transport, indicating distinct mechanisms of action between these two classes of molecules. Although traditional genetic approaches failed to identify genes that confer high-level resistance to ceragenins, using a Clustered Regularly Interspaced Short Palindromic Repeats interference (CRISPRi) approach we identifiedE. coliessential genes that when knocked down modify sensitivity to these molecules. Comparison of the essential gene-antibiotic interactions for each of the CAMPs and ceragenins identified both overlapping and distinct dependencies for their antimicrobial activities. Overall, this study indicates that while some bacterial responses to ceragenins overlap with those induced by naturally-occurring CAMPs, these synthetic molecules target the bacterial envelope using a distinctive mode of action.IMPORTANCEThe development of novel antibiotics is essential since the current arsenal of antimicrobials will soon be ineffective due to the widespread occurrence of antibiotic resistance. Development of naturally-occurring cationic antimicrobial peptides (CAMPs) for therapeutics to combat antibiotic resistance has been hampered by high production costs and protease sensitivity, among other factors. The ceragenins are a family of synthetic CAMP mimics that kill a broad spectrum of bacterial species but are less expensive to produce, resistant to proteolytic degradation and have been associated with low levels of resistance. Determining how ceragenins function may identify new essential biological pathways of bacteria that are less prone to development of resistance and will further our understanding of the design principles for maximizing the effects of synthetic CAMPs.