2,145 research outputs found

    Prevalence and genomic characterization of zoonotic Salmonella and selected enteric pathogens in clinical and food samples in Thi-Qar Province, Iraq

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    Diarrhoeal diseases remain a major threat to young children in developing countries. Iraq is one such developing country where diarrhoeal diseases have a significant impact on child health, however, due to lack of systematic disease surveillance in Iraq, relatively little is known about the role and public health significance of the enteric pathogens involved in gastrointestinal infections. On a global scale, non-typhoidal Salmonella is the most important foodborne pathogen due to its widespread dissemination and resistance to antimicrobials used in veterinary and human sectors. The contribution of Salmonella to foodborne diseases in Iraq is, however, unknown. To address this, the overarching aim of this thesis was to determine the prevalence, genomic characterization, zoonotic potential and risk factors of non-typhoidal Salmonella associate with diarrhoeal disease in Iraqi children. A secondary aim was to provide contemporary information on select viral, bacterial and parasitic agents associated with enteric disease using molecular tools. A cross-sectional study was conducted in Thi-Qar Governorate, south-eastern Iraq, to estimate the prevalence, risk factors and antimicrobial resistance of Salmonella infection associated with diarrhoea. Fresh faecal samples were collected from children under five years of age suffering from diarrhoea who attended children's hospitals. Among 320 stool specimens cultured, 33 (10.3%, 95% CI 8.4–12.4) were positive for non-typhoidal Salmonella spp. Culture positivity for Salmonella was higher in children below two years of age. The source of drinking water (pipe water) (OR 4.7; 95% CI 1.6–13.9), a lower education (illiterate and primary) level of the mother (OR 3.9; 95% CI 1.0–6.4) and exposure to domestic animals (OR 10.5; 95% CI 3.8–28.4) were found to be a significant risk factors associated with Salmonella infection in children in a multivariable logistic regression model. Protective factors that decreased the risk of Salmonella infection included boiling water, exclusive breastfeeding and mother’s hand washing before feeding the child and after cleaning child defecation. Antimicrobial susceptibility tests of the Salmonella isolates demonstrated high levels of resistance to tetracycline (78.8%), azithromycin (66.7%), ciprofloxacin (57.6%), trimethoprim/sulfamethoxazole (51.5%), streptomycin (48.4%), and nalidixic acid (45.5%). Prompt and appropriate healthcare-seeking is one of the factors associated with reducing diarrhoea duration, which then reduces the possibility of dehydration and its complications, and also avoidance of unnecessary use of antimicrobials. A total of 500 mother-child pairs were interviewed using a structured questionnaire to determine the socio-demographic factors associated with maternal health-care seeking practices in order to improve the maternal management of the diarrhoeal disease. Multivariable logistic regression model of predictor factors indicated that mothers aged >25 years were found to have a much lower odds (OR 0.4, 95% CI 0.2–0.6; P = <0.001) of reported childhood diarrhoea compared to those younger. Almost half of the interviewed mothers (52.4% (262/500)) preferred self-ordered medicine from a pharmacy as an alternative management option for diarrhoea. Relative to mother’s health-care seeking practices with a university education, those with high school education had more possibility of seeking medical center (relative risk ratio (rrr) = 2.4) and pharmacy (rrr = 3.7) as against no treatment. Faecal samples were further screened using PCR to investigate the prevalence of common enteric pathogens known to be associated with diarrhoea in children, and determine potential risk factors. The most frequently identified pathogen in the faecal samples was adenovirus (34.2 %) followed by Salmonella spp. (14.8%), Entamoeba spp. (13.5%), and Campylobacter spp. (10.9%). Of interest, co-infection with a bacterial, viral, and a parasitic etiologic agent all together was detected in nine cases (9/155 (5.8%)). A logistic regression analysis indicated that children who exclusively breastfed had lower odds of adenovirus DNA detection (P = 0.051; OR 0.46, 95% CI 0.21–0.99) compared to children exclusively bottle-fed. Campylobacter infection in children from households supplied by pipe water was 5.12 (95% CI 1.12–23.27) times higher (P = 0.034) compared with those supplied with treated water. Entamoeba infection was three times lower [P = 0.030, OR 0.34 (95% CI 0.14–0.90)] in children belonging to caregivers who reported always washing hands after cleaning children following defecation, versus those belonging to caregivers who did not wash hands. In addition, for the first time in Iraq, whole genome sequence (WGS) analysis data for 23 Salmonella isolates in the present study indicated that S. Typhimurium ST49 was the most frequent sequence type, and floR, blaCARB-2 and mphA antimicrobial resistance genes were identified for the first time in Salmonella isolated from children. Chicken meats may play the potential role as sources/carriers of human Salmonella pathogenic strains in the zoonotic transmission and epidemiology of salmonellosis. To evaluate the role of chicken in causing human salmonellosis, 400 frozen chicken carcasses imported from Iran, Turkey, Brazil and India were collected from various retail stores and markets around Thi-Qar to determine the occurrence, serotypes distribution, phenotypic and genotypic characteristics of antibiotic resistance, and multilocus sequence types (ST) of Salmonella. Overall, the frequency of Salmonella contamination was 11.5% (95% CI 8.5%–15.0%) using culture techniques with PCR confirmation. Of the 46 Salmonella species, S. Typhimurium [23.9% (11/46)] and S. Enteritidis [21.7% (10/46)] were the most predominant serotypes. All of the Salmonella isolates tested exhibited resistance to one or more antimicrobial agents used, with common resistance being to tetracycline (84.4%), nalidixic acid (80.4%), streptomycin (69.6%) and trimethoprim/sulfamethoxazole (65.2%). This pilot study provided the first reporting on the genomic characterization of Salmonella isolates from imported chicken carcasses in Iraq. Eight sequence types (STs) were assigned by multilocus sequence typing (MLST) for 40 Salmonella isolates. The most frequent STs among S. Enteritidis was ST-11 and among S. Typhimurium was ST-19. WGS analysis also revealed that Salmonella isolates harboured resistance gene profiles which correlated with their resistance phenotypes. For β-lactamase genes, 18 isolates carried four β-lactamase resistance genes, with blaCARB-2 was the most commonly (14/18) seen while fifteen isolates carried the florfenicol resistance gene (floR) among the 46 isolates. Among nontyphoidal Salmonella isolated from chicken carcasses, 84.8% (39/46) were classified as with multiple drug resistance (MDR). These results indicate that chicken meat may acts as the reservoir for multidrug-resistant Salmonella infection in foodborne exposure to human. In summary, this study provides baseline carriage of pathogens responsible for causing diarrhoea in children under the age of five in Iraq. In addition, the present study for the first time provides insights into the genomic characteristics of Salmonella isolates collected from children and chicken meat. It also details the distribution of multidrug-resistant (MDR) profiles and resistance genes among Salmonella isolates to the first line antimicrobials regularly used in veterinary and human sectors, with potential for transfer to humans. Furthermore, the identification of common enteric pathogens causing diarrhoea in children will inform future epidemiological conservation studies. The household survey also identified areas to improve the management of diarrhoea in children under the age of five. The outcomes of this thesis may be used to inform public health and zoonotic disease programs for formulating appropriate recommendations for the management of diarrhoea and food safety

    The Value of Peer Mentoring in a Service Learning Program

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    Peer mentorship is a critical component of service learning programs (SLPs) at several medical institutions. The objectives of this project were: To explore the value of peer mentorship in SLPs within the setting of medical education To describe an effective mentorship structure that can be utilized in SLPs by employing reverse mentorship and a near-peer mentorship structure to positively impact participant

    Classification Supervisée de Questions : Rôle de l'Expansion Sémantique

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    http://asso-aria.org/coria/2010/147.pdfInternational audienc

    AMPA receptor trafficking and regulation by prominent auxiliary subunits in cultured hippocampal neurons

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    α-Amino-3-hydroxy-5-methyl-4-isoxazole propionate type receptors (AMPARs) are ligand-gated cation channels that reside at glutamatergic synapses throughout the vertebrate central nervous system and play a prominent role in excitatory synaptic transmission. Regulated plasma membrane delivery and reuptake of AMPARs are critical for synaptic receptor accumulation, synaptic homeostasis, and neurotoxicity. While AMPARs are thought to continuously cycle between plasma membrane and intracellular compartments via exocytosis and endocytosis (Ehlers*, 2000; Yudowski et al., 2007), many organizational and regulatory aspects of AMPAR turnover are still unclear to this date. Here, we have analyzed AMPAR dynamics in dendritic and somatic areas of cultured hippocampal neurons in live cell imaging, taking advantage of genetically encoded tags for the visualization of receptors. To study the membrane delivery of AMPAR from transport organelles, GRIA1 subunits were N-terminally fused with the pH-dependent GFP derivative superecliptic pHluorin, which is quenched in the acidic lumen of transport organelles but regains its full fluorescence in a neutral environment during exocytosis. In a basic characterization of our model system, we show that AMPARs are predominantly (>80% of all events) inserted from recycling endosomes into adjacent plasma membrane areas. Interestingly, AMPAR delivery was associated with fluorescence transients that exhibit considerable variation, ranging from fast flickers to long-lasting events, in accord with previous work (Jullie et al., 2014; Yudowski et al., 2007). These varying signal types likely represent mechanistically different fusion events, with the fluorescence decay frequently reporting reacidification of recycling endosomes after transient membrane merger rather than an actual receptor dispersion on the plasma membrane. To analyze receptor uptake, we employed genetically-encoded self-labelling tags that allow for pulse-chase assays. Using an N-terminal HaloTag-GRIA1 fusion protein, we established an acute staining procedure to label the surface pool of AMPAR in neurons. For this purpose, HaloTag-GRIA1-expressing neurons were incubated with membrane-impermeable fluorescently-labelled ligands for short intervals, resulting in covalent attachment of the fluorophores to the HaloTag domain due to its enzymatic activity. By using fluorescently-labeled synaptic markers, we could specifically follow the progressive uptake of labelled HaloTag-GRIA1 at synaptic as well as extrasynaptic sites. It has become evident during recent years that native AMPARs are generally associated with auxiliary subunits, which modulate channel function and facilitate forward trafficking from the ER towards the plasma membrane. Two prominent auxiliary subunits, TARPɣ8 and CKAMP44a, have been shown to govern AMPAR function in hippocampal neurons (Khodosevich et al., 2014; Rouach et al., 2005). While auxiliary subunits putatively contribute to the synaptic anchorage of AMPARs via C-terminal interactions with scaffolding proteins, little is known about the influence of these auxiliary subunits on the local dendritic turnover of AMPARs. Here, we have investigated how changes in the abundance of TARPɣ8 or CKAMP44a affect the trafficking of AMPAR under basal conditions. For this purpose, we overexpressed each type of auxiliary subunit and investigated AMPAR behavior in live cell imaging experiments. Strikingly, we found that overexpression of TARPɣ8 or CKAMP44a did not significantly change surface expression of AMPAR but exerted profound effects on receptor cycling: First, the fusion rate of AMPAR-containing transport organelles with the plasma membrane appeared dramatically reduced when assayed by pHluorin-GRIA1 after overexpression of TARPɣ8 or CKAMP44a. This change was accompanied by a reduced pool of AMPAR in recycling endosomes, pointing to an overall reduced recycling of AMPARs. Second, the endocytic reuptake of receptors was significantly reduced in cells overexpressing either auxiliary subunit, as indicated by a decelerated constitutive incorporation of labelled HaloTag-GRIA1-containing receptors under basal conditions. This effect was specific for the extrasynaptic receptor pool, excluding the possibility that enhanced synaptic anchorage of receptors led to an apparent stabilization of the surface receptor pool. A similarly reduced receptor uptake in the presence of the auxiliary subunits was also observed, when endocytosis of AMPARs was directly stimulated by application of insulin, suggesting that the effect on endocytosis is not restricted to constitutive turnover. These novel data indicate that association with auxiliary subunits protects AMPARs from rapid recycling processes, in effect stabilizing the extrasynaptic receptor pool. Noteworthy, TARPɣ8 and CKAMP44a exhibit a similar capacity to increase surface lifetime of AMPARs, suggesting that they employ a similar mechanistic avenue to inhibit endocytosis despite belonging to different protein families. In summary, we provide here new insight into the local dendritic turnover of AMPAR in hippocampal neurons, demonstrating that association of receptors with auxiliary subunits affects their propensity to be rapidly incorporated and recycled. It will be highly interesting to explore how auxiliary subunits mechanistically delay endocytosis in future experiments.Glutamat gesteuerte AMPA Rezeptoren (AMPAR, α-amino-3-hydroxy-5-methyl-4-isoxazole propionate auf englisch genannt) bilden Kationenkanäle, die sich in glutamatergen Synapsen im zentralen Nervensystem von Wirbeltieren befinden. AMPA Rezeptoren sind hauptsächlich für die schnelle Komponente des postsynaptischen Stroms verantwortlich. Die regulierte Bereitstellung des AMPA Rezeptors auf der Zelloberfläche und die entsprechende Wiederaufnahme in die Zelle sind wichtige Prozessen für die synaptische Akkumulation von Rezeptoren, die synaptische Homöostase und Neurotoxizität. Der regulierte Transport an die Plasmamembran und die Wiederaufnahme des AMPA Rezeptors sind für die synaptische Akkumulation von Rezeptoren, die synaptische Homöostase, und Neurotoxizität entscheidend. Auch wenn grundsätzlich beschrieben ist, dass AMPA Rezeptoren in einem ständigen Zyklus zwischen Plasmamembran und intrazellulärem Bereich durch Exo- und Endozytose wechseln (Ehlers*, 2000; Yudowski et al., 2007), sind viele Fragen über die Dynamik und Regulierung dieses Prozesses ungelöst. Die vorliegende Arbeit beschäftigt sich im wesentlichen mit der Dynamik von AMPA Rezeptoren im dendritischen und somatischen Bereichs von hippokampalen Neuronen der Maus in Kultur. Dazu wurden mit bildgebenden Verfahren (live cell imaging) und unter Verwendung genetischer Marker (englisch: Tag) die AMPA Rezeptoren visualisiert und ihre Membranrecycling als Zeitverlauf gemessen und analysiert. Um den Transport der AMPA Rezeptoren (Glutamate Ionotropic Receptor AMPA subtype1 (GRIA1)) in Transportorganellen zu untersuchen, haben wir GRIA1 (Untereinheit des AMAPA Rezeptors) mit pH-abhängigem Green Fluorescent Protein (GFP), auch Superecliptic Phluorin (SEP) genannt, N-Terminal fusioniert. SEP Fluoreszenz ist im saueren Medium der Transportorganellen unterdrückt, emittiert jedoch zunehmend Licht, wenn der pH Wert des Mediums ansteigt, was während der Exozytose der Fall ist. Es zeigte sich, dass die Mehrheit der AMPA Rezeptoren (>80 %) von Recycling Endosomes in nahliegende Abschnitte der Plasmamembran durch Exozytose eingefügt werden. Interessanterweise konnten wir beobachten, dass die Exozytoseereignisse, bestimmt als Fluoreszenzzunahme, sehr variabel sowohl im zeitlichen Verlauf als auch der Intensität der Fluoreszenz waren, was auf verschiedene Fusionstypen hinweist. Auffällig war ein häufig auftretender Fluoreszenzabfall unmittelbar nach Exozytose, den wir als Reazidifizierung nach Endozytose des zuvor exozytierten Vesikels (recycling Endosome) interpretieren. Um diese Hypothese zu prüfen, haben wir selbstmarkierende Tags für Pulse-Chase Experimente kloniert. Mit Hilfe des N-Terminalien HaloTag-GRIA1 Fusionsproteins, haben wir eine akute Färbungsprozedur etabliert um den Bestand an Oberflächen- AMPA Rezeptoren in Neuronen zu markieren. HaloTag-GRIA1 exprimierende Neurone wurden kurzzeitig mit fluoreszierenden Membranimpermeblen Liganden inkubiert. Durch die entstehende kovalente Bindung zwischen Tag und Ligand entsteht eine spezifische Färbung. Gleichzeitig wurde ein Fluoreszenz markierter Synapsen-Marker benutzt. So konnte das Schicksal von markiertem HaloTag-GRIA1 sowohl in den Synapsen als auch im extrasynaptischen Bereich verfolgt werden. Es hat sich über die letzten Jahre gezeigt, dass native AMPA Rezeptoren generell mit auxiliar (Helfer) Untereinheiten assoziieren, die die Kanal Funktion modulieren und den vorwärts Transport des Proteins vom endoplasmatisches Retikulum zur Plasmamembran fördern. Es wurde gezeigt, dass zwei bekannte auxiliare Untereinheiten, TARPɣ8 und CKAMP44a, die Funktion der AMPA Rezeptoren in hippokampalen Neurone modulieren (Khodosevich et al., 2014; Rouach et al., 2005). Anscheinend helfen diese Untereinheiten bei der Verankerung der AMPA Rezeptoren in den Synapsen. Wenig ist hingegen über den Einfluss der Helferuntereinheiten auf das lokale Recycling der Rezeptoren bekannt. Deshalb haben wir den Effekt der beiden Helferuntereinheiten auf den Transport der AMPA Rezeptoren bei basale neuronaler Aktivität untersucht. Wir haben die Helferuntereinheiten zu diesem Zweck überexprimiert und das Verhalten der AMPA Rezeptoren mit Live Imaging beobachtet. Überraschenderweise war die Oberflächenexpression der AMPA Rezeptoren mit der Überexpression der TARPɣ8 oder CKAMP44a nicht verändert, wohingegen das Rezeptor Recycling stark beeinflusst war. Erstens war die Fusionsrate von AMPA Rezeptor enthaltenden Transportorganellen mit der Plasmamembran stark verringert. Diese Veränderung war mit einer reduzierten Anzahl von Recycling Endosomen verbunden, was ein reduziertes Recycling der AMPA Rezeptoren nahelegt. Zweitens konnten wir beobachten, dass die Endozytose der AMPA Rezeptoren bei Überexpression der Helfer Untereinheiten ebenfalls stark reduziert war, was durch die verlangsamte Internalisierung der HaloTag-GRIA1 unter basale Bedingungen gezeigt werden konnte. Die Effekte der Helferuntereinheiten waren auf die extrasynaptischen Bereiche beschränkt, was synapsenspezifische Effekte, wie eine stärkere Verankerung der AMPA-Rezeptoren, als Ursache des reduzierten Recyclings ausschließt. Die Helferuntereinheiten entfalteten ihre Effekte nicht nur bei basaler neuronaler Aktivität. Bei Stimulation mit Insulin trat die gleiche inhibitorische Wirkung auf das Recycling von AMPA Rezeptoren auf, was dafür spricht, dass Helferuntereinheiten eine Rolle in aktivitätsabhängiger als auch in konstitutiven Endozytose spielen. Unsere Ergebnisse sprechen dafür, dass die Assoziierung von auxiliar Untereinheiten die AMPA Rezeptoren vor einer schnellen Endozytose schützen, um auf diese Weise das extrasynaptische Rezeptorenangebot zu stabilisieren. Obwohl TARPɣ8 und CKAMP44a zu zwei verschiedene Proteinfamilien gehören, zeigen sie eine vergleichbare Fähigkeit die Lebensdauer der AMPA Rezeptoren auf der neuronalen Oberfläche zu vergrößern. Zusammenfassend lässt sich sagen, dass wir einen Einblick in das lokale Recycling von AMPA Rezeptoren in den Dendriten der hippokampalen Neurone gewonnen haben. Wir konnten zeigen, dass mit Hilfe der auxiliar Untereinheiten das Recycling von AMPA Rezeptoren verlangsamt wird. In der Zukunft wird es sehr interessant sein, die Mechanismen, die hinter der verzögerten Endozytose von AMPA Rezeptor liegen zu entschlüsseln

    COVID-19 Resources for Speakers of Other Languages (COVID ReSOL)

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    Objectives identify barriers to COVID 19 testing and vaccination in NJ Hispanics with limited English proficiency (LEP) develop resources targeted towards vaccination for Hispanic NJ residents and communities in Atlantic, Camden, and Cumberland counties share evidence based information regarding the COVID 19 pandemic and disease spread prevention Conclusions Barriers to equitable COVID 19 care for NJ Hispanics with LEP may include but is not limited to resource availability in Spanish, misinformation about COVID 19, a lack of understanding about where and how to get tested and/or vaccinated, and transportation accessibility Increased efforts for providing equitable access to vaccination and testing are needed in our NJ communities to combat the disproportionate impact of COVID 19 on Hispanic residents (ex. community based vaccination clinics

    Understanding the State of LGBTQIA+ Healthcare and Support in Camden County

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    4.5% of American adults identify as lesbian, gay, or bisexual and about 1.4 million adults identify as transgender. This demographic is impacted by many social determinants of health and health disparities, particularly for transgender patients. 33% of LGBTQIA+ patients ranging from a pool of 28,000 surveyed patients have had a negative experience with their health providers, and 8% of them had to educate their physicians about their needs due to physicians’ lack of knowledge about this demographic. Research suggests that there is a reluctance to access mental health services in the LGBTQIA+ community due to homophobia,, difficulties disclosing sexual and gender identity, and fears of being misunderstood

    Lead Poisoning, Education, and Advocacy for Prevention (L.E.A.P.) study

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    Lead poisoning has been regarded as a major threat due to its irreversible and harmful effects. This includes severe cognitive and developmental impairments, especially in children. Over the years, the CDC has reduced the benchmark for acceptable blood lead levels (BLL) from 10 μg/ml to 3.5 μg/ml to allow for earlier intervention and prevention. Despite increased awareness and government programs that lead to a decline in mean blood levels across the country, testing for elevated BLLs, especially in low-income households, continues to be disproportionately lower

    Curricula Management and ABET Alignment at the Lebanese International University School of Engineering

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    Since 2011, the School of Engineering (SoE) at the Lebanese International University has been actively engaged in the development and constant evolution of engineering programs that are aligned with an assessment protocol aimed at determining how well graduating students achieve intended learning outcomes of their respective programs.  This is all done with the intention of having programs that are fully compatible with the Accreditation Board for Engineering and Technology (ABET) and in anticipation of future accreditation. This paper highlights the curriculum management approach that has emerged from the collaboration between the various engineering departments, the development of program students’ outcomes (PSOs) and their indices, and the results from the preliminary outcomes reporting that involves the collection of data in line with best practices, well established key performance indicators and standardized benchmarking in the engineering education community.  All of which has been done as a part of education quality management and continual improvement purposes. A novel approach was adopted dependent on students’ evaluation of the PSOs.  The evaluation process is used in a feedback loop to enhance the rankings of the PSOs.  Preliminary Results indicate the usefulness of this technique.  More data will be collected in the coming years to be able to establish statistical significance. Keywords: Curricula management, ABET accreditation, PSO, KPI, benchmarking, academic assessment, reporting, engineering education

    Challenging the Stigma of Sex Work: Creating the Framework to Train Student Doctors in Providing Affirming Care

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    The intention of this proposed intervention is to provide a foundation for medical students to include affirming care for sex workers in their future practice by understanding the complex institutional violence & discrimination experienced by this community. Additionally, dispelling misconceptions surrounding sex work is another of the foci of the service project. Future physicians can combat the stigma by providing patient care that centers sex worker agency, harm reduction, & judgement free strategies. Making the workshop guide open access allows other medical schools and special interests groups to incorporate a social justice framework into their medical practice
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