281 research outputs found

    A universal genome sequencing method for rotavirus A from human fecal samples which identifies segment reassortment and multi-genotype mixed infection.

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    BACKGROUND: Genomic characterization of rotavirus (RoV) has not been adopted at large-scale due to the complexity of obtaining sequences for all 11 segments, particularly when feces are used as starting material. METHODS: To overcome these limitations, we developed a novel RoV capture and genome sequencing method combining commercial enzyme immunoassay plates and a set of routinely used reagents. RESULTS: Our approach had a 100% success rate, producing >90% genome coverage for diverse RoV present in fecal samples (Ct < 30). CONCLUSIONS: This method provides a novel, reproducible and comparatively simple approach for genomic RoV characterization and could be scaled-up for use in global RoV surveillance systems. TRIAL REGISTRATION (PROSPECTIVELY REGISTERED): Current Controlled Trials ISRCTN88101063 . Date of registration: 14/06/2012

    A prospective multi-center observational study of children hospitalized with diarrhea in Ho Chi Minh City, Vietnam.

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    We performed a prospective multicenter study to address the lack of data on the etiology, clinical and demographic features of hospitalized pediatric diarrhea in Ho Chi Minh City (HCMC), Vietnam. Over 2,000 (1,419 symptomatic and 609 non-diarrheal control) children were enrolled in three hospitals over a 1-year period in 2009-2010. Aiming to detect a panel of pathogens, we identified a known diarrheal pathogen in stool samples from 1,067/1,419 (75.2%) children with diarrhea and from 81/609 (13.3%) children without diarrhea. Rotavirus predominated in the symptomatic children (664/1,419; 46.8%), followed by norovirus (293/1,419; 20.6%). The bacterial pathogens Salmonella, Campylobacter, and Shigella were cumulatively isolated from 204/1,419 (14.4%) diarrheal children and exhibited extensive antimicrobial resistance, most notably to fluoroquinolones and third-generation cephalosporins. We suggest renewed efforts in generation and implementation of policies to control the sale and prescription of antimicrobials to curb bacterial resistance and advise consideration of a subsidized rotavirus vaccination policy to limit the morbidity due to diarrheal disease in Vietnam

    Mapping for engagement: setting up a community based participatory research project to reach underserved communities at risk for Hepatitis C in Ho Chi Minh City, Vietnam

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    Background: Approximately 1. 07 million people in Vietnam are infected with hepatitis C virus (HCV). To address this epidemic, the South East Asian Research Collaborative in Hepatitis (SEARCH) launched a 600-patient cohort study and two clinical trials, both investigating shortened treatment strategies for chronic HCV infection with direct-acting antiviral drugs. We conducted ethnographic research with a subset of trial participants and found that the majority were aware of HCV infection and its implications and were motivated to seek treatment. However, people who inject drugs (PWID), and other groups at risk for HCV were under-represented, although injecting drug use is associated with high rates of HCV. Material and Methods: We designed a community-based participatory research (CBPR) study to engage in dialogues surrounding HCV and other community-prioritized health issues with underserved groups at risk for HCV in Ho Chi Minh City. The project consists of three phases: situation analysis, CBPR implementation, and dissemination. In this paper, we describe the results of the first phase (i.e., the situation analysis) in which we conducted desk research and organized stakeholder mapping meetings with representatives from local non-government and community-based organizations where we used participatory research methods to identify and analyze key stakeholders working with underserved populations. Results: Twenty six institutions or groups working with the key underserved populations were identified. Insights about the challenges and dynamics of underserved communities were also gathered. Two working groups made up of representatives from the NGO and CBO level were formed. Discussion: Using the information provided by local key stakeholders to shape the project has helped us to build solid relationships, give the groups a sense of ownership from the early stages, and made the project more context specific. These steps are not only important preliminary steps for participatory studies but also for other research that takes place within the communities

    Evaluation of Luminex xTAG Gastrointestinal Pathogen Panel Assay for Detection of Multiple Diarrheal Pathogens in Fecal Samples in Vietnam.

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    Diarrheal disease is a complex syndrome that remains a leading cause of global childhood morbidity and mortality. The diagnosis of enteric pathogens in a timely and precise manner is important for making treatment decisions and informing public health policy, but accurate diagnosis is a major challenge in industrializing countries. Multiplex molecular diagnostic techniques may represent a significant improvement over classical approaches. We evaluated the Luminex xTAG gastrointestinal pathogen panel (GPP) assay for the detection of common enteric bacterial and viral pathogens in Vietnam. Microbiological culture and real-time PCR were used as gold standards. The tests were performed on 479 stool samples collected from people admitted to the hospital for diarrheal disease throughout Vietnam. Sensitivity and specificity were calculated for the xTAG GPP for the seven principal diarrheal etiologies. The sensitivity and specificity for the xTAG GPP were >88% for Shigellaspp.,Campylobacterspp., rotavirus, norovirus genotype 1/2 (GI/GII), and adenovirus compared to those of microbiological culture and/or real-time PCR. However, the specificity was low (∼60%) for Salmonella species. Additionally, a number of important pathogens that are not identified in routine hospital procedures in this setting, such as Cryptosporidiumspp. and Clostridium difficile, were detected with the GPP. The use of the Luminex xTAG GPP for the detection of enteric pathogens in settings, like Vietnam, would dramatically improve the diagnostic accuracy and capacity of hospital laboratories, allowing for timely and appropriate therapy decisions and a wider understanding of the epidemiology of pathogens associated with severe diarrheal disease in low-resource settings

    Intracellular localisation and extracellular release of Y RNA and Y RNA binding proteins

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    Cells can communicate via the release and uptake of extracellular vesicles (EVs), which are nano-sized membrane vesicles that can transfer protein and RNA cargo between cells. EVs contain microRNAs and various other types of non-coding RNA, of which Y RNA is among the most abundant types. Studies on how RNAs and their binding proteins are sorted into EVs have mainly focused on comparing intracellular (cytoplasmic) levels of these RNAs to the extracellular levels in EVs. Besides overall transcriptional levels that may regulate sorting of RNAs into EVs, the process may also be driven by local intracellular changes in RNA/RBP concentrations. Changes in extracellular Y RNA have been linked to cancer and cardiovascular diseases. Although the loading of RNA cargo into EVs is generally thought to be influenced by cellular stimuli and regulated by RNA binding proteins (RBP), little is known about Y RNA shuttling into EVs. We previously reported that immune stimulation alters the levels of Y RNA in EVs independently of cytosolic Y RNA levels. This suggests that Y RNA binding proteins, and/or changes in the local Y RNA concentration at EV biogenesis sites, may affect Y RNA incorporation into EVs. Here, we investigated the subcellular distribution of Y RNA and Y RNA binding proteins in activated and non-activated THP1 macrophages. We demonstrate that Y RNA and its main binding protein Ro60 abundantly co-fractionate in organelles involved in EV biogenesis and in EVs. Cellular activation led to an increase in Y RNA concentration at EV biogenesis sites and this correlated with increased EV-associated levels of Y RNA and Ro60. These results suggest that Y RNA incorporation into EVs may be controlled by local intracellular changes in the concentration of Y RNA and their protein binding partners

    TNFR2 Costimulation Differentially Impacts Regulatory and Conventional CD4+ T-Cell Metabolism

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    CD4+ conventional T cells (Tconvs) mediate adaptive immune responses, whereas regulatory T cells (Tregs) suppress those responses to safeguard the body from autoimmunity and inflammatory diseases. The opposing activities of Tconvs and Tregs depend on the stage of the immune response and their environment, with an orchestrating role for cytokine- and costimulatory receptors. Nutrient availability also impacts T-cell functionality via metabolic and biosynthetic processes that are largely unexplored. Many data argue that costimulation by Tumor Necrosis Factor Receptor 2 (TNFR2) favors support of Treg over Tconv responses and therefore TNFR2 is a key clinical target. Here, we review the pertinent literature on this topic and highlight the newly identified role of TNFR2 as a metabolic regulator for thymus-derived (t)Tregs. We present novel transcriptomic and metabolomic data that show the differential impact of TNFR2 on Tconv and tTreg gene expression and reveal distinct metabolic impact on both cell types

    Gallbladder carriage generates genetic variation and genome degradation in Salmonella Typhi

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    Despite recent advances in typhoid fever control, asymptomatic carriage of Salmonella Typhi in the gallbladder remains poorly understood. Aiming to understand if S. Typhi becomes genetically adapted for long-term colonisation in the gallbladder, we performed whole genome sequencing on a collection of S. Typhi isolated from the gallbladders of typhoid carriers. These sequences were compared to contemporaneously sampled sequences from organisms isolated from the blood of acute patients within the same population. We found that S. Typhi carriage was not restricted to any particular genotype or conformation of antimicrobial resistance genes, but was largely reflective of S. Typhi circulating in the general population. However, gallbladder isolates showed a higher genetic variability than acute isolates, with median pairwise SNP distances of 21 and 13 SNPs (p = 2.8x10-9), respectively. Within gallbladder isolates of the predominant H58 genotype, variation was associated with a higher prevalence of nonsense mutations. Notably, gallbladder isolates displayed a higher frequency of non-synonymous mutations in genes encoding hypothetical proteins, membrane lipoproteins, transport/binding proteins, surface antigens, and carbohydrate degradation. Specifically, we identified several gallbladder-specific non-synonymous mutations involved in LPS synthesis and modification, with some isolates lacking the Vi capsular polysaccharide vaccine target due to the 134Kb deletion of SPI-7. S. Typhi is under strong selective pressure in the human gallbladder, which may be reflected phylogenetically by long terminal branches that may distinguish organisms from chronic and acute infections. Our work shows that selective pressures asserted by the hostile environment of the human gallbladder generate new antigenic variants and raises questions regarding the role of carriage in the epidemiology of typhoid fever

    Overseas Treatment of Latent Tuberculosis Infection in US-Bound Immigrants.

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    Seventy percent of tuberculosis (TB) cases in the United States occur among non-US-born persons; cases usually result from reactivation of latent TB infection (LTBI) likely acquired before the person's US arrival. We conducted a prospective study among US immigrant visa applicants undergoing the required overseas medical examination in Vietnam. Consenting applicants >15 years of age were offered an interferon-γ release assay (IGRA); those 12-14 years of age received an IGRA as part of the required examination. Eligible participants were offered LTBI treatment with 12 doses of weekly isoniazid and rifapentine. Of 5,311 immigrant visa applicants recruited, 2,438 (46%) consented to participate; 2,276 had an IGRA processed, and 484 (21%) tested positive. Among 452 participants eligible for treatment, 304 (67%) initiated treatment, and 268 (88%) completed treatment. We demonstrated that using the overseas medical examination to provide voluntary LTBI testing and treatment should be considered to advance US TB elimination efforts

    Повышение цифровых навыков: ключ к цифровой вовлеченности пожилых людей (на примере Вьетнама)

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    Digital transformation taking place rapidly in all aspects of socioeconomic activities across Vietnam in recent years is affecting the lives of people of all ages. Vietnamese older people, due to the impact of digitization, demographic category and socioeconomic status as well as age-related issues, become vulnerable, facing many challenges in adapting to the digital environment. In the article, the existence of a digital divide within Vietnamese older persons at different levels and the disparities in digital skills that have a dominant influence on Internet usage and benefits have been confirmed; low basic digital skills was considered as a barrier to digital inclusion of older adults in the emerging digital society. The aim of the study is to predict the socio-economic consequences and find practical solutions to improve the literacy and disease skills of people in Vietnam, including the formation of an effective form of digital literacy and digital skills training. The article proposes measures to bridge the sudden gap in human diseases and encourage their adaptation to the emerging digital societyЦифровая трансформация, быстро происходящая во всех аспектах социально-экономической деятельности во Вьетнаме в последние годы, влияет на жизнь людей всех возрастов. Пожилые вьетнамцы под влиянием цифровизации, объективных демографических и социально-экономических процессов, а также проблем, связанных с возрастом, становятся уязвимыми, сталкиваясь со многими проблемами при адаптации к цифровой среде. В статье подтверждается наличие цифрового неравенства среди пожилых вьетнамцев на разных уровнях овладения цифровыми навыками, которые оказывают доминирующее влияние на использование преимуществ сети Интернет. В ходе исследования установлено, что низкие базовые цифровые навыки послужили препятствием для интеграции пожилых людей в развивающееся цифровое общество. Цель исследования заключается в прогнозировании социально-экономических последствий и поиске практических решений по повышению цифровой грамотности и навыков пожилых людей Вьетнама, включая становление эффективных форм распространения цифровой грамотности и обучения цифровым навыкам. В статье предложены меры по преодолению цифрового разрыва среди пожилых людей и поощрению их адаптации к формирующемуся цифровому обществ

    Extracellular vesicles from seminal plasma interact with T cells in vitro and drive their differentiation into regulatory T-cells

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    Seminal plasma induces immune tolerance towards paternal allogenic antigens within the female reproductive tract and during foetal development. Recent evidence suggests a role for extracellular vesicles in seminal plasma (spEVs). We isolated spEVs from seminal plasma that was donated by vasectomized men, thereby excluding any contributions from the testis or epididymis. Previous analysis demonstrated that such isolated spEVs originate mainly from the prostate. Here we observed that when isolated fluorescently labelled spEVs were mixed with peripheral blood mononuclear cells, they were endocytosed predominantly by monocytes, and to a lesser extent also by T-cells. In a mixed lymphocyte reaction, T-cell proliferation was inhibited by spEVs. A direct effect of spEVs on T-cells was demonstrated when isolated T cells were activated by anti-CD3/CD28 coated beads. Again, spEVs interfered with T cell proliferation, as well as with the expression of CD25 and the release of IFN-γ, TNF, and IL-2. Moreover, spEVs stimulated the expression of Foxp3 and IL-10 by CD4+CD25+CD127- T cells, indicating differentiation into regulatory T-cells (Tregs). Prior treatment of spEVs with proteinase K revoked their effects on T-cells, indicating a requirement for surface-exposed spEV proteins. The adenosine A2A receptor-specific antagonist CPI-444 also reduced effects of spEVs on T-cells, consistent with the notion that the development of Tregs and their immune suppressive functions are under the influence of adenosine-A2A receptor signalling. We found that adenosine is highly enriched in spEVs and propose that spEVs are targeted to and endocytosed by T-cells, after which they may release their adenosine content into the lumen of endosomes, thus allowing endosome-localized A2A receptor signalling in spEVs targeted T-cells. Collectively, these data support the idea that spEVs can prime T cells directly for differentiation into Tregs
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