427 research outputs found

    Geometry and Adhesion of Extracellular Domains of DC-SIGNR Neck Length Variants Analyzed by Force–Distance Measurements

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    Force-distance measurements have been used to examine differences in the interaction of the dendritic cell glycan-binding receptor DC-SIGN and the closely related endothelial cell receptor DC-SIGNR (L-SIGN) with membranes bearing glycan ligands. The results demonstrate that upon binding to membrane-anchored ligand, DC-SIGNR undergoes a conformational change similar to that previously observed for DC-SIGN. The results also validate a model for the extracellular domain of DC-SIGNR derived from crystallographic studies. Force measurements were performed with DC-SIGNR variants that differ in the length of the neck that result from genetic polymorphisms, which encode different numbers of the 23-amino acid repeat sequences that constitute the neck. The findings are consistent with an elongated, relatively rigid structure of the neck repeat observed in crystals. In addition, differences in the lengths of DC-SIGN and DC-SIGNR extracellular domains with equivalent numbers of neck repeats support a model in which the different dispositions of the carbohydrate-recognition domains in DC-SIGN and DC-SIGNR result from variations in the sequences of the necks

    Knowledge and Perceptions of Latent Tuberculosis Infection among Chinese Immigrants in a Canadian Urban Centre

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    Background. Since most tuberculosis (TB) cases in immigrants to British Columbia (BC), Canada, develop from latent TB infection (LTBI), treating immigrants for LTBI can contribute to the eradication of TB. However, adherence to LTBI treatment is a challenge that is influenced by knowledge and perceptions. This research explores Chinese immigrants\u27 knowledge and perceptions towards LTBI in Greater Vancouver. Methods. This mixed methods study included a cross-sectional patient survey at BC\u27s Provincial TB clinics and two focus group discussions (FGDs) with Chinese immigrants. Data from FGDs were coded and analyzed in Simplified Chinese. Codes, themes, and selected quotes were then translated into English. Results. The survey identified a mean basic knowledge score: 40.0% (95% CI: 38.3%, 41.7%). FGDs confirmed that Chinese immigrants\u27 knowledge of LTBI was low, and they confused it with TB disease to the extent of experiencing LTBI associated stigma. Participants also expressed difficulties navigating the health system which impeded testing and treatment of LTBI. Online videos were the preferred format for receiving health information. Conclusion. We identified striking gaps in knowledge surrounding an LTBI diagnosis. Concerns of stigma may influence acceptance and adherence of LTBI treatment in Chinese immigrants. Integrating these findings into routine health care is recommended

    Stability of methylation markers in head and neck squamous cell carcinoma

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    BackgroundAs cancer progresses, methylation patterns change to promote the tumorigenic phenotype. However, stability of methylation markers over time and the extent that biopsy samples are representative of larger tumor specimens are unknown. This information is critical for clinical use of such biomarkers.MethodsNinety‐eight patients with tumor specimens from 2 timepoints were measured for DNA methylation in the promoter regions across 4 genes.ResultsThere were no significant differences in overall methylation of CCNA1 (cyclin A1), NDN (necdin), deleted in colorectal carcinoma (DCC), and cluster of differentiation 1a (CD1A) within paired specimens (p values = .56, .17, .66, and .58, respectively). All genes showed strong correlations between paired specimens across time. Methylation was most consistent for CCNA1 and NDN over time.ConclusionThis report provides the first evidence that methylation markers measured in biopsy samples are representative of gene methylation in later specimens and suggests that biopsy markers could be representative biomarkers for use in defining personalized treatment utilizing epigenetic changes. © 2015 Wiley Periodicals, Head Neck 38: E1325–E1331, 2016Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137576/1/hed24223.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137576/2/hed24223_am.pd

    Diverse sapovirus genotypes identified in children hospitalised with gastroenteritis in selected regions of South Africa

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    BACKGROUND : Sapoviruses (SaVs) are recognised as causative agents of gastroenteritis worldwide. How-ever, data on the genetic diversity of this virus in Africa are lacking, particularly in the form of currentlong-term studies. OBJECTIVE : To determine the genetic diversity of SaVs in children hospitalised with gastroenteritis in SouthAfrica (SA). STUDY DESIGN : From April 2009 to December 2013, SaVs were characterised from stool specimens fromchildren hospitalised with gastroenteritis in four provinces of SA.RESULTS : Fourteen different SaV genotypes were identified from the 221 strains that were characterised.Genogroup (G) IV predominated overall and was detected in 24% (53/221) of specimens. The other iden-tified genotypes included six belonging to GI (GI.1–GI.3, GI.5, GI.6, and GI.7) and seven belonging to GII(GII.1–GII.7). CONCLUSION : This study has provided the first comprehensive data on the genetic diversity of SaVs in aclinical setting in SA, contributing to the global knowledge of this virus.http://www.elsevier.com/locate/jcv2017-03-31hb2016Medical Virolog

    Epidemiology of human astroviruses among children younger than 5 years : prospective hospital‐based sentinel surveillance in South Africa, 2009‐2014

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    BACKGROUND : The epidemiology of human astroviruses (HAstVs) in hospitalised patients less than 5 years of age from selected sites in South Africa was investigated. Diarrheagenic stool specimens collected from April 2009 to May 2014 were screened retrospectively for selected viruses, bacteria and parasites. METHOD : Patient data were analysed to identify epidemiologic factors most frequently detected with HAstV infections. The following case‐comparisons were investigated; HAstV‐positive and HAstV‐negative children, human immunodeficiency virus (HIV)‐infected and HIV‐uninfected (HAstV‐positive) children and HIV‐exposed and unexposed (HAstV‐positive HIV‐uninfected) children. RESULTS : Astrovirus was identified in 7.0% (234/3340) of cases and most frequently in ages 7 to 12 months (9.2%; 90/975) compared with 5.8% to 6.6% in other 6‐month age groups. No seasonal trends were observed. More HAstVs were detected in children from homes that used outdoor water sources (7.6%) compared to indoor sources [5.7%; adjusted odds ratio (aOR), 1.5; 95% CI, 1.1‐2.1; P = 0.009]. Astroviruses were detected in 8.4% (67/799) of HIV‐uninfected patients that were exposed to HIV compared with 5.9% (74/1257) of HIV‐unexposed patients ( P = 0.032). CONCLUSION : Astroviruses were most prevalent in children aged 7 to 12 months and were detected throughout the study period. The study was limited as only hospitalised patients were investigated and no comparisons were made to diarrhoea‐free control groups. Future HAstV surveillance should include community‐based studies and children presenting at outpatient facilities.The Rotavirus Sentinel Surveillance Program was funded by GlaxoSmithKline (E‐Track 200238). Research was supported by a National Health Laboratory Service Research (004_94494) (SN) and the Poliomyelitis Research Foundation (15/22) (NAP).http://wileyonlinelibrary.com/journal/jmv2020-02-01hj2018Medical Virolog

    Pretreatment dietary intake is associated with tumor suppressor DNA methylation in head and neck squamous cell carcinomas

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    Diet is associated with cancer prognosis, including head and neck cancer (HNC), and has been hypothesized to influence epigenetic state by determining the availability of functional groups involved in the modification of DNA and histone proteins. The goal of this study was to describe the association between pretreatment diet and HNC tumor DNA methylation. Information on usual pretreatment food and nutrient intake was estimated via food frequency questionnaire (FFQ) on 49 HNC cases. Tumor DNA methylation patterns were assessed using the Illumina Goldengate Methylation Cancer Panel. First, a methylation score, the sum of individual hypermethylated tumor suppressor associated CpG sites, was calculated and associated with dietary intake of micronutrients involved in one-carbon metabolism and antioxidant activity, and food groups abundant in these nutrients. Second, gene specific analyses using linear modeling with empirical Bayesian variance estimation were conducted to identify if methylation at individual CpG sites was associated with diet. All models were controlled for age, sex, smoking, alcohol and HPV status. Individuals reporting in the highest quartile of folate, vitamin B12 and vitamin A intake, compared with those in the lowest quartile, showed significantly less tumor suppressor gene methylation, as did patients reporting the highest cruciferous vegetable intake. Gene specific analyses identified differential associations between DNA methylation and vitamin B12 and vitamin A intake when stratifying by HPV status. These preliminary results suggest that intake of folate, vitamin A and vitamin B12 may be associated with the tumor DNA methylation profile in HNC and enhance tumor suppression

    Taking Snapshots, Living the Picture: The Kodak Company's Making of Photographic Biography

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    In this article I explore how George Eastman and the Eastman Kodak Company encouraged early twentieth-century camera users to think of snapshots as pictorial biographies. Analysing a wide selection of articles from the Kodakery, one of Kodak’s most popular magazines in the first half of the twentieth century, I demonstrate that the company endeavoured to secure its prominence in the photographic market by encouraging members of the public to integrate picture-taking into everyday life, and regard photographs as self-contained repositories of biographical details. To this end, Kodak framed the speedy pace of life that characterised the practice of being in the industrial world as a reality that allegedly weakened the human eye and mind’s ability to process the experience of life itself. Introducing the idea of the camera and picturetaking as the ultimate cures for this purported human deficiency, Kodak provided camera users with advice that helped to cement an understanding of photographs as surrogates of both the changing human body and individual subjects’ experiences in time and space. As in popular culture, and sometimes also in academia, photographs are still widely regarded as pictorial biographies, I argue that considering the popular photographic industry’s role in shaping photographic practices and photographs’ perceived meanings can help clarify the relationship between photography and life-writing
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