15 research outputs found

    Prevalence of anogenital HPV infection, related disease and risk factors among HIV-infected men in inner-city Johannesburg, South Africa: baseline findings from a cohort study.

    Get PDF
    BACKGROUND: Persistent high-risk human papillomavirus (HR-HPV) infection is associated with the development of anogenital cancers, particularly in men living with HIV (MLWH). We describe the prevalence of anogenital HPV infection, abnormal anal cytology and anogenital warts (AGWs) in MLWH in Johannesburg, and explore whether HPV infection and receipt of antiretroviral treatment is associated with detection of abnormal anal cytology and AGWs. METHODS: We enrolled a cohort of 304 sexually-active MLWH ≥18 years, who completed a questionnaire and physical examination. Genital swabs were collected from all men and intra-anal swabs from 250 (82%). Swabs were tested for HPV DNA and genotypes, and anal smears graded using the Bethesda classification. Factors associated with anogenital disease were assessed by logistic regression models. RESULTS: Two thirds were receiving antiretroviral treatment, for a median 33 months (IQR = 15-58) and 54% were HIV-virologically suppressed. Only 5% reported ever having sex with men. Among 283 genital swabs with valid results, 79% had any HPV, 52% had HR-HPV and 27% had >1 HR-HPV infection. By comparison, 39% of the 227 valid intra-anal swabs had detectable HPV, 25% had any HR-HPV and 7% >1 HR infection. While most anal smears were normal (51%), 20% had ASCUS and 29% were LSIL. No cases had HSIL or cancer. Infection with >1 HR type (adjusted OR [aOR] = 2.39; 95%CI = 1.02-5.58) and alpha-9 types (aOR = 3.98; 95%CI = 1.42-11.16) were associated with having abnormal cytology. Prevalence of AGWs was 12%. Infection with any LR type (aOR = 41.28; 95%CI = 13.57-125.62), >1 LR type (aOR = 4.14; 95%CI = 1.60-10.69), being <6 months on antiretroviral treatment (aOR = 6.90; 95%CI = 1.63-29.20) and having a CD4+ count <200 cells/μL (aOR = 5.48; 95%CI: 1.60-18.78) were associated with having AGWs. CONCLUSIONS: In this population, anogenital HR-HPV infection and associated low-grade disease is common, but severe anal dysplasia was not detected. Findings reinforce the need for HPV vaccination in men for preventing both AGWs and HR-HPV infection. Given the absence of anal HSILs, however, the findings do not support the use of anal screening programmes in this population

    Cyanobacterial nitrogenases: phylogenetic diversity, regulation and functional predictions

    Full text link

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

    Get PDF
    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Is obesity a risk for anal neoplasia in a group of HIV-infected Hispanics from Puerto Rico?

    No full text
    Background: Obesity has been associated with the development of cancer, including cervical cancer, probably due metabolic dysregulation and chronic inflammation. Given the similarity in the pathophysiology of cervical and anal neoplasia, we aimed at evaluating if overweight (BMI: 25–29.9 kg/m2) and obesity (BMI ≥30 kg/m2) are a risk for anal high-grade squamous intraepithelial lesions (HSIL) in a group of HIV-infected Hispanics from Puerto Rico. Methods: A cross-sectional study was performed using data from the medical records of 291 HIV-positive patients of the Anal Neoplasia Clinic of the University of Puerto Rico Comprehensive Cancer Center from June 2015 to April 2018. Logistic regression models were used to estimate the odds ratio (OR) with 95% confidence intervals (CI) for estimating the association between overweight and obesity with HSIL (based on histopathology and based on the definition of the LAST project), controlling for potential confounders. Results: Overall, 35.4% and 25.1% of patients were overweight and obese, respectively. The prevalence of HSIL was 45.2% among under/normal weight patients, 36.9% among overweight patients and 35.6% for obese patients (p-trend=0.16). Although decreased odds of HSIL were observed among overweight (OR=0.67, 95% CI=0.37–1.21) and obese (OR=0.71, 95% CI=0.36–1.38) patients than under/normal weight patients after adjusting for age, gender, history of diabetes, and having > 10 lifetime sexual partners, these results were not statistically significant. Conclusions: Overweight and obesity are frequent among our patients, but we found no significant association between overweight/obesity and HSIL. Although our study may be limited in sample size, future studies should further assess this association and the potential biological mechanisms for it

    United Kingdom: reforming the Westminster model

    No full text
    Marine nitrogen-fixing cyanobacteria are largely confined to the tropical and subtropical ocean. It has been argued that their global biogeographical distribution reflects the physiologically feasible temperature range at which they can perform nitrogen fixation. In this study we refine this line of argumentation for the globally important group of unicellular diazotrophic cyanobacteria, and pose the following two hypotheses: (i) nitrogen fixation is limited by nitrogenase activity at low temperature and by oxygen diffusion at high temperature, which is manifested by a shift from strong to weak temperature dependence of nitrogenase activity, and (ii) high respiration rates are required to maintain very low levels of oxygen for nitrogenase, which results in enhanced respiratory cost per molecule of fixed nitrogen at low temperature. We tested these hypotheses in laboratory experiments with the unicellular cyanobacterium Cyanothece sp. BG043511. In line with the first hypothesis, the specific growth rate increased strongly with temperature from 18 to 30?°C, but leveled off at higher temperature under nitrogen-fixing conditions. As predicted by the second hypothesis, the respiratory cost of nitrogen fixation and also the cellular C:N ratio rose sharply at temperatures below 21?°C. In addition, we found that low temperature caused a strong delay in the onset of the nocturnal nitrogenase activity, which shortened the remaining nighttime available for nitrogen fixation. Together, these results point at a lower temperature limit for unicellular nitrogen-fixing cyanobacteria, which offers an explanation for their (sub)tropical distribution and suggests expansion of their biogeographical range by global warming
    corecore