24 research outputs found

    Bacterial vaginosis and the risk of trichomonas vaginalis acquisition among HIV-1 negative women.

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    Centre for the AIDS Programme of Research In South Africa.Background: The vaginal microbiota may play a role in mediating susceptibility to sexually transmitted infections, including Trichomonas vaginalis (TV). Methods: Data were analyzed from HIV-1-seronegative women participating in HIV Prevention Trials Network Protocol 035. At quarterly visits for up to 30 months, participants completed structured interviews and specimens were collected for genital tract infection testing. T. vaginalis was detected by saline microscopy. Bacterial vaginosis (BV) was characterized by Gram stain using the Nugent score (BV = 7Y10; intermediate = 4Y6; normal = 0Y3 [reference group]). Cox proportional hazards models stratified by study site were used to assess the association between Nugent score category at the prior quarterly visit and TV acquisition. Results: In this secondary analysis, 2920 participants from Malawi, South Africa, United States, Zambia, and Zimbabwe contributed 16,259 follow-up visits. Bacterial vaginosis was detected at 5680 (35%) visits,and TV was detected at 400 (2.5%) visits. Adjusting for age, marital status, hormonal contraceptive use, unprotected sex in the last week and TV at baseline, intermediate Nugent score, and BVat the prior visit were associated with an increased risk of TV (intermediate score: adjusted hazard ratio [aHR], 1.73; 95% confidence interval [CI], 1.21Y2.19; BV: aHR, 2.40; 95% CI, 1.92Y3.00). Sensitivity analyses excluding 211 participants with TV at baseline were similar to those from the full study population (intermediate score: aHR, 1.54; 95% CI, 1.10Y2.14; BV: aHR, 2.23; 95% CI, 1.75Y2.84). Conclusions: Women with a Nugent score higher than 3 were at an increased risk for acquiring TV. If this relationship is causal, interventions that improve the vaginal microbiota could contribute to reductions in TV incidence

    First Phase 1 Double-Blind, Placebo-Controlled, Randomized Rectal Microbicide Trial Using UC781 Gel with a Novel Index of Ex Vivo Efficacy

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    Objectives: Successful control of the HIV/AIDS pandemic requires reduction of HIV-1 transmission at sexually-exposed mucosae. No prevention studies of the higher-risk rectal compartment exist. We report the first-in-field Phase 1 trial of a rectally-applied, vaginally-formulated microbicide gel with the RT-inhibitor UC781 measuring clinical and mucosal safety, acceptability and plasma drug levels. A first-in-Phase 1 assessment of preliminary pharmacodynamics was included by measuring changes in ex vivo HIV-1 suppression in rectal biopsy tissue after exposure to product in vivo. Methods: HIV-1 seronegative, sexually-abstinent men and women (N = 36) were randomized in a double-blind, placebo-controlled trial comparing UC781 gel at two concentrations (0.1%, 0.25%) with placebo gel (1:1:1). Baseline, single-dose exposure and a separate, 7-day at-home dosing were assessed. Safety and acceptability were primary endpoints. Changes in colorectal mucosal markers and UC781 plasma drug levels were secondary endpoints; ex vivo biopsy infectibility was an ancillary endpoint. Results: All 36 subjects enrolled completed the 7-14 week trial (100% retention) including 3 flexible sigmoidoscopies, each with 28 biopsies (14 at 10 cm; 14 at 30 cm). There were 81 Grade 1 adverse events (AEs) and 8 Grade 2; no Grade 3, 4 or procedure-related AEs were reported. Acceptability was high, including likelihood of future use. No changes in mucosal immunoinflammatory markers were identified. Plasma levels of UC781 were not detected. Ex vivo infection of biopsies using two titers of HIV-1 BaL showed marked suppression of p24 in tissues exposed in vivo to 0.25% UC781; strong trends of suppression were seen with the lower 0.1% UC781 concentration. Conclusions: Single and 7-day topical rectal exposure to both concentrations of UC781 were safe with no significant AEs, high acceptability, no detected plasma drug levels and no significant mucosal changes. Ex vivo biopsy infections demonstrated marked suppression of HIV infectibility, identifying a potential early biomarker of efficacy. (Registered at ClinicalTrials.gov; #NCT00408538). © 2011 Anton et al

    Detectable clonal mosaicism and its relationship to aging and cancer

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    In an analysis of 31,717 cancer cases and 26,136 cancer-free controls from 13 genome-wide association studies, we observed large chromosomal abnormalities in a subset of clones in DNA obtained from blood or buccal samples. We observed mosaic abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of >2 Mb in size in autosomes of 517 individuals (0.89%), with abnormal cell proportions of between 7% and 95%. In cancer-free individuals, frequency increased with age, from 0.23% under 50 years to 1.91% between 75 and 79 years (P = 4.8 × 10(-8)). Mosaic abnormalities were more frequent in individuals with solid tumors (0.97% versus 0.74% in cancer-free individuals; odds ratio (OR) = 1.25; P = 0.016), with stronger association with cases who had DNA collected before diagnosis or treatment (OR = 1.45; P = 0.0005). Detectable mosaicism was also more common in individuals for whom DNA was collected at least 1 year before diagnosis with leukemia compared to cancer-free individuals (OR = 35.4; P = 3.8 × 10(-11)). These findings underscore the time-dependent nature of somatic events in the etiology of cancer and potentially other late-onset diseases

    Colonization of the Rectum by Lactobacillus

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    Quantitative Survival of Aerobic and Anaerobic Microorganisms in Port-A-Cul and Copan Transport Systems▿

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    Transport media should preserve the viability and stability of microorganisms in clinical specimens. In this study, the Port-A-Cul transport system and the Copan transport system without charcoal, both designed to preserve anaerobes, were evaluated. Dacron swabs were inoculated with two combinations of facultative and anaerobic organisms typically found in vaginal swab samples. Combination I contained Candida albicans, Escherichia coli, Enterococcus spp., group B streptococci, Lactobacillus crispatus, and Staphylococcus aureus. Combination II contained Lactobacillus iners, Peptoniphilus asaccharolyticus, Mycoplasma hominis, Prevotella bivia, Prevotella corporis, Porphyromonas asaccharolytica, Mobiluncus curtisii, Peptostreptococcus anaerobius, and Gardnerella vaginalis. Duplicate swabs were placed into the two transporters and held for 24, 48, 72, and 96 h at 4 and 24°C. Both transporters maintained the viability of organisms better at 4°C than at 24°C. Prevotella bivia and Prevotella corporis had a loss of viability in both transporters at both temperatures. However, at 24°C, there was a significantly greater loss of viability for Mycoplasma hominis, Prevotella bivia, Prevotella corporis, and Peptoniphilus asaccharolyticus when the organisms were stored in Copan transport medium than when they were stored in Port-A-Cul transport medium for 96 h (P < 0.002). Some organisms proliferated in the transport media, but when transporters were held at 24°C for 96 h, a significantly greater increase in the concentrations of group B streptococci and Candida albicans, Escherichia coli, and Enterococcus spp. organisms in Copan medium than in Port-A-Cul medium was observed (P < 0.002). At room temperature, the Port-A-Cul system is superior to the Copan system with respect to the preservation of fastidious microorganisms and the prevention of the proliferation of facultative organisms

    Protection of HIV Neutralizing Aptamers against Rectal and Vaginal Nucleases: IMPLICATIONS FOR RNA-BASED THERAPEUTICS*

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    RNA-based drugs are an emerging class of therapeutics. They have the potential to regulate proteins, chromatin, as well as bind to specific proteins of interest in the form of aptamers. These aptamers are protected from nuclease attack by chemical modifications that enhance their stability for in vivo usage. However, nucleases are ubiquitous, and as we have yet to characterize the entire human microbiome it is likely that many nucleases are yet to be identified. Any novel, unusual enzymes present in vivo might reduce the efficacy of RNA-based therapeutics, even when they are chemically modified. We have previously identified an RNA-based aptamer capable of neutralizing a broad spectrum of clinical HIV-1 isolates and are developing it as a vaginal and rectal microbicide candidate. As a first step we addressed aptamer stability in the milieu of proteins present in these environments. Here we uncover a number of different nucleases that are able to rapidly degrade 2′-F-modified RNA. We demonstrate that the aptamer can be protected from the nuclease(s) present in the vaginal setting, without affecting its antiviral activity, by replacement of key positions with 2′-O-Me-modified nucleotides. Finally, we show that the aptamer can be protected from all nucleases present in both vaginal and rectal compartments using Zn2+ cations. In conclusion we have derived a stable, antiviral RNA-based aptamer that could form the basis of a pre-exposure microbicide or be a valuable addition to the current tenofovir-based microbicide candidate undergoing clinical trials
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