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A human colorectal explant culture was developed to assess the safety and efficacy of topical microbicides proposed for use in humans. Because any product marketed for vaginal application will likely be used for anal intercourse, it is important to evaluate these products in colorectal explant tissue. Microbicides tested included cellulose acetate 1,2-benzenedicarboxylate (CAP), PRO 2000, SPL7013, Vena Gel, and UC781, along with their accompanying placebos. Colorectal tissues were exposed to microbicides overnight and either fixed in formalin to evaluate toxicity by histological analysis or placed in 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT) to quantitatively determine tissue viability. Histological analysis showed minimal toxicity for CAP, UC781, and Vena Gel. Shedding of epithelium with intact lamina propria occurred for the PRO 2000 and SPL7013 products, and shedding of epithelium and necrosis of the lamina propria occurred in explants cultured with nonoxynol-9. The MTT assay confirmed these results for PRO 2000 (4% and 0.5%), SPL7013 (and placebo), and nonoxynol-9 but also demonstrated reduced viability for CAP. However, viability of tissues treated with all products was not significantly different from that of the medium control. Efficacy of the microbicides was evaluated by measuring human immunodeficiency virus type 1 (HIV-1) infection of explants in the absence or presence of products. All microbicide formulations tested were highly effective in preventing HIV infection. However, explants treated with some of the placebo formulations also exhibited a lower level of infection. Most of the products developed for vaginal application showed minimal toxicity and were effective in reducing HIV-1 infection in colorectal tissues. These results suggest that this model is useful for evaluating the safety and efficacy of topical microbicides when used rectally. [ABSTRACT FROM AUTHOR]

Human T cell lymphotropic virus type I (HTLV-I) is sexually transmitted. The purpose of this study was to determine the prevalence and risk factors for cervical shedding of HTLV-I DNA among Peruvian sex workers. HTLV tax DNA was detected in cervical specimens from 43 (68%) of 63 HTLV-I-infected sex workers and in samples obtained during 113 (52%) of 216 clinic visits between 1993 and 1997. Detection of HTLV DNA was associated with the presence of > or =30 polymorphonuclear cells (PMNs) within cervical mucus per 100x microscopic field (odds ratio [OR], 4.3, 95% confidence interval [CI], 1.8-10.1) and with the presence of cervical secretions (OR, 2.0; 95% CI 1.2-3.4). Hormonal contraceptive use (OR 1.7; 95% CI, 0.8-3.6) and concomitant cervical infection by Chlamydia trachomatis (OR, 1.5; 95% CI, 0.3-4.3) or Neisseria gonorrhoeae (OR, 1.1; 95% CI, 0.6-3.7) were not significantly associated with HTLV-I shedding. Our results suggest that cervicitis may increase cervical HTLV-I shedding and the sexual transmission of this virus. [ABSTRACT FROM AUTHOR]

Presents information on a study which examined the primary prostate and cervical epithelial cells and epithelial cell lines for human immunodeficiency virus type 1 (HIV-1) infection or transmission to peripheral blood mononuclear cells. Correlation between plasma viral RNA levels and HIV-1 transmission; Analysis of HIV receptor/coreceptor; Exposure of ephithelial cell to HIV-1; Results.

Examines the role of mycobacterium avium isolates in modulating HIV-1 replication using an in vitro resting T cell system. Replication not associated with cell activation or differential cytokine production or utilization; Addition of matrix metalloprotetinase inhibitors and n vivo regulars.