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

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

Expanding contraceptive options for PMTCT clients: a mixed methods implementation study in Cape Town, South Africa

Abstract Background Clients of prevention of mother-to-child transmission (PMTCT) services in South Africa who use contraception following childbirth rely primarily on short-acting methods like condoms, pills, and injectables, even when they desire no future pregnancies. Evidence is needed on strategies for expanding contraceptive options for postpartum PMTCT clients to include long-acting and permanent methods. Methods We examined the process of expanding contraceptive options in five health centers in Cape Town providing services to HIV-positive women. Maternal/child health service providers received training and coaching to strengthen contraceptive counseling for postpartum women, including PMTCT clients. Training and supplies were introduced to strengthen intrauterine device (IUD) services, and referral mechanisms for female sterilization were reinforced. We conducted interviews with separate samples of postpartum PMTCT clients (265 pre-intervention and 266 post-intervention) to assess knowledge and behaviors regarding postpartum contraception. The process of implementing the intervention was evaluated through systematic documentation and interpretation using an intervention tracking tool. In-depth interviews with providers who participated in study-sponsored training were conducted to assess their attitudes toward and experiences with promoting voluntary contraceptive services to HIV-positive clients. Results Following the intervention, 6% of interviewed PMTCT clients had the desired knowledge about the IUD and 23% had the desired knowledge about female sterilization. At both pre- and post-intervention, 7% of clients were sterilized and IUD use was negligible; by comparison, 75% of clients used injectables. Intervention tracking and in-depth interviews with providers revealed intervention shortcomings and health system constraints explaining the failure to produce intended effects. Conclusions The intervention failed to improve PMTCT clients’ knowledge about the IUD and sterilization or to increase use of those methods. To address the family planning needs of postpartum PMTCT clients in a way that is consistent with their fertility desires, services must expand the range of contraceptive options to include long-acting and permanent methods. In turn, to ensure consistent access to high quality family planning services that are effectively linked to HIV services, attention must also be focused on resolving underlying health system constraints weakening health service delivery more generally

Contraceptive Use and Method Preference among Women in Soweto, South Africa: The Influence of Expanding Access to HIV Care and Treatment Services

Objective: Preventing unintended pregnancy among HIV-positive women constitutes a critical and cost-effective approach to primary prevention of mother-to-child transmission of HIV and is a global public health priority for addressing the desperate state of maternal and child health in HIV hyper-endemic settings. We sought to investigate whether the prevalence of contraceptive use and method preferences varied by HIV status and receipt of highly active antiretroviral therapy (HAART) among women in Soweto, South Africa. Methods: We used survey data from 563 sexually active, non-pregnant women (18–44 years) recruited from the Perinatal HIV Research Unit in Soweto (May–December, 2007); 171 women were HIV-positive and receiving HAART (median duration of use = 31 months; IQR = 28, 33), 178 were HIV-positive and HAART-naïve, and 214 were HIV-negative. Medical record review was conducted to confirm HIV status and clinical variables. Logistic regression models estimated adjusted associations between HIV status, receipt of HAART, and contraceptive use. Results: Overall, 78 % of women reported using contraception, with significant variation by HIV status: 86 % of HAART users, 82 % of HAART-naïve women, and 69 % of HIV-negative women (p,0.0001). In adjusted models, compared with HIVnegativ

TUNABLE COMPOSITE MEMBRANES FOR GAS SEPARATIONS

Poly 2-(3-thienyl)ethylacetate (PAET) was synthesized and solution cast as thin films to form dense membranes. These membranes are mechanically robust and are redox active, holding out promise as gas separation materials. The permeability properties of PAET membranes were evaluated for N{sub 2} (0.048 {+-} 0.008 Barrers), O{sub 2} (0.24 {+-} 0.02 Barrers), CH{sub 4} (0.081 {+-} 0.005 Barrers), and CO{sub 2} (1.4 {+-} 0.1 Barrers). The corresponding selectivity values ({alpha}) were: O{sub 2}/N{sub 2} = 5.1, CO{sub 2}/N{sub 2} = 29, and CO{sub 2}/CH{sub 4} = 18

Reinforcement of macroscopic carbon nanotube structures by polymer intercalation: The role of polymer molecular weight and chain conformation

Novel polymer nanotube composites were fabricated by intercalating poly(vinylpyrrolidone) into Buckypaper from solution. This was carried out for both low (10kg∕mol) and very high (1.3Mg∕mol) molecular weight polymers. Measurements of the polymer mass uptake as a function of time allowed the calculation of diffusion coefficients as 1.66×10−9cm2∕s and 3.08×10−12cm2∕s for the low and high molecular weight strands, respectively. Taking into account the molecular weights, comparison of these coefficients suggests that each polymer type undergoes a different mode of diffusion: normal diffusion for the 10kg∕mol polymer, but reptation for the 1.3Mg∕mol polymer. This means that while the low weight polymer retains its randomly coiled conformation during diffusion and adsorption, the 1.3Mg∕mol molecule is forced to adopt an extended, high entropy state. These differences are reflected in the mechanical properties of the intercalated papers. While reinforcement was observed in all cases, modulus (increase ∼×3.5) and strength (increase ∼×6) enhancement occurred at lower polymer content for the longer chain polymer. However, the papers intercalated with the shorter chain molecules were much tougher (increase ∼×25). This is consistent with the conformation scheme described above