Self-perceived HIV risk and the use of risk reduction strategies among men who engage in transactional sex with other men in Ho Chi Minh City, Vietnam.

An emerging HIV epidemic can be seen among men who have sex with men (MSM) in Vietnam, with prevalence as high as 18%. Transactional sex represents a risk factor for HIV transmission/acquisition among MSM globally, particularly in urban contexts, but remains largely underinvestigated in Ho Chi Minh City (HCMC), Vietnam. In 2010, 23 MSM who reported exchanging sex for money in the last month completed a brief survey and semistructured qualitative interview at The Life Centre, a non-governmental organization in HCMC, to assess sociodemographics, individual- and structural-level HIV risk factors and explore acceptable future prevention interventions. Participants' mean age was 24 years. Equal proportions of respondents self-identified as heterosexual/straight, homosexual/gay, and bisexual. Participants had a mean of 158 male clients in the past year, with a median of 60 male clients in the past year (interquartile range [IQR]=70) and reported inconsistent condom use and inaccurate perceptions of HIV risk. Nearly half of the sample reported engaging in unprotected anal sex with a male partner in the past 12 months and one-third with a male client. Major themes that emerged for HIV prevention interventions with male sex workers were those that: (1) focused on individual factors (drug and alcohol use, barriers to condom use, knowledge of asymptomatic STIs, enhancement of behavioral risk-reduction skills, and addressing concomitant mental health issues); (2) incorporated interpersonal and relational contexts (led by peer educators, built interpersonal skills, attended to partner type and intimacy dynamics); and (3) considered the exogenous environments in which individual choices/relationships operate (stigma of being MSM in Vietnam, availability of alternative economic opportunities, and varied sexual venues). HIV prevention efforts are needed that address the specific needs of MSM who engage in transactional sex in HCMC. Universally, MSM endorsed HIV prevention interventions, suggesting a need and desire for efforts in this context.

A study of edema disease in pigs in Vietnam with particular reference to the use of autovaccine for the prevention of disease.

Edema disease caused by Escherichia coli is one of the most common diseases in postweaning piglets throughout Vietnam. Verotoxigenic E. coli (VTEC) was isolated from 197 of 261 samples (75.5%). All isolates were confirmed by basic biochemical tests and carbohydrate fermentation characteristics. Of these, 70.1% of isolates are hemolytic, 45% isolates belonged to serotypes O149:K91, possessed the VT2e gene, and was the most predominant VTEC pathotype associated with edema disease in pigs. Serogroup O139 accounted for 30% of the isolates, followed by serogroup O138 and O141 (25%). In addition to VT2e gene, the ST (72.7%) and LT (52.7%) genes were also recognized. A total of 10 representative isolates were subjected to toxigenicity testing by intraperitoneal injection in mice and experimental infection in pigs. It was shown that 100% of the mice were killed 17-24 h post injection (p.i.). All pigs experimentally infected with challenge strains and developed typical symptoms of edema disease 36-72 h p.i. A multivalent killed whole-cells vaccine containing aluminum hydroxide was prepared from 5 VTEC strains. The vaccine was 100% safe when administered by the intramuscular route into the pigs. A field trial for over 100,000 pigs (21-90 days old) showed that vaccinated pigs were protected against edema disease at a level of 90% compared to 100% of pigs from unvaccinated groups.

Antimicrobial resistance phenotypes of ETEC isolates from piglets with diarrhea in North Vietnam.

Both disk diffusion and broth micro-dilution assays were employed to determine the level of resistance in Enterotoxigenic Escherichia coli (ETEC) isolates (n = 170) obtained from preweaning piglet colibacillosis from the two different pig production systems (commercial piggeries and small holder farmers) in Vietnam. Overall, tetracycline, streptomycin, amoxicillin, trimethoprim/sulfamethoxazole, and chloramphenicol showed markedly higher rates of resistance. Both apramycin and ceftiofur are active against all ETEC isolates. These antimicrobials could be recommended as the drugs of choice for the treatment of E. coli infections in young pigs in North Vietnam. Resistance to third-generation cephalosporin (ceftiofur, ceftazidime, and cefoxitin) was not observed in Vietnamese ETEC isolates. Multiple resistances to greater than three antimicrobials were widely distributed (approximately 79.4%).

Effectiveness of the angiogenesis inhibitor TNP-470 in reducing the growth of human neuroblastoma in nude mice inversely correlates with tumor burden.

Angiogenesis plays an important role in the growth and metastasis of malignant tumors. We have previously reported that in children with neuroblastoma (NB), tumor vascularity directly correlates with metastatic disease, MYCN amplification, and poor outcome. The angiogenesis inhibitor TNP-470 has been shown to reduce the rate of NB growth in rodents with macroscopic tumors without ultimately impacting survival. To investigate whether TNP-470 could more effectively inhibit NB growth in animals with a low tumor burden, we treated 30 nude mice with minimal disease with this angiogenesis inhibitor (supplied by TAP Pharmaceuticals, Inc.). Therapy was initiated before tumors were clinically evident after s.c. inoculation of 5 x 10(6) cells from the MYCN-amplified NB cell line NBL-W-N. TNP-470 was administered 3 days/week, and after 12 weeks of treatment, 53% of the treated mice remained tumor free, whereas 100% of the control mice developed tumors (P < 0.0001). To further assess the relationship between the efficacy of TNP-470 treatment and tumor burden, TNP-470 was also administered s.c., 3 days/week, to mice with clinically evident small (<400 mm3; n = 15) and large (>400 mm3; n = 11) tumors. For animals with small tumors, the mean rate of growth was significantly decreased in the treated mice compared to the controls (P = 0.02). In contrast, there was no difference in the mean rate of tumor growth between animals with large tumors treated with TNP-470 and controls (P = 0.64). Our studies demonstrate that the effectiveness of TNP-470 inversely correlates with tumor burden. We speculate that TNP-470 may most effectively inhibit NB tumor growth in children with a low tumor burden.

Antiangiogenic therapy inhibits human neuroblastoma growth.

BACKGROUND: Angiogenesis plays a crucial role in the progression and metastasis of malignant solid tumors. In many types of cancer, including neuroblastoma, high tumor vascularity correlates with poor outcome. Recently, a number of angiogenic inhibitors have been identified that had antitumor activity in preclinical studies. PROCEDURE: To investigate the effect of the antiangiogenic agent TNP-470 on neuroblastoma tumor growth, we treated nude mice with TNP-470 after they were inoculated subcutaneously with 5 x 10(6) cells from the MYCN-amplified, human neuroblastoma cell line NBL-W-N. RESULTS: TNP-470 did not significantly affect tumor growth when it was administered to mice with large tumors (>600 mm3). However, when TNP-470 was administered in the setting of microscopic disease 12 hr following tumor cell inoculation, treated mice had a significantly improved tumor-free survival at 12 weeks (P < 0.001), and overall survival at 45 weeks (P < 0.001), compared to control animals. CONCLUSIONS: Our studies suggest that TNP-470 treatment may be most effective if it is administered in the setting of microscopic disease. We speculate that TNP-470 may inhibit neuroblastoma growth in children if treatment is initiated following intensive multimodality therapy, when residual disease is minimal.