Rapamycin even when combined with cyclosporine attenuates tumor growth but does not induce regression of established walker sarcomas.

PURPOSE: To investigate the effect of rapamycin (Rapa) on growth or regression of Walker tumor used alone or in combination with CsA and MMF. METHODS AND RESULTS: Wistar rats received water (control) or Rapa or CsA 1 day before and daily after tumor inoculation. On day 10, tumor volume (TV) was smaller among Rapa (6.8 +/- 2.7 cm(3)) versus control (14.9 +/- 4.2 cm(3), P <.001) or CsA (13.9 +/- 3.0 cm(3), P <.0001) treatment groups. Tumor growth was greatly inhibited (TI) by Rapa (-49.3%). Tumor weight (TW) was significantly (P < or =.001) lower in Rapa (3.7 +/- 1.2 g) versus CsA (8.8 +/- 2.1 g) or control (7.3 +/- 2.0 g) animals. An additional set of rats received water or Rapa or CsA + Rapa, or MMF + Rapa 1 day before tumor inoculation. On day 10, TV and TW were lower among Rapa (3.8 +/- 1.5 cm(3)) and Rapa + CsA (3.1 +/- 1.2 cm(3)) and Rapa + MMF (4.6 +/- 2.7 cm(3)) groups compared with controls (10.9 +/- 3.8 cm(3), P <.0001). TI was -52.1% in Rapa, -68.5% in Rapa + CsA, and -63% in Rapa + MMF. A further set of rats received either water or Rapa on the day 4 after tumor inoculation. On day 10, tumor growth and TW among the Rapa and control groups were similar. CONCLUSION: Rapamycin greatly inhibited tumor growth when used alone or with CsA or MMF, but did not produce an effect on a well-established Walker sarcoma.

Mycophenolate mofetil attenuates Walker's tumor growth when used alone, but the effect is lost when associated with cyclosporine.

PURPOSE: To investigate the effect of mycophenolate mofetil on Walker's carcinosarcoma, without versus with the growth and regression of cyclosporine. METHODS AND RESULTS: Wistar rats received water (control), MMF, and/or CsA-N 1 day before tumor inoculation. On day 10, tumor volume (TV) was lower among MMF (10.3 +/- 2.8 cm(3)) than control rats (14.9 +/- 4.2 cm(3), P <.05), and similar to that in CsA-N (13.9 +/- 3.0 cm(3)). However, tumor weight (TW) was significantly lower in MMF (5.2 +/- 2.0 g) than CsA-N (8.8 +/- 2.1g) or control hosts (7.3 +/- 2.0 g, P < or =.01). Growth was inhibited by MMF (-28.2%). In experiment II, CsA-N, MMF + CsA-N, or water were introduced 1 day before tumor inoculation. On day 10, TV and TW were similar for MMF + CsA-N as compared to CsA-N and control animals. In experiment III, water or MMF was introduced on the day 4 after tumor inoculation. On day 10, tumor growth are TW in the MMF group was similar to, that in the controls. CONCLUSIONS: MMF produces an anti-tumoral effect against Walker's carcinosarcoma. However, this inhibitory effect was lost when MMF was used in combination with CsA-N or administered in the presence of a well- established tumor.

Self-reported sexual behaviour and HIV risk taking among men who have sex with men in Fortaleza, Brazil.

OBJECTIVES: To describe and identify sociodemographic and behavioural characteristics and other factors related to high-risk behaviour for HIV infection of men who have sex with men (MSM) living in Fortaleza, Brazil. METHODS: A survey was carried out among 400 MSM aged 14-65 years and recruited through the snowball technique or in gay-identified venues. A semi-structured questionnaire was conducted among them. Logistic regression analysis was used to model the dichotomous outcome (high risk or low risk). RESULTS: Forty-four per cent of the participants reported engaging in high-risk sexual behaviour in the previous year. MSM less informed about AIDS, reporting more sexual partners, reporting at least one female partner in the previous year, having anal sex as the favourite way to have sex, and having great enjoyment of unprotected anal sex were more likely to be engaged in risky behaviour. Twenty-three per cent of participants reported at least one sexual contact with women during the previous year. Two-thirds of men who had unprotected sex with their female partners also had unprotected anal sex with their male partners. CONCLUSIONS: A large proportion of MSM in Fortaleza still remain at elevated risk for contracting HIV infection. The factors predictive of high-risk sexual behaviour are significant in spreading HIV infection among the MSM population and also among their female partners. The lifestyles of these men are different to those of men from other parts of Brazil or outside the country. Preventive interventions need to be culturally and socially specific in order to be effective.