Role of sexual behavior in the acquisition of asymptomatic Epstein-Barr virus infection: a longitudinal study.

BACKGROUND: The natural history of Epstein-Barr virus (EBV) infection is poorly defined. We report the prevalence and subsequent incidence of EBV infection in a cohort of sexually active young women and explore the social and sexual determinants of incident infections. METHODS: The study population was drawn from a cohort of young women, who were recruited for a longitudinal study of risk factors for early cervical neoplasia. A case-control analysis, nested within the cohort of 45 women for whom the first EBV sample tested was EBV-negative and who had further follow-up, was undertaken. EBV serostatus was determined in serum with a synthetic peptide-based enzyme-linked immunosorbent assay; EBV DNA was measured in cervical smears with the use of quantitative polymerase chain reaction. RESULTS: Of 1023 women 15-19 years of age included in this analysis, 978 (95.6%) tested positive for antibodies to EBV in their first serum sample. Of 45 women who tested negative, 22 subsequently acquired an asymptomatic EBV infection; the median time to seroconversion was 25 months (range, 1-60 months), and the median age at seroconversion was 18 years (range, 16-21 years). The risk of seroconversion increased with increasing number of sexual partners [compared with 1 partner, odds ratio (OR) was 1.28 for 2 partners and 2.23 for 3 or more; chiTREND 5.02; df 1; P < 0.05] and was greatest when a new sexual partner had been acquired in the 2 years before seroconversion (OR 4.78; chi 4.62; df 1; P < 0.05). EBV DNA was detected in 9 of 14 women who seroconverted and who also provided cervical samples. CONCLUSIONS: In susceptible young women, the acquisition of EBV infection is associated with their sexual behavior.

Peroxisome proliferator-activated receptors (PPARs) in health and disease.

Peroxisome proliferator-activated receptors (PPARs) belong to the superfamily of steroid-thyroid-retinoid nuclear receptors. PPARs are transcription factors activated by specific ligands and play an important role during cell signalling. Intensive study of PPARs during recent years has revealed their importance in both normal physiology and in the pathology of various tissues. They participate in the regulation of lipid metabolism, inflammation and the development of atherosclerosis or diabetes. They also play a role in the regulation of growth and differentiation of cancer. It has been suggested that PPAR ligands may have potent anticancer effects and therefore may serve as potential anticancer drugs. In this review we focus on a role of PPARs in breast cancer and in glial tumors of the brain.