Sexually transmitted infections, sexual risk behaviors and the risk of heterosexual spread of HIV among and beyond IDUs in St. Petersburg, Russia.

AIMS: This study investigates whether sexual transmitted behaviors and infections (STIs) among injection drug users (IDUs) may promote the spread of HIV among and beyond IDUs in Russia. METHODS: We conducted a cross-sectional survey of behavior and tested for STIs in a convenience sample of 159 IDUs in St. Petersburg, Russia. RESULTS: The median age was 27 and 57% were male. Almost all were sexually active, half had casual partners and 40% reported > or =2 sex partners in the previous 3 months. Of those who answered, 81% reported sex without condoms, 44% reported having sex with at least one partner who was not an IDU. Of 139 (87%) subjects who were actively injecting, 29% reported receptive syringe sharing. Twenty percent of subjects were seropositive for HIV-1 and 42% of HIV-1-negative subjects tested positive for an STI. CONCLUSIONS: The sample exhibited high levels of sexual risk behaviors and STIs, and a large proportion had sexual partners who were not IDUs. This population requires comprehensive interventions that ensures access to condoms and sterile injection supplies and that encourage safer sexual behaviors in an attempt to keep sexual transmission of HIV low.

Organization, replication and modification of the human genome: synthesis and methylation of palindromic, repeated and unique HeLa nDNA sequences during the S-phase.

At least five supermethylated nDNA families have been found in HeLa cells. The concentration of 5-methylcytosine increases on palindromes from 1 to 5 hours during the nDNA duplicative phase, decreasing again at the 6th hour of S. The early S-phase involves the accumulation of 5-methylcytosines on the nDNA sequences reassociating near a Cot = 3 x 10(-1). Late S involves increment of this base on the sequences which reassociate near a Cot = 9 x 10(-1) and Cot = 7 x 10(1). The unique sequences show a moderate methylation from 3 to 6 hours of S. This information shows that genes are methylated with an order during the S-phase in a system in which nDNA organization, modification and replication appear to be severely subordinated one to another. The possible role of methylation of foldback nDNA in regulation of transcription during the eukaryotic cell life cycle is discussed.