Incidence of and risk factors for sexual orientation-related physical assault among young men who have sex with men.

Objectives: We sought to determine incidence of, prevalence of, and risk factors for sexual orientation-related physical assault in young men who have sex with men (MSM).

Methods: We completed a prospective open cohort study of young MSM in Vancouver, British Columbia, surveyed annually between 1995 and 2004. Correlates of sexual orientation-related physical assault before enrollment were identified with logistic regression.

Sexual violence among two populations of men at high risk of HIV infection.

This study sought to compare the prevalence of, and relationship between, age at first experience of sexual violence and HIV and other health risk behaviors in two populations of men at high risk of HIV infection. Data were drawn from two cohorts: Vanguard, a prospective study of young men who have sex with men (MSM), and VIDUS, the Vancouver Injection Drug Users Study. Controlling for fixed sociodemographics, multivariate logistic regression was used to assess the relationship between age at first sexual violence (vs.

Randomized clinical evaluation of self-screening for anal cancer precursors in men who have sex with men.

Background: Self-collection of anorectal swab specimens could greatly facilitate the completion of prerequisite studies and future implementation of anal cancer screening among men who have sex with men (MSM). We therefore compared self- versus clinician- collection procedures with respect to specimen adequacy for cytological evaluation, concordance of paired cytological results, and concordance of cytological with biopsy results.

Methods: Paired self- and clinician- collected anorectal Dacron swabs for liquid-based (Thin Prep) cytological evaluation were collected in random sequence from a mostly HIV-1 seronegative cohort of young MSM in Vancouver.

Illustrated instructions for self-collection of anorectal swab specimens and their adequacy for cytological examination.

Background: Self-collection of anorectal swab specimens would facilitate screening for anal cancer precursors and sexually transmitted rectal infections among men who have sex with men (MSM). However, pictorial guides for self-collection were not previously available.

Goals: Develop and field test a set of illustrated self-collection instructions.

Crystal methamphetamine and ecstasy differ in relation to unsafe sex among young gay men.

Objective: Poly-substance use in gay social ('club') settings is common. Recent studies suggest a link between 'club' drug use and sexual risk behaviours. In this qualitative study, we compare and contrast two 'club' drugs: crystal methamphetamine and ecstasy (MDMA).

Similar sexual behaviors with casual partners among gay men with and without a regular partner.

Objectives: We hypothesized that men in a relationship would engage in less risky sexual activity with their casual partners compared to men with only casual partners.

Study: Cross-sectional data were collected between 1999 and 2003 in a study of young human immunodeficiency virus-seronegative gay men in Vancouver, British Columbia. We assessed the substance use and sexual behaviors of 156 men and compared those having casual partners in addition to 1 regular partner for the duration of the previous year (n = 43) to those reporting only casual partners during the previous year (n = 113).

Sexual risk profile of young men in Vancouver, British Columbia, who have sex with men and inject drugs.

We compared sexual risk behaviors of men who have sex with men and inject drugs (MSM/IDU) with those of other men who have sex with men (MSM). Of 910 MSM surveyed, 106 (12%) injected drugs in the previous year. MSM/IDU were younger than MSM and more likely to be HIV-seropositive, Aboriginal, economically disadvantaged, engaged in the trade of sex for money or drugs, and to report having female sexual partners.

Erratum: Optical Calibration of a Submicrometer Magnification Standard.

[This corrects the article on p. 267 in vol. 97.

Optical Calibration of a Submicrometer Magnification Standard.

The calibration of a new submicrometer magnification standard for electron microscopes is described. The new standard is based on the width of a thin thermal-oxide film sandwiched between a silicon single-crystal substrate and a polysilicon capping layer. The calibration is based on an ellipsometric measurement of the oxide thickness before the polysilicon layer is deposited on the oxide.