Many of the IgA producing plasma cells in murine gut are derived from self-replenishing precursors in the peritoneal cavity

Long term B lineage chimeras are used here to study the originof plasma cells in the mouse. Chlmeric mice are constructedby reconstituting lethally irradiated mice with peritoneal cells(PerC) and bone marrow cells from congenic pairs of mice differingIn Igh-C allotype. All conventional B cells in these mice expressthe allotype of the bone marrow donor and nearly all Ly-1 Blineage cells express the allotype of the PerC donor. FACS analysisand immunohistology of these mice shows that virtually all (sig⁺)B cells in peripheral lymphoid organs are derived from the bonemarrow donor. However, despite this overwhelming number of bonemarrow-derived B cells in these animals, immunohistologicalstaining of lymphold organs and gut shows that nearly half ofthe IgM, IgG, and IgA plasma cells derive from the PerC donor.These data demonstrate that the peritoneal cavity contains amajor reservoir of self-replenishing cells that play a significantrole in the mucosal immune response. The possibility that theseare B cells that belong to the Ly-1 B lineage is discussed.     

A meta-analytic review of HIV behavioral interventions for reducing sexual risk behavior of men who have sex with men

This meta-analysis examines the efficacy of international HIV prevention interventions designed to reduce sexual risk behavior of men who have sex with men (MSM). We performed a comprehensive search of published and unpublished English-language reports of HIV prevention interventions that focus on MSM and evaluated changes in risky sexual behavior or biologic outcomes related to sexual risk. Data from 33 studies described in 65 reports were available as of July 2003. Studies with insufficient data to calculate effect sizes were excluded from the meta-analysis. Interventions were associated with a significant decrease in unprotected anal intercourse (odds ratio [OR] = 0.77, 95% confidence interval [CI]: 0.65-0.92) and number of sexual partners (OR = 0.85, 95% CI: 0.61-0.94) and with a significant increase in condom use during anal intercourse (OR = 1.61, 95% CI: 1.16-2.22). Interventions successful in reducing risky sexual behavior were based on theoretic models, included interpersonal skills training, incorporated several delivery methods, and were delivered over multiple sessions spanning a minimum of 3 weeks. Behavioral interventions provide an efficacious means of HIV prevention for MSM. To the extent that proven HIV prevention interventions for MSM can be successfully replicated in community settings and adapted and tailored to different situations, the effectiveness of current HIV prevention efforts can be increased.     

Collaborative community research consortium: a model for HIV prevention.

In 1991, the Center for AIDS Prevention Studies (CAPS) at the University of California, San Francisco, set out to develop a model of community collaborative research that would bring the skills of science to the service of HIV prevention and the knowledge of service providers into the domain of research. Essential elements of the model were training for community-based organizations (CBOs) in research protocol writing, partnership between CBOs and CAPS researchers, program research funding, support to implement studies and analyze results, and a program manager to oversee the effort and foster the relationships between CBOs and researchers. In this article, the authors describe the CAPS model of consortium-based community collaborative research. They also introduce a set of papers, written by researchers and service providers, that describes collaborative research projects conducted by research institutions and CBOs and illustrates how collaboration can change both HIV prevention research and service.     

Pathways to recovery: recovery housing models for men who have sex with men (MSM)

Background & Aims: Gay, bisexual, and other men who have sex with men (MSM) face distinct recovery challenges. This mixed-methods study examines the service needs and help-seeking pathways of MSM (N?=?25) living in a group of recovery residences operated in Texas, one of which is a home specifically designated for gay and bisexual men.

Methods: Upon intake, adult MSM were recruited to complete an interview assessing the extent of their service needs as well as their recovery goals and expectations about their stay. Men were recruited regardless of whether they moved into the home designated for gay and bisexual men or into another one of the men’s homes.

Results: MSM in the sample reported high rates of health conditions, depression, victimization, and sex risk behaviors. A greater number of them entering the gay and bisexual men’s home reported being in recovery from amphetamine use, having a chronic medical problem, and being physically assaulted as an adult. The majority of MSM, regardless of home type, were seeking emotional and social support as well as accountability in their recovery home experience, but MSM in the gay and bisexual men’s home talked about emotion and social support most frequently and within the context of emotional safety.

Conclusions: MSM entering recovery housing have complex service needs. Recovery housing may play an important role in supporting recovery among MSM. Residences specifically for them could be tailored to address their unique needs by fostering connections to other sexual minorities in recovery and facilitating social identity transformation.     

Heterotopic Bone Formation About the Hip Undergoes Endochondral Ossification: A Rabbit Model

Background

Heterotopic ossification (HO) occurs most commonly after trauma and surgery about the hip and may compromise subsequent function. Currently available animal models describing the cellular progression of HO are based on exogenous osteogenic induction agents and may not reflect the processes following trauma.

Questions/purposes

We therefore sought to characterize the histologic progression of heterotopic bone formation in an animal model that recapitulates the human condition without the addition of exogenous osteogenic material.

Methods

We used a rabbit model that included intramedullary instrumentation of the upper femur and ischemic crush injury of the gluteal muscle. Bilateral surgical induction procedures were performed on 30 animals with the intention of inciting the process of HO; no supplemental osteogenic stimulants were used. Three animals were sacrificed at each of 10 predetermined times between 1 day and 26 weeks postoperatively and the progression of tissue maturation was graded histologically using a five-item scale.

Results

Heterotopic bone reliably formed de novo and consistently followed a pathway of endochondral ossification. Chondroid elements were found in juxtaposition with immature woven bone in all sections that contained mature osseous elements.

Conclusions

These results establish that HO occurs in an animal model mimicking the human condition following surgical trauma about the hip; it is predictable in its histologic progression and follows a pathway of endochondral bone formation.

Clinical Relevance

By showing a consistent pathway of endochondral ossification leading to ectopic bone formation, this study provides a basis for understanding the mechanisms by which HO might be mitigated by interventions.     

Improving recovery outcomes among MSM: The potential role of recovery housing

Background: Gay, bisexual, and other men who have sex with men (MSM) face unique recovery challenges. Recovery housing may play an important role in improving outcomes among MSM, but little is known about their experiences in these settings. Methods: This study examined 3-month outcomes among MSM (N = 22) living in a group of recovery residences in Texas, one of which is a home specifically designated for gay and bisexual men. Upon intake, adult MSM were recruited to participate in the study, which involved a baseline and 3-month phone interview and allowing study staff to access records maintained by the program about their stay. Results: At follow-up, only two (9.1%) reported used of any substances in the past 30 days. The vast majority (73%) had attended outpatient substance use treatment in the past three months, and 86% reported working for pay during the past 30 days. All participants reported attending four or more 12-step meetings in the past 30 days. Use of dysfunctional coping strategies significantly decreased, however, so did scores on health-related quality of life. Conclusions: MSM have complex treatment needs. Recovery housing may help improve outcomes among MSM by bridging formal substance use treatment with community-based recovery support.     

Sexual orientation and adolescent substance use: a meta-analysis and methodological review

AIMS: Several decades of research have shown that lesbian, gay and bisexual (LGB) adults are at high risk for substance use and substance use disorders (SUDs). These problems may often start prior to young adulthood; however, relatively little is known about risk for substance use in LGB adolescents. The primary aims of this paper were to conduct a meta-analysis of the relationship between sexual orientation and adolescent substance use and a systematic review and critique of the methodological characteristics of this literature. METHODS: Medical and social science journals were searched using Medline and PsychInfo. Studies were included if they tested the relationship between sexual orientation and adolescent substance use. Eighteen published studies were identified. Data analysis procedures followed expert guidelines, and used National Institutes of Health (NIH)-sponsored meta-analysis software. RESULTS: LGB adolescents reported higher rates of substance use compared to heterosexual youth (overall odds ratio = 2.89, Cohen's d = 0.59). Effect sizes varied by gender, bisexuality status, sexual orientation definition and recruitment source. None of the studies tested mediation and only one tested moderation. One employed a matched comparison group design, one used a longitudinal design, and very few controlled for possible confounding variables. CONCLUSIONS: The odds of substance use for LGB youth were, on average, 190% higher than for heterosexual youth and substantially higher within some subpopulations of LGB youth (340% higher for bisexual youth, 400% higher for females). Causal mechanisms, protective factors and alternative explanations for this effect, as well as long-term substance use outcomes in LGB youth, remain largely unknown.