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Biomedical subjects

D C Barrett

Publications and source records attributed to D C Barrett.

At least 37 records · Page 2Linked to original sources
PubMed1998

Histories of substance use and risk behavior: precursors to HIV seroconversion in homosexual men.

OBJECTIVES: This study compared history of substance use and episodic use in terms of HIV seroconversion. METHODS: A sample of 337 baseline HIV-negative gay men was followed for 6 years. Bivariate and survival analyses were used to compare 39 converters with nonconverters on substance use behaviors. RESULTS: Seroconverters were consistently more likely to report use of marijuana, nitrite inhalants, amphetamines, and cocaine than nonconverters. Consistent use of nitrite inhalants and amphetamines increases the relative risk of seroconversion, while episodic use does not. Both patterns of cocaine use increase seroconversion risk. CONCLUSIONS: There are three potential mechanisms for an increased risk of conversion due to consistent substance use.

HIV Seropositivity↗
PubMed1997

Sexually transmitted disease (STD) and HIV risk in heterosexual adults attending a public STD clinic: evaluation of a randomized controlled behavioral risk-reduction intervention trial.

OBJECTIVE: To evaluate the efficacy of a cognitive/behavioral skills-building intervention to prevent sexually transmitted diseases (STD) in high-risk heterosexual adults. DESIGN: A randomized controlled trial with assessments at baseline, and at 3 and 5 months. SETTING: San Francisco STD Clinic. PATIENTS: A total of 399 patients were randomly assigned to a four-session, individual, multi-component, cognitive/behavioral intervention (n = 199), or a brief standardized counseling session offered to all patients (n = 200). INTERVENTION: Based on the AIDS Risk-Reduction Model, the aims of the intervention were to increase prevention knowledge, reduce high-risk psychosocial factors, and build decision-making and communication skills to modify sexual behaviors. MAIN OUTCOME MEASURES: The primary outcome of interest was STD. The secondary outcome was number of risky sexual activities. RESULTS: There were no differences between the intervention (13%) and control (11%) groups in their acquisition of STD. Among men, condom use increased more at 3 months in the intervention group than the control group (56.8 versus 42.3%; P < 0.05). In addition, the mean number of sexual partners without condom use was lower in the intervention group than in the control group at 5 months (0.6 versus 0.9; P < 0.01). CONCLUSIONS: The results suggest that a cognitive/behavioral, skills-building intervention consisting of individual, multiple sessions and follow-up assessments can be implemented and evaluated with high-risk heterosexually active adults attending public STD clinics. Our intervention did not have a significant impact on STD, although it had some impact on behavior in men, but not in women.

Adolescent↗
PubMed1996

Depressive affect and survival among gay and bisexual men infected with HIV.

BACKGROUND: Although depression has been related to chronic disease processes and outcomes, studies examining the relationship between depression and disease progression in persons with human immunodeficiency virus (HIV) infection have produced inconsistent results. OBJECTIVE: To investigate whether depressive affect is associated with HIV mortality. METHODS: This was a prospective cohort study (San Francisco Men's Health Study) using a population based probability sample of single men living in areas of San Francisco, Calif, with high case rates of acquired immunodeficiency syndrome. Data collection was at 6-month intervals with up to 15 waves of follow-up. Subjects included all 402 homosexual or bisexual men who in July 1984 had serologic evidence of HIV infection and who survived a minimum of 1 wave after baseline. Depressive affect was measured at each wave with the affective subscale of the Center for Epidemiologic Studies-Depression Scale. Laboratory markers, World Health Organization staging, antiretroviral use, and hospitalizations were also used as predictor variables. The primary outcome measure was survival. RESULTS: In a Cox proportional hazards model, a time-dependent measure of depressive affect was associated with greater mortality (adjusted risk ratio, 1.67; 95% confidence interval, 1.01-2.78). CONCLUSIONS: Depressive affect was associated with mortality risk, highlighting the importance of diagnosis and treatment of depression among HIV-infected gay and bisexual men. Replication of this effect in incident cohorts with well-characterized dates of HIV infection is needed and, if replicated, an exploration of mediating pathways suggested.

Adult↗
PubMed1996

The efficacy of brief group counseling in HIV risk reduction among homosexual Asian and Pacific Islander men.

OBJECTIVES: The incidence of AIDS is increasing at a higher rate among homosexual Asian and Pacific Islanders (API) than white homosexual men in the United States. The number of homosexual API men engaging in unsafe sex is increasing at an alarming rate. HIV risk reduction is urgently needed in this population. SUBJECTS AND METHODS: We developed and evaluated culturally appropriate brief group counseling with 329 self-identified homosexual API recruited in San Francisco between 1992 and 1994. Participants were randomized into a single, 3-h skills training group or a wait-list control group. The intervention consisted of four components: (1) development of positive self-identity and social support, (2) safer sex education, (3) eroticizing safer sex, and (4) negotiating safer sex. Data were collected at baseline and 3 months after the intervention. RESULTS: Significant reductions in number of sexual partners were observed among all treatment subjects, regardless of ethnicity (P = 0.003). Treatment decreased the number of partners reported at 3-month follow-up by 46% [95% confidence interval (CI), 28-77]. Chinese and Filipino men further benefited from the intervention: treatment subjects from these two ethnic groups reduced unprotected anal intercourse at follow-up by more than half when compared to their counterparts (odds ratio = 0.41; 95% CI, 0.19-0.89; P = 0.024). CONCLUSIONS: We demonstrated the efficacy of brief group counseling in reducing HIV risk among homosexual API. Cities with significant API populations should adopt culturally tailored skills training as part of HIV prevention strategies for this group of homosexual men.

Adult↗
PubMed1996

Longitudinal changes in alcohol and drug use among men seen at a gay-specific substance abuse treatment agency.

OBJECTIVE: This study describes changes over a 12-month period in prevalence and frequency of alcohol and other drug use and correlates of change at 12 months in a sample of gay/bisexual men entering gay-identified outpatient substance abuse treatment. METHOD: A sequential sample of gay/bisexual men (n = 455) were recruited for a study in which substance use, sexual risk and psychological factors were assessed every 3 months. Changes in substance use were evaluated in 321 men who used in the 90 days before entering treatment and who completed at least one follow-up interview, whether or not they continued in treatment. RESULTS: At baseline, 95% of the sample reported alcohol use in the prior 90 days; 64%, marijuana/hashish use; 46%, amphetamine use; 33%, inhalant nitrites use; and 31%, cocaine use. Most men were polydrug users: 10% reported using only one drug (including alcohol); 39% used > or = 4 drugs. A marked reduction occurred in prevalence of use over time; declines on the order of 50% occurred in the first 90 days; prevalence then stabilized in remaining assessments. Frequency of usage by those reporting use of any given class of drugs also declined. No consistent predictors of reduction or cessation of use across different drug categories were found at 1 year. CONCLUSIONS: Substance use declined considerably in this sample. Given the scope of substance abuse problems among gay/bisexual men, and linkages to the HIV epidemic, considerable resources need to be focused on treatment and prevention for gay/bisexual men.

Adult↗
PubMed1996

Differences between gay men in primary relationships and single men: implications for prevention.

This study describes psychological and behavioral differences between gay men in primary relationships and single men from 1985 through 1989. In addition, differences in sexual behavior, relationship status, and relationship quality between HIV positive and HIV negative men were investigated. Data are from the San Francisco Men's Health Study and included only men who were gay identified and who participated in the longitudinal surveys in 1985, 1987 and 1989 (N = 452). Participants were stratified by relationship status and by HIV status. HIV positive men were less likely than HIV negative men to be in primary relationships (38.9% vs. 52.9%, respectively in 1989). In addition, men in relationships had higher rates of unprotected anal intercourse than single men (32.6% vs. 17.0%, respectively in 1989). Differences in psychosocial and behavioral variables were found and have considerable implications for prevention programs and mental health services trying to meet the needs of the gay men's community.

Adult↗
PubMed1995

Female partners of AIDS patients in Uganda: reported knowledge, perceptions and plans.

OBJECTIVE: To assess reported knowledge of a partner's AIDS diagnosis, perceived risk of HIV infection, need for HIV testing and future support plans among women partners of male Ugandan AIDS patients. SUBJECTS AND METHODS: A cross-sectional descriptive survey was conducted at New Mulago Hospital, Kampala, Uganda. The subjects were women partners of consecutive male AIDS patients admitted to medical wards. RESULTS: Only 12% reported their partner's AIDS diagnosis; women who reported knowing were less likely to be financially dependent on the partner. Most women (76%) reported being at risk of HIV; in general, these women were older, in a newer relationship, had less children and were in customary rather than civil or cohabiting marriages. More than half (56%) of the women reported a need for HIV testing, though few (5%) had been tested. Those who stated the need for HIV testing were in a newer relationship, had less children and were more financially independent of their husbands; women in a cohabiting type marriage were less likely to report their need for testing than those in a civil or customary marriage. About half (56%) reported plans for future support if their husbands did not recover; these women were more likely to be in an older relationship and to have more children. CONCLUSIONS: Most women partners of AIDS patients in New Mulago Hospital reported no knowledge of their husbands' diagnosis. Over half perceived a need to be tested but very few reported having been tested, and only half reported having planned for the future of their families. Interventions are urgently needed to address barriers to knowledge and to acknowledgement of a partner's AIDS diagnosis, to HIV testing and to planning for the future.

AIDS Serodiagnosis↗
PubMed1995

AIDS risk-taking behavior during carnival in São Paulo, Brazil.

OBJECTIVE: The Brazilian Carnival is thought to be a time when the risk of HIV infection is likely to be high. We therefore compared the risk during Carnival to risk in the past month among male samba school participants in São Paulo, Brazil. SUBJECTS AND METHODS: A cross-sectional study was conducted among 380 male samba school drummers randomly sampled during rehearsal for the 1993 Carnival in São Paulo by means of a 20-min interviewer-administered questionnaire. The main outcome variable was condom use with non-steady partners. RESULTS: The sexual behavior of 36.1% of subjects risked HIV infection, but only 9.7% of all subjects were at risk only during Carnival. Subjects with a sexual risk of HIV differed from those without risk in substance use, attitudes towards condoms and expectations about Carnival; those who were at risk only during Carnival did not differ from those who were at risk at other times. About half of the subjects had been given free condoms during Carnival, although few of the men at risk had actually used them. CONCLUSIONS: Though more than a third of the drummers were at risk of HIV infection, only a small per cent were at risk only during Carnival. The level of sexual risk of HIV infection is probably better explained by factors in the men's daily lives, rather than through information on risks taken during Carnival. These results raise questions concerning the efficacy of universal condom distribution during Carnival, since about half of the men were given condoms but few of those at risk actually used them. A targeted distribution of condoms to populations with a high demonstrated risk may be more effective in preventing new HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Correlates of sexual risk-taking among gay male substance abusers.

This paper examines sexual risk-taking within a sample of sexually active gay and bisexual men entering substance abuse treatment (n = 383), and identifies correlates of unprotected anal sex within this group. Sexual risk-taking was high, with 55% of these men engaging in anal intercourse without a condom within a 90-day period. Correlates of unprotected anal sex varied somewhat when looking at unprotected anal sex with a primary partner only and with non-primary partners; substance use variables (number of drugs used, use of inhalant nitrites or stimulant drugs with sex, length of time since use of alcohol/drugs, loss of control problems associated with alcohol/drug use) appear to play more of a role in unprotected anal sex with non-primary partners. Overall, logistic regression analyses indicated that sexual risk was greater for those who were more sexually active, enjoyed unprotected anal sex with withdrawal prior to ejaculation, did not approve of sex outside of a love relationship, and identified themselves as more risky. In addition, those who reported more social problems due to substance use had fewer expectations that substance use increased risk, had been HIV-tested, and used reappraisal/problem-solving coping strategies showed greater risk with a primary partner only. Sexual risk with non-primary partners was greater for those who used more drugs, reported more difficulty avoiding high-risk sex when aroused and were HIV+. The paper discusses the implications of these findings for the design of sexual risk-reduction interventions.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Depressive symptoms and CD4 lymphocyte decline among HIV-infected men.

OBJECTIVE: To investigate whether high levels of depressive symptomatology at baseline predict more rapid decline of CD4 lymphocyte counts and progression of clinical disease in persons infected with the human immunodeficiency virus (HIV). DESIGN: Prospective cohort study with semiannual data collection waves and up to 66 months of follow-up. SETTING: Population-based probability sample of single men in areas of San Francisco with high case rates of the acquired immunodeficiency syndrome (AIDS). SUBJECTS: All 330 homosexual or bisexual men who by January 1985 had serological evidence of HIV infection but had not had an AIDS diagnosis. Analysis of CD4 lymphocyte change was performed for 277 subjects (83.9%) who had three or more CD4 lymphocyte counts recorded during the study period January 1985 through July 1990. OUTCOME MEASURES: Depressive symptoms were assessed using the Center for Epidemiologic Studies-Depression scale (CES-D). All subjects were classified according to two indicators of depression: (1) as overall depressed using a cut point of 16 or higher on the complete CES-D, and (2) as affectively depressed using a cut point of more than 1 SD above the mean on a subscale of the CES-D measuring affective depression. Laboratory and symptom measures, antiretroviral use, demographics, and behavioral measures were also used. The primary outcome measure was the rate of change of the CD4 lymphocyte count. Secondary outcomes were AIDS-free survival and mortality. RESULTS: At baseline 65 subjects (19.7%) were classified as depressed on the overall scale and 53 (16.1%) were classified as depressed on the affective scale. The unadjusted mean rate of CD4 change was 38% greater for overall depressed subjects than for the overall nondepressed (-0.0812 vs -0.0588 x 10(9)/L [-81.2 vs -58.8/microL per year; P = .07) and 34% greater for affectively depressed subjects than for the affectively nondepressed (-0.0804 vs -0.0598 x 10(9)/L per year; P = .06). In hierarchical multivariate analysis controlling for antiretroviral use, symptoms, and other predictors, baseline overall depression was associated with an excess decline in CD4 count of -0.0285 x 10(9)/L per year (95% confidence interval, -0.0496 to -0.0073), and baseline affective depression was associated with an excess decline in CD4 count of -0.0236 x 10(9)/L per year (95% confidence interval, -0.0464 to -0.0008). Neither overall depression nor affective depression was significantly associated with earlier AIDS diagnosis or earlier mortality. CONCLUSIONS: Overall depression and affective depression predicted a more rapid decline in CD4 lymphocyte counts; this association was not attributable to baseline physiological differences. While the mechanism of the association remains unknown and cannot be addressed directly by this study, the data suggest that it can be explained neither as simply a reflection of perceived somatic symptoms nor as the result of differences in recreational drug and alcohol use. Further study is necessary to determine whether treating depression can alter the course of HIV infection.

Adult↗
PubMed1991

Effect of long-term community health education on body mass index. The Stanford Five-City Project.

Being overweight is a risk factor for cardiovascular heart disease and other medical problems. The purpose of this study was to examine the effect of a community-wide cardiovascular risk reduction trial (the Stanford Five-City Project) on body mass index. In the Stanford Five-City Project, two treatment cities (n = 122,800) received a 6-year mass media and community organization cardiovascular risk reduction intervention. Changes in the treatment cities were compared with two control cities (n = 197,500) for changes in knowledge of risk factors, blood pressure, plasma cholesterol level, smoking rate, body mass index, and resting pulse rate after 5-1/3 years of the education program. Both cohort and cross-sectional (independent) samples were used in the study. In the independent surveys, subjects in the treatment communities gained significantly less weight than subjects in the control communities (0.57 kg compared with 1.25 kg) over 6 years. In the cohort, there were no significant overall differences. The study provides some evidence that a community health education program may help reduce weight gain over time, but more effective methods must be developed if this important risk factor is to be favorably affected in broad populations.

Adult↗
PubMed1990

Social class disparities in risk factors for disease: eight-year prevalence patterns by level of education.

This article examines the associations between education, a primary indicator of social class, and six risk factors for disease. Data are presented on a sample of 3,349 individuals ages 25-74 years who participated in one of four cross-sectional surveys conducted by the Stanford Five-City Project between 1979 and 1986. The six risk factors examined are knowledge about health, cigarette smoking, hypertension, serum cholesterol, body mass index, and height. A highly significant pattern of associations was found between education level and the six risk factors, in the direction of higher risk among those with lower education (all P values less than 0.01). These associations persisted for both sexes and in the younger as well as the older age groups, with the exception of cholesterol values for males and for those in the 50 to 74-year-old age group. Furthermore, all associations remained highly significant after controlling for income and occupation, two other indicators of social class. When a summary-adjusted risk score was plotted against year of survey for the five education levels, a gradient of effect was observed where each progressive education level showed a decrease in total risk score. This gradient was replicated in all four cross-sectional surveys, providing evidence for the consistency of the findings over time.

Adult↗
PubMed1985

The homogeneity of rat liver microsomal cytochrome P-448 activity and its role in the activation of benzo[a]pyrene to mutagens.

The O-deethylation of ethoxyresorufin and the metabolic activation of benzo[a]pyrene to mutagens were determined in hepatic microsomal preparations from control and induced animals. An excellent direct correlation (r = 0.95) has been observed between ethoxyresorufin O-deethylase and the metabolic activation of benzo[a]pyrene to mutagens when the fraction of cytochromes P-450 present as cytochrome P-448 was altered by the administration of phenobarbitone and 3-methylcholanthrene alone or in combination with 9-hydroxyellipticine. The correlation between these activities was maintained following treatment of animals with Arochlor 1254, benzo[a]pyrene, benzo[e]pyrene, 7,12-dimethylbenzo[a]anthracene,2-anthramine and 2-naphthylamine.

Animals↗
PubMed1982

Reintroduction of anti-inflammatory drug therapy after drug-associated gastro-intestinal disturbances.

The relative risks associated with anti-inflammatory drug prescription for patients with an earlier history of drug-associated gastro-intestinal disturbance have been investigated in a retrospective study. Under these circumstances ibuprofen was well tolerated. The risks associated with modified salicylates (principally aspirin in enteric-coated form) and indomethacin suppositories also appeared to be relatively slight. Retreatment with phenylbutazone, oral indomethacin, naproxen and combination therapy was hazardous.

Administration, Oral↗