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Biomedical subjects

Kenneth Mayer

Publications and source records attributed to Kenneth Mayer.

At least 19 recordsLinked to original sources
PubMed2006

Weight and body shape changes in a treatment-naive population after 6 months of nevirapine-based generic highly active antiretroviral therapy in South India.

BACKGROUND: The nutritional and body shape response after the initiation of highly active antiretroviral therapy (HAART) in resource-limited environments has not been documented. In this environment, nutritional compromise is a common complication of human immunodeficiency virus (HIV) infection. METHODS: We conducted a prospective study of 190 HIV-infected patients who initiated a nevirapine-based HAART regimen. CD4+ T cell count, body weight, body mass index, anthropometry, and bioelectrical impedance data were collected prior to initiation of therapy and after 6 months of therapy. RESULTS: The mean age of participants was 35 years, 85% of participants were male, and 59% received stavudine as 1 of the nucleosides in their initial HAART regimen. The members of the cohort were malnourished before the initiation of therapy and had a mean body mass index of 20.1 (calculated as weight in kilograms divided by the square of height in meters). Overall, body weight increased a mean of 2.8 kg (range, -12.5 to 22.5 kg), and CD4+ T cell counts increased by a mean of 140 cells/mm3. Patients were stratified into those who lost weight (loss of >1 kg, 22%; n=41), those whose weight remained stable (19%; n=37), and those who gained weight (gain of >1 kg, 59%; n=112). Patients in all groups retained body shape symmetry and experienced no change in waist-to-hip ratio or regional body shape by anthropometry. CONCLUSIONS: The group that lost weight and the group whose weight remained stable experienced significant CD4+ T cell count increases at 6 months. Although the majority of HIV-infected patients who received nevirapine-based HAART gained weight, there were participants who lost weight despite initiating their first HAART therapy.

Adult↗
PubMed2006

Willingness to receive an HIV vaccine among incarcerated persons.

BACKGROUND: Once an HIV vaccine becomes available, high-risk adults will be a target population for vaccination, and HIV vaccination programs for inmates may be a public health priority. Nothing is known about U.S. inmates' willingness to accept an anticipated HIV vaccine while incarcerated. The goal of this study was to examine inmates' attitudes toward a potential HIV vaccine. METHODS: In 2002, we interviewed 153 male and female inmates at the Rhode Island Department of Corrections (RIDOC) using a voluntary, anonymous survey. RESULTS: Ninety-three percent of inmates indicated they would be willing to receive a hypothetical HIV vaccine while incarcerated. Although 88% of inmates self-reported at least one HIV risk factor, only 20% perceived themselves to be at risk for HIV. CONCLUSION: Once an HIV vaccine becomes available, HIV vaccination programs in the correctional setting need to become a public health priority. These would be well received by inmates in Rhode Island.

Female↗
PubMed2006

Risk factors for HIV infection among men who have sex with men.

OBJECTIVES: Risk factors for HIV acquisition were examined in a recent cohort of men who have sex with men (MSM). DESIGN: A longitudinal analysis of 4295 HIV-negative MSM enrolled in a randomized behavioral intervention trial conducted in six US cities. METHODS: MSM were enrolled and assessed for HIV infection and risk behaviors semi-annually, up to 48 months. RESULTS: In multivariate analysis, men reporting four or more male sex partners, unprotected receptive anal intercourse with any HIV serostatus partners and unprotected insertive anal intercourse with HIV-positive partners were at increased risk of HIV infection, as were those reporting amphetamine or heavy alcohol use and alcohol or drug use before sex. Some depression symptoms and occurrence of gonorrhea also were independently associated with HIV infection. The attributable fractions of high number of male partners, use of alcohol or drugs before sex, and unprotected receptive anal intercourse with unknown status partners and the same with presumed negative partners accounted for 32.3, 29.0, 28.4 and 21.6% of infections, respectively. CONCLUSIONS: The challenge is to develop strategies to identify men in need. Interventions are needed to help men reduce their number of sexual partners, occurrences of unprotected anal intercourse, alcohol or drug use before sex and address other mental health issues.

Adult↗
PubMed2006

The effects of illicit drug use and HIV infection on sex hormone levels in women.

Drug use and HIV infection may affect sex hormone levels in women. One hundred and ninety-six women with and without a history of illicit drug use (50 HIV-negative and 148 HIV-infected), with regular menses, who never used antiretrovirals, were evaluated. Luteinizing hormone levels were significantly higher in women with a CD4 cell count <200/microl (p < 0.002). Current methadone use was associated with lower levels of total testosterone (p = 0.03) and higher levels of prolactin (p = 0.002); mean estradiol levels were 43% lower in women who used intravenous drugs (p < 0.001). Alcohol and crack cocaine use was not associated with sex hormone levels. Age, race, body mass index and degree of HIV immunosuppression were also associated with differences in sex hormone levels.

Adult↗
PubMed2005

The development and utility of a clinical algorithm to predict early HIV-1 infection.

The association between self-reported clinical factors and recent HIV-1 seroconversion was evaluated in a prospective cohort of 4652 high-risk participants in the HIV Network for Prevention Trials (HIVNET) Vaccine Preparedness Study. Eighty-six individuals seroconverted, with an overall annual seroconversion rate of 1.3 per 100 person-years. Four self-reported clinical factors were significantly associated with HIV-1 seroconversion in multivariate analyses: recent history of chlamydia infection or gonorrhea, recent fever or night sweats, belief of recent HIV exposure, and recent illness lasting > or =3 days. Two scoring systems, based on the presence of either 4 or 11 clinical factors, were developed. Sensitivity ranged from 2.3% (with a positive predictive value of 12.5%) to 72.1% (with a positive predictive value of 1%). Seroconversion rates were directly associated with the number of these clinical factors. The use of scoring systems comprised of clinical factors may aid in detecting early and acute HIV-1 infection in vaccine and microbicide trials. Organizers can educate high-risk trial participants to return for testing during interim visits if they develop these clinical factors. Studying individuals during early and acute HIV-1 infection would allow scientists to investigate the impact of the intervention being studied on early transmission or pathogenesis of HIV-1 infection.

Adolescent↗
PubMed2005

HIV sexual risk behavior over 36 months of follow-up in the world's first HIV vaccine efficacy trial.

Increased risk behavior among participants in HIV vaccine efficacy trials has been a concern. This study evaluated HIV sexual risk behavior among 5095 HIV-negative men who have sex with men (MSM) and 308 women enrolled in a randomized, double-blind, placebo-controlled efficacy trial of a bivalent rgp120 vaccine at 61 sites, primarily in North America. Sexual risk behavior data were collected at baseline and semiannually for 36 months. Overall, sexual risk behavior did not exceed baseline levels during the trial. Among MSM, younger age (< or =30 years), perceived assignment to vaccine, and nonblack race were associated with an increased probability of unprotected anal sex. Among women, unprotected vaginal sex initially decreased but was statistically equivalent to baseline by 24 months, whereas unprotected vaginal sex with HIV-infected partners decreased from baseline, where it remained throughout the trial. HIV sexual risk behavior did not increase among trial participants; however, it was substantial throughout the trial. Consistently high levels of risk behavior and the association of these behaviors to perceived assignment and demographic variables underscore the need for vigilant HIV risk reduction counseling, informed consent, and educational processes in the context of HIV vaccine efficacy trials.

AIDS Vaccines↗
PubMed2005

Knowledge, attitudes, and practices among physicians on HIV/AIDS in Quang Ninh, Vietnam.

Health care providers in Vietnam have been facing an increase in the number of HIV patients. However, little is known about physicians' knowledge, attitudes, and practices about HIV/AIDS and their correlates. A cross-sectional survey was conducted in 2003 with 151 physicians who had some contact with HIV-infected people. Anonymous data was collected by physicians' self-administration of the questionnaires. SAS version 8 (SAS, Cary, NC) was used for all descriptive and multivariate statistical analyses. We found that there were misconceptions on some transmission modes: 39.9% thought that good nutrition could protect from HIV/AIDS infection; 12.1% thought sharing the toilet with people living with HIV/AIDS (PLWHA) could transmit HIV infection. Only 41.6% of physicians knew that there was more than one type of HIV. Younger physicians or those with high patient volumes tended to be better informed. The one third of participants who reported positive attitudes regarding their interaction with HIV/AIDS patients were less likely to support mandatory testing or to exclude HIV/AIDS patients from their practices. Older physicians were more likely to have positive attitudes than the younger physicians. Approximately one fourth of the physicians prescribed antiretroviral medications but misuse was common. Among those prescribing antiretroviral medications, physicians working at provincial health care services were 3.1 times more likely to use antiretroviral medications than physicians working in district and commune health care services. In conclusion, even though Vietnamese physicians are providing health care for HIV/AIDS patients, the level of knowledge, attitudes, and practices regarding HIV/AIDS treatment suggest that further training is needed to improve their ability to deliver appropriate treatment to HIV/AIDS patients.

Adult↗
PubMed2005

Preparing for efficacy trials of vaginal microbicides in Indian women.

Vaginal microbicides are topical compounds that are expected to protect women against vaginal transmission of HIV and other sexually transmitted pathogens. A large number of compounds are being evaluated as possible microbicides. Considering the spread of the HIV epidemic among women in India, clinical trials on microbicides starting from the Phase I safety and acceptability studies to Phase III efficacy trials are important. Conducting efficacy trials is a major endeavour and this review discusses challenges and issues and the preparatory steps to make such efficacy trials possible in India.

Anti-Infective Agents, Local↗
PubMed2004

Substance use and sexual risk: a participant- and episode-level analysis among a cohort of men who have sex with men.

Prior reports associating substance use with sexual risk behavior have generally used summary measures and have not adjusted for participants' background levels of substance use. In this 1999-2001 US study (the EXPLORE study), the authors determined whether substance use during sex was independently associated with sexual risk during recent sexual episodes, as reported by 4,295 human immunodeficiency virus-negative men who have sex with men. The main outcome measure was serodiscordant unprotected anal sex (SDUA). The influence of participant-level characteristics was examined by using repeated-measures logistic models. In assessing the influence of episode-level predictors on SDUA, the influence of participant-level characteristics, including 6-month substance use, was removed by using conditional logistic regression, in effect making each participant his own control. The authors also adjusted for partner characteristics. Eleven percent of participants reported heavy alcohol use, 37% used poppers, 19% sniffed cocaine, and 13% used amphetamines. In the participant-level analysis, use of poppers, amphetamines, and sniffed cocaine as well as heavy alcohol use in the prior 6 months were independently associated with SDUA. In the conditional analysis, consumption of > or = 6 alcoholic drinks or use of poppers, amphetamines, or sniffed cocaine just before or during sex was independently associated with SDUA. The authors concluded that programs aimed at preventing human immunodeficiency virus transmission should emphasize the influence of substance use during sex on increased risk behavior.

Adolescent↗
PubMed2004

Persistence of inconsistent condom use: relation to abuse history and HIV serostatus.

This study longitudinally examines the relation between a history of experiencing childhood and adult physical or sexual abuse, and male condom use by women with or at risk for HIV. Abuse history and prospective condom use data were collected from 214 HIV infected and 189 uninfected women participating in the HIV Epidemiology Research Study (HERS) who were inconsistent condom users at baseline and received two safer sex counseling sessions. Analyses were conducted to assess the association between abuse history and condom use while controlling for sociodemographic variables and other risk factors. HIV-uninfected women with a history of adult physical abuse were five times less likely to report consistent condom use at 1-year follow-up than uninfected women without a history of abuse while holding control variables constant. Expectations of a negative reaction by the partner to suggested condom use did not explain this association. Though in the same direction as in uninfected women, abuse history was not significantly related to consistent condom use among HIV-infected women. These data indicate the need to develop risk prevention strategies tailored to uninfected women with a history of adult abuse. In lieu of specialized interventions, health care providers should assess women's abuse history and supplement HIV prevention counseling with mental health counseling when indicated.

Adolescent↗
PubMed2003

Longitudinal study of mucosal Candida species colonization and candidiasis among human immunodeficiency virus (HIV)-seropositive and at-risk HIV-seronegative women.

Acquisition and loss rates and estimates of duration of oral and vaginal Candida species colonization and candidiasis were examined among 868 human immunodeficiency virus (HIV)-seropositive and 437 at-risk HIV-seronegative women monitored prospectively during 1993-1999. Colonization and candidiasis acquisition rates, both oral and vaginal, were significantly higher among HIV-seropositive women; the magnitude of increase in candidiasis outcomes for HIV-seropositive women was greater for oral candidiasis than for vaginal candidiasis. Loss rates and estimates of duration of incident outcomes indicated that persistent mucosal colonization was more likely among HIV-seropositive women. However, results did not suggest persistent mucosal candidiasis. Higher HIV loads were significantly associated with increased odds of incident or persistent oral and vaginal colonization and candidiasis, an effect significantly reduced by highly active antiretroviral therapy for the incident outcomes of oral candidiasis and vaginal colonization. Cell-mediated immunodeficiency (CD4(+) lymphocyte count <500 cells/mm(3)) was significantly associated with increased odds of oral colonization or candidiasis, but not with vaginal colonization or candidiasis. In HIV-seropositive women, mucosal candidiasis is the consequence of multiple interacting factors.

AIDS-Related Opportunistic Infections↗
PubMed2003

Prevalence of and risk factors for viral infections among human immunodeficiency virus (HIV)-infected and high-risk HIV-uninfected women.

Viruses that can persist in the host are of special concern in immunocompromised populations. Among 871 human immunodeficiency virus (HIV)-infected and 439 high-risk HIV-uninfected women, seroprevalences of cytomegalovirus, hepatitis B virus, hepatitis C virus, and herpes simplex virus types 1 and 2 and prevalence of human papillomavirus DNA in cervicovaginal lavage fluids were all >50% and were 2-30 times higher than prevalences in the general population. Prevalences were highest among HIV-infected women, of whom 44.2% had >or=5 other infections, and were relatively high even among the youngest women (age 16-25 years). In multivariate analyses, viral infections were independently associated not only with behaviors such as injection drug use and commercial sex but also with low income, low levels of education, and black race. Disadvantaged women and women who engage in high-risk behaviors are more likely to be coinfected with HIV and other viruses and, thus, may be at high risk of serious disease sequelae.

AIDS-Related Opportunistic Infections↗
PubMed2003

Binding and neutralization activity of human IgG1 and IgG3 from serum of HIV-infected individuals.

The IgG1 and IgG3 subclasses represent the predominant antibody response to viral infections, including HIV. IgG subclasses differ in their interaction with antigen and functional effects due to specific physiochemical features. With an elongated hinge, IgG3 antibodies tend to have more segmental flexibility, which can render the antibody more effective at interacting with antigen. We have previously shown that the change of the human anti-CD4-binding site monoclonal antibody F105 from IgG1 to IgG3 results in neutralization of a T cell line-adapted isolate (TCLA) resistant to neutralization by the parental IgG1. In the studies presented here, we have purified IgG1 and IgG3 subclasses from the sera of HIV-infected individuals and tested for immunoreactivity with and neutralization of HIV. Purified total IgG3 tended to have less relative reactivity and mediated relatively poorer neutralization of either laboratory or primary isolates. IgG3 also tended to react relatively less well with gp160 and gp120 and more robustly with gp41 and p24. The contrasting results with serum, as opposed to F105, may result from the polyclonal nature of serum antibodies. There is also a failure to make a robust IgG3 response to neutralizing epitopes on envelope glycoproteins during natural infection. These studies suggest that the investigation of isotype effects on neutralization will require isotype-switched human monoclonal antibodies. Understanding isotype and neutralization will provide important data necessary for designing the most effective possible vaccines.

Antibodies, Monoclonal↗
PubMed2003

High-risk behaviors among men who have sex with men in 6 US cities: baseline data from the EXPLORE Study.

OBJECTIVES: We describe the prevalence of risk behaviors at baseline among men who have sex with men (MSM) who were enrolled in a randomized behavioral intervention trial conducted in 6 US cities. METHODS: Data analyses involved MSM who were negative for HIV antibodies and who reported having engaged in anal sex with 1 or more partners in the previous year. RESULTS: Among 4295 men, 48.0% and 54.9%, respectively, reported unprotected receptive and insertive anal sex in the previous 6 months. Unprotected sex was significantly more likely with 1 primary partner or multiple partners than with 1 nonprimary partner. Drug and alcohol use were significantly associated with unprotected anal sex. CONCLUSIONS: Our findings support the continued need for effective intervention strategies for MSM that address relationship status, serostatus of partners, and drug and alcohol use.

Adolescent↗
PubMed2003

An individually tailored intervention for HIV prevention: baseline data from the EXPLORE Study.

OBJECTIVES: We describe the intervention tested in EXPLORE, an HIV prevention trial aimed at men who have sex with men (MSM), and test the empirical basis of the individually tailored intervention. METHODS: Data on participants' self-efficacy, communication skills, social norms, and enjoyment of unprotected anal intercourse were examined in relation to sexual risk. Combinations of these factors, together with alcohol use and noninjection drug use, were also examined. RESULTS: The individual factors examined were associated with sexual risk behavior. The cohort was shown to be heterogeneous in regard to the presence of combinations of these risk-related factors. CONCLUSIONS: Baseline data from the EXPLORE study support the efficacy of the individually tailored intervention used.

Adolescent↗
PubMed2002

Human immunodeficiency virus (HIV)-specific antibody in cervicovaginal lavage specimens obtained from women infected with HIV type 1.

To evaluate correlates of anti-human immunodeficiency virus (HIV) type 1 (HIV-1) immunoglobulin (Ig) in the genital tract, anti-HIV-gp120 IgA and IgG titers in cervicovaginal lavage specimens obtained from 104 HIV-1-infected women were measured by enzyme-linked immunosorbent assay. Overall, 24% and 94% of women had detectable anti-gp120 IgA and IgG, respectively. CD4 cell count correlated negatively with total IgA concentration (r=-0.301; P=.0027) and positively with specific IgA activity (anti-gp120 IgA titer/total IgA concentration, r=0.306; P=.0023). Women with bacterial vaginosis had 5-fold lower anti-gp120 IgG titer (P=.0042), 5-fold lower total IgG concentration (P< or =.0001), and 4-fold higher specific IgG activity (P=.0474) compared with women who did not have bacterial vaginosis. Enhanced understanding of correlates of mucosal immunity to HIV-1 may assist in the design of vaccine strategies or in the prevention of vertical transmission of HIV-1.

Adult↗
PubMed2002

Sexual risk behaviors and implications for secondary HIV transmission during and after HIV seroconversion.

OBJECTIVES: To determine the potential for secondary HIV transmission among newly HIV-infected men who have sex with men (MSM) during their HIV antibody seroconversion period, and for the 12 months after seroconversion. DESIGN: A cohort study. METHODS: Risk assessment questionnaires administered before receipt of the first positive HIV antibody result, plasma and seminal viral load measurements, and risk assessments one month and quarterly after receipt of the first HIV-positive test, and generalized estimating equation modelling techniques to analyse behavioral trends. RESULTS: Of 66 seroconverters, more than half reported unprotected anal intercourse (UAI) with HIV-negative or unknown-serostatus partners during seroconversion, with 27% reporting insertive UAI with an HIV-negative partner. The initial median plasma viral load was 4.6 log/ml, the median seminal viral load was 2.7 log/ml, suggesting a high level of infectiousness. Compared with risk behavior during seroconversion, UAI with HIV-negative or unknown-serostatus partners was reduced after the receipt of positive antibody results; however, a substantial proportion of participants reported high-risk behaviors for transmission for 12 months of follow-up. After learning of their HIV infection, recent seroconverters did not reduce the risk of secondary transmission by engaging in proportionally more high-risk practices with HIV-infected partners (compared with HIV-negative or unknown-serostatus partners), or engaging in proportionally more receptive compared with insertive UAI. CONCLUSION: Substantial potential exists for secondary HIV transmission during and for one year after HIV seroconversion. Receipt of an HIV-positive test is associated with a significant reduction in risk behavior, reinforcing the need to identify and counsel recently HIV-infected MSM.

Adult↗