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Biomedical subjects

Z Stein

Publications and source records attributed to Z Stein.

At least 19 recordsLinked to original sources
PubMed2006

Results of a tuberculosis-specific IFN-gamma assay in children at high risk for tuberculosis infection.

The specificity of the tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection (LTBI) is adversely affected by bacille Calmette-Guérin (BCG) vaccination and infection with non-tuberculous mycobacteria. Interferon-gamma release assays (IGRAs) using TB-specific antigens promise higher specificity. We compared a new IGRA and TST in 184 schoolchildren at high risk for LTBI. The IGRA and TST were positive in 33.2% and 43.5% of the children, respectively (P < 0.001). If studies confirm that this difference is due to higher specificity of this IGRA, it may have an important role to play in the diagnosis of LTBI and identification of children at true risk for TB.

Adolescent↗
PubMed2001

T-helper cell responses to HIV envelope peptides in cord blood: protection against intrapartum and breast-feeding transmission.

BACKGROUND: Acquired HIV-specific cell-mediated immune responses have been observed in exposed-uninfected individuals, and it has been inferred, but not demonstrated, that these responses constitute a part of natural protective immunity to HIV. This inference was tested prospectively in the natural exposure setting of maternal-infant HIV transmission in a predominantly breast-fed population. METHODS: Cord blood from infants of HIV-seropositive women in Durban, South Africa, were tested for in vitro reactivity to a cocktail of HIV envelope peptides (Env) using a bioassay measuring interleukin-2 production in a murine cell line. Infants were followed with repeat HIV RNA tests up to 18 months of age to establish which ones acquired HIV-infection. RESULTS: T-helper cell responses to Env were detected in 33 out of 86 (38%) cord blood samples from infants of HIV-seropositive women and in none of nine samples from seronegative women (P = 0.02). Among infants of HIV-seropositive mothers, three out of 33 with T-helper responses to Env were already infected before delivery (HIV RNA positive on the day of birth), two were lost to follow-up, and none of the others (out of 28) were found to be HIV infected on subsequent tests. In comparison, six out of 53 infants unresponsive to Env were infected before delivery, and eight out of 47 (17%) of the others were found to have acquired HIV infection intrapartum or post-partum through breast-feeding (P = 0.02). CONCLUSIONS: T-helper cell responses to HIV envelope peptides were detected in more than one-third of newborns of HIV-infected women; no new infections were acquired by these infants at the time of delivery or post-natally through breast-feeding if these T-helper cell responses were detected in cord blood.

Animals↗
PubMed2001

A multi-sectorial committee in directing HIV/AIDS-specific interventions in the occupational setting: an example from South Africa.

We present a descriptive analysis of a mechanism to coordinate and implement human immunodeficiency virus (HIV) prevention and care in the occupational setting. The mechanism we describe is a multidisciplinary committee composed of stakeholders in the occupational health environment including unions, management, medical researchers, and medical personnel. The site chosen for the analysis was a South African sugar mill in rural KwaZulu-Natal. The factory is situated in an area of high HIV seroprevalence and has a workforce of 400 employees. The committee was initiated to coordinate a combined prevention-care initiative. The issues that were important in the formation of the committee included confidentiality, trust, and the traditional roles of the stakeholder relationships. When these points were addressed through the focus on a common goal, the committee was able to function in its role as a coordinating body. Central to this success was the inclusion of all stakeholders in the process, including those with traditionally opposing interests and legitimacy conferred by the stakeholders. This committee was functionally effective and demonstrated the benefit of a freestanding committee dedicated to addressing HIV/acquired immune deficiency syndrome (AIDS) issues. We describe the implementation and feasibility of a multisectoral committee in directing HIV/AIDS initiatives in the occupational setting in rural South Africa.

Feasibility Studies↗
PubMed2001

Achieving safer sex with choice: studying a women's sexual risk reduction hierarchy in an STD clinic.

A flexible, risk-reduction approach, as compared with a single method approach, may increase sexually transmitted disease (STD)/HIV protection for women attending STD clinics. A brief intervention was tested in an observational study of 292 STD clinic patients in three distinct cohorts. These included subjects counseled on (1) the "women's safer sex hierarchy of prevention methods" (hierarchy cohort, n = 118), including the female condom (FC), male condom (MC), diaphragm, cervical cap, and spermicides, (2) MC only (n = 62), or (3) FC (n = 112) only. We evaluate method use and level of protection achieved at 6-month follow-up among the women in the hierarchy cohort and compare the level of unprotected sex across the three cohorts, using ordinal logistic regression analyses and an imputation procedure to account for attrition. In the hierarchy cohort, the MC, FC, spermicidal film, foam, suppository, and diaphragm were used with main partners by 80%,46%, 37%, 28%, 17%, and 5% of women, respectively. Spermicides were used frequently, mainly in conjunction with condoms. As compared with hierarchy subjects, both MC cohort subjects (OR = 2.3, p = 0.01) and FC cohort subjects (OR = 1.6, p = 0.11) were more likely to report 100% unprotected sex. The tendency for subjects to move toward higher levels of protection was observed most strongly in the hierarchy group. Hierarchical-type counseling, compared with single method counseling, leads to increased protection during sex among women at high risk of STD/HIV infection and should be implemented in STD clinics.

Adult↗
PubMed2001

Reporting on methods of subgroup analysis in clinical trials: a survey of four scientific journals.

Results of subgroup analysis (SA) reported in randomized clinical trials (RCT) cannot be adequately interpreted without information about the methods used in the study design and the data analysis. Our aim was to show how often inaccurate or incomplete reports occur. First, we selected eight methodological aspects of SA on the basis of their importance to a reader in determining the confidence that should be placed in the author's conclusions regarding such analysis. Then, we reviewed the current practice of reporting these methodological aspects of SA in clinical trials in four leading journals, i.e., the New England Journal of Medicine, the Journal of the American Medical Association, the Lancet, and the American Journal of Public Health. Eight consecutive reports from each journal published after July 1, 1998 were included. Of the 32 trials surveyed, 17 (53%) had at least one SA. Overall, the proportion of RCT reporting a particular methodological aspect ranged from 23 to 94%. Information on whether the SA preceded/followed the analysis was reported in only 7 (41%) of the studies. Of the total possible number of items to be reported, NEJM, JAMA, Lancet and AJPH clearly mentioned 59, 67, 58 and 72%, respectively. We conclude that current reporting of SA in RCT is incomplete and inaccurate. The results of such SA may have harmful effects on treatment recommendations if accepted without judicious scrutiny. We recommend that editors improve the reporting of SA in RCT by giving authors a list of the important items to be reported.

Data Interpretation, Statistical↗
PubMed2001

Effects of vitamin A supplementation during pregnancy and early lactation on body weight of South African HIV-infected women.

Effects of vitamin A supplementation during pregnancy and early lactation on maternal weight among HIV-1-seropositive South African women were examined. Three hundred twelve HIV-seropositive pregnant women between 28 and 32 weeks gestation were studied as part of a randomized, double-blind, placebo-controlled trial at the King Edward VIII Hospital in Durban, South Africa. Patients were randomized to receive placebo or 5,000 IU of retinyl palmitate and 30 mg of beta-carotene daily during pregnancy. At delivery, patients received placebo or 200,000 IU of retinyl palmitate. The main outcome measures were prenatal and postnatal maternal weight and weight loss at three months after delivery as measured in body mass index (BMI). Supplementation of vitamin A was not associated with improvements in prepartum weight gain but was significantly associated with improved weight retention three to six months after delivery (p = 0.02). The benefit of vitamin A supplementation appeared to be confined to subgroups with baseline CD4+ count < 200 cells/microL and serum retinol 0-20 micrograms/dL. Similar trends were observed in maintenance of postpartum BMI. However, no statistically significant associations were observed. Although there was no benefit of vitamin A supplementation on prepartum weight gain, a benefit on maintenance of postnatal weight was observed. The benefit was highest among those who were vitamin A-deficient or whose CD4+ count was < 200 cells/microL presupplementation. In populations for whom antiretroviral therapy is not readily available or accessible, the finding that vitamin A may improve postpartum weight lends some hope to a relatively inexpensive treatment which could be used for helping ameliorate some weight loss which is common during HIV infection.

Adult↗
PubMed2000

A randomized trial of hierarchical counseling in a short, clinic-based intervention to reduce the risk of sexually transmitted diseases in women.

INTRODUCTION: Effective public health interventions to reduce the incidence of sexually transmitted disease (STD), including HIV, among women are urgently needed. METHODS: A randomized trial among STD clinic patients of two types of counseling regarding methods to reduce disease transmission: a 'hierarchical' message (HP), with counseling on male condoms, female condoms, diaphragms, cervical caps, and spermicides (three formulations) and a single method message (SM) covering male condoms only or female condoms only. For this analysis, 1591 subjects received one of three educational messages at the central public STD clinic in Philadelphia. Disease incidence data for up to 6 months following the index visit were extracted from the clinic's electronic database. The primary outcome was STD reinfection: laboratory-confirmed trichomonas infection and/or clinical diagnoses of at least one of four STD. Rates were based on the full sample of randomized women (full sample) and on the subset who spontaneously returned between 22 days and 183 days following their initial visit (returners). RESULTS: Rates of trichomonas infection (SM 2.5% full sample and 12.9% returners versus HP 2.4% full sample and 11.5% returners) and clinical diagnoses (SM 6.3% full sample and 39.7% returners versus HP 6.9% full sample and 41.2% returners) did not differ across the two arms of the randomized trial, both as a straight percentage and in survival analysis (P = .81). CONCLUSION: At least in this single-session intervention trial, increasing choices in protection for women did not produce a change in disease risk compared with single-method approaches.

Adult↗
PubMed2000

Randomized controlled trial assessing the effect of vitamin A supplementation on maternal morbidity during pregnancy and postpartum among HIV-infected women.

OBJECTIVE: To determine whether low-cost treatment of HIV using vitamin A would be beneficial, we examined the effect of vitamin A supplementation on morbidity of HIV-1 infected women. METHODS: We conducted a randomized, double blind placebo-controlled trial at King Edward VIII Hospital, in Durban, South Africa. In total, 312 HIV-seropositive pregnant women between 28 and 32 weeks' gestation were recruited into this trial. Patients were randomized to receive placebo or 5,000 IU retinyl palmitate and 30 mg beta-carotene daily. At delivery of their children, patients received placebo or 200,000 IU retinyl palmitate. The main outcome measures were pre- and postnatal report of HIV-related symptoms. RESULTS: Vitamin A did not confer any significant beneficial effect on the report of either HIV or pregnancy-related symptoms during the pre- or postnatal period. CONCLUSION: In this study of HIV-infected pregnant women, vitamin A supplementation given in doses designed to decrease mother-to-infant transmission did not result in significant beneficial effect on reported symptoms pre- or postnatally. Further investigation with larger number of participants, tailoring supplementation for specific clinical conditions, outside the context of pregnancy, is required to help clarify the possible clinical benefits of vitamin A.

Adult↗
PubMed2000

Male-condom and female-condom use among women after counseling in a risk-reduction hierarchy for STD prevention.

BACKGROUND: A concern with hierarchy messages, which promote male condoms and female-controlled barrier methods along a prevention continuum, is that they may discourage condom use. GOAL: To measure male-condom and female-condom use among women who received hierarchy counseling and compare this with women counseled about condoms only. STUDY DESIGN: Three observational cohorts that correspond to prevention message received were assembled, and consisted of female sexually transmitted disease clinic patients who were counseled about male condoms, female condoms, or a hierarchy message. The hierarchy message promoted male and female condoms, the diaphragm and cervical cap, spermicides, and withdrawal, in descending order of effectiveness against sexually transmitted diseases. After counseling, women were interviewed and returned for follow-up visits at 2 weeks, 4 months, and 6 months. The outcome was the mean proportion of male condom- or female condom-protected coital acts at each follow-up visit in the hierarchy cohort. The outcome was dichotomized as high (> or = 70% of coital acts protected) or low (< 70%), and generalized estimating equations were used to compare observed follow-up condom use with baseline within the hierarchy cohort and observed follow-up condom use between cohorts. It was assumed that condom use in persons not present at 6 months was equal to baseline levels, and condom use estimates were calculated for each full cohort that was initially enrolled.

Cohort Studies↗
PubMed2000

Vitamin A and HIV infection: disease progression, mortality, and transmission.

Among HIV-infected individuals, many nutritional factors that influence disease progress, mortality, and transmission are not well understood. Of particular interest is the role of vitamin A. The benefits of vitamin A have been recognized since ancient times by Egyptian physicians who successfully treated night blindness with vitamin A. Contemporary scientists have since recognized the importance of vitamin A and have provided evidence that it may help in repairing damaged mucosal surfaces; what remains unclear, however, is its role during HIV infection. In this review, we examine the evidence provided in both observational studies and randomized controlled trials that assessed the effect of vitamin A during HIV infection.

CD4 Lymphocyte Count↗
PubMed2000

Culture, sexuality, and women's agency in the prevention of HIV/AIDS in southern Africa.

Using an ethnographic approach, the authors explored the awareness among women in southern Africa of the HIV epidemic and the methods they might use to protect themselves from the virus. The research, conducted from 1992 through 1999, focused specifically on heterosexual transmission in 5 sites that were selected to reflect urban and rural experiences, various populations, and economic and political opportunities for women at different historical moments over the course of the HIV epidemic. The authors found that the female condom and other woman-controlled methods are regarded as culturally appropriate among many men and women in southern Africa and are crucial to the future of HIV/AIDS prevention. The data reported in this article demonstrate that cultural acceptability for such methods among women varies along different axes, both over time and among different populations. For this reason, local circumstances need to be taken into account. Given that women have been clearly asking for protective methods they can use, however, political and economic concerns, combined with historically powerful patterns of gender discrimination and neglect of women's sexuality, must be viewed as the main obstacles to the development and distribution of methods women can control.

Adolescent↗
PubMed2000

Frequent use of lubricants for anal sex among men who have sex with men: the HIV prevention potential of a microbicidal gel.

OBJECTIVES: This study assessed frequency of rectal lubricant use, opinions about rectal microbicidal gels, and willingness to participate in acceptability trials of rectal microbicides among Latino men who have sex with men (MSM). METHODS: Latino MSM (N = 307) living in New York City were surveyed from October 1995 through November 1996. Eleven Latino MSM participated in a focus group. RESULTS: Among those having anal sex during the prior year, 93% used lubricants (59% always and 74% in at least 80% of sexual encounters) regardless of condom use. Of the 29 men who practiced anal sed but did not use condoms, 90% used lubricants with similar frequency. Of those using lubricants, 94% used at least 1 teaspoon per occasion. A transparent product, free of smell and taste, was favored. Of the MSM in the sample, 92% said that they would use a lubricant with an anti-HIV microbicidal agent, and 87% expressed interest in participating in an acceptability trial. Product and dispenser preferences also were discussed. CONCLUSIONS: A rectal lubricant with microbicidal properties appears acceptable and desirable to Latino men who have anal sex with other men.

Administration, Rectal↗
PubMed1999

Phase 1 trial of nonoxynol-9 film among sex workers in South Africa.

OBJECTIVES: To assess the acceptability and safety of a vaginal nonoxynol-9 film in a group of sex workers at a truck stop in South Africa. DESIGN: A randomized double-blinded crossover trial was conducted between April 1995 and July 1995. INTERVENTION: Seventy-two mg nonoxynol-9 film and an identical glycerine placebo film. METHODS: Following informed consent, each study participant was randomly assigned the designated pre-coded film for 1 month. The second month was a film-free washout period and the participants used the alternate film in the third month. Besides measuring behavioural and clinical outcomes, colposcopy examination for genital lesions, serology and microbiology investigations for sexually transmitted diseases and semi-quantitative PCR for vaginal HIV load estimates were performed. RESULTS: Twenty women participated in the study. The women reported, on average, 19 sexual encounters per week. Vaginal intercourse was protected 25% of the time by condoms. On average, 11 vaginal films, either nonoxynol-9 or placebos were inserted per week. There were no statistically significant differences between the two treatment groups for genital lesions (P = 0.29), reported side effects (P = 0.73), and viral load (P = 0.9). However, the proportions of clinically detected genital lesions (six out of eight versus two out of eight) and self-reported side-effects (five out of eight versus three out of eight) were higher in the nonoxynol-9 group when compared with the placebo group. Incident sexually transmitted diseases occurred more frequently in the placebo group. An increased viral load was associated with the development of a genital lesion (relative risk, 6.0; 95% confidence interval, 0.81-44.4). CONCLUSIONS: The 72 mg film formulation of nonoxynol-9 was an acceptable product for use in this population of sex workers. Although no statistically significant differences in adverse outcomes were detected, clinically there appeared to be an increase in minor lesions and self-reported side-effects with nonoxynol-9 and less protection against sexually transmitted diseases with the placebo. Furthermore, HIV shedding was correlated with the presence of incident vaginal or cervical lesions. This brings into question the potential narrow margin of safety for this product; additional Phase 2 studies are therefore required.

Administration, Intravaginal↗
PubMed1999

Safer sex strategies for women: the hierarchical model in methadone treatment clinics.

Women clients of a methadone maintenance treatment clinic were targeted for an intervention aimed to reduce unsafe sex. The hierarchical model was the basis of the single intervention session, tested among 63 volunteers. This model requires the educator to discuss and demonstrate a full range of barriers that women might use for protection, ranking these in the order of their known efficacy. The model stresses that no one should go without protection. Two objections, both untested, have been voiced against the model. One is that, because of its complexity, women will have difficulty comprehending the message. The second is that, by demonstrating alternative strategies to the male condom, the educator is offering women a way out from persisting with the male condom, so that instead they will use an easier, but less effective, method of protection. The present research aimed at testing both objections in a high-risk and disadvantaged group of women. By comparing before and after performance on a knowledge test, it was established that, at least among these women, the complex message was well understood. By comparing baseline and follow-up reports of barriers used by sexually active women before and after intervention, a reduction in reports of unsafe sexual encounters was demonstrated. The reduction could be attributed directly to adoption of the female condom. Although some women who had used male condoms previously adopted the female condom, most of those who did so had not used the male condom previously. Since neither theoretical objection to the hierarchical model is sustained in this population, fresh weight is given to emphasizing choice of barriers, especially to women who are at high risk and relatively disempowered. As experience with the female condom grows and its unfamiliarity decreases, it would seem appropriate to encourage women who do not succeed with the male condom to try to use the female condom, over which they have more control.

Acquired Immunodeficiency Syndrome↗