Maternal vitamin A deficiency and mother-to-child transmission of HIV-1.

Studies show that around 10-40% HIV-positive women will give birth to children who are also infected. However, the risk factors for transmission from mother to child are not well understood and the effects of maternal nutritional status are unknown. We conducted a study of vitamin A status in pregnant women as a risk factor for mother-to-child transmission of HIV in Malawi.

A partition coefficient determination method for nonvolatile chemicals in biological tissues.

Partition or distribution coefficients are critical elements in efforts designed to describe the uptake, distribution, biotransformation, and excretion of organic chemicals in biological systems. In order to estimate the partition coefficients needed to describe the biological distribution of low-volatility compounds, an experimental method was developed to measure partitioning of nonvolatile compounds into biological tissues. Blood, fat, muscle, liver, and skin were individually incubated in a saline solution containing the chemical of interest.

Factors influencing survival after AIDS: report from the Multicenter AIDS Cohort Study (MACS).

The objective of this study was to determine if clinical signs, symptoms, laboratory variables, and use of therapeutic or prophylactic agents have prognostic associations with survival after diagnosis of clinical AIDS. A total of 2,168 homosexual men, seropositive for human immunodeficiency virus type 1 (HIV-1) participated in a longitudinal cohort study of the greater metropolitan areas of Baltimore, Maryland, Washington, D.C.

Nonidentified responses in a proportional hazards setting.

Nonidentified response (NR), an important form of nonindependent censoring, is modelled in a proportional hazards setting. Methods to test for existence of and identify NR censored observations are developed. Incorporation of NR censoring information into appropriate algorithms can improve parameter and underlying baseline hazard estimation.

Maternal IgG1 and IgA antibody to V3 loop consensus sequence and maternal-infant HIV-1 transmission.

Maternal-infant transmission of HIV-1 occurs in 13-40% of pregnancies. Studies on transmission of maternal immunity to HIV antigens have used antigens from viruses not representative of clinical isolates and have been conflicting. Using a consensus peptide sequence based on HIV isolates found in Haiti, we found that Haitian mothers who transmitted infection to their offspring had significantly higher mean concentrations of IgG1 antibodies to the V3 loop of the primary neutralising domain of the viral envelope (gp 160) than non-transmitters (p = 0.

Beta 2-microglobulin and other early predictors of human immunodeficiency virus type 1-related wasting.

The objective of this study was to determine whether beta 2-microglobulin, neopterin, nutritional status, clinical status, immunosuppression, and hematologic status are predictors of human immunodeficiency virus (HIV)-related wasting and wasting syndrome. In addition, we aimed to determine which factors are early predictors and which are late predictors of wasting. For this cohort study of HIV-1-seropositive men seen semiannually from 1984 to 1991, a nested case-control design was used to analyze the predictive value of independent variables collected at baseline (first study visit for the seropositive cohort, first seropositive visit for seroconverters), 12 to 18 months prior, 6 to 12 months prior, and less than 6 months prior to the time at which case patients and control subjects were identified.

Clinical manifestations of AIDS in the era of pneumocystis prophylaxis. Multicenter AIDS Cohort Study.

Background: Among patients infected with human immunodeficiency virus type 1 (HIV-1), early and widespread use of prophylactic regimens against Pneumocystis carinii is changing the pattern of illnesses related to the acquired immunodeficiency syndrome (AIDS).

Methods: We conducted a subcohort analysis of 844 men with AIDS (87 percent of whom have since died) from a prospectively followed cohort of 2592 HIV-1-infected homosexual men.

Results: A total of 138 men received prophylaxis before the diagnosis of AIDS, but 39 (28 percent) nevertheless had P.

Flavodoxin is required for the activation of the anaerobic ribonucleotide reductase.

The inactive anaerobic ribonucleotide reductase from Escherichia coli is transformed by a multienzyme system and S-adenosylmethionine + NADPH into a radical protein that is enzymatically active. One of the activating enzyme components was earlier shown to be ferredoxin (flavodoxin):NADP+ reductase. Here we present evidence that flavodoxin, but not ferredoxin, also is a component of the system.

Depressive symptoms as predictors of medical outcomes in HIV infection. Multicenter AIDS Cohort Study.

Objective: To ascertain whether depressive symptoms as determined by the Center for Epidemiologic Studies-Depression scale (CES-D) predict accelerated mortality and worse medical outcomes in patients infected with human immunodeficiency virus (HIV).

Design: Eight-year cohort study with semiannual follow-up.

Setting: Community volunteers.

Pharmacological characterization of the pressor response to tachykinins in isolated perfused rat kidney.

The pharmacological effects of substance P (SP), neurokinin A (NKA), an amino terminal fragment of SP and related tachykinin receptor agonists on renal resistance vessels were assessed in isolated rat kidney perfused at constant rate (3 ml min-1 g-1 of tissue) with a modified Krebs-Ringer bicarbonate buffer. At a basal perfusion pressure (PP) of 75 +/- 6 mm Hg (n = 5), bolus injections of SP (1-33.3 nmol) had no significant vasoactive effect.

Dementia in AIDS patients: incidence and risk factors. Multicenter AIDS Cohort Study.

We determined incidence and future projections of dementia after AIDS onset in 492 homosexual men with AIDS in the Baltimore/Los Angeles sites of the Multicenter AIDS Cohort Study, 64 of whom developed dementia. We studied various risk factors for dementia, including demographic and clinical features, medical history, markers of immune status before AIDS, and zidovudine use. During the first 2 years after AIDS, HIV dementia developed at an annual rate of 7%.

Racial and ethnic differences in human immunodeficiency virus type 1 (HIV-1) seroprevalence among homosexual and bisexual men. The Multicenter AIDS Cohort Study.

To determine whether the excess prevalence of human immunodeficiency virus type 1 (HIV-1) infection in US black and Hispanic homosexual men relative to white men can be explained by differences in sociodemographic factors, history of sexually transmitted diseases, or sexual and drug-use behaviors, the authors conducted a cross-sectional analysis of baseline HIV-1 seroprevalence and HIV-1 risk factors among 4,475 non-Hispanic white, 234 Hispanic white, and 194 black homosexual men from four centers in the United States (Baltimore/Washington, DC, Pittsburgh, Chicago, and Los Angeles). HIV-1 seroprevalence was significantly higher in Hispanic men (50%; odds ratio (OR) = 1.83, 95% confidence interval (CI) 1.

Survivability and infectivity of viscerotropic Leishmania tropica from Operation Desert Storm participants in human blood products maintained under blood bank conditions.

To assess the potential for leishmaniasis being transmitted through blood transfusion, we studied the survival of Leishmania in blood products under blood bank storage conditions. We report that L. tropica- or L.

Epidemiologic analysis of Kaposi's sarcoma as an early and later AIDS outcome in homosexual men.

The authors separately studied the epidemiology (risk and risk factors) of Kaposi's sarcoma occurring as an initial acquired immunodeficiency syndrome (AIDS) outcome (early Kaposi's sarcoma) and later after a different initial AIDS outcome (later Kaposi's sarcoma) in a cohort of 2,591 human immunodeficiency virus type 1-infected gay men of the Multicenter AIDS Cohort Study between 1984 and 1992. Among 844 AIDS cases, 202 presented with early Kaposi's sarcoma, 101 subsequently developed later Kaposi's sarcoma, and 541 were not diagnosed with Kaposi's sarcoma. Overall, 37.

Composite risk score for Kaposi's sarcoma based on a case-control and longitudinal study in the Multicenter AIDS Cohort Study (MACS) population.

The possibility that an agent in addition to human immunodeficiency virus type 1 may be involved in the etiology of Kaposi's sarcoma in acquired immunodeficiency syndrome (AIDS) patients was investigated between 1984 and 1992 in this nested case-control analysis from the Multicenter AIDS Cohort Study (MACS) of homosexual and bisexual men. A total of 316 cases of Kaposi's sarcoma were identified and compared with 510 participants with AIDS and no evidence of cancer. More of the Kaposi's sarcoma cases were from Los Angeles and used a higher number of recreational drugs.

Culture of human monocytes with granulocyte-macrophage colony-stimulating factor results in enhancement of IFN-gamma receptors but suppression of IFN-gamma-induced expression of the gene IP-10.

The initiation and promulgation of chronic inflammation are controlled in part by the various pro-inflammatory and anti-inflammatory cytokines present at the site of injury. IFN-gamma and granulocyte-macrophage CSF (GM-CSF) are two cytokines that can contribute to the inflammatory state and possess both pro- and anti-inflammatory properties. However, the characterization of the interaction between GM-CSF-cultured monocytes and IFN-gamma is poorly documented.

Results of a single lateral rectus resection for divergence and partial sixth nerve paralysis.

A single 5.5-millimeter to 8.0-millimeter lateral rectus resection eliminated diplopia in five of six adult patients with divergence paralysis and in all three patients with a sixth cranial nerve paresis.

Assessment of the antibody response to the immunosuppressive/immunodominant region of HIV gp41 in a 5-year longitudinal study.

The antibody response of HIV-infected individuals to the 581-609 amino acid (aa) region of HIV-1 gp41 containing the putative immunosuppressive and immunodominant sequences was examined. Sera collected every 5 to 6 months over a period of 5 years from 50 HIV-1-infected homosexual and bisexual men, 25 of whom progressed to AIDS during the collection period, were monitored for changes in ELISA reactivity against synthetic peptides encompassing aa581-609 of gp41. The data obtained in this blinded, historical prospective study were analyzed with respect to changes in mean ELISA absorbance over time and differences in absorbance between patient groups (those who progressed to AIDS and those who did not).

A method to test for a recent increase in HIV-1 seroconversion incidence: results from the Multicenter AIDS Cohort Study (MACS).

We have formulated the problem of determining whether there has been an upturn in HIV-1 seroconversion incidence over the first five years of follow-up in the Multicenter AIDS Cohort Study (MACS) as that of locating the minimum of a quadratic regression or examination of two-knot piecewise spline models. Under a quadratic model, we propose a method to obtain a direct estimate and a bootstrap estimate for the location of the temporal turning point (local minimum) for HIV-1 seroconversion incidence and three methods to estimate confidence intervals for the location of the turning point for HIV seroconversion incidence: (1) Wald confidence interval estimate with or without log transformation assuming the asymptotic normality and applying the Delta method; (2) asymmetric confidence intervals using Fieller's Theorem and its modification; and (3) bootstrapping confidence intervals. Inferences for the temporal turning point based on Wald tests for a single regression term in a non-linear regression model were not reliable compared to inferences based on confidence intervals placed on calendar time.

High socioeconomic status is a risk factor for human immunodeficiency virus type 1 (HIV-1) infection but not for sexually transmitted diseases in women in Malawi: implications for HIV-1 control.

A total of 6600 pregnant urban women attending an antenatal clinic of a major hospital in Malawi were evaluated for risk factors for human immunodeficiency virus type 1 (HIV-1) infection. HIV-1 seroprevalence was 23% and significantly (P < .001) associated with markers of heterosexual activity (history of sexually transmitted diseases [STDs], more than one sexual partner, reports of husbands with other partners, and all prevalent STDs except chlamydial infection) and higher socioeconomic status (as measured by husband's education).