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Biomedical subjects

A Saah

Publications and source records attributed to A Saah.

At least 37 records · Page 2Linked to original sources
PubMed1994

Incident HIV-1 infection in a cohort of young women in Butare, Rwanda.

OBJECTIVE: To determine the incidence of HIV-1 infection and associated risk factors among young, seronegative, and sexually active women in a mixed rural and urban population in southern Rwanda. DESIGN: A prospective cohort study. METHODS: Between October 1991 and April 1993, we completed a 2-year follow-up survey among HIV-1-seronegative women aged < or = 30 years at the time of their initial HIV-1 screening during pregnancy. All women aged < or = 25 years and a randomly selected sample of 26-30-year olds were invited to participate from five prenatal clinics in the Butare region. The interview focused on potential risk factors for HIV-1 acquisition during the 2-year interval between blood collection. RESULTS: Out of 1524 women selected, 1150 (75%) participated in the follow-up survey. The 2-year incidence of HIV-1 infection was 2.7% [95% confidence interval (CI), 1.8-3.9]. Teenage women were at the highest risk (incidence, 10.5%; 95% CI, 5.2-19.4), with incidence leveling off with increasing age (P < 0.001). Women who began sexual activity recently were also at higher risk; the lowest risk category consisted of women aged 26-30 years with 5 or more years of sexual experience. The more urban the geographic residence of the woman, the more likely she was to have acquired HIV-1 infection (P < 0.001). In the urban and peri-urban zones, the poorest women were at significantly higher risk of incident HIV-1 infection than women reporting higher household income. In a multivariate analysis, young maternal age, marital status (being single, divorced or widowed), multiple sexual partners, and a history of sexually transmitted diseases remained strongly associated with incident HIV-1 infection. Geographic residence, hormonal contraception, and receipt of injections were no longer significantly associated with incident HIV-1 infection when these other factors were accounted for simultaneously. CONCLUSION: Among young Rwandan women, the early years of sexual activity are particularly dangerous for acquisition of HIV-1 infection. Interventions should focus on young teenagers before they become sexually active.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Detection of HIV-1 proviral DNA in sperm from HIV-1-infected men.

OBJECTIVE: Sexual transmission is a major mode of the spread of HIV-1, although the cellular and molecular mechanisms are poorly defined. In this study, we sought to assess the cellular reservoirs of HIV-1 proviral DNA in the semen of HIV-1-infected men. DESIGN AND METHODS: An in situ polymerase chain reaction (IS-PCR), which amplifies specific genes within intact cells, was used to evaluate levels of HIV-1 provirus in seminal cells from HIV-1-infected men in various stages of clinical disease. RESULTS: Initial studies demonstrated HIV-1 provirus in relatively low numbers (1:100 to 1:6000) of both the seminal mononuclear cells and sperm from certain HIV-1-infected men. To extend these findings, 94 seminal samples from HIV-1-infected men were evaluated. HIV-1 proviral DNA was detected in seminal cells of a significant percentage of HIV-1-infected men (45%) at all stages of clinical immunodeficiency. Both seminal mononuclear cells and sperm (35 and 33% of samples studied, respectively) harbored HIV-1 proviral sequences. HIV-1-harboring sperm are shown to stain positively for HIV-1 in the mid-pieces of these cells, with rarer staining of the sperm heads. CONCLUSIONS: HIV-1 proviral DNA can be demonstrated by IS-PCR in seminal mononuclear cells and sperm from certain HIV-1-infected men. The role played by proviral DNA in these cells in the sexual transmission of this retroviral agent will require further study.

CD4 Lymphocyte Count↗
PubMed1994

Thrush and fever as measures of immunocompetence in HIV-1-infected men.

The occurrence of Pneumocystis carinii pneumonia (PCP) in human immunodeficiency virus type 1 (HIV-1)-infected individuals with high CD4+ counts indicates poor immunologic function. Thrush and persistent fever, easily recognized clinically, are potential measures of immunocompetence. This analysis establishes the complex interactions of CD4+ count, thrush, and persistent fever to predict the occurrence of PCP. Analyses used 20,632 person visits from 2,568 HIV-1-seropositive homosexual or bisexual men participating in the Multicenter AIDS Cohort Study (MACS). Comprehensive examinations were conducted semiannually, while occurrences of PCP were assessed continuously. The occurrence of thrush and fever increase in frequency as CD4+ levels decrease. The relative hazard of PCP in the presence of thrush compared with the absence of thrush rises (p < 0.05) from 1 for the lowest CD4+ category to approximately 5 in the highest categories. The relative hazard of PCP in the presence of fever compared with the absence of fever is above one (p < 0.05) in all CD4+ categories. No cases of PCP occurred in individuals on PCP prophylaxis with CD4+ counts > 200/mm3. These results suggest that HIV-1-related symptoms provide a measure of failing immune function that is not reflected by enumeration of CD4+ lymphocytes alone and support the United States Public Health Service recommendation that symptomatic individuals with CD4+ counts > 200/mm3 should be considered for PCP prophylaxis.

Bisexuality↗
PubMed1993

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. The Kaposi's sarcoma cases were also more active sexually. There was a dose-response relation between Kaposi's sarcoma and the number of sexual partners, with an odds ratio of 2 between the most and least sexually active subgroups. The odds ratio for Kaposi's sarcoma increased to 4.18 (95% confidence interval 1.29-14.1) in the presence of a history of five infections. Hepatitis and gonorrhea contributed the most to this relation. The various observed odds ratios did not change after multivariate adjustment for the other risk factors. A model was developed combining all predictive associations into a composite risk score ranging from one to 12 and based on history of infections, sexual activity, use of poppers/nitrites, and having had sexual partners from the West Coast of the United States. The subgroup with the highest scores, compared to the subgroup with the lowest score, had an odds ratio of 8.93 (95% confidence interval 3.21-30.44) for Kaposi's sarcoma. A longitudinal proportional hazards analysis among all 2,190 human immunodeficiency virus type 1-seroprevalent men at study entry, based on this risk score and CD4 cells at baseline, confirmed these findings. Identifying these specific subgroups that are at high and low risk for Kaposi's sarcoma will help future investigations to be more focused in their search for an additional etiologic factor for Kaposi's sarcoma in AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1993

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, 37.4% of AIDS cases were diagnosed with Kaposi's sarcoma prior to death. Kaposi's sarcoma diagnosed on the skin was significantly more common with early Kaposi's sarcoma (77.3%) than with later Kaposi's sarcoma (65.1%). Men presenting with an AIDS outcome other than Kaposi's sarcoma were at high risk for later Kaposi's sarcoma. Later Kaposi's sarcoma onset in men with a previous AIDS outcome was associated with the following characteristics: 1) lower immune status prior to AIDS and 2) longer post-AIDS survival. A Kaposi's sarcoma diagnosis in a man with a previous AIDS illness approximately doubled the risk (hazard) for death. Histories of urethral gonorrhea and scabies prior to study entry were more common in early Kaposi's sarcoma cases than in later Kaposi's sarcoma cases. However, self-reported sexual activity at study entry and prior to AIDS onset was highest in the later Kaposi's sarcoma group. In this cohort, cigarette smoking had a protective association against all Kaposi's sarcoma in univariate and multivariate models. Only 21.0% of the later Kaposi's sarcoma and 25.0% of the early Kaposi's sarcoma men smoked at least one-half pack of cigarettes daily at study entry compared with 33.8% of non-Kaposi's sarcoma and 35.5% of seroprevalent men still AIDS free. The reasons for this surprising association are unclear. However, other evidence which documents that habitual smoking alters the immune system (and possibly cytokine levels) in ways that could perhaps influence Kaposi's sarcoma pathogenesis should be considered.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Multiple sexual partners and mother-to-child transmission of HIV-1.

OBJECTIVE: To investigate risk factors for mother-to-child transmission of HIV-1, particularly sexual behavior before and during pregnancy. DESIGN AND METHODS: This study is part of a prospective cohort study in Butare, Rwanda, of 318 HIV-1-seropositive and 309 HIV-1-seronegative women enrolled during pregnancy and followed for a mean duration of 21 months (range, 8-34 months). Clinical follow-up of the mother-infant pairs was performed at 6-week intervals during the first year of life and at 4-month intervals thereafter. Detailed sexual history interviews were conducted during pregnancy and at the first postnatal visit. RESULTS: Of 184 singleton infants born to HIV-1-infected mothers who survived the neonatal period, 32 (17%) children were classified as HIV-1-infected, 130 (71%) as not infected, and 22 (12%) died with indeterminate HIV-1 infection status. The vertical transmission rate was estimated to be between 20 and 29%. Unprotected sexual intercourse with increased number of partners during the past 5 years was strongly associated with mother-to-child transmission (P < 0.001), even after adjustment for maternal CD4/CD8 ratio, parity, history of sexually transmitted diseases, and evidence of genital infection during pregnancy. In a multivariate analysis, excluding children with indeterminate HIV-1 status, odds ratios for vertical transmission were 2.6 [95% confidence interval (CI), 1.0-6.9] for maternal CD4/CD8 ratio < 0.5 and 3.6 (95% CI, 1.1-11.8) for more than three sexual partners versus a single partner. Women with more than one sexual partner during the first trimester of pregnancy were at particularly high risk of transmitting the virus. CONCLUSION: Unprotected sexual intercourse with multiple partners before and during pregnancy in a population with high HIV-1 seroprevalence may well increase the likelihood of HIV-1 transmission from an infected mother to her child.

CD4-CD8 Ratio↗
PubMed1992

Relationship of human immunodeficiency virus type 1 sequence heterogeneity to stage of disease.

V3 envelope sequences were determined from amplified human immunodeficiency virus type 1 (HIV-1) sequences of uncultivated leukocytes obtained sequentially from four infected adults over the course of infection. Lower levels of sequence heterogeneity were noted in samples obtained early in HIV-1 infection, prior to CD4 depletion, than in samples obtained at later times during disease. The pattern of amino acid sequence divergence included nonrandom changes, with evidence of sequence variants arising from HIV-1 quasi-species present earlier in infection. Consensus sequences for isolates obtained early after infection from different patients demonstrated a high level of conservation with one another and a consensus sequence for macrophage-tropic HIV-1 isolates. These findings suggest that a highly restricted subset of HIV-1 quasi-species can be transmitted and can establish infection.

Acquired Immunodeficiency Syndrome↗
PubMed1992

HIV-1 sequence variation between isolates from mother-infant transmission pairs.

To examine the sequence diversity of human immunodeficiency virus type 1 (HIV-1) between known transmission sets, sequences from the V3 and V4-V5 region of the envelope gene from four mother-infant pairs were analyzed. The mean interpatient sequence variation between isolates from linked mother-infant pairs was comparable to the sequence diversity found between isolates from other close contacts. The mean intrapatient variation was significantly less in the infants' isolates then the isolates from both their mothers and other characterized intrapatient sequence sets. In addition, a distinct and characteristic difference in the glycosylation pattern preceding the V3 loop was found between each linked transmission pair. These findings indicate that selection of specific genotypic variants, which may play a role in some direct transmission sets, and the duration of infection are important factors in the degree of diversity seen between the sequence sets.

Adult↗
PubMed1992

Association of antibody to human immunodeficiency virus type 1 core protein (p24), CD4+ lymphocyte number, and AIDS-free time.

Serum antibody to p24 (anti-p24) and p24 antigen, alone and in combination with CD4+ lymphocyte number, were evaluated as predictors of progression of human immunodeficiency virus type 1 (HIV-1) infection. Two hundred six HIV-1-prevalent seropositive men in the Multi-center AIDS Cohort Study since 1984-1985 were studied cross-sectionally and 84 seroconverters were evaluated longitudinally. Cross-sectional analyses revealed significant associations among titer of anti-p24, CD4+ cell count, disease status (Centers for Disease Control class), and progression to AIDS. A high titer of anti-p24 was associated with lack of p24 antigenemia. Longitudinal studies of seroconverters demonstrated that a low titer of anti-p24, low CD4+ cell count, and detection of HIV-1 p24 antigen are individually strong predictors of AIDS, but only low CD4+ cell count retains its independent predictive value in multivariate analysis of the three markers during the period immediately after infection with HIV-1.

Analysis of Variance↗
PubMed1992

The diagnostic utility of elevation in cerebrospinal fluid beta 2-microglobulin in HIV-1 dementia. Multicenter AIDS Cohort Study.

We measured serum and CSF beta 2-microglobulin (beta 2M) levels in HIV-1 seropositive individuals with and without dementia to determine the frequency and diagnostic utility of elevation of CSF beta 2M. We compared 34 samples from 27 patients with HIV-1 dementia with 110 samples from 54 HIV-1 seropositive participants in the Multicenter AIDS Cohort Study, none of whom had progressive dementia. Neurosyphilis and CNS opportunistic processes were excluded in all subjects. We stratified the nondemented subjects by duration of HIV seropositivity and peripheral blood CD4 count. Compared with the nondemented group, demented subjects had significantly higher CSF total protein, IgG%, and CSF albumin/serum albumin ratios. A highly significant association was found between elevated CSF beta 2M and reduced CD4 count (p less than 0.0001). No significant differences were noted between the demented and nondemented groups in CSF WBC count or in the frequency of CSF HIV-1 isolation. The mean CSF beta 2M was 1.9 mg/l in the nondemented subjects compared with 4.2 mg/l in those with dementia (p less than 0.0001). We derived a cutoff of 3.8 mg/l from the distribution of CSF beta 2M in the nondemented group. The determination of CSF beta 2M had a sensitivity of 44%, specificity of 90%, and a positive predictive value of 88% for diagnosis of HIV dementia when compared with nondemented subjects with CD4 counts less than 200. In those without dementia, there was a strong correlation between serum and CSF beta 2M (r = 0.50, p less than 0.0001), but in demented subjects CSF beta 2M was elevated independently of serum levels, suggesting that CSF beta 2M is produced within the brain in HIV dementia. In the absence of CNS opportunistic processes, elevated CSF beta 2M greater than 3.8 mg/l is a clinically useful marker for HIV dementia.

AIDS Dementia Complex↗
PubMed1992

The progression of untreated HIV-1 infection prior to AIDS.

Using a case-control study of untreated men, we investigated the physical, mental, and economic effects of human immunodeficiency virus (HIV-1) infection prior to the diagnosis of acquired immunodeficiency syndrome (AIDS). Beginning 2 to 2.5 years prior to AIDS, case subjects reported more of 12 HIV-1 related symptoms and during the year prior to AIDS, at least 30.6 extra days of these symptoms than did control subjects. Within the 6 months preceding AIDS, case subjects' unemployment rose to 9% (P < or = .05) and depression to 34.2% (P < or = .001). At 6 to 12 months and within 6 months before AIDS, 17.1% and 31.5%, respectively, were anemic, while 37.7% and 64.7% had CD4+ counts less than 200 x 10(6)/L. Diagnosing AIDS at CD4+ counts less than 200 x 10(6)/L could significantly reduce pre-AIDS morbidity. Other implications of these findings are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1992

The significance of western blot assays indeterminate for antibody to HIV in a cohort of homosexual/bisexual men. The Multicenter AIDS Cohort Study.

The objective of this study was to determine the frequency and significance of nondiagnostic Western blot (WB) assays in homosexual/bisexual men at risk of infection with HIV-1. The presence of a positive enzyme-linked antibody assay (EIA) confirmed by a positive WB was used as evidence of infection and seroconversion. Indeterminate WB assays were defined as reactions to only one viral gene product of HIV-1. Three analyses were conducted to (a) determine the frequency of such reactions in men who, during a 4-year period, did not develop diagnostic serologic reactions; (b) determine, retrospectively, the preseroconversion frequency of indeterminate WB assays in 286 men who seroconverted; and (c) evaluate in vitro production of specific antibody by peripheral blood mononuclear cells (PBMCs) as a method of indicating whether or not an indeterminate WB assay represents HIV-1 infection. Reactions to products of gag, pol, or env were noted in 8.0, 4.0, and 6.7% of 1,595 first-visit tests of men who remained seronegative for 4 years. Indeterminate reactions occurred in 204 men with negative EIAs who subsequently seroconverted and in 82 men with positive EIAs preconversion. Supernatants harvested from PBMCs of 2 of 36 seroconverters obtained one or two visits preseroconversion and cultured with pokeweed mitogen were antibody-positive. All were positive at the visit, with diagnostic serology. None of the supernatants from cells of 19 men with EIA-negative WB-indeterminate serologic assays were antibody-positive. Our results suggest that persistently EIA-negative homosexual/bisexual men who have indeterminate WB assays are unlikely to be infected with HIV-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Bisexuality↗