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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mechanism of transmission of HIV from the male to the female genital tract or in the reverse order is not clear. CD4 glycoprotein is the receptor for HIV and Langerhans cells and the related dendritic cells could play a role in the initial transmission of HIV. Fc receptors (FcR) for IgG might be involved in antibody-mediated binding of HIV. We carried out an immunohistological study of normal human cervical and vaginal epithelia for the presence of CD4 glycoprotein, Langerhans cells and FcR to IgG. CD4+ glycoprotein was not found in the vaginal or cervical epithelium, with the exception of a few endocervical epithelial cells. A small number of CD4+ mononuclear cells were found in the endocervical epithelium of a third of the specimens but a large number of CD4+ cells was found in the submucosa of most of the cervical and vaginal specimens. Langerhans cells expressing CD4, HLA class II, Fc gamma R2 and Fc gamma R3 were detected in most vaginal, ectocervical and transformation zone epithelia and in 9/14 endocervical tissues. Fc gamma R3 was detected in about two-thirds of the columnar endocervical epithelium and the transformation zone. A smaller number of specimens expressed Fc gamma R2 in these epithelia, but Fc gamma R1 was not detected. We then demonstrated mRNA for Fc gamma R3 in the columnar endocervical epithelial cells and transformation zone by in situ hybridization, using a CD16-RNA probe. Fc gamma R3 and Fc gamma R2 gene transcripts were also found in fetal cervical tissue by applying the polymerase chain reaction to amplify portions of the Fc gamma R3 and Fc gamma R2 coding sequences in cDNA prepared from fetal RNA. HLA-DR was found in the endocervical cells, transformation zone and in Langerhans cells of all specimens. The presence of Langerhans cells, Fc gamma receptors and HLA class II antigen offers three potential mechanisms for cervico-vaginal HIV transmission: (i) direct HIV infection of Langerhans cells, (ii) binding of HIV antibody complexes to cervical epithelial Fc gamma receptors and (iii) binding of HIV infected CD4+ cells to cervical HLA class II antigen which may infect these or the adjacent CD4+ cells.
Clin Exp Immunol 1992 Dec
PMID:Expression and gene transcript of Fc receptors for IgG, HLA class II antigens and Langerhans cells in human cervico-vaginal epithelium. 136 Aug 81

CDC has revised the classification system for HIV infection to emphasize the clinical importance of the CD4+ T-lymphocyte count in the categorization of HIV-related clinical conditions. This classification system replaces the system published by CDC in 1986 (1) and is primarily intended for use in public health practice. Consistent with the 1993 revised classification system, CDC has also expanded the AIDS surveillance case definition to include all HIV-infected persons who have < 200 CD4+ T-lymphocytes/microL, or a CD4+ T-lymphocyte percentage of total lymphocytes of < 14. This expansion includes the addition of three clinical conditions--pulmonary tuberculosis, recurrent pneumonia, and invasive cervical cancer--and retains the 23 clinical conditions in the AIDS surveillance case definition published in 1987 (2); it is to be used by all states for AIDS case reporting effective January 1, 1993.
MMWR Recomm Rep 1992 Dec 18
PMID:1993 revised classification system for HIV infection and expanded surveillance case definition for AIDS among adolescents and adults. 136 52

Limited data are available on cognitive performance in populations of intravenous drug users during the early, asymptomatic stages of human immunodeficiency virus type 1 (HIV-1) infection. Between 1988 and 1990, 151 participants from the AIDS Link to Intravenous Experience (ALIVE) Study in Baltimore, Maryland, were evaluated neuropsychologically on a semiannual basis. This analysis focused on whether history of substance abuse influenced neuropsychological test performance. At baseline, 102 participants were HIV-1-seropositives who were free of acquired immunodeficiency syndrome and 49 participants were seronegative. Multivariate analyses, adjusting for correlation of repeated outcome measures, were conducted to determine predictors of neuropsychological functioning. Effects of the frequency of reported past use of marijuana, heroin, cocaine, barbiturates, and alcohol were not statistically associated with performance on the tests. Age and education were the most important predictors of test performance, and a significant practice effect was observed for most measures. After adjustment for age, education, the practice effect, and frequency of drug use, neuropsychological performance over time did not vary by HIV-1 serostatus. Overall, after acutely intoxicated individuals were excluded, neither frequency of drug and alcohol use nor HIV-1 seropositivity significantly influenced neuropsychological test performance over a 1-year period.
Am J Epidemiol 1992 Dec 01
PMID:Effect of chronic substance abuse on the neuropsychological performance of intravenous drug users with a high prevalence of HIV-1 seropositivity. 136 30

Physicians examined the records of 47 adults with visceral leishmaniasis (VL) and HIV-1 infection who were patients at 3 urban teaching hospitals in the Andalucia region in southern Spain between January 1986 and November 1991. They wanted to identify the clinical, biological, and epidemiological features of VL in HIV-1 positive patients. 96% of the cases were diagnosed with both infections during the last 2 years of the study period and 79% between January and November 1991. All the patients had risk factors for HIV infection (65.9% IV drug use, 21.3% sexual contact, and 12.8% blood transfusion). 70% exhibited the classic symptoms of VL (fever, enlarged liver and spleen, and depressed counts of blood cells). Most patients were already very immunocompromised when VL was diagnosed. 87% had a total lymphocyte count of less than 1000 x 1 million/1 and a CD4 lymphocyte count of less than 200 x 1 million/1. In fact, 66% had full blown AIDS prior to diagnosis of VL. VL was the first severe infection in 10 cases. 68% also suffered from opportunistic infections, especially candidiasis, extrapulmonary tuberculosis, and Pneumocystis carinii pneumonia. Microscopic examination of Leishmania amastiogotes in tissue samples led to a diagnosis in 94% of cases, isolation of motile amastigotes in culture of bone marrow aspirate in 2%, and microscopic and culture in 4%. Just 46% completed a full course of treatment (pentavalent antimony, allopurinol, and/or pentamidine). Only 38% had a microbiological response. Immunofluorescence detected sizeable titers (1:40) of antileishmanial antibodies in just 31% of cases. 17% experienced clear clinical improvement. Physicians in endemic areas should consider VL in every HIV-1 infected patient with fever, hepatosplenomegaly, or hematological abnormalities to avoid underdiagnosis of leishmaniasis.
AIDS 1992 Dec
PMID:Visceral leishmaniasis in HIV-1-infected individuals: a common opportunistic infection in Spain? 136 80

The dramatic increase of new HIV/AIDS cases in women and their babies continues to require midwives to be vigilant in their efforts to identify clients at risk for HIV. The role of STDs in HIV transmission and disease progression is evident. Research is lacking on the effect of AIDS drugs, pregnancy and birth on the HIV-infected woman. Prevention, through safer sex, is a critical education strategy to consider. Data suggesting intrapartum transmission of HIV is particularly interesting and warrants further study. Development of the international framework for future clinical vaccine trials is underway. Initial studies on the ability of HIV vaccines to limit perinatal transmission may provide some encouraging future results.
Midwifery 1992 Dec
PMID:A world united against AIDS. Report on the Nursing Satellite Conference and the Eighth International Conference on AIDS, Amsterdam, The Netherlands, 19-24 July, 1992. 136 30

The evaluation of the presence of p24 antigen on the membrane of peripheral blood mononuclear cells from 31 HIV infected individuals is presented. The study was performed by indirect immunofluorescence and flow cytometry and the data were analyzed by the Kolmogorov-Smirnov test. Values obtained [D/s(n)] result from the comparison of the fluorescence histograms of each sample with a control one. Cases showing p24 Ag on peripheral blood mononuclear cells also presented percentages of CD3, HLA-DR positive cells significantly higher than p24 negative ones. In addition, D/s(n) values were superior in symptomatic patients than in asymptomatic ones, which indicate the existence of a correlation between flow cytometry results, viral replication and clinical course. Nevertheless in this study, as well and in previous ones, a high degree of cross reactivity between the anti-p24 monoclonal antibody employed and normal lymphocytes has been observed. This reactivity is localized preferentially in the CD4 positive subset.
Enferm Infecc Microbiol Clin 1992 Dec
PMID:[Detection of the HIV p24 antigen on lymphocyte membranes using flow cytometry]. 136 72

A sodium hydroxide extract from cacao husk inhibited the cytopathic effect of human immunodeficiency virus type 1 (HIV-1) against HTLV-1-transformed T-cell lines MT-2 and MT-4. It also inhibited syncytium formation between HIV-infected and uninfected lymphoblastoid T-cell line, MOLT-4. The anti-HIV activity was concentrated by membrane filter fractionation to a fraction with molecular weight of 100-300 KDa. Anti-HIV activity of the extract was attributable to interference with the virus adsorption, rather than to inhibition of the virus replication after adsorption.
Lett Appl Microbiol 1991 Dec
PMID:Effect of cacao husk extract on human immunodeficiency virus infection. 136 48

The architecture of the human immunodeficiency virus type 1 (HIV-1) genome presents an intriguing dilemma for the 3' processing of viral transcripts--to disregard a canonical 'core' poly(A) site processing signal present at the 5' end of the transcript and yet to utilize efficiently an identical signal that resides at the 3' end of the message. The choice of processing sites in HIV-1 appears to be influenced by two factors: (i) proximity to the cap site, and (ii) sequences upstream of the core poly(A) site. We now demonstrate that an in vivo-defined upstream element that resides within the U3 region, 76 nucleotides upstream of the AAUAAA hexamer, acts specifically to enhance 3' processing at the HIV-1 core poly(A) site in vitro. We furthermore show that efficient in vitro 3' processing requires the RNA stem-loop structure of TAR, which serves to juxtapose spatially the upstream element and the core poly(A) site. An analysis of the stability of 3' processing complexes formed at the HIV-1 poly(A) site in vitro suggests that the upstream element may function by increasing processing complex stability at the core poly(A) site.
EMBO J 1992 Dec
PMID:Activation of HIV-1 pre-mRNA 3' processing in vitro requires both an upstream element and TAR. 142 77

Aurintricarboxylic acid (ATA) has been shown to block the binding site for both HIV gp120 and mAb anti-Leu 3a on CD4. We have unexpectedly found that brief treatment with > or = 1 micrograms/ml ATA rapidly disengages another mAb, OKT4E, after it has been bound to CD4 on human PBL. OKT4E is specific for a discontinuous epitope overlapping the MHC class II-binding region in the N-terminal CD4 domain. Interestingly, among 10 other mAb tested, only anti-Leu 8, specific for a leukocyte homing receptor is also quickly released from the cells by ATA treatment. Disengagement of the OKT4E mAb is also seen on a CD4-positive cell line (HPB-ALL) and with recombinant soluble CD4 (sCD4) bound to immobilized OKT4E. In all of these cases, disengagement is prevented if OKT4E is cross-linked, or the Leu 3a site is blocked by the mAb, but not by gp120. Photobleaching fluorescence resonance energy transfer (pFRET) measurements suggest that OKT4E is released as an indirect consequence of ATA-evoked conformational changes of CD4. Similar changes were detected as a result of gp120 binding to PBL. These data raise the possibility of a novel type of immunomodulation: induced disengagement of a bound ligand from its Ag.
J Immunol 1992 Dec 01
PMID:CD4 changes conformation upon ligand binding. 143 Nov 29

Kaposi's sarcoma (KS) arises more frequently in homosexual and bisexual men than in other groups of HIV-1 infected individuals. Clinico-epidemiologic data indicate that homosexuals often are infected with multiple microbial agents and/or subjected to other antigenic stimuli, preceding or accompanying HIV-1 infection. Signs of immune activation, in fact, frequently have been detected in these individuals, and the onset of KS can precede any sign of immunodeficiency. These data have suggested that products from activated immune cells may affect the development of AIDS-KS. Here we report that conditioned media from activated or dysregulated T cells contain a variety of cytokines that promote the growth of spindle cells derived from KS lesions of AIDS patients (AIDS-KS cells) and induce normal vascular cells, potential cell progenitors of the AIDS-KS cells, to acquire features of the KS cell phenotype ("spindle" cell morphology and growth responsiveness to the mitogenic effect of extracellular HIV-1 Tat protein). The same conditioned media or cytokines promote HIV-1 gene expression and rescue defective HIV-1 proviruses, interrupting HIV-1 latency and increasing Tat production. The cellular and viral effects of cytokines are increased in an additive or synergistic manner by picomolar concentrations of extracellular Tat. These data suggest that cytokines produced by activated immune cells cooperate with HIV-1 infection in AIDS-KS pathogenesis.
J Immunol 1992 Dec 01
PMID:Effects of cytokines from activated immune cells on vascular cell growth and HIV-1 gene expression. Implications for AIDS-Kaposi's sarcoma pathogenesis. 143 Nov 44


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