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

Progressive multifocal leukoencephalopathy (PML) results from lytic infection of oligodendrocytes by JC virus (JCV). Although JCV has been identified in mononuclear cells in bone marrow and hematogenous dissemination of the virus to the central nervous system has been suspected, JCV has never been clearly demonstrated in the peripheral circulation. Using polymerase chain reaction technology, we examined peripheral lymphocytes of 19 patients with brain biopsy-proven PML for the JCV genome. Two non-PML control groups, consisting of 26 patients seopositive for human immunodeficiency virus type 1 (HIV-1) and 30 immunocompetent patients with Parkinson's disease, were also examined for the presence of the JCV genome in lymphocytes. Cerebrospinal fluid from 10 patients with PML was examined for the presence of the JCV genome as well. The JCV genome was detected in the lymphocytes of 89% (17) of the patients with PML, 38% (10) of the HIV-1-seropositive patients without PML, and none of the patients with Parkinson's disease. Sequencing of the JCV regulatory region from the lymphocytes of three patients revealed the prototype MAD-1 strain of JCV in one patient with PML, a MAD-4 strain in a second patient with PML, and a slightly modified MAD-4 strain in an HIV-1-positive patient without PML. Only 3 of 10 patients with PML who had JCV detected in lymphocytes had the JCV genome in their cerebrospinal fluid. These results demonstrate that the JCV genome can be found in circulating lymphocytes from patients with PML and suggest that lymphocytes are an important vector for hematogenous dissemination of JCV to the central nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Detection of JC virus DNA in peripheral lymphocytes from patients with and without progressive multifocal leukoencephalopathy. 131 34

Excesses of non-Hodgkin's lymphoma have been observed among farmers exposed to phenoxyacetic acid herbicides and, less persuasively, among workers exposed to insecticides. Exposure to organic solvents (particularly chlorinated hydrocarbons) has also been associated with an increased risk of NHL. TCDD (which is a contaminant of phenoxy herbicides), DDT, and chlorinated solvents have all been reported to induce impairment or suppression of cell-mediated immunity. We hypothesize that NHL is caused by common viruses, such as the Epstein-Barr virus, that induce proliferation and immortalization of B-cells, followed by T-cell impairment entailing cell-mediated immunodeficiency. The increased risk of NHL with HIV infection and heart or kidney transplantation, in which immunodeficiency also occurs, is consistent with this hypothesis.
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PMID:The role of occupational exposure and immunodeficiency in B-cell malignancies. Working Group on the Epidemiology of Hematolymphopoietic Malignancies in Italy. 131 21

We have established a line of malignantly transformed human B cells by infecting purified primary B lymphocytes with human immunodeficiency virus type 1 (HIV-1). This line, termed B-HIV1, may serve as a model system for a subset of AIDS-related B-cell lymphomas in which the transformed phenotype may be initiated and/or maintained through an HIV-1 gene product. The B-HIV1 line contains both Epstein-Barr virus (EBV) and HIV-1 genomes. In addition, the c-myc gene is expressed at levels 10 to 20 times those in normal B cells. Similarly, EBV sequences, including those for the latent membrane protein (LMP), are expressed at greatly enhanced levels relative to expression in normal, EBV-immortalized B cells. The upregulation of c-myc and of EBV gene expression can both be produced by infection of susceptible B cells (not already harboring HIV) with exogenous HIV-1. The B-HIV1 line exhibits properties of malignantly transformed cells, in that it grows logarithmically in 1% serum, clones in soft agar, and produces invasive, malignant B-cell lymphomas in severe combined immunodeficient (SCID) mice. We have shown that HIV-1 has the ability to infect primary human B cells and to activate expression of EBV and c-myc. HIV activation of EBV has been documented previously in certain cell lines, here we note that such activation can occur in primary B cells and, under certain conditions, can result in outgrowth of immortalized cell lines. This phenomenon may contribute to the clinical manifestation of lymphadenopathy early after infection with HIV. In addition, we have demonstrated that HIV infection of primary B cells in vitro can result in appearance of a fully malignant phenotype. This phenotype is likely to be due, at least in part, to the activation of c-myc by HIV. Preliminary experiments indicate that Tat, the gene product of the transactivator of viral gene transcription tat, can upregulate c-myc transcription after addition to the culture media of certain B-cell lines. This raises the possibility that Tat can bind to target sequences in cellular RNA and enhance transcription as it does for HIV.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Human immunodeficiency virus activates c-myc and Epstein-Barr virus in human B lymphocytes. 131 11

The metabolism of (-) enantiomeric 2'-deoxy-3'-thiacytidine (3TC) was examined in human immunodeficiency virus type 1 (HIV-1)-infected and mock-infected human cells. 3TC 5'-triphosphate levels accumulated comparably in HIV-1-infected and mock-infected phytohaemagglutinin-stimulated peripheral blood lymphocytes (PBL) and reached 40% or more of total intracellular 3TC metabolites after 4 hr. The rate of decay of 3TC triphosphate in HIV-1-infected and mock-infected PBL measured as a half-life (T1/2) ranged from 10.5 to 15.5 hr. 3TC did not significantly affect metabolism of deoxynucleotides in the U937 cell line, and was shown to be resistant to the action of human platelet pyrimidine nucleoside phosphorylase.
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PMID:Cellular metabolism of (-) enantiomeric 2'-deoxy-3'-thiacytidine. 131 48

A monoclonal antibody-based antigen capture enzyme-linked immunosorbent assay (ELISA) was developed and employed to detect p24 capsid antigen from human T-cell lymphotropic viruses type I and II (HTLV-I, HTLV-II), simian T-cell lymphotropic virus type I (STLV-I)-infected cell lines, and from mononuclear cell cocultures of HTLV-infected humans and STLV-I infected monkeys. A monoclonal antibody specific for HTLV p24 and p53 capsid antigens was coated onto 96-well microtiter plates to capture HTLV/STLV antigen. Captured antigen was then detected by the addition of a polyclonal, biotinylated human anti-HTLV-I antibody, and color developed with tetramethyl benzidine/H2O2 substrate. As little as 15 pg/ml of HTLV-I p24 antigen could be detected in this assay. Culture supernatants from HTLV-I-infected cell lines (HUT-102, MT-2, C5/MJ, HTLV-II-infected cell lines (Mo-T, Mo-B, PanG 12.1, NRA) and STLV-I-infected cell lines (Matsu, NEPC M39) were all positive in the assay. In addition, p24 was detected from peripheral blood mononuclear cell (PBMC) cocultures of 8 of 8 (100%) HTLV-I diseased patients, 14 of 20 (70%) HTLV-I and HTLV-II-infected, asymptomatic persons, and 8 of 8 (100%) STLV-I-infected, asymptomatic monkeys. Culture supernatants of cells infected with human immunodeficiency virus type (HIV-1), simian immunodeficiency virus (SIV), Chlamydia trachomatis, cytomegalovirus (CMV), herpes simplex I and II (HSV), feline leukemia virus (FELV), bovine leukemia virus (BLV), and bovine immunodeficiency virus (BIV) were all negative. Similarly, normal human peripheral blood mononuclear cells and uninfected, transformed human T cells, were also negative in the assay.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Development of a monoclonal antibody-based p24 capsid antigen detection assay for HTLV-I, HTLV-II, and STLV-I infection. 131 63

As the human immunodeficiency virus (HIV) epidemic continues, there are increasing numbers of patients with HIV-related disease. Those doctors studying for the MRCP exam will need to be familiar with the common manifestations of HIV infection and acquired immunodeficiency syndrome.
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PMID:Clinical cases in AIDS. 2. 131 67

Human monocytes stimulated with phorbol 12-myristate 13-acetate or opsonized zymosan in vitro were viricidal to human immunodeficiency virus type 1 (HIV-1) as measured by the inability of the virus to replicate in CEM cells. Monocytes, when stimulated, release myeloperoxidase (MPO) and produce H2O2; MPO reacts with H2O2 and chloride to form hypochlorous acid, a known microbicidal agent. The viricidal activity of stimulated monocytes was inhibited by the peroxidase inhibitor azide, implicating MPO, and by catalase but not heated catalase or superoxide dismutase, implicating H2O2. Stimulated monocytes from patients with chronic granulomatous disease (CGD) or hereditary MPO deficiency were not viricidal to HIV-1 unless they were supplemented with the H2O2-generating enzyme glucose oxidase or MPO, respectively. The viricidal activity of stimulated, glucose oxidase-supplemented CGD monocytes and MPO-supplemented MPO-deficient monocytes, like that of normal stimulated monocytes, was inhibited by azide and catalase. Monocytesmaintained in culture differentiate into macrophages with loss of MPO and decreased H2O2 production. The viricidal activity of 3- to 9-day monocyte-derived macrophages was decreased unless MPO was added, whereas the loss of viricidal activity by 12-day-old monocyte-derived macrophages was not reversed by MPO unless the cells were pretreated with gamma-interferon. These findings suggest that stimulated monocytes can be viricidal to HIV-1 through the release of the MPO/H2O2/chloride system and that the decreased viricidal activity on differentiation to macrophages results initially from the loss of MPO and, with more prolonged culture, also from a decreased respiratory burst that can be overcome by gamma-interferon.
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PMID:Viricidal effect of stimulated human mononuclear phagocytes on human immunodeficiency virus type 1. 131 66

The CD4 protein expressed on helper T lymphocytes is a restriction element for major histocompatibility class II immune responses. This molecule is also used by the human immunodeficiency virus as its specific cellular receptor facilitating binding of virus to cells. As soluble forms of CD4 inhibit HIV infection in tissue culture, attention has focused on this molecule. Bacterially produced CD4 would facilitate studies of the biology of the CD4 molecule. However, bacterially expressed CD4 must be refolded for assumption of its interaction with conformationally dependent anti-CD4 monoclonal antibodies as well as the HIV-1 envelope protein gp120. We report here the engineering of an external domain construct of the CD4 gene into a novel expression vector containing the nucleotide sequence encoding the pelB leader peptide of Erwinia carotovara (pDABL), to facilitate correct folding of CD4 in bacteria. Monoclonal antibodies specific for important conformational epitopes of the CD4 molecule were able to bind bacterial colonies containing the pDABL/CD4 vector but not colonies with vector alone. Importantly, recombinant gp120 produced in baculovirus bound specifically to bacterial colonies expressing the CD4 recombinant molecule. This system presents a simple screening mechanism for molecules that bind to the external domain of the CD4 glycoprotein. Vectors such as pDABL will also facilitate the production of large amounts of biologically active proteins in bacteria.
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PMID:Construction of a recombinant bacterial human CD4 expression system producing a bioactive CD4 molecule. 131 11

We investigated the effects of two behavioral interventions--aerobic exercise and cognitive behavioral stress management (CBSM)--on Epstein-Barr virus viral capsid antigen (EBV-VCA) and human herpesvirus type-6 (HHV-6) antibody modulation in 65 asymptomatic gay men measured at several time points in the 5 weeks preceding and following notification of their human immunodeficiency virus-type 1 (HIV-1) serostatus. After accounting for potential immunomodulatory confounds, we found that HIV-1 seropositive men had higher EBV-VCA antibody titers than those diagnosed as seronegative at every time point during the study; however, no significant differences were found with respect to HHV-6. Among HIV-1 seropositive and seronegative subjects, respectively, those randomized to either behavioral intervention had significant decreases in both EBV-VCA and HHV-6 antibody titers over the course of the intervention as compared with assessment-only controls (of HIV-1 seropositive and seronegative status) whose antibody titers did not significantly change and which remained consistently higher than either serostatus-matched intervention group over subsequent time points, independent of total immunoglobulin G levels and degree of polyclonal B cell activation. In attempting to explain serostatus differences in EBV and HHV-6 values, it was found that HIV-1 seropositive men had significantly lower CD4 cells, CD4:CD8 ratio, and blastogenic response to phytohemagglutinin (PHA), as well as significantly higher CD8 cells at baseline. No significant differences were found between the HIV-1 seropositive and seronegative men with respect to anxiety and depression at baseline. Since the greatest changes in EBV and HHV-6 occurred between baseline and week 10, we correlated changes in immune (CD4, CD8, CD4:CD8 ratio, PHA stimulation) and distress-related markers (state depression and anxiety) with EBV and HHV-6 change scores over this time period. No significant correlations were found between any of these immune- or distress-related variable and the antibody change scores suggesting that the mechanisms by which EBV and HHV-6 antibodies are being modulated by these interventions possibly involve other, yet to be determined, immune, neuroendocrine, and/or psychologic variables.
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PMID:Psychosocial modulation of antibody to Epstein-Barr viral capsid antigen and human herpesvirus type-6 in HIV-1-infected and at-risk gay men. 132 Feb 79

The human immunodeficiency virus type 1 (HIV-1) Gag-Pol fusion polyprotein is produced via ribosomal frameshifting. Previous studies in vitro and in Saccharomyces cerevisiae have argued against a significant role for RNA secondary structure 3' of the shift site, in contrast with other systems, in which such structure has been shown to be required. Here we show, by expressing the HIV-1 gag-pol domain in cultured vertebrate cells, that a stem-loop structure 3' of the HIV-1 shift site is indeed important for wild-type levels of frameshifting in vivo.
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PMID:Human immunodeficiency virus type 1 gag-pol frameshifting is dependent on downstream mRNA secondary structure: demonstration by expression in vivo. 132 Dec 94


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