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

Researchers conducted hematologic tests on 66 HIV-1 positive adults from Ethiopia and compared the results with those of 137 HIV-1 patients in Stockholm, Sweden, to determine the incidence of cell-free viremia, free or complexed p24 antigen, and p24 antibody levels. They isolated HIV-1 from peripheral blood mononuclear cells in 95% and from plasma in 81% of the Ethiopian subjects. The corresponding percentages for the Swedish subjects were 95% and 92%. They found p24 antigen in only 5% of AIDS patients from Ethiopia (none for asymptomatic HIV-1 subjects) compared with 76% of Swedish patients (p .01). The Ethiopian subjects had significantly higher p24 antibody levels than did the Swedish subjects (85% vs. 52%; p = .008). The ratio between reverse transcriptase activity and p24 antigen concentration stood much higher in the Ethiopians than in the Swedes (7.5 vs. 3.6; p = .0019). These results suggested that the HIV-1 strains in the Ethiopian subjects resembled rapid high HIV-1 strains. In addition, the high degrees of cell-free viremia, relative lack of free or immune complexed p24 antigen, and a persistence of p24 antibody during the entire course of infection in Ethiopian HIV-1 infected subjects intimated that the interaction between HIV-1 and the Ethiopians may be different in Africa than it is in Europe and North America. The results of another study conducted by the researchers supported this conclusion. They included high levels of tumor necrosis factor-alpha and neopterin and low levels of interferon-alpha in HIV-1 positive Ethiopians.
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PMID:Relationship between cell-free viraemia, antigenaemia and antibody levels in HIV-1-infected Ethiopian patients. 150 84

The Tat protein of human immunodeficiency virus type 1 (HIV-1) is essential for productive infection and is a potential target for antiviral therapy. Tat, a potent activator of HIV-1 gene expression, serves to greatly increase the rate of transcription directed by the viral promoter. This induction, which seems to be an important component in the progression of acquired immune deficiency syndrome (AIDS), may be due to increased transcriptional initiation, increased transcriptional elongation, or a combination of these processes. Much attention has been focused on the interaction of Tat with a specific RNA target termed TAR (transactivation responsive) which is present in the leader sequence of all HIV-1 mRNAs. This interaction is believed to be an important component of the mechanism of transactivation. In this report we demonstrate that in certain CNS-derived cells Tat is capable of activating HIV-1 through a TAR-independent pathway. A Tat-responsive element is found upstream within the viral promoter that in glial-derived cell lines allows transactivation in the absence of TAR. Deletion mapping and hybrid promoter constructs demonstrate that the newly identified Tat-responsive element corresponds to a sequence within the viral long terminal repeat (LTR) previously identified as the HIV-1 enhancer, or NF-kappa B domain. DNA band-shift analysis reveals NF-kappa B binding activity in glial cells that differs from that present in T lymphoid cells. Further, we observe that TAR-deleted mutants of HIV-1 demonstrate normal late gene expression in glial cells as evidenced by syncytia formation and production of viral p24 antigen.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:TAR-independent transactivation by Tat in cells derived from the CNS: a novel mechanism of HIV-1 gene regulation. 150 23

The aim of this study was to evaluate whether the amount of Pneumocystis carinii organisms found at fiberoptic bronchoscopy (FB) performed on HIV-positive patients correlated to the character of the P. carinii pneumonia (PCP). A consecutive series of 105 patients presented with 131 episodes of pulmonary symptoms requiring FB, and in 75 of these episodes a diagnosis of PCP was made. Specimens were stained with Giemsa and methenamine silver nitrate and the number of parasites found was given as: numerous, many, few or none. The following signs and symptoms were registered: cough, dyspnoea, fever, loss of weight, chest radiograph, haemoglobin, WBC, CD4 cell count, PO2 and HIV p24 antigen. The PCP was characterized by the clinical course: mild, moderate, severe, and by the outcome: pulmonary healthy, pulmonary insufficiency and death. No correlations between the number of P. carinii organisms and the clinical course or outcome of the PCP, the symptoms before the FB or the paraclinical examinations were found. In conclusion, the routinely obtained quantitative results of the microbiological examinations of material from the lungs were not correlated to the severity of the PCP.
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PMID:Pneumocystis carinii pneumonia in AIDS patients: clinical course in relation to the parasite number found in routine specimens obtained by fiberoptic bronchoscopy. 150 34

Reports of in vitro resistance of human immunodeficiency virus type 1 (HIV-1) to zidovudine (AZT) have raised concerns about the development of resistance to other dideoxynucleosides in clinical use. To address this, we have developed a screening assay which supports the growth of clinical isolates and have applied this to a series of paired isolates from patients entered into a phase I trial of didanosine (DDI). Thirteen patients (10 with AIDS, 3 with AIDS-related complex) who had been exposed to AZT for a mean of 6.5 months (range, 1 to 13 months) were treated with DDI at 750 mg/day. Paired isolates were obtained pretherapy and after a mean of 58 weeks (range, 21 to 90) of DDI therapy by coculture of peripheral blood mononuclear leukocytes (PBLs) with phytohemagglutinin-stimulated donor PBLs. Isolates were passaged only one additional time in PBLs and then tested in parallel in a microtiter assay with phytohemagglutinin-stimulated donor PBLs as targets. PBLs were infected with 10(5) 50% tissue culture infectious doses per 10(7) cells and exposed to DDI (1 to 50 microM) or AZT (0.01 to 100 microM), and supernatants were assayed for the HIV p24 antigen at 7 days postinfection. Control AZT-susceptible and resistant isolates were included. The median pre- and posttherapy DDI susceptibilities of the 13 pairs of isolates were 10.0 microM (range, 1 to 25 microM) and 17.5 microM (range, 2.5 to 50 microM), respectively (P = 0.036; Wilcoxon signed-rank test). These studies thus indicated that (i) the susceptibility to DDI tends to mildly decrease with drug exposure; (ii) the susceptibility to AZT improves with time off AZT; (iii) baseline susceptibilities to DDI have a wide range, and the CD4 response may correlate with the initial susceptibility; and (iv) a PBL-based microtiter assay is useful for screening clinical isolated for dideoxynucleoside susceptibility profiles.
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PMID:Didanosine and zidovudine resistance patterns in clinical isolates of human immunodeficiency virus type 1 as determined by a replication endpoint concentration assay. 151 Apr 14

The infectivity of human immunodeficiency virus (HIV-1) in human glomerular cells was evaluated by exposing homogeneous cultures of human glomerular capillary endothelial, mesangial and epithelial cells to HIV in vitro. Infectivity and HIV expression was assessed by: 1) the measurement of p24 antigen production from culture supernatants; 2) the presence of p24 antigen intracellularly by immunofluorescence; 3) levels of P24 antigen production or syncytia formation following the cocultivation of glomerular cells exposed to HIV with normal human peripheral blood mononuclear cells or MT-2 lymphocytes; and 4) the presence of intracellular HIV DNA by polymerase chain reaction. The results indicate that HIV can infect and replicate in glomerular capillary endothelial cells and in a small percentage of mesangial cells, but not in human glomerular epithelial cells in vitro.
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PMID:HIV infects glomerular endothelial and mesangial but not epithelial cells in vitro. 151 16

To determine safety and efficacy of tumor necrosis factor (TNF) and interferon-gamma (IFN gamma) in the treatment of patients with acquired immunodeficiency syndrome (AIDS)-related complex, a randomized, double-blind study was conducted. Twenty-five patients with AIDS-related complex and CD4 lymphocytes less than or equal to 500 x 10(6)/L attended an AIDS Clinical Trials Unit of a tertiary referral center. Patients were administered tumor necrosis factor (TNF) (10 micrograms/m2) or IFN gamma (10 micrograms/m2), or both intramuscularly three times weekly for 16 weeks. Side effects from all three preparations included fever, constitutional symptoms, and local reactions. No significant hematologic, hepatic, renal, or coagulation abnormalities were observed. CD4 lymphocyte counts, beta 2-microglobulin, p24 antigen levels, and anti-p24 antibody did not change significantly during therapy. Similarly, no significant change was noted in rates of HIV isolation from peripheral blood mononuclear cells or plasma. TNF and IFN gamma were tolerable after premedication with acetaminophen; however, no significant change in markers of human immunodeficiency virus infection was demonstrated. These cytokines alone do not appear to be of benefit, nor do they appear to hasten the progression of HIV infection.
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PMID:A randomized, double-blind, phase I/II trial of tumor necrosis factor and interferon-gamma for treatment of AIDS-related complex (Protocol 025 from the AIDS Clinical Trials Group). 151 11

3'-Fluoro-3'deoxythymidine (FLT), recombinant soluble CD4 (CD4), and recombinant interferon-alpha (IFN alpha) were evaluated in two- and three-drug regimens against HIV-1 replication in vitro. Peripheral blood mononuclear cells were studied using p24 antigen production as the virologic endpoints. FLT showed 2.5-fold higher efficacy and a similar selectivity index to zidovudine. Drug interactions were evaluated by the median effect principle and the isobologram technique. FLT, CD4, and interferon alpha at noncytotoxic concentrations inhibited HIV-1 synergistically in two- and three-drug combinations with a combination index smaller than one and dose reduction index greater than one. The three-drug regimen provided greater virus suppression than the two-drug regimen. These results suggest that FLT is an alternative agent to AZT for the treatment of HIV infection either as a single agent or in combination with CD4 and/or interferon-alpha.
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PMID:Three-drug synergistic inhibition of HIV-1 replication in vitro by 3'-fluoro-3'-deoxythymidine, recombinant soluble CD4, and recombinant interferon-alpha. 151 12

Short-term (1 h) treatment with a newly synthesized sulfated polysaccharide, curdlan sulfate (CRDS), showed relatively weak blocking effects on the binding of human immunodeficiency virus type 1 (HIV-1) to the surface of H9 cells. To investigate whether long-term treatment with CRDS could strengthen this effect, CRDS in various doses (0.1, 1, 10, and 100 micrograms/ml) was used in 2-week treatment periods in four separate protocols or "Procedures." SF titers and p24 antigen levels were partially suppressed during long-term CRDS treatment but returned to control levels after the treatment was terminated. In addition, no direct cytotoxicity of CRDS to H9 cells or H9/HIV-1 cells was observed in vitro in the course of continuous exposure to 100 micrograms/ml CRDS for 2 weeks. These results demonstrate the effectiveness of long-term treatment of cells infected with HIV-1 in inhibiting virus expression. The most dramatic inhibition results were obtained when the compound was present both at the time of exposure of cells to virus and during a long-term follow-up treatment. These results show that CRDS inhibits both the cell-free and cell-associated transmission of HIV-1 to host cells and interferes with early events in virus infection. In contrast, CRDS exhibits no significant virucidal activity and has little effect on already infected cells.
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PMID:Curdlan sulfate and HIV-1: II. In vitro long-term treatment of HIV-1 infection with curdlan sulfate. 151 13

Glutathione (GSH), its derivatives and N-acetylcysteine (NAC) inhibit the induction of HIV-1 expression in a chronically HIV-1-infected promonocytic cell line (U1/HIV) and peripheral blood mononuclear cells (PBMC). We have examined the effects of GSH and NAC on HIV-1 replication in human primary monocyte/macrophages cultured in vitro. Ficoll-gradient purified human monocytes were cultivated in vitro for 7-10 days and then infected with HIV-1 (Bal and Ada-M). Infection was blocked or substantially reduced by GSH or NAC (5-20 mM). Significant reduction (greater than or equal to 90%) in the amount of virus released, as determined by measuring supernatant reverse transcriptase activity and secreted p24 protein, was obtained when the cells were treated for 4 h with greater than or equal to 10 mM of GSH or NAC. The inhibitory effects of GSH and NAC were concentration dependent. This anti-HIV-1 effect persisted in these cultures for at least 35 days without evidence of significant increase in HIV-1 expression. Thus, a single pulse exposure of HIV-1-infected monocyte/macrophages with GSH or NAC led to a sustained, concentration-dependent decrease in HIV-1 p24 antigen levels, as well as, reverse transcriptase activity without producing detectable cellular toxicity in monocyte/macrophages.
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PMID:Glutathione and N-acetylcysteine suppression of human immunodeficiency virus replication in human monocyte/macrophages in vitro. 152 May 37

Quantitation of HIV in 115 seropositive individuals was undertaken to evaluate the potential for HIV transmission as a nosocomial infection through the use of medical devices that may come in contact with the peripheral blood of HIV-infected individuals. The virus burden in the peripheral blood was estimated from the level of: plasma HIV p24 antigenemia; plasma viremia; p24 antigen in peripheral blood mononuclear cell (PBMC) lysates as indicators of productive infection; and frequency of latently infected cells. Negligible HIV levels were observed in the plasma and PBMC lysates of the majority of samples except for late-stage patients with certain opportunistic infections and/or lack of zidovudine (AZT) therapy. Some individuals on AZT therapy and at late-stage of disease may show antigenemia without plasma viremia or alternatively, plasma viremia may be observed without plasma antigenemia. PBMC lysate data indicated that the frequency of productively infected cells was less than one in 20,000 PBMCs for the majority of samples irrespective of status on AZT therapy or disease stage. HIV was detected in greater than 95% of the cocultures and within 14 days for most of the samples, again regardless of the stage of disease or status on AZT therapy. The frequency of latently infected cells in this cohort ranged from 125 to 3125 per million PBMCs and was calculated to be as high as 2.5% of the helpter T-cell (CD4+ cell) population in the peripheral blood. The average latently infected cell frequency was 2-3-fold higher in early stage patients not on AZT than in late-stage patients on AZT therapy.
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PMID:Quantitation of human immunodeficiency virus (HIV) with respect to disease stage and zidovudine (AZT) therapy. 152 May 39


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