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

EDTA-anticoagulated blood samples from 19 HIV-1-positive subjects and 13 healthy laboratory worker controls were analysed for three lymphocyte subpopulations (CD3, CD4, CD8 T cells) (lysed whole blood method, Becton Dickinson FACScan flow cytometer) at 0, 24, 48, 72 and 96 h after venesection, having been stored at either 4 degrees C, 12 degrees C, 16 degrees C or 21 degrees C. In samples stored at 4 degrees C and 12 degrees C there was a significant fall in both %CD3 and %CD 4, and a significant rise in %CD8. At 16 degrees C the %CD8 remained stable, while there were marginal rises in %CD3 and %CD4. At 21 degrees C, the %CD8 again remained stable, while %CD3 and %CD4 rose significantly with time. These trends were independent of HIV-1 status. At each temperature studied, the rates of change of lymphocyte subpopulations were independent of each other. These results suggest that a temperature range of 14-16 degrees C may be optimal for sample storage prior to measurement of T cell subsets. They emphasise the importance of strict control on conditions if samples are to be kept for any length of time before analysis.
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PMID:The effect of the temperature and duration of sample storage on the measurement of lymphocyte subpopulations from HIV-1-positive and control subjects. 138 25

We have evaluated a simple and sensitive culture technique for isolation of Human Immunodeficiency Virus Type-1 (HIV-1) from small amounts of whole blood. Data shown in the paper demonstrate that: 1) cell cultures from small amounts of heparinized whole blood (HWB) allow a high isolation rate in infected subjects at all stages of diseases; 2) among asymptomatic subjects the HIV-1 isolation rate is increased in cell cultures from HWB, with respect to cell cultures from peripheral blood mononuclear cells; 3) cultural results from HWB are not influenced by the presence of detectable serum p24 antigen, but a good correlation was found with the titre of anti p24 antibodies in serum; 4) continuous cell lines (such as Molt-3 cells) instead of peripheral blood mononuclear cells can be used, obtaining good results, for HIV-1 isolation from HWB; 5) frozen samples of HWB can be used in cell cultures for HIV-1 isolation; 6) the type of anticoagulant (Heparin or EDTA) used for the collection of blood does not influence viral replication in cell cultures from whole blood; 7) viral isolation from HWB is highly sensitive; amounts so small as five microliters of whole blood are sufficient, in some cases, to obtain viral replication in cell cultures; 8) the minimal dose of HWB sufficient to infect cell cultures (HWB M.D.I.) varied among different patients. Although this work failed to establish a correlation between this parameter and the clinical and immunological status of patients, it is conceivable that HWB M.D.I. could give information about viral load in blood and have a prognostic significance; 9) the HWB M.D.I. rise in patients treated with Zidovudine, suggesting that this method could be employed in the virological evaluation of trials with antiretroviral drugs.
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PMID:HIV-1 isolation from small amounts of whole blood: a technical evaluation. 155 58

Human immunodeficiency virus type 1 (HIV-1) and human T-cell leukemia virus type I (HTLV-I) were purified by sucrose density gradient centrifugation in the presence of 1 mM EDTA. Pelleted gradient fractions were analyzed for total protein, total Gag capsid protein, and total zinc. Zinc was found to copurify and concentrate with the virus particles. Through successive cycles of resuspending in buffer containing EDTA and repelleting, the zinc content remained constant at about 1.7 mol of zinc per mol of Gag protein. Proteins from purified virus (HIV-1 and HTLV-I) were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, blotted to polyvinylidene fluoride paper, and probed with 65ZnCl2. Viral nucleocapsid (NC) proteins (HIV-1 p7NC and HTLV-I p15NC) bound 65Zn2+. Other retroviruses, including simian immunodeficiency virus, equine infectious anemia virus, bovine leukemia virus, Moloney murine leukemia virus, mouse mammary tumor virus, and Mason-Pfizer monkey virus, were found to contain amounts of zinc per milligram of total protein similar to those found in HIV-1 and HTLV-I. Collectively, these data support the hypothesis that retroviral NC proteins function as zinc finger proteins in mature viruses.
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PMID:Tightly bound zinc in human immunodeficiency virus type 1, human T-cell leukemia virus type I, and other retroviruses. 173 Nov 11

We report here for the first time that Zn2+ is an effective inhibitor of renin and the protease from HIV-1, two aspartyl proteinases of considerable physiological importance. Inhibition of renin is noncompetitive and is accompanied by binding of 1 mol of Zn2+/mol of enzyme. Depending on the substrate, inhibition of the HIV protease by Zn2+ can be either competitive or noncompetitive, but in neither case is loss of activity due to disruption of the protease dimer. Inhibition of both enzymes is first order with respect to Zn2+ and is rapidly reversed by addition of EDTA. Ki values are strongly pH dependent and optimal in the range of 20 microM at or above pH 7. All of the data in hand suggest that the inhibitory effect of Zn2+ is a consequence of its binding at, or near, the active-site carboxyl groups of these aspartyl proteinases. This inhibition of the viral enzyme may help to explain some of the beneficial effects seen in AIDS patients who have received Zn2+ therapy.
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PMID:Zinc inhibition of renin and the protease from human immunodeficiency virus type 1. 188 32

This paper summarises the information given on the 1986 EDTA Registry centre questionnaire which was returned by 82% of the 2,065 known dialysis and transplant centres in 33 European countries. Information is given on the number of patients alive on haemodialysis according to the type of dialysis facilities available where the patient was receiving dialysis and the number of patients receiving special types of dialysis. The centre questionnaire also included questions on testing for HIV infection, serological evidence or symptoms of AIDS and the diagnosis of hepatitis B in patients and staff. The data given in response to these questions are presented together with data on the involvement of dietitians and social workers in the treatment of patients with end stage renal failure. Finally, information on transplant activity in Europe and the treatment policies of transplanting centres is provided.
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PMID:EDTA Registry centre survey, 1986. Report from the European Dialysis and Transplant Association Registry. 249 73

The AIDS Clinical Trial Group's (ACTG) Immunology Committee was charged with initiating a quality control program for all laboratories participating in the ACTG program reporting flow cytometry data. Forty-one laboratories were evaluated. This report defines the goals of this program and the subsequent findings after 19 send-outs were made. Both HIV positive volunteer donors and normal age-matched donors were used. Sample sets included both heparin and EDTA anticoagulated bloods. Laboratories were asked to report hematologic parameters as well as flow cytometry data both in percentages and absolute numbers. Results were evaluated using nonparametric statistical analysis. Robust CVs and interquartile ranges were used to define the performance of individual laboratories for each CD subset analyzed. Intralaboratory reproducibility was analyzed by paired sample sets. All laboratories were found to be able to define normal samples as normal. Seventy-five percent of the laboratories were able to define abnormal samples as abnormal. Twenty-five percent could not identify two abnormal samples as abnormal. Forty percent of the labs were found unable to reproduce paired samples within an absolute of +/- 5%. EDTA was found slightly superior to heparin in bloods evaluated by flow cytometry within 30 hr of collection. The analysis of specific histograms, questionnaires, and data analysis led to a specific set of recommendations for performance of flow cytometry studies.
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PMID:Results of the flow cytometry ACTG quality control program: analysis and findings. 278 90

We describe a new immunoassay, time-resolved fluoroimmunoassay (TR-FIA), for detection of anti-HIV antibodies in human sera. This method is based on the use of a crude virus preparation coated on a polystyrene microtitre plate and of a swine anti-human IgG labelled with a rare earth metal, europium, as fluorescent label chelated with EDTA derivatives. A light pulse from a xenon lamp (340 nm) was used to excite the label and after a 400 microseconds delay time the emission fluorescence was counted for 400 microseconds at 613 nm. This cycle was repeated 1000 times during the total counting time of 1 s. TR-FIA presents considerable advantages over other techniques: (a) it avoids time-consuming, expensive and hazardous virus purification steps; (b) it excludes the use of radiotracers or substrates with potential health risks to reveal the reaction; (c) it has high sensitivity and specificity. A total of 475 serum specimens were tested by ELISA and by TR-FIA. The proportions of positivity were 29.6% by ELISA versus 26.7% by TR-FIA. The sensitivity of both systems was 100%. The specificity was 87.5% for ELISA, whereas it reached a value of 99.4% for immunofluorimetric assay.
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PMID:Time-resolved immunofluorescence: a sensitive and specific assay for anti-HIV antibody detection in human sera. 331 63

We recently purified the calcium-independent processing protease named viral envelope glycoprotein maturase (VEM), that converts human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein precursor gp160 to gp120 and gp41, from the human CD4+ T cell line, Molt-4 clone 8 [Kido, H., Kamoshita, K., Fukutomi, A., and Katunuma, N. (1993) J. Biol. Chem. 268, 13406-13413]. In this report, we deal with the inhibitor specificity and calcium requirement for intracellular gp160 processing in cultured HeLa cells and human CD4+ lymphocytes. Processing of gp160 in these cells infected with recombinant vaccinia virus encoding the gp160 gene was not affected by intracellular calcium depletion induced by the calcium ionophore A23187 and EGTA or by intracellular calcium administration. Processing of gp160 by the purified VEM in vitro was not inhibited by EDTA, EGTA, or the metallo-protease inhibitor phosphoramidon, but was specifically inhibited by a substrate analog, decanoyl-RVKR-chloromethylketone, and the trypsin-type protease inhibitors aprotinin, HI-30, and diisopropyl fluorophosphate (DFP). It was also inhibited by E-64 and thiol reagents. But intracellular gp160 processing was inhibited only by permeable, low molecular mass inhibitors of VEM, such as DFP, E-64, and thiol reagents. Syncytium formation induced by cell surface gp120 was also inhibited by permeable inhibitors of VEM. Taken together, our results indicate that calcium ions may not be essential for intracellular gp160 processing and so HIV-1 gp160 induced by recombinant vaccinia virus may be processed mainly by a protease(s) that does not require calcium ions, such as VEM in these cells.
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PMID:Calcium requirement and inhibitor spectrum for intracellular HIV type 1 gp160 processing in cultured HeLa cells and CD4+ lymphocytes: similarity to those of viral envelope glycoprotein maturase. 749 Feb 67

Using normal human serum and EDTA-plasma as the two sources of S-protein (vitronectin) in an enzyme-linked immunosorbent assay, we determined that heparin pretreatment of immobilized rgp120 or of immobilized CD4 caused the serum form of S-protein to deposit in a dose-dependent manner. Interestingly, the EDTA-plasma form of S-protein (native form) had little or no interaction with either of the heparin-treated surfaces. Several other sulfated polysaccharides such as dextran sulfate, pentosan polysulfate, heparan sulfate, and fucoidan, likewise mediated the deposition of the serum form S-protein on immobilized rgp120 and CD4. These findings may explain why certain glycosaminoglycans are effective against HIV infectivity in cell culture where the serum form of S-protein is present, yet ineffective in vivo where the native form of S-protein is predominant. The elevated glycosaminoglycan levels in gingival crevicular exudates, coupled with the effects of the serum form of S-protein and salivary-mediated neutralization mechanisms may explain the reduced rates of salivary HIV transmission.
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PMID:Heparin mediates binding of S-protein/vitronectin to the envelope glycoprotein of the human immunodeficiency virus and CD4. 752 89

The protease encoded by the human immunodeficiency virus-1 (HIV-1) is essential for processing viral polyproteins which contain the enzymes and structural proteins required for the infectious virus. It was previously found that cupric chloride, in the presence of dithiothreitol or ascorbic acid, could inhibit the HIV-1 protease. It was suggested that a Cu1+ chelate was the moiety responsible for inhibition of the protease. This hypothesis has now been investigated directly by utilizing the stable Cu1+ chelate, bathocuproine disulfonic acid Cu1+ (BCDS-Cu1+). BCDS-Cu1+ inhibited the HIV-1 wild type protease as well as a mutant HIV-1 protease lacking cysteines. BCDS-Cu1+ was a competitive inhibitor of the mutant HIV-1 protease with an apparent Ki of 1 microM. Replication of HIV-1 in human lymphocytes and the cytotoxic effect of HIV-1 in CEM cells was inhibited by micromolar BCDS-Cu1+. Inhibition of the protease and of HIV replication by BCDS-Cu1+ was dependent on the presence of Cu1+ as BCDS alone was ineffective. EDTA blocked the inhibition of the protease by Cu1+ but was unable to block inhibition of the protease by BCDS-Cu1+, indicating that the Cu1+ complex was the inhibitory agent. The apparent IC50 for BCDS-Cu1+ on the inhibition of replication by primary isolates of HIV-1 was 5 microM. However, BCDS-Cu1+ did not affect polyprotein processing in an H9 cell line chronically infected with HIV-1, indicating that BCDS-Cu1+ acts by yet another mechanism to block HIV infection. Other possible targets for BCDS-Cu1+ include inhibition of viral adsorption and/or inhibition of the HIV-1 integrase.
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PMID:Inhibition of the human immunodeficiency virus-1 protease and human immunodeficiency virus-1 replication by bathocuproine disulfonic acid Cu1+. 757 66


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