ISSN:0269-9370    

出版商:OVID    

年代:1990

数据来源: OVID

ISSN:0269-9370    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

With a view to obtaining human monoclonal antibodies against HIV-1 antigens we used the Epstein–Barr virus immortalization technique to induce lymphoblastoid cell lines from peripheral blood lymphocytes of 10 people who were seropositive for HIV-1 and had no clinical symptoms. A number of polyclonal lines were obtained which synthesized antibodies against most of the major proteins and glycoproteins of HIV-1. Three stable clones were characterized for class, secretion characteristics and specificity. Two of these clones produce antibodies which react with gp41, and the third reacts with p25. One of the anti-gp41 antibodies was found to have neutralizing activity.

ISSN:0269-9370    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Cytokines such as tumour necrosis factor (TNF) can induce HIV-1 production in T-cell tumour lines. However, it is not known if the same occurs in freshly isolated mononuclear cells, nor is it known if the virus can itself regulate cellular cytokine production. In this paper we report that HIV-1 induces peripheral blood mononuclear cells (PBMC) and CD4+ T lymphocytes to secrete TNFα, TNFβ and interferon-gamma (IFNγ), three cytokines having multifunctional activities and complex physiological roles. We also show that separate addition of exogenous recombinant (r) TNFα or rTNFβ or rlFNγ increases HIV-1-induced syncytium formation in both PBMC and CD4+ cells by up to 10 000-fold, with TNFα being most potent in this regard. Finally, we show that syncytium formation induced by diverse HIV-1 isolates and LAV-2 is inhibited without the addition of exogenous r-cytokines by the respective anti-cytokine antibodies. Our study therefore demonstrates that efficient HIV replication in primary mononuclear cells is associated with the ability of the virus to induce TNF and IFNγ secretion.

ISSN:0269-9370    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Severe thrombocytopenia (TP) accounted for 5.3% of cases in a consecutive series of 380 HIV-infected intravenous drug users (IVDUs) at presentation. Forty-one of 53 subjects with severe TP showed haemorrhages and were treated as follows: ten were splenectomized, 17 were given high-dose intravenous immunoglobulins (HDlg), and 10 received anti-Rh(D) immunoglobulins (anti-Rh lg). Splenectomy induced a complete clinical response in all cases: four out of 10 patients maintained platelet counts > 100 x 109/l. HDlg gave a good clinical response in all patients, but eight out of 17 suffered haemorrhages during the follow-up and recall treatments were necessary. Six out of 10 patients treated with anti-Rh lg maintained platelet counts > 30 x 109/l, but in two cases the treatment was interrupted because of severe haemolysis. No patient progressed to overt AIDS during the follow-up. Splenectomized patients in particular did not show adjunctive risks of worsening of the HIV-related clinical picture. A platelet kinetic study performed in 20 patients with severe HIV-related TP suggests a possible role for platelet sequestration in TP of HIV-infected IVDUs, in which a liver involvement is very frequent.

ISSN:0269-9370    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

To investigate whether there are variations in the growth capacity of HIV in peripheral blood mononuclear cell (PMBC) preparations from different individuals, PBMC cultures prepared from 27 healthy donors were infected with the fresh HIV-1 isolates JH/3 or JMH/1. After infection of the PBMC with HIV, the culture fluid was checked for infectivity (TCID50) and the level of p24 antigen. Significant diversity was observed in these values in different individuals. No correlation between the percentage of CD4-positive lymphocytes or the growth ability of PBMC and TCID50was shown. Whether PBMC was infected with JH/3 or JMH/1 also made no difference. In some cases, however, the culture fluid possessed high (or low) p24 levels despite a low (or high) infectious virus yield. The E-rosette-positive cell fraction was separated from the PBMC preparations which showed the highest and the lowest virus yield, and the yield was determined after infection with JMH/1. The difference in virus yield and the TClD50/p24 ratio between these donors was also observed in these T-cell-enriched cell cultures. The results suggest that variations in the growth capacity of HIV in different PBMC preparations are due to the T-cell population and that the source of the PBMC influences not only the binding of the virions onto the cell surface but also the replication of the virus in the cell.

ISSN:0269-9370    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Infection with HIV causes a reduction in the numbers and function of CD4+ lymphocytes and functional abnormalities of other cells. We have studied the effect of HIV infection on signal transduction in the H9 lymphoblastoid CD4+ cell line. Resting HIV-infected H9 cells show evidence of chronic activation with raised levels of lnsP3and lnsP4, the active metabolites of the inositol polyphosphate pathway, and a consequently raised intracellular free calcium concentration. Stimulation of HIV-infected H9 cells with phytohernagglutinin (PHA) leads to a fall in the previously raised levels of lnsP3but a further rise in lnsP4, whilst an attenuated intracellular calcium rise is seen with both PHA and anti-CD3 antibody. The observed effects of HIV infection on signal transduction provide a mechanism to explain the functional defects in CD4+ lymphocytes and, possibly, other cell types.

ISSN:0269-9370    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Any reduction in the rate of spread of HIV infection has consequences for the incidence and demographic effects of AIDS. In this paper, output from a published mathematical model of the dynamics of HIV transmission through heterosexual contact is used to study the implications of reducing HIV transmission on demographic patterns and national health budgets in sub-Saharan Africa. The major conclusion is that both the timing and the effectiveness of reducing HIV transmission are non-linearly related to their potential demographic and economic effects. The analysis emphasizes the benefits to be gained from a concerted effort to reduce the spread of HIV infection as early as possible in the time course of the epidemic.

ISSN:0269-9370    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Numerous studies performed over the past 5 years have indicated an association between HIV infection and other sexually transmitted diseases (STDs), particularly those involving genital ulceration. Such an association may be causal, indicating that STDs increase susceptibility to, or infectivity of, HIV infection or may result, in whole or in part, from the mutual dependence of HIV and STDs on patterns of sexual activity, or from an effect of HIV infection on the clinical course of STDs. In this paper we discuss the issues arising in the design and analysis of studies conducted to investigate this association. A numerical illustration is used to demonstrate non-causal associations that may arise in observational studies due to confounding and misclassification. Published cross-sectional and longitudinal studies are reviewed, and recommendations made for future studies. Special emphasis is given to the use of randomized intervention trials to overcome many of the biases associated with observational studies, and to provide information on the efficacy of intensive STD treatment programmes in reducing the transmission of HIV.

ISSN:0269-9370    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

A double-blind, randomized, placebo-controlled trial comparing two daily doses of oral ribavirin (600 and 800 mg) and a placebo was performed at four medical centers geographically distributed throughout the USA. One hundred and sixty-four HIV-infected adult men with lymphadenopathy were enrolled over a 2-month period and received active treatment for 24 weeks followed by a 4-week interval during which they did not receive the study drug. A marked interlaboratory variation in HIV isolation from peripheral blood mononuclear cells was observed, underscoring the critical role of quality assurance in similar multicenter trials. Nevertheless, the combined data indicate that ribavirin did not significantly suppress HIV activity (on measurement of reverse transcriptase activity) after week 6 or reduce serum p24 antigenemia.

ISSN:0269-9370    

出版商:OVID    

年代:1990

数据来源: OVID