ISSN:0269-9370    

出版商:OVID    

年代:1989

数据来源: OVID

ISSN:0269-9370    

出版商:OVID    

年代:1989

数据来源: OVID

ISSN:0269-9370    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We investigated whether human immunoglobulin G (IgG) directed to gp 110 may serve as an attachment system to Fc-gamma receptors (Fc-γR), allowing eventual infection of cells of the macrophage lineage. An anti-HIV IgG preparation that prevented viral particles and soluble recombinant radiolabelled envelope precursor gp160 from binding to CD4 on CEM lymphoid cells, and that strongly inhibited infection of these cells by HIV, was selected. In contrast, anti-HIV IgG, whether or not previously complexed to viral particles, bound to monocytic U937 cells that express both high Fc-γRI and low affinity Fc-γRII receptors. Precoating these cells with anti-HIV IgG or complexing the antibodies with soluble125-gp160 resulted in increased fixation of gp160 to the cells, which was inhibited by aggregated human normal IgG. These data indicate that anti-HIV IgG-dependent attachment of gp160 to monocytic cells occurs through both types of Fc-γR. In addition, this method of attachment resulted in productive infection of U937 cells that, since it was blocked in the presence of Leu3a, still appeared to involve gp110-CD4 interaction. Only slight enhancement of infectivity, such as described for other enveloped viruses, was noted, even when antibody concentration was titrated down. This mechanism may be one of the explanations why the humoral response to HIV is not usually protective.

ISSN:0269-9370    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Rates of sexual-partner change and patterns of high-risk behaviour are important determinants of the spread of HIV. We carried out a survey to assess the feasibility of studying sexual lifestyle in a random sample of the British population, aged 16–64 years, in November 1987.Two thousand and seventy-seven households were selected using a multi-stage probability sampling procedure. Seven hundred and eighty-five adults participated in a structured interview. The schedule included demographic details, attitudes to AIDS, numbers of sexual partners in different time periods, history of homosexuality and contact with prostitutes.An interview was obtained in 61% of households where contact was made, but the overall response rate was low (48%). There was marked variability between individuals in numbers of sexual partners in given time intervals. Men and women in younger cohorts had experienced first sexual intercourse earlier and had higher numbers of sexual partners than people in older cohorts. Surprisingly few reported high-risk behaviour such as homosexuality and use of prostitution. The methodological problems in trying to obtain unbiased and valid data on sexual behaviour are discussed. Further work is necessary to improve the response rate and questionnaire design.

ISSN:0269-9370    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

It has been recently advocated that avoiding partners who may be at high risk of carrying HIV provides 5000-fold better protection against HIV infection than usage of condoms [1]. In this paper, it is demonstrated that this guideline is largely based on unrealistic assumptions. If the sensitivity of identifying high-risk partners, realistic estimates of the efficiency of mechanical and chemical barrier methods, and the compliance in following either strategy are taken into account, use of condoms and/or suppositories containing nonoxynol-9 might be more effective than the attempt to avoid high-risk partners. Thus, both barrier methods should be strongly recommended for casual sexual heterosexual contacts.

ISSN:0269-9370    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

This report presents the results of a survey conducted between February and April 1988 to ascertain Ugandans' perception of AIDS as a problem, their knowledge of the disease and how it is spread, the resultant change in their sexual behaviour and their knowledge of, and attitudes towards, condoms. Two hundred and four people (98 women, 106 men) were interviewed from three locations; Kampala (an area with a high incidence of AIDS), Kabale, a town in central Kigezi, and villages in North Kigezi (both relatively low incidence areas).The main points to emerge are: (1) all the respondents were aware of the disease; (2) only 3.6% of respondents mentioned AIDS of their own accord as a problem for Uganda; (3) those in Kampala were most knowledgeable and men in all three areas were generally more informed than women; (4) change in behaviour was more pronounced in those who had known an AIDS victim personally; (5) 100% of men and 79% of women had heard of condoms but only eight men (9.4%) and one woman (1.0%) used condoms regularly for the prevention of AIDS, and (6) there was, nonetheless, a degree of willingness to use condoms once informed that they could reduce the risk of AIDS.

ISSN:0269-9370    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We have developed an enzyme-linked immunosorbent assay (ELISA) specific for antibodies to the envelope glycoproteins gp120 and gp160 of HIV-1 An antibody to a conserved epitope on gp120 is adsorbed to a solid phase and used to capture gp120 and/or gp160 from solution. This may be purified recombinant protein or in simple, non-denaturing detergent extracts of different strains of HIV-1. Human serum antibodies bound to the captured antigen are subsequently detected with an anti-human antibody coniugated to alkaline phosphatase, and the AMPAK ELISA amplification system (Novo BioLabs, Cambridge, UK). With this procedure, antibodies can be detected that recognize gp120 from a wide range of divergent HIV-1 strains. The ELISA is sufficiently sensitive to detectenvantibodies in sera from HIV-positive individuals at dilutions of 1.3000 00. No repeatable false-positives were detected in a screen of 250 normal serum samples.Envantibodies were detected in all 37 strongly HIV-positive sera tested, and in four sera that were borderline or weakly positive in commercial ELISA. However, 55 sera positive in commercial ELISA but unconfirmable by Western blot (‘ambiguously’ positive) did not contain detectableenvantibodies.

ISSN:0269-9370    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We produced recombinant envelope-derived peptides of HIV-2 for use in a diagnostic enzyme-linked immunosorbent assay (ELISA) or Western blot by expressing several restriction enzyme fragments from theenvgene of HIV-2 in the bacterial fusion vector pEX-3. On Western blots, 17 out of 18 anti-HIV-2-positive sera available to us reacted strongly with those recombinant peptides which were derived from, or extended into, the transmembrane protein of HIV-2. In contrast, recombinant peptides derived from the external envelope glycoprotein were only weakly recognized by two sera. We observed a cross-reactivity of some human sera containing antibodies to HIV-1 with the HIV-2 peptides derived from the transmembrane protein of HIV-2. In spite of this cross-reactivity, a serological distinction between anti-sera to HIV-1 and HIV-2 can be attempted by simultaneous testing in ELISA on recombinant peptides derived from the transmembrane protein of HIV-1 and HIV-2.

ISSN:0269-9370    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

GACPAT is a modification of a gelatin particle-agglutination test for the detection of anti-HIV-1 and anti-HTLV-I. In it, antigen-coated particles react with immunoglobulin captured from the specimens onto the surface of U-bottomed reaction wells previously coated with anti-γ chains. In initial tests on 1127 blood donations, of 628 HIV-1 high-risk specimens and 176 HTLV-I high-risk specimens, GACPAT for anti-HIV-1 was 98.9% specific and 100% sensitive, and for anti-HTLV-I was 99.0% specific and 93.0% sensitive. It rivalled the sensitivity of second-generation enzyme-linked immunosorbent assays (ELISA) for anti-HIV-1 in tests on specimen dilutions and on seroconversion series. GACPAT can be used as a cheap, large-scale test and as a simple confirmatory check on other assays.

ISSN:0269-9370    

出版商:OVID    

年代:1989

数据来源: OVID