ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Analysis of sera from hospitalized Brazilian patients by whole-virus lysate-based enzyme immunoassay and Western blot indicated that 0.4% were reactive to HIV-2 alone while 4% were reactive to both HIV-1 and HIV-2. When these sera were tested for HIV antibody by type-specific peptide enzyme immunoassays, dual seropositivity was confirmed in only 0.4% of patients. To define genetically the HIV strains within the population, we analyzed peripheral blood mononuclear cells from selected seropositive patients for the presence of HIV-1 and HIV-2 proviral DNA using the polymerase chain reaction (PCR). Independent primers/probes sets were used for the amplification and detection of viral sequences from the long terminal repeat (LTR), gag, and protease (prt) gene regions. Our findings confirmed the serologic evidence of HIV-2 in Brazil and determined the extent of mixed HIV-1 and HIV-2 infections. Detailed evaluation of the amplified viral protease sequences by endonuclease restriction analysis and DNA sequencing independently confirmed mixed HIV-1 and HIV-2 infections in the two patients seropositive for HIV-1 and HIV-2. The data further indicated that these isolates are distinct from the HIV laboratory standards. We interpret the combination of culture and PCR findings to demonstrate the presence of both HIV-1 and HIV-2 in Brazil.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The persistent infection of human glial cells with HIV-1 is characterized by prominent expression of the Nef protein. In order to evaluate the possible role of Nef in the development of HIV-1-associated neurological disorders, we compared Nef with known neuroactive proteins. We found that HIV Nef shares sequence and structural features with scorpion peptides known to interact with K+channels. Sequence similarity encompasses two distinct regions of scorpion peptides. Based on crystallography data, both regions in scorpion peptides cooperate in forming a common domain stabilized by ion pairs between charged amino-acid residues. Recombinant Nef protein, as well as a synthetic part of a scorpion channel active peptide (M10), reversibly increased the total K+current of chick dorsal root ganglions in patch-clamp experiments without killing the cells. These results indicate that a region conserved in HIV Nef and scorpion peptides concurs in both structure and electrophysiological activity and suggest that Nef, like scorpion peptides, may affect neuronal cell function.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

We used a human monoclonal antibody (MAb; 15e) to identify an antibody-dependent cell-mediated cytotoxicity (ADCC) epitope on HIV-1 gp120. 15e has been shown to recognize a conformation-dependent epitope on gp120 which is important in both CD4 binding and neutralizing of HIV-1 infection. 15e binds to gp120 of HIV-1IIIBbut not HIV-1RF. Using a standard ADCC assay, I5e was found to mediate ADCC against cells infected with HIV-1IIIBbut not HIV-1RF. l5e did not mediate ADCC against cells with recombinant gpl20 bound to surface CD4, indicating that l5e does not mediate innocent bystander ADCC against uninfected CD4 cells. To better define the l5e epitope, we performed ADCC against target cells infected with a vaccinia vector which expresses processed HIV-1IIIBgpl60 from which the third variable region was deleted (amino acids, 312–328). MAb l5e efficiently mediated ADCC against cells expressing this altered form of gpl20, indicating that this region is not contributing to the conformational epitope defined by l5e. l5e defines an important epitope in the human immune response to HIV-1 infection. Antibodies with l5e-like activity may be useful in immunoprophylaxis or immunotherapy of HIV-1 infection.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Early diagnosis of HIV infection in the child of an HIV-infected mother may be difficult as HIV-specific immunoglobulin (Ig) G antibodies are transmitted to the fetus transplacentally. In an attempt to provide a new, simpler tool for early identification of HIV-infected children we analysed the HIV-specific IgC subclass pattern during the first year of life. One hundred and one samples were collected from 35 children born to HIV-seropositive mothers, among whom 18 seroreverted during follow-up and 17 were HIV-infected (two Pl and l5 P2 according to the Centers for Disease Control classification). Serum HIV-specific lgG3 was detectable at least in one sample in 26 out of 35 children. All 17 HIV-infected children showed persistently detectable specific lgC3, both with stable or progressive disease. Out of the l8 uninfected children who seroreverted during follow-up, nine were HIV-specific lgC3-negative when first tested and nine lost HIV-specific-lgG3 within 28 weeks after birth. The correlation of the serological results with clinical information and any other diagnostic tool on each child suggests that the clearance of specific-lgG3 antibodies heralds seroconversion in uninfected passive antibody-carrier children. This observation provides the basis for a new, simple and effective method for early diagnosis of HIV infection in children born to seropositive mothers.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Hypergammaglobulinemia is one of the most consistent, and usually the first observable abnormality in infants vertically infected with HIV. We have analyzed serum interleukin (IL)-4, IL-6, tumor necrosis factor (TNF)-α, and immunoglobulin (Ig) concentrations in 23 HIV-infected and 21 uninfected children. IL-6 and TNF-α concentrations in HIV-infected children were significantly higher than those in uninfected children, and mutually correlated. No differences in serum IL-4 levels between infected and uninfected children were observed. There was a correlation between serum IL-6 and IgC and between IL-6 and IgA concentrations. Furthermore, during follow-up changes in IL-6 levels were usually accompanied by corresponding changes in IgC levels. Our data indicate an association between HIV, IL-6, TNF-α and hypergammaglobulinemia. Regardless of the source and initial stimulus, continued production of IL-6 and TNF-α may result in augmentation in an auto-feedback manner, accompanied by increases in Ig synthesis and, more importantly, HIV replication. Thus, elucidation of the mechanisms responsible for overproduction of these two cytokines in HIV-infected patients is not only interesting from a biologic point of view, but is likely to have important clinical implications as well.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

This study assesses the changes in the expression of histocompatibility antigen (HLA)-DR by mononuclear phagocytes from HIV-infected individuals. Overnight culture of monocytes resulted in an increase in HLA-DR expression by monocytes from uninfected individuals. In contrast, the expression of HLA-DR by monocytes from HIV-infected patients decreased spontaneously and was most pronounced in patients with clinical AIDS. We also found thatMycobacterium aviumgrew within monocytes from patients infected with HIV. The correlation between major histocompatibility complex (MHC) class II expression and Mycobacterial growth which has been reported in mice was not observed in monocytes from HIV-infected patients.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Abnormalities in pulmonary function tests have been observed in AIDS patients with pulmonary disease. In this study, the polymerase chain reaction (PCR) was used to determine if the reductions in transfer factor for lung carbon monoxide (TLCO) were due to the presence of HIV-1 or cytomegalovirus (CMV). HIV-1 was detected in cells from bronchoalveolar lavage (BAL) in 35 out of 60 (58%) of patients. The detection of HIV-1 had no significant effect on pulmonary function. CMV was detected in the BAL of 58% of patients in this study but CMV was the sole viral pathogen in the lung of only two out of 60 (3.3%) individuals. A significant reduction in TLCO was observed in individuals with PCP where CMV was also detected in the BAL. This study shows that reduction in TLCO in HIV-seropositive patients is not due to the presence of HIV-1 or CMV alone in BAL cells.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Candidiasis is the most common oral fungal infection seen in association with HIV infection. It may present in a number of clinical forms, including pseudomembranous and erythematous candidiasis. To determine whether erythematous candidiasis, like the pseudomembranous form, is predictive of the development of AIDS, we reviewed the records of 169 HIV-seropositive patients seen at clinic of the Oral AIDS Center, University of California, San Francisco who were diagnosed with pseudomembranous or erythematous (or both) forms of oral candidiasis at their first examination. Kaplan–Meier analysis showed a rapid rate of progression to AIDS (median, 25 months) and to death (median, 43.8 months) in all three groups. We conclude that erythematous candidiasis is as serious a prognostic indicator as pseudomembranous candidiasis. Because the erythematous form is more difficult to recognize and hence is underdiagnosed, efforts should be made to teach non-dental clinicians who care for HIV-infected patients to diagnose and treat this lesion.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

In this study we demonstrate that HIV-1-seropositive thrombocytopenic individuals, in contrast with immune thrombocytopenic purpura (ITP) patients, fail to have a compensatory increase of megakaryocytopoiesis. Thein vitrogrowth of bone-marrow megakaryocyte progenitors (CFU-MK) and the production of granulocyte/macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-1 and IL-6 by bone-marrow mononuclear adherent cells and peripheral blood (PB) light-density mononuclear cells were studied in 12 HIV-1-seropositive thromobocytopenic individuals with respect to 12 ITP patients and 15 normal controls. In HIV-1-seropositive thrombocytopenic individuals, CFU-MK size (number of megakaryocytes per colony) was similar to normal controls but significantly lower (P< 0.05) than in ITP patients. IL-1 and IL-6 production was similar in the three groups of subjects. On the other hand, GM-CSF production by bone-marrow mononuclear adherent cells in HIV-1-seropositive thrombocytopenic individuals was similar to normal controls but significantly (P< 0.05) lower than in ITP patients, whereas GM-CSF production by PB light-density mononuclear cells was markedly (P< 0.05) defective compared with both normal controls and ITP patients. The positive correlation between number and size of CFU-MK and production of GM-CSF by bone-marrow mononuclear adherent cells, observed in all three groups of subjects, demonstrates the central role of GM-CSF in the control of megakaryocytopoiesis.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID