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A Barboza

Publications and source records attributed to A Barboza.

9 recordsLinked to original sources
PubMed2004

Documentation of subtype C HIV Type 1 strains in Argentina, Paraguay, and Uruguay.

HIV subtypes B, F, and BF recombinants have been previously reported in South America. This report describes the presence of HIV-1 subtype C infection in the countries of Argentina, Uruguay, and Paraguay dating back to at least 1999. Surveillance for uncommon non-B/non-F subtype viruses circulating in South America has been conducted in samples obtained from nine countries. Peripheral blood mononuclear cells (PBMC), dried filter paper (FP), and fresh blood (FB) samples were collected from HIV-positive patients from Ecuador, Colombia, Venezuela, Peru, Chile, Bolivia, Argentina, Uruguay, and Paraguay. From a total of 2962 HIV seropositive samples examined during a 9-year period (1995-2003), only 11 (0.4%) were found to be infected with non-B/non-F HIV variants. Eight of these 11 strains were determined to be subtype C by heteroduplex mobility assay (HMA). Five of these 8 strains were further characterized by sequencing and phylogenetic analysis of the protease (Pro) and reverse transcriptase (RT) region of the genome and two were sequenced full length. One of the strains was found to be a unique BC recombinant. The spread of a third subtype of HIV, subtype C, should raise the question of its potential future role in the HIV epidemic in this region.

Adult↗
PubMed1992

Infection of cultured human adrenal cells by different strains of HIV.

OBJECTIVE: To determine whether human adrenal cells can be infected by HIV. METHODS: Cultured human fetal adrenal cells and the SW13 human adrenocortical carcinoma cell line were inoculated with several HIV-1 and HIV-2 strains. Virus replication was detected by viral core antigen enzyme-linked immunosorbent and reverse transcriptase assays. CD4 expression was measured by Northern blot and polymerase chain reaction procedures. RESULTS: HIV infection of these adrenal cells was detected and was most evident after cocultivation of the inoculated cells with peripheral blood mononuclear cells. Infection does not involve the CD4 molecule, which is not expressed by these adrenal cells. The relative level of HIV replication depended on the viral strain used. Virus production occurred best in cells that maintained evidence of adrenal cell function. Infection did not appear to disturb steroidogenesis measured in the cells. CONCLUSIONS: These observations indicate that human adrenal cells are susceptible to HIV infection, and provide further evidence of the polytropic nature of the virus.

Adrenal Cortex↗
PubMed1991

Characterization of human immunodeficiency virus type 1 strains recovered from the bowel of infected individuals.

HIV-1 isolates were recovered from biopsy tissues from the small bowel, colon, and rectum of 10 infected individuals with severe diarrhea. In general, the bowel strains grew well in primary macrophage and lymphocyte cultures, not in T or B cell lines. They induced cytopathic effects such as syncytia formation and cell killing in peripheral blood mononuclear cells and were usually sensitive to serum neutralization. Several of these isolates were able to infect bowel epithelial cell lines, but this characteristic was also observed with blood-derived strains. Differences could be identified in 3 of 6 cases of paired bowel and blood isolates from the same individual. When compared to blood-derived isolates, the bowel strains exhibited a relative inability to grow in established cell lines, a reduced ability to induce cytopathology in infected cells, and a greater sensitivity to serum neutralization. Thus, although distinct characteristics of bowel-derived HIV-1 strains were not found, certain biological and serological properties might differentiate these viruses from those isolated from other tissues.

Biopsy↗
PubMed1991

Several CD4 domains can play a role in human immunodeficiency virus infection in cells.

The human immunodefiency virus (HIV) uses the human CD4 glycoprotein as a receptor for infection of susceptible cells. Cells expressing a series of mutated forms of the CD4 gene have shown a variability in their ability to support replication of three HIV type 1 (HIV-1) and three HIV-2 strains. Moreover, when different stages of virus production were examined by a variety of assays, a consistent delay was observed in all cell lines containing CD4 mutants compared with those with intact full-length CD4. Cells expressing the CD4.415 mutant (modified at the serine 415 corresponding to a phosphorylation site of the cytoplasmic domain) showed only a minimal effect on virus replication. Cells expressing CD4.403 and CD4.401 mutants (lacking the whole cytoplasmic domain) manifested a moderate delay in production of virus progeny. The most substantial effect on HIV replication was observed in cells expressing a chimeric hybrid containing sequences corresponding to the first 177 residues of the N-terminal CD4 fused to CD8 sequences encoding the hinge, transmembrane, and cytoplasmic domains of the human CD8. Furthermore, in a cell-to-cell contact assay, fusion was absent when the CD4 proximal membrane domain was replaced by the CD8 counterpart. In addition, a strong correlation between the down-modulation of the surface CD4 and HIV expression was observed. These observations suggest that in addition to the known binding region, other domains of CD4 could play an important role in regulating HIV entry of cells.

CD4 Antigens↗
PubMed1988

Simultaneous isolation of HIV-1 and HIV-2 from an AIDS patient.

Two distinct human immunodeficiency viruses, HIV-1SF480 and HIV-2UC2 were isolated simultaneously from the blood of an Ivory Coast patient with AIDS. The HIV subtypes were segregated by their differential ability to infect established human cell lines and by the cell surface expression of type-specific viral antigens. The viruses could be distinguished by both immunoblot and Southern blot analyses. The results indicate that an individual can be infected by both HIV subtypes.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Characterization of a noncytopathic HIV-2 strain with unusual effects on CD4 expression.

A new isolate of the human immunodeficiency virus type 2, designated HIV-2UC1, was recovered from an Ivory Coast patient with normal lymphocyte numbers who died with neurologic symptoms. Like some HIV-1 isolates, HIV-2UC1 grows rapidly to high titers in human peripheral blood lymphocytes and macrophages and has a differential ability to productively infect established human cell lines of lymphocytic and monocytic origin. Moreover, infection with this isolate also appears to involve the CD4 antigen. However, unlike other HIV isolates, HIV-2UC1 does not cause cytopathic effects in susceptible T cells nor does it lead to loss of CD4 antigen expression on the cell surface. These results indicate that HIV-2 may be found in individuals with neurologic symptoms and that the biological characteristics of this heterogeneous subgroup can differ from those typical of HIV-1.

Acquired Immunodeficiency Syndrome↗