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Stephen J O'Brien

Publications and source records attributed to Stephen J O'Brien.

94 records · Page 6Linked to original sources
PubMed2002

Human immunodeficiency virus type 1 (HIV-1)-specific CD8+-T-cell responses for groups of HIV-1-infected individuals with different HLA-B*35 genotypes.

Human immunodeficiency virus type 1 (HIV-1)-infected individuals with HLA-B*35 allelic variants B*3502/3503/3504/5301 (B*35-Px) progress more rapidly to AIDS than do those with B*3501 (B*35-PY). The mechanisms responsible for this phenomenon are not clear. To examine whether cellular immune responses may differ according to HLA-B*35 genotype, we quantified HIV-1-specific CD8(+)-T-cell (CTL) responses using an intracellular cytokine-staining assay with specimens from 32 HIV-1-positive individuals who have B*35 alleles. Among them, 75% had CTL responses to Pol, 69% had CTL responses to Gag, 50% had CTL responses to Nef, and 41% had CTL responses to Env. The overall magnitude of CTL responses did not differ between patients bearing B*35-Px genotypes and those bearing B*35-PY genotypes. A higher percentage of Gag-specific CTL was associated with lower HIV-1 RNA levels (P = 0.009) in individuals with B*35-PY. A negative association between CTL activity for each of the four HIV antigens and viral load was observed among individuals with B*35-PY, and the association reached significance for Gag. No significant relationship between CTL activity and viral load was observed in the B*35-Px group. The relationship between total CTL activity and HIV RNA among B*35-Px carriers differed significantly from that among B*35-PY carriers (P < 0.05). The data are consistent with the hypothesis that higher levels of virus-specific CTL contribute to protection against HIV disease progression in infected individuals with B*35-PY, but not in those with B*35-Px.

Acquired Immunodeficiency Syndrome↗
PubMed2001

The influence of HLA genotype on AIDS.

Genetic resistance to infectious diseases is likely to involve a complex array of immune-response and other genes with variants that impose subtle but significant consequences on gene expression or protein function. We have gained considerable insight into the genetic determinants of HIV-1 disease, and the HLA class I genes appear to be highly influential in this regard. Numerous reports have identified a role for HLA genotype in AIDS outcomes, implicating many HLA alleles in various aspects of HIV disease. Here we review the HLA associations with progression to AIDS that have been consistently affirmed and discuss the underlying mechanisms behind some of these associations based on functional studies of immune cell recognition.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Risk factors for early failure after thermal capsulorrhaphy.

Thermal capsular shrinkage has rapidly become a common procedure for a variety of shoulder conditions usually associated with instability, although clinical data on outcomes are limited. The objective of this study was to identify risk factors for poor outcome after thermal capsulorrhaphy. Of 106 patients who underwent thermal shrinkage, 15 patients with treatment failures were identified. The mean time to failure after the procedure was 6.3 months (range, 1 to 16). Previous operations and multiple recurrent dislocations were associated with poor outcome at a highly significant level. Multidirectional instability and participation in contact sports did not attain statistical significance as risk factors. However, statistical power in these two comparisons was insufficient to exclude them as potential risk factors. A concomitant procedure at the time of thermal capsulorrhaphy was not associated with poor outcome. The data from early treatment failures can be useful in guiding patient selection for thermal capsulorrhaphy. This procedure may be of limited value for patients who have had prior operations or have a history of multiple dislocations. The data also suggest that thermal capsulorrhaphy should be used cautiously in patients with multidirectional instability or in those who are involved in contact sports.

Adolescent↗