A temperature-sensitive thy mutant blocked in the synthesis of thymidylate synthetase.
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Centrifugation, Density Gradient↗
Biomedical subjects
S T Roodman
Publications and source records attributed to S T Roodman.
Alteration of RNA polymerase during transcription of phage lambda DNA "in vivo".
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Coliphages↗
Immunoregulatory T cell subsets in chronic hepatitis B virus infection: the influence of homosexuality.
The purposes of this study were 2-fold: (i) To enumerate peripheral immunoregulatory T cell subsets in untreated patients with chronic hepatitis B virus (HBV) infection and (ii) to examine the relationship between disturbances in the balance of lymphocyte subsets with liver disease and the presence of homosexuality. Circulating T lymphocyte subsets were evaluated by monoclonal antibodies to the following cell antigens: OKT3 (total T cells), OKT4 (helper/inducer T cells), and OKT8 (suppressor/cytotoxic T cells). The following groups of subjects were examined: (i) 16 heterosexuals with HBV-associated chronic active hepatitis (CAHB); (ii) 10 heterosexual, healthy HBsAg carriers, and (iii) 16 male homosexuals with CAHB. Controls included 51 healthy heterosexuals and 12 healthy, noninfected male homosexuals. We were able to demonstrate that heterosexuals with CAHB had T4/T8 ratios which did not differ from those of noninfected heterosexuals. Both healthy carriers and healthy homosexuals, however, exhibited significantly lower T4/T8 ratios than did noninfected heterosexuals (p less than 0.05, p less than 0.01, respectively). In addition, homosexuals with CAHB had lower (1.5 +/- 0.1) T4/T8 ratios than did heterosexuals with CAHB (2.0 +/- 0.2). A possible mechanism for these findings is discussed. The data indicate that the presence of homosexuality may be an important factor to consider when evaluating immunoregulatory subsets in CAHB.
Chronic Disease↗
Elevated HLA class I antigen expression on peripheral blood mononuclear cells of HBsAg carriers with coexistent human immunodeficiency virus infection.
The density of HLA Class I antigen on peripheral blood mononuclear cells was evaluated by flow cytometry in the following groups of patients: 41 HBsAg carriers; 12 individuals with chronic non-A, non-B hepatitis, and 4 with acute hepatitis B. Fourteen of the carriers were positive for antibody to human immunodeficiency virus, and all were negative for antibody to delta agent. Elevated levels of Class I antigen were observed in only 19% of patients with chronic hepatitis B virus infection alone. In contrast, 86% of HBsAg carriers with coexistent human immunodeficiency virus infection demonstrated increased expression. These data suggest that HBsAg carriers are capable of sustaining a systemic interferon response to another chronic viral infection and further supports the hypothesis that a defective interferon response exists in chronic hepatitis B virus infection.
Acquired Immunodeficiency Syndrome↗
A medical follow-up of the health effects of long-term exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin.
The human health effects of long-term exposure to low levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) have not been well established. The results of a prior study showed that persons exposed to TCDD had depressed cell-mediated immunity, and 18 of 51 persons had anergy or relative anergy on skin testing. This paper presents the results of a medical follow-up on participants who were reported to be anergic or relatively anergic in the earlier study. None of the participants in the follow-up study was anergic, and only one exposed and one unexposed participant were relatively anergic. Several technical and biological possibilities for the difference in results of the two studies are presented. The possibility that recovery from the effects of TCDD exposure caused the differing results is the least plausible explanation for the changes in the skin test results.
Adult↗
Infectivity of titered doses of simian immunodeficiency virus clone E11S inoculated intravenously into rhesus macaques (Macaca mulatta).
The macaque infectious dose (MID) of a single-cell clone of simian immunodeficiency virus isolated from a pig-tailed macaque (SIV/Mne clone E11S) was determined in rhesus macaques (Macaca mulatta). Twenty-one macaques were inoculated with 10-fold dilutions of the virus stock (three or four animals per dose). The virologic and clinical status of these animals was monitored for 26 weeks. The 25% MID (MID25) occurred at a 10(5)-fold dilution of the viral stock.
Animals↗
Long-term protection of macaques against high-dose type D retrovirus challenge after immunization with recombinant vaccinia virus expressing envelope glycoproteins.
Recombinant vaccinia virus expressing the envelope proteins of type D retrovirus-Washington (SRV-2/W) was used to immunize macaques against SRV-2 infection. Four immunized macaques which had resisted a prior low-dose challenge were rechallenged with a high dose (10(6) infectious particles) of SRV-2 two years after being immunized. All four non-immunized control macaques became infected, but the four vaccinated animals resisted this intravenous challenge, as determined by the inability to detect SRV-2 in peripheral blood mononuclear cells and by the lack of seroconversion to new viral antigens.
Animals↗