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Biomedical subjects

R L O'Brien

Publications and source records attributed to R L O'Brien.

At least 73 records · Page 4Linked to original sources
PubMed1976

Transformation of human peripheral lymphocytes by galactose oxidase.

Human peripheral lymphocytes can be transformed by treatment with galactose oxidase alone. Prior treatment with neuraminidase enhances this effect. The aldehyde blocking agents thiocarbohydrazide, hydroxylamine, dimedone, and sodium borohydride block transformation when they follow, but not when they precede, galactose oxidase treatment. Thus, as is the case for periodate-induced lymphocyte transformation, the formation of free aldehyde at the cell surface would seem to be a critical event in the triggering of transformation by this agent. The degree of transformation is highly variable from individual to individual, and also for the same donor at different times. However, the lymphocytes of some people give a consistently poor response to galactose oxidase. Similar results have been obtained for periodate-induced transformation of human lymphocytes, but to this date this is unexplained.

Alcohol Oxidoreductases↗
PubMed1974

R factors in strains of Salmonella typhi and Shigella dysenteriae 1 isolated during epidemics in Mexico: classification by compatibility.

All 17 Salmonella typhi strains tested from the epidemic in Mexico carried R factors of compatibility group H, conferring resistance to chloramphenicol, streptomycin, tetracycline, and sulfonamides. Some S. typhi strains carried, in addition, non-conjugative, ampicillin resistance plasmids and R factors of the I or A-C complex. All 20 Shigella dysenteriae 1 strains tested of epidemic origin carried O-group R factors. Ampicillin resistance in S. dysenteriae 1 was not proved to be plasmid borne. R factors of group H were not identified in any of the tested Mexican isolates other than S. typhi, but R factors of group O were identified in Escherichia coli, Shigella flexneri, and one strain of S. typhi, as well as in the epidemic S. dysenteriae. An R factor was identified which seemed to have two compatibility specificities, groups Iomega and O.

Disease Outbreaks↗