ABSTRACT
A study was made of the effect of cycloheximide on the radioresistant DNA synthesis stimulated by preincubation of cells with 5-fluorodeoxyuridine (FdUrd). It was shown that after the cycloheximide treatment the radioresistant DNA synthesis was absent while in FdUrd-treated cells it did occur. It is assumed that the FdUrd-stimulated radioresistant DNA synthesis is of an inducible nature.
Subject(s)
DNA Repair/radiation effects , DNA/biosynthesis , Floxuridine/pharmacology , Radiation Tolerance , Caffeine/pharmacology , Cycloheximide/pharmacology , DNA/radiation effects , DNA Repair/drug effects , Gamma Rays , HeLa Cells , HumansABSTRACT
It was shown that preincubation of HeLa cells with 5-fluorodeoxyuridine (10(-6) M) induced DNA synthesis resistant to gamma-radiation (6 Gy). At the same time, the death rate of exposed cells increased and nucleoid relaxation decreased. The role of DNA synthesis inhibitors in the reproductive death of exposed cells is discussed.
Subject(s)
DNA, Neoplasm/biosynthesis , Floxuridine/pharmacology , HeLa Cells/radiation effects , Radiation-Sensitizing Agents/pharmacology , HeLa Cells/drug effects , HumansABSTRACT
Enzyme activity of lactate dehydrogenase, glutamate-oxalacetate and glutamate-pyruvate transaminase, creatine phosphokinase, cholinesterase, alkaline, acid and prostatic phosphatase and aldolase has been studied in a total of 213 subjects, of whom 97 were of good health, 63 had bone tumors and 53 suffered from osteomyelitis. The activities of the majority of the enzymes were found to become significantly changed in comparison with the norm. In both patient groups, the more striking differences being noted in that of osteomyelitis. However, enzymatic activity alone does not allow to differentiate the group of bone tumors from that of osteomyelitis, the differences between these two groups not being of significance in any one of the enzymes followed.