No abstract

Individuals occupationally exposed to cytotoxic drugs may be at risk owing to the effects of these agents on DNA. As an index of DNA damage, in vivo mutations were measured in lymphocytes from 24 oncology nurses or pharmacists and 24 matched controls. Mutation frequency was significantly increased in exposed individuals and appeared to be related to duration of exposure. However, the overall magnitude of the increase was small and its biological significance remains to be determined.

Limiting-dilution cloning of human lymphocytes was used to study cloning and proliferation of lymphocytes in 10 young and 10 elderly individuals. The cloning efficiency for elderly individuals, 3.5%, was significantly lower than that for young individuals, 19.8%. Mixing experiments showed that this decrease was due to both a decrease in the frequency of the clone-forming cells and a decrease in the interacting ability of the lymphocytes. Lymphocytes from elderly individuals which did form clones, however, proliferated at the same rate as did those from young individuals.