The effects of sodium cyanate, ferf-butyl isocyanate, and benzyl isothiocyanate on carcinogen-induced neoplasia were studied in experiments in which the test compound was fed starting 1 week following completion of carcinogen administra tions. Under these conditions, all three test compounds exerted an inhibitory effect on the occurrence of 7,12-dimethylbenz(a)anthracene-induced neoplasia of th...

The incidence of chromosome aberrations in rat bone marrow, examined 6 hr after the administration of 7,12-dimethylbenz(a)anthracene, was significantly enhanced by induction of anemia 0-48 hr before the carcinogen treatment and was suppressed by induction of polycythemia. The suppressive influence of polycythemia was reversed by sheep erythropoietin injected shortly before or after the carcinog...

Carcinogenesis in the mammary gland is thought to involve carcinogen-induced initiation in mammary epithelial cells. Recent experiments have demonstrated that the mammary stroma can be a target of carcinogenic agents, which results in the stroma positively affecting carcinogenesis. To determine whether the stroma or epithelium is the primary target in chemically induced mouse mammary tumorigene...

Treatment of Chironomus polytene chromosomes with the ultimate carcinogen benzo[a]pyrene diol epoxide I or in vivo administration of the parent hydrocarbon to larvae indicates that the carcinogen interacts with the genome in a nonrandom manner. Visualization of the carcinogen-DNA binding sites by immunofluorescence reveals that, in vivo, some sites are preferentially modified. The combined effe...