Spontaneous and mutagen induced sister chromatid exchange (SCE) frequencies have been studied in nine patients with multiple sclerosis and in nine age and sex matched healthy controls. The incidence of spontaneous SCE in lymphocytes of the MS patients was significantly greater, by about 50%, than in those of the control subjects. When exposed to mitomycin C (MMC) or ethyl methane sulfonate (EMS...

Results of a pilot program show that suspension cultured polyhaploid Nicotiana tabacum cells can be used to bioassay the effects of mutagens. Reproducible survival curves with significant regression coefficients are obtained. Putative mutation conferring resistance to amino acid analogs is significantly more frequent after exposure to mutagens; in contrast, habituants, cytokinin-independent clo...

Eight X-linked recombination-defective meiotic mutants (representing five loci) and 12 X-linked mutagen-sensitive mutants (representing seven loci) of Drosophila melanogaster have been examined cytologically in neuroblast metaphases for their effects on the frequencies and types of spontaneous chromosome aberrations. Twelve mutants, representing five loci, significantly increase the frequency o...

Male lacl transgenic rats were fed a diet containing 200 ppm of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a heterocyclic amine present in cooked meats. PhIP was found to be a powerful prostate mutagen. After 61 days of treatment, the lacl mutant frequency was 71 x 10(-5), >20-fold higher than the spontaneous mutant frequency of 3.2 x 10(-5). The predominant PhIP-induced mutations ...

Studies on the in vivo and in vitro disposition of 4,4'-[14C]-methylenebis(N,N-dimethyl)benzamine (reduced Michler's ketone, RMK) were performed. Osborne-Mendel rats retained, after 24 hr, 78% of a p.o. dose of [14C]RMK. At 24 hr after an i.p. dose, fat, liver, and intestine represented major sites for deposition of radioactivity. The major urinary metabolite of RMK, representing 36% of the tot...

Antigenic variants were derived from a mutagen-treated, apparently nonimmunogenic fibrosarcoma of strain 2 guinea pigs. Fibrosarcoma line 107C3, originally induced by exposure of fetal cells to a chemical mutagen, was treated in vitro with the same mutagen. Cells that survived mutagen treatment were cloned, and the clones were tested for growth in soft agar, in conventional and immunosuppressed...