We have characterized a new locus, BRA3, leading to deregulation of the yeast purine synthesis genes (ADE genes). We show that bra3 mutations are alleles of the GUK1 gene, which encodes GMP kinase. The bra3 mutants have a low GMP kinase activity, excrete purines in the medium, and show vegetative growth defects and resistance to purine base analogs. The bra3 locus also corresponds to the previo...

A parametric track structure model is used to estimate the cross section as a function of particle velocity and charge for mutations at the HGPRT locus in human broblast cell cultures . Experiments that report the fraction of mutations per surviving cell for human lung and skin broblast cells indicate small di erences in the mutation cross section for these two cell lines when di erences in ina...

The mutagenic responses of 13 antineoplastic drugs, namely, chlorambucil, busulfan, lomustine, dacarbazine, Adriamycin, daunomycin, bleomycin, VM-26, VP16-213, ellipticine, actinomycin D, mitomycin C, and cis-diamminedichloroplatinum(II) have been determined in two different assay systems in Chinese hamster ovary cells which measure mutation induction at multiple genetic loci and the frequencie...

Crocidante asbestos is known to cause cellular damage, leading to asbestosis, bronchogenic carcinoma, and mesothelioma in humans. The mechanism responsible for the carcinogenicity of asbestos is not known. Iron associated with asbestos is thought to play a role by catalyzing the formation of reactive oxygen species, which may cause DNA damage, leading to mutations and cancer. Here, we examined ...

Crocidolite asbestos is known to cause cellular damage, leading to asbestosis, bronchogenic carcinoma, and mesothelioma in humans. The mechanism responsible for the carcinogenicity of asbestos is not known. Iron associated with asbestos is thought to play a role by catalyzing the formation of reactive oxygen species, which may cause DNA damage, leading to mutations and cancer. Here, we examined...

The enzymic capacities of the de novo and the salvage pathways for purine nucleotide synthesis were compared in rat in normal, differentiating, and regenerating liver, and in three hepatomas of widely different growth rates. The activities of the key de novo and salvage enzymes were also determined in mouse lung and Lewis lung carcinoma, in human kidney and liver, and in renal cell carcinoma an...

Gout is classed among the inborn errors of metabolism,1 but unlike the majority of such disorders no single specific metabolic defect has yet been found to account for the hyperuricemia characteristic of this disease.2 Although impaired renal excretion of uric acid is responsible for the hyperuricemia of some patients, an increased rate of purine biosynthesis de novo contributes to the hyperuri...

Watts, R. W. E., McKeran, R. O., Brown, E., Andrews, T. M., and Griffiths, M. I. (1974). Archives of Disease in Childhood, 49, 693. Clinical and biochemical studies on treatment of Lesch-Nyhan syndrome. The clinical findings in a previously unreported case of the Lesch-Nyhan syndrome are described. Though formal intellectual testing is very difficult because of the severe choreoathetosis and co...