Fusion between HeLa and fibroblasts from complementation group D xeroderma pigmentosum (XPD) followed by challenge with small doses of ultraviolet light (u.v.) results in the production of hybrid cells expressing either HeLa (HD1) or XPD-like (HD2) sensitivity to u.v. and related repair capacity. Assays used included unscheduled DNA synthesis (UDS), DNA break accumulation in the presence of inh...

Due to long-term treatment toxicity and clinical resistance to drugs commonly used against E. histolytica, new drugs against amoebiasis are urgently needed. Castela texana ("chaparro amargo") is a shrub taken traditionally in teas and capsules of dry plant to treat intestinal amoebic infections. An aqueous extract was prepared and its mutagenic, genotoxic and cytotoxicity properties were evalua...

A cell lysate system by which DNA repair (unscheduled) synthesis induced by DNA damaging agents can be measured at high sensitivity as previously reported (9, 18) was characterized. Time-course experiments in which the in vivo incubation time with hydroxyurea and arabinofuranosyl cytosine after UV irradiation was changed suggested that the number of single strand gaps increased in the presence ...

The effects of exposure of early-passage Syrian hamster embryo cells in culture to sodium fluoride have been studied with respect to induction of morphological and neoplastic transformation, chromosome aberrations, sister chromatid exchanges, and unscheduled DNA synthesis. Exposure of Syrian hamster embryo cells to NaF concentrations between 75 and 125 micrograms/ml for 24 hr caused approximate...

Cdk1 kinase phosphorylates budding yeast Srs2, a member of UvrD protein family, displays both DNA translocation and DNA unwinding activities in vitro. Srs2 prevents homologous recombination by dismantling Rad51 filaments and is also required for double-strand break (DSB) repair. Here we examine the biological significance of Cdk1-dependent phosphorylation of Srs2, using mutants that constitutiv...

OBJECTIVES A study was conducted in coke oven workers to evaluate the biological consequences of the exposure of these workers, particularly production of potential genotoxic factors. METHODS 60 coke oven workers and 40 controls were recruited in the same iron and steel works. Exposure to polycyclic aromatic hydrocarbons (PAHs) was assessed by job and measurement of 1-hydroxypyrene (1OHP) in ...