Technical review of polysomnography.

Polysomnography has developed from our understanding of sleep and its associated physiologic processes. This important tool extends the clinical examination into dynamic states that typically do not permit intrusive inspection. The two critical components of polysomnography are the determination of sleep-wake stage and identification of related bodily processes.

Enhanced stimulation of chromosomal translocations by radiomimetic DNA damaging agents and camptothecin in Saccharomyces cerevisiae rad9 checkpoint mutants.

Saccharomyces cerevisiae rad9 checkpoint mutants exhibit pleiotropic phenotypes, including higher frequencies of chromosome loss, radiation sensitivity, and decreased induction of DNA damage-inducible genes. We had previously shown that rad9 mutants exhibit higher frequencies of DNA damage-associated translocations but lower frequencies of DNA damage-associated sister chromatid exchange (SCE), compared to wild type. Herein, we have shown that differences between the frequencies of DNA damage-associated recombination in the rad9 mutant and wild type depend on the identity and the concentration of the DNA damaging agent.

Saccharomyces cerevisiae rad51 mutants are defective in DNA damage-associated sister chromatid exchanges but exhibit increased rates of homology-directed translocations.

Saccharomyces cerevisiae Rad51 is structurally similar to Escherichia coli RecA. We investigated the role of S. cerevisiae RAD51 in DNA damage-associated unequal sister chromatid exchanges (SCEs), translocations, and inversions.

Radiosensitive and mitotic recombination phenotypes of the Saccharomyces cerevisiae dun1 mutant defective in DNA damage-inducible gene expression.

The biological significance of DNA damage-induced gene expression in conferring resistance to DNA-damaging agents is unclear. We investigated the role of DUN1-mediated, DNA damage-inducible gene expression in conferring radiation resistance in Saccharomyces cerevisiae. The DUN1 gene was assigned to the RAD3 epistasis group by quantitating the radiation sensitivities of dun1, rad52, rad1, rad9, rad18 single and double mutants, and of the dun1 rad9 rad52 triple mutant.