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M Otsuka,
Y Kajiwara,
S Ajimi,
H Shimazaki, T Kikuno,
S Ogura,
T Inai,
K Kakimoto,
H Tamura,
M Watanabe,
N Sumi
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ABSTRACT: The mutagenicity of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was investigated by the reverse mutation test in bacteria, the chromosome aberration test in vitro, and the micronucleus test in mice. The reverse mutation test was performed at a dose from 31.3 to 4000 micrograms/plate, at which dose cell killing was observed, using Salmonella typhimurium TA100, TA1535, TA98, and TA1537, and Escherichia coli WP2uvrA. NS-21 did not increase revertant colonies significantly in any of the test strains with or without metabolic activation system (S9 mix). The chromosome aberration test was carried out at a dose from 3.75 to 140 micrograms/ml, at which dose more than 50% cell proliferation was inhibited, using cultured Chinese hamster lung cells (CHL/IU). No significant increases of the frequencies of cells with chromosome aberrations were observed with or without S9 mix. The micronucleus test was conducted in the bone marrow cells of Slc : ddY male mice. Mice were given NS-21 by a single oral administration at doses of 0, 43.8, 87.5, 175, and 350 mg/kg, the geometric mean dose between the maximum tolerated dose and the minimum lethal dose. There were no significant increases in the frequencies of micronucleated polychromatic erythrocytes at any dose levels. These results show that NS-21 has no mutagenic activity in vitro or in vivo.
The Journal of Toxicological Sciences 05/1997; 22 Suppl 1:251-61. · 1.52 Impact Factor
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ABSTRACT: Using a multi-locus minisatellite Per-6 DNA probe, we performed DNA fingerprint analysis. Chinese hamster lung (CHL) cells were treated with six model chemicals: N-methyl-N'-nitro-N-nitrosoguanidine, mitomycin C, methyl methanesulfonate, furylfuramide, 2-acetylamino-fluorene, and cyclophosphamide, with or without S9 mix. 771 hypoxanthine phosphoribosyltransferase deficient clones (749 from mutagen-treated cells and 22 from untreated cells) and 90 unselected clones from untreated cells were isolated and analyzed. The spontaneous mutation frequency at CHL cell minisatellite loci was 0.31-0.63%. All the chemicals increased mutation frequencies. Almost all mutations localized to the three specific minisatellite loci corresponding to 4.2, 3.8, and 2.4 kb bands, suggesting that these regions are more unstable and susceptible to mutation. DNA fingerprint analysis is a promising technique for detecting mutations at neutral DNA regions, especially recombinational mutations, and may be useful for surveying genetic instability related to heritable defects or aging.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 11/1995; 338(1-6):87-93. · 2.85 Impact Factor
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ABSTRACT: Using the human acute monocytic leukemia cell line, THP-1, a hypermutability of minisatellite loci was demonstrated in cell culture by Southern blot analysis with minisatellite DNA probes. DNA was isolated from 98 subclones and hybridized to a panel of minisatellite probes consisting of three multilocus minisatellite probes (ML probes) and seven locus-specific minisatellite probes (LS probes). The Southern blot patterns of the hybridized subclones were compared with those of the parental THP-1. Four mutated bands with two ML probes and two mutated bands with two LS probes were detected. The mutation frequency was estimated roughly at 0.1% based on the total number of bands analyzed, and it was much higher than that expected for other DNA regions. Four of these mutations were thought to be alterations of repetitions caused by insertion or deletion of tandem repeats, and one mutant lost a complete minisatellite allele. The nature of the sixth mutant was unclear. Because of the hypermutability of minisatellite DNA, Southern blot analysis using minisatellite DNA probes can be used as a mutation assay system directly based on the DNA.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 05/1993; 286(2):165-72. · 2.85 Impact Factor
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ABSTRACT: This paper analyzes an association of a deviation of the actual cost (measured by person-month) from the estimated cost with the quality and the productivity of software development projects. Although the obtained results themselves may not be new from the academic point of view, they could provide motivation for developers to join process improvement activities in a software company and thus become a driving force for promoting the process improvement.We show that if a project is performed faithfully under a well-organized project plan (i.e. the plan is first constructed according to the standards of good writing, and then a project is managed and controlled to meet the plan), the deviation of the actual cost from the estimated one becomes small. Next we show statistically that projects with small deviation of the cost estimate tend to achieve high quality of final products and high productivity of development teams. In this analysis, the actual project data on 37 projects at a certain company are extensively applied.
Information and Software Technology.
