Environmental and Molecular Mutagenesis - Legacy Tobacco ...

228 1989 EMS Abstracts K~J
Notes is 165 .5/m: Chockjft-ophthalmology include history,. functional examination
of the eyes and physical examination of the eyes . The check results
of these two groups are similar(P :Q,05) . Because every worker will
change this work frequently, the contacting time, to methanol is short
for every one, the eyes of workers occupationally exposed to methanol
do not are harmed .
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
STRATEGIES FOR THE IDENTIFICATION OF RODENT CARCINOGENS BY IN VITRO
SHORT-TERM TESTS . Errol Zeiger, Cellular and Genetic Toxicology Branch,
National Institute of Envlronmental Health Sciences, Research Triangle
Park, NC, 27709 (USA)
The effectiveness of four short-term tests for genetic toxicity
(induction of mutations in Salmonella (SAL) and mouse lymphoma L5178Y
(MLA) cells, and induction of sister chromattd exchanges (SCE) and
chromosome aberrations (ABS) In Chinese hamster ovary cells) for
predicting rodent carcinogenicity was examined . A total of 114 chemicals,
including 73 previously evaluated, that had been tested for carcinogenicity
by the National Toxicology Program were evaluated . The results with the
114 chemicals confirm and extend the results previously reported with 73
chemicals (Tennant et al ., Science 236 :933-941,1987) . Salmonella had the
lowest sensitivity ( .48) and the highest speclficity ( .91), whereas mouse
lymphoma had the highest sensitivity ( .70) and lowest speclfictty ( .40) . The
concordances of the tests was .66, .61, .59, and .58, for SAL, ABS, SCE, and
MLA, respectively . Salmonella had the highest positive predictivity ( .89) .
None of the other tests complemented Salmonella, and no combination of the
four tests was more effective than Salmonella, alone, for predicting
carcinogenicity .
I9HIBITION Od Tr:6TICUlrin DNA SYNTNiSIS BY CNchIOAL MUThGc:NS
8ui-Juan Zhang, Ghi-iien We1 and Yu-Zhen Zhu
Shanghal Institute of Yharmaceutical Industry
1320 Beijing Xi 8oad, Shanghai, China
Friedman and staub reported the measurement of the inhibition of testicular DNA
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synthesie by chemical carcinogens and mutagens in sale mice and proposed this method
as a simple and effective in vivo mammalian screening test . The testicular tissue of
the mice is capable of utilizing the salvage pathway efficiently when synthesis of
thymidine is inhibited . It is possible to distinguish between DNA-dasaging agent and
non-DNA-damaging agent . We now report on the results obtained with eight chemicals .
Thio-Tepa, Cyclophosphamide and Adriamycin were DNA damaging agents . Fluorouracil and
Methotrexate were non-DNA-damaaging agents . Fluapyrimidone, Aurapromide and Nonylphe-
noxypolyethoxyethanol showed no evidence of genotoxicity .
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THE EFFECT OF 5-AZhCYTIDIHE ON REVERSION 0F ISOLATED HPHT MUTANTS IN V79 CHINESE
HAMSTER CELLS . L-H . Zhang and D . Jenssen, University of Stockholm, Sweden . The
purpose of the present study was to investigate rare types of spontaneously
occurring mutational events . Reverse mutation analysis using medium Containing
L-asaserine (HhsT) of 60 independently isolated HPET- mutants from four groups,
11 spontaneous mutants, 11 EMS-induced mutants and, 38 1010-induced mutants with or
without hydro :yurea pretreatment, showed that over 70% of mutant clones of each
group could be reverted either spontaneously or induced by treatments with Ei1U,
ICS191 or S-asacytidine (SAC), indicated to be caused by point mutations . Two of
the revertible mutant clones of spontaneous origin wer* found to be resistant to
HAT but not HA&T medium . The interestinq result of this study was that these two
eTGrHATr mutants were the only mutants isolated which could be affected by SAC
with a significant increase in the reversion frequency . Chromosome aberration
analysis did not indicate any enhancement in aberration frequency in the
X-chromosome by 5AC treatment . Studies on the mutagenicity at 00k-locus indicated
that the SAC- and ENU-induced mutation frequencies in these 2 mutants were
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