Environmental and Molecular Mutagenesis - Legacy Tobacco ...

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FREQUENCIES OF CHROMOSSOMAL ABERRATIONS AND MICRONUCLEUS IN RODENTS COLECTED IN COAL-
FIELD AND TOBACCO CULTURE REGION - CRICIOMA - SC - BRAZIL .Angela M . S . Bueno, Jeanete
M . S . Agostini, Karina Gaidzinsk, Riroko Nitta, Josane Moreira, Ivan Brognoli -
Departamento de Biologia - UFSC - Florianopolis - SC - Brazil - 88049 .
Criciuma - SC - is a town situated in the coal-field of South Brazil . The present work
has been done in the Basin of Sangao River, one of the local rivers that receiv the
rejectes of the coal washing, like mercury, cadmium, lead, etc . in wich bank exist many
proprieties of tobacco cultures where various organophosphorate and carbamate agrotoxics
are used . Our purpose in this area is to try to detect and estimate the possible action
of the environmental pollution in the organisms directly exposed to it - in this case
rodents collected in the local - through the study of the frequency of chromossomal
aberrations and micronucleus in bone marrow . Parallely the same methodology has been
used for rodents collected in regions free from these polluter factors to set up a
control group . With this finality we delimited two collect points in the Basin of Sangao
River (A and B), one point out of this area (C) and some points in Florian6polis 040Km
from Criciuma) free from the action of the above mentionate polluters . The points C and
D are considered control points . Our parcial results have showed the following
percentage for chromossomal aberration : A-3,62x, .B-1,30x, C-none, and D-1,46x, and the
following results for micronucleus analisis : 20% . for Criciuma's points and 10x .for the
control group .For the meantime we can say that these results suggest that this
methodology can be applied to detect the action of the environmental pollution in the
organisms . (FINEP) .
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STUDIES ON A GENOTO%ICITY TEST USING P . PHOSPHOREUM
Anthony A . Bulich, Mary Grace Schreibner, Ser-Eon , Charles C . Walbourn
Microbics Corporation, 2232 Rutherford Roa , ars a, CA 92008
Chemicals are essential for modern society, and proper application of them has
greatly improved general living conditions . However, the chemical wastes, and the
by-products of these wastes, are a major cause of environmental pollution . In order
to monitor and control these pollutants, simple and fast tests are needed . Following
the introduction of the Microtox (R) Acute Toxicity Test, we now propose a test for
genotoxic compounds (Mutatox (TM)) . The test uses a dark mutant of luminous bacteria
and determines the ability of the tested agent or sample to restore the luminescent
state . Genotoxic agents which are mutagens, DNA damaging agents, DNA synthesis
inhibitors, and DNA intercalating agents are detected with this test . This one-step
test can be performed as an overnight assay, under non-sterile conditions . Fifty
pure chemicals have been tested with the proposed method, and the results correlate
vell with published data obtained with the Ames test . The predictive value of this
method for carcinogenicity is also comparable to the Salmonella assay . Validation of
the test with an additional 50 extensively studied chemicals from the National
Toxicology Program is underway . The results from this study will be presented .
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MOUSE MODEL FOR SOlATIC MUTATION AT TH$ HPRT GENE : MOLECULAR AND CELLULAR
ANALYSES, Ic . Burkhart-Schults, C .L . Strout, and I_ H . Jenaa, Lawrence
Livermore National Laboratory, Livesmore, CA 94550 (USA)
We are using the mouse to study factors that affect the frequency and
molecular nature of somatic mutations that occur in vivo . We have
detected differential induction of thioquanine resistant mutants in thymus
and spleen T lymphocytes ; tissue, mutaqen and age dependent patterns of
mutant frequency with time ; and persistence of up to one year for both
ethylnitrosourea (sNU) and radiation induced mutants . Whereas the mutant
frequency increased linearly up to 72mg ZNO/kQ, and was not reduced by
fractionation of ENt1 dose, it increased curvilinearly to 400 cOy 1,7Ce and
was reduced by radiation dose fractionation . The molecular nature of
spontaneous and induced mutations is being studied by Southern analysis
and by polym.rase chain reaction based methods . Soon after acute exposure
of young adult, male mice to radiation the mutation spectrum is enriched
two-fold for total deletions of the hypoxanthine phosphoribosyltransferase
(hprt) locus, whereas after ZNO no deletions were detected . The recovery
of many deletions, of frameshifts, and of 3 different base substitutions
affecting the protein synthesis initiation codon, indicate that selection
of mutants with 2 .5 mq/ml thioguanine is highly stringent and may limit
the spectrum of point mutations recovered . This work performed under the
auspicies of the U .S . Department of inerqy by Lawrence Livermore National
Laboratory under contract number N-7405-iNG-48 .
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
1989 EMS Abstracts 31
Notes