Environmental and Molecular Mutagenesis - Legacy Tobacco ...

1989 EMS Abstracts
The test for somatic mutation and recombination in cells of the Notes
wing imaginal disc of Drosophila melanoyaster makes use of the two
recessive markers Dltitl (multiple wing hairs) and = (flare) on the
left arm of chromosome 3 . In cells trans-heterotygous for the two
markers, mutant clones can be induced which differentiate into somatic
spots on the wings of adult flies . Twin spots, consisting of an MWh
and aLIX clone, result from mitotic recombination ; mwh (and f-U)
single spots are due to point mutation, deletion, or mitotic recombination
. Compounds are tested by acute (2 to 6 h) or chronic (48 h)
feeding of 3-day-old larvae . Three different groups of structurally
related compounds have been tested : Alkylating agents (nitrogen mustard
and half mustard, three N-nitroso-guanidines), 5-nitrofurans
(nifurtimox and eight related compounds), and tricyclic antidepressants
(amitriptyline, desipramine, imipramine, nortriptyline, protriptyline)
. The results obtained demonstrate that the Drosophila wing
spot test is ideally suited for this type of study due to its fast and
easy performance .
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T:fE USE OF TRADESCANTIA AND VICIA FASA BIOASSAYS FOR THE IN p7 DETECTIO1 OF
MUTAGEdS IN AN AQUATIC ENVIRONMEiVT . Ff . F . Grantl, H . G . Lee , D .M . Logan and M .F .
Salamone3, IMcgill University, Montreal (Canada), 2York University, North York
(Canada), and Ministry of the Environment, Toronto (Canada)
Most studies with plant bioassays have been carried out in the laboratory, or
under atmospheric in situ conditions . The primary purpose of this study was to gain
some experience with plant mutagenicity bioaasays under in situ aquatic conditions .
The assay systems teated were the Tradescantia stamen hair and micronucleus assays
for the detection of gene mutations and chromosomal aberrations, respectively, and
the Vicia faba bioassay system which detects chromosomal aberrations in root tips .
The assays were used to test the effluent from a pulp and paper mill locatqd on the
north shore of Lake Superior . Assays were performed in a creek containing raw
effluent and in a bay of Lake Superior into which the creek emptied . All in situ
treatipents were carried out for 24 hours . On the creek, 11 .5 km from the source, the
effluent was toxic to the Vicia faba roots as expresse# by a reduction in the mitotic
index . The effluent in the creek induced a significant increase in the number of
stamen hair mutants, micronuclei, and chromosome aberrations . Likewise in the bay,
witn the exception of the two most distant sites, the creek effluent also induced
increases in stamen hair mutants, micronuclei, and chromosome aberrations .
Tradescantia tested in the laboratory several days later with water from the test
sites, demonstrated decreased mutagenicity compared to the in situ tests . This
suggests that at least part of the mutagenic fraction is unstable and indicates the
need for aquatic testing either in situ or as soon after sampling as possible .
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THE CARCINOGENICITY INFORMATION DATABASE OF ENVIRONMENTAL SUBSTANCES (CIDES) AND THE
ASSESSMENT OF POSSIBLE HUMAN RISK . Mildred R . Green, Technical Database Services,
Inc ., 10 Columbus Circle, New York, NY 10019
The Carcinogenicity Information Database of Environmental Substances (CIDES) contains
numeric data on the effects of approximately 1000 known or suspected environmental
carcinogens : cancer-relevant data covering a wide variety of long- and short-term
tests and physical/environmental property data . The carcinogenicity data are organized
into six categories - whole animal carcinogenesis, mammalian call lines, mammalian
tissues or cells, bacterial tests, all other assays and human epidemiological
studies . Searches can be directed to specific areas of interest, e .g ., species, route
of entry or assay type . A unique feature in CIDES is that the collected studies are
analyzed to provide a rating, the Carcinogenicity Ratio(CR), summarising the likelihood
and the weight of the evidence(w) that a substance is a carcinogen . The CR is the
means of the percent positive studies weighted by a factor that varies with teat category
; the w is based upon the extent of the testing . When thie approach was applied
to known human carcinogens, the CR was consistently above 50 . For example, for bensidine
and 2-naphthylamine the calculated CR/v ratios summarizing all the evidence included
in CIDES were 84 .9/94 .0 and 65 .6/83 .0 respectively . However, CR/v values may
vary as new studies are added to the database . This analysis can be used to identify
compounds for which data on human exposure are not available but whose test results
indicate that they are likely to be carcinogenic, and also, compounds which should be
tested furthtfi to improve the weight of the evidence . CIDES will be available through
the Numerica online service of Technical Database Services in the summer of 1989 .
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
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