Environmental and Molecular Mutagenesis - Legacy Tobacco ...

30 1989 EMS Abstracts
Notes WitTbut question, this discipline has ocntributed significanGly to the
protection of the genetic integrity of fuRazti+e ganesaticre of humans . In
additicn, basic researth infcrmatim devuloped by members of this field
during the past two decedes has lead to a clearer mechanistic
tadezstarxiirg of the prrooesees of cancer, cellular diffezantiation and
aging . mnowledge bases within the applied scienoes of inedicine and
taxicology would be poorer today if it w+ .re not for research into mutation,
aa repair, ssrleic acid biodwemistsy and da+omosmis funct.ions carried azt
under the domain of genetic toocicity .
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
qhile valleys have been enoaa*ared along the road travelled since 1969,
their existence has generally resulted in renewed snthusiasm and scientific
vigor . Any scientific discipline which tails to subject itself to critical
assesseent for fear that it will reveal possible flaws or lead to &Ange,
is docmed to be replaced. Ths field of erwiratnental mltagenesis is
forWnate to hn+e had a lartre manber of creative and dedicated visionaries
leading it Liuu4i i .i .ia uailwylny aua7 ew.iuig jwciery .
A COMPUTER-ASSISTED PROCEDURE FOR THE ASSEMBLY AND ANALYSIS OF SHORT-TERM
GENOTOXICITY TEST DATA
D .J . Brusick, P . Lohman, M . Mendelsohn, M . Waters, S . Nesnow, D . Moore, F . de Serres,
J . Ashby, B . Matte- r . T: Matsushima, ICPENC, Subcommittee 1 .
Determining the genetic hazard of a chemical is generally approached by using an
assortment of tests for measuring the DNA reactivity of a chemical or its resultant
genotoxicity . Over 100 short-term tests employing a wide diversity of species and
genetic mechanisms have been used to measure genetic hazard . To date, attempts to
achieve a standard test battery for defining genetic hazard have not been successful .
Consequently, testing for genetic hazard involves the use of test batteries with
variable types and numbers of assays . This increases the difficulties of interpreting
data sets since the data sets are often filled with inconsistent responses from
diverse types of assays .
Several years ago, the International Commission for Protection Against Environmental
Mutagens and Carcinogens (ICPEMC) established a Committee to establish a method to
compile and interpret diverse short-term test data . The Committee has produced a
quantitative weight-of-evidence approach that combines test data using certain
parameters such as dose, replication and metabolic capacity into a series of scores
for test type, test class test family and an overall score that defines the total
weight-of-evidence regard ;ng the genetic hazard of the agent . •
SISTER CHROMATID EXCHANGE AND MICRONUCLEUS ANALYSIS IN RAT PERIPHERAL
BLOOD LYMPHOCYTES AFTIR IN VIVO EIPOSURE TO BENZO(A)gYREVE . M .F .
Bryanta, G .L. Eregson , P . Kwanyuen , and A .D. Kligerman , EHRT,Inc,
RTP, NC 27709, and U .S . EPA, RTP, NC 27711 (USA) .
In an effort to determine the persistence of sister chromatid
exchange (SCE) and micronucleus (MN) induction following exposure to a
polycyclic aromatic hydrocarbon known to exist at hazardous waste
cleanup sites, experiments were conducted in peripheral blood
lymphocytes (PBLs) of male Sprague-Dawley rats injected ip . with
0, 100, or 250 mg benzo(a)pyrene/kg . Peripheral blood was removed by
cardiac puncture from each rat at 1, 2, 5, 7, 14, and 21 days after
injection. Isolated PBLs from three animals/dose/harvest time were
cultured, according to previously published methods, for analysis of
SCEs in second-division cells and MN in cytochalasin B-blocked
binucleated lymphocytes. Both the SCE and MN frequencies remained
elevated for 21 days post-injection . These results suggest that rat
PBLs containing SCE and MN inducing lesions remain viable for at least
three weeks . Due to variable SCE frequencies in isolated PBLs among
replicate animals, a 56 day study was undertaken in which whole blood
was used for SCE analysis . Results will be presented comparing SCE
responses in whole blood and isolated PBLs .
(This abstract does not necessarily reflect US EPA policy .)
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