Environmental and Molecular Mutagenesis - Legacy Tobacco ...

60 1989 EMS Abstracts
Notes A prospective study was campleted on micronucleus (FP() induction in cytokinesisblocked
(CB) lymphocytes in eleven cancer patients undergoing radiotherapy . This
study was performed to evaluate the CB micronucleus assay as an in vivo dosimeter .
Measurements before .during and at the end of therapy showed that-TFere was a clear
dose-related response in MM induction in all the patients and that the extent of
induction (between 59 .0 and 578 .0 MN/1000 CB cells) was directly proportional to the
estimated equivalent whole body dose . Measurements were also performed after completion
of therapy to estimate the rate of decline in MH frequency . These values were
expressed as a percentage of the values at the end of therapy with the results
showing that MN frquencies (mean + 1 s .e .) dropped to 91% (+ 11) after 3 months, to
72% (+ 13) after 6 months, to 57~(+ 10) after 12 months . Measurements made 24
months post-treatment showed that MR frequencies only returned to base-line levels
in two of the four patients studied . The other two patients retained very high
MN frequencies (212 .9 and 223 .3 MN/1000 CB gells) . These reults suggest that a state
of chromosome instability (loss or breakage) may have been induced In the surviving
lymphocytes of the latter patients .
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http://legacy.library.ucsf.edu/tid/clb93d00/pdf
ANTIb1LfA0ENIC eCTIVITISS OF CHLOHOPHYLLIh
Pko-ohaen 'r`en,YLn-Jiob Chand,Ji ..g-A1 ..6 Chu,Xiao-yinS Cha_~, and Luaaa
Fac~,Shar.g~i ..i lusL :Lui:e or Oecupa, .oual health in Chem .oal Indusi,ry
Shsnghai(PK Chi.na)
6hlorophyllin,the sodium and copper salt of ohlorophyll,was tested
for• its ability to Ii,hibit the mutagenic activitv of soc•s chericsl
pr•oducts(2-1 :oroartobenzimidezol, 0-Nitrouniline, 0-Phsnvlenedismine),
extrations of fr :ed beef and and red wine ooneentratfons of tap
wai~r #:nd knov.n mutagens(Duunomyoin, 2-AFj in TA98 of SaiTonslla
typhimurium . Complete inhibition of these were obtainel with l .cSm_¢
cf chlorophyllin per plate . The antimutaRenlc activit,y of chlorcphyllin
was heat-stuble . The results indicate that cn3orsphyllin is
potentially useful as sin ant .'mutagenic agent .
169
NEW Mf7D(1LAIVRS OF MMOXICITY IN YFAST CIIJ .S
L.R . Fbrguson and B .C . Baguley, Cancer Jbsearch Laboratory. University of Auckland
Medical Sohool, Private Bag, New Zealand .
We havee previously shown that verapsmil, a calciun antagonist which is )nown to
reverse multidzug resistance in memnalian oe11s, reduoes the ability of a nnrber
of DNA intercalating agents to induoe mitochondrial "petite" nutations in yeast
eells . We have developed an assay system enploying Sacchn:nrtyces oeaevisiae D6 and
a strongly basic analogue of the antileukemia agent amsacrine to search for other
conpounds which reduce mitochondrial nutagenesis . 'Petite' induction by the amsacrine
analogus can be reduced fram 80% to less than 104 by the oo-addition of appropriate
concentrations of some cartpounds . ZMieen 80, chloroquine and cyclosporin A
were found to be highly effective . The most likely axplanation for the andulation
of mutagenic activity is through the inhibiticn of m,itocriondrial nptake of the DNA
intercalating mutagen . This principle could be of inpox'tanoe in liroitiag mitochondrial
mutagenesis in rtemmalian cells .
170
DETECTION OF GENE MUTATIONS IN MOUSE SPERM WITH POLYMERASE CHAIN
REACTION (PCR) . G . Ficsor, L . C . Ginsberg J . F . Klepetka and T . P .
McManus . Western Michigan University, Kalamazoo, MI (USA)
To detect base-pair substitutions and small deletions in sperm, PCR
was used to amplify a 228 base-pair segment of the PGf:2 gene of mice .
The amplified DNA ran as a single baud on a 1 .4% agarose gel
corresponding to its expected size . Dot blot hybridization demonstrated
that we could detect a single base pair difference between the PGK-2a
and PGK-2b alleles by binding of the appropriate 21 mer probe under
stringent conditions . To detect a rare event such as a new gene mutation
in a single sperm amongst thousands and even millions of non-mutant
sperm the PCR alone is of limited help since it amplifies both the
mutant and non-mutant DNA resulting in more DNA, with the mutant
sequence still a minor component . We attempted to solve this problem
by restriction digesting sperm DNA before amplification with Hinc II
which cuts the normal DNA sequence to be amplified in two . If a basepair
substitution mutation or small deletion is present in the }(incll
sequence, that target DNA will not be cut by HinclI and will be
available for amplification by PCR . As a consequence the amplified DNA
will be enriched for mutant DNA sequences . The amplified DNA then can
be analyzed for the presence and amount of mutant DNA sequences .
Supported by NIH grant 1 R15 HD21171-O1A1 and by a Western Michigan
University Faculty Research Fellowship and Grant .
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