Environmental and Molecular Mutagenesis - Legacy Tobacco ...

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SCe and serum cotinine were determined for 17 smokers . SCE for each person
was determined by analyong 100 second-division lymphocytes from whole blood
cultures . SCE per persoiC ranged from 4 .54 to 10 .16 exchanges per coll .
Cotinine values were determined in duplicate for blood drawn at the same
time . These values were between 13 and 500 ng/ml . In this study, we found a
positive correlation (R .0 .53, p- 0 .03) between SCE and serum cotinine . Larger
studies are needed to confirm this finding .
473
4Hk: lNTEGENICITY STUDY OF 69'NINGOCOCCAI: I'OLYSACCIIARIED-TETANUS TOXOIL CONJUGATE
Ren Neiyue, Zhao Hong, tang Yaozhone, and Li genqing, Shanghai Institute of Biological
Products, Shanghai, China
Mer.ingococcal group A'polyaaccharide-tetanus toxoid conjugate was combined with po-
lysaccharide and protein so as to increase the immunogenicity of both the polysaccheride
and tetanus toxoid in the guinea-pigs and mice . It In hopeful that the conjugate
will be used widely in human beings, eapecielly in very young children In Chine . Here
we examined the mutagenicity of the conjugate for Ames assay, micronucleus test and
chromosome aberration analysis in Chinese Han .ater Lung cells . The result indicated th-
at the conjugate could not increase remarkarly either the revertants of four test strains
( TA97, TA98 . TA100, and TA102 ) with of without 89 mix In Ames asaay at the con-
centration range of 0 .2-125 ug/plate, or the rate of micronucleus after treatment for
2t hours in the polyghromatic erthrocytes of tho bone mRrrow cells in mice at the con-
centration range of 48-1200 ug/I(g body weight . The result also indicated that half of
the cells was inhirited In vitro when the roriugete was et the concentration if 0 .92
ug/ml and the conjugate could not increase remarkably the rate of chromosome aberrati-
on after treFtmertt for u hours with S9 mix or for 24 or 48 hours without 59 mix at the
concentration range of 0 .25-1 .0iug/ml in chromosorre aberration anelysis . It wss belie-
ved that the conjugate hae no mutegenicity in our leb. f
474 •
THE LACK OF DNA HOMOLOGY IN PAIRS OF DNA DIVERGENT CHROMOSOMES SENSITIZES THEN TO
LOSS BY DNA DAMAGE . M .A . Resnick and T .Nilsson-Tillgren . Yeast Genetics Group,
National Inst . Environmen-EaT~eafth Sciences, Research Triangle Park, NC, USA ;
Inst . of Genetics, U . Copenhagen, Denmark
Chromosomal DNA is considered a priori to be a target for production of numerical
(whole chromosome) aneuploidy and DNA repair would be expected to play a role .
Using the yeast Saccharom ces cerevisiae, we have addressed the importance of
recombinational repa r requ re or ouble-strand break [DSB] repair) in the
maintenance of complete chromosomes . Specifically, aneuploidy induction by Ionizing
radiation has been examined in diploids which had either one chromosome III
or chromosome V replaced by a DNA divergent (homoeologous) chromosome from S .
carlsber ensis . While they are functionally equivalent, the lack of precise DNA
omo oof chromosome III or all of V was expected to prevent recombinational
repair . The absence of recombinational repair (presumably of DSBs) in the
divergent chromosomes results in aneuploidy levels of 5 to 15% at nonlethal doses
and a low level of rearrangements . The induction appears to level off suggesting
alternative ways of dealing with double-strand breaks . For homologous chromosomes,
the aneuploidy frequency is 20 to 50 X lower . Based on genetic and physical analyses,
the aneuploidy is due to chromosome loss, not chromosome deletions nor
malsegregation . Thus, the absence of opportunity for homologous recombinational
repair of double-strand damage results in chromosome loss . We suggest that nonhomologous
regions of otherwise homologous chromosomes may be important targets for
the induction of aneuploidy . The relevance of these observations to those in mammalian
cells will be discussed .
475
BIOMOHITORIPG OF INDIVIDUALS OCCUPATIONALLY EIpOSED TO AROMATIC A11IwES .
L .R .Ribeiro,D .M .F .Salvadori,E .M .M .Cerqueira,H .S .Barbosa,M .D .M .Oliveira and A .R .Silva .
Universidade Federal da Bahia, Salvador, BA (BRASIL) .
Several reports show high frequency of genetic damage and high incidence of urinary
bladder cancer due to the presence of mutagenic and carcinogenic products in the urinary
tract,apecially the aromatic amines .The genetic and carcinogenic risks of workers occupationally
exposed to aromatic amines and the presumed antimutagenic and anticarcinogenic
potential of provitamin a-carotene are being studied at the production plant at
the Petrochemical Industrial Complex of CamaSari,BA,Brazi1 .30 male individuals exposed
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
1989 EMS Abstracts 163
Notes