Environmental and Molecular Mutagenesis - Legacy Tobacco ...

160 1989 EMS Abstracts
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
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NULEES" "' °°''tYNERGISTIC-AL$qNReTOXICIIY OF ALCOH9L AND LB IN PRINTING PRESS 11ORKBRS .
Talitha T Rajgh , NV Prasad , K Kashyap , YR AhuJeAq .1)Dept of Genetics, Osmania
University . 2)C~,o_v~rlnting Press, 3)Bureau of Police . RBD, Hyderebad, INDIA .
Lead (Pb) has been shown to have a mutagenic potential but reports on the
mutagenicity of alcohol (A) are controversial . Since there are no reports available
on the effect of Pb exposure in combination with A it was decided to study the
cytogenetic effects of this combination . Air sampling was done to estimate the content
of Pb In the working atmospherf~ The atmospheric Pb level was found to be elevited
in the printing press (3 .144g/m ) as compared to the background value (0 .5A.g/m ) .
Peripheral blood lymphocytes were cultured for 48 hrs from 20 adult males (10
of whom were A consumers) working in a printing press . These individuals were
exposed to Pb for more than 5 years . Twenty one healthy matched controls were
also included . Chromosome aberrations (CA) were analysed from 100 metaphases
per subject . A consumers did not show a significant increase in the frequency
of CA (structual+numerical) as com pared to the control group (11 .35 vs 7 .54%) .
But subjects exposed to Pb showed a significant increase In genotoxicity as compared
to the controls (17 .60 vs 7 .54%) . When a comparison was made between alcohol
consumers and nonconsumers within the Pb exposed group, there was a higher frequency
of CA In the consumers than the nonconsumers (20 .72 vs 17 .60%) . This finding
suggests that Pb and A interact In a synergistic manner In inducing genetic damage .
Financial Assistance from ICMR Ss acknowledged .
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MODULATION OF GENOTOXICITY, Claes Ramel, Department of Genetic and Cellular ToxicologK
Wallenberg Laboratory, University of Stockholm, S-106 91 Stockholm, Sweden .
In the absence of any principle breakthrough in cancer therapy, cancer prevention
must rely on hindrance of induction of malignant growth . Chemoprevention of cancer by
means of anticarcinogenic agents is one way towards this goal . This approach is favoured
by the multistage process of carcinogenicity, where each step can be subjected
to modulation by various agents . The critical role of genetic alterations In carcinogenicity,
revealed by activation of oncogenes and inactivation of antioncogenes, focuses
the attention on genotoxicity in this context . Modulation of genotoxicity can be
achieved at two levels - by preventing chemical induction of mutations and by affecting
the expression and regulation of altered genes . It has been shown that chemical
induction of mutations can be modified by a large variety of chemicals acting at
different levels - from the initial exposure to genotoxic chemicals to interactions
with DNA and the establishment of mutations . The development of neoplasm comprise
alterations of cellular messengers and interaction of gene products . The elucidation
of this cellular signal system opens new prospects for chemoprevention of cancer by
interference with the expression and regulation of genes involved In this system .
UV-INDUCED TNYMIDINE INOORPORATION IN A CLINICAL VARIANT OF XERJDER4A PIGMENTOSW
A . Shobha Rani . A . Jyothy, C.Kususe Kuearl, M . SuJetha, P.P .Raddy, and O .S.Rsddi.
Institute of Geiwtics . Hoapital for Ganetie Diseasae, Ossenle Universitv . Beuumpet,HVderabad-S00 016 .
A . P. Ind ia .
ABSTRACT
Xerodeima piymentosus Ss a rare autosoaal reaassive disease In which patients develop abnorael pigmentation
and salipnancies !n the areas of the skin ezposed to sunlipht . These patients are unable to repair
normally a certain type of UV induced daaape !n their DNA . The present lnvestl9etion is carried out
to sae Sf there is any Japsinssnt in the repair process In this clinical variant with only occul .r senlfastation
without any cutaneous manifestation .
For the scintillation eeasurewent of raoelr . we used leukocvte ooouletions contelnina 1Xio cells . The
cells vsre suspended In 1∎1 culture media with 205 serus . The cells were lrradiated with UV and then
HTdR was added and reincubated for 24 hrs ., at 37oC. The cells rsre washed In saline followed by Sf and
10% TCA ( trichloroacatie acid) and finally In chilled es thenol . 0 .1 •1 of triton X-100 was added to
dissolve the pellet and transferred to scintillation vials after which the activity was measured by
B-counter . UV-induced thyaidlne incroporation rate 1s decreased to 20-37% In the affected individuels
as compered to their unaffected sib (64%) parents ( 100% ) and controls (100f) lndicatin0 that ths
rapair mechenis+. !n this clinical variant 1s Upaired .
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