Environmental and Molecular Mutagenesis - Legacy Tobacco ...

114 1989 EMS Abstracts
Notes expzessed in quiescent calls . Enzyme induction may be a
pleiotropic lnduetion effect on gene expraasions of the inducers .
oNA methylation has been linked to alterations of gene
expression . Induction of oncogene expression leads to the
expression of aberrant oncogene products in "preinitiated" cells
which are essential for their ultimate development into tumors .
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
327
1+iUTA(iENETIC EFFECT OF 15 C0IPOUNDS IN DROJOPHILA Al1BIIPI+OIDY '1S8TIACt .
Li Hua1y1, Ca1 0on®min, Huang Jintang and Nan$ Zinmin, Department of
Tozicoiogy, Second Military Medical Ooilege, 200433 8hanghai, P .R . CHINA
In order to determine the sensitivity of Drosophila aneuploidy detecting
syatem, the females (yw/yw) and the malea (yB/Yy) are used in our
tests . The treatment sex male and/or lemale . The treatment stage lsrva
and/or adult . The treatment route feeding method . The brood schedule of
2-3-3 day broods ia carried out in all teats . Tested chemicals inoludes
(1) Colcemid, (2) Colohioine, (3) Catieine, (4) Aotinomyoin D!( 5)Mett~yl
methaneaullonate, (6) 5-Flurodeoxyuridine, (7) Proflavine, (8)0y0lophosphamide,
(9) Mitomyoin-C, (10) Meprobamate (11) 8orbitor, (12)Urethane,
(13) N-Methyl-N=nitroN-nitroaoguanidine, ~14) Sodium lluoride, (15) 5-
Bromodeox}ruridine . Normal test described by Margolin et al (1983) are
used in examine data for statistical aignifioanoe . The compounds which
aignilicant difference at the 5% level between the treated and oontrol
lrequencies of chromosome gain in treated d'inolude (1,2,5,7,9) and (3,
4) in treated Q . The compounds which significant difference at the 5%
level of chromosome loss in treated d inolude (4,6,7,8,9,11,12,13,14,15)
and (1) in treated Q . U! 15 compounds tested for non-diajtimotion and
loas, only six (4,5,8,9 .12,13) have definitive oaroinogeneais olaaaif ication
(a11 positive) . F ve (4 8,g,12,13) of these were significant di!lere
oe for loas, three ~4 5 .9) o3 these rrere aignilioant di!lerence !or
non-disjunction . Senaitivi~y ia 835: and 50>+, respectively.
328
MECHANISM OF ARSENITE INHIBITION OF REPAIR OF N-METHYL-N-NITROSOUREA-INDUCED DNA DAMAGE
J .-H . Li and T.G . Rossman
Institute of Environmental Medicine
NYU Medical Center, NY, NY 10016
Although inorganic arsenic compounds are known human carcinogens, they are not
mutagens . The lack of arsenic mutagenicity has led us to study its comutagenicity .
We have found that sodium arsenite at relatively nontoxic concentrations (5 uM for
24 hours or 10 aM for 3 hours) is comutagenic with N-methyl-N-nitrosourea (MNU) at
the hprt locus in Chinese hamster V79 cells . A nick translation assay, which measures
DNA strand breaks in permeabilized cells, was utilized to show that strand breaks
resulting from MNU or its repair accumulate in the presence of arsenite . MNU-induced
poly (ADP-ribose) synthesis, measured by the incorporation of [3H]-NAD in the permeabilized
cells, was also increased by post-treatment of the cells with araenite . This
supports the hypothesis that arsenite inhibits the completion of DNA repair . The
accumulated strand breaks in the presence of arsenite are probably not due to direct
inhibition of DNA polymerase alpha, the presumed repair polymerase of MNU-induced DNA
lesions, since very high concentrations of arsenite (about 7 .5 mM for 50% inhibition)
are needed to inhibit this enzyme . We thus suggest that the repair of MNU-induced DNA
lesions may be inhibited by arsenite by interfering with the ligation step .
Supported by grant CA29258 from National Cancer Institute .
GiNOlOIICMY Of ORCANIC gXIRAClS Q f3ggT foILS IN fICBI DIfZRIClS
IN NgBo NANIN , pNILIppIlt3
. .!s~ liaaoo . V . 1 . Isotiasds aad N . V . gotuysa , Iwtitute of
stsy, o sge of Saiewoe, Uaiwrsity of tka pkilippias ., Dilioaa ,
Quesoa City , pkilippiass
Seventy-five per eeat of air pollutiee !a lMtro Naaila is ooatributed by
emaissieas LrN sre tha 500,000 motor velioles operstiag daily . A awbsr of
th.se vehicles are disssel powered vbiek oaa expose tlr urksa populatiea to
diesel exlrusts wbiek eaatsia polyoyelie aresrtie Wreearkooa which posseas
kvmaa eareimejaale poteatial . Tbase pelyeyelie aremetie Iqdreesr6elM esa
aeeu .,late in street oils . orpaie extracts trem sieved soil Nmples trom
lodustrial, oasrroial sad reaidsatisl areas ia eiakt distriets around Nstro
Maaila - Nakati, Narikias, pasia, !sa Juaa, IMadaluyoaa, Csiata, Wleaswla
and parsasque - were studied wlag tlr Rsa assay, bost-msdiated assay aad
50g69 3626
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