To clone a genomic DNA f ragment containing mouse glucocorticoid receptor ( GR) gene for the const ruction of an inducible gene targeting vector used in the establishment of a GR gene dificient mouse model. The mouse genomic library was screened by using a 562bp PCR product from GR gene exon Ⅱas a probe. Six positive clones were got after screening. The DNA of positive clones was profoundly characterized by sequencing , rest riction mapping and Southern blotting to get the right f ragment . A 6. 5 kb DNA f ragment was separated from the C10 clone. The gene f ragment contains entire GR gene exon Ⅱ, and two flanking f ragment s which are 3. 9 kb and 1. 4 kb respectively can be used as homologous arm in the const ruction of the targeting vector.

The study investigated the C - mitotic effect s in mouse bone marrow cells induced by at ropine and dtubocurarine , which are antagonist s to muscarinic and nicotinic receptors , respectively. The doses used in the experiment s were 70 % LD50. The result s showed that the at ropine (highest dose , 5. 2mg/ kg) significantly induced increases of mitotic index(MI) and colchicine2mitotic frequency ( P < 0. 001 , P < 0. 05) , the f requency of anaphase was decreased ( P < 0. 001) . It is reqsonable to hypothesize that acetylcholine and it s receptor take part in the regulation of mitosis in mouse bone marrow cells. As C2mitotic effect s is a kind of sign for aneuploidy induction.

In this study , Fluorescence in situ hybridization (FISH) was used to investigate rates of sex chromosome aneuploidy in spermatozoa among 9 acrylonit rile2exposed workers and 9 healthy sperm donors. 74679 sperm nuclei were counted among 9 healthy sperm donors , and 91015 sperm nuclei among 9 acrylonit rileexposed workers. The average f requency of total chromosome numerical abnormalities was 0. 70 % in exposure group , and 0. 35 % in the cont rol. XY2bearing sperm was the most common sex chromosome disomy , with an average rate of 0. 37 % in exposure group , and 0. 20 % in the cont rol. XX2and YY2bearing sperm accounted for an additional 0. 10 % and 0. 23 % in exposure group , and 0. 05 % and 0. 10 % in the cont rol. Significantly increased f requencies of total sex chromosome disomy , and XX2 ,YY2and XY2bearing sperm were observed among acrylonit rile2exposed workers , as compared with healthy sperm donors. This study demonst rated that sperm FISH was a useful biomarker to detect and compare numerical chromosome aberration in human sperm cells for heritable risk assessment of acrylonit rile.

Allow MNNG administ ration in the xylE2ICR t ransgenic mice. We dosed for 5 days , then count survivors 21 days after the final dose. The result s showed : the spontaneous mutant f requency for xylE gene in the liver of xylE-ICR t ransgenic mice was much lower than the MNN G2induced mutant frequency. It is evident that the protocol could be used in the analysis of mutagenesis of chemicals.

In order to observe the histopathological change and the expression of P21 and Bcl - 2 protein in Aflatoxin B1 (AFB1)2induced rat hepatic putative preneoplastic lesions alleviated by lithium carbonate (Li2CO3) . 144 healthy Wistar rat s(155g～175g) were divided randomly into four groups (A , normal cont rol group ; B , positive cont rol group ; C , group t reated with Li2CO3 simultaneously ; D , group pre2t reated with Li2CO3) and sacrificed in batches in the 6th , 9th or 10th week of the experiment . Histopathological assay and immunohistochemical assay of P21 and Bcl - 2 protein was made on hepatic. The result showed that the severity of prenoplasm alleviated in Group C and Group D , and that , coinciding with the histopathological discoveries , a tendency of“Group B >Group C > Group D > Group A”could be found in observation of P21 and Bcl - 2 protein expressive , which occurred in the early stage ( the 6th week) and significantly increased in the 9th , 10th week. It suggested that Li2CO3 has definite anticarcinogenic and preventive effect on hepatoma induced by chemicals and the continual analysis of P21 and Bcl - 2 protein may help early discovery and prognostic judgment of hepatoma.

The antitumor effect s of Chinese herbs“Tian Bao Zhong Ning San”were studied on cells of fibroblast lines of mouse (3T3) , bladder carcinoma cell lines ( EJ ) , throat carcinoma cell lines( IIep22) , stomach carcinoma cell lines(MGC2803) , hepatic carcinoma cell lines (Q3) and lung carcinoma cell lines (Spc2A21) with cultured cells in vivo. And the decreasing toxicity effects of the prescription with normal mice and cyclophosphamide (CP) t reated mice were also studied. The result s showed that“Tian Bao Zhong Ning San”have the effets of antitumor , and cold decrease the toxicity of CP.

The HPV216 immortalized human bronchial epithelial cell line (BEP2D) was used to study NN K in2 duced cell t ransformation and it s mechanism of oxidative damage. The 5th passage BEP2D cells t reated with 500μg/ ml NN K(NN K2500 cells) could grow in meduum containing fetal calf serum. The 15th passage NN K500 cells increased significantly colony formation in soft agar. The 25th passage N K2500 cells had the ability to grow tumor in nude mice. The level of active oxygen species productions including hydrogen peroxides(H2O2) ,superoxide anions(O ÷2 ) and hydroxyl radicals (·OH) , and the contents of 2hydroxydeoxyguanosine (OH8dG) in NN K2t reated BEP2D cells , which maybe involved mechanism ofoxidative damage.

Two bacterial short2term testing systems , the SOS Chromotest ( tester st rain PQ37) and Ames test (tester st rains TA98 , TA100) ware applied to organic ext ract s of source water f rom the Pearl River in southern mainland China. One of the eight samples inducedboth gene mutation and SOS reaction. Another induced only SOS reaction. There was no obvious correlation among the genotoxicity and the chemical data. The conformity of Biological test s and chemical test s was found , to some extend , when the chemical data were t reated by fussy synthetic evaluation. The result s showe the complementary of the biological test s and chemical analysis in revealing the degree of pollution and the potential hazard of the organic chemicals of the water , and the application of fussy synthetic evaluation could be a way to compare the result s of biological test s and chemical analysis.

This paper reported the research result s of mutagenicity of rh2bFGF. The result s showed that rh -FGF at 5 doses of 0. 1 - 500μg/ plate did not induce positive mutation of st rains TA97 、TA98 、TA100 and TA10 with or without S9mix in the Ames Test . The rates of CHL Chromosome aberrations of rh - bFGF at 4 doses were negative range ( < 5 %) . The rates of micronuleus assay of polychromatic erythrocytes in mice of rh -bFGF at doses of 0. 53μg/ KG·bw ,2. 13μg/ KG·bw , 85μg/ KG·bw ,34μg/ KG·bw would not be to induce increase of it s micronuclei. It is proved that rh - bFGF would not be any mutagenicity in this experiment .

NIH3T3 cell line was used for the study t ransformation induction by organic ext racts from water in the Sriver. The result indicated that the malignant t ransformed foci were induced by organic extract s mentioned above and the cellular transformation frequencies presented a dose-response relationship and determination of malignant cells disappeared in rest raining of contact and grew in culture of soft agar while cont rol cells did not .Thus , the present study demonst rates further that organic pollution f rom water in the S river has the potential risk of carcinogencity.

The antimutagenicity of 21 t raditional Chinese herbal medicinal plant s on Trp2P21 were investigated with Ames bioassay system. It was found that Actinidia val vata Dunn , Dioscorea bulbif f era L . , A ristolochia manushuriensis Kom . , Selaginell adoederleinii Hieron . , Scutellaria rev ularis Wall . , Acanthopanax gracil2 i2styl us W . W . S mith. and Zanthox yl um bungeanum Maxim . possessed st rong antimutagenic effect s. The antimutagenic activity on the Trp2P21 of 60 % EtOH ext ract s f rom Cythula of f cinalis kuan . Curcuma Zedoaria ( Berg) . Rose had not been found but antimutagenic effect s of the aqueous ext ract s f rom Cythula of f icinalis kuan and Curcuma zedoaria ( Berg. ) Rose. on the Trp2P21 were observed.