To const ruct the inducible targeting vector for the mutagenesis of the mouse glicocorticoid receptor ( GR) gene , we cloned and analyzed a genomic f ragment containing the exon 2 and it s flanking regions of the GR gene , and then , we subcloned some fine regions of the f ragment . Basing on the feature of these regions and the requirement of knockout identification , we const ruct the targeting vector (p Flox2GR) , which provides the important base for the generation of the inducible knockout mice of the GR gene and it s functional analysis.

The zona2f ree golden hamster oocytes were genet rated in vit ro by human spermatozoa. The hybrid zygotes were exposed to promutagen cyclophosphamide (CPA) at the concent rations of 20μg/ ml , 40μg/ ml ,60μg/ ml respectively during the peroid of post2fertilization culture. Then human sperm chromosomes were prepared and analyzed. The f requencies of the spermatozoa with st ructural aberrations were 33 % ,50 % ,33 % and the means of chromosomal breakages were 0. 54 ,1. 94 ,0. 72 successively in the above dose2groups. The differences of two parameters between the test groups and the cont rols were significant ( P < 0. 05 , P < 0.1) . The results indicated that the mutagenicity of the romutagens could be evaluated in human/ golden hamster hybrid zygotes as the endogenous metabolic activation system. This finding would be very beneficial for toxi2genetic research in mammalian gamates.

Allele2specific PCR(AS2PCR) and multiplex differential PCR (MD2PCR) were used to identify the genotypes of CYP1A1 and GSTM1 in 68 lung cancer patients and 105 healthy cont rols. The result s showed that genotypes of CYP1A1 and GSTM1 could be detected simultaneously with AS2PCR and MD2PCR ; The frequency of CYP1A12Val/ Val in lung cancer patient s group was 12/ 68 (17. 6 %) , about 2. 052fold than that in healthy cont rols 9/ 105 (8. 57 %) , and the f requency of GSTM1 0/ 0 was 39/ 68 (57. 4 %) , remarkably higher compared with 42/ 105 (40 %) in healthy cont rols ( P < 0. 05) 1

Focus system was used to assay the cell t ransforming activity of crystalline nickel sulfide (NiS) in BALB/ c - 3T3 cells. The result s indicated that at the concent rations equal to or above 0. 25μg/ cm2 , NiS induced increases in t ransformation f requency ( P < 0. 05) , in a concent ration2dependent manner. The transformed cells f rom 6 different foci all grew to colonies on soft agar ccultures while cont rol cells appeared negative. This result showed the anchorage2independence of the transformed cells from various foci which is one of the features of malignancy.

V79 Chinese hamster cells were treated in vit ro by at ropine sulfate , which is an antagonist to cholinergic receptors and inhibitor of muscarinic receptor. The alteration of late telophase2early G1 configuration induced by at ropine were determined by analyzing present or lack of a cytokinesis furrow in late telophase and very early G1 cells , The abnormal cytokinesis were investigated for the f requency of binuclear cells in interphase cells.The tested chemical disturbed mitotic coordination and induced significantly high f requency of binuclear cells.The result indicated that at ropine is able to inhibit mammal mitosis by blocking the function of cholinergic receptor. The malfunction of cholinergic receptors may be a mechanism of aneuploid induction.

This paper reported the research result s of mutagenicity and teratogenicity effect of zinc acexamatie.The result showed that zinc acexamatie with doses level (1 - 5000μg/ plate) did not induce positive mutations of st rains TA97 、TA98 、TA100 and TA102 with or without S9mix in Ames test . It was divided into three groups of Zinc acexamatic received (po) dosages of 32. 97mg/ kg. body weight , 262. 34mg/ kg. body weight , 524. 67mg/ kg.body weight on the 6th to 15th day of gestation mouse respectively in the teratogenic test . The f requency of live fetuses of each dose group were no significant difference as compared with solvent cont rol group. It did not cause deformity of the fetus appearances , bone and internal organs. But there were significant differences between solvent cont rol group and 524. 67mg/ kg group in the growth of body weight in gestation of mouse , body weight and tail length in fetus. The result showed that zinc acexamatie possess maternal toxicity and embryotoxicity.

To evaluate the inhibition effect s on cancer cells of Chinese herbs“Tian Bao Zhong Ning San”with cultured cells in vivo such as fibroblast lines of mouse(3T3) , bladder carcinoma cell lines( EJ ) , throat carcinoma cell lines(Hep - 2) , stomach carcinoma cell lines(MGC - 803) , hepatic carcinoma cell lines(Q3) and lung carcinoma cell lines(Spc - A - 1) . The result s showed that the alcohol ext ract s of“Tian Bao Zhong Ning San”had significant inhibition on the growth of cancer cells. And there was a dose2effect relationship between them. But this alcohol ext ract s had no inhibition on 3T3. So the result s proved that this Chinese herbs could be used as a antitumor drug.

Inhibition of five substances on micronuclei and nuclear anomalies induced by the herbicide Jing Ke Cao Xing in the peripheral blood erythrocytes of Monopterus albus was studied. The result s showed that vitamin B2 、vitamin C、β2carotene 、ginger and garlic can all reduce the f requencies of genetic damage items mentioned above. It suggested that these five substances can protect fish cells. Also , the inhibition mechanisms of them were discussed.

A series of model mutagens were systematically tested with the in vit ro micronucleus test using established L5178Y mouse lymphoma and WTK1 human lymphoblastoid cell lines. The results showed that the in vit romicronucleus assay using L5178Y and WTK1 cells was simple and sensitive ,and it could be beneficial to improve the accuracy of screening mutagens when these two cell lines were simultaneously applied to a shortterm assay system.