Purpose : To investigate whether delayed genetic instability is associated with specific chromosomal alterations , this would facilitate the identification of genetic or epigenetic factors that cause delayed instability , and to investigate whether clones which exhibit increased f requencies of delayed int rachromosomal recombination also exhibit increased f requencies of delayed generation of chromosomal aberration. Methods : The pulsed field gel elect rophoresis methods was used to investigate the delayed genetic instability induced byγ2irradiation till 58th generations. Results : Average f requency of recombinations in Rsy - 112 derived f rom unirradiated cells was 3. 5 ×10 - 4 , ranging f rom 2. 7 ×10 - 4 to 4. 6 ×10 - 4 ; all the other clones of Rsy - 112 and HFD which were derived f rom the cells irradiated with doses between 0. 4 kGy～4. 0 kGy were 5. 9 ×10 - 4 and 19. 4 ×10 - 4 , ranging f rom 2. 8 ×10 - 4 to 11. 7 ×10 - 4 and 3. 9 ×10 - 4 to 35. 3 ×10 - 4 , respectively. Conclusion : ①γ2irradiation could lead to a process of delayed instability which could be t ransmissible over many generations ; ②the frequency of recombinations increased after irradiation of the cells ; ③other abnormal karyotypes could also be observed in RSY 112 clones and HFD clones of cell , such as band loss、split and new band appearance. Which indicated delayed genetic instability.

Purpose : To study the effect s of the two new-type pesticides , imidacloprid and RH25849 , on the DNA of human peripheral lymphocytes. Methods : Micronuclei test , SCE test and comet assay were employed in the experiment . Results : At the low dose (imidacloprid 0. 05 mg/ L and RH25849 5 mg/ L) , there were no effect on the micronuclei rate and the SCE rate , compared with the negative cont rolled groups ( P > 0. 05) . But there were adverse effect s when the dose increased , and the difference was significant as compared with the negative cont rol groups ( P < 0. 05) . In the comet assay , starting f rom the lowest dose the two pesticides caused DNA damages in the human peripheral lymphocytes as compared with the cont rol groups , and the differences were significant ( P < 0. 01) , and there were dose dependent relationship ( r = 0. 995 , r = 0. 965) . ConclusionBoth imidacloprid and RH-5849 damaged the DNA of human peripheral lymphocytes. Comparatively. Imidacloprid was more toxic than RH25849.

Purpose : To study the effect s of drinking water contaminated with microcystins (MC) on cell proliferation and apoptosis during the course of hepatocarcinogenesis ,and to probe the mechanism of promoting hepatocarcinogenesis of microcystic toxins. Methods : 50 healthy Wistar rat s were randomly divided into 4 groups :group A (normal cont rol) ; group B (t reated with DEN only) ; group C (t reated with DEN and MC contaminated water) ; group D (t reated with DEN and microcystins i. p ) . The PCNA , Bcl22 and Bax protein expression in preneoplastic liver tissue were detected using immunohistochemical assays. Results : The average integrated optical densities (AIOD) of PCNA in the experimental groups were 0. 0033 (group B) , 0. 0036 ( group C ) and 0. 0088 (group D) respectively , and they were all significantly increased as compared to group A (0. 0013) . But as comparing to group B , only group D had significantly higher PCNA expression. Up2regulation of Bcl22 and down-regulation of Bax expression were found in group C and group D. Conclusion : Uncont rolled cell proliferation caused by unbalanced expression of Bcl-2 and Bax gene may be one of the mechanisms of hepatocarcinoma promoted by microcystins.

Purpose : To study the effect s of arsenic t rioxide (As2O3) on the apoptosis in melanoma A375 and B16 cells. Methods : Apoptosis and necrosis in A375 and B16 cells were analysed by flow cytomet ry ; The serum biochemical parameters in mice concerned with the functions of heart , liver and kidney were also measured after the mice were t reated with As2O3 . Results : As2O3 could induce apoptosis and necrosis of A375 and B16 cells. The rates of apoptosis in A375 and B16 cells were 11. 85 % , 55. 51 % , 54. 90 % , and 9. 81 % , 26. 45 % , 9. 93 % ,respectively , as t reated with different doses of As2O3 (5μmol·L - 1 , 10μmol·L - 1 and 20μmol·L - 1) ,respectively. The total rates of apoptosis and necrosis were 11. 90 % , 55. 71 % , 57. 40 % and 12. 96 % , 26. 99 % ,87. 13 %, respectively. No significant differences were found in serum biochemical parameters in mice t reated with As2O3 . Conclusion : As2O3 can induce apoptosis and necrosis of A375 and B16 cells , but does not cause damage to the functions of liver , kidney and heart in mice.

Purpose : To study the relationship between p53 gene mutation and the prognosis of breast cancer ,and the relationship of the expression of p53 , Bcl-2 , C-erbB-2 , PCNA and Ki67 to the occurance , development of breast cancer. Methods : PCR-SSCP and immunohistochemical SP methods were used. Results : The p53 gene mutation and LOH (loss of heterozygosity) coincided with those bad prognostic factors such as high expression of PCNA , absence of ER and PR( P < 0. 05 or P < 0. 01) . The expressions of p53 , C-erbB-2 , PCNA and Ki67 were notably increased in the occurance and development of breast cancer ( P < 0. 05 or P < 0. 01) ,but the expression of bcl-2 decreased. Conclusion : p53 gene mutation (particularly LOH) is bad prognostic factor and marker of breast cancer. The high expressions of p53 , C-erbB-2 , PCNA and Ki67 are the factors and markers of the occurance and development of breast cancer , and particularly , the expressions of C-erbB-2 , PCNA and Ki67 are the indicators of breast carcinogenesis.

Purpose : To probe into the inherent and acquired expression of mdr21 gene on drug2resistance. Methods : Reverse transcription2polymerase chain reaction ( RT2PCR ) assay was used to detect the inherent and acquired expression of mdr21 in the peripheral lymphocytes of 51 patients with malignant tumours. Results : There were 66 % ( 11/ 51) inherent and 9. 8 % (5/ 51) acquired expression in negative groups , and 21 % ( 11/ 51) inherent and 60. 7 % (31/ 51) acquired in low positive groups , and 11. 8 % (6/ 51) inherent and 29 % (15/ 51) acquired expression in high positive groups. Obvious differences were demonstrated among the three groups ( P < 0. 01) . Conclution : The results showed that the mdr21 expression level can reflect the situation of drug2resistance. The method using RT2PCR assay to detect mdr21 expression in the peripheral lymphocytes is convenient for selecting sensitive drugs.

Purpose : To investigate the relativity of mdr-1 expression between the f resh tumour cells and the peripheral lymphocytes of 32 patients with malignant tumours. Methods : Using reverse t ranscription2polymerase chain reaction (RT-PCR) assay , mdr-1 expression induced by 8 anticancer drugs in the f resh tumour cells and the peripheral lymphocytes of 32 patients with malignant tumours was detected. Results : There was a positive relativity of mdr21 expression between the fresh tumour cells and the lymphocytes. Conclution : The lymphocytes of peripheral blood can replace tumour cells in selecting sensitive drugs with RT-PCR assay invit ro. It can provide a new way of using drug individually for patients with malignant tumours.

Purpose : To observed the inhibition effect of osthol on human lung adenocarcinoma and squamacarcinoma. Methods : Set up models of human lung adenocarcinoma and squamacarcinoma on the bodies of BALB/ C ,one kind of nude mice , then osthol was given to the mice in the dose of 1. 5μg/ (g·d) . Antitumor effect of osthol were valued by weighing the tumor and determing DR 2 70 , the mark of lung cancer in BALB/ C serum.Results : The inhibitory rates were 69. 5 % on lung squamacarcinoma , and 50 % on lung adenocarcinoma , respectively also obviously decreased the level of serum DR270. Conclusion : Osthol can inhibite the growing of lung adenocarcinoma and lung squamacarcinoma , especially the squamacarcinoma.

Purpose : Uterot rophic assay has been kown efficient for detecting endocrine disrupters. To examine the est rogenic activity of bisphenol A(BPA) using the immature female SD rat . Methods : The vehicle cont rol(the peanut oil) , positive cont rol (est radiol benzoate , E2B , 0. 4 mg/ kg ) and BPA(200 mg/ kg ,400 mg/ kg and 800 mg/ kg) were given orally for 3 and 7 consecutive days beginning postnatal day 21. Then rat s were sacrificed 24 hour after the last administ ration. Results : Uterine weight , uterine/ weight , the thickness of the myomet rium and the height of the luminal epithelium increased in E2B , BPA 400 mg/ kg and 800 mg/ kg group ( P <0. 01) with a dose2response relationship. Administered BPA for 7 days , the vaginal opening time of the immature female SD rat s advanced. Conclusion : BPA has weak est rogenic activity in SD rat . The hypert rophy andhyperplasia of myomet rial cell of uterus may induce the uterine weight increase.

Purpose : To observe the protective effects of the chloroform ext ract s of lsatis indigotica leaves onn the male germ cells f rom damage induced by cyclophosphamide (CP) in mice. Methods : The spermatozoon deformity rate and micronucleus rate of early spermatids were detected using spermatozoon deformity test and micronucleus test respectively. Results : Isatis indigotica had no genotoxic effect s , but showed significantly protective effect s to germ cell f rom damage induced by CP. The inhibited rates of spermatid micronucleus and spermatozoon deformity were 57. 38 % and 50. 87 % respectively at the dose of 100 mg/ kg + CP 10 mg/ kg. Conclusion : Isatis indigotica can diminish germ cell damage inducded by CP in mice.