Purpose : To explore the etiologic role of HPV infection in sophageal carcinoma , the association of HPV-16 E6 with the nuclear mat rix of carcinoma cells was investigated. Methods : Two esophageal carcinoma cell lines , EC/ CUHK1 and EC/ CUHK2 , were tested for HPV-16 E6 subgenic fragment by using polymerase chain reaction amplification of virus DNA associated nuclear matrix. RT-PCR and immunocytochemist ry were used to visualize the expression of E6 subgene in the cells. Results : The HPV-16 E6 subgenic fragment were found to be present in nuclear mat rix-associated DNA , E6 oncoprotein localized in the nucleus where it tightly associate with nuclear mat rix after sequential extraction in EC/ CUHK2 cells. This phenomenon was not detected , however , in EC/ CUHK1 cells. Conclusion : The interaction between HPV-16 E6 and nuclear mat rix may cont ribute to the viral induced carcinogenesis in esophageal carcinoma cell line EC/ CUHK2.

Purpose : To establish a method for screening the differential expression genes from the suppression subt ractive hybridization positive clones. Methods : The PCR products of suppression subtractive hybridization positive clones were arrayed onto nylon membrane , hybridized with a labelled polyA + RNA probe and investi- gated with chemical luminescence reagent . The intensity of the dots was scanned and analyzed using Leica Q550 Iw image analysis system. The intensity of the dots were calculated as average intensity per unit area which eliminates the intensity of background. If the ratio (R) of intensity of a pair of dots in two parallel arrays is ≥ 2. 00 , it is defined to be positive differential expression gene. Results : The differential expression genes are efficaciously screened f rom suppression subtractive hybridization positive clones using reverse mRNA dot blot technique. Conclusion : The reverse mRNA dot blot is a useful method for screening differential expression genes from suppression subtractive hybridization positive clones.

Purpose : To evaluate the cytogenetic effect of irradiation on the workers , early engaged in X-ray medicine in China , who had been exposed to X-ray at low dose rate for a long time (22244 years) . Method : The peripheral lymphocyte chromosome aberrations f rom 25 medical X-ray workers and 10 cont rols were analyzed by fluorescence in situ hybridization ( FISH) with probes of chromosomes 4 and 7 and verified with Giemsa staining. Results : The normal target chromosomes and their aberration were directly exhibited in morphology. The chromosomes translocations of X-ray workers were 84 % of all chromosome aberrations in this group. Ins (in-sertion) , Dic (dicent ric) and Ace (acent ric f ragment) were 1. 9 % , 4. 5 % and 9. 7 % , respectively. The f requencies of chromosome t ranslocation and total aberrations in X-ray workers were higher than that of the cont rol group ( P < 0. 005) . Conclusion : The peripheral lymphocyte of medical X-ray workers exists chromosomes aber-rations , the most part of which are translocations.

Purpose : To detect the f requencies of aneuploidy for chromosome 9 and 18 in sperm of healthy males. Methods : Two-color fluorescence in situ hybridization ( FISH) was performed on sperm nuclei using cent romeric probes for chromosome 9 and 18 , and the f requencies of aneuploidy were scored. Results : 156 955 sperm nuclei were detected in 16 healthy adults. About 10 000 sperm nuclei were scored from each of 16 donors and the average efficiency of hybridization was above 99 %. The mean f requencies of disomy obtained were 0. 050 % ±0. 030 % for chromosome 9 ,0. 033 %±0. 025 %for chromosome 18. The nullisomy frequencies of chromosome 9 and 18 were found to be 0. 067 %±0. 037 % , 0. 048 %±0. 034 % respectively. Diploidy was observed as 0. 040 %±0. 036 %. The f requency of total numerical aberration was 0. 218 %±0. 071 %. Con-clusion : The aneuploidy for chromosome 9 and 18 in sperm of 16 healthy males was detected in this research , the result was similar to that of traditional sperm karyotype analysis.

Purpose and Methods : Using immunohistochemical assay , the expression and significance of proliferating cell nuclear antigen (PCNA) were studied in aflatoxin B1 hepatocarcinogenesis of Wistar rats treated with lithium carbonate (Li2CO3) . Results : The expression of PCNA occurred in the early stage of carcinogenesis and significantly increased at week 9 or 10. The positive rate of positive control group (B) was highest and that of group treated simultaneously (C) and group pretreated with Li2CO3 (D) significantly decreased , but group C was higher than group D. Conclusion : It suggested that Li2CO3 has the effect on anti-expression of PCNA in aflatoxin B1-induced hepatic carcinoma of the rat and can rest rain cell proliferation ,and that the immunohisto-chemical assay of PCNA may help early diagnosis and monitoring.

Purpose : To study the over-expression of p53 protein and proliferation cell nuclear antigen (PCNA) in human esophageal basal cell hyperplasia , atypical hyperplasia , and carcinoma in situ , and to analyse the significance of the expression. Methods : 189 specimen of esophageal paracarcinoma epithelia and cancinoma in situ were tested for p53 and PCNA using immunohistochemical technic. Results : From basal cell hyperplasia to atypical hyperplasia to cancinoma in situ , the rates of p53 protein accumulation were 55 % , 79 % and 98 % ( P <0. 01) , respectively , and PCNA immunostain-positive cells increased in number as well. Conclusions : p53 protein accumulation occurs early in the pathogenesis of esophageal carcinoma. Over-expression of p53 protein and PCNA may serve as an indicator of precancerous lesions and malignancy in the human esophageal epithelium.

Purpose : To analyze the genotype frequency of aldehyde mdehydrogenase-2 (ALDH2) , and evaluate the relationship between ALDH2 polymorphism and drinking behavior in Chinese. Methods : Epidemiological data were collected from 273 healthy persons in Taixing city of Jiangsu province in China , and ALDH2 genotypes were detected by polymerase chain reaction-rest riction fragment length polymorphism (PCR2RFL P) . Results : The f requency of ALDH2 mutant allele was 47. 25 % in Chinese. No difference was found between ALDH2 1 and ALDH2 1 * 2/ ALDH2 2 in drinking f requency and alcohol consumption per occasion. Conclusion : The ALDH2 2 allele was relatively common in Chinese. Drinking behavior was not influenced by the individual genotypes of ALDH2.

Purpose : To test the antimutagenicity and anti-tumor activity of six kinds of Chinese medicinal herbs (hairyvein agrimony , hawthorn , mushroom , apricot kernel , jujube and isatis root) . Methods : The antimuta-genicity and mutagenicity of six kinds of Chinese medicinal herbs were investigated using the antimutagenicity and mutagenicity synchronous test , the anti-tumor activity of the six kinds of Chinese medicinal herbs to four kinds of tumor cells were investigated using in vit ro anti-tumor test . Results : With and without rat liver micro-somal enzymes ( S9) the tests showed that all the Chinese medicinal herbs had no mutagenicity. Mushroom、howthorn、apricot kernel and jujube were antimutagen against MMC. Four different concent ration groups of hairyvein agrimony、howthorn and mushroom ext racts all had the effect s of inhibiting the incorporation of 3 H- TdR. The inhibition had an increasing tendency with the increasing of concent ration. Conclusions : mushroom、 hawthorn 、apricot kernel and jujube have antimutagen activity , hairyvein agrimony、hawthorn and mushroom can apparently inhibit the synthesis of DNA of four kinds of tumor cells (MT2 Ⅱ, L929 , SKV20 , K562) .

Purpose : To observe the inhibitory effect of lithium carbonate (Li2CO3 ) on genetic and oxidative damage in cancer patients. Methods : The single cell gel elect rophoresis assay (SCGE) , micronucleus test were used to measure DNA and chromosomal damage. At the same time , SOD , GSH-Px , and2SH and MDA were detected by biochemical tests. Results : The genetic damage of peripheral blood cells in cancer patients was relieved gradually with Li2CO3 treatment , and the activity and content of the anti-oxidative material and WBC number increased significantly. Conclusion : Li2CO3 can inhibit genetic damage , increase the ability of anti-oxidation and relieve the myellogenic inhibition.

Purpose : To investigate the polymorphisms of exons 1 ～ 5 in human O6-methylguanine-DNA methylt ransferase (MGMT) gene and their relationship with the susceptibility to tumors. Methods : The poly- morphisms of exons 1～5 were analyzed with polymerase chain reaction (PCR)-single st rand conformation poly-morphism (SSCP) and DNA sequencing in 188 Chinese Han people (100 healthy people and 88 tumor patients) .Results : A polymorphism of exon 3 , a C-to-T missense mutation , was detected at the first base of codon 84 (CTT →TTT , Leu →Phe) , and a polymorphism of exon 4 , a C-to-T same sense mutation , was found at the third base of codon 94 ( TTC →TTT , both encode Phe) . There was no statistical significance of the polymor- phisms of the two sites between the two groups ( P < 0. 05) . Besides , there was a missense mutation of exon 5 in the tumor people , that is , a G-to-C change of the second base at codon 200 ( GGC →GCC , Gly →Ala) . This polymorphism didn’t exist in the normal people. Conclusion : There were the polymorphisms of exons 3 ,4 and 5 in MGM T gene. The relationship between the polymorphism of exon 3 or 4 and tumorigenesis might be weak. The polymorphism of exon 5 only existed in the tumor people , which indicated that the polymorphism might be correlated with carcinogenesis.

Purpose : To study the effect of the extract of Pleurotas sapidus on 4 tumor cell lines ( human hepatoma cell Q3 , human gastric cancer cell MGC-803 , human cervical carcinoma Hela cell , murine lung adenocar-cinoma cell SPC-A-1) . Methods : The survival cells and protein synthesis of tumor cell lines treated for 24 h with 10 - 1 g/ ml～10 - 6 g/ ml of the water and ethanol extracts from Pleurotas sapidus were determined by crystal violet staining and by Bradford assays. Results : ①There was a significant growth inhibition of tbe cell survival and protein synthesis of the cell lines at a dose of 10 - 1 g/ ml of the water and ethanol extracts ; ②The growth inhibition was found in different dose groups of ethanol extract . In the normal liver cells , the cell survival was not affected and the protein synthesis increased. Conclusion : The inhibition of the tumor cell lines with the extracts fom Pleurotas Sapidus may be related to the inhibition of cell growth and protein synthesis.

Purpose : To explore the mutagenicity of organic ext ract s of tap water in a certain city in mice. Methods : Each 200 L of water was collected separately from Huai river source water , water of clarifying filt ration , chlorinated tap water and reservoir’s water. After being adsorbed and concent rated , water samples were poured into mouse stomaches. Micronucleus frequency in mouse thoracic bone-marrow polychromatic erythrocyte ( PCE) and sperm deformity rate were determined. Results : Mutagenicity of some degree were determined from Huai river source water and chlorinated tap water. The order of mutagenic intensity was as follows ; chlorinated tap water > reservoir’s water > source water > water of clarifying filteration. Conclusions : The source water was contaminated by organic mutagens. After coagulation and precipitation , mutagenicity of source water decreased because some mutagenic organic chemicals could be removed. While chlorination increased mutagenicity of tap water.

Purpose and Methods : To study the potential mutagenicity of meloxicam , Ames test was carried out in TA97 , TA98 , TA100 , TA102 strains , chromosomal aberration test in Chinese hamster lung fibroblast sand micronucleus test in polychromatic erythrocytes in mice with and without S9mix. Results : No increase in the number of revertant colonies was found in the Ames test at a dose range from 0. 2 to 5 000μg per plate. These results were also negative in the micronucleus test and in the chromosomal aberration test at doses from 16 to 240 mg/ kg·bw. Conclusion : The mutagenicity of meloxicam was not observed in this study.

Purpose and Methods : The genotoxic activity of Gantaikang was studied by Ames test , micronucle-us test of polychromatic erythrocytes in bone marrow and sperm shape abnormality test in mice to provide the data basis for it's safety. Results and Conclusion : The results of the three test s were all negative , which suggested that Gantaikang is not mutagenic to tested strains , somatic cells and male germ cells in mice.