To define further the role of reactive oxygen species ( ROS) in ult raviolet radiation (UV)2induced the formation of Human skin’s CPD , experiment s were performed using alkaline gelelect rophoresis technique. Purified DNA was incubated with antioxidant s. After DNA was exposed to UV , T4 Endonuclease V was added , elect rophoresis was taken , CPD was measured by Gel Imaging and Image Analysis. It was found that antioxidant s exhibited some inhibitory effects on the formation of CPD ,β2carotene and superoxide dismutase ( SOD) are more obvious than GSH and CAT , but none of which were able to block the formation completely. The result s suggest that the formation of CPD is only partly dependent on ROS.

The MSU - 1 lineage of human fibroblast including 3 immortalized cell strains with wrowth advantage to varying extents , was generated by t ransfection of normal human fibroblasts with a v - myc oncogene and their gaining additional genetic alteration ( s) spontaneously. Those derived cell variant s may represent different premalignant stages in the progression from normal cells to malignant cells. To establish in vit ro model of human cell carcinogenesis , the 3 cell types were characterized for their responses to induction of malignant t ransformation by different carcinogens. The result s shwoed that cell st rains MSU - 1. 1 and MSU - 1. 2 were malignantly transformed after exposure to BPDE , ICR - 191 and 60 Coγ- ray , respectively , followed by selection for focus forming ability or anchorage independent growth. The parental cell of the lineage MSU - 1. 0 was not found to be malignantly tranformed. Studies using this in vit ro model with carcinogens revealed that different phenotypic properties of the resulted malignant cells were acquired by a step - wise progressive process.

Using PCR2SSCP silver staining technique , 20 patient s with large bowel cancer (LBC) ,and 20 their familial members ( FM) were analysed for mutation in exons 5 - 8 of p53 gene of peripheral lymphocytes. Among them ,p53 mutation were found in 6 cases with LBC and in 5 cases with FM. The mutation rates were 30 % and 25 % in LBC and FM ,respectively. It was showed that p53 gene mutation is a common event in LBC , which plays an important role in the progression of LBC. Our preliminary study indicates the detecting of p53 gene mutation may be used as a molecule diagnosis for susceptible individuals of LBC.

Human glutathione S2t ransferase ( GSTs) is considered as an important group of phase reaction enzymes involved not only in the detoxification metabolism ,in some cases , also in the bioactivation process of various types of environmental hazard chemicals. Among the glutathione S2t ransferases known so far , GSTT1 displays genetic polymorphism due to gene deletion. GSTT1 was genotyped in 226 healthy adults in Shanghai (permanent resident s) by an internal control allele2specific PCR amplification of blood nucleated cell DNA. The homozygous deletion of gene ( GSTT10/ 0 genotype) was identified in 50. 3 %(114/ 226) of the individuals tested. The deficiency frequency in normal population in Shanghai is higher than in normal Caucasian population (11 - 17 %) and among Af rican Americans (24 %) significantly.

Differential PCR was used to detect the variance of C - erbB - 2 gene copies in 63 fresh breast cancer tissues. Amplification of C - erbB - 2 oncogene was found in 13 of 63 breast cancer (20. 6 %) . The rate of amplification of C - erbB - 2 gene in patient s with positive lymph node metastasis was approximately equal to that in negative node patient s. It was identified that amplification of C - erbB - 2 gene existed in 5 of 17 on stage Ⅲ, 1 of 4 on stage Ⅳ, higher than that of stage Ⅱ (4/ 27) and stage Ⅰ(0/ 2) , but the difference was not significant ( P > 0. 50) .

A study on the effect s of 17β- est radiol against the expression of interleukin - 6 ( IL -6) and tumor necrosis factor ( TNF) induced by low - density lipoproteins(LDL) on vascular endothelial cells (VECs) was carried out . The level of IL - 6 and TNF were measured in cultured human umbilical vein endothelial cells. LDL significantly raise the level of IL - 6 and TNF in cultured endothelial cells. In LDL 100μg/ ml , TNF activity was 0. 74 ±0. 09 (ng/ ml) and IL - 6 activity was 91. 64 ±7. 39 (u/ ml) . 17β- est radiol can significantly decrease the expression of IL - 6 and TNF induced by LDL in cultured endothelial cells. However , when tamoxifen and 17β-est radiol were added at the same time , the level of IL - 6 and TNF significantly increased compared with that in the cont rol group ( P < 0. 05) . These indicate that the protection of 17β-est radiol on VECs may be through est rogen receptor partially.

The blood of 100 non - smoking female lung cancer cases and 95 healthy cant rols82cases and 89 cont rols were collected from Shanghai and Harbin population respectively. The DNA were ext racted from buffy coat with phenol2chloroform. Cytochrome P450 (CYP) 2E1 genotype were analyzed with rest riction enzyme Dra I for the sixth int ron and Rsa I for the 5’2flanking region. The OR reach 2. 56 and 5. 47 for CYP2E1 Dra I and Rsa I homozygous mutant respectively in Shanghai cases , but there were no statistic significance. Though in Harbin cases the OR reach 0. 49 and 0. 47 , also no significance.

The effect of allit radi on improving GJ IC and anti2oxidation was investigated by measuring oxygen f ree radicals , GJ IC(gap junction intercellular communication) and DNA. The result s showed that allit radi could prevent the cytotoxicity by anti2oxidation , relieve the inhibition of phenobarbitone on GJ IC( P < 0101) . It implys that allit radi could prevent the effect of phenobarbitone on promoting carcinogenesis by increasing the GJ IC function , and inhibit the toxic effect of oxygen f ree radicals on hepatocytes.

The analyses of chromosome aberrations and micronuclei in peripheral blood lymphocyte were performed in 26 cases exposed to low2dose radiation in 1966 and in 1971. The results show that the f requencies of chromosome aberration and micronucleus in the irradiated group were significantly higher than that in cont rol ( P < 0. 01) ,but a relationship between the radiation dose and the f requencies of chromosome aberrations and micronuclei was not found ; The rates of chromosome aberrations or micronuclei in the externally irradiatd group was higher than that in the internally irradiated one but the difference was not statistically significant ( P > 0. 05) . Meanwhile ,the dicent ric and t ranslocation chromosome abrerration was found only in the internally irradiated group. The results indicated that the radioactive contamination could not be removed from the body of the persons exposed to internal irradiation.