Purpose : To establish a nonradio - labelled method for measuring telomere length (mean length of telomere rest riction f ragment , TRF) of human chromosome. Methods : TRF was examined by Southern blotting by using labelled oligonucleotide (CCCTAA) 3 probe with digoxin. After hybridization , the blot was stained with NBT/ BCIP , analysed by using a densitomet ric imaging system and mean length of TRF calculated , comparing with standard kilobase sized marker. Results : The hybridization bands were showed under st ringently cont roling the prode working concent ration (1 :1 280 dilution) , loaded DNA sample ( > 20μg) and hybridization temperature (47 ±2 ℃) Conclusion : A digoxin - labelled , stable , reliable and low background method for determining the telomere length of human chromosome was established.

Purpose :To stuty the metabolic role of primary tissue cells in detecting indirect mutagen. Methods the DNA damage effect s of cyclophosphamide , dimethylbenz (a) anthracene and 2 - aminofluorene were studied using the single cell gel elect rophoresis technique (Comet assay) in isolated mice testicular cells. Results : In certain concent ration , the three tested substances could induce the breakage of DNA single st rand and resulted in comet cells with tail. Both the number of comet cells and the length of DNA migration increased with increasing of concent ration of tested substances. Conclusion : The primary mice testicular cells had certain metabolic role and could be used to detect the effect s of DNA damage induced by indirect mutagen in comet assay.

Purpose : To study the antimutagenicity of Oridonin Methods : Ames test and micronucleus assay of polychromatic erythrocytes in mice bone marrow were used. Results : Oridonin could evidently inhibit the reverse mutation on S almonella typhimuriun st rains TA98 and TA100 without S9mix. The rates of maximum inhibition were 89. 1 % and 80. 2 % respectively. In addition , Oridonin could significantly reduce micronucleus requencies induced by cyclophosphamide ( P < 0. 01) . Conclusion : Oridonin has significant antimutagenic effect .

Purpose and Methods : Population polymorphisms of the GSTT1 and M1 genes in the Shanghai“indigene”group were evaluated using the PCR procedure. Results : In this group , the f requencies of GSTT1 null and GSTM1 null genotype are 48. 53 % and 54. 40 % , respectively. No significant differences were detected between urban individuals (49. 32 % and 48. 86 % , respectively) and an“indigene”group in suburb of Shanghai for GSTT1 and GSTM1 genotypes alone , as well as for four combined genotypes of GSTT1 and GSTM1. Conclusion : Between the“indigene”population in remote suburb and the urban population in downtown of Shanghai the genetic polymorphism dist ribution of GSTT1 and GSTM1 genes is proved to be homogenous.

Purpose :To evaluate the probability of using chromosome aberrations induced by irradiation as a indicator of future cancer risk. Methods :Chromosome aberrations in peripheral blood lymphocytes of 10 irradiated and 6 nonirradiated nasopharyngeal carcinoma patient s were studied by two - colour fluorescence in situ hybridization (FISH) and coventional analysis. Results :Both the mean t ranslocation and dicent ric f requencies in irradiated patient s 1 to 10 years after exposure were still significantly higher than those in nonirradiated patientP < 0. 001) . For irradiated patients ,the translocation f requencies were about 3. 5 - fold as high as dicent ric f requencies. No significant difference was found between t ranslocation f requencies in patient s after exposure more than 3 years and that in patient s after exposure less than 3 years ( P > 0. 1) ,but the dicent ric f requencies in patient s after exposure more than 3 years were significantly lower than that in patient s after exposure less than years( P < 0. 001) Conclusion :The percentages of stable chromosome aberrations ( translocations) are still higher even a long time (10 years) after exposure and is expected to be a re1evant biomarker of future cancer risk.

Purpose and Methods : Using the alkaline single cell gel elect rophoresis technique (SCGE) detect the DNA damage of lymphocytes in human peripheral blood , which were exposed to Sulfur mustard in vit ro. Results and Conclusion : The result s show that the length of DNA migration and the f requency of tailed cells increase , and the dose - effect relation is obvious.

Purpose : To investigate the association of the in vivo micronucleus formation in lymphocytes of human peripheral blood with lung cancer. Methods : Case - cont rol study included 95 patient s with lung cancer and 90 cont rols. Slides were prepared by the in vivo micronucleus test in capillary blood lymphocytes. Results : Spontaneous and induced by smoking micronucleus f requencies (MNF) in lung cancer patient s ( 0. 87 ‰ and 1. 64 ‰) are significantly higher than those in cont rols(0. 47 ‰and 0. 76 ‰) ( P < 0. 05 and P < 0. 01) . Conclusion : Patient s with lung cancer were susceptible to mutagens ; In this study we confirmed first that the in vivo micronucleus formation in lymphocyte of peripheral blood is an excellent biomarker in assessing individual cancer susceptibility , persons with 1 ‰and 3 ‰of MNF had an increase of 5. 5 - fold and 21. 9 - fold higher relative risk for lung cancer.

Purpose : To investigate the difference of repairing DNA breaks in cells of lung cancer patients and it clinical expression. Methods : The cultures of human lymphocytes were t reated with blemycin , and the number of chromatid breaks per cell (b/ c) was recorded. The effect s of patient s with higher and lower DNA repair capability t reated with radiotherapy or chemotherapy were observed. Results : ①Mean value of b/ c in lung cancer patient s was 1. 02 , with standard deviation of 0. 72. Fifty two percent were low DNA repair capability class ; them , 37 % were ext remely low repair capability class. ②Low DNA repair capability class increased remarkably with the groups of increased age ( P < 0. 05) . ③The f requency of recurrence and metastasis in low DNA repair capability class was 31 % , higher than 23 % in normal DNA repair capability class. Of patient s appearing clinical side and toxical effect s , 78 % were those in low DNA repair capability class. Conclusion : DNA repair capability in cells of lung cancer patient s decreased with the increase of age. Low DNA repair capability class is susceptible to recurrence and metastasis , and appearing side toxical effects when t reated with radiotherapy and chemotherapy. DNA repair apability in cells is expected to become a biological marker in individual specific t reatment .

Purpose : To study the possible pathogenetic role of HPV16 E6 , E7 protein expression in verrucous carcinoma of the vulva. Methods : Immunohistochemist ry SABC method was used to examine HPV16/ 18E6 and HPV16E7 protein expression in the surgical specimens. Results : ①The most typical is koilocytosis , with perinuclear hole formation with a thick cytoplasmic border in the upper epithelial ; ②Immunohistochemical detection of E6 and E7 showed st rong positive psoduct s in the basal lamina of epidermis of cancer tissues ; ③There are only scattered positive cells for HPV E6 and weak positive or scattered st rong positive cells for HPV E7 in cancer nests ; ④HPV E6 and E7 in the adjacent tissue showed st rong positive expression whereas some region showed medium positive reaction. Conclusion : It is suggested that HPV16 E6 and E7 may be involved in the carcinogenesis of verrucous carcinoma.

Purpose : To explore the diagnosis value of serum lactic dehydrogenase and it s isoenzymes in carcimoma. Methods : Examination of LDH was done by CUI Fu - sheng’s method and LDH isoenzymes by agar - jelly elect rophoretogramic method. Results : Significant elevation of total LDH activity was seen in all kinds of carcinomas. The degrees of elevation was 3. 91 %～153. 86 %. Characteristic of the change in activity of LDH isoenzyme pattern was the significant elevation of LDH3 and higher positive rate (71. 43 %～93. 75 %) . LDH4 and LDH5 was raised , but LDH1 and LDH2 was declined. Conclusion : The examination of serum LDH and LDH isoenzymes has a great value in the diagnosis of carcinoma.

Purpose : To study the migration of the residual compounds f rom VDC/ VC copolymer products into food - simulating solvent s (e. g. distilled water , 4 % acetic acid , and hexane) , and the mutagenicity of migration. Methods : We used two pret reated methods in this experimental research , and studied the difference between f rozen - drying and heating method. The mutagenicity of migration was measured by Ames test . Results : The result s f rom the studies indicated that the migration f rom f rozen - drying increased by 6～27 times as compared with it f rom heating. The test for mutagenicity of migration was always negative for the storage periods of three months by Ames test with two S almonella st rains ( TA98 , TA100) , with and without S9. Conclusion : The studies suggested that the mutagenicity of the VDC/ VC copolymer was not observed in this experimental condition.

Purpose : Studies were conducted to evaluated the effect s of one t reatment protocol and sampling time on the micronucleus test s of two clastogens - mitomytin C and cyclophosphamide. Methods : Young adult ICR mice were t reated once with mitomytin C (MMC , 2 mg/ kg. bw) or cyclophosphamide (CP , 40 mg/ kg. bw) by int raperitoneal injection. The micronucleus incidences in polychromatic erythrocytes ( PCEs) of different sampling times - 12 h , 18 h , 24 h ,32 h , 48 h , 72 h after dose were evaluated in the peripheral blood and the bine marrow. Results : The date in this study indicated : ①The f requencies of micronucleatde polychromatic erythrocytes (MnPCEs) in the bone marrow and peripheral blood were almost identical at each optimal sampling time of the two clastogens ; ② The maximal increase of the incidence of MnPCEs of peripheral blood was delayed 12～14 h compared to that of bone marrow ; ③ The f requency of PCEs of peripheral blood was equal sensitive to that of bone marrow in detecting cytotoxicity to the h ematopoitic system. Conclusion : It is suggested that followingthe one injection protocol with MMC or CP , bone marrow and peripheral blood are both equaly efficacy.

Purpose and Methods : In order to characterize the antimutagenic effect of seaweed polysaccharides (SP) , the mouse bone marrow micronucleus test and mouse sperm malformation test were conducted. Results :The result s showed that the f requencies of micronucleus and abnormal sperms induced by cyclophosphamide (CP) were reduced significantly by SP( P < 0 ,01) . Conclusion : It is suggested that SP can significantly inhibit the mutagenesis of germ cells and stomatic cells induced by CP.