BACKGROUND＆AIM：The research evaluated the micronuclear induction effect by folic acid deficiency in human lymphoblast t(GM13705). The aim of the experiment was to find the optimized folic acid concentration of minimizing genomic damage in the employed cell line. MATERIAL AND METHODS:The experiment employed cytokinesis-block micronucleus assay(CBMN) to evaluate the frequencies of micronucleus induced by folic acid deficiency (6 ～240 nmol/L )in binucleated cell. RESULTS: The frequencies of micronucleated binucleated cell in 6, 60 and 120 nmol/L folic acid groups were significantly increased comparing with 240 nmol/L of folic acid and normal RPMI1640(P<0.05～0.001). But no significant differences were found among the three groups. There was no statistic significance was found between 240 nmol/L and normal RPMI1640 for their frequencies of micronucleated binucleated cell. CONCLUSION: 240 nmol/L of folic acid was able to minimize genetic damage of the tested cell line under the current experimental condition. The genome with BRCA1 mutation may be more sensitive to the stress of folic acid deficiency.

BACKGROUND ＆ AIM：Hepatitis B is a public health problem of worldwide importance. To explore feasibility of Hepatitis B virus(HBV) vertically transmitting via oocytes, the transfection of mouse oocytes with recombinant plasmid, pBR322-HBV was studied. MATERIAL AND METHODS： Genomic DNA was isolated and the metaphases were prepared, respectively from mouse oocytes co-cultured with pBR322-HBV DNA plasmids. PCR, Southern blot, Dot hybridization and FISH were performed to demonstrate if the mouse oocytes were transfected by pBR322-HBV plasmid. RESULTS: PCR detected positive bands in the tested samples, and then Southern blot revealed clear hybridization signal in above PCR products. Final washing solutions were collected for Dot hybridization and no signal for HBV DNA was observed, which excluded the possibility that contamination of washing solutions gave rise to positive results of PCR and Southern blot. FISH demonstrated that 36 of 1 000 metaphases presented positive signals. CONCLUSION: HBV DNA sequences were able to pass through the zona and oolemma to enter into oocytes and integrate into their chromosomes. It suggested that HBV DNA sequences might be brought into embryo via oocytes as vectors when they were fertilized with normal spermatozoa.

BACKGROUND ＆ AIM:To study the DNA damage in bone marrow cells of mice induced by rare_earth element Holmium. MATERIAL AND METHODS: Holmium_trioxide_HCl solution was administered orally in a single treatment in a cumulative dose series to mice. The bone_marrow cells of thighbone were collected in 24 hours after treatment and performed single cell gel electrophoresis(SCGE)to determine chromosomal and DNA damage. RESULTS: The exeperiment showed that,in dosage from 20 mg/kg to 80 mg/kg, the average tail length increased highly significantly with the rise of dosage compared with the control(P<0.001),while the average head diameter diminished gradually on the contrary. In dosage from 40 mg/kg to 80 mg/kg, the average head diameter showed highly significant difference compared with the control(P<0.001). Besides,the percentage of tailed cells and ratio of damaged DNA increased with the rise of concentrations. CONCLUSION: It suggests that rare_earth element Holmium may damage DNA in bone_marrow cells of mice in some degree.

BACKGROUND ＆ AIM： To explore the relationship of three proteins expression in esophageal mucosa epithelia between chronic esophagitis and esophageal para-cancer tissue. MATERIAL AND METHODS： Forty-seven cases of chronic esophagitis and 85 specimens with esophageal carcinoma and para-cancer tissue were analyzed by immunohistochemical staining for P53、P27 and MDM2 proteins expression. RESULTS： The P53 protein expression was not detected in normal mucosa， the positive rates of three groups, esophagitis, dysplasia epithelia and cancer tissue are similar(χ2=0.979, P=0.0615). From normal epithelium to chronic esophagitis and/or dysplasia to esophageal carcinoma, the positive-reactivity for P27 protein were detected. The differences for the four groups have no statistically significance(χ2=1.828, P=0.609).While the positive rates of MDM2 protein have statistically significance in the four groups(χ2=18.895, P=0.000).And are similar in normal epithelium, chronic esophagitis and dysplasia epithelia(χ2=3.585, P=0.167), and their positive rates are lower than esophageal carcinoma(χ2=14.802, P=0.301). The expressions of P53、 P27 and MDM2 proteins are similar in chronic esophagitis and mild, moderate and severe dysplasia epithelia(P53、P27, binomial distribution,minimum P=0.2140; MDM2,χ2=3.658,P=0.301). CONCLIUSION： The expression of P53、P27 and MDM2 proteins is similar in mucosa epithelia of chronic esophagitis and mild， moderate and severe dysplasia. This indicated that it is possible that chronic esophagitis is a kind of precancerous lesions.

BACKGROUND ＆ AIM:Centromeric dots(Cd)variation of HepG2 cells and its relation with aneuploidy aberration were studied. MATERIAL AND METHODS: A Cd-NOR in-phase argentums dye analysis technique modified by this laboratory was used to study centromeric dots(Cd)variation of HepG2 cells. RESULTS： Frequency of Cd loss in HepG2 cells was 2.30 ％, Frequency of Cd duplication laggard was 1.02 ％, Frequency of little Cd was 2.58 ％, Frequency of Cd-NOR amalgamation was 0.64 ％. Frequency of Cd loss, frequency of Cd duplication laggard and frequency of little Cd in HepG2 cells were significantly higher than that of normal embryonic villi cells(P<0.05). Frequency of Cd-NOR amalgamation showed no difference between HepG2 cells and normal embryonic villi. CONCLUSION：Cd loss,Cd duplication laggard and little Cd might be related with aneuploidy aberration of HepG2 cells.

BACKGROUND ＆ AIM： To study the adverse effect of coal tar pitch(CTP)on DNA damage of peripheral blood lymphocyte in occupationally exposed workers. MATERIAL AND METHODS： Micronucleus (MN)and single cell gel electrophoresis(SCGE)were used to determine DNA damage of peripheral blood lymphocyte in 43 workers exposed CTP and 21 controls. RESULTS: The frequencies of comet-like tail and MN of peripheral blood lymphocytes were(3.26±1.12)×10-2 and (1.23±0.27)×10-3 , significantly higher in CTP-exposed group than those in control group(P<0.01；P<0.01)， and these effects could increase with the extension of time exposed CTP(P<0.01;P<0.05). CONCLUTION: Exposing to CTP for a long-term may induce DNA damage in peripheral blood lymphocyte in workers, and thus SCGE and MN may be used as early monitoring markers for high-risk individual of occupational lung cacer.

BACKGROUND ＆ AIM: To Study the dose-effects relationship between Vitamin C(VC), Vitamin E(VE) , and lipid peroxidation with the model of rabbit injured by radiation. MATERIAL AND METHODS: Chinese rabbits were chosen as the experimental animals and were randomly divided into 5 groups. They were negative control group,positive group, and trial groups of VC,VE. The trial groups contained three different dosages of VC and three different dosages of VE. Peanut oil was selected as diluent which had been gotten rid of vit E.The five groups were supplied by injection of vein with the dosages of VC 10 mg/kg, VC 20 mg/kg, VC 30 mg/kg everyday respectively. The three VE groups were supplied by gavages with the dosage of VE 20 mg/kg,VE 40 mg/kg, VE 60 mg/kg, everyday rspectively too. On the third day all groups,except negative control group,were radiated by 60 Co with the dose of 4.5 Gy.Then they were fed as before,and on the sixth day all rabbits were killed,blood and liver were removed for the analysis of changes in catalytic activity of SOD and content of MDA by means of Auto-machine. RESULTS： After the radiation,the catalytic activities of hepatic SOD in radiation groups were higher than those in the negative control group(P<0.01),and trial groups of VC and VE showed some protective effect of rabbit against radiation, and there was a dose-effect relationship between the VC、VE and radiation injury. The content of hepatic MDA in trial group was lower than positive group (P<0.01). They showed some effect of protective effects against increase of MDA,and showed the dose-effect relationship between the dosage of VC、VE and protection against injury of irradiation. CONCLUSION： The effect of individual use of VC、VE has protest effect of SOD catalytic activity and inhibition on MDA which exists dose-effect relationship;The antioxidation of vit.E can not protest against radiation of peripheral blood and immunological cells. When VC and VE were given to rabbits toghter,there was a protective effect on of rabbits injured by radiation of 60Co γ ray.

BACKGROUND ＆ AIM: To investigate the suppression effect on human gastric carcinoma cell HGC27 by combination of wild-type P53, P16 genes mediated by retrovirus vector. METERIAL AND METHODS:Human gastric carcinoma cell line HGC27 was transfected via two retrovirus vectors pLNCX containing wild-type P53, P16 genes by lipofectamine. By using cell growth curve, MTT growth inhibition rate, Southern blot and flow cytometry assay, the clones obtained were detected and observed for the changes of their biologic characteristics. RESULTS:Overexpression of wild-type P53 and P16 gene inhibited the growth of human gastric carcinoma cell line. The HGC27 cell growth inhibition and apoptosis caused by combination transfection of wild-type P53 and P16 gene were higher than those caused by single gene transfection. CONCLUSION: The therapeutic effect of P53 and P16 gene combination therapy is significantly higher than that of single gene therapy.

BACKGROUND ＆ AIM: To study the antioxidative and antitumor effcts of Curcuma longa L decoction on H22 tumorigenic mouse. MATERIAL AND METHODS: The H22 tumorigenic mice were oral administrated with the decoction with 24 g /kg, 12 g/kg and 6 g/kg curcuma longa L respectively for 8 days. Weight of tumor, both GSH and SOD activities of animal blood were determined. RESULTS： Inhibition of tumor growth was found for curcuma longa L decoction. But curcuma longa L decoction could significantly increase the levels of GSH and SOD on H22 tumorigenic mice blood. CONCLUTION： In this investigation, Curcuma longa L decoction has no obvious antitumor effect, but has antioxidative effect on H22 tumorigenic mice.

BACKGROUND ＆ AIM: To study the cytotoxicity on normal cell and antiviral effect of organogermanium Poly-derivatives on breath virus, and provide a basis to clinical application. MATERIAL AND METHODS: The cytoxicity on FL was studied with the method of MTT. Establish the model of breath viral infected in vitro and observe protective function of organogermanium poly-derivatives on infected cells by methods of CPE and MTT. To study the antiviral effect of organogermanium poly-derivatives by changing time, way and concentration of giving medicine. RESULTS： The quantity of surviving cells was more than virus infecting group. When the dosage reached 160.00 μg/ml, inhibiting RSV effect of organogermanium poly-derivatives was higher than the ribavirin group.In the group that the Hela cells were infected by RSV first then treated with organogermanium poly-derivatives,the quantity of alive cell was more than the ribavirin group. CONCLUSION: organogermanium poly-derivatives is a kind of medicine that has definite antiviral function.

BACKGROUND ＆ AIM： To evaluate the genotoxicity of water organic pollutants of Chaohu Lake and the effects on drinking water quality. MATERIAL AND METHODS： Ames test, micronucleus test and single-cell gel-electrophoresis(SCGE) test were carried out in the water samples from Chaohu Lake water and the finished water plants which use water source from Chaohu Lake. RESULTS: Ames test indicated that the raw water presented suspectable mutagenicity which couldn't be eleminated by coagulation and chlorination. The rates of red cell micronucleus were increased significantly at dose level of 10 μg/g. The result of SCGE showed that the frequencies of comet cells in headwater, unfiltrated water,filtrated water and product water groups were significantly higher than that of negative group. CONCLUSION: The water organic pollutants of Chaohu Lake has potential mutagenicity. We should pay more attention to its genotoxicity and the effects on drinking water quality which related public health.

BACKGROUND ＆ AIM： Although Duzhong was listed on the function food roll, there was lack of data of systematic toxic/safety evaluation experiments. MATERIAL AND METHODS： Safety evaluation experiment was done using acute toxicity experiment, cell toxicity experiment and genetic toxicity experiment . RESULTS： CHL and CHO were 109.38 mg/ml;it was negative in toxicity. CONCLUSION: It was found that Du zhong was a non-toxic substance and was negative in genetic toxicity,although it had some toxic effect on the CHO and CHL cell at higher dose levels.

BACKGROUND ＆ AIM: To explore the acute toxicity and LD50,and study the genetic damage of bone marrow cells induced by Hydroxylammonium Nitrate. MATERIAL AND METHODS: After celiac administration of HAN in mice,the mortality and the physiological changes were observed; Chromosome aberration test,micronucleus test in mouse were used. RESULTS: The LD50 of HAN in male on 24 hour and 14 day was 186 mg/kg(185～187 mg/kg) and 183 mg/kg (182～184 mg/kg),respectively. No pathological change of the organs was found. There were significant findings in chromosome aberration and micronucleis rates in experimental groups compared with those of the negative control group(P<0.05). CONCLUSION: According to the standard of grading of acute toxicity,HAN belongs to the moderate class. The genetic damage of bone marrow cells can be induced by Hydroxylammonium Nitrate.

BACKGROUND ＆ AIM: To study the reproductive damage of testicular germ cell and the deformity of sperm in mouse induced by Hydroxylammonium Nitrate(HAN). MATERIAL AND METHODS: Testicular germ cell micronucleus test,sperm deformity assay and flow cytometry were used. RESULTS: It showed that the percentage of deformity in sperm was markedly increaed as the dose increased(P<0.05), the percentage of micronucleus was significately decreased as the dose increased(P<0.05). The toxic effect of sperm was correlated with exposuring HAN . CONCLUSION: It suggested that HAN might have reproductive damage effect to testicular germ cell and sperm in mice.

BACKGROUND ＆ AIM: To investigate the effects of Hydroxylammonium Nitrate (HAN) on the tk gene of mouse lymphoma cells. MATERIAL AND METHODS: L5178Y cells were treated with Hydroxylammonium Nitrate with different concentrations, to determine cytotxicity and mutation at different time phases. The numbers of positive wells were counted . The cell plating efficiency, relative suspension growth and mutation frequency were determined. RESULTS: The results showed that HAN (50～500 μg/ml) induced tk gene mutation with mutation frequency 1～19 times higher than that of spontaneous mutation frequency of L5178Y cells and severe cytotoxic responses. CONCLUSION: Hydroxylammonium Nitrate can exert cytotocicity and mutagenic effects on tk geng in L5178Y cells.

BACKGROUND ＆ AIM: To study the embryotoxicity,the teratogenic effect of Hydroxylammonium Nitrate(HAN) and its teratogenic characteristics. MATERIAL AND METHODS: The body weight,the death rate of fetuses and the rate of absorbed embryos were counted. The External appearances and internal organ and the skeleton of the mouse embyos were observed . RESULTS:After the mice were given different doses of HAN,their weight, the number of living embryo,the number of absorbed embryo and the number of dead embryo did not change obviously. The weight of the embryo did not changed apparently. The abnormality in statistics was not found in the skeleton of the mouseembryos,the exterior and the internal organs. CONCLUSION: HAN has no malformed effect on the mouse embryos.

BACKGROUND ＆ AIM: To study the effect of exposure to hydroxylammonium nitrate (HAN)on micronucleus(MN) frequency of polychromatic erythrocytes(PCE) from Wistar rats marrow. METERIAL AND METHODS: Different doses of HAN at 6.97 mg/kg, 13.93 mg/kg, 27.86 mg/kg were administered to the three treated groups by intraperitoneal injection，and the negative control group was treated with 0.9 ％ NaCl. The treatment had been performed every other day for 90 days. After the last treatment in 90 th day, 2/3 of the rats were sacrificed by cervical dislocation, and after 30 days' recovery we sacrificed the rests. The number of micronucleus per 1 000 polychromatic erythrocytes (PCE) from sternum bone marrow was counted and analysed. RESULTS: In the period of exposure to HAN, the MN frequency of bone marrow cells of Wistar rats treated by HAN wasn't significantly different from that of the negative control group, except for the highest dose group. After 30 days'recovery, the MN frequency treated by HAN was not significantly different from that of the control group. CONCLUSION: Our results suggested that HAN can produces certain genotoxicity，which was reversible but didn't have delayed effect.

BACKGROUND ＆ AIM: To study mutagenicity and acute toxicity of Yushengtang capsule safety. MATERIAL AND METHODS: Mutagenicity and acute toxicity of Yushengtang capsule were studied by using LD50 in mice,Ames test,micronucleus in mice, sperm shape abnormality test and thirty days feeding study in rats. RESULTS: Acute toxicity test: LD50>215 000 mg/kg. Ames test:Yushengtang at four concentration of 1.0,2.0,3.0,4.0 mg/plate were studied by TA97(a),TA98,TA100,TA102 bacterial,at the same time mutagenic were used as the control groups. The test were repeated under the action of metabolic activated enzyme. The bacterial numbers at every concentrations of Yushengtang had no significant differences from the control groups. Micronucleus and sperm shape abnormality test in mice: Micronucleus rate at 5 000, 10 000, 20 000 mg/kg and positive were 2.0 ‰,1.6 ‰,1.8 ‰,2.0 ‰ and 32.6 ‰ respectively. Sperm shape abnormality rate at 5 000,10 000,20 000 mg/kg and positive were 19.4 ‰,19.8 ‰,19.8 ‰,22.4 ‰ and 128.4 ‰. Thirty days feeding test: The rats were feed thirty days. All index were normal. CONCLUSION: Yushengtang had no potential mutagenicity.