OBJECTIVE: To investigate ERCC2/XPD (excision repair cross complementation group 2/Xeroderma pigmentosum D) function in the repair of DNA damage induced by benzo[a]pyrene. METHODS：China hamster ovary (CHO) cell line including wild type AA8 and ERCC2/XPD defective mutant UV5，was set up as a cell contrast model. DNA damage levels at different time points after benzo[a]pyrene treatment were evaluated by MTT cell inhibition assay，modified comet assay and Rad51 immunofluorescence test. RESULTS：UV5 was more sensitive to benzo[a]pyrene when compared with AA8. The DNA damage caused by benzo[a]pyrene was repaired by AA8 but not by UV5. CONCLUSION：ERCC2/XPD，as an important helicase in nucleotide excision repair，could play a critical role in repairing DNA damage induced by benzo[a]pyrene.

OBJECTIVE:  To observe the effects on T-lymphocyte subsets after different doses of irradiation. To investigate the cellular and molecular mechanisms of immune system injury induced by irradiation. METHODS：The C57BL/6j mice were divided into normal control group and model groups. The mice in radiation injury model were exposed to 60Co gamma rays (0.7, 1.4, 2.8 and 5.6 Gy). The surface markers and intracellular cytokines of lymphocytes were stained with fluorescence labeled monoclonal antibodies . The changes of T-lymphocyte subsets CD3+，CD4+，CD8+, IFN-r and interleukin-4 in spleen celles were analyzed by flow cytometry. RESULTS：T-lymphocyte subsets CD3+， CD4+，CD8+ were distinctly reduced after irradiation. This change was related to gamma ray doses. The CD4+/CD8+ was significantly increased. The Th1 and Th2 were depressed after irradiation and the decrement level of Th1 was larger than Th2. When irradiation dose was over 2.8 Gy, Th2/Th1 showed a marked increase compared with control group. CONCLUSION： Changes of mice T- lymphocyte subsets CD3+，CD4+，CD8+ and CD4+/CD8+ ratio could be caused by different doses of irradiation, especially the imbalance of Th1, Th2 and Th2/Th1 ratio that played an important role in radiation-induced immune injury.

OBJECTIVE: To study the mechanisms of ERK and SAPK/JNK pathways of ceramide-induced apoptosis in HT-29 cells. METHODS：HT-29 cells were treated with C2-ceramide for 24 hours at different doses (0，12.5，25.0，50.0μmol/L). AO/EB fluorescent staining was used to identify the morphological changes of HT-29 cells and evaluate the rate of apoptosis in 200 cells. The protein expressions of ERK and phosphorylated ERK(p-ERK) were evaluated by Western Blotting. The activity of phospho-c-Jun in different doses and treatment time of C2-ceramide groups was assessed using SAPK/JNK assay and Western Blotting. RESULTS：Apoptosis rate was increased and the expressions of ERK and p-ERK were reduced in a dose-dependent manner (P＜0.05). The activity of phospho-c-jun in different doses and treatment time showed no obvious changes (P＜0.05). CONCLUSION：C2-ceramide could directly induce apoptosis in human colon carcinoma HT-29 cells in vitro，and C2-ceramide could inhibit the ERK pathway without activating SAPK/JNK pathway during this process.

OBJECTIVE:  To analyze the gene expression in colon cancer including non-metastasized and already metastasized using cDNA gene chip. To screen cell adhesion genes in colon cancer metastasis-associated genes. METHODS：The cDNAs reversely transcribed from the mRNA derived respectively from one non-metastasized and already metastasized were labeled with Cy3 and Cy5 prior to hybridization with the gene chip with 16k genes. The acquired was analyzed by software. Genes associated with cell adhesion and their function were analyzed. RESULTS：There were significant differences in gene expression profiles between non-metastasized and metastasized. When the fold change criteria were set to be≥5 or ≤-5 fold，26 genes were differentially expressed，15 genes were significantly up-regulated，including CD44，ICAM1，NCAM，HMGB1，SELL，CHRNA5，CEACAM6，VCAM1，HMGA2， PECAM1，CEACAM1，CD18，ITGAL，TGFB1，ICAM-3；and 11 were down-regulated with CD99， CADM1， CD82， F11R，SELE，CD226，TSLC1，PTB，CAR，JAM-2 and PTEN included.  CONCLUSION： Colon cancer metastasis requires multiple genes to be involved. It is therefore important to use gene chip technology to screen cell adhesion among the genes associated with metastasis in colon cancer.

OBJECTIVE: To study the effects of Fas in combined treatment of TRAIL(tumor necrosis factor-related apoptosis-inducing ligand) and arsenic trioxide(As2O3)-induced apoptosis in human gastric cancer SGC-7901 cells. METHODS: SGC-7901 cells were cultured in vitro, Sense and Antisense SGC-7901 cells were obtained from transfection of sense and antisense oligo nucleic acid, respectively. Untransfected, Sense and Antisense cells were treated with 0.5 μg/ml As2O3+0.2 μg/ml TRAIL, respectively. Cell proliferation was evaluated by MTT assay after 24, 48 and 72 h; cell colony morphologies were examined under inverted microscope after 48 h; apoptosis rate measured by DAPI staining and flow cytometer; and Fas, FADD and Parp expression determined by Western blot. RESULTS: Treatment by Fas antisense oligo nucleic acid transfection decreased the number of dead cells as detected by microscopy, exerted cell growth inhibition and As2O3+TRAIL-induced apoptosis effects. The expressions of Fas，FADD and activated Parp were all down-regulated (P<0.05). CONCLUSION: Fas signaling pathway may be important in the process of SGC-7901 apoptosis induced by combined treatment of As2O3 and TRAIL.

OBJECTIVE: To detect the acute oral toxicity/pathogenicity of trichoderma wettable powder (WP)，and to explore the application of PCR method in the pathogenicity of microbial pesticides.  METHODS：56 Wistar rats were randomly divided into a control group and exposed groups with 28 rats in each group and half male and half female. Trichoderma WP was selected as the test sample. The rats of exposure group were treated with 108 spores by gavage. Animals of control group were gavaged with normal saline. At the 1st，7th，14th and 21st day after exposure，stools were collected，then rats were sacrificed and the kidneys，liver，heart，and other organs were eviscerated. DNA of the tissue samples were extracted，then amplified with PCR. The symptoms of poisoning including mortality and body weight of animals were recorded. Dead animals were dissected and histopathological examination were performed. RESULTS： Only the amplification products of stools on the 1st day appeared positive but not on the 7th，14th and 21st days.  The amplification products of the remaining organs did not appear positive. No mortality was observed after exposure . In the histopathological examination no pathological changes were found. CONCLUSION： The trichoderma was found to exist only in the gastrointestinal tract，and was gradually excreted，It did not infect the animal’s tissues and organs，suggesting the test sample had no pathogenicity in rats.  PCR method could effectively detect the excretion of the test substance，with a good specificity which could be used as a detection method for oral toxicity/pathogenicity of microbial pesticide.

OBJECTIVE:  To study four key enzyme complexes in the mitochondria that contribute to vitamin E succinate (VES)-inhibited cell growth in human gastric cancer cells SGC-7901. METHODS：Gastric cancer cells SGC-7901 were grown in vitro. Cells were treated with rotenone(ROT)，thenoyltri?uoroacetone(TTFA)，antimycin A(AA) or sodium azide(SA) alone before treatment with VES for 2 h. Then cells were treated with VES at 20 μg/ml. MTT assay was used to evaluate cell growth. ROS was detected by confocal microscope. FITC/Annexin V was used to assess apoptosis. RESULTS：Cell growth inhibition induced by VES were obviously down-regulated after complex Ⅱ was inhibited by TTFA (5 μg/ml) (P<0.05). ROS induced by VES was all down-regulated after four complexes were inhibited respectively. Percentage of apoptosis induced by VES was all up-regulated after four complexes were inhibited respectively (P<0.05). However，levels of ROS and apoptosis were obviously lower than other three groups after complex Ⅱ was inhibited by TTFA (5 μg/ml) (all P<0.05). Cytochrome C and caspase-3 induced by VES were all down-regulated after cells treated with ROT，TTFA，AA or SA，respectively (P<0.05). Cytochrome C and caspase-3 were obviously down-regulated compared with other three groups (P<0.05). CONCLUSION：Key enzyme of complex Ⅱ (succinate dehydrogenase，SDH) was affected by VES. SDH induced ROS retention in cells. This may be the mechanism that VES contributes to vitamin E succinate-induced apoptosis in human gastric cancer cells.

OBJECTIVE:  To observe the effect of conditioned medium(CM) obtained from actinomycin D(ACTD)-exposed cells on the mRNA and protein levels of p53 and cell cycle distribution in bystander V79 cells and to explore the probable mechanism underlying the bystander effect induced by ACTD. METHODS：V79 cells were treated with 4.0 mg/L ACTD for 1 h. Then conditioned medium was collected at 4，8，12 and 24 h to culture bystander cells for 24 h to observe the bystander effect. RT-PCR method was used to detect the mRNA levels of p53 in bystander cells. Immunohistochemistry staining was adopted to determine the protein expression of p53. Flow cytometry was used to observe the cell cycle distribution of bystander cells. RESULTS：p53 mRNA levels in CM-treated bystander cells were higher than the control. With time p53 mRNA level gradually decreased from 4-12 h while increased in 24 h CM group. The protein expression of p53 indicated as mean gray values and integrated optical density increased in CM-treated groups except for 12 h CM group (P＜0.05). p53 expression reduced with time (4-12 h) then increased in 24 h CM group which was associated with p53 mRNA. The cell number in G0/G1 phase all increased in CM-treated bystander cells amongst which 4 h CM was the highest and decreased gradually with time till 12 h then reduced in 24 h CM. The cell number in S phase decreased in CM-treated bystander cells but there was no difference between various CM groups (P>0.05). The cell number in G2/M phase decreased significantly in 4 h CM heaviest then increased gradually close to control level at 12 h and reduced again in 24 h CM (P＜0.05). CONCLUSION：ACTD could induce bystander effect in V79 cells by from ACTD-exposed cells influencing p53 gene expression and interrupting cell cycle progression.

OBJECTIVE: To establish an allergic rhinitis model induced by ovalbumin (OVA) in guinea pigs and identify the characteristics in clinical symptoms，pathology and immunology. METHODS：Hartley guinea pigs were randomly divided into two groups：normal group and model group. The model animals were sensitized systematically with 0.8 ml suspension containing OVA，aluminium hydroxide gel and physiological saline (0.2 mg：0.3 ml：0.5 ml)，by intraperitoneal injection and topically sensitized with 60 mg/ml ovalbumin dissolved in physiological saline by intranasal instillation，20 μl each nostril，for 21 days. After an interval of one week，the sensitized animals were challenged with 60 mg/ml ovalbumin，50 μl/kg each nostril，once daily for a week and one time every two days for two weeks. The normal animals were treated with physiological saline instead of the OVA suspension and solution for intraperitoneal injection and intranasal instillation. The symptoms of allergic rhinitis，such as sneezing，nose rubbing，lacrimation， nasal congestion and rhinorrhea were observed after every challenge. The serum and the nasal mucosas were prepared for the detection of IgE and histamine contents and histological examination. RESULTS：Compared with normal group animals，guinea pigs in the model group developed typical clinical symptoms，indicated by the increasing numbers of sneezing and nose rubbing，higher levels of the histamine and serum IgE (P＜0.05).  Pathological alterations in the nasal mucosa included eosinophil infiltration，vasodilatation and epithelial exfoliation. CONCLUSION：An OVA-induced model of AR in guinea pigs was established，mimicking the clinical characteristics of human AR and can be used in the mechanism study and the drug development for AR.

OBJECTIVE:  To investigate the teratogenic effects of HX531 on Xenopus tropicalis embryos. METHODS：Xenopus tropicalis embryos were exposed to 1-500 μg/L HX531 for 48 h. The percentages of survival，body length and malformations were measured. RESULTS：HX531 decreased the survival of embryos by 83% at the concentration of 400 μg/L and by 97% at the concentration of 500 μg/L. The half lethal concentration (LC50) of HX531 at 48 h was 352 μg/L. The body length of embryos decreased by 18.4%-41.1% in 200-500 μg/L HX531-treated groups. After 48 h of exposure，the total percentages of malformations significantly increased and reached 100% in 200-500 μg/L HX531-treated groups. HX531 also led to multiple abnormal phenotypes，including abnormal brains and eyes，narrow fins，pericardial edema and bent tails. The half-maximal effective concentration (EC50) at 48 h was 79 μg/L and the teratogenic index was 4.4. CONCLUSION：HX531 was a strong teratogen and that RXR played an important role in the development of vertebrate embryos.

OBJECTIVE:  To investigate the reproductive and developmental effects of triazophos in rats over multiple generations. METHODS：P(parental generation)and F1 (filia 1 generation) parent rats were fed triazophos at doses of 0，0.210，1.456 and 7.167 mg/(kg·d) for 8 weeks before breading. The weights of main organs，breeding indexes and pathological changes were observed in P and F1 parents. The growth indexes of the offsprings were measured such as weight，body and tail lengths，and F1/F2 weanlings were sacrificed with reproductive organs weighed. RESULTS：The reproductive index was normal. The 1.456 and 7.167 mg/(kg·d) groups of P and F1，body weights of pregnant rats were decreased (P＜0.05). The 1.456 and 7.167 mg/(kg·d) groups of F1 and F2，the lengths of rat tail at d4，d7，d14 and d21 were shorter than those of control group (P＜0.05)，and the litter size and litter weights were lower than those of control group (P＜0.05). CONCLUSION：Under this experiment condition，triazophos had reproductive toxicity in rats. The harmful effects in the offsprings included delayed tail growth，reduced litter size and litter weight . No observed adverse effect level(NOAEL) over two generations was 0.210 mg/(kg·d). Low observed adverse effect level(LOAEL) over two generations was 1.456 mg/(kg·d).

OBJECTIVE: To investigate the effects of different combinations of sucrose concentration and freezing carrier on oocyte survival after thawing. METHODS：853 failed-fertilization oocytes after conventional IVF were collected and frozen with vitrification method in Center for Reproductive Medicine，Chengdu Jinjiang Hospital for Women and Child Health Care from June 2009 to May 2012. All oocytes were divided into four groups；group A：79 oocytes were vitrified with the cryoloop carrier and thawed using the conventional method；group B：580 oocytes were vitrified with the hemi-straw carrier and thawed using the conventional method；group C：121 oocytes were vitrified with the cryoloop carrier and thawed using the modified method；group D：73 oocytes were vitrified with the hemi-straw carrier and thawed using the modified method. After thawing for 2 h，the oocyte survival rates were compared among the groups mentioned above. RESULTS：The rate of oocyte survival in group C (97.52%) was significantly higher than those in group A (72.15%)，group B (52.24%) and group D (64.38%) (P< 0.01，respectively). The rate of oocyte survival in group A was significantly higher than that in group B (P< 0.05). No statistical difference in the rate of oocyte survival was found between other groups (P>0.05). CONCLUSION：The survival rate of MⅡ oocytes could be improved when oocytes were vitrified with the cryoloop carrier and thawed using the modified method.

OBJECTIVE: To study the mutagenic action of notoginseng flower extract on mice. METHODS：The mice were treated by oral gavages twice 24 hours apart with notoginseng flower extract of different doses (10 000，5 000，2 500 mg/kg). Animals were killed after 6 h of the last treatment，and then the micronucleus frequency (MNF) of polychromatic erythrocytes (PCE) in bone marrow were measured. In addition，at the above doses and groups another group of mice were treated by oral gavages once a day for 5 consecutive days. The mice were killed after 35 days of the initial treatment and the sperm deformity rate was observed. The two experiments also consisted of the negative control group (pure water) and positive control group (cyclophosphamide 40 mg/kg) at the same time. RESULTS：Every dosage group of notoginseng flower extract showed no mouse bone marrow micronucleus nor sperm abnormality effect. CONCLUSION： Under the present experimental conditions，notoginseng flower extract showed no mutagenic effect on mice.

OBJECTIVE: To identify the toxic effects of Alibendol on the maternal rat in late trimester of pregnancy，the growth and development，and the abilities of learning and reproduction of the offsprings． METHODS：SD pregnant rats were given Alibendol orally from gestational day 15 to weaning day 21. The experimental groups received 50，100 and 200 mg/(kg·d) of Alibendol．The growth，development and reproductive capacity of pregnant rats and offsprings were recorded. RESULTS：There were no obviouse toxic effects on F0 rats．For the body weight of fetal rats(F1)，there was a significant increase in low-dose group compared with control group at birth， day 4 after birth and mature male (P＜0.05).  However，a significant difference of fetal rats in ear path opening in low-dose group and pain threshold time in meddle-dose group compared with control group (P＜0.05) were observed too. But there was no dose-effect relationship. There were no differences between treated groups and control group in other indexes. CONCLUSION： Among the dose range used，Alibendol was safe to reproductive capability of female rats and growth of fetal rats．

OBJECTIVE: To study the teratogenicity of the natural effective component piperlonguminine Piper longum L. on normal Wistar pregnant rats. METHODS: Rats were randomly divided into 5 group. Stomach of the Wistar rat was irrigated with different doses of piperlonguminine suspension， high dosage 500 mg/kg， medium dosage 100 mg/kg， low dosage 20 mg/kg on the 6th to the 15th day during the gestation period. Stomach of the negative group was irrigated with the same volume CMC-Na solution. For the positive group，intraperitoneal cyclophosphamide 10 mg/kg was administered on the 11th day of gestation. Weights on the 0，3rd，7th，10th， 13th，16th，20th days were recorded. All were killed on the 20th day of gestation. The situation of the pregnancy， appearance of internal organs and bone morphology were examined. RESULTS: Compared to each dose group and negative group，the appearance and weight gain of pregnant rats， the appearance of the fetus， growth indicators and the degree of ossification of the occipital bone， parietal bone， sternum， ribs and other bones ; and the appearance of the liver， kidney， testis or uterus and other organs revealed no significant difference (P>0.05). During the experiment，2 fetuses were absorbed in the high dose group，but was insignificant when compared with the negative group (P>0.05). CONCLUSION: The lipid-lowering active ingredients of Mongolian drug piperlonguminine，under our experimental dose range， did not demonstrated obvious toxicity in pregnant mice and fetuses .

OBJECTIVE: The genotoxicity on human peripheral lymphocytes by organic pollutants in the Zhuozhang River was investigated. METHODS：The comet assay was conducted to detect DNA damage induced by the organic extracts of three typical sample sites. RESULTS：Within certain concentrations，the DNA damage in human peripheral lymphocytes was induced by the substances  tested and increased with the dose of the organic extracts. Compared with the negative control group，there were significant differences(P<0.01). The differences of DNA damage were also shown in different samples by multiplex comparison at the dose of 100 ml/tube，with decreasing activity as follows，Baoma>Huangnian>Shiliang. CONCLUSION：The organic pollutants in Zhuozhang River caused DNA damage  in human peripheral blood lymphocytes. This study also demonstrated that comet assay could be successfully applied to the genotoxicity monitoring of water organic extracts.