BACKGROUND AND AIM: To explore the mechanism of toxic action as well as to provide basic data for prevention of dermatitis medicamentosa_like of trichloroethylene(DMLT). The changes of mitochondrial functions in keratinocytes after exposure to trichloroethylene and the protective effect of pre_treatment with ginkgo biloba extract (EGb) were performed. MATERIALS AND METHODS: Human keratinocytes were co_cultured with different concentrations of trichloroethylene for different times. To observe the protective effect of EGb, cells were pre_incubated with different concentrations of EGb for 2 hours, and then treated with 2.0 mmol/L TCE. MTT method was used to investigate cell viability and inhibition ratio of mitochondrial enzyme. ATPase activity was measured to indirectly find out the variation of mitochondrial energy production. Changes of mitochondrial membrane potential were assessed by flow cytometry(FCM) after dual_staining with rhodamine 123 and propidium iodide. RESULTS: Trichloroethylene decreased keratinocyte viability, ATPase activity and mitochondrial membrane potential while enhanced inhibition ratio of mitochondrial enzyme. Pre_treatment of EGb for 2 hours could dose_dependently attenuate the cytotoxicity of 2.0 mmol/L TCE, and the lowest effective protective dose of EGb was 10 mg/L(compared with 2.0 mmol/L TCE with no EGb pre_treatment,P<0.01). The mitochondrial functions in the human keratinocytes preincubated with 150 mg/L EGb prior to TCE could return to normal condition (compared with solvent control, P>0.05). CONCLUSION: Trichloroethylene induced changes of mitochondrial functions in keratinocytes through dose and time_dependent manner, and ginkgo biloba extract could protect mitochondria against functional damage.

BACKGROUND AND AIM: Effects of periplocin from cortex periplocae (CPP) on proliferation and apoptosis of human esophageal carcinoma cell and its relation with Rb protein expression were investigated. MATERIALS AND METHODS: Esophageal cancer cell line TE_13 was co_incubated with different concentrations of CPP and cell proliferation was measured by MTT method. Cell morphology changes were examined by light microscope. Apoptosis was studied by flow cytometry. Rb expression was analyzed by immunohistochemistry method. RESULTS: CPP could inhibit the proliferation of TE_13 cells significantly in a dose and time dependent manner (P<0.01). After treatment with CPP, TE_13 cells showed morphologic changes of apoptosis. The expression of Rb was enhanced. CONCLUSION: CPP could inhibit the growth of TE_13 cells，the mechanism might be related to enhanced Rb expression.

BACKGROUND AND AIM: To investigate the effects and mechanisms of sulindac on mice xenograft, angiogenesis and biologic behaviour of gastric cancer. MATERIALS AND METHODS: Twenty athymic xeograft models with human gastric cancer cell BGC_823 were established and randomly divided into four groups,sulindac treated group (12 mg/kg),sulindac preventive group(8 mg/kg),vitamin C group(Vit C 20 mg/kg) and control group. Immunohistochemistry was used to detect the expression of COX_2,VEGF and MVD in xenografts cells.TUNEL technique was applied to examine apoptosis. RESULTS: The growth of xenografts were markedly depressed by two weeks of sulindac treatment.The xenografts volume of sulindac_treated group and sulindac_preventive group were (57.2±3.2) mm3 and (77.8±6.7) mm3,respectively significantly smaller than those of vitamin C group and control group[(120.6±12.17) mm3 and (87.7±29.0) mm3 respectively,P<0.05]. The xenograft volume maintained the difference until the experiment was finished. In vitamin C and control groups, the xenograft, apoptosis indexes(3.5 and 3.1,respectively ) were lower than those in sulindac_treated and sulindac_preventive groups(11.6 and 10.4, respectively,P<0.05).Compared with vitamin C and control groups(19.6 and 20.7), the microvessel densities were remarkedly reduced in sulindac_treated and sulindac preventive groups(5.4 and 9.0, respectively, P<0.01). Compared with vitamin C and control groups,the expression of COX_2 and VEGF decreased markedly in sulindac_treated and sulindac_preventive groups (P<0.05). CONCLUSION: Sulindac had obvious anti_cancer effects in vivo against gastric cancer. The mechanism of its'anti_cancer effects may include suppressing proliferation, inducing apoptosis, and reducing angiogenesis.

BACKGROUND AND AIM: In order to investigate the anti_proliferative activity against HeLa cell line and to explore the possible mechanism of three natural compounds: 7_hydroxy_ 2_octen_5_olide (1), methyl 5,7_dihydroxy_2 (Z)_octenoate (2) and 3,7_dihydroxy_5_octanolide (3) isolated from leaves of Euscaphis japoneca Kantiz. MATERIALS AND METHODS: The anti_proliferative effects of the three compounds on HeLa cells were tested by MTT assay in vitro. The apoptosis induced by above three compounds was studied by FCM. The morphological changes of HeLa cells were examined by transmission electron microscope. RESULTS: Compounds 1 and 2 exhibited dose_dependent anti_proliferative activity on cultured HeLa cells. The concentrations of compounds 1 and 2 resulting in 50％ survival rates (IC50) for HeLa cells were 49.34 μmol/L and 24.53 μmol/L, respectively. Comparing with the control group, the apoptosis rate and the expression of P53 in HeLa cells were markedly higher for compound 1 group (P<0.01). The morphological changes of HeLa cells incubated with compound 1 showed chromatin condensation, marginal and nuclear fragmentation. CONCLUSION: 7_Hydroxy_2_octen_5_olide and methyl 5, 7_dihydroxy_2 (Z)_octenoate isolated from the leaves of Euscaphis japoneca Kanitz could inhibit the proliferation of HeLa cells in vitro. Its anti_prolifrative activity might be associated with upregulating the expression of P53 and inducing the occurrence of apoptosis.

BACKGROUND AND AIM: To evaluate the expression of UDP_ glucuronosyltransferase (UGT) 2B subfamily and hepatic nuclear factor1α(HNF1α)in colorectal cancer, and to explore its significance in colorectal tissue carcinogenesis. MATERIALS AND METHODS: RT_PCR was used to determine the mRNA levels of four UGT isoforms and hepatic nuclear factor1α(HNF1α) in 32 samples of colorectal cancer and 14 normal colorectal sambles.UGT2B protein was measured by western blot analysis and immunochemistry was used for HNF1α protein. RESULTS: Polymorphic regulation of UGT2B isoforms expression was found in colorectal tissue; compared to control group, UGT2B4 mRNA level of the 32 samples of colorectal cancer and its surrounding healthy tissue was not significantly different(P>0.05). UGT2B7,UGT2B15 mRNA level were significantly down_regulated in colorectal cancer and its surrounding healthy tissues when compared to control group(P<0.05). UGT2B7 protein level was significantly decreased in colorectal cancer and its surrounding healthy tissues(P<0.05). Compared to control group, mRNA and protein levels of HNF1α were not significantly changed in colorectal cancer and its surrounding healthy tissues(P>0.05). CONCLUSION: Decreased expression level of UGT isoform may be one cause of colorectal tissue carcinogenesis. As an upstream regulator of UGT genes, mRNA and protein levels of HNF1α were not significantly changed. This may be related to complicated control mechanisms in vivo.

BACKGROUND AND AIM: To investigate the correlation between infection of helicobacter pylori L_form (Hp_L) and gastric carcinoma, and to investigate the effect of Hp_L on angiogenesis of gastric carcinoma. MATERIALS AND METHODS: Hp_L was examined in 130 patients with gastric carcinoma and 50 control group by Gram staining and immunohistochemical stain SP method. The latter method was also used to detect the CD34 expression to measure MVD,and their relationship with clinicopathologic factors were analyzed. RESULTS: The positive rates for Hp_L form in gastric carcinoma was 70.00％(91/130) by Gram staining, which was similar to the positive rate(73.85％) by immunohistoc_hemical stain (P>0.05). Hp_L infection rate in gastric carcinoma was much higher than in control group (67.69％ vs 24.00％,P<0.05). MVD in gastric carcinoma was significantly higher than control groups (P<0.05). The MVD in Hp_L positive gastric carcinoma correlated with vessel invasion, depth of invasion, metastasis to the paragastric and distant lymph nodes but not with tumor size (P<0.05). CONCLUSION: Hp_L infection correlated with occurrence of gastric carcinoma. Hp_L infection may be an important promoting factor in angiogenesis of gastric carcinoma and related to invasion and metastasis.

BACKGROUND AND AIM: To investigate the association of precancerous lesion development with cell cycle characteristics and expressive activities of genes such as bax, bcl_2 and PCNA and the relationship between these and p53mt expression in nasal and nasopharyngeal epithelia of TgN(p53mt_LMP1)/HT mice containing human mutant p53 (p53mt) gene and EB virus latent membrane protein 1 (LMP1). MATERIALS AND METHODS: The pathohistological changes in nasal and nasopharyngeal epithelial tissues in the fourth generation transgenic positive mice and negative mice aged 12 months were determined by H_E staining methods, cell cycle characteristics of nasal and nasopharyngeal epithelia were detected by flow cytometry, and expression activities of apoptosis_related genes such as p53mt, bax, bcl_2 and that of cell proliferation_related gene PCNA were assayed by immunohistochemistry in the same tissue samples. Then, a correlative analysis was carried out among the different sets of data to investigate the pathogenetic association of naturally developed precancerous lesion with the expression activities of apoptosis_ and cell proliferation_related genes in the target organs. RESULTS: The rates of precancerous lesion in nasal and nasopharyngeal epithelia of positively transgenic mice and negative ones were 63.64％ and 0 respectively, with very significant difference between them(P<0.01). Compared with that of negatively transgenic mice, the number of nasal or nasopharyngeal epithelial cells in G0/G1 phase was markedly decreased, and that in S and G2/M phases were obviously increased, with proliferation index (PI) enhanced significantly (P<0.01). The expression activities of p53mt, bcl_2 and PCNA were raised and that of bax was decreased significantly, with an increased ratio of bcl_2/bax (P<0.01). CONCLUSION: The expression of p53mt in TgN(p53mt_LMP1)/HT mice may cause the inhibition of bax expression at first,followed by the increased expression of bcl_2 and PCNA, with an elevated ratio of bcl_2/bax. Thereafter, the activity of apoptosis would be reduced and cellular proliferating potentiality strengthened,as measured by PI. As a result, precancerous lesion may occur in nasal and/or nasopharyngeal epithelium.

BACKGROUND AND AIM: To explore the significance of genetic and environmental risk factors for ethnic esophageal cancer in Huaian. MATERIALS AND METHODS: A community_based pair_matching case_control study was performed. 97 patients with newly diagnosed, untreated ESCC and 97 healthy controls matched in age, sex, origin and residence were surveyed by questionnaire in the study. Logistic regression analysis was used to evaluate the risk of genetic and environmental factors for esophageal cancer. RESULTS: The conditional logistic regression analysis showed that the increased risk for esophageal cancer was significantly associated with a family history of gastrointestinal tumor(OR=4.203), environmental pollution around the residential area(OR=2.202), irregular meals(OR=1.988), and history of drinking non_tap water(OR=2.024). The protective factors of esophageal cancer included intake of eggs(OR=0.633) and tea_consumption (OR=0.669). Population attributable risk (PAR) of each factor was 12.9％ with environmental pollution around the residential area, 34.4％ with irregular meals, 25.0％ with lack of intake of eggs, 42.7％ with lack of tea_consumption, 21.4％ with history of drinking non_tap water, and 30.6％ with family history of gastrointestinal tumor. The combined PAR of the six factors was 86.6％. CONCLUSION: Genetic susceptibility factors play an important role in the high incidence of esophageal cancer in Huaian county. The influence of genetic factors should be considered in the surveillance and comprehensive prevention of esophageal cancer in Huaian.

ACKGROUND AND AIM: To investigate the alteration of reactive oxygen species (ROS) level ,the activity of nuclear factor kappa B (NF_κB)and the expression of C_IAP2 in apoptosis of HL_60 cells induced by As2O3 (arsenic trioxide,ATO) . MATERIALS AND METHODS: HL_60 cells were treated with 7.5 μmol/L As2O3 alone or together with 500 μmol/L N_acetyl_L_cysteine(NAC) for 12 and 24 h. Intracellular ROS level was measured by flow cytometry (FCM), the activity of NF_κB p65 was determined by Western blot and the expression of C_IAP2 mRNA was determined by semi_quantitative RT_PCR. RESULTS: After treatment with 7.5 μmol/L As2O3 for 12 and 24 h, the level of ROS increased obviously, and the relative amount of NF_κB p65 were 49.3％±4.4％ and 23.1％±2.1％,and the relative expressions of C_IAP2 mRNA were 72.9％±5.8％ and 59.3％±4.4％.After co_treatment of 7.5 μmol/L As2O3 and 500 μmol/L NAC for 12 and 24 h in HL_60 cells, the level of ROS was decreased, the relative amount of NF_κB p65 were 65.4％±4.9％ and 37.1％±3.4％, and the relative expressions of C_IAP2 mRNA were 81.1％±5.8％ and 73.7％±4.9％. CONCLUSION: As2O3 could increase the level of ROS in HL_60 ,inhibited the activity of NF_κB and down_regulated the expression of C_IAP2 mRNA. Moreover, co_treatment of As2O3 and NAC could protect HL_60 cells from apoptosis through decreasing reactive oxygen species (ROS), prohibiting partly the suppression of the activity of NF_κB and the expression of C_IAP2 mRNA.

BACKGROUND AND AIM: To make rats' chronic renal function impairment model through adenine induce. MATERIALS AND METHODS: 16 male SD rats were randomly divided into control group and renal function impairment model group. Distilled water was administered orally to rats in the control group and adenine suspension 100 mg/(kg·d) was given to establish the model of renal function impairment. The experiment lasted 12 weeks. Time_dependent changes in serum creatinine (Cr), urea nitrogen (BUN) levels and creatinine clearance rate (Ccr) were monitored. Renal morphological changes were examined. RESULTS: Cr, BUN levels in the model group were higher and Ccr was lower significantly than control group. Renal function impairment was aggravated with extended experimental time. Pathological and ultramicrostructural changes were observed. CONCLUSION: Chronic renal function impairment model in rats could be successfully induced by adenine suspension.

BACKGROUND AND AIM: To study the effects of dibutyl phthalate (DBP) exposure on learning and memory of the F1 generation rats, as well as the expression of spinophilin gene in the hippocampus. MATERIALS AND METHODS: Pregnant Wistar rats were randomly divided into 3 experimental groups and control group, each treated with 25、75、225 mg/kg DBP or vehicle only(corn oil) by gavage since gestation day 6 to postnatal day 28. The general effects of DBP on the pregnant rats and the offspring were observed. The expression level of spinophilin gene in hippocampus of the 21 day_old male pups was determined by Real Time RT_PCR, and the learning and memory abilities of the one month_old male pups was evaluated through Morris water maze. RESULTS: No overt sign of toxicity was found in the dams, but the male pups in the high dose group showed shortened AGD and tail length(P<0.01). In the water maze test, latency to find a hidden platform was longer in the low dose group than that of control(P<0.05). The pups in the former group also spent less time in the target quadrant in the probe test(P<0.01). Moreover, the expression of spinophilin gene was up_regulated 35.7％ in this group as compared with control(P<0.05). CONCLUSION: In utero and lactational DBP exposure decreased learning and memory of the F1 generation rats, associated with up_regulated spinophilin expression in the hippocampus, suggesting a causal relationship.

BACKGROUND AND AIM: To purify and investigate the enzyme kinetic properties of rabbit plasma semicarbazide_sensitive amine oxidases(SSAO), using methylamine as substrate. MATERIALS AND METHODS: Formaldehyde, an oxidative deamination product of methylamine, was analyzed by HPLC. Rabbit plasma SSAO was purified by chromatography with DEAE_sepharose FF(eluted with 30 mmol/L and then 100 mmol/L sodium phosphate buffers, all at pH 7.0), then assayed and Michaelis_Menten analyzed. RESULTS: Two fractions of plasma (labeled as peak A and peak B) obtained were catalytically active with methylamine as substrate. The kinetic parameters Km and Vmax of plasma were(1.83±0.13) mmol/L and(0.12±0.003)nmol/(min·mg), respectively. The Km of peak B (2.05±0.43)mmol/L was lower than that of peak A (3.14±0.63)mmol/L, the Vmax of the peak B (1.46±0.10) nmol/(min·mg) was lower than that of peak A (2.85±0.20) nmol/(min·mg). CONCLUSION: In rabbit plasma, there were two kinds of SSAO, which could catalyze the oxidative deamination of methylamine into formaldehyde, had significantly different kinetic parameters.

BACKGROUND AND AIM: To study the combined toxic effects of phoxim(Pho) and methomyl(Met) on reproductive function in male rats. MATERIALS AND METHODS: The adult SD rats were randomly divided into 4 groups (including a control and three treated groups).Various daily dose of Pho(1/50 LD50, 25.20 mg/kg), Met(1/50 LD50, 0.47 mg/kg), Pho＋Met(25.20＋0.47 mg/kg) were given to rats by gastric gavage for 60 successive days. 2×2 factorial analysis was used in the experiment. Body weight gain and organ weights were determined. Sperm counts, the spermatozoon survival rate and the aberration rate of the spermatozoon were measured. The activities of SOD, GST and the GSH and MDA level were ascertained in both serum and testiculer samples. The activities of ACP, LDH and ATP were assessed in testicular samples. The testosterone level was measured in serum samples and the histomorphology changes of testis and epididymis were examined. RESULTS: ① There was synergism between Pho and Met on the sperm counts, spermatozoon survival and aberration rates, as well as testosterone level. ② There was antagonism between Pho and Met on GSH level and the SOD activity in serum; on GSH level of SOD activity and GST in testicle as well as the activity of ACP and Na＋_K＋_ ATPase in testicle. ③ Testicular pathology showed shed spermatogenic cells in seminiferous tubules, the layers and counts of spermatogenic cell reduced and disordered cellular arrangement in testicular tissue. There was no pathological changes in the epididymis. CONCLUSION: Markedly increased toxic effect of the pesticide mixture was found on sperm counts, spermatozoon survival and aberration rates and testosterone level. The combined exposure to Pho and Met can produce enhaced toxic effects on reproductive function in male rats.

BACKGROUND AND AIM: In order to detect glycosides of tripterygium wilfordii Hook. f(GTW)male mice genital system toxicity,which can provid rationale and evidence to use safely during the period of clinical treatment. MATERIALS AND METHODS:30 Kunming male mice were randomly divided into five groups with 6 mice in each,three dosage groups (antifertility_dosage groups [10 mg/(kg·d)], medium_dosage groups[20 mg/(kg·d)] and remedy_dosage groups[30 mg/(kg·d)], one negative control and one positive control group.This essay introducts micronucleus of bone marrow,sperm deformity,chromosome aberration,and analyze of synaptonemal complex, approaching effect of GTW to male mice in genesis toxicity. RESULTS: Micronuclei of bone marrow cell indicates 20 mg/(kg·d) group and 30 mg/(kg·d) group of GTW generate somatocyte inherent toxicity, were significantly higher than that of negative control. Every_dosage group of GTW cause sperm deformity, do harm to primary spermatocyte chromosome aberration and synaptonemal complex, were significantly higher than that of negative control. CONCLUSION: GTW had somatocyte inherent and reproductive cell toxicity, reproductive cell was higher sensitivity than somatocyte ,which cann′t apply under large_dosage for a long time as the antifertility or the therapy drug.

BACKGROUND AND AIM: To evaluate the polymeric immunoglobulin receptor/secretory component(pIgR/SC) protein levels in the bronchoalveolar lavage fluid (BALF) samples derived from lung cancer patients, and explore its clinical significance. MATERIALS AND METHODS: BALF samples were obtained from 52 lung cancer patients from the affected side and also the matched healthy side in 18 patients, and were analyzed for the pIgR/SC protein levels by enzyme_linked immunosorbent assay (ELISA). RESULTS: In the 18 cases, the mean pIgR/SC value in BALF of the affected side was significantly greater than that of the matched healthy side(P=0.019). In 52 lung cancer patients, the protein level of pIgR/SC in BALF was significantly higher in adenocarcinoma patients than that in squamous cell carcinomas (P=0.014). The pIgR/SC levels in BALF of patients with squamous cell carcinoma with lymph node invasion were significantly higher than that of patients without (P=0.012). CONCLUSION: The high level of pIgR/SC in airways is likely to indicate host response to tumor carcinogenesis. Furthermore the pIgR/SC level in BALF may reflect the histological difference of lung cancers. In squamous cell carcinoma, pIgR/SC may be involved in lymph node invasion.

BACKGROUND AND AIM: To explore the expression of glucose transporter1(GLUT1) and Annexin_1 in endomentrial carcinoma , and investigate their correlations to clinicopathologic features of endometrial carcinoma. MATERIALS AND METHODS: The expression of GLUT1 and Annexin_1 were examined in 65 specimens of endomentrial carcinoma,27 endometrial dysplasia and 21 proliferative endometria by S_P immunohistochemistry. Their correlations to clinicopathologic features of endometrial carcinoma were analyzed . RESULTS: The positive expression rates of GLUT1 in proliferative endometrium,endometrial dysplasia and endometrial carcinoma were 28.6％,59.3％ and 81.5％ respectively,showing an increasing trend. There was a significant difference between groups (P<0.05). The positive expression rates of Annexin_1 in the above three groups were 85.7％,55.6％ and 49.2 ％, respectively. The rates were significantly lower in endometrial carcinoma than in normal endometrium(P<0.05).The higher expression of GLUT1 was correlated to histological grade and myometrial invasion, but not to pathologic stage,lymph node metastasis and histological type. The lower expression of Annexin_1 was not correlated to any of those features.Negative correlation was found between GLUT1 and Annexin_1 expression(r=-0.596,P=0.000). CONCLUSION: under_expression of Annexin_1 and over_expression of GLUT1 may be involved in carcinogenesis and development of endometrial carcinoma. This may contribute to early diagnosis and prognostic evolution of endometrial carcinoma.

BACKGROUND AND AIM: To determine the acute oral toxicity and genetic toxicity of Flammulina velutipes polysaccharide. MATERIALS AND METHODS: Acute oral toxicity test, Ames test，micronucleus test of polychromatic erythrocytes in bone marrow， mice sperm shape abnormality test were used．RESULTS:The acute oral LD50 of Flammulina velutipes polysaccharide was greater than 10 g/kg in mice．The results of genetic toxicity tests were all negative. CONCLUSION: Genetic toxicity of Flammulina velutipes polysaccharide was not found, and it was classified as non_toxic agent．