BACKGROUND＆AIM: To establish a convenient and feasible animal model of vestibular dysfunction in mice. MATERIAL AND METHODS： A dose of 400 mg gentamicin /(kg·d) was given to mice subcutaneously twice daily for 15 consecutive days. Vestibular function was assessed by contact righting reflex as well as the head tilt and swimming behavior, and histopathology of the animals' saccular and utricular macula or crista ampullaris was examined. RESULTS：Time of contact righting reflex was prolonged, scores of head tilt and swimming behavior were higher than control. Meanwhile, damage of saccular and utricular macula or crista ampullaris of mice were confirmed by histopathological examination. CONCLUSION： This is a convenient and feasible model of experimental vestibular dysfunction in small animals for research on pharmacodynamics of prophylactic drugs for motion sickness and vertigo.

BACKGROUND ＆ AIM: To study the expression of pEgr-TNFα induced by ionizing irradiation in stably transfected esophageal cancer cells and to study the inhibition effects of pEgr-TNFα combined with ionizing irradiation on esophageal cancer cells. MATERIAL AND METHODS: Esophageal cancer cell line EC9706 was transfected with pEgr-TNFα plasmids and selected through G418 to get stable expression cells. TNFα expression was detected by ELISA. The inhibition effect of pEgr-TNFα was observed after different doses of X-ray irradiation. RESULTS: pEgr-TNFα plasmids were transfected into EC9706 cells with stable expression. High dose and low dose X-ray irradiation could all enhance the expression of TNFα, about 6－6.3 times of control group (P<0.001). Cells stably transfected was given 0.075 Gy and 2 Gy X-ray irradiation, number of cells was less than non-transfected group and sham group (P<0.01～0.001) 8 d later. CONCLUSION: pEgr-TNFα gene-radiotherapy can significantly inhibit the growth of esophageal cancer cells in vitro.

BACKGROUND & AIM: To construct the RNA interference vector which can specially induce the expression silence of human DNA repair gene hMGMT. MATERIAL AND METHODS: The hMGMT specific siRNA expression cassette was made by two steps PCR, and then linked with pUC19 to get pU6-MGMTi. Co-transfected with pEGFP-C1 into 16HBE and screened by G418. The expression level of mRNA and protein was detected by RT-PCR and Western Blot respectively. RESULTS: hMGMT specific RNA interfere vector pU6-MGMTi was constructed successfully. Transfected 16HBE cell’s MGMT mRNA and protein expression level were dramatically suppressed. CONCLUSION: MGMT expression silence cell line was built by RNA interfere expression cassette and co-transfection technology, which offered condition for studying the gene function of MGMT.

BACKGROUND ＆ AIM: To investigate the in vitro effects of ferulic acid, caffeic acid, vanillic acid, aspirin, salicylic acid on DNA damage using the single cell gel electrophoresis(comet assay). MATERIAL AND METHODS: Lymphocytes from healthy volunteers were pre-incubated with these phenolic compounds at various concentrations(50,100, 500 μmol/L) or 500 μmol/L only, the comet assay was performed on challenged or unchallenged cells in parallel, oxidant challenge being induced by 10 min exposure to 40 μmol/L H2O2. RESULTS: Compared to positive control, the tail moments were all reduced after pretreatment of the cells with different phenolic acids at different concentrations and then challenged with H2O2. The protective effects of ferulic acid and vanillic acid were greater, and the upward trend was shown with the increasing dose. Whereas aspirin, salicylic acid, especially caffeic acid at high dose (500 μmol/L) exhibited greater tail moment than low doses(50 μmol/L, 100 μmol/L). The tail moment showed a marked increment compared to control group after treatment of the cells with caffeic acid (500 μmol/L) at 37 ℃ for 30 min (without H2O2 challenged), whereas aspirin(500 μmol/L) and salicylic acid(500 μmol/L) showed no effects. CONCLUSION: Protective effects were showed by all five phenolic compounds at different concentrations. The protective effects of ferulic acid and vanillic acid increased with dose. However caffeic acid showed less protective effects. In fact, incubating lymphocytes with 500 μmol/L caffeic acid alone actually induced DNA damage.Aspirin and salicylic acid also exhibited better antioxidant effects, but whether they have pro-antioxidant effects deserve further investigations.

BACKGROUND ＆ AIM: Betulin is an important triterpene. We investigated the antitumor activity of betulin, extracted from the bark of silver birch (Betula platyphylla Suk). MATERIAL AND METHODS: Betulin was isolated from dry powder of the bark of silver birch (Betula platyphylla Suk) by using ethanol circumfluence, decompress concentration and methanol-chloroform recrystallization. The inhibition rate on EC109 cell growth was detected by MTT (Methylthiazoletetrazolium) method, after the oesophageal cancer EC109 cells have been treated for 48h with different doses of betulin. RESULTS: With the increasing doses of betulin, the inhibition rate of EC109 cell growth was increased, and their morphological characteristics were changed significamtly. The inhibition rate showed dose-dependent relation. CONCLUSION: Betulin had potent inhibiting effects on EC109 cells growth in vitro.

BACKGROUND ＆ ATM: To establish a rapid automatic scoring method for micronucleated polychromatic erythrocytes in mice bone marrow by flow cytometer. MATERIAL AND METHODS: Treating male KM mice with cyclophosphamide(CP) and counting micronucleated cells in bone marrow and peripheral blood either by a single-laser flow cytometer(FCM)acridine orange(AO)or Giemsa, comparing the results from different methods. RESULTS: Contour configuration histograms of FL1(indicating DNA fluorescence)vs. FSC(Forward angle scatter，indicating cell size) were used to show clearly total nucleated cells(TNC)， polychromatic erythrocytes(PCE), normochromatic erythrocytes(NCE), micronucleated polychromatic erythrocytes(MNPCE) and micronucleated normochromatic erythrocytes(MNNCE)populations. CP-treated fMNPCE and fMNNCE displayed good dose-response relationship. Good correlation was demonstrated between the FCM and manual MNPCE data (r=0.973，P<0.01；r=0.978，P<0.01). C0ONCLUSION: The AO-FCM method developed in our department is applicable to detect micronucleated erythrocytes in mice bore marrow.

BACKGROUND & AIM: We applied a new SV40-based shuttle vector pSP189 and African Green kidney cells(Vero E6 cell line)，which constitute a shuttle vector /mammalian cell system to detect mutagenesis in vitro induced by animal drugs olaquindox. MATERIAL AND METHODS: The vector plasmids were induced by olaquindox , then were transfected into vero cells. After recovering from cells, the plasmids were transfacted into MBM7070 and selected mutant colonies. The mutation in 24 plasmids was determined by dideoxy sequence analysis. RESULTS: The lesion induced by 6.6µg•ml-1olaqiunxox included a large number of base substitutions, in addition to tandem base deletion. Point mutation frequencies for in vitro modified plasmids were dramatically increased over the spontaneous background lever, among which 70% of base substitutions happened on the site of G:C base pair, the predom in the mutation was G:C-T:A or G:C-A:T. Olaqiundox-induced mutations on the SupF shuttle vector did not distributed random, and had mutation hot spots (155bp) and sequence specificity, which were contained in the sequence 5’-NNTTNN-3’, mutation was easy appeared in N site, and tandem base deletion and rearrangement focused on ANGGCCNAAA sequence. CONCLUSION: Olaquindox induced the plasmid shuttle vector mutagenesis.

BACKGROUND ＆ AIM: To observe the teratogenicity of Arbidol hydrochloride(Ar) orally administered to rats. MATERIAL AND METHODS： Doses of Ar 100、330 and 1 000 mg/(kg·d) were given orally to the 6－15 d pregnant rats. The rats were sacrificed on day 20. RESULTS: The reduced parental body weight and number of live fetuses, as well as reduced pup weight and length, delayed ossification were observed in the rats treated with the daily dose of 1 000 mg/(kg·d). Compared with vehicle control group, no external, visceral and skeletal malformations were seen in these infant rats. No adverse effects were observed in the rats treated with the daily doses of 100 and 330 mg/kg. CONCLUSION: Ar 330 mg/kg was a safe dose in pregnant rats and 1 000 mg/kg had embryotoxic but without teratogenic effects in rats.

BACKGROUDA＆AIM: Previous research results showed that magnetic field treatment on rice can change its some hereditary characteristics such as germination,maturation of seed and fructification rate etc,but no reports on chromosomal structure at present.We chose model plant,Oryza.sativa as materials for studing the mechanism of magnetic field effect on genetic characteristics. MATERIAL AND METHODS: After 800,1 000,1 500,1 800 and 2 300 mT magnetic field treatments on Oryza.Sativa chromosom for 20 min,ASG method was adopted for chromosome staining,chromosome aberrations were examined with light microscope. RESULTS: Except 800 mT,some chromosomal aberrations were observed after 1 000,1 500,1 800 and 2 300 mT magnetic field treatment.These results showed that lasting magnetic field treatment could lead to chromosoal aberratinos such as no-centromere,centromere-loop and inverse B-loop on chromosome,and provide biochemical evidence for the effects of magnetic field on chromosome. CONLUSION: Chromosomal aberrations caused by lasting magnetic field changed the genetic characteristics of O.sativa.

BACKGROUND ＆ AIM: To investigate the teratogenicity of erythromycin propionate-N- acetylcysteinate(EPAC) in rats. MATERIAL AND METHODS: SD rats were used in this teratogenicity study. On days 6－15 of pregnancy, SD rats received the drug in three doses of 75, 200, and 400 mg/kg. RESULTS: After oral administration of EPAC, pregnant rats in the groups of 200 and 400 mg/kg doses had signs of anorexia, and decreased activity. The results showed that the body weight gains of pregnant rats on days 10－13 were significantly lower in the groups of the doses of 200 and 400 mg/kg than in the control group, and recovered to normal after the withdrawal of the drug. The fertility of pregnant rats was not different in each group compared with the control group. No morphologic malformation of rat fetuses was observed in each group compared with those in the control group. The body length and tail length of rats were not significantly different in each group. No abnormality was observed in the growth of bones and internal organs in rat fetuses in all groups. CONCLUSION: EPAC in the doses of 200 and 400 mg/kg has maternal toxicity in pregnant rats, characterized by decreased body weight and anorexia, but has no fetal toxicity or teratogenicity.

BACKGROUND & AIM: This study was designed to elucidate the acute toxicity and immune modulation of Rhubarb ecoction in mice. MATERIAL AND METHODS: LD50 test , The mice were randomly divided into four groups:the negative control,1000mg/kg,2500mg/kg,5000mg/kg, 0.1~0.2ml/10g,1/d,10d, They were fed with various doses of Rhubarb decoction. The complement activities and erythrocyte CR1 adherence function were measured by using trace fast plate complement activity assay and complement activating yeast rosette test, respectively.NK cell activities were measured by improved MTT method.RESULTS:LD50 was about 8043mg/kg.Rhubarb enhance NK cell activities and erythrocyte CR1 adherence function and decrase complement activity. CONCLUSION: Rhubarb enhance cell immunity ,promoting immune cell proliferation ;It activate NK cell activities and Erythrocyte CR1 adherence activity.It assistant therapy as an adjuvant medicine.

BACKGROUND & AIM: To probe the mechanism of potential carcinogenal effect on lung lesion in sprangue dawley (Sd) rats inhaled Cooking Siritch Oil Fume. MATERAIL AND METHODS: The pathomorphological variants of lung tissue were observed by microscope, Expression of P53 and P16 protein of Lung Tissues were observed by SABC method. Test animal were randomly divided into 3 test groups, such as exposure group dynamically inhaling (44.44±18.68) mg/m3 CSOF ,positive group pouring BaP and negative control group inhaling fresh air. All of the determinations and observations were done at the day 20th, 40th, 60th during the experiment. RESULTS: The main pathological changes of lung tissues in exposure group were inflammation, adenic metaplasia were also found. The expression of P53 protein was positive in exposure group, the expression of P16 protein decline. CONCLUSION: The cooking siritch oil fumes can induce the lung tissue damage.

BACKGROUND ＆ AIM: To explore the DNA damaging effect of lead acetate on germ cell of mice in vivo and in vitro. MATERIAL AND METHODS: Mouse testicular germ cells were exposed to 50, 100, 500 and 1 000 μmol/L lead acetate in vitro, and then exposed to 12.5, 25, and 50 mg/kg of lead acetate for five days by intraperitoneal injection. Mouse testicular germ cells were collected on the 6th day. Comet assay was used to detect the effects of the damage and electrophoretic mobility distance of DNA. RESULTS: In vitro DNA lesion were detected in all 4 lead acetate treated groups(compared with negative control P<0.01), and was dose_related (visual scoring r=0.5114, P<0.01, tail moment r=0.407, P<0.01). In vivo DNA damage was detected in 3 lead acetate treated groups (compared with negative control P<0.01), and was also dose_related (visual scoring r=0.4848,P<0.01, tail moment r=0.5314, P<0.01).CONCLUSION: Lead acetate is genotoxic to mouse testicular germ cells, by inducing mouse testicular germ cell DNA damage.

BACKGROUND ＆ AIM： To evaluate the inhibiting effects of Genistein on B16 melanoma cells. MATERIAL AND METHODS： B16 melanoma cells were treated with 10,30,90 μmol/L of Genistein for 1～4 days. Growth curve test served as the index to reflect proliferative activity of B16 melanoma cells.Morphological changes of B16 melanoma cells, melanin content in the supernatant of melanoma cells，distribution of cell cycle were assessed by Flow Cytometery. RESULTS: Genistein at the concentration of 10,30,90 μmol/L inhibited significantly the growth of B16 melanoma cells in a dose dependent manner with statistical significance (P<0.05 vs control). Interestingly, Genistein induced the differentiation of B16 melanoma cells and decreased the melanin granule and number of cells. Flow cytometry showed that numerous cells were arrested at S phase of cell cycle. CONCLUSION： Genistein at the dose of 10,30,90 μmol/L significantly induced differentiation of B16 cells while inhibiting their growth.

BACKGROUND ＆ AIM： To explore the mechanism of Helicobacter Pylori (H.pylori)-related gastric carcinogenesis and overexpression of the multidrug-resistant-1 (MDR-1) gene-encoded P-glycoprotein (P-gp) via examining Cyclooxygenase-2(COX-2) and P-gp expression in the affected gastric mucosa. MATERIAL AND METHODS: 155 chronic gastritis specimens (30 chronic superficial gastritis specimens, 40 chronic atrophic gastritis specimens, 45 intestinal metaplasia specimens, 40 dysplasia specimens) and 80 gastric carcinoma specimens(40 intestinal type and 40 diffuse type) were selected. COX-2 and P-gp expression were detected by immunohistochemistry. H. pylori infection was assessed by rapid urease test and histological examination(modified Giemsa staining). RESULTS: H.pylori infection rate，COX-2 positive expression rate and P-gp positive expression rate in intestinal-type gastric carcinoma specimens were significantly higher than those in diffuse-type gastric carcinoma specimens(P<0.01). Expression of COX-2 was positively correlated with H.pylori infection in chronic atrophic gastritis, intestinal metaplasia, dysplasia and intestinal-type gastric carcinoma(P<0.01). Expression of COX-2 was positvely correlated with that of P-gp in chronic superficial gastritis，chronic atrophic gastritis, intestinal metaplasia, dysplasia，and intestinal-type gastric carcinoma with H.pylori infection (P<0.01). CONCLUSION: H. pylori-dependent induction of COX-2 was associated with enhanced prodution of P-gp that might contribute to gastric tumourigenesis and resistance to chemotherapy.

BACKGROUND ＆ AIM: To explore the expression of cystatin M, a major cysteine protease inhibitor, in human breast cancer and its significance. MATERIAL AND METHODS: A semi-quantitative reverse transcription polymerase chain reaction and immunohistochemical methods were performed to evaluate the expression of cystatin M in cancerous and noncancerous tissues of fifty pairs of human invasive ductal adenocarcinoma of breast. The relationship between the expression of cystatin M gene in human breast carcinoma and clinilcopathological features was analyzed. RESULTS: Reduced expression level of cystatin M gene mRNA and protein has been noted in breast carcinoma cells compared to adjacent noncancerous breast tissue (P<0.01). The lower experssion levels in breast carcinoma cells was related with clinicopathological features including lymph-node metastasis and TNM staging (P<0.05) but not with the histological grade nor the estrogen and progesterone receptor status (P>0.05). CONCLUSION: The expression of cystatin M gene mRNA and protein was reduced in human invasive breast carcinoma. Down-regulated expression of cystatin M in breast carcinoma might be associated with tumor invasion and metastasis.

BACKGROUND & AIM: To study the correlation of chemosensitivity no peripheral blood lymphocyte and tumor cells . MATERIAL AND METHODS: 3-( 4，5-dimethylthiazol-2-yl )-2, 5- diphenyltetrazolium bromide (MTT) method was used to test the sensitivity of the peripheral blood lymphocyte and the tumor cells of 32 patients with esophageal carcinoma to 9 kinds of anti-cancer drugs. RESULTS: The peripheral blood lymphocyte and the tumor cells were sensitive to chemotherapeutic drugs of 5-fluorouracilum (5-Fu),diamminedichloroplatinum（DDP），carboplatinum (CBP)，methotrexate (MTX) and cyclophosphamide（CTX），but not sensitive to adriamycin ( ADM) ,vincristin (VCR); There was alack of correlation by lymphocyte and tumor cells to Vp-16 , THP. CONCLUSION:There were no statistical differences in the rate of sensitivity to the above-mentioned drugs between the peripheral blood lymphocyte and the tumor cells (P>0.05).Peripheral blood lymphocyte may replace tumor cells in clinical chemosensitivity test

BACKGROUND ＆ AIM： The aim of this study was to investigate the correlation between dendritic cell(DC) and gastrointestinal stromal tumors(GISTs). MATERIAL AND METHODS： Eighty-six cases of the mesenchymal tumors in the alimentary tract were studied by light microscopy and immunohistochemistry. RESULTS： There were 22 dendritic cell stromal tumors (DCSTs)among the 75 cases of confirmed gastrointestinal stromal tumors. The patients were adults, ranging from 24 to 70 years(mean 47.4 year), 11 male and 11 female. The most common symptom was GI bleeding. The tumor size ranged from 1.5 cm to 10.0 cm in the maximal diameter. Microscopically, the tumors were composed of spindle cells (3 cases), epithelioid cells (8 cases) and of both cells (11 cases). Five cases were benign, 5 were borderline and 12 were malignant. Immunohistochemically, CD1α,CD14, CD117 and CD34 all showed diffuse strong expression. CONCLUSION: GISTs had a close association with dendritic cells,GISTs might have originated from the precursor dendriticd cells or GISTs differentiated into dendritic cells. The relationship between them deserves further studies.

BACKGROUND ＆ AIM: To study the effects of lutein on mutagenicity and antimutation anti-mutagenicity. MATERIAL AND METHODS: The studies were conducted with Ames test. RESULTS: In Ames test, the mutagenicity of Lutein group was no more than 2 times that of the control group. In test, comparing with positive group, Lutein groups could decrease the colonies in TA98 and TA100 strains. CONCLUSION: No mutagenicity was observed with lutein in this study .Moreover, we demonstrated that lutein possessed significant antimutagenic properties.

BACKGROUND & AIM: This study was undertaken to determine the potentially teratogenic effects of Pseudoephedrine to SD rats and to provide toxicological information. MATERIAL AND METHODS: SD pregnant rats were randomly divided into four groups: Pseudoephedrine 50、100、200 mg/kg and negative control. Conventional teratogenicity test was performed. Female rats was given Pseudoephedrine by gastric intubation at 50,100,200 mg/kg on days 6~15 of gestation. RESULTS: Adjusted weight gain of pregnant rats and body weight of fetuses were comparable to the control at 200 mg/kg. The incidence of dead rats was significantly increased at 200 mg/kg. CONCLUSION: Among the range of experiment doses, Pseudoephedrine was considered to have a maternal toxicity, embryo toxicity and teratogenic effects in SD rats.

BACKGROUND ＆ AIM: To explore the potential mutagenicity of emamectin benzoate. MATERIAL AND METHODS: The potential mutagenicity of emamectin was examined with Ames test, micronucleus test of polychromatic erythrocytes in bone marrow and chromosomal aberration test of spermatocytes in mice. RESULTS: The number of revertant colonies was no more than twice that of spontaneous colonies for each dosage group. Compared with the control group, there was no significant difference in the ratio of micronucleus and the ratio of chromosomal aberration for each dosage group(P>0.05). CONCLUSION: No mutagenicity of emamectin benzoate was found.