Objective: To study the effect of phytic acid (PHA) on 1,2-dimethylhydrazine (DMH) induced colorectal carcinogenesis in rats. Methods: Thirty four weeks old healthy male Wistar rats were randomly divided into two groups,control group given basal diet and PHA group given basal diet plus 2% sodium phytate solution. Both groups were injected DMH weekly for 20 w and then killed . Body weight, mortality, tumour incidence and average size, and natural killer(NK)cell activity were measured. Result: The mortality was lower in PHA group (P

Objective: To evaluate the effect of dietary fiber and phytic acid inositol hexaphosphate (IP6 or Insp6) on 1,2-dimethylhydrazine(DMH) induced colorectal carcinogenesis in Wistar rats. Methods: 86 four-week-old male Wistar rats were divided randomly into 6 groups and fed with either basal fiber free diet or the basal diet supplemented with 10% pectin, 10% cellulose, 2% Na-InsP6 supplemented water, 10% pectin in combination with 2% Na-InsP6 supplemented water, 10% cellulose in combination with 2% Na-InsP6 supplemented water. After four weeks, the rats were given a weekly injection of DMH (20mg/kg bw) for 20 weeks. The rats were killed after 26 weeks. The number of total macroscopically visible neoplasms was counted and the volume of individual neoplasmas was calculated. Proliferation cell nuclear antigen (PCNA) was analyzed. Results: There was no significant difference between the treatment group and the control group in the incidence of tumors. InsP6 significantly reduced the number of tumors in rats and tumor volume. Pectin and Pectin+InsP6 significantly increased the number of tumors in rats. The expression of proliferation marker PCNA was significantly down-regulated by InsP6 and significantly increased by pectin. Conclusion: A treatment regimen of 2% Na-InsP6 in drinking water was effective in significantly reducing the risk of colorectal cancer in Wistar rats. Diet supplemented with pectin could increase the risk of colorectal cancer.

Objective: To investigate the effects and mechanisms of inositol hexaphosphate(IP6)on cell cycle of HT-29 human colon carcinoma cell line. Method: HT-29 cells were exposed to various concentrations of IP6 for certain time. The effect of IP6 on cells proliferation was evaluated by MTT assay. Flow cytometric analysis was performed for cell cycle progression. Immunocytochemical stain was used to detect the expression of p53 and p21 protein. Results: A significant dose-dependent as well as time-dependent growth inhibition was observed in IP6-treated HT-29 cells, and associated with an increase in G1 arrest; Different concentrations of IP6 decreased the abnormal expressions of p53 gene and strongly increased the expression of p21. Conclusions: IP6 had an inhibitory effect on proliferation of HT-29 cells .and its mechanisms might be related to many factors, such as inhibiting the abnormal expression of p53 gene, inducing the expression of cell cycle inhibitor p21 which block the cell cycle.

Humans ; Hyperplasia ; etiology ; Male ; Middle Aged ; Prosthesis Failure ; Stents ; Tomography, Optical Coherence ; adverse effects ; Tunica Intima ; pathology

A rapid and sensitive method has been developed for the simultaneous determination of four selenium species Se(Ⅵ), Se(Ⅵ), selenomethionine, and Se-methylselenocysteine in Se-enriched yeast by liquid chromatography-hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS). The isolation of the analytes from yeast samples was accomplished by proteaseⅩⅣ and trypsin enzymatic digestion. The target compounds were separated on a PRP-X100 anion exchange column and analyzed by HG-AFS. The mobile phase was 20 mmol/L (NH4)2HPO4. Good linearity was obtained for all the selenium species, with linear correlation coefficients higher than 0. 9996. The LODs of the four species were between 0. 5 and 5. 0 μg/kg. Average recoveries for the four analytes were in the ranges of 82 . 5%-101 . 2%, with intra-and inter-day RSD lower than 8. 6% and 14. 5, respectively. The proposed analytical method is simple, sensitive, with low operation cost, making it applicable for the determination of the selenium species in Se-enriched feeds.

Objective To explore the effect of different doses of dobutamine on acute lung injury (ALI) in rabbits with septic shock and to clarify the possible mechanism.Methods The rabbits model of septic shock was made by cecal ligation and puncture combined with intravenous injection of endotoxin,70 male New Zealand white rabbits were randomly divided into five groups (14 rabbits in each groups):shamc operation group (group A),ALI group (group B),dobutamine low-dose group (group C),dobutamine medium-dose group (group D) and dobutamine high-dose group (group E),7 rabbits from each group were sacrificed 3 h and 6 h after septic shock.The level of cyclic adenosine monophosphate (cAMP) in lung tissue was detected by ELISA.The expression of aquaporin 5 (AQP5) protein was determined by western blotting.The wet to dry weight (W/D) ratio was measured.The pathological and ultrastructural changes of lung tissue were evaluated by optical microscopy and electron microscope,and lung injury score was assessed.The differences among the different groups were analyzed by one-way ANOVA (LSD test).Results The level of cAMP and expression of AQP5 protein in lung tissue at 3 h and 6 h were dramatically lower in group B than those in group A (3.53 ±0.43) pmol/mLvs.(21.18 ±0.62) pmol/mL; (0.44 ± 0.04) pmol/mLvs.(0.99±0.06)pmol/mL; (2.71±0.56)pmol/mLvs.(21.78±0.62)pmol/mL; (0.29 ±0.05) pmol/mLvs.(0.91 ±0.06) pmol/mL; all P ＜0.001,while the W/D ratio was obviously higher in group B than those in group A (all P ＜0.001).Compared with group B,the level of cAMP and AQP5 protein expression in lung tissue were significantly increased at 6 h in group C (8.48 ±0.61) pmol./ mLvs.(2.71±0.56) pmol/mL,P＜0.01; (0.49 ±0.04) pmol/mLvs.(0.29 ±0.05) pmol/mL,P=0.001 and at3 hand6 hin groupDandE (10.86±0.66) pmol/mLvs.(3.53±0.43) pmol/mL; (0.60±0.05) pmol/mLvs.(0.44±0.04) pmol/mL; (13.80±0.49) pmol/mLvs.(2.71±0.56) pmol/mL; (0.64 ± 0.03) pmol/mLvs.(0.29 ± 0.05) pmol/mL; (15.57 ± 0.60) pmol/mL vs.(3.53±0.43) pmol/mL; (0.91 ±0.05) pmol/mLvs.(0.44 ±0.04) pmol/mL; (19.30±0.42) pmol/mL vs.(2.71 ±0.56) pmol/mL; (0.89 ±0.08) pmol/mL vs.(0.29 ±0.05) pmol/mL; all P ＜ 0.01,while the W/D ratio in group E was decreased obviously (P =0.002; P =0.001).Compared with group C and D,the level of cAMP and the expression of AQP5 protein at 3 h and 6 h in group E increased significantly (all P ＜0.01.The pathological and ultrastructural changes of lung tissue were more intensive in group B than those in group A and the lung injury scores were obviously higher (P ＜0.01).The degree of lung pathological and ultrastructural lesion was ameliorated after administration of dobutanmine.Additionally,histological scores decreased significantly (P ＜ 0.01).Conclusions Our study demonstrated that dobutamine could improve ALI induced by endotoxin,the mechanism of protective effect may involve in increasing the level of cAMP and up-regulating the AQP5 protein expression,and high-dose dobutamine had better effects.

BACKGROUND:Bone marrow mesenchymal stem cells(BMSCs)differentiating into neural cells is an effective way of cell therapy of nervous system disease.However,the methods used nowadays still need to be improved.OBJECTIVE:To induce the differentiation of rhesus monkey BMSCs into neuron-like cells by using sonic hedgehog factor.METHODS:Rhesus monkey BMSCs differentiating into neuron-like cells was induced by typical retinoic acid and sonic hedgehog factor.Rhesus monkey BMSCs were isolated and cultured by density gradient centrifugation method.Cell growth was observed under an inverted phase contrast microscope and cell growth curve was determined using MTT assay.Flow cytometry was performed to characterize the phenotype of BMSCs,and immunohistochemistry was utilized to assess differentiated cells.Ultra-structure of the differentiated cells was observed by transmission and scanning electron microscopes.RESULTS AND CONCLUSION:Rhesus monkey BMSCs cultured in vitro were identified by flow cytometry,with high homogenicity.Following sonic hedgehog factor disposal for 7 days,differentiated cells were mainly positive for neurone specific enolase,neurofilament protein,Tau and glial fibrillary acidic protein(GFAP).Image statistical analysis found that in sonic hedgehog factor scheme,neural stem cells marker Neetin positive rate was significantly higher compared with the rstinoic acid scheme(P＜0.01).GFAP-positive rate was greater in the retinoic acid scheme than in the sonic hedgehog factor scheme(P＜0.05).Results indicated that sonic hedgehog factor scheme is an effective pathway of rhesus monkey BMSC differentiation into neuron-like cells.

BACKGROUND: Present studies have demonstrated that during neural development, differentiation of neural stem cells (NSCs) was affected by various regulatory factors from surrounding microenvironment. Sonic hedgehog (Shh) is a key induction signal during neural fetal development, and can be an effective inductor to regulate differentiation of neural cells. OBJECTIVE: To investigate the signal transduction pathway of SHH for differentiation of rhesus monkey bone marrow mesenchymal stem cells (BMSCs) into of neuron-like cells by sonic hedgehog factor. METHODS: Rhesus monkey BMSCs were isolated and cultured by conventional density gradient centrifugation. BMSCs in the induction group were treated with L-DMEM containing FGF2, B27 and fetal bovine serum for preinduction of 24 hours, and then with DMEM supplemented with 0.5 μmol/L retinoic acid or 400 μmol/L SHH for 8 days. Non-induced cells served as control group. Following labeling with neuron enolase, positive cells were screened by flow cytometry. RT-PCR and Western-blot were used to detect SHH- and retinoic acid-induced cell membrane receptor and intracellular signal protein changes. RESULTS AND CONCLUSION: SHH specific membrane receptor Ptc, retinoic acid specific receptor RARα, signal protein molecule ptch1 and Smad expressed in normal cells. Ptc expression upregulated in SHH-induced cells. High expression lasted for a long time with induction time, which was significantly stronger compared with the retinoic acid and control groups (P < 0.01). Intracellular ptch1 protein molecule expression showed similar tendency as this, but could not induce upregulation of RARα expression. During induction, retinoic acid-stimulated cells did not activate Ptc pathway. Four days following induction, RARα expression upregulated and lasted till 6 days, but there were no significant differences. No significant change in ptch1 expression was determined. SHH- and retinoic acid-induced cell Smad molecule expression upregulated, but no significant difference was determined. Results verified that SHH-induced scheme participated in cell induction and differentiation by persistently activating its specific receptors. However, there was no significant receptor pathway crossing between retinoic acid-induced and SHH-induced schemes.

An evaluation system including experiment preparation,experiment process,com-prehensive design of experiment,experiment skills and written exam was established in order to adapt to the experimental teaching reform in our school. Experimental preparation assessment was to evaluate‘preview and self-evaluation report’prepared and submitted by students. Experimental process assess-ment was to evaluate students' classroom performance and experiment reports. Assessment of compre-hensive design experiments was to evaluate the overall participation of students. Skill assessment was consisted of oral test and experiment operation test. Final written examination,mainly consisting of subjective questions,emphasized on student's flexible use of knowledge and ability to solve practical problems. The evaluation system of promoting student's learning and teacher's teaching through the examination not only fully arouse student's attention on experiment,but also make teachers more ob-jectively and really understand students' learning situation and the teaching effectiveness.

6cm,the recrudescenc rates when factors were male,mild or moderate malignant,stage of Dukes C,distance from tumor to anus 4～6cm were significantly higher(?2=4.53,P