Prospective cohort study of comprehensive prevention to gastric cancer

AIM: To evaluate the preliminary effects of comprehensive prevention of gastric cancer in Zhuanghe County epidemiologically.METHODS: Stratified sampling and cluster sampling were applied to define the intervention group and the control group. The prospective cohort study was used for evaluating the effect of preventing gastric cancer. The relative risk (RR)and attributable risk percent (AR %) of intervention on gastric cancer death were calculated. Potential years of life lost (PLYY) of the disease was analyzed, and the RR and AR %of PYLL were calculated. Survival analysis was applied among the screened patients.RESULTS: In the first 4 years after intervening, the relative risk (RR) of intervention on death was 0.5059 (95 % CI:0.3462～0.7392,P＜0.05) with significance statistically. AR %of the intervention on death was 49.41%. The RR of intervention on cumulative PYLL was 0.6778 (95 % CI:0.5604～0.8198,P＜0.05) with statistic significance. AR %of the intervention on cumulative PYLL was 30.32 %. The four-year survival rate of the screened patients was 0.6751(95 % CI: 0.5298～0.9047).CONCLUSION: The initiative intervention results showed that the intervention approach used in the trial was effective, it reduced mortality and increased survival rate, and alleviated the adverse effect of gastric cancer on the health and life of screened population.

Chemical Characteristic of Bioactive Polysaccharides Isolated from Ornithogalum caudatum Ait

A water soluble crude extract prepared from Ornithogalum caudatum Ait. (OCA) showing a high immunomodulating activitiy was isolated and characterized by virtue of gel filtration and column chromatography. The presence of the monosaccharides has been established by the chemical analysis. The quantitative analysis of the alditol acetate derivatives of them showed the ratios of the monosaccharides analyzed by means of GC respectively. The concentrations of protein(280 nm) and carbohydrate(496 nm) were detected respectively. The information of the molecular weight from the pure polysaccharide was obtained by several standard Dextrans from the Sephadex chromatography.

Fusion expression of Helicobacter pylori neutrophil-activating protein in E.coli

AIM: To produce a recombinant protein rMBP-NAP, which was fusionally expressed by Helicobacter pylori(H pylori)neutrophil-activating protein (NAP) and E. coli maltosebinding protein (MBP) and to evaluate its immunoreactivity and immunogenicity.METHODS: Neutrophil-activating protein gene of H pylori (HP-napA) was subcloned from the recombinant plasmid pNEB-napA, and fused to MalE gene of expressing vector pMAL-c2x. The recombinant plasmid pMAL-c2x-napA was confirmed by restriction enzyme digestion, and then transformed into E. coli TB1. Fusion protein rMBP-NAP was induced by IPTG and identified by SDS-PAGE analysis.Soluble rMBP-NAP was purified by amylose affinity chromatography. Immunoreactivity and immunogenicity of the fusion protein were evaluated by animal experiment,Western blotting with human H pylori anti-sera.RESULTS: E.coli TB1 carrying recombinant plasmid pMAL-c2x-napA was constructed and led to a high efficiency cytosol expression of fusion protein rBMP -NAP when induced by IPTG.The molecular weight of rBMP-NAP was about 57 kD,accounting for 37.55% of the total protein in the sonicated supematant of E. coli TB1 (pMAL-c2x-napA). The purity of the fusion protein after one-step affinity chromatography was 94% and the yield was 100 mg per liter of bacterial culture.The purified fusion protein could be specifically recognized by both human anti-sera from clinical patients with H pylori infection and rabbit sera immunized by rMBP-NAP itself.CONCLUSION: Recombinant protein rMBP-NAP might be a novel antigen for vaccine development against H pylori.

Lipoxygenase—mediated N—demethylation of imipramine and related tricyclic antidepressants

The ability of soybean lipoxygenase to mediate the N-demethylation of imipramine and related drugs in the presence of hydrogen peroxide was examined.Under optimal assay conditions,Vmax values of 14 to 18 mol formaldehyde·min^-1·mol^-1 enzyme were observed.An inhibition of formaldehyde and desipramine formation by nordihydroguaiaretic acid confirmed the lipoxygenase involvement.The blockade of the reaction by glutathione,dithiothreitol butylated hydroxyanisole (BHA) and butylated hydroxytoluene(BHT) indicated the generation of a free radical intermediate from imipramine.Desipramine,trimipramine,clomipramine,and diltiazem,but not amitriptyline and doxepin,were also oxidized,albeit at a lower rate.Collectively,the evidence gathered in this study suggests,for the first time,that tricyclic antidepressant drugs may undergo lipoxygenase-catalyzed N-demethylation.

Effects of Fat-soluble Extracts From Vegetable Powder and β-carotene on Proliferation and Apoptosis of Lung Cancer Cell YTMLC-90

Objective The aim of this investigation was to study the effects of fat-soluble extracts from vegetable powder (FEFVP) and P-carotene on the proliferation and apoptosis of cultured YTMLC-90 lung cancer cells. Methods The lung cancer cells were continuously exposed to a broad range of concentration of FEFVP and P-carotene. The proliferation was evaluated in MTT test. The induction of apoptosis was evaluated by morphological change, DNA fragmentation analysis, and DNA content analysis combined with flow cytometric analysis. Results Both FEFVP and P-carotene were found to inhibit cell proliferation and to induce morphologic changes consistent with apoptosis in YTMLC-90 cancer cells, including cellular shrinkage, chromatin condensation and nuclear fragmentation. DNA agarose gel electrophoresis showed DNA fragmentation 'ladder'. Flow cytometric analysis revealed decreased DNA content and the presence of a sub-G1 apoptotic peak. Conclusion These findings are consistent with the induction of apoptosis. Moreover, the effects of FEFVP are stronger than those of P-carotene. FEFVP inhibits the growth of YTMLC-90 probably via the induction of apoptosis cancer cells.

Synthesis,Structure Characterization and Biological Activity of Adenine Salt of 12-Phosphotungstic Acid

A novel adenine(Ade) salt of 12-phosphotungstic acid was synthesized and characterized by elemental analyses,IR, 1H NMR,CV and single crystal X-ray diffraction. The compound crystallized in a triclinic system with a space group P 1 and a =1.3108(3) nm, b =1.3515(3) nm,c =1.3870(3) nm, V =2.0217(7) nm 3,Z =1,R _1=0.0391,wR _2=0.0959. The structure unit of the complex was constructed from [HPW_ 12 ·O_ 40 ] -,(C_5H_6N_5) + and C_3H_7NO,which further extends to form a novel three-dimensional host-guest network via hydrogen-bonding interactions. The anti-tumor activity of the compound was examined in two human tumor cell lines in vitro .

Screening of scFvs against cTnI from Phage Display Antibody Library and Their Expression in E.coli Rosetta

The single chain variable fragments of antibodies(scFvs) against cTnI were screened from the phage display antibody library by using cTnI as the target antigen. After four rounds of panning, four clones(H2, G5, A9, B9) from the phage display antibody library were verified to show higher binding affinity for cTnI by ELISA and to contain the variable region genes of the light and heavy chains of scFvs by sequencing. The variable region genes of scFvs H2 and G5 were successfully amplified by polymerase chain reactions(PCR) and cloned into expression vector pPELB and expressed as a soluble protein in E.coli Rosetta, whose expression yield was about 2% of total proteins. The expressed proteins were purified by nickel(Ni) affinity chromatography and a single band is shown in the position of 28 kDa on SDS-PAGE. The western blot analysis result verifies that the expressed scFv proteins are capable of binding with monoclonal antibodies against hexa-histidine, indicating that they are hexa-histidin-tagged aim proteins. The immunoassay demonstrates that the expressed scFv proteins are able to specifically react with cTnI molecules. The association constant(K_A) values range from 1.2×10 4 to 1.7 ×10 5 L/mol that are correspondent to the affinities of polyclonal antibodies against cTnI from rabbits. These antibodies can be valuable reagents for the immunoassay of cTnI.