Objective To study whether Helicobacter pylori CagA protein can control gastrin gene expression and the detailed mechanism. Methods First, pcDNA3. 1ZEO (-)/cagA7 was transfected into gastric cancer cell lines AGS and SGC-7901 cells. At the same time, culturing the Helicobacter pylori NCTC11637 and infecting AGS and SGC-7901 cells with it. Next, in the infected and transfecled AGS and SGC-7901 cells, respectively adding the JAK2 signaling pathway inhibitor AG490 and the ERK signaling pathway inhibitor U0126 to inhibit the two signaling pathway. Untreated gastric cancer cells and empty vector transfected cells as the control. Using real-time fluorescence quantitative PCR to detect the levels of gastrin mRNA in transfected and infected cells. Results After AGS and SGC-7901 cells were transfected with pcDNA3. lZE0(-)/cagA7 and infected with NCTC11637, the results showed that the expression of gastrin mRNA increased significantly (P ＜ 0. 05) in transfected and infected cells as compared with the control group, but after adding the inhibitor AG490 and U0126 respectively, the expression of gastrin mRNA decreased significantly(P＜0.05). Conclution These results suggest that CagA may up-regulate the expression of the gastrin gene, and CagA is one of the important proteins in regulating gastrin gene expression. The ERK/MAPK and JAK/STAT signaling pathways may be involved in controlling of gastrin gene expression by CagA.

Noroviruses (NoVs) are one of the most important foodborne viral pathogens worldwide. Shellfish are the most common carriers of NoVs as they can concentrate and accumulate large amounts of the virus through filter feeding from seawater. Shellfish may selectively accumulate NoVs with different genotypes, and this bioaccumulation may depend on the season and location. Our previous studies found various histo-blood group antigens (HBGAs) in shellfish tissues. While HBGAs might be the main reason that NoVs are accumulated in shellfish, the detailed mechanism behind NoV concentration and bioaccumulation in shellfish is not clear. Here we review current research into NoV bioaccumulation, tissue distribution, seasonal variation, and binding mechanism in shellfish. This paper may provide insight into controlling NoV transmission and decreasing the risks associated with shellfish consumption.
Animals ; Caliciviridae Infections ; transmission ; virology ; Food Contamination ; analysis ; Foodborne Diseases ; virology ; Humans ; Norovirus ; classification ; genetics ; isolation & purification ; physiology ; Shellfish ; virology

Objective To construct a recombinant human adenovirus type 3 ( HAd3 ) vector ex-pressing one major epitope of dengue virus type 1.Methods The gene encoding the envelope protein (304-314 aa) of dengue virus type 1 was inserted into the hypervariable region 1 ( HVR1 ) of HAd3 hexon by using overlap PCR.The recombinant gene was cloned into the shuttle plasmid, then linearized with AsisⅠrestriction enzyme and co-transformed into Escherichia coli BJ5183 strains with the digested backbone plas-mid for homologous recombination.The recombinant plasmid pBRAdΔE3GFP-DENV1 was transfected into AD293 cells to rescue recombinant adenovirus strains (rAdΔE3GFP-DENV1).ELISA and Western blot as-say were performed to evaluate the humoral responses induced in BALB/c mice after the immunization with rAdΔE3GFP-DENV1 strains.Results The recombinant adenovirus strains were successfully rescued. ELISA and Western blot assay showed that the antibodies in serum sample could recognize dengue virus type 1 strains.Conclusion The recombinant adenovirus strains expressing the epitope of dengue virus type 1 were successfully constructed.This study provided evidence for the development of multivalent vaccines against dengue virus.

AIM To construct differentiation subtractive cDNA library of human leukemia HL 60 cells induced by diallyl disfuld using suppression subtractive hybridization (SSH) technique and to clone differentiation associated genes in leukemia cells. METHODS Poly A + RNAs were isolated from HL 60 cells induced by dially disfuld and were reversely transcripted into double strand cDNAs (as tester). After the cDNAs were digested into short cDNAs with blunt ends, they were divided into two groups and were ligated to the special adaptor 1 and adaptor 2R, respectively. The tester cDNAs were then hybridized with driver cDNA from normal HL 60 cells and the products were amplified twice by nested PCR technique. The PCR products were ligated with pGEM T plasmid vectors and were transformed into E.coli JM109. The inserts of cDNAs were analyzed by restrictive enzyme EcoR I. RESULTS Subtractive cDNA library was constructed successfully and efficiently. Random analysis of 200 clones with enzyme restriction showed that about 84 5% clones contained 100～600 bp cDNA inserts. It can help clone novel genes associated with differentiation and explore the molecular mechanism of leukemia differentiation induced by diallyl disfuld. CONCLUSION DADS can induce human leukemia HL 60 cells differentiation, and suppression subtractive hybridization (SSH) technique is an effective method to isolate those differentially expressed genes.

Aim To observe effect of DADS on the differentiation of gastric adenocarcinoma cells and acetylation of human gastric cancer tumor cell transplantable histone.Methods Human gastric adenocarcinoma heterotransplantable tumor model was constructed through subcutaneously injecting MGC803 cells to nude mice.Morphologic changes of xenograft tumor cells were observed with optical microscope,the influence of DADS on xenograft tumor cells generationcycle distribution,the expression of p21~(WAF1) protein,histone H3 and and H4 acetylion were analyzed with flow cytometry and Western blot.Results There was obvious growth inhibitory effect of xenograft tumor while abdominal injection dose were 100 and 200 mg?kg~(-1)DADS;cells density and heteromorphism decreased after treated with DADS.Flow cytometry analysis revealed that treating xenograft tumor cells with increasing quantities of DADS increased the percentage of cells in the G_2/M phase.The proportion of xenograft tumor cells in the G_2/M phase after treatment with 100 mg?kg~(-1) and 200 mg?kg~(-1) DADS was 2.22 and 3.37 times of that in NS group.Western blot analysis showed H3 acetylion increase along with G_2/M arrest of xenograft tumor cells by DADS.DADS didn′t influence the expression level of H4 acetylion;the expression of p21~(WAF1) protein in xenograft tumor increased along with the increases in the concentration of DADS.Conclusion DADS cansignificantly inhibit the growth of human gastric carcinoma xenograft in BALB/C nucle mice and induce cell differentiation,which might be related with up-regulation of histone a cetylization and p21~(WAF1) protein level.

Objective Accumulating reports have suggested that hepatic stellate cells (HSCs) exhibit immunosuppressive ability and may be responsible for the occurrence and development of hepatocellular carcinoma (HCC).The mechanisms through which HSCs affect T-cell-induced adaptive immune responses and the relationship with the regulatory T cells (Treg cells) were studied.Methods We isolated HSCs from wildtype mice to demonstrate the influence of HSCs on T-cell proliferation and explored their effect on Treg cells through mixed leukocyte reactions (MLRs) in vitro.Results We found that activated HSCs could induce T-cell hyporesponsiveness in adaptive immune response by inhibiting the proliferation of T cells andincreasing the quantity of Treg cells.Conclusion Activated HSCs may lead to hypoergia of T cells in adaptive immune reaction and up-regulate the expression of Treg cells,thus facilitating immunotolarance.

ObjectiveTo explore the clinical effects of cold therapy in treatment of inflammatory hemorrhoids.MethodsSixty patients were separated into two groups according to the visiting sequence with 30 cases each.The treatment group accepted cold therapy,meanwhile the control group took the tablets diosmin and accepted hot compress with 50％ magnesium sulfate.ResultsThe symptoms evaluation score was ( 10.5 ± 1.3 ) scores and (6.4 ± 1.2) scores before and after treatment in treatment group,while ( 10.3 ±1.4) scores and(9.4 ± 1.3) scores in control group,there was no significant difference before treatment between two groups (P＞ 0.05 ),but there was significant difference after treatment between two groups (P＜0.05).After 3 days treatment,cure rate was 60.0％(18/30),eifficient rate was 90.0％(27/30) in treatment group,while 10.0％ (3/30),53.3％ ( 16/30 ) in control group,there were significant differences between two groups(P＜ 0.05).ConclusionCold therapy is good for inflammatory hemorrhoids.

Objective To investigate the effects of Trim34α on the activation of luciferase reporter gene containing NF-κB promoter induced by adaptor proteins TAB2. Methods The total RNA was isolated from HeLa cells. After amplification with RT-PCR, the target sequences were cloned into 5'-Flag-pcDNA3.1 (+) vector. The recombinant vector was confirmed by restriction enzyme digestion, colony PCR and sequencing. It was transfected into HEK293T cells to detected Trim34α expression by Western blot. Simultaneously, the effects of Trim34α on the NF-κB activation induced by TAB2 were determined by dual-luciferase reporter assay. Results Restriction enzyme digestion, colony PCR and sequencing confirmed the vector was constructed successfully, furthermore it expressed Trim34α protein in HEK293T cells. Moreover, trim34α could form high-molecular-weight oligomeric protein, and here we called it trimsome. Interestingly, dual-luciferase assay showed that Trim34α could effectively block TAB2-induced NF-κB activation. Conclusion Trim34α was involved in negative regulation of TAB2-induced NF-κB activation and could form high-molecular-weight oligomer.

Objective To test a full range of processes of sample collection,preparation,measurement and analysis by conducting the intercomparison of gamma-ray spectrometry measurement and analysis of radionuclides among key laboratories,so as to facilitate the development of gamma-ray spectrometry measurement and analysis technology.Methods To complete the collection and preparation of soil samples by Chinese Center for Disease Control and Prevention (CDC) laboratory and to measure and analyze the content in two soil samples of 214Pb,214Bi,208TI,228Ac,40K and 137Cs by three laboratories using gamma-ray spectrometry.Results The value calculated by any two laboratories were less than 1 in terms of assessment standards agreed by these three laboratories and based on the activity concentrations and the total uncertainty reported from them.The measurement results from our lab were acceptable.Conclusions Measurement results from these three laboratories are in agreement to some extent.This intercomparison activity has tested the analytical ability of the three laboratories and raised the level of our laboratory in testing homogeneity of sample preparation.

Objective To discuss the efficacy of application combination Of minimal immunosuppressive drugs in chronic allograft nephropathy after renal transplantation. Methods Data were drawn from the First Hospital of Tsinghua University.From September 1,2004 to July 1,2006,31 cadaver kidney transplantations were performed using triple immunosuppression with tacrolimus(n=31)and MMF plus steroids before using new strategy.The new strategy is Rapamycin+tacrolimus+MMF+Prednisone.The serum ereatinine,GFR(ml/min/1.73 m2)and 24-hours urine protein before and after 12 months of using lOW dose combination of calcineurin inhibitors,MMF,Rapamune,Predsone and Q80 were recorded.During this time,the concentration of tacrolimus,rapamune were monitored as well. Results After 12 months follow-up,the serum creatinine of 28 patients were decreased from(300±21)μmol/L to(215±38)μmol/L.GFR(ml/min/1.73m2)was elevated from 42.54±2.95 to 49.98±3.05.Three patients whose serum creatinine was 416-464μmol/L had to take hemodialysis.The 24-hours urine protein(g)of 31 patients below 0.8 g did not increase urine protein during follow-up.One patient's 24-hours urine protein(g)increased from 0.95 to 1.29.The patient and graft survival rate was 100%(31/31),90.3%(28/31)respectively.The rapamune main side effect was hyperlipidemia. Conclusions Rapamune and low dose Tacrolimus+Myeophenolate Mofetil+Corticosteroid could be a safe treatment.It may improve renal function in chronic allograft nephropathy.