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

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 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.

Objective To detect expression of TEL-AML1 fusion genes in pediatric cases with acute lymphoblastic leukemia(ALL) and discuss the role of reverse transcriptase polymerase chain reaction(RT-PCR)and fluorescence in situ hybridization(FISH) in detection of t(12 ;21) and the clinical significance. Methods TEL-AML1 fusion gene was identified in bone marrow munonuclear cells from 31 newly diagnosed childhood ALL patients by NRT-PCR, FISH and conventional cytogenetic analysis (CCA). Results TEL-AML1 fusion gene was found in 7 out of 31 cases, accounting for 22.6 % in pediatric ALL, and 7 out of 31 cases accounting for 25.9 % in B-ALL Seven cases were found with t (12;21) by FISH and NRT-PCR. The incidence of the t(12;21) was 22.6 % in newly diagnosed pediatric ALLs. Conclusion It is concluded that TEL-AML1 rearrangement is a frequent molecular abnormality in childhood ALL. t(12;21) is the most common cytogenetic translocations in Chinese pediatric ALLs, but it is always difficult to identify by routine CCA.Other molecular methods, e.g. NRT-PCR and FISH are powerful in detecting such a critical genetic translocation.

Objective To investigate the role of autophagy in radiation-induced death response of human nasopharyngeal carcinoma cells.Methods MTT method was used to detect cell viability of CNE-2 cells in different time after irradiation.Clonogenic survival assay was used to evaluate the effect of autophagy inhibitor (chloroquine phosphate) and autophagy inductor (rapamycin) on radiosensitivity of nasopharyngeal carcinoma cells.Cell apoptosis was assessed by flow cytometry.The expressions of LC3 and P62 were measured with Western blot.Cell ultrastructural analysis was performed under an electron microscope.Results Irradiation with 10 Gy induced a massive accumulation of autophagosomes accompanied with up-regulation of LC3-Ⅱ expression in CNE-2 cells.Compared with radiation alone,chloroquine phosphate (CDP) enhanced radiosensitivity significantly by decreasing cell viability (F =25.88,P ＜ 0.05),autophagic ratio (F =105.15,P ＜ 0.05),and LC3-Ⅱ protein level(F =231.68,P ＜0.05),while up-regulating the expression of P62 (F =117.52,P ＜ 0.05).Inhibition of autophagy increased radiation-induced apoptosis (F =143.72,P ＜ 0.05).Rapamycin (RAPA) also significantly decreased cell viability,but increased autophagic ratio and LC3-Ⅱ protein level while down-regulated the expression of P62.Induction of autophagy increased radiation-induced apoptosis(F =167.32,P ＜ 0.05).Conclusions Blockage of autophagy with CDP could enhance radiosensitivity in human nasopharyngeal carcinoma cells,suggesting that inhibition of autophagy could be used as an adjuvant treatment to nasopharyngeal carcinoma.

Objective To determine immune modulatory activity of activated hepatic stellate cells( HSCs) in hepatocellular carcinoma and immune response in tumor microenvironment. Methods Cell proliferation was measured by BrdU incorporation with a microtiter plate reader at 450 nm. The effect of HSCs on T cell proliferation was measured by MLR. Mouse hepatic cancer cell line H22 were implanted on the backs of BALB/c mice to establish the subcutaneous transplanted tumor model. Then the mice were sacrificed after 20 days for anatomical and size determination. Furthermore, Paraffin-embedded tissue was removed by serial tissue sectioning and immunohistochemically examined for expression of T lymphocyte subsets. T lymphocyte subsets in splenocytes were detected by FCM. Apoptotic mononuclear cells were evaluated by FITC-labeled Tunel assay. Results We determined that HSCsCM promoted hepatocellular carcinoma(HCC) cell line proliferation and HSCs inhibit T cell proliferation by MLR in vitro. We also examined normal immune mice to assess the immunosuppression of HSCs in the development of HCC. In the co-transplantation with HSCs group, T cells and their subtypes decreased obviously in the tumors and the spleen. The results showed that co-transplanted HSCs can induce more PD-L1 expression and more mononuclear cell apoptosis in tumor tissue. Conclusion Our results demonstrated that HSCs promote HCC progression partially because of their immune regulatory activity. Our data supply new information to support an integral role for HSCs in promoting HCC progression and suggest that HSCs may serve as a therapeutic target for HCC.

Objective To establish a method for estimating internal dose from aerosol inhalation in non-uranium miners.Methods Aerosol samples in a tunnel in Dongchuan Copper Mine in Yunnan Province were collected by portable high flux air sampler.Radionuclides collected at the sampler filters were analyzed by the gamma spectrometry.Annual committed effective dose due to inhalation of the aerosol dust was estimated using the formula provided by ASTM.Results Radionuclides collected in two aerosol samples were anlayzed,the annual committed effective doses due to inhalation of 1 μm and 5 μm aerosol were estimated.Conclusions The method of using high flux air sampling and gamma spectrometry is explored to estimate the dose from aerosol inhalation.

Objective To estimate the dose to non-uranium miners from external exposure.Methods Ore samples of non-uranium mines were collected in site and analyzed with gamma spcetrometry,then annual dose to the miners was estimated based on the measured radioactivities of radionuclides.Results Thirty-two ore samples in thirteen mines in seven provinces were collected and analyzed.Among them,radioactivity concentrations in two samples were higher than others,and the annual doses from external exposure to the radionuclides in the two ore samples were estimated to be higher than 1 mSv/a.Conclusions Gamma spectrometry is fit for determining the radionuclides concentrations and its results can be used for estimating dose from external exposure in non-uranium mines.