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 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.

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 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.

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 investigate the clinical value of the echocardiography in the diagnosis of congenital mitral valve malformation and summarize its occurrence and type associated with other cardiac malformations.Methods The echocardiographic image data of 101 patients with congenital mitral valve malformation were retrospectively analyzed,the characteristics of different types were summarized and compared with operation results,CT,cardiac catheterization,transesophageal echocardiography,as well as the data of echocardiographic follow-up.Results Among 101 patients with echocardiographic examination showed mitral valve congenital malformation,63 cases were isolated valve set malformation (62.4％),and multiple valve set malformation were found in 38 cases (32.7％).In another side,39 cases were of single mitral valve malformation (38.6％),while 62 patients combined with other type cardiac malformations (61.4％).No significant difference of dynamic change was shown between patients with solitary and multiple malformation of mitral valve (P ＞0.05).Conclusions Echocardiography can display congenital mitral valve malformation in a fast,robust,real-time way.It has an important clinical value in the diagnosis of congenital mitral valve malformation.

BACKGROUND:Studies have found that combination of two of chitosan (CS), nano-hydroxyapatite (nHA) and poly(lactide-co-glycolide) (PLGA) can improve the mechanical properties and biocompatibility of the composite stent in certain extent as wel as improve osteogenic differentiation of the cels, but there is a certain distance from the ideal bone tissue engineering scaffolds.
OBJECTIVE:To study biocompatibility and osteoinductive activity of nHA/CS/PLGA scaffolds with different proportions in vitro.
METHODS: nHA/CS/PLGA scaffolds were prepared at mass ratio of 10:10:80, 10:20:70, 20:10:70 respectively by particle leaching method. And human bone marrow stem cels (hBMSCs) were co-cultured with these scaffolds in vitro. Adhesion, proliferation, and osteoinductive activity of these scaffolds were examined qualitatively and quantitatively by growth curve of hBMSCs on scaffolds. Gene expression of alkaline phosphatase activity and osteocalcin was detected by RT-PCR.
RESULTS AND CONCLUSION: hBMSCs could be attached, proliferated, and osteoinduced better on the nHA/CS/PLGA scaffold with the mass ratio of 20:10:70, compared to the other two groups of scaffolds. The differences were significant statisticaly (P< 0.05). Alkaline phosphatase and osteocalcin expressions were respectively higher in the scaffold with the mass ratio of 20:10:70 after 9-27 days of co-culture and 15-27 days of co-culture, in comparison with the other two groups of scaffolds. These findings indicate that the nHA/CS/PLGA scaffolds with the mass ratio of 20:10:70 demonstrated preferable biocompatibility and osteogenic inductivity, which is expected to be a promising scaffold material for bone tissue engineering.

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 analyse the fusion genes derived from chromosome structural aberrations in acute myeloid leukemia(AML) and the relationship between fusion genes and the MICM classification, clinical diagnosis, chemotherapy and prognosis. Methods The expression of fusion gene in bone marrow samples was detected with multiplex RT-PCR technique and chromosome karyotypes, immunological phenotypes and clinical data were analyzed in 60 acute myeloid leukemia newly diagnosed. Results 37 cases(61.67 %) of 60 patients carried 5 kinds of fusion genes consisting of MLL-AF9, TLS-ERG, CBFβ-MYH1, AML1-ETO and PML-RARα. The activation of oncogene HOX11 was detected in 13 AML cases, three of them with other chromosome aberration simultaneously.23 cases of 31 patients carrying AML1-ETO or PML-RARα, reached complete remission(CR) after chemotherapy and without relapse. Conclusion Gene typing is the most precise classification method that can direct clinical treatment and evaluate prognosis. Multiplex RT-PCR technique, which can quickly screen 29 kinds of fusion gene derived from chromosome structural aberrations at one time, maybe helpful to improve M1CM classification and guide the choice of treatment.

Objective To explore the deletion of chromosome 13 in multiple myeloma (MM), clinical significance of FISH-defined partial deletion chromosome 13 in MM patients were investigate. Methods Fluorescence in situ hybridization (FISH ) was performed on bone marrow from 38 patients with MM to study the deletion of Rb-1 gene and locus 13q14 on chromosome 13. Fisher exact propability was used to study the relations between partial deletion of chromosome 13 and clinical features. Results 20 out of the 38 cases were found with deletion of chromosome 13; deletion of Rb-1 gene in 4 cases; deletion of locus 13q14 in 2 out of 38 cases; and 14 cases with both of deletions. Fisher exact propability showed that deletion of chromosome 13 was associated with hypso-serum lactic dehydrogenase, stage of ISS. Conclusion Deletion of Rb-1 gene and locus 13q14 were both common cytogenetic changes in MM patients with effect on the biological behavior of the disease, but the value of del (13q14) in MM needs further investigation. FISH was a rapid, accurate and sensitive technique in the analysis of del (13q14) in MM.