Purified GAI, one form of glucoamylase obtained from Aspergillus niger mutant T21 contained 17.6% total carbohydrate. Analyses of amino acid composition showed that GAI contained about 25% Ser and Thr, 20.3% Asx and Glx and 6% basic amino acids. The UV absorption and fluorescence spectra of GAI were determined. The maximum absorption wavelength was at 278nm and minimum at 250nm. For fluorescent analyses the excitation and maximum emission spectra were at 284nm and 342nm respectively. The CD-spectrum determined showed two negative peaks. Its dispersion of secondary structure in solution showed 10.6% ?-helix, 16.3% ?-form and 73.1% unordered.

BACKGROUND:Over the years, muscle, skin, skeletal muscle flaps and luminal tissues, such as stomach and intestines, are used as an artificial esophagus to repair esophagus defects, but the results are not good.
OBJECTIVE:To investigate the feasibility of chitosan tube stent combined with muscle flaps to repair partial defects of the cervical esophagus.
METHODS:Thirty white rabbits were used to make animal models of partial cervical esophageal defects, and randomly divided into experimental group (n=20) and control group (n=10). Esophagus defect in rabbits of experimental group was repaired using autologous muscle flap with a chitosan tube stent, and esophagus defect in the control group was repaired only with muscle flap. Gross and histological appearance was observed at weeks 2, 4 and 8 after operation, and barium sulphate X-ray screen was performed at week 10 after operation.
RESULTS AND CONCLUSION:After 2 weeks, muscle tissue structure, cellswel ing, and inflammatory cellinfiltration could be seen in the experiment and control groups, exhibiting an acute inflammatory reaction. After 4 weeks, the experimental group showed clear muscle flaps, reduced inflammatory reaction, and no obvious fibrosis;while in the control group, muscle tissue could be seen at defect site, with growth of fibrous tissue cells and a few of inflammatory cells. After 8 weeks, in the experimental group, squamous metaplasia could be seen on the gross surface of the muscle flaps,esophageal mucosa could be seen, accompanied by chronic inflammatory reaction under the mucosas that had a clear abate than that at 4 weeks after implantation;in the control group, chronic inflammatory reaction could be found, accompanied by clear fibrosis but no squamous metaplasia and mucosal regeneration. Barium sulphate examination found that the esophagus was smooth with a slight motility in the experimental group, but there was a part of stricture in the esophagus without motility. These findings suggest that the chitosan tube stent combined with muscle flaps could better repair partial defects of the cervical esophagus.

BACKGROUND:Adipose-derived mesenchymal stem cells have the ability to self-renew and have pluripotent potential under specific conditions in vitro, which have broad application prospects in clinical practice. However, isolation and culture of adipose-derived mesenchymal stem cells stil appear to have many difficulties and shortcomings. OBJECTIVE:To isolate and culture rabbit adipose-derived mesenchymal stem cells in vitro in order to study their morphology, cellsurface markers and biological properties as wel as to investigate the osteogenic and adipogenic potentials of adipose-derived mesenchymal stem cells in vitro. METHODS:Primary adipose-derived mesenchymal stem cells were isolated from the subcutaneous adipose tissue of posterior cervical region from New Zealand white rabbits and digested by 0.1%col agenase I. The cells were passaged and amplified by the trypsin digestion. The passage 4 adipose-derived mesenchymal stem cells were induced to differentiate after exposure to adipogenic or osteogenic medium. The oil red O staining, alkaline phosphatase and alizarin red staining were used to detect the results. The cellviability was detected by the cellcounting kit 8 method to drawn the growth curve. cellsurface markers were examined using flow cytometry. RESULTS AND CONCLUSION:The adipose-derived mesenchymal stem cells isolated from the subcutaneous adipose tissue of rabbits exhibited a fusiform adherent growth in a vortex pattern, and had a strong capability of proliferation that could be passaged stably to the 10th generation. Flow cytometry results showed that the cells highly expressed CD29, CD90, CD44, but lowly expressed CD45 and CD34. After adipogenic induction, the adipose-derived mesenchymal stem cells were positive for oil red O staining;after osteogenic induction, the cells were both positive for alkaline phosphatase and alizarin red staining. These findings suggest that the adipose-derived mesenchymal stem cells were successful y isolated and cultured from the subcutaneous adipose tissue of rabbits, and these cells are pluripotent with the potential to differentiate into adipocytes and osteoblasts, which are expected to be ideal seed cells for bone tissue engineering.

Objective To investigate the clinicopathologic characteristics and prognosis of medullary breast carcinoma.Methods We conducted a retrospective analysis on clinical and pathologic data of 166 patients with medullary breast cancer.Results All the patients were female with a median age of 52 years old.The proportion of patients with stage Ⅰ,Ⅱ and Ⅲ disease was 16.9％,68.1％,15.0％,respectively.The Luminal,HER-2 overexpressing and triple-negative subtypes constituted 31.3％,8.4％,and 60.3％,respectively.There was significant difference in regional lymph node status of medullary breast cancer patients with different molecular types (x2 =18.248,P =0.003),but not in tumor size,TNM stage,histological grade,and expression of Ki67 (all P ＞ 0.05).Multivariate survival analysis indicated that TNM stage was an independent predictor in the prognosis of medullary breast cancer (HR =5.664,P =0.001).All the patients were followed up from 15 months to 145 months with a median follow-up time of 108 months.The 5-year survival rate was 91.5％ and the 10-year survival rate was 87.2％.Conclusions The prognosis of medullary breast cancer is favorable.Personalized treatment according to the TNM stage and histopathologic characteristics achieve a favorable prognosis.

BACKGROUND:Fibroblast-like synoviocytes (FLS) in the synovial lining layer are related to the cell proliferation, invasion, migration and apoptosis as well as bone resorption in rheumatoid arthritis. OBJECTIVE:To compare the migration and invasion abilities of FLS (MH7A) in rheumatoid arthritis and normal FLS (HFLS). METHODS:The capacities of cell migration and invasion were evaluated by Transwell cell migration and invasion assays. The primers of the indicated microRNAs were designed and synthesized, and the expression levels of miRNAs were determined by real-time PCR according to the SYBR?PrimeScript?miRNA RT-PCR Kit instruction. RESULTS AND CONCLUSION:MH7A possessed stronger migration and invasion abilities than HFLS. Compared with HFLS, obviously upregulated miR-132, -155, -203, -223 and -124, and significantly downregulated miR-15a, -16, 18a, -19a, -26a and -146a were found in MH7A. These findings suggest that the differentially expressed 11 kinds of rheumatoid arthritis-associated miRNAs participate in the pathogenesis of rheumatoid arthritis probably by enhancing the migration and invasion capacities of MH7A.

Objective To study the risk factors related to recurrence of gastrointestinal stromal tumor (GIST) after discontinuing postoperative adjuvant imatinib mesylate (IM) treatment.Methods We retrospectively analyzed our clinical database of 138 GIST patients who received radical resection and subsequent IM adjuvant treatment at the Renji Hospital,Shanghai Jiaotong University School of Medicine between January 2006 and January 2014.Results For the entire Multivariate analysis study group,the overall 5-year recurrent free survival (RFS) rate was 54.5％.There were two tumor characteristics which were independent prognostic factors of GIST treated by postoperative IM:Ki67 index (P =0.005),and serosal invasion (P =0.026).The accuracy of comprehensive evaluation based on the two weighted variables was better than NIH staging criteria(AUC:0.714 vs.0.631).Furthermore,two risk groups were created according to the risk model with 5-year RFS of 81.3％ and 31.1％ as low-risk and high-risk groups,respectively (P ＜0.05).Conclusions For patients with intermediate or high risk in NIH classification,if there was tumor serosal invasion,or if there was no local invasion but Ki67 index ＞ 8％,extended continuous IM adjuvant treatment should be recommended after the primary tumor was radically resected.

BACKGROUND:Studies have shown that microRNAs (miRNAs) have moderating effect on the renewal and differentiation of cancer stem cels. However, there is no complete understanding on the effect of microRNA-17-92 gene on gastric cancer stem cel renewal and proliferation.
OBJECTIVE:To explore the effect of miRNA-17-92 in promoting self-renewal and proliferation of gastric cancer stem cels.
METHODS:(1) The gradualy reduced miRNAs during gastric cancer stem cel self-renewal were investigated using miRNA array based on RNAs from differentiated and adherent cels. (2) The miRNA-17-92 was constructed and transfected to gastric cancer stem cels. (3) The effects of miRNA-17-92 on the self-renewal of gastric cancer stem cels were studied by tumor sphere assayin vitro. (4) The effects of miRNA-17-92 on the proliferation of gastric cancer stem cels were investigated by MTT assay and colony formation assay.
RESULTS AND CONCLUSION:(1) miR-19b/20a/92a expression gradualy reduced in the adhesion and differentiation of gastric cancer stem cels. (2) The expression of lentivirus carrying miRNA-17-19 gene in MKN28 cels and CD44-/EpCAM- cels were significantly increased; transient transfection of pre-miR-19b/20a/92a increased the expression of CD44-/EpCAM- and MKN28 miRNA, transient transfection of pre-miR-19b/20a/92a antagonists reduced the expression of SGC7901 and CD44+/EpCAM+ miRNA; overexpression of lenti-miR-19b/20a/92a significantly increased the ability of gastric cels to form tumor spheres; chemotherapy drugs prolonged the survival time of lenti-miR-19b/20a/92a-infected cels; transient transfection of pre-miR-19b/20a/92a significantly increased the number of CD44+/EpCAM+ cels, but transfection of pre-miR-19b/20a/92a antagonist reduced the number of CD44+/EpCAM+ cels. (3) MTT proliferation assay showed that gastric cancer cel proliferation rate in miR-19b/20a/92a stably expressing group was faster than that in the control group. Transient transfection of miR-19b/20a/92a precursor accelerated the growth rate of gastric cancer cels, and transient transfection of its antagonist slowed down the growth rate of gastric cancer cels. Colony formation assay showed that transient transfection of miR-19b/20a/92a precursor significantly increased the colony formation number as compared with the control group; transient transfection of miR-19b/20a/92a antagonist reduced the colony formation as compared with the control group. These findings indicate that miR-19b/20a/92a gene presents with continuous deletion in gastric cancer stem cel differentiation process, and miRNA-17-92 gene can promote the renewal and proliferation of gastric cancer stem cels.

Objective To search for the neutralizing epitopos on hepatitis E virus (HEV) capsid besides the known neutralizing epitope (aa459-606). Methods By analysis of several strains of monoclonal antibodies against HEV capsid and their recognized epitopes, the neutralizing activity of epitope (aa394-458) at N-terminus was compared with that of an immunodominant neutralizing epitope (an459-606). Re-suits The research showed a novel potential neutralizing epitope in aa423-437 of HEV ORF2 though detec-ting and comparing the characteristics of several antibodies and corresponding determinations. The epitope is a linear non-immunodominant epitope which is different from the other neutralizing epitope in aa459-606.And the amino acids sequence of this novel epitope is conservative. Conclusion ORF2 aa423-437 is a no-vel potential neutralizing leaner epitope of HEV. It is believed that the present work adds fundamental knowl-edge to our understanding of HEV capsid domain and contributes to the prevention and control of this dis-ease.

Objective To identify the protein interacting with hepatitis E virus(HEV) recombi-nant capsomeric particles(P239). Methods Protein interacting with HEV was analyzed by the pull-down, MALDI-TOF-MS, co-immunoprecipitation (Co-IP) and CONFOCAL. Results A protein interacting with HEV recombinant particle (P239) was identified as HSP90 by MALDI-TOF-MS. The interaction between HSP90 and P239 was further confirmed by Co-IP. The protein level and localization of HSP90 and P239 in HepG2 were detected. The total quantity of HSP90 didn't change, and the movement of HSP90 from plasma membrane to perinuclei region with P239 was observed. Conclusion HSP90 may play an important role in the trafficking of P239. It suggests that HSP90 participate in the transportation of HEV after infection, which may contribute to the prevention and control of the disease.

Objective To express the recombinant caspid of genotype 4 hepatitis E virus(HEV) ORF2. Methods HEV recombinant capsid protein D66 was expressed in E. coli, using the ORF2 fragment (aa368-606, obtained from swine bile) of genotype 4 HEV. Results The recombinant capsid proteins D66 self-assemble to be particle with a radius of 13 nm through dimeric form in neutral solution. Coated particles reacted well with sera obtained from patients during acute or recovered phase of HEV infection. Immunofluorescence and immnoblot assay suggested that D66 bound and penetrated HepG2 cell lines, and the process of attachment was blocked by sera collected from patients during acute or recovered phase of HEV infection.Conclusion Recombinant D66 particles simulate the structure at the surface of genotype 4 HEV well and specifically adhere and penetrate the host cells, which lays the foundation for the investigation of the molecular mechanism of genotype 4 HEV infection.