The solid pseudopapillary tumor of pancreas (SPT) is a rare pancreatic tumor with low malignant potential. It primarily affects young women. The clinical characteristic is nonspecific, but the pathological characteristic is distinct. The tumor consists of both cystic and solid component. The typical histopathological appearance of SPT is the pseudopapillary structure with a fibrovascular surrounded by several layers of epithelial cells.Only a few SPTs present invasive behaviors. The tumor cells express a wide range of immunohistochemical markers. The pathogenesis is associated with the Wnt signaling pathway, which is changed by β-catenin, Pl20-catenin, adenomatous polyposis coli gene( APC), the cyclin-dependent kinase inhibitors p21 and p27.

Pancreatic cancer is a highly malignant tumor. Animal models of pancreatic cancer included xenograft models, carcinogen induced models, genetically engineered models. Xenograft models are relatively reliable and feasible, but the growth pattern is different between serve immunodeficienct animals and human beings. Carcinogens induced models simulated the environmental factors to reconstruct the development of pancreatic cancer. But carcinogens could have other biological effects. Genetically engineered models could make the occurrence of pancreatic cancer at the molecular level. But it is difficult to control the transgenic product accurately. No model could meet all the needs of different experiments. It is important to choose a suitable animal model in different experiments.

BACKGROUND: Presently, there is not an optimal cryopreservation protocol of the microcapsules, which has restrained the application of the microcapsules. OBJECTIVE: To investigate the characteristics of ice crystal and the morphology of alginate-chitosan-alginate (ACA) microcapsules cryopreserved at different solutions and different cooling rates, and to explore the optimal cryopreservationprotocol for ACA microcapsules. DESIGN, TIME AND SETTING: An observational study was performed at the Laboratory of Cryomicroecope in Shanghai University of Science and Technology (China) from February to April in 2008. MATERIALS: The high-voltage pulsing microcapsule shaping device was used to prepare ACA microcapsules.METHODS: The ACA microcapsules were preserved at different cooling rates (1 ℃/minute, 10 ℃/minute, 30 ℃/minute and 100 ℃/minute) by the cryomicroscopy system and then rawarmed at 50 ℃/minute. The protocols were repeated after the supplement of 10% dimethyl sulphoxide. MAIN OUTCOME MEASURES: The growth of ice crystals and the morphology of ACA microcapsules were checked at different cooling rates and in different solutions. The changes of forms and the rates of damage were checked after the microcapsules were rewarmed.RESULTS: The ice crystals grew into big crystals at the freezing process when the cooling rate was low than 10 ℃/minute and cryoprotector was not used. The growth of ice crystals would result in the distortion of microcapsules. It also could reduce the cryodamage of the microcapsules. The size of the ice crystals would grow down when raising the cooling rate and using thecryoprotector. The post-thaw ACA microcapsules were intact when dimethyl sulphoxide was used at a concentration of 10% and the cooling rate was higher than 30 ℃/minute (P ＜ 0.05). CONCLUSION: Mechanical damage occurs mainly during the growing of ice crystals at the time of microcapsules cryopreservation process. The growth of the ice could be restrained effectively by raising the cooling rate and using the cryoprotector.

OBJECTIVE:To compare the cost-effectiveness and quality of survival among different therapeutic regimens for diabetic patients with sulfonylureas secondary failure(SSF).METHODS:The cost-effectiveness and the effects on patients life quality of four therapeutic schemes(group A: mixed-human insulin;group B:repaglinide and metformin;group C:repaglinide and acarbose;group D:glipizide,metfonmin and novolin N) were compared using cost-effectiveness analysis in pharmacoeconomics and DSQOL(diabetic patients’ score on quality of life).RESULTS:Group A showed the best clinical efficiency,with cost-effectiveness ratio significantly lower,physiological and psychological dimension scores significantly higher and social dimension score significantly lower than in all the other 3 groups,and all were of significant differences,but no significant differences were noted in therapeutic dimension score as compared with the other 3 groups.CONCLUSION:Insulin is optimal among four schemes in the treatment of diabetic patients with sulfonylureas secondary failure in the cost-effectiveness analysis, and it has the best efficacy in the improvement of patients’ physiology and psychology.

The safety of leachable substances in medical devices is an important guarantee of the safety of medical devices, and is also the focus of attention in the review of medical devices in recent years. Combined with the difficult issues in the study of leachable substances, the challenges in the study of leachable substances in medical devices were briefly described, and the counter-measures were briefly described for reference by relevant institutions and researchers.

Centrifugal blood pumps drive blood flow by regulating blood flow rate,and have been widely used in clinical applications,including extracorporeal membrane oxygenation(ECMO),cardiopulmonary bypass(CPB),and extracorporeal circulation carbon dioxide removal(ECCO2R).However,because different structures and different forms of centrifugal pumps have different requirements for blood extracorporeal circulation in clinical application scenarios,blood pumps face different application conditions in clinical use.In this study,the effects of different structures of centrifugal pumps and different working conditions on blood damage are summarized for reference by relevant institutions and R&D personnel.

Objective The nursing treatment ability scale of patients with nuclear radiation damagein the hospital was developed to provide an evaluation basis for improving the nursing ability of nurses with nuclear radiation damage. Methods The scale was prepared by literature review, expert interview and expert consultation, and a total of 330 clinical nurses from a third-class hospital was randomly selected as the research objects. The scales were issued for item analysis and reliability and validity test. Results The scales were divided into 6 dimensions, including basic knowledge of nuclear radiation damage, specialized equipment use ability, specialized ward management ability, basic nursing ability, specialized nursing ability and self-ability recognition, with 51 items. After exploratory factor analysis, there were 6 principal components, and the cumulative interpreted variance was 70.757%. The χ², df, χ²/df, CFI, IFI, TLI, NFI, PNFI, PCFI, RMSEA fitting indexes of confirmatory factor analysis were all acceptable. Cronbach's α coefficient was 0.976, the retest reliability was 0.823, and the S-CVI (S-CVI/UA) was 0.84. The evaluation content validityS-CVI (S-CVI/AVE) was 0.98, and the content validity I-CVI of the item level was 0.78～1.00. Conclusion The items and dimension Settings of this scale have been tested, and all indicators met the requirements. The reliability and validity test results were good. It can be used as a scale for preliminary evaluation of hospital nursing ability of patients with nuclear radiation damage.