BACKGROUND: The existed repair method for cartilage defects has shortcomings of insufficient repairing tissue numbers, poor biomechanical properties, as well as donor site complication. Thus it is deficient to repair large-sized osteochondral defects using one method.OBJECTIVE: To investigate the therapeutic effect of tissue engineering modified Mosaicplasty on repairing large-sized osteochondral defects.DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Center Laboratory of Qingdao University Medical College from January to September 2009.MATERIALS: The hircine bone mesenchymal stem cells (BMSCs) were in vitro cultured, and resuspended with algin solution to obtain BMSCs-calcium alginate gel.METHODS: Totally 12 goats were prepared for osteochondral defects models and were divided into 3 groups.BMSCs-Mosaicplasty group, BMSCs compound with injectable alginate calcium gel was then applied to fill the "dead space" after Mosaicplasty. In the Mosaicplasty group, the defects were repaired by Mosaicplasty. There was no treatment in the control group.From 4 to 16 weeks postoperatively, the animals were sacrificed and the in gross and under electromicroscopy.MAIN OUTCOME MEASURES: ①Gross observation: the joint was exposed to observe the repair effect at weeks 4, 8,16 after operation. ②Histological examination: specimens were harvested at 16 weeks after operation and observed by haematoxylin-eosin staining, toluidine blue staining under light microscopy. ③Transmission electron microscope was used at 16 weeks after operation.RESULTS: The transplanted subchondral bone and superficial cartilage was integrated hardly with each other or with recipient sites in tissue engineering modified Mosaicplasty groups at 16 weeks after operation. The quality and appearance of the transplanted and regenerated cartilage was similar to normal hyaline cartilage. Under microscopy, the regenerated cartilage was integrated with neighbor tightly in regular arrange. ECM distributed evenly and deeply stained by alcian blue. There was no obviously repaired in the control group.CONCLUSION: Tissue engineering can ameliorate the outcome of Mosaicplasty to repair the osteochondral defects.

Objective To establish a model of full-thickness avascular meniscal defect to assess outcome of bone-marrow mesenchymal stem cells (BMSCs) modified with human insulin-like growth factor Ⅰ (hIGF-Ⅰ) gene and compounded with injectable calcium alginate gel in repair of meniscal defect.Methods Models of full-thickness defect were created in the anterior comer of meniscus in goats,an area lacking of blood supply.The trial categorized the models to four groups:gene-ehanced tissue engineering (GETE) group (hIGF-Ⅰ transfected BMSCs were mixed with calcium alginate gel),BMSCs group (BMSCs were mixed with calcium alginate gel),empty group (calcium alginate gel was used alone) and control group (the defect was excluded from repair).Macroscopy was done at 4,8,and 16 weeks after operation.Variation of repair tissue was observed by light and scanning electric microscopy and aggrecan in repair tissue was determined as well.Results Meniscal defect was on the mend at 4-16 weeks after operation in GETE group,with the defect area being thoroughly filled with the white,elastic and tight repair tissue similar to normal meniscal tissue.Macroscopic examination showed a better result in GETE group than that in other groups.Light microscopy showed that repair tissue which was mainly fibrochondrocytes was arranged in line with calcium alginate fibers and that space between the fibers was mostly crammed with the matrix secreted by those cells.At the same time,those cells were tightly arranged and the matrix secreted by those cells was equally distributed according to light microscopy.Electroscopy demonstrated neat and tight arrangement of fibers and tight extracellular matrix in fiber space in GETE group.Aggrecan concentration in GETE group was relatively higher than in other groups,but still had difference from the normal meniscus.Conclusion hIGF-Ⅰ gene-transfected BMSCs combined with injectable calcium alginate gel can improve the effect in repair of full-thickness meniscal defect.

Objective To study the cause,prevention and treatment of postpancreaticoduodenectomy hemorrhage.Method The clinical data of 422 patients who underwent PD in our hospital between January 2000 and January 2012 were retrospective analyzed.Results The incidence of postoperative hemorrhage was 8.1％ (34/422),and the mortality was 20.6％ (7/34).Early and delayed hemorrhage occurred in 19 and 15 patients,respectively.Intra-abdominal and gastrointestinal hemorrhage occurred in 20 and 14 patients,respectively.For the 19 patients who underwent reoperation,the mortality was 20.6％ (7/34).When compared with the delayed hemorrhage group,the mortality of the early hemorrhage group was significantly lower (P＜0.05).Conclusions Meticulous operation and reliable hemostasis during operation and prevention of pancreatic fistula,biliary fistula and peritoneal fluid collection after operation are the key points in reducing postoperative hemorrhage.A timely and decisive reoperation is important to manage postoperative hemorrhage.

Objective Explore the factors affecting rural residents'willingness to use telemedicine in China,and put forward relevant suggestions to promote the development of telemedicine in rural areas.Methods A research model was built based on Technology Acceptance Model,data were collected through using a questionnaire survey and analyze by structural equation modelling for validation.Results The awareness rate of telemedicine among rural residents was 62.0%and the usage rate was 10.0%,which was low.Perceived usefulness,perceived ease of use,social participation,social support,and facilitators positively influence rural residents'willingness to use telemedicine(P＜0.05),while perceived risk and social connection have no effect on the willingness of rural residents to use telemedicine(P＞0.05).Conclusion Promote the construction of telemedicine system infrastructure to comprehensively enhance the level of rural medical and health services;improve telemedicine laws and regulations to promote the policy guarantee of the three medical institutions;give full play to the role of social capital to improve the information literacy of rural residents in the use of telemedicine.