BACKGROUND:Xenogenic deproteinized bone is generally collected and has unique biological properties;however,its immunogen hopes be resolved so as to discover a new type of bone graft material.OBJECTIVE:To explore the performance of xenogenic deproteinized bone scaffold for tissue-engineered bone and the effect on spinal intertransverse fusion in goats.DESIGN,TIME AND SETTING:An in vivo cell-scaffold study was performed at the Key Laboratory of Fibrotic Biotherapy of Heilongjiang Province between February and October 2008.MATERIALS:Twelve healthy male goats aged 6-8 months were provided by Animal Center of Mudanjiang Medical College.METHODS:Cancellous bone at distal femur of adult swine was obtained to prepare xenogenic deproteinized bone scaffold using physical and chemical methods.Effects of the scaffold on morphology,structure,component,biomechanical property,and biological behavior of seed cells were detected and analyzed.Bone marrow was extracted from ilium of goat and gradient-centrifuged to obtain the third-passaged bone marrow mesenchyme stern cells (BMSCs).A certain quantity of autologous BMSCs and recombinant human bone morphogenetic protein 2 (rhBMP-2) were plated onto the scaffold to achieve tissue-engineeried bone.Models of bilateral L3,4 intertransverse bone graft were established on 12 goats.Tissue-engineeried bone was implanted into the left side in a repairing group,while the same volume of autologous ilium was implanted into the right side in a control group.MAIN OUTCOME MEASURES:X-ray examination and histological detection were performed at 4,8,and 12 weeks after implantation.RESULTS:Deproteinization-treated cancellous bone exhibited a spatial grid structure of variously sized,crossing and opening pores,composing hydroxyapatite and collagen.The pore diameter was 200-500 μm,and porosity was about 60%.Mechanical property and cell compatibility were well.X-ray examination demonstrated that at 4 weeks after implantation,some or even lateral intertransverse bridging regions were unclear,and material density in the repairing group was lower than control group;at 8 weeks after implantation,interspace between up and down bridging was shrunk,and a great quantity of calluses were successively formed;at 12 weeks after implantation,complete confluence was observed,and the density in the repairing group was closed to that in the control group.Histological detection indicated that at 4 weeks after implantation,new bone was multidrop-formed in the repairing group;at 8 weeks after implantation,bone tissue like the islet shape was passed through the whole implanted materials;at 12 weeks after implantation,woven bones arranged across,medullary cavity was formed,and osteogenic activity in the repairing group was closed to that in the control group.On the other hand,at 4 weeks after implantation,a large quantity of new bones were formed in the control group;at 8 weeks after implantation,a great quantity of collagen fibers were observed,and osteogenesis was clear in marginal region;at 12 weeks after implantation,fibrous tissues were reduced,and osteogenesis was active.CONCLUSION:BMSCs and rhBMP-2 incubated on xenogenic deproteinized cancellous bone is an ideal tissue-engineeried bone scaffold,characterizing by an excellent histocompatibility and a strong osteogenesis,based on in vitro X-ray diffraction analysis,mechanical test,and in vivo osteogenesis experiment.

Aim To observe the effect of the polymerization of HSF1 on the febrile response in fever rabbits,and further to investigate HSF1 action in thermoregulation and the possible central mechanism.Methods 70 rabbits were divided randomly into 4 groups:the control group(N),the quercetin group(Q),the LPS-feverish group(L),the quercetin+LPS-feverish group(Q+L).Changes in body temperature were continually observed;the expression of HSF1 and HSP70 in hypothalamus was detected by Western blot;the content of AVP in hypothalamus and VSA was measured by radioimmunoassay.Results ① The sequence of the maximum change of temperature(△Tmax)from low to high:group Q

0.05). The cell cycles of the two groups were similar, and heteroploid cells were not found out in both groups. CONCLUSION: Xenogeneic deproteinized cancellous bone has a good biocompatibility to bone mesenchymal stem cells and promotes cell growth and differentiation.

Objective:To discuss the application effect of digital classroom based on identifying sectional structure in the experimental teaching of sectional anatomy.Methods:A total of 180 students majoring in imaging diagnosis from six classes of Batch 2018 in Mudanjiang Medical University were randomly selected as the research objects and divided into the experimental group and the control group. Three classes (90 people) in the experimental group implemented the digital classroom teaching of learning platform + virtual digital person, while another three classes (90 people) in the control group adopted traditional teaching. After the course, the effect was evaluated according to the results of the questionnaire and the final exam results. SPSS 18.0 software was used for t-test and Chi-square test. Results:The questionnaire showed that the students in the experimental groups were superior to those in the control group in self-study ability, independent thinking ability, analytical and problem-solving ability, learning efficiency, learning interest and sectional thinking cultivation, and the difference was statistically significant ( P<0.05). The test scores showed that the theoretical scores [(56.08±1.65) vs. (45.19±1.74)], experimental scores [(37.13±3.24) vs. (30.16±2.04)] and total scores [(93.21±3.18) vs. (75.35±1.79)] in the experimental group were higher than those in control group, and the differences were statistically significant ( P<0.05). Conclusion:The digital classroom based on identifying sectional structure is a feasible teaching mode, which improves the students' ability to analyze and solve problems, increases their interest in sectional anatomy, and improves the teaching effect.