[Objective] To develop biomimicking chitosan scaffolds with longitudinally oriented micro-channels,and investigate their efficacy in bridging 15 mm sciatic nerve gap in rats.[Methods]Chitosan scaffolds with longitudinally oriented micro-channels were fabricated using unidirectional freezing-dry methods.The chitosan scaffolds were used to bridge 15 mm nerve defect in rats,and their efficacy in bridging nerve gap was evaluated by morphometric analysis,retrograde labeling,electrophysiological studies and behavioral analysis.[Results]The chitosan scaffolds developed in the present study showed longitudinally oriented micro-channels,which resembled the dimensions of basal lamina channels in normal nerves.Implantation of chitosan scaffold achieved axonal regeneration and functional recovery similar to autograft implantation in vivo.[Conclusion]The chitosan scaffolds have inner microstructures which resemble the basal lamina channels in normal nerves.The chitosan scaffold may be used as an alternative to autograft in bridging nerve gaps.

BACKGROUND:Spine, due to its complicated structure and special functions, is always the difficulty and emphasis in clinical practice and medical education. It is an interesting top how to apply modern software in clinical teaching. OBJECTIVE:To investigate the application of Spine Decide software in clinical teaching of spine surgery. METHODS:Teachers can actively guide students to learn the diagnosis of spine diseases and to design surgery program using Spine Decide software. Then the students wil participate in the surgical operation of the patients, which helps them better understand the diagnosis and treatment of spine surgery disease and the occurrence and development of spine diseases. RESULTS AND CONCLUSION:The students actively participated in the process of learning through Spine Decide software, which helps them learn systematical y, structural y the pathogenesis, diagnosis, treatment and prognosis of spine diseases in a short period. Application of Spine Decide into teaching activities has greatly improved the students’ abilities in self-learning and clinical analysis. Their enthusiasm to the learning and creativity has been greatly improved compared to traditional teaching methods;innovation and exploration have breakthrough improvement, final y achieving a good teaching effect.

Objective To induce directional differentiation from spinal cord-derived neural stem cells(SNSCs)into neurocytes in the simulated microenvironment of development of embryonic spinal cord of rat after isolation and culture of SNSCs and to investigate the proliferation and differentiation of SNSCs in vitro.Methods SNSCs were isolated mechanically from rat embryonic(E10 to 11d)spinal cord under microscope.SNSCs were cultured and maintained in serum-free medium.Directional differentiation from SNSCs to neurocytes was induced by adding N4 supplement.The morphologic features of the differentiated cells were noted.Cultured and differentiated cells were identified by immunochemistry stain and t he mean differentiating percentages of the positive cells were calculated.Resul ts SNSCs isolated by the mechanical method under microscope were vigorous and pr oliferative,and could differentiate into neurons,astrocytes and oligodendrocyt es.Conclusion The mechanical method under microscope of isolating SNSCs is simp le and efficient to obtain a high percentage of neurons.N4 supplement can induc e SNSCs to differentiate into neurocytes.

0.05).[Conclusion]There are the same correct effectiveness and the biomechanical stability in the treatment with the slidable pedicle screw system and universal pedicle screw system,meanwhile there is no effect in the adolescent growth.

[Objective]To initially approach the role of lumbar facet joint derived inflammatory factors in degenerative lumbar spinal canal stenosis. [Methods]Totally 75 cases of degenerative lumbar spinal canal stenosis(LSCS)(n=41)and lumbar intervertebral disc herniation(LDH)(n=34) undergoing posterior lumbar spinal surgery in our department were evaluated in terms of the extent of degenerative arthrosis according to the Weishaup grading criteria.The grading of backleg pain,melosalgia and functional impairment were recorded.The excised lumbar facet joints were collected as species.The content of interleukin-1? and tumor necrosis factor-? in the species were determined by ELISA.[Results]There was no TNF-? detected in both of the two groups.More IL-1? was detected in degenerative lumbar spinal canal stenosis group than that in lumbar intervertebral disc herniation group.It was demonstrated that the content of IL-1? in the species increased as the degeneration of lumbar facet joint sharpened.IL-1?-positive cases in degenerative lumbar spinal canal stenosis group showed higher grading of backleg pain,melosalgia and functional impairment.[Conclusion]The cartilage of degenerative lumbar spinal canal produced more IL-1?.Lumbar facet joint derived inflammatory factors might be one of the reasons that cause backleg pain and melosalgia and functional impairment in degenerative lumbar spinal canal stenosis patients.

[Objective]AIM To explore the differentiation of neural stem cells from rat embryonic spinalcord in the serum free condition culture medium of OECs.[Method]OECs were acquired by dissection ofolfactory nerve ensheathing and cultured for 20 hours,then suspending cells were put intoselective culture medium and cultured in the fibernectin coated plate.The activity of OECs was detected by MTT method on different periods and the best situation was selected out and serum-free cultured.Exudates of OECs was added into neural stem cells of the third generation.The differentiation of neural stem cells were observed under inverted microscope.The neural stemcells cultured were identified by immumofluorescence method.[Result]The activity of OECs was high on the 9~(th) day and the 12~(th) day.The serum free condition culture medium of OECs induced 53% neuralstem cells to differentiate into neuron-like cells and 42% neural stem cells into astrocytes cells.[Conclusion]The activity of OECs on different periods is different.The serum free condition culture medium of OECs can obviously induced neural stem cells to differentiate into mature neuronecells.

[Objective]To study therapeutic effect of different medicines on motorneuron of spinal cord after explosive injury of spinal cord.[Method]Thirty-six rabbits were randomly divided into model group(group A,n= 12),the dexamethasone experiment group(group B,n= 12) and the methylprednisolone experiment group(group C,n=12),all rabbits were made explosive wound by 0.9 g cyclotrimethylene trinitramine,group A injection NS after blast, group B injection dexamethasone and group C injection methylprednisolone,6 and 24 hours after specimen had been taken out,then morphological change and quantity of the spinal motorneurons be observed under light microscopes.[Result]The reversible change of the neurons of rabbits happened after six hours,after 24 hours,the died motoneuron increase obviously, some rabbits remedied with dexamethasone and methylprednisolone after explosive injury in group B and C,quantity of the died motorneuron marked significant difference than that in the control group(P0.05).[Conclusion]Glycocotical stdroid can protect spinal cord motoneurons after explosive injury of spinal cord.In the experiment,there is no preponderance in early treatment of explosive injury of spinal cord between methylprednisolone and dexamethasone.

[Objective]To explore the differentiation of bone marrow stromal cells(BMSCs) induced by OECs conditioned medium.[Method]The purified OECs were acquired by seleclive culture medium and cultivated in the polylysine coated plate.After 9～12 days culture, OECs conditioned medium was obtained by 2000 r/min configuration and then co-cultivated with purified BMSCs which were 3th generation.The differentiation of BMSCs were observed under inverted microscope and were identified by immumofluorescence method.[Result]The OECs conditioned medium had obviously effects on BMSCs' differentiation.BMSCs differentiation into neuron-like cells ratio was 55% and differentiation into astroctes cells ratio was 23%.[Conclusion]The conditioned medium which comes from OECs culture supernatant has obviously effects on BMSCs' differentiation into neuron-like cells.

[Objective] To develop a new type nerve tissue engineering scaffolds to repair the defect of peripheral nerve and observe the growth of bone marrow stromal cells cultured in vitro on the scaffolds.[Method]The biomaterial was made of I-collagen and gelatin by freeze-drying method,the alignment regularities of microscopic channels and there course directions were observed under the scanning electronic microscope.The size of the micropores and the factor of porosity were also measured.The bone marrow stromal cells were seeded on the collagen scaffolds and cultured for 5 days,then the growth of bone marrow stromal cells cultured in the scaffolds was observed.[Result]All the scaffolds were circular cylinder,the microscopic channels were arranged in parallel manners,and the pore sizes of the channels were uniform.The bone marrow stromal cells were seeded in the scaffolds successfully.[Conclusion]The developed nerve tissue engineering scaffolds have good structure and biocompatibility,which can be used in the repair of the nerve injuries.

[Objective]To evaluate the effect of selective kyphoplasty in treatment of osteoporotic thoracolumbar multi-vertebral compressive fractures based on preoperative magnetic resonance imaging(MRI).[Method]Twenty-one cases(fifty-seven vertebral bodies) of osteoporotic thoracolumbar multi-vertebral compressive fractures were treated from June 2003 to December 2006.The signal changes in different sequences were confirmed by preoperative MRI.Based on the MRI signal changes,57 vertebral bodies were treated by selective kyphoplasty.Normal balloon pressure and cement volume were performed for the painful vertebral bodies and lower pressure and cement volume were preferred for the vertebral bodies with old fracture.[Result]All patients tolerated the operation well with immediate relief of their back pain in 24 hours.The mean height of the anterior,media and posterior vertebral bodies were(1.7?0.9)cm,(1.7?0.7)cm,(2.5?0.9)cm preoperatively and(2.2?0.4)cm,(2.4?0.6)cm,(2.6?0.3)cm postoperatively.The mean kyphosis was improved from(33.7?10.9) degrees to(25.9?9.3) degrees(P