BACKGROUND:Oyster shels and other shels of marine organisms can transfer into mineral salts, which is closer to the actual situation of human being. OBJECTIVE:To explore the effect of natural oyster shel nanocomposite material for bone defect repair. METHODS:Thirty adult big-eared white rabbits were randomly divided into two groups after establishment of bilateral radial bone defect models: experimental group and control group were given implantation of natural oyster shel nanocomposite material and injectable calcium sulfate bone graft, respectively. X-ray examination was done at weeks 2, 8, 12 after implantation to understand the osseointegration of bone grafts. Bilateral radial bone specimens were taken at 12 weeks to detect bending strength using biomechanical testing system and quantitatively analyze the osteogenesis using a color image analyzer. RESULTS AND CONCLUSION:At 2 weeks after implantation, the bone mineral density of bone grafts was lower in the two groups than the normal value, there was a clear boundary between the defect and graft, and no bone repair was found. At 8 weeks after implantation, the bone grafts were covered with thick soft tissues in the two groups, and the vascular component was reduced dramaticaly in the experimental group. At 12 weeks after implantation, the bone grafts were closely connected to the adjacent tissues in the two groups, with no boundary; the radius surface in the experimental group recovered to the normal level, and exhibited no difference from the normal tissues in aspects of morphology, texture and structure, but in the control group, there was stil a clear projected boundary. The bending strength and osteogenic amount of the radius were significantly higher in the experimental group than the control group (P < 0.05). These findings indicate that the natural oyster shel nanocomposite material for bone defect repair can have a good blending strength of the radius that can promotenew bone formation.

Objective To study the correlation between MRI features and pathology of intraspinal neruilemmoma.Methods MRIfeatures of intraspinal neurilemmomas proved by operation and pathology in 16 cases were analysed retrospectively and in comparison with the results of pathology.Results All the tumors were intradural-extramedullary in location,including 6 in the cervical regions,5 in the upper thoracic regions,3 in the thoracic-lumbar junction and 2 in the lumbar regions.On MRI,the tumors were marginate elliptical heterogeneousisointense or slightly low intense with punctate or patchy more low intensity areas on T_1WI and heterogeneous slightly high intense orisointense with punctate or patchy more high intensity areas on T_2WI.Parts of the masses obviously enhanced with no enhancement of more low intensity areas on T_1WI.All of above imaging manifestations were corresponding to pathology of intraspinal neurilemmomas.Interlace of Antoni A and Antoni B was attributed to heterogeneous intensity.Antoni B that was no obviously enhancement was concentrated in bleeding and cystic areas and Antoni A that was obviously enhancement was concentrated in cellular area and collagen.Conclusion The imaging manifestations of intraspinal neurilemmoma is due to its varied pathologic changes,and this has guiding significance to the correct diagnosis.