Effect Of Cerebal Injury On Expression Of Nerve Growth Factor In Bony Callus Of Fractured Thighbone

Objective To study the expressive change of nerve growth factor (NGF) in bony callus after fracture of the thighbone in rats with cerebral injury .To identify the effect of nerve growth factor (NGF) in the prossesing of union of fracture. And approach the effects and mechanism of central nerve injury in the union of fracture..Try to offer a new theory and experiment mehhod to clinical application.Methods 60 adult healthy male SD rats were randomly divided into thighbone-Fracture group (group An= 30) and thighbone fracture with cerebral injury group (group B n = 30) ,The group A only to cut off the same side femoral bone and to fix by Kirschn-er wire, the other group's animal models were established by free weight dropping and knocking method, Then randomly selected 6 rats respectively from each group at five time points (1 day, 4 days, 1 week, 2 weeks and 3 weeks). To observe osteoplastic situation in every time point by mean of cell morphology observation and expressions of NGF in bony callus were determined by immunohistochemistry stain.Results1 Gross anatomy observation showed the speed of union of fracture in group B were more than that in group A.2 By histomorphology observation under light microscope: group A: The animal models in simple fracture group appeared a typical healing course, periosteal proliferation were lightly, Only a little bony callus ,both membrane bone formation and enchondral bone formation were existed.the periost began to thickening at 4 days,the quantites of cartilage cell and fibroblast in periost to increase gradually. Typical bone trabecula have emerged at 14 days. Group B:the fracture was appears blood tumor and Inflammatory reaction. Periost obviously thickening in lday;it began to emrge cartilage cell in periost at 4 days. there was a quantity of fibrous callus and collagenoblas;at 7 days,the cartilage cell in fibrous callus and Subperiosteum was increasing,some of them were coalesce together, endochondral bone formation were less;at 14 days ,there were still founed a great quantity fibrous callus and cartilage bone callus, a small quantity parce woven bone emerged in the beside of cartilage cell, the cartilage in ex-subperiosteum were still not completely to chang to woven bone.3 By mean of immunohistochemistry stain: group A: NGF expressed weakly in fibroblast and chondroblasts in callus.The masculine cell population have not obviously change bttween the 21 days.group B: NGF expressed in fibroblast and chondroblasts in callus were enhanced at 4 days, The masculine cell population increased obviously at 7 days, and bone formation with NGF highest expression at 14 days. we found masc bone cell number in group B is significantly more than that in group A at 4 days,1 weeks,2 weeks,3 weeks (P＜0.05) .Conclusion The experiment has showed that the expression of NGF and the speedof fracture recover exist direct correlation,in the thighbone fracture with cerebral injury.