Relationship Between Time And Dose-effect Of P75 NTR In Nonunion Of Fracture

Objective: To investigate the correlation between P75NTR(P75 neurotrophin receptor,P75NTR)and p75 NTR in the process of fracture nonunion,then the dose-effect relationship was analyzed.Provide a new idea for the treatment of fracture nonunion.Methods: Ninety New Zealand white rabbits were divided into two groups A and B,45 rats in each group.A group was experimental group,rabbits bone defect model was established,and B group was control group,only for simple fracture model.Then X-ray,HE staining and immunohistochemical techniques were used to dynamically observe the formation of non-union fracture.The expression of P75 NTR at different time points during fracture healing in group A and non-union during fracture healing in group A Situation,analysis of the relationship between P75 NTR and time.Results: The successful modeling of the right radial bone defect model in rabbits,X-ray examination confirmed the fracture nonunion.The expression of P75 NTR in the process of non-union fracture presented a rapid increase first,then gradually decreased,and finally maintained a higher level.A,B two groups were almost no obvious immune complex deposition on the first day after operation.After the first 3,5 days,a large number of immune complexes can be seen deposition in the non-healing fracture of the model.A group of 7,14,21,28 days after surgery,compared with 3,5 days significantly reduced,but still higher than the first day after surgery.On the 56 th and 84 th days after operation,it decreased compared with the 28 th day.The average absorbance value was statistically analyzed(P> 0.05).There was no statistical significance.After 2 weeks,though it decreased compared with the previous one,it was still higher than the first day after operation.The average absorbance value was statistically analyzed(P <0.05),with statistical significance.In group B within 2 weeks,the trend was not significantly different from that in group A.The deposition of immunocomplex was almost invisible at 56 and 84 days,similar to normal tissues.The average absorbance value was statistically analyzed(P <0.05).Conclusion: The expression of P75 NTR in non-union fracture presents a rapid increase first,then gradually decreases,and finally maintains at a higher level.P75 NTR acts as a negative regulator of osteogenesis in the formation of non-union fractures.This article provides a new idea for the treatment of fracture nonunion.