Objective： To observe serum and callus leptin expression within the setting of fracture and traumatic brain injury （TBI）.Methods： Atotal of 64 male SD rats were randomized equally into 4 groups： nonoperated group...Objective： To observe serum and callus leptin expression within the setting of fracture and traumatic brain injury （TBI）.Methods： Atotal of 64 male SD rats were randomized equally into 4 groups： nonoperated group, TBI group, fraeture group, and fracture＋TBI group. Rats were sacrificed at 2, 4, 8 and 12 weeks after fracture＋TBI. Serum leptin was detected using radioimmunoassay, and callus formation was measured radiologically. Callus leptin was analyzed by immunohistochemistry.Results： Serum ieptin levels in the fracture group, TBI group and combined fracture＋TBI group were all significantly increased compared with control group at the 2 week time-point （P〈0.05）. Serum leptin in the combined fracture ＋TBI group was significantly higher than that in the fracture and TBI groups at 4 and 8 weeks after injury （P〈0. 05）.The percentage of leptin-positive cells in the fracture＋TBI callus and callus volume were significantly higher than those in the fracture-only group （P〈0.01）.Conclusions： We demonstrated elevated leptin expression within healing bone especially in the first 8 weeks in a rat model of fracture and TBI. A close association exists between leptin levels and the degree of callus formation in fractures.展开更多
Objective: To dynamically monitor the bone mineral density (BMD) and the histomorphological changes during fracture healing in a rat femoral fracture model and to explore the role of dual energy X-ray absorptiometry (...Objective: To dynamically monitor the bone mineral density (BMD) and the histomorphological changes during fracture healing in a rat femoral fracture model and to explore the role of dual energy X-ray absorptiometry (DEXA) in evaluating bone fracture healing. Methods: Sixty three-month-old female Sprague Dawley rats were used to establish right femoral fracture models. The BMD of the callus of the fractured right femur were scanned by DEXA at 2, 4, 6, 8, 10 and 12 weeks after operation, respectively. A light microscope was used to evaluate the callus of each rat at the same time. The corresponding segment of the left femur was taken as a control. Results: The BMD at the fractured site increased significantly during the process of facture healing, which shows an obvious healing trend. The callus BMDs were 29.5%, 48.3%, 85.3%, and 105.2% of the BMD of the control limb at 2, 4, 6 and 8 weeks after fracture, respectively. There was a significantly difference between the groups. A compatibility on time was found between the BMD and the histomorphological characteristics at the fractured site during the process of fracture healing. The fracture healing was almost completed at 8 weeks after fracture as assessed by its histomorphological characteristics when the callus BMD reached to 105.2% of the BMD of the control limb. The BMD of the distal metaphysis decreased until 12 weeks after fracture. Conclusions: DEXA can evaluate the mineralization of the callus during the facture healing process accurately and quantitatively and is more sensitive than plain radiography in detecting impaired bone unions, which indicates that it may play an important role in monitoring fracture healing.展开更多
文摘Objective： To observe serum and callus leptin expression within the setting of fracture and traumatic brain injury （TBI）.Methods： Atotal of 64 male SD rats were randomized equally into 4 groups： nonoperated group, TBI group, fraeture group, and fracture＋TBI group. Rats were sacrificed at 2, 4, 8 and 12 weeks after fracture＋TBI. Serum leptin was detected using radioimmunoassay, and callus formation was measured radiologically. Callus leptin was analyzed by immunohistochemistry.Results： Serum ieptin levels in the fracture group, TBI group and combined fracture＋TBI group were all significantly increased compared with control group at the 2 week time-point （P〈0.05）. Serum leptin in the combined fracture ＋TBI group was significantly higher than that in the fracture and TBI groups at 4 and 8 weeks after injury （P〈0. 05）.The percentage of leptin-positive cells in the fracture＋TBI callus and callus volume were significantly higher than those in the fracture-only group （P〈0.01）.Conclusions： We demonstrated elevated leptin expression within healing bone especially in the first 8 weeks in a rat model of fracture and TBI. A close association exists between leptin levels and the degree of callus formation in fractures.
文摘Objective: To dynamically monitor the bone mineral density (BMD) and the histomorphological changes during fracture healing in a rat femoral fracture model and to explore the role of dual energy X-ray absorptiometry (DEXA) in evaluating bone fracture healing. Methods: Sixty three-month-old female Sprague Dawley rats were used to establish right femoral fracture models. The BMD of the callus of the fractured right femur were scanned by DEXA at 2, 4, 6, 8, 10 and 12 weeks after operation, respectively. A light microscope was used to evaluate the callus of each rat at the same time. The corresponding segment of the left femur was taken as a control. Results: The BMD at the fractured site increased significantly during the process of facture healing, which shows an obvious healing trend. The callus BMDs were 29.5%, 48.3%, 85.3%, and 105.2% of the BMD of the control limb at 2, 4, 6 and 8 weeks after fracture, respectively. There was a significantly difference between the groups. A compatibility on time was found between the BMD and the histomorphological characteristics at the fractured site during the process of fracture healing. The fracture healing was almost completed at 8 weeks after fracture as assessed by its histomorphological characteristics when the callus BMD reached to 105.2% of the BMD of the control limb. The BMD of the distal metaphysis decreased until 12 weeks after fracture. Conclusions: DEXA can evaluate the mineralization of the callus during the facture healing process accurately and quantitatively and is more sensitive than plain radiography in detecting impaired bone unions, which indicates that it may play an important role in monitoring fracture healing.
