OBJECTIVE: To investigate the variation of neurotrophic factors expression in spinal cord and muscle after root avulsion of brachial plexus. METHODS: Forty-eight Wistar rats were involved in this study and according to the observing time in 1st day, 1st week, 4th week, 8th week, and 12th week after avulsion, and the control, were divided into 6 groups. By immunohistochemical and hybridization in situ assays, the expression of nerve growth factor (NGF) on muscle, basic fibroblast growth factor(bFGF) and its mRNA on the neurons of corresponding spinal cord was detected. Computer image analysis system was used to calculate the result. RESULTS: After the root avulsion of brachial plexus occurred, expression of NGF increased and reached to the peak at the 1st day. It subsided subsequently but was still higher than normal control until the 12th week. While expression of bFGF and its mRNA increased in the neurons of spinal cord and reached to the peak at the 1st week. Then it dropped down and at the 12th week it turned lower than normal control. CONCLUSION: After root avulsion of brachial plexus, neurotrophic factors expression increase on target muscle and neurons of corresponding spinal cord. It maybe the autoregulation and may protect neuron and improve nerve regeneration.
Objective To investigate the effects of the recombinanthuman bone morphogenetic protein 2 (rhBMP-2) and/or the osteogenic agents on proliferation and expression of the osteoblast phenotype differentiation of the SD rat mesenchymal stem cells（MSCs）. Methods The rat MSCs were cultured in vitro and were randomly divided into the experimental groups(Groups A-I) and the control group. In the experimental group, MSCs were induced by rhBMP2 in different doses (10, 50, 100 and 200 μg/L) in Groups BE, the osteogenic agent alone (Group A) and by the combined use of rhBMP-2 ［in different doses (10,50, 100 and 200 μg/L)］ and the osteogenic agent in Groups F-I. The MTT colorimetric assay was used to evaluate the proliferation, and the activities of alkaline phosphatase (ALP) and osteocalcin (OC) were observed at 3, 6, 9, 12 days, respectively. Results The inverted phase contrast microscopy showed that MSCs by primary culture for 12 hours were adhibited, with a fusiform shape at 48 hours. At 4 days they were polygonal or atractoid, and were spread gyrately or radiately at 6 days. At 10 days, they were spread at the bottom of the bottle.The statistical analysis showed that the expression of the osteoblast phenotype differentiation of MSCs could be induced in the experimental groups. The proliferation of MSCs could be enhanced in a dosedependent manner in GroupsB-E. The expression of the osteoblast phenotype differentiation, which was tested by the activities of ALP and OC, was significantly higher in Groups F-I than in Groups A-E. Conclusion The combined use of rhBMP-2 and the osteogenic agents can enhance the MSC proliferation and induce an expressionand maintenance of the osteoblast phenotype differentiation of the rat MSCs.
Objective To probe a satisfactory surgical management of the limbsalvage for osteogenic malignant tumors around the knees. Methods From January1989 to December 2001, 42 patients (19 males and 18 females, aged 12-46) with osteogenic malignant tumors around the knees underwent surgical management of the limb salvage, including prosthesis replacement, allogenous bone grafting, and bone cement with adriamycin filled. Based on the pathological examination, osteosarcoma was found in 11 patients, synoviosarcoma in 4 patients, malignant fibrous histiocytoma in 3 patients, and giant cell tumor of the bone in 19 patients. All the patients underwent neoadjuvant chemotherapy for 1-2 courses before operatioexcept the patients with giant cell tumor of the bone. The patients underwent prosthesis replacement, allogenous bone grafting, bone cement with adriamycin filled, and postoperative chemotherapy. By the Enneking evaluating system, the patients were assessed on their reconstructed limb functions after the reconstructive operation for the musculoskeleta malignant tumors. Of the patients, 37 were followed up after operation. Results According to the follow-up for 3-11 years (mean, 5.6 years) in the 37 patients, 2 patients had recurrence and metastasis of the tumor, and died 3 and 4 years after operation, respectively. One patient underwent amputation of the limb for local recurrence of the tumor. One patient had amputation of the limb for the preoperative radiotherapy and the infection and necrosis of the operative wound after the limb-salvage surgery. Two patients had amputation of the limb for the rejection of the allogenous bone graft and theformation of the fistula.Thirty-one patients had good wound healing andgood functions of the limb. The results were evaluated by the Enneking evaluating system as follows: excellent in 7 patients, good in 14, fair in 10, and poor in 6. Conclusion Making an early diagnosis, recognizing the operative indication, choosing the operative method, and performing the preoperative and postoperative chemotherapy and/or radiotherapy are the keys to achieving an ideal limb-salvage surgery for osteogenic malignant tumors around the knees.
Objective To review researches on the relation between marrow stromal cells(MSCs) and repair of bone defect. Methods The latest original literatures about marrow stromal cells and their use in the treatment of bone defect were extensively reviewed. Results Marrow stromal cells were induced to osteoblasts under proper conditions and showed the potential of bone formation in vivo. The methods of bone tissue engineering using MSCs as seed cells and gene therapy using MSCs as target cells were bothuseful in the repair of bone defect.Conclusion MSCs have a promising future in the repair of bone defect.
Objective To investigate the influence of clenbuterol on the expression of nerve growth factor (NGF) in denervated red and white muscles and the neurotrophism of the denervated muscles.Methods Sixty-four Wister rats, weighed 200-250 g, were divided into 8 groups(8 rats per group), including 4 experimental groups and 4 control groups. The denervated model was made in rats by dissection of sciatic nerves. Clenbuterol was given at a dose of 200 μg/kg per day in the experimental group, saline in the control group. The expression of NGF was measured with immunohistochemistry after 1, 3, 7 and 14 days of injury. The culture methods of dorsal root ganglions of the chick embryos were used to measure the neurotrophism of extracts of the muscles. Results Compared with the control groups, the NGF content of gastrocnemious(GAS) increased on the 1st day (Plt;0.05) and the NGF content of soleus(SOL) increased greatly on the 1st, 3rd and 7th dayafter injury in the experimental groups (Plt;0.01). In the experimental groups, the NGF amount of GAS reached the highest value on the 1st day after injury(Plt;0.01) and then decreased gradually. And the NGF amount of SOL had slight difference between different time. The NGF content of the SOL was higher than that of GASon the 7th day (Plt;0.05). The sensory neurotrophism of the extracts was similar between SOL and GAS.Conclusion Clenbuterol can change the expression of NGF in denervated muscles, but the change was different in SOL and GAS. The sensory neurotrophism of the denervated muscles were determined by all of the neurotrophic factors in them.