【作者】 徐明珠；

【导师】 崔树森；

【作者基本信息】 吉林大学 ， 外科学， 2010， 博士

【摘要】 周围神经缺损的修复是外科领域至今尚未解决的难题之一。尽管许多学者对异体神经移植、异种神经移植、非神经组织材料替代移植、组织工程人工神经移植修复神经缺损进行了大量的研究,但自体神经移植仍是目前临床用于修复神经缺损的首选方法。然而,自体神经移植特别是长段神经移植后,临床疗效仍不尽人意。长段移植神经的血供、移植神经周围的瘢痕组织、跨越两个吻合口对神经再生的影响等因素,是目前许多学者重点关注的问题。但是,关于远侧吻合口与近侧吻合口在影响神经再生方面的作用有何不同?依据神经再生的速度,择期切除远侧吻合口并进行重新吻合后,对促进再生轴突跨越远端吻合口的作用如何?择期切除远侧吻合口,对相关感觉、运动神经元功能状况的影响如何?国内外相关研究少见。作为阐明上述问题系列研究的一部分,本课题采用大鼠坐骨神经原位移植模型,应用免疫组化、RT-PCR、Western-blot等技术,观察神经吻合口内I型和III型胶原的表达变化;观察择期切除远侧吻合口再修复后,相关感觉、运动神经元内AChE、ACP、BDNF的表达变化。以明确远侧吻合口瘢痕增生的情况;明确择期切除再吻合后瘢痕组织与神经轴突再生的状况;明确择期切除远侧吻合口,对相关感觉、运动神经元部分功能状况的影响。研究结果:1、择期切除移植神经的远侧吻合口再吻合后,术后4w时,实验组与对照组I型和III型胶原的表达无显著性差异,8w时实验组明显低于对照组。2、择期切除移植神经的远侧吻合口再吻合后,实验组运动神经元内AChE、ACP损伤性反应依然存在,但与对照组相比损伤反应减轻,差异具有显著性。3、择期切除移植神经的远侧吻合口再吻合后,BDNF在相应脊髓和背根神经节中再次出现表达高峰,与对照组有显著性差异。研究结论:1、择期切除移植神经的远侧吻合口再吻合后,明显减轻了远侧吻合口瘢痕组织的增生,有利于再生轴突跨越远端吻合口。2、择期切除移植神经的远侧吻合口再吻合后,尽管相应运动神经元仍存在酶学指标的损伤性反应,但其损伤程度明显减轻。3、择期切除移植神经的远侧吻合口再吻合后,相关感觉、运动神经元内促进轴突再生的能力再次得到激活和增强。更多还原

【Abstract】 It is one of the difficult problems left unsolved in surgical field to repair the peripheral nerve defect.Although many scholars have investigated a lot on xenogenous nerve graft, heterogenous nerve graft, alternating autologous biological tissue and tissue-engineered bioartificial nerve to repair nerve defect, autologous nerve graft has always been the first consideration for nerve restorative procedure in clinic. However, the healing efficacy of autologous nerve graft is still not so satisfactory, especially long nerve graft. Blood supply of long nerve graft, surrounding scar tissue and axons stepping over two anastomotic stomata influence the nerve regeneration are concentrated on by many scholars. But if there were the differences between the impacts from distal and proximal anastomotic stoma on nerve regeneration, how are the effects on regenerated axon growing through distal anastomotic stoma of re-anastomosis after selective excision of distal anastomotic stoma according to the speed of nerve regeneration? How will affect the function of sensory and motor neurons after selective excision of distal anastomotic stoma? These are still rare all over the world on these studies.Purposes:The distal anastomotic stoma after nerve graft was excised and re- anastomsed, then we observed whether hyperplasia of scar tissue could be suppressed and the growth through distal anastomotic stoma of regenerated axon could be promoted. Meanwhile, functional status of axons was observed which had grown to distal anastomotic stoma to see whether axonal growth promotion could be aroused again by sensory and motor neurons.Methods:Sciatic nerve graft in situ was built on Wistar mouse. The mice were grouped randomly into sham operation group (nerve exposed only), control group (nerve graft in situ) and experimental group (excision and repair distal anastomotic stoma 8 weeks after nerve graft). Nerve tissue of distal anastomotic stoma, corresponding spinal cord and dorsal root ganglion were excised in different time spots. Immunohistochemical methods were used to test the expression changes of collagen type I and III ,which could obtain the condition of hyperplastic scar tissue in distal anastomotic stoma. The changes of AChE, ACP and BDNF in sensory and motor neurons after re-anatomsis were detected by immunohistochemical methods, Rt-PCR and western blot .These changes could identify the state of axon regeneration and scar tissue and the influences on partical function of corresponding sensory and motor neurons.Results:1. There was no significant variation in expression of collagen type I and III in control group and experimental group 4 weeks after the re-anastomosis and 8 weeks later. It was lower in experimental group compared with control group.2. AChE and ACP leading to impaired reaction of motor neuron still existed after re-anastomosis in experimental group. There was significant deviation of AChE expression in experimental group than that of control group from 7th to 28th day (P<0.01).There was significant deviation of ACP expression in experimental group lower than control group from 7th to 56th day (P<0.01)3. After the re-anastomosis, there was a BDNF expression peak in spinal cord and dorsal root ganglion in 14th day and the deviation was significant between control group and experimental group(P<0.01).The expression went down gradually after 42th day .At 56th day, BDNF expression is still higher than that of control group (P<0.01).Conclusions:1. Re-anastomosis after selective excision of distal anastomotic stoma strongly suppresses hyperplasia of scar tissue and is helpful to stimulate axon growing throu- gh distal anas- tomotic stoma.2. Although there is still enzyme changes caused by selective excision in motor neurons,but the injury degree is obviously less than that caused by previous injury.3. Capability of promoting axon regeneration is aroused and enhanced in sensory and motor neurons after the re-anastomosis. 4. According to the speed of peripheral nerve regeneration, re-anastomosis after selective excision of distal anastomotic stoma could suppress hyperplasia of scar tissue and promote regenerative axon growing through distal anastomotic stoma preferably. It could stimulate efficiently the grown axons which have reached distal anastomotic stoma, which could evoke functional status of promoting axon growth in the correlated sensory and motor neurons once more.更多还原