【作者】 陈利锋；

【导师】 周定标；

【作者基本信息】 中国人民解放军军医进修学院 ， 外科学， 2009， 博士

【摘要】 背景缺血性卒中15%-20%因颈动脉粥样硬化性狭窄(CAS)所致,其发病机制包括狭窄所致的血流动力学障碍和栓子脱落造成的栓塞。颈动脉内膜切除术(CEA)被公认为CAS最有效的手术方式。CEA可去除可能导致脑栓塞的粥样硬化斑块,但对脑血流动力学的影响并不十分明确。近年有报道天冬酰胺酰(基)内肽酶(legumain)在动脉粥样硬化斑块内有高表达,legumain可能在不同的病理过程中参与动脉粥样硬化的发生和发展,但对CAS病变中legumain表达和作用的系统研究少见。第一部分颈动脉内膜切除患者手术前后脑血流动力学变化目的采用TCD技术观察分析CEA对症状性和无症状CAS患者脑血液动力学的影响。方法2007年1月-2009年1月在我院接受CEA手术资料完整的CAS患者:①有症状组32例:狭窄程度≥50%;②无症状组8例:狭窄程度≥80%。术前3-5天和术后8-10天接受TCD检查MCA、ACA、PCA的MFV和PI。结果1)症状性CAS患者CEA术后同侧和对侧MCA、ACA的MFV和PI较术前提高,差异有统计学意义(P＜0.01);同侧和对侧PCA的MFV较术前降低,差异有统计学意义(P＜0.01),PI与术前比较,差异无统计学意义(P＞0.05)。2)无症状患者术后除同侧PCA的MFV较术前降低,差异有统计学意义(P＜0.05)外,双侧MCA、ACA和对侧PCA的MFV以及双侧MCA、ACA、PCA的PI较术前的差异均无统计学意义(P＞0.05)。小结CEA能改善多数症状性CAS患者的脑血流动力学状况;多数无症状患者CEA后脑血流动力学无明显变化。第二部分颈动脉内膜切除患者手术前后脑血管储备能力变化目的采用TCD技术观察分析CEA手术前后症状性和无症状CAS患者BHI的变化,探讨CEA对CAS患者CVR的影响。方法2007年1月-2009年1月在我院接受CEA手术资料完整的CAS患者和门诊患者:①有症状组10例:狭窄程度≥50%;②无症状组8例:狭窄程度≥80%;③正常对照组8例:门诊接受检查无明显颈动脉狭窄患者。术前3-5天和术后8-10天接受TCD检查。CVR检测采用BHI,观察屏气引起的高碳酸血症对MCA的MFV的影响。结果1)CEA术前症状性CAS患者同侧BHI较无症状患者和正常对照者低,差异有统计学意义(P＜0.01),对侧BHI较无症状患者和正常对照者的差异无统计学意义(P＞0.05);无症状患者双侧BHI较正常对照者的差异无统计学意义(P＞0.05)。2)CEA术后症状性CAS患者手术同侧BHI较术前提高,差异有统计学意义(P＜0.01),对侧BHI较术前的差异无统计学意义(P＞0.05);无症状患者双侧BHI较术前的差异无统计学意义(P＞0.05)。小结TCD检测BHI能客观反映患者CVR;多数症状性CAS患者同侧CVR下降,CEA术后可提高;多数无症状CAS患者CVR无明显异常,CEA术后无明显变化。第三部分颈动脉粥样硬化斑块legumain表达的改变及意义目的对颈动脉粥样硬化斑块不同成份内legumain在蛋白分布、表达量和mRNA等层面的表达进行研究,以期了解legumain在动脉粥样硬化斑块的发生发展中的作用。方法2007年1月-2009年1月在我院接受CEA手术的颈动脉粥样硬化组织标本。30例制作石蜡标本,进行免疫组化检测;10例为不稳定斑块,进行Western blot分析和RT-PCR分析,分析legumain蛋白表达改变和分布及mRNA表达改变。结果免疫组化显示正常对照血管壁内存在少量Legumain表达,主要分布于成纤维细胞和血管内皮细胞核内,少数胞浆也有少量表达。CAS斑块内legumain表达明显增强,主要分布于钙化周边区、炎症坏死周边区和炎症细胞浸润区,以单核-巨噬细胞胞核、胞浆和间质内表达为主。炎症细胞浸润区内legumain阳性染色面积与炎症细胞浸润区面积比与单核-巨噬细胞计数之间呈现一定的线性相关。Western Blot和RT-PCR结果均显示legumain蛋白和mRNA在以坏死为主的斑块内表达最高,而在纤维化和脂质核为主的斑块内表达较低,相对正常区域表达最低。小结legumain表达的改变是CAS病变组织内炎症反应的一个重要环节,可能是导致病变演变的一个重要因素。全文结论1)CEA能改善多数症状性CAS患者的脑血流动力学状况;多数无症状CAS患者CEA后脑血流动力学无明显变化。2)TCD检测BHI能客观反映患者CVR;多数症状性CAS患者同侧CVR下降,CEA术后可提高;多数无症状CAS患者CVR未见明显异常,CEA术后无明显变化。3)legumain表达的改变是CAS病变组织内炎症反应的一个重要环节,可能是导致CAS病变演变的一个重要因素。更多还原

【Abstract】 Background:Carotid atherosclerotic stenosis is the reason for 15%-20%of brain ischemic stroke.The pathogenesis includes the disorder of hemodynamics caused by stenosis and stroke caused by embolus.CEA is the most effective operation for CAS.CEA can resect the atherosclerotic plaque that causes stroke.But the change of brain hemodynamics is indefinite.Recent research have found the Legumain expressed more in the atherosclerotic plaque.The Legumain plays a role during the AS progression.There is no systemic in vivo research on the distribution and expression of Legumain in CAS plaque.PartⅠ.Cerebral Hemodynamic Changes after Carotid EndarterectomyObjective To evaluate cerebral hemodynamic changes of symptomatic and asymptomatic patient groups before and after CEA by means of TCD.Methods 32 symptomatic patients underwent CEA for≥50%internal carotid artery stenosis,and 8 asymptomatic patients underwent CEA for≥80%internal carotid artery stenosis from Jan 2007to Jan 2009.TCD was done 1-3 days before CEA,and 8-10 days after CEA.MFV and PI of MCV,ACA,and PCA were evaluated.Results 1.On the ipsilateral side and contralateral side of symptomatic patients, MFV and PI of MCA and ACA increased significantly after CEA.MFV of PCA decreased significantly,with nonsignificant changes in PI after CEA. 2.On the ipsilateral side of asymptomatic patients,MFV of PCA decreased significantly,with nonsignificant change in PI after CEA.On the bilateral side of asymptomatic patients,nonsignificant changes were seen on MFV and PI of MCA and ACA after CEA.Conclusion Most symptomatic patients show increases of cerebral hemodynamics after CEA.The hemodynamic response of most asymptomatic patients to endarterectomy was negligible.PartⅡ.Cerebrovascular Reserve Changes after Carotid EndarterectomyObjective To evaluate cerebrovascular reserve of symptomatic and asymptomatic patient groups before and after CEA by means of TCD.Methods from Jan 2007to Jan 2009,10 symptomatic patients underwent CEA for≥50%internal carotid artery stenosis,8 asymptomatic patients underwent CEA for≥80%internal carotid artery stenosis,and 8 normal controls were compared. TCD was performed on 1-3 days before CEA,and 8-10 days after CEA.The cerebrovascular reserve was evaluated with TCD ultrasonography for hypercapnia induced by breath holding,which affected the mean blood velocity in MCA.Results 1.The BHI of the ipsilateral side in symptomatic patients was significantly lower than that in asymptomatic patients and normal controls before CEA.There were no significant differences between the BHI of the contralateral side in symptomatic patients with that in asymptomatic patients and normal controls before CEA.There were no significant differences between the BHI of the bilateral side in asymptomatic patients with that in normal controls before CEA. 2.The BHI of the ipsilateral side in symptomatic patients improved significantly after CEA as compared with preoperative BHI,however,There was no significant change between preoperative BHI with postoperative BHI in the contralateral side of symptomatic patients.There was no significant change between preoperative BHI with postoperative BHI in the ipsilateral side of asymptomatic patients.There was no significant change between preoperative BHI with postoperative BHI inthe contralateral side of asymptomatic patients.Conclusion TCD could be used successfully to monitor CVR of the CAS patients before and after CEA by means of BHI.most symptomatic patients showed a low CVR and their CVR increased after CEA.The asymptomatic CS group represented a normal CVR,and their CVR in response to endarterectomy was negligible.PartⅢ.Expression and Meaning of Legumain in the Carotid Atherosclerotic PlaquesObjective To investigate the expression and distribution of legumain through the detection of the protein and mRNA of legumain in CAS plaques.Methods from Jan 2007 to Jan 2009,the 30 atherosclerotic plaque paraffin slices are processed immunohistochemical staining of legumain,and the other 10 unstable atherosclerotic plaques are processed to gather protein and mRNA respectively for western blot and RT-PCR in order to analyze the expression and distribution of legumain.Results Immunohistochemistry staining show that there is legumain expression on normal artery walls symmetrically distributed and mainly situated in the nuclears of ECs,and fibroblast cells.In the plaques,there is a hyperexpression of legumain,mainly situated in the nuclears and cytoplasms of monocytes and macrophages in inflammatory areas.There is a certain liner correlation between the ratios of legumain positive areas to inflammatory areas and the counts of monocytes and macrophages.Western Blot and RT-PCR coincidently show that legumain protein and mRNA express the highest in necrotic areas,low in fibrosis and lipid pool areas,and the lowest in the normal areas.Conclusion Legumain,being a inflammatory factor,may play an important role in the pathological progress and development of CAS.Summary1.Most symptomatic patients show increases of cerebral hemodynamics after CEA.The hemodynamic response of most asymptomatic patients to endarterectomy was negligible.2.TCD could be used successfully to monitor CVR of the CAS patients before and after CEA by means of BHI.most symptomatic patients showed a low CVR and their CVR increased after CEA.The asymptomatic CS group represented a normal CVR,and their CVR in response to endarterectomy was negligible.3.Legumain,being a inflammatory factor,may play an important role in the pathological progress and development of CAS.更多还原