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1.
目的 探讨大鼠局灶性脑缺血再灌注脑组织缺血区不同时间点NF-κB、ICAM-1、VCAM-1蛋白表达的变化,及β-七叶皂甙钠干预效果.方法 采用大鼠大脑中动脉闭塞法(MCAO)制作局灶性脑缺血再灌注模型,用免疫组织化学方法观察大鼠脑缺血再灌注不同时间段,NF-κB、ICAM-1、VCAM-1蛋白的表达.并在大鼠于脑缺血前24h、1h及再灌注即刻分别腹腔给予β-七叶皂甙钠5mg/kg,2h MCAO,再灌注24h、48h后取脑,运用TTC染色测算脑梗死体积,免疫组化染色检测NF-κB、ICAM-1、VCAM-1蛋白表达,分析β-七叶皂甙钠的干预效应.结果 (1)脑缺血后缺血区脑组织NF-κB及ICAM-1、VCAM-1表达均增加,NF-κB于再灌注后12~24h表达达高峰,ICAM-1于再灌注后24h表达达高峰,VCAM-1于再灌注后24~48h表达达高峰.(2)NF-κB的表达与血管内皮ICAM-1、VCAM-1的表达呈正相关.(3)β-七叶皂甙钠能显著降低脑缺血再灌注后24h和48h缺血区NF-κB、ICAM-1及VCAM-1的表达增加.(4)β-七叶皂甙钠能明显减轻脑缺血再灌注后的脑组织损伤,再灌注24h脑梗死体积减少41.8%.结论 (1)脑缺血再灌注后NF-κB、ICAM-1、VCAM-1大量表达,这可能是脑缺血再灌注损伤机制之一.(2)脑缺血后NF-κB的活化可能与微血管内皮细胞ICAM-1、VCAM-1蛋白表达调控有关.(3)β-七叶皂甙钠能够减轻脑缺血后的脑组织损伤,有神经保护作用.  相似文献   

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目的探讨β-七叶皂甙钠在大鼠脑缺血-再灌注损伤时对自由基的影响。方法用Wistar大鼠45只制备局灶性脑缺血-再灌注模型,分为假手术组、缺血-再灌注组、β-七叶皂甙钠治疗组,每个组又分为缺血2 h后再灌注6 h、12 h、24 h三个时间点,每组每个时间点5只大鼠,术后观察脑组织梗死面积、大鼠的神经行为学变化评分、脑组织超微病理结构变化、脑组织TTC染色,对缺血区脑组织超氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(malondiadehyde,MDA)含量进行测定和分析。结果假手术组相应时间点神经功能损害评分显著低于缺血-再灌注组和治疗组(P<0.05),治疗组SOD含量明显高于缺血-再灌注组各时间点(P<0.05)。光镜显示假手术组脑组织结构未见明显病理改变,脑缺血-再灌注组神经细胞缺血坏死,细胞水肿明显,胶质细胞弥漫增生,炎性细胞浸润。结论自由基参与了脑缺血-再灌注损伤,β-七叶皂甙钠可降低缺血-再灌注后脑组织中MDA的含量,增加SOD的活性,减轻梗死体积,显著减轻大鼠神经功能损害和脑组织水肿,对局灶性脑缺血-再灌注损伤具有一定的保护作用。  相似文献   

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目的研究局灶性脑缺血再灌注过程中脑缺血区细胞间黏附分子-1(ICAM-1)、血管细胞间黏附分子-1(VCAM-1)的表达规律,并探讨β-七叶皂甙钠对其干预的脑保护作用。方法采用线栓法建立大鼠脑缺血再灌注模型,同时应用β-七叶皂甙钠予以干预。用HE染色和免疫组化染色观察大鼠脑缺血后再灌注不同时点组织学改变和ICAM-1、VCAM-1的阳性表达。结果(1)β-七叶皂甙钠明显减轻缺血再灌注后的脑组织损伤;(2)脑缺血再灌注后缺血区微血管内皮细胞ICAM-1、VCAM-1表达增加,ICAM-1于再灌注后24h表达达高峰,VCAM-1.于再灌注后24~48h表达达高峰,随后降低,但再灌注后72h两者表达仍高于正常水平;(3)β-七叶皂甙钠可以显著降低脑缺血再灌注后24h、48h缺血区ICAM-1、VCAM-1的表达。结论脑缺血再灌注后ICAM-1、VCAM—1大量表达,可能是脑缺血再灌注损伤的机制之一;β-七叶皂甙钠能降低ICAM-1和VCAM-1的表达及减轻脑组织损伤,有脑保护作用。  相似文献   

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目的探讨大鼠局灶性脑缺血再灌注脑组织缺血区不同时间点NF-кB、ICAM-1、VCAM-1蛋白表达的变化,及β-七叶皂甙钠干预效果。方法采用大鼠大脑中动脉闭塞法(MCAO)制作局灶性脑缺血再灌注模型,用免疫组织化学方法观察大鼠脑缺血再灌注不同时间段,NF-кB、ICAM-1、VCAM-1蛋白的表达。并在大鼠于脑缺血前24h、1h及再灌注即刻分别腹腔给予β-七叶皂甙钠5mg/kg,2h MCAO,再灌注24h、48h后取脑,运用TTC染色测算脑梗死体积,免疫组化染色检测NF-кB、ICAM-1、VCAM-1蛋白表达,分析β-七叶皂甙钠的干预效应。结果(1)脑缺血后缺血区脑组织NF-кB及ICAM-1、VCAM-1表达均增加,NF-kB于再灌注后12~24h表达达高峰,Ⅰ- CAM-1于再灌注后24h表达达高峰,VCAM-1于再灌注后24~48h表达达高峰。(2)NF-кB的表达与血管内皮I- CAM-1、VCAM-1的表达呈正相关。(3)β-七叶皂甙钠能显著降低脑缺血再灌注后24h和48h缺血区NF-кB、ICAM- 1及VCAM-1的表达增加。(4)β-七叶皂甙钠能明显减轻脑缺血再灌注后的脑组织损伤,再灌注24h脑梗死体积减少41.8%。结论(1)脑缺血再灌注后NF-кB、ICAM-1、VCAM-1大量表达,这可能是脑缺血再灌注损伤机制之一。(2)脑缺血后NF-кB的活化可能与微血管内皮细胞ICAM-1、VCAM-1蛋白表达调控有关。(3)β-七叶皂甙钠能够减轻脑缺血后的脑组织损伤,有神经保护作用。  相似文献   

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缝隙连接对大鼠脑缺血再灌注后血脑屏障通透性的影响   总被引:4,自引:0,他引:4  
目的 探讨缝隙连接(GJ)在脑缺血再灌注血脑屏障通透性变化中的作用及其可能机制.方法 ①应用激光共聚焦显微镜技术观察GJ蛋白Cx43在缺血再灌注半暗带区脑毛细血管周终足上含量及分布情况的变化.②将Wistar大鼠随机分成假手术组,手术组.线栓法制备大鼠大脑中动脉缺血再灌注模型.通过荧光分光光度定量的方法测定不同时间点脑组织中的伊文蓝含量来观察血脑屏障的通透性的改变.③取伊文蓝漏出最多的时间点,增设辛醇干预组和DMSO溶剂对照组,与相同时间点手术对照组比较,观察辛醇对血脑屏障通透性的影响.结果 缺血2 h再灌注3 h脑组织伊文蓝含量开始增加,再灌注24 h达高峰.激光共聚焦显微镜发现GJ蛋白Cx43在脑内毛细血管周围的星形胶质细胞终足上分布密集.在缺血2 h再灌注24 h半暗带内,终足上的Cx43分布发生变化,聚集成较大斑块.在缺血2 h再灌注24 h组术前给予辛醇干预,脑组织伊文蓝含量[(4.924±0.296)μg/g]低于手术对照组[(5.543±0.506)μg/g],二者差异有统计学意义(P<0.05).结论 GJ在脑缺血再灌注后半暗带终足上分布变化明显,可能加重了血脑屏障通透性的增加;辛醇阻断GJ可以降低脑缺血再灌注血脑屏障的通透性,从而起到减轻脑水肿的作用.  相似文献   

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目的探讨β-七叶皂甙钠对脑缺血-再灌注损伤的保护作用。方法45只Wistar大鼠随机平均分为假手术组、生理盐水对照组和β-七叶皂甙钠治疗组。线栓法阻塞大鼠右侧大脑中动脉,制备局灶性脑缺血-再灌注模型,在脑缺血2h、再灌注24h后,分别对各组大鼠的神经行为学变化评分,对缺血区白介素1β(IL-1β)和肿瘤坏死因子(TNF-α)进行测定和分析。结果在脑缺血2h再灌注24h后治疗组与对照组相比,前者行为学评分优于后者(P〈0.05),IL-1β和TNF-α含量降低(P〈0.05)。结论炎症反应参与了脑缺血-再灌注损伤,β-七叶皂甙钠可以降低缺血-再灌注后脑组织中的IL-1β和TNF-α含量,减轻梗死体积,减轻炎症反应,对局灶性脑缺血-再灌注损伤可能具有一定的保护作用。  相似文献   

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目的探讨β-七叶皂甙钠对大鼠脑缺血-再灌注损伤的保护效果。方法用健康雄性Sprague-Dawley大鼠74只,分为假手术组、缺血-再灌注(IR)组、治疗组,制备局灶性脑缺血-再灌注模型,术后2h治疗组予以腹腔注射β-七叶皂甙钠(5.0mg/kg),另2组给予腹腔注射等量生理盐水。再灌注48h时处死检测脑梗死体积、脑水肿、神经功能评分、NISSL染色、TUNEL染色和caspase-3活性。结果予β-七叶皂甙钠治疗后,大鼠的脑梗死体积显著下降(17±8)%。I/R组的脑含水量较正常对照和假手术组的TUNEL显著增加,而七叶皂甙钠治疗后的脑含水量显著下降。与假手术组相比,I/R组皮层和海马阳性细胞显著增加,而β-七叶皂甙钠治疗能显著降低TUNEL阳性细胞数。治疗组的皮层和海马caspase-3活性显著低于I/R组。结论缺血前及再灌注后采用七叶皂甙钠治疗能有效降低脑梗死体积,表现为脑水肿减轻、神经功能得到改善,可能与治疗能增加存活神经元数和抑制神经元凋亡(凋亡酶活性)有关。  相似文献   

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目的:探讨大鼠脑缺血再灌注后血脑屏障(BBB)通透性的改变以及转移生长因子β1(TGF-β1)在脑组织中的表达。方法:采用线栓法制备大鼠局灶性脑缺血再灌注模型,通过测定脑组织中伊文氏蓝(EB)含量及免疫组化法来观察TGF-β1的表达。结果:缺血2h再灌注3h,BBB 通透性开始增加,24h达高峰,72h后明显减弱。同时,TGF-β1在缺血再灌注3h开始表达,24h达高峰,持续至72h,72h后逐渐减弱。结论:脑缺血后BBB的破坏与TGF-β1的表达密切相关,提示TGF-β1参与了BBB内皮细胞破坏的修复过程。  相似文献   

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目的探讨七叶皂甙钠对大鼠大脑中动脉闭塞缺血再灌注后缺血区神经元凋亡的影响.方法选用健康雄性Wistar大鼠140只,用线栓法建立大鼠大脑中动脉缺血再灌注模型,切取不同时间段缺血半暗带和中心区皮质组织,采用逆转录-聚合酶链反应(RT-PCR)测定凋亡相关基因(Fas、Fas-L与Bcl-2)转录水平的变化;干预组再灌注即刻开始腹腔内注射七叶皂甙钠(5 mg/kg),以后5 mg·kg-1·24 h-1治疗量,而对照组再灌注即刻注射等量生理盐水;对选取的脑组织块行原位末端转移酶标记(TUNEL),计数缺血半暗带和中心区凋亡细胞数目.结果干预组各时段大鼠脑缺血组织神经元凋亡计数明显低于对照组(P<0.01),表达高峰下降明显,干预组脑缺血组织中Fas、Fas-LmRNA表达明显下调,同时可见Bcl-2mRNA表达上调.结论七叶皂甙钠具有抗神经元凋亡作用;调节神经元凋亡相关基因表达水平可能是其机制之一.  相似文献   

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目的探讨黄体酮对大鼠局灶性脑缺血再灌注后血脑屏障紧密连接蛋白ZO-1、occludin表达及血脑屏障通透性的影响。 方法将42只健康雄性SD大鼠按随机数字表法分为假手术组(6只)和缺血再灌注组,后者再按再灌注时间分为缺血2h再灌注3h、6h、12h、24 h、48 h及72h组(各6只)。缺血再灌注组用线栓法制备成大鼠大脑中动脉缺血再灌注模型。采用荧光分光光度法测定缺血侧脑组织中伊文氏蓝(EB)含量来评价血脑屏障的通透性,Western blotting法检测脑组织ZO-1和occludin的表达。取EB漏出最多组的时间点,增设黄体酮干预组和溶剂对照组(各6只),与相同时间点的缺血再灌注组比较,观察黄体酮对ZO-1、occludin表达及血脑屏障通透性的影响。 结果 缺血2h再灌注3h时脑组织EB含量开始增加,再灌注24 h时达高峰;ZO-1、occludin的表达在缺血2h再灌注3h时开始下降,再灌注24 h时达最低。黄体酮干预组EB含量明显低于缺血2h再灌注24 h组,差异有统计学意义(P<0.05)。黄体酮干预组ZO-1和occludin的表达水平均明显高于缺血2h再灌注24 h组,差异有统计学意义(P<0.05)。 结论 黄体酮町抑制缺血再灌注大鼠紧密连接蛋白ZO-1和occludin表达的降低,从而起到保护血脑屏障的作用。  相似文献   

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Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer haircell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of efferent axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.  相似文献   

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Tubocurarine (Tc) effect on membrane currents elicited by acetylcholine (ACh) was studied in isolated superior cervical ganglion neurons of rat using patch-clamp method in the whole-cell recording mode. The "use-dependent" block of ACh current by Tc was revealed in the experiments with ACh applications, indicating that Tc blocked the channels opened by ACh. Mean lifetime of Tc-open channel complex, tau, was found to be 9.8 +/- 0.5 s (n = 7) at -50 mV and 20-24 degrees C. tau exponentially increased with membrane hyperpolarization (e-fold change in tau corresponded to the membrane potential shift by 61 mV). Inhibition of the ACh-induced current by Tc (3-30 microM/1) was completely abolished by membrane depolarization to the level of 80-100 mV. Inhibition of ACh-induced current was augmented at increased ACh doses. It is concluded that the open channel block produced by Tc is likely to be the only mechanism for Tc action on nicotinic acetylcholine receptors in superior cervical ganglion neurons of rat.  相似文献   

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Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005  相似文献   

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After a hopeful beginning, the social process of the reintegration of those with severe mental illness has come to a standstill. I am led to wonder whether "the community" really wants to live together with people suffering from severe mental illness, and if so, how closely? As long as the medical treatment of mental illness provided by the general practitioners is fundamentally deficient, as they are not able to prescribe the necessary interventions--such as out-patient psychiatric nursing, and service providers in the out-patient sector are content with offering increasingly intensive forms of care for the less seriously ill at the cost of the Social Welfare System--the reintegration of those with serious mental illness remains an illusion--which is mainly to the benefit of providers of residential care in homes and hostels.  相似文献   

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