大鼠大脑中动脉超微结构的衰老性变化

目的 研究大脑中动脉超微结构的增龄变化，为探索脑血管疾病的发病机制提供参考资料。方法 应用透射电镜观察各年龄组大鼠大脑中动脉的超微结构。结果 老龄组大鼠大脑中动脉基膜增厚，内弹性膜变薄、不均质、边缘伸出分支到中膜，内皮细胞和平滑肌细胞向内弹性膜穿过，内弹性膜内出现脂质，并有分层、断裂现象，胶原纤维增多。结论 随着年龄的增加，大鼠大脑中动脉的超微结构具有明显的改变。     

猕猴大脑中动脉中央支的衰老性变化—透射电镜观察

用透射电镜方法对九只雄性猕猴大脑中动脉中央支脑外近脑段的增龄改变进行了观察,发现该动脉的主要变化有(1)内膜的局限性增厚并向管腔内突出.(2)中膜平滑肌细胞的局部变性和向内膜的侵入.(3)内皮细胞的脱失.显示该动脉随增龄而发生结构上的改变,这些改变为探讨该动脉最易受累的形态学基础、脑血管疾病的病因学以及它们的发病机理提供了形态学资料.     

大鼠大脑中动脉原弹性蛋白mRNA表达的增龄变化

目的 :检测各年龄组大鼠大脑中动脉原弹性蛋白mRNA表达的变化。方法 :原位杂交染色 ,常规光镜观察 ,图像分析 :结果 :大鼠大脑中动脉的内膜、中膜和外膜均有原弹性蛋白mRNA的表达 ,随年龄增加 ,表达显著减弱。结论 :原弹性蛋白mRNA表达减弱可能是弹性纤维含量随增龄而减少的主要原因之一 ,与老年性脑血管疾病关系密切。     

大鼠大脑中动脉弹性纤维的构筑与分布

目的 研究大脑中动脉弹性纤维的构筑及分布。方法 采用Weigert染色方法显示弹性纤维，光镜观察大鼠大脑中动脉弹性纤维的构筑与分布；透射电镜观察弹性纤维的超微结构。结果 大鼠大脑中动脉的弹性纤维构成一完整的、波浪状的内弹性膜，着色均匀，中膜、外膜仅有散在的弹性纤维分布，缺乏完整的外弹性膜；电镜下可见内弹性膜规则，均质，厚度均一，边缘光滑、清晰。结论 大鼠大脑中动脉弹性纤维形成完整的内弹性膜，这可能对脑组织具有一定的保护作用。     

高脂血症大鼠大脑中动脉神经肽Y能神经纤维的变化

观察高脂血症大鼠不同时期大脑中动脉神经肽Ｙ能神经纤维的变化。方法ＡＢＣ免疫组人方法；结果（１）定性观察；对照组各时期神经肽育神经纤维多呈网状攀附于血管周围，纤维较稀疏，并有明显的串珠状膨体；高脂组纤维亦呈网状分布于血管周围，较稠密，膨体清晰可见，这种变化见一实验组各时期。     

肝细胞生长因子对大鼠大脑中动脉梗塞后凋亡变化的实验分析

目的 探讨大鼠大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)模型中肝细胞生长因子(hepatocyte growth fac-tor,HGF)对凋亡影响的作用.方法 62只SD大鼠随机分为Sham组、MCAO组及HGF组,MCAO组及HGF组均采取线栓法建立MCAO模型.各...     

Wistar大鼠永久性局灶性大脑中动脉阻断脑缺血新模型的建立

在Ｗｉｓｔａｒ大鼠用改良的开颅方法两点阻断大脑中动脉,建立一个新的永久性局灶性脑缺血模型（ＰＭＣＡＯ）。通过大鼠脑梗塞后神经功能状况的观察,明胶－墨汁灌注、ＴＴＣ染色计算机图像分析及病理形态学的方法对模型进行研究评价。Ｗｉｓｔａｒ大鼠大脑中动脉阻断后２４　ｈ,神经功能为２级;模型组梗塞面积稳定,占对侧面积５７±５％,其梗塞灶位于脑皮质和纹状体外侧;病理形态学表现为典型的缺血性改变。结果表明,用本方法阻断大脑中动脉,阻断确切,梗塞灶的大小、位置恒定。这一模型为局灶性脑缺血机制的研究以及治疗药物的疗效观察提供了一个可重复、稳定可靠的动物模型。     

大脑中动脉及分支的研究

随着显微血管外科的普及和提高,为颅内、外动脉吻合术闭塞性脑血管的外科治疗提供形态学资料。作者于1993年11月～1995年10月用成人脑标本,对大脑中动脉的位置、走行、分支类型、口径及吻合进行了观察和测量,并对临床应用意义进行探讨。 材料与方法 用成人50例(男32例,女18例)防腐固定的完整头部和脑标本,去颅后细心地剥离蛛网膜,掰开大脑外侧裂,然后用弯脚规,直脚规,游标卡尺等观察和测量大脑中动脉主干及分支的口径、类     

大鼠大脑中动脉的解剖及其在脑缺血模型中的应用

用４５只大鼠脑标本观测大脑中动脉的起始，行程，分支及分布情况，确定制仡中灶性脑缺血模型血管阻断部位。大鼠的大脑中动脉可分三段，中段相对较长，位置恒定，分支较少，表面骨质较薄，易于凿骨开窗，是制作脑缺血模型阻断血管的最佳部位。     

高血压大鼠大脑中动脉内膜超微结构观察

目的:观察高血压大鼠大脑中动脉内膜的超微结构变化。方法:双肾双夹法建立肾血管性高血压大鼠模型,分别于7d、30d、90d处死动物,取大脑中动脉始段,用透射电镜观察。结果:高血压组7d内皮细胞肿胀明显,细胞膜呈虫蚀样改变,胞质内空泡明显增多,线粒体肿胀,呈大小不等的圆球状,内弹力膜肿胀,可见较多的空泡,局部增厚,与内皮细胞之间的边界模糊不清,核周隙增宽;30d内皮细胞和内弹力膜的变化与7d相似,肿胀略有减轻,但内皮细胞伸出伪足伸入内弹力膜形成的肌内皮细胞样连接多见;90d内皮细胞肿胀较7d、30d减轻,但线粒体肿胀更加明显,而且数量增多,可见散在的糖元颗粒,另外,内皮细胞间连接破坏明显,失去正常的形态,内弹力膜肿胀减轻,但仍可见空泡样改变,而且局部变薄,内皮下间隙增宽。结论:高血压大鼠脑动脉内膜结构的改变存在从水肿、肿胀减轻到结构性破坏的变化过程,这种变化可能是其在高血压晚期发生脑卒中的病理学基础。     

The infarct‐limiting effect of cerebral ischaemic postconditioning in rats depends on the middle cerebral artery branching pattern

Cerebral ischaemic postconditioning (PostCon) is a recently discovered endogenous neuroprotective phenomenon that occurs after several brief bouts of reperfusion/ischaemia instituted immediately after prolonged cerebral ischaemia. Data on the extent of PostCon‐mediated infarct size limitation in models of focal cerebral ischaemia–reperfusion are controversial. In this study, we investigated the infarct‐limiting effect of PostCon in the rat model of focal cerebral ischaemia–reperfusion. The relationship between anatomic pattern of the middle cerebral artery (MCA) and infarct size was also studied. The protocol of PostCon consisting of five episodes each of 10‐s ischaemia and 10‐s reperfusion was protective in terms of infarct size limitation only in animals with the typical bifurcating MCA branching pattern. The anatomic pattern of the MCA should be considered as one of the important factors influencing the outcome of neuroprotection studies.     

Branching pattern of middle cerebral artery in an African population

Branching pattern of middle cerebral artery influences frequency of its aneurysms, and is of potential value in their surgical repair and diagnosis of stroke. This pattern shows inter-population variations but there is paucity of data from Africans. This study aimed at describing branching pattern among black Kenyans. Middle cerebral arteries numbering 288 from 144 formalin fixed brains obtained during dissection and autopsy at Department of Human Anatomy, University of Nairobi, Kenya were studied. Origin of the middle cerebral artery was identified at base of brain and its stem followed by gently separating the fronto-parietal and temporal lobes. Pattern of early cortical, lenticulostriate, and terminal branching was recorded and macrographs taken. Results were analyzed using SPSS version 13.0 for windows and presented using macrographs. All the brains had bilateral middle cerebral arteries which were continuations of the internal carotid artery. Variations of the artery observed included duplication (1.7%), early bifurcation (5.2%), and early cortical branching (47%), predominantly temporal (63.9%). Lenticulostriate arteries arose predominantly from the pre-bifurcation segment as single branches (64.6%), and as common trunks (35.4%). Modes of termination were bifurcation (82.3%), trifurcation (10.8%), primary trunks (6.2%), and quadrifurcation (0.7%). Cortical branching pattern of the middle cerebral artery resembles that of Caucasian and Indian populations suggesting equal vulnerability to aneurysms and stroke. Pattern of origin of lenticulostriate arteries, predominantly from the pre-bifurcation segment and higher percentage of common trunks implies that the population is more prone to ischemia after aneurysm repair. Extra diligence during operation on proximal middle cerebral artery is called for.     

L-丝氨酸对永久性大脑中动脉栓塞大鼠的神经保护作用

目的: 研究L-丝氨酸对大鼠永久性脑梗死的神经保护作用、治疗剂量及有效治疗时间窗,并探讨相关作用机制。方法: 制作大鼠永久性大脑中动脉栓塞(pMCAO)模型,腹腔注射L-丝氨酸,通过神经行为学评分、脑梗死体积测定和尼氏染色法,观察L-丝氨酸的治疗剂量效应(56 mg/kg、168 mg/kg和504 mg/kg治疗组)和治疗时间窗(1 h、3 h、6 h、12 h和24 h治疗组);并测定丝氨酸消旋酶抑制剂对L-丝氨酸疗效的影响。利用激光多普勒血流监测仪观察缺血区血供及L-丝氨酸对缺血区局部脑血流量的影响。结果: 与pMCAO组相比,L-丝氨酸于pMCAO后3 h使用,168 mg/kg和504 mg/kg两个剂量都能较好地降低神经行为学评分,减少脑梗死体积,抑制海马CA1区神经细胞的丢失。在治疗时间窗的研究中,L-丝氨酸在pMCAO后6 h内治疗具有明显的神经保护作用,12 h及以后使用,神经保护作用不明显。丝氨酸消旋酶抑制剂不改变L-丝氨酸的疗效。脑缺血30 min时注射L-丝氨酸可明显增加缺血区局部脑血流量,并且这一作用不受甘氨酸受体阻断剂士的宁的影响。结论: L-丝氨酸对永久性脑梗死具有神经保护作用,其机制可能部分与增加缺血区皮质的血供有关。     

The accessory middle cerebral artery (AMCA). Diagnostic and therapeutic consequences

Summary The existence of the accessory middle cerebral artery (AMCA) is a rare anatomical variation with an estimated incidence of 0.31%. The embryological development of this artery is unknown. Three anatomical subtypes are described: in the type 1 variety the AMCA arises from the internal carotid artery; in the type 2, the AMCA originates from the proximal part of the anterior cerebral artery; in type 3, the AMCA arises from the distal part of the anterior cerebral artery. The use of endovascular techniques to treat cerebral vascular malformations requires knowledge of the anatomical subtype of AMCA and the brain regions it supplies (cortex, basal ganglia).

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L'artère cérébrale moyenne accessoire (ACMA). Conséquences diagnostiques et thérapeutiques

Résumé L'artère cérébrale moyenne accessoire est une variété rare (0,31 %) dont l'embryologie n'est pas connue. On en décrit trois types anatomiques: 1) né de l'artère carotide interne, 2) né de l'artère cérébrale antérieure dans sa partie proximale, 3) né de l'artère cérébrale antérieure dans sa partie distale. Dans la pratique thérapeutique des malformations vasculaires cérébrales par navigation intra-vasculaire, le type de variété doit être connu ainsi que les territoires auxquels cette artère se distribue (cortex, noyaux gris).

     

Ketamine-induced rotational asymmetry in evaluation of motor disturbances in rats with middle cerebral artery occlusion

Intraperitoneal injection of ketamine in subanesthetic doses to Wistar rats with unilateral occlusion of the middle cerebral artery caused ipsilateral rotation (2-10 rpm), which was recorded in an automatic rotameter. The optimal dose of ketamine was 50 mg/kg. The animals were examined in an automatic rotameter for 40 min. Motor asymmetry persisted for no less than 2 months after surgery. According to the neurological test (Menzies scale) motor asymmetry in animals with focal brain ischemia persisted for no more than 30 days. The degree of ketamine-induced motor asymmetry in intact rats was 0.10±0.03 rpm.     

Effect of decompressive hemicraniectomy in patients with acute middle cerebral artery infarction

Background/aim We aimed to determine in which cases this procedure may be more effective based on the data of patients who underwent decompressive hemicraniectomy (DHC).Material and methodsOverall, 47 patients who underwent DHC due to acute middle cerebral artery (MCA) infarction between January 2014 and january 2019 were retrospectively investigated. These patients were divided into two groups: those who died after DHC (Group A) and those who survived DHC (Group B). The groups were compared in terms of various parameters. We investigated whether the patient’s modified Rankin scale (mRS) status changed depending on age (> 60 and < 60 years).ResultsThe median age of all patients was 65 (37–80) years; groups A and B had median ages of 66.5 (37–80) and 61 (44–79) years (p = 0.111), respectively; 55.3% patients were male. The elapsed times until hospitalization after the onset of symptoms were 4.5 and 3 h in groups A and B, respectively (p = 0.014). The median GCS score at the time of admission was 7 (5–12) and 10 (8–14) in groups A and B, respectively (p = 0.0001). At the time of admission, 63.3% patients in group A had anisocoria, whereas no patient in group B had anisocoria (p = 0.0001). In postoperative period, 40% patients in group A and all patients in group B received AC/AA treatment. The survival of patients aged < 60 and > 60 years who underwent DHC for MCA infraction was 61.5% and 26.5%, respectively (p = 0,041). The median mRS of patients < 60 and > 60 years were 4 (1–6) and 6 (1–6), respectively (p = 0.018).Conclusion Age, DHC timing, and elapsed time until hospitalization or access to treatment directly affect the functional outcome and survival in MCA-infarcted patients who underwent DHC. In patients in whom the medical treatment fails, early DHC administration will increase survival without waiting for neurological worsening once herniation is detected radiologically.