活体微血栓形成过程的定量分析

在应用激发光照射荧光物质注射后的微血管来形成活体微血栓模型的基础上,开发了一种计算机图像处理方法,对微血栓形成的动态过程进行了定量的分析。利用这一方法不仅对形成过程中不同时刻微血栓形成的面积大小进行了测定,而且,进一步应用了计算机图像减影技术,将2幅不同时刻的形成过程中的图像相减,求出形成过程中血栓生长的程度和形状的变化。该方法不仅有利于血栓生长机制研究也可用作抗血栓药物的药效评价。     

槲皮素磷酸钾对大鼠脑血栓形成模型血小板聚集及血浆TXB_2和6-keto-PGF_(12)水平的影响

以大鼠脑血栓形成为模型,观察槲皮素磷酯钾对大鼠脑血栓形成术24h后血小板聚集、血浆TxB2和6-keto-PGF12水平的影响,以及脑电图、脑重量和病理组织学改变。结果表明:复合血栓诱导剂1ml kg-1经颈内动脉注射能诱发大鼠同侧大脑半球内血栓形成,槲皮素磷酯酶钾10-20 mg kg-1能对抗大鼠脑血栓形成,降低体内血小板自发性聚集,抑制血浆TxB2的升高。提示槲皮素磷酸酯钾可能通过其抗血小板聚集及影响花生回烯酸代谢而发挥抗脑血栓形成作用。     

活体微血栓形成过程的定量分析

本研究在大白鼠肠系膜的微血管中,采用荧光物质注射后用激发光照射选定的30～80μm血管的特定部位,逐步形成血小板粘附,继而凝聚在管壁后,形成微血栓的模型。为了详细分析该模型中血栓形成过程,本研究     

关于血小板与材料相互作用的研究——膜表面粘附受体与吸附蛋白质的关系

一、绪言血小板在材料表面的粘附、聚集是引起血栓形成的主要途径。血小板因粘附于材料表面而被激活,释放ADP和凝血酶、血栓烷A2(TxA_2)等血小板释放物质,这些释放出来的物质进而刺激周围的血小板,使之激活。被激活的血小板表现有与细胞粘附性蛋白的结合活性,在其存在下,形成牢固的粘附和聚集块,导致血栓形成。众所周知,这一粘附初期过程受到吸附蛋白的种类及其形     

血栓微颗粒诱导大鼠冠状动脉微血栓形成的机制探讨

目的:探讨大鼠自身血栓微颗粒诱导其心脏心内膜下微血管内血栓形成的机制。方法:通过向大鼠主动脉根部注入自身血栓微颗粒建立冠状动脉微血栓模型,于术后1h、1天、1周、2周、3周和4周取标本。HE染色观察心内膜下微血管内血栓形成情况;酶联免疫吸附双抗体夹心法(ELISA)检测血清中vonWillebrand因子(vWF)含量。结果:HE染色结果显示心内膜下微血管内有血栓形成,部分血栓与内膜紧密粘连。向大鼠体内注入自身血栓微颗粒后1h,血浆中vWF水平显著增高。结论:大鼠自身血栓微颗粒能够诱导其冠状动脉微血栓形成,其心脏心内膜下微血管内皮细胞活化是可能参与机制之一。     

全蝎提取液对家兔实验性动脉血栓的影响

目的:研究全蝎提取液对家兔实验性动脉血栓的影响。方法:采用双氧水(H2O2)损伤家兔颈总动脉复制血栓模型,观察全蝎提取液的抗血栓作用。结果:全蝎提取液能明显减轻兔血栓重量(P<0.01),使血浆6-酮-前列腺素1a(6-keto-PGF1a)含量明显升高(P<0.01),明显降低血栓烷B2(TXB2)含量(P<0.05),全蝎组的APTT、PT和TT较盐水对照组明显延长。结论:全蝎提取液有明显的抗动脉血栓形成作用,其作用机理可能与抗凝、抑制血小板活化和增加内皮细胞抗血栓能力有关。     

老年心脑血管病患者服用微量阿司匹林前后的微循环及血液流变性观察

60例老年缺血性心脑血管病患者口服微量阿司匹林(M—ASA)前后,甲襞微循环、血栓指数Q值明显改善(P<0.01),血液流变性除血沉、血球压积外,各项指标变化均不显著(P>0.05)。证实血小板微血栓形成是心脑血管疾病的重要病理基础,血液的高粘滞状态有利于血栓形成,但与血栓形成的机制无关。M—ASA有抗栓解聚作用,对缺血性心脑血管病防治作用显著。     

大鼠冠脉原位血栓模型中纤维介素的表达及意义

目的：探讨在大鼠冠脉原位血栓模型中纤维介素(fgl2)的表达及意义。〖HJ1.8mm〗方法:雄性SPF级SD大鼠78只，随机分到模型组36只，假手术组36只和正常对照组6只，模型组与假手术组术后1 h、1 d、1周、2周、3 周、4周各6只。模型组经主动脉根部注入月桂酸钠，假手术组注入生理盐水，正常对照组不予处理，分别用HE与纤维素快速染色(MMSB)、ELISA、RT-PCR法、免疫组化法观察冠脉微血管原位血栓的形成及血管性假血友病因子(vWF)与fgl2的表达。结果:模型组大鼠心肌微血管可见血小板纤维蛋白性原位血栓，有原位血栓形成的微血管数量显著增加；血浆中vWF水平明显升高；RT-PCR示fgl2表达明显增加，免疫组化示fgl2分布于心肌微血管壁。假手术组和正常对照组未见明显变化(P>0.05)。结论:在冠脉微血管内皮细胞功能紊乱的基础上，冠脉微血管壁fgl2表达显著增加并促进以血小板纤维蛋白沉积为主的原位血栓形成。     

小鼠肺脏微血栓形成模型的建立及评估

目的:建立一种新的小鼠肺脏微血栓形成模型。方法:80只小鼠随机分为模型组、假手术组和正常对照组,各组的存活小鼠再随机分为1h、5h、1天、3天、7天5个亚组。模型组自颈内静脉注入自体血栓微颗粒0.1ml,假手术组以等量生理盐水代替血栓微颗粒注入,正常对照组不予特殊处理。分别取各亚组小鼠外周血进行血小板计数,对肺组织进行大体观察及HE染色和纤维素染色,并在光镜下计数有微血栓形成的微血管数。结果:①血小板计数显示,模型组与假手术组外周血小板数均有不同程度减少,除7天组外模型组皆显著低于假手术组(P<0.01),假手术组1h,5h,1天3个亚组与正常对照组间有显著性差异(P<0.05)。②大体标本观察:模型组肺表面可见充血肿胀及点状出血灶,假手术组与正常对照组则无明显病理改变。③HE染色及纤维素染色显示,模型组各亚组除可见注入的血栓微颗粒所致的血栓栓塞,还可见继发的微血栓形成,假手术组与正常对照组则未见明显血栓栓塞及微血栓形成;微血栓计数则显示,模型组各亚组微血栓形成显著多于假手术组(P<0.01),而假手术组和正常对照组间无显著差异(P>0.05)。结论:利用自体血栓微颗粒能成功诱导小鼠肺脏微血栓形成模型,此模型为肺动脉微血栓栓塞的研究提供了一个理想的实验平台。     

柚皮素通过环核苷酸通路拮抗血小板聚集的体外研究

目的:探讨柚皮素拮抗二磷酸腺苷(ADP)诱导血小板聚集的作用机制。方法:采用ELISA检测柚皮素对ADP诱导的大鼠血小板内环磷酸腺苷(cAMP)、环磷酸鸟苷(cGMP)水平的影响。采用高效液相法检测柚皮素对血小板磷酸二酯酶(PDE)活性影响。采用Western blot检测柚皮素对ADP刺激的血小板内血管扩张刺激磷蛋白(VASP)磷酸化形式p-VASP(Ser157)、p-VASP(Ser239)的蛋白水平的影响。分别给予蛋白激酶A(PKA)抑制剂H89、蛋白激酶G(PKG)抑制剂Rp-8-Br-PET-cGMPS和蛋白激酶C(PKC)抑制剂GF109203X预先孵育血小板后,再用柚皮素处理,然后给予ADP刺激,Western blot检测p-VASP(Ser239)蛋白水平。采用血小板聚集仪进一步观察PKA抑制剂、PKG抑制剂预先孵育血小板是否影响柚皮素对ADP诱导血小板聚集的抑制作用。结果:柚皮素剂量依赖性地升高ADP抑制的血小板内cGMP水平,而并不改变cAMP水平。柚皮素还能显著升高血小板PDE活性。Western blot结果显示,柚皮素可明显升高由ADP抑制的p-VASP(Ser239)水平,但不影响p-VASP(Ser157)的蛋白水平,预先孵育PKG或PKC抑制剂并不影响柚皮素对p-VASP(Ser239)蛋白表达的作用,而预先孵育PKA抑制剂后,则能抑制柚皮素对p-VASP(Ser239)蛋白表达的作用。PKA抑制剂能阻断柚皮素对血小板聚集的拮抗作用,而PKG抑制剂并不影响其作用。结论:柚皮素可能通过升高血小板内cGMP水平和激活PKA依赖的信号通路来介导VASP的磷酸化,从而发挥抗血小板聚集的作用。     

Topical organization of the projections of neurons of the substantia nigra and the ventral field of the tegmentum of the midbrain to the head of the caudate nucleus of the cat

Neuroscience and Behavioral Physiology -     

Asymmetry of the internal connections of the striate cortex of the cat in the projection zone of the center of the field of vision

Studies were carried out on the organization of the internal connections of the striate cortex in cats in the projection zone of the center (0–5°) of the field of vision by microintophoretic application of horseradish peroxidase to electrophysiologically identified orientational columns. The area containing neurons showing retrograde labeling in most cases extended in the mediolateral direction. Labeled cells were located in the upper (II, III) and lower (V, VI) layers of the cortex, and the shapes and orientations of the areas containing labeled neurons in these layers coincided. Spatial asymmetry was detected in the distribution of labeled neurons relative to the orientational column studied. Labeled cells were located predominantly medial to the columns, regardless of the distance from the projection of the area centralis. Considering the visuotopical map of field 17, the asymmetry detected here provides evidence that neurons in orientational columns have more extensive connections with neurons of the peripheral part of the cortex. An asymmetrical distribution of “silent” zones around the receptive fields of neurons in orientational columns is suggested, and that these appear to receive influences from the periphery of the visual field. Laboratory of Visual Physiology and Laboratory of Central Nervous System Morphology, I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, 6 Makarov Bank, 199034 St. Petersburg, Russia. Translated from Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 82, No. 12, pp. 23–29, December, 1996.     

Characteristics of the topographic interrelation of the head of the pancreas and the duodenum and pathology of the organs of the pancreatoduodenal area

Seventy pancreatoduodenal complexes of 55 patients with chronic pancreatitis and tumours of this zone and 15 patients died from other diseases are studies histotopographically . The pieces of the pancreatic head tissue in the medial wall of the duodenum were found in 12 cases of the first group and in 4 control cases. The pancreatic tissue consisted either of all elements of this organ or cystically dilated ducts and seemed to infiltrate different layers of the duodenum wall. Three variants of the pancreatic head structure are suggested on the basis of anatomo-topographical interrelationships of the pancreatic head and duodenum. In 12 out of 14 cases chronic pancreatitis and carcinoma of organs of this zone were combined with the variants of the pancreatic head structure, in 2 cases there was a true heterotopy . Pathogenetic significance of these variants for the development of chronic pancreatitis is discussed.     

Influence of the level of the transmembrane potential on the dynamics of the extinction of the amplitude of the synaptic reactions of the snail under voltage clamping conditions

The influence of the level of the transmembrane potential on the dynamics of the extinction of the amplitudes of summary excitatory postsynaptic currents arising in identified giant parietal neurons in response to rhythmic stimulation of the intestinal nerve was investigated in a preparation of the isolated CNS of the common snail in order to identify the possibility of the participation of the postsynaptic element in synaptic plasticity. It was demonstrated that, at a greater value of the transmembrane potential, the decrease in the amplitudes of the postsynaptic currents which have been induced by rhythmic stimulation takes place more rapidly. It was also demonstrated that at a higher frequency of stimulation of the nerve, the effect of the influence of the membrane potential level on the dynamics of the synaptic reactions is more prominent. The data obtained may be regarded as an argument in favor of the possibility of the participation of the post-synapse in plasticity. This study was partially supported by the Russian Basic Research Fund (project No. 94-04-12209). Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow. Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 45, No. 1, pp. 171–179, January–February, 1995.     

Effects of the lesion of the postcommissural part of the septum on the behavior of the rat.

The effects of the lesion of the postcommissural part of the septum on behavior of the rat has been studied. Results may be summarized as follows. An increase in the exploratory behavior in the open field which decreases rapidly; a decrease in the number of defecations in this test and a decrease in time leaving a dark environment for exploration. In the shuttle box test, no facilitation of the acquisition, but a permanent and quite significant increase in the intertrial activity has been found. We conclude that the lesions tend to decrease the emotivity of the subjects. An interpretation on the basis of the species -- specific defensive reactions explains the transitory and permanent effects of the lesions on the spontaneous activity.