缺血性卒中无复流动物模型建立和多维度评价方案

目的 建立脑无复流模型并对灌注减低进行多维度评价。方法 利用激光散斑对比成像和双光子活体成像,比较C57BL/6(n=16)和BALB/c小鼠（n=37）短暂性大脑中动脉闭塞,以及BALB/c小鼠缺血1h或1.5h灌注改变情况。结合激光散斑对比成像、低倍率和较高放大倍率的灌注脑片图像,以及双光子显微镜监测红细胞流速和流量对短暂性大脑中动脉闭塞后脑灌注下降进行活体动态以及全脑切片和微血管的评估。用微管相关蛋白2染色和行为学评分评估梗死面积和行为学缺损。结果 在C57BL/6小鼠中,大脑中动脉区域大多数毛细血管在缺血期间仍然流动,而在BALB/c小鼠中,大多数毛细血管被阻断。此外,BALB/c小鼠缺血1.5 h后,24 h后再通时的皮质灌注减少至基线76.1%（与BALB/c sham组89.0%相比减少,P=0.046）,而缺血1 h减少至79.9%,与BALB/c sham组无明显差异（P=0.299）。切片全脑灌注评估BALB/c小鼠短暂性大脑中动脉闭塞1.5 h导致全脑灌注减少至75.1%（与BALB/c sham组100%相比降低,P<0.001）,双光子活体成像评估大脑中...     

重组人促红细胞生成素后处理缺血/再灌注前后骨骼肌诱导型一氧化氮合酶及一氧化氮的变化

背景：促红细胞生成素对包括心脑在内的多种组织器官的缺血/再灌注损伤有保护作用。 目的：观察重组人促红细胞生成素后处理对家兔后肢腓肠肌缺血/再灌注前后诱导型一氧化氮合酶、一氧化氮和超微结构的影响。 方法：将家兔随机分为空白对照组、模型组和重组人促红细胞生成素组,后2组建立兔左后肢腓肠肌缺血/再灌注实验模型,其中重组人促红细胞生成素组在兔左后肢缺血2 h后静脉注射重组人促红细胞生成素。 结果与结论：再灌注后4,12 h,重组人促红细胞生成素组诱导型一氧化氮合酶表达水平及一氧化氮浓度增高幅度较模型组低(P < 0.05)。电镜下腓肠肌细胞超微结构显示,模型组内皮细胞膜溶解,肿胀明显,肌纤维内线粒体水肿。重组人促红细胞生成素组肌纤维损伤较轻,肌节内Z线及肌节内各带结构基本正常,大部分线粒体结构正常,显示重组人促红细胞生成素组超微结构损伤程度明显轻于模型组。结果证实,重组人促红细胞生成素后处理可通过抑制诱导型一氧化氮合酶蛋白的表达,减少再灌注后过量一氧化氮生成,改善骨骼肌缺血/再灌注损伤。     

Elevation of platelet cyclic AMP level by thromboxane A2/prostaglandin H2 receptor agonists.

Arachidonic acid (AA)-or thromboxane A₂/prostaglandin H₂ (TXA₂/ PGH₂) analog (STA₂ and U-46619)-induced aggregations yielded a bell-shaped dose-response curve. The inhibitory mechanism by high concentrations of the agonists was examined. STA₂ elevated cAMP level of platelet in a dose-dependent manner. And the aggregation was affected by metabolic inhibitors of cAMP. AA also rised cAMP level, and the rise was suppressed by indomethacin. These results indicate that the reduction of aggregation by high dose of the agonists is through cAMP elevation. The cAMP elevation was not suppressed by ruling out phospholipase C effects by chelation of cytoplasmic Ca²⁺ and inhibition of protein kinase C (PKC). These results suggest that the cAMP elevation is not due to activation of phospholipase C-linked TXA₂/PGH₂ receptor. 13-APA, an antagonist of TXA₂/PGH₂ receptor, suppressed the cAMP elevation, although ONO-3708, another antagonist, had no effect. As to be expected from this result, inhibitory effect of 13-APA on high STA₂ level-induced aggregation was weaker than that of ONO-3708. The antagonists did not inhibit PGE,- or PGD₂-induced cAMP elevation. These findings suggest that platelet has adenylate cyclase-linked TXA₂/PGH₂ receptor.     

Direct Physical Factors and PGI2 and TXA2 Secretions by a Human Endothelial Cell Line: In Vitro Investigation of Pressure and Shear Stress Applied Independently or in Synergy

The direct effect of two types of mechanical stress was measured through the prostacyclin (PGI2) and thromboxane A2 (TXA2) secretions by a confluent monolayer of cells from the EA.hy926 line. Eight values of constant pressure were applied in the gas phase above the culture medium, around atmospheric pressure taken as a control (0 mm Hg), from −500 to +760 mm Hg. Three amplitudes of sine-wave modulated pressure (±40; ±80; ±160 mm Hg) were explored at a frequency of 1 Hz. Modulated pressure (±40 mm Hg) was also applied synergetically to a shear stress generated under steady state conditions by a rectilinear laminar motion of the medium. The cells remained adherent and exhibited unchanged morphology and viability. Constant pressure or depressure increased both PGI2 and TXA2 release but to an extent depending on the pressure value. Under pressure, the PGI2/TXA2 ratio was unchanged, but was higher under depressure, compared to the control. Pressure modulation strongly stimulated the secretion of PGI2 but had no effect on TXA2. Modulation strongly increased the PGI2/TXA2 ratio to a similar extent for the three amplitudes. Pressure-shear synergy enhanced secretion of PGI2 markedly more than shear stress alone, but the level reached was similar to the one induced by pressure modulation. No cumulative effect on the secretion of PGI2 was observed, whereas TXA2 synthesis undergoes a more than cumulative effect. The PGI2/TXA2 ratio remained unchanged under shear alone or under combined shear-pressure modulation but was higher with the modulated pressure alone. These results demonstrate that pressure has an outstanding effect on secretion that may be origin to local disturbances of the vascular system, thus inducing pathologies such as thrombosis or atherosclerosis.     

血栓素A2受体基因多态性与脑梗死的相关性研究

目的 探讨上海地区汉族居民血栓素A2受体(TXA2R)基因位点单核苷酸多态性与脑梗死的关系.方法 运用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法检测334例脑梗死患者和135例正常老年对照者TXA2R基因rs768963位点的单核苷酸多态性,计算等位基因的频率分布.结果 在脑梗死组与正常组之间,rs768963位点的基因型(T/T、T/C与C/C)频率分布差异均无统计学意义(P＞0.05),而等位基囚频率(T/C)分布差异有统计学意义(P＜0.05);Logistic回归分析示rs768963位点基囚突变与性别、年龄、血脂、血压、血糖均无关联.结论 TXA2R基因rs768963位点C等位基因可能是脑梗死的危险因素之一,携带C等位基因的患者具有更高的脑梗死发病易感性.     

急性前循环脑梗死患者血浆脂蛋白相关磷脂酶A2活性与颈内动脉狭窄的关系

目的 探讨血浆脂蛋白相关磷脂酶A2(Lp-PLA2)活性与急性前循环脑梗死患者颈内动脉狭窄的关系.方法 采用CTA检查133例急性前循环脑梗死患者的颈内动脉狭窄的程度,将其分为轻-中度狭窄组及重度狭窄组.收集133例患者及70名正常对照者(正常对照组)的临床资料,并采用速率法检测血浆Lp-PLA2活性.结果 重度狭窄组...     

A thromboxane synthetase inhibitor reorients endoperoxide metabolism in whole blood towards prostacyclin and prostaglandin E2

During incubation of citrated blood at 37°C the levels of 6-ketoprostaglandin F₁ (6-keto PGF₁) and prostaglandin E₂ (PGE₂) remain constant, but rise markedly within one minute after the addition of collagen, particularly when thromboxane synthetase is blocked. The amount of 6-keto PGF₁ formed is dose-dependent for both collagen and the thromboxane synthetase inhibitor (UK-37,248). Moreover, the number of platelets will determine the extent of the 6-keto PGF₁ jump, that does not occur when blood is drawn after aspirin ingestion. The production of 6-keto PGF₁ in function of time is composed of a fast platelet-related (intercept) and a slower probably leukocyte-dependent contribution (slope). In the absence of UK-37,248 the intercept is 115 ± 85 pg/ml, the slope is 12.9 ± 7.7 pg/min/ml whereas in the presence of the thromboxane synthetase inhibitor they are 411 ± 177 pg/ml and 56.2 ± 25 pg/min/ml respectively. The present findings indicate that a thromboxane synthetase inhibitor, by not only reducing thromboxane A₂ production but also enhancing prostacyclin generation when blood is exposed to thrombogenic stimuli such as collagen, should be superior to aspirin as an antithrombotic agent, although possible interference by enhanced PGE₂ production should be taken into account.     

急性脑梗死同型半胱氨酸与神经功能缺损的关系

目的探讨急性脑梗死患者血浆同型半胱氨酸（Hcy）浓度水平与神经功能缺损程度的相关性。方法采用全自动化学发光免疫分析仪测定脑梗死同型半胱氨酸的水平,神经功能缺损用中国卒中量表（GSS,1995）记分评定。结果血浆同型半胱氨酸（Hcy）的水平与脑梗死患者神经功能缺损程度两者具有相关性,Hcy水平越高,GSS评分也越高,恢复期预后越差。结论急性脑梗死时患者血浆同型半胱氨酸水平能反映病情的严重程度,且有助于评估患者的预后、指导治疗的意义。     

R 68 070: thromboxane A2 synthetase inhibition and thromboxane A2/prostaglandin endoperoxide receptor blockade combined in one molecule--I. Biochemical profile in vitro

R 68 070 or (E)-5-[[[(3-pyridinyl)[3-(trifluoromethyl)phenyl]- methylen]amino]oxy] pentanoic acid (Janssen Research Foundation, Belgium) combines specific thromboxane A2 (TXA2) synthetase inhibition with TXA2/prostaglandin endoperoxide receptor blockade in one molecule. In vitro, the compound specifically inhibits the production of TXB2 from [14C] arachidonic acid by washed human platelets (IC50 = 8.2 X 10(-9) M) and by platelet microsomes (IC50 = 3.6 X 10(-9) M), of MDA (IC50 = 1.91 X 10(-8) M) and of TXB2 (IC50 = 1.47 X 10(-8) M) by thrombin-coagulated human platelet-rich plasma (P.R.P.) and whole blood respectively and increases the levels of PGD2, PGE2, PGF2 alpha and 6-keto-PGF1 alpha. The activity of cyclo-oxygenase-, prostacyclin synthetase-, 5-, 12- and 15-lipoxygenase-enzymes are not affected. Additionally, R 68 070 inhibits human platelet aggregation in P.R.P. induced by U 46619 3 X 10(-7) M to 2 X 10(-6) M (IC50 = 2.08 X 10(-6) M to 2.66 X 10(-5) M, collagen 0.5 to 2 micrograms/ml (IC50 = 2.85 X 10(-6) M to 4.81 X 10(-5) M), arachidonic acid 7.5 X 10(-4) M to 2 X 10(-3) M (IC50 = 2.1 X 10(-8) M to 3.3 X 10(-8) M) and the U 46619 (1 X 10(-7) M)-induced accumulation of [32P] phosphatidic acid (IC50 = 5.24 X 10(-7) M) in washed human platelets.(ABSTRACT TRUNCATED AT 250 WORDS)     

急性脑出血患者C反应蛋白升高与预后的关系

目的研究急性脑出血患者发病早期血液中C反应蛋白(CRP)含量与病情程度及预后的关系。方法用散射比浊法测定89例脑出血患者发病24h内血浆中CRP的含量,与30名健康体检者进行对照,并分析其与病情、预后的关系。结果对照组CRP浓度均<8mg/L[(4.21±1.78)mg/L];脑出血组中51例CRP增高[(30.33±2.53)mg/L],异常率为57.30%;依病情轻、中、重程度不等,CRP的异常率及含量依次增高(均P<0.01);脑出血预后好转组CRP的异常率41.18%,明显低于无好转组的78.95%(χ2=12.70,P<0.005)。结论急性脑出血患者早期血液中CRP浓度的增高显示病情重、预后差。早期测定CRP有助于判断脑出血的预后。     

Effects of anisodamine on altered [Ca~(2+)]i and cerebral cortex ultrastructure following acute cerebral ischemia/reperfusion injury in rabbits

BACKGROUND： Calcium ion （Ca^2＋） overload plays an important role in cerebral ischemia/reperfusion injury. Anisodamine, a type of alkaloid, can protect the myocardium from ischemia and reperfusion injury by inhibiting intracellular calcium [Ca^2＋]i overload. OBJECTIVE： To investigate effects of anisodamine on [Ca^2＋]i concentration and cortex ultrastructure following acute cerebral ischemia/reperfusion in rabbits. DESIGN, TIME AND SETTING： Randomized and controlled trial was performed at the Department of Emergency, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology from September to December 2006. MATERIALS： Forty healthy rabbits were used to establish models of acute cerebral ischemia/reperfusion. Anisodamine was provided by Lianyungang Dongfeng Pharmaceutical Factory; Fura-2 was purchased from Nanjing Jiancheng Bioengineering Institute; dual-wave length fluorescent spectrophotometry system and DM-300 software were provided by Bio-Rad, USA; OPTON-EM10C transmission electron microscope was product of Siemens, Germany. METHODS： Forty rabbits were randomly divided into the following groups： sham operation, ischemia, ischemia/reperfusion, and anisodamine, with ten rabbits in each group. Models of complete cerebral ischemia injury were established. In addition, blood was collected from the femoral artery of rats in the ischemia/reperfusion and anisodamine groups to induce hypotension and establish repeffusion injury models. The bilateral common carotid artery clamp was removed from the anisodamine group 20 minutes after ischemia, and anisodamine （10 mg/kg body mass） was injected via the femoral vein. Rabbits in the sham operation group underwent only venous cannulation. MAIN OUTCOME MEASURES： [Ca^2＋]i concentration was determined using a dual-wave length fluorescent spectrophotometry system, and cortical ultrastructure was observed following uranyl-lead citrate staining. RESULTS： The levels of [Ca^2＋]i in the ischemia and ischemia/reperfusion gro