小鼠背根神经节中三个不同的钙激活氯离子通道基因家族的表达(英文)

目的在背根神经节(dorsal root ganglion,DRG)中等大小感觉神经元中可以观察到钙激活氯离子流(I_(Cl(Ca)))。在坐骨神经损伤模型中,在大多数大中神经元上诱导出类似的氯离子流。本文旨在探讨引起这个离子流的分子基础。方法使用常规的定量RT-PCR方法检测在DRG中三个基因家族的表达,这三个基因家族都具有诱导I_(Cl(Ca))的特点。结果在成年小鼠的DRG中,分别显示了在正常状态和坐骨神经损伤3天后CLCA,Bestrophin和Tweety基因家族成员的转录产物。结论mBestl和Tweety2可能在损伤诱导的DRG神经元I_(Cl(Ca))中发挥作用。     

血小板活化与冠心病关系的研究进展

病理性血小板活化与血栓性疾病密切相关,在心血管疾病中,这一病理生理过程不仅与冠心病的发生、发展有着非常重要的联系,而且对于该病的治疗策略的优化和近、远期预后等方面都有直接的影响。     

胆源性感染性休克兔血栓素、前列环素与血小板聚集率的变化

动态观察胆总管急性完全性梗阻并感染、继发休克兔的血浆血栓素(TXA_2)和前列环素(PGI_2)的稳定代谢产物 TXB_2和6-keto-PGF_(1α)含量及血小板聚集率的变化。结果,血浆 TXB_2呈进行性升高,20h 后(休克时)呈下降趋势,血浆6-keto-PGF_(1α)6h 升高,随后回降;血小板聚集率呈进行性下降。提示血栓素和前列环素、血小板聚集率的变化在重症急性胆管炎、胆源性感染性休克发病过程中起重要病理生理作用,与病情和预后转归有重要联系。     

RELATIONSHIP BETWEEN PLATELET CYTOSOLIC FREE CALCIUM CONCENTRATION AND PLASMA RENIN ACTIVITY

1. Plasma renin activity (PRA) and platelet cytosolic free calcium concentration ([Ca2+]i) were simultaneously determined in 18 untreated essential hypertensive subjects and 17 normotensive controls. A significant positive correlation was found between [Ca2+]i and PRA (slope = 42 nmol/l/ng/ml/h) in these 35 subjects. 2. Two determinations more than one week apart in nine subjects confirmed the parallel fluctuations of [Ca2+]i and PRA. A strict sodium restriction produced a progressive PRA elevation associated with a parallel rise in [Ca2+]i in one subject. 3. These results are consistent with the hypothesis that angiotensin II causes a concentration-dependent calcium mobilization.     

［5－（4－甲脒－苄基）－2，4－二氧代－咪唑烷－3－基］－乙酰基－L－天冬氨酰－L－缬氨酸的合成

根据由精氨酸－甘氨酸－天冬氨酸组成的肽能抑制血小板聚集的机制，设计并合成了［５－（４－甲脒－苄基）－２，４－二氧代－咪唑烷－３－基］－乙酰基－Ｌ－天冬氨酰－Ｌ－缬氨酸（９）。生物试验结果表明：（９）抑制血小板聚集作用最强，其活性以ＩＣ＿（５０）值相比，强于类似物。     

Prevalence and mechanism of streptokinase-induced platelet stimulation. Effect of acetylsalicylic acid.

It was recently shown that streptokinase may induce clot formation in vivo by immunoglobulin G mediated platelet stimulation. We evaluated the in vitro effect of streptokinase on platelet function in 103 subjects, of whom 52 were < or = 30 years and 51 were > or = 50 years old. Although streptokinase inhibited platelet aggregation in the majority of cases, in nine the threshold concentration of ADP required to induce irreversible aggregation decreased with streptokinase (1 million Units. l-1) by 30% or more. This observation was confirmed in five of the nine by repeated measurements indicating reproducible streptokinase-induced platelet stimulation. Among the five, two were < or = 30, and three were > or = 50 years old. In none of the five subjects did the radio allergo sorbent test detect type E immunoglobulins directed against streptokinase in the serum. In contrast, in four of the five subjects, streptokinase-induced platelet hyperaggregability was suppressed by addition of goat antibodies against human immunoglobulin G, or F(ab')2-fragments of such antibodies. Acetylsalicylic acid did not prevent streptokinase-induced platelet stimulation, but in three of five cases, led to an increase in the control threshold concentration for ADP, so that after the decrease induced by streptokinase the threshold concentration for ADP was in the same range as before acetylsalicylic acid and streptokinase administration. Thus, streptokinase led to an inhibition of platelet aggregation in the majority of subjects evaluated. In a minority of five out of 103, however, streptokinase reproducibly caused platelet stimulation, presumably mediated by immunoglobulin G.(ABSTRACT TRUNCATED AT 250 WORDS)     

山豆根碱与山豆根苏林碱对血小板聚集和粘附的影响

观察山豆根碱（Ｄａｕ）及山豆根苏林碱（Ｄａｓ）对人血小板聚集和粘附功能的影响，并探讨其作用机制。结果表明，两者可抑制由二磷酸腺苷、花生四烯酸和胶原引起的血小板聚集，药物浓度与聚集抑制率表现出明显的量效关系。Ｄａｕ处理的血小板其对二磷酸腺苷、花生四烯酸和胶原诱导聚集抑制的ＩＣ５０（ｍｍｏｌ／Ｌ）分别为０．０４２（ｎ＝５），０．０２８（ｎ＝９）及０．０４６（ｎ＝１０）；Ｄａｓ则分别为０．０４２（ｎ＝５     

冠心病不同临床类型患者血浆、血小板脂质过氧化损伤与TXA_2/PGI_2平衡的研究

作者观察98例正常人和109例不同临床类型冠心病人血浆、血小板LPO、SOD,SeGSHP_x,RBC—SOD及血浆TXB_2、6-keto-PGF_(1α)的变化,发现各型冠心病组均有LPO、PL—LPO、TxB_2、TxB_2/6-keto-PGF_(1α)比值明显升高,6-keto-PGF_(1α),SOD、PLSOD、RBC-SOD,SOD/LPO及SeGSHPX/LPO比值明显降低。但各型程度不同,以急性心肌梗塞和不稳定性心绞痛改变突出。血浆LPO与6-keto-PGF_(1α)呈显著负相关。提示脂质过氧化损伤与TXA_2/PGI_2平衡密切相关。认为SOD/LPO、SeGSHPx/LPO,TXB_2/6-keto-PGF_(1α)比值在冠心病诊断中是重要有意义的指标,血小板SOD/LPO比值能更敏感地反映冠心病人氧化与抗氧化能力的平衡状态。     

Alterations of the levels of glycoproteins Ib-IX and IIb-IIIa in platelets stored at 22°C

Platelets stored in CLX™ blood bags, under normal blood banking conditions, were studied for up to 7 days to determine if changes ocurred in the levels of membrane glycoproteins (GP) Ib-IX and IIb-IIIa. Radiolabeled monoclonal antibodies (MAB) were used to estimate the number of glycoprotein molecules on the surface membrane of intact platelets. GP IX and GP IIb-IIIa levels remained essentially unaltered during storage. In contrast, the content of GP Ib at day 7 decreased by 45% of the total when fresh. The aggregation response to ristocetin, which requires GP Ib, was also diminished after 7 days. Addition of protease inhibitors, leupeptin and/or aprotinin did not appear to influence the degradation of this glycoprotein. We conclude that storage at 22°C has deleterious effects on the GP Ib content of platelets.