纤溶酶原激活剂及其活性测定

纤溶酶原激活剂（plasminogen activator,PA）是一种特异性的蛋白水解酶，它能将无活性的酶前体转变为纤溶酶（plasmin）。纤溶酶是一种有效的非特异性的蛋白水解酶，能够裂解血液内的纤维蛋白凝块使其成为可溶性的多肽。本文描述了纤港酶原激活系统的一些生化特征，及对纤溶酶原激活剂活性的测定方法。纤溶酶原激活剂在血栓性疾病和出血性疾病的诊断具有潜在应用价值。     

纤溶酶原激活剂抑制物-1的研究进展

纤溶酶原转变成有纤溶活性的纤溶酶是纤溶过程决定性的一步?t-PA是体内主要的纤溶酶原激活物之一,而纤溶酶原激活剂抑制物(Plasminogen Activator Inhibitor PAI)是组织型纤溶酶原激活剂(t-PA)和尿激酶纤溶酶原激活剂(u-PA)的快速抑制剂,在纤溶系统中起着关键性调节作用?自1983年Chmielewska J等[1]发现纤溶酶原激活剂抑制物(PAI-1)以来,越来越多的证据表明PAI活性或含量的改变直接影响纤溶系统的活性,是许多疾病特别是血栓形成性疾病发病的危险因素之一[2～4]?1 生物学特性纤溶酶原激活剂抑制物(PAI)包括PAI-1,PAI-2,PAI-3,C…     

纤溶系统与炎症

纤溶系统包括纤溶酶原激活剂、纤溶酶原激活物抑制剂、纤溶酶原、纤溶酶、纤维蛋白原,是非常重要的细胞外基质降解系统,通过细胞外基质降解作用参与了组织屏障的破坏、炎症细胞的迁移.同时纤溶系统可以通过与整合素受体或非整合素受体的相互作用、信号传导等非蛋白降解功能来调节炎症细胞的激活分化及定向运动,在炎症反应中发挥了重要的作用.     

纤溶系统与炎症

纤溶系统包括纤溶酶原激活剂、纤溶酶原激活物抑制剂、纤溶酶原、纤溶酶、纤维蛋白原,是非常重要的细胞外基质降解系统,通过细胞外基质降解作用参与了组织屏障的破坏、炎症细胞的迁移.同时纤溶系统可以通过与整合素受体或非整合素受体的相互作用、信号传导等非蛋白降解功能来调节炎症细胞的激活分化及定向运动,在炎症反应中发挥了重要的作用.     

老年心力衰竭患者肾素-血管紧张素系统与纤溶活性变化的意义

目的探讨老年心力衰竭(HF)患者血浆肾素-血管紧张素系统(RAS)与纤溶活性的变化。方法老年HF患者46例(HF组),非器质性心脏病住院患者18例(对照组),取静脉血分别检测血浆纤溶酶原激活剂抑制物1(PAI-1)、组织纤溶酶原激活剂(t-PA)活性、血浆肾素活性(RA)及血管紧张素Ⅱ(AngⅡ)含量。结果老年HF患者血浆RA、PAI-1活性、AngⅡ含量明显高于对照组(P<0.05),t-PA活性则降低(P<0.05);血浆PAI-1活性与AngⅡ含量水平呈显著正相关(r=0.396,P<0.01)。结论老年HF过程中血浆RAS激活对纤溶活性改变有重要影响。     

口腔粘膜溃疡病患者血浆凝血、抗凝及纤溶系统研究

目的 观察白塞病患者血浆凝血、抗凝及纤溶系统指标变化情况,提升口腔粘膜溃疡的诊断和治疗效果.方法 选取30例白塞病患者与30例健康成人作为观察对象,将其分为两组,其中30例白塞病患者为观察组;30例健康成人为常规组.采用全自动凝血分析仪结合酶联免疫吸附法分别对白塞病患者及健康成人血浆凝血因子活性、总蛋白S抗原、蛋白C抗原、组织型纤溶酶原激活物、纤溶酶原激活剂抑制物-1以及D-二聚体的含量进行检测,对检测结果进行对比分析.结果 观察组患者血浆凝血因子活性、总蛋白S抗原、蛋白C抗原、纤溶酶原激活剂抑制物-1以及D-二聚体等的含量均高于常规组,组织型纤溶酶原激活物低于常规组.观察组凝血、抗凝及纤溶系统有异常,增加了该病血栓形成的可能.结论 通过对观察组患者凝血、抗凝及纤溶各指标的检测分析以及对血浆凝血、抗凝及纤溶系统的研究,对白塞病的治疗有一定的促进作用,对口腔黏膜溃疡以及动静脉血栓的治疗和预防有较高的价值.     

重组人尿型纤溶酶原激活剂规模生产中纯化过程的质量控制

尿型纤溶酶原激活剂(u-PA)是一种高效、出血副作用和再阻率低的溶栓制剂,由于在溶液中不稳定,在纤溶酶、激肽释放酶、胰酶及理化因素影响下,容易从158Lye-159Ile处断裂成双链,故u-PA有包括单链和双链两种形态.u-PA的国外临床用量最大剂量可达80 mg,因此对产品的质量提出更高的要求.为了保证产品的最终质量,必须在生产过程中加以严格控制,以确保产品的安全有效.我们对u-PA中试生产中纯化阶段的质量控制进行了研究,包括:蛋白含量、活性测定、活性回收率及比活计算、单双链比例测定、纯度分析几项指标的控制,以保证产品的质量.     

不同强度运动训练对大学生凝血及纤溶系统的影响

目的 :研究不同强度的运动训练对机体凝血及纤溶系统的影响。方法 :36名健康男青年进行不同强度的运动训练后 ,测定其血浆血栓素 (TXA2 )和前列环素 (PGI2 )含量及组织型纤溶酶原激活剂 (t-PA)和纤溶酶原激活剂抑制物 (PAI- 1 )活性。结果 :(1 )中小强度运动后 ,血浆t-PA活性及t-PA/PAI- 1比值明显升高 ,PAI- 1活性却明显降低 ;而大强度运动训练组t-PA活性没有改变 ,PAI- 1活性却明显增高 ,表明大强度运动训练不利于改善纤溶系统的功能。 (2 )运动训练使TXB2 和 6 -K -PGF1α含量的升高 ,其中中等强度组 6-K -PGF1α含量及 6 -K -PGF1α/TXB2 比值显著性升高 ,大强度组的TXB2 含量及TXB2 / 6 -K -PGF1α比值显著性升高 (P <0 0 1 )。结论 :中、小强度的运动训练可以改善机体的纤溶功能 ,而大强度的训练不利于改善纤溶功能 ;同时 ,中等强度的运动训练可以降低机体的凝血功能。     

PTCA后再狭窄与纤溶因子变化的研究

 为探讨纤溶因子在PTCA后发生RS时的变化及临床意义,对组织型纤溶酶原激活剂(t-PA)、纤溶酶原激活剂抑制物(PAJ-1)的血浆含量进行了为期210 d的观察追踪.结果发现,PAI-1血浆含量在RS组与WRS组的不同时间内比较差异有极显著意义(P<0.01),提示PAI-1血浆含量持续升高可帮助预告RS.     

t－PA、PAI与缺血性脑血管疾病

ｔ－ＰＡ、ＰＡＩ与缺血性脑血管疾病武警新疆总队医院内一科李卫综述吴宣富审校（乌鲁木齐８３００００）关键词组织型纤溶酶原激活剂，纤溶酶原激活剂抑制剂，缺血性脑血管疾病缺血性脑血管疾病（ＩＣＶＤ）的主要病理基础是动脉粥样硬化（ＡＳ），凝血与纤溶系统平衡紊...     

纤维蛋白诱导活化系膜细胞表达明胶酶A、B的机制研究

为观察纤维蛋白对系膜细胞（HMC）表达明胶酶A（MMP-2）、明胶酶B（MMP-9）的作用并探讨其活化机制,应用RT-PCR、明胶酶谱分析法分别在基因转录水平与蛋白质活性水平上检测纤维蛋白对HMC表达MMP-2、MMP-9的作用,采用纤维蛋白酶谱法与平板法检测纤维蛋白对HMC表达纤溶酶原激活物（PA）活性的影响。结果发现,纤维蛋白呈剂量与时间依赖性促进HMC MMP-2与MMP-9表达的上调,并同时促进HMCtPA与uPA的表达;应用抑肽酶阻断纤溶酶活性后能够完全阻断pro-MMP-2与pro-MMP-9的活化。提示肾脏局部沉积的纤维蛋白可以促进HMC表达与活化MMP-2、MMP-9、而MMP-2与MMP-9的活化依赖于PA/纤溶酶系统的调控。     

99mTc-plasmin test in deep vein thrombosis of the leg

A 99mTc-plasmin test and phlebography were performed on 45 consecutive unselected patients with suspected deep vein thrombosis of the leg. Phlebography showed thrombosis in 15 cases. In fourteen of these patients there was a positive result in the plasmin test. Eleven other patients had a positive plasmin test result as well. The most common causes for a false-positive result in the plasmin test in the diagnosis of deep vein thrombosis were acute inflammatory disease and disturbance in venous flow without fresh thrombosis. The sensitivity of the plasmin test in the diagnosis of deep vein thrombosis was 93% and the specificity was 63%. It is concluded that the plasmin test can be used for the screening of deep vein thrombosis.     

Cross-species pharmacologic evaluation of plasmin as a direct-acting thrombolytic agent: ex vivo evaluation for large animal model development

PURPOSE: Human plasma-derived plasmin has been developed for the treatment of thrombosed hemodialysis arteriovenous grafts and vascular occlusive diseases. To further investigate this drug in large animal models and derive preliminary dosing estimates, the authors compared plasmin's relative lytic potential in four species, including man. The goal was to find which species' whole blood clots best compared to human clots in terms of lysis with plasmin. The results from these studies will serve to guide species selection for large animal experimentation. MATERIALS AND METHODS: Clotted blood from human, pig, sheep, and bovine subjects were treated with saline solution control, plasmin, or tissue plasminogen activator. Electron microscopy (EM) techniques were used to investigate the effects of clot size and fragmentation on plasmin lysis, the effects of intrathrombic infusion by injection of plasmin directly into whole blood clots, and species fibrin structural differences. RESULTS: Under static conditions, plasmin efficiently lysed clots from all species studied at an optimal dose of 4-5 mg per 4-5 g of clot. With fragmented human clots, plasmin (5 mg)-induced lysis was 80% +/- 2% at 60 minutes. Porcine clots were more resistant to plasmin lysis compared with human, ovine, and bovine clots. Percent lysis at 60 minutes with plasmin for ovine clots was 72% +/- 3% (4-mg dose), compared with 50% +/- 4% for porcine clots (5-mg dose; P < .05). EM of porcine clots showed a compact fibrin network that appeared more dense than that in human or sheep clots, which may account for the decreased lytic rate. CONCLUSIONS: Human plasmin is an effective direct-acting thrombolytic agent that is capable of lysing fibrin from several species. Ex vivo lysis studies were used to investigate the most appropriate large animal model that best approximates plasmin lysis with human clots under certain conditions. It was determined that ovine clots treated with plasmin most closely resemble the lysis observed with human clots.     

99mTc-plasmin test in deep vein thrombosis of the leg

A ^99mTc-plasmin test and phlebography were performed on 45 consecutive unselected patients with suspected deep vein thrombosis of the leg. Phlebography showed thrombosis in 15 cases. In fourteen of these patients there was a positive result in the plasmin test. Eleven other patients had a positive plasmin test result as well. The most common causes for a falsepositive result in the plasmin test in the diagnosis of deep vein thrombosis were acute inflammatory disease and disturbance in venous flow without fresh thrombosis. The sensitivity of the plasmin test in the diagnosis of deep vein thrombosis was 93% and the specificity was 63%. It is concluded that the plasmin test can be used for the screening of deep vein thrombosis.     

纤溶酶对兔动脉血体外溶凝最佳时间与浓度研究

目的探讨纤溶酶溶解血凝块的最佳时间及浓度。方法采集日本白兔股动脉血,应用模拟脑出血微创穿刺体外实验模型,采用5×5拉丁方设计,分析纤溶酶浓度(25 U/ml、50 U/ml、100 U/ml、200 U/ml及300 U/ml)、用药时机(抽血后2、4、6、8、16 h)和溶凝时间(给予纤溶酶后2、4、6、8、10 h)对体外血肿溶凝的时效和量效的影响。抽取兔股动脉血5 ml制备血凝块,实验管加相应浓度的纤溶酶0.2 ml,对照管加0.2 ml生理盐水,在各个时间点测定血凝块质量。结果兔动脉血实验数据结果显示,25 U/ml组(=8.496 mg)的溶凝质量明显低于50 U/ml组(=28.770 mg)、100 U/ml组(=38.904 mg)、200 U/ml组(=34.080 mg)、300 U/ml组(=28.324 mg),组间比较,差异有统计学意义[(B、C、D、E)>LSR_(0.05),P<0.05],而后4组间比较,差异均无统计学意义(P>0.05)。用药时机和溶凝时间对溶凝质量的影响,组间比较,差异均无统计学意义(F=0.62,P>0.05;F=1.44,P>0.05)。结论纤溶酶溶凝的最佳有效浓度为50 U/ml,延迟16 h用药不影响溶凝效果,溶凝2 h足以发挥作用。     

Lys-plasminogen as an adjunct to local intra-arterial fibrinolysis for carotid territory stroke: laboratory and clinical findings

To improve the efficacy of local intraarterial fibrinolysis (LIF), we compared different fibrinolytic drugs in a cerebral circulation model in the laboratory. The technical efficacy of fibrinolysis, defined as the clot volume lysed per unit time, was found to be optimal with r-tissue plasminogen activator (TPA) activated lys-plasminogen (=plasmin). Subsequently, 20 patients with stroke due to carotid artery territory occlusion were treated by local intrarterial fibrinolysis using the plasmin regimen. The angiographic data and clinical outcome of these patients were compared with those of 40 patients who received plasminogen activators (urokinase or r-TPA) only. Laboratory and clinical data confirmed that plasmin lysis is superior to treatment using only plasminogen activators.     

Gamma camera detection of 99mTC-plasmin in the diagnosis of deep-vein thrombosis

99mTc-Plasmin scintigraphy of suspected vein thrombosis registered by a gamma camera was compared with phlebography. The results indicate that the plasmin test can be an alternative method to phlebography. The plasmin test registered by a gamma camera has a high sensitivity but relatively low specificity; this agrees with the results of previous investigations regarding registration with a single detector.     

99mTc plasmin in 394 consecutive patients with suspected deep venous thrombosis

Three hundred and ninety four consecutive out-patients with suspected deep venous thrombosis (DVT) were investigated with the 99mTc-plasmin test and physical examination and 307 of them with phlebography. Fresh thrombi were present in 124 patients and the plasmin test was pathological in 118 of these (sensitivity 95%). The thrombi that were missed were all located below the knee and measured less than 10 cm on the phlebographic films. The predictive values of negative and positive tests were 91% and 49%, respectively. The predictive value of a positive test was higher with an increasing number of measuring points with a pathological uptake. To get the final result, a single series of measurements 5 min after injection was sufficient. If clinical signs of inflammation were present. the plasmin test was usually pathological. Median time for the plasmin test to become normal during anticoagulant therapy was 14 days for calf DVT and 6 months for proximal DVT. The plasmin test was found to be useful as a screening test in patients without extensive signs of inflammation in the legs. It has a high sensitivity even in patients with long-standing symptoms.     

Gamma camera detection of 99mTC-plasmin in the diagnosis of deep-vein thrombosis

^99mTc-Plasmin scintigraphy of suspected vein thrombosis registered by a gamma camera was compared with phlebography. The results indicate that the plasmin test can be an alternative method to phlebography. The plasmin test registered by a gamma camera has a high sensitivity but relatively low specificity; this agrees with the results of previous investigations regarding registration with a single detector.     

99mTc plasmin in 394 consecutive patients with suspected deep venous thrombosis

Three hundred and ninety four consecutive outpatients with suspected deep venous thrombosis (DVT) were investigated with the ^99mTc-plasmin test and physical examination and 307 of them with phlebography. Fresh thrombi were present in 124 patients and the plasmin test was pathological in 118 of these (sensitivity 95%). The thrombi that were missed were all located below the knee and measured less than 10 cm on the phlebographic films. The predictive values of negative and positive tests were 91% and 49%, respectively. The predictive value of a positive test was higher with an increasing number of measuring points with a pathological uptake. To get the final result, a single series of measurements 5 min after injection was sufficient. If clinical signs of inflammation were present, the plasmin test was usually pathological. Median time for the plasmin test to become normal during anticoagulant therapy was 14 days for calf DVT and 6 months for proximal DVT. The plasmin test was found to be useful as a screening test in patients without extensive signs of inflammation in the legs. It has a high sensitivity even in patients with long-standing symptoms.