Acute changes of coagulation and fibrinolysis parameters after experimental thromboembolic stroke and thrombolytic therapy

Thrombolysis is the only effective pharmaceutical therapy in acute ischemic stroke in humans but has a high risk of intracerebral hemorrhage. We aimed to establish an animal model to study changes of coagulation and fibrinolytic parameters during thromboembolic ischemic stroke and thrombolysis with recombinant tissue plasminogen activator (rt-PA). We used a thromboembolic stroke model in the rat. Animals were treated with rt-PA thrombolysis (n=10) and compared with untreated (n=10), sham operated (n=10) and control animals (n=20). Coagulation parameters (APTT, PT, TT, fibrinogen, AT III, TAT) and fibrinolytic parameters (t-PA antigen concentration, t-PA activity, PAI-1 concentration, PAI activity, plasminogen, antiplasmin) were measured at two time points (2.5 and 5h after stroke induction) with a battery of commercially available test kits. We observed an (1) initiation of coagulation and inhibition of fibrinolysis by the operation procedure itself, (2) simultaneous activation of fibrinolysis and its inhibitors after stroke induction and (3) potent initiation of fibrinolysis and consumption of fibrinolysis inhibitors after rt-PA therapy of stroke. We established a model system to monitor coagulation and fibrinolysis during thrombolytic therapy of stroke in the rat. This model may be used to study the influence of these parameters on hemorrhagic stroke transformation and outcome in experimental stroke in future.     

蚯蚓蛋白激酶对体内纤溶活性的增强作用研究

目的：探讨蚯蚓蛋白激酶制剂（LK）的纤溶增强作用。方法：采用静脉给药方法，观察LK对SD大鼠纤溶激活因子t-PA及其抑制物PAI-1的急性作用。结果：给药后，PAI-1活性被显著抑制（P<0.01），t-PA活性则明显增强（P<0.01）。剂量1200 U/kg体重的LK，其增强t-PA作用显著大于600U/kg体重剂量LK（P<0.05）。此外，体外观察表明:LK具有明显的激活纤溶酶原（Plg）作用，且有量-效关系，具有一定的浓度依赖性（1.56-25 kU/L）。结论：结果表明，LK具备增强纤溶的特性，静脉给药作用快速而肯定。     

Blood coagulation and fibrinolysis after long-duration treadmill exercise controlled by individual anaerobic threshold

For rehabilitation training it is recommended that the intensity of exercise should be clearly below the individual anaerobic threshold (IAT). We investigated blood coagulation, particularly endogenous thrombin potential (ETP) and fibrinolysis following a standardized treadmill (TR) ergometer test at 90% IAT for 60–120 min. Sixteen healthy male non-smokers underwent the TR test. Blood samples were taken after a 30-min rest, immediately after exercise, and 2 h after exercise completion. Extrinsic and intrinsic total (TTP_ex+in) and endogenous (ETP_ex+in) thrombin potential, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), plasmin-2-antiplasmin complex (PAP), D-dimer, tissue plasminogen activator antigen and activity (tPA-AG and tPA-ACT) and plasminogen activator inhibitor type 1 antigen and activity (PAI-1-AG and PAI-1-ACT) were measured. Immediately after TR, F1+2, TAT and TTP_ex+in were increased (P<0.05) while ETP_ex+in remained unchanged. In contrast, PAP, D-dimer, tPA-AG, tPA-ACT (P<0.05) were distinctly enhanced while PAI-1-ACT was decreased (P<0.05) immediately after exercise. The changes in tPA-AG, tPA-ACT, and PAI-1-ACT were reversed to nearly baseline while the enhancement in PAP and D-dimer was prolonged by more than 2 h after exercise. Long-duration exercise between 60 and 120 min controlled by IAT (90%) on a TR ergometer only implicates a small increase in thrombin generation markers and total (free and ₂-macroglubulin-bound thrombin), but not in endogenous (free) thrombin potential alone. In contrast, fibrinolysis is distinctly increased after this type of exercise. Endurance exercise with an intensity below 90% IAT and a duration below 2 h generates a more favourable condition for fibrinolysis than for blood coagulation in healthy young subjects. Data are given as mean (SD).     

Pharmacological thrombolysis for acute ischemic stroke treatment: Gender differences in clinical risk factors

Background

In a stroke population, women have a worse outcome than men when untreated. In contrast, there is no significant difference in treated patients. In this study, we determined whether clinical variables represent a promising approach to assist in the evaluation of gender differences in a stroke population.

The effects of a combination of cigarette smoking and oral contraception on coagulation and fibrinolysis in human females

Summary Oral contraception as well as cigarette smoking influence haemostasis. The simulataneous effect of both on blood coagulation and fibrinolysis was studied in nine female smokers. While continuing oral contraception after a 4-week abstinence from smoking the concentration of fibrinogen, antithrombin III and alpha₁-Antitrypsin decreased (P<0.01 orP<0.04) and of plasminogen increased (P<0.03). The other coagulation parameters remained unchanged. Although all determinations of these parameters were in the normal range, the observed trends were statistically significant. The concentrations of the fibrinopeptide A and B 15–42 did not differ. It is concluded that the observed alteration is caused by cessation from cigarette smoking.This work has been supported by grants from Forschungsrat Rauchen und Gesundheit     

硫化氢对FeCl_3诱导的小鼠颈动脉血栓模型中凝血和纤溶活性的影响

目的:探讨外源性硫化氢(H_2S)对三氯化铁(FeCl_3)诱导的小鼠颈动脉血栓模型凝血和纤溶活性的影响。方法:本实验分为空白对照组、模型组、不同浓度(12.5、25和50μmol/kg)的硫氢化钠(NaHS,H_2S供体)处理组和30 mg/kg氯吡格雷(clopidogrel,阳性对照)。不同浓度NaHS腹腔注射及硫酸氢氯吡格雷灌胃给药处理3d后,采用10%FeCl_3诱导小鼠颈动脉血栓模型。取各组颈动脉制成冰冻切片后,HE染色观察血栓形成及血管病理变化;对形成的血栓重量进行测量,计算血栓形成抑制率;采用血凝仪检测血浆凝血酶原时间(PT)、活化部分凝血活酶时间(APTF)、纤维蛋白原(FIB)和纤维蛋白降解产物(FDP)的变化;ELISA法检测血浆中血栓烷素B_2(TXB_2)、6-酮-前列腺素F_(1α)(6-keto-PGF_(1α))和纤溶酶原活化抑制剂(PAI)的含量。结果:与模型组相比,NaHS剂量依赖性地抑制小鼠颈动脉血栓的形成;NaHS处理可延长血栓模型中PT和APTT,减少FIB含量,增加FDP含量;NaHS处理能够降低颈动脉血栓模型中TXB_2及PAI含量,恢复6-keto-PGF_(1α)含量,并且6-keto-PGF_(1α)/TXB_2与血栓重量呈负相关。结论:硫化氢通过抑制机体凝血功能并激活纤溶活性而抑制FeCl_3诱导的颈动脉血栓形成。     

Inhibited glutamate release by granulocyte-colony stimulating factor after experimental stroke

We investigated the ability of granulocyte-colony stimulating factor (G-CSF) on inhibiting glutamate release by microdialysis in a rat stroke model. Male Wistar rats (n=15) were treated with either intravenous saline or G-CSF (60 microg/kg) 30 min after temporary middle cerebral artery occlusion (MCAO). G-CSF significantly attenuated the release of glutamate in the infarcted striatum from 30 minutes to 180 minutes after tMCAO compared with control (p<0.05). Infarct volume in G-CSF treated group (135+/-13 mm(3)) reduced significantly compared to control (181+/-10mm(3)) at 24 hours after tMCAO. The result of present study show that G-CSF possess an ability to inhibit excitotoxicity after ischemic stroke.     

Speed of motor re-learning after experimental stroke depends on prior skill

Many motor rehabilitation therapies are based on principles of motor learning. Motor learning depends on preliminary knowledge of the trained and other (similar) skills. This study sought to investigate the influence of prior skill knowledge on re-learning of a precision reaching skill after a cortical lesion in rat. One group of animals recovered a previously known skill (skill training, followed by stroke and re-learning training, TST, n = 8). A second group learned the skill for the first time after stroke (ST, n = 6). A control group received prolonged training without stroke (n = 6). Unilateral partial motor cortex lesions were induced photothrombotically after identifying the forelimb representation using epidural stimulation mapping. In TST animals, re-learning after stroke was slower than learning before stroke (post hoc repeated measures ANOVA P = 0.039) and learning in the control group (P = 0.033). De novo learning after stroke (ST group) was not different from healthy learning. These findings show that skill learning can be performed if the motor cortex is partially lesioned; re-learning of a skill after stroke is slowed by prior knowledge of the skill. It remains to be tested in humans whether task novelty positively influences rehabilitation therapy.     

脂蛋白的氧化修饰对血凝及纤溶活性的影响

目的:研究脂蛋白的氧化修饰对凝血及纤溶活性的影响。方法:用Cu²⁺法及次氯酸法氧化修饰超速离心分离的正常人血浆极低密度脂蛋白(VLDL)、低密度脂蛋白(LDL)及高密度脂蛋白(HDL)。分别将天然及氧化修饰脂蛋白N-VLDL、Ox-VLDL;N-LDL、Ox-LDL、N-HDL及Ox-HDL加入由正常人新鲜混合血浆构成的反应系统中,以相应天然脂蛋白为对照,测定凝血酶原时间(PT)、活化部分凝血酶原时间(APTT)、组织型纤溶酶原激活物(t-PA)活性、纤溶酶原激活物抑制剂1(PAI-1)活性及血小板最大聚集率。结果:VLDL、LDL及HDL经Cu²⁺法及次氯酸法氧化修饰后其REM、234nm吸光度值、TBARS含量均显著大于对照组(P<0.01)。Ox-VLDL、Ox-LDL及Ox-HDL使PT及APTT明显短于对照组(P<0.05或P<0.01),血小板聚集率明显高于对照组(P<0.01)。Ox-VLDL及Ox-LDL使t-PA活性高于对照组,PAI-1活性低于对照组(P<0.05及P<0.01),而Ox-HDL对t-PA活性及PAI-1活性的影响与对照组无明显差别。结论:N-VLDL、N-LDL及N-HDL对凝血及纤溶活性无影响。Ox-VLDL、Ox-LDL及Ox-HDL促进血凝及血栓形成;Ox-VLDL及Ox-LDL使纤溶活性增加,而Ox-HDL对纤溶活性无明显影响。     

The effect of short-term aerobic training on coagulation and fibrinolytic factors in sedentary healthy postmenopausal women

Objective

The purpose of this study was to assess the effect of short-term aerobic training on the fibrinolytic and coagulative factors in postmenopausal women.

Study design

Twenty volunteer sedentary healthy postmenopausal women (48–53 years), who entered the menopause naturally, were divided randomly into two groups: training (n = 10) and control (n = 10).

Methods and main outcome measures

Training consisted of 10 sessions of submaximal aerobic cycling, 35 min for each session (5 min warm-up, 25 min aerobic training with 70% HRmax, 5 min active and 15 min passive recovery), 3 times a week. Coagulation and fibrinolytic factors were assessed both before and after aerobic program in both groups.

Results

Fibrinogen, von Willbrand factor (vWF-Ag) antigen, plasminogen activator inhibitor-1 activity (PAI-1:Ac) and antigen (PAI-1:Ag) showed significant reduction after 10 sessions in the training group (P < 0.05). Also after training, prothrombin time (PT), partial thromboplastin time (PTT), tissue plasminogen activator activity (tPA:Ac) and antigen (tPA:Ag) increased (P < 0.05).

Conclusion

It was concluded that fibrinolytic activity on postmenopausal women could be improved by a 3-week regular submaximal training program. These changes on the hemostatic factors suggest that short-term aerobic training may prevent the decline in fibrinolytic function observed in sedentary postmenopausal women.     

颅内大动脉狭窄致脑梗死患者静脉溶栓前后定量脑电图比较

目的：探讨定量脑电图（QEEG）对颅内大动脉狭窄的脑梗死患者重组组织型纤溶酶原激活（rt—PA）静脉溶栓后脑功能的评估作用。方法：给予70例急性脑梗死患者以rt—PA静脉溶栓治疗,分颅内大动脉狭窄组（30例）及无狭窄组（40例）,在治疗前、治疗后2h、24h、7d、14d、90d等6个时间点进行QEEG检查和美国国立卫生研究院卒中量表（NIHSS）评分;计算EEG大脑对称指数（BSI）及δ＋θ波与α＋β波的比率（DTABR）,最后两组进行比较。结果：与30例狭窄组比较,4例无狭窄组的BSI从治疗后2h、DTABR从治疗后24h及NIHSS评分从治疗后7d起各时间点均明显减低（改善）（P〈0．01）;而狭窄组各项指标则相应分别从治疗后24h、2d、7d起减低（均P〈0．05）。无狭窄组各时间点BSI、DTABR及7～90d的NIHSS评分均明显低于对照组（P〈0．01）。结论：QEEG能及时反映急性脑梗死患者静脉溶栓治疗后脑功能的改善,而且这种改善明显要早于临床神经功能缺损程度评分,其中以BSI的敏感性更高。颅内大动脉无狭窄者溶栓治疗后QEEG提示脑功能好转改变早于狭窄者,但两者NIHSS评分的改善时间无差异。     

Effects of the converting enzyme inhibitor captopril on blood coagulation and fibrinolysis in man

Summary Systematic blood coagulation analyses were conducted in 32 severely hypertensive patients treated with the angiotensin converting enzyme inhibitor captopril. Two hours after the first captopril dose, fibrin monomer complexes had already increased. This rise was even more distinct after 26 h and 1 week. Tests after 6 and 12 months of therapy showed a regression of fibrin monomer complexes to pretreatment values. In several patients with a marked increase in fibrin monomer complexes, the partial thromboplastin time (PTT) became shorter and antiplasmin activity increased. The most pronounced increase in fibrin monomer complexes was seen in patients with a rapid and excessive blood pressure reduction.The concentration of fibrin monomer complexes also rose in 15 healthy normotensive subjects, after a single oral dose of captopril (25 mg). Additionally, the PTT was shortened and antiplasmin significantly rose. An inhibition of fibrinolysis by captopril could be demonstrated by the effect on fibrin plates and thrombus weight after streptokinase. Out of 58 patients with severe hypertension and atherosclerosis treated with captopril, 7 patients suffered vascular complications during antihypertensive therapy: myocardial infarction (n=2), coronary insufficiency (1), cerebral ischemia (1), renal insufficiency (3). These ischemic lesions may be partly explained by the alterations of coagulation and fibrinolysis under captopril therapy.Dedicated to Prof. Dr. H.-J. Bretschneider on the occasion of his 60th birthday     

睾酮对人血管内皮细胞纤溶活性影响及机制

目的：观察睾酮对人血管内皮细胞分泌纤溶酶原激活物（tPA）、纤溶酶原激活物抑制物1（PAI-1）的影响及其机制。方法： 将体外培养的人血管内皮细胞（HUVEC）分为5个浓度睾酮组及单纯培养基对照组，MTT实验观察睾酮对细胞生长及活性影响。ELISA 法测各组tPA、 PAI-1含量。用雄激素受体拮抗剂(flutamide)预处理细胞后重复实验。结果： 生理及略低于生理剂量睾酮（3×10-10 mol/L-3×10-8 mol/L）可明显促进tPA 分泌（P＜0.01）；而大剂量则使tPA 含量明显减少（P＜0.01）。各睾酮组PAI-1含量均明显低于对照组（P＜0.05）。Flutamide 能有效消除睾酮的上述作用。结论： 生理浓度睾酮通过雄激素受体促进tPA分泌，降低PAI-1浓度而增强纤溶系统活性，有利于防止血栓性疾病的发生。     

Real-Time Measurement of Lysis of Mural Platelet Deposits by Fibrinolytic Agents under Arterial Flow

An in vitro whole blood reperfusion model was employed to quantify: (a) initial rates of lysis of mural platelet deposits from flowing blood onto fibrin-coated surfaces and (b) plasmin-mediated consumption of plasma plasminogen and fibrinogen, by recombinant tissue-type plasminogen activator (rt-PA) and two t-PA variants, KHRR 296–299 AAAA (K-tPA) and T103N, N117Q, KHRR 296–299 AAAA (TNK-tPA), at wall shear rates of either 500 or 1000 s^–1. K- and TNK-tPA are more fibrin-specific than rt-PA, and are also resistant to inactivation by plasminogen activator inhibitor–1 (PAI–1). At 500 s^–1, no agent showed significant lysis of mural platelet deposits on fibrin, even at concentrations as high as 10 g/ml of blood. At 1000 s^–1, each agent demonstrated a dose-dependent lysis of mural platelet deposits, due to plasmin-mediated lysis of the fibrin substrate (fibrinolysis). The local concentration of thrombolytic agents close to the fibrin-coated surface is probably higher than the concentration of released PAI–1 from the adherent and activated platelets. Hence, the initial rates of lysis achieved by K- and TNK-tPA were not significantly different from that by rt-PA, when each agent was tested at either 1 or 10 g/ml of blood. However, TNK-tPA, at 1 g/ml,> caused the most extensive lysis at the end of the 50 min reperfusion period (50% vs 29% and 17% by rt-PA and K-tPA, respectively). K- and TNK-tPA, at concentrations as high as 10 g/ml of blood, caused plasminogen activation that was controlled by the natural plasmin inhibitors, and, thus, no proteolytic degradation of plasma fibrinogen (fibrinogenolysis). On the contrary, rt-PA at 1 g/ml revealed slight fibrinogenolysis that became extensive at 10 g/ml. This study demonstrates the potential use of an in vitro model, that mimics the in vivo hemodynamic environment, in evaluating the performance of thrombolytic agents. The data suggest that: (a) adequate flow must accompany fibrinolysis for successful embolization, and (b) the TNK variant may lyse annular thrombi after recanalization, at least as efficiently as rt-PA does, while causing lesser defect of systemic hemostasis. © 1998 Biomedical Engineering Society. PAC98: 8745Hw, 8790+y, 8380Lz, 8715Kg     

胃癌中uPA、PAI-1表达及其与血管生成的关系

目的 观察胃癌组织中uPA、PAI-1mRNA及蛋白的表达，并探讨它们与肿瘤分化、血管生成及临床病理因素之间的关系。方法 用原位杂交及免疫组化S-P法检测110例胃癌组织中uPA、PAI-1的表达，根据CD34阳性的血管内皮细胞计数肿瘤组织微血管密度（MVD）。结果 （1）胃癌组织中uPA mRNA和蛋白、PAI-1 mRNA和蛋白阳性表达定位于胞质；uPA的表达随分化程度的降低有逐渐升高的趋势，PAI-1的表达随分化程度的降低有逐渐降低的趋势。（2）110例uPA mRNA及蛋白表达阳性组MVD值显著高于阴性组，差异均具有显著性（P值均＜0．05）。（3）uPA mRNA及蛋白的表达与临床分期呈正相关（P＜0．05），PAI-1的表达与临床分期和淋巴结转移无相关性。（4）uPA mRNA／蛋白与PAI-1 mRNA／蛋白的表达无相关性。结论uPA与促进胃癌的血管生成密切相关，阻断uPA的分泌和作用途径有望对胃癌浸润转移起抑制作用；胃癌组织中PAI-1可能担当重要的调节剂或者是肿瘤细胞防止自身降解的保护剂而不是这个系统的单纯抑制剂。     

Expression of fibrinolysis activators and their inhibitor in neointima of polyester vascular grafts

The aim of the study was to evaluate dynamic changes in the expression of fibrinolytic system components in neointima forming in polyester vascular grafts.

The study was carried out on 18 mongrel dogs divided into three groups, that underwent replacement of abdominal aorta with a polyester double velour prosthesis. Grafts were removed at 1, 4 and 12 months. The specimens were fixed according to AMeX method. Immunohistochemical labeling for von Willebrand factor (vWf), tissue plasminogen activator (t-PA), urokinase (u-PA), its receptor (u-PAR), plasminogen activator inhibitor type 1 (PAI-1) and D-dimer (DD) was performed.

Increasing intensity of vWf expression on the graft luminal surface was found in successive periods of the study. A light positive t-PA and u-PA staining was shown in neointima at 1 month and its intensity was significantly increased at 4 and 12 months. Expression of u-PAR appeared at 4 months. A light positive PAI-1 and DD staining was demonstrated in neointima in all periods of the study.

The results demonstrated increasing expression of fibrinolysis activators in neointima of polyester vascular grafts. Intensive expression of plasminogen activators, when compared to their inhibitor may reduce thrombotic properties of graft neointima particularly in the late period after prosthesis implantation.     

Hormone replacement therapy and hemostasis: principles of a complex interaction

Postmenopausal women on hormone replacement therapy (HRT) have been shown to be at reduced risk of arterial thrombotic disease. The risk of venous thrombosis appears not to be increased in HRT users in the absence of specific risk factors. However, while these data refer predominantly to women using conjugated equine estrogens, it is less clear whether the favourable impact on cardiovascular diseases may also be achieved by other preparations. Dose, as well as route of application and, particularly, the combination of steroids have been shown to affect both the clinical and the metabolic profile. With regard to cardiovascular diseases, differential effects on the hemostatic system are of particular interest. The principles of the interaction of steroids with the hemostatic system are reviewed. Also, the principal limitations of the assessment of the hemostatic system, as well as its interpretation, with regard to cardiovascular diseases are discussed. It is proposed to view the hemostatic system predominantly as a monitor of endothelial function rather than as a mediator of potential harmful effects on the cardiovascular system.     

足月危重新生儿抗凝和纤溶系统变化的研究

目的　研究足月危重新生儿抗凝和纤溶系统的变化。方法　采用ELISA法和免疫浊度法测定危重组 2 7例、非危重组 18例和健康组 15例足月新生儿的血浆蛋白C(PC)、总蛋白S(TPS)、抗凝血酶Ⅲ (AT -Ⅲ )、D -二聚体 (D -D)、血管性假血友病因子 (vWF)。结果　足月危重新生儿血浆PC、TPS、AT -Ⅲ低于对照组 ,D -D、vWF明显高于对照组。结论　足月危重新生儿存在抗凝、纤溶系统的激活及血管内皮细胞损伤 ,它们是发现早期DIC的敏感指标。     

PAI-1启动子区4G/5G基因多态性、ACE插入/缺失多态性与脑卒中的相关性

目的探讨纤溶酶原激活物抑制物-1(PAI-1)启动子区基因多态性和血管紧张素转换酶(ACE)插入/缺失多态性与脑卒中的关系。方法 PCR检测203例脑卒中患者和139名健康对照者PAI-1基因启动子区4G/5G多态性、ACE基因插入/缺失多态性,同时应用比色法测定血清ACE活性,发色底物法测定PAI-1活性。结果脑梗死(CI)组PAI-1活性(0.769±0.163 AU/mL)、ACE活性(43.42±14.36 U/L)明显高于对照组(0.652±0.116 AU/mL和31.28±8.64 U/L,P<0.01);CI组PAI-I基因4G纯合子、ACE D/I基因DD纯合子比例明显高于对照组(P<0.01);PAI-I基因4G/4G基因型与ACE基因D/D基因型对CI发病可相互协同作用(P<0.01)。结论 PAI-1基因4G/4G基因型和ACE基因D/D基因型均可能是CI发病的危险因素,且具有协同作用。     

凝血和纤溶失衡在急性肺损伤中的作用

急性肺损伤(acute lung injury,ALI),以肺泡上皮细胞和血管内皮屏障损伤、急性炎症反应、富含蛋白的肺水肿为特征,是一种临床常见的危重病症,可进一步发展为急性呼吸窘迫综合症(acute respiratory distress syndrome,ARDS).