新生儿纤维蛋白溶解的成分和纤溶酶的产生

本文作者对30名正常新生儿脐血和25名正常成人血标本中组织型纤溶酶原激活物(tPA)活性和抗原,纤溶酶原激活抑制物(PAI),纤溶酶原产生率进行了研究.结果显示新生儿纤溶酶活性和抗原分别比成人低63%和75%(p<0.001).tPA活性比成人低48%.tPA抗原浓度平均值和中电位数分别比成人低34%和47%.PAI活性与成人相同.酪蛋白溶解法确定纤溶酶原产生实验中,加入激活剂尿激酶1小时后成人纤溶酶原产生达最大值,新生儿3小时后才     

急性心肌梗死患者溶栓治疗前后凝血与纤溶系统的变化

目的　探讨急性心肌梗死 (AMI)患者溶栓治疗前后不同时间段凝血与纤溶系统的变化情况。方法　对 4 1例经溶栓治疗的AMI患者分别于治疗前及治疗后 4、8、12、4 8h和 3、7d共 7次抽取静脉血 ,分别检测凝血酶原时间 (PT)、活化部分凝血活酶时间 (APTT)、纤维蛋白原 (Fg)、D 二聚体 (DD)、纤溶酶原 (PLG)、α2 纤溶酶抑制物 (α2 PI)、组织型纤溶酶原激活物 (t PA)和纤溶酶原激活物抑制剂 1(PAI 1)等指标的活性或含量。结果　所有患者经溶栓治疗后 ,均导致PT、APTT的明显延长 ,t PA活性、DD含量的明显增高 ,PLG、α2 PI、PAI 1活性和Fg含量的明显降低 (与溶栓前比较 ,P均 <0 .0 1)。但这种变化为时较短 ,至溶栓后 12h ,各项指标已出现不同程度的恢复 ,t PA与PAI 1已回复至溶栓前水平。结论　凝血与纤溶活性的变化与溶栓疗效关系密切 ,应用时监测PLG、α2 PI、t PA、PAI 1、Fg和DD等指标 ,对判断溶栓疗效有重要价值。     

卡维地洛及TNF-α对内皮细胞释放t-PA和PAI-1的影响

目的　研究卡维地洛及肿瘤坏死因子α(TNF α)对内皮细胞分泌组织纤溶酶原激活物 (t PA)和纤溶酶原激活物抑制剂 1(PAI 1)的影响。方法　培养内皮细胞株 (ECV3 0 4) ,分为TNF α刺激组 ,培养基中TNF α加至终浓度为 5、10、2 5、5 0、10 0ng/ml;卡维地洛干预组 ,培养基中加TNF α (5 0ng/ml)后加入卡维地洛 ,终浓度为 2 0、5 0、10 0、2 0 0nmol/L ,2 4h后测定上清中的组织纤溶酶原激活物 (t PA)和纤溶酶原激活物抑制剂 1(PAI 1)的含量。结果　内皮细胞在TNF α刺激 2 4h后 ,其分泌的PAI 1抗原含量与对照组比有明显升高 ,有显著性差异 (P <0 0 5 ) ,而两组间t PA含量无明显差异 (P >0 0 5 )。而卡维地洛干预组却显著降低PAI 1(P <0 0 5 ) ,对t PA含量无明显作用 (P >0 0 5 )。结论　TNF α对内皮细胞株分泌的PAI 1有显著的升高作用 ,而对t PA无显著影响 ;用卡维地洛干预后 ,PAI 1显著降低 ,t PA含量无明显改变。     

慢性心力衰竭患者血浆组织型纤溶酶原激活物和纤溶酶原激活物抑制物-1含量变化及其临床意义

目的　研究慢性心力衰竭 (CHF)患者血浆组织型纤溶酶原激活物 (t PA)和纤溶酶原激活物抑制物 1(PAI 1)含量的变化及其临床意义。方法　用酶联免疫吸附法 (ELISA)检测 6 0例CHF患者 (CHF组 )和 2 0例健康体检者 (正常对照组 )血浆t PA及PAI 1抗原含量。结果　CHF组血浆t PA和PAI 1平均含量都明显高于对照组 (P<0 .0 1)。CHF患者血浆PAI 1含量增高随心功能恶化而愈加明显。结论　CHF患者纤溶功能明显下降 ,可用血浆t PA、PAI 1含量作为判断病情的参考指标之一。     

卡托普利对犬急性心肌梗死溶栓治疗中纤溶活性的影响

目的观察卡托普利对犬急性心肌梗死溶栓再灌注心肌损伤和纤溶系统的影响。方法选择健康杂种犬20条,随机分为2组,在犬急性心肌梗死尿激酶溶栓治疗的同时应用卡托普利药物干预,观察并测定治疗过程中组织型纤溶酶原激活物(tPA)、组织型纤溶酶原抑制物(PAI)和心肌酶谱等的动态变化。结果溶栓加用卡托普利治疗后:心肌酶谱峰值进一步减低;溶栓后期tPA活性无明显下降,PAI活性进一步减低。结论应用卡托普利可使溶栓治疗时再灌注心肌损伤进一步减轻,可以改善纤溶-凝血功能障碍,升高tPA,降低PAI,调节tPA/PAI比值,防治血栓形成对心肌缺血的进一步损害。     

阻塞性睡眠呼吸暂停低通气综合征患者血管内皮细胞及纤溶系统功能变化

目的：探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者血管内皮细胞及纤溶系统功能变化。方法：根据多导睡眠呼吸监测仪监测结果，选择年龄、性别、体重指数(BMI)无明显差异的OSAHS患者52例和健康者48例。以Clauss法测定纤维蛋白原(Fg)，以发色底物法测定组织纤溶酶原激活物活性(tPA：A)、纤溶酶原激活物抑制物-1活性(PAI-1：A)，以酶联免疫法测von Willebrand因子含量(vWF)、组织纤溶酶原激活物含量(tPA：Ag)、纤溶酶原含量(PLg：Ag)和纤溶酶原激活物抑制物-1含量(PAI-1：Ag)。结果：与对照组比较，(3SAHS组vWF、Fg、PAI-1：A、PAI-1：Ag水平明显升高，PLg：Ag、tPA：Ag含量明显降低，tPA：A无明显变化。结论：OSAHS患者血管内皮细胞功能受损，纤溶系统功能降低。     

冠心病患者凝血及纤溶系统功能的变化

为探讨冠心病(CHD)患者凝血及纤溶系统的变化,我们对20例稳定性心绞痛(SA),19例不稳定性心绞痛(UA),51例急性心肌梗死(AMI)患者作组织型纤溶酶原激活物(t-PA)、组织型纤溶酶原激活物抑制物(PAI)、纤溶酶原(PCG)、α_2抗纤溶酶(α_2AP)、纤维蛋白原(Fg)、D二聚体(D-Dimer)等凝血及纤溶指标的测定,结果显示与SA相比,UA及AMI患者t-PA活性、t-PA/PAI比值明显降低(P<0.05),血浆PAI活性、Fg含量及D-Dimer含量均明显增高(P<0.05),说明μA及AMI患者存在明显凝血活性增强及纤溶系统功能减退,这对冠心病的发生和发展起着重要作用。     

降纤酶对急性脑梗死患者凝血与纤溶指标的影响

目的：探讨降纤酶治疗后对脑梗死患者凝血与纤溶指标的影响及治疗意义。方法：测定38例降纤酶治疗前后急性脑梗死患者和25例正常对照组血浆纤维蛋白原（Fbg）、D－二聚体（D－D）、组织型纤溶酶原激活物（t-PA）、纤溶酶原激活物抑制剂（PAI－1）及α2-抗纤溶酶（α2－PI)含量。结果：急性脑梗死患者血浆Fbg、D－D、PAI－1及α2－PI明显升高，t-PA明显降低；降纤酶治疗后Fbg、D－D、PAI－1及α2－PI明显降低，t-PA明显升高，其中，Fbg、t-PA有非常显著性差异（P＜0．001）。结论：降纤酶有良好的降纤、溶纤作用，对急性脑梗死治疗有肯定作用。     

新产品讯息

Spectrolyse~(TM)/fibrin 该试剂是Biopool International公司产品,为用于测定组织纤溶酶原激活物(t-PA)活性或纤溶酶原激活物抑制物(PAI)活性的显色性检测药盒。本法应用一种纤溶酶原激活物/纤溶酶显色性底物以定量测定t-PA活性,灵敏度高,血浆样品中t-PA的可测知范围为0.01～30iu/ml,并应用刺激剂DESA-FIB-X~(TM)以保证检测的特异性。该刺激剂可使t-PA对纤溶酶原的作用增强300倍而不影响尿激酶。已知在深静脉血栓形成、     

急性白血病纤溶系统检测的临床意义

目的探讨急性白血病(AL)患者纤溶系统的异常. 方法发色底物法和ELISA法测定93例患者血浆一系列纤溶指标. 结果患者血浆组织纤溶酶原激活物活性、D-二聚体(D-D)水平显著升高;纤溶酶原活性(PLG)、α2抗纤溶酶活性(α2-PI)、纤溶酶原激活抑制物活性(PAI)水平降低;缓解后均恢复正常. 结论 AL患者存在纤溶系统的激活,部分指标与AL分型、出血程度和预后有关.     

The glycocalyx protects erythrocyte-bound tissue-type plasminogen activator from enzymatic inhibition

Coupling tissue-type plasminogen activator (tPA) to carrier red blood cells (RBC) prolongs its intravascular life span and permits its use for thromboprophylaxis. Here, we studied the susceptibility of RBC/tPA to PA inhibitors including plasminogen activator inhibitor-1 (PAI-1) that constrain its activity and may reduce the duration of its effect. Despite lesser spatial and diffusional limitations, soluble tPA was far less effective than RBC/tPA in dissolving clots formed in vitro from blood of wild-type (WT) mice (40 versus 80% lysis at equal doses of tPA). Furthermore, after i.v. injection, soluble tPA lost activity faster in transgenic mice expressing a high level of PAI-1 than in WT mice, whereas the activity of RBC/tPA was unaffected. PAI-1 inactivated soluble tPA at equimolar ratios in vitro, but it had no effect on the amidolytic or fibrinolytic activity of RBC/tPA. RBC/tPA was also more resistant than soluble tPA to in vitro inhibition by other serpins (alpha2-macroglobulin and alpha1-antitrypsin) and pathologically high levels of glucose. However, coupling to RBC did not protect a truncated tPA mutant, Retavase, from plasma inhibitors. Chemical removal of the RBC glycocalyx negated tPA protection from inhibitors: tPA coupled to glycocalyx-stripped RBC bound twice as much 125I-PAI-1 as did tPA coupled to naive RBC, and susceptibility of the bound tPA to inhibition by PAI-1 was restored. Thus, the RBC glycocalyx protects RBC-coupled tPA against inhibition. Resistance to high levels of inhibitors in vivo contributes to the potential utility of RBC/tPA for thromboprophylaxis.     

纤溶酶原激活物抑制物-1基因多态性及其血浆水平在急性肺动脉血栓栓塞中的作用

目的 探讨纤溶酶原激活物抑制物-1(plasminogen activator inhibitor-1,PAI-1)基因4G/5G多态性、PAI-1和组织型纤溶酶原激活物(tissue plasminogen activator,t-PA)血浆水平在急性肺动脉血栓栓塞(acute pulmonary thromboembolism,APTE)中的作用.方法 选择52例急性肺栓塞患者(分为2组:26例有环境诱因,26例无环境诱因)和57例正常对照者,聚合酶链反应-限制性片段长度多态性法检测PAI-1基因型,酶联免疫吸附试验测定血浆PAI-1和t-PA水平.结果 (1)无环境诱因组4G/4G基因型显著高于有环境诱因组和正常对照组(P=0.034),而有环境诱因组与正常对照组比较差异无统计学意义.(2)无明确环境诱因组t-PA明显降低,PAI-1明显升高与有环境诱因组、正常对照组比较差异有统计学意义(P＜0.05),而有环境诱因组与正常对照组比较无显著差异.(3)在三组中,无论何种基因型,无环境诱因组的PAI-1血浆水平均最高.在4G/4G基因型和4G/5G基因型中,无环境诱因组与正常对照组、有环境诱因组的差异有统计学意义(P＜0.05).4G等位基因与PAI-1血浆水平具有相关性.结论 纤溶酶原激活物抑制物-1基因多态性与急性肺栓塞有关,4G/4G基因型显著增加无肺栓塞环境诱因个体肺栓塞危险.急性肺栓塞无环境诱因患者存在明显的低纤溶状态.     

纤溶酶原激活物及其抑制剂-1的血浆含量测定在急性肺血栓栓塞症中的意义

目的探讨在急性肺血栓栓塞症(APE)发病中的组织型纤溶酶原激活物(tPA)及其抑制剂-1(PAI-1)的血浆含量、作用及其该病诊断中的意义。方法,对44例APE患者和56例健康正常对照者应用酶联免疫吸附双抗体夹心法(ELISA法)定量测定血浆tPA和PAI-1抗原水平。结果与正常对照组(tPA含量为11．05ng／ml和PAI-1含量为61．31ng／m1)相比,APE组的IPA含量(33．88ng／ml)和PAI-1含量(111．50ng／ml)较高,两组间差异有显著性。在急性肺血栓栓塞症的疾病诊断中,tPA和PAI-1的血浆含量合理诊断截断点分别为21．7ng／ml和79．4ng／ml.结论急性肺血栓栓塞症的发病是由于PAI-1抗原产生和释放增多,而非tPA抗原释放或产生不足所致．tPA和PAI-1抗原血浆含量测定在APE的疾病诊断中具有要意义。     

The regulation by fibrinogen and fibrin of tissue plasminogen activator kinetics and inhibition by plasminogen activator inhibitor 1

BACKGROUND: Tissue plasminogen activator (tPA) is unusual in the coagulation and fibrinolysis cascades in that it is produced as an active single-chain enzyme (sctPA) rather than a zymogen. Two chain tPA (tctPA) is produced by plasmin but there are conflicting reports in the literature on the behaviour of sc- and tctPA and little work on inhibition by the specific inhibitor plasminogen activator inhibitor-1 (PAI-1) under physiological conditions. OBJECTIVES: To perform a systematic study on the kinetics of sctPA and tctPA as plasminogen activators and targets for PAI-1. METHODS: Detailed kinetic studies were performed in solution and in the presence of template stimulators, fibrinogen and fibrin, including native fibrin and partially digested fibrin. Numerical simulation techniques were utilized to cope with the challenges of investigating kinetics of activation and inhibition in the presence of fibrin(ogen). RESULTS: Enzyme efficiency (k(cat)/K(m)) was higher for tctPA than sctPA in solution with chromogenic substrate (3-fold) and plasminogen (7-fold) but in the presence of templates, such as fibrinogen and native or cleaved fibrin, the difference disappeared. sctPA was more susceptible to PAI-1 in buffer solution and in the presence of fibrinogen; however, in the presence of fibrin, PAI-1 inhibited more slowly and there was no difference between sc and tctPA. CONCLUSIONS: Fibrinogen and fibrin modulate the activity of tPA differently in regard to their activation of plasminogen and inhibition by PAI-1. Fibrinogen and fibrin stimulate tPA activity against plasminogen but fibrin protects tPA from PAI-1 to promote fibrinolysis.     

Activation of the fibrinolytic system and utilization of the coagulation inhibitors in sepsis: comparison with severe sepsis and septic shock

OBJECTIVES: To determine whether the fibrinolytic system is activated and coagulation inhibitors are utilized in sepsis, to compare the findings detected in sepsis with those found in severe sepsis and septic shock, and to compare the role played by different infectious pathogens on fibrinolysis and coagulation inhibitors. DESIGN AND SETTING: Prospective study comparing patients with sepsis, severe sepsis, and septic shock and healthy volunteers in the general intensive care unit of a tertiary university hospital. PATIENTS: Eighty-two consecutive septic patients (47 with sepsis, 18 with severe sepsis, and 17 with septic shock), and 14 healthy volunteers (controls). MEASUREMENTS AND RESULTS: After blood sampling we measured activation markers of fibrinolysis [plasmin/alpha(2)-antiplasmin complexes (PAP), complexes of tissue plasminogen activator/plasminogen activator inhibitor (tPA/PAI), fibrin(ogen) degradation products (FDPs), D-dimmers fibrin degradation products (D-d)], the utilization marker of antithrombin III (ATIII) thrombin/antithrombin complexes (TAT), several factors of fibrinolysis [plasminogen, tissue plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1), alpha(2)-antiplasmin], and the natural coagulation inhibitors [ATIII, protein C (PrC), protein S (PrS)]. In sepsis, PAP, FDPs, D-d, and TAT were increased to 439.8+/-32.35 microg/l, 57% positive, 49% positive, and 3.46+/-0.27 microg/l, respectively, compared with control subjects (205.57+/-28.58 microg/l, 0% positive, 7% positive, and 1.61+/-0.1 microg/l, respectively). These markers further increased in severe sepsis and septic shock. With the exception of a decrease in ATIII and an increase in tPA and PAI-1, coagulation inhibitors and factors of fibrinolysis were not changed in sepsis. In severe sepsis and mainly in septic shock, coagulation inhibitors (ATIII, PrC) and plasminogen were markedly decreased, whereas tPA and PAI-1 were further increased. All changes were independent of the causative infectious pathogen. CONCLUSIONS: Fibrinolysis is strongly activated and ATIII is utilized in sepsis. These findings are further enhanced in severe sepsis and septic shock. In sepsis only ATIII is decreased. In contrast, in severe sepsis and mainly in septic shock plasminogen and the main coagulation inhibitors (i.e., ATIII, PrC) are depleted, indicating exhaustion of fibrinolysis and coagulation inhibitors. Finally, Gram-positive, Gram-negative and other micro-organisms produce identical impairment.     

Measurement of different forms of tissue plasminogen activator in plasma

BACKGROUND: We evaluated assays to measure both total tissue plasminogen activator (tPA) and the three principle forms of tPA in plasma: active tPA, tPA complexed with plasminogen activator inhibitor type 1 (PAI-1), and tPA complexed with C1-inhibitor. METHODS: Active tPA was measured by use of an indirect amidolytic assay and immunofunctional assays. tPA/PAI-1, tPA/C1-inhibitor, and total tPA antigen were measured by use of microtiter plates coated with anti-tPA antibodies and, respectively, anti-PAI-1, anti-C1-inhibitor, and anti-tPA antibodies conjugated to peroxidase. RESULTS: The immunofunctional tPA assay detected 1 U/L (0.001 U/mL) tPA and recovered 108% +/- 12% of active tPA added to samples containing high (mean, 60 000 IU/L) PAI-1 activities vs a detection limit of 10 U/L (0.01 U/mL) and 13% +/- 25% recovery for the indirect amidolytic tPA activity assay. For measurement of tPA/PAI-1 complex, polyclonal anti-PAI-1 conjugates recovered 112% +/- 20% of the expected tPA/PAI-1 vs recovery of only 38% +/- 16% when monoclonal anti-PAI-1 conjugates were used. Of three methods tested, two total tPA antigen assays correlated well (r(2) = 0.85) and showed recoveries near 100%, whereas the third method showed lower correlations, higher intercepts, and falsely high recovery. A single anti-tPA capture antibody that performed the best in the individual assay evaluations was used to measure the different forms of tPA in 22 samples with a range of tPA and PAI-1 values. The sum of the molar concentrations of active tPA, tPA/PAI-1, and tPA/C1-inhibitor using the optimized methods was equal to 94% +/- 7% of measured total tPA. CONCLUSION: Optimized assays based on a single anti-tPA capture antibody can be used to accurately measure the major forms of tPA in plasma.     

缺血性脑卒中患者血纤溶活性变化规律的研究

目的 研究脑梗死组和非脑梗死组患者急性期,亚急性期和恢复期组织型纤溶酶原激活物（tPA）,纤溶酶原激活物抑制物-1（PAI-1）的变化规律.方法 135例脑梗死组患者于发病96h内,病后14d、3月、6月、9月分别采血,77例非脑梗死组患者先采血一次,然后分别在第一次采血后14d、3月、6月、9月采血.结果 脑梗死急性期tPA含量明显升高,PAI-1的含量明显升高.恢复期脑梗死即发病后3月,6月,9月tPA的含量比急性期明显降低,且脑梗死后时间越长tPA含量越低,恢复期脑梗死PAI-1的含量比急性期明显降低.结论 在缺血性卒中的患者,高tPA含量提示纤溶活性的降低.高PAI-1代表纤溶抑制增强.     

TAFIa, PAI-1 and α2-antiplasmin: complementary roles in regulating lysis of thrombi and plasma clots

PAI-1 and alpha(2)-antiplasmin (alpha(2)AP) are the principal direct inhibitors of fibrinolytic proteases. Thrombin activatable fibrinolysis inhibitor (TAFI), a plasma procarboxypeptidase activated by thrombin-thrombomodulin to form TAFIa, also regulates fibrinolysis by modulating fibrin. In this study, the relative contributions of PAI-1, alpha(2)AP and TAFIa to inhibition of lysis were assessed. In platelet-poor plasma clots, alpha(2)AP, TAFIa and PAI-1 all inhibited lysis, as shown by the addition of neutralizing antibodies to alpha(2)AP and PAI-1 +/- CPI, a potato carboxypeptidase inhibitor. alpha(2)AP played the largest role in regulating plasma clot lysis, but neutralization of inhibitors in combinations was more effective in shortening lysis times, with a maximal effect when all three inhibitors were neutralized. In platelet-rich clots, a larger contribution of PAI-1 was evident. Tissue plasminogen activator induced lysis of model thrombi, made from whole blood, was approximately doubled on incorporation of CPI, illustrating a substantial contribution of TAFIa to inhibition of thrombus lysis. Similar increases in thrombus lysis were observed on inclusion of neutralizing antibodies to PAI-1 and alpha(2)AP, with alpha(2)AP playing the dominant role. Maximal thrombus lysis occurred upon neutralization of all three inhibitors. These observations suggest that, despite the differences in concentrations and activities of inhibitors, and the different modes of action, the roles of the three are complementary in both plasma clot lysis and thrombus lysis.