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。     

尿激酶型纤溶酶原激活剂诱发的纤溶反应及其调节因子

目的 研究一些凝血和纤溶因子对尿激酶型纤溶酶原激活剂（uPA)诱发纤溶反应的调节作用及机制。方法 采用凝块溶解测定和纤维蛋白检测板测定观察了一些凝血和纤溶因子对uPA诱导的纤溶反应的影响及相互作用。结果 凝血酶激活的纤溶抑制因子（TAFI）对uPA或单链uPA（scuPA）诱发的纤溶反应具有明显的拮抗作用，凝血酶调节因子（TM）可明显增强其抑制作用，凝血酶对uPA诱导的纤溶反应没有明显的影响，但可抑制scuPA诱导的纤溶反应，该作用亦可被TM所增强或被水蛭素所消除。结论 凝血酶／TM可通过激活TAFI对uPA或scuPA诱导的纤溶反应产生抑制作用，凝血酶对scuPA诱发的纤溶反应的抑制作用亦可通过其对scuPA的裂解失活而实现。     

脑梗死血浆纤溶酶原激活物及抑制物动态变化

我们于 19981999年观察了脑梗死 3 0例急性期及随后 3周内血浆组织型纤溶酶原激活物及其抑制物(ｔ ＰＡ、ＰＡＩ)活性水平 ,了解其在病程中血纤溶活性变化及临床意义。1　对象和方法1 1　对象　脑梗死组 3 0例均经ＣＴ或ＭＲＩ确诊 ,男22例 ,女 8例 ;年龄 60 82岁 ,平均 69 4± 8 2岁。病程162 8ｄ ,平均 16± 6 2ｄ。梗死部位 :侧脑室前角及尾状核头部 7例 ,内囊前肢 6例 ,豆状核 5例 ,内囊后肢 2例 ,丘脑 2例 ,脑叶及深部 8例。对照组为健康老人2 0名 ,男 16人 ,女 4人 ;年龄 60 81岁 ,平均 65 4± 5 2岁。1 2　方法　观察组取血 2次 ,…     

尿激酶型纤溶酶原激活剂及其抑制剂PAI-1 mRNAs的表达与人肝细胞癌的关系

为探讨尿激酶型纤溶酶原激活剂（ｕＰＡ）及其抑制剂ＰＡＩ－１ｍＲＮＡｓ的表达变化与人肝细胞癌（ＨＣＣ）浸润、转移间的关系,应用Ｎｏｒｔｈｅｒｎ印迹杂交技术对３０例新鲜活检肝组织作ｕＰＡ和ＰＡＩ－１ｍＲＮＡｓ表达的研究。结果显示：１６例伴肝内浸润和转移癌组织中ｕＰＡ和ＰＡＩ－１ｍＲＮＡｓ表达水平明显高于１４例无肝内浸润和转移肝组织;１８例高分化ＨＣＣ癌组织与１２例中、低分化ＨＣＣ相比,ｕＰＡ和ＰＡＩ－１ｍＲＮＡｓ含量差异有显著性意义。结果表明,癌组织内ｕＰＡ和ＰＡＩ－１基因转录水平的改变与ＨＣＣ浸润、转移及细胞分化密切相关。     

胰岛素及纤溶酶原激活物抑制物与动脉粥样硬化

胰岛素（INS）、纤溶酶原激活物抑制物-1（PAI-1）水平的升高是冠心病发生、发展的重要危险因素。INS作为一种生长因子,可导致血管内皮功能异常,并通过mRNA的诱导作用增加PAI-1的合成与分泌,PAI-1的升高导致纤溶系统的失衡,共同成为众多代谢病和心血管疾病的致病基础,可作为独立的冠心病危险因素来预测心血管病事件的发生。现就INS、PAI-1水平与动脉粥样硬化（AS）关系的研究进展作一综述。     

SDS-PAGE及转移电泳法测定纤溶酶原激活剂的分子量

纤溶酶原激活剂(PA)经 SDS-PAGE 分离后,在凝胶中用 Triton X-100取代SDS,使 PA 复活。在温和条件下转移到纤维蛋白板上,则纤维蛋白板上出现与 PA 对应的溶解带。该法不仅可以用来测定 PA 的分子量,鉴别 PA 的类别,同时灵敏度不低于溶解圈法,UK 可以测到0.005IU,而 t-PA 可以测到0.03IU。     

纤溶酶原激活物抑制物缺乏患者外伤性血肿的诊治

纤溶酶原激活物抑制物 - 1(plas minogenactivatorinhibitor - 1,PAI - 1)缺乏是一种极为罕见的疾病。由于PAI -1活性降低而导致纤溶亢进 ,临床表现为拔牙、小的创伤及手术后伤口持续、反复出血。常规实验室凝血功能检查常无异常发现 ,也缺少血小板、Ⅷ因子和α -2抗纤溶酶缺乏或功能异常的证据。国内尚未见PAI- 1缺乏病例的报道。现报告我科收治的 1例外伤后血肿反复发作的PAI- 1缺乏患者的诊治经过。临床资料患者　男 ,32岁。年幼时轻微碰撞后即出现皮下青紫、肿胀。 1年前因跌伤致右大腿外侧血肿 ,在当地医院行血肿清除术。术后 4个…     

重组人尿型纤溶酶原激活剂的冻干及其稳定性观察

由血栓引起的心血管系统疾病严重威胁着人类健康，临床上急需一种溶栓效果好、副作用小的药物。尿型纤溶酶原激活剂（ｕ－ＰＡ）作为一种有前景的溶栓药物已受到国内外普遍重视，我所构建的表达重组人ｕ－ＰＡ的ＣＨＯ工程细胞（ＣＬ－１１Ｇ株）培养上清经纯化可获得含约...     

组织型纤溶酶原激活剂cDNA在大肠杆菌中的表达研究

将去除信号肽编码序列的组织型纤溶酶原激活剂（ｔ－ＰＡ）结构基因片段插入载体ｐＢＶ２２０的ＥｃｏＲＩ位点。目的基因受λＰ＿ＬＰ＿Ｒ启动子调控，通过温度调节诱导，ｔ－ＰＡ基因获得表达。电镜观察可见表达产物以包含体形式存在；表达量占非溶性菌体总蛋白的５％－８％。包含体产物经溶解及复性处理，可恢复活性；用溶纤维琼脂糖平板法、中和试验等方法证明了复性产物具有特异的ｔ－ＰＡ溶纤活性．     

经皮冠状动脉介入术中止血活性的早期改变及与纤溶酶原激活剂抑制物-1基因多态性的相关性

目的探讨经皮冠状动脉介入(PCI)术中冠状动脉内血浆纤溶酶原激活剂抑制物-1(PAI-1)、D-二聚体(D-D)、凝血因子Ⅶ(FⅦa)及可溶性P选择素(CD62P)活性在球囊扩张和支架植入前后的早期改变及其与PAI-1基因多态性的相关性,评估其对急性支架血栓形成的预测价值。方法选择稳定型心绞痛患者20例,按标准方法行冠状动脉造影且证实冠状动脉狭窄均在70%以上。术中冠状动脉内血样采集顺序依次为:球囊扩张前冠状动脉入口处(Ostium)用引导导管,球囊扩张15min以后及支架植入后15min通过血栓吸引器穿过病灶在病变远端采血。结果PAI-1基因多态性在本组中分布为4G/5G型最多(12例,60%),4G/4G型其次(6例,30%),5G/5G型最少(2例,10%)。4G和5G等位基因频率分别为60%和40%。具有PAI-14G/5G基因型患者冠状动脉内血浆PAI-1、D-D以及FⅦ活性在球囊扩张后较球囊扩张前明显升高且有统计学意义(P均为0.01),然而这些指标在球囊扩张前与支架植入后比较无显著性差异。结论球囊扩张较支架植入更易损伤血管内皮并导致冠状动脉内局部、早期止血活性的一过性增高,具有PAI-14G/5G基因型患者对这种反应较为敏感。PCI术前双联抗血小板药物可以有效抑制血小板活性。     

胸腺素α1的研究进展

胸腺素α1(thymosin,Tα1)是1984年发现并由胸腺分泌的一种重要的T淋巴细胞调节因子,与细胞免疫调节有关.胸腺素α1作为一种生物反应调节剂(BRM),它的良好疗效已得到确证,临床应用前景极为光明.就乙型肝炎来说,乙型肝炎病毒(HBV)感染是人类最常见的病毒性感染之一.全世界慢性HBV感染者约有3亿,其中大部分在亚洲地区.我国人群中慢性HBV携带者约占10%～15%.慢性乙型肝炎(CHB)患者中每年发生肝硬变和肝细胞癌者分别占2%和1%.显然,积极治疗HBV感染,阻抑其向肝硬变和肝癌发展,具有重要意义[1].此外,它对爱滋病、恶性肿瘤等这些人类健康大敌亦有良好疗效.如果开发出治疗上述疾病的Tα1药物,其市场将会大为扩展.     

Plasminogen activator inhibitor-1 (PAI-1) expression in relation to hypoxia and oncoproteins in clinical cervical tumors

Purpose

Explore the role of plasminogen activator inhibitor-1 (PAI-1) in cervical cancer and its relationship to hypoxia and the expression of p53, Ku70/80, and cyclin D1.

Material and methods

The expression of PAI-1, cyclin D1, and p53, together with tumor oxygenation, were determined in 43 consecutive patients suffering from localized cervical carcinoma. Oncoprotein expression was determined by immunohistochemistry. Tumor oxygenation was measured using a polarographic probe system, ?pO₂ histography.??

Results

PAI expression was considered negative in 32.6% and overexpressed in 18.6% of cases. Cyclin D1 showed a median expression of 5.0 (range 0?C70). We observed a positive association between PAI expression and altered p53 (p?=?0.049) and cyclin D1 (p?=?0.020). An inverse association was detected between PAI and Ku70/80 expression (p?=?0.042). Cyclin D1 staining increased according to tumor volume (r?=?0.314, p?=?0.009). We did not observe a significant association between PAI and hypoxia or other clinicopathological parameters.

Conclusion

The present results show that PAI-1 overexpression is associated with nonhomologous end-joining DNA repair down-regulation (low Ku70/80 expression) and with increased p53 and cyclin D1 expression, and they suggest that PAI-1 plays a role in the tumor behavior in cervical carcinoma.     

Effects of short-term exercise training on plasminogen activator inhibitor (PAI-1)

PURPOSE: To observe the effects of exercise training on plasminogen activator inhibitor, type-1 (PAI-1), tissue plasminogen activator (tPA), and associated metabolic variables in sedentary men and women. METHODS: A randomized, controlled experimental design was used to examine the influence of 10 d of moderate-intensity exercise training on measures of fibrinolysis. Sixteen men and 16 women between the ages of 50 and 70 yr were randomly assigned to exercise (EX) and control groups (CON) that were balanced for gender and hormone replacement therapy. Blood samples were collected on days 1, 2, 11, and 12 for measurement of plasma PAI-1, tPA, insulin, glucose, and triglyceride. Subjects in EX performed 50 min of treadmill walking at an intensity corresponding to 65% of heart rate reserve each day for 10 consecutive days. RESULTS: There were no significant changes in PAI-1, tPA, or associated metabolic variables between EX and CON during the intervention period. Within EX subjects, those with higher body fatness had a significant decrease in insulin and triglyceride compared with those with lower body fatness. However, no changes in fibrinolytic measures were observed within these subgroups. CONCLUSIONS: Short-term exercise training does not change PAI-1 levels in normal, asymptomatic men and women. In addition, modest decreases in insulin and triglyceride in individuals with elevated body fatness do not result in changes in PAI-1 after short-term training. It appears likely that decreases in PAI-1 with exercise training require decreases in adiposity and/or marked changes in metabolic variables.     

Rapid resolution of pulmonary embolism by tissue plasminogen activator

A case of multiple bilateral pulmonary emboli demonstrating complete resolution 48 hours after the intravenous administration of tissue plasminogen activator is presented.     

Thrombolysis of clotted hemodialysis grafts with tissue-type plasminogen activator

PURPOSE: To evaluate prospectively the efficacy of treating thrombosed hemodialysis arteriovenous polytetrafluoroethylene (PTFE) grafts using tissue-type plasminogen activator (tPA) and percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: Forty-two sequential thrombosed PTFE dialysis grafts in 33 patients presented for declotting. All 42 grafts were treated with a modified lysis and PTA technique with use of 2 mg tPA and 3,000-5,000 U heparin in a total volume of 5 mL, administered into the graft via an angiocatheter. The elapsed time from tPA injection until completion was recorded. Prospective data collection included demographic information, technical details of the procedure, immediate outcomes, complications, and patency rates. RESULTS: Technical success, defined as complete graft recanalization with a palpable thrill after treatment plus successful hemodialysis, was achieved in all cases, except five. These five cases were deliberate graft closures due to inadequacy of the outflow veins to support an arteriovenous graft after successful lysis. Mean lysis time was 40.8 minutes and mean room procedure time after the lysis period was 65.4 minutes. Eight procedure-related complications occurred (two major and six minor). The follow-up period was 4-241 days, with an estimated mean of 157 days. The 30-day and 90-day primary patency rates were 57% and 50%, respectively. CONCLUSIONS: Treatment of thrombosed PTFE dialysis grafts with use of 2 mg tPA and 3,000 U of heparin is safe and effective. Use of this modified lysis and PTA technique allows an expeditious procedure in the angiography suite. However, this technique precludes imaging of the outflow veins before treatment, so that grafts entering diffusely diseased veins may need to be closed after successful lysis.     

Comparison of urokinase and tissue plasminogen activator for thrombolysis in rats

Microvascular thrombosis in free flap and replantation surgery may be amenable to thrombolytic therapy. A blinded, controlled, preliminary study in rats compared urokinase (UK) and tissue plasminogen activator (t-PA) on thrombolytic efficacy, systemic fibrinolytic effect, and reocclusion. Bilateral femoral vein clots were induced in 38 rats. Local infusion of UK, t-PA, or saline was performed. Fibrinogen levels were drawn from one group. A second group was evaluated for reocclusion up to one month. Ipsilateral lysis occurred for reocclusion up to one month. Ipsilateral lysis occurred in 10/12, 13/13, and 0/13 of the UK, t-PA, and saline groups, respectively, with no significant difference detected between the UK and t-PA groups. Contralateral clot lysis occurred in both the UK and t-PA groups. No significant differences in the fibrinogen levels was detected among the three groups. Reocclusion occurred only in the UK group.     

重组人尿型纤溶酶原激活剂中试产品的肽图分析

目的：证明重组人尿型纤溶酶原激活剂（ｒｅｃｏｍｂｉｎａｎｔ ｈｕｍａｎ ｕｒｉｎａｒｙ ｔｙｐｅ ｐｌａｓｍｉｎｏｇｅｎ ａｃｔｉｖａｔｏｒ,ｒｈｕ－ＰＡ）中试规模３批产品在结构上的同一性,建立生物工程产品质量控制的一项指标。方法：ｒｈｕＰＡ３批中试产品在非还原条件下经胰蛋白酶水解以后,进行ＲＰ－ＨＰＬＣ肽图分析。结果：ｒｈｕ－ＰＡ３批中试产品的肽图完全一致,且检出峰数目与理论推测值相符。结论：３批产品肽图一致性为ｒｈｕＰＡ产品的结构同一性提供了有利证据,并建立了ｒｈｕ－ＰＡ产品质量控制的一项指标。     

Effects of exercise training on plasminogen activator inhibitor activity.

Plasminogen activator inhibitor (PAI) activity, an important regulator within the fibrinolytic system, has been shown to be a risk indicator for venous and arterial thrombosis. The present study aimed to test the effects of exercise training on PAI activity, and to link possible changes in PAI activity to changes in cardiovascular fitness, body composition, and the lipid profile. Four groups of previously sedentary subjects were studied thrice in an 8-month period. A long-term training group (N = 11) trained during the entire 8-month period. A detraining group (N = 14) trained for 4 months and then reverted to sedentary habits. A postponed training group (N = 16) trained only during the second 4-month period, and a no-training control group (N = 9) remained untrained throughout the entire 8-month period. PAI activity always decreased in response to training, but the training effects were small and spontaneous seasonal shifts in PAI activity of the control groups clouded their interpretation. Furthermore, detraining failed to influence PAI activity and training-induced changes in PAI activity were not related to simultaneous changes in maximal oxygen consumption, diastolic blood pressure, triglycerides, or percentage body fat, and inconsistently related to the training-induced changes in LDL-cholesterol and HDL-cholesterol. The occurrence of simultaneous changes in body fat, blood pressure, and the lipid profile underscores the potential of regular exercise to protect against cardiovascular disease. Whether these beneficial effects are accompanied by changes in the fibrinolytic system remains to be proven.