重组水蛭素对兔髂总动脉球囊损伤后内膜增殖影响的实验研究

目的 :探讨重组水蛭素对兔髂总动脉球囊损伤后内膜增殖的影响。方法 :2 4只纯种日本大耳白兔随机分成肝素对照组 （n=12 ）和重组水蛭素组 （n=12 ） ,采用兔髂总动脉球囊扩张损伤后内膜增殖动物模型 ,术后 2周和 4周复查血管造影 ,术后 4周处死动物取髂总动脉标本。结果 :用药组术后 2周和 4周平均髂总动脉直径均较对照组明显增加 （P<0 .0 1） ,4周后新生内膜面积显著减少 （P<0 .0 1） ,管腔面积明显扩大 （P<0 .0 1）。结论 :重组水蛭素可显著减轻兔髂总动脉球囊扩张损伤后新生内膜增殖和管腔的狭窄     

罗格列酮对兔髂动脉球囊损伤术后脂联素表达及内膜增殖的影响

目的 观察罗格列酮对兔髂动脉球囊内膜剥脱术后,脂联素表达水平及内膜增殖的影响,并探讨罗格列酮预防血管再狭窄的可能机制。方法 将30只雄性新西兰大白兔随机分为3组,即正常对照组（给予普通饮食）、模型组（给予高脂饮食+球囊剥脱术）和罗格列酮组（给予高脂饮食+球囊剥脱术+罗格列酮）。分别于球囊损伤术后第1、4周,取血测定血脂、血糖;用ELISA法测定血浆脂联素的水平。取髂动脉标本进行病理形态学观察及弹力纤维染色。用免疫组化染色法测定增殖细胞核抗原（PCNA）的表达。结果 成功建立了兔髂动脉血管内皮损伤模型。与模型组兔相比,罗格列酮组在术后第1、4周末,总胆固醇（TC）、三酰甘油（TG）和低密度脂蛋白-胆固醇（LDL-C）等指标均明显降低（P<0.01）,HE及弹力纤维染色提示,内膜增殖程度显著减轻,PCNA的表达减少,血浆脂联素的水平明显升高（P<0.05或P<0.01）。以上变化在术后4周末更为显著。结论 罗格列酮可有效抑制血管损伤后内膜的增殖,其机制可能与通过PPARγ途径增加脂联素的表达水平有关。     

已酮可可碱对球囊损伤后血管胶原增生及狭窄的影响

目的 :探讨己酮可可碱 （PTX）对实验性兔髂动脉球囊成形术后狭窄的干预作用。方法 :新西兰大耳白兔 4 0只 ,建立髂动脉球囊损伤后狭窄模型 ,随机分成用药组与空白对照组 ,每组 2 0只 ,于血管成形术后 4周处死各组动物 ,取目标血管段用计算机图像分析检测血管管腔面积、新生内膜面积、胶原特殊染色平均灰度值。结果 :用药组与空白对照组的内膜胶原染色平均灰度分别为 18.6± 4 .6和 2 9.3± 5 .7（P <0 .0 1） ;两组血管管腔面积差异显著 ,（1.10± 0 .2 3vs 0 .84± 0 .19,P <0 .0 5 ） ;用药组较空白对照组的新生内膜面积减少 （0 .6 4± 0 .0 7vs0 .89± 0 .2 6 ,P<0 .0 1）。结论 :PTX能显著抑制内膜胶原的沉积 ,增大管腔面积 ,从而减轻血管损伤修复时再狭窄的程度。     

兔髂动脉球囊成形及支架术后血管壁超微结构的观察

目的 :比较兔髂动脉球囊成形及支架术后血管壁超微结构的变化 ,探讨支架内再狭窄与球囊血管成形术后再狭窄的不同机制。方法 :10支兔 ,分别于左髂动脉行 NIR支架置入术 （S组 ） ,右髂动脉行球囊成形术 （B组 ）。术前3d始予阿司匹林 2 5 mg· d- 1 ,直至处死动物。术后皮下注射肝素 2 5 0 0 U· d- 1 ,连续 7d。术后 7d和 30 d处死动物。用光镜、透射电镜及免疫组化染色技术观察损伤部位血管壁变化。结果 :术后 30 d光镜检查发现 S组新生内膜平滑肌细胞 （SMC）的增生程度明显高于 B组 （P<0 .0 5 ）。电镜检查 ,术后 7d,S组较 B组可见较多从外膜向中膜及内膜迁移的肌纤维母细胞 ,中膜及内膜大量以合成型为主的 SMC,细胞外基质 （ECM）以胶原及弹性纤维为主。30 d时 B组内膜下 SMC已转化为收缩型 ,ECM以胶原及弹性纤维为主 ;而 S组内膜下大量 SMC仍为典型合成型表现 ,周围 ECM以氨基聚糖及糖蛋白为主。结论 :球囊成形术及支架术后 ,新生内膜组成成分不同 ,支架术后新生内膜增生以 SMC增生为主 ,ECM以氨基聚糖及糖蛋白为主而球囊成形术后新生内膜增生 SMC较少 ,ECM以胶原及弹性纤维为主     

血管内32P放射治疗减少血管损伤后内膜增生的实验研究

目的　研究血管内放射源照射对损伤血管增生反应的影响。方法　 30只常规喂养新西兰大白兔 ,用大于血管直径的球囊过度扩张兔双髂动脉 (球囊 /血管 =1 5 4∶1) ,造成血管壁损伤 ,同时在扩张的球囊中灌注放射性3 2 P进行一侧损伤血管内照射 ,一侧血管单纯扩张作自身对照。按不同照射剂量分成三组 :10Gy、2 0Gy和 40Gy ,每组 10只。在扩张前后进行血管造影 ,4周后再次血管造影同时处死动物取双髂动脉作平滑肌细胞、弹力纤维和胶原纤维染色 ,观察血管受损后放射对血管腔径及其管壁增生的影响。结果　 4周后血管造影显示 ,三组兔髂动脉扩张损伤后均发生一定程度的狭窄反应 (P <0 0 0 1)。血管内照射一侧与对照侧比较 ,血管狭窄程度无明显差异 (P >0 0 5 )。病理组织分析 ,10Gy组照射一侧血管内膜增生与对照侧比较无差异 (P >0 0 5 ) ,而 2 0Gy和 40Gy二组照射一侧血管内膜增生较对照侧血管减少 (P <0 0 0 1,P <0 0 4) ,但二组间比较内膜增生减少无差异 (P >0 0 5 )。结论　过度扩张兔髂动脉可产生再狭窄样反应 ,血管内放射在 2 0Gy到 40Gy照射剂量时能减少血管损伤后内膜增生 ,但血管损伤后狭窄程度未受影响。     

新型颈动脉再狭窄兔模型的建立

目的 :为了解再狭窄发生机制 ,进行再狭窄预防研究建立新西兰兔动物模型。方法 :采用直流电刺激的方法刺激兔颈总动脉外膜 ,在初步产生动脉纤维斑块的基础上 ,给予球囊扩张。结果 :通过血管造影及组织形态学观察 ,证实兔颈总动脉发生了动脉再狭窄病理改变。模型组血管腔内面积明显缩小 （P<0 .0 1） ,血管内膜增厚 （P<0 .0 1）。结论 :采用封闭群动物新西兰兔建立的颈总动脉狭窄模型具有模拟性好、死亡率低、实用性强和成功率高等优点     

通过损伤动脉外膜建立兔颈动脉粥样硬化狭窄和再狭窄模型

目的 球囊扩张后动脉再狭窄严重制约着经皮血管腔内治疗术的治疗效果,为探讨动脉再狭窄的发病机制,本研究尝试建立动脉再狭窄模型.方法 采用右颈总动脉可吸收线套环缩窄术加高脂饲料喂养新西兰兔,建立颈动脉粥样硬化狭窄模型.4周后,自右颈外动脉远端结扎并切断颈外动脉,由结扎近心侧插入扩张球囊导管进行球囊扩张,建立动脉再狭窄模型.然后以普通饲料喂养4周后,对颈动脉标本进行组织学及形态学分析,并以对侧颈总动脉为正常对照组.结果 套环颈动脉管腔较对照组有缩窄,平滑肌细胞有增殖,排列紊乱,内皮细胞呈乳头状突入管腔.球囊扩张后,内膜较对照组及动脉缩窄组显著增厚(P<0.05).组织切片可见内、中弹力层断裂,内膜有大量泡沫细胞,脂质沉着,粥样斑块组织形成.外膜滋养血管数量增加.结论 通过本方法可成功构建实验兔血管再狭窄模型,且操作简单,建立模型时间短,为探讨血管再狭窄的发生机制提供了条件.     

32P液体球囊血管内照射预防血管介入治疗后再狭窄的实验研究

目的观察血管内液体球囊放射治疗对血管介入治疗后再狭窄的影响，为其临床应用提供实验依据；同时通过放射治疗效应来探讨放射治疗防止再狭窄发生的可能机制。方法兔髂动脉经球囊过度扩张损伤后，一侧经３２Ｐ液体球囊血管内照射作治疗，另一侧未经治疗作对照。用计算机图像分析方法观察血管组织形态学的变化；免疫组化方法测定增殖细胞核抗原（ＰＣＮＡ）阳性细胞以了解血管内膜增殖过程。结果兔髂动脉经球囊过度扩张损伤后，血管内膜可明显增生，ＰＣＮＡ染色为强阳性；经３２Ｐ液体球囊照射后的对侧损伤髂动脉，内膜增生明显受抑，ＰＣＮＡ染色为弱阳性，外弹力板围绕面积均增加，管腔面积无明显变化。结论３２Ｐ液体球囊确可防止再狭窄的形成，其机制可能是通过抑制平滑肌细胞增殖和改善血管重塑形成。     

兔髂动脉球囊内膜损伤后反应与胶原及血管紧张素Ⅱ的关系

本研究以兔髂动脉球囊内膜损伤为模型 ,以血管紧张素ＩＩ的Ｉ型受体 (ＡＴ1 )拮抗剂———氯沙坦和血管紧张素转换酶抑制剂———苯那普利分别干预不同组手术兔 ,观察胶原含量与内膜增生及组织血管紧张素ＩＩ(ＡｎｇＩＩ)含量对血管损伤后狭窄的可能影响及相互间可能存在的关系。1 .资料与方法 :建立兔髂动脉球囊内膜损伤模型 ,42只3～ 5个月龄新西兰雄性白兔 ,体重 2 4～ 2 8ｋｇ ,随机分为 4周和 8周氯沙坦组 (ｎ =6 ,9)、苯那普利组 (ｎ =5 ,8)和对照组 (ｎ =5 ,9)等 6组 ,前二组各分别于术前 5ｄ始喂氯沙坦(1 5ｍｇ·ｋｇ- 1 ·ｄ- 1 …     

蛋白酶体抑制剂MG132对球囊损伤后血管狭窄的影响

目的 观察蛋白酶体抑制剂MG132对球囊损伤后血管狭窄的影响.方法 将新西兰白兔40只随机分成正常对照组、高脂组、球囊损伤组和MG132组.球囊损伤组和MG132组兔采用球囊拉伤颈总动脉复制血管损伤后狭窄模型;MG132组在损伤血管局部应用蛋白酶体抑制剂MG132.喂养2周、4周和8周后取颈总动脉损伤段血管制成病理切片行HE染色,测定内膜厚度、中膜厚度和管腔面积,评价颈总动脉血管狭窄.结果 球囊损伤组颈总动脉发生明显狭窄、管腔减小、内膜增厚,有泡沫细胞和大量血管平滑肌细胞增殖,而MG132组的病变明显减轻.结论 用球囊拉伤新西兰白兔颈总动脉复制的血管狭窄模型,颈总动脉发生明显狭窄,局部应用蛋白酶体抑制剂MG132能够抑制血管内膜增生,抑制损伤后血管狭窄.     

Hirudin: Its biology and clinical use

Over a century has passed since the anticoagulant properties of hirudin were identified. Our understanding of this unique and promising 65 amino acid polypeptide has grown steadily, allowing clinical experience to be gained. In acute myocardial infarction, hirudin has been associated with a higher incidence of early and sustained TIMI grade 3 flow, a higher rate of infarct-related artery patency at 18–36 hours with a decreased rate of reocclusion, and a lower incidence of in-hospital death and reinfarction as compared with heparin. Hirudin has also been associated with a stable level of anticoagulation and an acceptable hemorrhagic complication rate when given in carefully chosen doses. In acute coronary syndromes, the initial results indicate that hirudin can improve the resolution of coronary thrombus and reduce the incidence of recurrent ischemic events. Similarly impressive reductions in thrombotic complications and ischemia have been observed in the early balloon angioplasty experience. Promising results have also been seen with hirudin in preventing deep venous thrombosis following orthopedic surgery. The favorable effects of hirudin as compared with heparin in phase II clinical trials have prompted further investigation in two large phase III trials, TIMI 9 and GUSTO 2. It is hoped that these initial results can be confirmed and that hirudin can be proved to be a safe and effective treatment for thrombotic syndromes of the venous and arterial circulatory systems.     

Management of heparin allergy in pregnancy.

Thromboembolic disease during pregnancy has traditionally been treated with heparin. If heparin cannot be used, then treatment options remain limited. Despite the recent availability of new anticoagulation agents, data relating to their use during pregnancy is lacking. Hirudin, a relatively new anti-thrombotic agent, through animal models has been shown to have a very low transplacental transfer, thus making it a candidate drug to be used during pregnancy in case of heparin allergy. This report describes a case of heparin allergy in a pregnant patient with recurrent DVT that was successfully managed with hirudin and coumadin.     

Hirudin in acute myocardial infarction

Summary The central role of thrombosis in the pathogenesis of acute myocardial infarction has led to intense interest in developing more effective thrombolytic-antithrombotic regimens. Hirudin is 65 amino acid polypeptide that binds in a 11 relationship with thrombin, thereby inhibiting the final step in the coagulation cascade. Hirudin has several potential advantages over the current antithrombin agent heparin: It is a direct inhibitor that does not require a cofactor, it has no known inhibitors that would attentuate its anticoagulant effects, and it can inhibit clot-bound thrombin, thereby achieving an antithrombotic effect at the site of potential rethrombosis. Initial clinical trials have shown promising results: Hirudin, as compared with heparin, provided a more consistent level of anticoagulation, as gauged by the activated partial thromboplastin time. As an adjunct to thrombolytic therapy in acute myocardial infarction, hirudin improved indices of coronary reperfusion and patency. Initial results with clinical end points, including death or myocardial infarction, also have shown favorable results for hirudin compared with heparin. In the first phases of the larger phase III trials, the rate of hemorrhagic events, including intracranial hemorrhage, was higher than expected in both the hirudin and heparin arms, indicating that a safety ceiling had been reached. The TIMI 9B and GUSTO IIb trials are using lower doses of intravenous hirudin and heparin, which should allow testing of the thrombin hypothesis: that more potent inhibition of thrombin will translate into improved clinical outcome for patients with acute MI.     

Newer antithrombotic agents: Potential for clinical use in venous and arterial thrombosis

Advances in the understanding of the pathophysiology of thrombosis and in the ability to produce recombinant or chimeric proteins that are active against thrombin or specific platelet receptors have resulted in the development of several new agents. Some of these antiplatelet agents and direct thrombin inhibitors are available now; others are likely to be approved by the U.S. Food and Drug Administration for release in the near future. This brief review discusses selected examples of the multiple agents that are currently in use or are likely to be used in specific clinical settings. Ticlopidine, one of the newer antiplatelet agents, is efficacious in reducing the risk of stroke in patients with known cerebrovascular or ischemic heart disease. The chimeric monoclonal antibody c7E3 Fab is a potent platelet GP IIb/IIIa receptor antagonist that has been extensively investigated. Integrelin is a cyclic heptapeptide directed against GP IIb/IIIa. The most potent naturally occurring thrombin inhibitor is hirudin, a 7 kD protein produced by the European medicinal leech,Hirudo medicinalis. Unlike heparin, hirudin can inhibit both free and clot-bound thrombin. Hirulog is a synthetic analog of hirudin. Defining the appropriate use of these antithrombotic agents and developing methods for rapid, accurate laboratory monitoring remain major challenges, but the future is a pomising one for these newer antithrombotic agents.The opinions expressed herein are solely those of the authors and do not reflect official views or policies of the Department of the Army or the Department of Defense.     

水蛭素对增生性瘢痕基质金属蛋白酶-2、9表达作用的影响

目的 研究水蛭素对增生性瘢痕组织基质金属蛋白酶-2(MMP-2)和基质金属蛋白酶-9(MMP-9)的影响,探讨水蛭素对增生性瘢痕作用机理.方法 取烧伤后6个月内的皮肤增生性瘢痕,体外培养成纤维细胞,ELISA法测定水蛭素作用后MMP-2、MMP-9表达含量.结果 水蛭素作用后增生性瘢痕组织内MMP-2、MMP-9含量增加,分别以0.5 U/mL和1 U/mL组作用最明显,与对照组比较差异均有统计学意义(P＜0.01).结论 水蛭素能促进MMP-2、MMP-9表达,有抑制增生性瘢痕的作用.     

Hirudin in Acute Coronary Syndromes: When Cents Override Good Sense

Two large multicenter clinical trials comparing heparin with hirudin in the management of patients with acute coronary syndromes have recently been completed. Direct thrombin inhibition was reported to result in only a modest reduction in the incidence of primary endpoint in GUSTO IIb, and to be of no demonstrable benefit in TIMI 9b. However, closer examination of the performance of hirudin in these trials suggests it to have been harshly judged. Hirudin provided a consistently more reliable anticoagulant effect than heparin, was associated with a comparable risk of bleeding and minimal risk of allergy. Furthermore, direct thrombin inhibition was more effective in preventing events in patients with unstable angina and non-Q wave infarction, and resulted in a significant reduction in the incidence of reinfarction among all facets of the acute coronary syndromes. There was in addition a striking benefit of combining hirudin with streptokinase in patients with acute myocardial infarction. Based on these data, there is little doubt that hirudin rather than heparin should form the foundation on which to base future strategies for management of the acute coronary syndromes.     

核转录因子κB在大鼠脑出血后血肿周围组织中的表达及水蛭素的保护作用

目的探讨大鼠实验性脑出血后脑组织核转录因子κB(NF-κB)的表达及水蛭素对其表达的影响。方法采用自体不凝血注入大鼠尾状核制备脑出血模型,免疫组化染色法检测脑组织NF-κB的表达和采用干湿比重法测定脑含水量。结果脑出血后6 h血肿周围组织NF-κB开始表达,3 d达高峰,脑含水量6 h升高,3 d达高峰。水蛭素组脑含水量、NF-κB表达与对照组及脑出血组比较均有统计学意义(P<0.05 orP<0.01)。结论NF-κB参与了脑出血继发性脑组织损伤。     

Use of recombinant hirudin as antithrombotic treatment in patients with heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia is a rare but severe complication of heparin therapy that can result in severe venous or arterial thromboembolic events and whose treatment remains partially unanswered. Recombinant hirudin is potentially effective as an antithrombotic treatment in the management of heparin-induced thrombocytopenia, given its potent antithrombin effects without known interaction with platelets. We report the results obtained with intravenous recombinant hirudin (HBW 023) administered on a compassionate basis to patients suffering from heparin-induced thrombocytopenia. Six patients suffering from heparin-induced thrombocytopenia were submitted to intravenous recombinant hirudin (HBW 023) administered at a dose of 0.05 mg/kg/hr after an initial bolus injection of 0.07 mg/kg in the case of a venous thromboembolic event, and at a dose of 0.15 mg/kg/hr with the same initial bolus injection in the case of an arterial thromboembolic event. Whenever possible, oral anticoagulation with acenocoumarol was introduced at the same time as recombinant hirudin, which was interrupted as soon as the international normalized ratio reached 3. Clinical events, particularly thromboembolism and bleeding, were noted; activated partial thromboplastin time (aPTT), and platelet count were assessed throughout the administration of recombinant hirudin. Heparins responsible for heparin-induced thrombocytopenia were porcine sodium or calcium heparinate in four cases, nadroparin in one case, and enoxaparin in one case. Thrombocytopenia was discovered on routine systematic platelet count in two patients and after the occurrence of arterial and venous thromboembolism in two patients, respectively. After discontinuation of heparin and the onset of recombinant hirudin, clinical evolution was uneventful in all patients, with no recurrence of thromboembolism, limb amputation, or hemorrhagic complication. The aPTT ratio varied from 1.8 to 3.5 (median 2.4) throughout administration of recombinant hirudin. Platelet count rose from nadir (median value 60 × 10⁹ 15 to 90) to above 100 × 10⁹/L in every patient within 3–6 days (median 5), after discontinuation of heparin. Intravenous administration of recombinant hirudin ensured safe anticoagulation in patients with heparin-induced thrombocytopenia and made it possible to wait for oral anticoagulation to become efficient and platelet count to return to normal values without occurrence or recurrence of thromboembolism.