溶栓剂的研发现状及展望

由血栓引起的血栓性疾病是一种常见的心脑血管疾病。溶栓剂是预防与治疗心脑血管疾病的主要抗血栓药物。本文总结性地概述了目前国内外各种新型溶栓剂的溶栓机理、临床应用效果及其副作用等。其中,第三代溶栓剂组织型纤溶酶原激活剂变异体、导向溶栓剂、嵌合体溶栓剂,以及部分天然溶栓剂包括蝙蝠唾液纤溶酶原激活剂、蛇毒纤溶酶原激活剂、水蛭素及其变异体等均通过将纤溶酶原激活为纤溶酶溶解血栓。临床实验结果表明它们在延长体内半寿期、增强对血纤维蛋白选择性和溶栓效率等方面有较大的改进,但溶栓治疗后的冠状动脉再栓塞,颅内出血等问题仍是目前未解决的难题;而纳豆激酶及豆豉纤溶酶由于溶栓原理的不同,引起内出血的几率较低。溶栓剂未来的发展方向为如何综合不同药物的优点,使其更加安全与廉价。     

蚯蚓纤溶酶研究与应用进展

蚯蚓纤溶酶作为新一代口服溶栓药物已试用于临床。对蚯蚓纤溶酶的生化及药理性质的研究日益深入。概述了蚯蚓纤溶酶的生化特性、药理性质和临床应用研究的最新进展。     

安舒克栓酶和水蛭素融合基因在枯草杆菌中的表达(简报)

安舒克栓酶(Antithromboase,AT)是本实验室从枯草杆菌N18中分离得到的具有强烈水解纤维蛋白活性的蛋白酶.研究表明,该酶具有直接纤溶和纤溶酶原激活剂的双重作用,且有较强的纤维蛋白亲和性,是极具开发价值的溶栓药物.来源于医用水蛭的水蛭素(hirudin,Hir)是凝血酶的最强有力的天然抑制剂,是极具优势的抗凝药物.但仍各有不足:安舒克栓酶只有溶栓功能,不能抗栓,不能解决血栓治疗中再栓塞的问题;水蛭素只有抗凝作用,不具溶栓功能.如果将这两种从不同途径治疗血栓的药物.通过融合     

微生物源纤溶酶的研究进展

本文阐述了微生物发酵生产纤溶酶的研究背景，并对几种主要的纤溶酶的来源及理化特征和作用机理进行分析和总结，为寻找新型的、相对廉价有效的溶栓药物提供了依据。     

微生物源纤溶酶基因的克隆及表达研究进展

血栓栓塞性疾病严重危害人类生命和健康,溶栓疗法效果显著。在新型溶栓制剂的研究中,微生物来源的纤溶酶研究引起越来越多的关注。通过分子生物学手段构建重组纤溶酶,实现酶的高效表达已经成为研究热点,本文对微生物来源的纤溶酶基因克隆与表达的研究现状进行了综述。     

磁性蚯蚓纤溶酶脂质体的制备

用超声法将磁流体和蚯蚓纤溶酶同时包入脂质体中,形成一种具有磁导向性能的溶栓药物──磁性蚯蚓纤溶酶脂质体。纤溶酶包封率达80％以上。在磁场作用下该脂质体定向聚集在血栓周围,脂质体破坏后释放出来的纤溶酶可以将血栓完全溶解。还介绍了一种简便、快速制备磁流体的方法。本系统对于制备水溶性药物的磁性脂质体可能有一定通用性。     

大平2号蚯蚓纤溶酶酶活的测定

本文以大平2号蚯蚓为材料,制作了纤溶酶纤维蛋白水解活性测定曲线及纤维蛋白溶酶原浓度选择曲线,确定了酶活的最佳测定范围扣测定条件。测定结果表明:大平2号蚯蚓所产生的纤溶酶具有很强的纤维蛋白水解活性和纤维蛋白溶酶原激活活性,是一种很有希望的溶栓药物。     

芽孢杆菌纤溶酶稳定性的研究

芽孢杆茵纤溶酶是一种微生物来源的新型溶栓酶，作者研究了pH，温度，金属离子及某些有机物质对该酶稳定性的影响，应用“系统数值化及数值全面反馈技术”进行了一系列系统行为控制实验，优化了酶复合稳定促进剂．同时，为研究其作为溶栓药物的应用前景，在模拟人体胃肠环境中对该酶的稳定性进行了研究，发现其在胃环境中酶活损失较大而肠道中相对稳定，有望开发为肠溶型溶栓新药．     

抗凝血蛋白药物的研究进展

除了血液中的抗凝因子外，自然界中还存在大量具有抗凝活性的生物大分子，如水蛭素、蚯蚓纤溶酶等．基础研究证实这些抗凝刑的作用一般是通过三方面得以实现：一是抑制凝血酶及凝血酶活化因子活性；二是水解血纤维蛋白或纤溶酶原；三是抑制血小板凝聚．由于这些活性物质具有高效的抗凝、溶栓作用，它们极有可能发展成治疗血栓性疾病的药物．     

地衣芽胞杆菌产纤溶酶的分离、纯化及其酶学性质研究

以地衣芽胞杆菌(Bacillus licheniformis)WBL-3进行固体发酵生产纤溶酶.通过生理盐水浸提、离心去除菌体、硫酸铵分级盐析、透析、离子交换层析和凝胶过滤层析对酶进行分离纯化,SDS-PAGE电泳检测酶的分子量大小,并对该纤溶酶的酶学性质进行研究.结果表明:经凝胶过滤层析后,纯化倍数为33.19,回收率12.39％;SDS-PAGE电泳检测为单一蛋白条带;酶学性质分析表明:酶的最适反应温度为55℃,稳定性随着温度的升高而降低;最适反应pH为8.5,pH7-10范围内酶活稳定性较高;Mg2+对该酶有微弱的激活作用,Cu2+、Ag+、Fe3+、Hg2+、Pb2+对酶有较强的抑制作用.本研究为开发新的溶栓药物提供了新的选择.     

溶栓酶的研究进展

随着人口老龄化的加剧及人们生活方式的改变,血栓类疾病已日益严重,成为当今人类健康的重大威胁,基于溶栓药物的治疗是血栓类疾病治疗的重要方法。本文首先概述了血栓的类型、形成机制及溶栓酶溶栓机制,然后总结了溶栓药物的发展、新型天然溶栓酶及制剂、溶栓酶制备方法的研究进展,最后指出获得溶栓效率高、成本低的新型天然溶栓药物是未来血栓类疾病治疗的重要研究方向。     

血小板聚集功能临床应用进展

血小板具有凝血和止血的功能.血小板聚集率在一定程度上能预示患者的出血风险,故对患者进行血小板功能试验的检测对临床治疗和患者出血风险评估方面有着重要的意义.血小板聚集功能的测定对于临床上诊断出血性疾病、血栓前状态、血栓性疾病及抗血小板药物监测方面具有重要意义.血小板聚集率检测在血液病、心内科疾病、神经内科疾病、内分泌科疾病及其并发症的预防、抗凝药物的监测、疾病辅助诊断和预后发挥着积极的作用.因此开展血小板聚集功能检测技术是临床不可缺少的项目之一.     

A potential basis for the thrombotic risks associated with lipoprotein(a)

Lipoprotein(a) (Lp(a)) has been strongly linked with atherosclerosis and is an independent risk factor for myocardial infarction. Distinguishing Lp(a) from other low-density lipoprotein particles is its content of a unique apoprotein, apo(a). The recently described sequence of apo(a) indicates a remarkable homology with plasminogen, the zymogen of the primary thrombolytic enzyme, plasmin. Lp(a) may contain 37 or more disulphide-looped kringle structures, which are 75-85% identical to the fourth kringle of plasminogen. Plasminogen receptors are widely distributed on blood cells and are present at extremely high density on endothelial cells. These receptors promote thrombolysis by accelerating plasminogen activation and protecting plasmin from inhibition. If, by molecular mimicry, Lp(a) competes with plasminogen for receptors, then thrombolysis would be inhibited and thrombosis promoted. Here we provide support for such a mechanism being responsible for the thrombotic risks associated with elevated Lp(a) by demonstrating that Lp(a) inhibits plasminogen binding to cells.     

急性脑血栓动脉内溶栓治疗研究

缺血性脑血管病是严重危害人类健康的常见病,具有高发病率、高病死率、高致残率和高复发率的特点.近些年随着溶栓药物的应用,介入导管技术的快速发展,动脉内溶栓技术已经成为急性血栓的主要治疗方法并在临床上广为应用.     

Modeling of the fibrin agarose plate assay and its application for thrombolytic analysis

The fibrin agarose plate assay is widely used in the detection of thrombolysis efficacy. However, a rigorous mathematical model for analyzing data or comparing activities of different thrombolytics has been absent. This study investigated the relationship between thrombolysis radius, R, and diffusion time, t, of molecular medicines in an agarose hydrogel system by deriving a model based on Fick’s law and experimental verification by the fibrin agarose plate assay method. The theoretical results showed that a plot of log(R) versus log(t) has a linear curve with the slope of 1/2 and this was verified by experimental results using urokinase as a modeling agent. Moreover, it was found that R÷t is constant for a specific thrombolytic and can be used as a parameter for evaluating activities of different thrombolytics. The theoretical model has potential for improving the understanding of mecha-nisms involved in molecular medicine diffusion and offers benefits for thrombolytic therapy.     

Enhancing protein C interaction with thrombin results in a clot-activated anticoagulant.

Human protein C is a vitamin K-dependent plasma glycoprotein that circulates as an inactive zymogen. At the endothelial cell surface, thrombin in complex with the integral membrane protein thrombomodulin converts protein C to its active form by specific cleavage of an activation peptide. The activated form of protein C has potent anticoagulant activity as a feedback regulator of thrombin generation (reviewed in refs 4-6), and also has profibrinolytic, anti-ischaemic and anti-inflammatory properties. Protein C is effective in the treatment of model and human thrombotic diseases but, except when it has been used to treat genetic or acquired deficiencies and microvascular thrombosis, it is administered as the activated enzyme, which has a short biological half-life. We have altered two putative inhibitory acidic residues near the thrombin cleavage site, which results in a 30-fold increase in substrate utilization by alpha-thrombin. We combined these changes with a genetically altered glycoform to generate a zymogen protein C with a 60-fold increased cleavage rate by free alpha-thrombin, independent of its cofactor thrombomodulin. We show that this 'proform' of protein C, unlike the natural circulating zymogen, can be activated by thrombin generated in clotting human plasma, resulting in an inhibition of further clot formation. Our data therefore show that we have engineered a site-activated agent, which only has anticoagulant activity when significant amounts of thrombin are being generated.     

黑果枸杞花色苷的肥胖干预作用研究进展

肥胖是目前受到世界广泛关注的慢性病之一,是心脑血管疾病及癌症等多种疾病的危险因素,成为目前威胁人类社会最主要的健康问题。现有减肥药物或方法大都存在毒副作用大、易反弹等缺点。因此,寻求安全、有效的干预肥胖的药物或方法具有极其重要的意义。花色苷等天然植物提取物具有有效干预肥胖的作用,且副作用小,相关研究与开发逐渐成为一个热点。黑果枸杞是近年来新发掘的食用植物资源之一,具有降血脂、抗氧化、抗突变、抗癌、抗炎、提高机体免疫力等多种生物学活性。黑果枸杞主要发挥机体营养健康作用的成分是有别于常见果蔬中的花色苷类物质,其花色苷结构同时具有矮牵牛素母核、芳香酸酰化等特征,且总花色苷含量远超于其他有色果实。通过总结国内外相关文献,综述黑果枸杞花色苷的肥胖干预作用研究进展,为黑果枸杞开发利用提供理论参考。     

Progress in study of structure-function relationship and protein engineering of plasminogen activators

Thrombolytic agents play an important role in the treatment of thrombus diseases. In clinic, traditional thrombolytic agents always resulted in the side effect of systemic thrombolysis because of the shortcomings, such as short half-life, poor specificity of thrombus. Recently, with the development of knowledge of the relationship between their structure and function, a series of new thrombolytic agents were constructed by means of molecular biological techniques. Developing new types of thrombolytic agents is of great significance for more effective treatment of cardiovascular diseases. The latest knowledge of the structure-function relationship of t-PA and u-PA and the progress in development of new thrombolytic agents are reviewed.     

TNF receptor 1 genetic risk mirrors outcome of anti-TNF therapy in multiple sclerosis

Although there has been much success in identifying genetic variants associated with common diseases using genome-wide association studies (GWAS), it has been difficult to demonstrate which variants are causal and what role they have in disease. Moreover, the modest contribution that these variants make to disease risk has raised questions regarding their medical relevance. Here we have investigated a single nucleotide polymorphism (SNP) in the TNFRSF1A gene, that encodes tumour necrosis factor receptor 1 (TNFR1), which was discovered through GWAS to be associated with multiple sclerosis (MS), but not with other autoimmune conditions such as rheumatoid arthritis, psoriasis and Crohn’s disease. By analysing MS GWAS data in conjunction with the 1000 Genomes Project data we provide genetic evidence that strongly implicates this SNP, rs1800693, as the causal variant in the TNFRSF1A region. We further substantiate this through functional studies showing that the MS risk allele directs expression of a novel, soluble form of TNFR1 that can block TNF. Importantly, TNF-blocking drugs can promote onset or exacerbation of MS, but they have proven highly efficacious in the treatment of autoimmune diseases for which there is no association with rs1800693. This indicates that the clinical experience with these drugs parallels the disease association of rs1800693, and that the MS-associated TNFR1 variant mimics the effect of TNF-blocking drugs. Hence, our study demonstrates that clinical practice can be informed by comparing GWAS across common autoimmune diseases and by investigating the functional consequences of the disease-associated genetic variation.     

真菌感染防控及真菌细胞壁靶标的研究进展

全球有超过10亿人患有真菌感染，每年有超过160万人因此而死亡，且真菌感染病例正呈激增趋势。此外，真菌病害不仅严重影响作物的生长，还会产生毒素影响农作物的质量，对农业生产带来严重影响。真菌的细胞壁结构在哺乳动物中不存在，且与植物细胞壁组分完全不同，因此成为开发抗真菌药物的理想靶标。本文详细阐述病原真菌对人类、动物和植物的风险，临床和农业上使用的抗真菌药物，以及真菌细胞壁不同组分在药物研发中的研究进展，并展望基于广西的天然资源在抗真菌药物研发中的潜在前景。