Studies on pathophysiology of surgical thromboembolic diseases with special reference to impaired regulation of blood coagulation.

在为期两年的研究期间，我们研究了凝血机制及其调控在外科血栓栓塞性疾病发病机制中的作用。我们分析了5个抗凝血酶III(AT III)缺乏、1个AT III分子异常、3个蛋白C(PC)缺陷、1个PC异常和14个先天性纤维蛋白原异常的家系。发现ATⅢ的分子异常具有与正常分子明显不同的构象和抗原决定簇，但其分子质量与正常分子相同。这种结构扰动明显导致激活的凝血因子包括凝血酶的缺陷中和，并损害了与肝素和血管内皮细胞表面的结合。因此，这种异常的分子无法调节血栓的形成。对于在一名18岁的血栓形成女性中发现的异常PC，命名为PC-Tochigi，我们鉴定了Arg到Trp亚单位的…基因分析显示，重链第12位的位置较多。由于这个位置被一种生理激活剂凝血酶参与到裂解部位，异常的PC不能转化为一种酶来调节血栓的形成。据我们所知，这个异常分子是迄今为止在分子水平上报道和阐明的与功能缺陷有关的第一个PC异常分子。由于血栓栓塞性疾病包括深静脉血栓形成和肺栓塞的发生率在这些患者中明显较高，因此对这些血凝调节蛋白的遗传性异常进行系统的调查显得尤为迫切。对于异常纤维蛋白原，我们可以精确定位所有14个家系的氨基酸替换，即4例&lt；Gamma&gt；Arg 275 to Cys，2例A&lt；Alpha&gt；Arg 16 to His和&lt；Gamma&gt；Arg 275 to His，以及A&lt；Alpha&gt；Pro 18 to Leu，&lt；Gamma&gt；Asn 308 to Lys，&lt；Gamma&Gt；Met 310 to Thr和&lt；Gamma&Gt；Asp 330 to Tyr。临床上，功能异常的纤维蛋白原可能不一定与血栓栓塞或出血倾向有关，但有关这些异常分子的信息肯定有助于在分子水平和临床水平上更好地了解血栓形成的机制。制备了针对各种血浆和内皮细胞衍生蛋白的单抗，并对其进行了鉴定。它们中的许多已被用于分析遗传性异常以及与血栓栓塞症相关的获得性疾病，其有用性已被证实并报告，如所附文献所列。较少

during the two-year term of this research project, We studied the mechanisms of blood coagulation and its regulation involved in the pathogenesis of surgical thromboembolic diseases. We analyzed 5 families with an antithrombin III (AT III) deficiency, 1 with a molecular abnormality of AT III, 3 with a protein C (PC) deficiency, 1 with an abnormal PC and 14 with a congenital dysfibrinogenemia. The molecular abnormality of AT III was found to have a conformation and antigenic determinants distinctly different from those of normal molecules although its molecular weight was identical with normal one. This structural perturbation apparently brought about defective neutralization of activated coagulation factors including thrombin, and impaired binding to heparin and vascular endothelial cell surfaces. This abnormal molexules thus fails to regulate thrombus formation. As to an abnormal PC designated as PC-Tochigi found in an 18-year-old thrombophilic female, we identified an Arg to Trp subs … More titution at position 12 of the heavy chain by gene analysis. Since this position is involved in the cleavage site by a physiological activator, thrombin, the abnormal PC could not be converted to an enzyme to exert regulation of thrombus formation. This abnormal molecule is, to our best knowledge, the first abnormal molecule of PC heretofore reported and elucidated at the molecular level in relation to defective functions. Since the incidences for thromboembolic diseases including deep vein thrombosis and pulmonary embolism are significantly higher in these patients, systemic surveys for these hereditary abnormalities of regulatory proteins of blood coagulation seem to be urgent. Concerning abnormal fibrinogens, we could pinpoint amino acid substitutions in all the 14 families, i.e., 4 cases of <gamma>Arg 275 to Cys, 2 each of A <alpha> Arg 16 to his and <gamma> Arg 275 to His, and 1 each of A <alpha> Pro 18 to Leu, <gamma>Asn 308 to Lys, <gamma>Met 310 to Thr and <gamma>Asp 330 to Tyr. Dysfunctional fibrinogens may not necessarily be related to thromboembolic or bleeding tendencies clinically, but informations obtained on these abnormal molecules were certainly of great help to better understand the mechanisms of thrombus formation at the molecular as well as clinical levels. Monoclonal antibodies against various plasma and endothelial cell-derived proteins were prepared and characterized. Many of them have been utilized for the analyses of hereditary abnormalities as well as acquired diseases related to thromboembolism and their usefulness was verified and reported as listed in the attached biblioqraphy. Less