Analysis of Neonatal Hemostatic and Thrombotic Mechanism, and Exploring of the New Therapeutic Approach.

新生儿止血血栓机制分析，探索新的治疗途径。

基本信息

批准号：
12671067
负责人：
TAKAHASHI Yukihiro
金额：
$ 2.37万
依托单位：
Nara Medical University.
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12671067/
关键词：
Thrombelastogram neonate actibated factor VII von Willebrand factor von Willebrand factor cleaving protease shear induced platelet aggregation ecto-ATPase Anti-thrombotic neonatal central catheter Thrombelastogram neonate shear induced

项目摘要

Neonatal hemoatatic mechanism was studied using thrombelastgram (TEG). In the early neonatal period, the r and k values of TEG in neonatal whole blood shortened and the ma value of TEG enlarged rather than these values in adult's whole blood. This characterized hypercoagulation prophile of TEG in neonate was able to be recreated by the addition of activated coagulation factors, such as thrombin, activated factor VIIa, ADP or epinephrine into normal adult whole blood. One of data, the results of activated factor VIIa, was recently submitted to the journal " Thrombosis and Haemostatic" enclosed in the booklet. And another paper concerning about the relationship between the hyper coagulation and anti-thrombotic drugs was recently subscribed. The bleeding time and coagulation time were almost normal in neonate despite the low function of platelets and the low concentrations of vitamin K dependent coagulation factors in neonate compared with adults. But, in pathological state, the thrombosis is more frequent in neonate than in children after neonate. The knowledge of the haemostatic mechanism is still obscure in neonate. From our recent study, von Willebrand factor (vWF) was relatively high and von Willebrand factor-cleaving protease was low in cord bloods of low birth weight to full term neonate. Furthermore, the higher multimer of vWF was detected. This higher multimer of vWF is more potent in hemostasis. And it may be suggested that it is related to be near normal bleeding time in neonate. We have also studied on the shear dependent platelet aggregation in cord bloods. And the low and high shear stress platelet aggregation were low, this mechanism were analyzed by the recreated blood components and the measurement of ecto-ATP activity. Ecto-ATPase in cord bloods was higher than that in adult blood. It may be suggested that ecto-ATP ase is related to the anti-thrombotic mechanism.

使用血栓弹力图（TEG）研究新生儿出血机制。新生儿早期，与成人全血相比，新生儿全血中TEG的r、k值缩短，TEG的ma值增大。通过将活化的凝血因子（例如凝血酶、活化的因子 VIIa、ADP 或肾上腺素）添加到正常成人全血中，能够重建新生儿 TEG 的这种高凝倾向。其中一项数据，即活化因子 VIIa 的结果，最近已提交给《血栓形成与止血》杂志，附在小册子中。另一篇关于高凝与抗血栓药物关系的论文最近被订阅。尽管与成人相比，新生儿血小板功能低下，维生素 K 依赖性凝血因子浓度低，但新生儿的出血时间和凝血时间几乎正常。但是，在病理状态下，新生儿中血栓形成比新生儿后的儿童更常见。关于新生儿的止血机制的知识仍然不清楚。根据我们最近的研究，低出生体重至足月新生儿的脐带血中，冯·维勒布兰德因子（vWF）相对较高，而冯·维勒布兰德因子裂解蛋白酶较低。此外，还检测到了更高的 vWF 多聚体。这种较高的 vWF 多聚体具有更有效的止血作用。可能与新生儿出血时间接近正常有关。我们还研究了脐带血中剪切力依赖性血小板聚集。低剪切应力和高剪切应力下血小板聚集均较低，通过重建血液成分和测定胞外ATP活性分析了其机制。脐带血中的外源ATP酶高于成人血液中的外源ATP酶。推测ecto-ATP酶可能与抗血栓机制有关。