CALCIFICATION IN BLOOD PUMPS

血泵钙化

• 批准号: 3341030
• 负责人: HIROAKI HARASAKI
• 金额: $ 11.11万
• 依托单位: CLEVELAND CLINIC FOUNDATION
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-12-01 至 1987-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3341030
• 关键词: alkaline phosphatase; analytical method; antithrombogenic surface; atomic absorption spectrometry; auxiliary heart prosthesis; blood cells; calcification stimulant; cell death; crystallization; electron microscopy; electron optics; electron probe spectrometry; histochemistry /cytochemistry; hydroxyapatites; polyurethanes; prosthetic heart valve

Calcificaton in blood pumps is a frequent complicaton regardless of the material and the animal species. The precise pathogenesis of pump calcification is not known. In the past 8 years we have studied this phenomenon in over 50 pumps lined with smooth gelatin, rough polyester flock or powdered metal and 200 tissue valve implantations, and we were the one of the first groups to publish findings of calcification in blood pumps. As a result of these studies, we hypothesize that calcification of cardiovascular implants, regardless of whether on smooth or rough surfaces, and whether on moving or non-moving regions, occurs with the same mechanism. The mechanism is dystrophic calcification occurring secondarily in degenerating cellular deposit. The specific aim of this project is to verify this hypothesis and to identify and characterize the nature and the time course of the calcifying process on the smooth polyurethane (Biomer) surfaces currently widely used by other groups in blood pumps. It is still not known whether calcificaton occurs directly on or in the polymer or if it is of the same mechanism as seen in other types of surfaces. In Phase 1, in vitro studies are designed to prove that the degraded blood cells can be the nidi for calcification. Various degraded blood cells are embedded in a gelatin layer and exposed to calcifying solution or plasma with physiological calcium and phosphorus levels. Effects of various lipids levels on calcification also will be tested. The initial calcification loci and their relation to cellular elements are searched for using histochemistry, electron microscopy (EM), x-ray microanalysis (EDX), electron diffraction (ED) and x-ray diffraction (XRD). Quantitation of calcium uptake by the cells will be performed using plasma ashing and atomic adsorption spectrophotometry. In Phase II in vivo study, 12 pusher plate type LVADs lined with a smooth Biomer surface will be implanted in calves for 2 weeks to 4 months. The surfaces of the explanted pumps will be studied by the same technique mentioned above. We also propose to expand our prior tissue valve calcification studies. The elucidation of the pathogenesis of calcification in blood pumps will also be beneficial in understading the mechanism of tissue valve calcification in young patients and of calicfying artherosclerosis.

血泵的钙化是一种常见的并发症 材料和动物种类。泵的确切发病机制 钙化情况尚不清楚。在过去的8年里，我们一直在研究这一点 50多台泵内衬光滑明胶、粗聚酯的现象 植入物或金属粉末和200个组织瓣膜植入物，我们是 最早发表血泵钙化发现的研究小组之一。 作为这些研究的结果，我们假设钙化 心血管植入物，无论是在光滑还是粗糙的表面， 无论是在移动区域还是在非移动区域，都会发生相同的 机制。其机制是继发性营养不良钙化。 在退化的细胞沉积中。 该项目的具体目标是验证这一假设，并 识别和表征钙化的性质和时间过程 目前广泛使用的光滑聚氨酯(生物体)表面的加工 被其他群体在血泵中使用。目前尚不清楚钙化是否 直接发生在聚合物上或聚合物中，或者如果它具有与 在其他类型的曲面中可见。 在第一阶段，体外研究旨在证明被降解的血液 细胞可作为钙化的载体。各种降解的血细胞是 嵌入明胶层并暴露在钙化溶液或血浆中 生理钙和磷水平。各种不同因素的影响 对钙化的血脂水平也将进行测试。首字母 寻找钙化基因及其与细胞元素的关系 使用组织化学、电子显微镜(EM)、X射线显微分析(EDX)、 电子衍射仪(ED)和X射线衍射仪(X射线衍射仪)。量化： 细胞的钙摄取将使用等离子体灰化和 原子吸附分光光度法。在第二阶段体内研究中，12名推进器 平坦的生物体表面衬里的平板型LVAD将被植入 小牛出生2周到4个月。移出的泵的表面将 用上面提到的相同技术进行研究。我们还建议 扩展我们之前的组织瓣膜钙化研究。 血泵中钙化的发病机制的阐明将 也有利于了解组织瓣膜的作用机制 年轻患者的钙化和钙化的动脉粥样硬化。