CALCIFICATION IN THE CARDIOVASCULAR SYSTEM

总的目标是获得关于动力学的充分资料， 心血管钙化的热力学和结构特性 存款，使可能的预防和治疗这方面的 病理 有强有力的证据表明钙化是通过 酸性磷酸钙（含HPO4）前体，形成 其速率可通过生理学上可接受的抑制剂来降低。 具体目标： I. 钙化改性剂，包括Zn 2+、Mg 2+、Sr 2+和P2O 74-离子， 将评估他们改变利率的比较能力， 钙化 二. 钙化机制的适用性将通过 随着牛心包植入物钙化的进展， 大鼠使用32P-热解技术和Ca/P比测量的 存款 三. 来自心血管系统不同部位的沉积物将 分析以确定是否有相似之处， 间接地形成了一种共同的机制来控制它们的形成。 四. 本文将对直接法所得产品进行比较， 与前体钙化机制相比;其中一个方面是， 确定导致形成化学计量的 羟基磷灰石 诉 生物磷灰石的前体成分和结构 心血管沉积物中的含量将通过使用化学物质 分析、IR、X射线粉末衍射和单晶分析。 六. 碳酸盐结合的另一种机制发现， 将研究心血管沉积物。 有待检验的假设是 其中一种前体可以将碳酸盐结合到其结构中， 形成盐，在生理条件下水解成碳酸磷灰石。 条件 元素分析、XRD、拉曼和IR将用于 表征化合物。 七. 白钨矿溶解度的测定， Ca18Mg2H2（PO4）14，偶尔在其他生物组织中发现， 确定它是否可能是钙化的心血管系统的一个组成部分， 沉积物，其中含有镁离子。 八. 导致血管内（表面下）钙化的机制 将研究组织衍生的植入物。 结果将 表征植入物组织的选择性渗透膜性质， 确定生理离子进入组织的扩散特征。 现代实验设计和统计分析方法 数据将被使用。

The overall objective is to develop sufficient information on the kinetic, thermodynamic, and structural properties of cardiovascular calcific deposits to make possible prevention and cure of this aspect of the pathology. There is strong evidence that the calcification occurs by way of acidic calcium phosphate (containing HPO4) precursors, the formation rates of which can be reduced by physiologically acceptable inhibitors. Specific aims: I. Calcification modifiers, including Zn2+, Mg2+, Sr2+, and P2O74- ions, will be evaluated for their comparative abilities to alter rates of calcification. II. The applicability of the calcification mechanism will be tested by following the progression of bovine pericardium implant calcification in rats using a 32P-pyrolysis technique and Ca/P ratio measurements of the deposits. III. Deposits from different sites of the cardiovascular system will be analyzed to determine whether there are similarities that would indicate indirectly a common mechanism that controls their formation. IV. A comparison will be made of the products obtained by the direct versus the precursor calcification mechanism; one aspect of this is to determine conditions that lead to the formation of stoichiometric hydroxyapatite. V. The compositions and structures of the precursors of bioapatites found in cardiovascular deposits will be determined with the use of chemical analysis, IR, X-ray powder diffraction, and single-crystal analysis. VI. An alternative mechanism for the incorporation of carbonate found in cardiovascular deposits will be investigated. A hypothesis to be tested is that one of the precursors can incorporate carbonate into its structure to form a salt that will hydrolyze to carbonate apatite under physiological conditions. Elemental analyses, XRD, Raman and IR will be used to characterize the compounds. VII. A determination of the solubility of whitlockite, which is Ca18Mg2H2(PO4)14, occasionally found in other biological tissues, will help determine whether it could be a component of calcified cardiovascular deposits, which contain Mg ions. VIII. Mechanisms that cause intrinsic (subsurface) calcification of tissue-derived implants will be investigated. The results will characterize the permselective membrane properties of implant tissues and determine the diffusion features of physiological ions into the tissues. Contemporary experimental designs and statistical methods for analyzing data will be used.