CHARACTERIZATION OF INORGANIC BONE MINERAL PHASES

无机骨矿物相的表征

• 批准号: 3456925
• 负责人: DOSUK D LEE
• 金额: $ 10.12万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1991-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3456925
• 关键词: calcium phosphate; chickens; computer graphics /printing; electron microscopy; laboratory rat; normal ossification; osteomalacia; vitamin D deficiency

The proposed study will identify the microchemical composition of the initial and subsequent mineral phases in sections of normal and vitamin Ddeficient osteomalacic bone tissues. in addition, to determine the temporal relationship, this study will use high voltage electron stereomicroscopy together with computer graphic reconstructions to obtain threedimensional locations of the minerals in respect to the tissue ultrastructure. While the presence of hydroxyapatite has been well established, the same is not true for secondary calcium phosphate mineral phases with lower calcium/phosphate ratios, such as brushite, octacalcium phosphatem, and tricalcium phosphate (which exist in some pathologicallyrelated calcification in teeth). No investigation has yet been reported on diseased bone tissues involving inadequate mineralizaiton resulting from deficient calcium and/or phosphate levels. These secondary calcium phosphate phases inherit higher solubility and dissolution rate than the hydroxypatite phase. Therefore, determining the presence of these phases in metabolic bone diseases, such as osteomalacia, or other diseases involving insufficient amount of minerals in osteoid, is critical in not only understanding the physicochemistry of mineral formation in bone but also to developing concepts and potential solutions to bone tissue pathologies. In order to eliminate chemical fixation and staining, we will employ the ultracryomicrotomy method for specimen preparation. To maximize instrumental sensitivity for the detection of small amounts of inorganic constitutents, high voltage electron microdiffraction techniques will be adapted. The high voltage electron microscope is equipped with an environmental chamber that allows the examination of the tissue in their natural state, in their unfrozen hydrated condition. In addition, high voltage stereomicroscopy and threedimensional computer reconstruction will be used to obtain the structural information, and thus, spatial and temporal sequence will be determined. These are the most uptodate methods for obtaining the most complete and intimate knowledge of the inorganic constituents of bone tissue heretofore obtained.

拟议的研究将确定微量化学成分 正常部分的初始和后续矿物相 和维生素 D 缺乏的骨质软化骨组织。 此外， 为了确定时间关系，本研究将使用高 电压电子立体显微镜与计算机联用 图形重建以获得三维位置 矿物质与组织超微结构的关系。 虽然羟基磷灰石的存在已得到充分证实， 对于磷酸二钙矿物来说，情况并非如此 钙/磷酸盐比率较低的相，例如透钙磷石， 磷酸八钙和磷酸三钙（存在于 牙齿中一些病理相关的钙化）。 不 尚未报道对患病骨组织的调查 涉及因缺乏而导致的矿化不足 钙和/或磷酸盐水平。 这些二次磷酸钙相继承了更高的 溶解度和溶解速率均高于羟基磷灰石相。 因此，确定代谢中这些阶段的存在 骨骼疾病，例如骨软化症或其他涉及疾病 类骨质中矿物质含量不足，不仅对 了解骨骼中矿物质形成的物理化学 还开发骨骼的概念和潜在的解决方案 组织病理学。 为了消除化学固定和染色，我们将 采用超低温切片法进行标本制备。 最大限度地提高仪器检测微小物质的灵敏度 无机成分含量、高压电子 将采用微衍射技术。 高电压 电子显微镜配备环境室 允许在自然状态下检查组织， 它们未冻结的水合状态。 另外，高电压 立体显微镜和三维计算机重建 将用于获取结构信息，因此，空间 并且时间顺序将被确定。 这些是最 获得最完整和最亲密的最新方法 迄今为止对骨组织无机成分的了解 获得。