Bromage Timothy G, Goldman Haviva M, McFarlin Shannon C, Warshaw Johanna, Boyde Alan, Riggs Christopher M
City University of New York, USA.
Anat Rec B New Anat. 2003 Sep;274(1):157-68. doi: 10.1002/ar.b.10031.
Bone exhibits positive form birefringence dominated by and dependent upon the orientation of its collagen. The biomechanical efficacy of bone as a tissue is largely determined by collagen fibers of preferred orientation and distribution (and corresponding orientation of mineral crystallites), and evidence is accumulating to demonstrate that this efficacy extends to function at the organ level. This study has three aims. The first is to provide a Background to the study of circularly polarized light (CPL) investigations of collagen fiber orientation in bone. The significance of preferred collagen fiber orientation in bone, linearly polarized light and CPL imaging principles, and a short history of CPL studies of mammalian functional histology are reviewed. The second is to describe, in some detail, methodological considerations relating to specimen preparation and imaging appropriate for the quantitative analysis of preferentially oriented collagen. These include section transparency, section thickness, the uniformity of the illuminating system, and CPL paraphernalia. Finally, we describe a grey-level standard useful for quantitative CPL, based upon mineralized turkey tendon, which shall be provided to investigators upon request. When due consideration is paid to specimen preparation and imaging conditions, quantitative assessment of collagen fiber orientation provides insight into the effects of mechanical loading on the skeleton.
骨骼呈现出以其胶原蛋白取向为主导并依赖于该取向的正性形态双折射。骨骼作为一种组织的生物力学效能在很大程度上由具有优先取向和分布的胶原纤维（以及矿物质微晶的相应取向）决定，并且越来越多的证据表明这种效能延伸至器官水平的功能。本研究有三个目标。第一个目标是为骨中胶原纤维取向的圆偏振光（CPL）研究提供背景。回顾了骨中优先胶原纤维取向的意义、线偏振光和CPL成像原理，以及哺乳动物功能组织学CPL研究的简短历史。第二个目标是详细描述与适合优先取向胶原定量分析的标本制备和成像相关的方法学考虑因素。这些因素包括切片透明度、切片厚度、照明系统的均匀性以及CPL设备。最后，我们描述了一种基于矿化火鸡肌腱的、对定量CPL有用的灰度标准，如有需要将向研究人员提供。当对标本制备和成像条件给予应有的考虑时，胶原纤维取向的定量评估能够深入了解机械负荷对骨骼的影响。
