ELECTRON OPTICAL STUDIES OF BONE & OTHER MINERALIZED TISSUES

(部分由NASA2-538和NIH AR41452至W.Landis支持) 矿物晶体和胶原纤维的形态和取向 鸟类和小鼠的肌腱和骨骼，以及异常矿化的皮肤 正在作为人类疾病的模型进行研究，并 HVEM断层扫描显影。最初的研究重点是 胶原蛋白、非胶原基质结构细节的差异 组分、矿物和矿物-基质相互作用。重建 在BMIRR以前的工作过程中所做的工作为此提供了基础 工作。一段纳米金标记的断层的地形重建 小鸡的头骨是用HVEM制作的，以证明 正在开发的渗透技术使标签能够 穿透成骨细胞的细胞膜。厚立体声对 成骨不全(脆性)的胫骨和股骨切片 用双膦酸盐处理的小鼠)记录在 嗯。双膦酸盐可能通过以下途径参与矿化修复 矿物质-胶原蛋白反应。我们观察到一种有趣和不同寻常的 胶原/骨界面处的结晶排列。我们发现了什么 似乎是骨头上的一层矿物质。电子 在1.0 MeV下的衍射没有显示出不同的晶体结构 从大块矿物中分离出来，但显示出可能的取向变化。我们 协助兰迪斯医生准备牙釉质薄片， 在哈佛录制了一个倾斜系列，并 在这里进行了重建。我们做了四个额外的重建 出自Hvem Tilt系列。这些倾斜系列的图像 重建没有我们通常使用的金色记号笔 对齐，所以我们实现了一个无标记的对齐过程。Dr。 兰迪斯多次来到实验室做显微镜检查，并与 断层重建。兰迪斯博士现在有一台SGI工作站 和实验室里的蜘蛛软件，我们正在帮助他学习如何 对他的断层图进行重建和可视化。兰迪斯，W.J. K.J.霍金斯，J.Arena，M.J.Song，B.F.McEwen。(1996年年底) 骨骼中胶原蛋白与矿物质的结构关系 由高压电子显微镜断层扫描确定。Microsc. 理工学院，33：192-202。兰迪斯，W.J.，K.J.霍金斯。(1996年年底) 胶原的矿化可能发生在原纤维表面：证据 从常规和高压电子显微镜和 三维成像技术。J·斯特鲁特。生物，117：24-35。兰迪斯。 W.J.(1996年末)钙化组织中的矿物特性： 原子、分子和大分子的观点。连接。这就是。 答案：34：239-246。兰迪斯，W.J.(1997)胶原蛋白与蛋白质的相互作用 脊椎动物组织中的矿物质。Acta Metall。马特。(记者发稿)。 首页--期刊主要分类--期刊细介绍--期刊题录与文摘--期刊详细文摘内容本地化 骨组织中骨桥蛋白的三维免疫细胞化学研究。第五 国际矿化化学和生物学会议 纸巾。《连接组织研究》35：413,1996。兰迪斯·WJ。 有机相中矿物成核与生长的表征 脊椎动物组织的基质。美国化学会212：INOR 174,1996年。

( Supported in part by NASA2-538 and NIH AR41452 to W. Landis) The shapes and orientation of mineral crystals and collagen fibers in avian and murine tendon and bone, and abnormally mineralized skin in rats, are being investigated as models for human disease and development by HVEM tomography. Initial studies focused on differences in structural details of collagen, non-collagenous matrix components, mineral and mineral-matrix interaction. Reconstructions made in the course of previous work at BMIRR provided basis for this work. A topographic reconstruction of a section of nanogold-labeled chick skull was made using the HVEM, to demonstrate that permeabilization techniques being developed permit the label to penetrate the cell membrane of the osteoblasts. Stereo pairs of thick sections of tibia and femur from an osteogenesis imperfecta (brittle bone disease) mouse treated with biphosphonate were recorded on the HVEM. Biphosphonate may be involved in mineralization repair by mineral-collagen reactions. We observed an interesting and unusual crystalline arrangement at the collagen/bone interface. We found what appeared to be a surface coating of mineral on the bone. Electron diffraction at 1.0 MeV did not reveal a different crystal structure from the bulk mineral, but showed possible orientation changes. We assisted Dr. Landis with preparation of thin-sections of tooth enamel, from which a tilt series was recorded at Harvard, and the reconstruction made here. We made four additional reconstructions from HVEM tilt series. The tilt-series images for these reconstructions did not have the gold markers we normally use for alignment, so we implemented a markerless alignment procedure. Dr. Landis visited the lab several times to do microscopy and to work with the tomographic reconstructions. Dr. Landis now has a SGI workstation and the SPIDER software in his lab, and we are helpng him learn how to do reconstruction and visualization of his tomogrrams. Landis, W.J., K.J. Hodgens, J.Arena, M.J. Song, and B.F. McEwen. (Late 1996) Structural relations between collagen and mineral in bone as determined by high voltage electron microscopic tomography. Microsc. Res. Tech., 33:192-202. Landis, W.J., K.J. Hodgens. (Late 1996) Mineralization of collagen may occur on fibril surfaces: evidence from conventional and high-voltage electron microscopy and three-dimensional imaging. J. Struct. Biol., 117:24-35. Landis. W.J. (Late 1996) Mineral characterization in calcifying tissues: atomic, molecular and macromolecular perspectives. Connect. Tis. Res., 34:239-246. Landis, W.J. (1997) Interactions of collagen and mineral in vertebrate tissues. Acta Metall. Mater. (in press). Landis WJ, Hodgens KJ, Berkery D, Owen CH. Localization of osteopontin in bone by immunocytochemistry in three dimensions. Fifth International Conference on the Chemistry and Biology of Mineralized Tissues. Connect Tissue Research 35:413, 1996. Landis WJ. Characterization of the nucleation and growth of mineral in organic matrices of vertebrate tissues. American Chemical Society 212:INOR 174, 1996.