ELECTRON OPTICAL STUDIES OF BONE & OTHER MINERALIZED TISSUES

（部分由NASA 2 -538和NIH AR 41452支持，W。兰迪斯） 矿物晶体和胶原纤维的形状和取向 鸟类和鼠类的肌腱和骨骼，以及 大鼠作为人类疾病的模型正在研究中， 通过HVEM断层扫描进行开发。 最初的研究集中在 胶原、非胶原基质的结构细节差异 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 使用HVEM制作鸡头骨，以证明 正在开发的透化技术允许标签 穿透成骨细胞的细胞膜。 立体声对厚 胫骨和股骨的切片来自骨生成骨（脆性 骨疾病）小鼠的数据记录在 HVEM。 双膦酸盐可能参与矿化修复， 矿物质-胶原反应。 我们观察到了一个有趣的和不寻常的 晶体排列在胶原/骨界面。 我们找到了什么 似乎是骨头表面的一层矿物质。 电子 在1.0 MeV的衍射没有揭示不同的晶体结构 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的薄片， 其中倾斜系列记录在哈佛，和 在这里进行重建。 我们做了四个额外的重建 HVEM倾斜系列。 这些倾斜系列图像 重建没有我们通常使用的黄金标记 因此，我们实施了无标记比对程序。 博士 兰迪斯多次访问实验室，做显微镜检查， 断层重建 兰迪斯博士现在有一个SGI工作站 和他实验室里的SPIDER软件，我们正在帮助他学习如何 重建并可视化他的断层扫描图 兰迪斯，W. J.， K. J. Hodgens、J.竞技场、M. J. Song和B.F.麦克尤恩 (Late一九九六年） 骨中胶原与矿物质的结构关系 通过高压电子显微镜断层扫描确定。 Microsc. Res.技术员：33：192-202。 兰迪斯，W. J.，K·J·哈金斯 (Late一九九六年） 胶原蛋白的矿化可能发生在原纤维表面：证据 从传统和高压电子显微镜， 三维成像。 J. Struct. Biol.，117：24-35。 兰迪斯 W. J.（1996年末）钙化组织中的矿物质特征： 原子、分子和大分子的观点。 Connect. 是的 结果：34：239-246。 Landis，W. J.（1997）胶原蛋白和 脊椎动物组织中的矿物质。 金属学报 Mater. (in Press）。 张文，等.神经网络的局部化 骨桥蛋白的三维免疫细胞化学。 五 矿化的化学和生物学国际会议 组织中 Connect Tissue Research 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.