Quantitative determination of the mineral distribution in different collagen zones of calcifying tendon using high voltage electron microscopic tomography.
Quantitative determination of the mineral distribution in different collagen zones of calcifying tendon using high voltage electron microscopic tomography.
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发表时间：
1991
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通讯作者：
B. McEwen;M. J. Song;W. Landis
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作者：
B. McEwen;M. J. Song;W. Landis
采用高压电子显微断层扫描技术，首次定量测定了家火鸡正常腿腱中发生早期钙化的胶原纤维不同区域之间的矿物质分布。断层扫描3-D重建计算从倾斜系列的61个不同的意见，跨越角度范围为+/- 60度，2度的间隔。交互式计算机操作的连续应用被用于将孔或重叠区的胶原带型掩蔽到重建的单独版本中。在这样的3-D体积中，由掩模指定的区域保留其原始图像密度，而其余体积被设置为背景水平。这种方法也被应用到矿物晶体存在于相同的体积，以产生版本的3-D重建的晶体质量和相应的胶原蛋白区被掩盖。来自这些体积的密度分布包含仅对应于晶体质量的独特峰。比较每个曲线的该峰的积分密度，确定观察到的晶体中有64%位于胶原蛋白孔区，36%位于重叠区。如果一旦晶体形成，晶体稳定性不发生变化，则该结果表明矿物的成核优先地且最初与空穴区相关，成核在空穴区中更频繁地发生，晶体生长的速率在空穴区中更快，或这些替代方案的组合的可能性。所有这些都得出结论，在早期胶原纤维钙化期间，与重叠区相比，胶原孔洞区中矿物质物质的总体积累占主导地位。
High voltage electron microscopic tomography was used to make the first quantitative determination of the distribution of mineral between different regions of collagen fibrils undergoing early calcification in normal leg tendons of the domestic turkey, Meleagris gallopavo. The tomographic 3-D reconstruction was computed from a tilt series of 61 different views spanning an angular range of +/- 60 degrees in 2 degrees intervals. Successive applications of an interactive computer operation were used to mask the collagen banding pattern of either hole or overlap zones into separate versions of the reconstruction. In such 3-D volumes, regions specified by the mask retained their original image density while the remaining volume was set to background levels. This approach was also applied to the mineral crystals present in the same volumes to yield versions of the 3-D reconstructions that were masked for both the crystal mass and the respective collagen zones. Density profiles from these volumes contained a distinct peak corresponding only to the crystal mass. A comparison of the integrated density of this peak from each profile established that 64% of the crystals observed were located in the collagen hole zones and 36% were found in the overlap zones. If no changes in crystal stability occur once crystals are formed, this result suggests the possibilities that nucleation of mineral is preferentially and initially associated with the hole zones, nucleation occurs more frequently in the hole zones, the rate of crystal growth is more rapid in the hole zones, or a combination of these alternatives. All lead to the conclusion that the overall accumulation of mineral mass is predominant in the collagen hole zones compared to overlap zones during early collagen fibril calcification.