ELECTRON MICROPROBE IMAGING AND QUANTITATION OF ALZHEIMER'S ASSOCIATED PLAQUES

死后钙的分布和浓度， 慢性阻塞性肺疾病患者脑斑块中的硅和铝 阿尔茨海默氏症是通过元素图像和 用波长色散X射线光谱学方法获得的光谱 计算机控制的Cameca MBX电子束X射线显微分析仪。 风干和冷冻干燥低温.第8-10微米 从新鲜的冷冻标本中提取的厚的，没有化学制剂 分析过了。在风干切片中，硅和 斑块中的铝被发现与基质对照相似 钙的浓度约为50%。 斑块的位置更高。在冻干切片中，浓度 大多数斑块和基质中的硅是相同的； 斑块中钙和铝的浓度被发现是 高达十倍的矩阵级别。这些结果与那些 由其他工人使用固定材料或提纯的岩芯获得。 其含义是化学制剂显著地改变了 剖面中的元素分布。

The post-mortem distributions and concentrations of calcium, silicon, and aluminum in plaques from brains of patients with Alzheimer's disease have been determined from elemental images and spectra acquired by wavelength-dispersive x-ray spectroscopy on a computer-controlled Cameca MBX electron beam x-ray microanalyzer. Both air dried and freeze-dried cryo-sections 8-10 micrometers thick from fresh frozen specimens with no chemical preparation were analyzed. In air-dried sections the concentrations of silicon and aluminum in the plaques were found to be similar to matrix control levels; the concentration of calcium was about fifty per cent higher in the plaques. In freeze-dried sections the concentration of silicon was the same in matrix and most plaques; the concentrations of calcium and aluminum in plaques were found to be up to ten times matrix levels. These results differ from those obtained by other workers using fixed material or purified cores. The implications are that chemical preparation significantly alters the elemental distributions in the sections.