ALUMINUM IN ALZHEIMER'S DISEASE

铝在阿尔茨海默病病因学中的作用仍然存在 由于报告的结果相互矛盾， 许多实验室在现场。 许多实验室依赖于 固定剂和染色剂，以便于明确识别 斑块和神经纤维缠结（NFT）， 疾病 然而，固定和染色的化学过程 损害铝和其它金属的分布和浓度， 感兴趣的元素。 未固定、未染色切片上的测量 假设保留的元素分布是 质疑，因为被测量的结构的识别 难以 已经制定了一种方法， 在未固定、未染色的细胞中明确识别斑块和NFT 不改变元素分布， 提供铝分布的可检测性和快速成像 浓度在ppm范围内。 该方法使用 硫磺素染色切片，通过荧光LM观察，和 背散射电子观察用冷冻干燥切片 用于电子感应成像（BSI）和定量测量 X射线显微分析和西姆斯。 没有铝高于正常 背景浓度已被观察到在缠结的神经元， 用这种方法制备的切片。 然而， 已经在NFT中观察到硫相对于磷的变化，并且在NFT中观察到Fe相对于磷的变化。 斑块

The role of aluminum in the etiology of Alzheimer's disease remains controversial because of the contradictory results reported by the many laboratories in the field. Many of the laboratories relied on fixatives and stains to facilitate the unambiguous identification of plaques and neurofibrillary tangles (NFTs), the indicators of the disease. However, the chemical processes of fixing and staining compromise the distributions and concentrations of aluminum and other elements of interest. Measurements on unfixed, unstained sections in which elemental distributions are assumed to be preserved are questioned because the identification of the structures being measured is difficult. A methodology has been developed that permits the unambiguous identification of plaques and NFTs in unfixed, unstained sections, that does not alter the elemental distributions, and that provides detectability and rapid imaging of the aluminum distribution at concentrations in the ppm range. This methodology uses thioflavin-stained sections for observation by fluorescent LM, and freeze-dried cryosections for observation by backscattered-electron imaging (BSI) and for quantitative measurement by electron-induced X-ray micro-analysis and SIMS. No aluminum above the normal background concen-tration has been observed in tangled neurons in sections prepared by this method. However, a marked increase in sulphur relative to phosphorus has been observed in NFTs, and of Fe in plaques.