ALUMINUM IN ALZHEIMER'S DISEASE

铝在阿尔茨海默病病因中的作用仍然存在 有争议的是因为许多人的结果相互矛盾 阿尔茨海默病脑标本的测量方法包括 电子探针X射线显微分析(EPMA)，质子诱导的X射线发射 (PIXE)、二次离子质谱仪(SIMS)和激光微探针质谱 分析(南丫)。对于这些测量中的许多，固定剂和污渍 以促进斑块的明确识别 以及神经原纤维缠结(NFTs)，这是疾病的指标。 然而，固定和染色的化学过程损害了 铝和其他元素的分布和浓度 利息。对未固定、未染色的切片上元素的测量 假定分布被保留是受到质疑的，因为 识别被测量的结构是困难的。一个 方法学，允许明确地识别斑块和 NFTS，不改变元素分布，并提供 铝分布的可探测性和快速成像 浓度在ppm范围内正在开发中。方法论 利用硫代黄素染色的切片进行荧光光镜观察， 和冷冻干燥切片以供电子和电子显微镜观察 背散射电子成像(SEI、BSI)及其定量测量 通过电子诱导X射线微区分析和SIMS分析。

The role of aluminum in the etiology of Alzheimer's disease remains controversial because of the contradictory results of the many measurements of Alzheimer's brain specimens by methods including electron-probe x-ray microanalysis (EPMA), proton-induced x-ray emission (PIXE), secondary ion mass spectrometry (SIMS), and laser microprobe mass analysis (LAMMA). For many of these measurements, fixatives and stains were relied upon 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 which permits the unambiguous identification of plaques and NFTs, does not alter the elemental distributions, and provides detectibility and rapid imaging of the aluminum distribution at concentrations in the ppm range is being developed. The methodology utilizes thioflavin-stained sections for observation by fluorescent LM, and freeze-dried cryosections for observation by electron and backscattered-electron imaging (SEI, BSI) and quantitative measurement by electron-induced x-ray microanalysis and SIMS.