16 - Laser microprobe mass spectrometry: Applications to biological specimens

Abstract

Computer-assisted analysis has enabled quantitation of both relative and absolute elemental concentration distributions in tissue by means of laser microprobe mass spectrometry or mass analysis (LAMMA). However, analogous to electron probe microanalysis, LAMMA experiments are complicated by sample-dependent and instrumental influences on emission intensity. Thus, the relationship of spectral intensity to the absolute concentration distribution in living tissue is an extremely complex one. A number of studies have employed LAMMA to study the relationship between metallic elements and degenerative diseases of the central nervous system. The majority of these articles has investigated the association between aluminum and Alzheimer's disease (AD). Studies have shown that there is selective accumulation of aluminum within neurons bearing neurofibrillary tangles (NFT) in AD. Quantitative studies using LAMMA indicate that aluminum accumulation is small and generalized in both NFT-free and NFT-bearing neurons and that the analyses of bulk samples for aluminum are likely to be unrevealing because differences between AD and control patients would be masked by the large amount of unaffected neuropil sampled. Further studies are necessary to determine whether there is a causal connection between aluminum in drinking water and cognitive impairment. Iron is also increased within neurofibrillary tangles in AD and there are increased levels of aluminum and iron in NFT within neurons of patients with dementia pugilistica (boxer's dementia).