Imaging Mass Spectrometry of Medical Tissues

At present the application of LA-ICP-MS in biological research and in medicine focuses on 

LA-ICP-MS enables images to be produced of the distribution of essential elements such as Zn, Cu, Fe, S, P, Se and Mn as well as of toxic and also radioactive metals (e.g., Hg, Pb, Cd, Th and U) in thin tissue sections with a spatial resolution in the (im range. This spatial resolution of element distribution analysis is sufficient to distinguish between several layered structures in human brain tissue from the hippocampus, as described by Zilles et al.162 

Platinum complexes are actually a major constituent in the treatment of testicular, ovarian, bladder, colon and non-small cellular lung cancer. The anticancer activity of cisplatin (cis-diammine-dichloro-platinum (II)) was discovered in 1969.164 Two additional compounds, 

Of special interest is the distribution analysis of selenium in certain brain regions. Because the concentration of selenium in brain tissues is relatively low (mostly in the sub-ngg-1 range) and since selenium detection is difficult by LA-ICP-MS due to interference problems by isobaric polyatomic ions, tracer experiments with selenium of natural isotopic pattern were carried out. For example, snails were fed lOOOp-gmF1 selenium solution for 60h. Cross sections lOO/xg 

LA-ICP-MS has been developed for the detection and imaging of (3-amyloid protein in immuno-histochemical sections from the brain of a transgenic mouse model of Alzheimer s disease. The distribution of (3-amyloid deposits in tissue based on measurements of Eu and Ni coupled antibodies has been studied by McLeods group.170 

By two dimensional (2D) imaging of brain tissues, a defined sample area (several cm ) of a thin section of brain tissue (thickness 20(j,m) was ablated hue by line with a focused laser beam in a cooled laser ablation chamber (using two Peltier elements behind the target holder made of aluminium). The spot size of the laser beams was about 50(xm, the laser power density 3 x 10 Wcm . Ion intensities of the analytes, e.g., P+, Cu or Zn , were 

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