Biomedical subjects
R E Van Grieken
Publications and source records attributed to R E Van Grieken.
X-ray spectrometry.
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Laser microprobe mass spectrometry in biology and biomedicine.
An overview is given of laser microprobe mass spectrometry (LMMS) in biology and biomedicine (1989-1993). The present instrumentation and its analytical features are surveyed. Applications are presented with special attention on human and animal tissue samples, as well as plant material. The capabilities of LMMS to study the element distribution in histological sections, to identify the chemical composition of inorganic inclusions and to generate structural information from organic compounds are evidenced.
Laser microprobe mass spectrometric identification of cyclosporin-induced intrarenal microliths in rat.
Using laser microprobe mass analysis (LAMMA), the composition of 'micro-calcifications (dystrophic type)' or 'metastatic calcifications', previously described in rats given high doses of cyclosporin, have been identified. Female Wistar rats given 12.5, 25 or 50 mg kg-1 per day of cyclosporin in olive oil by gastric gavage developed intrarenal calcifications detected by silver nitrate staining (von Kossa) in the outer medulla after two weeks. The calcifications stained red with periodic acid-Schiff reagent and appeared to be intraluminal microliths with concentric laminations. They could be identified by LAMMA as calcium phosphate (hydroxyapatite), indistinguishable from undecalcified bone. These studies indicate that intraluminal obstruction by calcium phosphate microliths, similar to that seen with magnesium depletion or high phosphate diets, may contribute to renal damage in rats given high-dose cyclosporin. LAMMA appears to be an appropriate technique for identifying both the elemental and organic moieities of intrarenal calcium deposits.
Iron, copper, zinc and lead in hair from Sudanese populations of different age groups.
Energy-dispersive X-ray fluorescence was used for the analysis of hair samples from three different age groups of the Sudanese population. Hair samples were digested in a mixture of nitric and perchloric acids and the metals were then precipitated with ammonium pyrrolidine dithiocarbamate. The variations of the Fe, Cu, Zn and Pb content of hair with age were investigated. The averages of the elemental concentrations in each age group were compared with the other age groups and with literature values. The correlation of each pair of elements in the hair samples was also investigated.
Phosphorus, calcium and lead distribution in collagen in lead induced soft tissue calcification. An ultrastructural and X-ray microanalytical study.
Repeated intraperitoneal injections of lead acetate in rats caused a calcification of the skin of the abdomen near the site of the injections. In the lead-induced calcifications, electron dense collagen bundles could be observed. On the surface of the collagen fibrils, needle-like crystals were visible. With energy-dispersive X-ray analysis, phosphorus, calcium and lead were detected in the electron dense collagen bundles. X-ray maps of the P-K alpha, Ca-K alpha, and Pb-L alpha plus Pb-L beta lines showed an equivalent distribution along the collagen fibrils for phosphorus and calcium. The occurrence of the most electron dense areas in the STEM-image was comparable to the lead distribution. A good correlation existed between the structural and the elemental images of the same area. Although the medicinal use of preparations containing lead is no longer recommended, some are still prescribed. From our results we can conclude that they should not be applied to injured or inflamed skin.
Influence of fixation procedures on the microanalysis of lead-induced intranuclear inclusions in rat kidney.
Using Laser Microprobe Mass Analysis (LAMMA), we studied the chemical composition of lead-induced intranuclear inclusions in rat kidney tissue prepared by three different wet chemical fixation procedures for transmission electron microscopy. Fixation with glutaraldehyde-Na2S gave the same results as fixation with glutaraldehyde only: a high lead concentration could be detected. Therefore, for lead strongly bound to proteins, precipitation procedures are not essential. Post-fixation with osmium tetroxide drastically changed the composition of the inclusions: the lead concentration decreased substantially, while sodium, calcium, and barium were introduced. The osmium tetroxide fixative was found to be the source of the contamination. It also contained aluminum, and we suggest that other proteins (e.g., in neurofibrillary tangles) might be able to take up Al out of solution and that care must be exercised in interpreting the microanalytical results of osmium-fixed material. For the microanalysis of the lead inclusions, fixation with glutaraldehyde only provides a good compromise between preservation of the ultrastructure and maintenance of the element distribution.
Ultrastructural localization of aluminium in liver of aluminium maltol-treated rabbits by laser microprobe mass analysis.
By means of laser microprobe mass analysis (LAMMA), we have studied the ultrastructural localization of aluminium in livers of aluminium maltol-treated rabbits. This animal model was developed to study long-term aluminium toxicity using systemic (intravenous) administration of aluminium. We could only detect aluminium in electron-dense inclusion bodies found in large, sometimes multinucleated cells. These results prove that the actual observation of aluminium deposits in liver with LAMMA gives more information than bulk analysis and can be very useful to explore mechanisms of toxicity.
Characterization of the spheroliths present in primary atypical bandkeratopathy using laser microprobe mass analysis.
Laser microprobe mass analysis was applied to study the chemical composition of spheroliths in the Bowman's membrane of patients suffering from primary atypical bandkeratopathy. The inclusions appear to consist mainly of calcium phosphate.
X-ray spectrometry.
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Localization of aluminum in tissues.
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Laser microprobe mass analysis (LAMMA) to study lead intoxication at the subcellular level.
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Laser microprobe mass analysis: a review of applications in the life sciences.
The characteristics and analytical utility of laser microprobe mass analysis (LAMMA) are described and evaluated, and a short history of this recent microanalytical technique is presented. A review of the areas of application of LAMMA and related laser microprobes is presented with special emphasis on applications in the life sciences.
Microanalysis in biology and medicine: ultrastructural localization of aluminum.
Four methods for the ultrastructural tracing of elements in man and animal are discussed. In addition to histochemical staining, emphasis was put on three innovative sophisticated microanalytical techniques: electron probe X-ray microanalysis, secondary ion mass spectrometry, and laser microprobe mass analysis. The principles and merits of these methods for microanalysis are reviewed. The application of these techniques for the detection of aluminum at the microscopic level is described in detail because of the clinical importance of this metal in severe chronic renal failure. A literature survey concerning the microanalysis of aluminum in biology and medicine is presented.
Laser microprobe mass analysis: a tool for evaluating histochemical staining of trace elements.
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Laser microprobe mass spectrometry of platinum in dog kidney after cisplatin administration.
By means of laser microprobe mass analysis ( LAMMA ) platinum was detected in the renal proximal tubular cells of a dog that had been intravenously administered the antitumor drug cisplatin (5 mg per kg body weight). No definite subcellular localization of the heavy metal was obtained. Sample preparation and analytical features are examined to increase spatial resolution of analysis while maintaining sufficient detection efficiency. The LAMMA method is destructive, but the amount and type of evaporated material can readily be determined when using LAMMA in combination with transmission electron microscopy. Instrumental optimization and standardization of mass signals is possible by using platinum-loaded, ion-chelating resin beads embedded and sectioned with the tissue.
Patterns of iron storage in patients with severe renal failure.
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Ultrastructural localization of aluminum in patients with dialysis-associated osteomalacia.
Using laser microprobe mass analysis, we studied the ultrastructural localization of aluminum in liver and bone tissue of chronic-hemodialysis patients with proven aluminum-induced osteomalacia. In the liver, aluminum was observed to be almost exclusively associated with iron. Detectable aluminum and large amounts of iron were found in lysosomes of both hepatocytes and Kupffer cells. In bone, aluminum was localized at the osteoid/calcified-bone interface and also was associated with iron in some cases.