title: [Determination of the Ca/P atomic ratio in the spinal cord of patients with amyotrophic lateral sclerosis by neutron activation and X-ray fluorescence analysis].
abstract: Ca/P atomic ratios in spinal cords of seven amyotrophic lateral sclerosis (ALS) cases were determined by neutron activation and X-ray fluorescence analyses, and were compared with those of seven control cases. In order to obtain calibration curves, the standard samples with 0.01-0.1 of Ca/P atomic ratio were prepared by mixing diammonium hydrogen phosphate with calcium carbonate. In neutron activation analysis, gamma-ray spectra of 49Ca and beta-ray intensities of 32P produced from (n, gamma) reactions of the spinal cords and standard samples were measured by Ge(Li) and GM detectors, respectively. In X-ray fluorescence analysis, the samples were excited with 1.6 MeV alpha particle beam accelerated by a Van de Graaff accelerator, manganese K X-rays from 55Fe radioactive source and rhodium K alpha X-rays from X-ray tube, respectively. The characteristic X-ray spectra were measured by Si(Li) or proportional detector. From the peak areas on the spectra and beta-ray intensities, the Ca/P atomic ratios in spinal cords were determined. Based on these results, the Ca/P atomic ratio of precipitate including calcium and phosphorus in spinal cord of ALS case was calculated. As a result, the Ca/P atomic ratios in spinal cords of ALS and control cases were 0.018-0.021 and 0.030-0.049, respectively. The calculated Ca/P atomic ratio in the precipitate of ALS case was estimated to be 1.6.
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000378:metabolism*; D002118:Calcium / Q000032:analysis*; D006801:Humans; D009501:Neutron Activation Analysis; D010758:Phosphorus / Q000032:analysis*; D013052:Spectrometry, X-Ray Emission; D013116:Spinal Cord / Q000032:analysis*
chemical_list: D010758:Phosphorus; D002118:Calcium