Toshihiko Yoshida

Effect of urinary macromolecules on aggregation of calcium oxalate in recurrent calcium stone formers and healthy

SummaryThe inhibitory activity of urinary macromolecules on the aggregation of calcium oxalate crystals was studied using an aggregometer originally devised to measure thrombocyte aggregation capacity by means of the optical turbidity at 660 nm. The macromolecular fraction of the urine (molecular weight above 5000) of recurrent calcium stone formers showed much less inhibitory activity than that of healthy controls (P0.05). It was speculated on the basis of the results of gel filtration that there were some proteins (molecular weight about 10000–30000) which had inhibitory activities for the aggregation of calcium oxalate. This gives support to the assumption that macromolecules are important during the phase of aggregation of calcium oxalate crystals.

Preoperative localization of parathyroid adenomas using 99mTc-MIBI scintigraphy in patients with hyperparathyroidism.

Background Technetium (Tc) 99m methoxyisobutyl isonitrile (99mTc‐MIBI) has recently been introduced for parathyroid imaging, as well as for myocardial imaging. We studied the usefulness of 99mTc‐MIBI scintigraphy for preoperative localization of abnormal parathyroid glands.

Effect of Dietary Calcium and Magnesium on Experimental Renal Tubular Deposition of Calcium Oxalate Crystal Induced by Ethylene Glycol Administration and Its Prevention with Phytin and Citrate

Oral administration of ethylene glycol to rats, and the resultant intratubular depositions of microcrystals of calcium oxalate were studied investigating the influences of dietary calcium or magnesium and assessing the protective efficacies against the crystallizations by treatment with phytin and sodium citrate. With increase of calcium intake and consequent increase of urinary calcium excretion there was a marked increase in the amount of tubular deposit of calcium oxalate crystal and in the calcium content of renal tissue. Although magnesium deficiency accelerated renal tubular calcium oxalate deposition, the protection against the crystal formation was not observed with excessive dietary magnesium. When rats were fed a high-calcium diet supplemented with phytin, a significant inhibition of the intratubular crystallization was observed. It appeared obvious that a hypocalciuric action of phytin was attributed to the effect of the prevention. There was vigorous protection of crystal formation by treatment with sodium citrate, which correlated with the level of citrate concentration in the drinking water.