Promotive effect of urine from patients with primary hyperparathyroidism on calcium oxalate crystal aggregation in an in vitro whole urine system.

Urine from patients with calculi produced by primary hyperparathyroidism was examined to determine its promotive effect on calcium oxalate crystal aggregation. The study was carried out in an in vitro whole urine system and the particle size distribution assay was done by Coulter Counter, Model TAII. Of urine samples from 19 hyperparathyroid patients, 15 showed obvious promotion of calcium oxalate crystal aggregation. It is not known what kind of substances in such urine led to this phenomenon and whether these unknown factors act by actually promoting crystal aggregation or by blocking substances of inhibitors.