Summary
A method is described for analysis of the risk of calcium phosphate (CaP) crystallization in urine samples. The pH required for formation of 500 crystals in the size range 3.5 to 5 μm (pHCaP) was determined in a Coulter Counter following addition of sodium hydroxide. The risk of CaP crystallization (CaP-CR) was defined as: 1/(pHCaP−5.8). CaP-CR was determined in 24 h urine collections from 25 patients with calcium stone disease and 26 normal subjects, each urine diluted to a creatinine concentration of 5 μmol per ml. The mean (±SD) CaP-CR was 0.71±0.18 and 0.63±0.14 respectively and did not differ significantly. This method might be useful for evaluations and follow-up of stone formers with respect to the risk of CaP precipitation and stone formation.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Fleisch H (1978) Inhibitors and promoters of stone formation. Kidney Int 13:361–71
Nicar MJ, Hill K, Pak CYC (1983) A simple technique for assessing the propensity for crystallization of calcium oxalate and brushite in urine from the increment in oxalate or calcium necessary to elicit precipitation. Metabolism 32:906–910
Tiselius H-G (1984) A simplified estimate of the ion-activity product of calcium phosphate in urine. Eur Urol 10:191–195
Tiselius H-G, Almgård LE, Larsson L, Sörbo B (1978) A biochemical basis for grouping of patients with urolithiasis. Eur Urol 4:244–249
Tiselius H-G, Larsson, L (1981) Biochemical evaluation of patients with urolithiasis. Eur Urol 7:31
Tiselius H-G (1985) Measurement of the risk of calcium oxalate crystallization in urine. Urol Res 6:297–300
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Tiselius, HG. Measurement of the risk of calcium phosphate crystallization in urine. Urol. Res. 15, 79–81 (1987). https://doi.org/10.1007/BF00260937
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00260937