New Methods of Assessing Crystal Growth and Saturation of Brushite in Whole Urine

Effect of pH, Calcium and Citrate

Charles Y C Pak, Kathy Rodgers, John R. Poindexter, Khashayar Sakhaee

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Purpose: Brushite crystallization might be important in stone formation and prevention. To explore this question new methods for the saturation and crystal growth of brushite were devised that are applicable to whole urine without any computer program. Materials and Methods: The saturation value (concentration-to-product ratio) was determined by dividing the molar concentration product of Ca ([Ca]) and phosphate ([P]), that is [Ca] × [P], of original urine by the steady state solubility obtained after incubating with an excess of brushite (10 mg/ml) for 5 hours. Crystal growth was measured from the depletion of filtrate ([Ca] × [P]) 3 hours after seeding with brushite (0.25 mg/ml). To test the effect of pH, Ca and citrate the saturation value and crystal growth were determined in 24-hour urine samples from 4 normal volunteers and 2 stone formers, and modified artificially to produce 4 ranges of pH, Ca and citrate by adding acid, base, Ca or citrate. Results: The saturation value and crystal growth of brushite increased with an increase in pH or the Ca concentration but they decreased when the citrate concentration increased. The saturation value correlated strongly with crystal growth. Conclusions: The new methods of brushite saturation value and crystal growth should help discern how abnormalities in urinary pH, Ca and citrate interact to influence the formation of Ca stones in cases of distal renal tubular acidosis and alkali therapy.

Original languageEnglish (US)
Pages (from-to)1532-1537
Number of pages6
JournalJournal of Urology
Volume180
Issue number4
DOIs
StatePublished - Oct 2008

Fingerprint

Calcium Citrate
Crystallization
Urine
Citric Acid
Renal Tubular Acidosis
Alkalies
dibasic calcium phosphate dihydrate
Solubility
Healthy Volunteers
Software
Phosphates
Acids

Keywords

  • brushite
  • calcium
  • crystallization
  • kidney calculi
  • urine

ASJC Scopus subject areas

  • Urology

Cite this

New Methods of Assessing Crystal Growth and Saturation of Brushite in Whole Urine : Effect of pH, Calcium and Citrate. / Pak, Charles Y C; Rodgers, Kathy; Poindexter, John R.; Sakhaee, Khashayar.

In: Journal of Urology, Vol. 180, No. 4, 10.2008, p. 1532-1537.

Research output: Contribution to journalArticle

@article{1d08dd88ca1d4825a060e043279fd6ef,
title = "New Methods of Assessing Crystal Growth and Saturation of Brushite in Whole Urine: Effect of pH, Calcium and Citrate",
abstract = "Purpose: Brushite crystallization might be important in stone formation and prevention. To explore this question new methods for the saturation and crystal growth of brushite were devised that are applicable to whole urine without any computer program. Materials and Methods: The saturation value (concentration-to-product ratio) was determined by dividing the molar concentration product of Ca ([Ca]) and phosphate ([P]), that is [Ca] × [P], of original urine by the steady state solubility obtained after incubating with an excess of brushite (10 mg/ml) for 5 hours. Crystal growth was measured from the depletion of filtrate ([Ca] × [P]) 3 hours after seeding with brushite (0.25 mg/ml). To test the effect of pH, Ca and citrate the saturation value and crystal growth were determined in 24-hour urine samples from 4 normal volunteers and 2 stone formers, and modified artificially to produce 4 ranges of pH, Ca and citrate by adding acid, base, Ca or citrate. Results: The saturation value and crystal growth of brushite increased with an increase in pH or the Ca concentration but they decreased when the citrate concentration increased. The saturation value correlated strongly with crystal growth. Conclusions: The new methods of brushite saturation value and crystal growth should help discern how abnormalities in urinary pH, Ca and citrate interact to influence the formation of Ca stones in cases of distal renal tubular acidosis and alkali therapy.",
keywords = "brushite, calcium, crystallization, kidney calculi, urine",
author = "Pak, {Charles Y C} and Kathy Rodgers and Poindexter, {John R.} and Khashayar Sakhaee",
year = "2008",
month = "10",
doi = "10.1016/j.juro.2008.06.011",
language = "English (US)",
volume = "180",
pages = "1532--1537",
journal = "Journal of Urology",
issn = "0022-5347",
publisher = "Elsevier Inc.",
number = "4",

}

TY - JOUR

T1 - New Methods of Assessing Crystal Growth and Saturation of Brushite in Whole Urine

T2 - Effect of pH, Calcium and Citrate

AU - Pak, Charles Y C

AU - Rodgers, Kathy

AU - Poindexter, John R.

AU - Sakhaee, Khashayar

PY - 2008/10

Y1 - 2008/10

N2 - Purpose: Brushite crystallization might be important in stone formation and prevention. To explore this question new methods for the saturation and crystal growth of brushite were devised that are applicable to whole urine without any computer program. Materials and Methods: The saturation value (concentration-to-product ratio) was determined by dividing the molar concentration product of Ca ([Ca]) and phosphate ([P]), that is [Ca] × [P], of original urine by the steady state solubility obtained after incubating with an excess of brushite (10 mg/ml) for 5 hours. Crystal growth was measured from the depletion of filtrate ([Ca] × [P]) 3 hours after seeding with brushite (0.25 mg/ml). To test the effect of pH, Ca and citrate the saturation value and crystal growth were determined in 24-hour urine samples from 4 normal volunteers and 2 stone formers, and modified artificially to produce 4 ranges of pH, Ca and citrate by adding acid, base, Ca or citrate. Results: The saturation value and crystal growth of brushite increased with an increase in pH or the Ca concentration but they decreased when the citrate concentration increased. The saturation value correlated strongly with crystal growth. Conclusions: The new methods of brushite saturation value and crystal growth should help discern how abnormalities in urinary pH, Ca and citrate interact to influence the formation of Ca stones in cases of distal renal tubular acidosis and alkali therapy.

AB - Purpose: Brushite crystallization might be important in stone formation and prevention. To explore this question new methods for the saturation and crystal growth of brushite were devised that are applicable to whole urine without any computer program. Materials and Methods: The saturation value (concentration-to-product ratio) was determined by dividing the molar concentration product of Ca ([Ca]) and phosphate ([P]), that is [Ca] × [P], of original urine by the steady state solubility obtained after incubating with an excess of brushite (10 mg/ml) for 5 hours. Crystal growth was measured from the depletion of filtrate ([Ca] × [P]) 3 hours after seeding with brushite (0.25 mg/ml). To test the effect of pH, Ca and citrate the saturation value and crystal growth were determined in 24-hour urine samples from 4 normal volunteers and 2 stone formers, and modified artificially to produce 4 ranges of pH, Ca and citrate by adding acid, base, Ca or citrate. Results: The saturation value and crystal growth of brushite increased with an increase in pH or the Ca concentration but they decreased when the citrate concentration increased. The saturation value correlated strongly with crystal growth. Conclusions: The new methods of brushite saturation value and crystal growth should help discern how abnormalities in urinary pH, Ca and citrate interact to influence the formation of Ca stones in cases of distal renal tubular acidosis and alkali therapy.

KW - brushite

KW - calcium

KW - crystallization

KW - kidney calculi

KW - urine

UR - http://www.scopus.com/inward/record.url?scp=50949119446&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=50949119446&partnerID=8YFLogxK

U2 - 10.1016/j.juro.2008.06.011

DO - 10.1016/j.juro.2008.06.011

M3 - Article

VL - 180

SP - 1532

EP - 1537

JO - Journal of Urology

JF - Journal of Urology

SN - 0022-5347

IS - 4

ER -