The Effects of Citrate and Phosphocitrate on the Kinetics of Mineralization of Calcium Oxalate Monohydrate.

1989 ◽  
Vol 174 ◽  
Author(s):  
C. F. Richardson ◽  
M. Johnsson ◽  
F. K. Bangash ◽  
V. K. Sharma ◽  
J. D. Sallis ◽  
...  
Keyword(s):  
Calcium Oxalate ◽  
Composition Studies ◽  
Calcium Oxalate Monohydrate ◽  
Supersaturated Solution ◽  
Constant Composition ◽  
Kinetics Of ◽  
Saturated Solutions

AbstractThe adsorption of citrate and phosphocitrate on calcium oxalate monohydrate (COM) surfaces has been measured in saturated solutions of calcium oxalate monohydrate at 37°C. In separate adsorption experiments, the uptake of phosphocitrate was markedly greater than that of citrate. When both additives were present, the adsorption of phosphocitrate was further increased. In constant composition studies of the crystallization of CON from supersaturated solution, phosphocitrate was more effective as an inhibitor than was citrate.

Constant Composition Studies Verify the Utility of the Cabrera−Vermilyea (C-V) Model in Explaining Mechanisms of Calcium Oxalate Monohydrate Crystallization

2006 ◽  
Vol 6 (8) ◽  
pp. 1769-1775 ◽  
Author(s):  
Lijun Wang ◽  
James J. De Yoreo ◽  
Xiangying Guan ◽  
S. Roger Qiu ◽  
John R. Hoyer ◽  
...  
Keyword(s):  
Calcium Oxalate ◽  
Composition Studies ◽  
Calcium Oxalate Monohydrate ◽  
Constant Composition

Epitaxial Relationships in Urolithiasis: The Calcium Oxalate Monohydrate—Hydroxyapatite System

1975 ◽  
Vol 49 (5) ◽  
pp. 369-374 ◽  
Author(s):  
J. L. Meyer ◽  
J. H. Bergert ◽  
L. H. Smith
Keyword(s):  
Calcium Phosphate ◽  
Calcium Oxalate ◽  
Calcium Oxalate Monohydrate ◽  
Chemical Kinetic ◽  
Urinary Stones ◽  
Supersaturated Solution ◽  
Phosphate Solution ◽  
Epitaxial Relationship ◽  
Experimental Conditions ◽  
Seed Crystals

Chemical kinetic data, complemented with scanning electron-microscope observations of the crystalline phase, show that seed crystals of hydroxyapatite have the ability to induce the growth of calcium oxalate monohydrate crystals epitaxially from a metastable supersaturated solution of calcium oxalate. The rate of growth of calcium oxalate crystals is dependent on the surface area of the seed material and follows a second-order rate law. It is suggested that there may be a causal relationship between the occurrence of apatite crystals in the urinary tract and the formation of both ‘pure’ and mixed urinary stones containing calcium oxalate. Under similar experimental conditions, however, seed crystals of calcium oxalate monohydrate appeared unable to induce epitaxially the growth of calcium phosphate crystals from a supersaturated calcium phosphate solution, indicating the absence of an epitaxial relationship between calcium oxalate monohydrate and the initially precipitating calcium phosphate phase(s).

Epitaxial Relationships in Urolithiasis: The Brushite—Whewellite System

1977 ◽  
Vol 52 (2) ◽  
pp. 143-148 ◽  
Author(s):  
J. L. Meyer ◽  
J. H. Bergert ◽  
L. H. Smith
Keyword(s):  
Crystal Growth ◽  
Calcium Oxalate ◽  
Calcium Oxalate Monohydrate ◽  
Supersaturated Solution ◽  
Scanning Electron Micrographs ◽  
Phosphate Dihydrate ◽  
Acid Environment ◽  
Time Required ◽  
Insight Into ◽  
Scanning Electron

1. Whewellite (calcium oxalate monohydrate) crystals were found to induce epitaxially the heterogeneous nucleation of brushite (calcium monohydrogen phosphate dihydrate) from its metastable supersaturated solution in approximately one-quarter of the time required for spontaneous precipitation in the absence of added nucleating agents. Scanning electron-microscope observation of the crystalline phase showed brushite crystals originating from the whewellite seed crystals. 2. Crystal growth, upon nucleation, proceeded rapidly, and the metastable solutions quickly approached saturation. 3. Brushite crystals also induced the precipitation of calcium oxalate crystals in about one-quarter of the time required for spontaneous precipitation; however, the rate of crystal growth was considerably slower. In support of the chemical data, scanning electron micrographs showed few crystals of calcium oxalate nucleated on the surface of the brushite seed. 4. The results provide some insight into the cause of stones containing calcium oxalate or calcium phosphate (or both), which form in the normally acid environment of human urine.

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