It is reasonable to assume that the rate of pH increase in urine induced by urease-producing microorganisms is one of the factors which determine whether crystallisation with subsequent stone formation will occur or not. To evaluate how the time needed to increase urine pH varies between different u
How variations in the composition of urine influence urease-induced crystallization
โ Scribed by Hugosson, J. ;Grenabo, L. ;Hedelin, H. ;Pettersson, S. ;Tarfusser, I.
- Publisher
- Springer
- Year
- 1990
- Tongue
- English
- Weight
- 473 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0300-5623
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โฆ Synopsis
To Study how the composition of urine influences urease-induced crystallization, human urine samples were incubated with urease and the subsequent precipitation measured. Beside the pH increase, the urinary content of magnesium and calcium had profound effects on the precipitation of magnesium ammonium phosphate and calcium phosphate, respectively. Urine phosphate, ammonium and osmolarity had no direct effects on the precipitation. Among the urine components with potential inhibitory properties, only albumin was found to be correlated with such an effect. This inhibitory activity was especially influential in urines with high calcium and magnesium levels. These findings suggest that the composition of urine could also influence the formation of stones consisting of magnesium ammonium phosphate and calcium phosphate.
๐ SIMILAR VOLUMES
The effects of serum, albumin and gammaglobulins on urease-induced crystallization have been studied in synthetic and in human urine. Serum and the studied proteins increased urease enzymatic activity in synthetic urine. In human urine only serum had this effect. In synthetic urine, the proteins and
Previous studies have shown human urine to have an inhibitory action on urease-induced crystallisation. Centrifugation and 0.45 microns filtration of the urine did not reduce this activity. This eliminates larger urine particles as being the cause of the inhibitory activity. Both the retenate and th