The influence of pH and urine composition on urease enzymatic activity in human urine

[Metastatic cerebral abscess from Klebsiella pneumoniae after extracorporal shock wave lithotripsy for kidney stone (a case report)]

Extra-corporeal Shock Wave Lithotripsy (ESWL) is widely used to treat urinary calculi. With increasing numbers of ESWL, more patients prone to infectious complications. A 62-year-old man presented with cerebral abscess following ESWL. The authors discuss presenting conditions, risk factors and preventive measures.

Urease-induced crystallizations of calcium phosphate and magnesium ammonium phosphate in synthetic urine and human urine

An aggregometer technique was used to study urease-induced crystallizations in synthetic urine and human urine from healthy subjects and patients with chronic spinal cord injuries. The two different phases of crystallization, calcium phosphate and magnesium ammonium phosphate, were easily evaluated with a single assay using this technique. The crystallization of calcium phosphate and magnesium ammonium phosphate varied markedly among the different urine specimens after incubation with urease. The turbidity curves from human urine were divided into four patterns. We assumed that the variations in the patterns of the turbidity curves appeared to be mainly due to differences in the composition of the urine and in the original pH, and that the calcium and magnesium concentrations were very important in the urinary constituents.