Urates in uric acid renal calculi.

Objectives: To investigate the presence of calcium urate, sodium, potassium and calcium in 'pure' uric acid calculi.

Methods: Ten spontaneously passed uric acid urinary calculi have been examined by stereoscopic microscopy, infrared spectroscopy, scanning electron microscopy and energy dispersive X-Ray analysis.

Results: The analysis of selected uric acid calculi revealed the presence of a near-pure calcium urate in two cases and of calcium enriched urate zones in all of the samples.

[Current indications of percutaneous nephrostomy associated with extracorporeal shock wave lithotripsy in the treatment of renoureteral stones].

Objectives: To evaluate the usefulness of PN as urinary diversion in the treatment of urinary stones by ESWL.

Methods: Between April 1996 and June 2003 9554 ESWL were performed at the lithiasis unit of the Fundación Jiménez Diaz; 0.91% required previous insertion of a PN.

[Mechanisms of ureteral contraction-relaxation in nephritic colic].

Objective: From the clinical perspective, pharmacological research on ureteral dynamics--the contraction-relaxation mechanisms of the ureter--, has been prompted by renal colic. Studies of the events triggered by the calculus have been conducted to identify the pharmacological aspects that permit pain relief, passage of the calculus and protection of the kidney from injury caused by acute obstruction.

Methods: Many and varied studies on ureteral pharmacology, both in vivo and in vitro, have been carried out since the beginning of the 20th century.