[Hypercalciuric and hyperparathyroid renal lithiasis]. / Litiasi renale ipercalciurica e iperparatiroidea

Idiopathic hypercalciuria was noted in 10% of a series of 1635 subjects with renal lithiasis. Eight-day administration of thiazide diuretics as a test for the discovery of latent hyperparathyroidism in idiopathic hypercalciuria is described. In 6 cases diagnosed in this way, surgery disclosed the presence of a parathyroid adenoma. Resection was followed by persistent hypercalciuria and, in some instances, renal lithiasis activity. The pathogenesis of associations of these frequently observed diseases is examined.

[Alkalinizing treatment as a preventative of recurrent calcium oxalate lithiasis]. / El tratamiento alcalinizante como preventivo de la litiasis oxalocálcica recidivante.

Alkalinization of urine does not dissolve calcium oxalate but simply inhibits its formation, thus reducing to a high degree the risk of crystallization, precipitation and secondary aggregation. Slight alkalinization is the most effective inhibitor of many recurrent oxalate stones. The solubility of calcium oxalate is always very low and constitutes a different issue of precipitability of oxalate radical as calcium salt which can be satisfactorily influenced by slightly alkalinizing urine. We discuss the reported results of in vitro studies, experiments in animals submitted to oxalate and ethylene glycol overload and the clinical results achieved by alkalinizing treatment of recurrent calcium oxalate stones.

Calcified bacteria in renal stones: electron-microscopic aspects.

In some renal calculi whose structure was studied in thin sections, we have found large numbers of rods of the size and shape of bacteria, included in a material consisting of defective apatite calcium phosphates and organic matter. Electron transmission microscopy showed patterns of partially calcified bacteria. With the scanning electron microscopy we obtained only images of bacterial impressions. In struvite stones bacteria are rarely found in thin sections. Extremely high ammonium alkalinisation does not seem to be compatible with the preservation of bacterial bodies capable of being calcified.

[Potassium urate in urinary tract calculi]. / Urato potásico en los cálculos del aparato urinario.

In a study of renal calculi, performed with scanning electronic microscope, Edax, element mapping and semiquantitative analysis with a Nova 2 computer, we have found, among the urates, ratios K/Na from 0.016, in the almost pure monosodium urate stones, to 1.856 in other areas. The presence of monopotassium urate has, to our knowledge, no previous reference in the literature on human lithiasis.