X-ray diffractometric analysis of L-cystine stones in 12 patients.

In 12 of 21 cystinuric patients, the components of cystine stones, either previously passed or removed at surgery, were studied by X-ray diffractometry and chemical analysis. The results of diffractometry suggested that, in addition to cystine, the stones contained sodium urate and ammonium magnesium orthophosphate hydrate, although chemical analysis was negative for these components. The role of uric acid in cystinuria is discussed.

Metabolic disturbances in cystinuria.

Metabolic investigations were made in 21 cystinuric patients. The results showed a low output of urinary phosphorus and an increase of plasma IgG. These findings and the presence of uric acid in the urine, even in normal values, could play an important role in pathogenesis and stone formation, and also in cystinuria.

[The use of mercapto-propionyl-glycine in the treatment of cystine lithiasis (author's transl)].

The authors report the first results of the use of mercaptopropionyl-glycine (M.P.G.