Recurrent Oxalate Stone Formers Research Articles

Patterns of oxalate metabolism in recurrent oxalate stone formers

Patterns of oxalate metabolism in recurrent oxalate stone formers. The concentration of oxalate in the blood (isotopic procedure), the renal clearance of oxalate, the rate of 14 C-oxalate excretion in the urine and the intestinal absorption of 14 C-oxalate were used as indexes to classify different disturbances of oxalate metabolism in recurrent oxalate stone formers with hyperoxaluria. By comparison with a control group, three major patterns of oxalate metabolism were found. The first group had normal concentrations of blood oxalate, an increased excretion rate of isotopic oxalate and higher oxalate clearance. The second group had higher concentrations of blood oxalate, decreased 14 C-oxalate excretion and normal or decreased oxalate clearance. Finally, in the third group an increased oxalate absorption rate was the main alteration.

Estimating Aberrant Homeostasis: Variance in Serum Calcium Concentration as an Aid in Diagnosis of Hyperparathyroidism

Abstract Frank hypercalcemia is diagnostic of hyperparathyroidism; borderline values present a diagnostic dilemma. Serum calcium and phosphorus concentrations were measured on three or more days in three groups of subjects: 13 healthy controls, 13 hyperparathyroid patients, and six recurrent oxalate stone-formers with idiopathic hypercalciuria. Variances in the concentration of each ion for all individuals were compared by a rank-order runs test. Only individual variances in serum calcium concentrations of patients with hyperparathyroidism were significantly greater than individual variances in the other two groups. Excessive day-to-day variance in serum calcium seems to reflect autonomy of parathyroid function, and can be used to help detect hyperparathyroidism. A similar approach may be diagnostically useful in other diseases in which homeostatic feedback control is aberrant.

Glyoxylate Metabolism in Normal and Stone-Forming Humans and the Effect of Allopurinol Therapy

SummaryAfter injection of glyoxylate-14C, detectable amounts of glyoxylate appeared in the urine for less than 1 hour. The radioactivity primarily appeared as longer persisting oxalate with a minor proportion of very transient glycolate. The rate of conversion and the proportion of the administered radioactivity recovered in 2 hours was closely similar for both normal controls and severely recurrent oxalate stone formers and was unaffected in the latter by allopurinol therapy.