ABSTRACT
Since hypocitraturia in distal renal tubular acidosis, we screened the asymptomatic children in three families with familial dRTA, by comparing their 24-hour urine citrate excretion to values obtained in 45 normal children. Subsequent acid loading uncovered four new cases of dRTA suspected because of the finding of hypocitraturia. Because hypocitraturia probably contributes to nephrolithiasis/nephrocalcinosis and subsequent renal damage in dRTA, affected family members were treated with alkali (4 mEq/kg/day), which normalized urine citrate in three children; in a fourth child citrate excretion rose but was not normal. Measurement of urine citrate excretion was superior to other currently proposed screening tests for dRTA (first morning urine pH and sediment, urine concentration).
Subject(s)
Acidosis, Renal Tubular/diagnosis , Citrates/urine , Acidosis, Renal Tubular/genetics , Acidosis, Renal Tubular/urine , Adult , Child , Female , Humans , Kidney Tubules, Distal , MaleABSTRACT
A simple, quantitative method is described for the photometric determination of gangliosides. The procedure is based on the sulfo-phospho-vanillin reaction, and does not require prior hydrolysis. It has been shown that the reaction is probably due to oxidation by sulfuric acid of the sphingosine moiety which results in the formation of aldehydes or ketones or both which then react with the phosphoric acid-vanillin reagent to produce a rose-colored complex. The reaction permits the determination of the amount of ganglioside present in a sample; and, together with the resorcinol reaction to measure the NANA content, it can be used to determine whether a purified ganglioside is a mono-, di-, or trisialoganglioside.
