1. Excretion of amino acids in childhood. A reliable method for the determination of amino acid nitrogen in urine
- Author
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C. Danelatou-Athanassiadou and N.S. Constantsas
- Subjects
Adolescent ,Fever ,Urease ,Nitrogen ,Physiology ,Coefficient of variation ,Clinical Biochemistry ,Inorganic chemistry ,chemistry.chemical_element ,Urine ,Kidney ,Biochemistry ,Excretion ,chemistry.chemical_compound ,Ammonia ,Urea ,Amino Acids ,Renal Aminoacidurias ,Child ,Amino Acid Metabolism, Inborn Errors ,chemistry.chemical_classification ,Chromatography ,biology ,Biochemistry (medical) ,Collagen Diseases ,General Medicine ,Creatine ,Body Fluids ,Amino acid ,chemistry ,Creatinine ,biology.protein ,Colorimetry ,Indicators and Reagents - Abstract
A reliable and relatively simple colorimetric determination of amino acid nitrogen in urine is described; urea and ammonia are completely eliminated. The average coefficient of variation calculated from 39 triplicate analyses is ± 3.7%. Colour yields of the main free amino acids occurring in the urine of children are established in relation to the most satisfactory composition of a standard for the determination. Equilibration of urine with ion exchangers for the selective elimination of ammonia from urine is experimentally evaluated. Data for the computation of approximate urea concentration from the pH of urease-buffer treated urine, are given. Averages and standard deviations are given for the ratio of amino acid nitrogen to creatinine nitrogen at different ages in childhood. Detailed statistical analyses are presented which provide conclusive evidence for the enhancement of amino-aciduria with decreasing age, as well as in cases of fever, and collagen diseases.
- Published
- 1964
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