title: Simple tests to determine urinary risk factors and calcium oxalate crystallization in the outpatient clinic.
abstract: We developed 2 simple and rapid tests for measurement of constituent concentrations and the stone-forming tendency of urine in the outpatient clinic. The concentrations of urinary constituents of calcium, magnesium, phosphorus, uric acid and oxalic acid were measured using 2 types of simple colorimetric tests (vial and quantitative filter types). The intensity of the color developing after a given interval was compared with a color standard of 4 levels. The results obtained using the colorimetric test were slightly lower in value than but significantly correlated with those obtained with standard measurements. The second test measured the crystal-forming ability of urine. A 10 ml. urine sample was pipetted into 4 vials that each contained different concentrations of oxalic acid and calcium. After a given interval the turbidity in each vial was compared with a control (0 mg. oxalic acid and calcium). If turbidity occurred in urine with low concentrations of oxalic acid and calcium the sample had a large tendency for crystals to form.
authors.affiliation: Department of Urology, Kinki University School of Medicine, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kohri
authors.forename: M
authors.initials: M
authors.lastname: Kodama
authors.forename: Y
authors.initials: Y
authors.lastname: Ishikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Katayama
authors.forename: K
authors.initials: K
authors.lastname: Kataoka
authors.forename: M
authors.initials: M
authors.lastname: Iguchi
authors.forename: S
authors.initials: S
authors.lastname: Yachiku
authors.forename: T
authors.initials: T
authors.lastname: Kurita
mesh_terms: D000553:Ambulatory Care; D002118:Calcium; D002129:Calcium Oxalate / Q000652:urine*; D003124:Colorimetry / Q000379:methods; D003460:Crystallization; D004305:Dose-Response Relationship, Drug; D006801:Humans; D010070:Oxalates; D019815:Oxalic Acid; D012307:Risk Factors; D014545:Urinary Calculi / Q000175:diagnosis / Q000453:epidemiology / Q000652:urine*
chemical_list: D010070:Oxalates; D002129:Calcium Oxalate; D019815:Oxalic Acid; D002118:Calcium