title: Re-evaluation of the "week-end effect" data: possible role of urinary copper and phosphorus in the pathogenesis of renal calculi.
abstract: Early morning urinary concentrations of 10 elements which had demonstrated a "week-end effect" in a previous study, were subjected to a normalization procedure thereby allowing a re-assessment of their potential role in urolithiasis. After transformation of each concentration to a weighted proportion of the total concentration on each day, only Cu and P values were significantly different for kidney stone formers and healthy controls on all three days indicating that these elements may play a role in the pathogenesis of renal calculi. The results obtained in this study demonstrate that a more meaningful picture of the possible differences in the urinary concentrations of stone formers and normal controls might emerge if "proportional" rather than "raw" concentrations are compared.
authors.affiliation: Department of Chemistry, University of Cape Town, South Africa.
authors.forename: A L
authors.initials: AL
authors.lastname: Rodgers
authors.forename: L J
authors.initials: LJ
authors.lastname: Barbour
authors.forename: B M
authors.initials: BM
authors.lastname: Pougnet
authors.forename: C J
authors.initials: CJ
authors.lastname: Lombard
authors.forename: R L
authors.initials: RL
authors.lastname: Ryall
mesh_terms: D001966:Bromine / Q000652:urine; D002118:Calcium / Q000652:urine; D003300:Copper / Q000652:urine*; D006801:Humans; D007669:Kidney Calculi / Q000209:etiology* / Q000503:physiopathology / Q000652:urine; D008274:Magnesium / Q000652:urine; D008297:Male; D010758:Phosphorus / Q000652:urine*; D011188:Potassium / Q000652:urine; D012016:Reference Values; D012964:Sodium / Q000652:urine; D013052:Spectrometry, X-Ray Emission; D013054:Spectrophotometry, Atomic; D013223:Statistics as Topic; D013324:Strontium / Q000652:urine; D013455:Sulfur / Q000652:urine; D015032:Zinc / Q000652:urine
chemical_list: D010758:Phosphorus; D013455:Sulfur; D003300:Copper; D012964:Sodium; D008274:Magnesium; D015032:Zinc; D011188:Potassium; D001966:Bromine; D002118:Calcium; D013324:Strontium