The role of common urinary constituents in the precipitation of ammonium acid urate.

Royal Perth Hospital and the University of Western Australia, Perth, Australia
Clinica Chimica Acta (Impact Factor: 2.85). 01/1980; 99(3):221-7. DOI: 10.1016/0009-8981(79)90265-1
Source: PubMed

ABSTRACT A high proportion of the inhibitory activity shown by urine toward precipitation of ammonium acid urate is ultrafilterable and most of this can be accounted for by the common, low molecular weight components of urine. The individual inhibitory effects of sodium chloride, sodium sulphate, potassium chloride, calcium chloride, magnesium sulphate, sodium dihydrogen phosphate, sodium pyrophosphate, citric acid, hippuric acid, creatinine and urea upon the precipitation of ammonium acid urate have been quantified in an aqueous test system.

  • [Show abstract] [Hide abstract]
    ABSTRACT: A retrospective study of Community Health Service patient records revealed 10 cases of urolithiasis in Aboriginal children under 5 years of age in a remote central Australian Aboriginal community over a 4 year period, out of a total under-5 population estimate of 62. The highest attack rate was in the 0-2 age group, where nearly one in 10 children presented per year. All children had significant associated morbidity. Two children underwent pyelolithotomy. Aboriginal children in the remote arid zone study community suffer exceptionally high rates of urolithiasis. Inadequate diet, dehydration and recurrent infectious disease are factors in pathogenesis. Further study may elucidate aetiology, but the implications of these data for improving environmental conditions and health service delivery in Aboriginal communities are urgent.
    Journal of Paediatrics and Child Health 09/1996; 32(4):344-6. · 1.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The objective of the study was to characterize the signalment, clinicopathologic data, and diagnostic imaging of cats with urate urolithiasis, as well as the salts of uric acid present in the uroliths. A retrospective analysis of feline urate uroliths submitted to the GV Ling Urinary Stone Analysis Laboratory between 2000 and 2008 was included. From these data, records were assimilated from referring veterinarians (143); furthermore, all recorded cases from within the William R Pritchard Veterinary Medical Teaching Hospital (16) were included. Median values for the complete blood count and chemistry panels available were within the reference intervals, when provided, with only a few outliers present. Of all cases evaluated, seven had a portosystemic shunt (PSS). Cats with urate uroliths and a PSS were younger than cats without a PSS (2 years vs 7 years). The pathogenesis of urate uroliths in cats is poorly understood. Most cats were not completely evaluated for a PSS, however, clinicopathologic parameters indicating hepatic dysfunction were seldom noted; more sensitive diagnostics such as serum bile acids were rarely performed to confirm or negate the presence of a shunt. Studies are warranted to evaluate pathogenesis of urate uroliths to tailor proper management and breeding strategies.
    Journal of feline medicine and surgery. 08/2011; 13(10):725-32.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although ammonium acid urate (AAU) stones are endemic in Asia, pure AAU calculi have almost disappeared from industrialized countries and clinical pathophysiologic relevance of sporadic stones containing AAU crystals is currently unknown. We reviewed 1,396 crystallographic stone analyses performed in our institution over a 10-year period. Prevalence of stones containing AAU crystals and predominantly AAU stones were 3.1% and 0.2%, respectively. In more than two thirds of cases, AAU crystals represented less than 10% of stone crystal composition. No pure AAU stone was found. According to crystalline predominance, 42%, 35%, and 12% of these calculi were uric acid, infectious, and calcium oxalate stones, respectively. AAU crystals were detected as discrete intercrystalline or peripheral deposits in 74.4% of stones. In only one calculus was AAU crystals detected in the nucleus. The hospital charts of 37 patients who presented with 43 calculi containing AAU crystals were also reviewed. The mean age was 53.1 +/- 16.6 years. Fifty-seven percent of calculi were upper urinary tract stones and 43% were bladder stones. Upper urinary tract calculi were more frequently uric acid stones, followed by infectious and calcium oxalate stones. Lower urinary tract calculi were more frequently infectious stones, followed by uric acid stones. Upper urinary tract stones were passed spontaneously in 13 patients and removed surgically in nine patients. Nine of these subjects were idiopathic recurrent stone formers who had passed other calculi with no trace of AAU crystal. Fifty-seven percent of lower urinary tract stones were associated with documented bladder dysfunction. In conclusion, although AAU-containing urolithiases are occasionally seen in our population, predominantly or primarily AAU stones are exceptional. AAU crystal formation usually appears as a minor and secondary phenomenon of no primary pathophysiologic relevance in stone formation.
    American Journal of Kidney Diseases 09/1997; 30(2):237-42. · 5.29 Impact Factor