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Query: UMLS:C0451641 (urolithiasis)
 3,973 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Apart from a minority with urolithiasis, the majority of children diagnosed with idiopathic hypercalciuria present with macro- or microhematuria, abdominal or back pain, or voiding symptoms. With dietary and pharmacological interventions, most such children become asymptomatic and are lost to follow-up, hence their long-term outcome is unclear. In the present study, we evaluated the status of 14 males and 19 females aged 8-17 years (mean 11.9 years, median 11.2 years) 4-11 years (mean 6.9 years, median 6.5 years) after the initial diagnosis of idiopathic hypercalciuria not associated with urolithiasis. A questionnaire was answered and two random urine samples provided 3-4 weeks apart were analyzed for calcium (Ca), sodium (Na), potassium (K), and creatinine (Cr). Urine Ca/Cr ratio > or =20.21 (mg/mg) was defined as hypercalciuria. At the time of the study none were under follow-up, although 7 children were still exhibiting voiding symptoms. No child developed clinical urolithiasis. Based on the first urine specimen, 16 of the 33 (48.4%) were hypercalciuric. Their 2nd urinalysis showed persistent hypercalciuria in 8 and normocalciuria in 8. Urine Na/K ratio (mEq/mEq) decreased in the latter 8 from 5.08+/-2.67 to 3.03+/-2.23 (P<0.05). Of the 17 initially normocalciuric children, 5 did not submit a 2nd specimen, 11 remained normocalciuric, and 1 became hypercalciuric with an increase in urine Na/K ratio. Twenty-three children (all 8 persistently and 9 intermittently hypercalciuric plus 6 normocalciuric) were studied by ultrasonography. Only in 1 asymptomatic persistently hypercalciuric child was a single small renal calcification noted. Introduction of a low-Na/high-K diet in 7 persistently hypercalciuric children resulted in a decrease in UNa/K ratio from 7.34+/-2.15 to 4.14+/-3.09 (P<0.01) and UCa/Cr ratio from 0.25+/-0.04 to 0.13+/-0.03 (P<0.01). We conclude that even though over time most hypercalciuric children become asymptomatic, many remain hypercalciuric. Further follow-up is required to ascertain whether these children are at risk of developing kidney stones. If they are at risk then long-term compliance with a low-Na/high-K diet might be beneficial, as it can normalize calciuria in the majority of these children.
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PMID:Idiopathic hypercalciuria of childhood: 4- to 11-year outcome. 1097 18

Kidney stones have been associated with use of the ketogenic diet in children with refractory seizure disorders. We performed a case-control study examining risk factors for the development of stones on the ketogenic diet, and prospectively followed children initiating the ketogenic diet to evaluate the incidence of urolithiasis. Clinical characteristics of 18 children presenting with stones (8 uric acid stones, 6 mixed calcium/uric acid stones, 1 calcium oxalate/phosphate stone, 3 stones not evaluated) were compared with characteristics of non-stone-forming children initiating the ketogenic diet at Johns Hopkins since July 1996. Since July 1996, 112 children initiating the ketogenic diet have been followed for development of stones. Follow-up times on the diet range from 2 months to 2.5 years. Of 112 children, 6 have developed stones (3 uric acid, 3 mixed calcium/uric acid stones) (0.8 children developing stones/ 100 patient-months at risk). Comparisons of children presenting with stones on the ketogenic diet with characteristics of the entire cohort initiating the ketogenic diet suggest younger age at diet initiation and hypercalciuria are risk factors for the development of stones. Prospective evaluation of children initiating the ketogenic diet revealed that almost 40% of patients had elevated fasting urine calcium: creatinine ratios at baseline; this increased to 75% after 6 months on the diet. Median urine pH was 5.5 at diet initiation, and remained at 6.0 thereafter. In a subset of patients tested, urinary citrate excretion fell from a mean of 252 mg/24 h pre diet initiation to 52 mg/24 h while on the diet. Uric acid excretion remained normal. Patients maintained on the ketogenic diet often have evidence of hypercalciuria, acid urine, and low urinary citrate excretion. In conjunction with low fluid intake, these patients are at high risk for both uric acid and calcium stone formation.
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PMID:Risk factors for urolithiasis in children on the ketogenic diet. 1109 28

Proton Nuclear Magnetic Resonance (NMR) Spectroscopy of urine (as well as of other biological fluids) is a very powerful technique enabling multi-component analysis useful in both diagnosis and follow-up of a wide range of inherited metabolic diseases. Among these pathologies, cystinuria is characterised by accumulation in urine of four dibasic amino acids, namely lysine, arginine, ornithine and cystine; the last one, being only slightly water soluble, generates urolithiasis. The mentioned aminoacids can be detected in the urine NMR spectrum of cystinuric patients, the most abundant being the lysine (5 mM and over are often detected), whose typical signals become very high; arginine and ornithine are also usually detectable, although pathologic concentrations are lower (usually below 2mM). The proposed NMR technique is also suitable in monitoring the therapy with alpha-mercaptopropionylglycine (MPG), providing quantitation of several metabolites of interest in the follow-up of the pathology, like cystine, creatinine and citrate.
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PMID:Diagnosis and follow-up of cystinuria: use of proton magnetic resonance spectroscopy. 1112 53

Biochemical tests by 12 metabolic blood and urine indices reflecting the condition of renal function and metabolism of urolithogenic substances were made in the course of 1-6 year follow-up of 35 and 79 patients (46 females and 68 males aged 18-65 years) with recurrence-free and recurrent urolithiasis, respectively. The risk of recurrence for uric acid urolithiasis in serum concentration of urea 5.67 +/- 0.14 mmol/l and creatinine 0.090 +/- 0.008 mmol/l, in hyperuricemia and hyperuricuria was associated with elevation of renal excretion of total calcium to 5.88 +/- 0.49 mmol/day and ratio of daily renal excretion of sodium to renal daily excretion of potassium to 3.28 +/- 0.08; for calcium-oxalate lithiasis--with a rise in serum concentration of uric acid to 0.310 +/- 0.042 mmol/l and sodium to 114 +/- 0.8 mmol/l in hypercalciuria and hyperuricuria.
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PMID:[Recurrence-free and recurrent urolithiasis: metabolic differences]. 1115 Jan 60

Natural low-mineralized hydrocarbonate-calcium-magnesium mineral water (total mineralization 2 g/l) in bottles has been examined for therapeutic effects on metabolism in urolithiasis patients. The complex of biochemical blood and urine indices indicative of the renal function and concentration of lithogenic components was studied in 52 patients (age 23-68 years, 23 males and 29 females). Ten of them had nephrostoma. All the patients have undergone extracorporeal lithotripsy or other operations for renal or ureteric calculi. In nephrostoma patients urine samples were obtained both from nephrostoma and urinary bladder. The tests were made before the treatment and on the treatment day 3-5 and 10-12. TIB-2 mineral water was taken 3 times a day in a dose 200 ml 30-45 minutes before meal. The data were statistically processed. From the data obtained it was concluded that mineral water TIB-2 normalizes azotemia and clearance of endogenic creatinine, plasma values of calcium and uric acid, enhances urinary elimination of uric acid and calcium oxalate microcrystals that is TIB-2 improves metabolism of lithogenic substances and ions. Indications to drinking mineral water TIB-2 for urological patients are formulated.
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PMID:[Effects of mineral water TIB-2 on metabolic processes in urolithiasis patients]. 1118 1

Hypercalciuria is of continuing interest as a risk factor for kidney stones in children. We screened 592 healthy Turkish children (308 boys, 284 girls, aged 3 month-16 years) for hypercalciuria by measurement of urinary calcium/creatinine (UCa/Cr) ratio in the second-morning urine samples. Hypercalciuria was noted in 17 children (2.9%), 9 of them were boy and 8 of them were girl. Oral calcium-loading test could only be done in 7 children who were diagnosed as having hypercalciuria, and it revealed absorptive hypercalciuria in 2 cases and renal hypercalciuria in no cases. The frequency of a family history of urolithiasis in asymptomatic hypercalciuric children was 50%. Median UCa/Cr ratios and urinary magnesium/creatinine (UMg/Cr) ratios were 0.11 and 0.10 and the 97th percentiles were 0.32 and 0.23 respectively. The UCa/Cr ratio in second-morning urine samples was correlated with the UMg/Cr ratio (r = 0.44) and was independent of age and sex.
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PMID:Asymptomatic hypercalciuria: prevalence and metabolic characteristics. 1137 Apr 36

The evaluation of urinary oxalate excretion is one of the most important diagnostic methods in patients with urolithiasis and/or nephrocalcinosis. Since reliable 24-h urine collections are difficult to obtain in children, excretion ratios of oxalate over creatinine are increasingly being used from single urine specimens. The aim of the study was to determine the normal values of oxalate/creatinine ratios in the second morning urine sample in healthy school children. The study involved 109 children between 6 and 16 years of age. The results showed that the values of Ox/Cr ratios are decreased in older children and there was significant difference between children under and above 12 years of age (values of the 95th percentile--0.076 and 0.051 mmol/mmol respectively). The significant correlation between 24-hours urinary oxalic acid excretions and Ox/Cr ratios (r-0.756) was found. We conclude, that Ox/Cr ratio is valuable parameter for screening purposes in children.
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PMID:[Evaluation of oxalate/creatinine ratio in the second morning urine sample of health school children]. 1143 74

Commercial anti-uric acid diets for dogs may contain insufficient protein to sustain growth and lactation. In order to investigate the efficacy of an experimental purine-free diet moderately low in protein, its effect on urinary uric acid excretion was compared with that of a commercial dog food and a commercial low-protein anti-uric acid diet. The experimental diet, commercial dog food and commercial anti-uric acid diet contained 10.0, 12.8 and 5.0 g crude protein/MJ metabolizable energy, respectively. Twelve Dalmatian dogs were subjected to a 3 x 3 Latin square study. Although the plasma uric acid concentration was significantly lower when the dogs were fed either the commercial anti-uric diet (18.7 +/- 6.0 mumol/l, mean +/- SD, n = 12) or the experimental diet (19.2 +/- 8.3 mumol/l), when compared to the commercial dog food (29.2 +/- 11.1 mumol/l), no significant decrease of uric acid concentration in urine collected before the morning meal was seen. The average concentration of urinary uric acid was 60 mumol/l. There was a significant increase in the urea:creatinine ratio in urine when the dogs were fed the experimental diet compared to the commercial anti-uric acid diet, confirming that the experimental diet contained more protein. The experimental diet lowered plasma uric acid and was relatively high in protein and thus may be suitable for use in growing and lactating dogs to prevent ammonium urate urolithiasis.
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PMID:Comparison of the efficacy of two anti-uric acid diets in dalmatian dogs. 1170 41

In idiopathic calcium urolithiasis the relationships between oxypurines, accompanying proteins and glucose in urine and plasma, and the associated metabolic activity (MA) are unknown. To establish whether MA is related to these parameters and to calcium oxalate crystallization, or whether it reflects a reaction of metabolism to systemic insults was the major goal of the work. One hundred fifty one males were studied in three trials: trial 1 (n=130 patients) and trial 2 (n=24 patients) were cross-sectional; trial 3 included 11 patients and 14 controls). Mean age was 46 years (trials 1 and 2) and 29 years (trial 3). In trial 1 the stratification was based on the median urinary oxypurine excretion, in trial 2 on the median plasma oxypurine concentration (below or above: Low and High subgroups). No dietary restrictions were imposed, but standardized ambulatory laboratory testing was carried out. MA was quantitated by a score. Established analytical methods were used, except for oxypurine measurement which was done by high performance liquid chromatography. Patients with kidney stones tended to be overweight (body mass index >25 kg/(m)2) and to have fasting hyperglycemia. In trial 1 severe oxypurinuria, and especially severe xanthinuria, was associated with an increase in urinary pH, creatinine clearance, proteins, uric acid, malonedialdehyde (indicator of lipid peroxidation), systolic blood pressure, and with a decrease in plasma uric acid (synonymous with a decrease of antioxidant capacity). Tubular reabsorption of proteins and stone-forming substances was diminished but MA remained unchanged despite slightly increased calcium oxalate crystal growth. In trial 2 high adenosine and xanthine coincided with elevated systolic and diastolic blood pressure, high uric acid with high urinary malonedialdehyde, high summed oxypurines minus uric acid with an increase of diastolic blood pressure, glycemia and MA; urinary nitrate (indicator of systemic vasodilation) was unchanged. In trial 3 patients' oxypurinemia and proteinuria were normal, but body mass index, glycemia and insulinemia were increased. Urinary total protein, albumin and non-albumin proteins were positively predicted (multivariate regression analysis) by urinary xanthine, glucose and pH (trial 1); MA was positively (trial 3) or negatively (trial 2) predicted by urinary total protein. In calcium urolithiasis, a disorder of affluence, 1) oxypurinuria and proteinuria and oxypurinemia and MA appear causally linked, presumably via oxidant/antioxidant imbalance-induced renal tissue damage; 2) urinary proteins may act as inhibitors or promoters of stone-forming processes; 3) a stone-initiating role of impaired vasodilatation is conjectural; 4) overweight, obesity, mild glucosuria and hyperdynamic blood circulation are regular signs.
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PMID:Oxypurines, protein, glucose and the functional state of blood vasculature are markers of renal calcium stone-forming processes? Observations in men with idiopathic recurrent calcium urolithiasis. 1200 17

Cystinuria is an autosomal recessive defect in transepithelial transport of dibasic amino acids (e.g. cystine) which involves the proximal canaliculi, small intestine and central nervous system. It is the least common cause of nephrolithiasis, accounting for 1 to 3% of renal calculi. The natural course of the disease, characterised by recurrent stone formation, can frequently lead to renal failure, if left untreated. Until recently, treatment of cystinuria has been limited to symptomatic management including intensive hydration and urine alkalinisation. Different drugs that react with cystine to form soluble complexes have been used but their efficacy remains questionable. We present the case of a 6-year-old boy with severe, recurrent cystine urolithiasis treated with captopril. The diagnosis of cystine urolithiasis was established after a 3-year course of clinically apparent nephrolithiasis, characterised by stone passage. At the age of 5 years he underwent lithotripsy and nephrolithotomy for removal of staghorn calculi. Since then treatment with citrate and magnesium supplementation combined with captopril was introduced. After a follow-up of 12 months the patient remained stone-free. Urinary cystine decreased from 230 to 136 mg per gram creatinine. We conclude that captopril can be useful in the treatment of cystine urolithiasis in children.
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PMID:[Beneficial effect of angiotensin converting enzyme inhibitor treatment in severe cystine urolithiasis]. 1291 8


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