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

The objective of the study was to update the evaluation and treatment of idiopathic urolithiasis in children in Western society. A secondary goal was to evaluate patients' compliance with high fluid intake. Over 2 years we prospectively studied children referred to us for idiopathic urolithiasis confirmed radiographically, excluding those with secondary disorders. A metabolic urinalysis, which included calcium, citrate, uric acid, oxalate, cystine, and creatinine, was ordered in all patients. Hypercalciuric patients were first treated with a low-sodium (Na)/high-potassium (K) diet and if hypercalciuria persisted, thiazides or potassium citrate was added. Follow-up ultrasound scans were scheduled every 10-12 months. Urine specific gravity (SG) measured during clinic visits was used to assess compliance with high fluid intake. A survey was sent to pediatric urologists and nephrologists to establish a recommended maximal SG value. Thirty healthy school-aged children served as controls. There were 45 children (24 males, 21 females) aged 10.4+/-2.0 years (median 11.0) studied. Stones were retrieved and analyzed in 28 showing calcium composition in all. Urine chemistry analysis was incomplete in 3, and in the others showed hypercalciuria in 33 (78.6%), hypocitraturia in 1 (2.4%), and normal values in 8 (19.0%). Treatment of 33 hypercalciuric patients consisted of diet alone in 13, potassium citrate in 17, thiazides in 2, and potassium citrate and thiazide in 1. All 33 achieved normocalciuria, apart from 2 who remained mildly hypercalciuric on diet alone. The 12 normocalciuric children were treated by diet modification alone. Follow-up ultrasonography showed no new stones in 36 of 39 patients. In 3, new stone formation was associated with recurrence of hypercalciuria after the potassium citrate dose was lowered or discontinued. Upon their first clinic visit, the urine SG of stone formers (1.021+/-0.007) was significantly higher than the maximum SG recommended by 18 physicians of 1.010+/-0.003 ( P<0.001), and not different from the SG in the control group (1.018+/-0.007). Urine SG at follow-up visits was unchanged in stone formers. We therefore propose a step-wise approach in evaluating children with idiopathic urolithiasis in Western society, in which first only urine calcium is studied. Only if urine calcium is normal, should other chemistries be studied. In many hypercalciuric children, low-Na/high-K diet alone is effective, while in most others the addition of potassium citrate is well tolerated, normalizes calciuria, and protects against new stone formation. Children rarely comply with the recommendation of high fluid intake.
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PMID:Evaluation and treatment of pediatric idiopathic urolithiasis-revisited. 1501 63

Oxalate induced renal calculi formation and the associated renal injury is thought to be caused by free radical mediated mechanisms. An in vivo model was used to investigate the effect of phycocyanin (from Spirulina platensis), a known antioxidant, against calcium oxalate urolithiasis. Male Wistar rats were divided into four groups. Hyperoxaluria was induced in two of these groups by intraperitoneal infusion of sodium oxalate (70 mg/kg) and a pretreatment of phycocyanin (100 mg/kg) as a single oral dosage was given, 1h prior to sodium oxalate infusion. An untreated control and drug control (phycocyanin alone) were also included in the study. We observed that phycocyanin significantly controlled the early biochemical changes in calcium oxalate stone formation. The antiurolithic nature of the drug was evaluated by the assessment of urinary risk factors and light microscopic observation of urinary crystals. Renal tubular damage as divulged by urinary marker enzymes (alkaline phosphatase, acid phosphatase and gamma-glutamyl transferase) and histopathological observations such as decreased tubulointerstitial, tubular dilatation and mononuclear inflammatory cells, indicated that renal damage was minimised in drug-pretreated group. Oxalate levels (P < 0.001) and lipid peroxidation (P < 0.001) in kidney tissue were significantly controlled by drug pretreatment, suggesting the ability of phycocyanin to quench the free radicals, thereby preventing the lipid peroxidation mediated tissue damage and oxalate entry. This accounts for the prevention of CaOx stones. Thus, the present analysis revealed the antioxidant and antiurolithic potential of phycocyanin thereby projecting it as a promising therapeutic agent against renal cell injury associated kidney stone formation.
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PMID:Prophylactic role of phycocyanin: a study of oxalate mediated renal cell injury. 1529 40

Urinary stone disease is frequent, and characterized by a high recurrence rate. Prevention of recurrent urolithiasis is possible using an appropriate diet with or without medications. Patients should be encouraged to have a high fluid intake. For an adult, urine volume should exceed 2000 ml/day. Diet modification should be done according to the various metabolic factors contributing to the formation of the stone (ie, hypercalciuria, hyperoxaluria, hypocitraturia, hyperuricuria, and so forth). Calcium intake should be around 1000 mg/day, protein intake limited to 1.2 g/kg/day, and salt intake kept to less than 100-150 mEq/jour. For uric acid urolithiasis, patient should limit uric acid intake to less than 500 mg/day. If these dietary manoeuvers fail, one can use thiazide diuretics to treat hypercalciuria, potassium citrate to correct hypocitraturia or sodium bicarbonate to alkalanize urine and prevent uric acid stone formation.
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PMID:[Medical treatment of urinary lithiasis]. 1549 68

Nutrient intake and urine composition were analyzed in calcium oxalate (CaOx)stone-forming and healthy control dogs to identify factors that contribute to CaOx urolithiasis. Stone-forming dogs had significantly lower intake of sodium, calcium, potassium, and phosphorus and significantly higher urinary calcium and oxalate concentrations, calcium excretion, and CaOx relative supersaturation (RSS). Feeding a diet used in the treatment of canine lower urinary tract disease for 1 month was associated with increased intake of moisture, sodium, and fat; reduced intake of potassium and calcium; and decreased urinary calcium and oxalate concentrations, calcium excretion, and CaOx RSS. No clinical signs of disease recurrence were observed in the stone-forming dogs when the diet was fed for an additional 11 months. The results suggest that hypercalciuria and hyperoxaluria contribute to the formation of CaOx uroliths in dogs and show that dietary modifications can alter this process.
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PMID:Nutrient intake and urine composition in calcium oxalate stone-forming dogs: comparison with healthy dogs and impact of dietary modification. 1557 54

The purpose of this study was to investigate the prophylactic and therapeutic effects of a hitherto untested preparation containing sodium citrate in the management of calcium oxalate urolithiasis. In this study, a host of calcium oxalate kidney stone risk factors was investigated using a randomised, placebo controlled, "within-patient" clinical trial. The trial involved four groups of subjects: healthy male controls, healthy female controls , calcium oxalate stone-forming males and calcium oxalate stone-forming females. There were 30 subjects in each group. Twenty subjects in each group ingested the preparation containing sodium citrate and ten subjects in each group ingested a placebo for 7 days. Collection of 24 h urines were carried out at baseline, at day 7 and day 10 (i.e. 3 days after suspension of drug/placebo ingestion). These were analysed for biochemical and physicochemical risk factors. They were also tested for their inhibitory properties in crystallization experiments. Data were statistically analyzed using analysis of variance (ANOVA). Key risk factors were significantly and beneficially altered across all groups after ingestion of the preparation. The pH and urinary citrate excretion increased while urinary oxalate and calcium excretions decreased, as did relative supersaturations of calcium oxalate and uric acid. In addition, inhibition of calcium oxalate crystallization increased. Beneficial carryover effects were observed for some risk factors. The results of this study have demonstrated, for the first time, that a sodium citrate-containing preparation favourably alters the risk factors for calcium oxalate urolithiasis.
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PMID:Prophylactic and therapeutic properties of a sodium citrate preparation in the management of calcium oxalate urolithiasis: randomized, placebo-controlled trial. 1587 Oct 14

Inappropriate dietary habits, overweight and lifestyle are suggested to contribute considerably to the increasing incidence and prevalence of urolithiasis. Numerous dietary factors can alter urinary composition and supersaturation, which can affect the process of stone formation. Dietary oxalate, calcium, protein, purines, sodium and ascorbic acid are known to be promoters of stone formation, whereas potassium and magnesium have been shown to be effective inhibitors. Although a high fluid supply has been demonstrated to decrease the incidence of urolithiasis, data from clinical and epidemiological studies on the effect of various beverages on the risk of urinary stone formation are conflicting. Continued research is warranted to clarify controversies concerning the impact of dietary calcium, oxalate, n-3 fatty acids, and phytate in calcium stone formation. Further randomized controlled studies should explore the long-term effects of dietary interventions in stone formers.
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PMID:Recent advances in nutritional research on urolithiasis. 1628 26

The assumption of oxidative stress as a mechanism in oxalate induced renal damage suggests that antioxidants might play a beneficial role against oxalate toxicity. An in vivo model was used to investigate the effect of C-phycocyanin (from aquatic micro algae; Spirulina spp.), a known antioxidant, against calcium oxalate urolithiasis. Hyperoxaluria was induced in two of the 4 groups of Wistar albino rats (n = 6 in each) by intraperitoneally injecting sodium oxalate (70 mg/kg body weight). A pretreatment of phycocyanin (100 mg/kg body weight) as a single oral dosage was given, one hour prior to oxalate challenge. An untreated control and drug control (phycocyanin alone) were employed. Phycocyanin administration resulted in a significant improvement (p < 0.001) in the thiol content of renal tissue and RBC lysate via increasing glutathione and reducing malondialdehyde levels in the plasma of oxalate induced rats (p < 0.001), indicating phycocyanin's antioxidant effect on oxalate mediated oxidative stress. Administering phycocyanin after oxalate treatment significantly increased catalase and glucose-6-phosphate dehydrogenase activity (p < 0.001) in RBC lysate suggesting phycocyanin as a free radical quencher. Assessing calcium oxalate crystal retention in renal tissue using polarization microscopy and renal ultrastructure by electron microscopy reveals normal features in phycocyanin-- pretreated groups. Thus the study presents positive pharmacological implications of phycocyanin against oxalate mediated nephronal impairment and warrants further work to tap this potential aquatic resource for its medicinal application.
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PMID:Oxalate mediated nephronal impairment and its inhibition by c-phycocyanin: a study on urolithic rats. 1647 83

Oxalic acid is found in dietary sources (such as coffee, tea, and chocolate) or is produced by the intestinal microflora from metabolic precursors, like ascorbic acid. In the human intestine, oxalate may combine with calcium, sodium, magnesium, or potassium to form less soluble salts, which can cause pathological disorders such as hyperoxaluria, urolithiasis, and renal failure in humans. In this study, an operon containing genes homologous to a formyl coenzyme A transferase gene (frc) and an oxalyl coenzyme A decarboxylase gene (oxc) was identified in the genome of the probiotic bacterium Lactobacillus acidophilus. Physiological analysis of a mutant harboring a deleted version of the frc gene confirmed that frc expression specifically improves survival in the presence of oxalic acid at pH 3.5 compared with the survival of the wild-type strain. Moreover, the frc mutant was unable to degrade oxalate. These genes, which have not previously been described in lactobacilli, appear to be responsible for oxalate degradation in this organism. Transcriptional analysis using cDNA microarrays and reverse transcription-quantitative PCR revealed that mildly acidic conditions were a prerequisite for frc and oxc transcription. As a consequence, oxalate-dependent induction of these genes occurred only in cells first adapted to subinhibitory concentrations of oxalate and then exposed to pH 5.5. Where genome information was available, other lactic acid bacteria were screened for frc and oxc genes. With the exception of Lactobacillus gasseri and Bifidobacterium lactis, none of the other strains harbored genes for oxalate utilization.
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PMID:Transcriptional and functional analysis of oxalyl-coenzyme A (CoA) decarboxylase and formyl-CoA transferase genes from Lactobacillus acidophilus. 1651 36

Hyperoxaluria is a risk factor for renal stones. It appears to be sustained by increased dietary load or increased intestinal absorption. The aim of this study was to evaluate whether oral administration of lactobacilli could prevent urolithiasis in stone-forming rats. Oxalate-degrading activities of lactobacilli were evaluated by measuring the oxalate level in a culture medium after inoculation with lactobacilli. Only the strains of Lactobacillus having oxalate-degrading activity were used. Sprague-Dawley rats were fed a powdered standard diet containing 3% sodium oxalate and/or received 100 mg/kg of celecoxib for the first 8 days by gavage, before or after the beginning of this experiment (groups with previous treatment or with co-treatment). Rats were sacrificed after 4 weeks and kidneys were harvested for the assay of crystal formation under a dissecting microscope. Twenty-four-hour urine collections were performed before kidney harvest. Only two strains, Lactobacillus casei HY2743 and L. casei HY7201 out of 31 strains of Lactobacillus were able to degrade oxalate. In both groups of co-treatment and previous treatment with L. casei HY2743 and L. casei HY7201, urine oxalate excretion decreased compared to the group without lactobacilli. The dissecting microscope examination of kidneys in the rats in two previous treatment groups and the co-treatment group with L. casei HY7201 showed less abundant crystals than control groups. Our results show that lactobacilli may be used as a potential therapeutic strategy in the prevention of urinary stones.
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PMID:Prevention of nephrolithiasis by Lactobacillus in stone-forming rats: a preliminary study. 1663 9

Gout refers to heterogeneous group of metabolic diseases characterized by production of deposits of sodium urate crystals in tissues. Gout manifests as acute gouty arthritis with classic clinical picture, or as chronic gouty arthropathy with periarticular and subcutaneous deposits of sodium urate crystals, i.e. tophi. As for kidney, gout is manifested as acute or chronic gouty nephropathy and urolithiasis. These manifestations occur separately or they are combined. Hyperuricemia of primary gout is caused rather by impaired renal secretion than overproduction of uric acid. Secondary hyperuricemia is associated with many pathological conditions; it is also connected with the use of various medicaments. Pathogenesis of gouty arthritis is critically influenced by sodium urate crystals and inflammatory processes they induce. Hyperuricemia is part of metabolic syndrome X which is associated with unanswered question of the relationship between uric acid and atherosclerosis. Although gouty arthritis is the most frequent inflammatory disease of joints in men over 50 years of age, it is often diagnosed and treated inadequately. On that account, the indication of long-term hypouricemic therapy should be always based on the following criteria: secondary causes of hyperuricemia have to be excluded first; frequency of gout attacks and the risk of their recurrence should be taken into consideration; then it is necessary to search for renal manifestations of gout; and last but not least, we should check whether there are any associated diseases classified in metabolic syndrome X.
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PMID:[Pathogenesis, diagnostics and therapy of gout]. 1696 17


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