Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0451641 (urolithiasis)
 3,973 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To better define the relative role of metabolic factors in the recurrence of stone formation, we studied the 24-hour urinary excretion of calcium (uCa), citrate (uCit), oxalic acid (uOx) and uric acid (uUa) in 73 male patients with primary calcium oxalate urolithiasis. According to the episodes of stone formation per year, we identified 51 recurrent stone formers (RSF) and 22 single stone formers (SSF). 20 normal adult males constituted the control group (C). uCa and uOx were higher in RSF than in C, but quite similar in SSF and RSF. The only difference between RSF and SSF was uCit, significantly lower (2.06 +/- 1.04 mmol/24 h) in RSF than in SSF (3.22 +/- 1.18 mmol/24 h, p less than 0.001) and in C (3.42 +/- 1.33 mmol/24 h, p less than 0.001). Hypocitraturia (uCit less than 1.5 mmol/24 h) was found in 16 of 51 RSF (31.4%) and in 1 of 22 SSF (4.5%). These data confirm that high levels of uCa and uOx represent a risk factor for lithogenesis, but also strongly indicate the low uCit excretion as the most important urinary abnormality accounting for the recurrence of calcium oxalate stones.
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PMID:Low urine citrate excretion as main risk factor for recurrent calcium oxalate nephrolithiasis in males. 152 45

The effect of a promoter (calcium) and an inhibitor (magnesium) of urolithiasis was spectrophotometrically studied on urokinase (0.45 IU) and sialidase (5 mM). Although these mineral did not affect the sialidase activity, total inhibition of urokinase activity was observed with either 0.05 M calcium chloride or 0.1 M magnesium chloride. This observation might explain why calcium and magnesium respectively function as a promoter and an inhibitor of stone formation.
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PMID:The effect of calcium and magnesium ions on urinary urokinase and sialidase activity. 153 Dec 76

Oxalic acid seems to play a far greater role in the formation of calcium oxalate stone than calcium. Three grams of calcium lactate and 3 g of sodium potassium citrate were administered to 46 urolithiasis patients, whose stones were mainly composed of calcium oxalate. Urinary oxalate level was reduced significantly without raising urinary calcium level by the administration of the two drugs for two weeks. The reduction of urinary oxalic acid was particularly remarkable in patients without hypercalciuria. The mechanism of action of these drugs was discussed.
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PMID:Reduction of urinary oxalate by combined calcium and citrate administration without increase in urinary calcium oxalate stone formers. 154 Oct 59

In idiopathic recurrent calcium urolithiasis (RCU) in men (n = 37) the metabolic effects of oral tripotassium citrate (PC) were investigated in a longitudinal field study. The patients were either normo- (n = 22) or hypocitraturic (n = 15). Laboratory examinations were performed before, and after 3, 6, and more than 12 months of medication. Acceptance of PC was poor, mainly because of the salty taste of the tablet preparation chosen, and a number of participants dropped out of the study. In the remaining participants, compliance was acceptable when evaluated on the basis of urinary potassium and undesired side effects did not occur. In the short term (up to 3 months), PC evoked compensated metabolic alkalosis (pH and citrate in urine increased; blood gases remained normal), a drop in urinary calcium, together with increasing oxaluria, hydroxyapatite supersaturation, and calcium phosphate crystalluria. In the long term (greater than 12 months) PC urinary pH and citrate "dissociated", in that pH returned to pretreatment baseline values, whereas citrate stayed at high levels. In normocitraturics but not in hypocitraturics, urinary urea and sodium increased with PC. Hypocitraturics appeared to be less sensitive to the effects of PC, as reflected by the relatively small rise in urinary pH and citrate, and they maintained higher mean levels of indicators of bone metabolism (osteocalcin, alkaline phosphatase, hydroxyproline) despite continuous administration of PC. It was concluded that although the PC tablet preparation was effective it may not be an ideal anti-stone drug treatment in the long term and that, especially in hypocitraturics, the intrinsic metabolic defect of RCU may not be sufficiently well controlled.
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PMID:Citrate and recurrent idiopathic calcium urolithiasis. A longitudinal pilot study on the metabolic effects of oral potassium citrate administered over the short-, medium- and long-term medication of male stone patients. 155 90

A retrospective study was done on the nature and degree of crystalluria in fasting and postprandial urine in patients with recurrent idiopathic calcium urolithiasis (RCU) for whom stone analysis was available. RCU was stratified into subgroups in accordance with stone analysis. The crystals were obtained and identified using a filter technique and polarization microscopy, respectively. Crystalluria score, relative saturation products (RSPs), and low-molecular-weight inhibitors were assessed. Calcium oxalate crystals were never observed in either male or female patients with stones composed exclusively of calcium oxalate, and only sporadically in patients with mixed stones (the additional component was calcium phosphate in most cases). Other crystalluria phases, such as amorphous calcium phosphate, a urate-containing phase, and a phase presenting as spherolytic particles, were slightly more frequent in patients with mixed stones. In contrast to crystalluria, RSPs and inhibitors differed in male and female patients, suggesting that crystalluria may not be under the exclusive control of these factors. The following conclusions were reached. (1) Calcium oxalate crystalluria is absent from RCU with pure calcium oxalate stones; hence, calcium oxalate crystalluria does not qualify as a diagnostic aid. (2) The co-existence of the isotropic phase and mixed stones may indicate that the formation of these concretions is characteristic for a major RCU subgroup. (3) On the basis of clinical chemistry and physicochemical data in urine and of crystalluria, it appears that the pathogenesis of RCU differs in male and female subjects.
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PMID:Crystalluria in idiopathic recurrent calcium urolithiasis. Dependence on stone composition. 155 91

Studies in experimental animals showed that vitamin A deficiency enhanced the severity of urinary calculi disease. In India, children with low socioeconomic status are the major victims of bladder stone disease, and vitamin A deficiency is also more prevalent among these children. However, no systematic study is available to correlate the vitamin A-deficient status of children with their predisposition to urinary calculi disease. Vitamin A-deficient and normal boys were the subjects of this study. Twenty-four-hour samples of urine were collected from all the children at the beginning of the study and after normalizing the vitamin A status of the deficient children. Important risk factors were estimated in urine. Plasma vitamin A levels were also measured in these children. Among the deficient group, only children with plasma vitamin A levels of 15 micrograms and lower exhibited calcium oxalate crystalluria. Most importantly, abnormal crystalluria was observed in all children whose plasma vitamin A levels were 13 micrograms/dl or less. Compared to normal children the urine of vitamin A-deficient children showed the following changes: (a) reduced concentration of crystal growth inhibitors, namely citrate and glycosaminoglycans; (b) a decline in inhibitory activity toward calcium oxalate crystal growth; and (c) enhanced excretion of high risk factors, namely calcium and oxalate. Correction of vitamin A status normalized the above abnormal properties of urine. The results of this study strongly support the hypothesis that the vitamin A-deficient state is one of the factors that can enhance the risk of urolithiasis in susceptible populations.
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PMID:Contribution of vitamin A deficiency to calculogenic risk factors of urine: studies in children. 156 52

The data from literature on the problem of urolithiasis pathogenesis have been analyzed. A physico-chemical theory (hypothesis) of the possible mechanism of lithogenesis in urinary tracts is suggested on the basis of results from studies of surface tension, light transmission and crystallization of urine depending on the concentration of exogenous calcium chloride in it.
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PMID:[The colloidal-crystalline properties of the urine and stone formation]. 156 2

A total of 15 patients with unilateral nephrostomy tubes after extracorporeal shock wave lithotripsy received either 0 (placebo), 100, 500, 1,000 or 2,000 mg. ascorbic acid on days 2 and 3 postoperatively. Before and after administration, successive 6-hour urine specimens were collected from the nephrostomy tube and from the contralateral kidney directly into a preservative to stabilize ascorbic acid and oxalate. In 1 patient in each group preservative was omitted from the collection pouch. Urinary oxalate was then measured enzymatically after removal of ascorbic acid with sodium nitrite. Preservatives proved necessary for full recovery of analyte. At doses of 500 mg. or more of ascorbic acid there was a statistically significant increase in urinary oxalate equivalent to 1.2 to 1.8% of the millimoles of ascorbate administered. This represented an increase in urinary oxalate excretion of 6 to 13 mg. per day per 1,000 mg. ascorbic acid supplement. This amount would increase the risk of calcium oxalate urolithiasis.
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PMID:Ascorbic acid overdosing: a risk factor for calcium oxalate nephrolithiasis. 848 36

Population based data on 24-h urinary excretion of calcium, oxalate, magnesium, phosphate, uric acid and creatinine were collected from 220 children (aged 3-16 years) living in Cimitile, Campania, southern Italy. Mean excretion rates for 7 days were correlated with age, body weight, body mass index and height. The prevalence of hypercalciuria (greater than 4 mg/kg body weight) and of hyperoxaluria (greater than 60 mg/day) were 9.1% and 1.8%, respectively. The same 20 children were also identified as hypercalciuric when a calcium/creatinine ratio of greater than 0.15 was considered. No significant differences between boys and girls were found in the urinary excretion of the five constituents implicated in urolithiasis. The study data provide additional childhood reference values for urinary excretion of compounds related to stone formation.
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PMID:Population based data on urinary excretion of calcium, magnesium, oxalate, phosphate and uric acid in children from Cimitile (southern Italy). 157 Dec 11

Pathogenesis of urolithiasis cannot be explained only by metabolic disorder. In the present study, morphologic differences of the renal pelvic-caliceal system (PCS) were examined on both the stone and normal sides in calcium-containing stone formers. The results indicated that as compared to the normal side, the urine flow in the PCS was stagnant or not straight on the stone side even in the same individual, showing unfavorable conditions for stone formation. It is therefore considered that morphologic disorders of the urinary tract may be one of the causes for stone formation.
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PMID:Influence of morphologic factors on calcium-containing stone formation. 158 16


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