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

Enteric hyperoxaluria and oxalate urolithiasis in patients with ileal resection seem to be caused by intestinal hyperabsorption of oxalate. The mechanism responsible for hyperabsorption of oxalate is not known. Intestinal transport of oxalic acid was therefore examined by an in vitro technique in rat intestine. Oxalic acid was absorbed by a mechanism of simple passive diffusion. The rate of absorption decreased from the colon to the duodenum (colon greater than ileum greater than jejunum greater than duodenum). Bile acids enhanced oxalic acid absorption in the large and small intestine and increased extracellular space; calcium, however, markedly decreased mucosal-serosal transport of oxalic acid. Cholestyramine known to reduce oxalate excretion in hyperuxaluria associated with ileal resection did not directly affect absorption of oxalic acid, but decreased the enhanced absorption of oxalic acid induced by bile acids. The results suggest that the beneficial therapeutic effect of cholestyramine in hyperuxaluria is rather mediated by its bile acid binding activity than by direct binding of oxalic acid.
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PMID:Intestinal oxalate absorption. I. Absorption in vitro. 41 86

The incidence of urolithiasis was registered in 87 patients with chronic inflammatory bowel disease and compared with that of renal oxalate excretion. All patients were studied while on a standardized diet with fixed amounts of fat, calcium, and oxalate. Pyelography had been performed in all. Nine, or 35%, of 26 hyperoxaluric patients had urolithiasis, compared with 14, or 23%, of 61 patients were normal renal oxalate excretion, the difference being statistically insignificant. No significant difference in urinary oxalate or urinary calcium in stone-formers as compared with non-stone-formers could be demonstrated. Oxalate was a more frequent component of calculi in patients with normal renal oxalate excretion than in patients with hyperoxalura. Thus, we were unable to demonstrate an increased incidence of urolithiasis in patients with hyperoxaluria compared with a control group with normal renal oxalate excretion. Our results cast doubt on the concept that enteric hyperoxaluria per se is the cause of stone diathesis in chronic inflammatory bowel disease.
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PMID:Urolithiasis and hyperoxaluria in chronic inflammatory bowel disease. 48 60

Oxalate-urolithiasis and hyperoxalaria have been reported to be a frequent complication in patients with small bowel disease, especially in patients with ileal resection due to Crohn's disease. Hyperabsorption of oxalate seems to be the main patholgenetic factor for "enteric" hyperoxalaria. Intestinal absorption and urinary excretion of oxalate was measured in patients with various gastrointestinal diseases after oral or rectal administration of 14C-oxalate. Kinetic data suggest that 14C-oxalate is absorbed in the small, the large bowel and the rectum as well. Oxalate absorption was decreased in patients with a colectomy and in active ulcerative colitis, but increased in patients with ileal resection, chronic liver disease, and steatorrhea due to chronic pancratitis or sprue. There existed a positive correlation between 14C-oxalate absorption and the amount of fecal fat excretion. The data suggest that hyperoxaluria and hyperabsorption of oxalate are not a specific finding in patients with bile acid malabsorption, but may occur too, in steatorrhea without alteration of bile acid metabolism.
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PMID:[Enteric hyperoxaluria. I. Intestinal oxalate absorption in gastrointestinal diseases (author's transl)]. 68 26

Excretion of oxalic acid in urine was measured in 28 healthy and 97 patients with gastrointestinal diseases. We found significantly higher values in the following groups: patients after resection of parts of the small intestine, patients with sprue and other diseases with malabsorption, patients with M. Crohn of the small intestine, colitis ulcerosa and granulomatosa, patients with chronical diseases of the pancreas gland and patients with cirrhosis of the liver. In 4 patients after resection of parts of the small intestine or pancreas urolithiasis could be verified. Reduction of fat and food without ballast reduced the excretion of oxalic acid in urine. Hyperoxaluria correlied significantly with the following parameters: excretion of fat in feces, exhalation of 14CO2 in the glykocholate breath test, resorption of vit. B12 and the length of resected small intestine. This form of hyperoxaluria is caused by hyperresorption of oxalic acid from food. The mechanism of this hyperresorption is not clarified yet, an important factor seems to be ill resorption of fat.
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PMID:[Hyperoxaluria in intestinal and liver diseases]. 83 13

Five patients with jejunoileal shunt for morbid obesity in whom postshunt hyperoxaluria and recurrent urinary tract calculi developed are presented. All the stones were composed of calcium oxalate. The twenty-four hour urinary oxalic acid levels were also elevated in twenty of twenty-six patients who had had jejunoileal shunt for six months or longer. No correlation was present between urolithiasis and the degree of hyperoxaluria.
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PMID:Hyperoxaluria and urinary tract calculi after jejunoileal bypass. 111 99

Oxalate urolithiasis in male rats was experimentally induced by feeding a basal diet composed of Purina laboratory chow and 3 per cent glycolic acid. When this basal oxalate calculus-producing diet containing 10 per cent alanine was fed to rats, the incidence of oxalate urolithiasis was markedly reduced. Moreover, when Purina laboratory chow containing 10 per cent alanine was fed to rats which had been on the calculi-producing basal diet for 4 weeks, it appeared that most uroliths were dissolved. Excess intake of alanine increased the concentration of alanine in urine and this apparently aided in the prevention and treatment of urolithiasis.
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PMID:Control of oxalate urolithiasis by DL-alanine. 118 33

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

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

Urinary concentrations of certain biochemical constituents that play an active role in stone formation were determined in 2 h urine collections in healthy men and women (at four phases of the estrous cycle) to elucidate the sex difference in the incidence of urolithiasis. The excretion of the lithogenic substance, calcium, was higher in men than in women during phase I (p less than 0.01) and phase II (p less than 0.05) of the estrous cycle. Oxalate excretion was marginally elevated in men compared to women during each phase. Urinary citrate was lower in men compared to women during each phase (p less than 0.05). Uric acid excretion was lower (p less than 0.05) in men compared with phase I and phase III in women. Estrous phase-related alterations were also observed in the excretion of calcium and citrate in women. The data suggest that low concentrations of calcium and oxalate with an elevated citrate excretion might be responsible for the reduced risk of stone disease in women compared to men.
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PMID:Urinary composition in men and women and the risk of urolithiasis. 177 89

Because human urine contains various substances which can affect each other, it is quite difficult to clarify the mechanism of formation of calcium oxalate (CaOx) crystal in urine. The authors recently determined CaOx crystalline content and the concentrations of other substances in urine specimens from patients with urolithiasis and healthy volunteers, and subjected the data to multi-regressive analysis for the purpose of assessing the effect of these urinary substances on CaOx crystal formation. 1. In analysis of urine from patients with urolithiasis, the partial correlation coefficients of CaOx crystal formation with oxalic acid, sodium, calcium, uric acid magnesium were 0.67, 0.28, 0.18, and -0.10, respectively. The formula of regression was as follows: Amount of CaOx crystal (X 10(6) microns3/ml) = 3.59 X 10(-2) Ox (mM/L) + 4.72 X 10(-3) Ca (mM/L) + 4.52 X 10(-3) Na (mM/L) + 2.51 X 10(-4) UA (mM/L) -2.39 X 10(-2) Mg (mM/L) -1.65. The multiple correlation coefficient was 0.759. Thus, in patients with urolithiasis, urinary crystal formation was most dependent on the oxalic acid level, sodium, calcium, and uric acid were found to promote crystal formation, while magnesium to suppress it. 2. In analysis of urine from healthy volunteers, the partial correlation coefficients of CaOx crystal formation with oxalic acid and inorganic phosphorus were 0.51 and -0.24, respectively. The formula of regression was as follows: Amount of CaOx crystal (X 10(6) microns3/ml) = 1.91 X 10(-2) Ox (mM/L) -3.43 X 10(-4) P (mM/L) +0.29 The multiple correlation coefficient was 0.525.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Studies on calcium oxalate crystal formation in urolithiasis. Multi-regressive analysis of urinary CaOx crystalline volumes and the effects of urinary various substances on CaOx crystal formation]. 187 73


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