Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020438 (hypercalciuria)
 2,502 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A Ca kinetic study with a four-compartment model being fitted to radioisotope and balance data using the CONSAM (conversational, simulation, analysis, and modeling) computer program was conducted to examine the effects of dietary cation-anion balance, calculated as milliequivalents [(Na + K] - (Cl + S)]. Twelve crossbred wethers were used as eucalcemic control (period 1); then Ca loss during lactation was simulated by continuous infusion of ethylene glycol tetraacetate (period 2). Dietary cation-anion balance was manipulated by supplementation of various mineral salts and was +339, +35, and -127 meq of kg DM-1 during period 1 and +429, +68, and -147 meq of kg DM-1 during period 2 for control and two treatments, respectively. Animals responded to the simulated lactational Ca loss (period 2) by increasing true intestinal absorption of Ca and bone resorption and by reducing Ca accretion by bone. No difference was observed in concentration of total Ca in plasma, but treatments produced increased concentration of plasma ionized Ca during both periods. Both treatments produced hypercalciuria during both periods, and the lowest cation-anion balance increased true intestinal absorption of Ca and reduced bone accretion during period 2. The size of total exchangeable Ca pool did not differ between treatments or periods, but amount of Ca movement between the pools increased with the intermediate cation-anion balance during period 1 and with both treatments during period 2 compared with control. These results indicated that feeding reduced cation-anion balance diets increased Ca flux through the exchangeable Ca pool with no changes in the size of the pool, particularly when Ca demand was increased.
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PMID:Effects of reducing dietary cation-anion balance on calcium kinetics in sheep. 178 93

The circadian rhythm of urinary total hydroxyproline (THP) excretion was determined in matched groups of ten male idiopathic calcium stoneformers and ten normal subjects in order to determine whether enhanced resorption of bone might contribute to hypercalciuria in these patients. THP increased progressively in normal subjects in successive eight-hour urine collections from period 1 (8 AM to 4 PM) to period 3 (12 midnight to 8 AM), the nocturnal high level in period 3 being significantly greater than in period 1 (P less than 0.01) and in period 2 (P less than 0.05). By contrast, no significant circadian rhythm was observed in THP excretion in the stoneformers. Their THP excretion was similar to that of normal subjects in period 3, but was significantly higher than that of normal subjects in period 1 (THP/creatinine ratio(mg/mg): 0.026 +/- 0.003 v 0.017 +/- 0.001; P less than 0.05. Indices of parathyroid hormone activity were not significantly different between stoneformers and normal subjects; mean serum 1,25(OH)2 vitamin D levels were higher in the stoneformers than the normal subjects (44 v 37 pg/mL) but the difference was not significant (P greater than 0.05). These studies suggest that increased bone turnover may contribute to hypercalciuria in these calcium stoneformers.
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PMID:Bone resorption and hypercalciuria in calcium stoneformers. 301 44

Effects of subclinical metabolic acid-base disturbances, caused by dietary fixed ion imbalances on kinetics of calcium (Ca) metabolism were examined in eucalcemic caprine does (period 1) and does during simulated lactational Ca loss (period 2). In both experiments, Ca balance data and serial blood, fecal and urine samples were collected after an iv injection of 45Ca. In period 2, lactational Ca loss was simulated by continuous infusion of ethylene glycol-bis (beta-amino ethyl ether)N,N,N'N'-tetraacetic acid (EGTA) to standardize the loss of Ca among goats. The data were fit to a four-compartment model of Ca metabolism. In period 1, fixed anion excess, [sodium + potassium - chloride] = -2 meq/100 g diet dry matter (ANEX) increased urinary Ca excretion relative to fixed cation excess, [sodium + potassium - chloride] = 71 meq/100 g diet dry matter (CATEX). Consequently, rates of Ca absorption and resorption were elevated in goats made acidotic by dietary fixed anion excess. During period 2 (EGTA infusion), urinary Ca loss was elevated to similar levels in goats fed ANEX and CATEX, but Ca absorption remained higher in goats fed ANEX. Consequently, size of the exchangeable Ca pool, accretion rate and balance across bone were higher in these goats. Fixed anion excesses (found in corn silage and grains) cause subclinical metabolic acidosis, which elevates rates of Ca absorption but does not affect size of the exchangeable Ca pool. Fixed cation excesses (associated with diets containing alfalfa and buffers) cause subclinical metabolic alkalosis, which diminishes Ca absorption and urinary Ca excretion. Acidosis-induced hypercalciuria is the metabolic cost of maintaining high prepartum Ca absorption rates and high flux of Ca through the exchangeable Ca pool that may aid in adjustment to sudden Ca losses at parturition.
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PMID:Effects of acid-base disturbances caused by differences in dietary fixed ion balance on kinetics of calcium metabolism in ruminants with high calcium demand. 336 5

Calcium phosphate (CaP) stones account for about 15% of all urinary stones, with a marked female preponderance, and reflect a wide diversity of etiology. Variation of the relative prevalence of CaP urolithiasis over time is disputed, and relevance of CaP stone analysis for etiologic diagnosis is underestimated or even negated. Based on the analysis of more than 50,000 stones over the past three decades, we evaluated the changes in the relative proportion of CaP stones between 1980-1989 (period 1) and 2000-2009 (period 2). In addition, using morphologic examination combined with Fourier-transform infrared analysis, we assessed the associations between CaP stone analysis and etiopathogenic factors. Between periods 1 and 2, the overall proportion of struvite-free stones remained essentially unchanged (11.6 vs. 11.1%), with a decreasing proportion of carbapatite stones (10.6 vs. 8.4%, p < 0.001) and a rising proportion of brushite stones (0.8 vs. 2.2%, p < 0.001). Hypercalciuria was associated with 87% of brushite, and 60% of carbapatite stones. Urinary tract infection was associated with presence of minor amounts of struvite and/or with a carbonation rate of carbapatite > 15%. In CaP stones associated with primary hyperparathyroidism, the main component was carbapatite in 66.9% and brushite in 29.1% of cases. Distal renal tubular acidosis was always associated with carbapatite stones exhibiting a peculiar, virtually pathognomonic, morphology. In conclusion, comprehensive analysis of stones involving morphologic examination is of clinical relevance for improved etiologic evaluation of patients with CaP urolithiasis.
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PMID:Composition and morphology of phosphate stones and their relation with etiology. 2096 36