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

Stress is a response state of the body which may be evoked by various stimuli. The effect of such stress factors on the quantitative composition of 24-hour urine in young male Wistar rats is examined using short, repetitive, weak electric impulses. Changes in body development and, in particular, of the absolute and relative increases in size and weight of the adrenal glands compared with control groups are used as evidence of the endured stress procedure. Three 24-hour urine groups can be clearly distinguished. While concentrations of calcium and sodium remain unaltered by the adaptation syndrome of the body, the concentrations of potassium and magnesium are clearly reduced during the first days of the stress period compared with the control group. Inorganic phosphorus and uric acid concentrations, however, are markedly increased during the experimental period. The combination of increased uric acid and inorganic phosphorus concentrations and reduced potassium and magnesium levels favors a disposition to urolithiasis since uric acid and inorganic phosphorus are recognized promoters, and potassium and magnesium are known inhibitors, of stone formation.
 ...
PMID:[Stress and urolithiasis]. 674 Aug 6

We induced the deposition of calcium oxalate crystals in rat kidney by intraperitoneal administration of 4-hydroxy-L-proline or sodium oxalate and studied the amounts and size distribution characteristics of the deposited crystals. Intravenous administration of sodium copper chlorophyllin inhibited the deposition and growth of calcium oxalate crystals induced by 4-hydroxy-L-proline or sodium oxalate. This finding may be of importance in calcium oxalate urolithiasis.
 ...
PMID:Effect of sodium copper chlorophyllin on the formation of calcium oxalate crystals in rat kidney. 705 81

The ratio of urinary calcium (UCa)/urinary creatinine (UCr) concentrations (mg/mg) during calcium loading has been used to diagnose hypercalciuric states in adults. The UCa/UCr ratios have been examined before and after an oral dose of calcium in 48 healthy children following five days of abstinence from dietary milk products. No differences in UCa/UCr ratios were observed between sexes, races, or age groups. UCa/UCr ratio before the calcium dose was 0.09 +/- 0.12 (mean +/- 2 SD) and increased to 0.12 +/- 0.15 in urine samples collected for four hours after the calcium load. A direct relationship between UCa/UCr ratio and urinary sodium (UNa)/UCr ratio was observed (r = .57, P less than .01). In six children, calcium loading studies were repeated without prior restriction of dietary calcium. Dietary calcium intake before the calcium loading had little effect upon UCa/UCr ratio before the calcium in these six children (0.068 vs 0.08); however, UCa/UCr values after the calcium load were significantly lower (0.08 vs 0.15) when no dietary calcium restriction preceded the calcium-loading study. These data may allow characterization of renal hypercalciuria and gastrointestinal hyperabsorption of calcium in children with urolithiasis.
 ...
PMID:Urinary excretion of calcium following an oral calcium loading test in healthy children. 707 15

The prevalence of urinary stones in a group of subjects living with a permanent ileostomy has been determined by intravenous urography. Thirty-nine of the ileostomists had previously suffered from ulcerative colitis, while the remaining 12 suffered from Crohn's disease. Four of the ileostomists who had had ulcerative colitis had urinary stones (10.3 per cent). These four subjects were all male, so that among the 23 male ileostomists who had had ulcerative colitis 17.4 per cent had urinary stones. No urinary stones were found in the ileostomists with Crohn's disease. Various factors thought to be associated with a liability to urolithiasis have been examined in the ileostomists and also in a control group of 39 healthy subjects matched for age and sex with the ileostomists who had had ulcerative colitis. The ileostomists commonly showed a reduced urinary volume, a low urinary sodium and magnesium content and low urinary pH. The ileostomists were much more prone to be hyperuricaemic than the controls, and hyperuricaemia was strongly associated with the presence of urinary stones.
 ...
PMID:Urinary stones in subjects with a permanent ileostomy. 712 51

The nucleation kinetics of calcium oxalate were studied in the presence and absence of sodium urate monohydrate crystalline material by three experimental measurements. These included analytical determinations of calcium and radiotracer analysis of oxalate in the metastable calcium oxalate solution phase and the independent detection of new crystal nuclei by solution turbidity measurements. None of the methods gave any evidence that sodium urate increases the induction time for nucleation of calcium oxalate, in contrast to previously published reports. These results are discussed in relation to the mechanisms advanced to explain the interdependency of hyperuricosuria and calcium oxalate urolithiasis.
 ...
PMID:Nucleation kinetics in the calcium oxalate-sodium urate monohydrate system. 729 92

Urinary glycosaminoglycans are selectively included into calcium oxalate (CaOx) crystals precipitated from whole human urine: The presence of glycosaminoglycans (GAGs) in the organic matrix of urinary stones, and their known effects on CaOx crystallization have prompted speculation regarding their role in CaOx urolithiasis. The aim of this study was to examine the involvement of GAGs in the early stages of CaOx crystallization in human urine. Urine samples were collected from healthy men and CaOx crystallization was induced by the addition of a sodium oxalate load. The crystals were harvested and demineralized, and the GAG content of the resulting extract analysed by cellulose acetate electrophoresis. Only one GAG, heparan sulphate (HS) was detected in the organic matrix of the crystals; chondroitin sulphate (ChS), the most abundant urinary GAG, was conspicuously absent. Further experiments, in which varying amounts of HS and ChS were added to ultrafiltered (10,000 Da) urine prior to induction of calcium oxalate crystallization, showed that ChS was included into the crystals only when HS was absent from the urine. It was concluded that the selective inclusion of GAGs into crystals and stones is a function related more to relative binding affinity than to ambient GAG concentration and that HS and ChS compete for specific binding sites on the crystal surface.
 ...
PMID:Urinary glycosaminoglycans are selectively included into calcium oxalate crystals precipitated from whole human urine. 774 54

Urine activity product ratios of uric acid, sodium urate, and ammonium urate and urinary excretion of metabolites were determined in 24-hour samples produced by 6 healthy Beagles during periods of consumption of a low-protein, casein-based diet (diet A) and a high-protein, meat-based diet (diet B). Comparison of effects of diet A with those of diet B revealed: significantly lower activity product ratios of uric acid (P = 0.025), sodium urate (P = 0.045), and ammonium urate (P = 0.0045); significantly lower 24-hour urinary excretion of uric acid (P = 0.002), ammonia (P = 0.0002), sodium (P = 0.01), calcium (P = 0.005), phosphorus (P = 0.0003), magnesium (P = 0.01), and oxalic acid (P = 0.004); significantly (P = 0.0001) higher 24-hour urine pH; and significantly (P = 0.01) lower endogenous creatinine clearance. These results suggest that consumption of diet A minimizes changes in urine that predispose dogs to uric acid, sodium urate, and ammonium urate urolithiasis.
 ...
PMID:Diet effect on activity product ratios of uric acid, sodium urate, and ammonium urate in urine formed by healthy beagles. 777

Examination of renal function have been carried out in sheep with acute prerenal (n = 6), renal (n = 15) or postrenal failure (n = 3), pyelocystitis (n = 4), and in cases of urolithiasis in rams (n = 16) and billy goats (n = 11) respectively. The calculation of parameters was done on the basis of the estimated weight dependent endogenous creatinine excretion. A control group of 56 healthy non pregnant or early pregnant (< 120th day of pregnancy) ewes have been used. The renal creatinine clearance was reduced and the absolute as well as the fractional renal water excretion was enhanced in all groups of sick animals. An elevated fractional excretion of sodium and phosphate could be seen as well. Functional disturbances could be observed in urolithiasis in like manner as in acute renal failure. There was proteinuria, glucosuria, excessive potassium excretion and often decreased plasma concentration of potassium in both syndromes. A hyperkalemia occurred only in the final state of urolithiasis. No clinical outcome of chronic nephropathies could be seen. Mortality of the described acute nephropathies was about 76%. The results of examination were suitable to control the course and restitution of renal function. They were not helpful for differential diagnosis and prognosis of acute renal failure.
 ...
PMID:[Clinical kidney function studies in sheep. III. Pathologic function changes in nephropathies of sheep and in urolithiasis of rams and billy goats]. 778 44

The serum and 24 hour urinary excretion levels of various lithogenic and inhibitory substances were assessed in 24 male patients with calcium stone and no previous history of urolithiasis and in 19 age-matched controls. Two groups did not differ significantly (P < 0.01) except in the excretions of sodium, citric acid (being higher in normals) and inorganic phosphate (being higher in patients). Fifty percent patients had hyperphosphaturia, 29.2% hypocitraturia, 20.8% hyperoxaluria and 16.7% hypercalciuria. The present data suggests that hypocitraturia in association with phosphaturia might be one of the main risk factors responsible for calcium urolithiasis in this area.
 ...
PMID:Is hypocitraturia associated with phosphaturia--a potential cause of calcium urolithiasis in first-time stone formers. 799 62

The aim of the study was to compare the renal citrate excretion and the degree of urine saturation with calcium oxalate in patients with active calcium oxalate urolithiasis and in healthy subjects under basal conditions and after alkalization. There were 20 women before menopause with calcium stone disease aged 33.5 +/- 7.1 in the first group and 20 healthy women aged 32.3 +/- 7.6 in the second one. Sodium bicarbonate was administrated intravenously in a dose 16.8 g during 2 h. 24h excretion of calcium, magnesium and citrate, the degree of urine saturation with calcium oxalate and pH of urine before and after alkalization were evaluated. Hypocitraturia occurred in 45% of patients under basal conditions. The degree of urine saturation with calcium oxalate was significantly higher in women with nephrolithiasis (p < 0.01). A significant increase of citrate excretion (p < 0.001) and a decrease of calcium excretion (p < 0.05) after alkalization took place in both groups. The degree of urine saturation with calcium oxalate decreased significantly in patients with urolithiasis and in healthy subjects. During acute alkalosis, induced by sodium bicarbonate, increase of citrate excretion was observed in patients with urolithiasis in spite of hypocitraturia under basal conditions. This indicates that kidney function following alkalization is normal in "stone kidney". Significantly decreased saturation of urine with calcium oxalate was due to the decrease of calcium excretion and the increase of citrate excretion. In conclusion, the results show that the use of alkalizing factors in prevention of recurrent calcium urolithiasis is justifiable.
 ...
PMID:[Effect of urine alkalization on excretion of renal citrate and degree of urine saturation with calcium oxalate in patients with calcium-oxalate urolithiasis and in healthy subjects]. 800 19


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>