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

To address whether a renal tubular dysfunction is encountered in a particular patient subgroup with urolithiasis, the following parameters of tubular function were measured in urine taken in the morning from 214 stone formers after fasting: pH, excretion of lysozyme and gamma-glutamyl transferase (gamma-GT); fractional excretion (FE) of glucose, insulin, Mg, K, and HCO3 after an alkali loading; and the renal threshold for phosphate (TmP/GFR). The following diagnoses were made in the patient group: primary hyperparathyroidism (N = 8), medullary sponge kidneys (N = 21), hyperuricemia (N = 10), cystinuria (N = 2), struvite stone disease (N = 6), idiopathic hypercalciuria of the absorptive (N = 25), dietary (N = 69) or renal (N = 7) type, and normocalciuric idiopathic urolithiasis (N = 66). In 31% of the patients TmP/GFR was below 0.80 mmole/liter and in 13% of the patients, FE HCO3 after alkali loading was above normal. Urinary excretion of lysozyme and that of gamma-GT both were elevated in 17% of the patients. FE glucose, FE insulin, FE Mg, and FE K were elevated in 8, 9, 3, and 7% of the patients, respectively. This study demonstrates that a significant number of stone formers present with signs of renal tubular dysfunction, primarily involving the proximal tubule since apparent leaks of phosphate and of bicarbonate were most frequently encountered. The defects were not specific for a given etiologic group of patients; on the other hand, occurrence was related to the presence of large stones in the pyelocaliceal system at the time data were gathered. Taken together these data suggest that the tubulopathy in nephrolithiasis is the consequence rather than the cause of the stone.
 ...
PMID:Tubulopathy in nephrolithiasis: consequence rather than cause. 287 Dec 16

Urinary volume in 24-hour urine collections was examined in 50 children with hypercalciuria and urolithiasis or hematuria, 12 with idiopathic calcium oxalate urolithiasis and 36 healthy children. Urinary volume was 22.2 +/- 2.0 ml. per kg. per day in healthy children and 25.4 +/- 2.0 ml. per kg. per day in children with hypercalciuria, and it was similar in children with absorptive and renal hypercalciuria, and significantly lower in children with idiopathic calcium oxalate urolithiasis (12.2 +/- 1.4 ml. per kg. per day, p less than 0.001 from controls and children with hypercalciuria). Volume was not statistically different in hypercalciuric children with and without urolithiasis. Urinary sodium excretion in children with idiopathic calculi was not statistically different from controls. Urine osmolality was similar among the groups. Urinary volume represents a risk factor in children with idiopathic calcium oxalate urolithiasis, and increased fluid intake should be emphasized in such patients.
 ...
PMID:Urinary volume in children with urolithiasis. 292 90

Between July 1, 1980 and August 1984, 222 patients (112 men and 112 women) were referred to the Nephrology out-patient clinic of a hospital serving a population of about 250,000. Urolithiasis was revealed by renal colics in 71% of the cases; 64 patients (29%) had been suffering from one or several attacks of renal colic before the study period. The first clinical symptoms appeared between the ages of 20 and 59 years in over 80% of the cases, with a peak of incidence between 30 and 39 years. Calcium stone lithiasis was as frequent in women as in men; the sex ratio was around 1 whatever the patient's age at the onset of the disease; 65% of patients had hypercalciuria on an unrestricted diet. The annual incidence of urolithiasis (hospital cases) was 15.6 for 100,000 inhabitants, and the theoretical prevalence (distribution of new patients aged about 50) 0.8 for 100 inhabitants. These epidemiological data compared with those in the literature, show a relatively low incidence of urolithiasis, notably among men, in that particular region of France.
 ...
PMID:[Epidemiology of calcium calculi in a French region. Initial results after 4 years]. 294 11

Abnormalities in renal tubular function have been reported in adult patients with idiopathic renal hypercalciuria. To determine if such abnormalities are present early in the natural history of renal hypercalciuria, we evaluated renal tubular function in ten children with idiopathic renal hypercalciuria, aged 5-17 years. Seven of the children presented with urolithiasis and three with hematuria. Urinary calcium excretion ranged from 4 to 9 mg/kg per day, (5.2 +/- 0.5, mean +/- SEM) with a mean fasting urinary calcium to creatinine ration of 0.31 +/- 0.03. Studies described in this report were performed after 1 week of ingesting a diet containing 1,000 mg calcium, 3,000 mg sodium, and 100 mg purine. Clearance of creatinine ranged from 84 to 159 ml/min per 1.73 m2. Tm phosphate (mg/100 ml GFR) was normal in each child (mean 4.66 +/- 0.06 mg/100 ml GFR). Fractional excretion of uric acid, sodium and beta-2-microglobulin were also normal in each child. Serum bicarbonate concentrations ranged from 21.5 to 27 mEq/l with a mean of 24.4 +/- 0.5 mEq/l and all patients lowered urinary pH to less than 5.5. Hypotonic diuresis demonstrated normal free water clearance with a mean of 12.8 ml/min per 100 ml Cin. Distal sodium delivery and fractional distal sodium reabsorption were normal with a mean of 13.6 +/- 1.2% and 92.7 +/- 0.5%, respectively. Water deprivation studies demonstrated a range of maximum urinary osmolality from 711 to 1,020 mosmol/kg H2O with a mean of 864 +/- 34 mosmol/kg H2O. Seven healthy children, ingesting an identical study diet, concentrated their urine to a mean of 1,059 +/- 31 mosmol/kg h2O.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Renal function in children with idiopathic hypercalciuria. 315 15

1. Because urinary prostaglandin excretion could play a role in idiopathic hypercalciuria (IH), we studied the excretion of prostaglandin E (PGE), calcium and sodium at various urine flows in 21 patients (14 males) with urolithiasis and IH, seven stone formers (five males) with normal calciuria and 20 controls (11 males). Dietary composition was comparable and sodium intake was restricted to 100-120 mmol/day. 2. Analyses were performed on 30 min urine collections obtained after overnight water deprivation and during water diuresis. Male IH patients had increased levels of urinary PGE at all ranges of urine flow. PGE excretion correlated directly with urine flow in patients and controls, but the slope of this relationship in individual IH male patients was steeper than in controls (P less than 0.01). Calciuria correlated directly with urine output in patients with IH but not in controls. Calcium and sodium excretion were directly correlated (P less than 0.0001) in patients and controls. There were no significant differences between absorptive IH (seven patients) and renal IH (eight patients). There were no significant differences between stone formers with normocalciuria and control subjects. 3. The findings suggest that increased urinary PGE could play a role in the hypercalciuria syndrome, possibly by promoting natriuresis.
 ...
PMID:Increased urinary excretion of prostaglandin E in patients with idiopathic hypercalciuria. 320 91

The effect of mild high-calcium diet or regular-calcium diet on urinary calcium excretion, urinary oxalate excretion, urinary calcium/creatinine ratio, urinary oxalate/creatinine ratio, and the probability of being a stone former (PSF) were studied in 85 patients with idiopathic urolithiasis. Intake of high-calcium diet for 5-6 days reduced (p less than 0.01-p less than 0.001) urinary oxalate excretion, urinary oxalate/creatine ratio and PSF in patients with idiopathic hypercalciuria. Under the regular-calcium diet, administration of 60 mg/day of pyridoxal phosphate for 3 months lowered (p less than 0.05-p less than 0.01) urinary oxalate excretion, urinary oxalate/creatinine ratio and PSF in patients with idiopathic hypercalciuria alone. From these findings, intake of mild high-calcium diet appears to be beneficial to decrease the urinary oxalate excretion and PSF in patients with idiopathic hypercalciuria. Pyridoxal phosphate has all the features of suppressing such risk factors for stone formation in patients with idiopathic hypercalciuria.
 ...
PMID:Effect of high-calcium diet on urinary oxalate excretion in urinary stone formers. 321 61

Urolithiasis occurs less frequently in children than it does in adults living in contemporary industrialized nations. However, renal calculi continue to be identified with greater frequency in certain children: those who live in some areas of North America (e.g., the Southeastern United States), in those with relatively common metabolic disorders such as idiopathic hypercalciuria or with congenital urinary tract malformations, and in patients who have remained immobilized for long periods. Evaluation of children with suspected urolithiasis should include a careful history and physical examination to identify associated symptoms and signs and factors known to predispose to calculus formation, appropriate radiographic and blood studies, and timed urine collections. Appropriate management varies with etiology but should include maintaining adequate fluid intake, and long-term monitoring of the activity of the stone disease.
 ...
PMID:Urolithiasis in childhood. 329 22

According to the dynamics of the urinary calcium excretion mechanism, we have classified the patients with urolithiasis into 4 groups, namely group I (normocalciuria; urinary calcium excretion of 270 mg/day or less for male patients and 210 mg/day or less for female patients), group II (absorptive hypercalciuria; hypercalciuric with urinary calcium excretion of 200 mg/day or less under the low calcium diet), group III (renal hypercalciuria; hypercalciuric with urinary calcium excretion exceeds 200 mg/day even under a low calcium diet), and group IV (hyperparathyroidism; hypercalciuric patients as in group III with high serum calcium). Of the 97 stone formers, 77 were classified into group I, 9 into group II, 8 into group III and 3 into group IV. Both under the restricted diet and under the ambulatory free diet, urinary calcium excretion of groups II, III and IV was significantly higher than that of the group I patients. It was noteworthy, however, that some of the patients in group I excreted much calcium without restriction of their diet. Although no difference in excretion of oxalate, magnesium and phosphate was observed between the 4 groups, the patients in groups II, and III excreted more uric acid into their urine than group I patients. As for stone recurrence rate, no difference was noted between group I and group II, III or IV. Based on these findings, we conclude that hypercalciuria has no significant role in the stone forming mechanism. However, lowering of urinary calcium and other stone forming constituents is mandatory in preventing stone recurrence until the mechanism of stone formation is elucidated more precisely.
 ...
PMID:[Clinical studies on recurrence of urolithiasis. (2) Hypercalciuria and recurrence of urolithiasis]. 344 58

Ureteral calculi were found in 5 children who were receiving or had recently completed remission induction therapy for acute leukemia or lymphoma. All 5 patients had abdominal or back pain and 3 had gross hematuria. The diagnosis of urolithiasis was suggested by excretory urograms that showed obstructive uropathy (4 patients) and by computerized tomography scans that demonstrated ureterovesical obstruction (1 patient with acute renal failure and anuria). With a single exception the calculi were not associated with urinary tract infections. Chemical analyses in the 2 patients tested indicated that the stones were composed of calcium, in contrast to the uric acid and xanthine compositions of stones in earlier studies of patients with leukemia or lymphoma. Factors that might have predisposed our patients to calculi formation include corticosteroid therapy, immobilization owing to bed rest and urinary alkalization. Other possible contributing factors were urinary stasis (2 patients) and a familial tendency for renal calculi to develop. There was no evidence of idiopathic hypercalciuria in either patient tested. Prompt detection of urolithiasis in children undergoing induction chemotherapy for a malignant disease may avoid potentially serious consequences from urinary tract obstruction.
 ...
PMID:Urolithiasis in childhood acute leukemia and nonHodgkin's lymphoma. 346 63

Distal RTA is characterized by decreased distal renal tubular hydrogen ion secretion, decreased ability to acidify urine, hypercalciuria, hyperphosphaturia, hypocitraturia, and metabolic acidosis. Because of the resulting alterations in urine composition and pH, patients with distal RTA are predisposed to urolithiasis and renal calcification. Diagnosis of distal RTA is important because it is a potentially reversible disorder that, left untreated, may cause nephrocalcinosis, recurrent urolith formation, moderate to severe metabolic acidosis, and renal failure.
 ...
PMID:Canine distal renal tubular acidosis and urolithiasis. 348 13


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