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

Three types of hypercalciuria are described; their existence and frequent association with calcium urolithiasis in humans are accepted. Various dietary factors such as minerals, electrolytes, fluids, vitamin D, carbohydrates, proteins are discussed with regard to their ability to alter the nature and the degree of calcium excretion following their ingestion. It is emphasised that at present we have only limited knowledge on the chain of events linking calorie intake and the response of the kidney.
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PMID:A survey of calcium urolithiasis in normocalcemic hypercalciuria: possible role of nutrients and diet-mediated factors. 38 96

It is generally accepted that acromegaly is often associated with hypercalciuria, but there are few reports on the frequency and the mechanisms of urolithiasis. Recently we consecutively experienced 2 cases of acromegaly with urolithiasis, and these experiences made us investigate the association between urolithiasis and acromegaly. Among 18 acromegalies from 1977 to March 1990 (10 males, 8 females, 24-64 years old), 13 cases (72%) fulfilled the criteria of hypercalciuria (urinary calcium (u-Ca) greater than or equal to 200 mg/day or u-Ca/urinary creatinine (u-Ca/u-Cr) greater than or equal to 0.15), and 7 cases (39%) suffered from urolithiasis that was diagnosed by KUB (4 cases) or X-ray computed tomography (CT) (3 cases). Especially in the last 2 years, 5 out of 7 cases (71%) were complicated with urolithiasis and all 7 cases were associated with hypercalciuria. These results suggest that hypercalciuria and urolithiasis are both much more frequent than previously reported. In 6 cases who were treated by pituitary adenomectomy from 1988-1989 (4 males, 2 females, 24-59 years old), we examined Ca metabolism before and after operation. Before operation, the levels of serum growth hormone (GH), u-Ca (mg/day), u-Ca/u-Cr (in all cases) and plasma somatomedin-C (Sm-C) (in 4 cases) were increased above the normal range. To determine the etiology of hypercalciuria, we performed the oral Ca load test under restriction of Ca (400 mg/day) and P (650 mg/day) intake. The results suggested that the hypercalciuria might be mainly due to the increased absorption of Ca from the intestine (so-called "Absorptive hypercalciuria"). However, the levels of serum vitamin D (Vit. D) metabolites were all within the normal range before operation. After operation, GH and u-Ca/u-Cr (in 5 cases) and u-Ca (mg/day) (in all cases) decreased significantly compared with before operation, and the levels of Sm-C (in all cases), serum 25-(OH)D3, 1 alpha, 25-(OH)2D3 (in 4 cases) and 24,25-(OH)2D3 (in 3 cases) were also reduced after operation. Surprisingly, u-Ca and u-Ca/u-Cr normalized only in 4 cases who showed a reduction in 1 alpha, 25-(OH)2D3 levels after operation, although there were no correlations between u-Ca (mg/day) or u-Ca/u-Cr and 1 alpha, 25-(OH)2D3. Significant correlations were found between u-Ca (mg/day) or u-Ca/u-Cr and Sm-C. The parathyroid function evaluated by the rapid Ca infusion test or nephrogenous cyclic adenosine monophosphate (NcAMP) was normal before and after operation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[The frequency and mechanisms of urolithiasis in acromegaly]. 188 13

In this paper, urolithiasis is reviewed from the standpoint of analytical epidemiology, which examines a statistical association between a given disease and a hypothesized factor with an aim of inferring its causality. Factors incriminated epidemiologically for stone formation include age, sex, occupation, social class (level of affluence), season of the year and climate, dietary and fluid intake and genetic prodisposition. Since some of these factors are interlinked, they are broadly classified into five categories and epidemiologically looked over here. Genetic predisposition is essentially endorsed by the more frequent episodes of stone formation in the family members of stone formers, as compared to non-stone formers. Nevertheless, some environmental factors (likely to be dietary habits) shared by family members are believed to be relatively more important than genetic predisposition. A hot, sunny climate may influence stone formation through inducing dehydration with increased perspiration and increased solute concentration with decreased urine volume, coupled with inadequate liquid intake, and possibly through the greater exposure to ultraviolet radiation which eventually results in an increased vitamin D production, conceivably correlated with seasonal variation in calcium and oxalate excretion to the urine. Urinary tract infections are importantly involved in the formation of magnesium ammonium phosphate stones in particular. The association with regional water hardness is still in controversy. Excessive intake of coffee, tea and alcoholic beverages seemingly increase the risk of renal calculi, though not consistently confirmed. Many dietary elements have been suggested by numerous clinical and experimental investigations, but a few elements are substantiated by analytical epidemiological investigations. An increased ingestion of animal protein and sugar and a decreased ingestion of dietary fiber and green-yellow vegetables are linked with the higher probability of stone formation in the industrialized countries. No trace elements in foodstuffs and liquids have been epidemiologically associated. The dietary guidelines for avoiding stone formation and/or recurrence are summarized in this paper, including other daily-life recommendations.
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PMID:[Analytical epidemiology of urolithiasis]. 267 78

We found that a few patients with urolithiasis had normal parathyroid hormone levels but high cyclic AMP excretion. The purpose of this paper was to study the endocrinological mechanism. Male rats were given intraperitoneally dibutyryl cyclic AMP (DBcAMP), a derivative of cyclic AMP, per 100 gm of body weight for 50 days. Feed and water were supplied ad libitum. Crystal formation or calcification in mainly the dystal tubules and collecting system were found in 3 out of 10 rats, and renal calcium stones in 2 rats. The cyclic AMP of the renal parenchyma, especially the renal medulla, was elevated by more than 100 times after DBcAMP administration. Serum calcium levels, urinary calcium and phosphate excretion, and the adrenaline levels of the renal parenchyma were significantly increased. Serum parathyroid hormone was slightly enhanced, but vitamin D and the noradrenaline levels of the renal parenchyma were not changed. Based on these findings, it is suspected that stone formation in rats injected DBcAMP occurs through the action of DBcAMP on the renal tubules to increase urinary calcium excretion and to make renal stones as a form of primary hyperparathyroidism.
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PMID:[Studies on the endocrinological metabolism of the parathyroid. I. The production of renal calcinosis by cyclic AMP injection in rat]. 300 37

Hypercalciuria is a major cause of urolithiasis in adults and has reached increasing attendance in childhood. Traditionally urinary excretion of calcium is evaluated by 24-hour urine collection. Previous reports proposed the urinary calcium/urinary creatinine ratio (Ca/Cr-ratio) to diagnose hypercalciuric states. In 10 children with normocalciuria and 8 children with hypercalciuria the values of calcium excretion and Ca/Cr-ratio in a 24-hour urine collection were compared. 40 analyses showed a significant correlation (p = 0.001, r = 0.91) and hypercalciuria (urinary calcium greater than 4 mg/kg/day) is present if the Ca/Cr-ratio exceeds 0.23 (mg/mg). In 10 of the 18 patients the Ca/Cr-ratio of the 24-hour collection was compared with the Ca/Cr-ratio of a random urine sample collected 3 hours after breakfast. No significant difference was present. In 9 of 10 patients the correct diagnosis (normocalciuria or hypercalciuria) was possible by evaluation of this random urine sample. Our studies indicate that the evaluation of Ca/Cr-ratio in a random urine sample is a simple and reliable method to detect hypercalciuria and should be performed in all children with urolithiasis or unexplained hematuria. It is also a simple test for early detection of hypercalciuria in patients with long-term administration of vitamin D metabolites.
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PMID:[Use of the calcium-creatinine ratio in diagnosis and therapy]. 368 17

Six children with idiopathic hypercalciuria and their families were examined with an oral calcium loading test. Family members were divided into two clinical categories: group 1 consisted of the six index children and their parents and siblings with urolithiasis or unexplained hematuria; group 2 comprised the remaining parents and siblings without signs or symptoms associated with hypercalciuria. The results revealed that fasting urinary excretion of calcium was similar in both groups, but group 1 displayed a greater calciuric response to an oral calcium load. Serum concentrations of calcitriol (1,25-dihydroxyvitamin D3) and calcium were higher in group 1 than in group 2, while parathyroid activity was lower in group 1 patients. Urinary excretion of sodium, phosphorus, and magnesium, urine pH, serum levels of calcifediol (25-hydroxyvitamin D3) and phosphorus, and the renal tubular threshold for phosphate were not significantly different in the two groups. These findings suggest that idiopathic hypercalciuria may arise from a disturbance in the regulation of vitamin D metabolism that mediates enhanced intestinal absorption of calcium.
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PMID:Families of children with idiopathic hypercalciuria. Evidence for the hormonal basis of familial hypercalciuria. 383 4

A 52-year-old man with an acromegalic appearance of prolonged duration suffered abdominal colic attacks and hematuria during the middle of the course of the disease. The patient was diagnosed as having urolithiasis caused by increased urinary calcium. The calcium metabolic disorder was not considered to be due to hyperparathyroidism because serum calcium and PTH levels were within the normal range and no abnormality was observed in a parathyroidal scintigraph. The serum 1,25-dihydroxyvitamin D (1,25-(OH)2D) levels (55.0 and 73.0 pg/ml) were higher than the normal range (27.2-53.8 pg/ml). A selective adenomectomy by the transsphenoidal route (Hardy's method) was performed, resulting in an improvement in the hypercalciuria and urolithiasis, and a decrease in the levels of serum 1,25-(OH)2D (23.0 and 23.0 pg/ml). These findings suggest that GH may promote the activation of vitamin D in the kidney in acromegaly, resulting in an acceleration of calcium absorption in the intestine through the action of activated vitamin D and the induction of increased urinary calcium excretion by the urinary excretion of excessive blood calcium.
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PMID:An acromegalic patient with recurrent urolithiasis. 384 20

Hypercalcaemia is one of the extra-pulmonary symptoms of sarcoidosis. We describe a case of acute and chronic renal failure due to urolithiasis and nephrocalcinosis probably caused by sunlight-induced hypercalcaemia in a patient with undiagnosed sarcoidosis. Attention must be given to excessive sun exposure and vitamin D intake in patients with sarcoidosis.
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PMID:[Nephrocalcinosis and urolithiasis as primary symptoms in Boeck's sarcoidosis]. 864 14

Hypercalciuria in the absence of urolithiasis has been considered to be a cause of asymptomatic hematuria. No mechanism for this association has been demonstrated. In an effort to establish the specificity of this association, we induced hypercalciuria in 10 healthy subjects by oral administration of 1,25(OH)2 vitamin D for 10 days. This protocol reproducibly produced markedly increased urinary calcium excretion (mean calcium:creatinine ratio 0.5). Despite this, no subject developed hematuria as seen by dipstick urinalysis or by alteration in erythrocyte Addis counts (mean counts 1.02 x 10(6)/12 h before vitamin D and 0.84 x 10(6)/12 h after 10 days of therapy). This study provides no evidence that short-term hypercalciuria alone produces hematuria in otherwise healthy individuals.
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PMID:Short-term experimental hypercalciuria does not produce hematuria in normal subjects. 877 38

Poor calcification of the teeth and the bones of the skull predisposes pet rabbits to dental disease. This study is a preliminary investigation into the dietary habits of pet rabbits. Owners were questioned about the feeding preferences of their pets. Manufacturers of rabbit foods were asked about the calcium, phosphorus and vitamin D content of their foods and how they had decided upon the formulation of their rations. Samples of rabbit food were analysed for calcium and phosphorus. Rabbits were found to be selective feeders. Rabbit food from pet shops consists of a mixed ration, of which the most commonly rejected ingredients were pellets and whole grain. The food manufacturers reported that calcium, phosphorus and vitamin D supplements are incorporated into the pellets. Food analyses demonstrated that rejection of the pellets and whole grain from the food can reduce a rabbit's calcium intake to below the minimum dietary requirement. The rabbit's unusual calcium metabolism is discussed. Calcium deficiency may cause osteomalacia but dietary excess may cause urolithiasis. Vitamin D deficiency may also exacerbate calcium deficiency. Recommendations are made for preventing calcium deficiency and dental disease in rabbits.
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PMID:Calcium deficiency, diet and dental disease in pet rabbits. 912 6


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