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Query: UMLS:C0020438 (hypercalciuria)
 2,502 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Children with hyperprostaglandin E syndrome, a neonatal variant of Bartter syndrome with enhanced renal and systemic formation of prostaglandin E2, have hypercalciuria, nephrocalcinosis, and osteopenia. Because prostaglandin E2 affects tubular calcium handling, stimulates the formation of calcitriol in vitro, and has osteolytic activity, we studied calcium homeostasis and the influence of prostaglandin E2 formation on hypercalciuria in nine patients with hyperprostaglandin E syndrome during long-term indomethacin treatment and after its withdrawal. Suppression of prostaglandin E2 formation by indomethacin resulted in improvement of biochemical and clinical features of hyperprostaglandin E syndrome. However, hypercalciuria, osteopenia, and nephrocalcinosis did not completely resolve. Despite a low calcium diet, daily urinary calcium excretion was enhanced during and after withdrawal of indomethacin treatment (median 6.3, range 5.3 to 14, and median 9.4, range 4.4 to 38 mg/kg per day, respectively). Daily urinary calcium excretion was greater after withdrawal than during indomethacin treatment. Urinary calcium excretion was not correlated with urinary prostaglandin E2 excretion. Plasma levels of intact parathyroid hormone (median 11, range 6.8 to 12 pmol/L) and calcitriol (median 157, range 108 to 236 pg/ml) were elevated during indomethacin treatment and decreased after withdrawal of indomethacin. These data suggest that hypercalciuria in hyperprostaglandin E syndrome is mainly due to a renal leak of calcium, which is caused by enhanced renal formation of prostaglandin E2 and a tubular defect not related to prostaglandin E2 formation. There is no evidence for prostaglandin-stimulated calcitriol formation. Decreasing plasma levels of parathyroid hormone in the presence of renal calcium losses after withdrawal of indomethacin treatment may be due to a bone resorption process caused by systemic prostaglandin formation; the process may contribute to hypercalciuria in the patient not receiving indomethacin.
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PMID:Calcium homeostasis and hypercalciuria in hyperprostaglandin E syndrome. 834 40

I. Time has come to distinguish "Bartter syndrome" from "Bartter disease". The latter is an autosomal recessive renal tubulopathy which manifests itself mostly during infancy and childhood. II. Bartter disease is caused neither by a primary renal potassium loss nor by a primary renal hyperprostaglandinism. All evidence is in favor of a defect in the chloride pump located at the thick ascending limb of Henle's loop. III. The most severe expression of Bartter disease is its neonatal form which is characterized by polyhydramnios, premature delivery and a life threatening sodium chloride loss during the early weeks of life. It takes several weeks before sodium wasting turns into renal potassium wasting. IV. Polyhydramnios not associated with echographically detectable fetal malformation is highly suggestive of Bartter disease. Prenatal diagnosis is based on the combination of fetal polyuria and elevated chloride in the amniotic fluid. V. In this setting the administration of indomethacin is useless and even dangerous from the 32nd week of gestation on. Similarly, indomethacin should not be given to the newborn Bartter patient for the first weeks and months of life. Treatment at that stage consist mainly of the administration of large amounts of fluid and sodium chloride. VI. Indomethacin can be used as soon as children with Bartter disease stop growing normally and preferably after the age of 18 months when kidney maturation is established. The daily dose should not exceed 2.5 mg/kg body weight. VII. Hypercalciuria is part of (the neonatal form of) Bartter disease and it is so severe that nephrocalcinosis seems to be the rule. This hypercalciuria is the direct consequence of the chloride reabsorption defect in Henle's loop. Research is needed to find an adequate solution to this problem.
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PMID:[The neonatal form of Bartter's syndrome: current findings in etiology and physiopathology]. 141 86

Clinical or biochemical findings were reevaluated in 34 pediatric patients with primary renal tubular hypokalemic metabolic alkalosis. The patients were subdivided into two groups. Bartter syndrome (primary renal tubular hypokalemic metabolic alkalosis with normocalciuria or hypercalciuria) was diagnosed in 18 patients with molar urinary calcium/creatinine ratios greater than 0.20, and Gitelman syndrome (primary renal tubular hypokalemic metabolic alkalosis with magnesium deficiency and hypocalciuria) was diagnosed in 16 patients with molar urinary calcium/creatinine ratios less than or equal to 0.20 and plasma magnesium levels less than 0.75 mmol/L. Some clinically important differences between the groups were observed. Patients with Bartter syndrome were often born after pregnancies complicated by polyhydramnios (8/18) or premature delivery (7/18) and had short stature (11/18) or polyuria, polydipsia, and a tendency to dehydration (16/18) during infancy (12/18) or before school age (18/18). Patients with Gitelman syndrome had tetanic episodes (12/16) or short stature (3/16) at school age (14/16). We conclude that the Bartter and Gitelman syndromes represent two distinct variants of primary renal tubular hypokalemic metabolic alkalosis and are easily distinguished on the basis of urinary calcium levels.
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PMID:Use of calcium excretion values to distinguish two forms of primary renal tubular hypokalemic alkalosis: Bartter and Gitelman syndromes. 841 May 32

Fifty-five children (34 boys, 21 girls; age range, 1 day to 18 years) with increased echogenicity of the renal medullary pyramids at ultrasound evaluation were identified. The clinical diagnoses associated with hyperechoic medullary pyramids could be separated based on the presence or absence of hypercalciuria. Patients with drug-induced hypercalciuria included 10 infants treated with furosemide, two treated with long-term steroid therapy, and one treated with excessive amounts of vitamin D. Other clinical conditions associated with hypercalciuria included renal tubular acidosis (n = 10), Bartter syndrome (n = 5), hyperparathyroidism (n = 3), Williams syndrome (n = 2) and medullary sponge kidney (n = 2). Ten children with transient renal insufficiency and three with sickle cell disease had normal urine calcium concentration. Isolated disease entities accounted for the remainder of cases. A specific diagnosis can usually be made in a patient with hyperechoic renal medullary pyramids by using a systematic clinical approach that includes evaluation of patient age, serum and urine calcium concentration, and renal function.
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PMID:Hyperechoic renal medullary pyramids in infants and children. 188 61

Prostanoids belong to the growing family of eicosanoids, which are all derived from arachidonic acid. Prostanoids act as modulators and mediators in a large spectrum of physiological and pathophysiological processes within the kidney. On the one hand, the potent vasoconstrictor and platelet-aggregating thromboxane (TX) A2 is involved in the pathophysiology of a variety of glomerular diseases, such as haemolytic-uraemic syndrome and immune-mediated glomerulopathies. Prostaglandin (PG) E2, on the other hand, interferes with tubular electrolyte and water handling. Clinical data support the hypothesis that this member of the prostanoid family contributes to the pathophysiology of Bartter's syndrome, hyperprostaglandin E syndrome, idiopathic hypercalciuria and renal diabetes insipidus. Both prostanoids, TXA2 and PGE2, are involved in the pathophysiology of obstructive uropathies. The physiological and protective role of renal vasodilator prostanoids (PGI2 and PGE2) has been studied during treatment with non-steroidal anti-inflammatory drugs. Part of the pharmacological effects of frusemide and converting enzyme inhibitors is mediated by PGI2 and PGE2. The role of renal prostanoids in cyclosporine toxicity is still equivocal. Future investigations on the physiological and pathophysiological role of renal prostanoids will have to consider the multiple interactions between prostanoids on the one hand, and classical hormones and other mediators (e.g. cytokines) on the other hand.
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PMID:Prostanoids in paediatric kidney diseases. 191 Nov 54

Some children with Bartter syndrome have hypercalciuria. To determine the mechanism for this phenomenon, we studied tubular function and calcium metabolism in six such children. All patients had hypokalemic alkalosis, normotension, hyperreninemia, growth retardation, low fractional distal chloride reabsorption (4/5), and elevated urinary prostaglandin E2 excretion (5/6). In addition, all had hypercalciuria (urinary calcium 6.5 to 25.0 mg/kg/day), with evidence of nephrocalcinosis in five. None, however, had evidence of rickets or hyperparathyroidism. There was a marked elevation in the serum concentration of 1,25-dihydroxyvitamin D in all, and four patients had a response to oral calcium loading suggestive of absorptive hypercalciuria. Five children have had long-term therapy with indomethacin. They have had improvement in hypokalemia and reduced urinary prostaglandin E2 excretion as well as reductions in the serum concentration of 1,25-dihydroxyvitamin D and in urinary calcium excretion. These data suggest that hypercalciuria in some children with Bartter syndrome is associated with an excess of 1,25-dihydroxyvitamin D. The improvement in hypercalciuria with prostaglandin synthesis inhibition may result in part from correction of this vitamin D abnormality.
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PMID:Hypercalciuria with Bartter syndrome: evidence for an abnormality of vitamin D metabolism. 267 27

A 28-year-old male presented with profound hypokalemia and was found to have a variant of Bartter's syndrome with nephrocalcinosis, hypercalciuria, normal distal fractional reabsorption of chloride and normal sodium delivery to the distal tubule.
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PMID:Hypokalemia with nephrocalcinosis: a variant of Bartter's syndrome. 276 7

Growth from birth to the age of 19 years was studied in a patient with the neonatal form of Bartter syndrome. The initial modes of therapy (extra fluid, potassium supplements and triamterene) resulted in satisfactory but not optimal growth. Treatment with spironolactone together with potassium led to impressive catch-up growth. When the patient reached the age of 9 years, indomethacin therapy was started, which resulted in a second growth acceleration and was also accompanied by a significant reduction of both polyuria and hypercalciuria. Puberty developed normally, menarche occurred at 12 years 4 months and a normal adult height of 162 cm was reached at the age of 14 years. Treatment with prostaglandin synthetase inhibitors seems to be the best therapy for children with the neonatal form of Bartter syndrome.
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PMID:Growth from birth to adulthood in a patient with the neonatal form of Bartter syndrome. 315 13

Nephrocalcinosis was demonstrated by computerized tomography (CT) in all five children with Bartter's syndrome followed at our institution. In three of these five patients, nephrocalcinosis was also noted on ultrasound examination. Hypercalciuria was present in only one case. The mechanism leading to renal calcification remains unclear in this disease. It is noteworthy, however, that Bartter's syndrome is associated with such a high incidence of nephrocalcinosis.
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PMID:Nephrocalcinosis in Bartter's syndrome. 315 33

Cases of hypomagnesaemia of hereditary renal origin represent at least three different congenital disorders of tubular reabsorption of magnesium (Mg). Isolated familial hypomagnesaemia has been reported in a heterogeneous group of patients and an autosomal dominant pattern of inheritance has often been found to be present. Familial hypokalaemia-hypomagnesaemia, inherited as an autosomal recessive trait, has been reported in 17 patients and we now describe 3 additional cases. Hypomagnesaemia is accompanied by hypokalaemia, metabolic alkalosis, hypocalciuria and moderate sodium chloride wasting. Titration of renal Mg reabsorption indicates the presence of a low threshold but a normal Tm. The inherited defect is probably situated at the level of the distal convoluted tubule and mimics the therapeutic effect of thiazides. This condition is frequently confused with Bartter's syndrome. Familial hypomagnesaemia-hypercalciuria, also inherited as an autosomal recessive trait, has been reported in at least 15 patients and we now add 3 new cases. Hypomagnesaemia is always accompanied by hypercalciuria and nephrocalcinosis. Ocular abnormalities such as myopia and horizontal nystagmus are often present. Hypermagnesiuria is of a greater degree than that observed in the previous entity and reflects a low Tm of Mg reabsorption. The defect must be situated at the level of the ascending limb of the loop of Henle and affects the transport of both calcium and Mg but not of sodium and chloride. This condition has not been clearly separated from hereditary distal renal tubular acidosis in the literature.
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PMID:Hypomagnesaemia of hereditary renal origin. 315 19


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