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)

This baby boy was born after a pregnancy complicated by severe polyhydramnios at a gestational age of 28 weeks. Analysis of the amniotic fluid had shown a high chloride content, but normal concentrations of sodium, potassium, and calcium. After birth he displayed extreme polyuria, severe renal sodium and chloride loss, and marked hypercalciuria. Five weeks after birth, his sodium chloride loss turned into renal potassium loss, along with a marked decrease in urine output. All these features are characteristic of the neonatal variant of Bartter syndrome. He was discharged after 11 weeks with oral supplements of sodium chloride, potassium gluconate, and 500 ml of fluid. The follow-up for a period of 6 years showed a surprising evolution: he has no hypokalemic alkalosis, no polyuria, and no hypercalciuria; growth and development are within the normal ranges and, at the time of writing, he is a healthy boy needing no medication and with no medical problems whatsoever.
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PMID:Neonatal Bartter syndrome: spontaneous resolution of all signs and symptoms. 963 34

Nearly 50 years after its initial description by Dr. F. Albright, the term idiopathic hypercalciuria (IH) is still in use. The exact mechanism of hypercalciuria is still unknown despite extensive pathophysiologic investigations; recent advances represent the focus of this review. A precise definition of true IH is proposed, taking into account the various nutritional conditions influencing calcium excretion. The potential pathogenic mechanisms are discussed, and the limits of the classical Pak's pathophysiological classification are recalled. The evidence supporting the role of an increased intestinal calcium absorption, a defect in renal tubular calcium reabsorption, or an increased bone loss as a primary mechanism in IH are successively examined. Since overall available human data indicates that all three mechanisms may be found in IH, the hypothesis that a broader disorder encompassing all these various abnormalities may be involved in IH is discussed. Three global hypotheses to account for IH physiopathology are examined: a diffuse defect in fatty acid content of cell membranes, an increased expression of the vitamin D receptor of the 25(OH) vitamin D 1 alpha-hydroxylase, or of the calcium sensor receptor and a monocyte disease. Finally, the available clinical data justifying the therapeutic approaches are reviewed, and guidelines for dietary recommendations regarding calcium and also animal protein, sodium chloride, alcohol, carbohydrate, phosphate, and potassium intakes are proposed, and drug therapy indications are discussed.
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PMID:Pathophysiology and treatment of idiopathic hypercalciuria. 972 2

The acute renal effects of chemotherapy are known, but long-term nephrotoxicity has rarely been investigated. The aim of the present study was to assess long-term renal function in children and adolescents who received at-risk chemotherapy, including cisplatin, ifosfamide, and methotrexate, to treat an osteosarcoma. Renal function tests [creatinine clearance, microalbuminuria, and renal excretion of sodium, potassium, chloride, calcium, magnesium (Mg), phosphorus (P), and uric acid] were prospectively performed 5.4+/-2.2 (+/-SD) years after chemotherapy (total cumulative dose: methotrexate 41+/-31 g/m2, ifosfamide 39+/-14 g/m2, cisplatin 674+/-188 mg/m2) in 18 children and adolescents. The results were compared with 13 normal volunteers matched for age and sex. Creatinine clearance, which was greater than 80 ml/min per 1.73 m2 in all patients, correlated with the total dose of ifosfamide (r=0.55, P<0.05) and cisplatin (r=0.48, P<0.05). Microalbuminuria was noted in 4 patients. Hypomagnesemia was present in 4 and hypercalciuria in 3 patients; renal excretion of P, Mg, and uric acid was higher in patients than in controls. Glomerular function was not significantly altered and only mild tubular dysfunction was present. Since renal excretion of P and Mg were increased in patients compared with normal volunteers and hypercalciuria was occasionally seen, divalent ion disorders are the most-likely potential complications.
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PMID:Long-term nephrotoxicity of cisplatin, ifosfamide, and methotrexate in osteosarcoma. 976 57

Increasing urinary net acid (titratable acid + NH4 - HCO-3) excretion is accompanied by an increased urinary Ca excretion because of reduced renal tubular reabsorption of filtered Ca. The relationships between urinary Ca excretion rates and urinary net acid excretion rates are reviewed for data: (1) among healthy adults eating constant diets when net acid excretion is increased by increasing dietary protein, administering NH4Cl, or withdrawal of dietary KHCO3 or reduced by administering KHCO3; (2) among healthy adults eating constant diets providing varying amounts of protein and potassium, and (3) among healthy adults and Ca stone formers with and without idiopathic hypercalciuria eating ad libitum. The results show that urinary Ca excretion varies directly with net acid excretion by 0.035 mmol/mEq. The urinary net acid excretion increases by 0.10-0.15 mEq/mmol urinary urea, and urinary Ca increases by about 0.04 mmol/g dietary protein, while the urinary net acid excretion decreases as the ratio of urinary K/urea, a reflection of the dietary K relative to dietary protein, increases. The relationships between net acid excretion and both urinary urea and K/urea are similar among Ca stone formers without and with idiopathic hypercalciuria, but those with idiopathic hypercalciuria exhibit increased rates of urinary Ca excretion at all levels of net acid excretion.
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PMID:Relationship between urinary calcium and net acid excretion as determined by dietary protein and potassium: a review. 987 10

This review describes the supposed mechanisms leading to idiopathic hypercalciuria (IHU) in childhood, further the diagnostic criteria and the proposed treatment modalities are discussed. IHU is not only one of the main causes of renal stone disease in children but it's also at the origin of the postglomerular haematuria and the frequency-dysuria syndrome. Its role in the development of osteoporosis in adults is also documented. The diagnosis of raised calcium excretion is based on age specific values during early infancy. In older children and adults a urinary calcium/creatinine ratio exceeding 0.6 mmol/mmol is regarded as elevated. Dietary calcium restriction can no longer be recommended for the treatment of IHU because it results in secondary hyperoxaluria and on the long-term causes decreased bone mineral density. Patients should be kept on dietary sodium restriction and high fluid intake. In cases IHU associated with recurrent episodes of macroscopic haematuria or recurrent stone disease a therapeutic trial with hydrochlorothiazide in the dose of 0.5-1 mg/kg/day with potassium-citrate supplementation and possibly magnesium citrate should be started. In some special forms of hypercalciuria such as the X-linked recessive nephrolithiasis syndrome or Bartter syndrome the localization and in some cases even the molecular mechanism of the events leading to increased calcium excretion are elucidated. In IHU enhanced Ca(++)-ATPase, and Na-Li countertransport activity and decreased Na+/K+ ATPase activity were described in the erythrocyte membrane model. It is expected that with the molecular genetic development the clinical classification of the hypercalciuric syndromes will become a rational genome-based one.
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PMID:[Idiopathic hypercalciuria in childhood]. 987

Population based data on urinary excretion of various metabolites of pathological importance, Calcium, Magnesium, Sodium, Potassium, Oxalates, Citrates, Phosphates, Uric acid and urea have been collected from around three hundred children of the Quetta valley. The body weight was in the range of 11-50 kg and the age was in between 4-16 years. The urine excretion average was 987.5 +/- 452.5 ml per 24 hours. There was 11.5% incidence of hypercalciuria, 8.5% incidence of hyperuricosuria, 2.0% hyperphosphaturia, 2.5% hypomagnesuria, 3.5% hypocitraturia, 6.5% hypernatriuria, 43.5% hypokaliurea and 2.1% hyperoxaluria. Urea excretion average was 23.11 +/- 14.99 g per 24 hours. The study provided the basis for childhood reference pattern in urinary excretion of compounds related to various pathological conditions, in particular stone formation in this region.
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PMID:Population based data on urinary excretion of various metabolites in children of north western region of Pakistan. 1006 40

The relationship between bone mineral status and hypercalciuria is controversial. The effect on bone composition of different forms of hypercalciuria was studied in female rats made hypercalciuric by 7-week administration of oral furosemide (F, n=12), intraperitoneal 1,25-dihydroxy vitamin D (VD, n=11), or oral ammonium chloride (AC, n=12). Seven untreated rats served as controls (C). Hypercalciuria (mg/100 g per 24 h, mean +/-SEM) of F (4.3+/-0.2), VD (4.1+/-0.4), and AC (3.9+/-0.3) groups was of similar intensity (C rats 1.3+/-0.1, P<0.01). Weight and length gains and serum CO2, sodium, potassium, calcium, and phosphate were no different among the four groups. Bone was studied by dual-energy X-ray absorptiometry of left tibiae. AC rats had significantly less bone area (1.505+/-0.018 cm2) than VD and C (1.602+/-0.020 and 1.587+/-0.019 cm2). Bone mineral content was decreased in F (0.357+/-0.007 g) and AC (0.362+/-0.006 g) compared with VD (0.407+/-0.008 g) and C (0.389+/-0.009 g) groups. Bone mineral density was different between F (0.231+/-0.002 g/cm2) and VD and C rats (0.254+/-0.004 and 0.245+/-0.003 g/cm2), and also between AC (0.240+/-0.003 cm2) and VD rats. In these rat models, hypercalciuria of renal origin (F) and hypercalciuria caused by acid load (AC) adversely impaired bone mass.
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PMID:Influence of three different types of hypercalciuria on bone. An experimental study. 1041 59

Mutations in genes encoding ion channels have increasingly been identified to cause disease conditions collectively termed channelopathies. Recognizing the molecular basis of an ion channel disease has provided new opportunities for screening, early diagnosis, and therapy of such conditions. This synopsis provides an overview of progress in the identification of molecular defects in inwardly rectifying potassium (Kir) channels. Structurally and functionally distinct from other channel families, Kir channels are ubiquitously expressed and serve functions as diverse as regulation of resting membrane potential, maintenance of K(+) homeostasis, control of heart rate, and hormone secretion. In humans, persistent hyperinsulinemic hypoglycemia of infancy, a disorder affecting the function of pancreatic beta cells, and Bartter's syndrome, characterized by hypokalemic alkalosis, hypercalciuria, increased serum aldosterone, and plasma renin activity, are the two major diseases linked so far to mutations in a Kir channel or associated protein. In addition, the weaver phenotype, a neurological disorder in mice, has also been associated with mutations in a Kir channel subtype. Further genetic linkage analysis and full understanding of the consequence that a defect in a Kir channel would have on disease pathogenesis are among the priorities in this emerging field of molecular medicine.
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PMID:Channelopathies of inwardly rectifying potassium channels. 1054 73

Recent studies of hereditary renal tubular disorders have facilitated the identification and roles of chloride channels and cotransporters in the regulation of the most abundant anion, Cl-, in the ECF. Thus, mutations that result in a loss of function of the voltage-gated chloride channel, CLC-5, are associated with Dent's disease, which is characterized by low-molecular weight proteinuria, hypercalciuria, nephrolithiasis, and renal failure. Mutations of another voltage-gated chloride channel, CLC-Kb, are associated with a form of Bartter's syndrome, whereas other forms of Bartter's syndrome are caused by mutations in the bumetanide-sensitive sodium-potassium-chloride cotransporter (NKCC2) and the potassium channel, ROMK. Finally, mutations of the thiazide-sensitive sodium-chloride cotransporter (NCCT) are associated with Gitelman's syndrome. These studies have helped to elucidate some of the renal tubular mechanisms regulating mineral homeostasis and the role of chloride channels.
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PMID:Chloride channels in renal disease. 1056 51

Bartter syndromes are defined as a family of inherited recessive autosomal tubulopathies. They are characterized by hypochloremia, hypokalemia, metabolic alkalosis associated with potassium renal leakage and normal blood pressure despite increased plasma renin activity. Three forms of the disease are identified as followed: 1) Gitelman syndrome or hypocalciuria hypomagnesemia syndrome is a mild form often discovered in childhood or teenagers in reason of tetany. It is an homogeneous disorder related to mutations of the genes encoding the thiazide-sensitive Na-Cl cotransporter located in the distal convoluted tubule. 2) Antenatal Bartter syndrome with hypercalciuria and nephrocalcinosis or hyperprostaglandin E syndrome is a severe form, often revealed by hydramnios, prematurity and growth delay. It is related to mutations of two types of genes encoding for transporters of Henle's loop: the bumetanide-sensitive cotransporter Na-K-2Cl (NKCC2) [type I] or the inwardly-rectifying potassium channel (ROMK) [type II]. 3) the classical form or type III Bartter syndrome, often revealed by dehydration in the first year of life, is associated with hypomagnesemia in 20% of cases and normal or increased calciuria. This form is related to mutations of CLCNKB gene encoding for a chloride channel in Henle's loop. This classification, in part related to the demonstration of mutations in the genes encoding for tubular chloride or potassium channels, does not fit all cases, overlapping syndromes are frequent. Moreover some endocrinological (diabetes) and neurological (deafness) abnormalities are sometimes associated with Bartter syndromes. Both phenotypic and genetic approach must help to the diagnosis of these tubulopathies.
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PMID:[Bartter's syndromes]. 1061


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