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)

Topical vitamin D analogues offer a new, effective, more convenient and generally well-tolerated option for the treatment of psoriasis. Only psoriasis vulgaris has been intensively studied, but other forms of the disease may also respond. Both calcitriol and calcipotriol have been shown to be effective in numerous clinical trials, and the latter has compared well with betamethasone valerate and short-contact dithranol in controlled studies. Their mechanism of action is not yet fully understood and may prove complex. The most important effect may be a direct regulation of keratinocyte proliferation and differentiation. However, these compounds also have potent immunological properties, and may act by inhibition of cytokine production by keratinocytes or lymphocytes. Topical application of vitamin D analogues appears generally to be remarkably safe, but hypercalcaemia and hypercalciuria may develop if large quantities are used.
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PMID:Vitamin D analogues and psoriasis. 139 Jan 59

Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a new autosomal form of hypophosphatemic rickets, recently described. This disease is characterized, and differs from other forms of hereditary hypophosphatemic rickets and/or osteomalacia by increased serum levels of 1,25-dihydroxyvitamin D, hypercalciuria and complete remission of the disease on phosphate therapy alone. However, only another probable Israeli kindred, and seemingly a few sporadic cases from Europe, North America and Japan have been reported in the literature. We describe here a new kindred of Jewish Yemenite origin (unrelated to other Israeli families) with typical HHRH. Two additional members of this family suffer from a milder asymptomatic form of the disease, which presents as absorptive hypercalciuria without signs or symptoms of bone disease. It seems to us that HHRH is underdiagnosed, due to its similarity to other hypophosphatemic syndromes in clinical, radiological and most biochemical parameters. Therefore, it is recommended that urinary calcium excretion and serum 1,25-dihydroxyvitamin D concentrations be measured in every patient with hypophosphatemic rickets/and or osteomalacia before the initiation of any therapy. The correct diagnosis of HHRN is of immense therapeutic implications. Phosphate therapy alone could cause a complete remission in HHRH, while the addition of active vitamin D metabolites, as is recommended in hypophosphatemic vitamin D resistant rickets, could cause deterioration in the patient's condition.
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PMID:A new kindred with hereditary hypophosphatemic rickets with hypercalciuria: implications for correct diagnosis and treatment. 143 10

Ketoconazole was used to probe the pathogenetic importance of the serum 1,25-dihydroxyvitamin D [1,25-(OH)2D] concentration in 19 patients with well characterized absorptive hypercalciuria (AH). Patients were studied while receiving a constant metabolic diet before and after 2 weeks of ketoconazole administration (600 mg daily). Twelve of the patients were classified as ketoconazole responders, because in conjunction with a reduction of serum 1,25-(OH)2D from 113 +/- 36 to 70 +/- 26 pmol/L, intestinal 47Ca absorption decreased from 76.3 +/- 8.1% to 61.9 +/- 7.7%, and 24-h urinary Ca excretion declined from 7.6 +/- 1.4 to 5.7 +/- 1.1 mmol (P < 0.001 each). In these patients, intestinal 47Ca absorption was directly correlated with serum 1,25-(OH)2D levels and 24-h Ca excretion. In another group of 7 patients, termed ketoconazole nonresponders, despite reduction of 1,25-(OH)2D from 122 +/- 36 to 84 +/- 17 pmol/L (P = 0.015), there was no significant change in intestinal Ca absorption (76.0 +/- 8.2% to 72.1 +/- 10.6%) or 24-h urinary Ca excretion (7.3 +/- 1.3 to 7.2 +/- 1.0 mmol). In these patients, neither intestinal Ca absorption nor urinary Ca excretion was correlated with serum 1,25-(OH)2D levels. It, thus, appears that AH is a heterogeneous disorder comprised of both vitamin D-dependent and vitamin D-independent subsets. Although useful to probe the pathogenesis of AH, chronic treatment with ketoconazole is not recommended because of its generalized effects in inhibiting steroid synthesis.
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PMID:Use of ketoconazole to probe the pathogenetic importance of 1,25-dihydroxyvitamin D in absorptive hypercalciuria. 146 46

The influence of insulin on plasma and bone mineral homeostasis was studied in the BB rat model, which develops an autoimmune form of diabetes at the age of about 100 days. Untreated diabetes of short duration resulted in hypercalciuria and intestinal calcium malabsorption despite increased free concentrations of serum 1,25-dihydroxyvitamin D. The concentrations of two vitamin D-dependent calcium-binding proteins were also decreased: a low duodenal calbindin-D 9K concentration corresponding to the low intestinal active calcium absorption and a low serum osteocalcin concentration, corresponding to a low bone formation and highly correlated with serum IGF-I concentration. Indeed, on bone histology a very low number of osteoblasts and low osteoblast activity (osteoid formation and mineral apposition rate) were observed. Similar abnormalities persisted in rats with long-standing diabetes resulting in markedly decreased bone mass and increased brittleness of bone. Diabetes therefore resulted in low-turnover osteoporosis. Several hormones (testosterone, growth hormone and 1,25-dihydroxyvitamin D) and growth factors (IGF-I and its binding proteins) with known effects on bone were markedly decreased in diabetic rats. A continuous infusion of testosterone, GH or 1,25-(OH)2D3 for 14 d by miniosmotic pumps could not improve the biochemical or histomorphometric abnormalities. Insulin infusion for 2 weeks, however, rapidly increased and overcorrected the number of osteoblasts, normalized serum osteocalcin and IGF-I concentrations but could not yet normalize bone mineralization. Continuous infusion of IGF-I alone did not improve the osteoblast number of osteocalcin but markedly stimulated bone mineralization. From these data we can conclude that both insulin and IGF-I are potent bone growth factors but with different mode of action. In human type 1 diabetes, a similar decrease in serum osteocalcin and IGF-I was observed. A reduction of regional bone mass, both in long and trabecular bones, is frequently observed in human diabetes. Cumulative data from case control studies indicate that the life-time fracture risk is increased in diabetes.
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PMID:Diabetic bone disease. Low turnover osteoporosis related to decreased IGF-I production. 146 60

Overproduction of the active metabolite of vitamin D 1,25-dihydroxyvitamin D (1,25(OH)2D) has been described in sarcoidosis and other granulomatous diseases. High circulating concentrations of 1,25(OH)2D lead to increased intestinal absorption of calcium, possibly to enhanced bone resorption, and may result in hypercalcaemia and/or hypercalciuria. Data obtained in vivo and in vitro demonstrated that the unregulated production of 1,25(OH)2D lies within the granulomatous tissue and is controlled by glucocorticoids. This abnormal production of 1,25(OH)2D seems to be a general phenomenon of granulomatous processes, which is not exceptional in sarcoidosis, but appears seldom in tuberculosis. These abnormalities, however, are not pathognomonic of granulomatous processes, since they have been described in other diseases such as lymphomas.
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PMID:Calcium and vitamin D metabolism in granulomatous diseases. 158 15

Idiopathic hypercalciuria, though a common cause of nephrolithiasis, has not been recognized to cause hypocalcemia and severe bone disease. We describe an adolescent with idiopathic hypercalciuria who presented initially with severe hypocalcemia and osteoporosis and this was later complicated by recurrent renal calculi formation after calcium and vitamin D supplement. After treatment with thiazide, hypercalciuria was controlled and serum biochemistry normalized. While idiopathic renal hypercalciuria may cause a negative calcium balance in adults, a variant of this syndrome with severe renal calcium leak occurring in a growing subject could lead to severe hypocalcemia and osteoporosis.
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PMID:Idiopathic hypercalciuria causing osteoporosis and hypocalcemia. 163 May 50

In 9 children with idiopathic hypercalciuria, an oral calcium-loading test was performed. After this calcium excretion, vitamin D levels, parathyroid hormone levels and phosphate excretion were measured during a period of calcium restriction, a period of high calcium intake and a period of low calcium intake and phosphate supplementation. In our patients, there was no correlation between calcium excretion following acute and long-term calcium loading. Phosphate excretion was normal during the periods of low and high calcium intake and there were no signs of renal phosphate leakage. Elevated levels of 1,25-dihydroxyvitamin D were found with no significant change after altering phosphate or calcium intake (95% confidence intervals for the difference in 1,25-dihydroxyvitamin D levels were -2.2-15.4 pg/ml in the period with low and high calcium intake; -19.8-28.2 pg/ml in the period with low calcium intake and extra phosphate, and -24.2-19.6 pg/ml in the period with high calcium intake and extra phosphate). These data support the hypothesis of an autonomously elevated 1,25-dihydroxyvitamin D level as pathogenetic mechanism for idiopathic hypercalciuria.
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PMID:Role of 1,25-dihydroxyvitamin D production in idiopathic hypercalciuria. 175 23

Hypercalciuria and bone disease are frequently associated with total parenteral nutrition (TPN) in children and adults. The aim of this study was to assess the influence of calcium, phosphorus, and vitamin D intakes on hypercalciuria. We observed seven children aged 4-13 years receiving home cyclic TPN for 4 consecutive years. Calcium and phosphorus intakes, constant during the 1st year, were reduced during the last 3 years to 50 and 30% of the initial intakes, and vitamin D was stopped during the 3rd and the 4th years. All children had hypercalciuria and one of them had acute painful osteopenia and nephrocalcinosis at the beginning of the study. Hypercalciuria was corrected and painful bone disease did not occur during the three following years, with TPN daily intakes of calcium, 0.35 mmol/kg, and phosphorus, 0.70 mmol/kg. Cessation of vitamin D administration during 48 months led to no further decrease in calciuria nor to the occurrence of clinical or biological signs of vitamin D deficiency. However, we hypothesize that excessive vitamin D intake may have facilitated the occurrence of the TPN-related bone disease in one patient and should be avoided. The possible role of parenteral aluminum loading is also discussed.
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PMID:Calcium metabolism in children during long-term total parenteral nutrition: the influence of calcium, phosphorus, and vitamin D intakes. 177 10

A retrospective study of 68 children with increased medullary echogenicity on renal ultrasound (US) examination showed nephrocalcinosis to be present in 42 patients. The cause was believed to be iatrogenic in 30 and noniatrogenic in 12. Furosemide therapy was responsible for 11 of the cases of iatrogenic nephrocalcinosis and vitamin D therapy for the remaining iatrogenic cases. Noniatrogenic nephrocalcinosis was seen with hypercalcemia, hypercalciuria, renal tubular acidosis and dystrophic calcification following renal tubular necrosis. In 26 patients, medullary deposits of urates or proteins, medullary fibrosis, or vascular congestion (due to a variety of diseases) appeared to account for the finding. These possibilities should be added to the differential diagnosis of hyperechoic renal pyramids when nephrocalcinosis is unlikely.
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PMID:Echogenic renal pyramids in children. 184 53

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


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