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)

Bone loss is a known complication of severe burn injury. It is, in part, due to increased endogenous glucocorticoids that contribute to the reduction in bone formation and osteoblast differentiation, hypercalciuria secondary to hypoparathyroidism, and vitamin D deficiency. In this study we attempted to prevent post-burn bone loss by acute intravenous administration of the bisphosphonate pamidronate. We enrolled 43 children, with burns of > 40% total body surface area, in a randomized, double-blind, placebo-controlled study, administering the study drug within 10 days of burn injury and again 1 week later. Dual energy X-ray absorptiometry was performed prior to drug therapy, at hospital discharge and at 6 months post-burn. Urine specimens were obtained at baseline and discharge for determination of calcium and free deoxypyridinoline. Blood was obtained along with the urine specimens for measurement of intact parathyroid hormone (iPTH) and ionized calcium (Ca) levels. Following doxycycline labeling, intra-operative iliac crest bone biopsies were obtained, and bone histomorphometry was determined. At time of discharge there were no differences in total body bone mineral content (BMC), but lumbar spine BMC was significantly higher in the pamidronate group (P < 0.005). By 6 months post-burn the differences in lumbar spine BMC persisted, but, now, total body BMC was significantly higher in the pamidronate group (P < 0.05). Bone histomorphometry and levels of urine Ca and free deoxypyridinoline failed to show significant increases in bone formation or decreases in bone resorption. Pamidronate did not exacerbate the hypocalcemia in burn patients. In summary, acute intravenous pamidronate administration following burns may help to preserve bone mass, perhaps by inhibiting the glucocorticoid-induced apoptosis of osteoblasts and osteocytes.
 ...
PMID:The efficacy of acute administration of pamidronate on the conservation of bone mass following severe burn injury in children: a double-blind, randomized, controlled study. 1545 89

Mutations in the calcium-sensing receptor gene (CaSR) may result in disorders of calcium homeostasis manifesting as familial benign hypocalciuric hypercalcaemia (FBHH), neonatal severe hyperparathyroidism (NSHPT) or autosomal dominant hypocalcaemia with hypercalciuria (ADHH). FBHH may have a population prevalence as high as one in 16 000, and ADHH one in 70 000. NSHPT is very rare. The FBHH condition is usually asymptomatic. Parathyroidectomy does not result in normal serum calcium, and no active treatment is indicated. To differentiate FBHH from primary hyperparathyroidism (PHPT), a guideline which includes measurement of serum calcium, intact parathyroid hormone (PTH), magnesium and fasting urinary calcium excretion is proposed. Screening of family members for hypercalcaemia, and occasionally a search for mutations in the CaSR gene, may be required. The NSHPT condition may manifest with hypercalcaemia, (usually) very elevated serum PTH concentration, subperiosteal erosions and fractures. Milder cases may be managed medically, but respiratory failure, extreme hypercalcaemia and failure to thrive are indications for early parathyroidectomy. The ADHH condition may result in asymptomatic hypocalcaemia, but some affected family members have minor symptoms, and a minority experience seizures in infancy which can recur into adulthood. A significant proportion of cases previously reported as idiopathic hypoparathyroidism (IHP) may in fact be due to mutations in the CaSR gene. In a moderately hypocalcaemic patient with no other clearly discernible cause, an elevated urine calcium:creatinine ratio is suggestive of ADHH, as is the presence of a first-degree relative with hypocalcaemia. If treatment with vitamin D analogues is undertaken, serum and urine calcium should be monitored, advice which applies equally to ADHH and IHP.
 ...
PMID:Clinical and laboratory features of calcium-sensing receptor disorders: a systematic review. 1558 33

Hypoparathyroidism patients devided two groups. One group is low PTH group and the other is pseudo hypoparathyroidism group. Hypoparathyroidism in these patients has been managed by 1,25- (OH)(2)D(3) or 1alpha-OHD(3). However inappropriately high doses active vitamin D usually lead to marked hypercalciuria. It is important to control serum Ca level (absolute hypo within normal values) without hypercalciuria.
 ...
PMID:[Vitamin D and its analogs in the treatment of hypoparathyroidism]. 1577 71

Herein we describe the case of a 64-year-old woman with hypoparathyroidism diagnosed at the age of 40, after an acute episode of tetany and seizures due to severe hypocalcemia. She was treated for more than 20 years with calcitriol and calcium supplementation but she presented with marked hypercalciuria and recently nephrolithiasis, although serum calcium was maintained at levels below normal range. Provided that any attempt to increase the recommended dose of calcitriol was leading to an exacerbation of hypercalciuria, we decided to enroll an alternative tool in the treatment strategy. In order to avoid further deterioration of renal function she was administered once-daily a subcutaneous (sc) injection of synthetic human parathyroid hormone (PTH 1-34) while doses of calcium and calcitriol were gradually decreased depending on the response of calcium metabolism in serum and urine samples taken periodically. Within two months of administration, PTH (1-34) significantly reduced the level of urine calcium excretion compared with calcitriol therapy and maintained serum calcium in the normal range. The relevant literature is reviewed in light of this alternative therapeutic approach in long-standing hypoparathyroidism, illustrating the potential benefits and the unresolved issues in parathyroid hormone replacement.
 ...
PMID:Sporadic hypoparathyroidism treated with teriparatide: a case report and literature review. 1728 36

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is a rare autosomal recessive tubular disorder characterized by excessive renal magnesium and calcium wasting, eventually, progressing to renal failure. It has been recently attributed to a mutation in the Claudin 16 (CLDN 16) gene of the Paracellin-1 (PCLN-1) tight junction protein. Herein, we report 2 sisters with FHHNC. Both sisters presented at an early stage with hypomagnesemia and hypocalcemia. The first patient was initially mislabeled and treated as a case of hypoparathyroidism, while the second patient was diagnosed retrospectively after the diagnosis of her sister. The 2 patients developed end stage renal disease.
 ...
PMID:Familial hypomagnesemia with hypercalciuria and nephrocalcinosis in 2 sisters. 1832 78

Pseudohypoparathyroidism (PHP) is a rare inherited syndrome characterized by parathyroid hormone (PTH) resistance and is frequently associated with Albright's hereditary osteodystrophy and resistance to other cAMP-mediated hormones. The usual neonatal presentation is mild primary hypothyroidism secondary to resistance to thyroid-stimulating hormone; hypocalcemia usually develops after age 3-5 years. This work describes the diversity in the clinical expression and course of PHP, with emphasis on calcium levels by age and treatment, in 8 children under long-term follow-up at our pediatric tertiary center. The calcium levels at presentation ranged from transient neonatal hypocalcemia to infantile hypercalcemia to childhood/adolescence hypocalcemia. Interestingly, relative hypocalciuria at diagnosis and during therapy, in the presence of renal PTH resistance, was the rule. These findings indicate that transient neonatal hypocalcemia associated with other clinical features or a family history of PHP may be a flag for clinicians to screen for PTH resistance later in life. In addition, PTH resistance may be missed by surveying calcium levels only; thus the PTH levels have to be checked as well. In addition, the recommendation for patients with hypoparathyroidism that strict low-normal calcium levels be maintained during therapy in order to prevent hypercalciuria is probably not applicable in PHP.
 ...
PMID:Clinical heterogeneity of pseudohypoparathyroidism: from hyper- to hypocalcemia. 1866 13

Autosomal dominant hypocalcemia (ADH) is an inherited form of hypoparathyroidism caused by activating mutations in the calcium-sensing receptor (CaR). Treatment with PTH(1-34) may be superior to conventional therapy but is contraindicated in children, and long-term effects on the skeleton are unknown. The patient is a 20-yr-old female with ADH treated with PTH continuously since 6 yr and 2 mo of age. A bone biopsy was obtained for histomorphometry and quantitative backscattered electron imaging (qBEI). Her data were compared with one age-, sex-, and length of hypoparathyroidism-matched control not on PTH and two sex-matched ADH controls before and after 1 yr of PTH. The patient's growth was normal. Hypercalciuria and hypermagnesuria persisted despite normal or subnormal serum calcium and magnesium levels. Nephrocalcinosis, without evidence of impaired renal function, developed by 19 yr of age. Cancellous bone volume was dramatically elevated in the patient and in ADH controls after 1 yr of PTH. BMD distribution (BMDD) by qBEI of the patient and ADH controls was strikingly shifted toward lower mineralization compared with the non-ADH control. Moreover, the ADH controls exhibited a further reduction in mineralization after 1 yr of PTH. These findings imply a role for CaR in bone matrix mineralization. There were no fractures or osteosarcoma. In conclusion, long-term PTH replacement in a child with ADH was not unsafe, increased bone mass without negatively impacting mineralization, and improved serum mineral control but did not prevent nephrocalcinosis. Additionally, this may be the first evidence of a role for CaR in human bone.
 ...
PMID:PTH(1-34) replacement therapy in a child with hypoparathyroidism caused by a sporadic calcium receptor mutation. 1906 86

This study aimed to determine differences in the rates of growth, endocrine- and calcium-related abnormalities in the various thalassemia syndromes in North America treated with current therapies. Medical history, physical examinations and blood and urine collections were obtained from patients with all thalassemia syndromes age 6 years and older in the Thalassemia Clinical Research Network. 361 subjects, 49% male, mean age 23.2 years (range 6.1-75 years) were studied. Approximately 25% of children and adults, regardless of the thalassemia syndrome, had short stature. Overall growth in children was mildly affected. Final height was close to midparental height (z = -0.73 +/- 1.24). Patients with beta thalassemia major (TM) had higher rates of hypogonadism, multiple endocrinopathies, worse hyperglycaemia, subclinical hypoparathyroidism and hypercalciuria. Hypogonadism remained the most frequent endocrinopathy and was frequently under-treated. 12.8% of the subjects had 25 vitamin D concentrations less than 27 nmol/l and 82% less than 75 nmol/l, regardless of the thalassemia syndrome. Adolescents had lower 25 vitamin D levels than children and adults. Compared to patients with other thalassemia syndromes, those with beta TM suffered from higher rates of multiple endocrinopathies, abnormal calcium metabolism and hypercalciuria. Vitamin D abnormalities were high among adolescents.
 ...
PMID:Differences in the prevalence of growth, endocrine and vitamin D abnormalities among the various thalassaemia syndromes in North America. 1960 41

The calcium sensing receptor (CaSR) and fibroblast growth factor 23 (FGF-23) play central roles in the regulation of calcium and phosphorus metabolism, respectively. CaSR controls parathyroid hormone secretion and renal calcium reabsorption. Inactivating mutations of the CaSR result in conditions characterized by hypercalcemia and hypocalciuria, whereas activating lesions cause hypoparathyroidism and hypercalciuria. Calcimimetics are a group of agonists for the CaSR that have been shown to be powerful agents in the treatment of secondary hyperparathyroidism. FGF-23 acts on the kidney to inhibit the reabsorption of phosphate and the synthesis of 1,25(OH)(2)D. Disorders of increased FGF-23 function are associated with hypophosphatemia, inappropriately low 1,25(OH)(2)D levels, and either rickets or osteomalacia. Conversely, decreased FGF-23 activity results in hyperphosphatemia, increased 1,25(OH)(2)D levels, and abnormal soft-tissue calcification. In chronic kidney disease, increases in FGF-23 are being investigated as markers of disease progression.
 ...
PMID:Emerging topics in pediatric bone and mineral disorders 2008. 1961 58

McKusick type metaphyseal chondrodysplasia, or cartilage hair hypoplasia (CHH), is a rare autosomal recessive osteochondrodysplasia secondary to a mutation in the RMRP gene. In addition to the metaphyseal chondrodysplasia and the short-limb dwarfism, patients may present with a multisystemic disease, associating immune deficiency with recurrent infantile or childhood infections, hematological abnormalities, and gastrointestinal dysfunction. The probability of malignancy is increased in these patients, as are disimmune manifestations. We report on a 12-year-old girl with a new mutation of the RMRP gene and a severe multisystemic CHH (hematological and pulmonary lesions, severe immune deficiency, arthritis, pancreatic insufficiency, malabsorption, chronic diarrhea) receiving parenteral nutrition who presented with acute symptomatic hypocalcemia and hypercalciuria associated with the presence of autoantibodies directed against the calcium-sensor receptor. At the same time, there was an important escalation of diarrhea. Corticosteroids led to a progressive improvement of biological signs (hypocalcemia, hypoparathyroidism). By contrast, gastrointestinal symptoms and malabsorption did not improve. To our knowledge, this is the first report of autoimmune hypoparathyroidism in CHH.
 ...
PMID:Autoimmune hypoparathyroidism in a 12-year-old girl with McKusick cartilage hair hypoplasia. 1962 44


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