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)

Some children with idiopathic hypercalciuria (IH) develop bone alterations at some stage of the disease. The aims of this study were to evaluate bone mass in 88 children with IH (G1) at the time of diagnosis and to compare the findings with data for a control group of 29 normal children (G2). Kidney and bone metabolism markers were measured in both groups, and bone densitometry was performed. Serum alkaline phosphatase, intact parathyroid hormone, urinary calcium and uric acid were significantly higher in G1, whereas urinary volume and urinary citrate excretion were lower. The following densitometric parameters were significantly lower in G1: (1) lumbar spine (L(2)-L(4)) bone mineral density (BMD), bone mineral content (BMC), BMC corrected for height and for width of the vertebra, volumetric BMD (BMDvol), and Z score; (2) whole-body BMD; (3) femoral neck BMD. Lumbar spine BMDvol was reduced (osteopenia) in 35% of the patients compared with G2. N telopeptide, a urinary marker of bone resorption, was significantly higher in G1 than in G2, and was negatively correlated with lumbar spine BMD and BMDvol. Children with urinary lithiasis or idiopathic hyperuricosuria associated with IH showed no significant differences in bone metabolism compared with children without these associations. We conclude that (1) there is an altered bone metabolism in IH, with osteopenia already present at diagnosis in 35% of the patients; (2) N telopeptide is one of the most useful markers of bone alterations in IH, especially at an early stage of the disease; (3) investigation of bone metabolism is necessary in IH to prevent future serious consequences such as osteoporosis and bone fractures.
 ...
PMID:Bone alterations in children with idiopathic hypercalciuria at the time of diagnosis. 1257 2

Dent's disease is a nephrolithiasis disorder associated with hypercalciuria and low molecular weight proteinuria that is caused by mutations in the voltage-gated chloride channel ClC-5. Because the exact cause of hypercalciuria in this disease is unknown and could come from a renal, intestinal, or bone origin, we have investigated overall calcium handling in the ClC-5 knockout mouse (ClC-5 KO). On a high calcium diet, ClC-5 KO mice had elevated serum 1alpha,25-dihydroxyvitamin D3 (1alpha,25D3), alkaline phosphatase (AP), osteocalcin (OC), and urinary deoxypyridinoline (DPD), but serum parathyroid hormone (PTH), calcium, and intestinal calcium uptake was similar to that of wild-type (WT) mice. A 30-fold decrease in dietary calcium intake caused elevation of serum PTH and urinary cyclic adenosine monophosphate in ClC-5 KO mice and decreased the renal calcium excretion, which still remained 2-fold above that of WT mice. On this low calcium diet, both groups of mice had the same serum 1alpha,25D3, with similar increments in intestinal calcium absorption, serum AP, OC, and urinary DPD. These data indicate that the hypercalciuria in the ClC-5 KO mice on low and high calcium diets is of bone and renal origin and is not caused by increased intestinal calcium absorption, despite an elevated serum 1alpha,25D3. These mice data suggest that young patients with this disease may have a propensity for altered bone homeostasis that should be monitored clinically.
 ...
PMID:The ClC-5 knockout mouse model of Dent's disease has renal hypercalciuria and increased bone turnover. 1267 22

A 63-year-old man was admitted to our hospital for the evaluation of hypercalcemia and anterior neck mass. Laboratory findings revealed hypercalcemia, hypophosphatemia, and hypercalciuria, as well as elevated serum levels of parathyroid hormone (PTH) and alkaline phosphatase. Computerized tomography and magnetic resonance images showed that the mass contained a cystic area. Parathyroid scintigraphy using either 99mTc-sestamibi alone or 201Tl-chloride in conjunction with 99mTc-pertechnetate for thyroid image subtraction showed uptake of the radioactivity into the cyst wall, suggesting that the mass originated from the parathyroid. Fine needle aspiration biopsy revealed that the cyst fluid was serous and bloody with extremely high concentrations of both PTH and CA19-9. The patient was diagnosed as primary hyperparathyroidism caused by parathyroid cyst and cervical exploration was performed. The cyst was dissected away along with the right lobe of the thyroid gland. After tumor removal, serum calcium and PTH levels were normalized. Histological study showed that the tumor possessed malignant potential with capsular invasion as well as moderate cellular atypia with trabecular pattern in arrangement. Parathyroid cells in the wall of the cystic tumor were immunostained positively for CA19-9, suggesting that CA19-9 in the cyst fluid was produced from the cells.
 ...
PMID:Functional giant parathyroid cyst with high concentration of CA19-9 in cystic fluid. 1280 42

The objective of this study was to determine the frequency of nephrocalcinosis and hypercalciuria in cystic fibrosis (CF) patients, and to search possible causes of this phenomenon. Forty-three CF children (24 boys, 19 girls; mean age 64.9 months, range 5 months-18 years) were included in this study. Plasma sodium, potassium, chloride, BUN, creatinine, calcium, phosphorus, magnesium, alkaline phosphatase; spot urine sodium, potassium, chloride, creatinine, calcium, magnesium; and serum 25-hydroxyvitamin-D levels were measured in all patients. Urine samples were examined for microscopic hematuria. Fractional sodium, potassium, chloride excretion and estimated glomerular filtration rate (GFR) were calculated. All patients underwent renal ultrasonography. Hypercalciuria, nephrocalcinosis and microscopic hematuria were detected in 15 patients (34.2%), 10 patients (23.2%) and two patients (5%), respectively. There was no significant but borderline correlation between 25-hydroxyvitamin-D levels and hypercalciuria (r: 0.308, p:0.05). There were no correlations between Shwachman clinical scoring system results and hypercalciuria (r: 0.221, p: 0.148) and age and hypercalciuria (r: -0.229, p: 0.135). Patients with chronic Pseudomonas colonization showed no hypercalciuria or nephrocalcinosis. There was no difference for plasma biochemical results, renal function tests, hypercalciuria and nephrocalcinosis between CF patients who had or had not experienced pseudo Bartter's syndrome (PBS) before. There was no relation between detected CF mutations of the patients and hypercalciuria and nephrocalcinosis. These results suggested that it is a primary abnormality of calcium metabolism in the kidney.
 ...
PMID:Hypercalciuria and nephrocalcinosis in cystic fibrosis patients. 1507 70

We studied bone mineral metabolism changes complicated by acute gastroenteritis in a clinical acute metabolic acidosis milieu where we observed hypercalcemia, hypercalciuria, and elevated urinary hydroxyproline excretion. Serum magnesium and plasma osteocalcin, alkaline phosphatase, and IGF-1 levels were decreased. No significant changes in serum inorganic phosphate and plasma PTH, calcitonin, or 25-hydroxy vitamin D3 levels were detected. All abnormalities disappeared with the correction of acidosis. Observed hypercalcemia seems to be the result of increased calcium efflux from bone due to metabolic acidosis-induced catabolism of type 1 collagen and decreased osteoblastic activity. This study provides data regarding acute metabolic acidosis-induced changes in noninvasive parameters of bone modeling, assessed for the first time in humans.
 ...
PMID:Bone mineral changes in acute metabolic acidosis due to acute gastroenteritis. 1559 94

High-protein and acidogenic diets induce hypercalciuria. Foods or supplements with excess sulfur-containing amino acids increase endogenous sulfuric acid production and therefore have the potential to increase calcium excretion and alter bone metabolism. In this study, effects of an amino acid/carbohydrate supplement on bone resorption were examined during bed rest. Thirteen subjects were divided at random into two groups: a control group (Con, n = 6) and an amino acid-supplemented group (AA, n = 7) who consumed an extra 49.5 g essential amino acids and 90 g carbohydrate per day for 28 days. Urine was collected for n-telopeptide (NTX), deoxypyridinoline (DPD), calcium, and pH determinations. Bone mineral content was determined and potential renal acid load was calculated. Bone-specific alkaline phosphatase was measured in serum samples collected on day 1 (immediately before bed rest) and on day 28. Potential renal acid load was higher in the AA group than in the Con group during bed rest (P < 0.05). For all subjects, during bed rest urinary NTX and DPD concentrations were greater than pre-bed rest levels (P < 0.05). Urinary NTX and DPD tended to be higher in the AA group (P = 0.073 and P = 0.056, respectively). During bed rest, urinary calcium was greater than baseline levels (P < 0.05) in the AA group but not the Con group. Total bone mineral content was lower after bed rest than before bed rest in the AA group but not the Con group (P < 0.05). During bed rest, urinary pH decreased (P < 0.05), and it was lower in the AA group than the Con group. These data suggest that bone resorption increased, without changes in bone formation, in the AA group.
 ...
PMID:Amino acid supplementation alters bone metabolism during simulated weightlessness. 1569

In order to examine the etiology of refractory rickets, we evaluated the case records of patients presenting between 1990 and 2002. Subjects with impaired renal functions were excluded. Of 131 patients, 25.9 % each had hypophosphatemic rickets and distal renal tubular acidosis (RTA), 19.6 %vitamin D dependent rickets (VDDR), 11.3 % proximal RTA, 9.1 % liver disease and 6.1 % malabsorption. A significant proportion of patients with VDDR and proximal RTA showed deformities in the first year of life, whereas those with distal RTA and hypophosphatemic rickets presented later. Patients with hypophosphatemic rickets had predominant involvement of lower limbs; hypercalciuria was found in 4. Distal RTA was associated with marked rickets and normal levels of alkaline phosphatase. Hypophosphatemia and low tubular reabsorption of phosphate, though characteristic of hypophosphatemic rickets, was also seen in patients with VDDR (19.2%) and distal RTA (17.6 %). Our findings suggest that application and interpretation of appropriate investigations are useful in determining the cause of non-azotemic refractory rickets allowing initiation of specific therapy.
 ...
PMID:Non-azotemic refractory rickets in Indian children. 1569 54

The aim of this investigation was to evaluate bone mineral density (BMD), by use of DXA, and bone turnover, in patients with Bartter syndrome (BS). Ten patients (2 with BS type II and 8 with BS type III) were included in the procedure. Age at study varied between 2 and 30 years. During the studies usual treatment with indomethacin, spironolactone, and potassium chloride was maintained. Results were compared with those obtained in the 20 asymptomatic parents. Height of the patients at the time of the study did not differ from reference values (Z-score -1.2 to +0.8). Three patients (1 with BS type II and 2 with BS type III) presented reduced lumbar spine BMD or overt osteopenia (BMD Z-scores: -2.3, -1.3, and -1.1). BMD did not correlate significantly with age. Paternal and maternal femoral neck BMD values correlated significantly with lumbar spine BMD of the patients (r=0.65, P<0.05, and r=0.80, P<0.01). Lumbar spine BMD Z-scores correlated negatively with urinary Ca excretion when values both from patients and parents were jointly analyzed (r=-0.43, P<0.05). Plasma calcium concentration was significantly higher (P<0.001) and plasma phosphate Z-score was significantly lower (P<0.05) in the patients than in the parents. However, no significant differences were observed in values for intact PTH, 1,25 (OH)(2)D(3) and 25 (OH)D(3). Intact PTH values correlated positively with BMD Z-scores at lumbar spine (r=0.45, P<0.05) and at femoral neck (r=0.63, P<0.01). Age-corrected biochemical markers of bone formation (plasma alkaline phosphatase and osteocalcin concentrations) were normal whereas age-corrected markers of bone reabsorption (urinary PYD and DPD excretion) were significantly higher than parental values (P<0.01 and <0.05, respectively). We conclude that: (1) reduced BMD is not an exclusive feature of neonatal BS and it can be also observed in classic BS; (2) the loss of bone mineral is not progressive, probably because of the hypocalciuric effect of indomethacin therapy; and (3) this study did not determine whether loss of bone mass is the cause or the consequence of hypercalciuria although the beneficial effect of indomethacin therapy implies the latter.
 ...
PMID:Bone mineral density and bone turnover in patients with Bartter syndrome. 1594 90

This study reports the benefits and side effects of conventional treatment, phosphate and calcitriol supplementation in patients with heritable hypophosphatemic rickets and a long-term follow-up, median of 60.9 months. The group is composed of 17 patients (ten girls). Sixteen patients presented with bone pain and/or deformities, and in one patient the diagnosis was radiological. All the patients had increased alkaline phosphatase, hypophosphatemia, decreased fractional phosphate tubular reabsorption (TRP) and maximum tubular phosphate reabsorption/glomerular filtration rate ratio (TPO4/GFR). Ten of 17 patients had metabolic acidosis, which was corrected only with the conventional treatment. Potassium citrate was prescribed to the patients who developed hypercalciuria. Excluding one patient with pulmonary dysfunction, the remaining 16 patients were divided into two groups according to the age at treatment onset (T0): group I (GI) > or =4 years (n =9) and GII <4 years (n =7). GI and GII had similar follow-up periods and treatment protocols. Seven out of nine GI patients underwent orthopedic surgery, in contrast to none of GII. Anthropometric data results showed that within each group there is no difference in weight and stature z -score at T0 and at the end of the observation (Tf), but, when both groups are compared, GII shows higher z-score for stature at T0 (p <0.05) and at Tf (p <0.05). Nephrocalcinosis developed in three cases and correlated with hypercalciuria (p <0.001) and dose of calcitriol (p =0.03). In conclusion, higher stature z-score is associated with early treatment. A careful protocol is recommended to detect such complications as nephrocalcinosis. We suggest potassium citrate for patients with hypercalciuria to avoid calcium precipitation.
 ...
PMID:Hypophosphatemic rickets: results of a long-term follow-up. 1625 97

Pyridoxine-responsive seizures (PRS) and the role of pyridoxine (PN, vitamin B(6)) in hypophosphatasia (HPP) are incompletely understood. Typically, PRS and HPP are rare, independent, metabolic disorders. In PRS, seizures resist standard anticonvulsants apart from PN, yet have a good prognosis. In HPP, inactivation of the tissue nonspecific isoenzyme of alkaline phosphatase (TNSALP) impairs skeletal mineralization and causes rickets in infants that can be fatal. Here, we report a 7-month-old girl, newly diagnosed with infantile HPP, who presented as a neonate with PRS but without bony abnormalities. Analysis of biogenic amines in cerebrospinal fluid (CSF) suggested brain pyridoxal 5'-phosphate (PLP) deficiency, although PLP in CSF was not decreased. She had normal cognitive milestones but failure to thrive and rickets. Nearly undetectable serum ALP activity, elevated plasma PLP and urinary phosphoethanolamine (PEA) and inorganic pyrophosphate (PPi) levels, hypercalcemia, hypercalciuria and nephrocalcinosis were consistent with infantile HPP. Only prednisolone reduced serum calcium levels. Despite improved growth and weight gain, she developed rib fractures and died from respiratory failure at age 9 months. Sequence analysis of the TNSALP gene revealed novel missense mutations in exon 7 (c.677T>C, p.M226T) and exon 10 (c.1112C>T, p.T371I). Our patient demonstrated that PRS in neonates may not necessarily be "idiopathic"; instead, such seizures can be caused by severe HPP that becomes clinically apparent later in infancy. The pathophysiology of PRS in HPP differs from the three other genetic defects known to cause PRS, but all may lead to brain PLP deficiency reducing seizure thresholds. All reported HPP patients with neonatal seizures died within 18 months of birth, suggesting that PRS is an indicator of HPP severity and lethal prognosis. We recommend that assessment of any neonate with PRS should include measurement of serum ALP activity.
 ...
PMID:Pyridoxine-responsive seizures as the first symptom of infantile hypophosphatasia caused by two novel missense mutations (c.677T>C, p.M226T; c.1112C>T, p.T371I) of the tissue-nonspecific alkaline phosphatase gene. 1739 61


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