Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Composition of diet may influence growth, diseases, tumor rates, and responses to chemical treatment. Since 1980 the NIH-07 open formula nonpurified diet has been the selected diet for the National Toxicology Program (NTP) toxicity and carcinogenicity studies in rodents. Studies with nonpurified experimental diets with lower protein and higher fat and fiber than the NIH-07 diet indicated that the diet for Fischer-344 (F344) rats in long-term studies could be modified to decrease the severity of chronic diseases and to decrease/delay the development of spontaneous tumors. Based on the results of these studies a new open formula nonpurified diet designated as NTP-2000 was formulated to contain approximately 14.5% protein, approximately 8.5% fat, and approximately 9.5% fiber. Corn, wheat, and wheat middlings contribute to about 60% of the ingredients; soybean meal, fish meal, and alfalfa meal are the additional sources of protein; purified cellulose, oat hulls, and alfalfa meal are the major sources of fiber; and soy oil and corn oil are the major sources of fat in the NTP-2000 diet. The Ca:P ratio and mineral and vitamin concentrations were reformulated based on AIN-93 and NRC-95 recommendations. The NIH-07 and the NTP-2000 diets were fed to groups of 6-week-old F344 rats for 13 weeks and evaluated for growth patterns, food and water consumptions, hematology and clinical chemistry parameters, and organ weights and pathological changes. Growth patterns and body weights were similar for both diets. Food consumptions were slightly higher and water consumptions were slightly lower for the groups fed NTP-2000 diet. There were no differences in hematological parameters between the groups fed the above diets. Serum levels of cholesterol, alkaline phosphatase, and 5' nucleotidase were slightly higher in groups fed the NTP-2000 diet possibly due to higher fat content of this diet. However, the serum triglyceride levels were slightly lower in groups fed the NTP-2000 diet and it may be related to higher fiber content of the NTP-2000 diet. The liver and kidney weights of the groups fed NTP-2000 diet were significantly lower possibly due to lower protein content of this diet and lower protein consumption associated changes in Phase I and Phase II drug metabolizing enzyme systems. The adrenal weights were also lower in groups fed the new diet. The NTP-2000 diet prevented nephrocalcinosis and decreased the severity of nephropathy and cardiomyopathy, the common lesions of F344 rats in 13-week studies. These results indicate that the NTP-2000 diet is adequate for growth and maintenance of rats and appears to prevent or decrease the severity of diet-associated lesions.
...
PMID:New diet (NTP-2000) for rats in the National Toxicology Program toxicity and carcinogenicity studies. 881 43

Routinely used renal function tests remain normal in uncomplicated hypercalciuria. The aim of this study was to assess the value of N-acetyl-beta-D-glucosaminidase (NAG), a sensitive marker of renal proximal tubular damage, in experimental hypercalciuria. Oral calcium providing 75 mg/kg per day elementary calcium and 20,000 IU/day vitamin D3 was administered for 15 days to 7 rabbits (Orytolagus cuniculus-New Zealand white) and 7 rabbits were given placebo as a control group. Serum calcium, phosphorus, and alkaline phosphatase, daily urinary calcium excretion and NAG/creatinine ratio were measured before and after drug administration. Kidneys were examined macroscopically and microscopically following the study period. Serum calcium, phosphorous and urinary calcium excretion increased, while alkaline phosphatase decreased significantly in response to drug treatment [10.8 +/- 1.5 vs. 12.2 +/- 1.3 mg/dl, 4.6 +/- 0.6 vs. 6.7 +/- 0.7 mg/ dl, 22.3 +/- 8.3 vs. 46.8 +/- 22.5 mg/kg per day, and 138.0 +/- 57.1 vs. 70.1 +/- 33.1 IU/l, respectively (P < 0.05)]. The NAG/creatinine ratio prior to the study (0.5 +/- 0.1 mU/ mg) was significantly different from that after the study (5.4 +/- 1.5 mU/mg, P < 0.01). In the control group, changes in serum and urinary parameters were not significant (P > 0.05). The relationship between the urinary NAG/ creatinine ratio and the daily urinary calcium excretion was statistically significant (r = 0.67, P < 0.05). In the study group, nephrocalcinosis was present in all rabbits except 1 (85.7%), whereas none of the control group rabbits had nephrocalcinosis. In conclusion, in rabbits urinary NAG excretion increases significantly in nephrocalcinosis induced by hypercalciuria.
...
PMID:Urinary N-acetyl-beta-D-glucosaminidase activity in rabbits with experimental hypercalciuria. 926 Feb 50

X-linked hypophosphatemia (XLH) is characterized clinically by rickets, hypophosphatemia and hyperphosphaturia. Conventional treatment of XLH with oral phosphate and vitamin D is associated with hypercalcuria and nephrocalcinosis. Recently, intravenous and oral dipyridamole has been reported to decrease fractional excretion of phosphate in adults with idiopathic hyperphosphaturia. Our objective was to determine whether oral dipyridamole therapy reduces urinary phosphate excretion and increases serum phosphate concentration in children with XLH. A prospective study was performed in six children with XLH. The average age of the patients at the start of the study was 12.5+/-1.0 years. The effects of 12 weeks of oral dipyridamole therapy, at 4.4+/-0.4 mg/kg body weight per day, on serum phosphorous, parathyroid hormone (PTH), 1,25 (OH)2 vitamin D, osteocalcin, tubular maximum for phosphate reabsorption (TmP/GFR), urinary calcium excretion, and cyclic adenosine 3',5'-monophosphate (cAMP) excretion, were compared to baseline levels. Our results show that there was no change in serum phosphorous concentration or TmP/GFR after 12 weeks of dipyridamole therapy. Dipyridamole therapy also had no effect on serum PTH, serum 1,25 (OH)2 vitamin D, alkaline phosphatase, osteocalcin levels, urinary calcium or cAMP excretion. We therefore concluded that in children with XLH, a 12-week course of dipyridamole had no effect on serum phosphorous or its urinary excretion. Dipyridamole therapy is unlikely to improve the bone disease in children with XLH.
...
PMID:Effect of dipyridamole on serum and urinary phosphate in X-linked hypophosphatemia. 1109 12

To determine whether an "atherogenic" diet (excess of cholesterol and neutral fat) induces pathological calcification in various organs, including the kidney, and abnormal oxalate metabolism, 24 male Sprague-Dawley rats were fed either normal lab chow (controls, n = 12) or the cholesterol- and fat-rich experimental diet (CH-F, n = 12) for 111 +/- 3 days. CH-F rats developed dyslipidemia [high blood levels of triglycerides, total, low-density lipoprotein (LDL)-, very low-density lipoprotein (VLDL)-, high-density lipoprotein (HDL)-bound cholesterol, total phospholipids], elevated serum total alkaline phosphatase and lactate dehydrogenase (LDH) levels, in the absence of changes in overall renal function, extracellular mineral homeostasis [serum protein-corrected total calcium, magnesium, parathyroid hormone (PTH), 1,25-dihydroxyvitamin D (1,25(OH)2D)], plasma glycolate and oxalate levels. There was a redistribution of bone calcium and enhanced exchange of this within the extraosseous space, which was accompanied by significant bone calcium loss, but normal bone histomorphometry. Liver oxalate levels, if expressed per unit of defatted (DF) dry liver, were three times higher than in the controls. Urinary glycolate, oxalate, calcium and total protein excretion levels were elevated, the latter showing an excess of proteins > 100 kD and a deficit of proteins > 30-50 kD. Urinary calcium oxalate supersaturation was increased, and calcium phosphate supersaturation was unchanged. There were dramatically increased (by number, circumference, and area) renal calcium phosphate calcifications in the cortico-medullary region, but calcium oxalate deposits were not detectable. Electron microscopy (EM) and elemental analysis revealed intratubular calcium phosphate, apparently needle-like hydroxyapatite. Immunohistochemistry of renal tissue calcifications revealed co-localization of phospholipids and calcium phosphate. It is concluded that rats fed the CH-F diet exhibited: (1) a spectrum of metabolic abnormalities, the more prominent being dyslipidemia, hyperoxaluria, hypercalciuria, dysproteinuria, loss of bone calcium, and calcium phosphate nephrocalcinosis (NC); and (2) an interaction between calcium phosphate and phospholipids at the kidney level. The biological significance of these findings for the etiology of idiopathic calcium urolithiasis in humans is uncertain, but the presented animal model may be helpful when designing clinical studies.
...
PMID:Nephrocalcinosis and hyperlipidemia in rats fed a cholesterol- and fat-rich diet: association with hyperoxaluria, altered kidney and bone minerals, and renal tissue phospholipid-calcium interaction. 1122 20

In patients with uncomplicated idiopathic hypercalciuria renal function is normal except for increased renal calcium excretion. In this study, the level of fractional urinary enzyme excretion was assessed in relation to calciuria. Fourteen patients with a mean age of 5.8 +/- 0.8 years who had daily urinary calcium excretion more than 4 mg/kg and with otherwise normal renal function tests were included in the study. None of the patients manifested either renal calculus or nephrocalcinosis. Fourteen normal children with a mean age of 5.4 +/- 0.74 were included in the control group. The level of the urinary N-acetyl beta-D glucosaminidase (NAG) to creatinine ratio, fractional aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) excretion were not significantly different compared to the control group (p > 0.05). The patients were subdivided according to the type of hypercalciuria. The levels of NAG/creatinine ratio, fractional ALT, AST, ALP, LDH excretion were not significantly different in the absorptive type of calciuria group compared to the control group (p > 0.05). In conclusion, hypercalciuria during childhood which is 6.46 +/- 1.83 mg/kg/day is not related to the levels of NAG/creatinine ratio, fractional ALT, AST, ALP and LDH excretion in urine.
...
PMID:Investigation of relationship between idiopathic hypercalciuria and urinary enzyme activities. 1122 47

Hypophosphatasia is a rare autosomal recessive inborn error of metabolism characterized by a defective bone mineralisation and deficiency of serum and tissue liver/bone/kidney alkaline phosphatase activity. We report the characterisation of tissue-nonspecific alkaline phosphatase (TNSALP) gene mutation in a patient affected by infantile hypophosphatasia. This boy was the first child of non affected, non related parents. At 1 month of age he presented with palsy of the left upper limb with hypotonia. Length was - 2SD. The anterior fontanel was large. There was a markedly decreased ossification of all bones. All limbs were shortened. Ultrasonographic examination of the kidneys showed nephrocalcinosis. Level of alkaline phosphatases was decreased in the child as well as in the parents. Bone density was decreased. At 2 years of age development was delayed. Weight was - 3,5 SD and OFC - 3SD. The child had craniosynostosis. Molecular studies showed 2 missense mutations, both in exon 6 of the TNSALP gene.
...
PMID:Severe hypophosphatasia due to mutations in the tissue-nonspecific alkaline phosphatase (TNSALP) gene. 1241 36

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

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

Extracellular pyrophosphate (PPi) plays a central role in the control of normal bone mineralization since it antagonizes inorganic phosphate in the promotion of hydroxyapatite deposition. Studies using knock-out mice have established the functional importance of PPi generation via nucleotide pyrophosphatase phosphodiesterases (NPP) and of PPi transmembrane transport by the progressive ankylosis (ANK) protein. Tissue non-specific alkaline phosphatase activity counteracts this by hydrolysis of PPi to inorganic phosphate. The molecular nature and transport function of ANK are reviewed. A close parallel is drawn between the controlled mineralization of bone and the prevention of abnormal calcium crystal deposition within the kidney, especially when concentrated urine is produced. Pyrophosphate is present in urine, and ANK is expressed in the cortical collecting duct where PPi transport to both the tubular lumen and the renal interstitium may occur. Pyrophosphate may also be generated here by nucleoside triphosphate diphosphohydrolases (NTPD2 and 3) together with NPP1. Alkaline phosphatase activity is restricted to the proximal nephron, remote from these sites of PPi generation, transport and function. The physiological importance of PPi generation and transport in preventing idiopathic calcium renal stone disease and nephrocalcinosis now needs to be established.
...
PMID:Renal calcium stones: insights from the control of bone mineralization. 1791 53


<< Previous 1 2 3 4 Next >>

---