Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A survey of calcium metabolism in epileptic patients in a residential centre showed a subnormal serum calcium level in 22.5% of patients and a raised alkaline phosphatase in 29%. Hypocalcaemia was related to high dosage of anticonvulsant drugs, to multiple drug therapy, and to the use of individual anticonvulsant drugs in the following order, with decreasing order of importance: pheneturide, primidone, phenytoin, phenobarbitone. Subnormal serum calcium levels occurred more commonly in patients with a raised liver alkaline phosphatase isoenzyme than in those whose phosphatase was mainly of bone origin.Preliminary results of treatment with calciferol suggested that the disturbance of calcium metabolism was the result of vitamin D deficiency. It is possible that anticonvulsant drugs accelerate the breakdown of vitamin D by liver enzyme induction.
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PMID:Disturbance of calcium metabolism by anticonvulsant drugs. 547 72

The levels of vitamin D metabolites were measured in three children with a decreased dietary intake of calcium and vitamin D and sun exposure. All three children had hypocalcemia, hypophosphatemia, and elevated alkaline phosphatase activities. Two children had rickets, aminoaciduria, and elevated immunoreactive parathyroid hormone (iPTH) concentrations. The concentrations of vitamins D2 and D3, 25-hydroxyvitamins D2 and D3 (25-OH-D2 and 25-OH-D3), and 24,25-dihydroxyvitamin D (24,25-[OH]2D) were reduced. Nonetheless, the levels of calcitriol (1,25-[OH]2D) were normal. The combination of hypocalcemia, hypophosphatemia, and increased iPTH concentrations should result in supranormal calcitriol concentrations. Moreover, the ratio of PTH to calcitriol is significantly higher than in normal subjects. Accordingly, in patients with vitamin D deficiency and "normal" calcitriol values, the synthesis of this compound may be reduced. The evaluation of vitamin D deficiency should include the measurement of all metabolites.
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PMID:Vitamin D metabolite concentrations in vitamin D deficiency. Are calcitriol levels normal. 627 Oct 9

Plasma concentrations of 25-hydroxyvitamin D (25-OHD), 1,25-dihydroxyvitamin D (1,25-(OH)2D), and 24,25-dihydroxyvitamin D (24,25-(OH)2D) were determined in 17 children with vitamin D deficiency rickets before therapy was started. Thirteen of them also had these tests repeated during treatment. The median 25-OHD concentration was at the lower limit of the reference range before, but increased distinctly within one week of treatment with 1 700-4 000 IU vitamin D per day (17 vs. 37 nmol/l, p less than 0.01). 24,25-(OH)2D was undetectable in twelve of the patients before therapy. Detectable concentrations were in the range of 1.7 to 3.5% of the corresponding 25-OHD levels throughout the study, and the two metabolites were closely correlated (r = 0.84, p less than 0.0005). The median 1,25-(OH)2D concentration was near the average of the reference range before, but increased to well above the upper limit of normal within one week of treatment (121 vs. 368 pmol/l, p less than 0.01). The levels were largely normal after 10 weeks of therapy, as were the plasma concentrations of calcium, phosphate, and alkaline phosphatase. Parathyroid activity, as judged by serum parathyroid hormone or urinary cyclic AMP concentrations, was stimulated in 11 of 12 children studied prior to treatment. It is concluded that there may be no clear-cut differences between normal nad rachitic values of the different vitamin D metabolites under practical clinical conditions. A low 25-OHD level combined with evidence of a stimulated parathyroid activity, and a rise of 1,25-(OH)2D levels to supernormal values following a few days of vitamin D therapy may be diagnostic clues.
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PMID:Plasma concentrations of vitamin D metabolites before and during treatment of vitamin D deficiency rickets in children. 633 Oct 57

The status of bone mineral metabolism was studied in 21 epileptic out-patients receiving carbamazepine as the sole anticonvulsant drug. Hypocalcaemia was found in 3, hypophosphataemia in one and elevated serum alkaline phosphatase in 4 of the cases. Serum 25-hydroxyvitamin D values were significantly lower in the patients than in the controls. No statistically significant difference was observed in bone mineral density between the patients and controls. Histomorphometric analysis of the iliac crest cancellous bone did not reveal any statistically significant difference in the amount of trabecular bone or osteoid between the patients and controls, but the patients had an increased amount of trabecular resorption surfaces. An increased amount of osteoid, suggesting histological osteomalacia, was found in 2 of the 18 biopsies. We conclude that epileptic out-patients receiving carbamazepine therapy have vitamin D deficiency and may develop osteomalacic changes in their skeleton.
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PMID:Carbamazepine and bone mineral metabolism. 648 47

This study compared growth of a group of very low birth weight infants fed a formula specifically developed for such infants (Formula) with another group fed expressed breast milk (EBM). The Formula contained 2.4 g/dl of protein (lactalbumin:casein ratio, 60:40); 4.1 g/dl of fat (40% medium-chain triglycerides); 8.8 g/dl of carbohydrates; and 81 kcal/dl, with more calcium, phosphorus, and electrolytes than are in human milk. Premature babies with birth weights between 1,200 and 1,500 g and gestational age less than 36 weeks were eligible for the study and were fed either pooled EBM or Formula until they reached a weight of 1,800 g. Twenty infants fed EBM and 19 infants fed Formula completed the trial. Weight gain was faster in the Formula-fed infants after a caloric intake of 100 kcal/kg/day was achieved (Formula 27.7 g/day vs. EBM 17.2 g/day; p less than 0.001). Time to reach 1,800 g was 27 days for the Formula group and 39 days for those on EBM (p less than 0.001). Increments in head circumference and skinfold thickness were also greater in the Formula-fed group. Laboratory studies in the two groups of infants showed higher alkaline phosphatase levels, which were not due to vitamin D deficiency, in the EBM-fed infants.
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PMID:Growth and biochemical response of premature infants fed pooled preterm milk or special formula. 650 75

Concentrations of serum calcium and inorganic phosphate and serum alkaline phosphatase activity have been determined in 75 males over the age of 60 years and 40 young adult controls. Serum calcium and inorganic phosphate levels were significantly lower in the elderly group. Serum calcium-inorganic phosphate product was below 30 in 36% of the aged individuals. Serum alkaline phosphatase activity was elevated in one subject only. These results indicate the existence of mild vitamin D deficiency in the elderly males in this region.
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PMID:Prevalence of hypocalcaemia and hypophosphataemia in the elderly males in Haryana. 651 Oct 64

Anticonvulsant drug-induced disorders in mineral and bone metabolism are discussed. 'Anticonvulsant osteomalacia' includes hypocalcaemia, elevated serum alkaline phosphatase, decreased serum 25-hydroxycholecalciferol (25 OHD3), radiological and histological signs of osteomalacia and a lower bone mineral content (BMC) than normal. The pathophysiological mechanism behind anticonvulsant osteomalacia is thought be an induction of the microsomal enzyme system in the liver, leading to a disturbance in the metabolism of vitamin D and a resulting vitamin D deficiency. It has been shown that treatment with vitamin D2 increase BMC whereas serum calcium was unchanged. Treatment with vitamin D3 or 25 OHD3 increases serum calcium whereas BMC was unchanged. These findings suggest that vitamin D2 and D3 are metabolized differently in anticonvulsant treated patients. With the present knowledge, preventive treatment of this relative mild pathological condition is not generally indicated.
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PMID:Pathophysiology behind anticonvulsant osteomalacia. 657 95

In a survey of 108 subjects with a history of epilepsy in a hospital for the mentally handicapped, administration of both phenobarbitone and phenytoin was associated with low serum calcium and plasma 25-hydroxyvitamin D (25-(OH)D) levels in female subjects only. Intake of phenytoin (as mg/kg body weight) in female subjects exceeded that in males by 22 per cent, whilst the intake of phenobarbitone was 37 per cent higher. The doses of phenobarbitone and phenytoin were each inversely related to plasma 25-(OH)D concentration, but anticonvulsant drug dosage did not correlate with the magnitude of the decline of plasma 25-(OH)D concentration in winter (November-February). No influence of sodium valproate was detected on serum calcium or on plasma 25-(OH)D levels. Limited exposure to ultraviolet irradiation (UVR) or oral administration of vitamin D restored plasma 25-(OH)D to normal levels and healed osteomalacia in a subject with tuberous sclerosis. In this subject, fit frequency declined in response to UVR and to a lesser extent in response to oral vitamin D, despite the attainment of similar levels of serum calcium and of plasma 25-(OH)D. Serum calcium levels in the other 108 subjects were lower in those experiencing the most frequent fits, but serum calcium could not be restored to levels found in subjects not receiving anticonvulsant drugs unless supraphysiological doses of vitamin D were given. Vitamin D deficiency in the epileptic population receiving drugs was assessed by the response of alkaline phosphatase to vitamin D administration. A consistent fall of serum alkaline phosphatase was found only if the initial level exceeded 175 per cent of the normal value established by reference to a population not receiving phenobarbitone or phenytoin. By this criterion five out of 45 subjects (11 per cent), aged nine to 36 years were vitamin D deficient.
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PMID:Low plasma 25-hydroxyvitamin D and serum calcium levels in institutionalized epileptic subjects: associated risk factors, consequences and response to treatment with vitamin D. 660 29

OH-P/Cr was measured in morning fasting urine specimens of 300 healthy subjects and of children with disorders of calcium metabolism receiving no diet. In healthy children the values were sex and age dependent reflecting the different height velocities. The OH-P excretion was not different in schoolchildren receiving a OH-P-poor diet for at least two days in comparison to subjects of the same age group with unrestricted diet. OH-P/Cr correlated well with serum alkaline phosphatase (AP) activity and decreased rapidly after a calcium load. OH-P/Cr and AP were elevated in patients with increased bone turnover (hyperparathyroidism and hypophosphatemic rickets). In contrast, the OH-P excretion was normal in children with permanent or transient isolated hyperphosphatasemia. In children with vitamin D deficiency rickets there was a further increase of OH-P/Cr in response to vitamin therapy, while the AP activity, which reflects osteoblastic activity, tended to fall. This indicates that the observed increment of the OH-P excretion in these children is due to a temporary resorption of osteoid caused by the increasing levels of vitamin D metabolites. It is concluded that the measurement of OH-P/Cr provides a useful tool of bone turnover in children, in that it makes complete 24 h-urine collections and a OH-P free diet unnecessary. In combination with other indices of calcium metabolism the determination of the OH-P ratio is considered to be a valuable measure for the diagnosis and follow-up of bone disorders.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Hydroxyproline in morning urine. A reliable parameter for bone turnover in childhood]. 666 48

Biochemical parameters of vitamin D metabolism were measured in late winter among 40 institutionalized mentally retarded patients. Twenty of them had carbamazepine as their only antiepileptic drug, while the 20 remaining patients had no antiepileptic drugs. Serum calcium and 25-hydroxyvitamin D were significantly lower and alkaline phosphatase significantly higher in patients with than without carbamazepine. Supplementation of the diet with vitamin D in carbamazepine-treated patients abolished the differences. A possibility of hypovitaminosis D should be considered in patients on a long-term carbamazepine therapy, especially if other risks for vitamin D deficiency exist.
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PMID:Does carbamazepine treatment lead to a need of extra vitamin D in some mentally retarded children? 674 35


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