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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)
The regulation of three Salmonella typhimurium phosphatases in reponse to different nutritional limitations has been studied. Two enzymes, an acid hexose phosphatase (EC 3.1.3.2) and a cyclic phosphodiesterase (EC 3.1.4.d), appear to be regulated by the cyclic adenosine 3' ,5'-monophosphate (AMP) catabolite repression system. Levels of these enzymes increased in cells grown on poor carbon sources but not in cells grown on poor nitrogen or
phosphorus
sources. Mutants lacking adenyl cyclase did not produce elevated levels of these enzymes in response to carbon limitation unless cyclic AMP was supplied. Mutants lacking the cyclic AMP receptor protein did not produce elevated levels of these enzymes in response to carbon limitation regardless of the presence of cyclic AMP. Since no specific induction of either enzyme could be demonstrated, these enzymes appear to be controlled solely by the cyclic AMP system. Nonspecific acid phsphatase activity (EC 3.1.3.2) increased in response to carbon, nitrogen,
phosphorus
, or sulfur limitation. The extent of the increase depended on growth rate, with slower growth rates favoring greater increases, and on the type of limitation. Limitation for either carbon or
phosphorus
resulted in maximum increases, whereas severe limitation of Mg2+ caused only a slight increase. The increase in nonspecific acid phosphatase during carbon limitation was apparently not mediated by the catabolite repression system since mutants lacking adenyl cyclase or the cyclic AMP receptor protein still produced elevated levels of this enzyme during carbon starvation. Nor did the increase during
phosphorus
limitation appear to be mediated by the
alkaline phosphatase
regulatory system. A strain of Salmonella bearing a chromosomal mutation, which caused constitutive production of
alkaline phosphatase
(introduced by an episome from Escherichia coli), did not have constitutive levels of nonspecific acid phosphatase.
...
PMID:Regulation of two phosphatases and a cyclic phosphodiesterase of Salmonella typhimurium. 19 13
A 5-year-old boy was found to have severe rickets in association with hyperpigmented, linear, verrucous, epidermal tumors, typical of the epidermal nevus syndrome. Normocalcemia (9.6 mg/dl), hypophosphatemia (2.0 mg/dl), elevated serum
alkaline phosphatase
concentration (313 IU), decreased renal tubular reabsorption of
phosphorus
(35%), radiologic evidence of rickets, and lack of response to usual therapeutic doses of vitamin D suggested hypophosphatemic vitamin D-resistant rickets. Therapy with vitamin D in doses to 750,000 IU and oral phosphate, 2.0 gm/day, failed to induce healing of the rickets. A subtotal parathyroidectomy performed when the patient was 9 years old was also without effect. When he was 12 years old several fibroangiomas on the face and left lower limb were excised. Within three months all biochemical abnormalities resolved and radiologic evidence of healing was observed. A portion of excised tissue was homogenized and injection of the supernate into a 6-week-old puppy induced excessive phosphaturia. The data suggest that the rickets was induced by a phosphaturic substance extractable from the tumors.
...
PMID:Vitamin D-resistant rickets associated with epidermal nevus syndrome: demonstration of a phosphaturic substance in the dermal lesions. 19 29
The relative importance of cholecalciferof (vitamin D3) and ergocalciferol (vitamin D2) in maintaining the vitamin D level in children (1/2 to 6 years old) living in the upper midwestern United States was determined by measurement of total 25-hydroxyvitamin D (25-OH-D), its components, and other indices of calcium homeostasis in serum. In 38 normal children, mean (range) serum total 25-OH-D was 32.8 (less than 5 to 53) ng/ml; in 25 of the 28 sera partitioned, the major component was 25-OH-D3. Significant seasonal variation in serum 25-OH-D3 (mean, range: 35.2, 17 to 51 ng/ml in summer and 15.9, less than 5 to 32 ng/ml in winter) was not accompanied by changes in mean serum 25-OH-D2, calcium,
phosphorus
, or
alkaline phosphatase
values. However, individual serum total 25-OH-D values correlated with serum
phosphorus
values (r = 0.37; P less than 0.05). The proportion of the total represented by 25-OH-D3 varied widely, with a a mean of 83% in summer and 67% in winter. Sources of D3, which include both dermal synthesis and intestinal absorption of D3 added to milk, appear to be more important than sources of D2 in maintaining vitamin D nutrition of young children throughout the year. However, sources of D2 offset the decrease in total 25-OH-D in winter months.
...
PMID:Components of 25-hydroxyvitamin D in serum of young children in upper midwestern United States. 19 55
Biochemical evidence for hypoparathyroidism and roentgenographic evidence for hyperparathyroidism were present in a 7-year-old girl with seizures and tetany. She was hypocalcemic (4.7 mg/dl), hyperphosphatemic (11 mg/dl), and normomagnesemic, with elevated parathyroid hormone level (2,603 pg/dl and 3,693 pg/dl in immunoassays utilizing two different antisera). Somatic features of pseudohypoparathyroidism were absent. Increased serum
alkaline phosphatase
activity (335 IU/liter) with evidence of subperiosteal bone resorption suggested parathyroid hormone activity on bone. Intramuscular administration of parathyroid extract caused a rise in serum calcium level (9.6 mg/dl) and a fall in serum
phosphorus
level (7.9 mg/dl). The serum calcium,
phosphorus
, and
alkaline phosphatase
activity became normal during vitamin D therapy. Parathyroid hormone values and bone roentgenograms became normal. With serum calcium and
phosphorus
levels normal, ethylenediaminetetraacetic acid infusion was followed by an increase in plasma parathyroid hormone level but not in urinary cyclic adenosine monophosphate (AMP) or phosphaturia; in contrast, parathyroid extract induced cyclic AMP excretion and phosphaturia. These results suggest that endogenous parathyroid hormone in this patient affects bone resorption but not renal handling of phosphate. We infer that this represents a defective endogenous parathyroid hormone.
...
PMID:Hypo-hyperparathyroidism: evidence for a defective parathyroid hormone. 19 77
Ten patients with vitamin D resistant hypophosphataemic osteomalacia are described. They had hypophosphataemia with a decreased tubular reabsorption of phosphate, malabsorption of calcium and
phosphorus
, proximal myopathy and extensive osteomalacic changes on iliac crest bone biopsy. The plasma
alkaline phosphatase
and urine hydroxyproline, however, were raised in only some of the patients. Treatment with 1alpha-hydroxyvitamin D3 in high doses rapidly cured the myopathy, increased calcium and
phosphorus
absorption and retention and healed the osteomalacia.
Phosphorus
supplements were not required.
...
PMID:Vitamin D resistant hypophosphataemic osteomalacia: treatment with 1alpha-hydroxyvitamin D3. 20 18
Five patients with nutritional osteomalacia or rickets and six children with rickets unresponsive to physiological doses of vitamin D were treated with 1alpha-hydroxyvitamin D3 (1alpha-OHD3). Patients with nutritional osteomalacia responded to 1--2 microgram/day of 1alpha-OHD3. The most striking findings were rises in plasma calcium and, in one case, a decrease in faecal calcium. In some cases there was a rise in plasma
phosphorus
,
alkaline phosphatase
remained unchanged. There was radiological healing. In three patients with cystinosis and one with hypophosphataemia and Barrter's syndrome 2 microgram of 1alpha-OHD3 produced healing of rickets. Plasma phosphate rose on treatment, possibly by a suppression of parathyroid activity. The response to such low doses of 1alpha-OHD3 suggests impaired 1alpha-hydroxylation of 25-hydroxyvitamin D in these patients. A patient with intestinal malabsorption was resistant to high doses of 1alpha-OHD3 by mouth but responded to parenteral administration. A boy with osteopetrosis and the biochemical changes of rickets was resistant to large doses of 1alpha-OHD3 presumably because of failure of osseous response.
...
PMID:1alpha-hydroxyvitamin D3 in the treatment of nutritional and metabolic rickets and osteomalacia. 20 19
Fatty acid composition of the cells of Escherchia coli wild strains K-10, and K-12 and the mutants of the regulatory genes for
alkaline phosphatase
was studied in conditions of repression and derepression of biosynthesis of phosphohydrolases. Derepression of phosphohydrolases was not accompanied with specific changes in fatty acid composition of the cells. An increase in the content of cyclopropanic acid in conditions of
phosphorus
deficiency and a decrease in the level of unsaturated fatty acids are related to deceleration of growth of the cells in these conditions.
...
PMID:[Fatty acid makeup of Escherichia coli cells with repressed and derepressed phosphohydrolase biosynthesis]. 20 8
A method for the synthesis of an analog of vitamin D3--1alpha-hydroxy vitamin D3 (1alpha-OH D3) from cholesta-4,6-dien-3beta-ol was developed. Biological activity of this compound in the chick organism was measured. The growth stimulating effect of 1alpha-OH D3 and its effect on bone tissue mineralization and serum biochemical parameters (content of calcium, inorganic
phosphorus
and activity of
alkaline phosphatase
) were 4--5 times higher than those of vitamin D3 in low doses (19.5--39 pmole/day). In chicks given 1alpha-OH D3 at doses of 39--195 pmole/day most biochemical parameters reached plateau typical of chicks adequately provided with vitamin D. A peculiar feature of 1alpha-OH D3 was a rapid response of the chick organism to/low doses. As early as one hour after intramuscular injection of 650 pmole of 1alpha-OH D3 to D-avitaminotic chicks, the content of calcium-bound protein in the intestinal mucosa and active transport of calcium ions in the inverted intestinal sac increased drastically. It was demonstrated that 1alpha-OH D3 showed antirachitic action, when the physiological reaction to vitamin D3 was inhibited by dietary strontium.
...
PMID:[1 alpha-hydroxyvitamin D3: chemical synthesis and biological effect]. 20 64
In six infants aged between 4 and 8 months with chronic renal failure, we have studied blood levels of calcium (Ca),
phosphorus
(P),
alkaline phosphatase
, immunoreactive parathyroid hormone (PTH), and calcitonin (CT), as well as urinary excretion of Ca, P, hydroxyproline and cyclic AMP under basal conditions and during an infusion of 20 mg/kg of 10% Ca gluconate in normal saline over 4 h. Under basal conditions four infants had normal serum Ca and P values,
alkaline phosphatase
levels at the upper limit of normal, and very high PTH (range: 1450--2550 pg Eq/ml) and CT (range: 700--1900 pg/ml) levels. The urinary Ca excretion was low, whereas the urinary excretion of P, hydroxyproline and cyclic AMP was high. During Ca infusion, the total serum Ca and CT levels increased, PTH fell without however reaching the normal upper limit, and urinary P and cyclic AMP excretion decreased. In two infants with osteodystrophy and the highest levels of PTH (2900 and 3500 pg Eq/ml respectively) there was no suppression of PTH during Ca infusion.
...
PMID:Parathyroid hormone and calcitonin secretion in uraemic infants. 21 73
In six infants aged between 5 and 8 months with vitamin D deficient rickets, we have studied blood levels of calcium (Ca),
phosphorus
(P),
alkaline phosphatase
, immunoreactive parathyroid hormone (PTH) and calcitonin (CT), as well as urinary excretion of Ca, P, hydroxyproline and cyclic AMP, both under basal conditions and during a 4h infusion of 20 mg/kg 10% Ca gluconate in normal saline. Under basal conditions all the infants had high
alkaline phosphatase
(range: 470--770 U.I./1); PTH (range: 620--1200 pg Eq/ml) and CT (range: 440--750 pg/ml) but two infants had hypocalcaemia and four had normocalcaemia and hypophosphataemia. The urinary Ca excretion was low whereas the urinary P, hydroxyproline and cyclic AMP excretions were high. During Ca infusion the total serum Ca and CT levels increased, while
alkaline phosphatase
and PTH fell. After the end of the infusion, CT levels fell perceptibly; phosphaturia, hydroxyprolinuria and cyclic AMP decreased on the day of the infusion.
...
PMID:Parathyroid hormone and calcitonin levels in vitamin D deficient rickets. 21 86
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