Showing papers on "Alkaline phosphatase published in 1982"
TL;DR: The high phosphate content of the 200,000 dalton polypeptide was reflected by the extensive shifts both in its isoelectric point and apparent molecular weight after treatment of neurofilaments with alkaline phosphatase.
385 citations
TL;DR: The data suggest that 1,25-dihydroxyvitamin D3 exerts differential effects on skeletal cells depending on their state of growth or maturation, and may help resolve apparently conflicting experimental findings on the effects of the hormone on osteoblast-like cells in culture.
325 citations
TL;DR: The aim of future research should be to remove the limitations at present imposed on quantitative analysis by the close similarities of bone and liver alkaline phosphatases.
Abstract: The human alkaline phosphatases constitute a system of multiple molecular forms of enzymes in which heterogeneity is partly due to genetic factors and partly to posttranslational modifications. Recognition of the nature and occurrence of these multiple forms has made a significant contribution both to the understanding of changes in alkaline phosphatase values for serum in disease and to the use of alkaline phosphatase measurements in diagnosis. Many of the diagnostic advantages of alkaline phosphatase isoenzyme analysis can be obtained with the aid of qualitative methods such as zone electrophoresis. However, quantitative methods are needed to take full advantage of the potential benefits of isoenzyme analysis. Selective inactivation methods can be applied successfully to the quantitative analysis of bone and liver alkaline phosphatases in serum. However, the aim of future research should be to remove the limitations at present imposed on quantitative analysis by the close similarities of bone and liver alkaline phosphatases.
299 citations
TL;DR: The pep4-3 mutation results in a 90-95% reduction in the levels of five vacuolar hydrolases in yeast, including proteinases A and B, carboxypeptidase Y, RNase(s) and the repressible alkaline phosphatase.
Abstract: The pep4-3 mutation results in a 90-95% reduction in the levels of five vacuolar hydrolases in yeast, including proteinases A and B, carboxypeptidase Y, RNase(s) and the repressible alkaline phosphatase. The mutation is without effect on two secreted glycoproteins, on an enzyme of the vacuolar membrane, and on a proteinase located outside of the vacuole. Mutations at the PEP4 locus exhibit a dosage effect on the levels of some, but not all, of the enzymes whose expression requires the function of the gene.
204 citations
TL;DR: In this paper, the levels of soil enzyme activities have a specific role in the N, C, P, and S cycles of saline soils, and the level of inhibition varied among the enzymes assayed and the nature and amounts of salts added.
Abstract: Efforts were made to assess the levels of soil enzyme activities that have a specific role in the N, C, P, and S cycles of saline soils. Fieldmoist soil samples were treated with four rates of CaCl₂, NaCl, and Na₂SO₄ solutions applied to produce electrical conductivity readings of saturation extracts (ECₑ) ranging up to 22 mmho/cm. The range of ECₑ values included threshold salinity levels associated with reduced yields of agronomic crops. After 7 d of equilibration, the following soil enzymes were assayed: amidase, urease, acid phosphatase, alkaline phosphatase, phosphodiesterase, inorganic pyrophosphatase, arylsulfatase, rhodanese, α-glucosidase, α-galactosidase, dehydrogenase, and catalase. Soil enzyme activities decreased with increasing ECₑ; however, the degree of inhibition varied among the enzymes assayed and the nature and amounts of salts added. Dehydrogenase activity was severely inhibited by salinity, whereas, the hydrolases showed a much lesser degree of inhibition. Generally, the inhibition of soil enzyme activities by the salt solutions decreased in the following order when compared at the same ECₑ level: NaCl > CaCl₂ > Na₂SO₄. Reduced enzyme activities in saline soils may be due to the osmotic desiccation of microbial cells releasing intracellular enzymes which become vulnerable to attack by soil proteases, a “salting-out” effect modifying the ionic conformation of the active site of the enzyme-protein, and specific ion toxicities causing nutritional imbalances for microbial growth and subsequent enzyme synthesis.
189 citations
TL;DR: Data show that the particulate forms of phosphotyrosyl-protein phosphatase and p-nitrophenylosphatase represent the activities of very similar or identical proteins.
181 citations
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166 citations
TL;DR: Results obtained suggest that surface blebs formed by heat treatment almost completely consist of the outer membrane and that the blebs may be gradually released from the cell surface into the heating menstruum to partially form vesicles.
Abstract: Thermal damage to the outer membrane of Escherichia coli W3110 was studied. When E. coli cells were heated at 55 degrees C in 50 mM Tris-hydrochloride buffer at pH 8.0, surface blebs were formed on the cell envelope, mainly at the septa of dividing cells. Membrane lipids were released from the cells during the heating period, and part of the released lipids formed vesicle-like structures from the membrane. This vesicle fraction had a lipopolysaccharide to phospholipid ratio similar to that of the outer membrane of intact cells, whereas it had a lower content of protein than the isolated outer membrane. After heating bacterial cells at 55 degrees C for 30 min, the resulting leakage from the cells of a periplasmic enzyme, alkaline phosphatase, amounted to 52% of the total activity, whereas no release of a cytoplasmic enzyme, glucose-6-phosphate dehydrogenase, was detected. The results obtained suggest that surface blebs formed by heat treatment almost completely consist of the outer membrane and that the blebs may be gradually released from the cell surface into the heating menstruum to partially form vesicles.
163 citations
TL;DR: The osteoblastic properties of the ROS 17/2 osteosarcoma cell line are documented, and it is suggested that PTH inhibition of alkaline phosphatase represents a physiological response to the hormone in these cells, and cyclic AMP as a mediator of this PTH effect.
Abstract: The effect of parathyroid hormone (PTH 1–34 bovine) on alkaline phosphatase activity was investigated in an osteoblast-like clonal cell line derived from rat osteosarcoma (ROS 17/2). ROS 17/2 alkaline phosphatase resembled the bone enzyme in levamisole sensitivity and electrophoretic mobility but differed in heat stability. The specific activity of ROS 17/2 alkaline phosphatase increased with time in culture. This increase was inhibited by PTH (1–34) and (-)-isoproterenol in a dose-dependent manner starting at near-physiological hormone concentrations. The ID50 values were 0.02 nM for PTH (1–34) and 1.7 nM for isoproterenol. The two hormones stimulated ROS 17/2 adenylate cyclase, albeit at higher concentrations: Km values were 13 nM for PTH (1–34) and 16 nM for isoproterenol. The rise in alkaline phosphatase was also inhibited by dibutyryl cyclic AMP and 8-bromocyclic AMP (0.1 mM). These findings further document the osteoblastic properties of the ROS 17/2 osteosarcoma cell line, suggest that PTH inhibition of alkaline phosphatase represents a physiological response to the hormone in these cells, and implicate cyclic AMP as a mediator of this PTH effect.
162 citations
Journal Article•
TL;DR: Data indicate that the use of butyrate, DMSO, and retinoic acid may provide useful information concerning the identification of differentiation-associated markers of human rectal cancer cells.
Abstract: The effects of sodium butyrate, dimethyl sulfoxide (DMSO), and retinoic acid on the growth, morphology, carcinoembryonic antigen content, cell surface membrane-associated enzyme activities, and glycoprotein profiles of a human rectal adenocarcinoma cell line (HRT-18) in culture were compared. All three agents reversibly caused a marked increase in doubling times, a decrease in saturation densities, and a markedly reduced colony-forming efficiency in soft agar. Only butyrate caused gross morphological changes including cell enlargement, flattening, and increased membranous process formation. Carcinoembryonic antigen content was increased during culture in butyrate, while it was reduced by DMSO and unchanged by retinoic acid. The activities of membrane-associated enzymes were altered significantly in the butyrate-treated cells. For example, an increase in the activities of alkaline phosphatase (10-fold), γ-glutamyl transpeptidase activity (3-fold) and sucrase activity (2-fold) was observed, while those of aminooligopeptidase and K + -stimulated phosphatase actually showed slight decreases. DMSO- or retinoic acid-treated cells showed a marked decrease in alkaline phosphatase activity, but other enzyme activities remained unchanged. Surface protein-labeling patterns of lactoperoxidase-catalyzed iodinated HRT-18 cells showed no significant change from the control cells following treatment with DMSO or retinoic acid. The most prominent change caused by butyrate treatment was the appearance of a major glycoprotein band with an apparent molecular weight of 60,000. These data indicate that the use of butyrate, DMSO, and retinoic acid may provide useful information concerning the identification of differentiation-associated markers of human rectal cancer cells. Furthermore, these agents, although having similar effects on the growth properties, have different effects on the morphology and on the biochemical properties of human rectal cancer cells.
148 citations
TL;DR: In this article, the pH stability of urease, acid phosphatase, alkaline phosphatases and phosphodiesterase was investigated by first incubating a soil sample at the indicated pH (1−13) for 24 h and then measuring the activity at its optimal pH under standardized conditions.
Abstract: The pH stability of urease, acid phosphatase, alkaline phosphatase and phosphodiesterase in soils was investigated by first incubating a soil sample at the indicated pH (1–13) for 24 h and then measuring the activity at its optimal pH under standardized conditions. Generally, the decline in enzyme activity in a pH-profile near the optimum pH range was due to a reversible reaction that involved ionization or deionization of acidic or basic groups in the active centre of the enzyme-protein. Irreversible inactivation of the enzyme was particularly evident at the lower and higher ranges of acidic and alkaline conditions. Results showed that the pH stability of soil enzymes was highly dependent on the soils being assayed. The variation among soils may be attributed to the diversity of vegetation, micro-organisms and soil fauna as sources contributing to the enzyme activity and to the protective sites which allowed entrapment of the enzyme within colloidal humus and organo-mineral complexes. Adherence of the enzyme-protein to the humic-clay fractions would allow some resistance to pH denaturation.
TL;DR: The target antigens of a series of monoclonal antibodies raised against a complex mixture of proteins have been identified by incubating nitrocellulose strips with the 'hybridoma' culture supernatants and detecting bound antibody using alkaline phosphatase conjugated to rabbit anti-mouse F(ab')2 antibody, and histochemical substrates.
TL;DR: Two lines of evidence showed that the PHO8 gene encodes the structure of repressible, nonspecific alkaline phosphatase in Saccharomyces cerevisiae: the enzyme produced by a temperature-sensitive pho8 mutant at the permissive temperature was more thermolabile than that of the wild-type strain, and the PHo8 gene showed a gene dosage effect on the enzyme activity.
Abstract: Two lines of evidence showed that the PHO8 gene encodes the structure of repressible, nonspecific alkaline phosphatase in Saccharomyces cerevisiae: (i) the enzyme produced by a temperature-sensitive pho8 mutant at the permissive temperature (25 degrees C) was more thermolabile than that of the wild-type strain, and (ii) the PHO8 gene showed a gene dosage effect on the enzyme activity. The pho8 locus has been mapped on chromosome IV, 8 centimorgans distal to rna3. A new mutant carrying the pho9 gene was isolated which lacks repressible alkaline phosphatase, but has the normal phenotype for the synthesis of repressible acid phosphatase. The pho9 gene segregated independently of all known pho-regulatory genes and did not show the gene dosage effect on repressible alkaline phosphatase activity. The pho9/pho9 diploid hardly sporulated and showed no commitment to intragenic recombination when it was inoculated on sporulation medium. Hence the pho9 mutant has a phenotype similar to the pep4 mutant, which was isolated as a pleiotropic mutant with reduced levels of proteinases A and B and carboxypeptidase Y. An allelism test indicated that pho9 and pep4 are allelic.
TL;DR: It is concluded that Cl2MDP is effective in the treatment of Paget's disease of bone and provides a prolonged response and dietary supplementation with calcium and vitamin D is desirable to prevent secondary hyperparathyroidism.
Abstract: Dichloromethylene diphosphonate (C12MDP) is a diphosphonate which markedly inhibits bone resorption. We have tested CUMDP in Paget's disease, a disorder characterized by increased bone remodeling. Sixty-three patients with progressive Paget's disease were treated for 6 months with Cl2MDP at daily oral doses of 400, 800, 1600, or 2400 mg. Thirty-nine patients received calcium and vitamin D supplements during treatment. Patients in all treatment groups had significant reduction in serum alkaline phosphatase, urinary hydroxyproline, skeletal uptake of 99mtechnetium-diphosphonate scintiscans, and resorption parameters on iliac crest biopsy samples as assessed by quantitative histomorphometry. Treatment was well tolerated and did not induce a skeletal mineralization defect. The reduction in alkaline phosphatase and urinary hydroxyproline persisted 1 yr after withdrawal of treatment. The biochemical remission was sustained in half of the patients 2 yr after the end of treatment and was accompanied by a marked r...
TL;DR: It is proposed that molybdate may act by complexing with sulfur groups on the receptor in a form such that reduction returns the receptor to the steroid binding state.
TL;DR: Human non-malignant testis, cervix, lung and thymus tissues contain small amounts of placental or placental-like ALPs, which appear to have the same characteristics as placental ALP and are probably encoded by the same gene locus.
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TL;DR: Treatment of the human rectal cancer cell line HRT-18 with sodium butyrate caused a reversible elevation of alkaline phosphatase activity which was inhibited by cycloheximide and actinomycin D, and the enzyme became more sensitive to all the inhibitors tested and more heat stable, compared to the enzyme in control cells.
Abstract: Treatment of the human rectal cancer cell line HRT-18 with sodium butyrate caused a reversible elevation of alkaline phosphatase activity which was inhibited by cycloheximide and actinomycin D. The alkaline phosphatase in untreated cells was heat stable at neutral pH and inhibited by phenylalanine but not by homoarginine, and 80% of the enzyme activity was precipitated by antibody against human term-placental enzyme. Following butyrate treatment, the enzyme became more sensitive to all the inhibitors tested and more heat stable, compared to the enzyme in control cells. In addition, the butyrate-induced enzyme could be completely precipitated by anti-placental alkaline phosphatase antibody. The electrophoretic pattern of the butyrate-induced enzyme was different from that of control cells. Control HRT-18 cells contained a butyrateinsensitive heat-labile alkaline phosphatase component with an electrophoretic mobility similar to the enzyme from human colon cancer tissues. The alkaline phosphatase from four human colon cancer tissues was of the early placental form, while the enzyme from human normal mucosa was of the intestinal type.
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TL;DR: The results show that the vitamin D metabolism is slightly abnormal in severely obese patients, following jejunoileal bypass, which is followed by severe disturbances ofitamin D metabolism.
Abstract: The serum levels of the three major vitamin D metabolites [25-hydroxyvitamin D (25-OHD), 1,25-dihydroxyitamin D (1,25-(OH)2D), 24,25-dihydroxyvitamin D (24,25-(OH)2 D)] and immunoreactive parathyroid hormone (iPTH) were measured in 14 morbid obese patients, who later on were subjected to jejunoileal bypass surgery. The preoperative median values of 25-OHD and 24,25-(OH)2D were reduced compared with controls (P less than 0.001), whereas elevated concentrations were found of 1,25-(OH)2D (P less than 0.005). Median levels of iPTH in the obese group were significantly higher than those found in normal subjects (P less than 0.001). A decrease was observed in serum concentrations of all three vitamin D metabolites following jejunoileal bypass (P less than 0.005). An increase in the serum levels of iPTH and alkaline phosphatase was seen postoperatively (P less than 0.002), probably indicating a secondary hyperparathyroidism. The results show that the vitamin D metabolism is slightly abnormal in severely obese patients. Jejunoileal bypass is followed by severe disturbances of vitamin D metabolism.
TL;DR: The results suggest that the pH of the medium may play an important role in the survival of the organism in phosphorus-limited environments.
Abstract: Summary: Growth conditions (carbon source and pH of the medium) affected the level and distribution of derepressed acid and alkaline phosphatases in Neurospora crassa. Regardless of the pH, the production of both acid and alkaline phosphatases was stimulated by sucrose. Irrespective of the carbon source used, at pH values higher than 7.4 the secretion of alkaline phosphatase was stimulated, while the production and secretion of acid phosphatase was restricted. The converse was true at pH values lower than 5.7. The secretion of one of these enzymes did not exclude the simultaneous secretion of the other at pH values of around 7.0. These results suggest that the pH of the medium may play an important role in the survival of the organism in phosphorus-limited environments.
TL;DR: The findings suggest that the infantile form of hypophosphatasia results from defective production of AP rather than from accelerated destruction of circulating enzyme, and that hydrolysis of AP substrates like PEA and PPi occurs primarily in tissue rather than blood.
TL;DR: The histone H1 fraction from the murine embryonal carcinoma cell line F9 can be resolved by two-dimensional gel electrophoresis into at least 15 components and shows that neither H1b nor H1d is essential for cell division.
TL;DR: The data suggest that an activity of five times the upper limit of the normal adult reference range is acceptable in the preterm infant but an activity higher than this may suggest rickets.
TL;DR: Four lines of evidence presented here suggest that the activity of cholesterol 7 alpha-hydroxylase in rat liver is modulated by changes in its phosphorylation state.
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TL;DR: The predictive value of the preoperative level of bilirubin, alkaline phosphatase and amylase as indicators of choledocholithiasis was determined by prospectively evaluating 304 consecutive patients undergoing cholecystectomy.
Abstract: The predictive value of the preoperative level of bilirubin, alkaline phosphatase and amylase as indicators of choledocholithiasis was determined by prospectively evaluating 304 consecutive patients undergoing cholecystectomy. Elevated levels of bilirubin and alkaline phosphatase are associated with an increased incidence of common duct stones, and the percentage incidence of stones increases with rising bilirubin and alkaline phosphatase levels. Alkaline phosphatase levels as great as 200 are associated with common duct stones in a low percentage of instances, being equivalent to that for unsuspected stones. Levels of 200 or greater are associated with a marked increase in the incidence of common duct stones. An elevated serum or urine amylase level, or both, is of little, if any, value as a predictor of common duct stones. Alkaline phosphatase appears to be a better indicator of common duct stones than does bilirubin, but neither bilirubin nor alkaline phosphatase in themselves are statistically significant indicators. Bilirubin and alkaline phosphatase in combination is a statistically significant predictor of common duct stones at all levels. The combination of a bilirubin level of greater than 3.0 and an alkaline phosphatase level of greater than 250 has a 76.2 per cent probability of an associated common duct stone. The quite important role of operative cholangiography in demonstrating unsuspected stones and in preventing unnecessary common duct explorations is reinforced.
TL;DR: It is demonstrated that T3 directly stimulates maturation and, to a lesser degree, growth-related processes in fetal mammalian growth-plate cartilage.
Abstract: A B S T R A C T We studied the effect of triiodothyronine (T3) on mammalian growth-plate cartilage in vitro. Growth-plate cartilages from fetal pigs scapulae were incubated for 3 or 7 d in serum-free medium alone or medium containing T3. Alkaline phosphatase activity, a marker of hypertrophied chondrocytes, was increased in T3 (10 nM)-treated growth-plate cartilage 152±36% above that of cartilage incubated in medium alone after 3 d of incubation, and 324±47% after 7 d of incubation. There was a dose-response increase in alkaline phosphatase activity to T3 over the range of 0.01-10 nM. The rise in alkaline phosphatase activity was specific for T3 since growth-plate cartilage alkaline phosphatase activity was not increased by cortisol, insulin, parathyroid hormone, or 5% fetal calf serum. Histological studies of growth-plate cartilage showed that T3 in a concentration-dependent manner increased the width of the zone of maturation (hypertrophied chondrocytes). Histochemical staining for alkaline phosphatase activity demonstrated that T3 caused the recruitment of new cells into the zone of maturation. T3 also stimulated incorporation of L[3H]leucine into protein and 35SO4 into proteoglycan in growth-plate cartilage. In contrast, T3 did not increase alkaline phosphatase activity or radiolabeled precursor incorporation into nongrowth-plate scapular cartilage. These studies demonstrate that T3 directly stimulates maturation and, to a lesser degree, growthrelated processes in fetal mammalian growth-plate cartilage.
TL;DR: The molecular characteristics of G6PD in the patient differed from those of all previously reported variants associated with CNSHA, so the present variant was provisionally called G 6PD Barcelona to distinguish it from other G6 PD variants previously described.
TL;DR: It was concluded that the increased Plasma levels of prolacting during lactation lead to high plasma levels of 1,25(OH)2D3 which are responsible for the enhanced intestinal calcium absorption.
Abstract: Intestinal calcium absorption and plasma levels of 1,25-dihydroxycholecalciferol (1,25(OH)2D3) were measured in lactating and non-lacting rats and the effects of bromocriptine and exogenous prolactin treatment were evaluated. In lacting rats calcium absorption and plasma levels of parathyroid hormone, 1,25(OH)2D3 and alkaline phosphatase activity were significantly increased. Bromocriptine treatment significantly reduced the enhanced calcium absorption and levels of plasma 1,25(OH)2D3 and alkaline phosphatase but had no significant effect on plasma levels of parathyroid hormone. Prolactin administered with bromocriptine to lactating animals prevented all the changes observed with bromocriptine treatment alone. It was concluded that the increased plasma levels of prolacting during lactation lead to high plasma levels of 1,25(OH)2D3 which are responsible for the enhanced intestinal calcium absorption.
TL;DR: The overall results showed no significant difference for serum calcium, phosphorus, alkaline phosphatase, immunoreactive parathyroid hormone, or 25-hydroxyvitamin D between thalassemic and control children, however, during the winter, serum 25-Hydroxycholecalciferol levels were very significantly decreased in thAlassemic children.
Abstract: Calcium and phosphate metabolism were studied in 22 patients with homozygous thalassemia. The overall results showed no significant difference for serum calcium, phosphorus, alkaline phosphatase, immunoreactive parathyroid hormone, or 25-hydroxyvitamin D between thalassemic and control children. However, during the winter, serum 25-hydroxycholecalciferol levels were very significantly decreased in thalassemic children. A study of the hands showed thin metacarpal cortices related to increased resorption. Histomorphometric study of four iliac bone biopsies showed normal osteoclastic resorption and decreased bone formation. Prussian blue staining and x-ray electron microprobe analysis showed iron deposits inside the bone. Whether this finding is critical in the pathogenesis of the bone disease is unknown.
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TL;DR: Evidence is provided that specific, partial dephosphorylation of NS molecules is the only detectable change in nucleocapsids treated with bacterial alkaline phosphatase under conditions that prevent the action of adventitious protease.
Abstract: In vitro transcription by vesicular stomatitis virus nucleocapsids is inhibited by enzymatic dephosphorylation of the NS protein. We provide evidence that specific, partial dephosphorylation of NS molecules is the only detectable change in nucleocapsids treated with bacterial alkaline phosphatase under conditions that prevent the action of adventitious protease. Dephosphorylation appeared to affect only the rate of transcription; there were no changes in sedimentation rates of transcripts. To identify the sites of phosphorylation required for NS activity in transcription, we examined phosphopeptides produced by chymotrypsin digestion of the two electrophoretic classes of NS molecules found in virions and infected cells. The electrophoretically slower class, NS1, abundant in the intracellular soluble pool, has a lower activity in transcription; it contained six chymotryptic phosphopeptides. Five of these peptides contained both phosphoserine and phosphothreonine, indicating that this peptide cluster represents at least 11 separate sites of phosphorylation. In the electrophoretically faster nucleocapsid-associated NS2 class of molecules, which support a higher rate of transcription, another group of eight phosphopeptides was superimposed on this pattern. Two of these peptides contained both phosphoserine and phosphothreonine, so this cluster of peptides represents at least 10 additional phosphorylation sites. These sites were especially sensitive to dephosphorylation by bacterial alkaline phosphatase. One or more of them appears to be responsible for the higher transcription rates medicated by NS2 molecules.