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

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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)

This study investigates the efficacy of using hydrogen peroxide as adjuvant therapy after extended local curettage for benign giant cell tumors of bone. Hydrogen peroxide is used clinically as a chemical adjuvant for removal of residual tumor cells, presumably by effervescent cleansing with minimal damage to surrounding soft tissue and bone cells. This investigation examined the effects of hydrogen peroxide on giant cell tumor cells and osteoblasts grown in culture. Fresh fragments of histologically confirmed giant cell tumor tissue (six patients) and trabecular bone (one patient) were excised. Cells obtained from the fragments were grown in culture. Confluent cell cultures were exposed to saline (control) or hydrogen peroxide (0.1-1000 mm) for 2 minutes, and incubation was continued for 12, 24, or 48 hours without hydrogen peroxide. Protein content, deoxyribonucleic acid content, tartrate resistant acid phosphatase activity, and alkaline phosphatase activity were measured in the cell layers. The medium from the final 12 hours of each incubation period was used to evaluate lactate production. Cell lysis or death occurred after exposing giant cell tumor cells and osteoblasts to 100 mm and 30 mm hydrogen peroxide, respectively, concentrations substantially lower than the 3% (880 mm) hydrogen peroxide commonly used clinically. These results support the theory of using a minimal concentration of hydrogen peroxide as a chemical adjuvant in the surgical treatment of giant cell tumors of bone.
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PMID:Hydrogen peroxide inhibits giant cell tumor and osteoblast metabolism in vitro. 952 Aug 98

The surface of implantable biomaterials is in direct contact with the host tissue and plays a critical role in determining biocompatibility. In order to improve the integration of implants, it is desirable to control interfacial reactions such that nonspecific adsorption of proteins is minimized and tissue-healing phenomena can be controlled. In this regard, our goal has been do develop a method to functionalize oxidized titanium surfaces by the covalent immobilization of bioactive organic molecules. Titanium first was chemically treated with a mixture of sulfuric acid and hydrogen peroxide to eliminate surface contaminants and to produce a consistent and reproducible titanium oxide surface layer. An intermediary aminoalkylsilane spacer molecule was then covalently linked to the oxide layer, followed by the covalent binding of either alkaline phosphatase or albumin to the free terminal NH2 groups using glutaraldehyde as a coupling agent. Surface analyses following coating procedures consisted of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Enzymatic activity of coupled alkaline phosphatase was assayed colorimetrically, and surface coverage by bound albumin was evaluated by SEM visualization of colloidal gold immunolabeling. Our results indicate that the linkage of the aminoalkylsilane to the oxidized surface is stable and that bound proteins such alkaline phosphatase and albumin retain their enzymatic activity and antigenicity, respectively. The density of immunolabeling for albumin suggests that the binding and surface coverage obtained is in excess of what would be expected for inducing biological activity. In conclusion, this method offers the possibility of covalently linking selected molecules with known biological activity to oxidized titanium surfaces in order to guide and promote the tissue healing that occurs during implant integration in bone and soft tissues.
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PMID:Chemical modification of titanium surfaces for covalent attachment of biological molecules. 954 28

Acute hypertension provokes a rapid decrease in proximal tubule sodium reabsorption with a decrease in basolateral membrane sodium-potassium-ATPase activity and an increase in the density of membranes containing apical membrane sodium/hydrogen exchangers (NHE3) [Y. Zhang, A. K. Mircheff, C. B. Hensley, C. E. Magyar, D. G. Warnock, R. Chambrey, K.-P. Yip, D. J. Marsh, N.-H. Holstein-Rathlou, and A. A. McDonough. Am. J. Physiol. 270 (Renal Fluid Electrolyte Physiol. 39): F1004-F1014, 1996]. To determine the reversibility and specificity of these responses, rats were subjected to 1) elevation of blood pressure (BP) of 50 mmHg for 5 min, 2) restoration of normotension after the first protocol, or 3) sham operation. Systolic hypertension increased urine output and endogenous lithium clearance three- to fivefold within 5 min, but these returned to basal levels only 15 min after BP was restored. Renal cortex lysate was fractionated on sorbitol gradients. Basolateral membrane sodium-potassium-ATPase activity (but not subunit immunoreactivity) decreased one-third to one-half after BP was elevated and recovered after BP was normalized. After BP was elevated, 55% of the apical NHE3 immunoreactivity, smaller fractions of sodium-phosphate cotransporter immunoreactivity, and apical alkaline phosphatase and dipeptidyl-peptidase redistributed to membranes of higher density enriched in markers of the intermicrovillar cleft (megalin) and endosomes (Rab 4 and Rab 5), whereas density distributions of the apical cytoskeleton protein villin were unaltered. After 20 min of normalized BP, all the NHE3 and smaller fractions of the other apical membrane proteins returned to their original distributions. These findings suggest that the dynamic regulation of proximal tubule sodium transport by acute changes in BP may be mediated by rapid reversible regulation of sodium pump activity and relocation of apical sodium transporters.
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PMID:Reversible effects of acute hypertension on proximal tubule sodium transporters. 957 7

This paper describes the employment of a novel phenoxy-substituted acridinium ester (di-ortho-bromophenyl-AE) as a chemiluminescent endpoint indicator for ligand binding assays. The reactivity of this compound is such that it is capable of generating a high-intensity chemiluminescent signal at neutral pH. Under these conditions, when present in excess, it has been used as an indicator of hydrogen peroxide generation by the action of glucose oxidase (GOx, EC 1.1.3.4) on glucose substrate. The resulting chemiluminescent signal is a long-lived glow. The magnitude of the chemiluminescent signal is directly proportional to the quantity of GOx present and has been used to measure GOx with a sensitivity of 1.8 x 10(-16) mol. In addition, this ability to monitor GOx activity has been utilized in an alkaline phosphatase (ALP, EC 3.1.3.1) amplification cascade assay. Here ALP catalyzes the formation of FAD from a prosthetogenic substrate FADP. FAD, a cofactor for a number of oxidase enzymes, then converts inactive apo-GOx to holo-GOx, the activity of which is monitored by the chemiluminescent endpoint and facilitates detection of ALP over the range 10(-15) to 4.1 x 10(-19) mol. The clinical utility of this system has been demonstrated by application to the assay of human thyrotrophin (TSH, sensitivity 0.005 mU/liter).
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PMID:Employment of a phenoxy-substituted acridinium ester as a long-lived chemiluminescent indicator of glucose oxidase activity and its application in an alkaline phosphatase amplification cascade immunoassay. 960 55

Off- and on-line strategies for a non-competitive heterogeneous flow immunoassay were developed comparing three different labels. The samples, containing the model compounds digoxin or digoxigenin, were either pre-incubated off-line or on-line in a mixing coil with excess of labelled anti-digoxigenin Fab-fragments. The excess of Fab-fragments was then separated from the digoxin bound Fab-fragments by passing the sample through a column with immobilised digoxin. The off-line immunochemical detection system is suitable for sensitive high through-put screening of the analytes, whereas the on-line system is more suitable for coupling as a post-column detection unit to liquid chromatography. The digoxin and digoxigenin content in the sample were quantified using fluorescein (F) and enzyme (peroxidase (POD), alkaline phosphatase (AP)) labelled Fab-fragments. The fluorescein label was directly measured with the fluorescence detector, whereas a fluorescent enzyme product was measured in the two enzyme based systems, using 3-(p-hydroxyphenyl)-propionic acid (HPPA) and hydrogen peroxide for POD and, and 4-methylumbelliferyl phosphate (4-MUP) for AP. The highest sensitivity and lowest limit of detection (LOD) was obtained with the Fab-POD system with LODs for digoxin and digoxigenin in the off- and on-line configurations of 0.025 and 0.01 nM, respectively. The sample through-put for the off- and on-line systems were 43 and 32 samples per hour, respectively.
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PMID:Optimisation of a heterogeneous non-competitive flow immunoassay comparing fluorescein, peroxidase and alkaline phosphatase as labels. 961 29

The lower levels of serum alkaline phosphatase (AP) activity found in patients with diabetes mellitus apparently originate from the selective disappearance or decrease in bone AP activity in the circulation. Hence, we investigated in vitro the effect of glycation on the activities of five AP isozymes. Aseptic incubation with 25 mmol/L of D-glucose and APs rapidly reduced bone and placental AP activities before those of liver, kidney and intestinal enzymes. The resulting bone and placental AP molecules were clearly glycated, according to the result of aminophenylboronic acid affinity chromatography. Furthermore, Western blotting analysis revealed that the placental AP molecule was fragmented, and its partial cleavage took place at Ala154 on the AP molecule. Since glycation of serum proteins causes the generation of reactive oxygen species, the effects of reactive oxygen species on placental AP activity were assayed, and the results indicated that hydroxyl radicals might be a major factor for the specific inactivation of AP activities. The reduction in AP activity by incubation with glucose in vitro was reversed by the further addition of catalase. Furthermore, ferrous ion with hydrogen peroxide, which generates hydroxyl radicals, had an inhibitory effect on AP activities. These findings suggest that the reduced AP activity in diabetic patients might result from partial cleavage of the bone AP molecule by reactive oxygen species induced by glycation.
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PMID:Partial breakdown of glycated alkaline phosphatases mediated by reactive oxygen species. 970 41

Ciprofibrates (racemate and both enantiomers, Raccip, R- and Scip) were administered orally in doses of 1 and 10 mg/kg once daily over 28 days to male inbred Fischer 344 rats, age 90-110 days at the beginning of the experiment. Body mass gain was observed in all groups. The 1 mg groups showed almost no difference to the control group. The 10 mg groups exhibited less body mass gain, most pronounced in the Scip group. Liver masses were increased in a dose dependent manner up to more than 200%, only the 10 mg Scip group was not significantly different from the 1 mg group which exhibited an increase in liver weight to about 175%. Also the kidney weights increased to 130%, whereas thymus and spleen weights were decreased in the high dose groups. Liver microsomal cytochromes P450 (P450) concentrations were not altered in the 1 mg groups and distinctly lowered in the 10 mg groups. Ethoxyresorufin and ethoxycoumarin O-deethylations were lowered in all experimental groups in a dose dependent manner, after administration of the high doses down to 30% of the control levels or less. Pentoxyresorufin O-depentylation, however, was increased in all 1 mg groups. In the high dose groups it was not altered. Ethylmorphine N-demethylation was decreased after administration of the high doses by about 50%, but only Scip decreased this reaction also after administration of the low dose. NADPH/Fe2+-stimulated microsomal luminol and lucigenin amplified chemiluminescence was increased, whereas hydrogen peroxide formation was depressed even by the low doses to 50% of the normal values, to about 25% by the high doses. Microsomal lipid peroxidation, however, was only slightly or not influenced. Glutathion concentrations (in the reduced and the oxidized form) were increased in a dose dependent manner by about 20 to 30%, the concentration of lipid peroxides was not significantly influenced. Thus, the effects of the enantiomers were not different and were similar to those of the racemate. In serum, cholesterol and triglycerides were only moderately lowered. Albumin concentrations were significantly enhanced in all groups, total proteins after 1 mg/kg Raccip only. Serum bilirubins were not altered, and among the indicator enzymes for liver damage only ALAT, alkaline phosphatase and the dehydrogenases were increased, in no case higher than twofold. Histologically distinct effects were seen after administration of both doses, more pronounced after 10 mg/kg, but with no differences between the enantiomers and Raccip: marked hypertrophy of the hepatocytes, reduced staining of the nuclei, strongly acidophilic granulated cytoplama, no basophilia of the cell bodies, loss of glycogen. These changes were most pronounced around the central veins. Hepatocyte apoptoses also were observed. By immunohistochemistry an increased staining was seen for all P450 isoforms tested (1A1, 2B1, 2E1, 3A2 and 4A1), predominantly perivenously and most pronounced after administration of the high doses without differences between Rcip, Scip or Raccip (preliminary results). By electron microscopy a moderate proliferation of peroxisomes after treatment with 1 mg/kg Cips with a ratio between mitochondria and peroxisomes of about 1:1 (controls: 10:1) was observed, and the peroxisomes were a more heterogeneous population. The relative portions of glycogen and both forms of the ER decreased. Treatment with 10 mg/kg Rcip, Scip or Raccip led to a strong increase in the number of peroxisomes, in some hepatocytes the ratio between mitochondria and peroxisomes was 1:3 with an increased heterogeneity among the peroxisomes evidenced by a broad range of electron densities. Most peroxisomes lacked a nucleoid. Thus, the biochemical effects differed only slightly and the morphological effects of the enantiomers were not different and were similar to those of the racemate.
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PMID:Ciprofibrate--racemate and enantiomers: effects of a four-week treatment on male inbred Fischer rats. A biochemical and morphological study. 978 2

Metabolic acidosis is almost invariably a consequence of advanced renal failure, although its severity can vary widely. To evaluate the determinants of the severity of metabolic acidosis, with special interest in determining if there is any difference in the prevalence and severity of metabolic acidosis between patients with and without diabetes, 113 predialysis patients with renal failure were studied. Criteria for inclusion onto the study were: creatinine clearance (Ccr)/1.73 m2 less than 30 mL/min, no alkali therapy within the previous 30 days, and the absence of respiratory diseases. Forty-eight patients had diabetes (33 patients with diabetic nephropathy). The following data were analyzed: demographics; cause of renal failure; hematocrit; serum urea, creatinine, uric acid, albumin, glucose, hemoglobin A1c, bicarbonate, sodium, potassium, chloride, calcium, phosphorus, and alkaline phosphatase levels; anion gap; urinary protein excretion; Ccr/1.73 m2; half of the sum of creatinine and urea clearances (Ccr-Cu); protein-equivalent nitrogen appearance (PNA); and whether the patients received diuretics (75 patients), angiotensin-converting enzyme inhibitors (54 patients), and/or calcium channel blockers (55 patients). After the exclusion of eight patients because of hypochloremia (three patients with and five patients without diabetes), mean serum bicarbonate levels were significantly greater in patients with diabetes than in the rest of the patients (20.7 +/- 2.3 v 18.2 +/- 2. 3 mmol/L; P = 0.0001). The mean anion gap (mmol/L) was also significantly less in patients with than without diabetes (19.70 +/- 3.65 v 22.35 +/- 3.64; P = 0.003). Eleven of 105 patients had serum bicarbonate levels of 23 mmol/L or greater (9 patients with and 2 patients without diabetes). Pure elevated anion gap followed by mixed (high anion gap and hyperchloremia) were the most common types of metabolic acidosis observed in both groups. There were no differences in PNA, diuretic treatment, or vomiting history between patients with and without diabetes. By multiple logistic regression analysis, the best determinants for a serum bicarbonate level greater than 19 mmol/L were: the diagnosis of diabetic nephropathy (odds ratio, 0.107; P = 0.0002), Ccr-Cu (odds ratio, 0.824; P = 0. 014), and age (odds ratio, 0.966; P = 0.046). In conclusion, patients with diabetes with advanced renal failure showed a less severe metabolic acidosis, which cannot be explained by gastrointestinal hydrogen ion losses, drugs, or reduced protein catabolic rate. Patients with diabetes may have a more efficient extrarenal generation of bicarbonate than end-stage renal failure patients without diabetes.
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PMID:Metabolic acidosis in advanced renal failure: differences between diabetic and nondiabetic patients. 1021 45

The motivation of simulating real-world environmental exposure in a number of long-term studies with dogs was to address the question of whether or not perpetual inhalation of air pollutants can initiate diseases in healthy lungs and can thus contribute to the increasing prevalence of respiratory diseases in industrialized countries. The major conclusion of this article is that this question has to be answered in the negative for the simultaneous inhalation of the major constituents of combustion-related air pollution, particle-associated sulfur(IV), and particle-associated hydrogen ions. Over 13 mo, 8 healthy beagle dogs were exposed in 2 whole-body chambers daily for 16.5 h to 1 microm neutral sulfite [sulfur(IV)] particles at a mass concentration of 1.5 mg m-3 and for 6 h to 1.1 microm acidic sulfate particles carrying 15 micromol m-3 hydrogen ions into the canine lungs. This longitudinal study was characterized by repeated observations of individual respiratory response patterns. To establish baseline data the dogs were repeatedly examined preexposure while the chambers were ventilated over 16 mo with clean air. Each individual served thus as its own control. Another eight dogs served as additional controls. They were housed in 2 chambers ventilated with clean air over the entire study period of 29 mo. To assess response patterns, respiratory lung function tests were performed pre- and postexposure, segmental lung lavages were repeatedly performed to obtain epithelial lining fluid from the lungs for analysis of cell content, cell function, and biochemical indicators of lung injury, and radiolabeled test particles were used to study pathways of intrapulmonary particle elimination. At the end of the study, the lungs of all animals were morphologically and morphometrically examined. Functional and structural responses were finally compared to those observed previously as a result of a sole exposure of canine lungs to neutral sulfite particles over 10 mo (Heyder et al., 1992). Interactions between responses induced by neutral sulfite and acidic sulfate particles occurred, but antagonism rather than synergism was observed. The responses induced by sulfur(IV) were less pronounced, not detectable, or even reversed when hydrogen ions were also delivered to the lungs. On the other hand, responses not induced by the sole exposure to sulfur(IV) were observed: The activity of alkaline phosphatase was elevated and type II pneumocytes proliferated. It can, however, be concluded that long-term exposure of healthy lungs to particle-associated neutral sulfur(IV) and hydrogen ions at concentration close to ambient levels causes subtle respiratory responses but does not initiate pathological processes in the lungs. In other words, the perpetual inhalation of sulfur(IV) and hydrogen ions from the atmospheric environment presents no health risk to the healthy lungs. It is thus also very unlikely that respiratory diseases can be initiated by the inhalation of these pollutants.
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PMID:Health effects of sulfur-related environmental air pollution. I. Executive summary. 1038 Jan 74

Recently, concern has been raised about effects related to environmental sulfur and/or acidic aerosols. To assess long-term effects on nonrespiratory lung function, 8 beagle dogs were exposed over a period of 13 mo for 16.5 h/day to a neutral sulfite aerosol at a sulfur(IV) concentration of 0.32 mg m(-3) and for 6 h/day to an acidic sulfate aerosol providing a hydrogen concentration of 15.2 micromol m(-3) for inhalation. Prior to exposure the dogs were kept under clean air conditions for 16 mo to establish physiological baseline values for each animal. A second group of eight dogs (control) was kept for the entire study under clean air conditions. No clinical symptoms were identified that could be related to the combined exposure. Biochemical and cellular parameters were analyzed in sequential bronchoalveolar lavage (BAL) fluids. The permeability of the alveolo-capillary membrane and diethylenetriaminepentaacetic acid (DTPA) clearance was not affected. Similarly, oxidant burden of the epithelial lining fluid evaluated by levels of oxidation products in the BAL fluid protein fraction remained unchanged. Both the lysosomal enzyme beta-N-acetylglucosaminidase and the alpha-1-AT were increased (p <.05). In contrast, the cytoplasmic marker lactate dehydrogenase remained unchanged, indicating the absence of severe damages to epithelial cells or phagocytes. Various surfactant functions were not altered during exposure. Three animals showed elevated levels of the type II cell-associated alkaline phosphatase (AP), indicating a nonuniform response of type II cells. Significant correlations were found between AP and total BAL protein, but not between AP and lactate dehydrogenase, suggesting proliferation of alveolar type II cells. Absolute and relative cell counts in the BAL fluid were not influenced by exposure. Alveolar macrophages showed no alterations with regard to their respiratory burst upon stimulation with opsonized zymosan. The percentage of alveolar macrophages capable of phagocytozing latex particles was significantly decreased (p<.05), while the phagocytosis index was not altered. In view of the results of this and previous studies, we conclude that there is no synergism of effects of these two air pollutants on nonrespiratory lung functions. It is hypothesized that antagonistic effects of these air pollutants on phospholipase A2-dependent pathways account for compensatory physiological mechanisms. The results emphasize the complexity of health effects on lung functions in response to the complex mixture of air pollutants and disclose the precariousness in the risk assessment of air pollutants for humans.
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PMID:Health effects of sulfur-related environmental air pollution. II. Cellular and molecular parameters of injury. 1038 Jan 75


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