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)

Colorectal epithelium is composed of a variety of cell types, including absorptive, mucous and endocrine cells. All of these cell types are thought to arise from stem cells located at the base of the crypt. However, the factors which control these differentiation pathways are poorly understood. In attempts to establish differentiated in vitro systems, one approach has been to grow primary human colorectal adenocarcinomas as cell lines. Some of these cell lines retain a sufficient number of the differentiated features of their tissue of origin to make them useful experimental systems for studying differentiation. This study describes the characterisation of such a cell line, the HRA-19 line. HRA-19 cells were derived from a primary human rectal adenocarcinoma. The cells grew as monolayers in vitro on tissue-culture plastic and remained pleomorphic even after 150 passages in vitro. Some colonies of cells expressed alkaline phosphatase activity, an enzyme normally expressed in vivo by absorptive cells of the upper crypt and surface epithelium. No evidence of differentiation into goblet or endocrine cells was obtained in monolayer cultures of HRA-19 cells. Xenografts of this cell line contained cells with the ultrastructural characteristics of absorptive and endocrine cells. These endocrine cells exhibited Grimelius silver staining, displayed formaldehyde-induced fluorescence and contained many basally located, electron-dense granules. When grown as monolayers, clones of this cell line retained the heterogeneity with respect to morphology and alkaline phosphatase expression of the parent cell line. It is proposed that this cell line is derived from malignant progenitor cells which retain the ability to differentiate.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Endocrine differentiation by a human rectal adenocarcinoma cell line (HRA-19). 356 97

Male and female albino Wistar rats were exposed to concentrations of 0, 1, 10 or 20 ppm formaldehyde vapour during 6 h/day, 5 days/wk for 13 weeks. Treatment-related changes observed at 20 ppm included in both sexes: stared coats, uncoordinated locomotion and excitation during the first 30 minutes of each exposure, yellowing of the fur, growth retardation, a decreased level of plasma protein, severe and extensive karatinized stratified squamous metaplasia of the nasal respiratory epithelium, and focal degeneration and squamous metaplasia occasionally accompanied by keratinization of the olfactory epithelium; in males only; increased activities of plasma aspartate amino transferase (ASAT), alanine amino transferase (ALAT) and alkaline phosphatase (ALP) and squamous metaplasia of the laryngeal epithelium. Lesions seen at 10 ppm included yellowing of the fur and moderate squamous metaplasia of the nasal respiratory epithelium. The only change observed in three out of twenty 1 ppm exposed animals that might or might not be treatment-related was minimal focal epithelial hyperplasia and squamous metaplasia of the respiratory epithelium lining the nasal septum and maxillary turbinates. No histopathological evidence of hepatotoxicity was detected in any of the formaldehyde-treated groups. An in vivo/in vitro cell proliferation study showed an increase in [3H]-thymidine labeling index of the respiratory epithelium lining the nasoturbinates of rats exposed to 10 or 20 ppm formaldehyde on three successive days, whereas at the 1 ppm level the labeling index was similar to that of controls. It was concluded that under the conditions of the present 13-week inhalation study, formaldehyde at concentrations up to 10 ppm was not hepatotoxic to rats. At the 20 ppm formaldehyde level, a slight effect on the liver of male rats cannot be completely excluded. The study was inconclusive with respect to 1 ppm formaldehyde being a cytotoxic or a no-cytotoxic effect level for the nasal epithelium.
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PMID:Subchronic (13-week) inhalation toxicity study of formaldehyde in rats. 361 96

Photobiotin was used to prepare biotinylated, nonradioactive nucleic acid probes for the detection of the RNA of barley yellow dwarf virus (BYDV) in plant extracts. A 1.7-kb cDNA of the PAV isolate of BYDV in the plasmid pUC8 vector was biotinylated and then used intact or as sonicated double-stranded DNA fragments. Simple methods were developed for the preparation of partially purified nucleic acid extracts of cereals and their spotting, after formaldehyde treatment, onto nitrocellulose membranes. After hybridization, biotin-labelled DNA bound to BYDV RNA on the nitrocellulose was detected with an avidin-alkaline phosphatase conjugate. BYDV RNA was readily detected with a sensitivity similar to that found with the same probe labelled with 32P by nick translation. Healthy plant extracts gave colourless spots.
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PMID:Nonradioactive, photobiotin-labelled DNA probes for the routine diagnosis of barley yellow dwarf virus. 365

Despite biochemical demonstration of acid phosphatase (AcP) activation or reactivation in bone, few attempts have been made to show similar effects histochemically. Bones from growing rats, when fixed in 4% buffered formaldehyde at room temperature and demineralized in 5% formic acid, exhibited expected inactivation of AcP. The inhibited AcP, however, was reactivated by pre-incubation of sections for 1 hr at 37 degrees C in the following buffers: 0.2 M Tris, 0.2 M glycine, 0.2 M NaHCO3, or 0.1 M borax, as well as in alkaline water, but not in 0.2 M Na2HPO4 (all at pH 9). The reactivation was (a) site-specific (e.g., osteoclasts, osteoblasts, osteocytes, and cement lines), (b) temperature- and pH-dependent, (c) unaffected by OH- or SH--binding agents or by an alkaline phosphatase inhibitor, and (d) inhibited completely by 10 mM Na2HPO4. The reactivation process, much simplified and/or more effective than with the methods previously reported, was observed in all 83 human biopsy bones embedded in methyl methacrylate and in human bones stored in cold buffered formaldehyde for 7 months. This study demonstrates a unique method for reactivating and thus localizing the inhibited AcP in bones, and suggests possible applications in bone histomorphometry.
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PMID:Reactivation of inhibited bone acid phosphatase and its significance in bone histomorphometry. 368 Sep 30

The latex immunoassay can be considered a quickly practicable and simple methodic variant of the immunoassay. In this work principles and present capability of this assay are stated. Own experiments deal with the adsorption reaction of alkaline phosphatase and horseradish peroxidase at polystyrol respectively melanin formaldehyde lattices. The adsorption reaction of several lattices is partly extremely different. Problems concerning the construction of an assay useful for practical purposes are discussed.
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PMID:[Latex immunoassay]. 373 58

Cytochemical studies of Escherichia coli at the light and electron microscopic levels have revealed alkaline phosphatase, hexose monophosphatase, and cyclic phosphodiesterase reaction products in the periplasmic space and at the cell surface. In preparations for both light and electron microscopy, reaction product filled polar caplike enlargements of the periplasmic space, such as those described in plasmolyzed cells, indicating significant terminal concentrations of these enzymes; dense substance was often seen within these polar caps in morphological specimens. Staining of the bacterial surface was commonly encountered, but could represent artifactual accumulation of precipitate along the cell wall. Alkaline phosphatase was demonstrated with several substrates (ethanolamine phosphate, glycerophosphate, p-nitrophenylphosphate, and glucose-6-phosphate) over a wide pH range in a bacterial strain (C-90) known to be constitutive for this enzyme, whereas strains deficient in this enzyme (U-7, repressed K-37), showed no activity with these substrates. Hexose monophosphatase and cyclic phosphodiesterase activities were characterized by reaction-product deposition with specific substrates at acid or neutral, but not at alkaline, pH in strains of E. coli lacking alkaline phosphatase (U-7 and repressed K-37). Fixation in Formalin or the use of calcium as a capture reagent seemed to interfere with periplasmic staining in cells prepared for electron microscopy. Formalin fixation had little effect on biochemical assays of the phosphatase activity of intact cells in suspension, but partially reduced the activity evident in sonically treated extracts or in suspensions of dispersed cryostat sections. Glutaraldehyde treatment impaired enzyme activity more drastically.
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PMID:Cytochemical localization of certain phosphatases in Escherichia coli. 431 24

(11)CO(2) produced in the Brookhaven 152-cm cyclotron was converted to formaldehyde, which in turn was used for the enzymatic conversion of deoxyuridine-5'-phosphate to [(11)C]thymidylate. Enzymatic treatment of the nucleotide with alkaline phosphatase gave [(11)C]thymidine.The preparation of [(11)C]thymidine from cyclotron-generated (11)CO(2) required 110 min (about 5 half-lives): 35 min for the synthesis of H(11)CHO, 25 min for the enzymatic conversion to [(11)C]thymidylate, 20 min for column chromatography, 5 min for phosphatase treatment, 10 min for evaporation, 2 min for filtration through an anion-exchange resin, and 13 min for miscellaneous manipulations.Positron-emitting [(11)C]thymidine and [(11)C]thymidylate were used for in vivo tracer studies of DNA synthesis in mice for periods of up to 3 hr. Findings with carbon-11 were consistent with earlier studies in which carbon-14 and tritium-labeled thymidine were used. For example, 3 hr after injection of [(11)C]thymidine, spleen DNA was labeled to a much greater extent than was liver DNA.
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PMID:Detection of DNA synthesis in intact organisms with positron-emitting (methyl- 11 C)thymidine. 455 38

Inosine 5'-diphosphatase (IDPase) activity was demonstrated cytochemically in the endoplasmic reticulum of rat kidney proximal tubule cells in tissue fixed by perfusion with glutaraldehyde--formaldehyde. Incubation for IDPase activity at pH 7.2 was performed with and without 0.5 mM levamisole, a potent inhibitor of alkaline phosphatase (AlkPase) (M Borgers, J Histochem Cytochem 21:812, 1973). Levamisole treatment of sections eliminated all reaction product in the brush border, but did not affect the IDPase activity the endoplasmic reticulum (ER). The ER appears as a basilar-luminal-oriented transcellular structure, suggesting a possible cellular transport route. This study supports and extends earlier observations made by others that suggest a transport role for the ER in these cells. It also emphasizes the value of thick section cytochemistry.
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PMID:Transepithelial endoplasmic reticulum in rat proximal convoluted tubule. 613 47

We applied a simple lead salt-based stain for interstitial and vascular 5'-nucleotidase to 150 muscle biopsy specimens. No reaction was obtained with 2'- or 3'-adenosine monophosphate, indicating that the stain was specific, and distinct from phosphatases. Staining was not inhibited by alpha, beta-methylene adenosine 5'-diphosphate, but was prevented by formaldehyde fixation or by brief immersion in octoxynol 9 (Triton X-100). Nucleotidase stains the following specific histologic sites that distinguish it from alkaline phosphatase: the intima and adventitia of medium-sized and large arteries, perineural and muscle spindle sheaths, and tendon insertions. Aside from these structures, normal muscle shows little reaction, as the sarcoplasm and sarcolemma do not stain. Neither of these enzymes shows a compensatory increase, histochemically, in myo-adenylate deaminase deficiency. In Duchenne's muscular dystrophy, however, and particularly in inflammatory myopathy, interstitial staining of 5'-nucleotidase is increased, leading to investment of most muscle fibers in the affected area. The stain rarely identifies regenerating fibers. Although alkaline phosphatase commonly shows a corresponding increase in interstitial staining, we encountered six cases of inflammatory myopathy in which this was absent, despite pronounced endomysial staining in the 5'-nucleotidase reaction. 5'-Nucleotidase thus appears to provide a valuable adjunct in the diagnosis of inflammatory myopathy.
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PMID:Interstitial 5'-nucleotidase stain for frozen biopsy specimens of skeletal muscle. A useful adjunct in the diagnosis of polymyositis. 619 1

Exposure to formaldehyde appears to be associated with hepatoxicity in many species, including humans, following injection, ingestion, or inhalation. Macroscopic, microscopic, and biochemical manifestations in the liver include alterations in weight, centrilobular vacuolization, focal cellular necrosis, and increased alkaline phosphatase concentrations. Time-related changes in the pattern of the effects are suggested as one goes from acute exposure by inhalation at greater concentrations to repeated exposure at lesser concentrations. Although the hepatic changes are generally not extensive and can be reversible following acute exposure, the potential exists for them to progressively become more serious with repeated exposures. There are several possible mechanisms for the toxicity. Depending on the route of exposure could include direct effects on hepatocytes and/or indirect effects through the circulatory and immune systems. The catabolism of formaldehyde includes conversion to CO2 by reactions involving glutathione. Many hepatotoxic chemicals require glutathione for detoxification. Formaldehyde may then have the potential to cause additive toxicity with such chemicals in some circumstances.
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PMID:Formaldehyde and hepatotoxicity: a review. 638 92


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