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)

Various biologic and non-biologic materials may be embolized to the brain after the use of cardiopulmonary bypass (CPB) pumps during open heart surgery but their relative frequency and importance are uncertain. Among the nonbiologic materials, Antifoam A, which contains organosilicates and silicon, continues to be employed as an additive to prevent frothing. Recent improvements in filtration and oxygenation techniques have clearly reduced the incidence of large emboli and complications like stroke but other neurologic sequelae following open heart surgery are common and in many cases poorly explained. A recently developed histochemical technique for the demonstration of the endothelial alkaline phosphatase (AP) was employed in a post-mortem study of brains from 8 patients and 6 dogs dying within a few days after open heart surgery employing cardiopulmonary bypass perfusion. Brains from 38 patients and 6 dogs who were not subjected to heart surgery were studied as controls with the same technique. The AP-stained slides are suitable for both light microscopic examination of the thick celloidin sections as well as a subsequent processing for high-resolution microradiography. Small capillary and arteriolar dilatations (SCADs) were seen in the test subjects/animals but not controls. SCADs were seen in all parts of the brain. Approximately 50% of the SCADs showed birefringence when examined with polarized light. SCADs are putative embolic phenomena and the exact nature and source of the embolic material is under investigation. A glycolipid component is indicated by preliminary studies. SCADs are difficult to find in routine paraffin sections and most if not all of the offending material seems to be dissolved during processing.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Brain embolic phenomena associated with cardiopulmonary bypass. 841 59

In this study we have investigated the behavior of fetal rat osteoblasts, cultured up to 23 days, on a bioactive apatite-wollastonite (AW) glass-ceramic and on the same material on which a carbonated apatite layer had been formed by a biomimetic process (AWa). At the last day of culture, the specific activity of alkaline phosphatase activity, as determined biochemically, was about 30% greater on AWa compared with AW disks. After the cell layers had been scraped off, scanning electron microscopic (SEM) observations of the materials' surfaces revealed that mineralized bone nodules remained attached to both surfaces but in larger amounts on AWa. X-ray microanalysis indicated the presence of calcium (Ca) and phosphorus (P) in the bone tissue throughout the AWa surface and Ca, P, and silicon (Si) on the AW surface. The AW/ and AWa/bone interfaces also were analyzed after fracturing of the disks. The interfacial analysis showed firm bone bonding to the AW and AWa surfaces, confirmed by the X-ray microanalytic mappings. These results indicate the importance of surface composition in supporting differentiation of osteogenic cells and the subsequent apposition of bone matrix, which allows a strong bond of the bioactive materials to the bone. Furthermore, prefabrication of a biologic apatite layer by a method that mimics biomineralization could find application to bone-repairing materials.
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PMID:In vitro bone formation on a bone-like apatite layer prepared by a biomimetic process on a bioactive glass-ceramic. 1060 76

Emboli become lodged in the brains of patients undergoing cardiopulmonary bypass (CPB) and can cause death, stroke, or more subtle neurological and neuropsychological deficits. Using a specialized vascular stain (for alkaline phosphatase) in autopsy tissues from the brains of patients who underwent CPB shortly before death, we found large numbers of microemboli. All of these microemboli contain lipid, some contain small birefringent particles, and some may contain aluminum or silicon. Within a few weeks after CPB, most of the microemboli had disappeared from the brain tissues, but some persisted for at least 6 months. After several days, the endothelial cells of some of the vessels containing microemboli showed subtle damage in the form of loss of alkaline phosphatase reactivity, and some vessels appeared to be degenerating. Sometimes the surrounding neuropil also showed degeneration. Since skin and muscle biopsies can be readily obtained before, during, and after CPB, we investigated their suitability as surrogate tissues for brain; however, they were unsuitable because they had so few microemboli. By injecting microspheres into dogs at various times during CPB, we have investigated the timing of the production of microemboli. We are also exploring the use of rat brains to trap microemboli from the injected blood of patients undergoing CPB. (ECHOCARDIOGRAPHY, Volume 13, September 1996)
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PMID:Histologic Studies of Brain Microemboli in Humans and Dogs After Cardiopulmonary Bypass. 1144 70

A sensitive conductimetric immunosensor has been demonstrated based on an ultrathin platinum film on an oxidized silicon base. The film is about 25 A thick and is seen to consist of a discontinuous layer with channels 20-30 A wide. Monoclonal antibodies were bound to the sensor surface using conventional biosensor chemistry. Impedance at fixed frequencies across the film was used to track modification and binding at the surface. Impedance increased 55% at 20 Hz during the activation of the surface with anti-alkaline phosphatase (anti-AP). Binding of alkaline phosphatase (AP) to the prepared surface results in a further increase of 12%. p-Nitrophenyl phosphate hydrolysis confirmed binding and activity of the AP. About 40 amol AP were bound on the 0.5 cm(2) electrode. Non-specific binding of horseradish peroxidase caused an impedance change <6%. Control experiments showed small impedance changes and trace enzyme activity. Since the mechanism of electrical conduction of the thin film was not established, modeling of thin-film response was used to distinguish between redox processes, capacitance and tunneling mechanisms. The data fit well with the diffusion distributed elements (DE) model as well as a transmission line distribution element (DX) model. The first model, DE, is distributed elements for diffusion. The second DX model represents a transmission line. The sensors behave in a distributed network or like a transmission line.
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PMID:An ultrathin platinum film sensor to measure biomolecular binding. 1167 51

Both arginine and silicon affect collagen formation and bone mineralization. Thus, an experiment was designed to determine if dietary arginine would alter the effect of dietary silicon on bone mineralization and vice versa. Male weanling Sprague-Dawley rats were assigned to groups of 12 in a 2 x 2 factorially arranged experiment. Supplemented to a ground corn/casein basal diet containing 2.3 microg Si/g and adequate arginine were silicon as sodium metasilicate at 0 or 35 microg/g diet and arginine at 0 or 5 mg/g diet. The rats were fed ad libitum deionized water and their respective diets for 8 wk. Body weight, liver weight/body weight ratio, and plasma silicon were decreased, and plasma alkaline phosphatase activity was increased by silicon deprivation. Silicon deprivation also decreased femoral calcium, copper, potassium, and zinc concentrations, but increased the femoral manganese concentration. Arginine supplementation decreased femoral molybdenum concentration but increased the femoral manganese concentration. Vertebral concentrations of phosphorus, sodium, potassium, copper, manganese, and zinc were decreased by silicon deprivation. Arginine supplementation increased vertebral concentrations of sodium, potassium, manganese, zinc, and iron. The arginine effects were more marked in the silicon-deprived animals, especially in the vertebra. Germanium concentrations of the femur and vertebra were affected by an interaction between silicon and arginine; the concentrations were decreased by silicon deprivation in those animals not fed supplemental arginine. The change in germanium is consistent with a previous finding by us suggesting that this element may be physiologically important, especially as related to bone DNA concentrations. The femoral and vertebral mineral findings support the contention that silicon has a physiological role in bone formation and that arginine intake can affect that role.
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PMID:Dietary silicon and arginine affect mineral element composition of rat femur and vertebra. 1246 47

The biological activity of osteoblasts on the newly developed bioactive poly(methyl methacrylate) (PMMA)/silica hybrid containing calcium salt was investigated. The attachment, proliferation, and differentiation of primary cultured mouse calvarial osteoblasts were evaluated by hexosaminase, MTT, and alkaline phosphatase activity assays, respectively. The PMMA/silica hybrid showed higher biological activities than those of pure PMMA with regard to all three parameters. Besides, the calcium phosphate layer, determined by scanning electron microscopy with energy dispersive spectroscopy, occurred only on the PMMA/silica hybrid. Better biological activities on the PMMA/silica hybrid than those on the PMMA were explained by the role of calcium phosphate layer formed on the PMMA/silica hybrid and the released calcium and silicon ions from it during the cell culture. These results suggest that the PMMA/silica hybrid might be useful as a bone substitute or filler.
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PMID:Biological activities of osteoblasts on poly(methyl methacrylate)/silica hybrid containing calcium salt. 1250 10

Silicon deficiency in animals leads to bone defects. This element may therefore play an important role in bone metabolism. Silicon is absorbed from the diet as orthosilicic acid and concentrations in plasma are 5-20 microM. The in vitro effects of orthosilicic acid (0-50 microM) on collagen type 1 synthesis was investigated using the human osteosarcoma cell line (MG-63), primary osteoblast-like cells derived from human bone marrow stromal cells, and an immortalized human early osteoblastic cell line (HCC1). Collagen type 1 mRNA expression and prolyl hydroxylase activity were also determined in the MG-63 cells. Alkaline phosphatase and osteocalcin (osteoblastic differentiation) were assessed both at the protein and the mRNA level in MG-63 cells treated with orthosilicic acid. Collagen type 1 synthesis increased in all treated cells at orthosilicic acid concentrations of 10 and 20 microM, although the effects were more marked in the clonal cell lines (MG-63, HCCl 1.75- and 1.8-fold, respectively, P < 0.001, compared to 1.45-fold in the primary cell lines). Treatment at 50 microM resulted in a smaller increase in collagen type 1 synthesis (MG-63 1.45-fold, P = 0.004). The effect of orthosilicic acid was abolished in the presence of prolyl hydroxylase inhibitors. No change in collagen type 1 mRNA level was seen in treated MG-63 cells. Alkaline phosphatase activity and osteocalcin were significantly increased (1.5, 1.2-fold at concentrations of 10 and 20 microM, respectively, P < 0.05). Gene expression of alkaline phosphatase and osteocalcin also increased significantly following treatment. In conclusion, orthosilicic acid at physiological concentrations stimulates collagen type 1 synthesis in human osteoblast-like cells and enhances osteoblastic differentiation.
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PMID:Orthosilicic acid stimulates collagen type 1 synthesis and osteoblastic differentiation in human osteoblast-like cells in vitro. 1263 84

Exposure to components of air pollution may cause adverse effects on lung cellular and organ functions through several mechanisms. Cell death, altered gene expression including production of cytokines, and modifications of normal cellular processes are possible outcomes that may be independent or coupled. To assess the effects of materials representative of a variety of particulate components of air pollution on lung epithelium, a human cell line of type II origin (A549 cells) was exposed to these materials in vitro. Materials tested included carbon black (CB), diesel soot from two sources (DS), residual oil fly ash (ROFA), Ottowa Ambient Air particulate (OAA), silicon dioxide (SiO2), and nickel subsulfide (Ni3S2). Endpoints included loss of adherence measured by crystal violet staining (CV), lactate dehydrogenase release (LDH), release of interleukin-8 (IL-8) measured by ELISA, and alkaline phosphatase activity in the cells (APc) and released into the supernatant (APS). Nuclear morphology was also examined. SiO2 and Ni3S2 both caused dose-dependent acute toxicity as assessed by LDH and CV, and caused alterations in nuclear morphology consistent with apoptosis. However, much more IL-8 was released into the tissue culture supernatant by SiO2 at the same levels of cytotoxicity than by Ni3S2. Neither of these acutely toxic materials increased APc or APS, but the less cytotoxic materials caused very significant release of AP in the order OAA > DS > ROFA >> SiO2 = Ni3S2. OAA and, to a lesser extent, DS caused increases in mitotic fraction and increased CV staining, consistent with stimulation of proliferation. These results suggest multiple modes of responses to toxic materials and imply that a toxicological screening process should address these and possibly other endpoints.
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PMID:Multiple modes of responses to air pollution particulate materials in A549 alveolar type II cells. 1288 95

An electrochemical enzyme-linked immobilized DNA-hybridization assay for the detection of Cryptosporidium parvum in water has been developed. The target molecule was a 121-nucleotide sequence from the C. parvum heat shock protein 70 (hsp70 mRNA from U71181 gene). This analyte offers the possibility of distinguishing dead from live oocysts. The assay involves covalent attachment of a primary DNA probe via its 5'-amine-terminus to self-assembled monolayers of mercaptoundecanoic acid to a gold surface. The primary DNA probe was used to capture the target (sequence 1039-1082 of U71181 gene for the mRNA), by hybridization to a 20-base complementary sequence on the target (at sequence 1063-1082). A secondary DNA probe labeled with alkaline phosphatase (AP) was then hybridized to base sequence 1039-1062 on the target. p-Aminophenol, which is enzymatically generated by the immobilized AP from p-aminophenyl phosphate (PAPP), is detected using electrochemistry. The peak current of cyclic voltammograms from a PAPP solution, in which gold-coated silicon wafer modified with the complete assembly of the assay components was incubated, is linear with concentration of the target (5-50 microg/mL, where P1 and P2-AP concentrations are 50 microg/mL). A detection limit of 2 microg/mL (or 146 nM) of the DNA target was obtained. Cross-reactivity tests showed high selectivity for heat-shocked C. parvum. No signal was obtained for either the synthetic DNA for hsp70 of Campylobacter lari, Escherichia coli, Giardia lamblia, Salmonella typhimurium, and Listeria monocytogenes or for the products of heat-shocked whole organisms of E. coli, G. lamblia, Staphylococcus aureus, and Cryptosporidium muris.
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PMID:Immobilized enzyme-linked DNA-hybridization assay with electrochemical detection for Cryptosporidium parvum hsp70 mRNA. 1457 58

Centromeres and telomeres are key structures of mitotic and meiotic chromosomes. Especially telomeres develop particular structural properties at meiosis. Here, we investigated the feasibility of scanning near-field optical microscopy (SNOM) for light-microscopic imaging of meiotic telomeres in the sub-hundred nanometer resolution regime. SNOM was applied to visualise the synaptonemal complex (SC) and telomere proteins (TRF1, TRF2) after differential immuno-fluorescent labelling. We tested and compared two different preparation protocols for their applicability in a SNOM setting using micro-fabricated silicon nitride aperture tips. Protocol I consisted of differential labelling of meiotic chromosome cores (SC) by SCP3 immuno-fluorescence and telomeres by TRF1 or TRF2 immuno-fluorescence, while protocol II combined absorption labelling with alkaline phosphatase substrates of cores with fluorescent labelling of telomeres. The results obtained indicate that protocol I reveals a better visualisation of structural (topographic) details than protocol II. By means of SNOM, meiotic chromosome cores could be visualised at a resolution overtopping that of far-field light microscopy.
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PMID:Imaging of human meiotic chromosomes by scanning near-field optical microscopy (SNOM). 1468 Sep 31


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