Okadaic Acid
Mostrando 1-12 de 240 artigos, teses e dissertações.
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1. Presença de dinoflagelados bentônicos potencialmente tóxicos: identificação do perigo em áreas destinadas à maricultura na Baía de Sepetiba, RJ. / Presence of potentially toxic benthic dinoflagellates: identification of hazard in shellfish growing areas in the Sepetiba Bay, RJ.
The malacoculture (cultivation of shellfish) is the second most significant activity of the Brazilian mariculture, where the cultivation of bivalve molluscs (mussels, oysters and scallops) stands out nationally. The bivalves show an excellent nutritional value when they are used as food by humans, containing a great biological value of protein, low in fat, v
Publicado em: 2009
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2. Detecção de ácido ocadaico em cultivo de mexilhões Perna perna (Linnè, 1758) e identificação do fitoplâncton potencialmente produtor, em Maciéis, Angra dos Reis, RJ. / Okadaic acid detection in mussel cultivation, Perna perna (Linnè, 1758), and the fitoplankton identification potencially producer in the coast area of Maciéis, Angra dos Reis, RJ.
A ficotoxina ácido ocadaico (AO) é produzida por um grupo de microalgas conhecidas como dinoflagelados. Os mexilhões ao se alimentarem destas microalgas acumulam em seu hepatopâncreas, esta toxina, desencadeando no ser humano a Síndrome ou Envenenamento Diarréico por Moluscos - EDM. Os sintomas se apresentam em torno de 30 minutos após o consumo do mo
Publicado em: 2007
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3. Papel de fosfatases na viabilidade de celulas da leucemia mieloide humana tratadas com diterpeno lactona
patient with acute myeloid leukemia. This culture proliferates continuously in suspension and predominantly consists of promyelocytes and has been used as tool for cytotoxic studies of drugs, differentiation and cell death. ln this work was evaluated the cytotoxicity of protein phosphatases inhibitors (okadaic acid and pervanadate) and dehydrocrotonin (tDCTN
Publicado em: 2002
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4. Okadaic acid: an additional non-phorbol-12-tetradecanoate-13-acetate-type tumor promoter.
Okadaic acid is a polyether compound of a C38 fatty acid, isolated from a black sponge, Halichondria okadai. Previous studies showed that okadaic acid is a skin irritant and induces ornithine decarboxylase (OrnDCase; 3-hydroxyl-L-glutamate 1-carboxy-lyase, EC 4.1.1.17) in mouse skin 4 hr after its application to the skin. This induction was strongly inhibite
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5. Electromechanical effects of okadaic acid isolated from black sponge in guinea-pig ventricular muscles.
Okadaic acid is a monocarboxylic acid with a unique molecular structure of C44H66O13. Okadaic acid, at concentrations above 10(-5) M, caused a dose-dependent increase of contractile force in guinea-pig isolated ventricular muscles. The increase of contractile force by okadaic acid (1-4 X 10(-5) M) was accompanied by a prolongation of action potential duratio
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6. Okadaic acid suppresses calcium regulation of mitosis onset in sea urchin embryos.
We show that a phosphatase inhibitor, okadaic acid, induces premature and persistent mitosis during the first cell cycle in sea urchin embryos. Okadaic acid-induced mitosis requires protein synthesis, suggesting that it activates the protein synthesis-requiring mitotic H1 kinase. By microinjecting the calcium chelators BAPTA and EGTA and by measuring Cai usi
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7. Flat reversion by okadaic acid of raf and ret-II transformants.
Okadaic acid is a non-phorbol 12-myristate 13-acetate (PMA)-type tumor promoter on mouse skin and known to be a potent inhibitor of serine/threonine protein phosphatases. Contrary to expectation from its tumor-promoting activity, okadaic acid was shown to have a potential to revert the phenotypes of cells transformed by raf and ret-II to that of normal cells
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8. Okadaic acid regulation of the retinoblastoma gene product is correlated with the inhibition of growth factor-induced cell proliferation in mouse fibroblasts.
Okadaic acid, a specific inhibitor of protein phosphatases 1 and 2A, was used to study the mechanism of action of transforming growth factor beta (TGF-beta) on cell cycle progression in C3H/10T1/2 mouse embryonic fibroblasts, where TGF-beta exerts a growth-stimulatory effect. Concentrations of okadaic acid as low as 5 nM inhibited TGF-beta (5 ng/ml)- or 10%
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9. Regulation of collagenase gene expression by okadaic acid, an inhibitor of protein phosphatases.
Human collagenase gene expression is regulated transcriptionally and is inducible by various mitogens in many cell types. To investigate the molecular mechanisms of this response, we examined the effects on collagenase gene expression of okadaic acid, a non-12-O-tetradecanoyl-phorbol-13-acetate (TPA)-type tumor promoter, which induces apparent "activation" o
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10. Okadaic acid, an inhibitor of protein phosphatase 1 in Paramecium, causes sustained Ca2(+)-dependent backward swimming in response to depolarizing stimuli.
Backward swimming is a stereotypic behavioural response of Paramecium. It is triggered by depolarizing stimuli, which open calcium channels in the excitable ciliary membrane. The influx of Ca2+ causes the reversal of ciliary beat and initiates backward swimming. Here, we demonstrate that the protein phosphatase inhibitor okadaic acid does not affect the norm
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11. Hyperphosphorylation of N-60, a protein structurally and immunologically related to nucleolin after tumour-promoter treatment.
Okadaic acid, a non-TPA-type tumour promoter, induces hyperphosphorylation of a 60-kd protein in primary human fibroblasts. Treatment with TPA-type tumour promoters (e.g. TPA and teleocidin) did not cause this hyperphosphorylation. Phosphorylation of this protein was not seen at times earlier than 90 min after the addition of 75 ng/ml okadaic acid to the pro
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12. An okadaic acid-sensitive phosphatase negatively controls the cyclin degradation pathway in amphibian eggs.
Inhibition of okadaic acid-sensitive phosphatases released the cyclin degradation pathway from its inhibited state in extracts prepared from unfertilized Xenopus eggs arrested at the second meiotic metaphase. It also switched on cyclin protease activity in a permanent fashion in interphase extracts prepared from activated eggs. Even after cdc2 kinase inactiv