Consulta: subjectFacets:"Chemiluminescence"
Registros recuperados: 5
Data/hora: 01/06/2024 08:06:35

Determination of iron-porphyrin-like complexes at nanomolar levels in seawater
Provedor de dados: 5
Autores: Vong, Lilita; Laes, Agathe; Blain, Stéphane.
A new method for the non-specific determination of iron-porphyrin-like complexes in natural waters has been developed. It is based on the chemiluminescent oxidation of the luminol in the presence of dioxygen (O-2) at pH 13. The method has been implemented in a FIA manifold that allowed the direct injection of seawater. The limit of detection is 0.11 nM of equivalent hemin (Fe-protoporphyrin IX). Fe2+, Fe3+, H2O2, siderophore (deferoxamin mesylate), humic acid and phytic acid did not interfere when the), were present at the concentrations expected in seawater. Metal free porphyrin and Mg, Cu, Co porphyrin complexes did not induce a significant chemiluminescent signal. Poisoned unfiltered samples could be stored for several weeks before analyses. The new...
Tipo: Text
Palavras-chave: Chemiluminescence; Complexation; Flow injection; Seawater; Porphyrin; Iron.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3298.pdf

Toxicity to bivalve hemocytes of pathogenic Vibrio cytoplasmic extract
Provedor de dados: 5
Autores: Lambert, Christian; Nicolas, Jean-louis; Bultel, Valérie.
Using a chemiluminescence (CL) test, it had been previously demonstrated that Vibrio pectenicida, which is pathogenic to Pecten maximus larvae, was able to inhibit completely the CL activity of P, maximus hemocytes and partially inhibit those of Crassostrea gigas, Conversely, a Vibrio sp, strain, S322, pathogenic to C,gigas larvae was more active in reducing the CL activity of oyster hemocytes than of scallop hemocytes, Using this same CL biotest, V, pectenicida and S322 cytoplasmic extracts were shown to reproduce CL inhibition while the cytoplasmic extract of a nonpathogenic strain (U1, Pseudoalteromonas) was without effect. Moreover, cytoplasmic extract as well as live V, pectenicida cells provoked, within a few hours, death of P. maximus hemocytes...
Tipo: Text
Palavras-chave: Bivalves; Hemocyte; Toxin; Chemiluminescence; Crassostrea gigas; Pecten maximus; Vibrio pectenicida.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-466.pdf

Chemical, enzymatic and cellular antioxidant activity studies of Agaricus blazei Murrill
Provedor de dados: 42
Autores: HAKIME-SILVA,RICARDO A.; VELLOSA,JOSÉ C.R.; KHALIL,NAJEH M.; KHALIL,OMAR A.K.; BRUNETTI,IGUATEMY L.; OLIVEIRA,OLGA M.M.F.
Mushrooms possess nutritional and medicinal properties that have long been used for human health preservation and that have been considered by researchers as possible sources of free radical scavengers. In this work, the antioxidant properties of water extracts from Agaricus blazei Murill, produced by maceration and decoction, are demonstrated in vitro. Resistance to oxidation is demonstrated through three mechanisms: i) inhibition of enzymatic oxidative process, with 100% inhibition of HRP (horseradish peroxidase) and MPO (myeloperoxidase); ii) inhibition of cellular oxidative stress, with 80% inhibition of the oxidative burst of polymorphonuclear neutrophils (PMNs); and iii) direct action over reactive species, with 62% and 87% suppression of HOCl and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agaricus blazei Murrill; Antioxidant; Oxidant species; Chemiluminescence; Polymorphonuclear neutrophils.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652013000301073

Aluminum induces lipid peroxidation and aggregation of human blood platelets
Provedor de dados: 56
Aluminum (Al3+) intoxication is thought to play a major role in the development of Alzheimer's disease and in certain pathologic manifestations arising from long-term hemodialysis. Although the metal does not present redox capacity, it can stimulate tissue lipid peroxidation in animal models. Furthermore, in vitro studies have revealed that the fluoroaluminate complex induces diacylglycerol formation, 43-kDa protein phosphorylation and aggregation. Based on these observations, we postulated that Al3+-induced blood platelet aggregation was mediated by lipid peroxidation. Using chemiluminescence (CL) of luminol as an index of total lipid peroxidation capacity, we established a correlation between lipid peroxidation capacity and platelet aggregation. Al3+...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Aluminum; Lipid peroxidation; Chemiluminescence; Platelet aggregation.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000500005

Effect of therapeutic plasma concentrations of non-steroidal anti-inflammatory drugs on the production of reactive oxygen species by activated rat neutrophils
Provedor de dados: 56
Autores: Paino,I.M.M.; Ximenes,V.F.; Fonseca,L.M. da; Kanegae,M.P.P.; Khalil,N.M.; Brunetti,I.L.
The release of reactive oxygen specie (ROS) by activated neutrophil is involved in both the antimicrobial and deleterious effects in chronic inflammation. The objective of the present investigation was to determine the effect of therapeutic plasma concentrations of non-steroidal anti-inflammatory drugs (NSAIDs) on the production of ROS by stimulated rat neutrophils. Diclofenac (3.6 µM), indomethacin (12 µM), naproxen (160 µM), piroxicam (13 µM), and tenoxicam (30 µM) were incubated at 37ºC in PBS (10 mM), pH 7.4, for 30 min with rat neutrophils (1 x 10(6) cells/ml) stimulated by phorbol-12-myristate-13-acetate (100 nM). The ROS production was measured by luminol and lucigenin-dependent chemiluminescence. Except for naproxen, NSAIDs reduced ROS production:...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Non-steroidal anti-inflammatory drugs; Neutrophils; Myeloperoxidase; Hypochlorous acid; Reactive oxygen species; Chemiluminescence.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000400007