15 results for “Reaction Department”
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Medical study · Medical research · 1992
Generation of hydroxyl radical by crocidolite asbestos is proportional to surface [Fe3+]
…in concentrations varying from 0 to 250 mM. Inclusion of deferoxamine in the reaction mixture provided similar results of diminishing both TBA reactive products and dihydroxybenzoic acid generation. We conclude that oxidant generation by crocidolite is…
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Medical study · Medical research · 1993
Activation of UICC crocidolite: the effect of conversion of some ferric ions to ferrous ions
…The amount of iron in asbestos fibers, its oxidation state, and its availability to specific chelating agents determine their ability to catalyze the aforementioned reactions. In the present study, the activation of UICC crocidolite was achieved…
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Medical study · Medical research · 1997
Cellular mechanisms of reactive oxygen metabolite generation from human polymorphonuclear leukocytes induced by crocidolite asbestos
…an enhancement. We conclude that crocidolite-induced ROM generation involves a cell surface reaction due to influx of extracellular calcium through calcium channels and the activation of NADPH oxidase on the PMN cell membrane. This hypothesis…
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Medical study · Medical research · 1998
Modulation of mitochondrial gene expression in pulmonary epithelial cells exposed to oxidants
…RNA was extracted, reverse transcribed, and amplified by polymerase chain reaction with degenerate primers to visualize alterations in gene expression. The seven clones obtained were sequenced and encoded the mitochondrial genes, NADH dehydrogenase subunits ND5 and…
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Medical study · Medical research · 1994
Asbestos fibers and interferon-gamma up-regulate nitric oxide production in rat alveolar macrophages
…in macrophage conditioned medium, was assayed by the Griess reaction. Production of NO2- by AM was significantly increased by both chrysotile (P < 0.01) and crocidolite (P < 0.05) asbestos fibers (10 micrograms/ml…
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Medical study · Medical research · 1996
A study of the synergistic interaction of asbestos fibers with cigarette tar extracts for the generation of hydroxyl radicals in aqueous buffer solution
…This enhancement progressed with time, probably due to the reaction of the extracted iron with the slow released hydrogen peroxide from tar extracts. It was observed a fivefold increase in the ESR signal (for crocidolite and…
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Medical study · Medical research · 1997
Pleural macrophage recruitment and activation in asbestos-induced pleural injury
…by scanning electron microscopy. Pleural macrophage supernatants were assayed for production of nitric oxide (NO) (by the Griess reaction) and tumor necrosis factor alpha (TNF-alpha) (by an enzyme-linked immunosorbent assay method). Significantly greater amounts…
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Medical study · Medical research · 1997
Short-term inhalation and in vitro tests as predictors of fiber pathogenicity
…and SiC. However, measurements of BrdU uptake into lung cells showed that amosite and SiC produced a greater reaction than code 100/475, which itself caused no more proliferation than that seen in untreated lungs. These…
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Court case · Louisiana Supreme Court · April 13, 1999 · in the opinion
Ruckstuhl v. Owens Corning Fiberglas Corp. (1999)
…3201, listed specific activities by a defendant which would subject it to the personal jurisdiction of this state.\[2\] In reaction to [\885] the decision of the United States Supreme Court in World-Wide Volkswagen Corp…
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Medical study · Medical research · 1997
Efflux of reduced glutathione after exposure of human lung epithelial cells to crocidolite asbestos
…in the same level of intracellular GSH depletion and efflux and the same decrease in gamma-GCS activity as treatment with unmodified crocidolite, which suggests that iron-catalyzed reactions were not responsible for the GSH depletion.
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Medical study · Medical research · 1999
Role of transcription factor NF-kappaB in asbestos-induced TNFalpha response from macrophages
…were inhibited by oxygen radical scavengers and were enhanced by antioxidant enzyme inhibitors. These results indicate that asbestos-induced TNFalpha gene expression is mediated through a process that involves NF-kappaB activation and free radical reactions.
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Medical study · Medical research · 1997
Mechanism of asbestos-mediated DNA damage: role of heme and heme proteins
…in the presence of asbestos and hydrogen peroxide/organic peroxide/hydroperoxides. HRP catalyzes oxidation reactions in a manner similar to that of prostaglandin H synthetase. Iron released from asbestos is only partially responsible for DNA damage…
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Medical study · Medical research · 1997
Cell signaling pathways elicited by asbestos
…integrins. Alternatively, signaling pathways may be stimulated by active oxygen species generated both during phagocytosis of minerals and by redox reactions on the mineral surface. At least two signaling cascades linked to activation of transcription factors…
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Medical study · Medical research · 1998
Wollastonite fibers in vitro generate reactive oxygen species able to lyse erythrocytes and activate the complement alternate pathway
…ferric chloride and dithionite. In addition, ROS generation was partially inhibited (by 46-54%) in the reactions performed in the presence of 1,3-dimethyl-2-thiourea (DMTU), a strong hydroxyl radical scavenger. Wollastonite fibers were…
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Medical study · Medical research · 1997
Mobilization of iron from urban particulates leads to generation of reactive oxygen species in vitro and induction of ferritin synthesis in human lung epithelial cells
…Urban air particulates also contain iron, and some of the pathological effects after inhalation may be due to reactive oxygen species produced by iron-catalyzed reactions. Two standard reference material (SRM) urban air particulate samples were…