14 results for “Reaction Department”
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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
An experimental approach to the evaluation of the biopersistence of respirable synthetic fibers and minerals
…initial evaluation of solubility and durability, they cannot simulate the dynamics of inhalation deposition and clearance and the subsequent systemic reaction to fibers and minerals that occurs in the animal. To evaluate the biopersistence of synthetic…
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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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Medical study · Medical research · 1998
Contribution of reactive oxygen and nitrogen species to particulate-induced lung injury
…reactive oxygen species (superoxide anion, hydrogen peroxide, hydroxyl radical formed through Fenton/Haber-Weiss reactions) and of reactive nitrogen species, in which nitric oxide reacts with superoxide to form peroxynitrite, an oxidant that nitrates tyrosine residues…
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Medical study · Medical research · 1998
Reactive oxygen species: their relation to pneumoconiosis and carcinogenesis
…caused lung immune cells to release an inflammatory signaling protein (TNF-alpha), which the authors linked to metal-driven free radical reactions. The authors concluded that their studies support the hypothesis that ROS are involved in…
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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 · 1994
Oxygen radicals and asbestos-mediated disease
Asbestos fibers are potent elaborators of active oxygen species whether by reactions involving iron on the surface of the fiber, or by attempted phagocytosis of fibers by cell types resident in the lung. The link between…
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Medical study · Medical research · 1997
The role of oxygen free radicals in occupational and environmental lung diseases
…ROS-induced lung injury at different target levels may contribute to similar patterns of cell injury and alterations at the molecular level by initiation, propagation, and autocatalytic chain reactions. Intracellular signalling, activation and inactivation of enzymes…
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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
Mechanisms of fiber-induced genotoxicity
…during phagocytosis. Secondary molecules that are more stable than ROS are probably involved in DNA damage. Oxidoreduction reactions originating from cells can induce mutations. Genotoxicity is also demonstrated by chromosomal damage associated with impaired mitosis, as…
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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 · 1990
The effects of acid precipitation runoff episodes on reservoir and tapwater quality in an Appalachian Mountain water supply
…Several simultaneous reactions were hypothesized to be taking place in the distribution system that involved corrosion of metallic components and coating of asbestos-cement pipe components in part with corrosion products and in part by cations…
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Medical study · Medical research · 1997
Mineral properties and their contributions to particle toxicity
…that might influence a mineral's biological activity. Several important mineralogical characteristics control a mineral's reactivity in geochemical reactions and are likely to determine its biological reactivity. In addition to the traditionally considered variables of…