51 results for “Reaction Department”, page 1 of 3
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Medical study · Medical research · 1987
Hydroxyl radical production in the presence of fibres by a Fenton-type reaction
…of people who inhale them. Results in the present study however indicate that these fibres are able to produce hydroxyl radicals in the presence of hydrogen peroxide by a Fenton-type reaction. Since hydroxyl radical is…
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Medical study · Medical research · 2006
Analysis of asbestos-induced gene expression changes in bronchiolar epithelial cells using laser capture microdissection and quantitative reverse transcriptase-polymerase chain reaction
…Extraction of RNA from microdissected tissue followed by quantitative reverse transcriptase-polymerase chain (QRT-PCR) reaction permits the analysis of cell-type or microstructure-specific gene expression changes that occur in response to various stimuli in…
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Medical study · Medical research · 1987
Response of mouse lung to crocidolite asbestos. 1. Minimal fibrotic reaction to short fibres
This was an animal experiment from the University of Manitoba, Winnipeg, on how mouse lungs respond to short crocidolite asbestos fibres. The authors separated short fibres from a standard UICC crocidolite sample. These had a mean length of 0.6…
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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 · 2003
Asbestos bodies: clues to the mechanism of asbestos toxicity?
…lung, ascorbate was oxidized to oxalate in the presence of H2O2, a reaction inhibited by the iron chelator deferoxamine. The author called this a novel mechanism that may contribute to the pathogenicity of asbestos fibers. Oxidation…
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Medical study · Medical research · 2002
Early inflammatory response to asbestos exposure in rat and hamster lungs: role of inducible nitric oxide synthase
…inducible nitric oxide synthase (iNOS) plays a role in the development of asbestos-related pulmonary disorders. The pulmonary reactions of rats and hamsters upon exposure to asbestos fibers are well known to be disparate. In addition…
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Medical study · Medical research · 1983
Lipid peroxidation in microsomes induced by crocidolite fibres
…produced a concomitant induction in microsomal lipid peroxidation. This increase was very rapid as the reaction was almost complete within 10 min. The ability of these fibres to induce this process after a short period of…
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Medical study · Medical research · 2001
Study of inflammatory responses to crocidolite and basalt wool in the rat lung
…dehydrogenase (LDH) activity were determined in the bronchoalveolar lavage (BAL). Both types of fibers induced a prolonged inflammatory reaction in the lung. All the parameters studied in the experimental groups were more markedly elevated after 3…
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Medical study · Medical research · 1987
Enhanced lipid peroxidation and lysosomal enzyme activity in the lungs of rats with prolonged pulmonary deposition of crocidolite asbestos
…for example 75.87 versus 30.81 mg at three months), and microscopy showed granulomas containing fibres. The fibrotic reaction tended to diminish by seven months. Activity of two lysosomal enzymes, beta-glucuronidase and cathepsin D…
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Medical study · Medical research · 2003
Ascorbic acid modifies the surface of asbestos: possible implications in the molecular mechanisms of toxicity
…consequence of the erosion of the outmost layers while hydration of silica tetrahedra yields new silanol groups. The activity in the Fenton-like reaction (OH from H(2)O(2)) decreases following surface iron depauperation. Conversely…
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Medical study · Medical research · 2001
Free radical generation in the toxicity of inhaled mineral particles: the role of iron speciation at the surface of asbestos and silica
…1.3 to 29 nmol/mg. It also increased one radical reaction, breaking a carbon-hydrogen bond, about 3-fold, while heating in air fully stopped that reaction. The other reaction, hydroxyl radical release from hydrogen…
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Medical study · Medical research · 1987
Response of mouse lung to crocidolite asbestos. 2. Pulmonary fibrosis after long fibres
…These findings suggest that injury to bronchial and bronchiolar epithelium allows long fibres to reach the interstitium where subsequent macrophage-fibroblast interactions result in a severe fibrotic reaction that resembles the bronchiolar component of human asbestosis.
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Medical study · Medical research · 1987
Crocidolite-induced lipid peroxidation in rat lung microsomes. I. Role of different ions
…in rat lung microsomes both from rats pretreated with 3-methylcholanthrene and from untreated controls. This increase was dependent on the concentration of these ions in the reaction mixture. Crocidolite alone increased peroxidation in microsomal fractions…
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Medical study · Medical research · 2011
A 3-dimensional in vitro model of epithelioid granulomas induced by high aspect ratio nanomaterials
The most common causes of granulomatous inflammation are persistent pathogens and poorly-degradable irritating materials. A characteristic pathological reaction to intratracheal instillation, pharyngeal aspiration, or inhalation of carbon nanotubes is formation of epithelioid granulomas accompanied by…
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Medical study · Medical research · 2021
MicroRNA expression in lung tissues of asbestos-exposed mice: Upregulation of miR-21 and downregulation of tumor suppressor genes Pdcd4 and Reck
…mice four times weekly. We extracted total RNA from lung tissues and performed microarray analysis for miRNA and gene expression. We also carried out real-time polymerase chain reaction (PCR), Western blotting, and immunohistochemistry to confirm…
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Medical study · Medical research · 2020
Induction of Gamma-Glutamyltransferase Activity and Consequent Pro-oxidant Reactions in Human Macrophages Exposed to Crocidolite Asbestos
…its fibers as well as to its content of iron. The latter can in fact react with macrophage-derived hydrogen peroxide in the so called Fenton reaction, giving rise to highly reactive and mutagenic hydroxyl radical…
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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 · 2001
Changes in DNA 8-hydroxyguanine levels, 8-hydroxyguanine repair activity, and hOGG1 and hMTH1 mRNA expression in human lung alveolar epithelial cells induced by crocidolite asbestos
…and human MUtT homologue (hMTH1). This was done using a high-performance liquid chromatography system equipped with an electrochemical detector, endonuclease nicking assay and reverse transcription polymerase chain reaction, respectively. Crocidolite induced the formation of 8…
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Medical study · Medical research · 2008
Characteristics and modifying factors of asbestos-induced oxidative DNA damage
…Natural iron chelators, such as citrate, adenosine 5'-triphosphate and guanosine 5'-triphosphate, did not inhibit this reaction. Second, we used time-lapse video microscopy to evaluate how cells cope with asbestos fibers. RAW264.7 cells…