Minerals, Fibrosis, and the Lung

Heppleston, A. G.

doi:10.2307/3431309

Cited by 20 publications

(15 citation statements)

References 182 publications

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“…A calculation of the number of particles in 250 µg of zeolite Y, based on a density of 2.3 g/cm 3 and a radius of 0.9 µm (assuming a spherical shape) gives rises to an estimated value of 300 particles/cell. Although this number is high, cell viability is retained: Light microscopy showed similar numbers of living cells before and after exposure to particles.…”

Section: Phagocytosis and The Oxidative Burstmentioning

confidence: 99%

“…Epidemiologic data suggest that environmental and/or occupational exposure to minerals, metals, and fibers can cause lung disease (1)(2)(3). These diseases typically develop over many years after exposure to the agents.…”

mentioning

confidence: 99%

“…These diseases typically develop over many years after exposure to the agents. The most studied fiber is asbestos (1)(2)(3). Man-made mineral or vitreous fibers can also be bioactive, though their role in respiratory disease in humans is not yet well established and is an active area of study (4,5).…”

mentioning

confidence: 99%

“…Epidemiologic and experimental data have demonstrated that exposure to asbestos can induce pulmonary inflammation, fibrosis of the lower respiratory tract (asbestosis) (1)(2)(3)6) and is a risk factor for developing bronchiogenic carcinoma and mesothelioma (7). Numerous studies have been performed over the past 30 years to determine the mechanism(s) by which asbestos causes disease, and several hypotheses have been generated (8).…”

mentioning

confidence: 99%

“…Numerous studies have been performed over the past 30 years to determine the mechanism(s) by which asbestos causes disease, and several hypotheses have been generated (8). Activation of macrophages by phagocytosis of the fibers results in the formation of reactive oxygen species (ROS) (1)(2)(3)6,9,10), where ROS is a collective term that includes radicals (superoxide anion, hydroxyl, peroxyl, and alkoxyl radicals), and hydrogen peroxide (H 2 O 2 ). Iron bound to the fibers can generate hydroxyl radicals via the Fenton reaction, which can initiate lipid peroxidation, resulting in the production of intermediates that oxidize intracellular proteins and DNA (11,12).…”

mentioning

confidence: 99%

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Analysis of the biological and chemical reactivity of zeolite-based aluminosilicate fibers and particulates.

Fach

Waldman

Williams

et al. 2002

Environ Health Perspect

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Environmental and/or occupational exposure to minerals, metals, and fibers can cause lung diseases that may develop years after exposure to the agents. The presence of toxic fibers such as asbestos in the environment plus the continuing development of new mineral or vitreous fibers requires a better understanding of the specific physical and chemical features of fibers/particles responsible for bioactivity. Toward that goal, we have tested aluminosilicate zeolites to establish biological and chemical structure-function correlations. Zeolites have known crystal structure, are subject to experimental manipulation, and can be synthesized and controlled to produce particles of selected size and shape. Naturally occurring zeolites include forms whose biological activity is reported to range from highly pathogenic (erionite) to essentially benign (mordenite). Thus, we used naturally occurring erionite and mordenite as well as an extensively studied synthetic zeolite based on faujasite (zeolite Y). Bioactivity was evaluated using lung macrophages of rat origin (cell line NR8383). Our objective was to quantitatively determine the biological response upon interaction of the test particulates/fibers with lung macrophages and to evaluate the efficacy of surface iron on the zeolites to promote the Fenton reaction. The biological assessment included measurement of the reactive oxygen species by flow cytometry and chemiluminescence techniques upon phagocytosis of the minerals. The chemical assessment included measuring the hydroxyl radicals generated from hydrogen peroxide by iron bound to the zeolite particles and fibers (Fenton reaction). Chromatography as well as absorption spectroscopy were used to quantitate the hydroxyl radicals. We found that upon exposure to the same mass of a specific type of particulate, the oxidative burst increased with decreasing particle size, but remained relatively independent of zeolite composition. On the other hand, the Fenton reaction depended on the type of zeolite, suggesting that the surface structure of the zeolite plays an important role.

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Section: Phagocytosis and The Oxidative Burstmentioning

confidence: 99%

mentioning

confidence: 99%