Linked Life Data

11537569

Source:http://linkedlifedata.com/resource/pubmed/id/11537569

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1995-7-14
pubmed:abstractText
Exposure to thermal degradation products arising from fire or smoke could be a major concern for manned space missions. Severe acute lung damage has been reported in people after accidental exposure to fumes from plastic materials, and animal studies revealed the extremely high toxicity of freshly generated fumes whereas a decrease in toxicity of aged fumes has been found. This and the fact that toxicity of the freshly generated fumes can be prevented with filters raises the question whether the toxicity may be due to the particulate rather than the gas phase components of the thermodegradation products. Indeed, results from recent studies implicate ultrafine particles (particle diameter in the nm range) as potential severe pulmonary toxicants. We have conducted a number of in vivo (inhalation and instillation studies in rats) and in vitro studies to test the hypothesis that ultrafine particles possess an increased potential to injure the lung compared to larger-sized particles. We used as surrogate particles ultrafine TiO2 particles (12 and 20 nm diameter). Results in exposed rats showed that the ultrafine TiO2 particles not only induce a greater acute inflammatory reaction in the lung than larger-sized TiO2 particles, but can also lead to persistent chronic effects, as indicated by an adverse effect on alveolar macrophage mediated clearance function of particles. Release of mediators from alveolar macrophages during phagocytosis of the ultrafine particles and an increased access of the ultrafine particles to the pulmonary interstitium are likely factors contributing to their pulmonary toxicity. In vitro studies with lung cells (alveolar macrophages) showed, in addition, that ultrafine TiO2 particles have a greater potential to induce cytokines than larger-sized particles. We conclude from our present studies that ultrafine particles have a significant potential to injure the lung and that their occurrence in thermal degradation events can play a major role in the highly acute toxicity of fumes. Future studies will include adsorption of typical gas phase components (HCl, HF) on surrogate particles to differentiate between gas and particle phase effects and to perform mechanistic studies aimed at introducing therapeutic/preventive measures. These studies will be complemented by a comparison with actual thermal degradation products.
pubmed:grant
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
S
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0094-5765
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NASA
pubmed:authorsComplete
Y
pubmed:pagination
251-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:11537569-Administration, Inhalation, pubmed-meshheading:11537569-Aluminum Oxide, pubmed-meshheading:11537569-Animals, pubmed-meshheading:11537569-Bronchoalveolar Lavage Fluid, pubmed-meshheading:11537569-Cells, Cultured, pubmed-meshheading:11537569-Cytokines, pubmed-meshheading:11537569-Dose-Response Relationship, Drug, pubmed-meshheading:11537569-Fibroblast Growth Factors, pubmed-meshheading:11537569-Fires, pubmed-meshheading:11537569-Instillation, Drug, pubmed-meshheading:11537569-Lung, pubmed-meshheading:11537569-Macrophages, Alveolar, pubmed-meshheading:11537569-Male, pubmed-meshheading:11537569-Particle Size, pubmed-meshheading:11537569-Phagocytosis, pubmed-meshheading:11537569-Rats, pubmed-meshheading:11537569-Rats, Inbred F344, pubmed-meshheading:11537569-Silicon Dioxide, pubmed-meshheading:11537569-Smoke, pubmed-meshheading:11537569-Smoke Inhalation Injury, pubmed-meshheading:11537569-Titanium
pubmed:year
1992
pubmed:articleTitle
Thermal degradation events as health hazards: particle vs gas phase effects, mechanistic studies with particles.
pubmed:affiliation
Environmental Health Sciences Center, University of Rochester, NY 14642.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.