Environmental Health Perspectives

  title={Environmental Health Perspectives},
  author={J. S. Harington},
A review of fibrogenesis by asbestos fibers is given. There is nothing to indicate that the fibrogenic effects of inhaled asbestos fibers should differ in any way from those of ingested asbestos. Recently, ingestion has assumed some importance concerning human exposure. Three sections dealing with the process of fibrogenesis are covered: the first deals with in vitro fibrogenesis, in particular the interrelation of macrophages damaged by dusts and the subsequent laying down of collagen by… 

Figures from this paper

Short-term inhalation and in vitro tests as predictors of fiber pathogenicity.
The only test to show potential as a predictive measure of pathogenicity was that of cell proliferation in lungs after brief inhalation exposure (BrdU assay), and it is believed that this assay should be validated with a wider range of fibers, doses, and time points.
Early mesothelial cell proliferation after asbestos exposure: in vivo and in vitro studies.
  • I. Adamson
  • Biology, Medicine
    Environmental health perspectives
  • 1997
The results show that an early growth phase of MC after asbestos exposure appears unrelated to particle translocation to the pleura but is associated with cytokine release, most likely KGF, by lung cells.
Pleural macrophage recruitment and activation in asbestos-induced pleural injury.
Significantly greater amounts of NO as well as TNF-alpha were generated by pleural macrophages at 1 and 6 weeks after either crocidolite or chrysotile inhalation than after sham exposure.
Analyzing the genes and peptide growth factors expressed in lung cells in vivo consequent to asbestos exposure and in vitro.
It is postulate that cell proliferation and production of extracellular matrix is mediated in large part by three peptide growth factors, transforming growth factors alpha and beta (TGF-alpha and -beta), and platelet-derived growth factor (PDGF) A- and B-chains, and four genes and their concomitant proteins are expressed within 24 hr in the bronchiolar-alveolar epithelium and underlying mesenchymal cells.
Selected new developments in asbestos immunotoxicity.
This review will focus on recent studies that examine the influence of asbestos on pulmonary immunity as well as the role of host immune competence in asbestos-related disease.
Silica-induced apoptosis in alveolar and granulomatous cells in vivo.
It is concluded that intratracheal instillation ofsilica could induce apoptosis in both alveolar and granulomatous cells, and the apoptotic change and subsequent engulfment by macrophages might play a role in the evolution of silica-induced effects.
Effects of mineral fibers on the expression of genes whose product may play a role in fiber pathogenesis.
The expression of IL-1 alpha by fibers was greatest in TW, crocidolite, chrysotile, TW, and RCF-instilled rat AM, in that order, and may be a good indicator of the pathologic potential of fibers.
Chemical characterization and reactivity of iron chelator-treated amphibole asbestos.
It is found that chelators can affect the amount of iron at the surface of the asbestos fibers and its valence, and that they can modify the chemical reactivity of these surfaces, and it is proposed that iron mobility in the silicate structure may play a larger role in the chemical reactions of asbestos than previously assumed.
Formation and persistence of 8-oxoguanine in rat lung cells as an important determinant for tumor formation following particle exposure.
Investigation of the effects of quartz and of the nontumorigenic dust corundum on the induction of 8-oxoGua in the DNA of rat lung cells, as well as on cell proliferation and pulmonary inflammation support the suggestion that inflammation associated with increased 8-OxoG Hua levels in lung cells and increased cell proliferation is an important determinant for particle-induced development of lung tumors in the rat.
Modes of action of trichloroethylene for kidney tumorigenesis.
Proposed modes of action for TCE or its metabolites in kidney, including peroxisome proliferation, alpha(2u)-globulin nephropathy, genotoxicity, and acute and chronic toxicity mechanisms are considered, including oxidative stress, alterations in calcium ion homeostasis, mitochondrial dysfunction, protein alkylation, cellular repair processes, and alterations in gene expression and cell proliferation.


Some biochemical effects of asbestos on macrophages.
Evidence of cytopathic effects was seen by changes in lipid components of cells which had ingested silica and chrysotile and a decrease in total lipid content and an increase in lysolecithin apparently indicate specific, secondary and toxic effects following the release of lysosomal enzymes.
Activity of a Macrophage Factor in Collagen Formation by Silica
There is a correlation between the toxicity of various forms of silica and of other particulate materials to macrophages in culture and the capacity of these particles to stimulate fibrosis in vivo, but this relationship does not seem to have been demonstrated directly in tissue culture.
Atypical Reaction to Inhaled Silica
The response of SPF rats differed greatly from that of the standard ones used in the earlier studies, and it is confirmed that it remains focal and discrete.
It is suggested that repeated cycles of macrophage killing in vivo leads to the mobilization of fibroblasts and fibrogenesis characterizing the disease silicosis.
Lysosomes and the toxicity of particulate pollutants.
  • A. Allison
  • Chemistry
    Archives of internal medicine
  • 1971
The pathogenesis resulting from inhaled particulate pollutants centers around their effects upon the macrophage. An analysis of pathogenesis must proceed in two stages: first, determining how
The fibrogenic effects of mineral dusts injected into the pleural cavity of mice.
  • J. M. Davis
  • Geology, Medicine
    British journal of experimental pathology
  • 1972
It was found that long fibre dust specimens produced widespread cellular granulomata which formed firm adhesions between the lungs, diaphragm and chest wall which were gradually replaced by fibrous tissue and in old animals the dust was often found embedded in masses of acellular collagen.
  • J. Harington
  • Chemistry
    Annals of the New York Academy of Sciences
  • 1972
In this paper, some of the problems and priorities in research on coal workers' pneumoconiosis (CWP) are delineated, in particular to the behavior of coal dust towards macrophages maintained in cell culture under carefully defined conditions.