The pathogenesis of asbestos-induced pleural fibrosis is poorly understood. Moreover, there has been a long-standing controversy regarding the relative potential of different commercial types of asbestos to cause pleural disease. We postulated that inhaled asbestos fibers translocate to the pleural space where they stimulate the recruitment and activation of pleural macrophages. To test this hy...

Feeding of baboons with crocidolite showed small numbers of asbestos needles 0.5-1 mum in ashed tissue of the gut wall, which probably came from iron-containing macrophages. It is suggested that pleural plaques and hyaline nodules in the peritoneum represent a hypersensitivity reaction to ferritin protein coating on asbestos fibers. In South Africa only a few peritoneal mesotheliomas come from ...

Inhalation of asbestos fibers results in a variety of neoplastic and nonneoplastic diseases of the respiratory tract. Some of these diseases, such as asbestosis, generally occur after prolonged and intensive exposure to asbestos, whereas others, such as pleural mesothelioma, may occur following brief exposures. Inhalation of nonasbestiform mineral fibers can occur as well, and these fibers can ...

The toxicity of sized and characterized chrysotile, crocidolite, and amosite preparations obtained from Dr. K. R. Spurny have been evaluated using alveolar macrophage (AM) migration inhibition assays and viability tests. These results have been compared with asbestos samples obtained from the National Institute of Environmental Health Sciences (NIEHS). These latter samples are designated chryso...

The large respiratory epithelial cells within primary cultures of newt (Taricha granulosa) lung are uniquely suited for high resolution video-enhanced light-microscopic studies. We show here that these cells incorporate crocidolite asbestos fibers within 18 h by endocytosis. Once inside the cell, fibers less than 5 microns in length are seen by video light microscopy to undergo saltatory transp...

The cytogenetic effects of chrysotile asbestos on Syrian hamster embryo cells in vitro were investigated at doses which induced morphological and neoplastic transformation but which failed to induce measurable gene mutations in the cells at two genetic loci. Chrysotile asbestos treatment of the cells significantly induced chromosome changes in a dose-dependent manner. Up to 50% of the cells had...

Asbestos fibers are an important cause of lung fibrosis; however, the biological mechanisms are incompletely understood. The lung epithelium serves an important barrier function in the lung, and disrupting the epithelial barrier can contribute to lung fibrosis. Lung epithelial permeability is increased in patients with asbestosis, and asbestos fibers increase permeability across cultured human ...

Malignant mesothelioma is a highly aggressive tumor of the serous membranes, which in humans results from exposure to asbestos and asbestiform fibers. Although occupational malignant mesothelioma is still the most common form of this lesion, naturally contaminated soil can play an important role in the development of environmental malignant mesothelioma in some parts of the world. Fifty cases o...

Asbestos and other mineral fibers have long been known to induce lung cancer and mesothelioma. However, the primary mechanisms of fiber-induced carcinogenesis still remain unclear. We investigated the occurrence of mitotic disturbances induced by asbestos (amosite, crocidolite, chrysotile) in an in vitro approach using Syrian hamster embryo (SHE) fibroblast cells. The following endpoints were i...

Like many other human cancers, the development of malignant mesothelioma is closely associated with a chronic inflammatory condition. Both macrophages and mesothelial cells play crucial roles in the inflammatory response caused by asbestos exposure. Here, we show that adipocytes can also contribute to asbestos-induced inflammation through dysregulated adipocytokine production. 3T3-L1 preadipocy...