The asbestos contents of the lungs of former employees of an asbestos textile factory were determined at necropsy using a transmission electron microscope. Those who had died of mesothelioma were compared with a matched sample of those who had died of other causes. The predominant fibre processed in the factory was chrysotile, but crocidolite had also been used. The lung content was consistent ...

In a previous study, we found that crocidolite (an asbestos fiber) had an inhibitory effect on the differentiation process of HL-60 cells induced by dimethyl sulfoxide (DMSO). Here we describe the cathepsin B-like enzyme HL-60 cells and the changes of its activity during cell differentiation with or without crocidolite treatment. The cathepsin B-like enzyme in HL-60 cell extracts had almost the...

Titanium dioxide (TiO2) nanofibres are a novel fibrous nanomaterial with increasing applications in a variety of fields. While the biological effects of TiO2 nanoparticles have been extensively studied, the toxicological characterization of TiO2 nanofibres is far from being complete. In this study, we evaluated the toxicity of commercially available anatase TiO2 nanofibres using TiO2 nanopartic...

This study investigated possible relationships between fiber bio-persistence in the lung and previously observed differences in pulmonary toxicity between asbestos and man-made vitreous fibers (MMVF) following inhalation exposure. Fischer 344/N rats were exposed nose only, 6 hr/day for 5 days to 30 mg/m3 MMVF (two fiberglass compositions, rock wool, or slag wool) or to 10 mg/m3 crocidolite asbe...

In this study, we analyzed the effects of synthetic vitreous fibers (SVFs) on a mesothelial (MeT5A) and a fibroblast cell line (NIH3T3), compared to those exerted by crocidolite asbestos fibers. SVFs (glass wool, rock wools) do not induce significant changes in cell mortality, whereas crocidolite asbestos fibers caused a dose-dependent cytotoxicity. We investigated the correlation between the f...

Asbestos-induced mutagenicity in the lung may involve reactive oxygen/nitrogen species (ROS/RNS) released by alveolar macrophages. With the aim of proposing an alternative in vitro mutagenesis test, a coculture system of rat alveolar macrophages (NR8383) and transgenic Big Blue Rat2 embryonic fibroblasts was developed and tested with a crocidolite sample. Crocidolite exposure induced no detecta...

The community members of Libby, MT, have experienced significant asbestos exposure and developed numerous asbestos-related diseases including fibrosis and lung cancer due to an asbestos-contaminated vermiculite mine near the community. The form of asbestos in the contaminated vermiculite has been characterized in the amphibole family of fibers. However, the pathogenic effects of these fibers ha...

Crocidolite is a well known causative agent for mesothelioma. Studies have shown that the pathogenicity of the fiber from different mines varies considerably and it has been postulated the parameter that appears most likely to account for this variation is fiber width. Epidemiological studies have shown that ‘thin’ fibers from mining areas of Western Australia and the Cape Province, in South Af...

OBJECTIVES To compare the clearance rate, the related pathology, and the chemical and morphological changes of three man made mineral fibres (MMMFs) in the sheep model of pneumoconiosis. METHODS Fibrous particles were extracted from lung parenchyma and analysed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). RESULTS The concentration of MMMF11, MMMF21, re...