Stimulation of cell signaling cascades by oxidants may be important in the pathogenesis of pulmonary and pleural diseases. Here, we demonstrate in rat pleural mesothelial cells that apoptotic concentrations of crocidolite asbestos and H2O2induce phosphorylation and activation of extracellular signal-regulated protein kinases (ERK). Activation of c- jun-NH2-terminal protein kinases (JNK)/stress-...

In 1979 all former workers from the Wittenoom asbestos industry who could be traced to an address were sent a questionnaire to determine smoking history. Occupational exposure to crocidolite was known from employment records. Of 2928 questionnaires sent, satisfactory replies were received from 2400 men and 149 women. Eighty per cent of these had smoked at some time and 50% were still smoking. S...

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...

The inhalation of asbestos is a risk factor for the development of malignant mesothelioma and lung cancer. Based on the broad surface area of asbestos fibers and their ability to enter the cytoplasm and nuclei of cells, it was hypothesized that proteins that adsorb onto the fiber surface play a role in the cytotoxicity and carcinogenesis of asbestos fibers. However, little is known about which ...

OBJECTIVES To estimate the relations between exposure to both tobacco smoke and crocidolite and the incidence of various histological types of lung cancer. METHODS In 1979 all former workers from the Wittenoom asbestos industry who could be traced were sent a questionnaire on smoking history. Of 2928 questionnaires sent, satisfactory replies were received from 2400 men and 149 women. Of the m...

Rats injected intrapleurally with either crocidolite or chrysotile asbestos or silica or saline, were killed at intervals up to 2 years of age. The pleural cavities were washed out immediately after death and the washing used for enumerating cells. In addition tissue from granulomas and mesotheliomas was sectioned and stained for lysosomal enzymes. The total cellular response to silica found in...

This report focuses on identifying the important asbestos fibertype(s) in the etiology of the asbestos-related cancer mesothelioma. In the last century all three of the commercial fiber types grunerite (amosite) asbestos, chrysotile asbestos and riebeckite (crocidolite) asbestoswere mined, milled and used to fabricate asbestos-containing products in South Afiica. The cases are a consecutive ser...

The in vitro effect of stone-wool has been studied in primary cultures of pulmonary alveolar macrophages (AM) and type II pneumocytes (T2) by morphological, biochemical and immunological methods. UICC crocidolite was applied as a positive control. Although stone-wool brought about frustrated phagocytosis, it did not induce serious membrane damage, whereas crocidolite gave rise to very severe me...

A mortality (1942-80) study was carried out on 13460 workers of a factory producing friction materials. The only type of asbestos used was chrysotile, except during two well-defined periods before 1945 when crocidolite was used, and over 99% of the population was traced. Compared with national death rates there were no detectable excesses of deaths due to lung cancer, gastrointestinal cancer, o...

Mesothelioma is an incurable form of cancer located most commonly in the pleural lining of the lungs and is associated almost exclusively with the inhalation of asbestos. The binding of asbestos to epidermal growth factor receptor (EGFR), a transmembrane signal protein, has been proposed as a trigger for downstream signaling of kinases and expression of genes involved in cell proliferation and ...