The mesothelial cell appears to be a major target of the asbestos fibre. This cel is the likely progenitor of the tumour, mesothelioma, a tumour strongly associated with asbestos exposure. In addition, the mesothelial cell may play a role in other asbestos-induced pathology, including pleural plaques, benign asbestos pleurisy and pleural fibrosis.
After much study of the asbestos fibre and its interaction with the mesothelial cel in vitro, it is still unclear what determines asbestos-induced pleural disease. On the one hand, the uniqueness of this pleural pathology may be dependent on the tendency of asbestos fibres to accumulate in the pleural space by their lodging in the parietal pleura around the draining lymphatic stomata. In fact, with decreases in occupational exposure to asbestos fibres, lung disease is waning in incidence, but pleural disease is rising.
One explanation is that, with a lower burden of fibres in the lung, the lung can avoid injury as the fibres gradually clear to the pleural space where they accumulate, thereby shifting disease from lung to pleura. This may in part explain how the risk of mesothelioma can be enhanced by only low exposure to asbestos.
On the other hand, the pleura pathology may arise from the unique features of the mesothelial cell, a lining cell neither epithelial nor endothelial but derived from the mesoderm. Indeed, the mesothelia cell is unusual in several respects: it coexpresses different intermediate filaments, it alters their expression during the cell cycle and it has a sensitivity to a wide array of growth factors. There is some evidence that mesothelial cells in vitro are more sensitive to the toxic effects of asbestos than other cells, although the cell appears to be no more sensitive than other cells to oxidant-induced DNA damage.
The lungs and pleura are the major sites of asbestos-related disease. Inhaled into the body, the fibres reach distal bronchi and lodge there, later to migrate to other areas of lung and to enter the pleural space. Over many years, asbestos fibres can induce lung diseases such as pulmonary fibrosis and lung cancer and a wide array of pleural diseases including pleural plaques, pleural effusions, pleural fibrosis, and the tumour mesothelioma.
No relationship has been recognised between other asbestos induced diseases and mesothelioma. Although asbestos acts together with tobacco smoke to produce lung cancer, asbestos is a complete carcinogen for the tumour mesothelioma.
After much study of the asbestos fibre and its interaction with the mesothelial cel in vitro, it is still unclear what determines asbestos-induced pleural disease. On the one hand, the uniqueness of this pleural pathology may be dependent on the tendency of asbestos fibres to accumulate in the pleural space by their lodging in the parietal pleura around the draining lymphatic stomata. In fact, with decreases in occupational exposure to asbestos fibres, lung disease is waning in incidence, but pleural disease is rising.
One explanation is that, with a lower burden of fibres in the lung, the lung can avoid injury as the fibres gradually clear to the pleural space where they accumulate, thereby shifting disease from lung to pleura. This may in part explain how the risk of mesothelioma can be enhanced by only low exposure to asbestos.
On the other hand, the pleura pathology may arise from the unique features of the mesothelial cell, a lining cell neither epithelial nor endothelial but derived from the mesoderm. Indeed, the mesothelia cell is unusual in several respects: it coexpresses different intermediate filaments, it alters their expression during the cell cycle and it has a sensitivity to a wide array of growth factors. There is some evidence that mesothelial cells in vitro are more sensitive to the toxic effects of asbestos than other cells, although the cell appears to be no more sensitive than other cells to oxidant-induced DNA damage.
The lungs and pleura are the major sites of asbestos-related disease. Inhaled into the body, the fibres reach distal bronchi and lodge there, later to migrate to other areas of lung and to enter the pleural space. Over many years, asbestos fibres can induce lung diseases such as pulmonary fibrosis and lung cancer and a wide array of pleural diseases including pleural plaques, pleural effusions, pleural fibrosis, and the tumour mesothelioma.
No relationship has been recognised between other asbestos induced diseases and mesothelioma. Although asbestos acts together with tobacco smoke to produce lung cancer, asbestos is a complete carcinogen for the tumour mesothelioma.
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