Showing papers by "Jaishree Jagirdar published in 1997"

Immunohistochemical localization of transforming growth factor beta isoforms in asbestos-related diseases.

Abstract: Transforming growth factor beta (TGF-beta), a multifunctional cytokine and growth factor, plays a key role in scarring and fibrotic processes because of its ability to induce extracellular matrix proteins and modulate the growth and immune function of many cell types. These effects are important in inflammatory disorders with fibrosis and cancer. The asbestos-related diseases are characterized by fibrosis in the lower respiratory tract and pleura and increased occurrence of lung cancer and mesothelioma. We performed immunohistochemistry with isoform-specific antibodies to the three TGF-beta isoforms on 16 autopsy lungs from Quebec, Canada, asbestos miners and millers. There was increased immunolocalization of all three TGF-beta isoforms in the fibrotic lesions of asbestosis and pleural fibrosis. The hyperplastic type II pneumocytes contained all three isoforms. By contrast, there was differential spatial immunostaining for the TGF-beta isoforms in malignant mesothelioma, with TGF-beta 1 in the stroma but TGF-beta 2 in the tumor cells. These data are consistent with an important role for TGF-beta in accumulation of extracellular matrix and cell proliferation in asbestos-related diseases.

AIDS-related airway disease.

Abstract: To our knowledge, the importance of airway disease in HIV-positive patients has been infrequently noted. This deficit likely reflects a combination of factors including lack of familiarity with recent changes in clinical and epidemiologic patterns of pulmonary manifestations of HIV infection and documented limitations of chest radiography for identifying and differentiating airway disease from other causes of pulmonary disease in HIV-positive patients. Familiarity with the imaging findings for these various entities should facilitate prompt diagnosis and treatment. The accuracy of CT in detecting airway disease [55-59] is well established and should be of value in excluding more common diseases that may be initially confused with airway abnormalities [60, 61]. Small airways disease, in particular, which may be occult or mimic an interstitial infiltrate on chest radiography, can be recognized with CT as likely representing infectious bronchitis or bronchiolitis. Patients with findings suggesting bacterial infections may benefit from empiric antibiotic therapy. CT also may be valuable for differentiating between various noninfectious pulmonary diseases, allowing a presumptive diagnosis of parenchymal Kaposi's sarcoma in the appropriate clinical context. In distinction, by detecting localized endobronchial or parenchymal abnormalities in patients with mycobacterial or fungal infections or lymphoma, CT may be valuable for deciding between various invasive methods of obtaining either histologic or bacteriologic diagnoses.

Immunohistochemical localization of transforming growth factor-β and insulin-like growth factor-I in asbestosis in the sheep model

Abstract: Asbestosis is characterized by increased collagen deposition along the walls of terminal respiratory bronchioles that extends into the alveolar ducts and septae. Alveolar macrophages are activated and release growth factors that stimulate mesenchymal cell proliferation and enhanced formation of extracellular matrix. Both insulin-like growth factor-I (IGF-I), and transforming growth factor β (TGF-β) regulate cellular growth and promote matrix accumulation and are hypothesized to play important roles in asbestosis. We performed immunohistochemistry using polyclonal antibodies to specific synthetic peptides of the three mammalian isoforms of TGF-β (TGF-β1, -β2, -β3) and to IGF-I on lungs of sheep treated intratracheally with chrysotile asbestos. All three TGF-β isoforms were found in bronchial and bronchiolar epithelium, macrophages, and bronchial and vascular smooth muscle in control lungs. The distribution of TGF-β was increased in these lung constituents as fibrotic lesions developed. Fibrotic lesions additionally demonstrated intense immunostaining of all three TGF-β isoforms that localized to the extracellular matrix zones with little staining of interstitial cells. In the control sheep lungs, IGF-I staining was detected in bronchial and bronchiolar epithelium, bronchial glands, bronchial and vascular smooth muscle, endothelium, and macrophages. IGF-I immunostaining was detected in macrophages in peribronchial fibrosis and in fibroblasts along the periphery of and within lesions, but not in the extracellular matrix. Metaplastic proliferating epithelium and macrophages were strongly immunoreactive for IGF-I in advanced lesions. Our data demonstrate different immunostaining patterns for IGF-I and TGF-β in asbestosis, with IGF-I in the cellular periphery and TGF-β in the extracellular matrix consistent with a complementary role in stimulating interstitial fibroblast proliferation and new collagen deposition in areas of active fibrosis.

Angular and fibrous particles in lung in relation to job category

Abstract: A. Dufresne,* R. Begin,t C. Dion,* J. Jagirdar,§ W. N. Rom,§ P. Loosereewanich,* D. C. F. Muir,1f A. C. Ritchie^ and G. Perraultt *McGill University, Department of Occupational Health, Faculty of Medicine, 3450 University Street, suite 22, Montreal (Quebec), Canada, H3A 2A7; fService de pneumologie, Centre Hospitalier de l'Universite de Sherbrooke, Sherbrooke (Quebec), Canada J1H 5N4; $Institut de recherche en sant6 et s6curit6 du travail, Direction des laboratoires, 505 Ouest, de Maisonneuve, Montreal (Qu6bec), Canada H3A 3C3; §Bellevue NYU Medical Centre, 27th Street-lst Avenue, New York, NY 10016, U.S.A.; and f McMaster University, 1200 Main Street West, Hamilton, Ontario, Canada L8N 3Z5