Theory building for hypothesis specification in organisational studies Badrinarayan ShankarPawarTheory building for hypothesis specification in organisational studies2009Response Books, Sage Publications133 pages, Price: Rs. 495 (Hardbound)

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Biochemical & histochemical changes relating to fibrosis following, infection with Mycobacterium tuberculosis in the guineapig

Guineapigs infected with M. tuberculosis were studied for pammeters relating to fibrosis following infection. The infected animals were followed up to a period of 44 wk and the changes that occurred in the lung, liver and spleen were studied. Corresponding tissues from animals injected with bleomycin, an anti-mitotic drug which has the ability to produce pulmonary fibrosis, served as positive controls. Tissue collagen, elastin and hexosamines were estimated biochemically. The presence of granuloma and stainable collagen in paraffin sections of these tissues was also studied. Establishment of the infection was assessed bacteriologically by culturing the viable organisms from the spleen. It was observed that a self-limiting infection was established in the guineapigs and none of the animals died of the infection. In the infected animals, collagen, elastin and hexosamines showed an initial decrease followed by an increase. While the elastin and the hexosamine levels returned to the basal levels in all the three organs, collagen levels increased in the lung and were comparable to those of the bleomycin control. Collagen stainable by Van Gieson’s method was found to be increased in the lung from the 4th wk onwards. The present report indicates the potential of adopting this system for studying mechanisms of fibrogenesis in tuberculous infection

Biochemical and histochemical changes pertaining to active and healed cutaneous tuberculosis

Background Fibrosis is one of the major causes of post-treatment morbidity in tuberculosis. The molecular basis of fibrosis in active and healed tuberculous lesions is yet to be fully characterized. Objectives To measure the tissue levels of collagen, elastin, fibronectin, transforming growth factor-b (TGF-b) and zinc in active and healed lesions of cutaneous tuberculosis. Patients and methods Biopsy lesions obtained from 17 patients with active cutaneous tuberculosis and 12 patients after a 6-month regimen of antituberculous chemotherapy were examined. Collagen, elastin and zinc were estimated biochemically. In addition, the presence of collagen IV, TGF-b and fibronectin were determined immunohistochemically. Results It was found that collagen, elastin, fibronectin and TGF-b levels were higher in the active lesions. The levels of zinc were similar in both active and healed lesions. Clinically, scar tissue or keloid formation was not seen in any of the healed lesions. Conclusions Effective antituberculous chemotherapy will lead to a substantial reduction of fibrosis and the consequent disability that can arise in patients with tuberculosis