Investigation of the Ultrastructural Changes and Hydroxyproline Levels in Mice Lungs Induced by Bleomycin Treatment

The present study was planned to investigate the ultrastructural changes and hydroxyproline level in the lungs of the mice induced by bleomycin treatment, Following 4 weeks of bleomyein treatment, the lungs were examined histologically (using light and electron microscopes) and the hydroxyproline level was measured at 4th, 6th, 8th, and 10th weeks of the experiment. Biochemical and structural changes that normally occur in lung fibrosis were also observed in our study, For example; lung hydroxyproline level increased progressively (p<0.05) and structural changes advanced to interstitial fibrosis from 4th to 10th weeks of the experiment Alveolar septum thickening, type II pneumoeytes increase and mononuclear cell  infiltration (lymphocyte, monocyte and macrophage) were seen. In addition, membrane-bound rod-shaped amorphous structures in the cytoplasm of alveolar macrophages were increased significantly (p<0.05).It is concluded that. bieomycin treatment may produce fibrosis due to increase in interstitial connective tissue, hydroxyprolinc level and the number of alveolar macrophages However, more studies are needed to demonstrate whether there isa relationship between the increased membranebound rod shaped amorphous structures and the occurrence of fibrosis

Calvarial bone defects in ovariectomised rats treated with mesenchymal stem cells and demineralised freeze-dried bone allografts

Background: The aim of the study was to investigate the ability of a combination of bone marrow mesenchymal stem cells (BM-MSCs) with and without demineralised freeze-dried bone allografts (DFDBAs) to induce bone regeneration incalvarial defects in ovariectomised rats.Materials and methods: Critical size defects were filled with a combination of DFDBAs and BM-MSCs or BM-MSCs alone. Eight weeks after calvarial surgery, the rats were sacrificed. The samples were analysed histologically and immunohistochemically.Results: No difference was observed in vascularisation between groups C1 (animals with cranial defect only, control group) and O1 (animals with cranial defect only, ovariectomy group). Intramembranous ossification was observed at a limited level in groups C2 (animals with cranial defect with MSCs, control group) and O2 (animals with cranial defect with MSCs, ovariectomy group) compared to C1 and O1. In group C3 (animals with DFDBAs with MSCs, control group), the fibrous structures of the matrix became compact as a result of a bone graft having been placed in the cavity, but in group O3 (animals with DFDBAs with MSCs, ovariectomy group), the fibrous tissue was poorly distributed between the bone grafts for the most parts.Conclusions: We conclude that the insertion of BM-MSCs enhances bone healing; however, the DFDBA/BM-MSC combination has little effect on overcoming impaired bone formation in ovariectomised rats

The impact of human capital on the early success of necessity versus opportunity-based entrepreneurs

This paper examines whether founders' backgrounds influence new firm survival in the early years after startup, focusing, in particular, on the impact of unemployment-driven entrepreneurship. For entrepreneurs who left their previous employment to found a new firm, both general and specific human capital play a key role in enhancing early survival chances. However, various forms of human capital have little effect on early survival of unemployment-driven entrepreneurs, who rely mostly on previous entrepreneurial experience to persevere. Results suggest that pre-entry capabilities play an important role in the early success of opportunity-based entrepreneurs, but have little influence on the early success of necessity-based ones

The impact of human capital on the early success of necessity versus opportunity-based entrepreneurs

This paper examines whether founders' backgrounds influence new firm survival in the early years after startup, focusing, in particular, on the impact of unemployment-driven entrepreneurship. For entrepreneurs who left their previous employment to found a new firm, both general and specific human capital play a key role in enhancing early survival chances. However, various forms of human capital have little effect on early survival of unemployment-driven entrepreneurs, who rely mostly on previous entrepreneurial experience to persevere. Results suggest that pre-entry capabilities play an important role in the early success of opportunity-based entrepreneurs, but have little influence on the early success of necessity-based ones

Flor zehirlenmesi oluşturulmuş tavşanlarin böbrek dokusunda yapisal ve biyokimyasal değişiklikler

In this study, the effects of sodium fluoride given subchronically at the doses of 1, 10 and 40 mg/L for 70 days were investigated. For this purpose, 21 male New Zealand rabbits were used. At the end of the 70th day, the level of blood urea nitrogen (BUN), creatine (CRE) and ?-GT activity in the plasma and the activities of the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rd), catalase (CAT) and glucose 6-phosphate dehydrogenase (G6PD) and the level of malondialdehyde (MDA) were detected from blood samples taken from the control group (1 mg/L) and the trial group (10 mg/L and 40 mg/L). There was a significant increase in the level of BUN, CRE and ?-GT and MDA activity, which was correlated with the increase in dose. When compared with the control group, a significant increase in the trial group given 10 ppm fluoride and a significant decrease in the group given 40 ppm fluoride were detected in the activity of SOD, GSH-Px, GSH-Rd and CAT. Only in the group given 40 ppm flouride was a significant decrease detected. In addition, the fluoride level significantly increased. A significant increase was seen in the levels of plasma BUN and CRE and the activity of tissue MDA with the increase in fluoride in the drinking water. The activity level of the antioxidant enzymes SOD, GSH-Px, GSH-Rd, CAT and G6PD varied according to the dose. A significant increase in the 10 ppm group and a significant decrease in the 40 ppm in these enzymes activities