Aim of work: To demonstrate the bleomycin induced histological changes in the lung and the possible protective and/or therapeutic effect of stem cell therapy. Materials and methods: Study was carried out on 36 adult male albino rats, classified into 4 groups: group I (control), group II (bleomycin treated group), group III (early stem cell treated group: immediately after bleomycin), group IV (late stem cell treated group: 7 days after bleomycin). Sections were taken at the 14 th day of experiment. stained with Hematoxylin and Eosin, Masson’s trichrome, immunohistochemichal stains for α -SMA & PCNA. Sections were examined by light & immunofluroscent microscopy. Area percent of collagen fibers, area percent & optical density of α -SMA immunopositive cells were measured as well as the number of H&E and PCNA stained pneumocytes type II was counted. Results: Group II showed, thickening of septa, extravasation of blood, dividing pneumocytes type II cells with acinar formation, cellular infiltration, fibroblast cells, almost complete loss of normal lung architecture in certain fields, consolidation and replacement of the lung tissue with fibrous tissue in other fields. Restoring of lung tissue with significant decrease in mean area % of collagen fibers, α -SMA immunopositive cells were detected in group III. Conclusions: Early treatment with bone marrow derived mesenchymal stem cells (BMSCs) immediately after bleomycin administration showed a significant reduction in fibrotic changes, however the late treatment with BMSCs (7 days) after bleomycin administration showed non significant results.

No abstract

No abstract

Background and aim of workPrimary myopathies of skeletal muscle are diseases with worldwide prevalence for which effective treatment is urgently needed. The aim of this study was to investigate the ability of human umbilical cord blood (HUCB) stem cells to repair damaged skeletal muscle in a rat model of statin-induced myopathy. Materials and methodsThis study included 24 adult male albino rats divided equally into four groups: the control group; the myopathy group in which myopathy was induced by administration of simvastatin (80 mg/kg/day orally for 6 weeks); the stem cell-treated myopathy group in which myopathy was induced by administration of simvastatin with subsequent local injection of 1×10 6 HUCB stem cells in the right gastrocnemius; and the untreated myopathy group in which myopathy was induced by administration of simvastatin and then left without treatment for 2 weeks. Specimens of the right gastrocnemius from all rats were prepared, sectioned, and subjected to H&E, Prussian blue, and Masson's trichrome stains in addition to immunohistochemical staining for α smooth muscle actin to reveal myofibroblasts. The area% of collagen and muscle fibers and the number of myofibroblasts/high-power field were ascertained. All measurements were statistically analyzed. ResultsThe gastrocnemius of the myopathy group showed frequent necrotic and damaged muscle fibers, which were replaced by fibrous and fatty tissues. Compared with control rats, there was significant decrease in the area% of muscle fibers and significant increase in the area% of collagen and in the number of myofibroblasts. Two weeks later, there was partial repair of the muscle with no significant differences between stem cell-treated and untreated myopathy groups, which reflects the failure of stem cells to repair damaged myofibers. Conclusion HUCB stem cells have poor therapeutic effect for myopathy and might be hindered by the complex environment of a severely inflamed and degenerated muscle.

Background: Chemical peels represent useful tool for improving skin texture and the effects of ageing. With the advent of newer chemical peels, there is now a wide range of peeling agents that can be applied on specific patients. Aim of the work: The present work was designed to evaluate and compare histologically between two of the most commonly used peeling agents in medium depth chemical peel: TCA (35%) and GA (70 %). Materials and Methods: This study was carried out on forty adult male albino rats. They were divided into five groups, eight rats each. Group І: Control rats that received no peeling session. Groups П and ПI: Received a peel session of TCA 35% and skin specimens were taken after one week and three weeks respectively. Groups IV and Group V: Received a peel session of glycolic acid 70% and skin specimens were taken after one week and three weeks respectively. Sections were prepared to be stained by H&E, Masson's trichrome, Orcein and immunohistochemichal staining for CD34, which is a marker for stem cells in hair follicle bulge region. Morphometric measurements of epidermal thickness, dermal thickness, area percent of collagen and elastic fibers, area percent and optical density of immunopositive cells for CD34 were done by image analyzer. Data obtained were statistically analyzed. Results: The present study revealed that after one week of medium depth chemical peel (by TCA (35%) or GA (70 %), the skin showed increase in epidermal and dermal thickness, increase in elastic and collagen fibers which became more organized and regularly arranged. It also showed pronounced increase in CD34 immunopositive cells (hair bulge stem cells, spindle cells of the reticular dermis, endothelial cells of dermal vessels and sebaceous glands). Three weeks after the chemical peel, the skin showed further significant increase in epidermal thickness, dermal thickness, collagen and elastic fibers. However, there was marked decrease in area percent and optical density of CD34 immunopositive cells. Conclusion: The present study revealed that both TCA (35%) and GA (70%) are effective in stimulation bulge stem cells and in improving the skin morphology with no significant difference between the two reagents.