Histolgical AND Immunohistochemical Study on the Effect of Stem Cell Therapy on Bleomycin Induced Pulmonary Fibrosis in Albino Rat

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 14th day of experiment. stained with Hematoxylin and Eosin, Masson's trichrome, immunohistochemichal stains for alpha-SMA & PCNA. Sections were examined by light & immunofluroscent microscopy. Area percent of collagen fibers, area percent & optical density of alpha-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, alpha-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.

Effect of surface area and air-drying distance on shear bond strength of etch-and-rinse adhesive

We evaluated the effects of air-drying distance and bond surface area on the shear bond strength of a 2-step etch-and-rinse adhesive. A total of 120 bovine anterior teeth were equally divided into 6 main groups based on bonding surface area. The main groups were divided into sub-groups (n = 5) according to air-drying distance. The shear strength was determined using a universal testing machine at a crosshead speed of 0.5 mm/min. The averaged results were subjected to two-way ANOVA and Tukey's test (α = 0.05). Two-way ANOVA testing identified no significant cross-product interactions (p > 0.05), but the main factors of area (p < 0.0001) and air-drying distance (p < 0.00001) significantly affected the mean bond strength. Shorter air-drying distances improved bond strength, and increased surface area decreased the bond strength.

Histological study of the effect of induced diabetes on the zona glomerulosa of the adrenal cortex of adult male albino rat

Diabetes is one of the chronic diseases affecting many organs in the body. However, studies concerning its effect on the zona glomenilosa are limited. This work is concerned with studying the histological effects of streptozotocin [STZ]-induced diabetes on the zona glomenilosa of the adrenal gland of adult male albino rats Thirty healthy adult male albino rats were utilized, divided into two groups; Group A: Control and Group B: Experimental group. Rats of experimental group treated with five intra-peritoneal injections of [STZ] with 7-day intervals. The first three doses were 75 mg/kg and the remaining two doses were 150 mg/kg body weight. The control group received only 0.1 ml of 0.1 M citrate buffer, pH 4.4, by the intra-peritoneal route, Thirty days after the detection of the diabetic status, the animals of the two groups were anaesthetized with ether inhalation and the suprarenal glands were removed and processed for light and electron microscopy examination. Plasma level of aldosterone was measured by radioimmunoassay. At light microscopic level, the zona glomerulosa cells of the STZ-induced diabetic rats showed apparent increase in the cytoplasmic vacuolation and pyknotic nuclei. Electron microscopic study of the cells in the previous group revealed degenerative changes in the form of an apparent increase in the number of lipid droplets associated with mitochondrial degeneration. Plasma aldosterone decreased in STZ-induced diabetic rats. The results of this work suggested that streptozotocin induced diabetes changed the ultrastructures of the zona glomerulosa cells which may consequently lead to disturbance of their functions