Murat Yarim

Repairing critical-sized rat calvarial defects with a periosteal cell-seeded small intestinal submucosal layer.

Background: Small intestinal submucosa was evaluated as a bioscaffold candidate for periosteum-derived osteoblasts, and its suitability as a bone replacement material for cranial defects was investigated. Methods: In the in vitro phase, osteoblasts were expanded in osteogenic medium and were then seeded onto small intestinal submucosa. To confirm osteoblast phenotype, they were tested for alkaline phosphatase, collagen type 1, and calcium expression. In the in vivo phase, calvarial critical-sized defects were created in 35 rats. The defects were either left untreated for surgical control (group 1), treated with small intestinal submucosa alone (group 2), treated with an osteoblast-embedded construct (group 3), or treated with an autogenous bone graft (group 4). The results were evaluated 12 weeks after surgery with radiopacity measurements and with stereologic analysis. Results: Periosteal cells grew successfully in vitro. The percentage radiopaque area at the defect was measured to be 42, 74, 76, and 89 percent for groups 1, 2, 3, and 4, respectively. The pixel intensity of the same site was 36.4, 48.1, 47.5, and 54.5 for the same groups, respectively. Tissue-engineered constructs did not achieve enough bone formation and calcification to be effective as autogenous bone grafts and were not superior to the small intestinal submucosa alone. However, both small intestinal submucosa and cell-seeded small intestinal submucosa showed significantly more bone formation compared with the untreated group. Conclusions: Although it was demonstrated that the small intestinal submucosa itself has osteogenic properties, it was not significantly increased by adding periosteum-derived osteoblasts to it. The osteogenic properties of small intestinal submucosa are promising, and its role as a scaffold should be investigated further.

Mammary fibroadenoma in a lamb.

A fibroadenoma was diagnosed in the left udder of a 3-month-old female Chios lamb. No recurrence was observed after surgery. Grossly, the tumor had a whitish-gray lobular appearance, and the lobules were interlaced with thin septa. Microscopically, the tumor was composed of proliferating fibroepithelial tissue, including differentiated ducts lined by whorls and interlacing bundles of abundant loose fibrovascular stroma. Immunohistochemistry revealed the ductal epithelium to be positive for pancytokeratin (AE1/AE3) and loose fibrovascular stroma was positive for vimentin and basal cells covering the ductal epithelium of alpha-smooth-muscle actin. Immunostaining for the estrogen and progesterone receptors was negative. A diagnosis of mammary fibroadenoma was made based on the histological and immunohistochemical findings.

Evaluation of bee venom and hyaluronic acid in the intra-articular treatment of osteoarthritis in an experimental rabbit model.

The aim of this study was to investigate bee venom and hyaluronic acid in the intra-articular treatment of osteoarthritis in an experimental rabbit model. Forty-five rabbits were used and they were randomly divided into three groups (BVI, BVII, and HA) and each group was divided to two subgroups to evaluate the radiologic, magnetic resonance imaging, histopathologic, and biochemical evaluation in post treatment second week (a) and twelfth week (b). Radiologically, a significant difference was observed in the HA group (P<0.05). The MRI evaluation of at any time in group BVI(b) was found to be different. No significant differences were seen between the groups, biochemically. Histopathologically, cellularity, and orthochromasia was evident with Safranin-O in the BVI(b) and BVII(a); adhesions were seen in the BVII(a) group and clustering of chondrocyte in the HA(b) group were found to be different. Consequently, intra-articular application of HA and BV for experimental model of osteoarthritis has no significant influence upon recovery after therapy.

The expressions of HSP70 and αB-crystallin in myocarditis associated with foot-and-mouth disease virus in lambs.

This study describes the expression of heat shock protein70 (HSP70) and alpha-basic-crystallin (α-BC) and their association with apoptosis and some related adaptor proteins in the pathogenesis of foot-and-mouth disease virus (FMDV)-induced myocarditis in lambs. HSP70 was generally overexpressed in the myocardial tissues and inflammatory cells of FMDV-induced myocarditis with differential accumulation and localization in same hearts when compared to non-foot-and-mouth disease control hearts. α-BC immunolabeling showed coarse aggregations in the Z line of the cardiomyocytes in FMDV-infected hearts in contrast to control hearts. Overall, the results of this study show that the anti-apoptotic proteins, HSP70 and α-BC, were overexpressed with increased apoptosis in FMDV-infected heart tissues. Both proteins failed to protect the cardiomyocytes from apoptosis as defense mechanisms to the FMDV during the infection, suggesting that the virus is able to increase apoptosis via both downregulation and/or upregulation of these anti-apoptotic proteins.

Immunohistochemical detection of autophagy-related microtubule-associated protein 1 light chain 3 (LC3) in the cerebellums of dogs naturally infected with canine distemper virus.

We investigated the expression of microtubule-associated protein 1 light chain 3 (LC3) protein in the cerebellums of dogs infected with canine distemper virus (CDV) using immunohistochemistry to detect autophagy. The cerebellums of 20 dogs infected with CDV were used. Specimens showing demyelination of white matter were considered to have an acute infection, whereas specimens showing signs of severe perivascular cuffing and demyelination of white matter were classified as having chronic CDV. Cerebellar sections were immunostained with CDV and LC3 antibodies. The cytoplasm of Purkinje cells, granular layer cells, motor neurons in large cerebellar ganglia and some neurons in white matter were positive for the LC3 antibody in both the control and CDV-infected dogs. In the infected cerebellums, however, white matter was immunostained more intensely, particularly the neurons and gemistocytic astrocytes in the demyelinated areas, compared to controls. Autophagy also was demonstrated in CDV-positive cells using double immunofluorescence staining. Our findings indicate that increased autophagy in the cerebellum of dogs naturally infected with CDV may play a role in transferring the virus from cell to cell.

Effects of low level electromagnetic field exposure at 2.45 GHz on rat cornea

Abstract Purpose: To investigate the effects of low level electromagnetic field (low level-EMF) exposure, as frequently encountered in daily life, on the normal rat cornea using histological and stereological method. Methods: Twenty-two adult male Wistar rats were randomly divided into two groups: Study group (n = 11) and control group (n = 11). Rats in the study group were exposed to 2.45 GHz microwave (MW) radiation (11.96 ± 0.89 V/m), 0.25 W/kg specific absorption rate (SAR) for 2 hours each day for 21 days. The corneal thickness and the anterior epithelium corneal thickness were measured using two different methods. Results: Using the histological method, the mean corneal thicknesses in the control and study group were 278.9 ± 54.5 μm, and 272.4 ± 85.6 μm, respectively. There was no statistically significant difference between the groups (p > 0.05). The anterior corneal epithelium thickness was 28.1 ± 4.9 μm in the control group and 31.7 ± 5.5 μm in the study group. There were statistically differences between the groups with regard to the thickness of anterior epithelium (p < 0.05). In the measurement made by the stereological method, the percentage of the cornea occupied by anterior corneal epithelium was 15.94% in the control group and 17.9% in the study group. Despite the fact that there was a relation between increased anterior epithelial area (AEA) and radiation exposure, no statistically significant relationship in area fraction of each compartment was found between the control and study groups. Conclusions: Results of this preliminary study show that exposure to MW radiation might cause alterations in the rat cornea.

Characterization of local immune response against lungworms in naturally infected sheep

This study describes the immunohistochemical and histochemical phenotypes of inflammatory cells in sheep lungs infected with lungworms. A total of 20 naturally infected sheep lungs were used. Protostrongylus spp., Muellerius capillaris, Neostrongylus linearis, and Cystocaulus ocreatus were the chief organisms determined from such lesions, which were of a chronic nature. All the lungs had many developmental stages of the parasites and a similar inflammatory response, which included numerous mast cells, eosinophils, T cells, B cells, dendritic cells, and macrophages. In the bronchial and interstitial tissues, the inflammatory cells were dominated by MHCII, CD1, CD4, CD5, CD14, CD21, IgM, and CD172a positive cells, whereas CD2 and WC1 positive cells were detected less. The data provided additional evidence that subsets of inflammatory cells were included within ovine lungs infected with lungworms; however, understanding the entire immune-response process and development of resistance to lungworms in sheep remain to be clearly elucidated.

Immunohistochemical characterization of peroxisome proliferator-activated receptors in canine normal testis and testicular tumours.

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Recent studies have demonstrated that PPARs regulate lipid metabolism and are expressed in various cancers. The aim of the present study was to investigate the expression of PPAR-α, -β and -γ in normal canine testicular tissue and canine testicular tumours (CTTs). Expression of PPAR-α, -β and -γ was greater (P <0.05) than in normal testicular tissue. PPARs were therefore induced in CTTs and they may play a role in the biology of these tumours.

Alpha basic crystallin expression in canine mammary tumors.

The aim of this study was to evaluate prognostic and/or diagnostic factors of canine mammary tumors by immunohistochemically analyzing the expression of alpha basic crystallin (αB-c). For this, formalin-fixed, paraffin-embedded blocks of 51 naturally-occurring canine mammary tumors (11 benign and 40 malignant) were used. Tissue from eight normal canine mammary glands were served as a control. Immunohistochemically, in the control mammary tissues, a few luminal epithelial cells were αB-c positive but myoepithelial cells were negative. In benign or simple type malignant tumors, αB-c expression was observed in luminal epithelial cells while the myoepithelial basal cells were negative. In benign or complex type malign tumors, positive staining was predominantly found in the cytoplasm of epithelial cells. Immunoreactivity of αB-c was also observed in neoplastic myoepithelial cells. Statistically, the number of cells immunolabeled with αB-c was found to be significantly different among tissues from normal canine mammary glands, benign lesions, and malignant tumors (p < 0.05). αB-c immunoreactivity was higher in malignant tumors than the control mammary tissues (p < 0.001). Data obtained in the current study revealed a strong association between high expression levels of αB-c and primary mammary gland tumors in canines.

Telbivudine attenuates gentamicin-induced kidney injury in rats

Nephrotoxicity has been associated with nucleos(t)ide analogues other than telbivudine (LdT). This study investigated the potential effects of LdT and lamivudine (LAM) on renal function in an experimental rat model of gentamicin-induced acute nephrotoxicity. A total of 28 healthy Wistar albino rats were randomly divided into four experimental groups: negative control; positive control (PC); LdT; and LAM. Nephrotoxicity was induced by gentamicin in the LdT, LAM and PC groups. LdT and LAM were administered to two groups for 6 weeks starting on the ninth day. Blood samples were collected weekly and cystatin C levels were measured by ELISA. Animals were sacrificed on the 50th day and the kidneys were removed for histological examination. Serum cystatin C levels differed significantly between the LdT and LAM groups (P <0.007) and between the LdT and PC groups (P <0.001). Renal function was significantly improved in the LdT group at the start of antiviral treatment on Day 8 and at the end of treatment on Day 50 (P = 0.001 and 0.007). Glomerular injury, acute tubular necrosis and total injury score were significantly reduced in the LdT group relative to the PC and LAM groups upon histopathological examination. LdT was associated with significant improvements in renal function as measured by biochemical and histopathological methods. The acute kidney injury model data should be supported by clinical studies to suggest that LdT treatment may have advantages for patients with underlying chronic kidney disease receiving chronic hepatitis B treatment.