Browsing by Author "Barut T."

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    Immunolocalization of VEGF, VEGFR-1 and VEGFR-2 in lung tissues after acute hemorrhage in rats
    (2008) Ekerbicer N.; Tarakci F.; Barut T.; Inan S.
    In treatment of hypovolemia it is important to reestablish normal tissue hemodynamics after fluid resuscitation. Vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) have been identified as important in many physiological and pathological processes. In this study, we aimed to investigate the histo-physiological effects of VEGF, VEGFR-1 (flt-1) and VEGFR-2 (KDR/flk-1) in resuscitation with different plasma substitutes on lung tissues after acute hemorrhage in rats. Male Sprague-Dawley rats (n=25) were used in this study. The left femoral vein and artery were cannulated for the administration of volume expanders and for direct measurement of mean arterial blood pressure (MAP) (Power-Lab) and heart rate (HR). Fifteen rats were bled (5 ml/10 min) and infused (5 ml/5 min) with one of three randomly selected fluids: (a) dextran-70 (Macrodex); (b) gelatin (Gelofusine); or (c) physiological saline (PS, 0.9% isotonic saline) solutions. Five rats were bled and none were infused (hypovolemia group) and five rats were untreated as the control group. At the end of the experiment, rats were sacrificed and lung tissues were removed for routine processing and paraffin wax embedding. Sections of tissue were stained with hematoxylin and eosin (H&E) and selected blocks were then prepared for indirect immunohistochemical labeling for anti-VEGF, anti-VEGFR-1 and anti-VEGFR-2 primary antibodies. It was observed that both MAP and HR decreased parallel to blood withdrawn in this time interval. The MAP and HR were restored in the following periods. In the control rats, positive immunoreactivity of VEGF and its receptors (VEGFR-1 and VEGFR-2) were detected in respiratory epithelial cells, respiratory and vascular smooth muscle cells, alveolar cells and endothelial cells. While strong immunoreactivities of VEGF and VEGFR-1 were observed in the hypovolemia group, only moderate immunoreactivity of VEGFR-2 was seen in this group. Moderately strong immunolabeling of VEGF and VEGFR-1 were observed in the dextran-70, gelatin and PS resuscitated groups, whereas only weak immunolabeling of VEGFR-2 was observed in these groups. In summary, the vascular protecting effects of these factors were observed with fluid resuscitation, contributing to the pathophysiological changes seen in hypovolemia. © 2007 Elsevier GmbH. All rights reserved.
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    The contribution of differentiated bone marrow stromal stem cell-loaded biomaterial to treatment in critical size defect model in rats; [Biyomateryal üzerinde farklılaşmış kemik İliǧi stromal kök hücrelerinin kritik hacim defektli sıçan modelinde uygulanmasının tedavideki yeri]
    (Veteriner Fakultesi Dergisi, 2010) Tuǧlu M.I.; Özdal-Kurt F.; Koca H.; Sarac A.; Barut T.; Kazanç A.
    Mandibular fractures present a challenge in maxillo-facial surgery due to difficulties in healing and complications. In recent years, advances in bio-engineering as well as stem-cell studies suggest that it may be possible to treat these fractures by stem cell treatment with biomaterials. In the present study, we explored the efficacy of differentiated stem cells placed on biomaterials on fracture treatment and its relation with oxidative stress and apoptosis. A 4 mm circular defect was made on the mandibulae of 20 adults Wistar rats. Hydroxyapatite gel (control, n=5) and bone marrow stromal cells differentiated into osteoblast-seeded hydroxyapatite gel (n=5) were implanted within these defects. We were also used empty cavities (n=5) and cavities filled with only cells (n=5) for negative controls. Animals were sacrificed after a 6-week healing period and samples were examined blindly by histological, immunohistochemical, radiological and morphometric methods. Compared to the control cavities that underwent no procedure or filled with just cells, there were significant (P<0.001) healings in both groups. Hydroxyapatite gel with differentiated stem cells on, however, yielded significantly (P<0.05) better new bone formation and osteoid production decreased fibrous tissue and increased cellular activity. Differentiated stromal cells combined with biomaterial accelerated the treatment in defects of critical volume within a 6-week period of healing, activated and resulted in significant formation of bone of higher quality. Promotion of bone formation by the helps of bioengineering and stromal cells has gained importance in the treatment and reconstruction of fractures.
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    The histologic evaluation of atorvastatin and melatonin treatment on oxidative stress and apoptosis of diabetic rat pancreas; [Atorvastatin ve melatonin tedavisinin diyabetik siçan pankreasinda oksidatif stres ve apoptozise etkilerinin histolojik incelemesi]
    (2010) Gürpinar T.; Nuran E.; Uysal N.; Barut T.; Tarakçi F.; Tuǧlu M.
    In the diabetic state, there is an enhanced oxidative stress due to excessive production of reactive oxygen compounds and decreased bioavailability of nitric oxide. Antioxidant treatment has been used to prevent oxidative damage in diabetes. The objective of the present study was to explore the effects of atorvastatin (AT) and melatonin (MLT) on oxidative stress in diabetic rat pancreas. We also assessed nitric oxide synthase (NOS) activity and apoptosis. Diabetes was induced by an alkylating agent steptozotocin (STZ, 55 mg/kg, IP). Six weeks later rats were divided into five groups: STZ-induced diabetic group received atorvastatin (STZ+AT), STZ-induced diabetic group received melatonin (STZ+MLT) and STZ-induced diabetic group received atorvastatin and melatonin (STZ+AT+MLT). The vehicle-treated non-diabetic (CT) and diabetic group (STZ-CT) served as normoglycemic and diabetic controls. AT was given 8 mg/kg orally and MLT was given 10 mg/kg/IP once a day for 2 weeks beginning from the sixth week. Pancreatic tissue was examined by immunohistochemical methods. Although no significant difference was observed with respect to antioxidant status, NOS activity was tended to be higher in the untreated diabetic rats than in the treated rats. We observed that AT and MLT treatment improved the histopathological changes including apoptosis and oxidative stress in diabetic pancreas.
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    Statin treatment reduces oxidative stress-associated apoptosis of sciatic nerve in diabetes mellitus
    (2011) Grpinar T.; Ekerbiçer N.; Harzadin N.U.; Barut T.; Tarakçi F.; Tuglu M.I.
    Statins are lipid-lowering drugs that are widely used for treating hyperlipidemia, especially in diabetic patients. The aim of our study was to explore the effects of atorvastatin on oxidative stress and apoptosis in the sciatic nerve due to hyperglycemia. Diabetes was induced by streptozotocin. Atorvastatin was given orally for two weeks beginning from the sixth week. Microscopic examination of sciatic nerve revealed that normal tissue organization was disrupted in streptozotocin induced diabetic rats. Treatment with Atorvastatin reduced the histological damage and protected the morphological integrity of the sciatic nerve in streptozotocin induced diabetes. Increased expressions of transforming growth factor beta-1, endothelial nitric oxide synthase and TUNEL in sciatic nerve from streptozotocin induced diabetes were reduced by Atorvastatin. Atorvastatin could improve the effects of oxidative stress and apoptosis on the sciatic nerve due to diabetes. © 2011 The Biological Stain Commission.
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    Effects of acute treatment with dexamethasone on hemodynamic and histopathological changes in rats
    (2012) Ekerbiçer N.; Inan S.; Tarakç F.; Barut T.; Gürpnar T.; Ozbek M.
    We assessed the time-dependent effects of intraperitoneal (i.p.) and intravenous (i.v.) application of dexamethasone (Dexa) on the mean arterial blood pressure (MAP), heart rate (HR) and total blood volume (TBV). We evaluated also the relation between the effects and immunoreactivities of transforming growth factor-beta (TGF-β), epithelial nitric oxide synthase (eNOS), interleukin-1 beta (IL1-β) and vascular endothelial growth factor (VEGF) in rat brain, lung and kidney tissues. Rats were anesthetized and while still breathing spontaneously, a tracheotomy and femoral vein and artery catheterizations were performed. To determine TBV using the hemodilution method, 2 ml albumin-electrolyte solutions were applied by i.v. injection. Group 1 (control group) received a 1 ml bolus injection of physiologic saline, Group 2 received 15 mg/kg and Group 3 received 75 mg/kg Dexa i.p. The hematocrit was measured at 10, 20, 60 and 120 min. For each animal, the values of MAP, HR and TBV were measured within 2 h. For immunohistochemical evaluation, anti-TGF-β, anti-eNOS, anti-IL1-β and anti-VEGF primary antibodies were tested using the avidin-biotin-peroxidase method. TBV was decreased in Group 1 and the increase in MAP was statistically significant. HR values increased slightly. None of the values changed significantly in Group 2. Although TBV was unchanged in Group 3, the decrease in MAP was statistically significant. HR values increased, but the increase was not statistically significant. Mild IL1-β immunoreactivity and moderate TGF-β, eNOS and VEGF immunoreactivities were observed in the brain, lung and kidney samples in Group 1. Increased eNOS immunoreactivity in the kidney samples were observed in Group 2. eNOS immunoreactivity was as strong in the brain and the kidney samples in Group 3. Decreased VEGF immunoreactivity was observed in the lung and kidney tissues in Group 3. Significantly decreased TGF-β immunoreactivity was observed in all tissue samples in Group 3. The decreased MAP values in Group 3 differed from those in Groups 1 and 2. Despite increased eNOS immunoreactivity, especially in brain and kidney, the decrease in VEGF immunoreactivity in Group 3, especially lung and kidney, were consistent with a drop in blood pressure. © 2012 The Biological Stain Commission.
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    The effects of the melatonin treatment on the oxidative stress and apoptosis in diabetic eye and brain
    (Hindawi Limited, 2012) Gürpinar T.; Ekerbiçer N.; Uysal N.; Barut T.; Tarakçi F.; Tuglu M.I.
    Oxidative stress plays an important role in the development of complications in diabetes mellitus. Antioxidant therapy has been thought to decrease oxidative stress. The objective of the present study was to explore the effects of melatonin (MLT) on oxidative stress in diabetic rat eye and brain tissue by using immunohistochemical methods. Diabetes was induced by streptozotocin, (STZ,55mg/kg/i.p) in adult rats. MLT was given 10mg/kg/i.p once a day for 2 weeks beginning from the sixth week. Six weeks later, rats were divided into three groups: control (CR), STZ-induced diabetic (STZ), and STZ-induced diabetic group received melatonin (STZ+MLT). Although no significant difference was observed with respect to antioxidant status, NOS activity tended to be higher in the untreated diabetic rats than in the treated rats. It was observed that MLT treatment improved the histopathological changes including apoptosis and oxidative stress in brain and eye in diabetic rat. Copyright © 2012 Tuba Grpnar et al.