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Öğe The effects of plasma immersion ion implantation and deposition (PIII&D) process voltages on the morphology, phase formation and E. coli adhesion of Ag coatings obtained on the surface of Ti6Al4V orthopedic implant material in nitrogen plasma(Gazi Univ, Fac Engineering Architecture, 2017) Gencer, G. Mehmet; Karadeniz, Suleyman; Lambrecht, Fatma Yurt; Havitcioglu, Hasan; Ozkal, Sermin; Baskin, HuseyinIn order to combine the antimicrobial effect of silver with mechanical and chemical properties of titanium nitrate, Ag was deposited on the surface of Ti6Al4V (orthopedic implant material) in N-2 plasma by using plasma immersion ion implantation and deposition (PIII&D) method. The coatings were formed by using varied negative pulsed high voltage and magnetron sputtering voltage values of PIII&D process. Surface morphologies of coatings were determined with atomic force microscopy (AFM), while cross-section morphologies were determined with field emission scanning electron microscopy (FE-SEM). The phases and chemical compositions of coatings were investigated by using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. XPS depth profile analysis were done to reveal the penetration of Ag+ ions into the surface of specimen. In in vitro anti-bacterial effectiveness experiments, the adhesion of E. coli (Escherichia coli) microorganism, which were marked with Tc-99m radioisotope, on surfaces of specimens was investigated. It was consequently determined that Ag was dominant in the coatings obtained by applying 8 kV negative pulsed high voltage, while Ag decreased on the surface depending on the increase in the voltage.Öğe Endothelin Receptor-Independent Correlation Between HSP47 and Collagen in Rabbit Model of Early Atherosclerosis(Ortadogu Ad Pres & Publ Co, 2011) Reel, Buket; Cavdar, Zahide; Ergur, Bekir Ugur; Ozkal, Sermin; Ozsarlak-Sozer, Gonen; Oktay, Gulgun; Kerry, ZelihaObjective: Collagen in the extracellular matrix (ECM) plays an important role in modulation of response to the vascular injury during the progression of atherosclerosis and restenosis. Collagen can regulate smooth muscle cell (SMC) proliferation, migration and matrix metalloproteinase (MMP) production. Therefore, collagen turnover in the arteries is an important determinant of intimal thickening. Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, is thought to be essential for the processing and secretion of procollagen molecules. Endothelin (ET) is a strong chemoatractant and mitogen promoting SMC proliferation and migration. The aim of this study was to investigate the possible role of HSP47 and its relation to collagen synthesis, and the effects of a nonselective ETA/ETB receptor antagonist, TAK-044 in collar-induced early atherosclerosis model. Material and Methods: New Zealand white rabbits were divided into two groups. Both groups received vehicle (0.9% NaCl 0.8 ml/kg/day, s.c.) or TAK-044 (5 mg/kg/day, s.c.) for three weeks. On 8th day, a non-occlusive silicon collar was placed around the left carotid artery. The right carotid artery was sham-operated. HSP47 expression in carotid arteries were determined immunohistochemically. Furthermore, total collagen levels, collagen expression and type I procollagen expression were established. Results: HSP47 expression correlated with collagen expression did not change in collared arteries. TAK-044 treatment did not affect HSP47 and collagen levels. Conclusion: There was a correlation between HSP47 expression and collagen expression in carotid arteries. However, intimal thickening did not induce HSP47 expression and early collagen development. The ineffectivenes of TAK-044 suggests that ET-1 signaling may not be implicated in HSP47 and collagen in this model.Öğe MMP-2 and MMP-9 Alteration in Response to Collaring in Rabbits: The Effects of Endothelin Receptor Antagonism(Sage Publications Inc, 2009) Reel, Buket; Oktay, Gulgun; Ozkal, Sermin; Islekel, Huray; Ozer, Erdener; Ozsarlak-Sozer, Gonen; Cavdar, Zahide; Akhisaroglu, Serpil Tanriverdi; Kerry, ZelihaMatrix metalloproteinases (MMPs), and, in particular, gelatinases (MMP-2 and MMP-9), have been implicated in vascular cell proliferation and/or migration, contributing to intimal thickening, an essential stage in the development of atherosclerosis and restenosis following balloon angioplasty. Endothelin, a strong chemoatractant and mitogen, has been shown to promote smooth muscle cell proliferation and migration by activating MMPs via endothelin-A (ETA) receptors. The positioning of a soft silicon collar around the left carotid artery in rabbits results in intimal thickening. In this study, we investigate the possible role of gelatinases and the effect of a nonselective ETA/ETB receptor antagonist, TAK-044 (5 mg/kg body weight/day, subcutaneously [sc]), on these enzymes. Our results demonstrated that both MMP-2 and MMP-9 activities increased in response to collaring in placebo group, while treatment with TAK-044 significantly suppressed both gelatinase activities and proMMP-2 levels, and inhibited intimal thickening in collared arteries. These results suggest that either enhanced MMP expression or endothelin receptor antagonism may be involved in the formation of intimal thickening in this model.Öğe MMP-2 and MMP-9 Alteration in Response to Collaring in Rabbits: The Effects of Endothelin Receptor Antagonism(Sage Publications Inc, 2009) Reel, Buket; Oktay, Gulgun; Ozkal, Sermin; Islekel, Huray; Ozer, Erdener; Ozsarlak-Sozer, Gonen; Cavdar, Zahide; Akhisaroglu, Serpil Tanriverdi; Kerry, ZelihaMatrix metalloproteinases (MMPs), and, in particular, gelatinases (MMP-2 and MMP-9), have been implicated in vascular cell proliferation and/or migration, contributing to intimal thickening, an essential stage in the development of atherosclerosis and restenosis following balloon angioplasty. Endothelin, a strong chemoatractant and mitogen, has been shown to promote smooth muscle cell proliferation and migration by activating MMPs via endothelin-A (ETA) receptors. The positioning of a soft silicon collar around the left carotid artery in rabbits results in intimal thickening. In this study, we investigate the possible role of gelatinases and the effect of a nonselective ETA/ETB receptor antagonist, TAK-044 (5 mg/kg body weight/day, subcutaneously [sc]), on these enzymes. Our results demonstrated that both MMP-2 and MMP-9 activities increased in response to collaring in placebo group, while treatment with TAK-044 significantly suppressed both gelatinase activities and proMMP-2 levels, and inhibited intimal thickening in collared arteries. These results suggest that either enhanced MMP expression or endothelin receptor antagonism may be involved in the formation of intimal thickening in this model.
