Browsing by Author "Türköz, E"

Now showing 1 - 4 of 4
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    Expression of Nitric Oxide Synthase in Primary and Recurrent Pterygium
    Emre, S; Vatansever, SH; Türköz, E; Kayikçioglu, ÖR
    Purpose: The aim of this study was to investigate the expression of different nitric oxide synthases (NOSs) in primary and recurrent pterygia and to investigate the probable role of any nitric oxide synthase on pterygium recurrence. Materials and Method: Specimens of 40 primary pterygia and 10 recurrent pterygia excised during pterygium surgery were included in the study. Also, 15 normal conjunctiva of medial limbus obtained from patients free of pterygia and removed during other ophthalmologic surgeries formed the control group. Specimens were stained with hematoxylin and eosin for general histological and morphologic evaluation. The distribution of n-NOS, e-NOS and i-NOS were analyzed using indirect immunoperoxidase staining. Results: Histological evaluation of specimens revealed that the epithelium in primary and recurrent pterygia groups was thicker compared to that in the control group. Immunohistochemical analysis revealed that in both primary pterygium and control groups, immunoreactivity was positive for all NOSs in both epithelium and connective tissue. For recurrent pterygium group, NOS immunoreactivity could be detected moderately for n-NOS in the epithelium and weakly for e-NOS in both epithelium and connective tissue. However, in recurrent pterygium samples, i-NOS immunoreactivity was lacking in both epithelium and connective tissue. Discussion: These data are the first to demonstrate that NOS expression may differ between primary and recurrent pterygia. Meanwhile, continuous expression of n-NOS with suppression of i-NOS and e-NOS may be an important step in the recurrence process of pterygia.
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    The Differentiation of Neuronal Cells from Mouse Embryonic Stem Cells
    Umur, N; Vatansever, HS; Umur, AS; Türköz, E; Özbilgin, K
    With new technologies emerging today, the importance of stem cells in the cell therapy of nervous system diseases is supported by recent studies. Therefore, the development of neuronal cell differentiation protocols from stem cells is of great importance. In our study, the differentiation of neuronal and neuroglial cells from mouse embryonic stem (ES) cell line and their analysis with neuronal cell markers are aimed. Mouse ES cells were differentiated to neurogenic series cells by adding N2 and bFGF to the culture medium on coated Fibronectin dishes. For the identification of differentiated cells, they were evaluated by light microscopy using immunhistochemistry techniques and by electron microscopy. Indirect immunohistochemical staining method was performed with SSEA-1 (mouse embriyonic stem cells marker), Nestin (neural precursor cells marker), beta III-Tubulin (neuronal cells marker), MAP-2 (neuronal cells marker), GFAP (astrocyte marker), and O4 (oligodendrocyte marker). After 1 week of differentiation of cells, immunoreactivities of SSEA-1 and Nestin were detected to be negative and moderate, respectively. After 2 weeks culture time, the differentiation was still continuing and especially positive immunoreactivities of beta-III Tubulin and MAP-2 and weak immunoreactivities of O4 and GFAP were supported neuronal differentiation. In conclusion, our results suggest that neuronal cell derived from mouse ES cells were differentiated particularly to neuron using N2+bFGF+fibronectin culture condition. Therefore, these differentiated cells may be used as a treatment method in degenerative diseases of the nervous system.
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    Antibiotic treatment is superior to ursodeoxycholic acid on total parenteral nutrition associated hepatic dysfunction
    Günsar, C; Vatansever, S; Var, A; Aygören, R; Yilmaz, Ö; Türköz, E; Sencen, A; Mir, E
    This study aimed to investigate the apoptotic mechanisms, oxidative stress, and mechanisms of effect of antibiotics and ursodeoxycholic acid (UDCA) in total parenteral nutrition (TPN)-associated liver injury. Four groups of young rabbits were used in the study as follows: Group 1 (n: 7): TPN + Metronidazole (30 mg/kg IV) + Gentamicin (6 mg/kg IV); Group 2 (n: 7): TPN + UDCA (15 mg/kg per oral); Group 3 (n: 6): TPN only; and Group 4 (n: 7): Control group. After 10 days, the animals were killed and livers were removed. Hepatic apoptosis, apoptotic proteins, malondialdehyde (MDA) and myeloperoxidase (MPO) levels were studied in liver, and direct bilirubin values were assessed in the blood samples. Direct bilirubin increased with TPN, and antibiotic combination, as the most effective group, significantly lowered its levels (p < 0.01). MDA values also showed significant differences in comparisons between G1 and G3 (p < 0.05) and G1-G4 (p < 0.01). An increased number of apoptotic cells was detected particularly in G2 and G3, whereas the lowest levels, other than in the control group, were found in G1. All TUNEL-positive cell number data were statistically significant except between G2 and G3(p < 0.05). Caspase-3 and Bax immunoreactivities were greatest in G2. Significant differences were shown in caspase-3 immunoreactivity between the groups (p < 0.01), except between G1 and G3 (p > 0.05). All comparisons between the groups were significant for Bax (p < 0.01). In contrast, Bcl-2 immunoreactivity was moderate and highest in G1: comparisons between G1 and the other groups demonstrated statistically significant differences (p < 0.01). Fas-L immunoreactivity was greatest in G2, and all comparisons between the groups were statistically significant (p < 0.01). Metronidazole and gentamicin combination is effective on TPN-induced liver injury by the Bcl-2 anti-apoptotic pathway, total anti-apoptotic effect and by decreasing bilirubin levels. Oxidative injury in the liver increased with therapy. UDCA seems less effective on TPN-associated liver injury.
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    Levosimendan up-regulates transforming growth factor-beta and Smad signaling in the aorta in the early stage of sepsis
    Erbüyün, K; Tok, D; Vatansever, S; Ok, G; Türköz, E; Aydede, H; Erhan, Y; Tekin, I
    BACKGROUND This prospective, controlled experimental study was planned to investigate the effects of levosimendan on transforming growth factor (TGF)-beta 3 and Smad1, Smad2 and Smad3 expression in the early stages of sepsis. METHODS Twenty-four rats were randomized into four groups: 1) sham-operated controls, 2) dobutamine group - subjected to abdominal hypertension and peritonitis-induced sepsis using cecal ligation and puncture (CLP), then treated with 10 mu g.kg(-1)min(-1) intravenous (IV) dobutamine infusion, 3) levosimendan group - as in 2, then treated with levosimendan IV bolus 200 mu g.kg(-1) followed by 200 mu g.kg.(-1)min(-1) IV infusion, and 4) a control group as in 2, with no treatment. All rats were killed 8 hours after CLP. Aorta tissue samples were analyzed by immunohistochemical staining. RESULTS CLP caused mild interleukin (IL)-1 immunostaining in both control and dobutamine groups. Immunoreactivity of tumor necrosis factor (TNF)-alpha was mild in both sham and control groups. TGF-beta 3 immunostaining was mildly increased in groups sham, control and dobutamine, whereas it was found moderate in group levosimendan. Smad1, Smad2 and Smad3 were found moderately increased only in group levosimendan. CONCLUSION Beneficial effects of levosimendan on hemodynamics and global oxygen transport were reported in experimental and clinical trials. Besides its potency on C++ ion sensitivity, it should influence inflammatory cytokine production by diminishing TGF-beta 3 and Smad1, Smad2 and Smad3 expression.