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    An analysis of the impact of buthionine sulfoximine and N-nitro-L-arginine on blood pressure
    (Biomedpress, 2023) Gungor, Buket; Akdur, Secil; Sılan, Coşkun; Coskun, Ozlem; Aksulu, Hakki Engin
    Introduction: The presence of weaknesses in the efficacy of endogenous natriuretic and vasodilator agents plays a significant role in developing high blood pressure. It is often suggested that oxidative stress is critical in developing hypertension due to nitric oxide synthase (NOS) inhibition. This study aimed to investigate the intrarenal dopaminergic system activities, involvement of oxidative stress, and blood pressure changes resulting from NOS inhibition with N-nitro-L-arginine (L-NNA) and/or L-buthionine sulfoximine (BSO).Methods: Male Wistar albino rats (n = 24) were administered water containing 50 mg/L L-NNA for 21 days and/or intraperitoneal injections of BSO (125 mg/kg twice daily) for seven days; control rats were administered tap water. The rats' blood pressure; water and salt balance; total oxidant and antioxidant capacities; and urinary dopamine, adrenaline, and noradrenaline levels were measured.Results: While L-NNA and BSO alone did not significantly alter blood pressure, their coadministration caused rats to develop hypertension and significantly reduced the fractional excretion of sodium, increasing its tubular reabsorption. Urinary dopamine levels, indicators of intrarenal dopamine synthesis, did not change significantly Conclusion: These results indicate the importance of the weakness of endogenous natriuretic systems such as nitric oxide in hypertension development. While BSO did not induce oxidative stress in the measured parameters, it was shown for the first time as an actor in hypertension development in subjects with NOS inhibition to the extent that such inhibition did not increase blood pressure.
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    Assessment of BMP-6 polymorphism and relationship with disease activity in Ankylosing Spondylitis patients
    (Elsevier Science Bv, 2016) Oztopuz, R. Ozlem; Sılan, Fatma; Akbal, Ayla; Coskun, Ozlem; Özdemir, Öztürk
    [Anstract Not Available]
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    Clinical significance of serum ADP-ribosylation and NAD glycohydrolase activity in patients with colorectal cancer
    (Springer, 2014) Varol, Basak; Coskun, Ozlem; Karabulut, Senem; Serin, Kursat Rahmi; Asoglu, Oktar; Albeniz, Isil; Tas, Faruk
    The objective of this study was to evaluate the clinical significance of serum ADP-ribosylation and NAD glycohydrolase activity in patients with colorectal cancer (CRC). A total of 108 patients with CRC who underwent curative surgery and 20 healthy volunteers were enrolled in this study. ADP-ribosylation and NAD glycohydrolase activity levels were determined. The association of ADP-ribosylation and NAD glycohydrolase with clinical and laboratory factors and their impact on overall survival (OS) and disease free survival (DFS) were shown. The preoperative ADP-ribosylation and NAD glycohydrolase activity levels were significantly higher in patients with CRC than in the control group (p < 0.001). ADP-ribosylation and NAD glycohydrolase activity levels were correlated with tumor stage (p = 0.05, p = 0.001), stage of disease (p < 0.001, p < 0.001), serum CEA level (p < 0.001, p < 0.001), and site of lesion (p < 0.001, p < 0.001), respectively. Patients with high ADP-ribosylation had significantly unfavorable OS and DFS compared with those with lower levels (p < 0.001, p < 0.001), respectively. Moreover, the patients with high NAD glycohydrolase activity showed significantly worse OS and DFS rates, similar to ADP-ribosylation. Serum levels of ADP-ribosylation and NAD glycohydrolase activity correlate well with tumor stage, stage of disease, serum CEA level, and site of lesion. In conclusion, elevated levels of preoperative ADP-ribosylation and NAD glycohydrolase levels in serum are associated with poor prognosis in patients with CRC.
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    Expression levels of KCNQ1 and KCNQ3 genes in experimental epilepsy model
    (Cukurova Univ, Fac Medicine, 2020) Coskun, Ozlem; Oztopuz, Ozlem; Cokyaman, Turgay
    Purpose: Status epilepticus (SE) is a highly common neurological disease in children, with recurrent generalized convulsions for more than 30 minutes, and when not controlled, neuronal damage occurs in the brain. The aim of this study was to evaluate the changes in KCNQ1 and KCNQ3 gene expression levels in the acute period after SE. Materials and Methods: In rats, an experimental SE model was created with Li-Pc. Study; female Wistar albino [250-350 g, 21 (n=7)] rats were used in 3 groups as SE, control and sham groups. The total RNA obtained from brain tissues was converted to cDNA, and gene expression levels of KCNQ1 and KCNQ3 genes were assessed by quantitative real-time PCR (qRT-PCR) method. Results: Statistically in SE group; compared to the control and sham groups, a significant difference was observed in the gene expression levels of the KCNQ1 and KCNQ3 ion channels. The KCNQ1 and KCNQ3 gene expression levels of the experimental group was found higher than the other groups. Conclusion: Determining the changes in mRNA expression levels of genes encoding K+ ion channels will help to better understand the pathological mechanisms that occur during epilepsy. In the SE experimental model created, it is believed that an increase in mRNA expression of KCNQ1 and KCNQ3 will lead to drug therapy studies planned for the future.
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    Gender in Medical Education in Turkey: The Intern Perspective
    (Shiraz University of Medical Sciences, 2020) Midik, Ozlem; Aytuğ Koşan, Ayşen Melek; Coskun, Ozlem; Baykan, Zeynep; Karabilgin Öztürkçü, Özlem Sürel; Şenol, Yeşim
    Introduction: Gender insensitivity (lack of gender awareness) in the physician’s professional role and practice can lead to outcomes such as gender discrimination and gender-based harassment in various areas, such as medical education, career opportunities, and specialty selection. The purpose of this study was to reveal the place that the concept of gender occupies in medical education in Turkey by canvassing the opinions of final-year medical students regarding theories of gender roles and socialization, academic capitalism, and liberal feminism. Methods: This study was a Cross-sectional survey. The study population consisted of 1739 interns in six medical faculties in four different geographical regions of Turkey. The reason behind the selection is having different socio-economic factors. Students were selected by simple random sampling technique. For determining it is jumped five students from the lists in faculties. For the validity and reliability of the 14 survey questions, 5 expert opinions were examined and the preliminary instrument was applied to 10 students. Chi-square test was used for comparative analysis. Results: The students who stated that their gender had not affected their educational lives during clinical training reported that it had adversely impacted their internships (P<0.001). More male students than female ones stated that male physicians were more confidence-inspiring and more industrious, that they managed better, and that they were more likely to recommend a male surgeon. A high number of students reported being undecided on the subjects of concepts or behaviors concerning gender/gender inequality. Conclusion: We recommend greater focus on role modeling and purposeful teaching of gender concepts from the earliest stages of medical education, with particular concentration on gender culture within a process of change involving all hospital personnel in order to prevent gender discrimination. © 2020, Shiraz University of Medical Sciences. All rights reserved.
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    Melatonin ameliorates sodium valproate-induced hepatotoxicity in rats
    (Springer, 2020) Oztopuz, Ozlem; Turkon, Hakan; Buyuk, Basak; Coskun, Ozlem; Sehitoglu, Muserref Hilal; Ovali, Mehmet Akif; Uzun, Metehan
    Valproic acid (VPA) is a anticonvulsant and mood-stabilizing agent used to treat epilepsy in patients of all ages. However, it can cause hepatotoxicity with increased oxidative stress. Melatonin (MEL) is known as antioxidant and antiinflammatory agent. Therefore, the present study designed to investigate the probable protective role of melatonin against VPA-induced liver toxicity. For that purpose, 28 Wistar rats were randomly selected and divided into four groups, namely the Group C (vehicle), VPA (500 mg/kg/day VPA), MEL + VPA (10 mg/kg/day melatonin + 500 mg/kg/day VPA) and MEL (10 mg/kg/day melatonin). The agents were given by oral gavage for 14 days. Blood and liver tissue samples from all the rats were harvested on the 15th day of experiment. Biochemical analyses were conducted on the blood samples. The levels of malondialdehyde (MDA), superoxide dismutase (SOD), alpha glutathione S-transferases (alpha-GST), nuclear factor-kappa B (NF-kappa B), myeloperoxidase (MPO) and changes in gene expression were examined in the liver tissues. Also, liver histopathological analyses were conducted. VPA administration significantly increased the levels of alpha-GST, MDA, NF-kappa B and of IL-1 beta, TNF-alpha gene expression in the liver compared to Group C. Moreover, vacuolization, hydropic degeneration, inflammatory cell infiltration, and sinusoidal congestion were commonly detected in the VPA-treated group along with the highest apoptotic index (TUNEL staining) values. Melatonin administration was revealed to exhibit powerful protective properties at cellular, inflammatory and oxidative level activities against VPA-induced liver toxicity. Therefore, melatonin administration may be used as an adjuvant therapy against to VPA-induced liver toxicity.
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    Preoperative serum TNF-?, IL-6 and VEGF levels in patients with colorectal cancer
    (Elsevier Science Bv, 2017) Coskun, Ozlem; Oztopuz, Ozlem; Ozkan, Omer Faruk
    [Anstract Not Available]
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    Purification of NAD+ glycohydrolase from human serum
    (Spandidos Publ Ltd, 2013) Coskun, Ozlem; Nurten, Rustem
    In the present study, NAD(+) glycohydrolase was purified from serum samples collected from healthy individuals using ammonium sulfate fractionation, Affi-Gel blue (Cibacron Blue F3GA) affinity chromatography, Sephadex G-100 column chromatography and isoelectric focusing. The final step was followed by a second Sephadex G-100 column chromatography assay in order to remove the ampholytes from the isoelectric focusing step. In terms of enhancement of specific activity, the NAD(+) glycohydrolase protein was purified similar to 480-fold, with a yield of 1% compared with the initial serum fraction. The purified fraction appeared to be homogeneous, with a molecular weight of 39 kDa, as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, and also corresponded to the soluble (monomeric) form of surface antigen CD38.
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    Separation techniques: Chromatography
    (Kare Publ, 2016) Coskun, Ozlem
    Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis. Proteins can be purified based on characteristics such as size and shape, total charge, hydrophobic groups present on the surface, and binding capacity with the stationary phase. Four separation techniques based on molecular characteristics and interaction type use mechanisms of ion exchange, surface adsorption, partition, and size exclusion. Other chromatography techniques are based on the stationary bed, including column, thin layer, and paper chromatography. Column chromatography is one of the most common methods of protein purification.
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    Studying protein-protein interactions: Latest and most popular approaches
    (Academic Press Inc Elsevier Science, 2024) Akbarzadeh, Sama; Coskun, Ozlem; Guncer, Basak
    PPIs, or protein-protein interactions, are essential for many biological processes. According to the findings, abnormal PPIs have been linked to several diseases, such as cancer and infectious and neurological disorders. Consequently, focusing on PPIs is a path toward disease treatment and a crucial tool for producing novel medications. Many methods exist to investigate PPIs, including low- and high-throughput studies. Since many PPIs have been discovered using in vitro and in vivo experimental approaches, the use of computational methods to predict PPIs has grown due to the expanding scale of PPI data and the intrinsic complexity of interacting mechanisms. Recognizing PPI networks offers a systematic means of predicting protein functions, and pathways that are included. These investigations can help uncover the underlying molecular mechanisms of complex phenotypes and clarify the biological processes related to health and diseases. Therefore, our goal in this study is to provide an overview of the latest and most popular approaches for investigating PPIs. We also overview some important clinical approaches based on the PPIs and how these interactions can be targeted.
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    The effect of Oleuropein on liver in experimental allergic rhinitis model
    (Bayrakol Medical Publisher, 2020) Oztopuz, Ozlem; Coskun, Ozlem; Buyuk, Basak
    Aim: The aim of this study is to investigate the supplemental effect of oleuropein which is the most commonly used corticosteroid in AR (Allergic rhinitis) treatment and to evaluate possible inflammatory-reducing properties in the liver. Material and Methods: The study was carried out on 42 male Wistar rats. The animals were randomly divided into 6 groups including G1 (C), G2 (AR), G3 (AR +SF), G4 (AR+MF), G5 (AR+OLE), G6 (AR+OLE+MF). Tumor necrosis factor-alpha (TNF-alpha) and Interleukin-1 beta (IL-1 beta) gene expression levels were assessed by RT-PCR analysis in liver tissues. In addition, liver tissues were evaluated histopathologically as a result of hematoxylin eosin (H&E) staining. Results: TNF-alpha and IL-1 beta gene expression levels in liver tissues were compared between groups and the results were statistically significant in all groups (p<0.000). Histopathological evaluation in H&E sections, sinusoidal dilatation, and hydropic degeneration were not observed in the liver tissue architecture of G1 (C). As a result of the examination of the sections belonging to G2 (AR), the location of hepatocyte cords and minimal destruction in portal areas were observed in organ architecture, and intensive sinusoidal dilatation was observed. Sinusoidal dilation was advanced in G3 (AR+SF). In addition, swelling and moderate hydropic degeneration were observed in hepatocytes, and focal lytic necrosis areas were not observed in G3 (AR+SF). All groups in terms of sinusoidal dilation and hydropic degeneration were significant differences statistically (p=0.000;0.001). Discussion: The present data indicated that oleuropein treatment suppresses inflammation in liver tissue caused by AR and it has no side effect in the experimental AR model. Oleuropein can be used as an auxiliary agent in the treatment of routine AR.