Elif Ozkok

Prof. Dr. Elif Ozkok

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 November 2010 in Brain Injury
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Journal Article
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IKIhsan Kara
Ihsan Kara
ANAsiye Nurten
Asiye Nurten
MAMakbule Aydin
Makbule Aydin
EOElif Ozkok
Elif Ozkok
IÖIlknur Özen
Ilknur Özen
SKSacit Karamürsel
Sacit Karamürsel
Primary objective: The present study was undertaken to evaluate whether enoant, which is rich in polyphenols, has any effect on electroencephalogram (EEG), oxidative stress and inflammation in ischemia/reperfusion (I/R) injury. Methods: Ischemia was induced by 2-hour occlusion of bilateral common carotid artery. Animals orally received enoant. Group 1 was the ischemic control group. Group 2 was treated with enoant of 1.25 g kg−1 per day for 15 days after I/R. Group 3 received the same concentration of enoant as in group 2 for 15 days before and after I/R. Group 4 was the sham operation group. EEG activities were recorded and the levels of TNF-α, IL-1β and IL-6, TBARS and GSH were measured in the whole brain homogenate. Results: There were significant changes in EEG activity in groups treated with enoant either before or after ischemia when compared with their basal EEG values. TNF-α, IL-6 and IL-1β levels were significantly increased after I/R. GSH levels in group 3 treated with enoant in both pre- and post-ischemic periods were significantly increased and TBARS concentration was decreased compared with the ischemic group. Conclusion: The findings support that both pre-ischemic and post-ischemic administrations of enoant might produce neuroprotective action against cerebral ischemia.

28 November 2023 in Acta Neuropsychiatrica
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Journal Article
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EDElif Delen
Elif Delen
CKCem Ismail Kucukali
Cem Ismail Kucukali
ZKZerrin Karaaslan
Zerrin Karaaslan
HYHande Yuceer
Hande Yuceer
SPSeyma Punar
Seyma Punar
EOElif Ozkok
Elif Ozkok
Objectives: Recent studies have shown that the distribution of the tryptophan/kynurenine pathway (KP) plays a role in the development of obsessive-compulsive disorder (OCD). We aimed to reveal the relationship between CYP1A1 rs464903 and aryl hydrocarbon receptor (AhR) rs10249788 associated with the KP and interferon gamma (IFN γ) and oxidative stress in OCD. Methods: In our study, the serum and DNAs of 150 samples, including 100 OCD patients and 50 controls, were used. The activity of glutathione peroxidase (GSH-Px), and the levels of IFN γ, thiobarbituric acid reactive substances (TBARS), tryptophan, and kynurenine were determined by biochemical methods. AhR rs10249788 and cytochrome P450 family CYP1A1 rs4646903, which interact directly with the KP, were analysed by polymerase chain reaction followed by restriction fragment length polymorphism. P < 0.05 was considered statistically significant. Result: There were no significant differences between groups in CYP1A1 rs4646903 and AhR rs10249788 while tryptophan and IFN γ were found to be higher in controls (p < 0.001, for both), and TBARS and indolamine-2,3-dioxygenase were found to be higher in OCD (p < 0.001, for both). There were significant correlations between IFN γ and TBARS and GSH-Px (p = 0.028, p = 0.020, respectively) in the OCD group. Conclusions: For the first time studied in OCD, it has been shown that IFN γ, tryptophan, oxidative stress parameters, and gene variants of CYP1A1 rs4646903 anAhR rs10249788 are shown effective on the KP.

2 April 2022 in Experimental Biology and Medicine
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Journal Article
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GAGulten Ates
Gulten Ates
STSule Tamer
Sule Tamer
HYHatice Yorulmaz
Hatice Yorulmaz
SMSevcihan Mutlu
Sevcihan Mutlu
VOVakur Olgac
Vakur Olgac
EOElif Ozkok
Elif Ozkok
We aimed to investigate the effects of melatonin administered before and during endotoxemia on the lung tissue of rats, cytokine, YKL-40, matrix metalloproteinase (MMP) and inhibitor levels, oxidative stress parameters, and energy balance. Sepsis was induced with lipopolysaccharide (LPS), the cell wall molecule of gram negative bacteria. Rats were divided into four groups, Control, LPS (Escherichia coli O127:B8, 20 mg/kg), melatonin (10 mg/kg), and melatonin+LPS (M+LPS). After injections, lung tissues samples were taken for experimental analyses. YKL-40, thiobarbituric acid reactive substances (TBARS), glutathione reductase (GR), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) enzymes levels were measured, high-energy components were analyzed; tumor necrosis factor-alpha (TNF-α), MMP-2, YKL-40, MMP-9, myeloperoxidase (MPO), tissue inhibitors of matrix metalloproteinase (TIMP)-1, and interleukin (IL)-10 immunoreactivities were investigated. In LPS group, YKL-40, creatine phosphate (both, p < 0.05), SOD, GR, adenosine mono-phophate (AMP), adenosine tri-phosphate (ATP) (for all, p < 0.01) were significantly decreased, while TBARS and adenosine di-phosphate (ADP) levels were increased ( p < 0.01, p < 0.05; respectively) compared to other groups. MMP-2 and -9, TIMP-1, TNF-α, IL-10, and MPO immunoreactivity were investigated in LPS group. On the contrary, in M+LPS group, MMP-9, TIMP-1 immunoreactivities were not found and IL-10 and MMP-2 immunoreactivities were found with little involvement. In M+LPS group, YKL-40, GR, AMP, ATP, creatine phosphate (for all, p < 0.05), and SOD ( p < 0.01) levels were significantly increased and TBARS levels were decreased ( p < 0.05). In our study, we suggest that melatonin exerts a protective and curative effect by reducing the matrix metalloproteinase levels responsible for tissue damage balance, stimulating the release of antioxidant enzymes, regulating cytokines and energy balance during endotoxemia.

1 August 2014 in Genetic Testing and Molecular Biomarkers
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Journal Article
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YCYilmaz Cetinkaya
Yilmaz Cetinkaya
SDSelcuk Dasdemir
Selcuk Dasdemir
MGMehmet Gencer
Mehmet Gencer
SBSinem Bireller
Sinem Bireller
EOElif Ozkok
Elif Ozkok
BCBedia Cakmakoglu
Bedia Cakmakoglu
Migraine is a common and debilitating episodic disorder characterized by recurrent headache attacks associated with autonomic symptoms. It affects an estimated 12% of the population. The etiology of the underlying neurodegenerative process is widely unknown; however, oxidative stress is a unifying factor in the current theories of migraine pathogenesis. After demonstrating the observation that oxidative DNA damage is detectable in migraine disease, searching the role played by DNA repair systems in migraine diseases could bring us much significant information about the pathogenesis of migraine. We prospectively investigated whether DNA repair gene polymorphisms (XRCC1 Arg399Gln, XRCC3 Thr241Met XPD Lys751Gln, XPG Asp1104His, APE1 Asp148Glu, hOGG1 Ser326Cys) account for an increased risk of migraine. The present analyses are based on 135 case subjects with migraine disease and 101 noncase subjects. Genotyping of DNA repair gene polymorphisms (XRCC1 Arg399Gln, XRCC3 Thr241Met XPD Lys751Gln, XPG Asp1104His, APE1 Asp148Glu, hOGG1 Ser326Cys) was detected by polymerase chain reaction-restriction fragment length polymorphism. We demonstrated that apurinic endonuclease (APE), X-ray repair complementing defective repair in Chinese hamster cells 3 (XRCC3), xeroderma pigmentosum D (XPD), and hOGG1 gene variants were associated with an increased risk for development of migraine disease (p0.05). Our findings have suggested that APE1, XRCC3, XPD, and hOGG1 gene variants could facilitate the development of migraine disease.

1 January 2015
Verified
Journal Article
Closed access
HYHatice Yorulmaz
Hatice Yorulmaz
EOElif Ozkok
Elif Ozkok
MEMine Erguven
Mine Erguven
GAGulten Ates
Gulten Ates
IAIrfan Aydin
Irfan Aydin
STSule Tamer
Sule Tamer

1 January 2018 in Archives of Neuropsychiatry
Verified
Journal Article
Closed access
AIAli Isikli
Ali Isikli
AKAyse Kubat-Uzum
Ayse Kubat-Uzum
ISIlhan Satman
Ilhan Satman
ZMZeliha Matur
Zeliha Matur
AOA. Emre Oge
A. Emre Oge
EOElif Ozkok
Elif Ozkok
Introduction: Diabetes mellitus (DM) affects peripheral nerves inducing diabetic polyneuropathy (DPN). Mitochondria! dysfunction and oxidative stress are potential causes of DPN. Methods: Nerve conduction studies were performed in 20 type 2 DM patients (11 with DPN) and 15 healthy controls. Perception threshold values of cold, warm and vibration were measured by quantitative sensory testing. Variants of a superoxide dismutase 2 (SOD2) gene single nucleotide polymorphism (SNP) (rs5746136) were determined by polymerase chain reaction (PCR) and following NexteraXT DNA Library. Results: DPN patients showed significantly increased threshold values. DM patients without DPN and healthy controls showed comparable values. TT variant of the SOD2 SNP was more prevalent in DM and DPN patients. DM patients with the TT variant displayed increased perception threshold values. Conclusions: Quantitative sensory testing is not superior to standard nerve conduction studies in DPN. Carriers of SOD2 SNP manifested increased sensory threshold levels which is important in further corroborating the link between oxidative stress and DPN.