Person: KOÇYİĞİT, ABDÜRRAHİM
8 results
Search Results
Now showing 1 - 8 of 8
Publication Open Access Diagnostic potential of Brucella melitensis Rev1 native Omp28 precursor in human brucellosis(2018-01-01) Koyuncu, Ismail; Kocyigit, ABDÜRRAHİM; Ozer, Ahmet; SELEK, Sahabettin; Kirmit, Adnan; Karsen, Hasan; KOÇYİĞİT, ABDÜRRAHİM; SELEK, ŞAHABETTİNSerologic tests for brucellosis aim to detect antibodies produced against membranous lipopolysaccharide of bacteria. Diagnostic use of this method is limited due to false positiveness. This study evaluates an alternative antigen to lipopolysaccharides (LPS), outer membrane 28-precursor-protein, of Brucella melitensis Rev1 for its diagnostic value. Omp28 precursor of B. melitensis Rev1 was cloned, expressed, and purified. 6-His and sumo epitope tags were used to tag the protein at N-termini. Omp28 gene was amplified based on the ORF sequence and cloned into a pETSUMO vector. The recombinant construct was propagated in Escherichia coli One Shot® Mach1™ cells then transformed into E. coli BL21(D3) cells for protein expression. The purified protein was studied in an indirect ELISA for diagnosis of brucellosis. Sera samples from 60 patients were screened by ELISA and the results were compared to Rose Bengal plate test. Recombinant antigen-based iELISA has given a successful outcome with the sensitivity, specificity, positive predictive value, and negative predictive value of 87.8%, 96.2%, 96.6%, and 78.78%, respectively. In conclusion, recombinant production and purification of the immunodominant Omp28 precursor protein has been achieved successfully in a one-step process with efficient yield and can be used for diagnosis of brucellosis in humansPublication Metadata only Paraoxonase-1 activity and oxidative status in patients with knee osteoarthritis and their relationship with radiological and clinical parameters(2012-09-01T00:00:00Z) Erturk, Cemil; Altay, Mehmet Akif; Selek, Sahbettin; Kocyigit, ABDÜRRAHİM; SELEK, ŞAHABETTİN; KOÇYİĞİT, ABDÜRRAHİMBackground. The aim of this study was to investigate serum paraoxonase-1 (PON1) activity and oxidative/anti-oxidative status in knee osteoarthritis (OA), and evaluate their relationship using radiological and clinical parameters. Materials and methods. The study population comprised 127 patients with knee OA and 107 healthy volunteers. Patients with knee OA were divided into four subgroups according to the Kellgren-Lawrence (K&L) grading scale. In addition, each patient was clinically evaluated by the Western Ontario and McMaster University Osteoarthritis Index (WOMAC). Serum PON1 activity was measured spectrophotometrically. Oxidative status was assessed by measuring serum lipid hydroperoxide (LOOH) and total oxidant status (TOS). Anti-oxidative status was assessed by measuring serum free sulfydryl groups (-SH = total thiol) and total antioxidant capacity (TAC). Oxidative stress index (OSI) was calculated. Lipid parameters were determined by routine laboratory methods. Results. Serum PON1 activity was significantly lower in the knee OA group compared to the control group (p 0.05). The lowest and highest mean serum PON1 activities were detected in patients with grades 4 and 1, respectively (ANOVA p < 0.001). In multiple regression analysis, WOMAC score was independently associated with serum PON1 activity (beta = -0.248, p = 0.027). Conclusions. Decreased serum PON1 activity and elevated LOOH, TOS, and OSI levels may be associated with knee OA, and serum PON1 activity may be a useful adjunctive indicator of the severity of knee OA for follow-up.Publication Metadata only Mononuclear leukocyte DNA damage and oxidative stress: The association with smoking of hand-rolled and filter-cigarettes(2011-04-03T00:00:00Z) Kocyigit, ABDÜRRAHİM; Selek, ŞAHBETTİN; Celik, Hakim; Dikilitas, Murat; KOÇYİĞİT, ABDÜRRAHİM; SELEK, ŞAHABETTİNCigarette smoking is a major cause of human cancer at various sites, although its carcinogenic mechanisms still remain unestablished. Based on the use of a filter, cigarette smoke can be divided into a gas phase and a tar phase. Both contain different concentrations of oxidants, free radicals and tobacco-specific carcinogens. To explore the effects of both filtered and non-filtered cigarette smoke on DNA damage and oxidative status, we measured the level of mononuclear leukocyte DNA damage by use of the single-cell gel electrophoresis (Comet) assay. We also determined malondialdehyde (MDA), protein carbonyl content (PC) and total antioxidative capacity (TAC) levels in blood plasma of smokers of manufactured filter-cigarettes and of hand-rolled cigarettes. Cotinine levels were also measured in plasma to estimate the degree of smoking. Mononuclear leukocyte DNA damage, plasma MDA, plasma PC and plasma cotinine levels were found significantly higher, while plasma TAC levels were found significantly lower in smokers of filter-cigarettes and smokers of hand-rolled cigarettes, compared with control subjects. TAC levels in hand-rolled and manufactured filter-cigarette smokers were not significantly different from each other. However, the levels of DNA damage. plasma MDA, plasma cotinine, and plasma protein oxidation were significantly higher in hand-rolled cigarette smokers than in filter-cigarette smokers. There was a significant positive correlation between MDA and DNA damage in both hand-rolled cigarette smokers and manufactured filter-cigarette smokers. This study indicates that smoking of hand-rolled cigarettes has stronger genotoxic and oxidative effects on the metabolism than smoking of manufactured filter-cigarettes. We propose that these harmful effects could be attributed to the higher level of oxidants. (C) 2011 Elsevier B.V. All rights reserved.Publication Metadata only Peripheral DNA damage in active pulmonary tuberculosis(2012-05-01T00:00:00Z) Selek, Sahbettin; ASLAN, Mehmet; Horoz, Mehmet; Celik, Hakim; Cosar, Niyet; Gunak, Faruk; Kocyigit, ABDÜRRAHİM; SELEK, ŞAHABETTİN; KOÇYİĞİT, ABDÜRRAHİMIn pulmonary tuberculosis patients, little is known about peripheral DNA damage, although increased oxidative stress is a well documented entity. Therefore, we aimed to investigate DNA damage along with oxidative status parameters in pulmonary tuberculosis patients. Twenty-seven pulmonary tuberculosis patients and 26 controls were included. DNA damage was assessed by comet assay. Total oxidant and antioxidant status, and oxidative stress index were determined. DNA damage, total oxidant status and oxidative stress index were higher in pulmonary tuberculosis patients than controls (all P < 0.05), while total antioxidant status was lower (P < 0.05). DNA damage was correlated with total oxidant and antioxidant status, and oxidative stress index (r = 0.69, P < 0.05; r = 0.48, P < 0.05, r = -0.47, P < 0.05; respectively) in pulmonary tuberculosis patients. Oxidative stress and DNA damage are increased in pulmonary tuberculosis patients. Increased oxidative stress associated DNA damage may be one of the pathogenetic mechanisms involved in the disorders suggested to be associated with pulmonary tuberculosis. (C) 2011 Wiley Periodicals, Inc. Environ Toxicol, 2012.Publication Metadata only Oxidative and antioxidative balance in patients of migraine.(2010-10-01T00:00:00Z) Alp, R.; Selek, S.; Alp, S. Ilhan; Taskin, A.; Kocyigit, ABDÜRRAHİM; SELEK, ŞAHABETTİN; KOÇYİĞİT, ABDÜRRAHİMBackground: Migraine is characterized by multiple attacks of severe headaches often unilateral. The molecular mechanisms of migraine have not yet been clearly defined. Disorders of oxidant-antioxidant balance are observed in a number of acute and chronic diseases of the central nervous system. Oxidative stress is also believed to play a role in the pathogenesis of migraine. To the best of our knowledge, this is the first study investigating oxidant and antioxidant status of patients having migraine without aura (MWoA) and comparing them with those of age and sex matched healthy controls (CG).Publication Open Access Oxidative Stress Status in Childhood Obesity: A Potential Risk Predictor(2016-10-13) Kılıç, Elif; Ozer, Omer Faruk; Erek, Aybala Toprak; ERMAN, HAYRİYE; Torun, EMEL; AYHAN, Siddika Kesgin; Caglar, HİFA GÜLRU; Selek, Sahbettin; Kocyigit, ABDÜRRAHİM; ÖZER, ÖMER FARUK; TORUN, EMEL; ÇAĞLAR, HİFA GÜLRU; SELEK, ŞAHABETTİN; KOÇYİĞİT, ABDÜRRAHİMBackground: Childhood obesity characterized by excessive fat in the body is one of the most serious health problems worldwide due to the social, medical, and physiological complications. Obesity and associated diseases are triggering factors for oxidative stress and inflammation. The aim of this study was to explore the possible association between childhood obesity and inflammatory and oxidative status. Material/Methods: Thirty-seven obese children and 37 healthy controls selected from among children admitted to BLIND University Paediatrics Department were included in the study. Anthropometric measurements were performed using standard methods. Glucose, lipid parameters, CRP, insulin, total oxidant status (TOS), total anti-oxidant status (TAS) levels, and total thiol levels (TTL) were measured in serum. HOMA index (HOMA-IR) were calculated. The differences between the groups were evaluated statistically using the Mann-Whitney U test. Results: Body mass index was significantly higher in the obese group (median: 28.31(p<0.001). Glucose metabolism, insulin, and HOMA-IR levels were significantly higher in the obese group (both p<0.001). Total cholesterol, HDL cholesterol, LDL cholesterol, and triglyceride levels were significantly higher in the obese group (p<0.001). TAS (med: 2.5 µmol Trolox eq/L (1.7–3.3)) and TOS (med: 49.1 µmol H2 O2 eq/L (34.5–78.8)) levels and TTL (med: 0.22 mmol/L (0.16–0.26)) were significantly higher in the obese group (p=0.001). CRP levels showed positive correlation with TOS and negative correlation with TTL levels (p=0.005, r=0.473; p=0.01, r=–0.417; respectively). TTL levels exhibited negative correlation with TOS levels (p=0.03, r=–0.347). Conclusions: In conclusion, obese children were exposed to more oxidative burden than children with normal weight. Increased systemic oxidative stress induced by childhood obesity can cause development of obesity-related complications and diseases. Widely focussed studies are required on the use of oxidative parameters as early prognostic parameters in detection of obesity-related complicationsPublication Metadata only The predictive value of M30 and oxidative stress for left ventricular remodeling in patients with anterior ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention(2016-12-01) TURKOGLU, Caner; GUR, Mustafa; SEKER, Taner; Selek, Sahbettin; Kocyigit, ABDÜRRAHİM; SELEK, ŞAHABETTİN; KOÇYİĞİT, ABDÜRRAHİMBackground Left ventricular (LV) remodeling is an important pathophysiological event that develops following acute myocardial infarction and causes LV systolic dysfunction. Mechanisms such as apoptosis, necrosis, and oxidative stress play an important role in LV remodeling.Publication Metadata only The protective effect of newly derivatized compound naringenin-oxime and relative to naringenin against cisplatin-induced nephrotoxicity and genotoxicity in rat(2016-09-01) Koyuncu, I.; GULER, E. M.; Turkkan, B.; Yuksekdag, O.; Kocyigit, ABDÜRRAHİM; Kirmit, A.; Ozer, A.; SELEK, S.; GÜLER, ERAY METİN; KOÇYİĞİT, ABDÜRRAHİM; SELEK, ŞAHABETTİN