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Now showing 1 - 10 of 101
  • PublicationMetadata only
    Iron deficiency anemia and levels of oxidative stress induced by treatment modality
    (2013-06-01T00:00:00Z) Akarsu, Saadet; Demir, Hatice; Selek, ŞAHBETTİN; Oguzoncul, Ferdane; SELEK, ŞAHABETTİN
    Background The effects of iron deficiency anemia (IDA) and its treatment on plasma total antioxidant capacity (TAOC) were investigated. Methods Sixty patients with IDA and 20 healthy controls were divided into four subgroups: an oral (per os: PO) group (n = 20); an intramuscular (IM) group (n = 20); an intravenous (IV) group (n = 20); and the control group (n = 20). Blood samples were obtained from all patients before treatment, and at 24h, 7 days, 6 and 13 weeks after initiation of IDA therapy. Results TAOC in the IDA group was low when compared with the control group (P < 0.001). Although TAOC at 24h in the PO group was not different from the control group, the TAOC in the IM and IV groups was relatively lower (P < 0.001). The TAOC in the PO group at 7 days, and at 6 and 13 weeks was closest to the control group level. The mean TAOC in the IV group at 13 weeks was clearly lower relative to the PO and IM groups. Conclusions Oxidative stress was minimally induced with oral therapy, while IM and IV therapies induced higher levels of oxidative stress, in increasing order of intensity.
  • PublicationMetadata only
    Molecular cloning and characterization of NAD(+) dependent isocitrate dehydrogenase enzyme from Shewanella putrefaciens
    (2021-10-01T00:00:00Z) Fahri, Akbas; Metin, Demirel; Ahmet, Ozaydin; Sahabettin, ŞAHBETTİN; AKBAŞ, FAHRİ; DEMİREL, METİN; SELEK, ŞAHABETTİN
    Isocitrate dehydrogenase (IDH) is a fundamental enzyme for carbon metabolism in the Krebs cycle. This enzyme is required for oxidation-reduction reactions in both eukaryotic and prokaryotic cells and plays a critical role in their growth and pathogenesis. In this study, we cloned the gene encoding NAD(+) dependent isocitrate dehydrogenase from Shewanella putrefaciens. The expression of recombinant protein was induced with 0.5 mM of IPTG. His-tagged IDH overexpressed in E. coli was purified and characterized. The expressed IDH enzyme was purified in an active soluble form. The molecular weight of the enzyme was confirmed with Western blotting. High sequence homology was observed with IDH sequences of other Shewanella strains and remarkable sequence homology was found with other bacteria reported in the database.
  • PublicationOpen 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, ŞAHABETTİN
    Serologic 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 humans
  • PublicationMetadata only
    Gamma glutamyl transferase activity is Independently associated with oxidative stress rather than SYNTAX score
    (2015-01-01) UCAR, Hakan; GUR, Mustafa; GOZUKARA, Mehmet Yavuz; KALKAN, Gulhan Yuksel; BAYKAN, Ahmet Oytun; TURKOGLU, Caner; KAYPAKLI, Onur; SEKER, Taner; SEN, Omer; Selek, Sahbettin; CAYLI, Murat; SELEK, ŞAHABETTİN
    Background. Gamma glutamyl transferase (GGT) is involved in the pathophysiologic process of coronary atherosclerosis. GGT activity plays a role in the catabolism of glutathione which is known as one of the major antioxidants. However, there is a lack of research on direct examination of relevance between serum GGT activity with systemic oxidative stress. Objectives. We aimed to investigate the relationship between GGT activity with systemic oxidative stress markers and the extent and complexity of coronary artery disease (CAD) assessed with SYNTAX score in stable CAD. Methods. Measurements were obtained from 359 patients with stable CAD (Mean age = 57.7 +/- 10.1 years). The patients were divided into two groups according to the median GGT level (GGT median group > 22). Angiography was performed and SYNTAX score was calculated in all patients. Oxidative stress markers (total oxidant status [TOS], total antioxidant capacity [TAC] and oxidative stress index [OSI]) were measured in all patients. Results. While SYNTAX score and oxidative stress markers such as TOS and OSI have been increased, TAC was decreased in GGT > median group compared with GGT < median group (p < 0.05, for all). GGT activity was independently associated with diabetes (beta = 0.106, p = 0.015) and OSI (beta = 0.556, p < 0.001) in multiple linear regression analysis. However, the independent association between GGT activity and SYNTAX score was not found in present study (beta = 0.063, p = 0.238). Conclusion. In stable CAD, increased GGT activity within the normal range is associated with increased oxidative stress rather than increased extent and complexity of CAD.
  • PublicationMetadata only
    An evaluation of Neuropeptide Y status in subacute sclerosing panencephalitis patients
    (2013-01-01T00:00:00Z) Abuhandan, M.; Calik, M.; Almaz, V.; Taskin, A.; Cakmak, A.; Selek, ŞAHBETTİN; SELEK, ŞAHABETTİN
    Aim. This study aimed to evaluate the neuropeptide Y values of patients with subacute sclerosing panencephalitis.
  • PublicationOpen Access
    Oxidative Stress and Spontaneous Reperfusion of Infarct-Related Artery in Patients With ST-Segment Elevation Myocardial Infarction
    (2016-03-01) Borekci, Abdurrezzak; Gur, Mustafa; TURKOGLU, Caner; Selek, Sahbettin; BAYKAN, Ahmet Oytun; SEKER, Taner; HARBALIOGLU, Hazar; OZALTUN, Betuel; MAKCA, Ilyas; Aksoy, Nurten; GOZUKARA, Yavuz; CAYLI, Murat; SELEK, ŞAHABETTİN
    In the pathogenesis of atherosclerosis, oxidative stress plays a major role in plaque instability, rupture, and erosion, which subsequently leads to thrombus formation and causes total infarct-related artery (IRA) occlusion. We investigated the relationship between spontaneous reperfusion (SR) of IRA and oxidative stress in patients with anterior ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention. A total of 341 consecutive patients with anterior STEMI were prospectively included in the present study. Patients were divided into 2 groups according to their thrombolysis in myocardial infarction (TIMI) flow grade: SR group (66 patients, TIMI flow 3) and non-SR group (275 patients, TIMI flow 0-2). On multivariate logistic regression analysis, oxidative stress index ( = 0.868, 95% confidence interval [CI] = 0.806-0.934, P < .001), neutrophil to lymphocyte ratio, uric acid, mean platelet volume, Killip 2 to 4 class, and initial SYNTAX score were independently associated with SR. Oxidative stress as well as inflammation may play a pivotal role in the pathogenesis of SR in patients with STEMI.
  • PublicationMetadata only
    Serum paraoxonase enzyme activity and oxidative stress in obese subjects
    (2011-01-01T00:00:00Z) ASLAN, Mehmet; Horoz, Mehmet; Sabuncu, Tevfik; Celik, Hakim; Selek, Sahbettin; SELEK, ŞAHABETTİN
    Introduction Obesity is an important risk factor for atherosclerotic cardiovascular disease. Paraoxonase-1 (PON1) may play a significant role in the prevention of obesity-related accelerated atherosclerosis by hydrolyzing lipid peroxides in oxidized low-density lipoproteins.
  • PublicationMetadata only
    MicroRNA expressions are altered in endometrial tissues of PCOS women
    (2017-09-01) BULUT, HURİ; BULUT, Berk; SERDARZADE, A.; Yuksel, B.; Selek, S.; BULUT, HURI; SELEK, ŞAHABETTİN
  • PublicationMetadata only
    Hipotroidili hastalarda paraoxonase aktivitesinin ölçülmesi ve ateroskleroz ile ilişkisinin araştırılması
    (2018-05-11T00:00:00Z) ÇELİK, HAKİM; Aksoy, Nurten; SELEK, ŞAHBETTİN; EREL, ÖZCAN; SELEK, ŞAHABETTİN
  • PublicationMetadata only
    Farelede Radyoterapinin Etkileri