Person: YÜKSEL, MERAL
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YÜKSEL
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MERAL
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Publication Metadata only The effect of magnesium and vitamin E pre-treatments on irradiation-induced oxidative injury of cardiac and pulmonary tissues in rats: a randomized experimental study(TURKISH SOC CARDIOLOGY, 2012) ATASOY, BESTE MELEK; Atasoy, Beste M.; Ozgen, Zerrin; Bostanci, Korkut; Yuksel, Meral; Ozen, Zeynep; Ibrahimov, Roman; Abacioglu, UfukObjective: The aim of this study was to investigate the effect of pre-treatment with the free radical scavenging molecules, magnesium and vitamin E, on lipid peroxidation to limit radiation-induced heart and lung injury. Methods: Female Sprague-Dawley rats were divided into 4 groups by a simple randomization method as saline-treated control (n=4), saline-treated irradiated (IR; n=6), magnesium sulphate-treated irradiation (IR) (Mg+IR; n=6) and vitamin E-treated IR (vit E+IR; n=6), respectively. The animals were given either saline, Mg (600mg/kg/day) or vit E (100 mg/kg/day) intraperitoneally for five days prior to irradiation. Twelve hours after the fifth injection, animals in irradiation groups were irradiated to 20 Gy using 6 MV photons in linear accelerator. Twenty-four hours later cardiac and lung tissue samples were obtained for determination of myeloperoxidase activity (MPO), malondialdehyde (MDA) levels, and luminol and lucigenin levels measured by chemiluminescence (CL) methods. Results: No significant changes were observed between cardiac and pulmonary MDA and CL results of the experimental groups. However, cardiac and pulmonary MPO activities in the saline-treated IR group were increased as compared to control group (p<0.05 for all), while in the Mg-pretreated and vit E pretreated groups neutrophil infiltration was reduced, reaching to statistical significance only in the Mg-pretreated group (p<0.05). Conclusion: Prophylactic use of magnesium sulfate has limited the infiltration of neutrophils to both the cardiac and pulmonary tissues at the early 24 h of irradiation. However, how limiting neutrophils as the sources of free radicals and inflammatory mediators would alter oxidative stress of heart and lung tissues in the long-term is not clear yet. (Anadolu Kardiyol Derg 2012; 12: 508-14)Publication Open Access Superoxide Anion Production by the Spermatozoa of Men with Varicocele: Relationship with Varicocele Grade and Semen Parameters(KOREAN SOC SEXUAL MEDICINE & ANDROLOGY, 2018) YÜKSEL, MERAL; Alkan, Ilter; Yuksel, Meral; Canat, Halil Lutfi; Atalay, Hasan Anil; Can, Osman; Ozveri, Hakan; Basar, Mehmet MuradPurpose: To investigate the pathophysiological role of superoxide anion and total reactive oxygen species (ROS) production by the spermatozoa of men with varicocele and its relationship with varicocele grade and semen parameters. Materials and Methods: This prospective study included 34 men with grade II-III varicocele, regardless of their fertility status. The control group consisted of 13 healthy men. Semen characteristics were examined according to the 2010 World Health Organization criteria. The swim-up method was used for sperm preparation. Total ROS and superoxide anion production was assayed by luminol-and lucigenin-dependent chemiluminescence (CL), respectively. Results: The men with varicocele had significantly higher total ROS and superoxide anion levels than the healthy control subjects (2.9 +/- 0.4 relative light unit (RLU) vs. 2.4 +/- 0.1 RLU, p=0.001 for luminol-dependent CL and 2.8 +/- 0.4 RLU vs. 2.3 +/- 0.2 RLU, p=0.002 for lucigenin-dependent CL). Cases of grade III varicocele had significantly higher superoxide anion and total ROS levels than grade II cases and control subjects (p<0.001). Superoxide anion and total ROS levels were negatively correlated with all semen parameters. Conclusions: The superoxide anion levels produced by spermatozoa were significantly higher in varicocele patients than in control subjects. ROS production was related to increased varicocele grade, impaired semen concentration, and abnormal morphology in men with varicocele. Our findings suggest that superoxide anion overproduction may be an important step in the cascade of ROS-related damage to spermatozoa, resulting in impaired semen parameters in patients with varicocele.Publication Metadata only Apocynin attenuates testicular ischemia-reperfusion injury in rats(W B SAUNDERS CO-ELSEVIER INC, 2015) ŞİMŞEK, FERRUH; Sener, T. Emre; Yuksel, Meral; Ozyilmaz-Yay, Nagehan; Ercan, Feriha; Akbal, Cem; Simsek, Ferruh; Sener, GokselObjective: This study was designed to examine the possible protective effect of apocynin, a NADPH oxidase inhibitor, against torsion/detorsion (T/D) induced ischemia/reperfusion (I/R) injury in testis. Methods: Male Wistar albino rats were divided into sham-operated control, and either vehicle, apocynin 20 mg/kg-or apocynin 50 mg/kg-treated T/D groups. In order to induce I/R injury, left testis was rotated 720 degrees clockwise for 4 hours (torsion) and then allowed reperfusion (detorsion) for 4 hours. Left orchiectomy was done for the measurement of tissue malondialdehyde (MDA), glutathione (GSH) levels, myeloperoxidase (MPO) activity, and luminol, lucigenin, nitric oxide (NO) and peroxynitrite chemiluminescences (CL). Testicular morphology was examined by light microscopy. Results: I/R caused significant increases in tissue luminol, lucigenin, nitric oxide and peroxynitrite CL demonstrating increased reactive oxygen and nitrogen metabolites. As a result of increased oxidative stress tissue MPO activity, MDA levels were increased and antioxidant GSH was decreased. On the other hand, apocynin treatment reversed all these biochemical indices, as well as histopathological alterations that were induced by I/R. According to data, although lower dose of apocynin tended to reverse the biochemical parameters, high dose of apocynin provides better protection since values were closer to the control levels. Conclusion: Findings of the present study suggest that NADPH oxidase inhibitor apocynin by inhibiting free radical generation and increasing antioxidant defense exerts protective effects on testicular tissues against I/R. The protection with apocynin was more pronounced with high dose. (C) 2015 Elsevier Inc. All rights reserved.Publication Metadata only The antifibrotic drug halofuginone reduces ischemia/reperfusion-induced oxidative renal damage in rats(ELSEVIER SCI LTD, 2013) YEGEN, BERRAK; Cerit, Kivilcim Karadeniz; Karakoyun, Berna; Yuksel, Meral; Ozkan, Naziye; Cetinel, Sule; Dagli, E. Tolga; Yegen, Berrak C.; Tugtepe, HalilAim: The objective of the present study was to evaluate the protective effects of halofuginone against renal ischemia/reperfusion (I/R) injury. Materials and methods: Male Wistar albino rats were unilaterally nephrectomized and the left renal pedicles were occluded for 45 min to induce ischemia and then reperfused for 6 h (early) or for 72 h (late). The rats were treated intraperitoneally with either halofuginone (100 mu g/kg/day) or saline 30 min prior to ischemia and the dose was repeated in the late reperfusion groups. In the sham groups, rats underwent unilateral nephrectomy and were treated at similar time points. The animals were decapitated at either 6 h or 72 h of reperfusion and trunk blood and kidney samples were obtained. Results: I/R injury increased renal malondialdehyde levels, myeloperoxidase activity and reactive oxygen radical levels, and decreased the renal glutathione content. Halofuginone treatment was found to reduce oxidative I/R injury and improve renal function in the rat kidney, as evidenced by reduced generation of reactive oxygen species, depressed lipid peroxidation and myeloperoxidase activity, and increased glutathione levels. Conclusions: The present findings demonstrate the anti-inflammatory and antioxidant effects of halofuginone in renal I/R injury, supporting its potential use where renal I/R injury is inevitable. (C) 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.Publication Metadata only Oxygen radicals and nitric oxide in rat mesenteric ischaemia-reperfusion: Modulation by L-arginine and N-G-nitro-L-arginine methyl ester(WILEY, 1998) YALÇIN, AHMET SUHA; Haklar, G; Ulukaya-Durakbasa, C; Yuksel, M; Dagli, T; Yalcin, AS1. The aims of the present study were to detect changes in superoxide anion (O-2(.-)), nitric oxide (NO) and other reactive oxygen species (ROS) directly by measurement of chemiluminescence (CL) and to investigate the role of L-arginine, a nitric oxide synthase (NOS) substrate, and N-G-nitro-L-arginine methyl ester (L-NAME), a NOS inhibitor, together with their molecular enantiomers D-arginine and D-NAME, in a rat mesenteric ischaemia-reperfusion (I/R) model. 2, Seventy-nine female Wistar albino rats were divided into eight groups, The first three groups underwent sham operation; group 1 was the control group, group 2 received L-arginine and group 3 received L-NAME. Ischaemia was produced in the remaining five groups by ligation of the superior mesenteric artery for 30 min followed by 60 min reperfusion, Group 4 rats were control I/R rats and groups 5-8 received either L-arginine, L-NAME, D-arginine or D-NAME, respectively. 3, Both luminol and lucigenin CL was significantly increased in I/R groups compared with sham-operated groups. L-Arginine significantly reduced CL measurements. D-Arginine was also protective, but not as much as L-arginine. Both L- and D-arginine had in vitro O-2(.-)-scavenging potential, as tested by the xanthine-xanthine oxidase system. N-G-Nitro-L-arginine methyl ester decreased lipid peroxidation values in addition to reducing CL measurements. Nitric oxide concentrations were significantly increased in VR groups in comparison with sham-operated groups. Peroxynitrite formation was increased by I/R. Treatment with L-NAME was beneficial by reducing NO concentrations in the reperfused ileum, 4, In our I/R model, O-2(.-), NO and other ROS were increased. Although NOS inhibitors were effective in reducing oxidative damage, increasing NO concentrations with L-arginine was also beneficial, presumably due to the ability of L-arginine to inhibit phagocyte adherence and its radical scavenging potential. In fact, NO may have different effects in terms of tissue injury or protection depending on the concentration of oxygen and the haemodynamic state of the tissue.Publication Open Access Vitamin D receptor and estrogen receptor gene polymorphisms in men with type 2 diabetes: Effects on Bone Metabolism(2022-12-01) ÜSTAY, ÖZLEM; YAVUZ, DİLEK; YÜKSEL, MERAL; YAVUZ D., YÜKSEL M., Sancak S., Yazici D., ÜSTAY Ö., Deyneli O., Akalin S.Purpose There is an increased fracture risk in type 2 diabetes mellitus [DM] patients independent of bone mineral density [BMD], both in men and women. Estrogen receptor [ER]-alpha and vitamin D receptor [VDR] gene polymorphisms may predispose patients to increased osteoporosis and fracture risk. This study aims to analyze the relationship of the ER-alpha gene and VDR gene polymorphisms with indicators of bone turnover and BMD in male type 2 diabetic patients. Methods Type 2 diabetic men diagnosed with diabetes for at least one year and healthy controls were included in this cross-sectional study. BMD was measured by dual X ray absorptiometry. Gene polymorphisms were evaluated with polymerase chain reaction-restriction length polymorphism. Serum iPTH, calcium, beta-CrossLaps (cTx), osteocalcin, and free testosterone levels were also evaluated. Results Participants were 141 type 2 diabetic men [55 +/- 8 years] and 100 healthy controls [53 +/- 7 years]. BMD measurements were not statistically different between the groups. While iPTH [p < 0.05] and serum calcium levels [p = 0.03] were higher in men with type 2 DM; beta-CrossLaps [p = 0.0001], osteocalcin [p = 0.005], and free testosterone [p = 0.04] were lower than controls. The differences in terms of the frequencies of VDR Apa, Taq, Bsm, Fok and ER-alpha polymorphisms were not statistically significant between the groups. No relationship was observed between polymorphisms and BMD in both groups. Conclusions VDR and ER-alpha gene polymorphisms seem to have no effect on BMD and bone turnover in men with DM.Publication Metadata only Semen reactive oxygen species levels are correlated with erectile function among chronic prostatitis/chronic pelvic pain syndrome patients(NATURE PUBLISHING GROUP, 2018) YÜKSEL, MERAL; Alkan, Ilter; Yuksel, Meral; Ozveri, Hakan; Atalay, Anil; Canat, Halil Lutfi; Culha, Mehmet Gokhan; Arabaci, Cigdem; Bozkurt, Muammer; Basar, MuradChronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) is often associated with erectile dysfunction (ED). However, the underlying pathophysiological mechanisms of ED occurrence are still unclear in patients with CP/CPPS. The aim of the study was to investigate superoxide anion (O-2(center dot-)) and total reactive oxygen species (ROS) production in semen of men with category IIIA CP/CPPS and their association with ED. This prospective study included 33 men with category IIIA CP/CPPS. Control group consisted of 13 healthy men. Total ROS and O-2(center dot-) production were assayed by luminol and lucigenin-dependent chemiluminescence (CL) methods, respectively. ED was evaluated using the IIEF-5 questionnaire. Patients with CP/CPPS had significantly higher seminal total ROS and O-2(center dot-) levels than healthy control subjects (2.9 +/- 0.5 relative light unit (RLU) vs. 2.4 +/- 0.2 RLU, p < 0.001; luminol-dependent CL and 2.5 +/- 0.4 RLU vs. 2.3 +/- 0.2 RLU, p = 0.02; lucigenin-dependent CL, respectively). Seminal O-2(center dot-) and ROS levels were negatively correlated with IIEF-5 scores (r = -0.556, r = -0.536; p < 0.001, respectively). These results may suggest O-2(center dot-)/ROS overproduction could be one of the important mechanisms in the etiology of ED development in CP/CPPS patients.Publication Metadata only Erdosteine treatment attenuates oxidative stress and fibrosis in experimental biliary obstruction(SPRINGER, 2007) ERCAN, FERİHA; Sener, Goeksel; Sehirli, A. Ozer; Toklu, Hale Z.; Yuksel, Meral; Ercan, Feriha; Gedik, NursalOxidative stress, in particular lipid peroxidation, induces collagen synthesis and causes fibrosis. The aim of this study was to assess the antioxidant and antifibrotic effects of erdosteine on liver fibrosis induced by biliary obstruction in rats. Liver fibrosis was induced in Wistar albino rats by bile duct ligation (BDL). Erdosteine (10 mg/kg, orally) or saline was administered for 28 days. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels were determined to assess liver functions and tissue damage, respectively. Pro-inflammatory cytokines, TNF-alpha, IL-1 beta and IL-6 and antioxidant capacity (AOC) were assayed in plasma samples. Liver tissues were taken for determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content. Production of reactive oxidants was monitored by chemiluminescence assay. Serum AST, ALT, LDH, and plasma cytokines were elevated in the BDL group as compared to controls and were significantly decreased by erdosteine treatment. Hepatic GSH level and plasma AOC, depressed by BDL, were elevated back to control level with erdosteine treatment. Furthermore, hepatic luminol and lucigenin chemiluminescence (CL), MDA level, MPO activity and collagen content in BDL group increased dramatically compared to control and reduced by erdosteine treatment. Since erdosteine administration alleviated the BDL-induced oxidative injury of the liver and improved the hepatic functions, it seems likely that erdosteine with its antioxidant and antifibrotic properties, may be of potential therapeutic value in protecting the liver fibrosis and oxidative injury due to biliary obstruction.Publication Metadata only Vitamin D receptor gene BsmI, FokI, ApaI, TaqI polymorphisms and bone mineral density in a group of Turkish type 1 diabetic patients(SPRINGER-VERLAG ITALIA SRL, 2011) YAVUZ, DİLEK; Yavuz, Dilek Gogas; Keskin, Lezan; Kiyici, Sinem; Sert, Murat; Yazici, Dilek; Sahin, Ibrahim; Yuksel, Meral; Deyneli, Oguzhan; Aydin, Hasan; Tuncel, Ercan; Akalin, SemaPrevious studies have suggested an influence of vitamin D receptor alleles on bone metabolism and on susceptibility to type 1 diabetes mellitus in different ethnic populations. We aimed to investigate the distribution of vitamin D receptor (VDR) alleles in relation to biochemical bone turnover parameters and bone densitometry measurements in a group of Turkish type 1 diabetic patients. One hundred and seventeen patients (M/F 57/60, 27.6 +/- A 7.3 y duration of diabetes 8.1 +/- A 6.3 y) and 134 healthy controls (M/F 61/73, 26.2 +/- A 5.3 y) were included in the study. Bone mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry (DEXA). The vitamin D receptor gene (VDR) polymorphisms FokI, Bsm1, Apa1, and Taq1 were examined using a PCR-based restriction analysis. Serum levels of calcium, phosphor osteocalcin, intact parathyroid hormone, and C telopeptide were measured. Vitamin D receptor Bsm1 Fok1, Apa1, and Taq1 genotype distributions were not different between patient with diabetes and control groups. BMD was 0.77 +/- A 0.2 g/cm(2) vs. 0.97 +/- A 0.2 g/cm(2) (P = 0.0001) for the femur, 1.0 +/- A 0.1 g/cm(2) vs. 1.13 +/- A 0.1 g/cm(2) (P = 0.001) for type 1 diabetic patients and controls. Bone turnover markers were significantly lower in type 1 diabetic group. BMD measurements and bone metabolic markers were not different between the genotypes in either the patient with diabetes or the controls. The VDR gene polymorphisms, Bsm1, Fok 1, Apa1, and Taq1 showed no influence on bone metabolism in our group of type 1 diabetic patients.Publication Metadata only Apigenin’in hafif travmatik beyin hasarı modelinde olası antienflamatuar, antioksidan ve nöroprotektif etkisinin incelenmesi(2021-11-21) AKAKIN, DİLEK; PEKER EYÜBOĞLU, İREM; YILDIRIM, ALPER; YÜKSEL, MERAL; KURU BEKTAŞOĞLU P., DEMİR D., KOYUNCUOĞLU T., YÜKSEL M., KARAGÖZ KÖROĞLU A., AKAKIN D., PEKER EYÜBOĞLU İ., YILDIRIM A., ÇELİKOĞLU E., GÜRER B.