Yazar "Gokbel, Hakki" seçeneğine göre listele
Listeleniyor 1 - 20 / 21
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Coenzyme Q(10) and alpha-lipoic acid supplementation in diabetic rats: Conduction velocity distributions(PROUS SCIENCE, SAU-THOMSON REUTERS, 2008) Ayaz, Murat; Tuncer, Seckin; Okudan, Nilsel; Gokbel, HakkiDiabetic neuropathies are a family of nerve disorders caused by diabetes. Patients with diabetes can develop nerve problems at any tune, but the longer a person has diabetes the greater the risk. This study aims to investigate diabetes- and coenzyme Q(10) (CoQ(10)) or alpha-lipoic acid (ALA) supplementation-induced changes in the conduction velocity (CV) distributions of rat sciatic nerve fibers. Sciatic nerve compound action potentials (CAPs) were recorded by suction electrode and CV distributions by the collision technique. Diabetes resulted in a significant increase in time to peak, rheobase and chronaxie values of these CAP waveforms, whereas the maximum depolarization, area, kinetics and CVs of both fast and slow nerve fiber groups were found to be decreased, Coenzyme Q(10) (CoQ(10)) supplementation was found to have some positive effect on the diabetes-induced alterations. CoQ(10) supplementation induced positive changes mainly, in the area and fall-down phase of the kinetics of CAP waveforms, as well as rheobase. chronaxie and speed of the intermediately conducting groups (congruent to 40 m/s). alpha-Lipoic acid (ALA) supplementation did not produce statistically significant effects. This stud), has shown for the first tune that diabetes induces a shift of actively contributing nerve fibers toward slower CVs(10) and supplementation with CoQ(10) not only stopped this shift but also tended to restore velocities toward those of the age-matched control group. In addition to its effects on mitochondrial alterations, these positive effects of CoQ(10) on diabetic neuropathy) can be attributed to its antioxidant activity Copyright 2008 Prous Science, S.A.U. or its licensors. All rights reserved.Öğe Coenzyme Q(10) and its Relation with Oxidant and Antioxidant System Markers in Patients with End-Stage Renal Disease(INFORMA HEALTHCARE, 2011) Gokbel, Hakki; Atalay, Huseyin; Okudan, Nilsel; Solak, Yalcin; Belviranli, Muaz; Turk, SuleymanRationale and objectives: Oxidative stress is increased in chronic kidney disease (CKD) patients and end-stage renal disease (ESRD) patients undergoing dialysis treatment. Coenzyme Q(10) (CoQ(10)) is a ubiquitous and strong antioxidant. Role of CoQ(10) is not fully evaluated in renal patients. We aimed to investigate the relationship of CoQ(10) with oxidant and antioxidant system markers in patients with renal disease. Material and methods: Forty patients with CKD (stages 3--5) who were managed conservatively without dialysis treatment, 40 hemodialysis, and 60 chronic ambulatory peritoneal dialysis (CAPD) patients were included in the study. Biochemical and whole blood analyses were done using hospital auto-analyzers from stored samples. Serum CoQ(10), malondialdehyde (MDA), superoxide dismutase (SOD), and antioxidant activity (AOA) levels were determined. Main findings: There was no difference among the groups in terms of serum CoQ(10) levels. However, other components of antioxidant system, namely, SOD and AOA were significantly higher in CAPD patients when compared to CKD patients. MDA levels were not significantly different among the groups. Principal conclusion(s): The results of this study showed no difference among CKD, CAPD, and hemodialysis patients in terms of serum CoQ(10) levels.Öğe Cytokeratin 18 and h-FABP levels in intestinal ischemia-reperfusion injury: role of coenzyme Q10(TUBITAK SCIENTIFIC & TECHNICAL RESEARCH COUNCIL TURKEY, 2013) Belviranli, Muaz; Okudan, Nilsel; Gokbel, Hakki; Kiyici, Aysel; Oz, Mehmet; Kumak, AyseAim: The objective of this study was to investigate whether coenzyme Q10 (CoQ10) supplementation affects M30 and heart-type fatty acid binding protein (h-FABP) levels in intestinal ischemia reperfusion injury-induced rats. Materials and methods: Thirty-two male Wistar rats were randomly divided into 4 groups. 1) Sham: Animals exposed to laparotomy without clamping the superior mesenteric artery (SMA); 2) ischemia-reperfusion (IR): rats exposed to laparotomy with occlusion of the SMA for 45 mm, followed by 120 min of reperfusion period; 3) CoQ10 plus sham: 10 mg kg body weight(-1) CoQ10 was administrated via intraperitoneal injection for 20 days, and thereafter animals were exposed to laparotomy without clamping the SMA; 4) CoQ10 plus IR: 10 mg kg body weight(-1) CoQ10 was administrated via intraperitoneal injection for 20 days and thereafter animals were exposed to laparotomy with occlusion of the SMA for 45 mm, followed by 120 min of reperfusion period. Blood samples were taken by cardiac puncture for the analysis of serum h-FABP and M30 levels. Results: There was no difference among the groups for serum h-FABP and M30 antigen levels. Conclusion: Neither intestinal ischemia-reperfusion injury nor CoQ10 supplementation affect serum h-FABP and M30 levels in rats.Öğe DEVELOPING SUSTAINABLE RELATIONS WITH INTERNAL AND EXTERNAL STAKEHOLDERS IN UNIVERSITIES: VISION AND MISSION VIEWS(ELSEVIER SCIENCE BV, 2013) Kuzu, Omur Hakan; Gokbel, Hakki; Gules, Hasan KursatThe basic mission of the universities in the current century has been undergoing a transformation since the last two centuries. This transformation also affects the degrees of emphasis on missions with the content. Community service missions have been taking precedence over education and research missions in 21st century universities. Also current missions have been redesigned by integrating each other and the key elements such as strategy and sustainable development. The biggest difference of this design from the earlier models in universities is effective and permanent participation of the internal and external environmental conditions to this process. The success of this participation is possible by making the participation of the students, academic and administrative employees as internal stakeholders and alumni, business, central and local governments and civil society organizations as external stakeholders to the processes in higher education more functional. In this context the subject of this study is researching the internal and external stakeholders view on mission and vision of Selcuk: University's surveys data in the axis of a conceptual model designed for developing sustainable relations with a comparative method. In this study first, university and stakeholders relations are discussed with conceptual dimension and changing process's components. In the second part of the study, the questionnaire prepared in the form of case study and applied to university's internal and external stakeholders has been analysed in comparison. In the last part of the study, the process and system suggestions have been developed for building up planned and sustainable relationships with internal and external stakeholders through analysed findings. (C) 2013 The Authors, Published by Elsevier Ltd.Öğe The Effect of Supplementation of Grape Seed Proanthocyanidin Extract on Vascular Dysfunction in Experimental Diabetes(MARY ANN LIEBERT, INC, 2011) Okudan, Nilsel; Bariskaner, Hulagu; Gokbel, Hakki; Sahin, Ayse Saide; Belviranli, Muaz; Baysal, HaticeIncreased oxidative stress and impaired endothelium-dependent relaxation could underlie many of the vascular complications associated with diabetes. We aimed to investigate the effect of supplementation with grape seed proanthocyanidin extract (GSPE), a natural antioxidant, on vascular responses and oxidative stress in streptozotocin-induced diabetic rats. Male Sprague-Dawley rats were divided into three groups: control rats, untreated diabetic rats, and GSPE (100 mg/kg, for 6 weeks)-supplemented diabetic rats. Thoracic aorta rings of the rats were mounted in organ baths, and relaxant responses to acetylcholine (ACh), A23187, and sodium nitroprusside (SNP) were assayed in tissues precontracted with 60mM KCl. Plasma samples used for the measurement of malondialdehyde (MDA) level and superoxide dismutase (SOD) activity. The endothelium-dependent relaxations in response to ACh and A23187 were impaired, but endothelium-independent relaxation in response to SNP did not change in diabetic rats. Supplementation with GSPE significantly improved the relaxant responses to ACh and A23187. The MDA level was significantly elevated and the plasma SOD activity was decreased in diabetic rats, but supplementation with GSPE attenuated the elevated MDA levels and increased plasma SOD activity. Thus supplementation of GSPE may attenuate oxidative stress through the inhibition of lipid peroxidation and may restore endothelial function and reduce the risk of vascular disease in diabetes.Öğe EFFECTS OF COENZYME Q10 AND alpha-LIPOIC ACID SUPPLEMENTATION ON EXERCISE-INDUCED LIPID PEROXIDATION AND ANTIOXIDANT STATUS OF DIABETIC RATS(SPRINGER TOKYO, 2009) Okudan, Nilsel; Tav, Rahime Celik; Gokbel, Hakki; Buyukbas, Sadik[Abstract not Available]Öğe Effects of Coenzyme Q10 Supplementation on Exercise Performance and Markers of Oxidative Stress in Hemodialysis Patients: A Double-Blind Placebo-Controlled Crossover Trial(LIPPINCOTT WILLIAMS & WILKINS, 2016) Gokbel, Hakki; Turk, Suleyman; Okudan, Nilsel; Atalay, Huseyin; Belviranli, Muaz; Gaipov, Abduzhappar; Solak, YalcinCoenzyme Q10 (CoQ10) supplementation has been shown to decrease oxidative stress in a number of clinical settings. However, there are mixed results regarding the role of CoQ10 supplementation on exercise performance. Chronic kidney disease is recognized as an inflammatory state, and hemodialysis patients have low level of exercise performance. We aimed to evaluate the effect of CoQ10 supplementation on oxidative stress markers and exercise performance measures. This was a prospective, double-blind, placebo-controlled, crossover study in which all patients received placebo and oral CoQ10 200 mg/d. Participants underwent 6-minute walking test and cycle ergometer. Blood samples were drawn to determine malondialdehyde, oxidized low-density lipoprotein, superoxide dismutase, and glutathione peroxidase. Walking distance in 6-minute walking test and estimated maximal oxygen consumption (VO2max) were recorded. Twenty-eight patients were randomized, but 23 patients completed the study protocol. Serum CoQ10 level significantly increased with supplementation compared with basal values (P < 0.05). Neither walking distance nor estimated VO2max was different between the placebo and CoQ10 groups (P > 0.05). Serum malondialdehyde levels significantly increased in both groups compared with baseline values just after the exercise (P < 0.05). There was no difference in markers of oxidative stress and antioxidant system between placebo and CoQ10 supplementation with exercise (P > 0.05). The results of this study showed no significant effect of CoQ10 supplementation on exercise performance measures and oxidative system markers compared with placebo in maintenance hemodialysis patients.Öğe Effects Of Exercise Training And Coenzyme Q10 On Acute Exercise-induced Oxidative Stress In Muscles(LIPPINCOTT WILLIAMS & WILKINS, 2013) Okudan, Nilsel; Balci, Serdar; Belviranli, Muaz; Revan, Serkan; Gokbel, Hakki; Pepe, Hamdi[Abstract not Available]Öğe Effects of grape seed extract on oxidative stress and antioxidant defense markers in streptozotocin-induced diabetic rats(TUBITAK SCIENTIFIC & TECHNICAL RESEARCH COUNCIL TURKEY, 2015) Belviranli, Muaz; Gokbel, Hakki; Okudan, Nilsel; Buyukbas, SadikBackground/aim: To evaluate the effects of grape seed extract (GSE) supplementation on oxidative stress and antioxidant markers in streptozotocin (STZ)-induced diabetic rats. Materials and methods: Thirty-six male rats were divided into the following four groups: control, GSE-supplemented control, diabetic, and GSE-supplemented diabetic. Beginning on day 7 after STZ injection, the rats were administered GSE (100 mg kg(-1) day(-1)) in drinking water for 6 weeks. At the end of week 6, rats were sacrificed by cardiac puncture. Plasma nitric oxide (NO) levels and xanthine oxidase (XO), adenosine deaminase (ADA), and glutathione peroxidase (GPx) activities were analyzed. Results: Both XO and ADA activities increased and NO levels decreased in diabetic rats (P < 0.05). GSE supplementation normalized all of these changes. Antioxidant enzyme activities decreased in diabetic rats compared to the controls (P < 0.05). GSE supplementation increased antioxidant enzyme activities in both diabetic and healthy rats (P < 0.05). Conclusion: These findings suggest that 6 weeks of oral GSE supplementation may prevent oxidative stress and improve antioxidant status in diabetic rats.Öğe Effects of grape seed extract supplementation on exercise-induced oxidative stress in rats(CAMBRIDGE UNIV PRESS, 2012) Belviranli, Muaz; Gokbel, Hakki; Okudan, Nilsel; Basarali, KemalThe aim of the present study was to investigate the effects of grape seed extract (GSE) supplementation on exercise performance and oxidative stress in acutely and chronically exercised rats. A total of sixty-four male rats were used in the study. Rats were divided into six groups: control, chronic exercise control, acute exercise control (AEC), GSE-supplemented control, GSE-supplemented chronic exercise and GSE-supplemented acute exercise groups. Chronic exercise consisted of treadmill running at 25 m/min, 45 min/d, 5 d a week for 6 weeks. Rats in the acute exercise groups were run on the treadmill at 30 m/min until exhaustion. GSE were given at 100 mg/kg of body weight with drinking water for 6 weeks. Plasma was separated from blood samples for the analysis of oxidative stress markers. There was no significant difference in time of exhaustion between the acute exercise groups. Plasma malondialdehyde (MDA) levels were higher in the acute exercise groups and lower in the chronic exercise groups. GSE supplementation decreased MDA levels. Xanthine oxidase and adenosine deaminase activities were higher in the AEC group compared to all the other groups. NO levels were increased with both chronic exercise and GSE supplementation. Superoxide dismutase and glutathione peroxidase activities were lower in the acute exercised groups and higher in the chronic exercised groups. GSE supplementation caused an increase in antioxidant enzyme activities. In conclusion, GSE supplementation prevents exercise-induced oxidative stress by preventing lipid peroxidation and increasing antioxidant enzyme activities.Öğe Effects of Grape Seed Polyphenols on Oxidative Damage in Liver Tissue of Acutely and Chronically Exercised Rats(WILEY, 2013) Belviranli, Muaz; Gokbel, Hakki; Okudan, Nilsel; Buyukbas, SadikThe objective of the present study was to investigate the effects of grape seed extract (GSE) supplementation on oxidative stress and antioxidant defense markers in liver tissue of acutely and chronically exercised rats. Rats were randomly assigned to six groups: Control (C), Control Chronic Exercise (CE), Control Acute Exercise (AE), GSE-supplemented Control (GC), GSE-supplemented Chronic Exercise(GCE) and GSE-supplemented Acute Exercise (GAE). Rats in the chronic exercise groups were subjected to a six-week treadmill running and in the acute exercise groups performed an exhaustive running. Rats in the GSE supplemented groups received GSE (100 mg.kg1.day1) in drinking water for 6 weeks. Liver tissues of the rats were taken for the analysis of malondialdehyde (MDA), nitric oxide (NO) levels and total antioxidant activity (AOA) and xanthine oxidase (XO) activities. MDA levels decreased with GSE supplementation in control groups but increased in acute and chronic exercise groups compared to their non-supplemented control. NO levels increased with GSE supplementation. XO activities were higher in AE group compared to the CE group. AOA decreased with GSE supplementation. In conclusion, while acute exercise triggers oxidative stress, chronic exercise has protective role against oxidative stress. GSE has a limited antioxidant effect on exercise-induced oxidative stress in liver tissue. Copyright (c) 2012 John Wiley & Sons, Ltd.Öğe The effects of omega-3 fatty acids on exercise induced bronchospasm in nonasthmatic obese and non-obese children(WILEY-BLACKWELL, 2015) Ozdemir, Ayse; Okudan, Nilsel; Yuca, Sevil Ari; Belviranli, Muaz; Gokbel, Hakki[Abstract not Available]Öğe EFFECTS OF REPEATED SUPRAMAXIMAL EXERCISES ON PLASMA ADIPONECTIN, IL-6 AND TNF-alpha LEVELS(SPRINGER TOKYO, 2009) Gergerlioglu, Hasan Serdar; Gokbel, Hakki; Okudan, Nilsel; Gul, Ibrahim; Belviranli, Muaz; Basarali, Mustafa Kemal[Abstract not Available]Öğe THE EVALUATION OF THE EFFECTS OF GRAPE SEED EXTRACT ON SERUM PARAOXONASE ACTIVITY IN STREPTOZOTOCIN-INDUCED DIABETIC RATS(SPRINGER TOKYO, 2009) Gokbel, Hakki; Kiyici, Aysel; Okudan, Nilsel; Belviranli, Muaz[Abstract not Available]Öğe Lack of association between leptin levels and leptin gene polymorphism in obese women(INFORMA HEALTHCARE, 2014) Okudan, Nilsel; Gokbel, Hakki; Acar, Hasan; Uzunoglu, Selim; Belviranli, MuazThe aim of the present study was to evaluate the relationship between oligopolymorphism in the 25th codon of leptin gene and obesity. Eighty-seven obese women and 75 healthy women were constituted obese and control groups. Body fat percent, fat mass and lean body mass were determined by bioimpedance meter and leptin levels were determined. The presence of 25th codon oligopolymorphism in the leptin gene was done by PCR-RFLP technique. Mean leptin levels were 38.5 +/- 22.0 ng/ml, and 147.9 +/- 44.8 ng/ml in the control and obese groups, respectively. The correlations of serum leptin level to body fat percentage and fat mass in the control group were significant. The correlations in the obese group were not significant. This data implies that the difference of leptin levels between control and obese groups are more likely to be associated with alterations in the leptin gene other than 25th codon or alterations in the leptin receptor gene.Öğe Oxidative stress and Antioxidant Defense in Patients with Chronic Kidney Disease: Association with Plasma Coenzyme Q10 Levels(ELSEVIER SCIENCE INC, 2009) Gokbel, Hakki; Atalay, Hueseyin; Okudan, Nilsel; Solak, Yalcin; Belviranli, Muaz; Turk, Suleyman[Abstract not Available]Öğe OXIDATIVE STRESS AND ANTIOXIDANT MARKERS IN PLASMA AFTER REPEATED SUPRAMAXIMAL EXERCISES: THE EFFECT OF COENZYME Q(10)(SPRINGER TOKYO, 2009) Gokbel, Hakki; Gul, Ibrahim; Belviranli, Muaz; Okudan, Nilsel; Buyukbas, Sadik; Basarali, Kemal M.[Abstract not Available]Öğe Quercetin and caffeic acid phenethyl ester (CAPE) attenuate acute exercise-induced oxidative stress(MATTIOLI 1885, 2015) Gergerlioglu, Hasan Serdar; Gokbel, Hakki; Okudan, Nilsel; Gergerlioglu, Nursadan; Demir, Enver AhmetFlavonoids are naturally occurring antioxidant molecules that are abundantly existing in the human diet. We investigated effects of quercetin and caffeic acid phenethyl ester to redox balance in acute treadmill exercise. Malondialdehyde, superoxide dismutase activity, xanthine oxidase activity and total nitrite in blood, skeletal muscle and liver were analyzed in 58 male Sprague-Dawley rats that were exposed to a single bout of exercise. We found that exercise provoked the increment of analyzed parameters except for total nitrite which indicates nitric oxide. Quercetin and caffeic acid phenethyl ester decreased malondialdehyde levels in skeletal muscle and liver. However, they were ineffectual in preventing lipid peroxidation in blood probably due to limited repair and biosynthesis capability of erythrocytes. Since quercetin and CAPE successfully weakened oxidative stress in liver and skeletal muscle, they may be seen as promising in preventing acute exercise-induced oxidative injury.Öğe Serum leptin, adiponectin, resistin and ghrelin levels in psoriatic patients treated with cyclosporin(WILEY-BLACKWELL, 2012) Ozdemir, Mustafa; Yuksel, Mavise; Gokbel, Hakki; Okudan, Nilsel; Mevlitoglu, InciCyclosporin has various effects on adipose tissue and glucose metabolism. This situation may lead to changes in serum levels of adipocyte-derived cytokines which have influence on the pathogenesis of psoriasis. The aim of this study was to evaluate the effect of cyclosporin treatment on some adipocyte-derived cytokines in psoriatic patients. This casecontrol study was performed between June 2009 and March 2010, at the Department of Dermatology of Meram School of Medicine. Serum leptin, adiponectin, resistin and ghrelin levels were assessed in 26 patients with psoriasis before and after cyclosporin treatment and body mass index-matched 26 healthy control subjects. The adipokines levels were compared between the groups. Serum leptin, ghrelin, resistin and adiponectin levels in patients with psoriasis before the treatment were higher than those of the control group but the differences were not statistically significant. A positive correlation between serum leptin and family history of psoriasis was detected (r = 0.398, P = 0.044). A strong negative correlation between the Psoriasis Area and Severity Index and serum ghrelin levels was seen (r = -0.52, P = 0.001) and there was a strong positive correlation between the Nail Psoriasis Severity Index and serum resistin levels (r = 0.62, P = 0.001). Following the treatment, a significant increase was seen in the serum level of adiponectin (P = 0.02) and resistin (P = 0.003). The correlations between the adipokines and the disease parameters before the treatment were lost after the treatment. Our results suggest that levels of some adipocyte-derived cytokines in psoriatic patients are affected by cyclosporin treatment.Öğe Single dose of tiotropium improves the 6-minute walk distance in chronic obstructive pulmonary disease(SPRINGER, 2006) Okudan, Nilsel; Gok, Mehmet; Gokbel, Hakki; Suerdem, MecitThe aim of this study was to evaluate the effect of a single dose of tiotropium on the exercise capacity of stable chronic obstructive pulmonary disease (COPD) patients. The study was a randomized, placebo-controlled, double-blind, cross-over study. Forty-four stable COPD patients with moderate to severe airway obstruction were selected according to the GOLD criteria. The regular anticholinergic therapies of the patients were interrupted one week before the test. In the morning hours of the first day, half the group was given one capsule (18 mcg) of tiotropium and the other half was given placebo as inhalation using the HandiHaler (R) device. Before and 120 min after the medication, the 6-min walk test was performed * Oxygen saturation, modified Borg dyspnea ratings, blood pressure, and heart rate were recorded before and after the test. The same procedure was repeated at the same time on the third day but this time the patients were given placebo if they used tiotropium on the first day and vice versa. Before using tiotropium or placebo there was no difference between 6-min walk distances. The 6-min walk distance after the use of tiotropium (429.3 +/- 70.6 m) was significantly longer than that after the use of placebo (414.7 +/- 74.6 m). The changes in Borg dyspnea ratings and arterial oxygen saturation values with tiotropium and placebo use were not significant. We conclude that exercise capacity might be improved by using a single-dose tiotropium inhalation in moderate to severe COPD patients.
