Browsing by Author "Gunay O."

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    Oxidative stress impairs endothelial nitric oxide levels in Behçets' disease
    (2011) Onur E.; Kabaroglu C.; Inanir I.; Var A.; Guvenc Y.; Gunay O.; Gunduz K.
    Background: Behçet's disease (BD) is an inflammatory vasculitis. Endogenous nitric oxide (NO), produced by endothelial cells, has pleiotropic effects such as vasodilatator, antiplatelet, antiproliferative. Reactive oxygen species (ROS) are produced at sites of endothelial inflammation. ROS target polyunsaturated lipids, which results in malondialdehyde (MDA) production. Objective: The aim was to investigate the oxidative stress in BD patients by measuring MDA and total antioxidant status (TAS) levels and to establish a possible relationship with respect to NO levels regarding disease activity. Materials and methods: 55 BD patients (30 active/25 inactive) and 20 healthy volunteers were included in the study. Blood samples were drawn following an overnight fasting. TAS and MDA levels were determined spectrophotometrically. Serum nitrite (NO 2-) and nitrate (NO 3-) levels were measured to estimate NO production. Data were expressed as mean ± SD. Results: TAS levels were significantly lower in BD patients than the controls (1.19 ± 0.34 vs. 3.29 ± 0.89 mmol/L). In the active BD group, MDA levels (0.36 ± 0.19 nmol/mL) were significantly higher than both the inactive BD group (0.25 ± 0.18 nmol/mL) and controls (0.18 ± 0.41 nmol/mL). NO levels were significantly lower in the active group compared to the inactive group (18.0 ± 2.80 vs. 19.40 ± 2.70 μmol/L). MDA levels correlated negatively with NO levels in the active group. Conclusion: Decreased NO levels mediated by increased oxidative stress significantly contribute to endothelial dysfunction observed in BD. © 2011 Informa Healthcare USA, Inc.
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    Effects of physical exercise on lung injury and oxidant stress in children with asthma
    (2012) Gunay O.; Onur E.; Yilmaz O.; Dundar P.E.; Tikiz C.; Var A.; Yuksel H.
    Background: The aim of this study was to investigate the influence of exercise training on oxidative stress and markers of lung inflammation in children with asthma. Methods: Thirty children aged 8-13 years diagnosed with asthma were enrolled in the study as well as 13 healthy children. One group received only pharmacological treatment and the other group was also enrolled in an exercise programme. Venous blood and 24-hour urine samples were obtained from the children enrolled in the study at the beginning and end of the study. Leukotriene E4 and creatinine levels were measured in the urine and matrix metallopeptidase (MMP-9), endothelin-1(ET-1), malnodialdehyde (MDA), IgE and specific IgE levels were measured in blood samples. Results: Leukotriene E4, MDA and MMP9 levels decreased significantly with treatment in both groups (p<0.001). However, ET-1 levels decreased significant only in the exercise group (26.5 ± 3.6 vs 21.3 ± 2.4pg/ml respectively, p=0.001). Moreover, ET-1 levels were found to be significantly lower in the exercise group compared to the only pharmacotherapy group (24.2 ± 3.1 vs 21.3 ± 2.4pg/ml, p=0.007). Conclusions: Positive influences of exercise training in children with asthma may be mediated by decrease in ET-1 levels. © 2010 SEICAP.
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    Is melatonin protective in contrast material related renal failure?; [Melatonin kontrast madde ile ilişkili renal yetmezlikten korur mu?]
    (Journal of Clinical and Analytical Medicine, 2015) Tuncyurek O.; Gunay O.; Taneli F.; Ayhan S.; Nese N.; Pabuscu Y.
    Aim: The aim of the study was to investigate the effect of melatonin on the renal injury resulting from radiocontrast media and myoglobinuria in male Wistar albino rats. Material and Method: 50% glycerol at equal amounts was intramuscularly administered to both hind legs of all animals under ether anesthesia at the dose of 10 mg/kg. Three hours later, the groups were ad-ministered the following: Group I (number:7): Iopromide(Ultravist -300®) at the dose of 2 ml/kg (intracardiac); Group II (number:7): Iopromide(Ultravist -300®) and intraperitoneally administered Melatonin at the dose of 10 mg/kg (Melatonin was dissolved in 7.5% absolute ethanol and further dilutions were made in saline.); and Group III (number:7): 2 ml/kg of sterile physiologic saline (Control group). The levels of Uurea, Ccreatinine and Ccystatin C were studied on the blood samples collected. The renal samples were evaluated by 2two distinct pathologists who did not know the protocol. Results: There was no difference in the values of Creatinine and cystatin c between Groups 2 and 3 (p=0.9; 0.2). Discussion: In conclusion, we evaluated the possible prevention of contrast-induced oxidative stress in the kidney with using melatonin. How-ever, additional clinical studies are needed to evaluate the role of preventive melatonin treatment in humans. © 2015, Journal of Clinical and Analytical Medicine. All rights reserved.