Yazar "Yetkin, Ö" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim Yok
    Öğe
    Changes in nitric oxide levels and antioxidant enzyme activities may have a role in the pathophysiological mechanisms involved in autism
    (Elsevier Science Bv, 2003) Sögüt, S; Zoroglu, SS; Özyurt, H; Yilmaz, HR; Özugurlu, F; Sivasli, E; Yetkin, Ö
    Background: There is evidence that oxygen free radicals play an important role in the pathophysiology of many neuropsychiatric disorders. Although it has not been investigated yet, several recent studies proposed that nitric oxide (NO) and other parameters related to oxidative stress may have a pathophysiological role in autism. Methods: We assessed the changes in superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and thiobarbituric acid-reactive substances (TBARS) levels in plasma as well as NO levels in red blood cells (RBC) in patients with autism (n = 27) compared to age- and sex-matched normal controls (n = 30). Results: In the autistic group, increased RBC NO levels (p < 0.0001) and plasma GSH-Px activity (p < 0.0001) and unchanged plasma TBARS levels and SOD activity were detected. Conclusions: These findings indicate a possible role of increased oxidative stress and altered enzymatic antioxidants, both of which may be relevant to the pathophysiology of autism. (C) 2003 Published by Elsevier Science B.V.
  • Küçük Resim Yok
    Öğe
    Comparison of low-dose dobutamine stress echocardiography and echocardiography during glucose-insulin-potassium infusion for detection of myocardial viability after anterior myocardial infarction
    (Lippincott Williams & Wilkins, 2002) Yetkin, E; Senen, K; Ileri, M; Atak, R; Tandogan, I; Yetkin, Ö; Kosar, F
    Background Low-dose dobutamine stress echocardiography (LDDSE) is one of the methods most used to assess myocardial viability. Glucose-insulin-potassium (GIK) infusion has been shown to increase contraction of the ischemic zone. The aim of this study was to compare LDDSE and echocardiography during GIK infusion for detection of myocardial viability. Methods Thirty-two patients who had first anterior myocardial infarction (MI) without previous MI were included in the study. Echocardiographic evaluation was carried out on the 7th +/- 2 days after MI. During continuous electrocardiographic, blood pressure and echocardiographic monitoring, an intravenous infusion of dobutamine (3 mug/kg body weight/min) was started with an infusion pump, continued for 5 min and then increased to 5 mug/kg/min and 10 mug/kg/min for another 5 min. The GIK protocol consisted of a fixed dose of insulin (100 muU/kg/h intravenously) and a variable glucose/potassium infusion rate. GIK echocardiography was done at baseline and after 60 min of GIK. The detected viable myocardium was defined as one or two scores decreasing in at least two adjacent abnormal segments during LDDSE and GIK echocardiography. Results Under resting conditions 225 segments (44%) were normokinetic, 21 segments (4%) dyskinetic, 117 segments (23%) akinetic and 149 segments (29%) hypokinetic. Viability was detected in 20% (57 segments) of the asynergic segments at baseline with GIK echocardiography and in 22% (62 segments) of those segments with LDDSE (P < 0.05). Left ventricular wall motion score index at baseline was 1.87 and it decreased significantly indicating improvement in left ventricular systolic function during both LDDSE and GIK echocardiography (P < 0.001, versus 1.75 and 1.76 respectively). The agreement between LDDSE and GIK echocardiography for detection of myocardial viability was 96%. Conclusion We have shown that GIK echocardiography is similar to LDDSE for detection of myocardial viability. With the support of further clinical studies GIK echocardiography could be used to detect myocardial viability after acute MI.
  • Küçük Resim Yok
    Öğe
    Pathophysiological role of nitric oxide and adrenomedullin in autism
    (John Wiley & Sons Ltd, 2003) Zoroglu, SS; Yürekli, M; Meram, I; Sögüt, S; Tutkun, H; Yetkin, Ö; Sivasli, E
    Several studies indicate that nitric oxide (NO) is involved in the aetiopathogenesis of many neuropsychiatric disorders such as schizophrenia, bipolar disorder, depression, Alzheimer's disease, Hungtington disease and stroke. Although it has not been investigated yet, several recent studies proposed that NO may have a pathophysiological role in autism. Adrenomedullin (AM), a recently discovered 52-amino acide peptide hormone, induces vasorelaxation by activating adenylate cyclase and also by stimulating NO release. AM immune reactivity is present in the brain consistent with a role as a neurotransmitter. It has been stated that NO and AM do function in the regulation of many neurodevelopmental processes. We hypothesized that NO and AM activities have been affected in autistic patients and aimed to examine these molecules. Twenty-six autistic patients and 22 healthy control subjects were included in this study. AM and total nitrite (a metabolite of NO) levels have been measured in plasma. The mean values of plasma total nitrite and AM levels in the autistic group were significantly higher than control values, respectively (p < 0.001, p = 0.028). There is no correlation between total nitrite and AM levels (r = 0.11, p = 0.31). Certainly, this subject needs much further research investigating autistic patients in earlier periods of life and with subtypes of the disorder. Copyright (C) 2002 John Wiley Sons, Ltd.