Yazar "Yazici S." seçeneğine göre listele

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    Dietary addition of caffeic acid phenethyl ester protects myocardial tissue against ethambutol induced oxidative stress
    (2013) Yavuz C.; Demirta S.; Yazici S.; Çalikan A.; Güçlü O.; Karahan O.; Mavitaş B.
    Objective: The myocardial effect of ethambutol (ETM) has not yet been clarified. The main purpose of this study was to determine both the oxidative status in myocardial tissue after administration of ETM and the adjuvant benefits of caffeic acid phenethyl ester (CAPE). Material and Method: Twenty four male rats were divided into three experimental groups as follows: a control group (without any drug administration) was created for obtaining normal myocardial tissue; an ETM group (rats received only ETM for thirty days) was created for ethambutol administration; and an ETM+CAPE group was created for administration of the full regimen (rats received ETM+CAPE for thirty days). Rats were sacrified at the end of day 30 and heart tissues were obtained for histopathological and biochemical examination. Oxidant and antioxidant parameters were biochemically investigated in all tissue samples. Results: In the ETM group, myocardial malondialdehyde (MDA) levels and total oxidant status (TOS) were significantly higher than in the control group (p<0.001). Conversely, total antioxidant capacity (TAC), the activity of superoxide dismutase (SOD) and of serum paraoxonase (PON1) were reduced in the ETM group (p<0.05). Furthermore, MDA and TOS activity was significantly reduced in the ETM+CAPE group (p<0.05); TAC, SOD, and PON1 activities were increased with adjuvant CAPE therapy (in the ETM+CAPE group) rather than in the ETM group. Conclusion: ETM may lead to increased myocardial oxidative stress due to lipid peroxidation. Nevertheless, adjuvant CAPE administration seems to provide a partial enhancement of myocardial damage.
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    Evaluating the anti-angiogenic properties of iloprost and dipyridamole in the chick embryo chorioallantoic membrane model
    (Scientific Publishers of India, 2014) Guclu O.; Karahan O.; Yazici S.; Caliskan A.; Demirtas S.; Yavuz C.; Muratoglu A.
    Dipyridamole is an antithrombotic agent that is widely used in the treatment of many vascular disorders. Also, the prostacyclin analogue iloprost has been utilized to salvage limbs in patients with severe limb ischemia. In this study we investigated whether dipyridamole and iloprost have anti-angiogenic properties and their anti-angiogenic properties were compared to bevacizumab, a known inhibitor of angiogenesis, using the in vivo chick chorioallantoic membrane animal model. Agar pellets were prepared with three different drug concentrations at 10-6 M, 10-5 M, and 10-4 M. For each drug concentration twenty fertilized eggs were used. The entire experiment was performed in duplicate. Blood vessel density and loss were examined and scored under a stereoscopic microscope. For the 10-4 M, 10-5 M and 10-6 M concentrations, the anti-angiogenic scores of iloprost were 0.2, 0.1 and 0.05, respectively. In the same order, the anti-angiogenic scores for dipyridamole were 0.2, 0.3 and 0.8. The anti-angiogenic scores for bevacizumab were significantly higher than dipyridamole and iloprost over all concentrations (p<0.05). There were no significant differences found between the anti-angiogenic scores for iloprost and dipyridamole for all concentrations (p>0.05). Iloprost demonstrated no anti-angiogenic properties in the chorioallantoic membrane animal model, while dipyridamole did exhibit very weak anti-angiogenic activity only at very high doses of 10-4 M. These results reveal that both agents can be prescribed safely for the treatment of medical conditions that require angiogenesis to facilitate healing.
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    Öğe
    Use of C-type natriuretic peptide as an indicator in detection of inducible peripheral ischemia
    (Baycinar Medical Publishing, 2014) C¸alis¸kan A.; Yazici S.; Karahan O.; Gü?lü O.; Tezcan O.; Demirtas¸ S.; Yildiz B.
    Background: In this experimental study, alterations in plasma C-type natriuretic peptide (CNP) levels were evaluated during the critical initial hours of peripheral ischemia. Methods: Forty male Sprague-Dawley type rats (aged 8 to 12 weeks, weighing 230±30 g) were included in the study. Four groups were created with 10 rats namely control group, group 1, group 2, and group 3. Baseline plasma CNP levels were detected in the control group without any intervention, while the plasma CNP levels were determined in the second hour of peripheral ischemia in group 1. Plasma CNP levels were determined in the fifth hour of peripheral ischemia for group 2, whereas plasma CNP levels were determined in group 3 at the eighth hour of peripheral ischemia. Results: The baseline plasma CNP levels were 0.285±0.011 pmol/L in the control group. In rats with peripheral ischemia, a significant time-dependent increase was detected in plasma levels of CNP (p<0.05). The plasma CNP levels were detected as 0.350±0.015, 0.486±0.084, and 0.534±0.048 pmol/L in group 1, 2, and 3 respectively. Conclusion: Plasma CNP, an endothelium-derived vasodilator, is associated with the cellular response in ischemic tissues in a time-dependent manner.