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    The alteration of asymmetric dimetilarginine (ADMA) levels in cardiac and gastrocnemius muscles following radioactive iodine application in guinea pigs and the effect of L-carnitine on this alteration
    (Taylor & Francis Ltd, 2011) Vardar, Selma Arzu; Gunduz, Ozgur; Altun, Gulay Durmus; Aydogdu, Nurettin; Karadag, Hakan; Torun, Nese; Kaya, Oktay
    Purpose: Tissue levels of asymmetric dimetilarginine (ADMA) and symmetric dimetilarginine (SDMA) were investigated in cardiac ventricle and gastrocnemius muscles of guinea pigs treated with radioactive iodine (RAI) alone or in combination with L-carnitine (LC). Material and methods: Group 1 received no treatment (control group). Group 2 received a total dose of 30 mCi(-1)kg(-1) body weight iodine-131 alone. Group 3 received 200 mg(-1)kg(-1) of LC for 10 days alone. Group 4 received 200 mg(-1)kg(-1) of LC plus RAI therapy. Free thyroid hormones, ADMA and SDMA concentrations were measured. Results: Serum free thyroid hormone concentrations were found decreased in the RAI and LC-RAI groups after RAI application. A significant decrease in ADMA and SDMA concentration was observed in ventricle muscle following RAI application. The LC-RAI group had significantly decreased ADMA levels in ventricle muscle compared with those of the control group. Similarly, SDMA concentrations in ventricle and gastrocnemius muscles of the LC-RAI groups were significantly lower than those of the control groups. Conclusions: Our results indicated that RAI appears to exert an inhibitory effect on ADMA and SDMA levels of ventricular muscle. LC administration when given adjuvant to RAI therapy may cause a marked decrease in ADMA concentrations of both ventricular and gastrocnemius muscles.
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    Comparison of vasospasm and vasodilatation response of saphenous vein grafts harvested by conventional and no-touch techniques
    (Baycinar Medical Publ-Baycinar Tibbi Yayincilik, 2012) Gur, Ozcan; Gurkan, Selami; Ozkaramanli, Demet Gur; Karadag, Hakan; Ege, Turan
    Background: In this study, we aimed to compare vasoconstriction and vasodilatation responses of saphenous vein grafts (SVG) harvested by conventional and no touch techniques in tissue bath system. Methods: Between February 2007 and September 2007, 12 patients (10 males, 2 females; mean age 55.6 +/- 5.8 years; range 38 to 75 years) who underwent coronary artery bypass graft (CABG) surgery in our clinic with signed informed consents were included. Based on the techniques used during harvesting, the grafts were divided into two groups, including group 1 (n=16) with SVGs harvested by conventional technique and group 2 by no-touch technique. In group 1, SVG was removed completely from adjacent adipose tissues. In group 2, SVG was removed with adjacent adipose tissues, preserving saphenous nerves. Results: The vasodilatation response of SVGs was significantly higher with the no touch technique, while the vasoconstriction response of SVGs was significantly higher with the conventional technique at lower doses. Conclusion: We belive that no-touch harvesting technique of SVGs may decrease early graft failure and reduce also postoperative morbidity and mortality rate, contributing to improve graft patency rate in the long-term.
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    The effect of acute and chronic formaldehyde exposure on learning and memory in male and female rats
    (Taylor & Francis Ltd, 2023) Aydin, Didem Donmez; Taskinalp, Oguz; Ulucam, Enis; Karadag, Hakan; Ozfidan, Gulnur Kizilay; Topuz, Ruhan; Ersoy, Onur
    AimFormaldehyde is a chemical that lies behind the various systemical failures in organism. Many products that people use contain formaldehyde. Owing to its tissue fixative properties, scientists who work in life sciences are exposed to this substance more than others. Several studies have shown that formaldehyde affects the CA1 and CA3 regions of the hippocampus, which play crucial roles in memory consolidation. In this study, we aimed to investigate anxiety levels and indicate the short and long term effects of formaldehyde and sex-related differences by exposing formaldehyde to male and female rats.Materials and MethodsFormaldehyde (10 mg/kg) was administered intraperitoneally for 7 days for acute exposure and 30 days for chronic exposure. Cognitive assessment was performed using fear conditioning, elevated plus maze, and Morris water maze tests. TUNEL staining was used to identify apoptosis in the brains obtained after decapitation.ResultsExposure to intraperitoneal formaldehyde does not impair learning and memory in acute and chronic periods and has no effect on depression or anxiety. After acute exposure, apoptosis was observed in the hippocampal CA1 and CA3 regions in males. When the cognitive test results were examined, no differences were found between the experimental and control groups. There was also no significant difference between males and females.
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    The Evaluation of In Vitro Effects of Dipyridamole on Coronary Artery Bypass Grafts
    (Galenos Publ House, 2011) Ege, Turan; Karaca, Okay Guven; Gur, Ozcan; Karadag, Hakan; Gurkan, Selami; Duran, Enver
    Objective: The aim of this study is to evaluate the efficacy of dipyridamole in relieving the vasospasm of coronary artery bypass grafts. Material and Methods: Twenty two patients who underwent elective coronary artery bypass grafting (CABG) were admitted to the study (Men/Women:14/8, mean age: 62.4 +/- 8.8 years). Ten samples from left internal mammary(LIMA), radial arterial (RA) and saphenous vein (SV) grafts were collected for each. The samples were transported to the vascular laboratory in 4 C Krebs solution. Submaximal smooth muscle contraction was achieved first by 10-7M of phenylephrine solution. Dipyridamole was then added, starting from a concentration of 10-9M to a concentration of 10-3.5M in two minutes intervals and half logarithmic dose increments. The concentration-response curves were obtained of the vasodilatation response relative to the begining. Results: In the LIMA graft samples, the vasodilation response to dipyridamole was 43.2 +/- 1.6% and 97.6 +/- 4.1% at concentrations of 10-6M and 10-3.5M respectively. In RA graft samples, the vasodilation response to dipyridamole was 36.3 +/- 1.8% and 95.3 +/- 2.7% at concentrations of 10-6M and 10-3.5M respectively. In SV graft samples, however, the vasodilation response to dipyridamole was 43.2 +/- 1.4% and 96.6 +/- 2.2% at concentrations of 10-6M and 10-3.5M respectively. Conclusions: The amplitude of relaxation response to dipyridamole of all grafts samples were similar, without statistically significant difference among the IMA, RA and SV grafts in the in vitro tissue bath system. These results prove that dipyridamole has a potential use as a vasodilatatory drug in all graft types.
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    High asymmetric dimethylarginine, symmetric dimethylarginine and L-arginine levels in migraine patients
    (Springer-Verlag Italia Srl, 2017) Reyhani, Aylin; Celik, Yahya; Karadag, Hakan; Gunduz, Ozgur; Asil, Talip; Sut, Necdet
    Experimental and clinical data strongly suggests that nitric oxide (NO) plays a pivotal role in migraine. This is also supported by studies of migraine induced by substances that release NO. NO is synthesized from L-arginine by endothelial NO synthase (NOS). Asymmetric dimethylarginine (ADMA) is the major endogenous competitive inhibitor of NOS. Symmetric dimethylarginine (SDMA) is an inactive stereoisomer of ADMA. It may reduce NO production by competing with arginine for cellular uptake. The aim of this study was to measure the levels of ADMA, SDMA and L-arginine in migraine patients during the interictal period. One hundred migraine patients and 100 healthy volunteers were recruited. The patients were in the interictal period and classified into two groups as having migraine with aura and migraine without aura. Their serum ADMA, SDMA and L-arginine levels were measured by high-performance liquid chromotography (HPLC) method. ADMA, SDMA and L-arginine levels were significantly higher in migraine patients compared to the control group. But there was no difference between the patients with and without aura. These results suggest that NOS inhibitors and L-arginine/NO pathway plays an important role in migraine pathopysiology.
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    In vitro effects of prostaglandin E1, prostaglandin I2 and papaverine on internal thoracic artery graft
    (Baycinar Medical Publ-Baycinar Tibbi Yayincilik, 2015) Misirlioglu, Ganime; Huseyin, Serhat; Yuksel, Volkan; Guclu, Orkut; Karadag, Hakan; Canbaz, Suat; Ege, Turan
    Background: This study aims to investigate the effects of prostaglandin E1, prostaglandin I2, and papaverine on internal thoracic artery grafts which are used during coronary artery bypass graft operations. Methods: Ten patients (9 males, 1 female; mean age 53.7 years; range 46 to 68 years) who were operated in our clinic between March 2013 and September 2013 were enrolled in the study. Dose-dependent effects of prostaglandin E1 and prostaglandin I2 on internal thoracic artery at a concentration interval of 10(-9) M-10(-2.5) M were observed. Results: While prostaglandin I2 had stronger relaxation response than prostaglandin E1 on internal thoracic artery graft, papaverine had the strongest relaxation response. Conclusion: Prostaglandin E1 and prostaglandin I2, which are used in the treatment of many aterosclerotic cardiovascular and peripheral artery diseases, may prevent vasoconstriction in internal thoracic artery grafts. Further clinical studies are required regarding decreasing perioperative mortality and morbidity by increasing graft patency.