Omer Yalcin
Trakya University
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Featured researches published by Omer Yalcin.
Clinical and Experimental Pharmacology and Physiology | 2006
Nurettin Aydogdu; Gülizar Atmaca; Omer Yalcin; Recep Taskiran; Ebru Tastekin; Kadir Kaymak
1 Muscle injury (rhabdomyolysis) is one of the causes of acute renal failure (ARF). Iron, free radicals and nitric oxide (NO) play a critical role in the pathogenesis of glycerol‐induced myoglobinuric ARF. l‐Carnitine is an anti‐oxidant and prevents the accumulation of end‐products of lipid peroxidation. Therefore, the aim of the present study was to investigate the effects of l‐carnitine on myoglobinuric ARF induced by intramuscular (i.m.) hypertonic glycerol injection. 2 Sprague‐Dawley rats were divided into three groups. Rats in group 1 (n = 8) were given saline, whereas those in groups 2 (n = 10) and 3 (n = 10) were injected with glycerol (10 mL/kg, i.m.). Concomitant with and 24 h after glycerol injection, l‐carnitine (200 mg/kg, i.p.) was administered to group 3 rats. Forty‐eight hours after glycerol injection, blood samples and kidney tissues were taken from anaesthetised rats. 3 Plasma creatine kinase (CK) activity, urea, creatinine and NO levels, as well as kidney tissue superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) enzyme activity and malondialdehyde (MDA) and glutathione (GSH) levels, were determined. In the kidney tissue, histopathological changes and iron accumulation in the tubular epithelium were also investigated. 4 Glycerol treatment caused severe ARF: a marked renal oxidative stress, significantly increased CK activity, urea and creatinine levels and decreased plasma NO levels. Histopathological findings in group 2 rats confirmed that there was renal impairment by cast formation and tubular necrosis and a marked increase in iron accumulation in the tubular epithelium. All these factors were significantly improved by l‐carnitine supplementation. 5 These results may indicate that l‐carnitine treatment protects against functional, biochemical and morphological damage and iron accumulation in glycerol‐induced myoglobinuric ARF in rats. In this model, the protective effect of l‐carnitine treatment may provide a new insight into the treatment of rhabdomyolysis‐related ARF.
European Journal of Haematology | 2004
F. Oz Puyan; Selcuk Bilgi; Ercüment Ünlü; Omer Yalcin; Semsi Altaner; Muzaffer Demir; B. Cakir
Inflammatory pseudotumor (IPT) of the spleen is a rare benign tumor with unknown etiology. It causes problems in the diagnosis because of mimicking some hematopoetic malignancies. Here we report the case of a 36‐yr‐old woman complaining of nausea and insomnia. Laboratory investigations were limited to increase of leukocyte and thrombocyte count. Ultrasonography and magnetic resonance (MR) imaging showed circumscribed solid lobulated mass, measuring about 6.5 cm in diameter, located in the dorsal region of the spleen. Splenectomy was performed with the differential diagnosis including hamartoma and lymphoma of the spleen. Histological examination of the sharply demarcated splenic mass consisted of myofibroblasts and admixture of inflammatory cells. Immunohistochemistry and in situ hybridization were performed. IPT of the spleen was diagnosed. Epstein–Barr virus (EBV) was detected in the tumor by in situ hybridization. This rare entity is presented because of its clinical, radiological and pathological difficulties in the differential diagnosis.
Renal Failure | 2007
Tevfik Aktoz; Nurettin Aydogdu; Bülent Alagöl; Omer Yalcin; Gulara Huseyinova; İrfan Hüseyin Atakan
Reactive oxygen species (ROS) were shown to contribute to the cellular damage induced by ischemia-reperfusion. The purpose of this study was to investigate and compare the efficiency of melatonin and vitamin E in the reduction of injury induced by ROS in a rat model of renal ischemia-reperfusion. Twenty-four Wistar-albino rats were divided into four groups. Rats in the Sham group were given saline 1 mL/kg, intraperitoneally (ip) 72 h, 48 h, 24 h, and 30 min before the sham operation. Rats in ischemia-reperfusion (IR), IR+Melatonin, and IR+Vitamin E groups were given saline (1 mL/kg), melatonin (10 mg/kg), and vitamin E (100 mg/kg) ip, respectively, 72 h, 48 h, 24 h, and 30 min before the ischemia for 60 min, followed by reperfusion for 60 min. The blood samples and kidney tissues of the rats were taken under anesthesia. Ischemia-reperfusion significantly increased urea, creatinine, and malondialdehyde (MDA) levels, and decreased superoxide dismutase (SOD) and catalase (CAT) activities. Histopathological findings of the IR group confirmed that there was renal impairment by cast formation and tubular necrosis in the tubular epithelium. In the IR+Melatonin group, while MDA levels significantly decreased, SOD activities increased. In the IR+Melatonin group, the level of tubular necrosis and cast formation are significantly decreased than those seen in the ischemia-reperfusion group. Melatonin in particular was effective to reverse hot ischemia of kidney by its antioxidant effects. These results may indicate that melatonin pretreatment protects against functional, biochemical, and morphological damage better than vitamin E in renal ischemia-reperfusion injury.
Renal Failure | 2008
Sedat Ustundag; Omer Yalcin; Saniye Sen; Ziya Cukur; Senturk Ciftci; Bora Demirkan
During times of war and natural disasters, rhabdomyolysis-induced myoglobinuric acute renal failure (ARF) can assume epidemic proportions. Free radicals play an important role in the pathogenesis of myoglobinuric ARF. Vitamin C is a major antioxidant, scavenging free radicals. We have not found any studies on the effect of vitamin C on myoglobinuric ARF. Thus, we aimed to investigate the effects of vitamin C on the myoglobinuric ARF formed by glycerol in rats. Three groups of rats were employed in this study. Group 1 served as control, group 2 was given 50% glycerol (10 mL/kg, i.m.), and group 3 was given glycerol plus vitamin C (20 mg/kg, i.p. for four days). Ninety-six hours after glycerol injections, blood samples and kidney tissues were taken from the anesthetized rats. Urea and creatinine levels in plasma; N-acetyl-beta-D-glucosaminidase activity in urine; malondialdehyde levels, superoxide dismutase and catalase enzyme activity in kidney tissue were determined. Histopathological changes and iron accumulation in the kidney tissue were evaluated. In this study, glycerol administration led to marked renal oxidative stress and severe renal functional and morphological deterioration. The treatment of animals with vitamin C partially corrected the renal dysfunction and morphological impairment. In this respect, vitamin C appears to be a promising candidate for the prevention of rhabdomyolysis-induced ARF. Higher dosages of vitamin C than in 20 mg/kg may be beneficial for better functional and morphological recovery in this model ARF.
Clinical and Experimental Pharmacology and Physiology | 2004
Nurettin Aydogdu; Gülizar Atmaca; Omer Yalcin; Kadir Batcioglu; Kadir Kaymak
1. Free radicals and nitric oxide (NO) play a crucial role in the pathogenesis of myoglobinuric acute renal failure (ARF). The aim of the present study was to investigate the effects of caffeic acid phenethyl ester (CAPE), an anti‐oxidant, on the myoglobinuric ARF induced by intramusculer hypertonic glycerol injection.
Renal Failure | 2009
Sedat Ustundag; Saniye Sen; Omer Yalcin; Senturk Ciftci; Bora Demirkan; Mevlut Ture
There is increasing evidence indicating that oxidative stress plays an important role in the pathogenesis of rhabdomyolysis-induced myoglobinuric acute renal failure (ARF). During times of war and natural disasters, myoglobinuric ARF can assume epidemic proportions. Thus, early and effective renoprotective treatments are of utmost importance. It has been shown that L-carnitine, used as a safe and effective nutritional supplement for more than three decades, is effective in preventing renal injury in many renal injury models involving oxidative stress. The present study was performed to investigate the effects of L-carnitine in an experimental model of myoglobinuric ARF. Four groups of rats were employed in this study: group 1 served as a control; group 2 was given glycerol (10 mL/kg, i.m.); group 3 was given glycerol plus L-carnitine (100 mg/kg, i.p.), starting at the same time as the glycerol injection; group 4 was given glycerol plus L-carnitine (100 mg/kg, i.p.), starting 48h before the glycerol injection. After glycerol injections, the i.p. injections of L-carnitine were repeated every 24h for four days. Ninety-six hours after glycerol injections, blood samples and kidney tissues were taken from the anesthetized rats. Urea and creatinine levels in plasma, N-acetyl-beta-D-glucosaminidase activity in urine, and malondialdehyde levels and catalase enzyme activity in kidney tissue were determined. Histopathological changes and iron accumulation in the kidney tissue were evaluated. In this study, glycerol administration led to marked renal oxidative stress, as well as severe functional and morphological renal deterioration. L-carnitine, possibly via its antioxidant properties, ameliorates glycerol-induced myoglobinuric kidney injury.
Otolaryngology-Head and Neck Surgery | 2005
Abdullah Tas; Recep Yagiz; Omer Yalcin; Cem Uzun; Gulara Huseyinova; Mustafa Kemal Adali; Ahmet Rifat Karasalihoglu
OBJECTIVE: We aimed to investigate, histopathologic changes in the nasal mucosa of guinea pigs after prolonged administration of oxymetazoline and the development of rhinitis medicamentosa, and the efficacy of mometasone furoate aqueous nasal spray and saline in reversing the ultrastructural changes attributable to rhinitis medicamentosa. METHODS: In the study, 24 male guinea pigs (500 to 600 gr) were used. Oxymetazolin (0.05%) was sprayed into the nasal cavities of the guinea pigs 3 times daily for 8 weeks. At the end of this period, 6 guinea pigs were killed and examined to make sure that the animals had developed rhinitis medicamentosa. The remaining guinea pigs were randomly divided into 3 groups. In the first group, one spray-puff of 0.05% mometasone furoate aqueous nasal spray (50 μg) was applied twice daily for 14 days. In the second group, saline solution (0.9% NaCl) was applied twice daily for 14 days. No treatment was performed in the third group. At the end of the treatment period, nasal mucosal changes were evaluated by light microscopy and electron microscopy. RESULTS: After oxymetazolin application for 8 weeks, the main histologic changes were edema, congestion, proliferation of subepithelial glands, and squamous cell metaplasia. After topical mometasone furoate aqueous spray application for 2 weeks, the edema fluid was found to diminish markedly. In the saline and no treatment groups, edema and congestion continued. In these groups of guinea pigs, fibrosis has been seen in the nasal mucosa. CONCLUSION: We found that mometasone furoate nasal spray was effective against experimentally induced rhinitis medicamentosa in guinea pigs. Mometasone furoate nasal spray may have value in the treatment of patients with rhinitis medicamentosa.
International Journal of Pediatric Otorhinolaryngology | 2008
Ahmet Güzel; Umit Nusret Basaran; Burhan Aksu; Mehmet Kanter; Omer Yalcin; Cevat Aktas; Aygul Guzel; Serap Karasalihoğlu
OBJECTIVES The aim of this study was to evaluate the efficiency of inducible nitric oxide synthase (iNOS) specific inhibitor, S-methylisothiourea sulfate (SMT) in preventing lung injury after different pulmonary aspiration materials in rats. MATERIAL AND METHODS The experiments were performed in 80 Sprague-Dawley rats, ranging in weight from 220 to 250 g, randomly allotted into one of the eight groups (n=10): normal saline (NS, control), Biosorb Energy Plus (BIO), sucralfate (SUC), hydrochloric acid (HCl), NS+SMT treated, BIO+SMT treated, SUC+SMT treated, and HCl+SMT treated. NS, BIO, SUC, HCl were injected in to the lungs in a volume of 2 ml/kg. The rats received twice daily intraperitoneal injections of 20 mg(kg day) SMT (Sigma Chemical Co.) for 7 days. Seven days later, rats were killed, and both lungs in all groups were examined immunohistochemically and histopathologically. RESULTS Our data show that SMT inhibits the inflammatory response significantly reducing (p<0.05) peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, alveolar exudate, alveolar histiocytes, interstitial fibrosis, granuloma, and necrosis formation in different pulmonary aspiration models. Furthermore, our data suggest that there is a significant reduction in the activity of iNOS and arise in the expression of surfactant protein D in lung tissue of different pulmonary aspiration models with SMT therapy. CONCLUSION It was concluded that SMT treatment might be beneficial in lung injury, therefore shows potential for clinical use.
Clinical and Experimental Pharmacology and Physiology | 2007
Mustafa Inan; Umit Nusret Basaran; Dikmen Dokmeci; Mehmet Kanter; Omer Yalcin; Nurettin Aydogdu; Nesrin Turan
1 Rosiglitazone plays a positive role in the reparation of ischaemia–reperfusion (I/R) injury in different tissues. Thus, we examined its biochemical and histological effects on the contralateral testes to determine whether exogenous rosiglitazone affords any protection against testicular damage. 2 Forty‐eight prepubertal male Wistar‐Albino rats were divided into six groups. Testicular torsion was created by rotating the right testis 720° in a clockwise direction for 5 h in all groups except group I, which was the sham‐control group. In group II, bilateral orchiectomy was performed following the torsion period. After detorsion both testes were removed in the fifth hour in group III and on the seventh day in group IV. In group V, one‐shot rosiglitazone (4 mg/kg) was administered 40 min before detorsion and both testes were removed following the torsion period. In group VI, rosiglitazone was administered (4 mg/kg) 40 min before detorsion and for 7 days, and then both testes were harvested. The tissue levels of malondialdehyde (MDA) were measured and mean testicular biopsy score (MTBS) and mean seminiferous tubule diameter (MSTD) were examined. Immunoexpression of endothelial nitric oxide synthase (eNOS) in testes tissues was investigated by immunohistochemical studies. 3 In the contralateral testis, the MTBS and MSTD values of group VI were significantly higher than those in group IV. Immunohistochemically, mild eNOS immunostaining was present in the germ cells of the contralateral testes in group IV after I/R. In group VI, intense eNOS immunoreactivity was seen in the contralateral testes. 4 Rosiglitazone reduces contralateral testicular damage formed after unilateral testicular torsion and alleviates the oxidative events.
Onkologie | 2006
Kazim Uygun; Hakan Karagol; Zafer Kocak; Irfan Cicin; Omer Yalcin; Murat Caloglu; Osman Simsek; Ferda Akbay Harmandar
Background: In testicular germ cell tumors (GCT), bone metastases are usually seen late in the disease progress and are almost always associated with involvement of other sites. However, isolated bone metastasis is an extremely rare finding in these patients. Case Report: A 43- year-old man was admitted to the neurosurgery department of our hospital suffering from dysarthria, ataxia, headaches and a progressive swelling above the parietooccipital region of the skull. Radiological, biochemical and pathologic tests showed that the lesion of the skull was an isolated skull metastasis as an initial manifestation of nonseminomatous GCT of the testis. Discussion: When a young patient presents with bone pain or painless swelling, even if it is an unusual site and isolated, testicular GCT should be considered as a differential diagnosis, as these lesions could be the first evidence of metastatic GCT.