Person: ERZİK, CAN
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ERZİK
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Publication Open Access Propylthiouracil-induced hypothyroidism protects ionizing radiation-induced multiple organ damage in rats(BIOSCIENTIFICA LTD, 2006-05) VELİOĞLU ÖĞÜNÇ, AYLİZ; Sener, G.; Kabasakal, L.; Atasoy, B. M.; Erzik, C.; Velioglu-Ogunc, A.; Cetinel, S.; Contuk, G.; Gedik, N.; Yegen, B. C.The objective of this study was to examine the potential radioprotective properties of propylthiouracil (PTU)-induced hypothyroidism against oxidative organ damage induced by irradiation. Sprague-Dawley rats were pre-treated with saline or PTU (10 mg/kg i.p.) for 15 days, and were then exposed to whole-body irradiation (800 cGy). A group of rats were decapitated at 6 h after exposure to irradiation, while another group was followed for 72 h after irradiation, during which saline or PTU injections were repeated once daily. Lung, liver, kidney and ileum samples were obtained for the determination of malondialdehyde (MDA; an index of lipid peroxidation) and glutathione (GSH, an antioxidant) levels, myeloperoxidase activity (MPO; an index of tissue neutrophil accumulation) and collagen contents, while oxidant-induced DNA fragmentation was evaluated in the ileal tissues. All tissues were also examined microscopically and assayed for the production of reactive oxidants using chemiluminescence (CL). Lactate dehydrogenase (LDH), an indicator of tissue damage, and turnout necrosis factor-alpha (TNF alpha) were assayed in serum samples. Irradiation caused a significant decrease in GSH level, which was accompanied by significant increases in MDA levels, MPO activity, CL levels and collagen content of the tissues studied (P < 0.05-0.001). Similarly, serum TNFa and LDH were elevated in the irradiated rats as compared with the control group. On the other hand, PTU treatment reversed all these biochemical indices, as well as histopathological alterations induced by irradiation. Our results suggested that PTU-induced hypothyroidism reduces oxidative damage in the lung, hepatic, renal and ileal tissues probably due to hypometabolism, which is associated with decreased production of reactive oxygen metabolites and enhancement of antioxidant mechanisms.Publication Metadata only Oxytocin ameliorates skin damage and oxidant gastric injury in rats with thermal trauma(ELSEVIER SCI LTD, 2008) YEGEN, BERRAK; Iseri, Sevgin Oezlem; Gedik, Ismail Ertugrul; Erzik, Can; Uslu, Bahar; Arbak, Serap; Gedik, Nursal; Yegen, Berrak C.Transient splanchnic vasoconstriction following major burns causes oxidative and/or nitrosative damage in gastrointestinal tissues due to ischemia, which is followed by reperfusion injury. Oxytocin (OT), a hypothalamic nonapeptide, possesses antisecretory and antiulcer effects, facilitates wound healing and is involved in immune and inflammatory processes. To assess the possible protective effect of oxytocin (OT) against burn-induced gastric injury, Sprague-Dawley rats (250-300 g) were randomly divided into three groups as control (n = 8), OT-treated burn (n = 8) and saline-treated burn (n = 8) groups. Under anesthesia, the shaved dorsal skin of rats was exposed to 90 degrees C water for 10 s to induce burn injury covering 30% of total body surface area in a standardized manner. Either oxytocin (5 mu g/kg) or saline was administered subcutaneously immediately after and at 24 h following burn, and the rats were decapitated at 48 h. Serum samples were assayed for TNF-alpha, and stomach was taken for the determination of malondialdehyde (MDA), myeloperoxidase (MPO) activity, DNA fragmentation rate (%) and histopathological examination. MDA and MPO were assayed for products of lipid peroxidation and as an index of tissue neutrophil infiltration, respectively. When compared to control group, burn caused significant increases in gastric MDA and MPO activity and increased microscopic damage scores at 48 h (p < 0.001). Oxytocin treatment reversed the burn-induced elevations in MDA and MPO levels and reduced the gastric damage scores (p < 0.001, p < 0.01), while TNF-alpha levels, which were increased significantly at 48th h after injury (p < 0.001), were abolished with OT treatment (p < 0.001). The results of this study suggest that oxytocin may provide a therapeutic benefit in diminishing burn-induced gastric inflammation by depressing tissue neutrophil infiltration and decreasing the release of inflammatory cytokines, but requires further investigation as a potential therapeutic agent in ameliorating the systemic effects of severe burn. (C) 2007 Elsevier Ltd and ISBI. All rights reserved.Publication Metadata only Bizarre parosteal osteochondromatous proliferation of the little toe(AMER PODIATRIC MED ASSN, 2006) ERZİK, CAN; Saygi, B; Karadag-Saygi, E; Erzik, C; Erkan, M; Yildirim, YA 19-year-old woman presented with pain at the lateral side of the fifth toe of her left foot, which was separated from the adjacent toe. Initial examination suggested dislocation of the fifth metatarsophalangeal joint due to a past fracture. Radiographs showed a mass arising from the proximal phalanx of the little toe, with no medullary and cortical continuity. Excisional biopsy of the mass was performed, and a histologic diagnosis of bizarre parosteal osteochondromatous proliferation of bone (Nora's lesion) was made.Publication Metadata only Neoadjuvan kemoterapi alan lokal ileri evre meme kanseri hastalarında dolaşımdaki tümör hücresi moleküler analizleri(2017-10-26) UĞURLU, MUSTAFA ÜMİT; ERZİK, CAN; PEKER EYÜBOĞLU, İREM; AKKİPRİK M., YUMUK P. F., UĞURLU M. Ü., KOCA S., ERZİK C., ALAN Ö., PEKER EYÜBOĞLU İ., GÜLLÜ AMURAN G., ÖZER S. A.Amaç: İzole edilen dolaşımdaki tümör hücrelerinin (CTC) analizi bir "sıvı biyopsi" olarak kanser tedavisinin ve prognozunun öngörülebilmesini sağlayan invaziv olmayan bir kişiye özel tıp uygulamasıdır. Bu çalışmanın amacı neoadjuvan kemoterapi alan lokal ileri evre meme kanserli hastalardan tedavi öncesi ve sonrası periferal kan örnekleri alınarak, CTC moleküler karakterizasyonunu yapmak ve tedaviye verilen yanıt ile ilişkisini ortaya koymaktır. Gereç-Yöntem: Çalışmaya 36 neoadjuvan kemoterapi alan lokal ileri evre meme kanserli hasta dahil edilmiş ve hastalardan tedavi öncesi ve sonrası 10 ml kan örnekleri alınmıştır. CTC izolasyonu, tanımlanması ve moleküler analizlerinde immuno-magnetik temelli AdnaTest kitleri kullanılmış, meme kanseri (GA733-2, Muc-1 ve Her-2, Aktin), EMT (PI3Kα, Akt-2, TWIST1) ve kök hücre (ALDH1) markerları incelenmiştir. Görüntüleme Agilent 2100 Bioanalyzer cihazı kulllanılarak DNA 1000 LabChip ile gerçekleştirilmiştir. CTC pozitifliği ve çalışılan markerlar ile tedaviye yanıt (patolojik tam cevap (PCR) ve rezidual hastalık) açısından anlamlılık, Fisher’s Exact test ile analiz edilmiştir. Bulgular: Otuzaltı hastanın 6'sında (%16,7) tedavi öncesinde CTC pozitifliği saptanmıştır. CTC pozitif olan 6 hastanın 4'ünde kök hücre markeri olan ALDH1 pozitifliği gözlenmiştir (p=0,0245) (Tablo 1). EMT markerlarından PI3Kα ise 3 hastada pozitif bulunmuştur. Hasta takipleri ve tedaviye verilen cevaplar izlenmeye devam etmektedir. Sonuç: Neoadjuvan kemoterapi alan lokal ileri evre meme kanseri hastalarında CTC pozitifliği ve kök hücre markerlarının analizi tedaviye verilecek olan cevabın ve hasta sağkalım oranlarının ön görülebilmesi için önemli bir yöntem olabilir. Çalışmalarımız bu kapsamda devam etmektedir.Publication Metadata only Effect of hormone replacement therapy on plasma lipoproteins and apolipoproteins, endothelial function and myocardial perfusion in postmenopausal women with estrogen receptor-alpha IVS1-397C/C genotype and established coronary artery disease(KARGER, 2006) ERZİK, CAN; Emre, Ayse; Sahin, Sinan; Erzik, Can; Nurkalem, Zekeriya; Oz, Dilaver; Cirakoglu, Beyazit; Yesilcimen, Kemal; Ersek, BirsenEffect of hormone replacement (HRT) therapy on plasma lipoproteins and apolipoproteins, endothelial function and myocardial perfusion in postmenopausal women with estrogen receptor-alpha (ER-alpha) IVS1-397 C/C genotype and established coronary artery disease. Background/ Aims: Associations between various ER-a polymorphisms and clinical phenotypes have been studied, including lipid levels and coronary atherosclerosis. We studied 48 postmenopausal women to determine the effect of ER-a IVS1-397 polymorphism on the response to treatment with HRT. Methods: The study had a randomized, double-blind, placebo-controlled and crossover design. Patients were divided into two groups according to ER-alpha IVS1-397 polymorphism: CC genotype (n = 9); CT or TT genotype (n = 39). HRT was given continuously for 4 weeks, with 4-week washout periods between the treatment periods. Brachial artery Doppler and TI-201 scintigraphy were performed at the end of each treatment period. Results: HRT lowered total cholesterol, LDL-c and Apo-B levels from baseline values (all p < 0.05) and to a similar degree in CC and CT/TT genotype patients. HRT increased estradiol, HDL-c and Apo A-1 levels relative to baseline values, but to a greater degree in CC patients (p = 0.04, 0.05 and 0.04 by ANOVA, respectively). HRT increased peak forearm blood flow, brachial artery diameter during reactive hyperemia and endothelium-dependent dilation in both groups, but to a greater degree in CC patients (p = 0.03, 0.03 and 0.04 by ANOVA, respectively). Summed stress and rest scores were also more markedly reduced in CC patients (p = 0.04 and 0.05, respectively). The increase in estradiol levels was strongly correlated with the improvement in endothelium-dependent dilation (r = 0.66, p < 0.01), which in turn showed negative correlation with summed stress (r =-0.62, p < 0.01) and rest scores (r =-0.52, p < 0.05) in the CC genotype group. Conclusion: These data suggest that the improvement in endothelium-dependent dilation and the reduction in perfusion abnormalities by increasing estradiol levels with HRT in postmenopausal women with coronary artery disease may differ with respect to different genotypes, the effect being more prominent in those patients with ER-alpha IVS1-397 CC genotype. Copyright (c) 2006 S. Karger AG, Basel.Publication Metadata only Role of TRF2 and TPP1 regulation in idiopathic recurrent pregnancy loss(ELSEVIER SCIENCE BV, 2019) ERZİK, CAN; Pirzada, Rameez Hassan; Orun, Oya; Erzik, Can; Cagsin, Huseyin; Serakinci, NedimeTelomeres are the tandem repeats (TTAGGG) present at the ends of the chromosomes that ensure chromosome stability and protect chromosomes from degradation. Telomeres in somatic human cells shorten after every cellular division and are linked to the cellular senescence. In this study we have investigated telomere length and expression of shelterin genes in aborted fetus material from idiopathic recurrent pregnancy losses. Telomere length was measured using Telomere Restriction Fragment Length (TRF) analysis. The gene expression levels for important shelterin complex proteins (TRF1, TRF2, POT1, and TPP1) were determined by Real-time Quantitative Reverse Transcriptase PCR (qRT-PCR). Our results demonstrated down regulation of TRF2 and TPP1 and a strong decline in average telomere length in abort material from women suffering from idiopathic recurrent pregnancy loss. We suggest that shorter telomere length and downregulation of the major shelterin components TRF2 and TPP1 leading to telomere uncapping, might play a critical role in recurrent pregnancy loss. (C) 2019 Elsevier B.V. All rights reserved.Publication Metadata only Resveratrol protects against irradiation-induced hepatic and ileal damage via its anti-oxidative activity(TAYLOR & FRANCIS LTD, 2009) VELİOĞLU ÖĞÜNÇ, AYLİZ; Velioglu-Ogunc, Ayliz; Sehirli, Ozer; Toklu, Hale Z.; Ozyurt, Hazan; Mayadagli, Alpaslan; Eksioglu-Demiralp, Emel; Erzik, Can; Cetinel, Sule; Yegen, Berrak C.; Sener, GoekselThe present study was undertaken to determine whether resveratrol (RVT) could ameliorate ionizing radiation-induced oxidative injury. After a 10-days pre-treatment with RVT (10 mg/kg/day p.o.), rats were exposed to whole-body IR (800 cGy) and the RVT treatment was continued for 10 more days after the irradiation. Irradiation caused a significant decrease in glutathione level, while malondialdehyde levels, myeloperoxidase activity and collagen content were increased in the liver and ileum tissues. Similarly, plasma lactate dehydrogenase and pro-inflammatory cytokine levels, 8-hydroxy-2'-deoxyguanosine and leukocyte apoptosis were elevated, while antioxidant-capacity was reduced in the irradiated rats as compared with the control group. Furthermore, Na-1, K-1 -ATPase activity was inhibited and DNA fragmentation was increased in the ileal tissues. Resveratrol treatment reversed all these biochemical indices, as well as histopathological alterations induced by irradiation. In conclusion, supplementing cancer patients with adjuvant therapy of resveratrol may have some benefit for a more successful radiotherapy.Publication Open Access Protective effects of St. John's wort in the hepatic ischemia/reperfusion injury in rats(AVES, 2018-09-28) VELİOĞLU ÖĞÜNÇ, AYLİZ; Atalay, Suleyman; Soylu, Belkis; Aykac, Asli; Ogunc, Ayliz Velioglu; Cetinel, Sule; Ozkan, Naziye; Erzik, Can; Sehirli, Ahmet OzerObjectives: The purpose of this study was to investigate possible protective effects of St. John's wort in the hepatic ischemia/reperfusion injury. Material and Methods: The hepatic artery, portal vein, and bile duct were all clamped for 45 minutes to induce ischemia in rats, and after that reperfusion for 1 hour. SJW was administrated orally, once a day for 3 days before ischemia/reperfusion. The aspartate aminotransferase, alanine aminotransferase, tumor necrosis factor, and interleukin levels were measured in the serum samples. Luminol chemiluminescence, lucigenin luminol chemiluminescence levels; myeloperoxidase. The sodium-potassium ATPase (Na+/K+ ATPase) activity was determined in the liver tissue, and caspase-3 and caspase-9 activity with the bcl-2/bax ratio were measured by the western blot analysis. Results: The St. John's wort administration recovered the aspartate aminotransferase, alanine aminotransferase, tumor necrosis factor, and IL-1 beta levels serum parameters meaningfully, while ischemia/reperfusion caused an increase in luminol chemiluminescence, lucigenin luminol chemiluminescence, myeloperoxidase, caspase-3, and caspase-9 activity and led to a decrease in the B-cell lymphoma-2/bcl-2-associated X protein (bcl-2/bax) ratio and the Na+/K+ ATPase activity. Conclusion: The obtained results indicate protective effects of St. John's wort on the ischemia/reperfusion injury through various mechanisms, and we are able to suggest that St. John's wort can clinically create a new therapeutic principle.Publication Open Access Effects of Circadian Rhythm Hormones Melatonin and 5-Methoxytryptophol on COXs, Raf-1 and STAT3(2018-08-01) ERZİK, CAN; Savtekin, Gokce; Serakinci, Nedime; Erzik, Can; Cetinel, Sule; Sehirli, Ahmet OzerPublication Metadata only Ghrelin improves burn-induced multiple organ injury by depressing neutrophil infiltration and the release of pro-inflammatory cytokines(ELSEVIER SCIENCE INC, 2008) YEGEN, BERRAK; Sehirli, Oezer; Sener, Emre; Sener, Goeksel; Cetinel, Sule; Erzik, Can; Yegen, Berrak C.Mechanisms of burn-induced skin and remote organ injury involve oxidant generation and the release of pro-inflammatory cytokines. In this study the possible antioxidant and anti-inflammatory effects of ghrelin were evaluated in a rat model of thermal trauma. Wistar albino rats were exposed to 90 degrees C bath for 10 s to induce thermal trauma. Ghrelin, was administered subcutaneously (10 ng/kg/day) after the burn injury and repeated twice daily. Rats were decapitated at 6 h and 48 h after burn injury and blood was collected for the analysis of pro-inflammatory cytokines (TNF-alpha and IL-1 beta), lactate dehydrogenase (LDH) activity and antioxidant capacity (AOC). In skin, lung and stomach tissue samples malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) and Na+-K+-ATPase activity were measured in addition to the histological analysis. DNA fragmentation ratio in the gastric mucosa was also evaluated. Burn injury caused significant increase in both cytokine levels, and LDH activity, while plasma ACC was found to be depleted after thermal trauma. On the other hand, in tissue samples the raised MDA levels, MPO activity and reduced GSH levels, Na+-K+-ATPase activity due to burn injury were found at control levels in ghrelin-treated groups, while DNA fragmentation in the gastric tissue was also reduced. According to the findings of the present study, ghrelin possesses a neutrophil-dependent anti-inflammatory effect that prevents burn-induced damage in skin and remote organs and protects against oxidative organ damage. (C) 2008 Elsevier Inc. All rights reserved.