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Featured researches published by Turan Tunc.


Journal of Surgical Research | 2009

Erdosteine and Ebselen As Useful Agents in Intestinal Ischemia/ Reperfusion Injury

Turan Tunc; Bulent Uysal; Cüneyt Atabek; Vural Kesik; Bahadır Çalışkan; Emin Oztas; Nail Ersoz; Sukru Oter; Ahmet Guven

BACKGROUND Reactive oxygen and nitrogen species generated during reperfusion of the tissue are characteristic of ischemia/reperfusion (I/R) injury. The purpose of the present study was to investigate whether erdosteine and ebselen, molecules with antioxidant properties and peroxynitrite scavenging capability, respectively, can reduce oxidative stress and histological damage in the rat small bowel subjected to mesenteric I/R injury. MATERIALS AND METHODS Forty Sprague-Dawley rats were divided into five groups equally: sham, I/R, I/R plus erdosteine, I/R plus ebselen, and I/R plus erdosteine and ebselen. Intestinal ischemia for 45 min and reperfusion for 3 d were carried out. Ileal specimens were obtained to determine the tissue levels of malondialdehide (MDA), protein carbonyl content (PCC), superoxide dismutase (SOD), glutathione peroxidase (GPx), nitrite/nitrate (NO(x)) level and histological changes. RESULTS Intestinal I/R resulted in increased tissue MDA, PCC, and NO(x) levels and decreased SOD and GPx activities. Both erdosteine and ebselen alone significantly decreased MDA, PCC, and NO(x) levels and increased antioxidant enzymes activities, but all values were different from control. These changes almost returned to control values in the group treated with erdostein and ebselen. Histopathologically, the intestinal injury in rats treated with erdosteine and ebselen as well as combination were less than I/R group. CONCLUSIONS Both erdosteine and ebselen were able to attenuate I/R injury of the intestine via inhibition of lipid peroxidation and protein oxidation, maintenance of antioxidant, and free radical scavenger properties. Nevertheless, combination treatment showed more promising results, suggesting that scavenging peroxynitrite nearby antioxidant activity is important in preventing intestinal I/R injury.


Journal of Pediatric Gastroenterology and Nutrition | 2009

Enteral glutamine and/or arginine supplementation have favorable effects on oxidative stress parameters in neonatal rat intestine.

Mustafa Kul; Sabahattin Vurucu; Erkan Demirkaya; Turan Tunc; Secil Aydinoz; Cihan Meral; Vural Kesik; Faruk Alpay

Objective: To investigate and compare the effects of enteral glutamine and arginine supply on lipid peroxidation and antioxidant enzyme levels in the small intestine of healthy breast-fed rats. Materials and Methods: The study comprised 40 newborn Sprague-Dawley rats born to 5 mother rats. Newborn rats were randomly divided into 4 groups. Starting from day 1 until day 21, group I received only breast milk; group II received breast milk and 200 mg/kg/day oral glutamine; group III received breast milk and 200 mg/kg/day oral arginine; and group IV received breast milk, 200 mg/kg/day glutamine, and 200 mg/kg/day arginine. Malondialdehyde levels and glutathione peroxidase (GPx) and superoxide dismutase activities were measured. Results: The lowest malondialdehyde levels were found in group II (P = 0.0001). Superoxide dismutase activity was found to be significantly higher in group II than group I (P < 0.001). Of the 4 groups, GPx activity was highest in group IV. GPx activity in group II was significantly higher than in group I (P = 0.001) or group III (P = 0.001). GPx activity was higher in group IV than in group I (P = 0.001) or group III (P = 0.001). Conclusions: Enteral glutamine alone or in the presence of arginine has favorable effects on oxidative stress not only in experimental models of hypoxia-reoxygenation, but also in healthy newborn rats. This suggests that in premature neonates with insufficient oxidative resistance, glutamine and arginine supplementation may help prevent necrotizing enterocolitis.


Journal of Surgical Research | 2009

Melatonin and 1400 W Ameliorate both Intestinal and Remote Organ Injury Following Mesenteric Ischemia/Reperfusion

Vural Kesik; Ahmet Guven; Sabahattin Vurucu; Turan Tunc; Bulent Uysal; Emin Oztas; Ahmet Korkmaz

OBJECTIVE Acute intestinal ischemia reperfusion (I/R) injury affects not only the intestines but also remote organs due to pro-inflammatory and tissue injurious factors. Thus, we aimed to investigate the roles of melatonin (a powerful antioxidant) and 1400W (a strong inhibitor of inducible nitric oxide) in a rat intestinal I/R injury model, since oxidative and nitrosative injury are believed to be the major causes. METHODS A total of 56 Wistar albino rats were used, with seven rats in each group. After I/R induction in the intestines by clamping/unclamping the superior mesenteric artery, we measured malondialdehyde, superoxide dismutase, glutathione peroxidase, nitric oxide, and 3-nitrotyrosine levels in lung, kidney, and liver tissues (to evaluate remote organ injury) as well as in the intestines. Study groups received melatonin, 1400W or both to examine the roles of these molecules in the pathogenesis of injury following I/R. RESULTS Melatonin and 1400W had an ameliorating effect on both oxidative and nitrosative stress in the intestine and the lung against mesenteric I/R injury in rats. Moreover, each of these two agents had an inhibitory effect on oxidative injury and histopathological changes in the intestine and the lung. Furthermore, the combination of both agents (melatonin and 1400W) was more effective than either of the agents alone (P < 0.05). CONCLUSION Melatonin and 1400W, either alone or in combination, were efficient in ameliorating experimental I/R injury of the intestines.


Surgery Today | 2008

α-Lipoic Acid and Ebselen Prevent Ischemia/Reperfusion Injury in the Rat Intestine

Ahmet Guven; Turan Tunc; Turgut Topal; Mustafa Kul; Ahmet Korkmaz; Onder Onguru; Haluk Öztürk

PurposeReactive oxygen species (ROS) and reactive nitrogen species (RNS), generated during tissue reperfusion, are characteristic of ischemia/reperfusion (I/R) injury. We conducted this study to evaluate the protective effect of α-lipoic acid (α-LA) and ebselen against intestinal I/R injury.MethodsForty Sprague-Dawley rats were divided into five groups: a sham-operated group; an I/R group, subjected to intestinal ischemia for 45 min and reperfusion for 3 days; an I/R+α-LA group; an I/R+ebselen group; and an I/R+α-LA+ebselen group. We collected ileal specimens, to measure the tissue levels of malondialdehyde (MDA), protein carbonyl content (PCC), superoxide dismutase (SOD), and glutathione peroxidase (GPx), and to evaluate the histologic changes.ResultsThere was a significant decrease in SOD and GPx levels, with an increase in MDA and PCC levels and intestinal mucosal injury in the intestinal I/R group (P < 0.05). Superoxide dismutase and GPx levels were significantly higher, MDA and PCC levels were significantly lower, and intestinal injury was significantly less severe in the I/R+α-LA+ebselen group than in the I/R group (P < 0.05). Although shortened villi and epithelial lifting were seen in the I/R group, only slight mucosal injury was seen in the treatment groups.Conclusionα-Lipoic acid and ebselen played an important role in attenuating I/R injury of the intestine by scavenging ROS and RNS.


Journal of Gastroenterology and Hepatology | 2009

Protective effect of sulfhydryl-containing antioxidants against ischemia/reperfusion injury of prepubertal rat intestine

Turan Tunc; Sukru Oter; Ahmet Guven; Turgut Topal; Mustafa Kul; Ahmet Korkmaz; Onder Onguru; Umit Sarici

Background and Aim:  Reactive oxygen species generated during reperfusion of the tissue are known to play an important role in the basic pathophysiology of ischemia/reperfusion (I/R) injury. The aim of this study was to investigate and compare the protective effects of three sulfide‐based antioxidants, N‐acetylcysteine (NAC), erdosteine (ERD), and α‐lipoic acid (LA), on I/R injury of the small intestine tissue.


Pediatrics and Neonatology | 2015

Endocan and Soluble Triggering Receptor Expressed on Myeloid Cells-1 as Novel Markers for Neonatal Sepsis

Mehmet Saldir; Turan Tunc; Ferhat Cekmez; Merih Cetinkaya; Tugce Kalayci; Kursat Fidanci; Oguzhan Babacan; Galip Erdem; Necmettin Kocak; Erkan Sari; Emin Ozgur Akgul; Mustafa Kul

BACKGROUND Neonatal sepsis is an important cause of neonatal morbidity and mortality in the neonatal intensive care unit. Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) has been evaluated in sepsis and septic shock, and it was found to be valuable in distinguishing septic cases from nonseptic cases. Endocan is constitutively expressed by endothelial cells, and high levels of endocan may be of relevance for the promotion of systemic inflammation. The aim of this study was to investigate whether the levels of sTREM-1 and endocan were increased in late-onset neonatal sepsis. METHODS Patients were classified into septic and nonseptic groups. Blood was collected from a peripheral vein of all septic newborns and healthy newborns at the time of initial laboratory evaluation before any treatment, and within 48-72 hours after initiation of treatment. Serum sTREM-1 and endocan measurements were performed when the study was finished. RESULTS The study population comprised of 50 neonates: 20 nonseptic neonates and 30 septic neonates. The groups were similar with regards to baseline characteristics. The initial measurements of interleukin-6 (IL-6), sTREM-1, endocan, and immature/total neutrophil ratio (I/T ratio) were significantly higher in septic neonates in comparison with nonseptic neonates. Receiver operating characteristic (ROC) curve analyses revealed that IL-6, sTREM-1, endocan, and I/T ratio resulted in significant areas under the curve (AUC) with respect to early identification of septic neonates. Soluble TREM-1 and IL-6 performed best to distinguish septic neonates from nonseptic neonates. Univariate logistic regression analysis showed that increased IL-6 and sTREM-1 were strong predictors of neonatal late-onset sepsis. CONCLUSION Serum sTREM-1, IL-6, endocan levels, and I/T ratio increased in septic neonates. However, the diagnostic accuracy of circulating sTREM-1 seemed to be better than endocan and I/T ratio, but lower than IL-6.


Archivos De Bronconeumologia | 2013

Efectos protectores del aceite de Nigella sativa en la lesión pulmonar inducida por hiperoxia

Cüneyt Tayman; Ferhat Cekmez; Ilker Mustafa Kafa; Fuat Emre Canpolat; Merih Cetinkaya; Alparslan Tonbul; Sema Uysal; Turan Tunc; S. Umit Sarici

BACKGROUND Oxygen-induced lung injury is believed to lead to the development of bronchopulmonary dysplasia in premature infants. We have evaluated the beneficial effects of Nigella sativa oil (NSO) on rats with hyperoxia-induced lung injury. METHODS Thirty newborn Sprague-Dawley rats were randomly divided into 3 groups as hyperoxia (95% O(2)), hyperoxia+NSO and control (21% O(2)). Pups in the hyperoxia+NSO group were administered intraperitoneal NSO at a dose of 4ml/kg daily during the study period. Histopathologic, immunochemical, and biochemical evaluations (superoxide dismutase [SOD], glutathione peroxidase [GSH-Px], malonaldehyde [MDA] and myeloperoxidase [MPO]) were performed. RESULTS In the histopathologic and immunochemical evaluation, severity of lung damage was significantly lower in the hyperoxia+NOS group (P<.05). Tissue GSH-Px and SOD levels were significantly preserved, and MDA, MPO levels were significantly lower in the hyperoxia+NSO group (P<.05). CONCLUSION NSO significantly reduced the severity of lung damage due to hyperoxia.


Regulatory Peptides | 2013

Toll-like receptor levels and caffeine responsiveness in rat pups during perinatal period.

Turan Tunc; Gokhan Aydemir; Abdulbaki Karaoglu; Ferhat Cekmez; Mustafa Kul; Secil Aydinoz; Oguzhan Babacan; Halil Yaman; Serdar Umit Sarici

Infants born prematurely are prone to bronchopulmonary dysplasia which is a devastating form of chronic lung disease that develops in very low birth weight infants. Toll-like receptors (TLRs) are pattern recognition receptors that initiate innate immune responses. We tested TLR2, 4, and 9 levels in the lungs of rat pups given caffeine at the first days of postnatal life. Twenty-four rat pups equally divided into three groups. The study group received caffeine immediately after birth for ten days. The levels of TLR9 were found significantly higher in study group than control groups. We conclude that the beneficial and anti-inflammatory effects of caffeine in the lungs of newborn rats may be due to increased TLR9 levels.


Pediatric Research | 2013

Cytidine 5′-diphosphocholine ameliorates hyperoxic lung injury in a neonatal rat model

Merih Cetinkaya; Mehmet Cansev; Ilker Mustafa Kafa; Cüneyt Tayman; Ferhat Cekmez; Fuat Emre Canpolat; Turan Tunc; S. Umit Sarici

Background:Bronchopulmonary dysplasia (BPD) is an important cause of morbidity. The aim of this study was to evaluate the preventive effect of cytidine 5′-diphosphocholine (CDP-choline) treatment on hyperoxic lung injury in a neonatal rat model.Methods:A total of 30 newborn pups were divided into control, hyperoxia, and hyperoxia + CDP-choline groups. After birth, pups in the control group were kept in room air and received saline injections, whereas those in hyperoxia and hyperoxia + CDP-choline groups were exposed to 95% O2 and received daily injections of saline and CDP-choline throughout postnatal day 10, respectively. Histopathological scoring, radial alveolar count, lamellar body membrane protein expression, fibrosis, proinflammatory cytokine levels, lung tissue and bronchoalveolar lavage (BAL) fluid phospholipid content, and apoptosis were evaluated.Results:Hyperoxia-induced severe lung damage was reduced significantly by CDP-choline treatment. Radial alveolar count and lamellar body membrane protein expression were significantly recovered, and the number of terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling–positive cells, active caspase-3 expression, and tissue proinflammatory cytokine levels were decreased by CDP-choline administration. Lung tissue and BAL phospholipid contents showed significant increases after CDP-choline administration.Conclusion:These data show that CDP-choline ameliorates hyperoxic lung injury in a neonatal rat model. It may therefore be suggested that CDP-choline may be a novel therapeutic option for the prevention of BPD.


European Journal of Pediatrics | 2009

Congenital cytomegalovirus infection associated with severe lung involvement in a preterm neonate: a causal relationship?

Esad Koklu; Ahmet Karadag; Turan Tunc; Demet Altun; S. Umit Sarici

We report a preterm neonate with congenital cytomegalovirus (CMV) infection associated with severe lung involvement progressing to early chronic lung disease (CLD) and death. The present case represents the earliest and the most severe lung involvement depending on recurrent maternal CMV infection reported in the literature. Neonatal mortality and progression to early CLD should be considered in the list of possible neonatal sequelae resulting from recurrent maternal CMV infection.

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Mustafa Kul

Military Medical Academy

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Ferhat Cekmez

Military Medical Academy

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S. Umit Sarici

Military Medical Academy

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Halil Yaman

Military Medical Academy

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Emin Oztas

Military Medical Academy

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Gokhan Aydemir

Military Medical Academy

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Mehmet Saldir

Military Medical Academy

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Secil Aydinoz

Military Medical Academy

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