Yazar "Aktuna, Zuhal" seçeneğine göre listele
Listeleniyor 1 - 9 / 9
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe The effect of experimentally induced carbon dioxide pneumoperitoneum on intra-abdominal and intra-esophageal pH(Tubitak Scientific & Technical Research Council Turkey, 2009) Soyer, Tutku; Aydos, Tolga Resat; Aktuna, Zuhal; Korkut, Oguzhan; Ozmanoglu, Goekhan; Hancerliogullari, Oeymen; Cakmak, MuratAim: An experimental study was performed to evaluate the effect of CO2 pneumoperitoneum on intra-abdominal (IA) and intra-esophageal (IE) pH. Material and methods: The study included 18 Wistar rats. In the control group (n = 6) a pH catheter was inserted into the peritoneal cavity via a left upper quadrant incision and another catheter was inserted into the lower esophagus via the oral route. Pre- and post-insufflation IA and IE pH were recorded every 5 min for 1 h. In the experimental groups, in addition to pH catheters, a 16-G catheter was inserted into the abdomen above the umbilicus. In the O-2 group (n = 6) 95% O-2 and 5% CO2 were insufflated with a pressure of 10 mmHg. In the CO2 group (n = 6), CO2 was insufflated with the same pressure and duration. Results: In the CO2 group, IA and IE pH values significantly decreased (P < 0.05). IA pH values decreased in the CO2 group when compared to the control and O-2 groups (P < 0.05). There was not a significant difference in IE pH between the CO2 group and the other groups. Conclusion: CO2 insufflation decreased IA pH values. Decreased pH values obtained with continuous recordings of the esophagus may have been related to increases in intra-abdominal pressure, rather than the metabolic effects of CO2 pneumoperitoneum.Öğe Effect of phototherapy on gastrointestinal smooth muscle activity and oxidative stress(Springer, 2011) Soyer, Tutku; Aliefendioglu, Didem; Aktuna, Zuhal; Caglayan, Osman; Aydos, Tolga Resat; Cakmak, MuratAim To evaluate the effect of phototherapy on gastrointestinal smooth muscle activity and oxidative stress. Methods Wistar albino rats (n = 18, in the first 7 days of life) weighing 7 +/- 2 g with both sexes were included in the study. The animals were randomized into three groups. In control group (CG), median laparotomy was performed to obtain 1 cm of jejunum, terminal ileum and colonic segments. In the phototherapy group (PTG), led phototherapy with a wave density of 40 mu w/cm(2)/nm were used (Bilitron 3006, Fanem, Brasil). The efficacy surface of phototherapy was 30-40 cm and the exposure distance was 30 cm. The duration of phototherapy was 24 h. Sham group (SG) received white light with the same wave density and exposure distance. The oxidative stress markers and contraction responses were investigated from intestinal segments obtained from experiments. Results The jejunum segments showed significantly lowered contraction response to carbachol in SG when compared to CG and PTG (p < 0.05). Decreased contractile response to KCl was detected in both SG and PTG in terminal ileum segments. MDA levels showed no difference between groups (p > 0.05). Total sulfhydryl (T-SH) levels were found significantly increased in PTG when compared to CG and SG (p < 0.05). When NO levels were evaluated, NO levels were found decreased in PTG and SG with respect to CG (p < 0.05). Conclusion PT may cause various alterations in oxidant/antioxidant system in intestinal segments. Unlike to clinical findings, decreased contractile responses were detected in rat gastrointestinal smooth muscles after PT.Öğe Effect of phototherapy on growth factor levels in neonatal rat skin(W B Saunders Co-Elsevier Inc, 2011) Soyer, Tutku; Ayva, Sebnem; Aliefendioglu, Didem; Aktuna, Zuhal; Aslan, Mustafa Kemal; Senyucel, Mine Fedakar; Cakmak, MuratAim: Neonates undergoing surgery may receive phototherapy (PT) for the treatment of hyperbilirubinemia. Although the effects of PT on neonatal structures are well documented, the effect of PT on wound healing has not been previously evaluated. An experimental study was performed to evaluate the effect of PT on growth factor levels responsible for wound healing in neonatal rat skin. Materials and Methods: Eighteen Wistar newborn rats (7 +/- 2 g) were included in the study. Rats were randomized into 3 groups: control (CG), PT, and sham (SG) (n = 6). Both groups had 1-cm median dorsal skin incision. In CG, 1 x 1 cm of dorsal skin was sampled including the incised skin. The PT group received 5 banks of blue light (wave density, 30-40 mu w/cm(2) per nanometer; exposure distance, 45 cm). Phototherapy was started 24 hours after birth and exposed during light period (mean duration, 21 hours to 15 minutes perpendicular to 2 hour to 1.5 minutes). Sham group consisted of animals that received a bank of white light with same exposure distance and a total duration of 26 hours to 18 minutes +/- 3 hours to 9.1 minutes. After exposure, 1 x 1 cm dorsal skin samples were obtained from both PT and SG groups, including the median incision. The effect of PT was evaluated with the expressions of vascular endothelial growth factor (VEGF), its receptor (VEGF receptor), and transforming growth factor beta (TGF-beta) in endothelial vessels and fibroblasts of neonatal skin samples. Results: There was no significant difference between groups in VEGF receptor and transforming growth factor beta expressions. The VEGF levels in endothelial vessels were significantly decreased in PT and SG when compared with CG (P < .05). Conclusion: Vascular endothelial growth factor is a mediator of angiogenesis and may decrease in neonatal rat skin after light exposure. It can be suggested that decreased levels of VEGF after PT application may alter angiogenesis and also may adversely affect the healing features of neonatal skin. (C) 2011 Elsevier Inc. All rights reserved.Öğe Effect of whole gut irrigation solutions on gastrointestinal smooth muscle activity(W B Saunders Co-Elsevier Inc, 2009) Soyer, Tutku; Aydos, Tolga Reşat; Hancerlıoğulları, Oymen; Korkut, Oğuzhan; Aktuna, Zuhal; Çakmak, MuratBackground/Purpose: It has been suggested that whole gut irrigation (WGI), which is a preparation method for large bowel surgery or colonoscopy, increases gastrointestinal motility by creating a gastrocolic reflex. An experimental study was performed to evaluate the effect of different WGI solutions on gastrointestinal smooth muscle activity. Materials and Methods: Thirty Wistar albino rats weighing 200 to 250 g were enrolled in the study. After anesthetization with thiopental sodium (50 mg/kg), proximal ileum, terminal ileum, and colon segments were removed via median laparotomy to obtain a control group. Four different groups (n = 6) were designated as having WGI with saline solution (SS), lactated Ringer's solution (RL), polyethylene glycol (PEG), and dibasic sodium phosphate (DNP). Bowel cleaning was performed by infusing solutions at a rate of 2 mL/min via gastric tube, until the stool was cleared. After completing the bowel cleaning, 2 cm of tissues were removed and suspended in Tyrode solution in an isolated organ bath with a resting tension of I g, to obtain carbachol and potassium chloride (KCl) responses. Results: The mean bowel cleaning times were 87.5 +/- 9.35, 81.6 +/- 9.83, 86.6 +/- 11.6, and 85.0 +/- 0.0 minutes in SS, RL, PEG, and DNP groups, respectively. The total amounts of solutions needed for cleaning were 156.67 +/- 21.6, 195.0 +/- 20.0, 197.5 +/- 32.8, and 70.0 +/- 0.0 mL, respectively. Although there was no difference in cleaning time between the groups, the amount of solution required was significantly less in the DNP group (P = .02). In the proximal ileum segments, though there was no difference in carbachol responses between groups, KCl responses were significantly increased in the RL group (P < .05). When we evaluated the terminal ileum responses, carbachol responses were significantly increased in RL and PEG groups (P = .011) and decreased in the DNP group (P = .049). The KCl responses were also significantly increased in the R-L group with respect to the other groups (P < .05). Colon segments showed no difference in contractile responses with respect to different WGI solutions (P >.05, analysis of variance, post hoc Dunn's test). Conclusion: The different WGI solutions demonstrated no significant differences in colon contractions. The increased contractile responses in the proximal and terminal ileum segments after WGI with RL may be related to the electrolyte composition of RL. Although the lower amount of DNP solution required to achieve bowel cleaning seems to be an advantage, the decreased ileal contractions can be assessed as a disadvantage of DNP irrigations. (c) 2009 Elsevier Inc. All rights reserved.Öğe The Effects of Beta-blockers on Endothelial Nitric Oxide Synthase Immunoreactivity in the Rat Corpus Cavernosum(Elsevier Science Inc, 2010) Dogru, Mehmet Tolga; Aydos, Tolga Resat; Aktuna, Zuhal; Korkusuz, Petek; Zeybek, Dilara; Gorgu, Nart; Basar, Mehmet MuradOBJECTIVES To explain the mechanism of the effects of beta-blockers on endothelial dysfunction and release of nitric oxide from the endothelium. METHODS A total of 72 Sprague-Dawley rats were divided into 9 different groups as follows: group 1: control (n = 10), group 2: metoprolol (Beloc) 100 mg/kg/d (n = 7), group 3: carvedilol (Dilatrend) 50 mg/kg/d (n = 7), group 4: nebivolol (Vasoxen) 10 mg/kg/d (n = 6), group 5: estrogen receptor (ER) antagonist ICI 182.780 (Fluvestrant) 50 mu g/g (n = 10), group 6: nebivolol +ER antagonist (n = 8), group 7: androgen receptor (AR) antagonist (flutamide) 20 mg/kg (n = 7), group 8: nebivolol + AR antagonist (n = 7), and group 9: DMSO (solvent for ER antagonist) (n = 10). All beta-blockers were applied with gastric gavage after dilution with 5 mL of serum physiological; ER and AR were both applied intraperitoneally (i.p.) for 14 days. In the isolated rat cavernous tissues, endothelial nitric oxide synthase (eNOS) and ER and AR immunoreactivity were analyzed quantitatively. One-way analysis of variance and Tukey test were used for statistical analysis. RESULTS Although increased eNOS immunoreactivity was observed with nebivolol and nebivolol-flutamide in endothelial cells laying cavernous tissue, a lower score was observed after ICI-182.780 application, when compared with control cases. AR immunoreactivity in cavernosal endothelium was clearly higher with nebivolol. Higher H score and ER immunoreactivity were observed in the cavernous endothelium and smooth muscles in the nebivolol, carvedilol, and metoprolol groups when compared with control cases. CONCLUSIONS We showed that eNOS activity was increased in the nebivolol and nebivolol-flutamide groups, whereas it was decreased in the ICI 182.780 group. We believe that an ER-dependent mechanism triggered by nebivolol played a role in nitric oxide formation. UROLOGY 75: 589-597, 2010. (C) 2010 Elsevier Inc.Öğe Effects of cell phone radiation on lipid peroxidation, glutathione and nitric oxide levels in mouse brain during epileptic seizure(Elsevier Science Bv, 2016) Esmekaya, Meric Arda; Tuysuz, Mehmet Zahid; Tomruk, Arin; Canseven, Ayse G.; Yucel, Engin; Aktuna, Zuhal; Seyhan, NesrinThe objective of the this study was to evaluate the effects of cellular phone radiation on oxidative stress parameters and oxide levels in mouse brain during pentylenetetrazole (PTZ) induced epileptic seizure. Eight weeks old mice were used in the study. Animals were distributed in the following groups: Group I: Control group treated with PTZ, Group II: 15 min cellular phone radiation + PTZ treatment + 30 min cellular phone radiation, Group III: 30 min cellular phone radiation + PTZ treatment + 30 min cellular phone radiation. The RF radiation was produced by a 900 MHz cellular phone. Lipid peroxidation, which is the indicator of oxidative stress was quantified by measuring the formation of thiobarbituric acid reactive substances (TBARS). The glutathione (GSH) levels were determined by the Ellman method. Tissue total nitric oxide (NOx) levels were obtained using the Griess assay. Lipid peroxidation and NOx levels of brain tissue increased significantly in group II and III compared to group I. On the contrary, GSH levels were significantly lower in group II and III than group I. However, no statistically significant alterations in any of the endpoints were noted between group II and Group III. Overall, the experimental findings demonstrated that cellular phone radiation may increase the oxidative damage and NOx level during epileptic activity in mouse brain. (C) 2016 Elsevier B.V. All rights reserved.Öğe Esophageal and Gastric Smooth Muscle Activity After Carbon Dioxide Pneumoperitoneum(Academic Press Inc Elsevier Science, 2010) Soyer, Tutku; Aktuna, Zuhal; Aydos, Tolga Reşat; Osmanoğlu, Gökhan; Korkut, Oğuzhan; Akman, Hülya; Çakmak, MuratBackground. The metabolic changes associated with carbon dioxide (CO(2)) pneumoperitoneum include metabolic acidosis and lowered intra-abdominal pH values. An experimental study was performed to evaluate the effect of CO(2) pneumoperitoneum on esophageal and gastric smooth muscle sensitivity in response to several agonists. Methods. Wistar albino rats, weighing 200-250 g, were allocated into three groups. After anesthetization with ketamine hydrochloride and xylazine, abdominal esophagus, gastroesophageal junction, and gastric fundus were removed via median laparotomy in the control group. In the oxygen (O(2)) group, a 16G catheter was inserted into the abdomen above the umbilicus and insufflated with 95% O(2) and 5% CO(2) with a pressure of 10 mm Hg. In the CO(2) group, CO(2) was insufflated at the same pressure within the same time and the tissues were removed at the end of a 60 min period of pneumoperitoneum. Abdominal esophageal segment (n:6), gastroesophageal junction (n:6) and gastric fundus (n:12) were suspended under 0.5 to 2 g resting tension in Tyrode solution in organ baths. Contraction responses were obtained by carbachol and serotonin and relaxation responses were evaluated by isoproterenol in each group. All the responses were compared by nonparametric Kruskal Wallis test. Results. Carbachol and serotonin induced contractile responses of abdominal segments, gastroesophageal junction, and gastric fundus showed no difference between the control, O(2), and CO(2) groups (P > 0.05). Isoproterenol relaxation responses of the three groups were also not statistically different from each other (P > 0.05). Conclusion. CO(2) pneumoperitoneum of 60 min has no influence on esophageal and gastric smooth muscle responses to different agonists in rats. (C) 2010 Elsevier Inc. All rights reserved.Öğe In vitro sensitivity of rat esophagus to agonists in different alkaline mediums(W B Saunders Co-Elsevier Inc, 2012) Hancerliogullari, Oymen; Cakmak, Murat; Soyer, Tutku; Aktuna, ZuhalAim: An in vitro study was performed to determine the in vitro sensitivity of rat esophagi to contracting and relaxing agonists in different alkaline mediums. Materials and Methods: Twenty-four Wistar rats weighing 200 to 250 g were included in the study. After inducing anesthesia with thiopental sodium (50 mg/kg), the rats were killed, and the distal esophagus (DE) and gastroesophageal junction (GEJ) were removed. Excised tissues were suspended under 0.6 g of resting tension in a tissue bath containing 10 mL of Tyrode solution at 37 degrees C. The esophageal segments were divided into 4 groups, each with a different pH medium: 7.4, 7.6, 7.8, and 8. To evaluate the smooth muscle activity of the rat esophagus in different alkaline mediums, cholinergic agonist carbachol (a cholinergic agonosit) and KCl (which acts on calcium channels) were added to the organ baths to obtain concentration-dependent contraction responses. Relaxation responses were obtained using an adrenergic agonist, isoproterenole. Data obtained from different pH mediums were analyzed using Kruskal-Wallis nonparametric analysis of variance and post hoc Dunn's test. Results: The pH of the medium has no effect on the concentration-dependent contracting responses to carbachol in the DE, but responses obtained in pH 8 medium were significantly lower in the GEJ (P < .05). In pH 8 medium, concentration-dependent relaxation responses to isoproterenole were also significantly lower (P < .05). When contractile responses to KCl were evaluated, the groups with pH 7.6 and 7.8 medium were found to have higher responses in the DE segments than other groups (P < .05). However, the GEJ segments had lower contractile responses to KCl in pH 8 medium (P < .05). Conclusion: Although different alkaline mediums caused no alteration in esophageal smooth muscle responses to cholinergic stimulation, GEJ responses were lower in pH 8 medium. Relaxation responses, owing to increased adrenergic activity, decreased when the pH of the medium was increased to 8. Calcium-dependent contractions caused by KCl decreased in both segments in pH 8 medium but increased in the DE in pH 7.6 medium. (C) 2012 Elsevier Inc. All rights reserved.Öğe The Smooth Muscle Contractility In Aflatoxicated Broiler Chicken Ileum(Parlar Scientific Publications (P S P), 2013) Yildirim, Ebru; Aktuna, Zuhal; Yalcinkaya, Ilkay; Eraslan, Gokhan; Kanbur, Murat; Aydos, Tolga R.; Oruc, ErtanThis study was conducted to investigate the contractility of aflatoxicated isolated broiler ileum smooth muscles. Fourty-eight, one-day old broiler chicks were divided into 4 groups, each containing 12 chicks. The 1st group was the control group, the 2nd group received 1 g/kg yeast glucomannan (Mycosorb), the 3rd group received 2 mg/kg aflatoxin, and the 4th group received 1 g/kg yeast glucomannan + 2 mg/kg aflatoxin in the feed. At the 21st day of the study, chicks were decapitated and the ileum isolated. Decapitation lasted on 28th day of the study. The isolated ileum strips were mounted under a basal tension of 1 g. The contractions of acetylcholine (ACh), nicotine, and bethanechol were calculated as g contraction/mg wet weight of ileum. For histopathologic examination, ileum sections were stained with hematoxylin-eosin and masson trichrome. The isolated ileum muscle contractions with ACh, nicotine, and bethanechol were not statistically significant in the study groups as compared to control group (P>0.05). Pathological examination revealed no histopathological changes in the smooth muscle tissues of the study group chicks when compared with control group. It is concluded that aflatoxins do not specifically change the contractility of broiler chick ileum to agonists most likely due to lack of aflatoxin-induced pathologic changes in the broiler chick ileum.
