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Melatonin reverses depressive and anxiety like-behaviours induced by diabetes: involvement of oxidative stress, age, rage and S100B levels in the hippocampus and prefrontal cortex of rats

Ergenç, Meryem | Özaçmak-Sayan, Hale | Turan, İnci | Özaçmak, Veysel Haktan

Makale | 2019 | Archives of Physiology and Biochemistry

Diabetes is associated with depression and anxiety symptoms. The current investigation was designed to explore the effect of melatonin on depressive and anxiety like-behaviours, oxidative stress, levels of AGE, RAGE and S100B in streptozotocin-induced diabetic rats. The animals were divided into four groups: Normoglycemic; Normoglycemic + melatonin; diabetic; diabetic + melatonin (10 mg/kg, for 4 weeks). The malondialdehyde (MDA), reduced glutathione (GSH), AGE, RAGE and S100B were measured and the depressive and anxiety like-behaviours were assessed by forced swimming and elevated plus maze tests, respectively. Melatonin ameliorate . . .s depressive and anxiety like-behaviours. Concomitantly, melatonin reversed diabetes induced increase of MDA, AGE and decrease of GSH and S100B levels in the hippocampus and prefrontal cortex. In conclusion, our results showed that melatonin administration may exert antidepressant-like and anxiolytic effects in diabetic rats through normalising of AGE/RAGE, S100B and oxidative stress in the prefrontal cortex and hippocampus. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group Daha fazlası Daha az

The effects of 17 beta estradiol, 17 alpha estradiol and progesterone on oxidative stress biomarkers in ovariectomized female rat brain subjected to global cerebral ischemia

Özaçmak, Veysel Haktan | Sayan, Hale

Makale | 2009 | Physiological Research58 ( 6 ) , pp.909 - 912

Neuroprotective effects of estrogens and progesterone have been widely studied in various experimental models. The present study was designed to compare possible neuroprotective effects of 17alpha-estradiol, 17beta-estradiol, and progesterone on oxidative stress in rats subjected to global cerebral ischemia. Global cerebral ischemia was induced in ovariectomized female rats by four vessel occlusion for 10 min. Following 72 h of reperfusion, levels of malondialdehyde (MDA, oxidative stress marker), and reduced glutathione (GSH, major endogenous antioxidant) were assessed in hippocampus, striatum and cortex of rats treated with either . . . 17alpha-estradiol, 17beta-estradiol, progesterone or estradiol + progesterone beforehand. Steroid administration ameliorated ischemia-induced decrease in GSH and increase in MDA levels. Our data offers additional evidence that estrogens and progesterone or combination of two exert a remarkable neuroprotective effect reducing oxidative stress. © 2009 Institute of Physiology v.v.i., Academy of Sciences of the Czech Republic, Prague, Czech Republic Daha fazlası Daha az

Protective effects of L-arginine on rat terminal ileum subjected to ischemia/reperfusion

Sayan, Hale | Özaçmak, Veysel Haktan | Altaner, Şemsi | Aktaş, R. Gülhan | Arslan, S. Oktay

Makale | 2008 | Journal of Pediatric Gastroenterology and Nutrition46 ( 1 ) , pp.29 - 35

OBJECTIVES: Studies have shown that nitric oxide (NO) may play a major role in sustaining mucosal integrity; however, NO has been also implicated in the pathogenesis of ischemia/reperfusion (I/R)-related tissue injury. We investigated the effects of L-arginine and N-nitro L-arginine methyl ester (L-NAME) on the acetylcholine-induced contractile response of ileum and the levels of malondialdehyde (MDA) and reduced glutathione (GSH). Histopathological changes were also evaluated in ileal preparations. MATERIALS AND METHODS: Male Wistar Albino rats were subjected to mesenteric ischemia (30 min) followed by reperfusion (3 hours). Four g . . .roups were designed: sham-operated control; I/R; I/R and L-arginine pretreatment; and I/R and L-NAME pretreatment. After reperfusion, ileum specimens were collected to determine the parameters mentioned above. RESULTS: Following reperfusion, a significant decrease in acetylcholine-induced contractile response, an increase in lipid peroxidation, a decrease in GSH content, and mucosal damage of the ileal preparations were observed. We showed that decreased contractility, increased lipid peroxidation, and reduced GSH content have been reversed by L-arginine but not by L-NAME. Mucosal injury was significantly lowered in the L-arginine group. CONCLUSIONS: Treatment with L-arginine exerted a protective effect in intestinal I/R injury, which was mediated in part by regulating MDA and GSH levels, consequently ameliorating impaired contractile response and mucosal injury. © 2008 Lippincott Williams & Wilkins, Inc Daha fazlası Daha az

Use of autopsy to determine live or stillbirth: new approaches in decision-support systems

Yılmaz, Rıza | Erkaymaz, Okan | Kara, Erdoğan | Ergen, Kıvanç

Makale | 2017 | Journal of Forensic Sciences62 ( 2 ) , pp.468 - 472

Fetal deaths are important cases for forensic medicine, as well as for criminal and civil law. From a legal perspective, the determination of whether a deceased infant was stillborn is a difficult process. Such a determination is generally made during autopsy; however, no standardized procedures for this determination exist. Therefore, new facilitative approaches are needed. In this study, three new support systems based on 10 autopsy parameters were tested for their ability to correctly determine whether deceased infants were alive or stillborn. Performances were analyzed and compared with one another. The artificial neural network . . .s and radial basis function network models had 90% accuracy (the highest among the models tested), 100% sensitivity, and 83.3% specificity. Thus, the models presented here provide additional insights for future studies concerning infant autopsies. © 2016 American Academy of Forensic Science Daha fazlası Daha az

Rosiglitazone treatment reduces hippocampal neuronal damage possibly through alleviating oxidative stress in chronic cerebral hypoperfusion

Özaçmak-Sayan, Hale | Özaçmak, Veysel Haktan | Barut, Figen | Jakubowska-Doğru, Ewa

Makale | 2012 | Neurochemistry International61 ( 3 ) , pp.287 - 290

Oxygen free radicals and lipid peroxidation may play significant roles in the progress of injury induced by chronic cerebral hypoperfusion of the central nervous system. Rosiglitazone, a well known activator of PPAR?, has neuroprotective properties in various animal models of acute central nervous system damage. In the present study, we evaluate the possible impact of rosiglitazone on chronic cerebral hypoperfused-rats in regard to the levels of oxidative stress, reduced glutathione, and hippocampal neuronal damage. Chronic cerebral hypoperfusion was generated by permanent ligation of both common carotid arteries of Wistar rats for . . .one month. Animals in treatment group were given rosiglitazone orally at doses of 1.5, 3, or 6 mg/kg per day of the 1 month duration. The treatment significantly lowered the levels of both malondialdehyde and neuronal damage, while elevated the reduced glutathione level markedly. These findings suggest that the beneficial effect of rosiglitazone on hypoperfusion-induced hippocampal neuronal damage might be the result of inhibition of oxidative insult. © 2012 Elsevier Ltd. All rights reserved Daha fazlası Daha az

AT1 receptor blocker candesartan-induced attenuation of brain injury of rats subjected to chronic cerebral hypoperfusion

Özaçmak, Veysel Haktan | Sayan, Hale | Çetin, Alpay | Akyıldız-İğdem, Ayşenur

Makale | 2007 | Neurochemical Research32 ( 8 ) , pp.1314 - 1321

One of common pathophysiological states associated with central nervous system is chronic cerebral hypoperfusion (CH) that frequently occurs in conditions such as vascular dementia and Alzheimer's disease. Long term blockage of angiotensin II type 1 (AT 1 ) receptor provides protection from ischemia induced injury of brain as well as reduction of cerebrovascular inflammation. Examining effect of the blockage on reduced glutathione (GSH), ascorbic acid (AA), and lipid peroxidation were of purpose in the present study. Modeling CH, rats were subjected to permanent occlusion of common carotid arteries bilaterally. AT 1 receptor antagon . . .ist, candesartan, was given daily for 14 days after surgery. CH caused a significant increase in lipid peroxidation and decrease in GSH content of cerebral hippocampal tissue with no change in AA level. Candesartan (0.5 mg/kg, oral) not only reduced lipid peroxidation but also restored GSH significantly besides elevating AA and improving histopathological alterations. In conclusion, long term AT 1 receptor blockage may be considered as novel therapeutic approach for protection from damage associated with CH. Underlying mechanism(s) may in part be related to suppressing oxidative stress and preserving brain antioxidant capacity. © 2007 Springer Science+Business Media, LLC Daha fazlası Daha az

L-Arginine and melatonin interaction in rat intestinal ischemia--reperfusion.

Arslan, S. Arslan | Gelir, Ethem | Sayan, Hale | Özaçmak, Veysel Haktan

Makale | 2005 | Fundamental & clinical pharmacology19 ( 5 ) , pp.533 - 535

We investigated the combinative effects of L-arginine and melatonin on the contractile responses of terminal ileum after the intestinal ischemia-reperfusion (I/R), in vivo. Male rats were subjected to mesenteric ischemia (30 min) followed by reperfusion (180 min). We have observed a dramatic decrease in spontaneous basal activity and Ach-induced contractile response. Our data clearly showed that the contractility decrease was ameliorated by L-arginine but not by L-NAME. Melatonin has reversed the inhibition of contractility caused by I/R injury in part. We did not observe an augmentation in the contractility of ileum when we use mel . . .atonin and L-arginine in combination, in fact, melatonin decreased the protective effect of L-arginine in intestinal I/R injury Daha fazlası Daha az

Attenuation of contractile dysfunction by atorvastatin after intestinal ischemia reperfusion injury in rats

Özaçmak, Veysel Haktan | Sayan, Hale | Akyıldız-İğdem, Ayşenur | Çetin, Alpay | Özaçmak, İhsan Diler

Makale | 2007 | European Journal of Pharmacology562 ( 01.Feb ) , pp.138 - 147

Growing number of studies implicate that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, have beneficial effects on ischemia/reperfusion injury that are unrelated to their cholesterol-lowering action. In the present study, we aimed to evaluate possible effects of atorvastatin on oxidative stress, neutrophil accumulation, and contractile response of terminal ileum segments in rats subjected to intestinal ischemia/reperfusion. Intestinal ischemia/reperfusion model was generated by clamping the superior mesenteric artery for 30 min followed by reperfusion for 3 h. Oral administration of atorvastatin at a dose of . . . 10 mg/kg/day lasted 3 days just before induction of intestinal ischemia. At the end of reperfusion period, terminal ileum samples were removed to determine the concentrations of malondialdehyde, reduced glutathione, and myeloperoxidase. Samples were collected also to assess histopathological alterations and contractile response to agonists. Ischemia/reperfusion significantly decreased contractile responses, and this decrease was attenuated by atorvastatin. Pretreatment with atorvastatin caused remarkable decrease in both oxidative stress and neutrophil accumulation. Atorvastatin appeared to be restoring amount of reduced glutathione back to about control level. Furthermore, the pretreatment lowered mucosal damage at histopathological level. Our results suggested that pretreatment with atorvastatin attenuated intestinal muscle dysfunction associated with ischemia/reperfusion. This remarkable effect of atorvastatin is accomplished at least by decreasing oxidative stress and neutrophil accumulation as well as preventing the depletion of reduced glutathione. © 2007 Elsevier B.V. All rights reserved Daha fazlası Daha az

Synthesis, characterization, and antibacterial activity of metal nanoparticles embedded into amphiphilic comb-type graft copolymers

Kalaycı, Özlem A. | Cömert, Füsun B. | Hazer, Baki | Atalay, Turgay | Cavicchi, Kevin A. | Çakmak, Mükerrem

Makale | 2010 | Polymer Bulletin65 ( 3 ) , pp.215 - 226

The synthesis, spectroscopic characterization, and antimicrobial efficiency of gold and silver nanoparticles embedded in novel amphiphilic comb-type graft copolymers having good film-forming properties have been described. Amphiphilic comb-type graft copolymers were synthesized by the reaction of chlorinated polypropylene (PP) (Mw = 140,000 Da) with polyethylene glycol (PEG) (Mn = 2,000 Da) at different molar ratios. Metal nanoparticles embedded graft copolymers were prepared by reducing solutions of the salts of silver or gold and the copolymer in tetrahydrofuran. The optical properties of the metal nanoparticle embedded copolymers . . . were determined by using UV-visible spectroscopy. Surface plasmon resonance (SPR) of the gold and silver nanoparticle embedded copolymers in toluene was observed at a maximum wavelength (?max) of 428 and 551 nm in the UV-VIS absorption spectra, respectively. The average particle diameters of the gold and silver nanoparticles were found to be 50 nm from the high resolution scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Amphiphilic polymer films containing silver and gold nanoparticles were found to be highly antimicrobial by virtue of their antiseptic properties to Escherichia coli and Staphylococcus aureus. © Springer-Verlag 2009 Daha fazlası Daha az

The protective and anti-inflammatory effect of methylene blue in corrosive esophageal burns: An experimental study

Tanrıkulu, Ceren En | Tanrıkulu, Yusuf | Kılınç, Fahriye | Bahadır, Burak | Can, Murat | Köktürk, Fürüzan | Kefeli, Ayşe


BACKGROUND: In developing countries, esophageal burns are quite common. They are caused by the ingestion of corrosive substances that may lead to esophageal perforation in the short-term and stricture formation in the long-term. Prevention of stricture progression in the esophagus is the main aim of the treatment for corrosive esophageal burns. We aimed to investigate the protective and anti-inflammatory effects of methylene blue (MB) treatment on corrosive esophageal burns. METHODS: Twenty-eight rats were used in the study and randomly divided into four equal groups; group 1 (Sham), group 2 (control), group 3 (topical treatment), a . . .nd group 4 (topical plus systemic treatment). Except for group 1 (Sham group), all three groups received sodium hydroxide (NaOH) in order to generate esophageal burns. In addition, group 2 was given normal saline, group 3 topical MB, and group 4 topical and systemic MB. RESULTS: Hydroxyproline levels were found to be lower in each of the treatment groups as compared to the control group (p=0.005 for group 3 and p=0.009 for group 4). There were no differences in the tumor necrosis factor-alpha (TNF-alpha) levels between the groups. The stenosis index (SI) in the treatment groups was also lower than the control group (p=0.016 for group 3 and p=0.015 group 4). The histopathologic damage score (HDS) was prominently lower in group 4 as compared to the control group (p=0.05). CONCLUSION: MB is effective in treating tissue damage caused by corrosive esophageal burns and in preventing esophageal stenosis. Complication rates of corrosive esophageal burns may be decreased by using MB in the initial treatment stage Daha fazlası Daha az

Vitamin E protects against acetone-induced oxidative stress in rat red blood cells

Armutçu, Feraf | Coşkun, Ömer Faruk | Gürel, Aykut | Şahin, S. | Kanter, Marek | Cihan, Ali | Numanoğlu, Kemal Varın

Makale | 2005 | Cell Biology and Toxicology21 ( 1 ) , pp.53 - 60

Acetone may induce oxidative stress leading to disturbance of the biochemical and physiological functions of red blood cells (RBCs) thereby affecting membrane integrity. Vitamin E (vit E) is believed to function as an antioxidant in vivo protecting membranes from lipid peroxidation. The aim of the present study was the evaluation of possible protective effects of vit E treatment against acetone-induced oxidative stress in rat RBCs. Thirty healthy male Wistar albino rats, weighing 200-230 g and averaging 12 weeks old were randomly allotted into one of three experimental groups: Control (A), acetone-treated (B) and acetone + vit E-tre . . .ated groups (C), each containing ten animals. Group A received only drinking water. Acetone, 5% (v/v), was given with drinking water to B and C groups. In addition, C group received vit E dose of 200 mg/kg/day i.m. The experiment continued for 10 days. At the end of the 10th day, the blood samples were obtained for biochemical and morphological investigation. Acetone treatment resulted in RBC membrane destruction and hemolysis, increased thiobarbituric acid reactive substance (TEARS) levels in plasma and RBC, and decreased RBC vit E levels. Vit E treatment decreased elevated TEARS levels in plasma and RBC and also increased reduced RBC vit E levels, and prevented RBC membrane destruction and hemolysis. In conclusion, vit E treatment appears to be beneficial in preventing acetone-induced oxidative RBC damage, and therefore, it can improve RBC rheology. © 2005 Springer Daha fazlası Daha az

Frozen section experience with emphasis on reasons for discordance

Özdamar, Şükrü Oğuz | Bahadır, Burak | Ekem, Tulu Emre | Kertiş, Gürkan | Gün-Doğan, Banu | Numanoğlu, Gamze | Yünten, Zafer | Kuzey-Mocan, Gamze

Makale | 2006 | Turkish Journal of Cancer36 ( 4 ) , pp.157 - 161

Intraoperative consultation is a high-risk procedure of pathology departments with important consequences. Therefore, it is critical to determine institutional efficiency of frozen section performance periodically. Frozen section diagnoses of 552 specimens from 401 cases between June 2001 and January 2005 were rewieved and correlated with subsequent histopathological examination, to assess concordant, discordant and deferred diagnoses as well as false negative and false positive rates and to determine reasons for discordance. Each individual specimen from the same case was considered and evaluated as one case. Excluding deferred dia . . .gnosis constituting 4.53% of the cases, accuracy, false negative and false positive rates were consecutively found 97.47%, 2.08%, and 0.57%. Interestingly, a great proportion of false negative cases were found to be associated with papillary carcinoma of thyroid. Gross sampling error and misinterpretation appeared as the leading reasons for frozen section discordance. Considering discordant frozen section diagnoses have a great impact on patient's care, intra and interinstitutional monitoring of frozen section performance may serve as a quality control programme Daha fazlası Daha az

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