Bulunan: 53 Adet 0.001 sn
Koleksiyon [20]
Tam Metin [2]
Yayın Türü [5]
Yazar [20]
Yayın Yılı [15]
Konu Başlıkları [20]
Yayıncı [20]
Yayın Dili [2]
Dergi Adı [20]
Melatonin and oxidation

Özaçmak, Veysel Haktan

Book Part | 2011 | Melatonin in the Promotion of Health: Second Edition , pp.541 - 551

[No abstract available]

The effects of ethyl pyruvate on cognitive function, oxidative stress, and Na-K ATPase levels in vascular dementia model

Özaçmak-Sayan, Hale | Gencer, Ercan | Özaçmak, Veysel Haktan

Proceedings | 2016 | ACTA PHYSIOLOGICA218 , pp.72 - 72

WOS: 000383578300190

Analysis of glomerular filtration rate, serum cystatin C levels, and renal resistive index values in cirrhosis patients

Üstündağ, Yücel | Samsar, Ufuk | Açıkgöz, Şereften | Çabuk, Mehmet | Kıran, Sibel | Külah, Eyüp | Aydemir, Selim

Article | 2007 | Clinical Chemistry and Laboratory Medicine45 ( 7 ) , pp.890 - 894

Background: The aim of this study was to evaluate the relation of glomerular filtration rate (GFR) to serum cystatin C levels, renal resistive index (RRI), serum creatinine and creatinine clearance in patients with different stages of cirrhosis. Methods: The study sample was 25 cirrhotic patients (10 females and 15 males; mean age 57.3±2.04 years), 10 in the compensated stage without ascites and 15 in the decompensated stage with new-onset ascites. None had azotemia nor were on diuretic treatment. The control group comprised 25 healthy adults (11 female and 14 men; mean age 56.56±1.91 years). Serum cystatin C, RRI, serum creatinine . . .and creatinine clearance were measured. GFR was determined by technetium99m- diethylene triamine pentaacetic acid renal scintigraphy. Results: Cirrhosis cases had lower mean scintigraphic GFR than controls (64.5±4.03 vs. 87.96±4.16 mL/min, p<0.05). Serum cystatin C and RRI were significantly higher in the cirrhotic group compared to controls (1.16±0.09 mg/L and 0.68±0.01 vs. 0.86±0.03 mg/L and 0.64±0.01, respectively; p<0.05). Subgroup comparative analysis showed that only two parameters, scintigraphic GFR and serum cystatin C, were significantly different between compensated and decompensated cirrhotics (75.62±4.9 mL/min and 0.89±0.07 mg/L vs. 57.23±5.14 mL/min and 1.34±0.13mg/L, respectively; p<0.05). Scintigraphic GFR showed significant correlation with cystatin C, but not with serum creatinine or creatinine clearance (r=-0.877, p<0.05) in decompensated patients. No correlation was observed between scintigraphic GFR and RRI or between serum cystatin C and RRI in all subjects. A receiver operator characteristics curve showed that cystatin C at a cutoff value of 1.01 mg/L can significantly differentiate patients with GFR <70 mL/min with 80% sensitivity and 80% specificity. Conclusions: Serum cystatin C, but not serum creatinine or RRI measurement, correlates with GFR in each stage of liver failure and has a significant diagnostic advantage in detecting lower GFR in such cases. © 2007 by Walter de Gruyter Daha fazlası Daha az

Polymeric linoleic acid-polyolefin conjugates: Cell adhesion and biocompatibility

Çakmaklı, Birten | Hazer, Baki | Tekin, İshak Özel | Açıkgöz, Şerefden | Can, Murat

Article | 2007 | JAOCS, Journal of the American Oil Chemists' Society84 ( 1 ) , pp.73 - 81

To diversify edible-oil polymer composite, polymeric linoleic acid (PLina) peroxide was obtained by the auto-oxidation of linoleic acid in a simple way for use as a macroinitiator in free radical polymerization of vinyl monomers. Peroxidation, epoxidation, and/or perepoxidation reactions of linoleic acid under air at room temperature resulted in PLina, having soluble fraction more than 91 weight percent (wt%), with molecular weight ranging from 1,644 to 2,763 Da, and containing up to 1.0 wt% of peroxide. PLina initiated the free radical polymerization of ether styrene (S), methyl methacrylate (MMA), or n-butyl methacrylate (nBMA) to . . . give PLina-g-polystyrene (PS), PLina-g-poly-MMA (PMMA), and PLina-g-poly- nBMA (PnBMA) graft copolymers. The polymers obtained were characterized by proton nuclear magnetic resonance (1H NMR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC) techniques. Microstructure of the graft copolymers was observed by using scanning electron microscope (SEM). Graft copolymers obtained contained polymeric linoleic acid in a range between 8.5 and 19.3 mol percent (mol%). PLina-g-PS, PLina-g-PMMA and PLina-g-PnBMA graft copolymer samples were also used in cell culture studies. Fibroblast and macrophage cells were strongly adhered and spread on the copolymer film surfaces. These newly synthesized copolymers were tested for their effects on human blood protein adsorption compared with PMMA graft copolymers containing polymeric soybean oil and polymeric linseed oil; interestingly we observed a dramatic decrease in the protein adsorption on the linoleic acid graft copolymer, which is important in tissue engineering. © AOCS 2007 Daha fazlası Daha az

Effects of ethanol on intracorporeal structures of the rat

Yeşilli, Çetin | Mungan, Görkem | Seçkiner, İlker | Akduman, Bülent | Numanoğlu, Gamze | Mungan, Aydın

Article | 2006 | International Urology and Nephrology38 ( 1 ) , pp.129 - 132

Objective: Previous studies demonstrated that acute in vitro exposure of corpus cavernosal tissue to ethanol decreased its response to field stimulation and pharmacological stimulation. In the present study we investigated the effects of chronic ethanol consumption on the ultrastructure of cavernosal smooth muscle cells, elastic fibres and collagen content. Material and methods: Fourteen adult wistar rats were divided into a control group (n = 7, fed a standard diet and tap water) and an alcoholic group (n = 7, fed a standard diet and 5% (v/v) ethanol in drinking water and by increasing the ethanol concentration for every week, at t . . .he end of 6th week 30% (v/v) ethanol concentration was attained. Same dose was given until 12th week. At the end of 12th week blood samples were obtained and the ethanol concentrations were determined. The cavernosal tissues were obtained and immunohistochemical examinations were performed. Results: Immunohistochemical analysis revealed that chronic ethanol exposure markedly decreased the content of smooth muscle cells, elastic fibres and collagen type 4. Conclusion: Our findings suggest that in this animal model chronic ethanol exposure decreases the percentage of staining for smooth muscle actin, elastin, and collagen type 4 which are the key structures fundamental for erection. © Springer 2006 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

Erythropoietin stimulates wound healing and angiogenesis in mice

Sayan, Hale | Özaçmak, Veysel Haktan | Güven, Aysel | Aktaş, R. Gülhan | Özaçmak, I. Diler

Article | 2006 | Journal of Investigative Surgery19 ( 3 ) , pp.163 - 173

Erythropoietin exerts hematopoietic effects by stimulating proliferation of early erythroid precursors. Nonhematopoietic effects of erythropoietin have also been shown. It may act as a new angiogenic factor in wound healing. This study aimed to investigate the effect of systemic administration of recombinant human erythropoietin on wound healing in mice. Dorsal incisional wounds were performed in mice, which were then divided into two groups; a group treated for 7 days with recombinant human erythropoietin, and a control group. Sacrificing animals on day 7, the wound tissues were collected for analysis of wound breaking strength, ma . . .londialdehyde, a marker of lipid peroxidation, hydroxyproline, an index of reparative collagen deposition, reduced glutathione levels, and for histological evaluation. The immunohistochemical determination of vascular endothelial growth factor (VEGF) which is believed to be the most prevalent angiogenic factor throughout the skin repair process, was also studied. The treatment significantly increased wound breaking strength by decreasing malondialdehyde and increasing hydroxyproline levels on day 7 after wounding. No statistically meaningful change was observed in reduced glutathione content. VEGF was immunostained significantly more on wound tissue of treated animals compared to the control group. Recombinant human erythropoietin treatment may be effective in wound healing due to inhibition of lipid peroxidation, deposition of collagen, and VEGF expression in wound area. Copyright © Taylor & Francis Group, LLC Daha fazlası Daha az

Mechanisms of the effects of Erythropoietin in wound healing: A morphologic study.

Aktaş, Ranan Gülhan | Güven, Alya | Özaçmak-Sayan, Hale | Özaçmak, Veysel Haktan | İçkin, Meltem | Tok, Olgu Enis | Oktayer, Adviye Gözde

Proceedings | 2012 | MOLECULAR BIOLOGY OF THE CELL23 , pp.163 - 173

WOS: 000209348606167

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

Article | 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 effect of melatonin on contractile activity and oxidative injury induced by ischemia and reperfusion of rat ileum

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

Article | 2005 | Life Sciences76 ( 14 ) , pp.1575 - 1588

Free radicals derived from molecular oxygen have been reported to be responsible for changes in motility and mucosal damage observed in intestinal ischemia-reperfusion injury. Melatonin has been considered as an antioxidant that prevents injuries resulted from I/R in various tissues. The present study was designed to determine the effect of melatonin on the contractile responses of acetylcholine (Ach) and KCl, on malondialdehyde (MDA), a product of lipid peroxidation, and reduced glutathione (GSH) levels and to assess histopathological changes in the smooth muscle of terminal ileum subjected to ischemia-reperfusion. The intestinal i . . .schemia-reperfusion was induced by occlusion of superior mesenteric artery of rat for 30 min, followed by a period of reperfusion for 3 h. Melatonin at doses of 10 or 50 mg/kg was administered via the tail vein in 5 min prior to reperfusion. Following reperfusion, segments of terminal ileum were rapidly taken and transferred into isolated organ bath and responses to Ach and KCl were recorded. Samples of terminal ileum were also taken for measuring the MDA and GSH levels. EC50 values of these contracting substances were seriously reduced in the ischemia-reperfusion group compared to that of the sham-operated control group. The decreased contraction response to Ach and KCl was significantly ameliorated by a dosage of 50 mg/kg of melatonin, while not by a dosage of 10 mg/kg. Similar pattern of the effect was observed in the tissue levels of MDA and GSH as well as in histological improvement. Melatonin appeared to be restoring the amounts of tissue MDA and GSH back to about control levels. These results suggest that the high dose of melatonin not only physiologically but also biochemically and morphologically could be useful to normalize contractility injured by oxidative stress in intestinal ischemia-reperfusion. © 2004 Elsevier Inc. All rights reserved Daha fazlası Daha az

Colonic tuberculosis mimicking tumor perforation: A case report and review of the literature

Cömert-Beğendik, Füsun | Cömert, Mustafa | Külah, Canan | Taşçılar, Öge | Numanoğlu, Gamze | Aydemir, Selim

Article | 2006 | DIGESTIVE DISEASES AND SCIENCES51 ( 6 ) , pp.1039 - 1042

3rd European Meeting on Molecular Diagnostics -- 37910 -- Scheveningen, NETHERLANDS WOS: 000239295700002 PubMed: 16865564

Ethyl pyruvate prevents from chronic cerebral hypoperfusion via preserving cognitive function and decreasing oxidative stress, caspase 3 activation and IL-1ß level

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

Article | 2018 | Bratislava Medical Journal119 ( 8 ) , pp.469 - 475

BACKGROUND: One of the important risk factors for dementia is chronic cerebral hypoperfusion (CCH) especially in patients with cerebrovascular disease. OBJECTIVES: In the present study, using rat model of bilateral common carotid artery occlusion, the possible protective effects of ethyl pyruvate (EP) have been explored in terms of memory impairment, oxidative stress, and levels of caspase-3, Na-K ATPase, and IL- 1ß. METHODS: Rats were treated with EP (50 mg/kg, i.p) for 4 weeks. Cognitive function was evaluated by Morris Water Maze (MWM). Both levels of caspase-3 and Na-K ATPase in tissue, IL-1ß in plasma were measured by ELISA met . . .hod. Status of oxidative stress in brain was assessed by the measurements of the tissue malondialdehyde (MDA) and reduced glutathione (GSH) contents. RESULTS: Results showed that CCH caused a striking impairment of spatial working memory, accompanied with increased levels of MDA and IL-1ß as well as caspase 3 level. The treatment with EP, however, significantly improved the memory impairment. Moreover, the treatment also provided beneficial effects on the disturbances of caspase 3, IL-1ß and MDA. CONCLUSION: This study strongly imply that the EP administration can alleviate the memory impairment observed due to CCH. The protection provided by EP may result from inhibition of inflammatory response, apoptotic processes and oxidative stress. © 2018, Comenius University Daha fazlası Daha az

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