Person: BECEREN, AYFER
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BECEREN
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AYFER
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Publication Metadata only Ginkgo biloba extract protects against mercury(II)-induced oxidative tissue damage in rats(PERGAMON-ELSEVIER SCIENCE LTD, 2007) VELİOĞLU ÖĞÜNÇ, AYLİZ; Sener, Goksel; Sehirli, Ozer; Tozan, Ayfer; Velioglu-Ovunc, Ayliz; Gedik, Nursal; Omurtag, Gulden Z.Mercury(II) is a highly toxic metal which induces oxidative stress in the body. In this study we aimed to investigate the possible protective effect of Ginkgo biloba (EGb), an antioxidant agent, against experimental mercury toxicity in rat model. Following a single dose of 5 mg/kg mercuric chloride (HgCl2; Hg group) either saline or EGb (150 mg/kg) was administered for 5 days. After decapitation of the rats trunk blood was obtained and the tissue samples from the brain, lung, liver, and kidney were taken for the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen contents. Formation of reactive oxygen species in the tissue samples was monitored by chemiluminescence (CL) technique. BUN, creatinin, ALT, and AST levels and tumor necrosis factor-alpha (TNF-alpha) and lactate dehydrogenase (LDH) activity were assayed in serum samples. The results revealed that HgCl2 induced oxidative damage Caused significant decrease in GSH level, significant increase in MDA level, MPO activity and collagen content of the tissues. Treatment of rats with EGb significantly increased the GSH level and decreased the MDA level, MPO activity, and collagen contents. Similarly, serum ALT, AST and BUN levels, as well as LDH and TNF-alpha, were elevated in the Hg group as compared to control group. On the other hand, EGb treatment reversed all these biochemical indices. Our results implicate that mercury-induced oxidative damage in brain, lung, liver, and kidney tissues protected by G. biloba extract, with its antioxidant effects. (c) 2006 Published by Elsevier Ltd.Publication Metadata only Comparison of inhaled and intraperitoneal formaldehyde toxicity in rats and the evaluation of the effects of melatonin(ELSEVIER IRELAND LTD, 2016) BECEREN, AYFER; Aydemir, S.; Akgun, S. G.; Ozkan, N.; Yuksel, M.; Beceren, A.; Erdogan, N.; Omurtag, G. Z.Publication Metadata only Evaluation of incision wound healing activity of Scorzonera veratrifolia in Wistar albino rats(ELSEVIER IRELAND LTD, 2017) BECEREN, AYFER; Gecim, Mert; Beceren, Ayfer; Aydemir, Sezgin; Sardas, SemraPublication Metadata only The wound healing effects of Nerium oleander extract against burn-induced oxidative injury(ELSEVIER IRELAND LTD, 2016) BECEREN, AYFER; Akgun, S. G.; Aydemir, S.; Ozkan, N.; Beceren, A.; Sardas, S.Publication Metadata only Protective role of St. John's Wort on formaldehyde-induced lung tissue injury: Inhibiton of inflammation and oxidative stress mediated apoptosis(ELSEVIER IRELAND LTD, 2017) BECEREN, AYFER; Beceren, Ayfer; Aydemir, Sezgin; Ozakpinar, Ozlem Bingol; Sehirli, Ahmet Ozer; Omurtag, Gulden ZehraPublication Metadata only The role of St. John's Wort against formaldehyde toxicity induced by inhalation in rats(ELSEVIER IRELAND LTD, 2017) BECEREN, AYFER; Aydemir, Sezgin; Beceren, Ayfer; Gecim, Mert; Ozakpinar, Ozlem Bingol; Sehirli, Ahmet Ozer; Omurtag, Gulden ZehraPublication Metadata only Comparision of biocompatibility and cytotoxicity of two new root canal sealers(ELSEVIER GMBH, 2010) BECEREN, AYFER; Gencoglu, Nimet; Sener, Goksel; Omurtag, Gulden Z.; Tozan, Ayfer; Uslu, Bahar; Arbak, Serap; Helvacioglu, DilekThe aim of this study was to investigate the remote organ toxicity and connective tissue reaction of two new root canal sealers (GuttaFlowa(R) and EndoREZ(R)) and to compare them with zinc oxide eugenol sealer using biochemical and histopatho-logical parameters A total of 60 white albino Wistar rats were used in the study 0 1 ml of GuttaFlow(R), EndoREZ(R) or Kerr Pulp Canal Sealer(R) were administered subcutaneously into the mid dorsal thoracic region of rats (15 in each group) Control rats were given saline only Rats were decapitated after 24 h, on day 7 and on day 30 of the experiment and tissue samples from lung, liver, kidney and skin were removed for the determination of malondialdehyde (MDA) and glutathione (GSH) levels In parallel, tissues were also examined histologically Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels, and creatinine and blood urea nitrogen (BUN), concentrations (BUN) were measured to assess liver and kidney functions, respectively Tumor necrosis factor (TNF) and lactate dehydrogenase (LDH) were also assayed in serum samples No statistical differences were found among the control and EndoREZ(R), GuttaFlow(R) and Kerr Pulp Canal sealers regarding tissue MDA, GSH levels or serum parameters (p>0 05) at all time points examined Both of the new root canal sealers showed good compatibility and acceptable tissue toxicity (C) 2009 Elsevier GmbH All rights reservedPublication Metadata only Evaluation of DNA damage in construction-site workers occupationally exposed to welding fumes and solvent-based paints in Turkey(SAGE PUBLICATIONS INC, 2010) BECEREN, AYFER; Sardas, Semra; Omurtag, Gulden Z.; Tozan, Ayfer; Gul, Hulya; Beyoglu, DirenIn this study, the comet assay was used to evaluate whether welding fume and solvent base paint exposure led to DNA damage in construction-site workers in Turkey. The workers (n = 52) were selected according to their exposure in the construction site and controls (n = 26) from the general population, with no history of occupational exposure. The alkaline comet assay, a standard method for assessing genotoxicity, has been applied in peripheral lymphocytes of all subjects. The mean percentages of DNA in tail (%DNA(T)) of each group were evaluated, including the comparisons between smokers in each different group and the duration of exposure. Significant increase in the mean %DNA(T) (p < 0.01) was observed in all exposed subjects (12.34 +/- 2.05) when compared with controls (6.64 +/- 1.43). Also %DNA(T) was significantly high (p < 0.01) in welders (13.59 +/- 1.89) compared with painters (11.10 +/- 1.35). There was a statistical meaningful difference in % DNA(T) between control and exposed smokers. Our findings indicate that exposure to welding fumes and paints induce genotoxic effect in peripheral lymphocytes, indicating a potential health risk for workers. Therefore, to ensure maximum occupational safety, biomonitoring is of great value for assessing the risk for construction workers.Publication Metadata only Protective effect of resveratrol against naphthalene-induced oxidative stress in mice(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2008) BECEREN, AYFER; Sehirli, Oezer; Tozan, Ayfer; Omurtag, Guelden Z.; Cetinel, Sule; Contuk, Gazi; Gedlk, Nursal; Sener, GoekselObjective: This investigation confirms the role of free radicals in naphthalene-induced toxicity and elucidates the mechanism of resveratrol (RVT). Methods: Both male and female BALB-c mice were administered with naphthalene (100mg/kg, i.p.) for 30 days, either along with saline or along with RVT (10 mg/kg, orally). At the end of the experiment, following treatment and sacrifice of animals by decapitation, lung, liver and kidney tissue samples were taken for histological examination or determination of malondialdehyde (MDA), glutathione (GSH), myeloperoxidase (MPO) activity and collagen contents. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine levels and lactate dehydrogenase (LDH) activity were measured in the serum samples, while TNF-alpha, IL-beta, IL-6 and total antioxidant capacity (AOC) were assayed in plasma samples. Results: Naphthalene administration caused a significant decrease in tissue GSH and plasma AOC, which was accompanied with significant increases in tissue MDA and collagen levels and MPO activity. Moreover, the pro-inflammatory mediators (TNF-alpha, IL-beta, IL-6), LDH activity, AST, ALT, creatinine and BUN levels were significantly increased in the naphthalene group. On the other hand, RVT treatment reversed all these biochemical indices as well as histopathological alterations induced by naphthalene. Conclusions: Oxidative mechanisms play an important role in naphthalene-induced tissue damage, and RVT, by inhibiting neutrophil infiltration, balancing oxidant-antioxidant status, and regulating the generation of inflammatory mediators, ameliorates oxidative organ injury due to naphthalene toxicity. (C) 2007 Elsevier Inc. All rights reserved.Publication Metadata only DNA repair capacity of the colorectal cancer patients and the correlation between the pathological parameters(WOLTERS KLUWER MEDKNOW PUBLICATIONS, 2019) BECEREN, AYFER; Tolan, H. K.; Tozan-Beceren, A.; Sardas, S.; Senkesen, O.; Celikel, C.; Gencosmanoglu, R.; Yegen, C.Background: Colorectal cancers are third most common cancer in both genders. They are associated with genetic and environmental factors. Staging is important in the prognosis. Carcinoembryonic Antigen (CEA) provides preliminary information and there is a correlation between Proliferation Index (PI) and prognostic variables. Our aim is to investigate the relationship between DNA repair capacity and clinico-pathologic factors. Patients and Methods: The blood samples taken from cancer patients were irradiated. DNA repair capacity by comet technique was calculated. The CEA values were recorded. Pathology reports were collected and PI values were calculated. sResults: Total of 30 patients; male (n: 14) and female (n: 16) with a median age of 66.37 10.32 were included. Mean CEA value was 42.85 (1.46 - 422.30 mgr/ml) mgr/ml. Mean % DNA repair capacity was 44.49 5.24. In the pathology; 21 (70%) were T3 tumors; 18 (60%) had lymphatic and 12 (40%) had vascular 2 invasion. Perineural invasion was present in 8 (26.7%). According to the proliferation index (PI); 16 (53.3%) were in high percentile (PI 66%) group. Conclusions: There was a significant correlation between; perineural invasion and tumor grade (P = 0.043); lymphatic and perineural invasion (P = 0.006); lymphatic invasion and vascular invasion (P = 0.034) and the DNA repair capacity with the lymphatic invasion (P = 0.026). There was also a statistically significant (P = 0.044) relationship between PI and lymphatic invasion. As a result in colorectal cancer patients DNA repair capacity can be used as a biomarker in the staging and also in the prediction of the tumor behavior.