Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Tevhide Sel is active.

Publication


Featured researches published by Tevhide Sel.


International Journal of Radiation Biology | 2012

The influence of 1800 MHz GSM-like signals on blood chemistry and oxidative stress in non-pregnant and pregnant rabbits.

Gorkem Kismali; Elcin Ozgur; Göknur Güler; Aytaç Akçay; Tevhide Sel; Nesrin Seyhan

Purpose: Environmental electromagnetic fields originate from man-made sources, such as mobile phones and base stations, and have led to increasing public concern about their possible adverse health effects. We aimed to investigate the possible effects of radiofrequency radiation (RFR) generated from these devices on oversensitive animals, such as pregnant rabbits. Materials and methods: In the present study, the effects of whole body 1800 MHz Global System for Mobile Communications (GSM)-like RFR exposure for 15 min/day for seven days on blood chemistry and lipid peroxidation levels in both non-pregnant and pregnant New Zealand White rabbits were investigated. Thirteen-month-old rabbits were studied in the following four groups: Non-pregnant control, non-pregnant RFR-exposed, pregnant control and pregnant RFR-exposed. Results: Lipid peroxidation, namely malondialdehyde (MDA) levels, did not change after RFR exposure. However, blood chemistry parameters, such as cholesterol (CHO), total protein (TP), albumin (ALB), uric acid, creatinin and creatine kinase (CK) and creatine kinase-myocardial band isoenzyme (CK-MB) changed due to both pregnancy and RFR exposure.Conclusion: Our investigations have been shown that no indication for oxidative stress was detected in the blood of pregnant rabbits upon RF exposure at specific conditions employed in the present study. Minor changes in some blood chemistry parameters were detected but CK-MB and CK increases were found remarkable. Studies on RFR exposure during pregnancy will help establish international standards for the protection of pregnant women from environmental RFR.


Tumor Biology | 2014

Capsaicin inhibits cell proliferation by cytochrome c release in gastric cancer cells.

Ogunc Meral; Merve Alpay; Gorkem Kismali; Funda Kosova; Dilek Ulker Cakir; Mert Pekcan; Serbulent Yigit; Tevhide Sel

Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is the principal pungent component in hot peppers. The role of capsaicin in carcinogenesis is quite controversial. Although some investigators suspect that capsaicin is a carcinogen, co-carcinogen, or tumor promoter, others have reported that it has chemopreventive and chemotherapeutic effects. The present study aimed to evaluate the cytotoxicity and chemosensitizing activities of capsaicin alone and on 5-flourouracil (5-FU)-treated gastric cancer cells. In this study, the gastric cancer cell line HGC-27 was used and capsaicin used as a chemosensitizer and 5-flourouracil (5-FU) was used as chemotherapeutic. Cytotoxicity and chemosensitizing activities were analyzed with MTT assay; supernatant levels of LDH and glucose were detected as biochemical markers of cell viability; cytochrome c and AIF were evaluated with western blot; and additionally, wound-healing assays were employed. Results suggested that capsaicin had significant anticancer abilities; such capsaicin were capable of causing multifold decreases in the half maximal inhibitory concentration IC50 value of 5-FU. The continuing controversy surrounding consumption or topical application of capsaicin clearly suggests that more well-controlled epidemiologic studies are needed to evaluate the safety and efficacy of capsaicin use. In summary, the present study demonstrated that capsaicin has the potential to be used for treating gastric carcinoma with 5-FU in vitro.


Journal of Applied Oral Science | 2012

Fluoride and aluminum release from restorative materials using ion chromatography.

Zeynep Okte; Sule Bayrak; Ulvi Reha Fidanci; Tevhide Sel

Objective The aim of this study was to determine the amounts of fluoride and aluminum released from different restorative materials stored in artificial saliva and double-distilled water. Material and Methods Cylindrical specimens (10 x 1 mm) were prepared from 4 different restorative materials (Kavitan Plus, Vitremer, Dyract Extra, and Surefil). For each material, 20 specimens were prepared, 10 of which were stored in 5 mL artificial saliva and 10 of which were stored in 5 mL of double-distilled water. Concentrations of fluoride and aluminum in the solutions were measured using ion chromatography. Measurements were taken daily for one week and then weekly for two additional weeks. Data were analyzed using two-way ANOVA and Duncans multiple range tests (p<0.05). Results The highest amounts of both fluoride and aluminum were released by the resin-modified glass ionomer cement Vitremer in double-distilled water (p<0.05). All materials released significantly more fluoride in double-distilled water than in artificial saliva (p<0.05). In artificial saliva, none of the materials were observed to release aluminum. Conclusion It was concluded that storage media and method of analysis should be taken into account when the fluoride and aluminum release from dental materials is assessed.


International Journal of Biological Markers | 2016

Evaluation of proinflammatory cytokine and neopterin levels in women with papillary thyroid carcinoma

Kemal Beksac; Cigdem Sonmez; Bahadır Çetin; Gorkem Kismali; Tevhide Sel; Yildirim Tuncer; Funda Kosova

Introduction Papillary thyroid cancer is a disease that has been associated with chronic inflammation. The purpose of this study is to measure the production of the proinflammatory cytokines IL-1β, IL-6 and IL-8 and neopterin, which is a novel biomarker for cellular immune response in papillary thyroid cancer. Materials and methods The serum IL-1β, IL-6, IL-8 and neopterin values of 31 papillary thyroid cancer patients undergoing bilateral total thyroidectomy were measured before and 20 days after surgery. The values were compared with those of 39 healthy controls. Results Serum IL-1β levels were similar across groups. IL-6 (p<0.001), IL-8 (p = 0.015) and neopterin levels (p = 0.002) were higher in presurgical samples and returned to normal following surgery. Conclusions The proinflammatory cytokines IL-6 and IL-8, but not IL-1β, were produced in greater amounts in papillary thyroid cancer. Serum neopterin seems to be a valid biological marker supporting the presence of papillary thyroid cancer.


Journal of Coordination Chemistry | 2015

Syntheses of crystal structures and in vitro cytotoxic activities of new copper(II) complexes of pyridine-2,6-dicarboxylate

Oğuzhan Orhan; Alper Tolga Çolak; Fatih Mehmet Emen; Gorkem Kismali; Ogunc Meral; Tevhide Sel; Gülbanu Koyundereli Çılgı; Murat Taş

[Cu(pydc)(im)]n (1), [Cu(pydc)(mim)3]∙2H2O (2), [Cu(pydc)(ampy)(H2O)]∙H2O (3), and [Cu(pydc)(phen)][Cu(Hpydc)2] (4) (H2pydc = 2,6-pyridinedicarboxylic acid or dipicolinic acid, im = imidazole, mim = 2-methylimidazole, ampy = 2-amino-4-methylpyridine, and phen = 1,10-phenanthroline) were synthesized and characterized by elemental analysis, spectroscopic measurements (UV–vis and IR spectra) and single crystal X-ray diffraction. Complexes 1, 2 and 3 were studied by thermogravimetric analysis from ambient temperature to 1100 K under nitrogen and thermal stabilities were investigated. The effects of complexes on proliferation of fibrosarcoma cells were investigated using the Quick Cell Proliferation Assay. The cell viability changes depend on the concentrations and type of complexes. According to cell proliferation/viability data, 4 was determined to be the most cytotoxic.


Animal | 2013

Nitric oxide concentrations in mammary quarters during heifer mastitis

Ayhan Bastan; Mehmet Cengiz; S. Cengiz; Tevhide Sel; Bülent Polat; Armağan Çolak; Mehmet Akan; I. Darbaz

The aim of this study was to evaluate nitric oxide (NOx) concentration in infected and non-infected mammary quarters of dairy heifers before and after calving. The relationship between bacterial species and NOx concentrations, as well as correlation between NOx concentrations and postpartum somatic cell count (SCC), was assessed. Coagulase-negative staphylococci, Staphylococcus aureus and Escherichia coli were the bacteria commonly isolated during the pre- and postpartum period. Infected quarters had greater NOx concentrations than non-infected quarters before (30.81 v. 22.83 μM/ml, P < 0.05) and after (9.56 v. 5.77 μM/ml, P < 0.0001) calving. It was determined that the interaction between sampling period and infectious status had no effect on NOx concentration (P < 0.16). Infected quarters had greater SCC (log(10)) than healthy quarters (4.95 v. 4.39; P < 0.0001). NOx concentrations, however, did not correlate with SCC (r = 0.02). In summary, changes in NOx concentration were mainly dependent on the infectious status of the quarters with variations among the bacterial species (P < 0.05).


Veterinary and Comparative Oncology | 2012

Serum neopterin, sialic acid and nitric oxide levels in dogs with malignant mammary tumours.

N. Tascene; Gorkem Kismali; Sevil Atalay Vural; H. Karagul; Tevhide Sel

Mammary cancer is one of the leading causes of death in pet population. Early diagnosis and malignancy detection is important for prognosis. The levels of neopterin, sialic acid and nitric oxide in serum of dogs with malignant mammary tumours were evaluated to investigate the importance of these biochemical parameters for malign mammary tumour. Twelve healthy dogs and twenty dogs with malignant mammary tumours were used as research materials. Blood samples were collected from both groups for neopterin analysis by enzyme-linked immunosorbent assay, whereas nitric oxide and sialic acid were measured by modified nitrate reductase method and spectrophotometry, respectively. Tissue specimens were evaluated and defined as malignant tumours. Serum nitric oxide and sialic acid levels in dogs with mammary tumours were significantly higher than those in the healthy dogs. Serum neopterin levels were not found significantly different in dogs with mammary tumours compared to healthy dogs. Malignancy of canine mammary tumours are accompained by an elevation of nitric oxide and sialic acid levels.


Journal of Cancer Research and Therapeutics | 2016

Antileukemic effects of piperlongumine and alpha lipoic acid combination on Jurkat, MEC1 and NB4 cells in vitro

Merve Alpay; Begum Yurdakok-Dikmen; Gorkem Kismali; Tevhide Sel

AIM OF STUDY This research indicated to evaluate the effects of piperlongumine (PL), a biologically active alkaloid, and alpha lipoic acid (ALA), a naturally occurring cofactor existed in multienzyme complexes regulating metabolism on leukemia cells. Excessive production of reactive oxygen species (ROS) can lead to oxidative stress, a state that has been observed in several hematopoietic malignancies, including acute and chronic myeloid leukemias. The importance of the association between oxidative stress and malignancy is not currently clear; however, there is evidence that tumor.derived ROS may promote cell survival, migration and metastasis, proliferation and even drug.resistance depending on the origin of the cancer. Increased oxidative stress in leukemic cells may represent a potential therapeutic target, although there are differing opinions on whether therapeutic strategies should aim to antagonize or further promote oxidative stress in leukemic cells. MATERIALS AND METHODS The effects of PL alone (5, 15, 30 μM) and in combination (30 μ M) with ALA (200 μ M) on Jurkat, NB4 and MEC1 leukemia cell lines were investigated through MTT, caspase-3 and cyclooxygenase-2 (COX-2) activities. RESULTS Inhibition of COX-2 and the induction of caspase.3 cleavage in Nb4 (acute promyelocytic leukemia) cells were found to be significant following PL application and synergistic effects with combination of ALA (inhibition of COX-2 as 23.74% and 3.55-fold increase of caspase-3). CONCLUSION PL and ALA may have a potential value as a therapeutic agent for patients with acute promyelocytic leukemia.


Cancer Research | 2016

Abstract 2177: Rutin enhances the antiproliferative effect of 5-FU and oxaliplatin in colon cancer cells

Farnoud Nasiri; Gorkem Kismali; Merve Alpay; Funda Kosova; Dilek Ulker Cakir; Tevhide Sel

Background: Rutin is a strong antioxidant molecule and it has advantageous over other flavonoids due to it is a nontoxic and nonoxidizable molecule. The concept of dual therapy of anti-cancer drugs with natural compounds has become a very promising approach in new strategy to treatment. The aim of this study was to evaluate the antiproliferative and apoptotic effects of rutin flavonoids and its efficacy in enhancing the anticancer effects of 5-FU (5-fluorouracil) and oxaliplatin against colon cancer cells. Material and Methods: Caco-2 human colon cancer cells were treated with rutin and/or anticancer drugs (5-FU and oxaliplatin), cell viability and apoptotic parameters were examined. Cell viability was determined by MTT assay. Apoptotic markers (cleaved caspase 3, cleaved PARP and phosphor-Bad) were determined using specific enzyme-linked immunosorbent assay kits. Caspase-8 and caspase-9 were analyzed by colorimetric activity assay kit. DNA fragmentation was analyzed by agarose gel electrophoresis. Results: The exposure Caco-2 human colon cancer cells to rutin, 5-FU and oxaliplatin resulted growth inhibition in a dose- and time-dependent manner. Cell viability assay shows that rutin inhibiting growth of Caco-2 cells at high concentrations (over 1000 μM). Combination with rutin markedly enhanced 5-FU and oxaliplatin growth inhibiting effects on Caco-2 cells. Results suggested that rutin had significant anticancer abilities; such rutin were capable of causing multifold decreases in the half maximal inhibitory concentration IC50 value of 5-FU and oxaliplatin. This flavonoid increased the levels of proteins associated with apoptotic cell death (phospho-Bad, cleaved caspase 3 and cleaved PARP) alone and combination. The activities of caspase 8 and caspase 9 were stimulated by the combination treatment of rutin and oxaliplatin then alone. DNA fragmentation was observed only on combination treatment. Conclusions: Combined treatment with rutin and anticancer drugs (5-FU and/or oxaliplatin) is more effective than the individual treatments of drugs at inhibiting growth of Caco-2 cells. The use of lower 5-FU and oxaliplatin doses, with similar effects, could be also useful to reduce possible adverse effects of these drugs. However, further studies at molecular level are required to elucidate chemopreventive and chemotherapeutic effects of rutin on colon cancer. Citation Format: Farnoud Nasiri, Gorkem Kismali, Merve Alpay, Funda Kosova, Dilek Ulker Cakir, Tevhide Sel. Rutin enhances the antiproliferative effect of 5-FU and oxaliplatin in colon cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2177.


Bratislavské lekárske listy | 2017

GSM-like radiofrequency exposure induces apoptosis via caspase-dependent pathway in infant rabbits.

Ogunc Meral; E. Ozgur; Gorkem Kismali; G. Guler; Merve Alpay; Tevhide Sel; Nesrin Seyhan

BACKGROUND There have been several Radio Frequency (RF) field researches on various populations and groups of different ages in recent years. However, the most important group for research has been declared as the pregnant women and their babies. OBJECTIVE The aim of the study was to analyse the effect on apoptotic factors of RF fields on newborn rabbit liver tissues. MATERIALS AND METHODS Cytochrome c and AIF (Apoptosis Inducing Factor) levels were measured by western blot and caspase 1, 3 and 9 activities were measured by colorimetric method. RESULTS Cytochrome c and AIF levels were not altered, but all caspase activities were increased in female infant rabbits that exposed to 1800 MHz GSM-like RF signals when they reached 1 month of age and caspase 1 and caspase 3 levels were decreased in male infant rabbits that exposed to 1800 MHz GSM-like RF signals between 15th and 22nd days of the gestational period. Results showed that 1800 MHz GSM-like RF exposure might lead to apoptosis in infant rabbits liver tissues. CONCLUSION According to the results, we suggest that postnatal RF exposure causes caspase dependent apoptosis in female infant rabbits liver tissues (Tab. 1, Fig. 2, Ref. 27).

Collaboration


Dive into the Tevhide Sel's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Dilek Ulker Cakir

Çanakkale Onsekiz Mart University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge