Person: GARİP, GÜNSELİ AYŞE
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GARİP
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GÜNSELİ AYŞE
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Publication Metadata only Differentiation of K562 Cells Under ELF-EMF Applied at Different Time Courses(TAYLOR & FRANCIS INC, 2010) GARİP, GÜNSELİ AYŞE; Ayse, Inhan-Garip; Zafer, Akan; Sule, Oncul; Isil, Isal-Turgut; Kalkan, TunayaThe time-course of ELF-EMF application to biological systems is thought to be an important parameter determining the physiological outcome. This study investigated the effect of ELF-EMF on the differentiation of K562 cells at different time courses. ELF-EMF (50 Hz, 5 mT, 1 h) was applied at two different time-courses; first at the onset of hemin induction for 1 h, and second, daily 1 h for four days. While single exposure to ELF-EMF resulted in a decrease in differentiation, ELF-EMF applied everyday for 1 h caused an increase in differentiation. The effect of co-stressors, magnesium, and heat-shock was also determined and similar results were obtained. ELF-EMF increased ROS levels in K562 cells not treated with hemin, however did not change ROS levels of hemin treated cells indicating that ROS was not the cause. Overall, these results imply that the time-course of application is an important parameter determining the physiological response of cells to ELF-EMF.Publication Metadata only Effect of extremely low frequency electromagnetic fields on bacterial membrane(TAYLOR & FRANCIS LTD, 2016) GARİP, GÜNSELİ AYŞE; Oncul, Sule; Cuce, Esra M.; Aksu, Burak; Garip, Ayse InhanPurpose: The effect of extremely low frequency electromagnetic fields (ELF-EMF) on bacteria has attracted attention due to its potential for beneficial uses. This research aimed to determine the effect of ELF-EMF on bacterial membrane namely the membrane potential, surface potential, hydrophobicity, respiratory activity and growth.Materials and methods: Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were subjected to ELF-EMF, 50Hz, 1mT for 2h. Membrane potential was determined by fluorescence spectroscopy with or without EDTA (Ethylenediaminetetraacetic acid) with DisC3(5) (3,3-dipropylthiacarbocyanine iodide), zeta potential measurements were performed by electrophoretic mobility, hydrophobicity of the membrane was measured with MATH (Microbial Adhesion to Hydrocarbons) test, respiratory activity was determined with CTC (5-Cyano-2,3-ditolyl tetrazolium chloride), colony forming unit (CFU) and DAPI (4,6-diamidino-2-phenylindole, dihydrochloride) was used for growth determinations.Results: ELF-EMF caused changes in physicochemical properties of both Gram-positive and Gram-negative bacteria. Hyperpolarization was seen in S. aureus and EDTA-treated E. coli. Surface potential showed a positive shift in S. aureus contrariwise to the negative shift seen in EDTA-untreated E. coli. Respiratory activity increased in both bacteria. A slight decrease in growth was observed.Conclusion: These results show that ELF-EMF affects the crucial physicochemical processes in both Gram-positive and Gram-negative bacteria which need further research.Publication Metadata only Effect of extremely low frequency electromagnetic fields on growth rate and morphology of bacteria(TAYLOR & FRANCIS LTD, 2011) ÖZAYDIN, AYŞE NİLÜFER; Inhan-Garip, Ayse; Aksu, Burak; Akan, Zafer; Akakin, Dilek; Ozaydin, A. Nilufer; San, TangulPurpose: To determine the effect of extremely low frequency (<300 Hz) electromagnetic fields (ELF-EMF) on the growth rate of Gram-positive and Gram-negative bacteria and to determine any morphological changes that might have been caused by ELF-EMF. Materials and methods: Six bacterial strains, three Gram-negative and three Gram-positive were subjected to 50 Hz, 0.5 mT ELF-EMF for 6 h. To determine growth rate after ELF-EMF application, bacteria exposed to ELF-EMF for 3 h were collected, transferred to fresh medium and cultured without field application for another 4 h. Growth-rate was determined by optical density (OD) measurements made every hour. Morphological changes were determined with Transmission electron microscopy (TEM) for two gram-negative and two gram-positive strains collected after 3 h of field application. Results: A decrease in growth rate with respect to control samples was observed for all strains during ELF-EMF application. The decrease in growth-rate continued when exposed bacteria were cultured without field application. Significant ultrastructural changes were observed in all bacterial strains, which were seen to resemble the alterations caused by cationic peptides. Conclusion: This study shows that ELF-EMF induces a decrease in growth rate and morphological changes for both Gram-negative and Gram-positive bacteria.Publication Open Access Synergistic Effects of 4-Aminopyridine and Paclitaxel on MCF 7 Cell Line(MARMARA UNIV, INST HEALTH SCIENCES, 2019-09-15) GARİP, GÜNSELİ AYŞE; Aydogmus, Esra M. Cuce; Garip, Gunseli Ayse InhanObjectives: Aim of this study is to increase the effectiveness of paclitaxel (PTX) with the use of 4 - aminopyridine (4-AP) on breast cancer cell line MCF-7. Methods: In this study, L-929 (ATCC CRL-6364) and MCF-7 (ATCC - HTB 22) cell lines were used. IC50 and survival values were determined by trypan blue exclusion; cell cycle analysis was determined by measuring levels of Cdk2 and Histone (H3) and plasma membrane potential (Vm) measurements were performed using fluorescent Bis-(1,3-dibutylbarbituric acid) trimethine oxonol (DiBaC4(3)). Results: IC50 values were determined for two agents and these values were combined. Combination treatments ie. 4-AP (4 mM) + PTX (5 nM) and 4-AP (4 mM) + PTX (7.5 nM) decreased viability 17% +/- 8.08 and 45% +/- 3.18, respectively for L-929 cells and decreased viability 60%+/- 3.7 and 74%+/- 2.6, respectively for MCF-7 cells. For L-929 cells, plasma membrane potential measurements resulted in depolarization for 4-AP, PTX (5 nM) and PTX (7.5 nM), and resulted in hyperpolarization for the combinations. For MCF-7 cells, plasma membrane potential measurements resulted in depolarization for 4-AP, PTX (7.5 nM) and 4-AP + PTX (5 nM), and resulted in hyperpolarization for PTX (5 nM) and 4-AP + PTX (7.5 nM). Changes of Cdk2 and H3 levels showed mostly G1 arrest for MCF-7 cells and G2/M arrest for L-929 cells. Conclusions: Combination treatments increased the cell death for MCF-7 cells. But, combination treatments didn't show synergistic effect on L-929 which is accepted as a non-cancerous cell. These data showed that use of 4-AP in combination with the anticancer agent paclitaxel is a promising approach for cancer treatment.Publication Metadata only Extremely Low-Frequency Electromagnetic Fields Affect the Immune Response of Monocyte-Derived Macrophages to Pathogens(WILEY, 2010) GARİP, GÜNSELİ AYŞE; Akan, Zafer; Aksu, Burak; Tulunay, Aysin; Bilsel, Serpil; Inhan-Garip, AyseThis study aimed to determine the effect of extremely low-frequency electromagnetic fields (ELF-EMF) on the physiological response of phagocytes to an infectious agent. THP-1 cells (human monocytic leukemia cell line) were cultured and 50 Hz, 1 mT EMF was applied for 4-6 h to cells induced with Staphylococcus aureus or interferon gamma/lipopolysaccharide (IF gamma/LPS). Alterations in nitric oxide (NO), inducible nitric oxide synthase (iNOS) levels, heat shock protein 70 levels (hsp70), cGMP levels, caspase-9 activation, and the growth rate of S. aureus were determined. The growth curve of exposed bacteria was lower than the control. Field application increased NO levels. The increase was more prominent for S. aureus-induced cells and appeared earlier than the increase in cells without field application. However, a slight decrease was observed in iNOS levels. Increased cGMP levels in response to field application were closely correlated with increased NO levels. ELF-EMF alone caused increased hsp70 levels in a time-dependent manner. When cells were induced with S. aureus or IF gamma/LPS, field application produced higher levels of hsp70. ELF-EMF suppressed caspase-9 activation by a small extent. These data confirm that ELF-EMF affects bacterial growth and the response of the immune system to bacterial challenges, suggesting that ELF-EMF could be exploited for beneficial uses. Bioelectromagnetics 31:603-612, 2010. (C) 2010 Wiley-Liss, Inc.