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    Characterisation of drug resistance of nosocomial ESBL-producing E. Coli isolates obtained from a Turkish university hospital between 2009 and 2012 by pulsed field gel electrophoresis and antibiotic resistance tests
    (EDIMES Edizioni Medico Scientifiche, 2016) Karagöz A.; Sunnetcioglu M.; Ceylan M.R.; Bayram Y.; Yalcin G.; Kocak N.; Suvak B.
    In this study, drug resistance of 28 ESBL-producing Escherichia coli isolates obtained from 144 patients hospitalized at the Yüzüncüyil University Hospital at Van (YUH), Turkey, between 2009 and 2012 were characterized by pulsed field gel electrophoresis and antibiotic susceptibility tests. Antibiotic resistance profile was determined by a Phoenix automated system (BD, USA). The ratio of ESBL-producing E. coli strains was determined to be 19.4% (28 out of 144 E. coli isolates). It was determined that the anaesthesiology, paediatrics and thoracic medicine intensive care units in YUH were cross-contaminated between 2009 and 2012 by ESBL-producing E. coli strains, which is a sign of nosocomial infection in YUH. Analysis of PFGE results gave rise to two main PFGE profiles, profile-A with four subprofiles and profile-B with three subprofiles, where profile-A predominates over profile-B (14%). Comparison of the antibiotic resistance profile with the PFGE profile yielded similarities while some differences also exist due to either identical restriction enzyme cutting sites with slightly different genetic sequences in between the cutting sites or newly formed restriction enzyme cutting sites that do not affect antibiotic resistance genes. Enterobacteriaceae, particularly E. coli, have developed resistance in YUH by producing ESBLs against oxyimino and non-oxyimino cephalosporins, and penicillin-type antibiotics. Therefore, more effective antibiotics such as cefoxitin or cefoperazone- sulbactam should be used for the treatment of future nosocomial infections in YUH while hospital staff should take care with hygiene, such as hand washing. © 2016, EDIMES Edizioni Medico Scientifiche. All rights reserved.
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    Fentanyl inhibits tumorigenesis from human breast stem cells by inducing apoptosis
    (Asian Pacific Organization for Cancer Prevention, 2017) Kocak N.; Ozen F.; Yildirim I.H.; Duran Y.
    Fentanyl is an opioid analgesic that it is widely used in cancer patients. Since there have been reports of effects of analgesic medications on the recurrence and development of resistance to treatment, influences of of fentanyl on MCF-7 and HEK293 cells were evaluated. Cell viability and apoptosis were assessed by MTT assay and flow cytometry, respectively. Gene expression analysis was performed by quantitative real-time PCR assay for the Oct4, Sox2 and Nanog genes as stem cell markers and Bax, Bcl2, and p53 genes as apoptosis markers. MTT assay results showed that fentanyl significantly inhibited the growth of MCF-7 cells in a dose-and time-dependent manner while significantly increasing apoptosis. In contrast, decrease was noted in HEK-293 cells. In MCF-7 derived cancer stem cells, fentanyl treatment decreased the expression of Bax, Bcl2, Oct4, Sox2, Nanog genes when compared to untreated cells. In HEK-293 stem cells, decrease was noted for Sox2, Nanog and Bax, but increase for Oct4. Our study supports an antitumor role of fentanyl by inducing apoptosis and reducing numbers of cancer stem cells in the MCF-7 human breast adenocarcinoma line.
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    The synthesis of catalytic-upconversion nanoparticles and their teragnostic applications
    (2014) Dulda A.; Yavuz C.T.; Yavuz M.S.; Kocak N.
    After realizing the wide applicability of upconversion nanoparticles from biomedical fields to environmental remediations through photocatalysis and solar energy harvesting there has been increasing interest to development of synthesis routes and design in band gap engineering for high efficient upconversion nanoparticles. In this study, the synthesis of upconversion nanoparticles having photocatalytic property is introduced and its applicability in cancer treatment is discussed due to generation of oxidative stress on MCF-7 cancer cell lines. In order to observe upconversion luminescence and extended luminescence life time wide-band-gap Ga2O3 was selected as a host material due to its optical property and high photocatalytic activity and Nd3+ and Yb3+ ions and their different concentrations were doped into host crystal structure with systematic studies. Particle size analyses, morphological features, crystalline structure and optical quality of synthesized nanocrystals ?20 nm were conducted at Transmission Electron Microscopy, X-Ray Diffraction spectroscopy and Photoluminescence spectroscopy. Copyright © 2013 MS&T'13®.