Karsy M.,New York Medical College |
Arslan E.,Istanbul Medeniyet University |
Moy F.,New York Medical College
Genes and Cancer | Year: 2012
Glioblastoma multiforme (GBM) is an aggressive grade IV astrocytoma with a 1-year median survival rate despite current treatment modalities. A thorough understanding of the vast genetic aberrations and signaling pathways involved in gliomagenesis as well as heterogeneous clinicopathological presentation remains elusive. The recent discovery of microRNAs (miRs) and their capability of simultaneously regulating multiple downstream genes may play a key role in explaining the complex mechanisms underlying GBM formation. miRs are 19 to 25 nucleotide non-protein-coding small RNA molecules involved in the suppression of mRNA translation. This review will summarize and discuss the most recent findings regarding miRs in GBM including downstream targets, functional effects, and therapeutic potentials. Specifically discussed miRs include miR-7, miR-9/miR-9*, miR-10a/miR-10a*/miR-10b, miR-15b, miR-17-92, miR-21, miR-26a, miR-34a, miR-93, miR-101, miR-124, miR-125a, miR-125b, miR-128, miR-137, miR-146b-5p, miR-153, miR-181a/miR-181b, miR-196a/miR-196b, miR-218, miR-221/miR-222, miR-296, miR-302-367, miR-326, miR-381, miR-451, and let-7a. In addition to gene regulatory roles, miRs have demonstrated significant diagnostic, prognostic, and therapeutic potential. These small molecules may both help in the understanding of GBM and in developing new therapeutic options. © The Author(s) 2012.
Sahinkaya E.,Istanbul Medeniyet University |
Dursun N.,Harran University
Chemosphere | Year: 2012
This study evaluated the elimination of alkalinity need and excess sulfate generation of sulfur-based autotrophic denitrification process by stimulating simultaneous autotrophic and heterotrophic (mixotrophic) denitrification process in a column bioreactor by methanol supplementation. Also, denitrification performances of sulfur-based autotrophic and mixotrophic processes were compared. In autotrophic process, acidity produced by denitrifying sulfur-oxidizing bacteria was neutralized by the external NaHCO3 supplementation. After stimulating mixotrophic denitrification process, the alkalinity need of the autotrophic process was satisfied by the alkalinity produced by heterotrophic denitrifiers. Decreasing and lastly eliminating the external alkalinity supplementation did not adversely affect the process performance. Complete denitrification of 75mgL-1 NO3-N under mixotrophic conditions at 4h hydraulic retention time was achieved without external alkalinity supplementation and with effluent sulfate concentration lower than the drinking water guideline value of 250mgL-1. The denitrification rate of mixotrophic process (0.45g NO3-NL-1d-1) was higher than that of autotrophic one (0.3g NO3-NL-1d-1). Batch studies showed that the sulfur-based autotrophic nitrate reduction rate increased with increasing initial nitrate concentration and transient accumulation of nitrite was observed. © 2012 Elsevier Ltd.
Selek S.,Istanbul Medeniyet University |
Saleh A.,Vanderbilt University
Scientometrics | Year: 2014
Several publication metrics are used for the evaluation of academic productivity. h index and g index are relatively new statistics for this purpose. Our aim is to evaluate academic psychiatrists' h and g indices at different academic ranks in the United States. 30 psychiatry programs from the American Medical Association's FREIDA online database were included to the study. From each academic rank, the total number of papers (P total), the single authored papers (P single) and the h and g indexes of faculty members were calculated by using one way ANOVA for multiple comparisons as primary analysis test. The metric medians as follows; P total = 34.5, P single = 13, g index = 19.5 and h index = 9. h index significantly differed between academic ranks except chairperson-professor. The other indices failed to distinguish junior academic ranks (associated professor-assistant professor) in addition to chairperson-professor. The strongest correlation was between h index and g indexes. Of the indices evaluated, the h-index is best tracked with academic ranking in psychiatry programs studied. © 2013 Akadémiai Kiadó, Budapest, Hungary.
Sahinkaya E.,Istanbul Medeniyet University |
Kilic A.,Harran University |
Kilic A.,Yeditepe Treatment Company
Water Research | Year: 2014
Nitrate and chromate can be present together in water resources as nitrate is a common co-contaminant in surface and ground waters. This study aims at comparatively evaluating simultaneous chromate and nitrate reduction in heterotrophic and sulfur-based autotrophic denitrifying column bioreactors. In sulfur-based autotrophic denitrification process, elemental sulfur and nitrate act as an electron donor and an acceptor, respectively, without requirement of organic supplementation. Autotrophic denitrification was complete and not adversely affected by chromate up to 0.5mg/L. Effluent chromate concentration was <50μg/L provided that influent chromate concentration was ≤0.5mg/L. Heterotrophic denitrification performance was not adversely affected even at 20mg/L chromate and complete chromate reduction was attained up to 10mg/L. Although autotrophic denitrification rate was much lower compared with heterotrophic one, it may be preferred in drinking water treatment due to the elimination of organic supplementation and the risk of treated effluent contamination. © 2013 Elsevier Ltd.
Totan Y.,Fatih University |
Karadag R.,Istanbul Medeniyet University
Journal of Refractive Surgery | Year: 2013
PURPOSE: To compare two different techniques for sutureless scleral fixation of posterior chamber intraocular lens (IOL) in patients with insufficient capsule support. METHODS: Of 29 patients, 17 received the needle technique using a 24-gauge needle for the scleral tunnel opening and 12 received the novel trocar technique, in which the scleral tunnel was prepared with a 25-gauge transconjunctival sutureless vitrectomy trocar and a three-piece foldable IOL was placed through clear corneal incision. Visual acuity, intraocular pressure, related complications, and IOL stability were assessed postoperatively. RESULTS: Postoperative visual acuities significantly improved with both techniques (P = .028 and .012, respectively). Postoperative intraocular pressure did not significantly change with either technique. Sufficient IOL stabilities were provided in all patients. Complications were similar in both techniques and none of the complications affected the patients' vision. CONCLUSIONS: Postoperative visual acuity improvement, intraocular pressure changes, and complications were similar in both techniques. Copyright © SLACK Incorporated.
Ozkok A.,Istanbul Medeniyet University |
Yildiz A.,Istanbul University
World Journal of Gastroenterology | Year: 2014
Hepatitis C virus (HCV) infection is a systemic disorder which is often associated with a number of extrahepatic manifestations including glomerulopathies. Patients with HCV infection were found to have a higher risk of end-stage renal disease. HCV positivity has also been linked to lower graft and patient survivals after kidney transplantation. Various histological types of renal diseases are reported in association with HCV infection including membranoproliferative glomerulonephritis (MPGN), membranous nephropathy, focal segmental glomerulosclerosis, fibrillary glomerulonephritis, immunotactoid glomerulopathy, IgA nephropathy, renal thrombotic microangiopathy, vasculitic renal involvement and interstitial nephritis. The most common type of HCV associated glomerulopathy is type I MPGN associated with type II mixed cryoglobulinemia. Clinically, typical renal manifestations in HCV-infected patients include proteinuria, microscopic hematuria, hypertension, acute nephritis and nephrotic syndrome. Three approaches may be suggested for the treatment of HCV-associated glomerulopathies and cryoglobulinemic renal disease: (1) antiviral therapy to prevent the further direct damage of HCV on kidneys and synthesis of immune-complexes; (2) B-cell depletion therapy to prevent formation of immune-complexes and cryoglob-ulins; and (3) nonspecifc immunosuppressive therapy targeting inflammatory cells to prevent the synthesis of immune-complexes and to treat cryoglobulin associated vasculitis. In patients with moderate proteinuria and stable renal functions, anti-HCV therapy is advised to be started as pegylated interferon-α plus ribavirin. However in patients with nephrotic-range proteinuria and/or progressive kidney injury and other serious extra-renal manifestations, immunosuppressive therapy with cyclophosphamide, rituximab, steroid pulses and plasmapheresis should be administrated. © 2014 Baishideng Publishing Group Inc. All rights reserved.
Karadag R.,Istanbul Medeniyet University
Cornea | Year: 2016
PURPOSE:: To evaluate the results of trocar-assisted, sutureless, scleral-fixated (SSF) intraocular lens (IOL) implantation combined with penetrating keratoplasty (PKP). METHODS:: This study comprised 4 eyes (4 patients) undergoing trocar-assisted SSF-IOL implantation during PKP. The combined technique was performed in 3 eyes of 3 patients with bullous keratopathy and in 1 eye with central corneal opacity. Two eyes had anterior chamber IOL implants, and 2 were aphakic. All eyes had inadequate capsular support. Evaluated parameters were biomicroscopy, corrected distance visual acuity, intraocular pressure, IOL position, and corneal graft status. Intraoperative and postoperative complications and additional surgeries were recorded. RESULTS:: The mean follow-up period was 28.3 ± 3.5 months. Trocar-assisted SSF-IOL implantation with PKP was successfully performed in all eyes. Visual acuity improved in all patients. During the follow-up period, a well-stabilized IOL without any IOL-related complication was obtained in all eyes. In one eye with corneal scarring and aphakic glaucoma caused by trauma, drug-resistant glaucoma developed 6 months after surgery requiring Express glaucoma shunt surgery. In one eye with a history of central retinal vein occlusion, repeat keratoplasty was performed after 10 months because of graft rejection. CONCLUSIONS:: Trocar-assisted SSF-IOL implantation combined with PKP is an alternative method for visual rehabilitation in the eyes with bullous keratopathy and corneal scarring without sufficient capsular support. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
Gozgor G.,Istanbul Medeniyet University
Renewable and Sustainable Energy Reviews | Year: 2016
This paper investigates whether there is a unit root in renewable energy consumption in three large developing economies: Brazil, China, and India over the period 1971–2014. To do so, it uses four unit root tests assuming one structural break, two structural breaks, and more than two structural breaks. It observes that renewable energy consumption is a unit root process in Brazil, but it is found as stationary in China and India. The paper also tackles issues and challenges in the unit root test methodology in energy economics literature and provides implications for renewable energy consumption in three economies. © 2016 Elsevier Ltd
Dinler A.,Istanbul Medeniyet University
Energy | Year: 2013
In the absence of long-term data, measure-correlate-predict methods are of great importance in the assessment of regional wind energy potential. In this study, a new MCP method is introduced for wind energy applications and tested using hourly wind data from four different regions. The method, named as multiple principal least squares (MPLS) method, has an advantage of applicability in the presence of low correlation between the target and reference site wind data. Therefore, this new method might particularly be advantageous when concurrent measurements are not available or when they contain major defects. The results show conclusively that the MPLS method is a strong competitor to the variance ratio method in the existence of concurrency. And without concurrency, the results indicate that it has potential of providing accurate predictions associated with more than 40% improvement using one year or six months long data. © 2013 Elsevier Ltd.
Cam S.,Istanbul Medeniyet University
Asian Pacific Journal of Cancer Prevention | Year: 2014
Background: Helicobacter pylori (H. pylori) is the most common chronic infectious agent in the stomach. Most importantly, it may lead to atrophy, metaplasia and cancer. The aim of this study was to investigate the incidence of H. pylori infection and to detect early mucosal changes that may lead to malignant degeneration in children. Materials and Methods: Children who underwent upper gastrointestinal endoscopy were included. Familial history of gastric cancer was noted. Endoscopic examinations were performed by a single pediatric gastroenterologist. A minimum of three biopsy samples were collected during endoscopy. The patients were accepted as H. pylori infected if results of biopsies and rapid urease test were both positive. Biopsies were evaluated for the presence and degree of chronic inflammation, the activity and severity of gastritis, glandular atrophy and intestinal metaplasia. Results: A total of 750 children (388 boys, 362 girls) were evaluated in our study, with a mean age of 10.1 years. A total of 390 patients (52%) were found to be infected with H. pylori. Among the H. pylori infected patients, 289 (74%) were diagnosed to have chronic superficial gastritis, 24 (6.2%) had gastric atrophy. Most strikingly, intestinal metaplasia was observed in 11 children, all were in the H. pylori positive group. There was no difference in the mean of age, gender and socioeconomic class between H. pylori infected and non-infected groups. The frequency of gastric cancer in family members (4 in number) was higher in patients with H. pylori infection. No gastric cancer case was reported from the parents of non-infected children. The worst biopsy parameters (atropy and metaplasia) were improved after H. pylori eradication on control endoscopy. Conclusions: The current study shows a higher prevalence of familial history of gastric cancer in H. pylori infected children. Intestinal metaplasia was also higher in the infected children. Eradication of H. pylori infection for this risk group may prevent subsequent development of gastric cancer.