Browsing by Author "Ateş, C."

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Overexpression of Insulin Receptor Substrate 1 (Irs1) Promotes Radioresistance in A172 Glioblastoma Cell Line
(Yuzuncu Yil Universitesi Tip Fakultesi, 2019) Görgişen, G.; Çakır, T.; Ateş, C.; Gülaçar, İ.M.; Yaren, Z.
Insulin receptor substrate 1 (IRS1) is the main adaptor molecule in insulin and insulin like growth factor signaling. Increased level of expression of IRS1 and IGF-1R proteins are associated with many human malignancies. They also induced resistance to therapeutic approaches such as chemo-and radiotherapy in cancer treatment however their molecular mechanisms are still unclear. Glioblastoma Multiforme (GBM) is the most common primary brain tumor in adults and radiotherapy has a pivotal role in its treatment. In this study, it is aimed to determine the relationship between IRS1 expression and radiosensitivity of GBM cells. Therefore, A172 cells transfected with pcDNA3.1-HA-tagged human IRS1 gene. Its overexpression was confirmed by western blot. IRS1 overexpressed A172 cells were irradiated with 5,8 and 10 Gray ionizing radiation and their effects on cell viability determined by MTT and clonogenic assay. Our results showed that overexpression of IRS1 led a decrease on sensitivity of the radiation in GBM cel ls. As a conclusion, this study should be confirmed by further molecular analysis and in vivo studies. IRS1 may be a predictive marker of radiosensitivity for GBM. © 2019, Yuzuncu Yil Universitesi Tip Fakultesi. All rights reserved.
Forecasting for the Number of Individual Per Dentist in Turkey; Comparison of Box-Jenkins and Brown Exponential Smoothing Estimation Methods
(Yuzuncu Yil Universitesi Tip Fakultesi, 2020) Ateş, C.
Oral and dental diseases and the fight against these diseases are a difficult and costly issue for our country and most of the world countries. Protective and informative dentistry practices may be realized with the prospective realistic planning of Dentist personnel trained at adequate number and Oral Dental Health services. Attaching importance to the protective services for development of health services are the leading among the issues, which the policy-makers are required to emphasize with caution. The aim of this study is to model the series of number of individual per dentist personnel in Turkey between the years of 1951-2016 with Box-Jenkins and Brown Exponential Smoothing methods, and to provide these forecast models derived to guide the policy-makers. Number of individual per dentist personnel is calculated prospectively in this study and values expected until 2023 are found with Box Jenkins and Brown Exponential Smoothing methods frequently used in making prospective forecasts. Calculations of these two models are compared in terms of decision-making criteria and it is concluded that Brown Exponential Smoothing model produces more coherent results than Box Jenkins model on behalf of making prospective forecasts. © 2020, Yuzuncu Yil Universitesi Tip Fakultesi. All rights reserved.
The Performances of Two Diagnostics Tests: Mcnemar and Newcombe Graphical Approach
(ISOSS PUBLICATIONS, 2017) Tekindal, M.A.; Ateş, C.; Kaymaz, Ö.G.; Yavuz, Y.
This study aims to address a simultaneous comparison of sensitivity and specificity of two different tests by taking into consideration of prevalence and clinical significance level of the tests under the condition that the result of the gold standard test is known. The proposed method involves the point and interval estimation of the weighted mean (for f) concerning the specificity and sensitivity differences of two tests. Getting a value between 0 and 1, the parameter λ represents the clinical cost of false positive and false negative and the occasion posing serious problems for the prevalence value belonging to the population to which tests are administered. Data is acquired from a study carried out at the Department of Cytopathology of Ankara University Medical School. In that study, the impact of the use of various antibodies in determining thyroid nodules as benign or malign via Preoperative Fine-Needle Aspiration Biopsy in order to achieve diagnostic accuracy was investigated. Considering the prevalence of Newcombe graphic approach that compares both the sensitivity and specificity, it can be concluded that Newcombe graphical approach gives better results than the classical McNemar test for the same sample group used in the study Simultaneously comparing the sensitivity and specificity of tests by taking into consideration the clinical costs of false positive/false negative values and prevalence, the Newcombe graphic approach method is also quite advantageous in terms of clinical interpretation. © 2017 Pakistan Journal of Statistics.