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Öğe The beneficial effects of 18?-glycyrrhetinic acid following oxidative and neuronal damage in brain tissue caused by global cerebral ischemia/reperfusion in a C57BL/J6 mouse model(Springer-Verlag Italia Srl, 2014) Oztanir, M. Namik; Ciftci, Osman; Cetin, Asli; Durak, M. Akif; Basak, Nese; Akyuva, YenerThis study investigated the effects of 18 beta-glycyrrhetinic acid (GA) on neuronal damage in brain tissue caused by global cerebral ischemia/reperfusion (I/R) in C57BL/J6 mice. All subjects (n = 40) were equally divided into four groups: (1) sham-operated (SH), (2) I/R, (3) GA, and (4) GA+I/R. The SH group was used as a control. In the I/R group, the bilateral carotid arteries were clipped for 15 min, and the mice were treated with the vehicle for 10 days. In the GA group, mice were given GA (100 mg/kg) for 10 days following a median incision without carotid occlusion. In the GA+I/R group, the I/R model was applied to the mice exactly as in the I/R group, and they were then treated with the same dose of GA for 10 days. Cerebral I/R significantly induced oxidative stress via an increase in lipid peroxidaitons and a decrease in elements of the antioxidant defense systems. However, GA treatment was protective against the oxidative effects of I/R by inducing significant increases in antioxidant defense systems and a significant decrease of lipid peroxidations. Additionally, cerebral I/R increased the incidence of histopathological damage and apoptosis in brain tissue, but these neurodegenerative effects were eliminated by GA treatment. Therefore, the current study demonstrated that GA treatment effectively prevents oxidative and histological damage in the brain caused by global I/R. In this context, GA may be useful for the attenuation of the negative effects of global cerebral I/R and, in the future, it may be a viable and safe alternative treatment for ischemic stroke in humans.Öğe Exemplar deep and hand-modeled features based automated and accurate cerebral hemorrhage classification method(Elsevier Sci Ltd, 2022) Din, M. Sait; Gurbuz, Sukru; Akbal, Erhan; Dogan, Sengul; Durak, M. Akif; Yildirim, I. Okan; Tuncer, TurkerBackground: : Cerebral hemorrhage (CH) is a commonly seen disease, and an accurate diagnosis of the type of CH is a very crucial step in treatment. Therefore, CH requires a prompt and accurate diagnosis. To simplify this process, an accurate CH classification model is presented using a machine learning technique. Material and method: : A computed tomography (CT) image dataset was collected retrospectively in this research. This dataset contains 9818 images with five categories. An exemplar fused feature generator is presented to classify these features. This generator uses pre-trained AlexNet, local binary pattern (LBP), and local phase quantization (LPQ). The neighborhood component analysis (NCA) method selects the top features, and the chosen feature vector is classified on the support vector machine. Results: : Six validation methods are utilized to calculate the performance of the presented exemplar fused features and NCA-based CH classification model. This model attained 97.47%, 96.05%, 95.21%, 93.62%, 91.28% and 96.34% accuracies using five hold-out validations and ten-fold cross-validation respectively. Conclusions: : The calculated results clearly demonstrate the success and robustness of the introduced exemplar fused feature generation and NCA-based model. Furthermore, this model can be used in emergency services to overcome a prompt diagnosis of CH.Öğe Non-traumatic non-aneurysmal subarachnoid haemorrhage: Single institutional experience(202) Pasahan, Ramazan; Tetik, Bora; Guldogan, Emek; Durak, M. Akif; Yildirim, İsmail OkanAim: Despite the advanced diagnostic methods we use today, the rate of negative digital subtraction angiography (DSA) is 15% in patients diagnosed with subarachnoidal hemorrhage (SAH), and these types of hemorrhages are named as non-aneurysmal (NASAH). Various factors such as inadequate interpretation of the beginning angiography, vasospasm, thrombosis, intra-cerebral hematoma pressure may cause DSA to be negative. This study aims to determine the causes of bleeding in patients who were suffered from NASAH. Materials and Methods: The study evaluated 664 patients with SAH from 2010 to 2016. DSA was performed on these patients within the first 3 or 6 hours. Sixty-seven patients with DSA negative were included in the study group. The patients were divided into three groups as perimesencephalic subarachnoidal hemorrhage (PMSAH), non-perimesencephalic subarachnoidal hemorrhage (nPMSAH), CT negative subarachnoidal hemorrhage (CT negative SAH). These three groups were evaluated based on age, gender, Glascow coma scale (GCS), World Federation of Neurosurgical Societies (WFNS) grade, Hunt and Hess Classification and Fisher’s scale, hospitalization time duration, complications and computerized tomography (CT), and cervical and cranial MRI was performed on patients without correlation between DSA results if needed. Results: Of the 664 patients diagnosed with SAH, 67 (10.09%) had NASAH. Statistically significant differences were found between CT Negative SAH and PMSAH and CT Negative SAH and nPMSAH in terms of the variables of GCS during hospital admission and total duration of hospitalization. Statistically significant differences were found between CT Negative SAH and PMSAH and nPMSAH in terms of the variables of GCS during hospital discharge. There were statistically significant differences between the types in terms of WFNS Classification, Hunt and Hess Classification and Fisher’s Scala. Conclusion: We believe that this study will contribute to the literature about the necessity of performing additional radiologic imaging during clinical follow-up since belated diagnosis in patients with NASAH may increase mortality.Öğe Non-traumatic non-aneurysmal subarachnoidhaemorrhage: Single institutional experience(2021) Paşahan, Ramazan; Tetik, Bora; Güldoğan, Emek; Durak, M. Akif; Yıldırım, İ. OkanAbstractAim: Despite the advanced diagnostic methods we use today, the rate of negative digital subtraction angiography (DSA) is 15% in patients diagnosed with subarachnoidal hemorrhage (SAH), and these types of hemorrhages are named as non-aneurysmal (NASAH). Various factors such as inadequate interpretation of the beginning angiography, vasospasm, thrombosis, intra-cerebral hematoma pressure may cause DSA to be negative. This study aims to determine the causes of bleeding in patients who were suffered from NASAH.Materials and Methods: The study evaluated 664 patients with SAH from 2010 to 2016. DSA was performed on these patients within the first 3 or 6 hours. Sixty-seven patients with DSA negative were included in the study group. The patients were divided into three groups as perimesencephalic subarachnoidal hemorrhage (PMSAH), non-perimesencephalic subarachnoidal hemorrhage (nPMSAH), CT negative subarachnoidal hemorrhage (CT negative SAH). These three groups were evaluated based on age, gender, Glascow coma scale (GCS), World Federation of Neurosurgical Societies (WFNS) grade, Hunt and Hess Classification and Fisher’s scale, hospitalization time duration, complications and computerized tomography (CT), and cervical and cranial MRI was performed on patients without correlation between DSA results if needed.Results: Of the 664 patients diagnosed with SAH, 67 (10.09%) had NASAH. Statistically significant differences were found between CT Negative SAH and PMSAH and CT Negative SAH and nPMSAH in terms of the variables of GCS during hospital admission and total duration of hospitalization. Statistically significant differences were found between CT Negative SAH and PMSAH and nPMSAH in terms of the variables of GCS during hospital discharge. There were statistically significant differences between the types in terms of WFNS Classification, Hunt and Hess Classification and Fisher’s Scala.Conclusion: We believe that this study will contribute to the literature about the necessity of performing additional radiologic imaging during clinical follow-up since belated diagnosis in patients with NASAH may increase mortality.