Tıp Fakültesi / Faculty of Medicine

Permanent URI for this collectionhttps://hdl.handle.net/11727/1403

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Author: search.filters.author.Borcek, Alp Ozgunsearch.filters.applied.f.rights: search.filters.rights.info:eu-repo/semantics/closedAccess

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    Pathological Evaluation of the Filum Terminale Tissue After Surgical Excision
    (2015) Durdag, Emre; Borcek, Pelin Bayik; Ocal, Ozgur; Borcek, Alp Ozgun; Emmez, Hakan; Baykaner, M. Kemali; 0000-0001-6939-5491; 0000-0002-6222-382X; 25712741; AAK-1734-2021; O-6840-2017
    Tethered cord syndrome (TCS) is an important disease and can produce progressive neurological symptoms. Studies about the filum terminale (FT) have drawn attention to the importance of histopathological investigation of this structure. The most interesting of these subtypes is the FT that incorporates peripheral nerve fibers (PNF). Our study aimed to analyze the frequency of PNF in the FT of 40 cases diagnosed with TCS. We performed a retrospective histopathological investigation of FT excised during surgery of patients with TCS who underwent de-tethering. Neurologic and other types of postoperative complications were also revised. Analysis of the samples showed six dominant histopathological subtypes in the FT: fibroadipose tissues including peripheral nerve bundles (n = 14, 37 %), fibroadipose tissue (n = 10, 25 %), fibrous or adipose tissue (n = 7, 17 %), glial tissues including peripheral nerve sections (n = 4, 10 %), and ependymal and glial tissues (n = 4, 10 %). None of the patients presented with neurologic postoperative complications. Embryologic studies revealed that it is common to encounter different histological subtypes of FT pathology. However, the presence of peripheral nerve cells in the FT is important for neurosurgical practice due to the risk of sectioning a functional structure during surgery. In our analysis, we demonstrated the high frequency of PNF in FT pathology. However, since none of the patients showed any symptoms of neurologic deterioration, we considered that these fibers were probably not functional. Our findings emphasize the importance of neuromonitoring in TCS surgery. Although we consider that most of the fibers are probably not functional, neuromonitoring after surgery may prevent serious complications.
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    Effects of Quercetin on Chronic Constriction Nerve Injury in an Experimental Rat Model
    (2016) Civi, Soner; Emmez, Gokcen; Dere, Umit Akin; Borcek, Alp Ozgun; Emmez, Hakan; https://orcid.org/0000-0002-1055-5152; 26960544; U-2400-2018
    Flavonoids are popular substances in the literature, with proven effects on cardiovascular, neoplastic and neurodegenerative diseases. Antioxidant effect is the most pronounced and studied one. Among thousands of flavonoids, quercetin (QUE) is a prototype with significant antioxidant effects. This study aims to demonstrate the effects of QUE in an experimental rat model of chronic constriction injury (CCI). A two-level study was designed with 42 adult Wistar rats that were randomly assigned to different groups. In the first part, animals in sham, control, quercetin, morphine and gabapentine groups received chronic constriction injury to their sciatic nerves and received a single dose of QUE, morphine and gabapentine. In the second part, different dose regimens of QUE were administered to different groups of animals. Pre-injury and post-injury assessments for mechanical hypersensitivity, thermal sensitivity, locomotor activity and anxiety were recorded and statistical comparisons were performed between different groups. Comparison of QUE with morphine and gabapentine has revealed significant effects of this agent in the current chronic constriction injury model. QUE was significantly superior to Gabapentine and morphine in terms of alleviating mechanical and thermal hypersensitivity. Additionally, pre-injury administration of QUE for 4 days demonstrated long-term effectiveness on mechanical hypersensitivity. This preliminary report the on effects of QUE in a chronic constriction injury model proved significant effects of the agent, which should be supplemented with different studies using different dose regimens.
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    Utilizing Deep Convolutional Generative Adversarial Networks for Automatic Segmentation of Gliomas: An Artificial Intelligence Study
    (2022) Aydogan Duman, Ebru; Sagiroglu, Seref; Celtikci, Pinar; Demirezen, Mustafa Umut; Borcek, Alp Ozgun; Emmez, Hakan; Celtikci, Emrah; 34542897
    AIM: To describe a deep convolutional generative adversarial networks (DCGAN) model which learns normal brain MRI from normal subjects than finds distortions such as a glioma from a test subject while performing a segmentation at the same time. MATERIAL and METHODS: MRIs of 300 healthy subjects were employed as training set. Additionally, test data were consisting anonymized T2-weigted MRIs of 27 healthy subjects and 27 HGG patients. Consecutive axial T2-weigted MRI slices of every subject were extracted and resized to 364x448 pixel resolution. The generative model produced random normal synthetic images and used these images for calculating residual loss to measure visual similarity between input MRIs and generated MRIs. RESULTS: The model correctly detected anomalies on 24 of 27 HGG patients' MRIs and marked them as abnormal. Besides, 25 of 27 healthy subjects' MRIs in the test dataset detected correctly as healthy MRI. The accuracy, precision, recall, and AUC were 0.907, 0.892, 0.923, and 0.907, respectively. CONCLUSION: Our proposed model demonstrates acceptable results can be achieved only by training with normal subject MRIs via using DCGAN model. This model is unique because it learns only from normal MRIs and it is able to find any abnormality which is different than the normal pattern.