Yazar "Cetin, Abdurrahman" seçeneğine göre listele

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    Antitumor activity of irinotecan with ellagic acid in C6 glioma cells
    (Assoc Medica Brasileira, 2022) Cetin, Abdurrahman; Biltekin, Burcu; Ozevren, Huseyin
    OBJECTIVE: Irinotecan-based combination chemotherapies in malignant gliomas need to be examined. The aim of this study was to investigate the synergetic effect of ellagic acid, a natural polyphenolic antioxidant compound, with irinotecan, an inhibitor of topoisomerase I enzyme, on the growth, cadherin switch, and angiogenic processes of a glioma cell line. METHODS: A combination of 100 mu M ellagic acid and 100 mu M irinotecan was applied to rat C6 glioma cells for 24th, 48th, and 72nd h. The cell proliferation was evaluated by 5-bromo-2'-deoxyuridine immunocytochemistry. The expression levels of vascular endothelial growth factor, E-cadherin, and N-cadherin were measured using real-time polymerase chain reaction and their immunoreactivities using immunocytochemistry. RESULTS: The treatment of irinotecan with combining ellagic acid enhanced antitumor activity and the synergistic effect of these reduced the cell proliferation of C6 glioma by inhibiting the cadherin switch and promoting the antiangiogenic processes. CONCLUSIONS: Further research is required to prove a negative relationship between C6 glial cell proliferation and irinotecan with ellagic acid application. Our preliminary data suggest that even with the extremely short-term application, irinotecan with ellagic acid may affect glioma cells at the level of gene and protein expression.
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    Comparison of histopathologic findings of initial and recurrent lumbar disc herniation
    (Taylor & Francis Ltd, 2024) Ozevren, Huseyin; Cetin, Abdurrahman; Baloglu, Murat; Deveci, Engin
    ObjectiveRecurrent lumbar disc hernia (RLDH) is a common and challenging complication after an initial discectomy. This study aimed to investigate the relationship between the histopathologic outcomes of the initial and recurrent disc tissues.MethodsThis study investigated 70 patients who underwent a microdiscectomy and subsequently developed same-level same-side lumbar disc herniation (LDH) recurrence. The clinic, western blot, and immunohistochemical evaluations of patients with initial LDH and RLDH were conducted and statistically analyzed.ResultsThe effect of inflammation and apoptosis in the degenerative changes of intervertebral disc hernia and increased histopathologic findings in RLDH was demonstrated. The degeneration of the hernia disc tissue is a major pathological process, which is characterized by cellular apoptosis, inflammation, and reduced synthesis of extracellular matrix. Currently, there is no clinical therapy targeting the reversal of disc degeneration.ConclusionsThis, therefore, stay away from factors that increase inflammation in the intervention of intervertebral disc hernia, applying to reduce inflammation the medicines, could allow reducing disc collagen degeneration, and more successful outcomes. These findings might shed some new lights on the mechanism of disc degeneration and provide new strategies for the treatments of initial and recurrent LDH.
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    The effects of systemically administered methylprednisolone and recombinant human erythropoietin after acute spinal cord compressive injury in rats
    (Springer, 2006) Cetin, Abdurrahman; Nas, Kemal; Bueyuekbayram, Hueseyin; Ceviz, Adnan; Oelmez, Goenuel
    The study design was to decrease the damage of spinal cord on the experimentally induced acute spinal cord injury in rats. The objective of this study was to evaluate whether recombinant human erythropoietin (rHu-EPO) and methylprednisolone (MPSS) improve neurological function and histopathological changes if systemically administered after traumatic spinal cord injury. This study included 48 rats that underwent experimental SCI. Forty-eight animals were randomly divided into six groups. Animals constituted a moderate compression of 0.6 N that was produced by application of an aneurysm clip at level T3 for 1 min. rHu-EPO (1,000 and 3,000 U (Unit) per kg of body weight i.p.) and MPSS (30 mg/kg) were administered 5 min after injury, and control group was saline treated. (1) Control group (n=8), (2) MPSS group (n=8), (3) rHu-EPO 1,000 U group (n=8), (4) MPSS + rHu-EPO 1,000 U group (n=8), (5) rHu-EPO 3,000 U group (n=8), and (6) MPSS + rHu-EPO 3,000 U group (n=8). The neurological function and histopathology were evaluated at 24 and 72 h. According to the neurological functional test scores significant improvements between the control group and the other groups that had taken medical treatment were observed (P < 0.001). Histopathologically severe ischemic findings were observed in the control group. A significant decrease in ischemic damage was detected in MPSS + rHu-EPO 3,000 U group (P < 0.001). The most significant neurological functional and histopathological improvements were observed after systemical administration of MPSS + rHu-EPO 3,000 U and rHu-EPO 3,000 U. Furthermore, the MPSS + rHu-EPO 3,000 U group provides the most improved neurological functional and histopathological recovery.
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    Evaluation of the association between biochemical and immunohistochemical score of caspase-9 and TNF?, and the grading of lumbar disc herniation
    (Taylor & Francis Ltd, 2021) Ozevren, Huseyin; Cetin, Abdurrahman; Baloglu, Murat; Deveci, Engin
    Objective The aim of our study is to investigate the influence of caspase-9 and tumour necrosis factor alpha (TNF alpha) in the grade of lumbar disc herniation. We determined the strength of different predictors such as age, gender, disc grading, caspase-9 and TNF alpha. Methods We retrospectively reviewed 84 patients who had discectomies. Histological and biochemical evaluations of disc specimens were performed. All patients were scanned by the magnetic resonance imaging (MRI) scanner before the operation. Masson's trichrome stain, biochemical analysis and immunohistochemical staining were performed to measure the expression levels of caspase-9 and TNF alpha. The results were evaluated statistically. Results This study included 84 patients (mean age: 41.59 +/- 12.21 years; range: 19-76): 60 men (age 40.47 +/- 12.63 years) and 24 women (44.42 +/- 10.81 years). No statistically significant age difference was found between the genders (p = 0.182). MRI scans showed 16 patients had protrusion, 44 had extrusion and 24 had sequestration of discs. There was a statistically significant negative correlation between the grading of lumbar disc herniations and age (p < 0.001,r = -0.509). Histological and biochemical analyses of disc materials were done. Inflammation, collagen fibre deterioration, apoptotic process, TNF alpha and caspase-9 were seen to increase with increasing disc grading (p < 0.01). Conclusions Biochemical and immunohistochemical score of caspase-9 and TNF alpha indicate the grading of lumbar disc herniation. As the grading of disc herniation increases, inflammation of cells and collagen fibre disruption increase and accelerate the apoptotic process. Apoptosis in disc nucleus pulposus cells may reduce disc herniation.
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    Importance of Clinical and Pathological Characteristics of Meningiomas and Their Relationship with Somatostatin Receptor-2 Positivity
    (Sci Printers & Publ Inc, 2020) Sogutcu, Nilgun; Lacin, Sahin; Cetin, Abdurrahman
    OBJECTIVE: Numerous studies have been conducted on risk factors for meningioma, mostly investigating the relationship between meningioma tumor somatostatin receptor 2 status (SSTR2), tumor size, age at diagnosis, and tumor grade. This single-center study performed in patients undergoing meningioma resection was performed to investigate the relationships between tumor characteristics. STUDY DESIGN: This study involved a retrospective analysis of patients undergoing meningioma resection at our hospital. Univariate and multivariate logistic regression models were used to investigate the relationships between tumor SSTR2 expression status, progesterone receptor status, Ki-67 proliferation index, grade, and size, as well as to identify factors. RESULTS: A total of 81 patients had a median age at diagnosis of 50 (21-80) years. The overall survival (OS) periods in female and male patients were 100.2 and 56.4 months, respectively (p=0.02). There was a significant difference in OS rates between the patients <= 65 years of age and those > 65 (99.1 and 58.8 months, respectively) (p=0.008). The patients with tumors > 3 cm had poorer OS than patients with tumors <= 3 cm (p=0.004). There was no association between tumor SSTR2 expression status and OS; i.e., the OS periods were 75 months in patients with SSTR2-negative tumors, 100.2 months in those with weakly SSTR2-positive tumors, and 89 months in those with strongly SSTR2-positive tumors (p=0.472). CONCLUSION: Interestingly, despite the high positive expression rate of SSTR2, there was no relation between SSTR2 expression status and characteristic features of meningiomas. Therefore, further investigations of the role of SSTR2 receptor expression in meningiomas other than its diagnostic value are required.
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    Progesterone Receptor Status May be the Most Important Prognostic Factor for Meningiomas
    (Akad Doktorlar Yayinevi, 2019) Cetin, Abdurrahman; Lacin, Sahin; Sogutcu, Nilgun
    The aim of this study examined the relationships between progesterone receptor (PR) and estrogen receptor (ER) status in meningiomas and tumor grade, proliferative index (Ki67), and prognosis. Immunohistochemistry with monoclonal rabbit antibodies was performed on 4 mm paraffin sections of all tumors that were confirmed as meningiomas. Samples were assessed for tumor grade, PR and ER expression, and Ki67 status. Correlations among these parameters and their prognostic values were investigated. Overall survival (OS) was 91.4 months, and there was a significant difference in OS between genders. OS for females and males was 100.2 and 45.7 months, respectively (p= 0.02). When patients were divided into two groups by age, there was a significant difference in OS between those aged 50 years and younger and those older than 50 years, 113.2 and 65.1 months, respectively (p= 0.001). There was also a significant difference in OS based on PR status. OS among PR-negative patients was 43.8 months, whereas it was 93.7 months in weakly positive patients, and 95.2 months in strongly positive patients (p= 0.035). Overall, 10 (13.5%) patients had ER expression detectable by the monoclonal antibody technique used. All ER-positive tumor samples were from female patients; all tumors from males were negative for ER staining. Female predominance of meningiomas as the most common primary intracranial neoplasm strongly suggests that sex hormones may affect meningioma growth. This study found that PR status was a prognostic factor in our meningioma series, as were gender and age.
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    Vimentin and Tumor Necrosis Factor-? Expression in Peripheral Nerves in Experimental Diabetic Neuropathy
    (Sci Printers & Publ Inc, 2018) Baloglu, Murat; Cetin, Abdurrahman; Tuncer, Mehmet Cudi
    OBJECTIVE: To investigate the role of intermediate filaments and cytokines in peripheral nerve injury in experimentally induced diabetic rats. STUDY DESIGN: Male Sprague-Dawley rats were administered streptozotocin (STZ) 55 mg/kg/day intraperitoneally to induce type 1 diabetes mellitus. At 2 days post-administration, the caloric intake from the tail vein was 250 mg/dL and the rats were considered to be diabetic. The diabetic and control groups were compared in terms of glucose values. Sciatic nerve specimens were taken for basic histology, immunohistochemistry, and western blot analyses. RESULTS: The blood glucose concentration in the diabetic rats was significantly increased (p <0.001). Histopathological examination of the diabetic group showed axonal degeneration with thinning in myelinated fibers, hypertrophy in Schwann cells, dilation in small blood vessels, and mononuclear cell infiltration in connective tissue areas. CONCLUSION: There was a deterioration in the myelination mechanism as a result of the influence of the intermediate filaments. The peripheral nerve caused the rapid development of axonal atrophy, resulting in the loss of nerve cells due to increased necrotic formation with cellular infiltration.