İntrakranial kitlelerin bilgisayarlı tomografi rehberliğinde sterotaktik mikrocerrahi rezeksiyonu]

Stereotactic microsurgical techniques allow for the precise localization and resection of lesions in critical areas of cortex or deep within the brain and minimize operative exposure to the surrounding tissues. This study presents our experience with CT-guided stereotactic microsurgical resection of cerebral lesions using the Leksell frame. A total of 42 patients undergoing computerized tomography guided stereotactic microsurgical resection of cerebral lesions between June 2000 and September 2017 were included in the study. Clinical, radiological, histological and follow-up data were retrospectively evaluated. Pre-and post-operative general status of the patients was assessed by Karnofsky Performance Scale (KPS). Except for the subjects with high-grade gliomas, complete resection could be accomplished in all cases. Of the 24 cases with convulsions, a complete cessation of epileptic attacks was attained in 20 and a decrease in their number and frequency was noted in 4 cases. Overall, 20 patients had no change in the KPS score, while 28 patients had increased and two had decreased KPS scores. No postoperative mortality occurred. CT-guided stereotactic microsurgical craniotomy is a safe, reliable and effective technique, which is particularly useful for the surgical treatment of small, benign cranial lesions and cerebral metastases. © 2018, Logos Medical Publishing. All rights reserved

Meningiom olgularının biyopatogenezinin literatür eşliğinde değerlendirilmesi

In this study, it was aimed to investigate the bio pathogenesis of the cases diagnosed with meningioma in the light of the literature. The patients (n=79) operated due to the meningioma in neurosurgery department between 2005 and 2010 were retrospectively examined. Findings that may affect the biological behavior and prognosis of the tumours recorded in these reported data were evaluated. A total of 79 cases meeting the research criteria were included in the study. When the histopathological grade of the cases was examined, it was seen that 59 cases (74.7%) were grade I and 20 cases (25.3%) were grade II. When the relation between the localization and histological grade of the cases was examined, it was determined that the meningiomas were most frequently located in convexity and that most of grade II cases were localized at this site. Preoperative peritumoral oedema was found to be more prevalent, especially in the sphenoid wing and convexity meningiomas. A total of 9 cases of recurrence (11.4%) occurred during follow-up period. When carrying out evaluation between surgical resection grade and recurrent cases, it was detected that all cases where it was performed Simpson grade IV and Kobayashi grade IVA and IVB resection had a recurrence. When the localization of recurrent cases was examined, it was seen that 4 cases (%44.4) were sphenoid wing meningioma, 2 cases (%22.2) were parasagittal meningioma, 1 case (%11.1) was tuberculosis sellae meningioma and 1 case (%11.1) was int-raventricular meningioma. In our study, histopathologic subtype and surgical resection grade were found to play a significant role in prognosis in meningiomas. It was also thought that the presence of peritumoral oedema and tumour localization could affect the biological behavior and prognosis of the meningioma. Findings obtained should be supported by multi-center studies that will include the cases of different races with more series. © 2018, Logos Medical Publishing. All rights reserved

Pre-emptive Use of Riboflavin in a Rat Model of Bilateral Cavernous Nerve Injury

Objective: Erectile dysfunction is commonly encountered after radical prostatectomy due to cavernous nerve injury (CNI). We investigated the effects of riboflavin (Rb) on bilateral CNI in a rat model. Materials and Methods: Twenty-four male rats were divided into four groups: control (C), patients with bilateral CNI, those with CNI receiving postoperative Rb treatment (CNI+Rb), and those with CNI receiving pre- and post-operative Rb treatment (Rb+CNI+Rb). Bilateral CNI was performed in all groups except for C. The CNI+Rb group was treated with 30 mg/kg Rb daily after CNI for two weeks; the Rb+CNI+Rb group was treated with 30 mg/kg Rb daily one week before CNI and then for two weeks after injury. Mean arterial pressure (MAP) and intracavernosal pressure (ICP) were measured 14 days after CNI in all groups. Tissue malondialdehyde, cyclic guanosine monophosphate, nerve growth factor, superoxide dismutase and total nitric oxide synthase (NOS) activities, neuronal NOS (nNOS) and inducible NOS (iNOS) were analyzed. Results: ICP/MAP ratio was significantly lower in the CNI (p<0.01) and CNI+Rb groups (p<0.05) compared to the control group, however, the Rb+CNI+Rb group had results comparable to the C group in terms of nNOS and iNOS expression in the Western Blot analysis. Conclusion Rb exerted anti-oxidative and anti-inflammatory effects on CNI in a CNI rat model. Rb can be a potential beneficial agent to improve erectile function in nerve-sparing radical prostatectomy patients as a preemptive penile rehabilitation strategy, although further clinical studies are needed

Otomobil lastiklerinin yanal kuvvet karakteristiklerinin sonlu elemanlar yöntemiyle analizi

A finite element model is developed to obtain the cornering force characteristics for rotating pneumatic tires which combines accuracy together with substantially reduced computational effort. For cord reinforced rubber sections such as the body plies and breaker belts, continuum elements with orthotropic material properties are used to improve solution times. Drastic reductions in computational effort are then obtained by replacing the continuum elements with truss elements which do not require orientation of element coordinate system to model textile body plies. With these simplifications, new model can be used produce a complete carpet plot of cornering force characteristics in substantially reduced solution times. The finite element model is used to obtain the cornering force characteristics of a tire, simulating the experiments on a tire test rig where the tire rotates on a flywheel. Results from both models are compared with each other and with the experimental results. It is concluded that the model developed provides results at least as accurate as the previously published models with a clear superiority in stability of solution.Ph.D. - Doctoral Progra

CT-guided Stereotactic Microsurgical Resection of Cerebral Mass Lesions

Stereotactic microsurgical techniques allow for the precise localization and resection of lesions in critical areas of cortex or deep within the brain and minimize operative exposure to the surrounding tissues. This study presents our experience with CT-guided stereotactic microsurgical resection of cerebral lesions using the Leksell frame. A total of 42 patients undergoing computerized tomography guided stereotactic microsurgical resection of cerebral lesions between June 2000 and September 2017 were included in the study. Clinical, radiological, histological and follow-up data were retrospectively evaluated. Pre-and post-operative general status of the patients was assessed by Karnofsky Performance Scale (KPS). Except for the subjects with high-grade gliomas, complete resection could be accomplished in all cases. Of the 24 cases with convulsions, a complete cessation of epileptic attacks was attained in 20 and a decrease in their number and frequency was noted in 4 cases. Overall, 20 patients had no change in the KPS score, while 28 patients had increased and two had decreased KPS scores. No postoperative mortality occurred. CT-guided stereotactic microsurgical craniotomy is a safe, reliable and effective technique, which is particularly useful for the surgical treatment of small, benign cranial lesions and cerebral metastases. © 2018, Logos Medical Publishing. All rights reserved

Evaluation of Biopathogenesis of Meningioma Cases in the Light of Literature

In this study, it was aimed to investigate the bio pathogenesis of the cases diagnosed with meningioma in the light of the literature. The patients (n=79) operated due to the meningioma in neurosurgery department between 2005 and 2010 were retrospectively examined. Findings that may affect the biological behavior and prognosis of the tumours recorded in these reported data were evaluated. A total of 79 cases meeting the research criteria were included in the study. When the histopathological grade of the cases was examined, it was seen that 59 cases (74.7%) were grade I and 20 cases (25.3%) were grade II. When the relation between the localization and histological grade of the cases was examined, it was determined that the meningiomas were most frequently located in convexity and that most of grade II cases were localized at this site. Preoperative peritumoral oedema was found to be more prevalent, especially in the sphenoid wing and convexity meningiomas. A total of 9 cases of recurrence (11.4%) occurred during follow-up period. When carrying out evaluation between surgical resection grade and recurrent cases, it was detected that all cases where it was performed Simpson grade IV and Kobayashi grade IVA and IVB resection had a recurrence. When the localization of recurrent cases was examined, it was seen that 4 cases (%44.4) were sphenoid wing meningioma, 2 cases (%22.2) were parasagittal meningioma, 1 case (%11.1) was tuberculosis sellae meningioma and 1 case (%11.1) was int-raventricular meningioma. In our study, histopathologic subtype and surgical resection grade were found to play a significant role in prognosis in meningiomas. It was also thought that the presence of peritumoral oedema and tumour localization could affect the biological behavior and prognosis of the meningioma. Findings obtained should be supported by multi-center studies that will include the cases of different races with more series. © 2018, Logos Medical Publishing. All rights reserved

Liver cancer cells are sensitive to Lanatoside C induced cell death independent of their PTEN status

Background: Hepatocellular carcinoma is the second deadliest cancer with limited treatment options. Loss of PTEN causes the P13K/Akt pathway to be hyperactive which contributes to cell survival and resistance to therapeutics in various cancers, including the liver cancer. Hence molecules targeting this pathway present good therapeutic strategies for liver cancer