Researcher: Ünsal, Ülkün Ünlü
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Ünsal, Ülkün Ünlü
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Publication Metadata only Inhibiting effect of oleocanthal on neuroblastoma cancer cell proliferation in culture(Taylor & Francis, 2020) Mete, Mesut; Aydemir, Işıl; Duransoy, Yusuf Kurtuluş; Umur, Ahmet Şükrü; Tuğlu, Mehmet İbrahim; Ünsal, Ülkün Ünlü; Doctor; School of Medicine; Koç University Hospital; N/AWe investigated the potential anticancer effects of oleocanthal (OC) on neuroblastoma cells. Cells were divided into four groups: group 1, neuroblastoma cells were treated with OC; group 2, neurons that differentiated from neuroblastoma cells were treated with phosphate-buffered saline(PBS); group 3, bone marrow derived neuronal (BMDN) cells that were differentiated from bone marrow derived mesenchymal stem cells (BMSCs) were treated with OC; group 4, BMDN cells that were differentiated from BMSCs were treated with PBS. Groups 2 and 4 were control groups. The effects of OC on cell viability, oxidative stress, neurite inhibition and apoptosis at IC50 dose were investigated using MTT analysis, i-NOS and e-NOS measurement, neurotoxicity screening test (NST) and TUNEL staining, respectively. MTT analysis demonstrated that cells were significantly less viable in group 1 than in group 3. i-NOS and e-NOS staining intensity was significantly greater in group 1 than in group 3. NST revealed that OC inhibited neurite growth in both neuroblastoma and BMND cells; inhibition was significantly less in group 3 than in group 1. Significantly more TUNEL labeled cells were found in group 1 than in group 3. We found that OC prevented growth and proliferation of neuroblastoma cells in culture by increasing oxidative stress and apoptosis. We also found that the cytotoxicity of OC is negligible in BMDN cells.Publication Metadata only Percutaneous full-endoscopic removal of lumbar intradural extramedullary tumor via translaminar approach(Elsevier Science Inc, 2019) N/A; N/A; Şentürk, Salim; Ünsal, Ülkün Ünlü; Doctor; Doctor; N/A; N/A; Koç University Hospital; Koç University Hospital; N/A; N/ABackground: Despite the fact that technologic advances and surgical experience expand the use of endoscope in spinal surgery, there are few reports on its application in the management of spinal tumors. We present a case report of intradural extramedullary tumor excision with the percutaneous full endoscopic translaminar approach. Case Description: A 67-year-old male presented to our clinic with lumbar, left thigh pain and paresthesia in both thighs. Preoperative magnetic resonance imaging revealed a contrast-enhanced intradural extramedullary mass with benign characteristics on L1 with the preliminary diagnosis of meningioma. The percutaneous translaminar endoscopic approach was planned to remove the intradural extramedullary tumor from a 7-mm skin incision. Surgery was planned in 4 stages: 1) exposure of the dura by opening a window on the lamina, 2) opening and expanding of the dura, 3) exposure of all sides of the tumor, and 4) excision of the tumor and hemostasis. Closing the dura and ending the surgery. Conclusions: This report supports that full endoscopic spinal intradural extramedullary mass excision may give good results in selected cases and in experienced hands.Publication Metadata only Minimally invasive translaminar endoscopic approach to percutaneous vertebroplasty cement leakage: technical note(Elsevier Science Inc, 2018) N/A; N/A; N/A; N/A; N/A; Şentürk, Salim; Akyoldaş, Göktuğ; Ünsal, Ülkün Ünlü; Yaman, Onur; Özer, Ali Fahir; Doctor; Faculty Member; Doctor; Doctor; Faculty Member; N/A; School of Medicine; N/A; N/A; School of Medicine; Koç University Hospital; Koç University Hospital; Koç University Hospital; N/A; 203677; N/A; 219524; 1022Background: Percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty are 2 common procedures that could be applied simply in treatment of vertebral compression fractures. Despite simplicity and safe application of these procedures, there are some drawbacks as well. Cement leakage into the spinal canal is the most common complication of PVP and PKV procedures. The aim of this article is to present a minimally invasive alternative technique for removing cement leakage fragment after the PVP. Methods: A 44-year-old female patient began to complain of L4 radiculopathy after L4 PVP. The lumbar computed tomography demonstrated cement fragment closed to upper medial aspect of the left L4 pedicle. A minimally invasive translaminar endoscopic procedure was performed to remove the cement fragment. Results: Following the endoscopic procedure, the patient's complaints resolved completely and she was discharged on postoperative day 1. The minimally invasive intervention provided shorter operation time, minimal blood loss, and reduced complication rate due to its simplicity. In particular, there was no need to undergo general anesthesia. Conclusion: Endoscopic translaminar approach could be safely performed in patients with symptomatic cement leakage after PVP or a percutaneous kyphoplasty procedure.Publication Metadata only Percutaneous endoscopic translaminar approach in a patient with pedicle screw malposition and cement leakage(Taylor and Francis Ltd) N/A; N/A; Şentürk, Salim; Ünsal, Ülkün Ünlü; Doctor; Doctor; N/A; N/A; Koç University Hospital; Koç University Hospital; N/A; N/AWe present a 79-year-old female patient who had L2-5 dynamic stabilization with cement (Polymethylmethacrylate) injection 6 weeks prior. Due to post-operative right radicular pain, a lumbar CT was scheduled in which a malposition of the right L4 screw and cement leakage was observed. Via a percutaneous translaminar endoscopic approach the leaked cement was removed and the portion of the screw in contact with the nerve root was drilled. With this minimal-invasive procedure, the patient was relieved of her radicular pain.Publication Metadata only Punicic acid inhibits glioblastoma migration and proliferation via the PI3K/AKT1/mTOR signaling pathway(Bentham Science Publ Ltd, 2019) Mete, Mesut; Aydemir, Işıl; Sönmez, Pınar K.; Tuğlu, Mehmet, İ.; Ünsal, Ülkün Ünlü; Doctor; School of Medicine; Koç University Hospital; N/ABackground: Punicic Acid (PA) is a polyunsaturated fatty acid that accounts for approximately 70%- 80% of Pomegranate Seed Oil (PSO). PA possesses strong antioxidant, anti-inflammatory, anti-atherogenic effects, and anti-tumorigenic properties. Pomegranate extracts have been shown to have anticancer activity in many studies. However, there is no evidence for the effect of PSO on T98 glioblastoma cells. Therefore, the present study was the first to investigate the mechanisms induced by PA on T98 cells, which is one of the major compounds extracted from PSO. Methods: The effects of PA on cell viability; oxidative stress; and migration, proliferation, and apoptosis at the IC50 dose were studied. Results: The proliferation and migration were inhibited in the treated group compared to the non-treated group by 9.85µl/ml PA. The difference was statistically significant (***p<0.001). Furthermore, PA-induced apoptosis in the T98 glioblastoma cells compared to non-treated group and the difference was statistically significant (***p<0.001). Apoptosis was determined via immunocytochemistry staining of caspase-3, caspase-9 and TUNEL methods. Apoptosis was checked by flow cytometry (using caspase 3 methods) and Scanning Electron Microscopy Analysis. We also investigated the potential signaling pathway underlying this apoptotic effect. The immunocytochemical stainings of PI3K/ Akt-1/ mTOR-1 demonstrated that Akt-1 staining was increased with PA treatment similar to mTOR-1 and PI3K staining (***p<0.001). These increases were statistically significant compared to the non-treated group. Conclusion: PA exhibited exceptional abilities as an anticancer agent against GBM cells. The use of punicic acid in combination with other drugs used in the treatment of glioblastoma may increase the efficacy of the treatment. This study provided a basis for future investigation of its use in preclinical and clinical studies.Publication Metadata only Radiological evaluation of the localization of sympathetic ganglia in the cervical region(Springer France, 2021) Şentürk, Salim; Ünsal, Ülkün Ünlü; Aygün, Murat Serhat; Doctor; Teaching Faculty; School of Medicine; School of Medicine; Koç University Hospital; N/A; 291692Purpose: To determine local variations of cervical sympathetic ganglia (CSG) according to vertebral levels on preoperative neck magnetic resonance imaging (MRI) by designating carotid artery (CA) as the standard landmark at the center, in attempts to prevent injury to CSG in the anterior-anterolateral approaches performed in the cervical spinal region. Materials and Methods: The retrospective study reviewed neck MRI images of 281 patients, of which the images of 231 patients were excluded from the study based on the exclusion criteria. As a result, the MRI images of the remaining 50 patients were included in the study. The circumference of carotid artery (CA) was divided into eight equal zones with CA defined as the standard landmark at the center. High-risk zones were determined based on the anterior-anterolateral approaches. Results: At C1 level, a superior ganglion was located on the right side in 32 (64%) and on the left side in 30 (60%) patients. At this level, it was most commonly located in Zone 6. Middle ganglion was observed most frequently at C3 level, which was detected on the right side in 17 (34%) and on the left side in 17 (34%) patients. At this level, it was most commonly located in Zone 2. Conclusion: Variations in the localizations of superior and middle cervical ganglia should be taken into consideration prior to surgical procedures planned for this region. This study sheds light on high-risk zones in the surgical site and could guide surgeons to better understand the location of cervical sympathetic ganglia before surgical planning.Publication Metadata only Minimally invasive far-lateral microdiscectomy: a new retractor for far-lateral lumbar disc surgery(Cureus Inc, 2021) Şentürk, Salim; Ünsal, Ülkün Ünlü; Doctor; School of Medicine; Koç University Hospital; N/ABackground: To date, a number of approaches have been described for far-lateral disc surgery, including midline, paramedian, and intertransverse approaches. These approaches pose challenges for surgeons due to the difficulty in retraction caused by the anatomy of the foramen. We designed a retractor suitable for the three-dimensional anatomical structure of the foramen. In this study, we aimed to evaluate the surgical outcomes of the patients who were operated on using this retractor in our clinic. Methods:The retrospective study included patients who were operated on due to far-lateral disc herniation using the retractor designed in our clinic between February 2013 and December 2018. Results: The study included 11 (64.7%) women and 6 (35.3%) men, with a mean age of 56 years (range: 42-70 years). The mean operative time was 49 minutes (range: 40-70 minutes), the mean estimated blood loss was 42 mL (range: 25-60 mL), and the mean follow-up period was 22.6 months (range: 13-48 months). No complication occurred in any patient. A minimally invasive discectomy was performed via the paramedian approach in each patient. The patients were evaluated using the visual analog scale (VAS) for radicular pain, Oswestry Disability Index (ODI), 36-Item Short Form Survey (SF-36), and the modified MacNab criteria. Conclusion: The retractor developed in our study provided numerous benefits during the surgical procedure as it led to minimal blood loss and reduced operative times by avoiding bone resection in extraforaminal discs and requiring minimal bone resection in foraminal discs.Publication Metadata only Neuroprotective effects of oleocanthal, a compound in virgin olive oil, in a rat model of traumatic brain injury(Turkish Neurosurgical Soc, 2018) Mete, Mesut; Aydemir, Işıl; Çöllü, Fatih; Vatandaş, Gökhan; Gürcü, Beyhan; Duransoy, Yusuf Kurtuluş; Taneli, Fatma; Tuğlu, Mehmet İbrahim; Selçuki, Mehmet; Ünsal, Ülkün Ünlü; Doctor; School of Medicine; Koç University Hospital; N/AAim: To evaluate the neuroprotective effects of deocanthal OC in a rat model of traumatic brain injury (TBI). Material and Methods: Twenty-six adult male, Wistar albino rats were used. The rats were divided into 4 groups. Group 1 was the sham group (n=5). Group 2 was the trauma group (n=5) where rats were treated with 10 mg/kg saline intraperitoneally (IP) twice a day. Groups 3 and 4, rats were treated with 10 (group 3, n=8) or 30 (group 4, n=8) mg/kg OC IP twice a day. For each group, brain samples were collected 72 hours after injury. Brain samples and blood were evaluated with histopathological and biochemical methods. Results: Histopathological evaluation revealed a significant difference between Group 2 and Group 4. Biochemical findings demonstrated that the oxidative stress index was highest in Group 2 and lowest in Group 4. Conclusion: OC has a protective effect on neural cells after TBI. This effect is achieved by reducing oxidative stress and apoptosis.Publication Metadata only A new technique that percutaneous endoscopic decompression and vertebroplasty in a patient with osteoporotic vertebral fracture a case report(Lippincott Williams & Wilkins, 2020) N/A; N/A; Şentürk, Salim; Ünsal, Ülkün Ünlü; Doctor; Doctor; N/A; N/A; Koç University Hospital; Koç University Hospital; N/A; N/AStudy Design: Technique note. Objective: To evaluate the feasibility of endoscopy in various spinal pathologies. Summary of Background Data. Osteoporotic vertebral fractures are a common pathology in the elderly. These fractures are often accompanied by serious complications such as neurological deficits due to the compression of the spinal cord or nerve roots. Methods: A 78-year-old female patient presented to our hospital with a severe pain in her left leg and back. Lumbar magnetic resonance imaging and computed tomography scan revealed an osteoporotic L3 burst fracture compressing the left L3 nerve root. A minimally invasive translaminar endoscopic approach was used to remove the fractured fragment and cement was injected into the L3 vertebra. The patient was mobilized the same evening and was relieved of her pain. Conclusion: Minimally invasive endoscopy is a safe and effective alternative to conventional major decompression with or without posterior stabilization, particularly in elderly patients with serious comorbidities.Publication Metadata only Percutaneous endoscopic interlaminar decompression of hypervascular spinal metastases(Elsevier Science inc, 2020) N/A; N/A; Şentürk, Salim; Ünsal, Ülkün Ünlü; Doctor; Doctor; N/A; N/A; Koç University Hospital; Koç University Hospital; N/A; N/ABackground: Percutaneous endoscopic surgery is a common technique used for the treatment of disk herniation and spinal stenosis. in this report, we present a patient who underwent percutaneous endoscopic decompression due to spinal metastasis. Case Description: a 72-year-old female patient with a known diagnosis of lung cancer presented to our clinic with a 10-day history of severe pain in the left leg and a 5-day history of muscle weakness in the left thigh. the patient had a history of multiple organ metastasis and multiple spinal metastasis. on neurologic examination, left hip flexion and extension were graded 2/5. Radiologic workup revealed compression on the left L3 nerve root caused by vertebral metastasis. the patient was planned for a percutaneous full-endoscopic interlaminar decompression due to her clinical condition. the tumor surrounding the left L3 nerve root was removed via endoscopic punch, which resulted in rapid relief of her back pain postoperatively. adjunct physical therapy was recommended after discharge. Conclusions: Percutaneous full-endoscopic interlaminar decompression can be an alternative minimally invasive treatment option in selected patients with radicular pain and neurologic deficit caused by spinal metastasis.