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Dive into the research topics where Ozlem Kurtkaya is active.

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Featured researches published by Ozlem Kurtkaya.


International Journal of Dermatology | 1997

Chemotherapy-induced acral erythema in leukemic patients: a report of 15 cases.

Zeynep Demircay; Oya Gürbüz; Tulin Budak Alpdogan; Deniz Yucelten; Önder Alpdoğan; Ozlem Kurtkaya; Mahmut Bayik

Background Chemotherapy‐induced acral erythema is a distinct localized cutaneous response to certain systemic chemotherapeutic agents.


Neurosurgery | 2002

Tenascin in meningioma: Expression is correlated with anaplasia, vascular endothelial growth factor expression, and peritumoral edema but not with tumor border shape

Turker Kilic; Yasar Bayri; Koray Özduman; Melih Acar; Semin Diren; Ozlem Kurtkaya; Gazanfer Ekinci; Kuyaş Buǧra; Aydin Sav; M. Memet Özek; M. Necmettin Pamir; Joseph M. Piepmeier; Maciej S. Lesniak; Henry Brem; Andrew H. Kaye; James T. Rutka

OBJECTIVE : Tenascin is an extracellular matrix glycoprotein that is expressed during embryogenesis, inflammation, angiogenesis, and carcinogenesis. The aim of this study was to investigate how tenascin expression relates to histological grade, angiogenesis, and radiological findings in meningiomas. Methods: Twenty typical, 20 atypical, and 5 malignant meningiomas were studied retrospectively. Tenascin expression and vascular endothelial growth factor (VEGF) expression in the tumor tissue were investigated by immunohistochemistry. Tenascin messenger ribonucleic acid expression was also studied by comparative reverse transciptase-polymerase chain reaction. Magnetic resonance images from each case were assessed for peritumoral edema and tumor border shape. Results: The atypical and malignant meningiomas showed higher levels of tenascin expression than the typical meningiomas. The more sensitive messenger ribonucleic acid-based methods confirmed this finding. Tenascin expression was correlated with peritumoral edema and VEGF expression byt not with tumor border shape. In the 13 tumors with marked tenascin expression, peritumoral edema was Grade 0 in one, Grade 1 in three, and Grade 2 in nine specimens. In the same 13 tumors, VEGF expression was Grade 1 in five and Grade 2 in eight specimens, and the findings for tumor border shape were Grade 0 in seven, Grade 1 in four, and Grade 2 in two speciemens. Conclusion: In meningiomas, tenascin expression is correlated with anaplasia, tumor-associated edema, and VEGF expression but not with tumor border shape. This protein may play a role in the neoplastic and/or angiogenic processes in atypical and malignant meningiomas and may thus be a potential target for meningioma therapy.


Neurosurgery | 2002

Expression of growth factors and structural proteins in chordomas: basic fibroblast growth factor, transforming growth factor alpha, and fibronectin are correlated with recurrence.

Deniz Ml; Turker Kilic; Almaata I; Ozlem Kurtkaya; Aydin Sav; M. N. Pamir

OBJECTIVE To test the hypothesis that the expression of certain growth factors and/or structural proteins is correlated with the biological behavior of cranial base chordomas. METHODS The study investigated 14 pathological specimens of cranial base chordomas from patients who were monitored for at least 2 years after their initial operations. Some cases involved multiple tumor recurrences and multiple operations. For those patients, the time to recurrence after each operation was recorded and a mean value was calculated. Nine patients with mean times to recurrence of 24 months or more or with 24 months of follow-up monitoring without recurrence after single operations were designated the “good-prognosis” group. Five patients with mean times to recurrence of less than 24 months were designated the “poor-prognosis” group. In each case, only the specimen from the initial operation was studied. Multiple sequential sections were cut from paraffin-embedded blocks of tissue and immunohistochemically prepared for detection of three growth factors and three structural proteins, i.e., basic fibroblast growth factor, transforming growth factor &agr;, vascular endothelial growth factor, fibronectin, collagen III, and collagen IV. Intensity of expression was graded by using a four-tier system (Grades 0, 1, 2, and 3). Levels of expression of the molecules in the two groups were evaluated and compared. RESULTS The mean transforming growth factor &agr; expression intensity grades for the good- and poor-prognosis groups were 0.8 and 2.6, respectively, and the corresponding mean basic fibroblast growth factor grades were 1.4 and 2.6. For both groups, the mean grade for vascular endothelial growth factor expression was 0.6. For fibronectin, the mean staining grades for the good- and poor-prognosis groups were 2.2 and 3.0, respectively. The corresponding mean intensities for collagen III were 1.1 and 0.8, and those for collagen IV were 2.5 and 2.6. CONCLUSION Our descriptive data from immunohistochemical analyses of chordomas suggest that high levels of transforming growth factor &agr; and basic fibroblast growth factor expression are linked to higher rates of recurrence. Strong fibronectin expression may also be a marker of aggressive biological behavior.


Spinal Cord | 2001

Spinal solitary fibrous tumor: seventh reported case and review of the literature

Ozlem Kurtkaya; Ilhan Elmaci; Aydin Sav; M. N. Pamir

We present the clinical, radiological, and pathological features of a solitary fibrous tumor in the spinal cord. This case is the seventh spinal solitary fibrous tumor in the literature. The tumor caused clinical symptoms in a 70-year-old female, which indicated compression of the spinal cord. Magnetic resonance imaging showed an intradural extramedullary mass at T3 vertebral level. Surgically, the tumor was firm, in an intradural extramedullary location and attached to the dura. Histologically, the tumor was composed of spindle cells in a collagen-rich matrix but exhibited regional variations. CD34 and vimentin were diffusely positive during immunohistochemical stain testing. The tumor displayed no positive staining for epithelial membrane antigen, cytokeratin, S-100 protein, smooth muscle actin or desmin. The Ki-67 labeling index was low. Solitary fibrous tumors have been found in a variety of locations suggesting that a solitary fibrous tumor has a mesenchymal origin. This rare tumor should be considered in the differential diagnosis of spinal tumors.Spinal Cord (2001) 39, 57–60.


Journal of Clinical Neuroscience | 2006

Superficial siderosis due to papillary glioneuronal tumor

Deniz Konya; Selçuk Peker; Serdar Özgen; Ozlem Kurtkaya; M. Necmettin Pamir

Superficial siderosis of the central nervous system is a rare, progressive, irreversible and debilitating neurological disease characterized by the deposition of haemosiderin in the leptomeninges and the subpial layers of the brain and spinal cord. The main clinical findings are progressive bilateral sensorineural hearing loss, cerebellar ataxia and pyramidal tract signs. The present report describes a 49-year-old woman who presented with intermittent headache of 5 years duration. The pain had become more severe in the previous 6 months. Neurological examination revealed nothing abnormal. Computed tomography showed a cystic mass with apparent internal haemorrhage in the right frontal lobe and T(2)-weighted magnetic resonance imaging showed material of low signal intensity coating the entire surface of the brain. The mass was completely excised via craniotomy. A histopathological study identified the mass as a papillary glioneuronal tumour. The patient recovered well and is still neurologically normal 1 year later. This is the first documented case of superficial siderosis caused by this type of tumour.


Tumori | 2001

Tumor in tumor: metastasis of breast carcinoma to intracranial meningioma.

Ilham Elmaci; Gazanfer Ekinci; Ozlem Kurtkaya; Aydin Sav; M. Necmettin Pamir

This report presents magnetic resonance imaging (MRI) findings of a breast carcinoma metastasis in an intracranial meningioma with correlated pathological findings. MRI showed multiple foci of intense enhancement with hypointense surrounding areas. The described foci appeared to be metastatic disease from the patients known breast carcinoma. In addition, this is the first study reported in the literature to have investigated the expression of a possibly common carcinogenic molecule in breast carcinoma metastatic to a coexisting meningioma: overexpressed c-myc oncogene was found both in the breast carcinoma compartment and in the meningioma component of the tumor.


European Journal of Cardio-Thoracic Surgery | 2004

Neuroprotective effects of FK-506, l-carnitine and azathioprine on spinal cord ischemia-reperfusion injury

Serdar Akgun; Atike Tekeli; Ozlem Kurtkaya; Ali Civelek; Selim Isbir; Koray Ak; Aydin Sav

OBJECTIVE In our experimental study, we aimed to test the effect of FK506, azathioprine and L-carnitine on protection of spinal cord injury due to ischemia-reperfusion. METHODS Twenty-seven Sprague-Dawley male rats were randomly divided into five groups. They were subjected to spinal cord ischemia by clamping the abdominal aorta for 45 min. Thirty minutes before the aortic clamping, group I received 0.5 mg/kg FK506, group II received 100 mg/kg L-carnitine, group III received 4 mg/kg azathioprine, the fourth group was the control group and received only normal saline injection intravenously and the last group was the sham group. Neurological status was scored by using the Tarlov scoring system. Sections of the lumbar cord were harvested for histopathological grades (1-4), having regard to percentage of the apoptotic cells. RESULTS Hind-limb motor function had recovered normally 48 h after the operation in all rats which received FK506, azathioprine and L-carnitine prophylactically. In contrast, all rats in the control group had deteriorated to paraplegia by 48 h after the operation (P<0.05). Histopathologic sections in the involved spinal cord segment showed that a greater number of motor neuron cells were preserved and there were less apoptotic cells in the rats that received FK506, azathioprine and L-carnitine than those in control group. CONCLUSIONS These results suggest that prophylactic use of FK506, azathioprine and L-carnitine protects motor neuron cells from ischemic spinal cord injury.


European Journal of Cardio-Thoracic Surgery | 2003

Ischemic preconditioning and nicotinamide in spinal cord protection in an experimental model of transient aortic occlusion.

C. Selim Isbir; Koray Ak; Ozlem Kurtkaya; Umit Zeybek; Serdar Akgun; Bernd W. Scheitauer; Aydin Sav; Adnan Çobanoğlu

OBJECTIVES Spinal cord injury is a devastating complication after aortic surgery. The aim of the present study is to examine the effects of ischemic preconditioning (IPC) and nicotinamide containing perfusate in transient aortic occlusion in the rat. METHODS Thirty-two male Spraque-Dawley rats under general anesthesia were randomly assigned to four groups (n=8 in each group). The infrarenal aortas were clamped for 45 min. Groups were as follows: Group 1, undergoing occlusion but receiving no treatment. Group 2, had 5 min of IPC before occlusion. Group 3, received nicotinamide (0.2 ml/l) during the transient occlusion. Group 4, received combined IPC (5 min) and nicotinamide infusion during the transient occlusion. The rats were then allowed for recovery and were tested for their neurological status. All animals were sacrificed at the end of the 48 h and spinal cords also examined histologically. Anti- poly (ADP-ribose) polymerase p85 fragment pAb was used as an immunohistochemical marker for detection of apoptosis. RESULTS In 24 h paraplegia represented as grade 0 and 1 occurred in six animals in Group 1 and two animals in Groups 2 and 3 and one in Group 4. In 48 h six animals in Group 1 and only one animal in Groups 2 and 3 showed a paraplegia. The incidence of neurologic deficit was significantly reduced in animals who had IPC and nicotinamide infusion (P<0.05). At 48 h, combined IPC and nicotinamide showed a significant benefit compared to nicotinamide but not to the IPC alone. Histologic examination of the spinal cords revealed that a neuronal necrosis contributes to acute spinal cord degeneration after a period of aortic occlusion and both nicotinamide and IPC have protective effects against neuronal necrosis. No difference was found among the groups. CONCLUSIONS Both IPC and nicotinamide are beneficial in protection against neurological damage in transient aortic occlusion. IPC alone as expected is significantly beneficial both at 24 and 48 h compared to controls. At 24 h combined nicotinamide and IPC show significant benefit compared to only nicotinamide, but this difference is not maintained at 48 h.


European Spine Journal | 2006

Lumbar spinal angiolipoma: case report and review of the literature

Deniz Konya; Serdar Özgen; Ozlem Kurtkaya; Necmettin Pamir

Spinal angiolipomas are extremely rare benign tumors composed of mature lipomatous and angiomatous elements. Most are symptomatic due to progressive spinal cord or root compression. This article describes the case of a 60-year-old woman who presented with a 6-month history of low back pain radiating to her right leg. The pain was multisegmental. The condition had worsened with time. Lumbar magnetic resonance imaging revealed a dorsal epidural mass at L5 and erosion of the lamina of the L5 vertebra. Laminectomy was performed, and an extradural tumor was totally excised. Neuropathologic examination identified it as a lumbar spinal angiolipoma. There was no evidence of recurrence in follow-up 12 months later. This rare clinical entity must be considered in the differential diagnosis for any spinal epidural lesion.


Pediatric Neurology | 1998

Hemimegalencephaly and Hirschsprung’s Disease: A Unique Association

Dilşad Türkdoğan-Sözüer; M. Memet Özek; Varol Şehıralti; Ozlem Kurtkaya; Aydin Sav

A 2-year-old boy with hemimegalencephaly and Hirschsprungs disease is reported. The unique association of these two entities is considered to be the presence of a common insult or insults that affect the innervation of the bowel and the formation of the cerebral cortex. Short-segment subtype of Hirschsprungs disease may suggest that this effect occurred between the eighth and twelfth weeks of gestation. Although there is a well-known coexistence of Hirschsprungs disease with the malformations that share a common neurocristopathic origin (abnormalities of neural crest cell growth, migration, or differentiation), a few extremely rare cases, as in this case, might reflect the coexistence of Hirschsprungs disease with a cerebral malformation (i.e., hemimegalencephaly) that is a nonneurocristopathic entity by itself.

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Deniz Konya

Bahçeşehir University

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