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Figen Soylemezoglu

Publications and source records attributed to Figen Soylemezoglu.

9 recordsLinked to original sources
PubMed2006

Expression of vascular endothelial growth factor a, matrix metalloproteinase 9 and extravascular matrix patterns in iris and ciliary body melanomas.

PURPOSE: It was the aim of this study to assess the expression of vascular endothelial growth factor (VEGF)-A, matrix metalloproteinase (MMP)-9 and extravascular matrix patterns (EMPs) in iris and ciliary body melanomas and their correlations with histopathologic parameters. METHODS: The study was conducted on 3 iris and 15 ciliary body melanomas. All tumors were subjected to immunohistochemical techniques for VEGF-A and MMP-9 expressions, the presence of EMPs was assessed, and routine paraffin sections were stained with hematoxylin-eosin. Cell type, tumor localization, degree of pigmentation, necrosis, mitotic index, lymphocytic infiltration and sclera invasion were analyzed using light microscopy. RESULTS: The mean patient age at the time of treatment was 43 years (range 19-69, median 39.5); 10 (55.6%) patients were males and 8 (44.4%) females. Histopathological cell types were spindle cells in 55.6%, mixed cells in 16.7%, and epithelioid cell types in 27.8% of tumors. Positive reaction for VEGF-A and MMP-9 was present in 66.7 and 72.3% of the tumors, respectively. Microvascular loops and/or networks were seen in 33.4% of the tumors, with the remaining 66.7% of tumors displaying one or more of the other patterns. Metastatic disease developed in only 1 patient during follow-up. Tumor cell type, tumor size, mitotic rate, degree of pigmentation and EMPs were not correlated with metastasis. CONCLUSIONS: This study suggests that VEGF-A and MMP-9 were positive in the majority of iris and ciliary body melanomas. No correlation was found between VEGF-A and MMP-9 immunoreactivity and EMPs and occurrence of metastases in cases of anterior uveal melanoma.

Adult↗
PubMed2006

Comparative dural closure techniques: a safety study in rats.

BACKGROUND: Some neurosurgical procedures have high morbidity and mortality rates due to cerebrospinal fluid (CSF) fistula development, particularly when dural defects are in relatively inaccessible areas or surrounded by friable dura. We used a rat model to test 4 different dural closure techniques to determine which one was significantly superior for achieving a watertight dural closure with minimal harm to brain tissue. METHODS: The rats were randomly divided into 2 groups. The first group (group A, n = 40) was used to test the strength of the adhesivity for CSF leakage. Histopathologic studies were used to evaluate the granulation tissue between the dura and dural graft. Effects on the brain tissue were studied in the second group (group B, n = 40) where lipid peroxidation was determined. These 2 groups consisted of 5 subgroups: control, methyl metacrylate, n-butyl cyanoacrylate, fibrin glue, and CO(2) laser. RESULTS: Methyl metacrylate and CO(2) laser techniques were inadequate for stopping dural leakage and had harmful effects on brain tissue. Cerebrospinal fluid leak was observed only in 1 rat in the n-butyl cyanoacrylate subgroup and this result was statistically significant (P = .0005), but lipid peroxidation levels for this material showed that it was not safe for dural closure in case it leaked through the dural defect. The lipid peroxidation levels of the fibrin glue subgroup were not statistically significantly different from the control group (P = .440). CONCLUSIONS: Fibrin glue was the safest material with a CSF leakage risk that was higher than n-butyl cyanoacrylate (25% vs 12.5%) but acceptable. This study showed no relationship between the CSF leak and histopathologic findings for sealant properties of the tissue adhesives.

Animals↗
PubMed2005

Postoperative radiotherapy and chemotherapy in the management of oligodendroglioma: single institutional review of 88 patients.

We retrospectively evaluate the prognostic factors affecting the local control, survival and the potential role of chemotherapy in the management of patients with oligodendroglioma. The medical records of 88 patients treated by postoperative external beam radiotherapy +/- chemotherapy at our institution between December 1993 and December 2002 were analyzed. Nine patients (10%) were treated with an accelerated fractionation scheme, while 79 patients were treated with conventional doses. The median RT dose was 54.8 +/- 2.58 Gy for low-grade tumors, and 58.7 +/- 2.46 Gy for high-grade tumors. PCV chemotherapy regimen was given to 18 patients; temozolamide was administered in three patients. Chemotherapy was not given concomitantly in any patients. The median follow-up was 56 months (range 7-134 months). The 5-year overall and progression-free survival rates for entire group were 86% and 79%, respectively. Patients with epilepsy at presentation had better 5-year overall survival (93% vs. 74%, P=0.04). High grade tumors had significantly lower overall survival rate. Age, presence of motor deficit at diagnosis and histological grade were found have a significant impact on progression-free survival. The 5-year overall and progression free survival rates of patients with high-grade tumors were 69%, 51% and 74%, 68% for chemotherapy and no-chemotherapy group, respectively (P=0.9 for OS, P=0.3 for PFS). In multivariate analysis no significant factor affecting the overall survival and progression-free survival was found. Chemotherapy given after postoperative radiotherapy in patients with oligodendroglioma did not improve survival in this retrospective study.

Adolescent↗
PubMed2005

Postoperative radiotherapy results in primary spinal cord astrocytomas.

BACKGROUND AND PURPOSE: We retrospectively evaluated the therapeutic outcomes of patients with primary spinal cord astrocytomas treated with conventional radiotherapy at our institute. PATIENTS AND METHODS: Between May 1975 and December 1997, 26 patients with histologically proven spinal cord astrocytomas were treated with conventional radiotherapy, and twenty-four eligible patients were evaluated. Median age was 19 years (2-41 years). Fourteen of astrocytomas were grade I, 6 of them grade II and 4 grade III. Ten patients had subtotal excision, and 14 had only biopsy of the primary lesion. Patients were treated with 1-2 Gy daily fractions, and given to a median total dose of 49.5 Gy (range 35-60 Gy) external radiotherapy to primary tumor. RESULTS: Median follow-up was 39 months. Seventeen patients died of their disease. Two patients have progression, and 5 patients are followed with stabile disease. Five-year overall survival was 45% and progression free survival was 40%. Among the analyzed factors only gender and age were found to be significant. CONCLUSIONS: Our results are slightly worse than previous retrospective radiotherapy series in the literature. With new imaging and radiation therapy techniques, radiotherapy may have a role as an adjuvant treatment especially in subtotally resected tumors.

Adolescent↗
PubMed2003

Is the cell death in mesial temporal sclerosis apoptotic?

PURPOSE: Mesial temporal sclerosis (MTS) is characterized by neuronal loss in the hippocampus. Studies on experimental models and patients with intractable epilepsy suggest that apoptosis may be involved in neuronal death induced by recurrent seizures. METHODS: We searched evidence for apoptotic cell death in temporal lobes resected from drug-resistant epilepsy patients with MTS by using the terminal deoxynucleotidyl transferase (TdT) and digoxigenin-11-dUTP (TUNEL) method and immunohistochemistry for Bcl-2, Bax, and caspase-cleaved actin fragment, fractin. The temporal lobe specimens were obtained from 15 patients (six women and nine men; mean age, 29 +/- 8 years). RESULTS: Unlike that in normal adult brain, we observed Bcl-2 immunoreactivity in some of the remaining neurons dispersed throughout the hippocampus proper as well as in most of the reactive astroglia. Bax immunopositivity was increased in almost all neurons. Fractin immunostaining, an indicator of caspase activity, was detected in approximately 10% of these neurons. Despite increased Bax expression and activation of caspases, we could not find evidence for DNA fragmentation by TUNEL staining. We also could not detect typical apoptotic changes in nuclear morphology by Hoechst-33258 or hematoxylin counterstaining. CONCLUSIONS: These data suggest that either apoptosis is not involved in cell loss in MTS, or a very slow rate of cell demise may have precluded detecting TUNEL-positive neurons dying through apoptosis. Increased Bax expression and activation of caspases support the latter possibility.

Actin Cytoskeleton↗
PubMed2003

Neuronal nuclear antigen (NeuN): a new tool in the diagnosis of central neurocytoma.

The use of neuronal nuclear antigen (NeuN) as a reliable neuronal marker in the differential diagnosis of clear cell neoplasms of the central nervous system was determined in a biopsy series of 23 cases. Immunohistochemical analyses were carried out by antisera against neuronal nuclear antigen, synaptophysin, neuron-specific enolase, microtubule-associated protein 2, and glial fibrillary acidic protein. All eight central neurocytomas were characteristically immunolabeled by NeuN. NeuN immunoreactivity was uniformly strong and basically located in the nuclei of neurocytes. Despite this uniform staining pattern of central neurocytomas, 12 cases of oligodendrogliomas and three cases of ependymoma were negative for NeuN. As the diagnostic criteria for central neurocytoma include immunohistochemical and/or ultrastructural evidence for neuronal differentiation, NeuN as a sensitive and specific neuronal marker in formalin-fixed, paraffin-embedded tissues may greatly facilitate the differential diagnosis of central neurocytomas.

Adolescent↗
PubMed2002

Transcorneal stimulation of trigeminal nerve afferents to increase cerebral blood flow in rats with cerebral vasospasm: a noninvasive method to activate the trigeminovascular reflex.

OBJECT: The goal of this study was to investigate whether stimulation of trigeminal afferents in the cornea could enhance cerebral blood flow (CBF) in rats after they have been subjected to experimental subarachnoid hemorrhage (SAH). Cerebral vasospasm following SAH may compromise CBF and increase the risks of morbidity and mortality. Currently, there is no effective treatment for SAH-induced vasospasm. Direct stimulation of the trigeminal nerve has been shown to dilate constricted cerebral arteries after SAH; however, a noninvasive method to activate this nerve would be preferable for human applications. The authors hypothesized that stimulation of free nerve endings of trigeminal sensory fibers in the face might be as effective as direct stimulation of the trigeminal nerve. METHODS: Autologous blood obtained from the tail artery was injected into the cisterna magna of 10 rats. Forty-eight and 96 hours later (five rats each) trigeminal afferents were stimulated selectively by applying transcorneal biphasic pulses (1 msec, 3 mA, and 30 Hz), and CBF enhancements were detected using laser Doppler flowmetry in the territory of the middle cerebral artery. Stimulation-induced changes in cerebrovascular parameters were compared with similar parameters in sham-operated controls (six rats). Development of vasospasm was histologically verified in every rat with SAH. Corneal stimulation caused an increase in CBF and blood pressure and a net decrease in cerebrovascular resistance. There were no significant differences between groups for these changes. CONCLUSIONS: Data from the present study demonstrate that transcorneal stimulation of trigeminal nerve endings induces vasodilation and a robust increase in CBF. The vasodilatory response of cerebral vessels to trigeminal activation is retained after SAH-induced vasospasm.

Animals↗