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Dive into the research topics where Gaye Guler Tezel is active.

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Featured researches published by Gaye Guler Tezel.


Pathology Research and Practice | 2003

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

Figen Soylemezoglu; Sevgen Onder; Gaye Guler Tezel; Mustafa Berker

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.


Journal of the Neurological Sciences | 2008

Investigation of HSV-1, HSV-2, CMV, HHV-6 and HHV-8 DNA by real-time PCR in surgical resection materials of epilepsy patients with mesial temporal lobe sclerosis

Hulya Karatas; Gunfer Gurer; Ahmet Pinar; Figen Soylemezoglu; Gaye Guler Tezel; Gulsen Hascelik; Nejat Akalan; Serdar Tuncer; Abdurrahman Ciger; Serap Saygi

OBJECTIVE The objective of this study is to investigate the presence of viral DNAs of HSV-1, HSV-2, HHV-6, HHV-8, and CMV in hippocampus of the patients with mesial temporal lobe epilepsy (MTLE) syndrome. METHODS Pathological specimens were obtained from 33 patients with MTLE undergone temporal lobectomy with amygdalo-hippocampectomy due to intractable seizures. Autopsy materials from the hippocampus of 7 patients without neurological disease were used as controls. The data was also correlated with the clinical history of patients including febrile convulsions, age, and history of CNS infections. Real-time polymerase chain reaction method was performed for detection of DNAs of these viruses. RESULTS HHV-6, HSV-1 and HHV-8 were detected in the hippocampus of 3, 2 and 1 patients with MTLE respectively. None of the hippocampus of patients with MTLE was positive for DNA of HSV-2 and/or CMV. Three patients with positive HHV-6 DNAs had febrile convulsions and family history for epilepsy. None of our control specimens showed PCR positivity to any of the 5 tested viruses. CONCLUSIONS Our study is the first to report the presence of HHV-8 viral genome in the brain tissue of patient with MTLE. Viral DNAs were detected in a total of 18% of the patients in this study; we can conclude that activity of the latent virus in patients with hippocampal sclerosis should be more extensively studied to establish its role in active infection.


Pathology International | 2007

Diffuse fatty infiltration in amyloid goiter

Cigdem Himmetoglu; Seda Yamak; Gaye Guler Tezel

Presented herein is a case of diffuse fatty infiltration of amyloid goiter in a 58‐year‐old woman with chronic renal failure. Bilateral total thyroidectomy was performed due to symptoms of dysphagia and hoarseness. Macroscopic and microscopic examination showed that almost all thyroid follicles were replaced by fat cells. Hyalinized stroma intervening the fatty infiltration was shown to harbor amyloid deposition.


Urology | 2011

Effect of Sildenafil Citrate on Penile Weight and Physiology of Cavernous Smooth Muscle in a Post–radical Prostatectomy Model of Erectile Dysfunction in Rats

Ender Özden; Bulent Ozturk; Murat Kosan; Gaye Guler Tezel; Fazil Tuncay Aki; Serap Gur; Ali Ergen; Haluk Ozen

OBJECTIVES To evaluate the gross morphometric changes and in vitro responses of the corpus cavernosus of rats treated with sildenafil citrate after cavernous neurotomy. METHODS The animals were divided into 3 groups. Group 1 consisted of sham-operated rats (n = 16); group 2 consisted of rats that underwent bilateral cavernous neurotomy (BCN) (n = 16); and group 3 consisted of rats that underwent unilateral cavernous neurotomy (UCN) (n = 16). Each group of rats was further classified into 2 subgroups according to whether or not they received sildenafil treatment. The rats were killed on postoperative day 14, and penectomy was performed. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL), and organ-bath studies were evaluated by Phenylephrine (Phe), acetylcholine (Ach), sodium nitroprusside (SNP), and electrical field stimulation (EFS) responses. RESULTS Penile weight in the BCN group was significantly lower than that of sham-treated group. UCN allowed much more preservation of penile weight compared with that in the sham-treated group. Sildenafil citrate treatment had positive effects on penile weight of both BCN (P = .003) and UCN (P = .004) groups. BCN increased smooth muscle apoptosis when compared with the sham or UCN group. Sildenafil citrate had a positive effect on the apoptotic index. In the BCN group, responses to Phe, Ach, SNP, and EFS decreased significantly, and sildenafil treatment corrected the responses to Phe, Ach, and SNP. CONCLUSIONS Our experimental study results support that early and daily sildenafil citrate treatment has a protective affect on the adrenergic and cholinergic systems, which play a role in erectile function.


Ophthalmic Research | 2007

Expression of Vascular Endothelial Growth Factor A, Matrix Metalloproteinase 9 and Extravascular Matrix Patterns in Iris and Ciliary Body Melanomas

Afsun Sahin; Hayyam Kiratli; Gaye Guler Tezel; Figen Soylemezoglu; Sevgül Bilgiç

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.


Acta Neurochirurgica | 2004

A glioma with an arteriovenous malformation: an association or a different entity?

Ibrahim M. Ziyal; K. Ece; Burcak Bilginer; Gaye Guler Tezel; Ozcan Oe

Case reportA 58-year-old male was admitted with headache to our neurosurgery clinic. His neurological examination revealed slight left hemiparesis. The radiological evaluation with contrast administred magnetic resonance imaging (MRI) scan demonstrated a right temporo-parietal ring enhancing mass lesion surrounded by edema which was resembling a typical glioma (Fig. 1). The patient was operated on via a temporo-parietal craniotomy and an arteriovenous malformation surrounded by abnormal glial tissue was observed during the exposure. A nidus supplied by several branches arising from the middle cerebral artery (MCA) was obvious. The venous drainage of the malformation was to the superficial venous system. The observed arterial feeders and the draining vein were coagulated and the nidus was macroscopically totally excised. The frozen examination from surrounding glial tissue revealed a high grade glioma. The tumor was also macroscopically totally excised. Postoperatively, the cerebral angiogram demonstrated a right temporal arteriovenous malformation with a centrally excised nidus. The remaning major feeders involved the angular gyrus and the posterior temporal arteries. The venous drainage was to the straight and sigmoid sinuses (Fig. 2). The final histopathological examination of the specimen revealed an arteriovenous malformation surrounded by a high grade glioma (Fig. 3). The patient refused a second operation for total removal of the AVM. Postoperatively, he is doing well with improvement of his left hemiparesis.


Childs Nervous System | 2001

Cranial infantile myofibromatosis: report of three cases

Figen Soylemezoglu; Gaye Guler Tezel; Fulya Köybaşoglu; Uygur Er; Nejat Akalan

Abstract. Background: Infantile myofibromatosis is a proliferative disorder of infancy and early childhood characterized by the development of single or multiple nodular lesions arising from cutaneous or subcutaneous tissue, muscle, bone or visceral organs. In approximately one-third of cases, this myofibroblastic proliferation involves the head and neck region. Case report: In this paper we report on three cases of cranial infantile myofibromatosis in infants. The clinical presentation and the deceptive histopathological features can make diagnosis difficult. Conclusion: The significance of recognizing this entity is stressed, since its indolent clinical behavior might prevent diagnosis.


Pathology Research and Practice | 2009

RET finger protein expression in invasive breast carcinoma: Relationship between RFP and ErbB2 expression☆

Gaye Guler Tezel; Aysegul Uner; Işıl Z. Yıldız; Gulnur Guler; Masahide Takahashi

RET finger protein (RFP), which belongs to the large B-box RING finger protein family, has been reported to be expressed in breast carcinoma cell lines. We conducted this study to evaluate the expression level of RFP in breast carcinomas. Tissue microarrays were constructed from 133 cases of invasive breast carcinoma. Sections obtained from tissue arrays and whole sections from 10 non-neoplastic breast tissues were stained for ER, PR, ErbB2, and RFP using immunohistochemistry, and ErbB2 gene status was evaluated by FISH. The correlation between various immunohistochemical markers was determined. We found nuclear RFP expression in 41.4% of invasive carcinomas and in none of the non-neoplastic breast tissues. We also stained whole sections of 29 cases of invasive breast carcinoma, which included the TMA study, and 10 cases of ductal carcinoma in situ (DCIS) by RFP. We observed that four (40%) of the DCIS cases were positive with RFP. In statistical analysis, there was a significant, positive association between RFP and ErbB2 status at the protein level (p=0.002) and the gene level (p=0.049). There was no statistically significant association between the expression of RFP and tumor size, LN status, ER, PR, and grade (p>0.05). However, we found a significant association between age and RFP expression. RFP expression was stronger in patients 50 years or older (p=0.048). In our study, the expression of RFP correlated strongly with ErbB2 status. Our study is the first in the literature to show expression of RFP in patients with breast carcinoma. However, the possible role of RFP in breast carcinogenesis needs to be investigated in more detailed clinical and experimental studies.


Japanese Journal of Ophthalmology | 2007

Expression of vascular endothelial growth factor-A, matrix metalloproteinase-9, and extravascular matrix patterns and their correlations with clinicopathologic parameters in posterior uveal melanomas.

Afsun Sahin; Hayyam Kiratli; Figen Soylemezoglu; Gaye Guler Tezel; Sevgül Bilgiç; Osman Saracbasi

PurposeTo assess extravascular matrix patterns (EMP) and expression of vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase-9 (MMP-9) in posterior uveal melanomas and their correlations with histopathologic parameters and metastasis.MethodsThis study was conducted on 100 consecutive eyes enucleated for posterior uveal melanomas. All tumors were examined by immunohistochemical techniques for VEGF-A and MMP-9 expression, and the presence of EMPs was assessed on routine paraffin sections stained with reticulin. Cell type, tumor localization, degree of pigmentation, necrosis, mitotic index, lymphocytic infiltration, and scleral and optic nerve invasion were analyzed by using light microscopy. No eyes had received prior treatment such as radiotherapy or transpupillary thermotherapy.ResultsIdentified histopathologically, cell types were spindle cells in 60% of the cases, mixed cells in 14%, and epithelioid cells in 26% of tumors. Positive reaction for VEGF-A and MMP-9 was present in 84% and 72% of the tumors, respectively. Microvascular loops and/or networks were seen in 34% of the tumors, with the remaining 16% of the tumors displaying an arc pattern, 21% displaying a parallel pattern, and 29% displaying the normal pattern. The relationships between VEGF-A and MMP-9 expression and necrosis, the degree of lymphocyte infiltration, mitotic rate, and the formation of loop and network patterns were found to be statistically significant (P < 0.05). Metastatic disease developed in 14 patients during follow up.ConclusionsThe incidence of metastatic melanoma increased with the increasing expression of VEGF-A and MMP-9. Our data suggest that increasing VEGF-A and MMP-9 expression and the EMP can be used as independent prognostic factors in the management of posterior uveal melanoma following enucleation. Jpn J Ophthalmol 2007;51:325–331


Childs Nervous System | 2005

Epidermoid cyst of the brain stem symptomatic in childhood

Ibrahim M. Ziyal; Burcak Bilginer; Gökhan Bozkurt; Oguz Cataltepe; Gaye Guler Tezel; Nejat Akalan

BackgroundEpidermoid cysts may remain asymptomatic for a long period of time due to their slowly growing pattern corresponding with the normal human skin turnover time and due to soft and light cyst content. They do not cause compression of neural and vascular structures initially that is why almost all of the cases in the literature are diagnosed during adulthood.MethodsWe report here an epidermoid cyst in childhood, which was located in the medulla oblongata, unusually and atypically with liquefied cyst content. The liquefaction may occur due to an intrauterine or early childhood infection. The reported case also suffered previously a severe respiratory infection. Although the cyst is located in and around a highly eloquent neural area, plasticity of the brain stem prevented neurological deterioration due to this very slow growing extraaxial mass lesion. The ordinary cyst content found in the center of the cyst cavity during the operation suggested that the same ordinary material, which was previously at the periphery, ran to get liquefied in time.ConclusionWe suggest that the symptoms of this present case appeared very early due to liquefaction of the cyst content with compression and displacement of the brain stem caudally. The recent infection process may predispose the pathological condition.

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