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Dive into the research topics where Nalan Akyürek is active.

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Featured researches published by Nalan Akyürek.


Cancer | 2012

Prognostic significance of MYC, BCL2, and BCL6 rearrangements in patients with diffuse large B-cell lymphoma treated with cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab.

Nalan Akyürek; Aysegul Uner; Mustafa Benekli; Ibrahim Barista

Diffuse large B‐cell lymphomas (DLBCLs) are a biologically heterogeneous group in which various gene alterations have been reported. The aim of this study was to investigate the frequency and prognostic impact of BCL2, BCL6, and MYC rearrangements in cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab (R‐CHOP)‐treated DLBCL cases.


Journal of Ethnopharmacology | 2002

In vivo gastroprotective effects of five Turkish folk remedies against ethanol-induced lesions

İlhan Gürbüz; Osman Üstün; Erdem Yesilada; Ekrem Sezik; Nalan Akyürek

Through evaluation of the data accumulated in Data Bank of Turkish Folk Remedies (TUHIB), five plant remedies, which are used to treat stomach ache were selected to test for their anti-ulcerogenic potency. In order to confirm the claimed activities, either decoction or methanol extracts were prepared from the roots of Asphodelus aestivus and Cichorium intybus, herbs of Equisetum palustre and Viscum album ssp. album and fruits of Laurus nobilis, according to their folkloric application way and tested for their effects on ethanol-induced gastric ulcer model in rats. Pharmacological experiments clearly demonstrated that the relevant extracts of all the plants given orally showed significant stomach protection against this model of ulcerogenesis. Results were further evaluated by using histopathological techniques.


Shock | 2007

Beta-glucan attenuates inflammatory cytokine release and prevents acute lung injury in an experimental model of sepsis.

Abdulkadir Bedirli; Mustafa Kerem; Hatice Pasaoglu; Nalan Akyürek; Tugan Tezcaner; Sehri Elbeg; Leyla Memis; Omer Sakrak

Sepsis is one of the most important risk factors in acute respiratory distress syndrome (ARDS). &bgr;-Glucan is a potent reticuloendothelial modulating agent, the immunobiological activity of which is mediated in part by an increase in the number and function of macrophages. In this study, we investigated the putative protective role of &bgr;-glucan against sepsis-induced lung injury. Sepsis was induced by cecal ligation and puncture (CLP) in Wistar rats. The control group received saline, and the treatment groups received &bgr;-glucan or &bgr;-glucan + &bgr;-1,3-D-glucanase. Five hours thereafter, plasma tumor necrosis factor (TNF) &agr;, interleukin (IL) 1&bgr;, and IL-6 levels were determined. Presence of lung injury was determined via lung tissue myeloperoxidase (MPO) activity, intercellular adhesion molecule (ICAM) 1 levels, and histopathological examination at 18 h after CLP. In a separate set of experiments, survival was monitored for 7 days after CLP. &bgr;-Glucan treatment led to a significant increase in survival rate (63% in glucan-treated rats vs 38% in saline-treated rats). Administration of the &bgr;-glucan inhibitor abrogated &bgr;-glucans survival benefit (50%). After CLP, plasma TNF-&agr;, IL-1&bgr;, and IL-6 concentrations were increased in control animals. When &bgr;-glucan was administered, it completely blocked the elevation of TNF-&agr;, IL-1&bgr;, and IL-6. Administration of &bgr;-1,3-D-glucanase suppressed glucan-induced decrease in cytokines. Animals treated with &bgr;-glucan showed a significant reduction in lung injury score, a marked decrease in ICAM-1 expression, and a significant decrease in MPO levels. In contrast, &bgr;-1,3-D-glucanase caused a significantly increased MPO and ICAM-1 levels in the lung. These data reveal that &bgr;-glucan treatment improved the course of CLP-induced peritonitis and attenuated the lung injury. Administration of &bgr;-glucanase inhibited the &bgr;-glucan activity and resulted in enhanced lung injury.


Journal of Asthma | 2003

Expression of Transforming Growth Factor β1 in Bronchial Biopsies in Asthma and COPD

Nurdan Kokturk; Turkan Tatlicioglu; Leyla Memis; Nalan Akyürek; Gülen Akyol

The role of transforming growth factor β1 (TGF β1) in airway remodeling in asthma and chronic obstructive pulmonary disease (COPD) has not been fully described. To evaluate the possible pathogenetic role of TGF β1 in asthma and COPD, immunohistochemical expression of TGF β1 was described in bronchial biopsies from patients with asthma and COPD compared with healthy individuals. Twelve subjects with asthma, 13 subjects with COPD, and 10 healthy individuals enrolled in the study. Bronchial biopsies were stained with hematoxylin and eosin and anti‐TGF β1 antibody. As a result, immunoreactive TGF β1 was mainly localized in association with connective tissue in all groups. The staining intensity was not statistically different among the groups in bronchial epithelium, whereas it was significantly higher in the group of asthma in the submucosa. Because there is evidence showing a significant increase of staining intensity in the submucosa from asthmatics but not from subjects with COPD, we may conclude that TGF β1 may play a significant role in pathogenesis of asthma but not in COPD.


Nephrology | 2007

Alterations in ocular surface and corneal thickness in relation to metabolic control in patients with chronic renal failure

Zeynep Aktaş; Şengül Özdek; Umut Asli Dinc; Nalan Akyürek; Veli Atalay; Galip Guz; Berati Hasanreisoglu

Aim:  Ocular surface changes and ocular symptoms may be encountered in patients with chronic renal failure (CRF) undergoing haemodialysis. The ocular surface changes and its relationship with metabolic control in CRF patients were aimed to be emphasized in this study.


Virchows Archiv | 2006

Survivin expression in pre-invasive lesions and non-small cell lung carcinoma

Nalan Akyürek; Leyla Memis; Özgür Ekinci; Nurdan Kokturk; Can Öztürk

Survivin is an inhibitor of apoptosis protein, which is overexpressed in many carcinomas, including lung carcinoma. The aim of this immunohistochemical study was to investigate the role of survivin in the early steps of lung carcinogenesis and non-small cell lung carcinomas (NSCLC), and its relationship with expression of p53 protein, a tumor suppressor gene involved in cell cycle control. In the normal bronchial epithelium, low-grade atypical adenomatous hyperplasia (AAH) and non-neoplastic lung parenchyma adjacent to tumor, survivin was found completely negative. Expression of survivin was detected in the areas of squamous metaplasia and dysplasia as well as high-grade AAH lesions adjacent to tumor. Survivin was expressed in 50 (64%) and p53 in 41 (53%) NSCLC. Survivin expression was significantly correlated with lymph node metastasis (p=0.02). There was no correlation between survivin and p53 expression. The patients with expression of survivin had significantly worse prognosis (Log-rank test, p=0.003). Multivariate Cox regression analysis showed TNM stage (p<0.001) and survivin expression (p=0.003) as independent prognostic indicators. In conclusion, survivin expression might be an early step in lung carcinogenesis. Survivin expression might also be used as a prognostic indicator predicting the worse outcome in NSCLC, and might be a novel target for the treatment of patients with preinvasive lesions of lung and NSCLC.


International Journal of Radiation Oncology Biology Physics | 2001

Inhibition of epidural scar tissue formation after spinal surgery: external irradiation vs. spinal membrane application.

Huseyin Bora; Şükrü Aykol; Nalan Akyürek; Muge Akmansu; Ömür Ataoǧlu

PURPOSE The scar tissue that forms after lumbar dissection is a severe complication and a cause of lumbar and radicular pain. It was recently shown that radiotherapy could inhibit peridural fibrosis after laminectomy. In this study, the efficiency of external irradiation was compared with spinal membrane application. METHOD AND MATERIALS Thirty male New Zealand rabbits underwent L5 laminectomy. Ten rabbits each received a single fraction of 900-cGy external irradiation administered by 9-MeV electron beam 24 h after the surgery. Ten other rabbits each had spinal membrane applied during laminectomy. The remaining 10 rabbits constituted the control group. All of the rabbits were killed 30 days after the laminectomy. Axial histologic sections through the laminectomy defect were evaluated. Each specimen was scored for the extent and density of fibrosis and arachnoidal adherence. RESULTS The extent and density of fibrosis and arachnoidal adherence differed significantly between the control group and the treatment groups (p < 0.05). However, the extent and density of fibrosis and arachnoidal adherence did not differ significantly between the spinal membrane and irradiation groups (p > 0.05). CONCLUSION This preliminary study showed that high-single-fraction/low-total-dose administered postoperatively can successfully inhibit postsurgical epidural fibrosis as effectively as applied spinal membrane.


Medical Oncology | 2010

Imatinib mesylate-induced acute liver failure in a patient with gastrointestinal stromal tumors

Onder Tonyali; Ugur Coskun; Ramazan Yildiz; Tarkan Karakan; Umut Demirci; Nalan Akyürek; Mustafa Benekli; Suleyman Buyukberber

Imatinib mesylate is a drug that has been approved for treatment of chronic myeloid leukemia, Philadelphia-positive acute lymphoblastic leukemia, and advanced gastrointestinal stromal tumors. Several cases of hepatotoxicity, including fatal liver failure, have been reported with the long-term use of imatinib mesylate. Generally hepatotoxicity resolves after discontinuation of imatinib. Despite discontinuation of imatinib, hepatotoxicity can be progressive. Steroid may be useful in these patients and should be started early. We report a 53-year-old woman with advanced gastrointestinal stromal tumors who developed hepatotoxicity while receiving imatinib and subsequently acute liver failure. Ten weeks after commencing imatinib treatment, hepatotoxicity was determined. Imatinib was immediately ceased. Subsequently, a week later hepatic encephalopathy, jaundice, and coagulopathy occurred. Prednisolone was commenced. Liver biopsy was performed five weeks after the determining of hepatotoxicity. Biopsy showed sinusoidal congestion, necrosis of hepatocytes, inflammation, and hepatocyte drop out around the hepatic venule consistent with drug toxicity. Her liver function tests normalized with a nine-week prednisolone treatment. The patient was discharged. Her liver enzymes remained in normal range following visits. In cases of imatinib-induced acute hepatitis, the administration of prednisolone may be useful in the resolution of the acute episode and allow the reintroduction of a drug without risking recurrence of hepatitis.


Pediatric Blood & Cancer | 2005

Prognostic factors and treatment outcome in childhood hodgkin disease

Aynur Oguz; Ceyda Karadeniz; F. Visal Okur; E. Çağlar Çitak; F. Güçlü Pınarlı; Huseyin Bora; Nalan Akyürek

The goals of this study included: (1) Identification of factors prognostic for event‐free survival (EFS) and overall survival (OS), and (2) Definition of risk groups for risk adapted therapy in children with Hodgkin disease (HD).


Pathology Research and Practice | 2002

Expression of MUC1 and MUC2 mucins in gastric carcinomas: Their relationship with clinicopathologic parameters and prognosis

Nalan Akyürek; Gülen Akyol; Ayse Dursun; Deniz Yamac; Nazan Günel

The aim of this study was to investigate the relationship between MUC1 and MUC2 mucin expressions and clinicopathologic variables in gastric carcinomas with regard to survival times. MUC1 and MUC2 expressions were revealed immunohistochemically in 143 gastric carcinomas. Of these 143 patients, follow-up data were available for 45 (median survival time of 30 months, ranging from 2 to 80 months). MUC1 was detected in 82 (58%), and MUC2 in 60 (42%) out of 143 cases. Papillary adenocarcinomas showed significantly higher MUC1 and MUC2 immunoreactivity than did signet-ring cell and mucinous tumors (p = 0.045 and p = 0.01, respectively). MUC1 was highly positive in intestinal-type carcinomas (p = 0.006), whereas intestinal and diffuse carcinomas did not differ in MUC2 expression. There was a positive correlation between tumor differentiation and MUC1 expression. However, no correlation was found between MUC1 and MUC2 expressions and angiolymphatic invasion. According to the TNM classification, stage 1A tumors have significantly lower rates of MUC1 reactivity compared to higher stages (p = 0.04). The patients with gastric carcinomas expressing MUC1 showed significantly poorer survival than those without MUC1 expression (p = 0.04). The present study suggests that MUC1 expression be a useful prognostic factor for predicting the outcome of gastric carcinoma patients, whereas the role of MUC2 expression is still unclear.

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