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Öğe Boost dose back again in elderly(AMER SOC CLINICAL ONCOLOGY, 2007) Gultekin, Melis; Selek, Ugur; Ozyigit, Gokhan; Cengiz, Mustafa; Yavas, Ozlem; Yildiz, Ferah[Abstract not Available]Öğe Classical Kaposi's Sarcoma: efficacy of single high dose radiotherapy(PERGAMON-ELSEVIER SCIENCE LTD, 2005) Yıldız, Ferah; Genç, Mine; Cengiz, Mustafa; Özyar, Enis; Akbulut, S.; Hurmuz, P.; Atahan, I.[Abstract not Available]Öğe Determination of antioxidant activities of solvent extracts from an endemic plant: Phlomis leucophracta(MARMARA UNIV, FAC PHARMACY, 2018) Sarıkürkçü, Cengiz; Cengiz, Mustafa; Küçükyumru, Ahmet; Zengin, GökhanThe members of the genus Phlomis have been traditionally used for therapeutic purposes in Turkey. In this study, the antioxidant properties of different extracts from P. leucophracta were investigated. Antioxidant properties were evaluated by different assays including free radical scavenging (DPPH assay), reducing power (potassium ferricyanide method), beta-carotene/linoleic acid, metal chelating and phosphomolybdenum. Moreover, total phenolic and flavonoid contents were detected for each extracts. Total phenolic and flavonoid contents were detected as 30.86-55.00 mg GAE/g extract and 4.93-26.09 mg QE/g extract, respectively. The methanol and water extracts exhibited higher DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging and reducing power abilities as compared to ethyl acetate and hexane extracts. The best activity was observed by the hexane extract in beta-carotene/linoleic acid assay (94.35% at 2 mg/mL). In metal chelating ability, those samples exhibited the following order (at 0.25 mg/mL concentration): Water (73.90%)>Hexane(64.87%)>Ethyl acetate(4.88%)>Methanol(2.28%). Based on our results, P. leucophracta may be utilized as a natural source of antioxidant compounds in food and pharmaceutical areas.Öğe İki ononis türünün antioksidan aktivitelerinin karşılaştırılması(2016) Sarıkürkcü, Cengiz; Cengiz, Mustafa; Çomak, Zafer; Zengin, Gökhan; Aktümsek, AbdurrahmanOnonis türleri Anadolu geleneksel halk hekimliğinde çeşitli rahatsızlıklar için kullanılmaktadır Bu çalışmada, iki Ononis türünden (O. pubescens ve O. ornithopodioides) elde edilen iki özütün (etil alkol ve su) antioksidan aktvite araştırıldı. Antioksidan etkiler serbest radikal (DPPH ve O2.), ?-karoten ağartma yöntemi, indirgeme gücü ve metal şelatlama testleri içeren farklı test sistemleri ile değerlendirildi. Ayrıca, her bir özüt için toplam fenolik ve flavonoit miktarı da hesaplandı. Toplam fenolik ve flavonoit madde miktarı gibi antioksidan aktivite de kullanılan çözücüyle güçlü bir ilişki göstermektedir. Bu çalışmadan elde edilen sonuçlar Ononis türlerinin gıda ve farmasötik uygulamalarda doğal ajanların bir kaynağı olarak faydalı olabileceğini göstermiştirÖğe Merkel Cell Carcinoma in a Child(LIPPINCOTT WILLIAMS & WILKINS, 2009) Koksal, Yavuz; Toy, Hatice; Talim, Beril; Unal, Ekrem; Akcoren, Zuhal; Cengiz, MustafaMerkel cell carcinoma, a rare tumor of the skin with aggressive behavior, is usually fatal when advanced disease is present. Merkel cell carcinoma occurs mostly in white race between 60 and 80 years of age, however, it can occur in any races and ages. It is extremely rare in children. We present here a Merkel cell carcinoma in a boy. Its features and treatment modalities were. discussed in the literature light.Öğe Merkel cell carcinoma in a child -- 2(WILEY-LISS, 2007) Unal, Ekrem; Koksal, Yavuz; Toy, Hatice; Talim, Beril; Unal, Ekrem; Akcoren, Zuhal; Cengiz, Mustafa[Abstract not Available]Öğe A Possible Mechanism of X-Ray-İnduced Injury in Rat Lens(Springer Tokyo, 2000) Avunduk, Avni Murat; Yardımcı, Serdar; Avunduk, Mustafa Cihat; Kurnaz, Levent; Cengiz, MustafaPurpose: X-ray and other radiation can cause cataract, but the pathogenic mechanism is largely unknown. The aim of this study was to investigate the accumulation of iron in the x-ray-exposed rat lens and its relationship to lens injury. Methods: Fifty male Wistar rats were divided randomly into five groups of 10. Groups 2 and 4 rats were sham-exposed, groups 3 and 5 were x-ray-treated, and group 1 served as control. X-ray radiation and sham exposure were performed in a similar manner. After 10 and 30 days of exposure, a lens from each rat in groups 2 and 3, and 3 and 5, respectively, were analyzed by flame atomic absorption technique for the assessment of metal content. Results: Significantly decreased zinc and increased iron and calcium concentrations were detected in the lens samples of groups 3 and 5 compared with groups 2 and 4 and controls. Similar results were obtained comparing groups 5 and 3. Conclusions: We propose that x-ray exposure may cause toxic cell injury of the rat lens via Fenton metals catalyzed damage. initial lens membrane damage in the radiolytic phase may permit the access of iron resulting in lens damage.Öğe Radiotherapy in the management of Kaposi's sarcoma: Comparison of 8 Gy versus 6 Gy(NATL MED ASSOC, 2006) Yıldız, Ferah; Genç, Mine; Akyürek, Serap; Cengiz, Mustafa; Özyar, Enis; Selek, Uğur; Atahan, I. LaleObjective: To evaluate prospectively the efficacy of a single fraction of high-dose radiotherapy in patients with Kaposi's sarcoma. Patients: Between 1994 and 2004, 47 patients with Kaposi's sarcoma were treated at Hacettepe University, Department of Radiation Oncology. Thirteen (28%) patients received chemotherapy before radiotherapy and were referred due to recurrent or progressive disease or intolerance to chemotherapy. All lesions were treated locally with a 2-3-cm safety margin with 4-6-MeV electron beams. Radiotherapy consisted of a single fraction of 8 Gy in the first four years and 6 Gy thereafter. Results: The male:female ratio was 4:1. The median age was 61 years (range 18-87). Eight out of 47 patients (17%) had an underlying immunocompromised state, and one had a previous diagnosis of Hodgkin's disease. Of 203 fields treated, 51 and 152 fields were treated with 8 Gy and 6 Gy, respectively. Overall response rates (RR) at 12 months for 8- and 6 Gy were 93% and 86%, which were not statistically different. However, the difference between complete RRs at 12 months (93% and 60% for 8 Gy and 6 Gy respectively) was significant (p < 0.0001). Progression-free survival and reirradiation rates were not significantly different. Side effects were tolerable in all but three patients with grade 2-3 fibrosis and edema. Conclusion: Radiotherapy is an effective mode of treatment for Koposi's sarcoma, and a single dose of 8 Gy is more effective in terms of complete RR compared to 6 Gy, though overall response and progression-free survival rates were similar.Öğe Salvage Stereotactic Body Radiosurgery in the Management of Recurrent Gynecological Cancer(AKAD DOKTORLAR YAYINEVI, 2013) Yazici, Gozde; Cengiz, Mustafa; Ozyigit, Gokhan; Yavas, Guler; Ayhan, Ali; Gurkaynak, Murat; Yildiz, FerahLocal tumor persistence in the pelvis is the major cause of death in patients with recurrent gynecological cancer. Pelvic exenteration has been the only treatment option providing a chance for cure in selected patients. The aim of this study is to analyze the efficacy of stereotactic body radiosurgery (SBRS) in patients with recurrent gynecological cancer. Sixteen patients treated with SBRS were analyzed retrospectively. The majority of the patients had cervical cancer. Eleven patients had a history of prior radiotherapy either as postoperative adjuvant external beam radiotherapy (EBRT) with a median dose of 50.4 Gy (range 45-60 Gy) or definitive chemoradiotherapy as EBRT and high dose rate brachytherapy with a dose of 85-90 Gy low dose rate equivalent to point A. The prescribed dose of SBRS was 15-40 Gy (mean 26.6 Gy) in 3-5 fractions. Five patients with no prior radiotherapy received additional EBRT before SBRS. The median follow-up in all patients is 12 months (range 3-36 months). Six patients (37.5%) showed complete radiological and functional response to salvage SBRS. Six patients (37.5%) showed partial response and 2 (12.5%) showed stable disease. One and 2 year overall survival rates are 60.3% and 40.2% respectively. Progression free survival is 59%. All patients with complete response after SBRS are alive with no evidence of disease with a median follow up time of 20 months. SBRS is a promising treatment modality with high local Control and reasonable complication rates in selected patients with recurrent gynecological cancer.
