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Öğe Detection of telomerase activity in bronchial lavage as an adjunct to cytological diagnosis in lung cancer(Elsevier Science Bv, 2003) Dikmen, E.; Kara, M.; Dikmen, G.; Cakmak, H.; Dogan, P.Objective: Definitive diagnosis of lung cancer with conventional methods may sometimes be difficult in clinical practice. Telomerase is a ribonucleoprotein DNA polymerase that maintains the telomeric region of chromosomes during successive rounds of cell division. Telomerase activity in body cavity fluids has been advocated to be a potential diagnostic marker for malignancy. We investigated the diagnostic value of telomerase activity in bronchial lavage samples of patients undergoing diagnosis of lung cancer. Methods: A total of 29 bronchial lavage samples were collected from patients in whom the diagnosis was confirmed with cytological and/or histological examinations. Patients were classified as lung cancer patients (Group 1, n = 22) and patients with benign disease (Group 2, n = 7). Telomerase activity was determined with polymerase chain reaction-based TRAP (The telomeric repeat amplification protocol) assay. Results: Cytological examination was diagnostic in 12 (54.5%) of 22 patients in Group 1, and in all seven patients of Group 2 (P = 0.063). Telomerase activity was positive in 16 (72.7%) of Group I patients, while it was positive in only 1 (14.3%) sample of a lung abscess in Group 2 (P = 0.011). The sensitivity rate of cytological examination when combined with telomerase activity (81.8%) was significantly greater than that of cytological examination alone (54.5%) (P = 0.031). The sensitivity and specificity of telomerase activity were 72.7 and 85.7%, respectively. Telomerase activity had a positive predictive value as 0.94 and negative predictive value as 0.50. Diagnostic accuracy of telomerase activity was 75.8%. Conclusion: Telomerase activity in bronchial lavage is a highly sensitive diagnostic biomarker for malignancy and a potential complementary diagnostic technique to cytological examination in the diagnosis of lung cancer. (C) 2002 Elsevier Science B.V. All rights reserved.Öğe Diagnostic implications of telomerase activity in pleural effusions(European Respiratory Soc Journals Ltd, 2003) Dikmen, G.; Dikmen, E.; Kara, M.; Şahin, E.; Dogan, P.; Özdemir, N.The aim of the present study was to investigate the diagnostic efficacy of telomerase activity for discrimination of malignant and benign pleural effusions. Pleural effusions were collected from 109 consecutive patients in whom the diagnosis was confirmed with cytological and/or histological examinations. Cytological samples were classified as malignant (n=63) and benign (n=46). Telomerase activity was determined with the polymerase chain reaction-based telomeric repeat amplification protocol assay. Telomerase activity was detected in 52 (82.5%) and nine (19.6%) samples from the malignant and benign groups, respectively, which was a significant difference. The sensitivity rate of cytological examination when combined with telomerase activity (92.1%) was significantly greater than that of cytological examination alone (53.9%). The sensitivity and specificity of telomerase activity were 82.5 and 80.4%, respectively. Diagnostic accuracy of telomerase activity was 81.6%. Telomerase activity is a highly sensitive diagnostic biomarker for malignancy and may be used as an adjunct to cytological findings in determining malignant pleural effusions.Öğe The protective effect of trapidil on ischemia reperfusion injury(Wiley, 2006) Somuncu, S.; Çakmak, M.; Dikmen, G.; Dogan, P.…Öğe The protective effect of trapidil on ischemia/reperfusion injury in intussusceptions(2009) Çakmak, Murat; Soyer, Tutku; Ayva, Şebnem; Dikmen, G.; Akman, H.Aim: An experimental study was performed to evaluate the protective effect of platelet-derivated-growth factor inhibitor (Trapidil) in ischemia reperfusion injury in intussusception. Methods: Sixty Wistar albino rats, weighing 200-250 g in both sexes were enrolled into study. In control group (CG, n:15), 2 cm of intestinal segment, 20 cm proximal to ileoceacal valve was removed after intraperitoneal NaCl infusion. In intussusception group, intussusception (IG, n:15) was performed at 20 cm proximal to ileoceacal valve by pushing the proximal intestinal segment distally through a stile. Two cm of intestinal segment was removed 4 hours after intussusception. Intussusception-reperfusion group (IRG, n:15) was obtained after performing intussusception similar to IG and allowed to perfusion 4 hours after intussusception. In this group, intestinal segment was removed 4 hours after reperfusion. In the last group (TG, n:15), Trapidil (40 mg/kg) was administered intraperitoneally, one hour before reperfusion, after achiving an ischemia/reperfusion injury similiar to IRG. Two cm of intestinal segments, 20 cm proximal to ileoceacal valve, were removed for histopathologic evaluation. The specimens were also evaluated for oxidative injury markers (catalase, glutathione peroxidase-G-px, superoxide dismutase-SOD, and malondialdehyde-MDA). Results: Although histopathologic evaluations revealed no intestinal injury in CG, other groups showed higher grades of intestinal injury (p<0.05). Though, there was no difference in histopathologic grades between IG, IRG and TG groups. MDA levels were significantly increased in experiment groups when compared to CG. But, significant alteration in MDA levels was detected in TG, when compared to IRG (p=0.00). Antioxidant enzymes; Catalase, G-px and SOD, significantly decreased in IG and IRG. Trapidil administration increased the levels of these three enzymes when compared to IRG (p=0.005, p=0.036, p=.0.02 respectively). Conclusion: Trapidil prevents ischemia-reperfusion injury in intussusception by increasing catalase, G-px, SOD levels and causes a significant reduction in MDA levels. However, similar results was not found in histopathologic findings.