Koray Erten
Military Medical Academy
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Featured researches published by Koray Erten.
Urologia Internationalis | 2007
Fikret Erdemir; Mete Kilciler; Selahattin Bedir; Yasar Ozgok; Hidayet Coban; Koray Erten
Introduction: During the last decades numerous prognostic factors have been studied for predicting survival of renal cell carcinoma (RCC). Platelet count has previously been reported to correlate with prognosis in RCC. The aim of the this study was to evaluate the significance of thrombocytosis in determining prognosis in patients with localized RCC who underwent radical nephrectomy. Patients and Methods: The study included 118 consecutive patients. Patients were divided into a normal platelet count group (group 1) and a thrombocytosis group (group 2) according to the preoperative platelet count. Thrombocytosis was defined as a platelet count greater than 400,000/µl. The data about stage distribution, grade, tumor size, histological subtype, hemoglobin level, Body Mass Index (BMI), age, ECOG score, gender, and survival rate of tumors between these two groups were compared. Survival estimates were compared with the Kaplan-Meier method and multivariate analysis was performed using a Cox model. Results: The mean age of the patients was 61.4 years (range 30–78), and the mean follow-up period was 52.7 ± 19.6 months (range 9–96). Thrombocytosis was present in 23 patients (19.49%). Fourteen (60.86%) of 23 patients with thrombocytosis died of disease progression. Patients with thrombocytosis had a worse prognosis than patients without thrombocytosis (p = 0.001). Thrombocytosis was noted in 8 (10.81%) of 74 patients with stage pT1-pT2 disease and in 15 (34.09%) of 44 patients with stage pT3-pT4 disease (p = 0.004). In univariate analysis, platelet count was correlated with T stage, hemoglobin level, lymph node positivity, ECOG score, and tumor size. Controlling for established prognostic indicators of pathologic stage, tumor size, platelet count, and lymph positivity using Cox’s regression test, the difference in survival between the groups remained significant (p < 0.05). Conclusion: The platelet count can be considered a useful prognostic factor in patients with RCC who undergo radical nephrectomy.
Urologia Internationalis | 2006
Mete Kilciler; Selahattin Bedir; Fikret Erdemir; Nazif Zeybek; Koray Erten; Yasar Ozgok
Introduction: We compare the postoperative early and late complications of patients who had undergone ileal conduit (IC) urinary diversion and transureteroureterostomy (TUU) with ureterocutaneostomy (UC) urinary diversion during the same interval and by the same surgeons. Materials and Methods: Between 1992 and 2004, we performed TUU with UC urinary diversion in 27 men and 7 women (group I) and ileal conduit urinary diversion in 57 men and 10 women (group II). The mean age of the TUU with UC diversion and the ileal conduit patients was 57 ± 11.2 (range 51–76) and 64 ± 12.6 (range 54–76) years, and the mean follow-up was 37 (range 14–52) and 56 (range 14–72) months, respectively. The 6F or 8F stents were used routinely. Results: Of 34 TUU with UC cases 8 (23.52%) had early postoperative complications and 2 (5.88%) had early reoperation rates, whereas 11 (16.42%) of 67 ileal conduit cases had early postoperative complications and 4 (5.97%) had early reoperation. The mean hospital stay was 7 (range 5–25 day) and 11 (range 7–34 day) days for each group, respectively. Of the TUU and UC cases, 6 (17.64%) had late complications and 3 had (8.82%) late reoperation, whereas 14 conduit cases (20.89%) had late complications and 6 had (8.9%) late reoperation. Early postoperative complications were defined as those that occurred before hospital discharge or within 30 days from the date of surgery and late complications were defined as those occurring greater than 30 days from the date of surgery as previously described. In group I, the mean operative time was 170 min (range 120–325) compared with 260 min (range 170–473) in group II. The mean blood loss in group I was 474 ml (range 250–1,400) and 589 ml (range 300–1,700) in group II (p > 0.05). Conclusions: Our results suggest that patients undergoing a TUU and UC diversion have no additional risk of reoperation and the TUU with UC urinary diversion is a safe procedure with postoperative early and late complications.
Urologia Internationalis | 2007
Mete Kilciler; Erkan Demir; Selahattin Bedir; Koray Erten; Cenk Kilic; Ahmet Fuat Peker
Background: The aim of the study was to evaluate the pain scores and complications of transrectal ultrasonography (TRUS)-guided prostate biopsy and to compare lithotomy position (LP) versus left lateral decubitis position (LLDP). Methods: A total of 340 patients were referred for TRUS-guided biopsy. In group 1 (n = 170), biopsies were performed in LP (n = 170), and in group 2 (n = 170) biopsies were performed in LLDP (n = 170). In 68 patients, biopsies were repeated. We constituted two additional groups: in group 3 (n = 33) patients underwent biopsies in LP and LLDP, respectively, and in group 4 (n = 35) patients underwent biopsies in LLDP and LP, respectively. Pain score, infection rates, hematospermia, hematuria, rectal bleeding, and serious complications were compared between group 1 and group 2. Pain scores were compared between the four groups. Results: There were no differences between group 1 and group 2 for age, prostate volume, prostate-specific antigen level, biopsy time, hematuria, infection, hematospermia, and rectal bleeding. Pain scores were lower in group 2 than in group 1. Also, for LLDP, pain scores were lower in group 3 and group 4. Conclusion: The effect of position on pain scores in TRUS biopsy patients has not been previously described. Our study indicates that pain scale values are lower in LLDP than in LP.
Human & Experimental Toxicology | 2012
Onur Erdem; Ayşe Eken; Cemal Akay; Zorica Arsova-Sarafinovska; Nadica Matevska; Ljubica Suturkova; Koray Erten; Yasar Ozgok; Aleksandar Dimovski; Ahmet Sayal; Ahmet Aydin
Prostate cancer is the second most common cancer in men worldwide. Although the aetiology of this disease remains largely unclear, several lines of evidence suggest that oxidative stress plays a role in prostate carcinogenesis. The antioxidant enzyme glutathione peroxidase 1 (GPX1) is part of the enzymatic antioxidant defence, preventing oxidative damage to DNA, proteins and lipids by detoxifying hydrogen and lipid peroxides that may contribute to prostate cancer development. Some studies indicate an association between GPX1 Pro198Leu polymorphism and an increased risk of cancer. The purpose of the present study was to determine the possible association of GPX1 Pro198Leu polymorphism and erythrocyte GPX activity with the risk of developing prostate cancer and to clarify whether erythrocyte GPX activity levels were correlated with the GPX1 Pro198Leu genotype in the Turkish population. The GPX1 Pro198Leu genotype was determined in 33 prostate cancer patients and 91 control individuals. As evident from our results, there was no difference between genotype and/or allele frequencies in prostate cancer patients and controls. No significant difference was found in GPX1 genotype or allele frequency between aggressive and non-aggressive prostate cancer patients. It can be suggested with these findings that individual susceptibility of prostate cancer may be modulated by GPX1 polymorphism, but it needs further studies.
Journal of Biochemical and Molecular Toxicology | 2013
Ayşe Eken; Onur Erdem; Zorica Arsova-Sarafinovska; Cemal Akay; Ahmet Sayal; Nadica Matevska; Ljubica Suturkova; Koray Erten; Yasar Ozgok; Aleksandar Dimovski; Ahmet Aydin
Manganese superoxide dismutase (MnSOD) is the most effective antioxidant enzyme in mitochondria and protects cells from reactive oxygen species‐induced oxidative damage. The aim of this study was to investigate the association between MnSOD Ala‐9Val gene polymorphism and prostate cancer (PCa) risk in Turkish men with prostate cancer. 33 patients with PCa and 81 control individuals were included in the study. We observed an association between MnSOD Ala/Ala frequency and a higher PCa risk. In addition, we found that the increased risk of early‐onset PCa (under age of 65) in the men homozygous for Ala allele was higher than the men homozygous for Val allele. However, we determined that MnSOD Ala‐9Val genotype was not associated with the aggressiveness of the disease. The results of our study suggest that MnSOD Ala/Ala genotype may influence on early‐onset of PCa patients, but no effect on subsequent development of the disease in Turkish men. However, our study has a limitation that is small numbers of individuals for cases and controls. Therefore, the presented study limited our statistical power to fully investigate the gene polymorphism on cancer risk.
Kaohsiung Journal of Medical Sciences | 2006
Mete Kilciler; Fikret Erdemir; Selahattin Bedir; Hidayet Coban; Koray Erten; Oğuz Güven; Hasret Topac
Ureteral stents have been widely used for more than two decades with different indications. Due to the widespread usage of ureteral stents, the number of possible complications of ureteral stents has increased, including stent migration, encrustation, stone formation, and fragmentation. Among these complications, ureteral stent fragmentation is rare. Herein, we present a case of spontaneous ureteral stent fragmentation and review the relevant literature.
Urologia Internationalis | 2005
Mete Kilciler; Fikret Erdemir; Selahattin Bedir; Hidayet Coban; Koray Erten; Onder Ors; Yasar Ozgok
Although double J (DJ) ureteral stents are widely used in extrinsic ureteral obstruction, there are few studies using ipsilateral two DJ stents in the same ureter. We report using ipsilateral two ureteral DJ stents in the same ureter in a patient with extrinsic ureteral obstruction due to colon carcinoma.
Journal of Liquid Chromatography & Related Technologies | 2007
Zorica Arsova-Sarafinovska; Ahmet Aydin; Ahmet Sayal; Ayşe Eken; Onur Erdem; Ayhan Savaser; Koray Erten; Yasar Ozgok; Aleksandar Dimovski
Abstract We undertook the present study to develop a validated HPLC method for the determination of malondialdehyde (MDA) levels and to use this method for determination of MDA levels in patients with prostate cancer and benign prostatic hyperplasia. MDA levels were estimated in the erythrocyte and plasma sample of the 25 non‐metastatic prostate cancer patients, 36 benign prostatic hyperplasia (BPH) patients and 24 age‐ and sex‐matched healthy subjects (controls) in HP Chromatographic systems consisting of a Model Agilent 1100 Series. We report a very rapid and simple isocratic reversed‐phase HPLC separation of MDA in normal human plasma and erythrocytes without previous purification of the MDA‐TBA complex. All validation parameters were performed in our methods. Using this methods we have found elevated MDA in the plasma and erythrocyte of the prostate cancer group as compared to controls and BPH group. We have improved and validated an analytical HPLC method for determination of MDA in plasma and erythrocyte, which is simple to perform and having high sensitivity, specificity and substantial improvement in column life. This method has been successfully applied to determination of MDA levels in prostate cancer patients and offers an oportunity to further characterize the role of oxidative injury in the pathogenesis of this disease specifically.
Clinical Biochemistry | 2006
Ahmet Aydin; Zorica Arsova-Sarafinovska; Ahmet Sayal; Ayşe Eken; Onur Erdem; Koray Erten; Yasar Ozgok; Aleksandar Dimovski
Urology | 2007
Erkan Demir; Mete Kilciler; Selahattin Bedir; Koray Erten; Yasar Ozgok