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Dive into the research topics where Cem Güler is active.

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Featured researches published by Cem Güler.


Journal of Endourology | 2004

Plasma Kinetic Vaporization of the Prostate: Clinical Evaluation of a New Technique

Cetin Dincel; M. Murat Samli; Cem Güler; Murat Demirbas; Mustafa Karalar

PURPOSE We evaluated our results with bipolar plasma kinetic electrovaporization in the treatment of benign prostatic hyperplasia (BPH). PATIENTS AND METHODS Twenty-one patients with infravesical obstruction by BPH have been treated with bipolar plasma kinetic electrovaporization. International Prostate Symptom Score (IPSS) with a quality of life (QOL) scoring questionnaire, uroflowmetry (maximum flow rate; Qmax), transrectal ultrasonography (TRUS), and residual urine volume and prostate specific antigen (PSA) measurements had been performed before surgery. The IPSS scores, prostate volumes, and residual urine volumes were reevaluated during the third postoperative month. Uroflowmetry was repeated on postoperative days 7, 15, 30, and 90. Total PSA and free PSA measurements were repeated on postoperative days 3, 5, 7, 15, 30, and 90. RESULTS The results of 20 patients could be evaluated. The median age of these patients was 61 years. The median volume of the prostates was 42 cc (95% CI 56-53). The median operation time and postoperative hospitalization were 55 minutes (95% CI 40-65) and 3 days (95% CI 3-5), respectively. The mean period of time needed for vaporizing 1 g of tissue was calculated as 2.8 +/- 1.3 minutes. Postoperative day 90 values of IPSS, QOL, prostate volume, residual urine volume, and Qmax showed significant improvement compared with preoperative values (p < 0.05). The median preoperative PSA value was 1.64 mg/mL (95% CI 1-3.6). The value showed a statistically significant increase 24 hours after the intervention (p < 0.0001), but the PSA values on the 30th (p = 0.041) and 90th (p = 0.025) days were below preoperative values. CONCLUSION The IPSS with QOL scores, prostate volumes, and residual urine volumes showed significant decreases and Qmax values showed a significant increase after bipolar plasma kinetic electrovaporization. This treatment modality causes a temporary increase in the PSA concentration, as do other interventional treatment methods, but the measurements on the 30th and 90th days were below preoperative values.


International Urology and Nephrology | 1994

Open stone surgery: Is it still a preferable procedure in the management of staghorn calculi?

Adil Esen; Ziya Kirkali; Cem Güler

We reviewed 43 patients with staghorn calculi to determine the effectiveness of various treatment modalities such as extracorporeal shock wave lithotripsy (ESWL) monotherapy, ESWL and percutaneous nephrolithotomy (PCNL) combined therapy, and open stone surgery.While ESWL monotherapy and ESWL+PCNL were performed in 25 and 8 patients, respectively, 10 patients underwent open stone surgery. Of the 25 patients treated with ESWL, 8 were stone-free, whereas 4 out of 8 patients treated with ESWL+PCNL and 8 out of 10 patients treated with open surgery were stone-free. The complications of ESWL monotherapy consisted of pyelonephritis in one patient, and stone street formations in three. In the group of ESWL+PCNL, one patient developed pyonephrosis, and another perinephritic abscess. No serious complication was noted in patients who underwent open surgery, but an average of 525 ml of blood transfusion was required.We conclude that open stone surgery, although invasive, is still beneficial in the treatment of staghorn calculi.


Journal of Endourology | 2004

Extracorporeal shockwave lithotripsy for solitary distal ureteral stones: Does the degree of urinary obstruction affect success?

Murat Demirbas; Ahmet C. Kose; Murat Samli; Cem Güler; Turgay Kara; Mustafa Karalar

BACKGROUND AND PURPOSE Extracorporeal shockwave lithotripsy (SWL) is a safe and effective way to treat stones in the distal ureter, but the impact of urinary obstruction on outcome is not clear. We investigated the relation between the degree of stone-induced urinary obstruction and the outcome of SWL treatment in patients with solitary distal ureteral stones. PATIENTS AND METHODS A series of 165 consecutive patients with solitary distal ureteral stones underwent SWL (Multimed 9200 Lithotriptor, Elmed Medical Systems, Turkey) between October 2002 and September 2003 at two separate centers. Distal ureteral stones were defined as those located below the lower border of the sacroiliac joint. Patients were divided into four groups according to the degree of stone-induced urinary obstruction: group I (N = 62) had no urinary system dilation; group II (N = 40) had mild dilation, group III (N = 35) moderate dilation, and group IV (N = 28) severe dilation. In addition to degree of obstruction, stone size, average fluoroscopy time, total number of shockwaves applied, number of sessions required to achieve stone-free status, and stone clearance time were recorded. Treatment failure was defined as persistence of fragments after three SWL sessions. RESULTS Overall, 152 (92.1%) of the patients became stone free after SWL. There were no statistically significant differences among the groups with respect to any of the factors studied. CONCLUSION In cases where there is a solitary calculus in the distal ureter, the degree of urinary obstruction caused by the stone does not affect the success of stone clearance with SWL.


European Urology | 2001

Significance of Tissue Laminin P1 Elastase and Fibronectin Levels in Transitional Cell Carcinoma of the Bladder

Güldal Kirkali; Emre Tüzel; Cem Güler; Semra Gezer; Ziya Kirkali

Objective: Elastase is a serine protease which hydrolyses connective tissue components. Laminin and fibronectin also play an important role in progression and invasion of cancer. The purpose of this study is to investigate the relation between tissue elastase, laminin P1 and fibronectin levels and tumor characteristics, and analyze the potential of these as prognostic factors in transitional cell carcinoma (TCC) of the bladder. Methods: Thirty–four patients with TCC of the bladder and 11 controls were included in this study. Elastase and fibronectin levels in tissue homogenates were determined using an enzyme immunoassay and laminin P1 by radioimmunoassay. Mean follow–up was 43 months. Results: The mean elastase level in bladder carcinoma tissue was 120±11.42 ng/homogenate protein, while normal tissue level was 12.36±2.70 (p<0.01). The carcinoma and normal tissue mean laminin P1 levels were 7.02±0.37 U and 0.65±0.10 U/mg homogenate protein, respectively (p<0.01). The mean fibronectin level was 19.97±1.45 ng/mg homogenate protein in the carcinoma tissue and 2.16±0.40 in normal tissue (p<0.01). There was no correlation between tumor stage, grade, size, multiplicity and elastase, laminin P1 and fibronectin levels. Conclusion: These results provide evidence that tissue elastase, laminin P1 and fibronectin levels increase in TCC of the human bladder. Further studies including serum and urine levels should be performed in order to analyze their value as tumor markers in a larger group of patients.


Journal of Endourology | 2004

Comparison of changes in tissue oxidative-stress markers in experimental model of open, laparoscopic, and retroperitoneoscopic donor nephrectomy

Murat Demirbas; Murat Samli; Yasemin Aksoy; Cem Güler; Asuman Kilinç; Cetin Dincel

PURPOSE We evaluated the oxidative stress in renal tissue during three types of surgery: open donor nephrectomy (ODN), laparoscopic donor nephrectomy (LDN), and retroperitoneoscopic donor nephrectomy (RDN). The aim was to find out which is the appropriate procedure for harvesting a donor kidney. MATERIALS AND METHODS Twenty-four New Zealand White rabbits were randomized to four groups, each consisting of six rabbits. Group I (control) was subjected to 180 minutes of anesthesia, and transperitoneal nephrectomy was performed without creation of warm ischemia. In group II (ODN), after 180 minutes of anesthesia, warm ischemia was created for 5 minutes, and nephrectomy was performed. Group III (LDN) was subjected to 5 minutes of warm ischemia after 180 minutes of pneumoperitoneum at 12 mm Hg, and the kidney was removed. In group IV (RDN), after pneumoretroperitoneum at 12 mm Hg for 180 minutes, warm ischemia was created for 5 minutes, and nephrectomy was performed. Renal tissues were analyzed to determine malondialdehyde (MDA) and reduced glutathione (GSH) as oxidative-stress markers. RESULTS Renal tissue GSH levels were decreased, whereas MDA levels were increased in groups II through IV compared with the control group (p<0.05). There was no statistically significant difference between the ODN, LDN, and RDN groups in the renal oxidative-stress markers. CONCLUSION No differences were detected in oxidative-stress markers in renal tissue samples between ODN, LDN, and RDN. Therefore, we believe LDN and RDN can be used for live donor kidney harvesting as effectively as ODN without creating greater oxidative stress, which can have deleterious effects on a donor kidney.


Journal of Endourology | 2004

Effects of carbon dioxide pneumoretroperitoneum on free radical formation in remote organs and use of verapamil as an antioxidant

Cem Güler; M. Murat Samli; Yasemin Aksoy; Murat Demirbas; Asuman Kilinç; Ender Ellidokuz; Cetin Dincel

BACKGROUND AND PURPOSE Pneumoretroperitoneum (Prp) acts as an ischemia/reperfusion (I/R) model. Ischemia/reperfusion (I/R) injury causes production of reactive oxygen species, which affect organs remote from the sites of I/R. The aim of this study was to assess the remote organ changes after Prp and to explore the effects of antioxidants. MATERIALS AND METHODS Eighteen adult rabbits were randomized to three groups, each consisting of six rabbits. Group I (control) underwent balloon dissection of the left retroperitoneal space without gas insufflation. In group II (Prp), carbon dioxide at 10 mm Hg was applied for 2 hours after the balloon dissection (ischemia period) and for 1 hour after desufflation (reperfusion period). In group III (Prp + antioxidant), 5 minutes before the experiment, verapamil at 0.2 mg/kg was given intravenously and the same procedure was employed as in group II. Hepatic, pulmonary, opposite kidney, and treated kidney malondialdehyde (MDA) and reduced glutathione (GSH) levels were evaluated to show response to Prp. RESULTS Pneumoretroperitoneum exerted oxidative stress on all tissues with an increase of MDA (P < 0.05) and a decrease of GSH (P < 0.05). The verapamil-treated group showed lower values of MDA (P < 0.05) and higher values of GSH (P < 0.05) than group II. CONCLUSION Pneumoretroperitoneum increased oxidative stress in all remote organs tested. Verapamil reduced the oxidative stress. We concluded that Prp should be employed carefully in patients with limited vital organ capacity. Verapamil administration may be considered for protection against tissue injury attributable to oxidative stress in these patients.


The Journal of Urology | 1997

CONTRACTILITY CHANGES OF THE DEEP DORSAL PENILE VEIN DUE TO SEROTONIN

A. Adil Esen; Sedef Gidener; Cem Güler; Ziya Kirkali

PURPOSE Penile erection is a complex neurovascular phenomenon that takes place with the active contribution of arterial and sinusoidal structures. However, some authors claim that larger veins including the deep dorsal veins that produce contractions, might be involved in the physiology of erection. This study was designed to clarify the contractile properties of deep dorsal penile veins (DDPV). MATERIALS AND METHODS The effect of serotonin (5-HT), noradrenaline (NA), adenosine triphosphate (ATP) and acethylcholine (Ach) on the isolated DDPVs of 16 impotent men, 9 with veno-occlusive dysfunction and 7 without venous leakage, and 5 potent men (controls) who underwent radical prostatectomy, were examined in vitro. RESULTS Although NA, ATP and Ach had no effect, 5-HT produced concentration-dependent contractions. Emax and pEC50 of 5-HT were 411 +/- 10 mg., 5.92 +/- 0.25; 1020 +/- 260 mg., 5.83 +/- 0.24 and 160 +/- 40 mg., 6.4 +/- 0.22 in controls and patients who had venous leakage and no venous leakage, respectively. Samples of controls were contracted only with 5-HT2 agonist, DOI (pEC50 = 5.63 +/- 0.02), and these contractions were antagonized with 5-HT2 antagonist ketanserin. On the other hand, both DOI (pEC50 = 6.30 +/- 0.77) and 5-HT1 agonist, 5-CT (pEC50 = 6.23 +/- 0.21) produced venoconstriction in patients with veno-occlusive dysfunction. CONCLUSIONS The present findings suggest that 5-HT receptor functions in the DDPVs are of 5-HT2 subtype in potent men and the altered response to 5-HT in patients with veno-occlusive disease may play a role in the pathophysiology of impotence.


Journal of Endourology | 2003

Effect of retroperitoneoscopic donor nephrectomy on tissue oxidative stress markers in rabbit pneumoretroperitoneum model.

Cem Güler; Murat Demirbas; M. Murat Samli; Tulay Koken; Ahmet Kahraman; Cetin Dincel

BACKGROUND AND PURPOSE Laparoscopic donor nephrectomy causes increased renal oxidative stress. There are no data about the effects of the retroperitoneoscopic route. The aim of our study was to evaluate the oxidative stress occurring in renal tissues during retroperitoneoscopic donor nephrectomy in a rabbit model. MATERIALS AND METHODS Eighteen adult rabbits were randomized to three groups, each consisting of six rabbits. Group I (control) underwent 50-mL balloon dissection of the left retroperitoneal space without CO(2) insufflation. Group II (pneumoretroperitoneum) received a 3-hour CO(2) insufflation at a pressure of 10 mm Hg in the retroperitoneal space after balloon dissection. Group III (pneumoretroperitoneum with warm ischemia), in addition to the procedure applied in Group II, underwent left renal artery clamping for 3 minutes and reperfusion for the next 5 minutes. Bilateral nephrectomy was performed in all animals for analysis of oxidative stress markers. Concentrations of malonyldialdehyde (MDA), protein carbonyl, and reduced glutathione (GSH) were measured in renal tissue samples. RESULTS The MDA and protein carbonyl content were increased both in the donor (P = 0.004 and P = 0.004, respectively) and in the remaining kidneys (P = 0.009 and P = 0.028, respectively) in Group II compared with Group I. There were no statistically significant increases in oxidative stress markers between Group II and Group III in donor kidneys. However, there were statistically significant decreases in MDA in the remaining kidneys in Group III compared with Group II (P = 0.009). CONCLUSION Pneumoretroperitoneum causes increased oxidative stress in both donor and remaining kidneys. Short-term warm ischemia and reperfusion do not exert an additive effect on pneumoretroperitoneum-associated oxidative stress in donor kidneys.


Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 2004

The effect of carbon dioxide pneumoretroperitoneum on free oxygen radicals in rabbit retroperitoneoscopy model.

Murat Samli; Cem Güler; Murat Demirbas; Tulay Koken

The aim of this study was to investigate the possible effects of carbon dioxide (CO2) pneumoretroperitoneum on free oxygen radicals in the kidney. Twelve male New Zealand rabbits were divided into 2 equal groups; group 1; control operation group (retroperitoneal space preparation without CO2 insufflation) and group 2; study group (10–12 mm Hg pneumoretroperitoneum for 3 hours with CO2). At the end of the procedure, laparotomy was performed to harvest ipsilateral and contralateral kidney in both groups after three hours. Kidney tissues were homogenized and were assayed for malondialdehyde (MDA), protein carbonyls (for protein oxidation), and reduced glutathione (GSH). Ipsilateral and contralateral kidney tissue levels of the MDA, protein carbonyls and GSH were not different in both the study and the control group (P > 0.05 for all comparisions). Corresponding ipsilateral and contralateral tissue levels of the markers, MDA and protein carbonyls were found to be significantly different in the study group as compared with the control group (P < 0.05 for the four comparisons mentioned). However, neither the ipsilateral nor the contralateral tissue levels of the marker GSH showed statistically relevant difference when the study group was compared with the control group. Oxidative stress was identified as a component of CO2 pneumoretroperitoneum-induced kidney injury using an animal model of retroperitoneoscopy. Oxidative stress is likely to contribute to the impairment of renal function after retroperitoneoscopy using a 10 mm–12 mm Hg CO2 pneumoretroperitoneum.


Türk Üroloji Dergisi/Turkish Journal of Urology | 2011

Evaluation of epithelial lesions of the bladder in an autopsy series - Urooncology

Kadir Polat; Emre Tüzel; Hudaverdi Kucuker; İbrahim Üzün; Cem Güler

Gereç ve yöntem: Travma, ateşli silah yaralanması gibi sebeplerle hayatını kaybetmiş 125 adli vakanın (106 erkek, 19 kadın) mesaneleri otopsi ile alındı. Her bir mesaneden, anterior duvardan, trigondan ve posterior duvardan olmak üzere 3 parça örnek alındı. Parafine gömülü dokulardan hazırlanan 5 μm kalınlığındaki kesitler hematoksilen-eozin ile boyandı ve mikroskopik olarak benign ve malign epitelyal lezyonların varlığı araştırıldı.

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Murat Demirbas

Afyon Kocatepe University

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Ziya Kirkali

National Institutes of Health

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Emre Tüzel

Dokuz Eylül University

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Cetin Dincel

Afyon Kocatepe University

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Murat Samli

Wayne State University

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A. Adil Esen

Dokuz Eylül University

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M. Murat Samli

Afyon Kocatepe University

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Murat Sade

Dokuz Eylül University

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Adil Esen

Dokuz Eylül University

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