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Dive into the research topics where Hakan Özveri is active.

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Featured researches published by Hakan Özveri.


The Journal of Urology | 1997

Reactive Oxygen Species Production by the Spermatozoa of Patients With Idiopathic Infertility: Relationship to Seminal Plasma Antioxidants

İlter Alkan; Ferruh Simsek; Goncagül Haklar; Ertan Kervancioglu; Hakan Özveri; Suha Yalcin; Atif Akdas

PURPOSE We attempted to determine reactive oxygen species production by the spermatozoa of patients with idiopathic infertility and healthy donors, and observe whether increased production was due to decreased seminal plasma reactive oxygen species scavengers. MATERIALS AND METHODS Reactive oxygen species production by spermatozoa and seminal plasma antioxidants was assayed in 18 patients with idiopathic infertility and 10 controls. Reactive oxygen species formation and seminal plasma antioxidants were measured by luminol and lucigenin dependent chemoluminescence, and enzymatic methods, respectively. RESULTS Higher reactive oxygen species production was observed in 16 of the 18 patients (88.8%, p < 0.0001 versus controls). Seminal plasma superoxide dismutase, catalase, glutathione peroxidase and total sulfhydryl group levels in infertile patients were significantly lower than in controls. CONCLUSIONS Decreased seminal plasma antioxidant activity and increased reactive oxygen species production can be responsible for idiopathic male infertility.


European Urology | 2002

Lack of effect of intrarectal lidocaine for pain control during transrectal prostate biopsy: a randomized prospective study.

Ibrahim Cevik; Hakan Özveri; Ozdal Dillioglugil; Atif Akdas

INTRODUCTION AND OBJECTIVES Transrectal ultrasound guided biopsy is an essential part in the diagnosis of prostate cancer. Although this procedure is well tolerated by most patients, sometimes it can result in some uneasiness. In this randomised double-blind placebo controlled study, we evaluated the effectiveness of intrarectal lidocaine during TRUS guided biopsy. MATERIALS AND METHODS 100 consecutive eligible patients who had elevated total prostate specific antigen (tPSA) and/or abnormal digital rectal examination (DRE) were included into this study. Patients were randomised into two groups. Group I received 20 cc of 2% intrarectal lidocaine 20 minutes before transrectal ultrasound guided biopsy and Group II received same amount of serum physiologic. Pain was assessed using a 10 point modified visual analog scale. RESULTS Mean patient age was 65.5+/-2.5 and 64.5+/-11.5 years, mean tPSA was 12.3+/-3.6 and 11.3+/-1.7 ng/ml, mean biopsy duration was 6.8+/-2.5 and 6.6+/-2.2 minutes, mean pain score during transrectal ultrasound guided biopsy was 4.8+/-2.2 and 4.4+/-2.1 in Groups I and II, respectively. No statistically significant difference was observed with respect to age, tPSA, mean biopsy duration and pain score between these groups. There was only one patient who could not tolerate the procedure at all, and he was paradoxically in the lidocaine group. CONCLUSION The use of intrarectal lidocaine is not superior to placebo during transrectal prostate biopsy for pain control.


European Urology | 1996

Short-term effect of digital rectal examination on serum prostate-specific antigen levels. A prospective study.

Ibrahim Cevik; Levent Türkeri; Hakan Özveri; Y. Ilker; Atif Akdas

OBJECTIVE Prostate-specific antigen (PSA) is widely used as a tumor marker in the early detection of prostate cancer. However, its value is limited by several factors such as not being specific for the cancer tissue, diurnal variations of the secretion, and changes in the serum levels observed following rectal manipulations. The effect of digital rectal examination (DRE) on serum PSA levels is still debatable. METHODS A prospective study is conducted by utilizing the IRMA count (monoclonal) PSA assay in order to determine the effect of DRE on PSA serum levels. A total of 50 men (median age 61, range 42-75 years) who presented to our outpatient clinic for the first time with lower urinary tract outflow obstruction symptoms were included in this study. Further evaluation revealed prostate cancer in 5 patients (10%) and benign prostate hyperplasia in the others. Blood samples were drawn for a PSA assay from all patients prior to and 30 min and 24 h following DRE (PSA 1-3). RESULTS The mean PSA values prior to and 30 min and 24 h following DRE were 4.09 +/- 0.67 range 0.2-19.47) ng/ml, 4.50 +/- 0.63 (0.15-17.75), and 4.28 +/- 0.68 (0.23-24.12) ng/ml, respectively. The median PSA levels for PSA 1, PSA 2, and PSA 3 were 2.49 +/- 4.74, 3.22 +/- 4.48, and 2.62 +/- 4.82 ng/ml, respectively. Although, there was a statistically significant increase in serum PSA levels 30 min after DRE, the clinical significance of this increase in PSA values with a mean difference of 0.4 ng/ml remains to be clarified. CONCLUSION Although the effect of DRE on PSA levels does not appear to be clinically significant, in order to prevent any confusion, it may be the best approach to perform DRE after obtaining serum for PSA analysis.


International Urology and Nephrology | 2002

The efficacy of neoadjuvant chemotherapy in invasive bladder cancer

Kamil Çam; Asıf Yıldırım; Hakan Özveri; Levent Türkeri; Atif Akdas

Radical cystectomy is the gold standard in the treatment of invasivebladder cancer. However, five-year disease-free survival is low mostprobably due to micrometastatic disease at the time of surgery. Theneoadjuvant chemotherapy may be performed as the first line managementfor invasive bladder tumors in order to treat micrometastases found at thediagnosis and improve resectability of larger neoplasms. A total of 43patients diagnosed with invasive bladder tumors and 11 patients receivedneoadjuvant chemotherapy. The mean age of patients was 64 (43–74) years,and mean follow-up period was 52 months (12–114). Neoadjuvantchemotherapy protocol consisted of methotrexate, vinblastine, doxorubicin,and cisplatin (MVAC) or cisplatin, methotrexate, and cisplatin (CMV). Allpatients in neoadjuvant chemotherapy group underwent radicalcystectomy. There was no significant difference between the groups withrespect to disease-free survival time and overall survival time. In patientswho received neoadjuvant chemotherapy, the respective disease-free andoverall survival times were 31 months and 36 months versus 30 months and35 months in patients who were treated with surgery only (p > 0.05). Five-year survival rates were 36% and 31% in the chemotherapy and no-chemotherapy groups, respectively. In the present study, 5-year survivalrate was not affected by neoadjuvant chemotherapy in invasive bladdertumor. Complete pathological remission (stage p0) was found in 28% andpathological downstaging (stage < T2) was seen in 9% of patients in theneoadjuvant chemotherapy group. Five-year survival rates were 75% and14.2% in patients who responded to chemotherapy, and in patients with noresponse, respectively (p < 0.05). The most favorable prognostic factor inthis study was the response to neoadjuvant chemotherapy revealed ascomplete remission or pathological downstaging. The most important issueremains the prediction of patients who would respond and benefit fromneoadjuvant chemotherapy.


International Journal of Urology | 1997

Evaluation of Prostate Specific Antigen Density and Transrectal Ultrasonography‐Guided Biopsies in 100 Consecutive Patients with a Negative Digital Rectal Examination and Intermediate Serum Prostate Specific Antigen Levels

Tufan Tarcan; Hakan Özveri; Tugrul Biren; Levent Türkeri; Atif Akdas

Background: This study was undertaken to assess the importance of prostate biopsies in patients with a negative digital rectal examination (DRE) and elevated prostate specific antigen (PSA) levels and to investigate the role of PSA density (PSAD) and hypoechoic lesions on transrectal ultrasound (TRUS) in increasing the diagnostic sensitivity and specificity for prostate cancer (PCa).


International Urology and Nephrology | 1999

Alteration of Epidermal Growth Factor Receptor Expression Following Ischaemia of Renal Tissue

A. Ertuğrul; Levent Türkeri; M. Özyürek; Hakan Özveri; Atif Akdas

This study was aimed to investigate Epidermal Growth Factor Receptor (EGF-R) expression after ischaemic injury in renal tissue and the effects of calcium channel blockers in the prevention of damage due to ischaemic insult. Simple nephrectomy was performed in a group of Sprague-Dawley rats, and kidneys were grouped according to cold ischaemia time (1, 6, 12, 24 and 48 hours, respectively) and to the type of calcium channel blockers (diltiazem and verapamil) used. EGF-R expression status was investigated in each group by immunohistochemistry on paraffin sections. Overall expression of EGF-receptor was detected in 8 822.8%) kidneys. In terms of localization of EGF-receptor expression cortical tubular staining was detected in 8 (100%) kidneys, medullar tubular staining in (62.5%) kidneys and glomerular mesangial staining in 5 (62.5%) kidneys. There was no difference between various ischaemia times and different calcium channel blockers used. It has been concluded that hypoxia and cold ischaemia causes widespread down-regulation of EGF-receptor expression in renal tissue regardless of treatment with calcium channel blockers.


The World Journal of Men's Health | 2018

Superoxide Anion Production by the Spermatozoa of Men with Varicocele: Relationship with Varicocele Grade and Semen Parameters

İlter Alkan; Meral Yüksel; Halil Lütfi Canat; Hasan Anıl Atalay; Osman Can; Hakan Özveri; Mehmet Murad Başar

Purpose To investigate the pathophysiological role of superoxide anion and total reactive oxygen species (ROS) production by the spermatozoa of men with varicocele and its relationship with varicocele grade and semen parameters. Materials and Methods This prospective study included 34 men with grade II–III varicocele, regardless of their fertility status. The control group consisted of 13 healthy men. Semen characteristics were examined according to the 2010 World Health Organization criteria. The swim-up method was used for sperm preparation. Total ROS and superoxide anion production was assayed by luminol- and lucigenin-dependent chemiluminescence (CL), respectively. Results The men with varicocele had significantly higher total ROS and superoxide anion levels than the healthy control subjects (2.9±0.4 relative light unit (RLU) vs. 2.4±0.1 RLU, p=0.001 for luminol-dependent CL and 2.8±0.4 RLU vs. 2.3±0.2 RLU, p=0.002 for lucigenin-dependent CL). Cases of grade III varicocele had significantly higher superoxide anion and total ROS levels than grade II cases and control subjects (p<0.001). Superoxide anion and total ROS levels were negatively correlated with all semen parameters. Conclusions The superoxide anion levels produced by spermatozoa were significantly higher in varicocele patients than in control subjects. ROS production was related to increased varicocele grade, impaired semen concentration, and abnormal morphology in men with varicocele. Our findings suggest that superoxide anion overproduction may be an important step in the cascade of ROS-related damage to spermatozoa, resulting in impaired semen parameters in patients with varicocele.


International Journal of Impotence Research | 2018

Semen reactive oxygen species levels are correlated with erectile function among chronic prostatitis/chronic pelvic pain syndrome patients

İlter Alkan; Meral Yüksel; Hakan Özveri; Anıl Atalay; Halil Lütfi Canat; Mehmet Gokhan Culha; çigdem Arabaci; Muammer Bozkurt; M. Murad Basar

Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) is often associated with erectile dysfunction (ED). However, the underlying pathophysiological mechanisms of ED occurrence are still unclear in patients with CP/CPPS. The aim of the study was to investigate superoxide anion (O2•−) and total reactive oxygen species (ROS) production in semen of men with category IIIA CP/CPPS and their association with ED. This prospective study included 33 men with category IIIA CP/CPPS. Control group consisted of 13 healthy men. Total ROS and O2•− production were assayed by luminol and lucigenin-dependent chemiluminescence (CL) methods, respectively. ED was evaluated using the IIEF-5 questionnaire. Patients with CP/CPPS had significantly higher seminal total ROS and O2•− levels than healthy control subjects (2.9 ± 0.5 relative light unit (RLU) vs. 2.4 ± 0.2 RLU, p < 0.001; luminol-dependent CL and 2.5 ± 0.4 RLU vs. 2.3 ± 0.2 RLU, p = 0.02; lucigenin-dependent CL, respectively). Seminal O2•− and ROS levels were negatively correlated with IIEF-5 scores (r = −0.556, r = −0.536; p < 0.001, respectively). These results may suggest O2•−/ROS overproduction could be one of the important mechanisms in the etiology of ED development in CP/CPPS patients.


International Urology and Nephrology | 2008

Asymptomatic retained surgical gauze towel diagnosed 32 years after nephrectomy

Ibrahim Cevik; Ozdal Dillioglugil; Hakan Özveri; Atif Akdas


Archive | 2001

THE SIGNIFICANCE OF HYPOECHOIC LESION DIRECTED AND TRANSITION ZONE BIOPSIES IN IMPROVING THE DIAGNOSTIC ABILITY IN PROSTATE CANCER

Kamil Cam; Hakan Özveri; Levent Türkeri; Atif Akdas

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Ibrahim Cevik

Yeni Yüzyıl University

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Kamil Cam

Abant Izzet Baysal University

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