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Dive into the research topics where Mehmet Dündar is active.

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Featured researches published by Mehmet Dündar.


Eye | 2001

Effect of sildenafil on ocular haemodynamics.

Sema Oruç Dündar; Mehmet Dündar; Izzet Kocak; Yelda Özsunar Dayanır; Seyhan B. Özkan

Purpose To study the effect of sildenafil, which is an effective agent for the treatment of erectile dysfunction, on ocular haemodynamics.Methods In this prospective study we examined the effect of a single oral dose of 50 mg sildenafil (Viagra) in a group of healthy young male volunteers, by using colour Doppler ultrasound imaging to measure haemodynamic variables in the central retinal artery (CRA), short temporal posterior ciliary artery (STPCA) and ophthalmic artery (OA). The following examinations were performed on both eyes immediately before and 1 h after a single oral dose of 50 mg sildenafil: visual acuity, intraocular pressure (IOP), colour vision, anterior segment, fundus appearance, resting heart rate, blood pressure and colour Doppler measurements.Results After sildenafil administration, peak systolic velocity, mean velocity and end-diastolic velocity significantly increased in the OA of both eyes. All Dopper indices remained non-significant for the CRA and STPCA of both eyes. Sildenafil did not cause any significant change in IOP, colour vision, visual acuity, systolic blood pressure or diastolic blood pressure. However, heart rate measurements increased significantly after sildenafil administration compared with baseline (p = 0.003).Conclusion The increased flow velocity in the ophthalmic artery seems to be due to a vasodilator effect of sildenafil.


Urologia Internationalis | 2006

Can the Effect of Antibiotherapy and Anti-Inflammatory Therapy on Serum PSA Levels Discriminate between Benign and Malign Prostatic Pathologies?

Haluk Erol; Nahit Beder; Tamer Çalışkan; Mehmet Dündar; Alparslan İnsal; Nil Culhaci

Objective: The primary aim was to evaluate the change in the total and free PSA levels after antibiotic and non-steroid anti-inflammatory treatment. The secondary aim was to compare this change among the histological subgroups to assess whether it was discriminating. Methods: 97 consecutive patients with PSA >4 ng/dl and scheduled for prostate biopsy were included in this prospective study. 65 patients (group 1) were then put on medical treatment of ciprofloxacin 500 mg bid and diclofenac sodium 75 mg during the routine waiting period before the 2- to 3-week procedure. Randomly selected (every third case) 32 patients (group 2) did not receive this treatment. Free and total PSA tests were repeated before the procedure. The change in the PSA values was compared between the groups and among the histological subgroups in group 1. Results: While in group 1 the decrease in PSA was significant (p = 0.000), this was not the case in group 2. The difference in free PSA values was unremarkable for both groups. In histologically determined cancer cases of group 1, the difference between pre- and post-procedure PSA level was not of note, while in BPH and prostatitis cases it was significant. Conclusion: In cases with increased PSA, medical treatment for a likely subclinical prostatitis resulted in a decrease of PSA, which was significant only in benign conditions.


International Journal of Urology | 2004

Relapse of brucellosis simulating testis tumor

Izzet Kocak; Mehmet Dündar; Nil Culhaci; Alparslan Ünsal

Abstract  We report on a case of a 32‐year‐old man referred for evaluation of a painless left testicular mass suggesting a testicular tumor. Previous history was uneventful except for a 3‐year history of systemic brucellosis without epididymo‐orchitis. Radical inguinal orchidectomy was performed. Clinical and histopathological findings indicated a brucellar abscess of the left testis. Even in the absence of systemic symptoms, the possible relapse of brucellosis as an abscess formation in the testis should be considered as a rare cause of testicular mass in patients who live in endemic regions.


Urologia Internationalis | 2001

Liposarcoma of the Spermatic Cord

Mehmet Dündar; Haluk Erol; Izzet Kocak; Firuzan Kaçar

A 64-year-old male presented with a 4-year history of a mass in the left scrotum. Radical orchiectomy was performed. Pathological analysis demonstrated a well-differentiated liposarcoma. No evidence of recurrence or metastasis has been noted during the 3-month follow-up without any postoperative adjuvant therapy.


Pathology & Oncology Research | 2005

Determination of apoptosis through Bax expression in cryptorchid testis: an experimental study

Mehmet Dündar; Izzet Kocak; Nil Culhaci; Haluk Erol

The aim was to determine the expression of Bax in germ cells of rats with unilateral experimental cryptorchidism, and to evaluate the role of apoptosis in germ cell loss. Twenty-one prepubertal rats were randomly subdivided into three groups after the execution of the left cryptorchidism model. Group 1 (n=8), group 2 (n=6) and group 3 (n=7) rats were killed at the end of the first, second and third month, respectively. Bax expression was assessed in Sertoli cells, spermatogonia and spermatocytes by immunohistochemistry. Percentages of Bax expression in spermatocytes and spermatogonia were decreased in the left testicles in the 2nd and 3rd months compared to results obtained in the 1st month (p<0.05). Percentage of Bax expression in the left testicles of group 1, at the level of both spermatogonia and spermatocytes was higher than that in the right one (p<0.05). However, in groups 2 and 3, the higher Bax expression on the left side was only seen in the spermatocytes (p<0.05). In all groups, the mean weight of the left testicle was lower than that of the scrotal counterpart where the difference was significant only in groups 1 and 3 (p<0.05). The weight of the left and right testicles was increasing with time. In this model of cryptorchidism, the affected testis had a decreased weight compared to the normal one. Based on the increased Bax expression, we think that apoptosis may play a role in the germ cell loss.


International Journal of Impotence Research | 2006

Effect of sildenafil on ocular hemodynamics in 3 months regular use.

Sema Oruç Dündar; Y Dayanir; A Topaloğlu; Mehmet Dündar; Izzet Kocak

The aim of this study was to evaluate the effect of sildenafil on ocular hemodynamics in a group of men with erectile dysfunction in 3 months regular use. A total of 15 patients with erectile dysfunction were included in this prospective study. All patients received 50 mg doses of sildenafil (Viagra, Pfizer) two times per week regularly for 3 months. The following examinations were performed on both eyes before and after sildenafil treatment: best-corrected visual acuity (BCVA), intraocular pressure (IOP), color vision, anterior segment, and fundus examination. Using color Doppler imaging, we measured hemodynamic variables in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary artery (SPCA). No significant changes in BCVA, color vision and IOP were found after sildenafil treatment. The anterior segment and fundus examinations showed no abnormalities. All Doppler parameters of OA, CRA, and SPCA remained nonsignificant for both eyes after sildenafil treatment. Oral sildenafil in 3 months regular use seems to have no effect on ocular hemodynamics.


Urological Research | 2001

A new experimental model for cryptorchidism: inguinoscrotal approach

Mehmet Dündar; Izzet Kocak; Nil Culhaci

Abstract We investigated the effect of inguinal canal closure as a new mechanically induced cryptorchid rat model. The effectiveness of this new model was evaluated by histopathological examination. Thirty-one 21-day-old Wistar rats were divided into four groups. In groups 1 (n=6), 2 (n=6) and 3 (n=7), unilateral undescended testis was created by performing inguinal canal closure with inguinoscrotal approach. Sham-operated rats were used as controls in group 4 (n=12). The rats were killed on day 30 after surgery in group 1, day 45 in group 2 and day 60 in group 3. The seminiferous tubular diameter, number of tubules with mature germ cell and Leydig cell clusters were evaluated. None of the rats were lost during the study period. Signs of infection were not detected in operation site although antibiotics were not used. Overall only three (16%) testes descended into scrotum in study groups. The operation time was 3–4 min for each rat. Histopathological examination revealed detrimental effects of cryptorchidism on testicular growth in study groups. In all groups, except the sham group, the mean tubular diameter and the number of tubules with mature germ cells in the left testicle were significantly decreased compared to the right ones. Our findings were in correlation with other experimental studies using different rat models of cryptorchidism. This new model of cryptorchidism is considered to provide a simple and effective technique for investigating the impaired development of the testes in cryptorchidism.


Urological Research | 2008

Unexpected complication: renal parenchymal perforation with double-J ureteral stent

Mehmet Dündar; Tamer Çalışkan; Izzet Kocak

Double-J ureteral stent is commonly used in various endourological procedures. This procedure may cause some complication. We present a case of renal parenchymal perforation due to double-J stent insertion.


Nephrology | 2004

Effects of long-term passive smoking on the diameter of glomeruli in rats: Histopathological evaluation

Mehmet Dündar; Izzet Kocak; Nil Culhaci

Background and Aims:  Long‐term smoking increases the risk of renal diseases and it also causes the progression of the diseases. The aim of this study was to evaluate the effects of smoking on glomeruli in healthy rats exposed to long‐term passive smoking for a short period of time after birth.


Scandinavian Journal of Urology and Nephrology | 2002

Changes in Urethral Connective Tissue after Estrogen Replacement Therapy in Ovariectomized Rats

Mehmet Dündar; Izzet Kocak; Muhan Erkus; B. Celasun

Objective: Genuine stress urinary incontinence is a common problem after the middle age. Various treatment modalities have been tried as a treatment for this entity and estrogens are one of the most common alternatives. Their effects on the urethral mucosa have been described in many studies, while the impact on the urethral connective tissue has been evaluated only in a few reports. In this study, we aimed to investigate the effect of estrogen on urethral connective tissue in ovariectomized rats. Material and Methods: Thirty-six Wistar rats (4 months old, 250-300 g weight) were included in the study. They were organized as group 1 (ovariectomized, n = 10), group 2 (ovariectomized + late estrogen treatment, n = 10), group 3 (ovariectomized + early estrogen treatment, n = 10) and group 4 (sham operated, n = 6). Rats in group 1 were killed 6 weeks after the ovariectomy. Group 2 was ovariectomized 6 weeks before treatment and then received estradiol for 6 weeks. Group 3 was treated with estradiol for 6 weeks immediately after the ovariectomy. After killing the rats, urethral tissues were removed. Quantitative analysis of collagen fiber content was done by computerized image analyzer system in specimens stained with Massons trichrome technique. Results: Percentages of collagen fiber content (mean - standard error of mean) were 58.4 - 5.9% in group 1; 53.3 - 4.8% in group 2; 46.3 - 3.4% in group 3 and 40.2 - 3.2% in group 4. There was not any significant difference among the groups (p > 0.05). Conclusions: Our results suggest that early and late estrogen replacements do not seem to have a discriminating effect on the urethral connective tissue. Further studies are needed to assess the preventive effect of estrogen on urethra.

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Izzet Kocak

Adnan Menderes University

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Haluk Erol

Adnan Menderes University

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Nil Culhaci

Adnan Menderes University

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Cigdem Yenisey

Adnan Menderes University

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Mukadder Serter

Adnan Menderes University

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Nahit Beder

Adnan Menderes University

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Fatih Özcura

Adnan Menderes University

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Muhan Erkus

Adnan Menderes University

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