Search PubMed⌕ Search

Biomedical subjects

Muammer Kendirci

Publications and source records attributed to Muammer Kendirci.

31 records · Page 2Linked to original sources
PubMed2005

The relationship between the type of penile abnormality and penile vascular status in patients with peyronie's disease.

PURPOSE: We evaluated penile vascular status using penile duplex Doppler ultrasound (PDDU) according to the type of abnormality in men with Peyronie's disease (PD). MATERIALS AND METHODS: A total of 523 patients with PD were evaluated retrospectively. Each patient underwent PDDU following injections of 10 to 15 mug prostaglandin E1 intracavernously with accompanying visual sexual stimulation to evaluate penile blood flow. Abnormalities were divided into 7 groups. Objective evaluation of penile curvature was done with a protractor during maximum erection. Specific criteria were used to categorize patients into varying definitions of vascular status. The results were compared statistically among groups. RESULTS: Mean patient age +/- SEM was 54.2 +/- 1.5 years. The most frequently noted type of curvature was dorsal (43.5% of cases), followed by lateral (24.8%). Mean peak systolic velocity in the ventrolateral group was the highest, while the lowest peak systolic velocity was noted in the hourglass abnormality group. The hourglass group had the highest rate of pure arterial insufficiency, while veno-occlusive dysfunction was seen most commonly in the ventral curvature group. The ventrolateral group showed the most normal vascular status parameters. CONCLUSIONS: This study demonstrates there is a relationship between the type of curvature and penile hemodynamics. Although patients with PD in the hourglass abnormality group were the youngest, this abnormality was associated with the poorest penile vascular status. Patients with ventrolateral curvature had the best penile hemodynamics in our series. PDDU findings may direct the treating physician to different treatment options.

Diabetes Mellitus↗
PubMed2005

Poly(Adenosine diphosphate-ribose) polymerase inhibition preserves erectile function in rats after cavernous nerve injury.

PURPOSE: We investigated the involvement of poly(adenosine diphosphate-ribose) (PAR) polymerase (PARP) activation in the development of erectile dysfunction and the therapeutic benefit of the potent PARP inhibitor INO-1001 (Inotek Pharmaceuticals Corp., Beverly, Massachusetts) in a bilateral cavernous nerve crush injury (BCNCI) model in rats. MATERIALS AND METHODS: Sprague-Dawley rats were divided into 3 groups, namely sham treated, BCNCI plus vehicle and BCNCI plus the PARP inhibitor INO-1001. One week after surgical intervention all groups underwent in vivo cavernous nerve stimulation. PAR activation, nitrotyrosine and inducible nitric oxide synthase were evaluated by immunohistochemistry and serum levels of INO-1001 were measured by high performance liquid chromatography. Penile tissues were analyzed for levels of malondialdehyde and myeloperoxidase. Data sets were statistically compared in all groups. RESULTS: Neurogenic mediated erectile responses were evaluated. Mean intracavernous pressure (ICP), the ICP-to-blood-pressure ratio and total ICP were significantly decreased in BCNCI plus vehicle rats. These values were not statistically different between the sham and PARP inhibitor treated groups. There was a marked decrease in PAR staining in the treatment group. There was a substantial increase in malondialdehyde tissue levels but not myeloperoxidase in response to BCNCI, which was unchanged with PARP inhibitor treatment. There was a marked increase in tyrosine nitration in the treatment group. Up-regulation of nitric oxide synthase and increased tyrosine nitration were not observed in the penile tissues of the treatment group. CONCLUSIONS: These data demonstrate that BCNCI in a rat model causes increased PARP activation, resulting in severe erectile dysfunction. Treatment with the PARP inhibitor INO-1001 decreases the degree of nitrosative stress, prevents PARP activation and provides significant cavernous neuroprotection, which in turn preserves erectile function.

Adenosine Diphosphate Ribose↗
PubMed2005

The impact of intralesional interferon alpha-2b injection therapy on penile hemodynamics in men with Peyronie's disease.

INTRODUCTION: Penile duplex Doppler ultrasound (PDDU) is currently the preferred method for the functional evaluation of penile hemodynamics. PDDU may be used to monitor objectively changes in penile vascular parameters in men who undergo treatment for Peyronie's disease (PD), including intralesional interferon alpha-2b (IFN alpha-2b). AIM: To investigate the impact of intralesional IFN alpha-2b therapy for PD on penile hemodynamics by using PDDU and to assess the objective role of PDDU in monitoring treatment outcomes. MATERIALS AND METHODS: Thirty-nine patients (20 in the placebo and 19 in the IFN alpha-2b treatment arm) were enrolled in this prospective, placebo-controlled, parallel study. Patients received either 10 mL saline or 5 x 10(6) units of IFN alpha-2b intralesional injections every other week for a total of six injections. Patients in each group were evaluated at baseline and after completion of treatment regarding changes in penile hemodynamic parameters, penile curvature, plaque size and density, pain on erection, and erectile function. Specific published criteria were used for PDDU measurements. Outcomes were statistically compared between each group by using Mann-Whitney U and chi-square tests. RESULTS: The mean age of the patients and the duration of PD were similar in both groups. The improvement in penile blood flow was significantly greater in IFN alpha-2b-treated patients than those in the placebo group. The number with the nonvascular classification increased significantly in the IFN alpha-2b arm from 31.5% to 57.8%. Additionally, improvements in penile curvature, plaque size and density, and pain on erection were better in the IFN alpha-2b group compared with the control. No significant improvement was observed in the erectile function domain in either group. CONCLUSION: This study reveals that intralesional IFN alpha-2b injections have a significant benefit on penile hemodynamic parameters. Moreover, intralesional IFN alpha-2b is an effective, minimally invasive treatment for PD, and PDDU is a useful adjunct to monitor objectively changes in penile vascular parameters. interferon alpha-2b injection therapy on penile hemodynamics in men with Peyronie's disease.

Adult↗
PubMed2005

Superoxide anion production in the rat penis impairs erectile function in diabetes: influence of in vivo extracellular superoxide dismutase gene therapy.

INTRODUCTION: Superoxide anion may contribute to erectile dysfunction (ED) in diabetes mellitus by reducing cavernosal nitric oxide (NO) bioavailability. The purpose of this study was to determine if gene transfer of extracellular superoxide dismutase (EC-SOD) can reduce superoxide anion formation and determine if this reactive oxygen species may contribute to diabetes-related ED in an experimental model of diabetes. METHODS: Three groups of animals were utilized: (1) control; (2) streptozotocin (STZ)-diabetic rats [60 mg/kg intraperitoneally (ip)] intracavernosally injected with AdCMVbetagal (negative control); and (3) STZ-rats intracavernosally injected with AdCMVEC-SOD. Two months after ip injection of STZ, groups 2 and 3 were transfected with the adenoviruses and 2 days after transfection, all animals underwent cavernosal nerve stimulation (CNS) to assess erectile function. Confocal microscopy for superoxide anion and von Willebrand Factor (vWF) was performed in the STZ-diabetic rat. Superoxide anion production, total SOD activity, and cyclic guanosine monophosphate (cGMP) levels were measured in each experimental group of rats. RESULTS: Confocal microscopy demonstrated superoxide in smooth muscle and endothelial cells of the STZ-rat cavernosum and colocalized with vWF in the endothelium. Higher superoxide anion levels and decreased cGMP levels were found in the penis of STZ-rats at a time when erectile function was reduced. Two days after administration of AdCMVEC-SOD, superoxide anion levels were significantly lower in the penis of STZ-rats. Total SOD activity and cavernosal cGMP was increased in the penis of EC-SOD-transfected rats. STZ-rats transfected with AdCMVEC-SOD had a peak intracavernosal pressure (ICP) and total ICP to CNS that was similar to control rats. CONCLUSIONS: These data demonstrate that in vivo adenoviral gene transfer of EC-SOD can reduce corporal superoxide anion levels and raise cavernosal cGMP levels by increasing NO bioavailability thus restoring erectile function in the STZ-diabetic rat.

Adenoviridae↗
PubMed2005

Short-term effects of arsenic sulfur in deficits of contractile and relaxant responses on urinary bladder: pharmacological and structural changes.

INTRODUCTION: Our goal was to investigate the effects of arsenic sulfur (AsS) on the detrusor smooth muscle reactivity. MATERIAL AND METHODS: AsS (100 ppm microg/g) in drinking water was administered for 2 weeks to two groups of female Wistar rats. The contractile responses of urinary bladders to electrical field stimulation, carbachol, ATP and KCl, and the relaxant responses to ATP, adenosine and isoproterenol were examined. Urinary bladder strips were collected for light microscopic examination. RESULTS: Our results demonstrate that oral inorganic AsS exposure induced enhanced contractile and reduced relaxant responses in rats. We hypothesize that AsS is involved in deficiencies of isolated urinary bladder in rats. CONCLUSION: These functional and morphological changes may be important as an intermediate link in urinary bladder oncogenesis induced by AsS.

Adenosine Triphosphate↗
PubMed2005

The impact of vascular risk factors on erectile function.

The main cause of erectile dysfunction is organic in nature, with vascular etiologies being the most common risk factors. The incidence of erectile dysfunction increases with the number of vascular comorbidities such as hypertension, diabetes, hyperlipidemia, smoking and atherosclerosis. The earliest signal of endothelial damage in men with vascular risk factors is the manifestation of erectile dysfunction. The penis is a barometer of the body's endothelial function, so it is reasonable then to correlate vascular pathologies as direct causes of erectile dysfunction. Moreover, erectile dysfunction may be the first clinical presentation of any of these comorbidities, with the vascular endothelium playing a pivotal role in regulating vascular homeostasis of the corpora cavernosa. This article addresses the impact of vascular risk factors on erectile function based on current evidence.

Arteriosclerosis↗
PubMed2004

Critical analysis of surgery for Peyronie's disease.

PURPOSE OF REVIEW: This review focuses on the surgical management of Peyronie's disease in the light of recent published reports from 2003 and 2004. RECENT FINDINGS: Although there have been a number of non-surgical innovations in this field, the surgical treatment of Peyronie's disease still remains the only alternative for patients not responding to other therapies. Various surgical modalities have recently been promulgated, however the ideal surgical procedure is still not perfected, particularly in cases of severe and complex penile curvature. The recent results of various surgical approaches have engendered concern about their long term benefits. SUMMARY: The initial management of the acute presentation of Peyronie's disease is conservative and non-surgical. Surgery for Peyronie's disease is contemplated only after stabilization of the fibrotic process, and is generally reserved for men with severe penile deformities that impede satisfactory sexual intercourse. If there is ample penile length and the deformity is mild to moderate in severity, a variety of plication techniques may be considered to provide a straight and functional penis. In patients with larger plaques, severe curvature, complete or hourglass deformities, then incision or excision of the plaque and the placement of a graft are recommended. Most authorities currently favor non-synthetic graft materials whose properties resemble the anatomy and functionality of the tunica albuginea. The implantation of a penile prosthesis, with or without excision/incision of the diseased tunica albuginea, is reserved for patients with erectile dysfunction who have not responded to medical therapies. Manual modeling of the deformed penis over a penile prosthesis may prevent some patients from needing more complex surgical grafting procedures.

Humans↗
PubMed2004

Association of positive serum anti-p53 antibodies with poor prognosis in bladder cancer patients.

AIMS: To assess the association of serum anti-p53 antibodies and overexpression of tumor p53 protein with survival and prognostic factors in patients with urinary bladder tumors. METHODS: Seventy-six patients with transitional cell carcinoma of the urinary bladder were assessed prospectively (Ta, 18; T(1), 30; > or =T(2), 28). Serum anti-p53 antibodies were detected by enzyme-linked immunosorbent assay. Tumor p53 gene overexpression was assessed by immunohistochemical staining. The mean follow-up time was 34 months. RESULTS: Serum anti-p53 antibodies were positive in 25 patients (33%). Overexpression of tumor p53 protein was positive in 41 patients (54%). There was an association between the presence of serum anti-p53 antibodies and tumor p53 gene overexpression (P = 0.001). The total survival of the patients with positive serum anti-p53 antibodies was shorter than the patients with positive tumor p53 gene overexpression (P < 0.001, P = 0.344, respectively). In the multivariate survival analysis, both tumor stage and serum-p53 antibodies were found to be independent survival predictors (P = 0.004, P = 0.006, respectively). CONCLUSION: Serum anti-p53 antibody positive tumors had a worse prognosis than those with negative serum levels, regardless of the p53 status of the tumor.

Adult↗
PubMed2004

Vardenafil: a novel type 5 phosphodiesterase inhibitor for the treatment of erectile dysfunction.

Orally administered phosphodiesterase type 5 (PDE5) inhibitors have become the first-line treatment option for erectile dysfunction (ED). Vardenafil is a potent and highly selective PDE5 inhibitor developed as an oral therapy for ED. Two pivotal, randomised, double-blind, multi-centre studies have evaluated the use of vardenafil in men with ED. Vardenafil improved the rate of achieving and maintaining an erection during sexual intercourse. Improvement was also noted in other aspects of sexual function, including confidence, orgasmic function and overall satisfaction. Vardenafil produces clinically and statistically significant improvements in erectile function regardless of age, baseline severity and aetiology and is efficacious for the treatment of ED in diabetic and postradical prostatectomy patients. Vardenafil has a rapid onset of action, in which erections sufficiently rigid for eventual intercourse completion can be achieved as early as 16 min after ingestion. Vardenafil 20 mg has sustained long-term efficacy by providing up to 92% of patients with improved erections during > 2 years of treatment. Vardenafil is well-tolerated, with an adverse event profile typical of this class of PDE5 inhibitors. The most common adverse events were headache, flushing, rhinitis and dyspepsia, which were mild-to-moderate in severity and they generally attenuated with continued use. Vardenafil may be associated with transient reductions in blood pressure and commensurate increases in heart rate, with the overall incidence of cardiovascular-related adverse events similar to that of placebo. Although claims can be made about potential features of benefit for each of the currently marketed PDE5 inhibitors, there are at present, no non-pharmaceutical company sponsored, peer-reviewed, head-to-head trials that have been published.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2004

Current concepts in the management of erectile dysfunction in men with prostate cancer.

Development in the management of prostate cancer has placed increased attention on patient quality of life after treatment, particularly sexual function. The incidence of erectile dysfunction (ED) in men following radical prostatectomy has been estimated to range from 16% to 82%. Several factors determine the postoperative incidence of erectile difficulties; these include patient age, degree of cavernosal nerve sparing during surgery, cancer stage, and associated comorbidities. Early initiation of available treatments after radical prostatectomy, such as phosphodiesterase-5 (PDE-5) inhibitors and intracavernosal alprostadil, may improve the speed and degree of recovery of erectile function. Oral PDE-5 inhibitors are recognized as the first line of therapy for men with ED after radical prostatectomy, with reasonable success rates reported for all commercially available PDE-5 inhibitors. In recognition of the neurogenic basis for erectile dysfunction after radical prostatectomy, new strategies have been devised, such as cavernous nerve graft interposition procedures, perioperative neuroprotection measures, and postoperative neurotrophic treatments. Hopefully, these efforts will improve quality of life for patients with prostate cancer. The aim of this article is to review the current modalities of ED management for men with prostate cancer.

Adult↗
PubMed2003

Penile hemodynamics in hypogonadal men with micropenis.

OBJECTIVES: To document the penile vascular and erectile response to intracavernous injection (ICI) of vasoactive agent in hypogonadal men with micropenis. METHODS: A total of 15, previously untreated, hypogonadal men with micropenis (stretched penis length less than 2.5 SD below the mean of the normal population) underwent a detailed urologic and endocrinologic evaluation. Their mean age was 21.2 +/- 4.2 years. Penile hemodynamics were assessed by color Doppler ultrasonography before and after ICI of 5 microg of prostaglandin E(1) combined with manual genital self-stimulation. RESULTS: Endocrinologic evaluation revealed that hypogonadism was hypogonadotropic in 10 (66.7%) and hypergonadotropic in 5 (33.3%). Karyotype analysis showed 46XY in all. Their mean stretched penile length was 6.2 +/- 1.4 cm (range 3 to 7.5) and increased to a mean of 6.96 +/- 1.5 cm (range 4 to 8.5) after ICI. The serum free testosterone levels ranged from 0.2 to 3.2 pg/mL (mean 1.9 +/- 0.92). None had had any previous sexual experience, and 14 (93.3%) reported a history of nocturnal erections. Penile color Doppler ultrasonography demonstrated a normal penile vascular system in 7 (46.7%) and penile arterial insufficiency in 4 (28.6%). All 11 of these patients (73.3%) achieved an adequate erectile response to ICI combined with manual stimulation. Mixed vascular disease was observed in the remaining 4 patients (28.8%), and they did not have a sufficient erectile response to ICI. Color Doppler ultrasonography revealed similar results in the hypogonadotropic and hypergonadotropic men. CONCLUSIONS: Our data suggest that the erectile response to ICI combined with manual genital self-stimulation is effective in most hypogonadal men having a micropenis with low serum androgen levels.

Adolescent↗
PubMed2002

Neurapraxic complications in operations performed in the lithotomy position.

In this study, we assessed the incidence and risk factors associated with lower extremity neurapraxia in operations performed in the lithotomy position. A total of 1170 patients, who were operated on in the lithotomy position, were evaluated retrospectively. During the post-operative neurological evaluation, those patients who developed neuropraxic complications were reviewed in detail to identify those with lower extremity sensory and motor deficiencies. The electromyographic (EMG) results of the patients with neurological deficiencies were evaluated. The patients were studied with respect to age, length of operation, type of operation and mode of anaesthesia. Fischer's Exact Probability Test was used for the statistical analyses. Post-operative neurapraxia complications developed in 12 of the patients (1.02%). Of these cases, two had irreversible neurological deficiencies. All other patients recovered without any treatment during the first post-operative month. No correlation was discovered between the type of anaesthesia used and neurapraxia (P> 0.05). However, it was found that age, type of operation and operation time contributed to neurapraxia developing (P < 0.05). Old age (older than 70), prolonged operation time (more than 180 min) and an inappropriate lithotomy position were seen as the main risk factors in developing post-operative neurapraxia. Mistakes in the positioning of the operating staff might be an additional contributing factor.

Aging↗