Vasovasostomies in Men 15 Years or More after Vasectomy / 대한비뇨기과학회지

PURPOSE: This study aimed to evaluate the results of vasovasostomies performed in men 15 years or more after a vasectomy. MATERIALS AND METHODS: Vasovasostomies were performed in 39 men 15 years or more after a vasectomy using a two-layer microscopic technique. The medical charts of the subjects were reviewed with regard to the age of the patients and their wives, the presence of sperm in vasal fluid and the gross appearance of the vasal fluid (watery, milky or creamy) during operation. The postoperative follow-up consisted of serial semen analyses and telephone interviews. RESULTS: The patency and pregnancy rates were 73.7 and 30%, respectively. Patients whose vasal fluid was watery or milky during operation had better patency rates (p=0.049). Other factors, including age of patients, obstructive interval and intraoperative detection of sperm, had no influence on the patency rates. When their wives were divided according to age (above and below 37 years), the pregnancy rates were 70 and 18% in the younger and older age groups, respectively (p=0.03). CONCLUSIONS: The rate of success of a vasectomy reversal in men 15 years or more after their vasectomy was lower than those whose vasectomies were performed more recently, but compared favorably with those obtained with assisted reproductive technology. We recommend that a microsurgical vasovasostomy should be performed preferentially in men 15 years or more after their vasectomy.

Pathophysiologic Investigation of Vasculogenic Erectile Dysfunction Using Newly Developed Rat Model / 대한남성과학회지

PURPOSE: We developed a novel rat model to investigate vasculogenic erectile dysfunction(ED) and investigated the possible mechanisms of atherosclerosis-induced ED. MATERIALS AND METHODS: Twenty male Sprague-Dawley rats(3 months old) were divided into control(n=10) and atherosclerosis(n=10) group. The control group was placed on a regular diet, while the atherosclerosis group received a 1% cholesterol diet for 6 weeks. To induce endothelial dysfunction, which is essential to the development of atherosclerosis, NG-nitro-l-arginine methyl ester(L-NAME) 1 mg/ml was added to the drinking water for the first 2 weeks. After six weeks, erectile function was assessed with cavernous nerve electrostimulation. Measurement of blood levels of cholesterol and histopathologic examination of the aorta and iliac artery were done. Semiquantitative RT-PCR for hypoxia-induced factor(HIF)-1alpha mRNA and Western blotting for HIF-1alpha and transforming growth factor (TGF)-beta1 were carried out on the penile tissues. RESULTS: Compared with the control group, both serum cholesterol level and arterial pressure were significantly elevated in the atherosclerosis group. The atherosclerosis group also showed prolonged and diminished erectile responses during cavernous nerve stimulation. Histologic study revealed definite atherosclerosis in the aorta and internal iliac artery, and the severity of atherosclerosis correlated well with decreased erectile function. Although RT-PCR did not show differences in the expression of HIF-1alpha mRNA, expression of HIF-1alpha and TGF-beta1 was significantly higher in the atherosclerosis group than in the control animals. CONCLUSIONS: In the rat, vasculogenic ED secondary to atherosclerosis could be generated by a high-cholesterol diet combined with an NOS inhibitor. Atherosclerosis might hamper erectile function by cavernosal ischemia secondary to a reduced blood supply and possibly by cavernosal fibrosis.

Evidence for Peripheral Effect of Serotonin on Ejaculatory Response / 대한남성과학회지

PURPOSE: Although serotonin (5-HT) has been implicated in central control of sexual desire, erection and ejaculation, its peripheral effect has been poorly studied. Here, we investigated the peripheral effects of 5-HT on ejaculation using in vivo and in vitro experiments. MATERIALS AND METHODS: Male Sprague-Dawley rats (weighed 250-300 g) were injected intravenously with serotonergic agents (serotonin, fluoxetine, clomipramine) at various concentrations 20 min before electrical nerve stimulation of the hypogastric nerve. Intraluminal pressure of seminal vesicle and vas deferens was measured on each side in the same animal and compared. Total RNA was isolated from brain, seminal vesicle and vas deferens. Expressions of mRNAs for 5-HT(1A), 5-HT(1B) and 5-HT(2C) receptors, which have been suggested for ejaculatory responses, were examined using semi-quantitative reverse-transcriptase polymerase chain reaction. RESULTS: All serotonergic agents caused dose-dependent inhibition of elevation in intraluminal pressure of the seminal vesicle. Vasal pressure responses were effectively inhibited by clomipramine and serotonin (clomipramine>serotonin), whereas no effect was seen by fluoxetine. There was no significant difference in relative expression levels of 5-HT(1A) receptor mRNAs between the seminal vesicle and vas deferens. However, the expression levels of 5-HT(1B) and 5-HT(2C) receptors mRNAs were lower in the vas deferens when comparing to those in the seminal vesicle. CONCLUSIONS: These results of in vivo and in vitro experiments provide evidence for the peripheral role of 5-HT in regulating ejaculatory response of male rats. Regional differences in distributions of 5-HT receptor subtypes between seminal vesicle and vas may contribute to the different response to serotonergic agents in these organs.

Development of New Gene Therapy for Erectile Dysfunction Using Antisense cDNA for Type V Phosphodiesterase Gene / 대한남성과학회지

PURPOSE: We examined the feasibility of gene therapy for erectile dysfunction using cultured human corpus cavernosal smooth muscle cells. MATERIALS AND METHODS: The vector construct was designed to contain a fusion gene of enhanced green fluorescent protein (gfp) and beta-galactosidase (lacZ) which was under control of CMV promoter. Cells within the second passage were transfected with the vector DNA only and vector DNA containing a part of cDNA in an antisense orientation for human type V phosphodiesterase (PDE) gene using lipofection. Reporter gene expressions were investigated by fluorescence microscopy and X-gal staining at 24-hour interval. Effects of gene transfer of type V PDE antisense cDNA were investigated after 48 hours of gene transfection using the RT-PCR for type V PDE gene and measurement of intracellular cGMP level treated by sodium nitroprusside (SNP), NO-donor, of various concentrations. RESULTS: Expressions of gfp and lacZ were observed for upto 72 hours after gene transfection. Results from RT-PCR analysis also confirmed the gene expression at the transcriptional level. Type V PDE mRNA expression was significantly inhibited and magnitude of cGMP increase was significantly enhanced by gene transfer of antisense cDNA for type V PDE gene compared with non-transfectant control cells. CONCLUSIONS: Our results demonstrate that the liposome-mediated gene transfer was shown to be effective in corpus cavernosal smooth muscle cells. Gene transfer of antisense cDNA for type V PDE gene effectively inhibited the expression of type V PDE gene at the transcriptional and translational levels, suggesting that this newly developed gene transfer system may be a potential gene therapy in the treatment of erectile dysfunction.

Studies on Intracellular Signal Transduction Pathway Involved in Human and Rabbit's Corpus Cavernosal Smooth Muscle Relaxation / 대한남성과학회지

PURPOSE: Nitric oxide (NO) and phosphodiesterases (PDEs) play key roles in mediating relaxation of corpus cavernosal smooth muscle by increasing intracellular cGMP level. Here, we investigated effects of NO-donor (sodium nitroprusside, SNP) and penile specific type-V PDE inhibitor (zaprinast) in human and rabbit corpus cavernosal cells and tissues in vitro. MATERIALS AND METHODS: The cultured smooth muscle cells and tissues of human and rabbit corpus cavernosum were treated with increasing concentrations of SNP or zaprinast for 5 and 20 minutes, respectively, and intracellular cGMP levels were measured by radioimmunoassay. Organ bath study was performed to measure the relaxation effects of drugs on precontracted corpus cavernosal muscle strips. RESULTS: Although both NO-donor and type-V PDE inhibitor effectively stimulated the accumulation of cGMP in a dose-dependent manner, magnitude of cGMP increase and specificity of drug were found to be species-dependent. In human corpus cavernosal tissues, cGMP was increased upto 10- and 5-folds by SNP and zaprinast, respectively. However, magnitude of increase was much less in cultured smooth muscle cells. In rabbit, SNP effect was most prominent in cultured cells and effects of SNP and zaprinast were modest in tissues. Both agents also resulted in effective relaxation of human and rabbit cavernosal tissue strips. Similar patterns of dose-response curves were shown between results from the organ bath studies and cGMP radioimmunoassay with cavernosal smooth muscle cells. CONCLUSIONS: Present results show that effects of SNP and zaprinast are not coincident in different species, suggesting possible species-specificities of these two agents. Measurement of cGMP changes in cultured cavernosal smooth muscles cells could be reflected to the relaxation effects of drugs on corpus cavernosal muscle strips.

The Value of Prostate Specific Antigen, Digital Rectal Examination, Transrectal Ultrasound, and Transrectal Ultrasound-Guided Biopsy in Prediction of Final Pathologic Diagnosis in Prostate Cancer / 대한비뇨기과학회지

PURPOSE: We evaluated the clinical utility of preoperative serum prostate specific antigen (PSA), digital rectal examination (DRE), transrectal ultrasound (TRUS), and findings of TRUS-guided biopsies in predicting the final pathologic diagnosis in patients who underwent radical prostatectomy. MATERIALS AND METHODS: The medical records of 53 patients with prostate cancer who underwent radical prostatectomy from september 1995 to June 2000 were reviewed. Pathologic variables evaluated on sextant biopsies included total length and percent of cancer on one core, number of cores involved and Gleason score. Clinical variables included PSA and PSA density (PSAD). Also subjects were divided into two groups; organ-confined group versus non organ-confined group. RESULTS: On final pathologic examination, 38 patients (72%) had organ-confined, 11 patients (21%) had margin positive, 6 patients (11%) had capsular penetration and 6 patients (11%) had seminal vesicle involvement. None had pelvic lymph node metastases. Chi-square analysis demonstrated significant correlations between PSA, PSAD, number of cores involved, total length of cancer on one core and organ-confined prostate cancer. When PSA level was 11 or more, PSAD was 0.34 or more, biopsies had Gleason scores of 7 or more, number of cores involved was two or more, and total length of cancer on one core was 0.4cm or more, possibility of cancer being non organ-confined increased CONCLUSIONS: This study demonstrates that PSA, PSAD, Gleason score in sextant biopsy, number of cores involved, total length of cancer on one core are clinically useful predictors of organ-confined disease. This may help both patients and clinician in selecting the most appropriate therapeutic approach.