Biomedical subjects

Kwanjin Park

Publications and source records attributed to Kwanjin Park.

10 recordsLinked to original sources

PubMed2006

Chronic administration of an oral Rho kinase inhibitor prevents the development of vasculogenic erectile dysfunction in a rat model.

INTRODUCTION: It has been shown that the Rho/Rho kinase calcium sensitizing pathway has been implicated in the pathogenesis of erectile dysfunction as well as systemic atherosclerosis. AIMS: To test whether chronic treatment of an oral Rho kinase inhibitor (fasudil, 5-Isoquinolinesulfonyl homopiperazine) could prevent the development of both vasculogenic erectile dysfunction and pelvic atherosclerosis in a rat model. METHODS: Rats (3 months old) were divided into three groups (N = 10 in each group): control (group 1); atherosclerosis (group 2); and fasudil-treated (group 3). Groups 2 and 3 received atherosclerosis-prone treatment (6 weeks of 1% cholesterol diet and early 2 weeks of N(G)-nitro-L-arginine methyl ester [3 mg/mL/day] treatment, but group 3 was concurrently treated with fasudil (30 mg/kg/day) for 6 weeks. MAIN OUTCOME MEASURES: The amount of systemic endothelial injury (plasma von Willebrand factor) and pelvic atherosclerosis was determined. Erectile function, cavernosal Rho kinase activity, and expressions of total and phosphorylated endothelial nitric oxide synthase (eNOS) were also determined. RESULTS: Group 2 showed a significant amount of pelvic atherosclerosis and endothelial injury. The rats also showed elevated cavernosal Rho kinase activity and impaired erectile function. Immunoblot showed a decreased total as well as phosphorylated eNOS expression. The treatment with fasudil partly but significantly ameliorated the development of pelvic atherosclerosis and plasma level of von Willebrand factor. The treatment also normalized the erectile function, cavernosal Rho kinase activity, and total eNOS expression. The overexpression of phospho-eNOS was observed in group 3. CONCLUSIONS: These results indicate that the Rho/Rho kinase pathway is substantially involved in the development of erectile dysfunction and pelvic atherosclerosis, both of which could be prevented by chronic treatment with fasudil. Thus, Rho kinase might be considered a novel target for the prevention of vasculogenic erectile dysfunction.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed2005

Significance of pad test loss for the evaluation of women with urinary incontinence.

AIMS: The aim of this study was to determine whether the objective incontinence severity, as measured by the pad test, correlated with urethral parameters, and if the objective incontinence severity was differentiated by the incontinence types and also, if it influenced the patient's clinical outcome. METHODS: Two hundred seventy-four female patients who had undergone a tension-free vaginal tape procedure between March 1999 and May 2003 were retrospectively reviewed. The 1 hr pad test was carried out as recommended by the International Continence Society, with some modification. The mean patient age was 55.1 years (range: 28-80). Two hundred-one women (73.3%) that complained of stress urinary incontinence and another 73 women (26.7%) that had additional symptoms of urge incontinence were enrolled as study subjects. A cure for incontinence, after the tension-free vaginal tape procedure, was defined as the absence of a subjective complaint of leakage and the absence of objective leakage on stress testing, and all other cases were considered failures. RESULTS: In linear regression analysis, the Valsalva leak point pressure (VLPP) was the only explanatory variable influencing the objective incontinence severity. The urine leakage was significant higher in the mixed urinary incontinence group than in the stress urinary incontinence group (39.7 +/- 7.5 g vs. 30.3 +/- 2.8 g, P < 0.05). For the total patients, the failure group had a more severe preoperative objective severity than the cure group (53.2 +/- 16.6 vs. 32.0 +/- 3.0, P < 0.05). Upon a subgroup analysis, a similar result was found in the stress urinary incontinence group (87.1 +/- 8.2 vs. 29.8 +/- 2.8, P < 0.05) but not in the mixed urinary incontinence group. CONCLUSIONS: Our findings suggest that the amount of urine leakage as measured during the pad test may be associated with the clinical outcome, after the anti-incontinence surgery.

Diagnostic Techniques, Urological↗

PubMed2005

Benefits of microsurgical repair of adolescent varicocele: comparison of semen parameters in fertile and infertile adults with varicocele.

OBJECTIVES: To compare preoperative semen parameters and the effect of microscopic varicocele repair on semen parameters in adolescents, fertile adults, and infertile adults with varicocele. METHODS: A total of 96 patients (35 adolescents, 20 fertile adults, and 41 infertile adults) were included in the primary analysis. RESULTS: The fertile adults had a higher sperm count than did the adolescents or infertile adults (P <0.001). In infertile adults, the percentage of normal sperm increased from 14.9% +/- 1.0% preoperatively to 21.2% +/- 2.2% at 3 months (P = 0.013) and 22.1% +/- 2.2% (P = 0.003) at 6 months. The infertile adults had a lower sperm count than did the adolescents and fertile adults at both 3 (P = 0.014) and 6 (P = 0.003) months. The postoperative sperm motility in adolescents was significantly greater than that in the infertile adults at 3 (P = 0.009) and 6 (P = 0.003) months. The proportion of sperm with normal morphology was not statistically different at either 3 or 6 months among the groups. No significant differences were detected in the increase in semen parameters at 3 or 6 months among patients before or after surgery. CONCLUSIONS: The results of our findings suggest that after varicocele repair the degree of improvement in semen parameters is not different. However, because the baseline values of the semen parameters in adolescents were better than those in infertile adults, the postoperative values in the adolescents were superior to those in infertile adults and at least as good as those in fertile adults.

Adolescent↗

PubMed2005

Risk factors in predicting a poor response to sildenafil citrate in elderly men with erectile dysfunction.

OBJECTIVE: To assess the clinical efficacy of sildenafil and the potential predictors of poor response to sildenafil in elderly patients with erectile dysfunction (ED). PATIENTS AND METHODS: The study included 162 patients (aged > or = 60 years) treated with sildenafil for at least 8 weeks; all patients were evaluated with a history, physical examination, measurement of total testosterone and a pharmacological erection test. Sexual function before and 8 weeks after treatment was assessed using the self-administered International Index of Erectile Function (IIEF). Treatment was considered successful when the patient attained a higher grade on the erectile function (EF) domain score, and an affirmative response to the overall assessment question. Factors influencing treatment outcome were evaluated by univariate and multivariate statistical analysis. RESULTS: The overall efficacy with sildenafil was 47% (76/162). On univariate analysis, uncontrolled diabetes, current smoking, hypogonadism (<3 microg/L testosterone) and low pretreatment EF domain score (<17) were selected as predictors of a poor response. On multivariate logistic regression, a low pretreatment EF domain score was the strongest independent prognostic factor for a poor response (odds ratio 2.25, 95% confidence interval, 1.45-7.33), and this was followed by hypogonadism (1.89, 1.12-3.16) and current smoking (1.34, 1.04-3.52). CONCLUSION: In a real clinical setting, sildenafil was effective for about half of the elderly men. The baseline EF domain score, hypogonadism and current smoking were significantly associated with failure of sildenafil. These results suggest that modifying reversible risk factors, e.g. stopping smoking and replacing testosterone, would be beneficial in augmenting the efficacy of sildenafil in elderly men.

Aged↗

PubMed2004

Clinical features determining the fate of a long-term, indwelling, forgotten double J stents.

We review our experiences with forgotten stents and investigate the potential factors determining the degree of encrustation. Our series consists of nine cases of forgotten stent that had remained indwelling for more than 1 year (mean 36.1 months). We describe and compare their various clinical parameters in terms of encrustation. In addition, we briefly summarize our management schemes. All patients showed few stent related irritative symptoms. Six cases showing minimal or no encrustation shared the common feature of urine hypotonicity. Cystoscopic pullout was possible in these cases. The remaining three cases showed moderate to severe encrustation around the stent which required multiple procedures. Pyuria was observed in all cases and two patients had a history of urolithiasis. Finally, all cases were rendered stent and stone free. The fate of forgotten stents was dependent on the amount of encrustation around the stent. In our study, lithogenic history and presence of pyuria were associated with moderate to severe encrustation. Interestingly, patients showing urine hypotonicity tended to have a minimal encrustation on their stents and the stents were easily removed. Therefore, in patients with an impaired renal concentrating ability and a poor medical condition, the duration of indwelling stents might be safely prolonged if the patient has no risk factor for encrustation. As patients with forgotten stents are less likely to complain of stent related symptoms, thorough education of patients is important to prevent stent related complications.

Adult↗

PubMed2004

Reasons for discontinuation of sildenafil citrate after successful restoration of erectile function.

AIM: To investigate the reasons for discontinuations of sildenafil after the successful restoration of erectile function. METHODS: One hundred fifty six patients, whose scores of erectile function domain of the 15-item International Index of Erectile Function (IIEF) increased to 26 or more after sildenafil medication, were included in this study. Six-months after the first sildenafil prescription, compliance to medication and the reason for discontinuity were reviewed by chart or surveyed by telephone. RESULTS: Fifty-four (34.6 %) of the 156 successfully treated patients discontinued sildenafil medication. The reasons for discontinuance were shortcomings in the partners' or patients' emotional readiness for the restoration of sexual life after long-term abstinence (37.0 %), fear of possible side effects (18.5 %), recovery of spontaneous erection (14.8 %), postponement of ED treatment because of co-morbid disease treatment (11.1 %), unwillingness to accept drug-dependent erection (7.4 %), high drug cost (3.7 %), unacceptability of planned sexual activity (3.7 %) and lack of sexual interest (3.7 %). CONCLUSION: The reasons for discontinuing sildenafil medication were primarily emotional or relationship-oriented, which indicates that simple recovery of a rigid erection is insufficient to restore sexual activity. More education about the effects of drug and the counseling of both partners is recommended to promote the successful recovery of sexual activity.

Adult↗

PubMed2003

Microsurgical vasovasostomy after failed vasovasostomy.

PURPOSE: We analyzed our experience with repeat microsurgical vasovasostomy after failed vasovasostomy and elucidate the possible predictors of surgical outcome. MATERIALS AND METHODS: We evaluated 62 repeat vasectomy reversal cases with followup data available. Regardless of the intraoperative observation of sperm in the vasal fluid bilateral microsurgical 2-layer vasovasostomy was performed when surgically possible. Of these 62 patients 60 (97%) underwent bilateral (58) or unilateral (2) vasovasostomy and 2 (3%) underwent unilateral vasovasostomy with contralateral epididymovasostomy. RESULTS: Patency and pregnancy followup data were available on 62 and 42 patients, respectively. The overall patency and pregnancy rates achieved were 92% and 57%, respectively, and the natural birth rate was 52%. Increased age of the wife proved a negative prognostic factor for pregnancy (p = 0.018). The intraoperative detection of sperm and other factors, including obstructive interval, reconstruction type, anastomotic site, patient age and postoperative semen parameters, did not influence the surgical outcome. CONCLUSIONS: Regardless of the detection of sperm in the intravasal fluid during the operation repeat microsurgical vasovasostomy resulted in a better outcome than in other studies, in which adopted epididymovasostomy was done when sperm was absent from the vas fluid. Our study suggests that compromised anastomosis after previous surgery is the most common cause of failed vasovasostomy. We recommend that microsurgical vasovasostomy should be performed preferentially in failed vasovasostomy cases.

Adult↗

PubMed2002

Laparoscopic nephrectomy for tuberculous nonfunctioning kidney: comparison with laparoscopic simple nephrectomy for other diseases.

OBJECTIVES: To summarize the results of our 31 consecutive laparoscopic nephrectomies for renal tuberculosis and compare them with 45 laparoscopic nephrectomies performed for other benign etiologies. We previously reported our initial successful experiences in expanding the role of laparoscopic surgery with the introduction of laparoscopic nephrectomy for renal tuberculosis. METHODS: Thirty-one laparoscopic nephrectomies for renal tuberculosis were performed between June 1996 and December 2001. The patients consisted of 11 men and 20 women with a mean age of 44.2 years (range 29 to 64). The control group consisted of 17 men and 28 women with a mean age of 48.6 years (range 17 to 60). The two groups were comparable with regard to demographic data. Statistical analyses were used to compare the two groups in terms of various parameters, including surgical time, blood loss, analgesic requirements, resumption of oral intake, and hospital stay. RESULTS: Laparoscopic nephrectomy was successful in 30 cases of the tuberculosis group and 44 cases of the control group. The two groups showed comparable perioperative and postoperative parameters, except for mean operative time, which, at 244 minutes for the tuberculosis group, was significantly greater than the 216 minutes for the control group (P <0.05). No significant intraoperative or postoperative complications were observed in either group. CONCLUSIONS: The results of this study indicate that laparoscopic nephrectomy for renal tuberculosis is a safe, effective, and less invasive treatment modality. Therefore, we suggest that the renal tuberculous nonfunctioning kidney should be approached initially using the laparoscopic approach.

Adult↗

PubMedDate not supplied

A different female partner does not affect the success of second vasectomy reversal.

The aim of the study was to determine whether the pregnancy rate with the same female partner or younger partners was higher compared with different or older partners after undergoing repeated vasectomy reversal. A total of 44 patients were enrolled in the present study. The cause of reversal in patients with the same partner was the desire to have more children in 14 cases, the loss of a child in 7 cases, and the desire for a son in 7 cases. Patients were asked about pregnancy and childbirth during follow-up visits and by telephone or mail. Following microsurgical vasectomy reversal, patency was observed in 38 men (86.4%). Twenty-five of the couples (56.8%) achieved pregnancy without any artificial conception technique. We did not observe a significant difference in the pregnancy rate (57.1% vs 56.3%, P=.954) between patients with the same or a different female partner. In the multivariate model used, partner age was the only independent predictor for pregnancy. Patients with a partner less than 35 years old had a 4.1-fold greater chance (odds ratio, 4.13; 95% confidence interval, 1.06-16.10; P=.041) of pregnancy than those with a partner 35 years old or older. The area under the receiver operating characteristics curve for partner age was 73.0% (95% confidence interval 56.8-89.2, P=.011). Our findings suggest that repeat microsurgical vasectomy reversal still remains a reasonable choice for patients with different female partners. However, it should be considered that the likelihood of achieving pregnancy after repeat vasectomy reversal may decrease with advancing age of the female partner.

Adult↗

PubMedDate not supplied

Restoration of erectile capacity in normotensive aged rats by modulation of angiotensin receptor type 1.

We investigated the effects of systemic modulation of angiotensin 2 on the erectile dysfunction of aged rats. Young and aged (18 months old) male Sprague-Dawley rats were either treated with daily administration of losartan (angiotensin type 1 receptor antagonist, 30 mg/kg/d PO) or the drug vehicle (control) for 4 weeks (n=6 in each group). We monitored the intracavernosal pressure (ICP) after administration of apomorphine (100 microg/kg), and we measured the degree of lipid peroxidation of corpus cavernosum and the cavernosal protein expression by an immunoblot technique. Compared to the control young rats, the control aged rats showed significant impairment of erectile function; however, losartan treatment effectively restored the erectile function of aged rat to a level similar to that of young rats. Despite the systemic pressure-lowering effect of the drug, the peak ICP was not significantly reduced; rather, the ICP/systemic arterial pressure (SAP) was increased by the losartan treatment. Measurement of lipid peroxidation revealed the fact that the drug was effective in diminishing oxidative stress. While the losartan treatment significantly enhanced the expression of endothelial nitric oxide synthase (eNOS), it had no effect on the expression of transforming growth factor (TGF)-beta1. The results obtained indicated that alteration of the renin-angiotensin system might be implicated in the erectile dysfunction of elderly males, and modulation of this system may be of great therapeutic value.

Aging↗