Tetsuo Okuno

Involvement of accumulated endogenous NOS inhibitors and decreased NOS activity in the impaired neurogenic relaxation of the rabbit proximal urethra with ischaemia

We examined the effect of ischaemia on the neurogenic and nitric oxide (NO)‐mediated urethral relaxation. Rabbits were divided into control and urethral ischaemia (UI) groups, which was prepared by the partial occlusion of bilateral iliac arteries using blood vessel occluders. Neurogenic and NO‐mediated proximal urethral relaxation induced by electrical field stimulation (EFS) was greatly impaired in the UI group, while relaxation by sodium nitroprusside (SNP) as a NO donor showed no difference between the two groups. Pretreatment with L‐arginine significantly improved but did not normalize the impaired relaxation in the UI group. Not only basal level, but also stimulated production of cyclic GMP with EFS, were significantly decreased in the UI group. The tissue contents of NG‐methyl‐L‐arginine (L‐NMA) and asymmetric NG, NG‐dimethyl‐L‐arginine (ADMA) in the proximal urethra were increased following ischaemia. While L‐arginine and symmetric NG, N′G‐dimethyl‐L‐arginine (SDMA) contents remained unchanged. Exogenously applied authentic L‐NMA and ADMA (1 – 100 μM) concentration‐dependently inhibited the EFS‐induced urethral relaxation in the control group. The inhibition with L‐NMA and ADMA was undetectable in the presence of 3 mM L‐arginine. The Ca2+‐dependent NOS activity in the urethra from the UI group was significantly lower than that from the control group and was not restored by an addition of 3 mM L‐arginine. These results suggest that the impaired neurogenic and NO‐mediated urethral relaxation with ischaemia is closely related to the increased accumulation of L‐NMA and ADMA and decreased NOS activity, which would result in an accelerated reduction in NO production/release.

Successful treatment of metastatic adenocarcinoma of the urachus: report of 2 cases with more than 10-year survival.

Metastatic urachal cancer is often considered lethal. We report 2 cases of metastatic urachal carcinoma successfully treated with surgical excision followed by combinations of surgery, radiation, and chemotherapy against local recurrence and/or distant metastases, with a recurrence-free survival period of more than 10 years. These cases provide support for multimodal treatments of metastatic urachal cancer.

Different distribution of nitric oxide synthase and soluble guanylyl cyclase activities in the detrusor and proximal urethra of the rabbit

PURPOSE We investigated the different distributions of nitric oxide synthase (NOS) and soluble guanylate cyclase activities in the detrusor and proximal urethra in the rabbit. MATERIALS AND METHODS The detrusor and proximal urethra were excised, the mucosa and muscularis were separated and each layer was homogenized to measure the activities of NOS as well as baseline and sodium nitroprusside (SNP) activated soluble guanylate cyclase. Isometric tension experiments were performed in detrusor and urethral strips with and without mucosa. RESULTS In the detrusor NOS and sodium nitroprusside activated soluble guanylate cyclase activities in the mucosa were much higher than in the muscularis. While in the proximal urethra NOS activity in the 2 layers was similar, SNP activated soluble guanylate cyclase activity in the muscularis was 2.8 times higher than in the mucosa. Removing the mucosa reduced nitric oxide (NO) mediated neurogenic relaxation in the proximal urethra, while no relaxation responses could be elicited by electrical field stimulation with or without mucosa in the detrusor. On the other hand, removing the mucosa did not affect SNP or 8-bromo-cyclic guanosine monophosphate induced relaxation in the detrusor and proximal urethra. CONCLUSIONS In the detrusor NOS and soluble guanylate cyclase activities were mainly detected in the mucosa, while in the urethra these activities were distributed throughout the mucosa and muscularis. Also, the mucosa in the urethra but not in the detrusor contributed to electrical field stimulation induced, NO mediated relaxation. These findings confirm previous studies demonstrating that NO has a different role in the detrusor than in the proximal urethra.

Simple prophylactic procedure of inguinal hernia after radical retropubic prostatectomy: isolation of the spermatic cord.

Abstract:  To reduce the incidence of inguinal hernia (IH) after radical retropubic prostatectomy (RRP), a simple prophylactic procedure was carried out during RRP. A consecutive 82 patients who had undergone RRP for clinically localized prostate cancer between July 2002 and October 2006 at Toride Kyodo General Hospital were enrolled. From July 2002 to November 2003, 20 patients underwent conventional RRP. Thereafter, 62 patients underwent conventional RRP with blunt dissection of the peritoneum at the internal inguinal ring and isolation of the spermatic cord from the peritoneum as a prophylactic procedure for IH. There was no significant difference in patient characteristics between the two groups. In the conventional RRP group, IH occurred in 10 patients during a median range follow‐up period of 41 (1 to 73) months. In contrast, in the RRP plus prophylactic procedure group, IH occurred in one patient (1.6%) during a median range follow‐up period of 41 (25 to 59) months. The incidence of IH after RRP plus the prophylactic procedure was significantly lower than that after conventional RRP, indicating the efficacy of the presented procedure.

Endoscopic minilaparotomy radical nephrectomy for chronic dialysis patients

Abstract Background : To assess the feasibility of laparoscope‐guided minilaparotomy (endoscopic minilaparotomy) for renal cell carcinoma in patients on chronic dialysis.

Suppression of spermatogenesis in ipsilateral and contralateral testicular tissues in patients with seminoma by human chorionic gonadotropin beta subunit

OBJECTIVES The pathologic complexity of the testicular tumor makes it difficult to demonstrate exactly the relationship between the impaired spermatogenesis in patients with a testicular tumor and the serum level of the human chorionic gonadotropin beta subunit (beta-hCG). Therefore, we performed quantitative evaluation of spermatogenesis in ipsilateral and contralateral testicular tissues of seminoma to simplify the relation pathologically and endocrinologically and to demonstrate the exact correlation between spermatogenesis and serum beta-hCG levels. METHODS Fifty-three biopsy specimens from ipsilateral and contralateral testicular tissues of seminoma were analyzed histologically. The quantitative evaluation of spermatogenesis was performed by the mean Johnsens score count (MJSC). Beta-hCG expression in seminoma was examined immunohistochemically. Serum beta-hCG, testosterone, estradiol, luteinizing hormone, and follicle-stimulating hormone levels were analyzed before orchiectomy. RESULTS A significant linear relationship (r = -0.82; P <0.005) was found between the serum level of beta-hCG and the MJSC in contralateral testicular tissues but not in ipsilateral ones, although the suppression of spermatogenesis was observed in both sides without suppression of luteinizing hormone and/or follicle-stimulating hormone production. CONCLUSIONS A clearcut fall in the MJSC with an associated rise in the serum level of beta-hCG was demonstrated in the contralateral testicular tissues but not in the ipsilateral ones of seminoma. It seems most likely that serum beta-hCG suppresses spermatogenesis in both ipsilateral and contralateral testicular tissues without the suppression occurring through the hypothalamus-pituitary-gonadal system, and also that some less well recognized factors affect spermatogenesis, making the relation between serum beta-hCG and MJSC obscure in ipsilateral testicular tissues.

Risk stratification for bladder recurrence of upper urinary tract urothelial carcinoma after radical nephroureterectomy

To identify risk factors and develop a model for predicting recurrence of upper urinary tract urothelial carcinoma (UTUC) in the bladder in patients without a history of bladder cancer after radical nephroureterectomy (RNU).

Young Age as Favorable Prognostic Factor for Cancer-specific Survival in Localized Renal Cell Carcinoma

OBJECTIVES To evaluate the prognostic effect of age in patients with localized renal cell carcinoma (RCC) and investigate the incidence of Xp11 translocation RCC in young patients who developed recurrence. METHODS From 1990 to 2007, 2403 Japanese patients underwent nephrectomy for presumed RCC at 9 institutions. Of those, 1143 patients had localized RCC (Stage pT1-2N0M0). Their clinical data were retrospectively reviewed. In the present study, 131 patients (11%) were considered young (≤45 years at diagnosis). In the young patients with recurrence, the nephrectomy specimens were immunostained with TFE3 to determine the incidence of Xp11 translocation RCC. RESULTS During the median follow-up of 47 months, 3 cancer deaths (2.2%) occurred among young patients and 51 (5.0%) among older patients. The 5-year cancer-specific survival (CSS) rate was significantly better for the younger patients than for the older patients (P = .049). Multivariate analysis showed that age was significantly associated with CSS, as were the pathologic T stage, tumor grade, and symptoms at diagnosis. The hazard ratio of young age was 0.31 (95% confidence interval 0.077-0.87). The recurrence-free survival curves revealed no difference between these 2 groups. Of the 74 patients with recurrence, the CSS after recurrence was significantly better in the younger patients than in the older patients (P = .0010). Of the 8 young patients with recurrence, 4 had Xp11 translocation RCC, and 3 survived for >5 years after recurrence. CONCLUSIONS Compared with the older patients, the young patients with RCC had similar recurrence-free survival rates but better CSS rates. This might have been because significant numbers of the young patients had Xp11 translocation RCC.

Equivalent survival and improved preservation of renal function after distal ureterectomy compared with nephroureterectomy in patients with urothelial carcinoma of the distal ureter: A propensity score-matched multicenter study

To investigate the oncological and functional outcome of distal ureterectomy compared with nephroureterectomy in the management of distal ureteral urothelial carcinoma.

A case of perirenal hemangioma mimicking renal cell carcinoma

Purpose: We present a rare case of perirenal hemangioma that was detected incidentally.