Kazuyuki Yoshikawa

High energy underwater shock wave treatment on implanted urinary bladder cancer in rabbits

The effects of focused high energy shock waves (SW) on the implanted urinary bladder cancer in rabbits were examined. The bladder cancer was exposed to 2000 to 8000 shots of focused SW under ultrasound guidance. Although only focal necrosis of the tumor was seen in the one day SW exposure, wider and deeper tumor necrosis was observed in the tumors following serial SW (2000 to 6000 shots, for two to three days). Eight to 10 day serial SW exposure (6000 to 8000 shots) decreased the tumor growth in comparison with that of the control. Lung metastases examined by periodic chest X-ray after SW treatment revealed that SW did not promote lung metastases. Pathological findings were also in accord with the X-ray examinations. Polyclonal antibody type 4 collagen was used for immunohistochemical staining of vascular wall in bladder cancer. Vascular wall destruction, not found in spontaneous necrotic tumor, were clearly visible in SW induced necrotic area. SW induces vascular damage in the tumor, which may be the primary cause promoting the tumor necrosis.

Somatosensory evoked magnetic fields elicited by dorsal penile, posterior tibial and median nerve stimulation

The aim of this study is to localize the primary sensory cortex of urogenital organs in the human brain. Using a newly developed MRI-linked magnetoencephalography system, we measured somatosensory evoked magnetic fields (SEFs) for unilateral stimuli on the dorsal penile nerve (DPN), posterior tibial nerve (PTN) and median nerve (MN). In five healthy male subjects, SEFs were clearly observed. Peak latency of the first cortical components were 63.8 +/- 9.2 ms for DPN, 39.8 +/- 3.0 ms for PTN and 20.7 +/- 0.7 ms for MN stimuli. Peak amplitude of the first cortical components were 63.1 +/- 10.8 fT for DPN, 160.2 +/- 50.1 fT for PTN and 335.2 +/- 70.3 fT for MN stimuli. Isofield map for the peak latencies indicated a single dipolar pattern for DPN as well as for PTN and MN stimuli. Using a single current dipole model, all SEF sources were localized on the contralateral central sulcus to the stimuli, indicating the primary sensory cortex. The DPN sources were localized on the interhemispheric surfaces, corresponding to previous speculations by direct cerebral stimulation. This non-invasive SEF technique promises further brain functional mapping for the urogenital organs.

High-energy Underwater Shock Wave Treatment for Internal Iliac Muscle Metastasis of Prostatic Cancer: A First Clinical Trial

The first clinical trial of high‐energy shock wave (SW) combined with chemotherapy to treat metastasis of prostate cancer in the internal iliac muscle was conducted. The patient, a 57‐year‐old man, diagnosed as having mucin‐producing, poorly differentiated adenocarcinoma of the prostate invading the bladder wall, had been treated by total cystoprostatectomy. Five months later, metastatic tumors were found in the left axillar subcutaneous tissue and the right internal iliac muscles. For the axillar metastasis we performed radiation and left subclavicular arterial infusion of cisplatin 70 mg, THP‐adriamycin (THP) 50 mg and methotrexate 50 mg. For the right internal muscular metastasis, 10,000 to 20,000 shots of SW and simultaneous intravenous injection of carboplatin 100 mg and THP 10 mg were carried out. Neither of the tumors decreased in size, but on magnetic resonance images, the SW‐treated tumor exhibited a central low‐intensity area. The SW‐treated tumor was resected and central necrosis and a collection of mucin in the central area were observed. Hormone‐resistant prostate cancer is well‐known to be a multidrug‐resistant tumor. It is noteworthy that SW and chemotherapy induced necrosis in such a refractory cancer without any significant side effects.

Stent failure in the management of malignant extrinsic ureteral obstruction: Risk factors

There is still controversy surrounding the indications for performing either a retrograde ureteral stent or percutaneous nephrostomy to manage malignant extrinsic ureteral obstruction (MEUO). We retrospectively analyzed 53 patients who underwent a decompression of MEUO using retrograde ureteral stent. Ureteral stent failure occurred in 18 of 53 patients (34%). Multivariate analysis showed that gastrointestinal cancer as the primary disease, poor preoperative performance status and severe preoperative hydronephrosis were independent predictors of stent failure. Based on the present data, we propose an algorithm for the management of MEUO.

The Effect of High‐energy Underwater Shock Waves on Implanted Urinary Bladder Cancer in Rabbits

We have examined the effects of high‐energy shock waves (HESW) on implanted urinary bladder cancer in rabbits. The bladder cancer was exposed to 2000 to 6000 shots of focused HESW under ultrasound guidance. Although only focal necrosis of the tumor was seen in the one‐day HESW exposure (2000 shots), wider and deeper necrosis was observed in the tumors following serial HESW (4000 or 6000 shots; 2 or 3 days). These results indicate that serial HESW exposure has destructive effects on implanted bladder cancer in rabbits.

Predictive value of N-acetylglucosaminyltransferase-V for superficial bladder cancer recurrence.

PURPOSE GnT-V is an enzyme that catalyzes beta1-6 branching of N-acetylglucosamine on asparagine (N)-linked oligosaccharides of cell proteins. GnT-V expression has been closely related to malignant potentials in colon cancer, brain cancer and hepatocellular carcinoma. We determined whether GnT-V expression is predictive of superficial bladder cancer recurrence. MATERIALS AND METHODS The cohort comprised 60 consecutive patients with first time superficial bladder cancer treated with transurethral resection. None of the patients received prophylactic intravesical therapy until recurrence. Paraffin embedded tumor specimens were immunohistochemically examined by the avidin-biotin peroxidase method using monoclonal antibody against GnT-V. Kaplan-Meier survival curves were generated to determine disease-free survival. Univariate and multivariate analyses were done to compare GnT-V expression to other clinical and pathological variables. RESULTS GnT-V expression correlated inversely with tumor grade and stage. The positive incidence of GnT-V in G1 to G3 tumors was 7 of 9 (78%), 21 of 43 (49%) and 3 of 8 (38%), respectively. GnT-V was positive in 26 of 44 cases of pTa (60%) and in 5 of 16 of pT1 (31%) disease. The 31 patients with positive GnT-V expression had significantly higher disease-free survival than the 29 with negative GnT-V expression (log rank test p = 0.0034). Multivariate analysis revealed that patient age, pT, grade and negative GnT-V expression were independent predictors of recurrence (p = 0.015, 0.001, 0.019 and 0.011, respectively). CONCLUSIONS Immunohistochemical detection of GnT-V is an independent predictor of superficial bladder cancer recurrence.

Adenocarcinoma arising from the prostatic duct mimicking transitional cell carcinoma

Abstract A 71‐year‐old man was first diagnosed with primary transitional cell carcinoma of the prostate with a skip lesion on the distal urethra. The patient received three courses of intra‐arterial chemotherapy of cisplatin (CDDP) and pirarubicin (THP‐ADM) followed by a radical prostatectomy. Histopathologic examination of the prostatectomy specimen revealed adenocarcinoma invasion along the prostatic duct extending to the peripheral acini, which was diagnosed as ductal adenocarcinoma. The clinical and histopathologic features of this case are entirely different from usual adenocarcinomas of the prostate. This rare histopathologic feature should be recognized as ‘ductal carcinoma of the prostate’, to distinguish it from papillary adenocarcinoma or adenocarcinoma with endometrioid features. The patient has had no sign of recurrence 14 months after the operation. CDDP‐based chemotherapy followed by radical prostatectomy may be one of the promising therapeutic modalities for this rare entity.

The significance of resections for residual masses after chemotherapy in metastatic testicular tumors

Background: After chemotherapy for metastatic testicular tumors, masses may remain, often in the metastatic sites. This study analyses the role of resections for the residual masses.

Endoscopic observation for detection and monitoring ofN-butyl-N-(4-hydroxybutyl)nitrosamine — induced bladder tumor in rats

Recent advances in tumor carbohydrate biochemistry have demonstrated antitumor effects of locally administered GM3 ganglioside on mouse MBT-2 tumor. When intravesical therapy inN-butyl-N(4-hydroxybu-tyl)nitrosamine (BBN)-induced rat bladder tumor is attempted, it is essential to identify the tumor, to classify its size before therapy and to monitor the effect of the therapy. To establish a more reliable experimental therapeutic system, we assessed the development of BBN-induced rat bladder tumor by endoscopic observation. BBN-induced bladder tumors in rats were observed serially using a 4.2-F flexible fiberscope. The endoscopic findings were compared with the histopathological findings. Intravesical tumor growth varied greatly between individual rats. The smallest change detected by endoscopy was a small edematous lesion histologically proved to be papilloma. The largest nodular lesion was determined to be a papillary, transitional cell carcinoma. This noninvasive method makes the BBN rat experimental system more reliable by allowing confirmation of tumor formation and classification of the tumor volume prior to therapy.

Surveillance study for clinical stage I testicular seminomas and nonseminomatous germ cell tumors.

Background: Optimal therapy for stage I testicular tumors is still controversial. This study evaluated the efficacy of a surveillance policy for patients with testicular stage I seminomas and nonseminomatous germ cell tumors (NSGCT).