Yoichi Arai

Tohoku University, Japan

Are you Yoichi Arai?

Claim your profile

Publications (545)1178.38 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Usually, benign tumors are not associated with an increased F-18 fluorodeoxyglucose (F-18 FDG) uptake on positron emission tomography (PET), although some exceptions have been reported in adrenal neoplasms. We present a rare case of adrenocortical oncocytoma associated with markedly increased FDG uptake, demonstrating a maximum standardized uptake value of 46.8. Histological examination demonstrated diffuse proliferation of tumor cells with eosinophilic and granular cytoplasm that were diffusely immunopositive for mitochondria and glucose transport protein 1, with focal and weak immunopositivity for 3β-hydroxysteroid dehydrogenase. Ultrastructural examination also revealed abundant mitochondria in the tumor cells. The tumor was diagnosed as adrenocortical oncocytoma and was considered benign according to Lin-Weiss-Bisceglia criteria. Diagnosis of adrenocortical oncocytoma can pose difficulties during both preoperative radiological and postoperative histopathological investigations.
    Endocrine Pathology 10/2014; · 1.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective To determine whether the currently available pretreatment risk classification systems are applicable in Japanese prostate cancer patients.Methods Using data obtained from 1264 consecutive patients with prostate cancer treated with radical prostatectomy at four hospitals in Japan, biochemical recurrence-free survival rates were estimated and compared between the D'Amico, the National Institute for Health and Clinical Excellence, the Cancer of the Prostate Strategic Urological Research Endeavor, the National Comprehensive Cancer Network, and the European Society of Medical Oncology risk groups by using the Kaplan–Meier method and log–rank test.ResultsThe 5-year biochemical recurrence-free survival rates in the D'Amico low-, intermediate-, and high-risk groups were 88.3%, 84.7% and 66.9%, respectively (low and intermediate risk vs high risk, P < 0.001). The 5-year biochemical recurrence-free survival rates in the National Institute for Health and Clinical Excellence, National Comprehensive Cancer Network, and European Society of Medical Oncology low-, intermediate- and high-risk groups were 88.3%, 84.3%, and 60.3%, respectively (low and intermediate risk vs high risk, P < 0.001). The 5-year biochemical recurrence-free survival rates in the Cancer of the Prostate Strategic Urological Research Endeavor low-, intermediate-, and high-risk groups were 90%, 83.5% and 60.3%, respectively (low and intermediate risk vs high risk, P < 0.001). Low- and intermediate-risk groups according to any of the risk stratification systems did not show significant differences in biochemical recurrence-free survival.Conclusion Current risk stratification systems do not discriminate between low- and intermediate-risk groups in the Japanese population. A novel, pretreatment risk stratification system including other prognostic factors is necessary for an adequate prostate cancer risk assessment in the Japanese population.
    International Journal of Urology 09/2014; · 1.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives To assess long-term health-related quality of life in patients undergoing radical prostatectomy.MethodsA total of 120 patients with at least 5 years of follow up after radical prostatectomy were included in the present study. Health-related quality of life outcomes were assessed using three questionnaires, the Short Form 36-Item Health Survey, the University of California, Los Angeles Prostate Cancer Index and the International Prostate Symptom Score.ResultsA total of 91 patients (73%) responded at a median follow-up time of 102 months (range 85–123 months). Among general health-related quality of life domains, mental and role composite summary score remained stable throughout the follow-up period. At the final survey, no significant differences were observed in any of the domains compared with the age-matched average score of the Japanese population. Although the slight decrease in urinary function scores and International Prostate Symptom Score beyond 5 years postoperatively compared with 5 years, the differences were not significant. The sexual function summary score showed a substantially lower score just after radical prostatectomy and remained at a deteriorated level (P < 0.001). Responders at the final survey were more likely to report favorable general, urinary and sexual outcomes at 60 months compared with non-responders.Conclusions When taking age-related changes into account, general health-related quality of life seems to remain stable in the long term after radical prostatectomy: patients with favorable health-related quality of life outcomes during the first 5 years after radical prostatectomy maintain favorable outcomes thereafter.
    International Journal of Urology 09/2014; · 1.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Objective. Prostate cancer (PCa) may be a multifocal and bilateral disease. Patients with low-risk PCa and a low number of positive biopsy cores may choose to undergo active surveillance or focal therapy. The aim of this study was to determine the correlation between a solitary positive prostate biopsy core and the pathological outcome after radical prostatectomy (RP). Material and methods. The Michinoku Japan Urological Cancer Study Group database contains data, including preoperative and postoperative information, on 1268 consecutive patients with PCa treated with RP alone at four institutions. This study focused on 151 patients with a single positive biopsy core, preoperative prostate-specific antigen (PSA) level less than 10 ng/ml, biopsy Gleason score less than 8, and clinical stage T1c/T2a/T2b disease. Potential preoperative predictors of unilateral PCa were age, preoperative PSA level, biopsy Gleason score and clinical T stage. Results. The median age and preoperative PSA level were 65 years (range 47-76 years) and 6.00 ng/ml (range 0.50-9.80 ng/ml), respectively. Unilateral PCa was identified in 41% of the patients. Extraprostatic extension or seminal vesicle invasion was observed in 26% of all patients. Conclusion. Serum PSA levels were significantly higher in the bilateral PCa group than in the unilateral PCa group in the current study. For patients with PCa having a solitary positive prostate biopsy core, definitive therapy such as RP should be considered.
    Scandinavian journal of urology. 08/2014;
  • Koji Mitsuzuka, Yoichi Arai
    [Show abstract] [Hide abstract]
    ABSTRACT: The incidence of prostate cancer in Japan is increasing due to both the spread of screening and the rapid aging of the population. Most of this increase is expected to be attributable to the increase in the elderly male population. The management of various types of cancers in elderly patients is of growing interest, but several problems are encountered when evaluating elderly patients with localized prostate cancer, especially when radical prostatectomy (RP) is under consideration. First, life expectancy, health status, lifestyle, and available treatment modalities differ between regions, countries, and individuals, which potentially affects the choice of treatment options by both physicians and patients. Second, life expectancy is key when considering indications for RP. Many tools are available for predicting life expectancy, but their utilization varies greatly among physicians. Third, the malignant potential of latent or incidentally detected prostate cancer in Japanese men might be higher than those in other countries, and elderly men with prostate cancer are likely to have high-risk or locally advanced tumors, which may in turn support the more frequent use of radical treatments in elderly men. Fourth, patients treated with RP are likely to have fewer and less severe comorbidities than those treated with other treatments, which would complicate the comparison of outcomes. Fifth, the balance between survival benefits and adverse effects is an important influence on indications for RP. If robot-assisted laparoscopic RP can reduce the risk of adverse effects, indications for RP could be altered. Sixth, although several general health status screening tools such as the Geriatric 8 are available, no screening tools specialized for localized or Japanese prostate cancer patients exist. In conclusion, further study is needed to clarify the management of elderly Japanese patients with localized prostate cancer, because prostate cancer often requires different considerations to other types of cancer.
    International journal of clinical oncology. 08/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Effects of tadalafil, a phosphodiesterase type 5 inhibitor, on the urethral continence reflex induced by sneezing were investigated.
    International Urogynecology Journal 07/2014; · 2.17 Impact Factor
  • International Journal of Urology 07/2014; · 1.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives To examine whether low-dose maintenance gemcitabine-carboplatin chemotherapy is beneficial for patients with metastatic urothelial carcinoma.Methods We retrospectively reviewed the records of 36 patients with metastatic urothelial carcinoma who received first-line chemotherapy (gemcitabine/cisplatin, gemcitabine/carboplatin, or methotrexate/vinblastine/adriamycin/cisplatin) between 2006 and 2012. Those who had responded, but were unable to tolerate ongoing first-line chemotherapy, had been switched to low-dose maintenance chemotherapy consisting of 1 g/m2 of gemcitabine and area under the curve 2–4 of carboplatin given on day 1 of a 6-week cycle, and were continued unless disease progression was seen.ResultsAfter a median of three cycles of first-line chemotherapy, 17 patients had been switched to low-dose maintenance chemotherapy. The median age was 70 years (range 56–79 years), and 12 patients (70.6%) had renal dysfunction (creatinine clearance <60 mL/min). The median number of cycles of low-dose maintenance chemotherapy was six (range 2–22), and the median survival time from initiation of first-line chemotherapy was 12 months (range 4–32 months). Adverse events requiring hospitalization were seen in three patients, but all of them recovered within a few days with conservative treatment. Seven patients discontinued within 9 months, whereas 10 patients continued on low-dose maintenance chemotherapy for ≥9 months. Patients with only lymph node metastases or who had a good response to previous first-line chemotherapy were likely to be able to continue low-dose maintenance chemotherapy.Conclusions Low-dose maintenance gemcitabine-carboplatin chemotherapy might represent an alternative for patients with metastatic urothelial carcinoma not tolerating continuous first-line standard chemotherapy regimens.
    International Journal of Urology 07/2014; · 1.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aldosterone-producing adenoma is a major subtype of primary aldosteronism. The number of cases of these adenomas, which are below the detection limit of computed tomography but diagnosed by adrenal venous sampling, has recently been increasing. However, the pathophysiology of these adenomas, especially those manifesting clinically overt hyperaldosteronism despite their small size, remains unknown. Therefore, we examined the correlation between tumor size and the status of intratumoral steroidogenic enzymes involved in aldosterone biosynthesis using immunohistochemistry. Forty patients with surgically proven aldosterone-producing adenomas were retrospectively studied. Multidetector computed tomography, adrenal venous sampling, and laparoscopic adrenalectomy were performed in all of the patients studied. The tumor area at the maximum diameter of the sections was precisely measured by ImageJ software. The status of the steroidogenic enzymes was immunohistochemically analyzed, and the findings were evaluated according to the H-score system, based on both the number of immunopositive cells and relative immunointensity. Adrenal masses were not detected by computed tomography in 20 patients. Blood pressure, plasma aldosterone concentration, urinary aldosterone excretion, and the number of antihypertensive agents also decreased significantly after the surgery in these patients, as well as in the patients with adenomas detectable by computed tomography. Maximum tumor area obtained in the specimens was significantly correlated with preoperative plasma aldosterone concentration, urinary aldosterone excretion, and the H score of 11β-hydroxylase and was inversely correlated with the H score of aldosterone synthase. These results demonstrated that small adenomas could produce sufficient aldosterone to cause clinically overt primary aldosteronism because of the significantly higher aldosterone synthase expression per tumor area.
    Hypertension 05/2014; In press(Online first). · 6.87 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: CYP19 catalyzes the conversion of androgens to estrogens and is a critical enzyme affecting the sex hormone milieu. In this study, we investigated the functions of CYP19A1 polymorphisms and their associations with prostate cancer risk and clinical outcome. This case-control study evaluated the effects of three single nucleotide polymorphisms (SNPs) in CYP19A1 on the risk of prostate cancer in 330 prostate cancer patients and 354 normal controls. The associations between each SNP and sex hormone levels were evaluated in 164 healthy male patients. The functions of the SNPs were determined by reporter gene assays in PC3 and DU145 cell lines. Prostate-specific antigen nadir was evaluated in 142 patients with metastatic prostate cancer treated with androgen deprivation therapy. Cancer-specific survival (CSS) was determined in 166 patients with metastatic prostate cancer, to evaluate the influence of the three SNPs. Each variant allele of the three SNPs significantly decreased the risk of prostate cancer. Haplotype analysis showed that the T-A-G haplotype (corresponding to rs2470152-rs10459592-rs4775936) increased the risk of prostate cancer, while the C-C-A haplotype decreased the risk. The estrone/androstenedione ratio was significantly higher in men with the C allele of rs2470152, the C allele of rs10459592, and the A allele of rs4775936 in a gene-dosage-dependent manner. Patients with the variant allele at rs4775936 had significantly shorter CSS. These results indicate that CYP19A1 polymorphisms may influence prostate cancer risk and survival by modifying promoter activity, with subsequent effects on the sex hormone milieu. © 2014 Wiley Periodicals, Inc.
    International Journal of Cancer 05/2014; · 6.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Patients with advanced local-stage, high-grade prostate cancer (Pca) and high pretreatment prostate-specific antigen (PSA) levels have inferior outcomes compared to their counterparts with more favorable clinical characteristics. However, some patients exhibit favorable pathological features or experience long-term PSA-free survival after radical prostatectomy (RP). We retrospectively examined the ability of preoperative characteristics to predict pathological and oncological outcomes in high-risk Pca patients who underwent RP. We examined data of 1,268 consecutive Pca patients treated with RP alone at 4 hospitals from the Michinoku Urological Cancer Study Group database. Preoperative predictors included age, PSA level, biopsy Gleason score, clinical T stage, and PSA density (PSAD). The outcome measures pathological T stage and PSA-free survival were evaluated by multivariate analysis. We identified 380 high-risk Pca patients, of which 44 % patients had extracapsular extension. Logistic regression analysis indicated that PSAD was an independent predictor of adverse pathologic stage. The 5-year PSA-free survival rates were 82.9 % for patients with PSAD ≤0.468 ng mL(-1) cm(-2) and 50.7 % for those with PSAD >0.468 ng mL(-1) cm(-2) (P < 0.0001). Multivariate analyses revealed that PSAD, cT, and the number of preoperative high-risk Pca criteria were independent predictors of PSA-free survival. PSAD may be an independent predictor of advanced pathological features and biochemical recurrence in high-risk Pca patients treated with RP alone. PSAD may be used for further risk stratification of high-risk Pca patients.
    International Journal of Clinical Oncology 04/2014; · 1.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To compare oncological outcomes of patients aged ≥70 years treated with radical prostatectomy with those of a clinically matched younger cohort. Data from 1268 patients undergoing radical prostatectomy between 2000 and 2009 were retrospectively reviewed. Patients were classified according to age (<70 or ≥70 years) at the time of prostatectomy. After matching pre-operative factors (i.e. prostate specific antigen, positive biopsy cores, Gleason score, clinical stage and D'Amico risk group), 333 patients were chosen from each group. The percentage of pathological stage ≥T3 in those of age <70 and ≥70 years was 30.3 and 33.0%, respectively (P = 0.51). The percentage of pathological Gleason score ≤6, 7 and ≥8 was not significantly different between the two age groups (P = 0.08). The percentage of organ-confined disease in those of age <70 and ≥70 years was 69.4 and 67.0%, respectively (P = 0.56). With a median follow-up of 50 months, 5-year prostate specific antigen recurrence-free survival in those of age <70 and ≥70 years was 83.4 and 80.1%, respectively (log rank, P = 0.199). Five-year cancer-specific survival in those of age <70 and ≥70 years was 100 and 99.4%, respectively (log rank, P = 0.317). Five-year overall survival in those of age <70 and ≥70 years was 98.4 and 96.4%, respectively (log rank, P = 0.228). Pathological and oncological outcomes in elderly patients (age ≥70 years) treated with radical prostatectomy were not significantly different from those of younger patients (age <70 years). This information will help refine the indications for definitive treatment for localized prostate cancer in elderly men.
    Japanese Journal of Clinical Oncology 04/2014; · 1.90 Impact Factor
  • Journal of Clinical Oncology 04/2014; · 18.04 Impact Factor
  • European Urology Supplements 04/2014; 13(1):e20. · 3.37 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the role of the glutamatergic pathway and its relationship to noradrenergic and serotonergic pathways in modulation of the urethral continence reflex during sneezing in rats. In female Sprague-Dawley rats under urethane anesthesia, the effects of an α-amino-3-hydroxy-5-meth-ylisoxazole-4-propionic acid (AMPA) glutamate receptor antagonist, a norepinephrine reuptake inhibitor and a serotonin [5-hydeoxytripitamine (5-HT)]2B/2C agonist on the amplitude of urethral responses during sneezing (AURS), urethral baseline pressure (UBP), and sneeze-induced leak point pressure (S-LPP) were investigated. Intrathecal application (i.t.) of NBQX disodium salt (an AMPA receptor antagonist) decreased AURS dose-dependently by approximately 60% without affecting UBP and caused stress urinary incontinence (SUI) during sneezing in 60% of normal rats. Nisoxetine (i.t.), a norepinephrine reuptake inhibitor, and mCPP (i.t.), a 5-HT2B/2C , agonist increased AURS, and NBQX (i.t.) abolished these excitatory effects of nisoxetine (i.t.) and mCPP (i.t.), whereas nisoxetine (i.t.) and mCPP (i.t.) did not enhance AURS in the presence of NBQX (i.t.). These results indicate that the glutamatergic pathway acting through AMPA receptors plays a crucial role on the active urethral closure reflex during sneezing at the spinal level, and noradrenergic and serotonergic pathways modulate the reflex via the spinal glutamatergic system in rats. Neurourol. Urodynam. © 2014 Wiley Periodicals, Inc.
    Neurourology and Urodynamics 03/2014; · 2.67 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study aimed to determine the antiemetic efficacy and safety of a combination of palonosetron, aprepitant, and dexamethasone in patients with testicular germ cell tumor (TGCT) receiving 5-day cisplatin-based combination chemotherapy. An open-label, single-arm, multicenter study was performed in patients with TGCT who were scheduled to receive 5-day cisplatin-based combination chemotherapy. The antiemetic therapy consisted of palonosetron 0.75 mg on day 1, aprepitant 125 mg on day 1 and 80 mg on days 2 to 5, and dexamethasone 9.9 mg on day 1 and 6.6 mg on days 2 to 8. The primary endpoint was complete response (CR) rate, which was defined as no vomiting and no rescue medication, in the overall period (0 to 216 h) in the first chemotherapy course. Incidence and severity of nausea were assessed based on the Common Terminology Criteria for Adverse Events (CTCAE) and a subjective rating scale completed by patients. Thirty patients were included in the analysis. CR was achieved in 90.0 % of the patients in the first chemotherapy course, and high CR rates were also observed in the second and third courses (82.1 and 78.3 %, respectively). The incidence of nausea peaked on days 4 to 6 in about 50 % of the patients. The reported adverse drug reactions were hiccups (13.3 %), anorexia (3.3 %), and stomach pain (3.3 %). None of these were unexpected and none were grade 3 or 4. The combination antiemetic therapy examined in this study was highly effective and well-tolerated in patients with TGCT receiving 5-day cisplatin-based combination chemotherapy.
    Supportive Care in Cancer 03/2014; · 2.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background:Disialosyl globopentaosylceramide (DSGb5) is a ganglioside originally isolated from renal cell carcinoma (RCC) tissue that has been associated with RCC metastasis. However, in prostate cancer, the expression of DSGb5 has not yet been fully assessed. In this study, we investigated DSGb5 expression in prostate tissues and the relationship between DSGb5 expression and clinicopathological characteristics of prostate cancer patients.Methods:A total of 130 patients who underwent radical prostatectomy (RP) at our hospital between January 2005 and December 2007 were analyzed in this study. The expression of DSGb5 in prostatectomy specimens was examined by immunohistochemical analysis with monoclonal antibody 5F3 (anti-DSGb5). Associations between 5F3 expression and clinicopathological findings were investigated and the factors that affected PSA failure-free survival were assessed by Kaplan-Meier analysis and a Cox regression model.Results:When immunoreactivities of 5F3 were measured, negative to strong staining was observed in prostate cancer tissue, whereas strong staining was observed in benign prostate glands. These expression patterns suggest that DSGb5 may act as a differentiation antigen in cancerization. The PSA failure-free survival was significantly higher in the 5F3 intact expression group than in the 5F3 reduced expression group (log-rank P=0.0220). On multivariate analysis, 5F3 intact expression showed significantly worse PSA failure-free survival following RP.Conclusions:5F3 expression reflects the clinical and pathological features of prostate cancer and is correlated with the outcomes following RP. Further studies are necessary to clarify the functional roles of DSGb5 and establish a novel biomarker for prostate cancer.Prostate Cancer and Prostatic Disease advance online publication, 18 March 2014; doi:10.1038/pcan.2014.9.
    Prostate cancer and prostatic diseases 03/2014; · 2.10 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Renal epithelioid angiomyolipoma (EAML) is a potentially malignant tumor type whose characteristics and biomarkers predictive of malignant behavior have not been elucidated. Here, we report three cases of renal EAML with malignant features but without histories of tuberous sclerosis complex. Case 1 involved a 29-year-old man with a 12-cm solid mass in the right kidney who underwent radical right nephrectomy. Case 2 involved a 22-year-old woman with a retroperitoneal mass who underwent radical right nephrectomy and retroperitoneal tumorectomy. Local recurrence was detected 7 years post-surgery. Case 3 involved a 23-year-old man with a 14-cm solid mass in the left kidney who underwent radical left nephrectomy. Microscopically, the tumors in all cases demonstrated proliferation of epithelioid cells with atypia, mitotic activity, necrosis, hemorrhage, and vascular invasion. Epithelioid cells in all cases were immunohistochemically positive for melanocytic and myoid markers and weakly positive for E-cadherin and β-catenin. Immunohistochemistry revealed activation of the mammalian target of rapamycin pathway. Here, we report the morphological and immunohistochemical features of clinically or histologically malignant renal EAML.
    Pathology International 03/2014; 64(3). · 1.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 73-year-old woman was referred to our hospital with a complaint of left lumbar backache. Computed tomography (CT) revealed left giant hydronephrosis containing high-density fluid suspected of hemorrhage in the renal pelvis and swelling of cervical and mediastinal lymph nodes. Positron emission tomography (PET)-CT showed a small high uptake lesion in the left kidney parenchyma, and cervical and mediastinal lymph nodes. Percutaneous pelvic puncture yielded discharge of hemorrhagic fluid with negative cytology. Preoperative diagnosis was left giant hydronephrosis due to ligation of a left ureter at uterine myomectomy 43 years ago with renal hemorrhage caused by recent back injury, and cervical and mediastinal lymph node involvement of unknown origin. Because severe lumbar backache persisted, we performed palliative left nephrectomy and biopsy of cervical lymph nodes. The pathological diagnosis was invasive urothelial carcinoma with squamous differentiation and lymph node involvement.
    Hinyokika kiyo. Acta urologica Japonica 03/2014; 60(3):137-41.
  • Source
    Akihiro Ito, Yasuhiro Kaiho, Yoichi Arai
    [Show abstract] [Hide abstract]
    ABSTRACT: A case of advanced anal canal cancer with skin metastases that extended to the scrotum, penis, and lower abdomen is presented. The patient had severe pain on contact with voided urine because of skin tumors. The curved penis did not allow insertion of catheter to treat painful urination, and suprapubic cystostomy insertion was also impossible because of skin tumors. A right cutaneous ureterostomy was performed using the retroperitoneoscopic approach in supine position, and the left renal artery was embolized using ethanol to eliminate left kidney function. The patient became completely free from all urinary-related pains until he died of progressive disease.
    Urology Case Reports. 01/2014; 2(1):5–7.

Publication Stats

5k Citations
1,178.38 Total Impact Points

Institutions

  • 2002–2014
    • Tohoku University
      • Department of Urology
      Japan
  • 2002–2013
    • Akita University Hospital
      Akita, Akita, Japan
  • 2012
    • National Cerebral and Cardiovascular Center
      Ōsaka, Ōsaka, Japan
    • National Center for Geriatrics and Gerontology
      • Department of Urology
      Ōbu, Aichi-ken, Japan
  • 2011
    • Zhejiang Cancer Hospital
      Hang-hsien, Zhejiang Sheng, China
    • National Hospital Organization Sendai Medical Center
      Сендай, Miyagi, Japan
    • Sapporo Medical University
      • Division of Urology
      Sapporo, Hokkaidō, Japan
  • 2009–2011
    • The Jikei University School of Medicine
      • • Department of Internal Medicine
      • • Department of Endoscopy
      Tokyo, Tokyo-to, Japan
    • CSU Mentor
      Long Beach, California, United States
  • 1994–2011
    • Kurashiki Central Hospital
      Kurasiki, Okayama, Japan
  • 2007–2009
    • University of Pittsburgh
      • Department of Urology
      Pittsburgh, PA, United States
  • 1988–2009
    • Kyoto University
      • Department of Urology
      Kyoto, Kyoto-fu, Japan
  • 1983–2009
    • Shiga University of Medical Science
      • Department of Urology
      Ōtu, Shiga, Japan
  • 2008
    • University of California, Los Angeles
      • Department of Urology
      Los Angeles, CA, United States
  • 2006
    • Hirosaki University
      • Department of Urology
      Khirosaki, Aomori Prefecture, Japan
  • 2001–2004
    • Kitasato University
      • Department of Urology
      Edo, Tōkyō, Japan
  • 2000
    • National Research Institute for Child Health and Development, Tokyo
      Edo, Tōkyō, Japan
  • 1991–2000
    • Rakuwakai Otowa Hospital
      Kioto, Kyōto, Japan
  • 1999
    • Chiba-East National Hospital
      Tiba, Chiba, Japan
  • 1997–1999
    • National Cancer Center, Japan
      Edo, Tōkyō, Japan
    • Shizuoka Hospital
      Sizuoka, Shizuoka, Japan
  • 1993–1999
    • Saitama Cancer Center
      Saitama, Saitama, Japan
  • 1998
    • Kobe City Medical Center General Hospital
      Kōbe, Hyōgo, Japan
  • 1996–1997
    • Osaka Medical Center for Cancer and Cardiovascular Diseases
      Ōsaka, Ōsaka, Japan
  • 1995
    • Kusatsu General Hospital
      Susatsu, Shiga, Japan