Takeshi Nagayasu

Nagasaki University, Nagasaki, Nagasaki, Japan

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Publications (321)440.25 Total impact

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    ABSTRACT: Prognostic influences of hepatic transection by an anterior approach using the liver hanging maneuver (LHM) has not been fully clarified.
    07/2014;
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    ABSTRACT: Portal hypertension is a major risk factor for hepatic failure or bleeding in patients who have undergone hepatectomy, but it cannot be measured indirectly. We attempted to evaluate the intraoperative ultrasonography parameters that correlate with portal pressure (PP) in patients undergoing hepatectomy.
    Journal of Surgical Research 06/2014; · 2.02 Impact Factor
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    ABSTRACT: Recently, the prone position has been used for thoracoscopic oesophagectomy for oesophageal cancer because it is known to facilitate mediastinal dissection. We hypothesized that this advantage of the prone position could apply to video-assisted thoracoscopic surgery, which has been commonly performed with the patient in the lateral position. Forty-six patients with clinical stage I, right-sided, non-small cell lung cancer were enrolled in this study. They were classified into three groups: conventional thoracotomy using rib retractors (n = 17), and the lateral (n = 15) and semi-prone (n = 14) positions in video-assisted thoracoscopic surgery. Surgical parameters, such as operation time, the amount of blood loss, and the number of dissected lymph nodes, of each group of patients were compared. There were three (6.5 %) minor complications in this study, chylothorax and heart failure in the thoracotomy group and atelectasis with the video-assisted thoracoscopic surgery in the lateral position group. No complications were seen in the semi-prone group. The number of dissected lymph nodes was significantly higher in the video-assisted thoracoscopic surgery in the semi-prone position group than in the conventional thoracotomy group for inferior mediastinal nodes (subcarinal, paraeosophageal, and pulmonary ligament, average 8.9 and 5.9 lymph nodes, p = 0.04). To the best of our knowledge, this is the first report that has described video-assisted thoracoscopic lobectomy with the patient in the semi-prone position. Although the number of cases was limited, the results of this study show that the semi-prone position could be attempted especially for right lower lobe lung cancer.
    General Thoracic and Cardiovascular Surgery 04/2014;
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    ABSTRACT: The number of young surgeons in Japan has significantly decreased in recent years, which may lead to future problems in the medical field. Therefore, comprehensive training programs for young surgeons are needed. Retrospective study SETTING: We developed a specific education program called the "Recruitment of Young Medical Apprentices" (RYOMA) project. We performed this project between January 2008 and August 2013 on fourth- to sixth-year medical students and internship doctors. The RYOMA project included step-by-step surgical education programs on open and scopic procedures as dry, wet, and animal laboratory training. Our goal was to increase the number of young and specialist surgeons. Based on an interview questionnaire answered by 90 medical students, most young students were interested in surgical training and several chose to become surgeons in the future. The most positive opinions regarding the field of surgery were the impressive results achieved with surgery, whereas negative opinions included the difficulty of the surgical skill, physical concerns related to difficult work environments, and the severity of surgical procedures. The present program has begun to resolve negative opinions through adequate training or simulations. Of the 19 medical students and internship doctors who attended the RYOMA project in 2008, 17 trainees (90%) were satisfied with this special surgical program and 16 (88%) showed interest in becoming surgeons. The number of participants considering the field of surgery increased between 2008 and 2013. Of 23 participants, 19 (83%) had a positive opinion of the program after the training. Gaining experience in surgical training from an early stage in medical school and step-by-step authorized education by teaching staff are important for recruiting students and increasing the number of young surgeons.
    Journal of Surgical Education 04/2014; · 1.07 Impact Factor
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    ABSTRACT: To evaluate hepatic fibrosis and tumor diagnosis preoperatively, we investigated the elasticity calculated by the new parameter of ultrasonography (US), Acoustic radiation force impulse (ARFI). We examined ARFI of the non-tumorous right and left lateral liver and in the tumor by push pulse of probe in 95 patients with hepatic malignancies undergoing hepatectomy Measurement of ARFI as hepatic stiffness was indicated as the Vs (m/s). Measuring the Vs in the non-tumor region was achieved in the right liver in 99% and at the left lateral liver in 94%. The Vs in the right liver (1.46±0.42) was significantly lower than in the left lateral liver (1.63±0.49) (p<0.01), and the Vs of the liver tumor (2.29±1.05) was significantly higher than in the non-tumorous liver (p<0.01). The Vs in the right and left lateral liver was correlated with the platelet count, AST, fibrotic indices and indocyanine green test (p<0.05). The Vs in the right liver was significantly correlated with the fibrotic marker or index (p<0.01). The Vs of liver cirrhosis and histological stage 4 in the right and left liver was significantly the highest compared to the others (p<0.05). The Vs in the right liver showed the high AUROCs value predicting histological fibrosis. The Vs in the right was significantly correlated with blood loss and postoperative complications, particularly uncontrolled ascites (p<0.05). Non-invasive ARFI imaging elastography is useful in evaluating impaired liver function or in the differential diagnosis of liver malignancies, highly hepatic fibrosis and in predicting posthepatectomy morbidity.
    Hepatology Research 02/2014; · 2.07 Impact Factor
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    ABSTRACT: Lung cancer surgery in octogenarians has already become common in Japan due to the high proportion of elderly people and the progress in perioperative management, including anesthesia and video-assisted thoracic surgery. However, there have been few reports about the surgical treatment of lung cancer in nonagenarians. Five cases (mean age: 91.2 years; 3 men, 2 women) of non-small cell lung cancer in nonagenarians in whom pulmonary resection was performed are reported. All were adenocarcinomas; three were clinical stage IA, and two were IB. Three patients underwent lobectomy, and two underwent wedge resection. Mediastinal lymph node dissection was omitted in all patients. There were no fatal postoperative complications. During follow-up, one patient died due to fatal arrhythmia, and one patient who underwent wedge resection had local recurrence, but the others are alive in good condition. Pulmonary resection of lung cancer is possible for highly selected, nonagenarian patients without lymph node metastasis.
    Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia. 02/2014;
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    ABSTRACT: The shortage of donor lungs for transplantation causes a significant number of patient deaths. The availability of laboratory engineered, functional organs would be a major advance in meeting the demand for organs for transplantation. The accumulation of information on biological scaffolds and an increased understanding of stem/progenitor cell behavior has led to the idea of generating transplantable organs by decellularizing an organ and recellularizing using appropriate cells. Recellularized solid organs can perform organ-specific functions for short periods of time, which indicates the potential for the clinical use of engineered solid organs in the future. The present review provides an overview of progress and recent knowledge about decellularization and recellularization-based approaches for generating tissue engineered lungs. Methods to improve decellularization, maturation of recellularized lung, candidate species for transplantation and future prospects of lung bioengineering are also discussed.
    Organogenesis 01/2014; 10(2). · 2.28 Impact Factor
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    ABSTRACT: This study was undertaken to investigate the efficacy of a video-assisted thoracoscopic (VATS) approach for stage I and II thymoma through comparisons with the transsternal approach. The indications for VATS resection were clinical stage I or II thymoma, a tumor less than 50 mm, located within the thymic lobes and separated from the brachiocephalic vein. Data were collected between 1995 and 2007. Twenty-seven patients underwent total thymectomy (15 by VATS and 12 by the transsternal approach). The mean tumor size was 36.3 (22-50) mm for VATS and 37.6 (15-55) mm for the transsternal group (p = 0.7862). The mean lengths of the operation were 249.8 min and 227.9 min (p = 0.2728), respectively. The mean intraoperative blood loss was significantly lower in VATS, at 92.3 ml, than the 225.1 ml lost in the transsternal group (p = 0.0020). The morbidity rates were 13.3 and 8.3 % (p = 0.6812), respectively. There was no mortality in either group. The mean follow-up periods were 109.0 (37-145) months following VATS and 102.0 (44-175) months following the transsternal approach. One stage II patient developed pleural dissemination three years after VATS resection. Other patients survived with no recurrence. VATS resection of early stage thymoma can be performed with less bleeding and with a comparable prognosis to the transsternal approach. VATS resection should thus be considered as a viable option for treatment.
    Surgery Today 01/2014; · 0.96 Impact Factor
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    ABSTRACT: Even after needle biopsy, the preoperative differential diagnoses of intracystic tumors of the breast are challenging because of their nonspecific radiological characteristics and subtle cytological and histological appearance. The aim of this study is to investigate a novel diagnostic method, targeting genomic instability (GIN) in intracystic tumors of the breast, using tumor DNA from samples obtained by fine-needle aspiration biopsy (FNAB). Thirteen consecutive intracystic tumors of the breast, including five cancers and eight benign tumors, were studied. Three FNAB passages per tumor were used for array comparative genomic hybridization (aCGH) analysis to quantify GIN in each tumor. Tumor DNA from the main tumor, taken from formalin-fixed, paraffin-embedded (FFPE) blocks corresponding to FNAB samples, was also analyzed to compare cytogenetic profiles between these sample types. After three FNAB passages, an average of 7.09 μg (0.24-25.0 μg) of DNA was obtained. The quality of the DNA and the aCGH data was excellent, as judged by the mean derivative log ratio spread (DLRSpread) of 0.22 (0.15-0.29). The cytogenetic profiles of paired FNAB and main tumor FFPE samples were highly similar, with an average concordance rate of 97.7 % (81.2-100 %). aCGH analysis from FNAB samples showed significantly more GIN in cancers than in benign tumors, with mean frequencies of aberrant chromosomal regions of 17.5 and 0.34 %, respectively (Wilcoxon's rank sum test, P = 0.0016). Our novel diagnostic method, which targets GIN, can clearly distinguish cancers from benign tumors of breast intracystic lesions with minimal invasion, thereby avoiding the need for surgical excisional biopsy.
    Breast Cancer 01/2014; · 1.33 Impact Factor
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    ABSTRACT: Background To clarify the factors associated with posthepatectomy surgical site infections (SSIs), the clinicopathological data of 526 patients who underwent hepatectomy was retrospectively examined as a retrospectively cohort study. Methods Patient demographics, liver functions, histological findings, surgical records and post-hepatectomy morbidity were compared between non-SSI and SSI groups; the SSI group included superficial and deep SSIs. Results The prevalence of SSIs (5-8%) has not changed over an 18-year period. Deep SSIs were significantly more increased in male patients with lower performance statuses and American Society of Anesthesiologists (ASA) scores (p<0.05). SSIs tended to be less prevalent, although not significant (p=0.10), in patients who underwent laparoscopic hepatectomies compared to those who underwent laparotomies. For patients in whom hemostatic devices were used, the prevalence of superficial SSIs was significantly lower than those in whom the devices were not used (p<0.05). Blood loss and transfusion were significantly more frequent in the deep SSI group compared to other groups (p<0.01). Hospital stay in the deep SSI group was significantly longer compared to other groups. The incidence of morbidity was more frequent in the SSI groups compared with the non-SSI group (p<0.001). A multivariate analysis showed that not using a vessel sealing device was significantly associated with superficial SSIs; male gender, hepatic failure and bile leakage were significantly associated with deep SSIs (p<0.05). Conclusions SSIs were important indicators of patient outcomes after hepatectomies, and preventing SSI development after surgical procedures is an important step in improving the overall prevalence of SSIs.
    International Journal of Surgery (London, England) 01/2014; · 1.44 Impact Factor
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    ABSTRACT: Objectives The number of young surgeons in Japan has significantly decreased in recent years, which may lead to future problems in the medical field. Therefore, comprehensive training programs for young surgeons are needed. Design Retrospective study Setting We developed a specific education program called the “Recruitment of Young Medical Apprentices” (RYOMA) project. Participants We performed this project between January 2008 and August 2013 on fourth- to sixth-year medical students and internship doctors. The RYOMA project included step-by-step surgical education programs on open and scopic procedures as dry, wet, and animal laboratory training. Our goal was to increase the number of young and specialist surgeons. Results Based on an interview questionnaire answered by 90 medical students, most young students were interested in surgical training and several chose to become surgeons in the future. The most positive opinions regarding the field of surgery were the impressive results achieved with surgery, whereas negative opinions included the difficulty of the surgical skill, physical concerns related to difficult work environments, and the severity of surgical procedures. The present program has begun to resolve negative opinions through adequate training or simulations. Of the 19 medical students and internship doctors who attended the RYOMA project in 2008, 17 trainees (90%) were satisfied with this special surgical program and 16 (88%) showed interest in becoming surgeons. The number of participants considering the field of surgery increased between 2008 and 2013. Of 23 participants, 19 (83%) had a positive opinion of the program after the training. Conclusions Gaining experience in surgical training from an early stage in medical school and step-by-step authorized education by teaching staff are important for recruiting students and increasing the number of young surgeons.
    Journal of Surgical Education 01/2014; · 1.63 Impact Factor
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    ABSTRACT: In 2008, Kawabata et al. described a lesion which they termed “airspace enlargement with fibrosis” that could be included on the spectrum of smoking-related interstitial lung diseases. This group also reported that patients with airspace enlargement with fibrosis but without coexisting interstitial pneumonia of another type had no acute exacerbations and favorable prognoses on clinical follow-up. Here we describe the first case, to our knowledge, of acute exacerbation of airspace enlargement with fibrosis without coexisting interstitial pneumonia of another type. An 82-year-old man was referred to our department for worsening dyspnea and new alveolar opacities on chest radiograph following left pulmonary segmentectomy (S6) for cancer. A diagnosis of acute exacerbation of airspace enlargement with fibrosis without coexisting interstitial pneumonia of other types was made, based on pathological evidence of airspace enlargement with fibrosis and organizing diffuse alveolar damage. Treatment with high-dose methylprednisolone followed by tapered oral prednisolone resulted in gradual improvement of the clinical condition and chest radiographic findings. Clinicians should be aware that patients with airspace enlargement with fibrosis may experience acute exacerbation.
    Respiratory Medicine Case Reports. 01/2014;
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    ABSTRACT: An 81-year-old man was admitted to a primary care hospital due to bloody diarrhea. The findings of abdominal computed tomography indicated ischemic colitis, so conservative therapy was started. On the 4th hospital day, the patient was transferred to our hospital because of renal dysfunction. Physical examination showed clouding of consciousness and abdominal distention. Abdominal computed tomography revealed massive ascites and thickening of the whole colonic wall. With a diagnosis of acute abdomen, an emergent laparotomy was performed. Extended right hemicolectomy was performed because of severe ischemic change and necrosis of the right side of the colon. In the stool culture before the operation, Escherichia coli O157 and verotoxin were found, so this case was diagnosed as hemorrhagic colitis with hemolytic uremic syndrome and acute encephalopathy due to Escherichia coli O157 infection. Postoperatively, the hemolytic uremic syndrome and acute encephalopathy were prolonged. However, with intensive care, the patient recovered and was discharged on the 33rd postoperative day.
    Case Reports in Gastroenterology 01/2014; 8(1):82-8.
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    ABSTRACT: Keratinocyte growth factor (KGF) is considered to be one of the most important mitogens for lung epithelial cells. The objectives of this study were to confirm the effectiveness of intratracheal injection of recombinant human KGF (rhKGF) during compensatory lung growth and to optimize the instillation protocol. Here, trilobectomy in adult rat was performed, followed by intratracheal rhKGF instillation with low (0.4 mg/kg) and high (4 mg/kg) doses at various time-points. The proliferation of alveolar cells was assessed by the immunostaining for proliferating cell nuclear antigen (PCNA) in the residual lung. We also investigated other immunohistochemical parameters such as KGF, KGF receptor and surfactant protein A as well as terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. Consequently, intratracheal single injection of rhKGF in high dose group significantly increased PCNA labeling index (LI) of alveolar cells in the remaining lung. Surprisingly, there was no difference in PCNA LI between low and high doses of rhKGF with daily injection, and PCNA LI reached a plateau level with 2 days-consecutive administration (about 60%). Our results indicate that even at low dose, daily intratracheal injection is effective to maintain high proliferative states during the early phase of compensatory lung growth.
    Acta histochemica et cytochemica official journal of the Japan Society of Histochemistry and Cytochemistry 12/2013; 46(6):179-185. · 1.48 Impact Factor
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    ABSTRACT: The pathogenesis of chronic pulmonary aspergillosis (CPA) including chronic necrotizing pulmonary aspergillosis (CNPA), chronic cavitary pulmonary aspergillosis (CCPA), and simple aspergilloma (SA) has been poorly investigated. We examined all types of CPA cases with histopathological evidence to clarify the differences in pathogenesis and clinical features. We searched for cases diagnosed as pulmonary aspergillosis by histopathological examination in Nagasaki University Hospital between 1964 and September 2010. All available clinical information including radiological findings were collected and analyzed. We found 7, 5, 8, and 7 cases of proven CNPA, probable CNPA, CCPA, and SA, respectively. The radiograph of proven and probable CNPA was initially infiltrates or nodules that progress to form cavities with or without aspergilloma, whereas the radiograph of CCPA showed pre-existed cavities and peri-cavitary infiltrates with or without aspergilloma. The patients with proven and probable CNPA exhibited not only respiratory symptoms but also systemic symptoms and malnutrition. Aspergillus fumigatus was the most frequently isolated Aspergillus species (n = 14), however, Aspergillus niger was the predominant isolated species in proven CNPA cases (n = 4). Our data indicate that the cases with chronic infiltration, progressive cavitation, and subsequent aspergilloma formation should be diagnosed as CNPA, and the cases with pre-existed cavities showing peri-cavitary infiltrates with or without aspergilloma would mean CCPA. However, it may be difficult to distinguish the two subtypes if a series of adequate radiography films are not available. We propose the term "chronic progressive pulmonary aspergillosis (CPPA)" for the clinical syndrome including both CNPA and CCPA.
    Journal of Infection and Chemotherapy 12/2013; · 1.55 Impact Factor
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    ABSTRACT: We report a rare case of mycotic pulmonary artery pseudoaneurysm (PAP) secondary to a lung abscess due to Streptococcus constellatus. PAP was confirmed by the pathological findings of the pseudoaneurysm, the presence of bacteria, and the microbiological analysis. PAP is uncommon, but it is important to recognize this condition because PAP can lead to fatal hemoptysis.
    International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 11/2013; 17(11):e1064-e1066. · 2.17 Impact Factor
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    ABSTRACT: Chest tube insertion seems to be one important factor leading to intercostal nerve impairment. The purpose of this prospective study was to objectively evaluate intercostal nerve damage using current perception threshold testing in association with chest tube insertion. Sixteen patients were enrolled in this study. Intercostal nerve function was assessed with a series of 2000-Hz (Aβ fiber), 250-Hz (Aδ fiber), and 5-Hz (C fiber) stimuli using current perception threshold testing (Neurometer CPT/C(®)). Current perception threshold values at chest tube insertion were measured before surgery, during chest tube insertion and after removal of the chest tube. Intensities of ongoing pain were also assessed using a numeric rating scale (0-10). Current perception thresholds at each frequency after surgery were significantly higher than before surgery. Numeric rating scale scores for pain were significantly reduced from 3.3 to 1.9 after removal of the chest tube (p = 0.004). The correlation between current perception threshold value at 2000 Hz and intensity of ongoing pain was marginally significant (p = 0.058). This is the first study to objectively evaluate intercostal nerve damage at chest tube insertion. The results confirmed that chest tube insertion has clearly deleterious effects on intercostal nerve function.
    General Thoracic and Cardiovascular Surgery 10/2013;
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    ABSTRACT: Epigenetic parameters such as DNA methylation and histone modifications play pivotal roles in carcinogenesis. Global histone modification patterns have been implicated as possible predictors of cancer recurrence and prognoses in a great variety of tumor entities. Our study was designed to evaluate the association among trimethylated histone H3 at lysine 27 (H3K27me3), clinicopathological variables and outcome in early-stage non-small cell lung cancer (NSCLC). The expression of H3K27me3 and its methyl-transferase, enhancer of zeste homolog 2 (EZH2) together with proliferating cell nuclear antigen (PCNA) were evaluated by immunohistochemistry in normal lung tissue (n=5) and resected NSCLC patients (n=42). In addition, the specificity of antibody for H3K27me3 was tested by western blot analysis. The optimal cut-off point of H3K27me3 expression for prognosis was determined by the X-tile program. The prognostic significance was determined by means of Kaplan-Meier survival estimates and log-rank tests. As a result, enhanced trimethylation of H3K27me3 was correlated with longer overall survival (OS) and better prognosis (P<0.05). Moreover, both univariate and multivariate analyses indicated that H3K27me3 level was a significant and independent predictor of better survival (hazard ratio, 0.187; 95% confidence interval, 0.066-0.531, P=0.002). Furthermore, H3K27me3 expression was positively correlated with DNA methylation level at CCGG sites while reversely related to EZH2 expression (P<0.05). In conclusion, H3K27me3 level defines unrecognized subgroups of NSCLC patients with distinct epigenetic phenotype and clinical outcome, and can probably be used as a novel predictor for better prognosis in NSCLC patients.
    International Journal of Oncology 08/2013; · 2.66 Impact Factor
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    ABSTRACT: Blood loss during resection of the hepatic parenchyma in hepatectomy can be minimized using vessel-sealing (VS) devices. Some sealing devices were retrospectively compared to evaluate the efficacy of each device for controlling blood loss, transection time and postoperative complications in hepatectomy as a cohort study. Between 2005 and September 2012, hepatectomy was underwent in 150 patients using one of three types of LigaSure™ (Dolphin Tip Laparoscopic Instrument, Precise or Small Jaw) or the Harmonic Focus or Ace ultrasonic dissecting sealer. Results were compared to crush-clamping alone as the control method by the historical study (n=81). Irrespective of the vessel-sealing device used for underlying chronic hepatitis, blood loss, blood transfusion rate, operating time and transection time were significantly reduced in the VS group compared with controls (p<0.05). Rates of postoperative bile leakage and intra-abdominal abscess formation were significantly lower in the VS group than in controls (p<0.05). Comparing devices, LigaSure Small Jaw and Harmonic Focus showed lower blood loss, shorter transection time and reduced rates of post-hepatectomy complications, in turn resulting in shorter hospital stays (p<0.05). Tendencies toward uncontrolled ascites and bile leakage were only concern with the use of Harmonic Focus. Satisfactory surgical results were achieved using the sealing device for laparoscopic hepatectomy. The use of energy sealing devices improves surgical results and avoids hepatectomy-related complications. Adequate use of vessel sealers is necessary for safe and rapid completion of hepatic resection.
    International Journal of Surgery (London, England) 08/2013; · 1.44 Impact Factor

Publication Stats

1k Citations
440.25 Total Impact Points

Institutions

  • 2001–2013
    • Nagasaki University
      • • Department of Surgical Oncology
      • • Department of Translational Medical Sciences
      • • Department of Internal Medicine
      Nagasaki, Nagasaki, Japan
  • 1994–2013
    • Nagasaki University Hospital
      Nagasaki, Nagasaki, Japan
  • 2011–2012
    • Ehime Prefectural Central Hospital
      Matuyama, Ehime, Japan
  • 2006–2009
    • Kyoto University
      • Institute for Frontier Medical Sciences
      Kyoto, Kyoto-fu, Japan
  • 2006–2007
    • Numazu City Hospital
      Sizuoka, Shizuoka, Japan