K. Kawaguchi

Hiroshima University, Hirosima, Hiroshima, Japan

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Publications (7)11.81 Total impact

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    ABSTRACT: The standard operation for colitic cancer in ulcerative colitis (UC) is restorative proctocolectomy; however, sporadic colorectal cancer (CRC) can coincidentally arise in patients with UC and the optimal procedure remains controversial. Therefore, it is crucial to preoperatively determine whether the CRC in UC is a sporadic or colitic cancer. We report a case of avoiding proctocolectomy for sporadic CRC in a patient with UC based on preoperative diagnosis involving p53 immunostaining. A 73-year-old man with CRC in UC had undergone sigmoid colectomy with lymphadenectomy because of the submucosal deep invasion pathologically after endoscopic mucosal resection. The cancer was diagnosed sporadic cancer preoperatively not only based on the endoscopic, clinical, and histological patterns but also that the colon epithelium was unlikely to develop dysplasia as the circumference and unaffected UC mucosa did not detect p53 protein overexpression. Recent reports have shown that the immunohistochemical detection of p53 protein overexpression can be useful for a differential diagnosis and as a predictor of dysplasia and colitic cancer. The analysis of p53 mutation status based on immunostaining of p53 protein expression in the unaffected UC mucosa can be useful for the decision regarding a surgical procedure for CRC in patients with UC.
    World Journal of Surgical Oncology 12/2015; 13(1). DOI:10.1186/s12957-015-0540-7 · 1.41 Impact Factor
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    ABSTRACT: Abstract Background: Virtual reality surgical simulators are becoming popular as a means of providing trainees with an opportunity to practice laparoscopic skills. The Lap-X (Epona Medical, Rotterdam, the Netherlands) is a novel VR simulator for training basic skills in laparoscopic surgery. The objective of this study was to validate the LAP-X laparoscopic virtual reality simulator by assessing the face and construct validity in order to determine whether the simulator is adequate for basic skills training. Material and methods: The face and content validity were evaluated using a structured questionnaire. To assess the construct validity, the participants, nine expert surgeons (median age: 40 (32-45)) (>100 laparoscopic procedures) and 11 novices performed three basic laparoscopic tasks using the Lap-X. Results: The participants reported a high level of content validity. No significant differences were found between the expert surgeons and the novices (Ps > 0.246). The performance of the expert surgeons on the three tasks was significantly better than that of the novices in all parameters (Ps < 0.05). Conclusions: This study demonstrated the face, content and construct validity of the Lap-X. The Lap-X holds real potential as a home and hospital training device.
    Minimally invasive therapy & allied technologies: MITAT: official journal of the Society for Minimally Invasive Therapy 04/2014; 23(5). DOI:10.3109/13645706.2014.903853 · 1.27 Impact Factor
  • T. Kihara · I. Katakura · M. Tokunaga · A. Matsuo · K. Kawaguchi · A. Kondo · K. Kindo · W. Ito · X. Xu · R. Kainuma ·
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    ABSTRACT: As novel tools to study magnetic shape memory alloys, a high-speed optical microscope system and a measurement system of magnetocaloric effects (MCEs) in pulsed magnetic fields are developed. Using the high-speed imaging system, successive changes in the surface morphology are visualized in the process of magnetic field-induced reverse martensitic transformation in Ni45Co5Mn36.7In13.3. The MCEs of Gd studied in pulsed fields show reasonable agreement with the earlier results obtained in steady fields. Application of high magnetic fields up to 55 T realizes a gigantic adiabatic heating of 63 K.
    Journal of Alloys and Compounds 11/2013; 577:S722-S725. DOI:10.1016/j.jallcom.2012.02.018 · 3.00 Impact Factor
  • Hiroyuki Egi · M Hattori · M Tokunaga · T Suzuki · K Kawaguchi · H Sawada · H Ohdan ·
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    ABSTRACT: Objective: The aim of this study was to determine whether any correlation exists between the performance of the Mimic® dV-Trainer (Mimic Technologies, Seattle, Wash., USA) and the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, Calif., USA). Methods: Twelve participants were recruited, ranging from residents to consultants. We used four training tasks, consisting of 'Pick and Place', 'Peg Board', 'Thread the Rings' and 'Suture Sponge', from the software program of the Mimic dV-Trainer. The performance of the participants was recorded and measured. Additionally, we prepared the same tasks for the da Vinci Surgical System. All participants completed the tasks using the da Vinci Surgical System and were assessed according to time, the Objective Structured Assessment of Technical Skill checklist and the global rating score for endoscopic suturing assessed by two independent blinded observers. After performing these tasks, the participants completed a questionnaire that evaluated the Mimic dV-Trainer's face and content validity. The final results for each participant for the Mimic dV-Trainer and the da Vinci Surgical System were compared. Results: All participants ranked the Mimic dV-Trainer as a realistic training platform that is useful for residency training. There was a significant relationship between the Mimic dV-Trainer and the da Vinci Surgical System in all four tasks. We verified the reliability of the assessment of the checklist and the global rating scores for endoscopic suturing assessed by the two blinded observers using Cronbach's alpha test (r = 0.803, 0.891). Conclusions: We evaluated the concurrent validity of the Mimic dV-Trainer and the da Vinci Surgical System. Our results suggest the possibility that training using the Mimic dV-Trainer may therefore be able to improve the operator's performance during live robot-assisted surgery.
    European Surgical Research 07/2013; 50(3-4):292-300. DOI:10.1159/000353435 · 2.47 Impact Factor
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    ABSTRACT: Recently, much progress has been made in generation of high magnetic fields in the International MegaGauss Science Laboratory at ISSP of the University of Tokyo. The electro-magnetic flux compression method has been improved to establish the world highest indoor-field of about 730 T. In addition to the destructive methods, a new project aiming at the non-destructive generation of both long pulsed- and 100 T-fields is progressing. The long pulse project is introduced. Not only for the highest field but also for various experiments, many kinds of coils have been developed. A microscope imaging system under pulsed fields, and miniature magnets for the X-ray measurements at the synchrotron radiation facility are also presented. High Field Lab-ISSP
    Journal of Low Temperature Physics 04/2010; 159(1):381-388. DOI:10.1007/s10909-009-0153-z · 1.02 Impact Factor
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    ABSTRACT: We developed a high-speed polarizing microscope imaging system combined with a 37 T pulse magnet. With utilizing this system, we can visualize some kinds of structural transitions induced by high magnetic fields. The efficiency of this system was tested through observation of the field-induced collapse of charge-orbital ordering (COO) in mixed-valent manganites. In perovskite-type Nd1/2Sr1/2MnO3, quantitative analyses of the obtained polarizing microscope images clearly show the discontinuous change in birefringence accompanied with hysteresis, which are characteristic of the first order transitions. This observation of field-induced melting of the COO was also successful in a layered manganite La1/2Sr3/2MnO4 in which changes in magnetization and magnetoresistance at the transition are less clear. The present success in observation of the melting of the COO demonstrates the potential applicability of this system to visualize other kind of structural transitions even in a tiny piece of crystal.
    Journal of Low Temperature Physics 04/2010; 159(1):319-323. DOI:10.1007/s10909-009-0141-3 · 1.02 Impact Factor
  • I Katakura · M Tokunaga · A Matsuo · K Kawaguchi · K Kindo · M Hitomi · D Akahoshi · H Kuwahara ·
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    ABSTRACT: A high-speed polarizing microscope system combined with a 37 T pulse magnet has been developed. This system was applied to successfully visualize the field-induced collapse of charge-orbital ordering in a layered manganite La(1/2)Sr(3/2)MnO(4). Quantitative analyses of the obtained polarizing microscope images provided clear evidence of this transition in contrast to rather moderate changes in magnetization and magnetoresistance. The ability of this system to carry out quantitative analysis was further tested through the observation of Faraday rotation in a Tb(3)Ga(5)O(12) crystal. The Verdet constant determined from the polarizing images is in reasonable agreement with that in literature. Local intensity analyses of the images indicate that we can investigate magneto-optical signals within an accuracy of 0.85% in an area of 9.6 x 9.6 microm(2).
    The Review of scientific instruments 04/2010; 81(4):043701. DOI:10.1063/1.3359954 · 1.61 Impact Factor