A 300 GHz CW gyrotron FU CW I has been developed and installed in the Research Center for Development of Far-Infrared Region, University of Fukui as a power source of a high frequency material processing system. Its performance was tested and the maximum power of 1.75 kW / CW has been attained at the beam voltage of 15 kVand the beam current of 1A. The maximum window power efficiency of 15.5% has been obtained at the cathode voltage slightly lower than 15 kV. This gyrotron is designed to deliver a Gaussian beam after mode conversion from the oscillation mode TE 22,8 in the cavity with a complex of an internal radiator and beam shaping mirrors. The detailed measurement with an infrared camera has confirmed that a Gaussian beam is radiated when the magnetic field strength B c at the cavity is adjusted at a proper value. However, within a range of B c , the output power is emerged into multiple directions, which suggests simultaneous oscillation of competing cavity modes.

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We encountered a case of plasmablastic extramedullary plasmacytoma with multiple myeloma. Histological findings revealed that the extramedullary plasmacytoma of this patient was of the plasmablastic type, which was positive for λ-stain and EBV-encoded RNA. In contrast, bone marrow aspiration demonstrated a common-type multiple myeloma, which was positive for λ-stain and negative for EBV-encoded RNA. This was a rare case of plasmablastic extramedullary plasmacytoma associated with Epstein-Barr virus arising in an immunocompetent patient with multiple myeloma.

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Patients with syndromic craniosynostosis have many problems involving the upper airway, laryngotracheal airway, and tracheobronchial tree. Evaluation of tracheobronchial disorders in syndromic craniosynostosis is very important for accurately diagnosing these problems. We have used three-dimensional computed tomography (CT) imaging of the tracheobronchial tree (three-dimensional tracheal CT imaging) since a multidetector CT was installed in our hospital in 2004. In this study, we assessed the configuration of the tracheobronchial system using three-dimensional tracheal CT imaging and bronchoscopy.During the period from 2004 to 2009, 48 patients with syndromic craniosynostosis underwent surgery at our hospital. Of those, 16 patients required tracheostomy. These syndromic craniosynostosis cases were examined with three-dimensional tracheal CT imaging and bronchoscopy. All CT scans were performed on a multidetector CT (120 kV, 22-120 mA, 0.5 s/slice, 1-mm slice; Aquilion; Toshiba Co, Tokyo, Japan) without respiratory suppression.All 16 study patients presented with severe stenosis of the upper airway on bronchoscopic examination. Seven were confirmed to have abnormalities by both bronchoscopy and three-dimensional tracheal CT imaging. Four were confirmed to have abnormalities on either bronchoscopy or three-dimensional tracheal CT imaging, whereas 5 patients were apparently free of abnormalities as determined by both modalities.In conclusion, it was possible to accurately assess the configuration of the tracheobronchial system using both three-dimensional tracheal CT imaging and bronchoscopy. Our results suggest these examinations to be very useful for assessing the optimal timing of decannulation and respiratory function prognosis.