Takuji KOIKE (小池 卓二)

Offer Organization: 日本学術振興会, System Name: 科学研究費助成事業, Category: 基盤研究(C), Fund Type: -, Overall Grant Amount: - (direct: 3400000, indirect: 1020000)
本年度は、まず、蛍光計測法の有用性評価のための予備実験を実施した。
牛肉ブロックとバルーンカテテールを用いてヒトの咽頭の梨状窩を再現し作成したファントムと、ヤギの頭頸部標本を使用した。実験項目は、①近赤外線ファイバおよび蛍光検出ファイバを取り付けたプローブの頚部への照射角の設定、②咽頭通過する食物中の蛍光を計測可能な蛍光強度積算時間の設定、③咽頭残留を計測する最適スパンの検討、である。その結果、①光プローブと頚部の接触角度が蛍光強度可否に大きく影響すること、②嚥下時に食塊が咽頭を通過する速度での蛍光検出は深さ25mmまでは可能であること、③最適スパンは10mmから20mmであること、がわかった。
また、人を対象とした計測では蛍光計測と嚥下造影検査を同時に実施する予定であったため、ICG入り検査食に硫酸バリウムやとろみ剤を混和した場合に、蛍光強度に影響するか調査した。その結果、混和前と比較し混和後は蛍光強度が大きくなる傾向が見られたが、検査自体には支障はないことがわかった。
予備実験終了後、実際に嚥下障害患者を対象とし計測を実施した。対象は、東京医科歯科大学病院摂食嚥下リハビリテーション外来を受診する嚥下障害患者4名である。嚥下時の蛍光計測および嚥下造影検査を同時に実施し、得られた蛍光強度と検査画像を対応させた。その結果、咽頭残留、咽頭通過の蛍光検出が可能であった。一方で、プローブの接触位置や接触強さが検出精度に影響するため、プローブ形態やセンサの感度を改良し、検査手技の簡易化と検出精度向上を検討する必要があることが示唆された。

Offer Organization: Japan Society for the Promotion of Science, System Name: Grants-in-Aid for Scientific Research, Category: Grant-in-Aid for Scientific Research (C), Fund Type: -, Overall Grant Amount: - (direct: 3300000, indirect: 990000)
Vibrational technologies applied to crop protection and cultivation are presented. Because vibrations modify behaviors in insect pests of tomatoes and mushrooms, vibrations can be exploited for physical pest management. In addition, vibrations promote pollination in tomatoes. Indeed, we revealed that vibrations decreased infestation of whitefly pests and increased yields of tomatoes in greenhouses installed with vibration exciters.

Offer Organization: Japan Society for the Promotion of Science, System Name: Grants-in-Aid for Scientific Research, Category: Grant-in-Aid for Challenging Research (Exploratory), Fund Type: -, Overall Grant Amount: - (direct: 4800000, indirect: 1440000)
For the purpose of evaluating pulmonary aspiration, we have developed a technology to inspect food residue in the piriform sinus noninvasively and easily. When fluorescence food is remained in the piriform sinus, it can be detected by an optical probe attached to the skin for measuring fluorescence emitted from the food. Selection of fluorescence agent emitting near-infrared light with high penetration depth, development of an instrument having high sensitivity to near-infrared fluorescence as well as an optical probe, preliminary experiments using phantoms, and measurements for healthy elderly subjects were conducted.
It was confirmed that fluorescence from the depth of about 25 mm was detectable, and fluorescence from fluorescence food remained in the piriform sinus of healthy elderly subjects were detected. Consequently, we have established the fundamental technology for inspecting food residue in the piriform sinus noninvasively and easily.

Offer Organization: Japan Society for the Promotion of Science, System Name: Grants-in-Aid for Scientific Research, Category: Grant-in-Aid for Scientific Research (B), Fund Type: -, Overall Grant Amount: - (direct: 13400000, indirect: 4020000)
Recently, abnormalities in frequency discrimination have been observed in some patients with abnormal sound perception, but the cause of these abnormalities is unknown and there are no objective diagnostic criteria. We reported the mice with abnormal frequency discrimination and confirmed the predicted abnormal propagation of basal menbrane vibration from basal (high frequency) to apical (low frequency) rotation. We further elucidated the possible causes of this abnormality by simulating the cochlear model and suggested the possiblity that high frequency hearing loss model abnormally recognize the sound as a low frequency sound. Furthermore, by developing a technology to generate cochlear cells from iPS cells, they were able to reproduce the pathophysiology of hearing loss and succeeded in generating hair cells using the same method, which is expected to lead to clinical applications of inner ear cell therapy in the future.