中川 誠司

症例は顕性WPW症候群の18歳男性.1年前当院で施行した心内膜側からのアブレーションは不成功であった.12誘導心電図上II誘導のデルタ波の極性は陰性で, 心外膜下の副伝導路が示唆された.室房伝導の心房最早期興奮部位は冠静脈洞 (CS) の近位部であつた.CS, 中心臓静脈 (MCV) を逆行性に造影後, 電極力テーテルで, 三尖弁輪部, CS, MCVの順にマツピングを行った.MCV内で巨大なKent電位が記録され, 双極および単極電位上, 最も大きくKent電位が記録できる部位で高周波通電した.計2回の通電により副伝導路のアブレーションに成功した.通電前および通電中に右冠動脈造影を行い, 合併狭窄のないことを確認した.その後はデルタ波や頻拍発作の再発を認めていない.静脈内通電は種々の合併症が危惧されるが, 慎重なアプローチによりアブレーション可能と考えられた.

This paper presents a study on the ultrasonic hearing aids and perception tests for both normal hearing subjects and profoundly deaf people and their active location of estimated signal sources in the brain. In these experiments auditory activities by bone-conducted ultrasonic stimuli were measured by magnetoencephalography (MEG) using a 122ch whole-head neuromagnetometer. Both subjects of the normal hearing and the profoundly deaf people could perceived the ultrasound stimuli, however their active center in the brain of the latter people was found in a different region (superior temporal area) from the former subjects. These results suggest the reorganization of the auditory central nervous system in human.

As part of studies on magnetoencephalography (MEG), the short-term visual memory processes were examined, focusing on the storage processes, in the human brain. Visually evoked brain magnetic fields associated with a delayed paired comparison task were measured. From the results, it appears that both the visual cortex and the posterior temporal region are engaged in the storage process of the visual short-term memory.

グラウチング試験後の亀裂性岩盤のはぎ取り調査結果をもとに, 亀裂およびグラウト侵入亀裂の分布および方向性を検討した結果, 次のようなことが分かった. 1) 各水平・鉛直掘削面の亀裂トレースの観察により, 立体的なグラウト侵入形態が再現された. 2) グラウト侵入亀裂の空間的分布は, 卓越する亀裂方向分布に支配される傾向を示した. 3) 方向別グラウト侵入頻度は層理面を切る高角度の亀裂グループが層理面に沿ったものより大きな頻度を示した. 4) グラウトの水セメント比は, 練り上げ時600%であったものが硬化後は水が分離し80%前後にあった.

In this study, we investigate an estimation of internal sources with poor information about their source profile, which is important in order to analyze the higher functions of the human brain. We used a 64-channel whole-head-type SQUID system to record MEG activities evoked by visually cognitive tasks. Three kinds of stimuli were presented: English words, nonsense words, and random dot patterns. Spatially distributed internal sources with latencies between 320 and 420 msec were estimated by using a sub-optimal least-squares subspace scanning technique. From three subjects data, the following results of distributed source estimations were shown: English words stimuli activated large area, the left temporal region, the parietal and right postero-temporal region, nonsense words activated the parertal region, random dot patterns activated the frontal region.

掌紋服合において, サーチ側部分掌紋画像がファイル側全掌紋画像のどの位置に対応するかを検出し二つの掌紋画像の位置を合わせる方法を提案する. 指紋はコアなどの紋様特徴を用いて中心点を定義し, それを用いて位置合わせを行なうことができるが, 掌紋にはそのような位置合わせに用いることができる紋様は存在しない. そこで本研究では,そのような紋様を使うことなく位置合わせ可能な手法の構築を目指す. そこで近傍マニューシャの元のマニューシャからの相対的な特徴量を用いてマニューシャを対応付けることにより位置を合わせる手法を提案する. 提案手法を掌紋マニューシャに適応した結果, 正しく位置合わせが行なえることが確認できた.

In recent years, techniques have been developed for estimating internal electrical sources in the human brain from measurements of magnetic fields (MEG). In this study, we investigate how to estimate spatially distributed sources, since this information is important for analyzing the higher functions of the human brain. We used a 64-channel whole-head-type SQUID system to record MEG activities evoked by visually cognitive tasks. Three kinds of stimuli were presented: English words, nonsense words, and random dot patterns. Spatially distributed internal sources with latencies between 320 and 420 ms were estimated by using the sub-optimal least-squares subspace scanning technique. The estimated sources were located in the frontal region for random-dot stimuli, the left temporal region for nonsense-word stimuli, and the right postero-temporal region in addition to the other regions for English-word stimuli.

Recent advances in telecommunication technology have been enormous. Application of this technology in public health has the potential to markedly improve global health through better surveillance and information systems. With this assumption the GHNet was established in 1994 by representatives from academia, WHO, Pan American Health Organization, the World Bank, NASA, IBM, and AT & T. The GHNet consists of seven components: 1) promotion of networking with the Internet among people in public health; 2) disease tele-monitoring; 3) distance learning system with the internet; 4) connection of non-governmental health organizations; 5) training cyberdocs who are educated in both public health and telecommunications; 6) establishment of an electronic scientific research server; and 7) a home page on the World Wide Web (WWW). In order to effectively incorporate the Internet into the field, connectivity and knowing how to use it are of critical concern. More and more facilities are connected to the Internet in Japan. However, few courses teaching how to utilize the Internet are provided for people in this field. An Internet training course for people in public health was held as joint venture of the World Health Organization (WHO) and the Global Health Network (GHNet) on October 31, 1996, at the 55th Annual Meeting of Japanese Society of Public Health. Most of the participants for the course were from local public health departments and very few had previous experience with the Internet before the course. During this course participants learned how to use e-mail, how to find health resources on the WWW, how to construct a home page, and how the Internet could be utilized to improve public health, with their computers actually hooked to the Internet. From this experience, we found that this kind of course is feasible and beneficial and hope that this course would serve as a model for training people in public health.

This study focuses on the investigation of higher brain function using electroencephalogram (EEG) and magnetoencephalogram (MEG) techniques. We observed verbal cognitive activities by measuring EEGs and MEGs evoked by visually cognitive tasks. English words, meaningless sets of letters, and simple flashes were presented. We analyzed the EEG and MEG data with a subtraction technique and topographic maps. Visual evoked potentials (VEPs) associated with cognition of meanings were obtained by subtracting VEPs evoked by random letters from VEPs evoked by English words. The topographic EEG maps in several subjects show a clear interhemispheric difference between latencies of 300 and 600 msec. The EEG maps in a few subjects, however, show no interhemispheric differences.

岩盤内部の節理は, しばしば規則的な方向, 大きさなどを有する. 岩盤構造物の設計・施工に際しては, こうした節理の特性を把握するための地質調査が行われるが, 現状ではその結果は定性的に用いられているだけである. 本研究では不連続性岩盤の解析に応用するために, 節理調査の結果からその特性を定量的に把握するための手法について改良を行った.

節理性岩盤の挙動は, その内部に多数存在する節理の方向性が大きな影響を持つと考えられる. 将来, 岩盤の信頼性設計を行う場合, この分布についてより詳細な記述を確率・統計的に行う必要が有る. 本報告では, 繰り返しによって節理の方向グループと各グループの確率分布を同時に推定する, 卓越方向解析の新しい手法の提案を行った.

中肝静脈を巻き込み,左右肝静脈と大きな肝内門脈枝にはさまれた内側区域から前区域にまたがる腫瘍に対し,比較的出血の少なくてすむ右3区域切除を行い,摘出した右3区域を冷却臓器保存液中に浸漬して体外手術により内側および前区域を切除し,後区域を同所性に自家移植した.本法は前・後区域間の広範囲な肝実質切離を無血下に行うので通常の中央2区域切除より出血は少なく,無肝期はないので安全に行える術式である.本症例では術中術後の総輸血量3,600mlであった.自家移植肝の血流再開直後より動脈血中ケトン体比は危険域を脱し術翌日からは安全域に入った.肝細胞障害は術後4日目に正常化したがそれ以後も高ビリルビン血症は数日間遷延した.移植肝の胆管ドレナージの胆汁排出や胆汁中直接型ビリルビン濃度はその生着機能の確認に有用であった.術後3か月の現在,肝機能のすべての指標は正常値を保っている.