Takashi Kojima

Inflammatory pseudotumor of the liver. Clinicopathologic study and review of the literature

Clinicopathologic analysis of nine patients with inflammatory pseudotumor of the liver was reported. The age of the patients varied from 22 to 83 years old, with a male to female ratio of 8 to 1. They complained of intermittent fever and abdominal pain, and laboratory data on admission suggested an inflammatory process. The solitary or multiple, well‐defined space‐occupying lesions were displayed by recently advanced imaging techniques. Partial hepatectomy, laparotomy, needle biopsy, or autopsy was performed in all nine patients with diagnoses of hepatocellular carcinoma, metastatic liver tumor, or liver abscess. Histologically, these lesions were composed of dense hyalinized fibrosis and/or infiltrating inflammatory cells constituting large numbers of foamy histiocytes, lymphocytes, and plasma cells. Obliterating phlebitis of relatively large branches of the portal vein was found, thus providing a diagnostic clue to distinction from the primary hepatic cancer by imagings. Considering the clinicopathologic features and the patients histories, in which four patients had been in the Southeast Asian countries or India, it is possible that infection of microorganisms through the portal vein could participate in these lesions as a cause. Two patients died of causes probably related to this lesion, indicating poor prognosis in some patients, in contrast to the generally fair prognosis of previously published cases.

Ameliorative effects of mulberry (Morus alba L.) leaves on hyperlipidemia in rats fed a high-fat diet: induction of fatty acid oxidation, inhibition of lipogenesis, and suppression of oxidative stress.

To determine the effects of mulberry (Morus alba L.) leaves on hyperlipidemia, we performed gene expression profiling of the liver. Rats were fed a high-fat diet and administered mulberry leaves for 7 weeks. Plasma triglyceride and non-esterified fatty acid levels were significantly lower in the rats treated with mulberry leaves as compared with the untreated rats. DNA microarray analysis revealed that mulberry leaves upregulated expression of the genes involved in α-, β- and ω-oxidation of fatty acids, mainly related to the peroxisome proliferator-activated receptor signaling pathway, and downregulated the genes involved in lipogenesis. Furthermore, treatment with mulberry leaves upregulated expression of the genes involved in the response to oxidative stress. These results indicate that consumption of fatty acids and inhibition of lipogenesis are responsible for the reduction in plasma lipids caused by mulberry administration. In addition, mulberry treatment maintains the body’s oxidative state at a low level despite enhancing fatty acid oxidation.

Facilitative effects of Eucommia ulmoides on fatty acid oxidation in hypertriglyceridaemic rats

BACKGROUNDnTea made from Eucommia ulmoides leaves is widely consumed as a health food, since recent studies have revealed various pharmacological effects of the tea, e.g. a hypotriglyceridaemic effect. This study was conducted to elucidate the mechanisms underlying the plasma triglyceride-lowering effect of E. ulmoides leaves.nnnRESULTSnRats were divided into four groups: a normal group, a group fed a high-fat/high-fructose diet (untreated group) and two groups fed a high-fat/high-fructose diet and E. ulmoides tea (4 or 20 g L(-1) extract, treated groups). Plasma triglyceride concentrations were reduced in treated groups in a dose-dependent manner compared with the untreated group. DNA microarray analysis revealed that genes involved in hepatic α-, β- and ω-oxidation, mainly related to the peroxisome proliferator-activated receptor α and δ signalling pathway, were up-regulated in the treated group. High-performance liquid chromatography analysis showed that E. ulmoides leaves contain three phytochemicals that make up 60 mg g(-1) of the material and are likely to be the active components.nnnCONCLUSIONnThis study indicates that the promotion of fatty acid oxidation, probably by the action of phytochemicals, participates in the ameliorative effect of E. ulmoides leaves on hypertriglyceridaemia. These findings provide the scientific evidence for the functionality of E. ulmoides.

Fault Detection of Railway Track by Multi-Resolution Analysis

This paper describes how conditions of track have conventionally been measured using exclusive inspection vehicles. If the conditions of the track can be detected by attaching simple sensors such as accelerometers on board commercial vehicles, more efficient maintenance of tracks would be possible. This paper describes rail corrugation detection from the vertical acceleration of a vehicle body by time frequency analysis. An actual vehicle running tests on a commercial line was conducted, in which vertical acceleration of axle-boxes and a vehicle body were measured. This paper shows the rail corrugation can be detected from the vertical acceleration of a vehicle body by multi-resolution analysis (MRA) using wavelet transform.

Immunohistochemical investigation of hepatitis B virus associated antigens, HLA antigens and lymphocyte subsets in type B chronic hepatitis

SummaryHLA antigens, hepatitis B virus (HBV)-assodated antigens and lymphocyte subsets in liver tissue from 35 patients with HBs antigenemia were studied using an immunoperoxidase double staining method arid immunoelectron microscopy in order to clarify the immune mechanism of hepatocyte lysis in type B hepatitis. Immune light and electron microscopy using monoclonal antibodies to lymphocyte subsets revealed that infiltrating lymphocytes in the areas of piecemeal necrosis and focal necrosis were predominantly CD8-positive, showing direct contact with hepatocytes. In contrast, CD4(+) cells were infrequently observed in necrotizing inflammatory lesions. HLA-A,B,C antigens were mainly found on hepatocytes in areas of piecemeal necrosis and focal necrosis, in association with CD8(+) lymphocyte infiltration. HLA-DR antigens were demonstrated on a few hepatocytes in the same lesions. In cases of CAH with serum HBeAg positive, HLA-A,B,C, antigens and HBV antigens simultaneously demonstrated on the same hepatocytes. Especially, hepatocytes expressing both HLA-A,B,C antigen and HBsAg on the plasma membrane showed direct contact with CD8(+) lymphocytes. This finding fullfilled the morphological requirements for HBsAg as a target antigen. On the other hand, HBcAg was hardly demonstrated in the liver cell membrane but was demonstrated mainly in the cytoplasm. Compared with the nuclear localization of HBcAg in cases of NSR, cytoplasmic localization of this antigen may be associated with membranous expression of new antigens induced by HBV infection.

Evaluation of braking behaviour for train drivers using phase-plane trajectories

This study analyses braking behaviour of train drivers and estimates drivers’ mental condition using a train simulator. The velocity deviation recognised by drivers is defined by the difference between the present vehicle velocity and the desired velocity that enables the vehicle to stop at the desired position if the present deceleration is kept constant. Observing the relation between the velocity deviation and the braking operation enables the detection of abnormal driving behaviour. The phase-plane trajectory of the velocity deviation and the brake command with mental workload indicates a large velocity deviation and repetition of the braking operation, while the trajectory without mental workload indicates that both the velocity deviation and the brake command gradually approach the origin of the coordinate axes.

Measurement of Train Driver’s Brain Activity by Functional Near-Infrared Spectroscopy (fNIRS)

This paper describes the feature of train driver focusing on brain activity measured by using the newly developed train simulator and functional near-infrared spectroscopy (fNIRS). The developed train simulator can simulate the real train operation with designed task condition for measuring brain function of train driver. Blood flow measurement is carried out manual and automatic train operation. It is pointed out that the difference between manual operation and automatic operation can be seen in the blood flow of frontal lobe.

Near-infrared spectroscopic measurement of brain activity for syntactic processing

We conducted a near-infrared spectroscopic experiment of brain activity for language processing. Syntactic aspects of language are particularly focused on in the stimuli. Increase in blood flow around Broca s area is measured, as expected.

Development of Train Simulator for Evaluation of Human-Machine Interface

Development of Train Simulator for Evaluation of Human-Machine Interface Kouichi YANAGAWA, Hitoshi TSUNASHIMA and Takashi KOJIMA 1 はじめに 列車の運転は,自動車と比較して運転が単調になり やすい特徴を有しており,ヒューマンエラーの原因の 一つに運転士の覚醒度低下が挙げられる.ヒューマン エラー事故の防止方策として,鉄道会社では乗務員の 教育・訓練が行われている.また,バックアップとし て自動列車停止装置(Automatic Train Stop: ATS)な どを採用してきた.一部の鉄道では,自動列車運転装 置(Automatic Train Operation: ATO)を導入し,運転 を自動化させている事例もある.しかし,自動化を進 めることにより運転士は監視作業が中心となり,覚醒 度低下が懸念される.自動車分野では,ドライバの生 体情報や運転挙動から居眠りを検知し,警告を与える 居眠り運転警報装置が研究されている 1) 2).鉄道にお いては,ヒューマンファクタに関する基礎的研究が行 われているが3),積極的な運転支援にまで至っていな いのが現状である.そこで,列車運転におけるヒュー マンエラーを事前に防止するために,人間の特性を考 慮した運転支援システムの開発が必要であると考えら れる.このようなシステムを開発するためには,運転 士がどのような情報認知を行い,それにもとづいてど のような判断を行い,行動をとるのかを把握すること が重要となる.このような運転行動を解析するために は,運転士の生体計測などを様々な条件のもとで行え る運転シミュレータが必要となる.そこで,本研究で は,人間 -機械系評価用列車運転シミュレータを開発 し 4) 5) ,運転士の生態計測を行っている.本稿では, 本装置の概要と立体視への展開について述べる. 2 シミュレータの構成 ヒューマンファクタに関する研究の実験手法として 運転シミュレータを用いるためには,実験の目的に即 した環境が柔軟に構築可能であることが有効である. この観点から,システムは,通常の運転操作が違和感 なく行える程度とし,研究目的からの必要性に応じて 機能を強化する方針で,最小の構成とした.また,ソ フトウェアを独自に作成することで,車両特性の変更 や路線の作成,また,運転支援システムの組み込み等 を可能にした.構成が簡単でかつ臨場感を与えるため に,ソフトウェアによる模擬を多く取り入れた. 本装置のシステム構成を図2に示す.車両制御コン ピュータ,運転台,計器盤表示モニタ,スピーカの車 両再現部と,視界生成コンピュータ,プロジェクタ, スクリーンの視界再現部,指令コンピュータから構成 される.運転士が操作する運転台のハンドル位置が車 両制御コンピュータに入力され,車両特性にもとづい て車両運動計算や音響の生成,計器盤画像の生成等を 行う.計算した車両位置は視界生成コンピュータに送 られる.この情報に視差を付加し,コンピュータグラ フィクスの視界画像を生成し,プロジェクタから前方 の 70インチスクリーンに投影する.計器の変更や運 転支援の表示システムの評価等が行えるように,計 器盤を計器盤表示モニタ上に表示した.また,指令コ ンピュータからは,事故の発生や駅の移動,運転デー タの記録等の操作が行える. 軌道不整と車両運動モデルによって車両の振動を計 算し,スクリーンの視界画像を揺らすことにより,