舌骨尾側に発生した乳頭癌の1例を経験した．症例は49歳，女性．前頸部舌骨下の腫脹と疼痛を主訴に当科を受診した．超音波検査で甲状軟骨左側に低エコー腫瘤を認めた．また，甲状腺左葉に微小石灰化を伴った低エコー腫瘤を認めた．ともに穿刺吸引細胞診検査で悪性，乳頭癌の診断であった．以上より，甲状腺左葉乳頭癌，喉頭前リンパ節転移，もしくは甲状舌管嚢胞癌ないし錐体葉乳頭癌の術前診断にて，甲状腺全摘術およびD1郭清術，喉頭前腫瘤切除を施行した．喉頭前腫瘤は錐体葉と連続していた．病理組織学的には甲状舌管嚢胞の構造を示唆する所見はなく，錐体葉乳頭癌の診断であった．明らかな術後合併症および再発は現在認めていない．

Benign nodular goiter is a common disease. Although large goiters with obstructive symptoms including shortness of breath and dyspnea are a clear indication for surgery, acute upper airway obstruction, particularly in benign cervical goiter cases, is rare. We herein report the case of 46-year-old female with acute upper airway obstruction due to benign nodular goiter. The patient had a large and elastic goiter which was more pronounced on the left side of her neck, and surgery was scheduled for within a few months. Three months after the initial presentation, while still waiting for surgery, the patient was brought to the emergency room due to loss of consciousness and breathing difficulty and was immediately intubated. A computed tomography (CT) scan revealed that the trachea was markedly compressed by a nodular lesion in the left lobe, and bilateral pneumonia was also evident. Total thyroidectomy was immediately performed via the supraclavicular approach. The patient had an uneventful postoperative course and recovered well. The resected specimen included a well-encapsulated solid and cystic mass. Histopathological examination mainly revealed adenomatous goiter. The present case suggests that benign asymptomatic nodular goiter mostly located in the neck may cause acute airway obstruction, even if the nodules are not large. Early surgery should be performed when tracheal deviation and stenosis due to a large goiter is prominent by CT scan.

Acinic cell carcinoma of the breast is an extremely rare, malignant neoplasm characterized by widespread acinar cell-like differentiation and clinically low-grade malignancy. Herein, we report a case of acinic cell carcinoma of the breast in a 41-year-old woman. The tumor was poorly demarcated but had a firm consistency. It was removed with lumpectomy, and sentinel lymph node biopsy was performed to check for metastasis. Microscopically, the tumor showed an infiltrative growth pattern with a combination of solid, trabecular, and microglandular areas. Many of the tumor cells had abundant clear vacuolated cytoplasm containing zymogen-typed granules which resemble acinar cells of the salivary glands. The immunohistochemical profile of the tumor was also similar to that of salivary gland acinic cell carcinoma: the tumor cells were positive for amylase, lysozyme, α -1-antichymotrypsin, S-100 protein, and epithelial membrane antigen and negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. She received postoperative chemoradiation therapy and has been well for 3 years since surgery. As studies on large series are lacking, further studies are needed to elucidate the biological characteristics of acinic cell carcinoma of the breast.

患者は52歳，女性．マンモグラフィ検診で右乳房の腫瘤影を指摘され，当科外来受診した．右乳房に8cm大の硬い腫瘤を触知し，画像診断では線維腺腫，葉状腫瘍などが疑われた．悪性病変の可能性を否定できないため，腫瘤摘出術を施行した．腫瘤割面は正常乳腺と境界明瞭で，白色調，充実性であった．組織学的には，導管や小葉の萎縮・減少と硝子化膠原線維の増加した間質から成っており，fibrous tumorと診断された．術後経過は問題なく，乳房の整容性も保たれている．乳腺fibrous tumorはまれな疾患であり，「乳癌取扱い規約・第16版」に腫瘍様病変として，乳腺線維症（fibrous disease）が追加されたが，その中で腫瘤を形成するものがこれに該当すると思われる．本症例のように比較的大きな腫瘤を形成するfibrous tumorがあることも念頭に置く必要がある．

Inter-Vehicle Communication (IVC) is currently the focus as a developing method of collision-warning and collision-avoidance systems. This paper presents a study of the performance of Medium Access Control (MAC) protocols in vehicle safety communication systems using IVC. The authors note that, in the IVC environment, the Carrier Sense Multiple Access/ Collision Avoidance (CSMA/CA) protocol is often used as a MAC protocol. However, the hidden-terminal problem would degrade the performance of CSMA/CA. The study evaluated MAC protocols with respect to safety application and communication quality. The results show three points: the hidden terminal problem needs to be solved in an IVC environment; good performance of the communication systems does not always imply the performance of safety applications; and the proposed decentralized Time Division Multiple Access (TDMA)-based MAC protocol is effective for the hidden terminal problem.

When the volume of traffic on a roadway is so high such as traffic jam, medium access control (MAC) protocols in inter-vehicle communication (IVC) systems do not work well. The primary reason is the huge amount of communication traffic, which could be resolved by conventional transmission cycle control (TCC) schemes. However, when using TCC schemes, the failure of packet transmission extends the communication interval between vehicles, which can cause driving support systems that use IVC to malfunction. This paper proposes an advanced TCC scheme for realizing a safe driving support system. The proposed scheme exploits the frame-information exchange in the autonomous decentralized TDMA protocol, so that subsequent packets are transmitted rapidly even when failure occurs. Such a scheme is shown to be effective in terms of both communication quality and driving support systems.

Purpose: Endoscopic ultrasonography (EUS) is useful in detecting biliopancreatic diseases. This study is designed to evaluate the usefulness of EUS in detecting the cause of acute pancreatitis. Methods: In this study, we retrospectively analyzed 80 available cases, which were diagnosed as acute pancreatitis by computed tomography (CT) at our hospital between April 2000 and September 2007. Cases with obstructive pancreatitis due to pancreatic ductal carcinoma were excluded. Final diagnoses were determined by endoscopic retrograde cholangiopancreatography and/or surgical exploration, and all cases diagnosed as idiopathic were followed up at least 12 months after the initial diagnosis. As choledocholithiasis and occult intraductal pancreatic tumor (IPT) are thought as determinant factors for the management of acute pancreatitis, we evaluate the diagnostic accuracy of detecting these diseases in the following diagnostic processes. First, we tried to diagnose these factors only using CT in all cases. If choledocholithiasis were detected, we performed endoscopic treatment without performing EUS. Second, we performed EUS additionally for further examination, and reconsidered the management according to EUS findings. All cause was classified into 5 groups: choledocholithiasis including debris, alcoholic, spontaneous stones pass, IPT and idiopathic. Results: The number of each group was as follows: choledocholithiasis, 41; alcoholic, 21; spontaneous stones pass, 4; IPT, 3; idiopathic, 11. Only using CT, 16 of 41 cases with choledocholithiasis and 2 of 3 cases with IPT were missed. So 18 cases were incorrectly diagnosed in total, and the over all accuracy was 77.5% (62/80). EUS was additionally performed in 55 cases, and 16 cases with choledocholithiasis and 2 cases with IPT were correctly diagnosed. Therefore, additional EUS correctly influenced 16 of 16 misdiagnosed cases correctly. Neither another CT nor MRI could detect any abnormal findings in 2 cases with IPT (intraductal acinar cell carcinoma and non invasive minute ampullary carcinoma). Furthermore, findings of chronic pancreatitis (hyperechoic foci, hyperechoic strands, lobularity) were detected in 7 of 21 alcoholic cases. The over all accuracy of EUS was 100% (54/54), and was statistically higher than that of using only CT (p < 0.0005). Conclusions: EUS is very useful in detecting not only choledocholithiasis but also minute intraductal pancreatic tumor. We recommend EUS for all cases which are diagnosed as acute pancreatitis without choledocholithiasis by CT.

This paper investigates an intervehicle communication method as a safe driving support system for intersection collision avoidance warnings. In this kind of system, realization of highly reliable communications in the physical layer is an absolute requirement. As a result, we propose a new MIMO-STBC (Space-Time Block Coding) method based on intersection propagation channel characteristics. MIMO transmission characteristics are determined by the propagation channel characteristics. First, we use a ray-tracing method simulation to clarify the propagation channel conditions, and then model the intersection propagation channel. We use the characteristics of this propagation channel to propose a MIMO-STBC method that utilizes decision feedback channel estimation, and verify the effectiveness of the proposed method in computer simulations. (c) 2007 Wiley Periodicals, Inc.

In order to improve the adhesion of 75 mass% Cr-Fe alloy plasma spray coatings, which provide sulfide corrosion resistance for the inner surface of NAS battery high-temperature type Al cylinders, the Al substrate temperature and the flattering behavior of the plasma spray particles were studied. Also, experiments were conducted to study how changes in the preheating temperature of the Al cylinder affected the spray coating's adhesion. The splat morphology of the spray particles changed significantly in relation to the preheating temperature of the Al substrate, from splash shaped to disk shaped as the preheating temperature increased. It was especially evident that the splat morphology of the particles changed sharply at over 433 K, forming disk shaped with excellent adhesion splats to the substrate. In addition, as the preheating temperature was increased, fewer coating defects such as blisters and peeling were seen on the spray coating. A good correlation was found between the flatness of the spray particles and the adhesion of the coating formed by changing the preheating temperature of the Al cylinder. When the preheating temperature was set at over 433 K, coating with good adhesion were formed. It was therefore shown that by studying the flattening behavior of the plasma spray particles, could be found an effective method for improving the adhesion of plasma spray coating.

Test methods were studied for determining whether permeable pores exist in high CrFe alloy plasma spray coatings applied to the inner surface NAS battery Al containers. Al containers were first filled with a NaOH solution. If permeable pores were to exist in the sprayed coating, the NaOH solution would reach the container wall through these pores, react with the Al, and generate H2 gas. When the Al in a container came into contact with the 0.256 mol・L-1 NaOH solution, the Al dissolved and H2 gas bubbles were immediately generated. However, the 75 massCrFe alloy plasma spray coating itself does not react with the NaOH solution and does not generate H2 gas. When Al containers with 75 massCrFe alloy plasma spray coating of different porosities were tested, results showed that the higher the porosity of the coating, the greater the amount of H2 gas produced. Thus the presence of permeable pores could be easily detected. When Al containers have 75 massCrFe alloy plasma spray coating applied under optimal spray conditions for mass production, the sprayed coatings were relatively dense. Therefore, when the NaOH solution was put into the container, H2 gas was not immediately found. H2 gas began to generate four minutes after the NaOH solution was added. It was confirmed that the amount of H2 gas generated is proportionate to the existence of permeable pores in the sprayed coating and the size of the pores.

Purpose: Precise evaluation of patients with dilated common bile duct (CBD) is extremely important. Computed tomography (CT) shows high sensitivity in detecting dilated CBD as well as the level of obstruction, and is usually used as the first modality. In some cases however, CT can not demonstrate the cause. This study is designed to evaluate the usefulness of endoscopic ultrasonography (EUS) in detecting the cause of CBD dilatation in patients in whom CT could not detect the cause or only revealed equivocal findings. Methods: In this study, we retrospectively analyzed 114 available cases with dilated CBD detected with CT (>9 mm in diameter) between April 2000 and August 2005. Final diagnoses were determined by endoscopic retrograde cholangiopancreatography and surgical exploration, and all cases diagnosed as only dilated CBD were followed up at least 6 months after diagnosed. As CBD stones and biliopancreatic carcinomas (BPC) are determinant factors for the management of patients with CBD dilatation, we evaluate the diagnostic accuracy in detecting these diseases in the following diagnostic processes. First, we evaluated these diseases solely using CT in all cases. When CBD stones were detected, we performed endoscopic treatment without EUS. Second, we performed EUS additionally for all cases and reconsidered the management of patients according to EUS findings. All cases were classified into 3 groups: dilated CBD only, with CBD stones, with BPC. Results: The number of each group was as follows: dilated CBD only, 20 (including post gastrectomy 2, post cholecystectomy 5); with CBD stones, 44; with BPC, 50 (gallbladder carcinoma 2, extra hepatic bile duct carcinoma 24, carcinoma of the ampulla of Vater 8 and pancreatic carcinoma 16). Solely using CT, 10 of 44 cases with CBD stones were misdiagnosed as dilated CBD only and 4 cases with BPC were missed (extra hepatic bile duct carcinoma 2 and ampullary carcinoma 2). So 14 cases were incorrectly diagnosed in total, and the over all accuracy was 87.7% (100/114). EUS was performed in 80 cases, and 10 cases with CBD stones and 4 cases with BPC were correctly diagnosed additionally. So, an additional EUS influenced all 14 misdiagnosed cases. Though CT could reveal equivocal findings in extra hepatic bile duct carcinomas, neither CT nor MRI could detect any findings except for CBD dilatation in non invasive minute ampullary carcinomas. Conclusions: EUS is very useful in detecting the CBD stones and BPC, particularly minute carcinoma of the ampulla of Vater. We recommend EUS in patients in whom CT could not detect any cause or only revealed equivocal findings.

Carcinoma showing thymus-like differentiation (CASTLE)は稀な甲状腺腫瘍であり,その組織学的特徴より,偏平上皮癌との鑑別が問題となる.今回われわれは,甲状腺CASTLEの1例を経験したので報告する.症例は61歳,男性.嗄声および左甲状腺腫瘤にて紹介により当科受診した.甲状腺左葉下極に1.5cm大の硬く,可動性不良な腫瘤を触知し,超音波検査ならびにCT検査では甲状腺癌が疑われた.穿刺吸引細胞診にて,低分化癌との診断を得たため,甲状腺左葉切除術,左保存的頸部郭清術を施行した.腫瘍は病理組織学的にCASTLEと診断され,左気管傍リンパ節に転移を認めた.術後頸部から上縦隔に放射線照射を行い,現在経過観察中である. CASTLEは偏平上皮癌と異なり,予後は良好であるため,本疾患に対するしっかりとした知識を持ち,正確な組織診断を導くことが重要である.

The reception of high-definition television in a mobile environment with the same quality as that achieved at home has been considered to be difficult to achieve. In an attempt to solve this problem, we have developed an adaptive beam steering reception system and evaluated the performance of this new system by both indoor and outdoor experiments involving the reception of high-definition television. The experimental results revealed that the reception performance was significantly improved, such that terrestrial digital television broadcasts can be received in high-speed moving environments, and with the same stability as broadcasts that are received at home in a fixed reception area.

Methods: We retrospectively analyzed 129 cases with dilated CBD detected with CT (>9mm in diameter) between April 2000 and November 2005. Final diagnoses were determined by endoscopic retrograde cholangiopancreatography and surgical exploration, and all cases diagnosed as only dilated CBD were followed up at least 6 months after diagnosed. As CBD stones and biliopancreatic carcinomas (BPC) are determinant factors for the management of patients with CBD dilatation, we evaluate the diagnostic accuracy in detecting these diseases in the following diagnostic processes. First, we picked up these diseases using CT. When CBD stones were detected, we performed endoscopic treatment without EUS. If CT could not detect any cause or only revealed equivocal findings, we performed EUS additionally and reconsidered the management.