1,640 results on '"T. Kurokawa"'
Search Results
102. A surface-normal asymmetric Fabry-Perot modulator at 1.3 μm using the Wannier-Stark effect of an InP/InGaAsP superlattice
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Chikara Amano, T. Kagawa, Osamu Tadanaga, Y. Ito, and T. Kurokawa
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Materials science ,Extinction ratio ,business.industry ,Superlattice ,Gallium arsenide ,symbols.namesake ,chemistry.chemical_compound ,Optics ,Optical modulator ,Stark effect ,chemistry ,symbols ,Insertion loss ,Optoelectronics ,business ,Normal ,Fabry–Pérot interferometer - Abstract
This report describes a 1.3-/spl mu/m surface-normal asymmetric Fabry-Perot modulator using the Wannier-Stark effect of an InP/InGaAsP superlattice. The extinction ratio of 11.6 dB is achieved at 14 V. The insertion loss is 9.9 dB. This is the first time an extinction ratio of over 10 dB has been obtained in surface-normal optical modulators operating at 1.3 /spl mu/m.
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- 2002
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103. VCSEL based smart pixels toward parallel optoelectronic processing systems
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Shinji Matsuo, T. Kurokawa, Hiroyuki Tsuda, and Tatsushi Nakahara
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Very-large-scale integration ,Interconnection ,Parallel processing (DSP implementation) ,Pixel ,Computer science ,business.industry ,Asynchronous Transfer Mode ,Embedded system ,Electronic engineering ,Information system ,business ,Throughput (business) ,Optical switch - Abstract
In the development of advanced information systems, such as parallel processing computers and ATM switching systems, the speed and capacity of board-mountable processors and switches will increase considerably through advances in VLSI technology. VCSEL based smart pixels will be the key devices to interconnect the VLSI chips, with high throughput at both the inter- and intra-board level. The technical issues involved in applying VCSEL based smart pixels to parallel optical interconnection systems are discussed from the viewpoint of their system applications.
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- 2002
- Full Text
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104. The differences of human muscle responses to magnetic nerve stimulation with different coil current waveforms
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A. Hyodo, Makoto Kobayashi, T. Kurokawa, and Shoogo Ueno
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Physics ,Amplitude ,Electromagnetic coil ,Phase (waves) ,Waveform ,Cable theory ,Biomagnetism ,Median nerve ,Excitation ,Biomedical engineering - Abstract
The differences of muscle responses to magnetic nerve stimulation with different coil current waveforms were predicted using cable theory and investigated on the median nerve in a human subject. The mono- and biphasic coil current whose time derivatives were bi- and triphasic with the equivalent 1st phase were compared concerning (1) the excitation threshold, (2) latency and (3) amplitude of compound muscle action potentials (CMAPs). The effect of different coil current directions, proximal or distal, at the intersection of a figure-eight coil were also considered. The combinations of the coil current waveforms and directions were termed MONO-PROX, MONO-DIST, BI-PROX and BI-DIST, where MONO- and BI-corresponded to monophasic and biphasic, and PROX and DIST to proximal and distal, respectively. The results in man were that (1) the excitation threshold was the lowest with BI-DTST, (2) the latencies with MONO-PROX and BI-PROX were equivalent to each other, and (3) the amplitudes of CMAPs with BIPROX and BI-DIST were almost equivalent and larger than with the others. The results in man were generally consistent with predictions, except for the evaluation of "cathode distal" effect.
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- 2002
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105. Selective magnetic stimulation of cervical nerve roots with a figure-eight coil
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S. Ueno, M. Kobayashi, and T. Kurokawa
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Flexor Carpi Ulnaris ,medicine.diagnostic_test ,business.industry ,Deltoid curve ,Stimulation ,Anatomy ,Electromyography ,musculoskeletal system ,Biceps ,body regions ,Electromagnetic coil ,Cervical Nerve ,Medicine ,business ,human activities ,Extensor Digitorum Communis - Abstract
We investigated the possibility of selective stimulation of cervical nerve roots in healthy subjects. The skin surface on the anterior neck was divided into 12 portions of 2 cm/spl times/2 cm each. Each portion was stimulated magnetically with a figure-eight coil. Induced eddy currents were downward. M-waves of the infraspinatus, the deltoid, the biceps brachii, the triceps brachii, the extensor digitorum communis, the flexor carpi ulnaris, the abductor pollicis brevis, and the abductor digiti minimi were monitored. The stimulation of some specific portions evoked M-waves of only the infraspinatus and the deltoid. The infraspinatus and the deltoid are innervated predominantly by the 5th cervical nerve, so these results suggest that the 5th cervical nerve root was selectively stimulated with a figure-eight coil.
- Published
- 2002
- Full Text
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106. [Clinical features and treatment of refractory epilepsy in children]
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T, Kurokawa
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Male ,Epilepsy ,Adolescent ,Valproic Acid ,Infant, Newborn ,Infant ,Isoxazoles ,Clonazepam ,Benzodiazepines ,Treatment Outcome ,Anti-Anxiety Agents ,Zonisamide ,Child, Preschool ,Clobazam ,Humans ,Anticonvulsants ,Female ,Child ,Retrospective Studies - Abstract
Clinical features of refractory epilepsy in children are symptomatic localization-related epilepsy, especially frontal lobe epilepsy, the onset in young age less than 3 years-old, and complication of developmental retardation. The treatments usually start with one drug of choice for specific seizure type. In the idiopathic epilepsy group, valproic acid was effective in 82% of the patients with generalized epilepsy and in 45% of localization-related epilepsy while carbamazepine was effective in 71% and 67%, respectively. However, in the refractory group which did not react to the drugs of choice at the initial treatment and continued to have seizures, no specific drugs were effective. Therefore, various kind of drugs, new or old, should be tried in sequence irrespective of the type of seizures. The seizure control was attained only in 10% (in the cases of CZP), and 17% (CLB) in localization-related epilepsy and in 9% (VPA), 12% (NZP) and 20% (ZNS) in generalized one in the refractory group. Although new drugs developed, the patients with refractory epilepsy do not tend to decrease in frequency and overall management including daily life or surgical therapy is mandatory for the children with refractory epilepsy.
- Published
- 2002
107. Selective occlusion with fibrin glue under fistuloscopy: seven cases of postoperative management for intractable complex fistulas
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M. Sunaga, Satoshi Kondo, S. Okushiba, D. Miyamoto, Y. Shinzato, H. Katoh, M. Kadoya, Y. Kurashima, H. Kitagami, T Kurokawa, J. Ikeda, and T. Ozawa
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medicine.medical_specialty ,Endoscope ,Fistula ,business.industry ,Gastroenterology ,Fistula closure ,Fibrin Tissue Adhesive ,medicine.disease ,Endoscopy, Gastrointestinal ,Postoperative management ,Surgery ,Catheter ,Postoperative Complications ,Occlusion ,Medicine ,Humans ,Tissue Adhesives ,business ,Fibrin glue ,Foreign Bodies ,Digestive System Surgical Procedures - Abstract
Background and Study Aim: Fistula occlusion is not achieved in some fistulas with complex branches. To obtain early fistula closure in such cases, we insert a double-lumen catheter into each fistula branch, with the aid of a guide wire positioned using a small-caliber endoscope, and attempt selective infusion of fibrin glue. Patients and Methods: Following removal of foreign bodies and necrotic granulation, we applied the selective occlusion method under fistuloscopic control to seven intractable external fistulas with complex branches, in which fistula closure had not been obtained by a simple occlusion method (SOM). All the fistulas were complex with more than two branches. Results: Fistula occlusion was obtained within 2 weeks in six of the seven patients, and there has been no sign of recurrence over a follow-up period of 4-59 months (average 29.8 months). Conclusion: Selective occlusion under fistuloscopy is highly effective for intractable external fistulas with complex branches.
- Published
- 2002
108. Optical nonlinear characteristics of a side-injection light-controlled laser diode with a multiple-quantum-well saturable absorption region
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Hidetoshi Iwamura, Hiroyuki Uenohara, K. Nonaka, T. Kurokawa, and Hiroyuki Tsuda
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Materials science ,Bistability ,Laser diode ,business.industry ,Physics::Optics ,Saturable absorption ,Laser ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Semiconductor laser theory ,Optical bistability ,law.invention ,Wavelength ,Optics ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Diode - Abstract
A multiple-quantum-well bistable laser-diode structure in which the input signal is launched into the main laser through an orthogonally configured subwaveguide is proposed. Insensitivity to input light wavelength (28 nm of 3 dB bandwidth) and high isolation of input versus output (over 30 dB) are observed. In addition, reflection of input signal is negligibly small. >
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- 1993
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109. [A case of paraneoplastic cerebellar degeneration with resting tremor]
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T, Kurokawa, T, Taniwaki, K, Arakawa, H, Kikuchi, T, Yao, K, Tanaka, M, Tanaka, T, Yamada, and J, Kira
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DNA-Binding Proteins ,HLA-A Antigens ,Stomach Neoplasms ,Tremor ,HLA-A24 Antigen ,Humans ,Female ,Nerve Tissue Proteins ,Adenocarcinoma ,Autoantigens ,Paraneoplastic Cerebellar Degeneration ,Aged ,Neoplasm Proteins - Abstract
A 65-year-old woman was operated for gastric adenocarcinoma in 1989. Six years later, peritonitis carcinomatosa, swelling of periaortic lymphnodes and high serum CA-125 were discovered. She received chemotherapy with 5-FU and cisplatin resulting in reduction of ascites. In September, 1998, the swelling of left supraclavicular lymphnodes and the elevation of serum CA-125 reappeared. Pathological diagnosis of supraclavicular lymphnodes was adenocarcinoma. Serum CA-125 was normalized by chemotherapy using cisplatin, farumorubicin and endoxan. However, unsteadiness appeared since December 10, 1998 followed by dysarthria and involuntary movement of neck and upper limbs. These symptoms progressed subacutely. The physical examination on admission revealed swelling of left suraclavicular lymphnodes, nystagmus on lateral gaze, saccadic eye movement on smooth pursuit and severe cerebellar ataxia. In addition, resting tremor of 3-4 Hz was observed at right hand, left wrist and neck which tended to increase amplitude by calculation. Similar movements were seen in the left first toe, though the frequency was lower. Brain MRI revealed mild cerebellar atrophy. She was diagnosed as paraneoplastic cerebellar degeneration (PCD) by serum anti Yo antibody and clinical course. The study of HLA showed positive link to A4 without A24. The primary focus of adenocarcinoma in cervical lymphnodes was suggested to be ovary rather than stomach due to the pattern of immunostaining for cytokeratin, CEA and CA125, although no carcinoma was found in ovarium clinically. The feature of this case is a PCD with resting tremor of frequency of 3-4 Hz and negative link to HLA-A24 in Japanese.
- Published
- 2001
110. [Organogenesis in flounder]
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T, Suzuki and T, Kurokawa
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Embryo, Nonmammalian ,Morphogenesis ,Animals ,Flounder ,Digestive System ,Bone and Bones ,Spine ,Skin - Published
- 2001
111. [A case of lung cancer underwent carinal resection with right upper lobectomy and carinal reconstruction with double-barreled anastomosis]
- Author
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Y, Hosokawa, T, Naruke, S, Yamazaki, S, Matsuge, Y, Murakami, K, Satoh, T, Yamakawa, H, Hatakeyama, T, Kan, and T, Kurokawa
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Male ,Fatal Outcome ,Lung Neoplasms ,Treatment Outcome ,Anastomosis, Surgical ,Humans ,Neoplasm Invasiveness ,Tracheal Neoplasms ,Plastic Surgery Procedures ,Pneumonectomy ,Aged - Abstract
A 70-year-old male complaining cough was admitted to our hospital. Bronchoscopic examination revealed a tumor mass which occluded the orifice of the right upper lobe. Chest computed tomographic (CT) scans gave the image of tumor invasion at the carina. The pathological diagnosis of the tumor was squamous cell carcinoma. Operation was accomplished by right posterolateral thoracotomy approach through the fifth rib bed. The carinal resection with right upper lobectomy was followed by a double-barreled anastomosis of the right intermediate trunk and left main-stem bronchus into the carina. The operation was successfully performed and was considered curative. The length of resected airway measured 4.0 cm from tracheal line of resection to the divided the right intermediate trunk. Reinforcement of the anastomosis was not performed in this case. No postoperative complication occurred but mild ischemia of the anastomosis. The patient died of recurrent tumor in a year and 2 months after operation.
- Published
- 2001
112. Initial strength of highpressed extrusion poly-L-lactide screw
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T, Matsushita, K, Nakamura, R, Shiro, H, Takazawa, K, Tsuji, and T, Kurokawa
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Molecular Weight ,Scapula ,Tibia ,Polyesters ,Absorbable Implants ,Bone Screws ,Materials Testing ,Animals ,Swine, Miniature - Abstract
We developed a poly-L-lactide material strengthened by a highpressed extrusion technique. The bending strength of a rod made of that material is higher than that of the same size rods made of poly-L-lactide strengthened by drawing technique, which has been used in clinical cases. The purposes of this study were, first to clarify if the initial strength of extrusion-strengthened poly-L-lactide screws is higher than that of draw-strengthened poly-L-lactide screws, and, secondly to investigate the safe torque for driving the screws in clinical usage. In accordance with AO screw design, five kinds of screws were manufactured. In a pull-out test and a twisting test using a DYRACON blocks, the strength of the highpressed extrusion-strengthened poly-L-lactide material was also higher than that of the draw-strengthened poly-L-lactide material after milling into screws. In the simulation using minipig bones and the 4.5 mm psi cortical screws, when the thickness was below 0.5 mm, between 0.5 and 2 mm or over 3 mm, the break locations were in the cortical bone, the thread of the screw and the under head fillet respectively. In the simulation using minipig bones and the 4.0 mm psi cancellous screws, breakage occurred not on the screws but on the cancellous bone in all screws.
- Published
- 2001
113. A tunable polarization-independent liquid-crystal Fabry-Perot interferometer filter
- Author
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K. Hirabayashi and T. Kurokawa
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Materials science ,business.industry ,Bandwidth (signal processing) ,Physics::Optics ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Interferometry ,Optics ,Liquid crystal ,Liquid crystal tunable filter ,Optoelectronics ,Electrical and Electronic Engineering ,Optical rotation ,Optical filter ,business ,Fabry–Pérot interferometer - Abstract
The authors propose a simple structure for a tunable polarization-independent wavelength-selective filter. This successfully fabricated filter consists of a liquid crystal Fabry-Perot interferometer, a gamma /4 plate, and a mirror. The input light is divided into a transmitted light and a reflected light. The polarization of this reflected light is rotated 90 degrees by the gamma /4 plate and the mirror and then this light is input again into the filter. The bandwidth is 0.48 nm and the tuning range is 50 nm. Fiber-to-fiber loss is approximately 3.9 dB and polarization dependence of the loss is approximately 0.3 dB. >
- Published
- 1992
- Full Text
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114. Photonic memory switch: monolithic integration of a voltage-controlled bistable laser diode and an optical gate
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Hiroyuki Tsuda, Hiroyuki Uenohara, T. Kurokawa, and Hidetoshi Iwamura
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Optical amplifier ,Distributed feedback laser ,Silicon photonics ,Materials science ,Laser diode ,Physics::Instrumentation and Detectors ,business.industry ,Photonic integrated circuit ,Physics::Optics ,Optical modulation amplitude ,Optical switch ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Optics ,law ,Optical transistor ,Optoelectronics ,Electrical and Electronic Engineering ,business - Abstract
An electrically controlled photonic memory switch which monolithically integrates a voltage-controlled bistable laser diode and an optical gate on an InP substrate is fabricated. Time-division optical signal processing such as pulsewidth conversion and a pulse delay control is successfully demonstrated. >
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- 1992
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115. Tunable wavelength-selective liquid crystal filters for 600-channel FDM system
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Hiroyuki Tsuda, T. Kurokawa, and Katsuhiko Hirabayashi
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Materials science ,business.industry ,Optical performance monitoring ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Frequency-division multiplexing ,Wavelength ,Finesse ,Optics ,Filter (video) ,Liquid crystal tunable filter ,Optoelectronics ,Electrical and Electronic Engineering ,Optical filter ,business ,Communication channel - Abstract
A tunable wavelength-selective filter is described that is capable of selecting one channel from over 600 channels at a wavelength of 1.47-1.60 mu m by stacking two liquid-crystal Fabry-Perot interferometers, one with a wide tuning range of 127 nm and a broad bandwidth of 3.4 nm and the other with a very narrow bandwidth of 0.07 nm (9 GHz) and a small tuning range of 12 nm. This filter has an efficient finesse of 1800, and it can select one channel from 600 light sources with 0.2-nm (25-GHz) spacing at a beam optics loss of 5 dB. >
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- 1992
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116. Room temperature pulsed operation of 1.5 mu m GaInAsP/InP vertical-cavity surface-emitting laser
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T. Kurokawa, H. Okamoto, Y. Kohama, T. Kawakami, and T. Tadokoro
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Materials science ,Laser diode ,business.industry ,Double heterostructure ,Distributed Bragg reflector ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Active layer ,Vertical-cavity surface-emitting laser ,Gallium arsenide ,chemistry.chemical_compound ,Distributed Bragg reflector laser ,chemistry ,law ,Optoelectronics ,Metalorganic vapour phase epitaxy ,Electrical and Electronic Engineering ,business - Abstract
Room-temperature pulsed operation of a GaInAsP/InP vertical-cavity surface-emitting laser diode (VCSELD) with an emission wavelength near 1.55 mu m is reported. A double heterostructure with a 34-pair GaInAsP ( lambda /sub g/=1.4 mu m)/InP distributed Bragg reflector (DBR) was grown by metalorganic chemical vapor deposition (MOCVD). The measured reflectivity of the semiconductor DBR is over 97% and threshold current is 260 mA for a 40- mu m phi device with a 0.88- mu m-thick active layer. Threshold current density is as low as 21 kA/cm/sup 2/ at room temperature. >
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- 1992
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117. All-optical bit-pattern matching with photonic switching arrays
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Hiroyuki Tsuda, Matsuo Shinji, Chikara Amano, and T. Kurokawa
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Digital electronics ,Pass transistor logic ,business.industry ,Computer science ,Logic level ,Optical burst switching ,Optical switch ,Atomic and Molecular Physics, and Optics ,Resistor–transistor logic ,Electronic, Optical and Magnetic Materials ,Logic gate ,Electronic engineering ,Optoelectronics ,Electrical and Electronic Engineering ,business ,XOR gate ,Hardware_LOGICDESIGN - Abstract
An all-optical XOR logic circuit is demonstrated using photonic switching arrays that integrate multiple-quantum-well reflection modulators and phototransistors. The switching element performs a Boolean logic A B operation on two binary input light signals that are separately incident on the phototransistor and modulator. The XOR logic function is derived by optical coupling of the switching elements. The device features high contrast that enables high-speed bit pattern matching in parallel. >
- Published
- 1992
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118. 20 dB contrast GaAs/AlGaAs multiple quantum-well nonresonant modulators
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T. Kurokawa, H. Iwamura, Matsuo Shinji, and C. Amano
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Materials science ,Fabrication ,business.industry ,Bandwidth (signal processing) ,Residual carrier ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Gallium arsenide ,Wavelength ,chemistry.chemical_compound ,Optical path ,Optics ,Absorption edge ,chemistry ,Optoelectronics ,Contrast ratio ,Electrical and Electronic Engineering ,business - Abstract
The authors report a successful fabrication of nonresonant GaAs/AlGaAs multiple quantum well (MQW) modulators with a contrast ratio of more than 20 dB and a wide bandwidth of 3 nm. The optical path, as long as 8 mu m, is attained by fabricating a high-purity thick MQW layer with a residual carrier concentration of less than 10/sup 14/ cm/sup -3/ and introducing a high-reflectivity AlAs/AlGaAs quarter-wavelength mirror. The driving wavelengths are located at the absorption edge, resulting in the low-absorption loss. >
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- 1992
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119. Efficacy of hepatic arterial infusion of prostaglandin E1 in the treatment of postoperative acute liver failure--report of a case
- Author
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T, Sato, Y, Asanuma, M, Hashimoto, J, Heianna, T, Kusano, T, Kurokawa, O, Yasui, and K, Koyama
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Male ,Carcinoma, Hepatocellular ,Hepatic Artery ,Postoperative Complications ,Vasodilator Agents ,Liver Neoplasms ,Hepatectomy ,Humans ,Infusions, Intra-Arterial ,Bilirubin ,Alprostadil ,Liver Failure, Acute ,Aged - Abstract
Prostaglandin E1 (PGE1) has received attention for its protective effects against various types of liver damage. However, it is known that approximately 70% of PGE1 is inactivated during a single passage through the lung. Therefore, direct infusion of PGE1 into the liver bloodstream is preferable to intravenous infusion. A 66-year-old man with hepatocellular carcinoma with liver cirrhosis developed postoperative acute liver failure following posterior segmentectomy under hepatic total vascular exclusion exceeding 1 hour. Because his liver function did not recover in spite of plasma exchange starting on postoperative day 8 and intravenous infusion of PGE1, hepatic arterial continuous infusion of PGE1 at a rate of 0.01 microgram/kg/min was carried out for 7 days from postoperative day 17. Immediately after the start of the arterial infusion, the bile flow significantly increased compared to before the arterial infusion, and the serum total bilirubin level decreased thereafter and finally recovered from the hepatic failure. In addition to its highly efficient drug delivery, the hepatic arterial infusion of PGE1 seems to be more advantageous in oxygen delivery to the liver compared with intravenous infusion. In conclusion, the hepatic arterial infusion of PGE1 may be useful in the treatment of acute liver failure.
- Published
- 2000
120. Prostaglandin E(1) continuous hepatic arterial infusion in the treatment of postoperative acute liver failure: basic study on hepatic hemodynamics and clinical application
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T, Sato, Y, Asanuma, T, Kurokawa, T, Kato, O, Yasui, T, Kusano, and K, Koyama
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Male ,Portal Vein ,Swine ,Vasodilator Agents ,Hemodynamics ,Liver Failure, Acute ,Oxygen ,Liver ,Regional Blood Flow ,Animals ,Humans ,Infusions, Intra-Arterial ,Female ,Alprostadil ,Infusions, Intravenous ,Aged - Abstract
In the treatment of severe liver damage, it is of greater advantage to administer prostaglandin E(1) (PGE(1)) directly to the liver compared with systemic intravenous infusion, because of its high inactivation rate in the lungs. In comparison with intraportal infusion, hepatic arterial infusion is more advantageous because of its easier and safer accessibility. This study was designed to prove the superiority of hepatic arterial infusion to intravenous infusion.Changes in hepatic hemodynamics and oxygen delivery accompanying PGE(1) infusion using both methods were investigated in pigs. In addition, continuous hepatic arterial infusion was applied in 3 cases of postoperative acute liver failure, for patients in whom other conventional treatments like plasma exchange failed to improve the functioning of the liver.Hepatic arterial flow increased significantly accompanying hepatic arterial infusion of PGE(1) at a rate of 0.1 microg/kg/min compared with intravenous infusion at the same rate in pigs. Such an increase resulted in elevation of total hepatic blood flow and oxygen delivery to the liver. Correspondingly, bile flow significantly increased accompanying hepatic arterial infusion of PGE(1). Continuous hepatic arterial infusion was applied in 3 cases of postoperative acute liver failure. The infusion was continued for 7-9 days at a rate of 0.01 microg/kg/min without any complications through heparin-coated catheters inserted via the femoral artery. Significant increase in bile flow was observed in 2 cases in whom bile was collected, serum total bilirubin began to decrease in all these 3 cases, and the patients recovered from acute liver failure.Hepatic arterial infusion of PGE(1) is very useful and effective in the treatment of acute liver failure.
- Published
- 2000
121. A novel mutation of KCNQ3 (c.925T--C) in a Japanese family with benign familial neonatal convulsions
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S, Hirose, F, Zenri, H, Akiyoshi, G, Fukuma, H, Iwata, T, Inoue, M, Yonetani, M, Tsutsumi, H, Muranaka, T, Kurokawa, T, Hanai, K, Wada, S, Kaneko, and A, Mitsudome
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Male ,Potassium Channels ,Base Sequence ,Sequence Homology, Amino Acid ,Molecular Sequence Data ,Chromosome Mapping ,Exons ,Polymerase Chain Reaction ,KCNQ3 Potassium Channel ,Pedigree ,Japan ,Potassium Channels, Voltage-Gated ,Seizures ,Humans ,Point Mutation ,Female ,Amino Acid Sequence ,Sequence Alignment - Abstract
At present, only one mutation of KCNQ3, a KCNQ potassium channel gene, has been identified as a cause of benign familial neonatal convulsions type 2 (BFNC2). We found a T to C substitution (c.925T-C) on one allele of affected individuals in a Japanese family with BFNC but not on 200 alleles from healthy subjects. c.925T--C replaced Trp309, a conserved residue within the P-loop of the KCNQ potassium channel family that holds the channel pore open, with an Arg (W309R). We report c.925T--C as the second mutation of KCNQ3 responsible for BFNC2.
- Published
- 2000
122. Continuous infusion of prostaglandin E1 via the superior mesenteric artery can prevent hepatic injury in hepatic artery interruption through passive portal oxygenation
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T, Sato, T, Kato, T, Kurokawa, O, Yasui, N, Hiroshi, H, Miyazawa, Y, Asanuma, and K, Koyama
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L-Lactate Dehydrogenase ,Portal Vein ,Swine ,Hemodynamics ,Hepatic Artery ,Oxygen Consumption ,Liver ,Ischemia ,Mesenteric Artery, Superior ,Animals ,Infusions, Intra-Arterial ,Aspartate Aminotransferases ,Alprostadil ,Liver Circulation - Abstract
Hepatic artery interruption (HAI) causes severe ischemic liver damage, especially following hepatopancreatobiliary surgery. In order to inhibit a decrease in oxygen delivery after HAI, continuous infusion of PGE1 via the superior mesenteric artery (SMA) was administered in pigs and changes in hepatic blood flow and oxygen delivery were investigated. Furthermore, its effectiveness in the prevention of liver injury was evaluated by histology and serum enzyme levels.Animals were subjected to HAI without PGE1 infusion (control group n=6) and to continuous infusion of PGE1 (0.02 microg/kg/min) into the SMA (PGE1 group n=6).PGE1 infusion via the SMA not only increased the portal blood flow but also elevated the oxygen content of the portal blood. The reduction in oxygen delivery to the liver was 50% in the control group, and only 13% in the PGE1 group. Serum aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) levels 24 h after HAI in the control group were 3415+/-1283 IU/L and 9839+/-2959 respectively while in the PGE1 group they were 939+/-426 IU/L and 5510+/-1545 IU/L respectively. Histological examination showed massive necrosis in the control group at 72 h but only focal liver cell necrosis in the PGE1 group. Based on this finding and the fact that this treatment can be performed easily and safely, continuous infusion of PGE1 via the SMA may be a useful intervention to prevent severe liver damage after hepatic artery interruption.
- Published
- 2000
123. [An adult case of recurrent myelopathy presenting with monoplegia following asthmatic attacks]
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T, Kurokawa, T, Taniwaki, K, Arakawa, T, Yamada, and J, Kira
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Adult ,Recurrence ,Status Asthmaticus ,Humans ,Female ,Hemiplegia ,Syndrome ,Spinal Cord Diseases - Abstract
A 22-year-old woman noticed an acute onset muscle weakness in her right leg after an asthmatic attack. A neurological examination showed moderate muscle weakness from the right iliopsoas muscle to the toe muscles, a decreased deep tendon reflex in her right lower limb and mild hypesthesia in her right L2-S1 segments. Needle EMG revealed fibrillation potentials in the right gastrocnemius muscle and a positive sharp wave in the right anterior tibialis muscle. The findings of motor nerve conduction studies and sensory nerve conduction studies were normal. The lesion was considered to be located at the posterior horns, as well as at the anterior horns at the L2-S1 levels and also at their roots on the right side. The anterior horn cells appeared to be the most severely affected. Polio-, echo-, entero- and coxsackie-virus antibody titers showed no significant changes on the 36th and 64th days of the disease. The serum IgE level was elevated and mite antigen-specific IgE was strongly positive. MRI revealed no abnormalities in either the thoracic or lumbar spinal cord. Although the sensory disturbance did rapidly improve after corticosteroid therapy, no improvement was seen in her muscle weakness which thus resulted in the atrophy of the affected muscle. While undergoing the corticosteroid therapy, she suffered another asthmatic attack. Nine days after the second attack, she further developed weakness in her right deltoid, biceps brachii, triceps brachii, wrist extensor, wrist flexor, digits extensor and digits flexor muscles with hyperreflexia in her left upper limb. Cervical MRI disclosed a high intensity area at the C3-6 level on the T2-weighted images and also a gadolinium enhancement of the lesion. Since monoplegia had appeared twice previously after bronchial asthma attacks in this case, Hopkins syndrome was suggested. Hopkins syndrome has so far been exclusively reported in children, and no recurrent cases have ever been reported with this condition. This is therefore considered to be the first case of Hopkins syndrome occurring in an adult and also demonstrating recurrence.
- Published
- 2000
124. Molecular and functional characteristics of APJ. Tissue distribution of mRNA and interaction with the endogenous ligand apelin
- Author
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M, Hosoya, Y, Kawamata, S, Fukusumi, R, Fujii, Y, Habata, S, Hinuma, C, Kitada, S, Honda, T, Kurokawa, H, Onda, O, Nishimura, and M, Fujino
- Subjects
Male ,Molecular Sequence Data ,CHO Cells ,Ligands ,Transfection ,Receptors, G-Protein-Coupled ,Pregnancy ,Cricetinae ,Animals ,Humans ,Amino Acid Sequence ,RNA, Messenger ,Virulence Factors, Bordetella ,Apelin Receptors ,Sequence Homology, Amino Acid ,Receptors, Dopamine D2 ,Reverse Transcriptase Polymerase Chain Reaction ,Cell Membrane ,Brain ,Recombinant Proteins ,Rats ,Kinetics ,Organ Specificity ,Apelin ,Intercellular Signaling Peptides and Proteins ,Cattle ,Female ,Carrier Proteins ,Sequence Alignment - Abstract
We have recently identified apelin as the endogenous ligand for human APJ. In rats, the highest expression of APJ mRNA was detected in the lung, suggesting that APJ and its ligand play an important role in the pulmonary system. When apelin-36 and its pyroglutamylated C-terminal peptide, [Glu(65)]apelin-13, were compared in microphysiometric analyses, the elevation of extracellular acidification induced in cells expressing APJ by [Glu(65)]apelin-13 was transient, whereas that by apelin-36 was sustained. These responses were almost completely inhibited by a specific inhibitor for G(i) or that for Na(+)/H(+) exchanger. (125)I -Labeled [Glu(65)]apelin-13 analogue specifically bound to APJ with a high affinity, and [Glu(65)]apelin-13 was more potent than apelin-36 in competitive inhibition assays. Because pretreatment with apelin-36 but not [Glu(65)]apelin-13 drastically reduced the binding of the labeled apelin to APJ, the different patterns of acidification induced by these two peptides appeared to reflect their dissociation rather than association with APJ. Apelin elicited the migration of APJ-expressing cells, and [Glu(65)]apelin-13 was more potent than apelin-36 in this activity. Heterogeneous molecular forms of apelin corresponding to apelin-36 and [Glu(65)]apelin-13 were produced in bovine colostrum. Apelin-36 and [Glu(65)]apelin-13 might have different functions in vivo and in vitro.
- Published
- 2000
125. Breast cancer cells express cathepsins B and L but not cathepsins K or H
- Author
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O, Ishibashi, Y, Mori, T, Kurokawa, and M, Kumegawa
- Subjects
Cathepsin H ,Reverse Transcriptase Polymerase Chain Reaction ,Cathepsin L ,Blotting, Western ,Cathepsin K ,Osteoclasts ,Bone Neoplasms ,Breast Neoplasms ,Osteolysis ,Adenocarcinoma ,Blotting, Northern ,Cathepsins ,Cathepsin B ,Neoplasm Proteins ,Cysteine Endopeptidases ,Enzyme Induction ,Endopeptidases ,Tumor Cells, Cultured ,Humans ,Female ,RNA, Messenger ,RNA, Neoplasm ,Bone Resorption ,Lysosomes - Abstract
Lysosomal cysteine proteinases (cathepsins) are considered to play a role in bone degradation mediated by metastatic breast cancers. To evaluate which cathepsin contributes to the osteolysis, we quantitatively determined the expression levels of four cathepsins in two breast cancer cell lines, MCF-7 and MDA-MB-231, by competitive RT-PCR. Cathepsin K, which is the most abundant cathepsin in osteoclasts, was not detected in either cell lines. We also failed to detect cathepsin H mRNA. By contrast, we found significant expression of cathepsins B and L in both cell lines. By Northern blot analysis cathepsin B mRNA was detected in a single form in these cells, whereas osteoclasts contained multiple forms of the mRNA. Cathepsin B protein was also detected by Western blotting as a single immunoreactive band corresponding to its mature enzyme. These findings suggest that osteolysis associated with metastatic breast cancers takes place in a different way from osteoclast-mediated bone resorption.
- Published
- 2000
126. Molecular evaluation of bone marrow involvement in peripheral T-cell lymphoma with a PCR-mediated RNase protection assay
- Author
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A, Hanamura, T, Kinoshita, T, Kurokawa, H, Nagai, T, Murate, T, Nagasaka, H, Mori, and H, Saito
- Subjects
Adult ,Male ,Cell Culture Techniques ,Genes, T-Cell Receptor gamma ,Lymphoma, T-Cell, Peripheral ,Middle Aged ,Polymerase Chain Reaction ,Ribonucleases ,Bone Marrow ,Tumor Cells, Cultured ,Humans ,Female ,Lymph Nodes ,Aged - Abstract
Bone marrow (BM) involvement in peripheral T-cell lymphoma was assessed by polymerase chain reaction (PCR)-mediated RNase protection assay. The sensitivity of this assay was approximately 10(-4) to 10(-5). In 16 of 30 patients (53.3%) with peripheral T-cell malignancies, consensus primers for the T-cell receptor (TCR)-gamma gene amplified the rearranged V(N)J region. Using the PCR products of diagnostic lymph nodes of the patients as probes, we analyzed the BM involvement of lymphoma cells in eight patients: four with peripheral T-cell lymphoma, unspecified; two with adult T-cell leukemia/lymphoma; and two with angioimmunoblastic T-cell lymphoma. BM involvement was detected by PCR-mediated RNase protection assay in four patients from BM smear and/or histo-pathological examination of clotted BM. Moreover, in two of four patients in whom BM involvement was not evident from morphological examination, BM involvement was detected by PCR-mediated RNase protection assay. Our results indicate that the PCR-mediated RNase protection assay targeting the TCR-gamma gene is useful in detecting minimal residual disease in about half of all T-cell lymphoma cases. In addition, in some patients with peripheral T-cell lymphoma, morphologically unproven BM involvement was found using the method.
- Published
- 2000
127. Effects of nafamostat mesilate, a synthetic protease inhibitor, on immunity and coagulation after hepatic resection
- Author
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H, Inagaki, T, Nonami, T, Kurokawa, Y, Takeuchi, N, Okuda, A, Nakao, and J, Sakamoto
- Subjects
Male ,alpha-2-Antiplasmin ,Serine Proteinase Inhibitors ,Fibrinolysis ,T-Lymphocytes ,Antithrombin III ,Liver Neoplasms ,CD4-CD8 Ratio ,Immunity ,Middle Aged ,Guanidines ,Antifibrinolytic Agents ,Benzamidines ,Killer Cells, Natural ,Hepatectomy ,Humans ,Female ,Fibrinolysin ,Infusions, Intravenous ,Killer Cells, Lymphokine-Activated ,Blood Coagulation ,Peptide Hydrolases ,Retrospective Studies - Abstract
Effects of nafamostat mesilate (NM), a serine protease inhibitor, on both coagulation-fibrinolysis activity and post-operative changes in immune responsiveness were investigated in a clinical study of 20 patients who underwent an extensive hepatic resection.The patients were randomly allocated into 2 groups of 10 patients each: The NM group was administered nafamostat mesilate (2 mg/kg/day) during and after the operation for 7 days. The control group received standard post-operative intensive therapies except NM.The post-operative increase in coagulation in the control group was significantly suppressed in the NM-treated group on post-operative day (POD) 7. Natural killer (NK) activity, which was impaired after the operation, was recovered in the NM group on POD 7 and was significantly higher than in the control group. Helper/suppressor ratios of T lymphocytes were significantly increased post-operatively by the administration of NM.These results demonstrate that NM controls the enhanced coagulation which occur in patients with extensive hepatic resection. It is also suggested that NM promptly restores the impaired immune responsiveness and decreases the risk of post-operative complications, as well as the risk of recurrence in patients with hepatic tumors.
- Published
- 2000
128. Image encipherment based on optical parallel processing using spatial light modulators
- Author
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T. Kurokawa, Sakai Yoshihisa, and S. Fukushima
- Subjects
Speedup ,Computer science ,Optical transistor ,Optical communication ,Electronic engineering ,Optical computing ,Image processing ,Electrical and Electronic Engineering ,Optical modulation amplitude ,Atomic and Molecular Physics, and Optics ,Decoding methods ,Electronic, Optical and Magnetic Materials ,Coding (social sciences) - Abstract
All-optical image coding and decoding are demonstrated for image encipherment communication. The optical parallel coder consists of two cascaded bipolar-operational spatial light modulators (BSLMs) that can select positive and negative image readout in response to the electrical pulse polarity. Coding is performed by an exclusive-OR operation, to a key and an input image, while decoding is the same operation performed to a decoding key and an enciphered image. Coding was performed within a 8-ms duration, which is even faster than the conventional television system. Increasing the voltages to the BSLMs two-fold or three-fold and shortening the pulse durations speed up the processing rate. >
- Published
- 1991
- Full Text
- View/download PDF
129. Polarization-independent tunable wavelength-selective filter using a liquid crystal
- Author
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Y. Ohiso, T. Kurokawa, and K. Hirabayashi
- Subjects
Materials science ,business.industry ,Physics::Optics ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Optics ,Band-pass filter ,Liquid crystal ,Physics::Accelerator Physics ,Optoelectronics ,Light beam ,Prism ,Electrical and Electronic Engineering ,Optical rotation ,business ,Optical filter ,Beam (structure) - Abstract
The authors demonstrate a polarization-independent liquid crystal Fabry-Perot interferometer. An input light beam was split into two orthogonal polarized beams by a polarization beam splitter and prism and the polarization of one beam was rotated 90 degrees by a half-wave plate. These two beams were filtered through different points of the filter and recombined. Two transmission peaks corresponding to these beams usually appeared. However, there were some regions where the two beams were superimposed. At these regions, the filter had a tuning range of over 50 nm with a band pass of 0.4-0.5 nm and a low fiber-to-fiber loss of 3 dB. At the regions where two peaks appeared, the two peaks could be superimposed by applying different voltages. >
- Published
- 1991
- Full Text
- View/download PDF
130. New structure of tunable wavelength-selective filters with a liquid crystal for FDM systems
- Author
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Hiroyuki Tsuda, Katsuhiko Hirabayashi, and T. Kurokawa
- Subjects
Materials science ,business.industry ,Bandwidth (signal processing) ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Frequency-division multiplexing ,Wavelength ,Full width at half maximum ,Optics ,Liquid crystal ,Astronomical interferometer ,Liquid crystal tunable filter ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Optical filter - Abstract
To decrease the bandwidth of liquid-crystal Fabry-Perot interferometers (LC-FPIs), LC-FPIs having a double-layer cavity were devised where the intracavity consists of the LC layer and a glass layer. This filter is shown to have a very narrow bandwidth (full width at half maximum >
- Published
- 1991
- Full Text
- View/download PDF
131. Novel photonic switch arrays consisting of vertically integrated multiple-quantum-well reflection modulators and phototransistors: excitation absorptive reflection switch
- Author
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Matsuo Shinji, T. Kurokawa, and C. Amano
- Subjects
Materials science ,business.industry ,Exciton ,Physics::Optics ,Heterojunction ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Optical switch ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Gallium arsenide ,chemistry.chemical_compound ,Optics ,chemistry ,Reflection (physics) ,Optoelectronics ,Contrast ratio ,Electrical and Electronic Engineering ,Photonics ,business ,Quantum well - Abstract
The authors report a novel photonic switch array, the exciton absorptive reflection switch (EARS), which operates as an optical three-terminal switch with a high contrast ratio and optical gain. The device consists of vertically integrated GaAs/AlGaAs multiple-quantum-well modulators and GaAs heterojunction phototransistors, which are optically isolated and electrically connected in series with distributed Bragg reflectors. 8*8 arrays of EARS with a contrast ratio of more than 20 dB and a high optical gain were demonstrated. >
- Published
- 1991
- Full Text
- View/download PDF
132. Optical parallel processor for binary images with cascaded bipolar-operational spatial light modulators
- Author
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T. Kurokawa and S. Fukushima
- Subjects
Imagination ,Computer science ,business.industry ,Binary image ,media_common.quotation_subject ,Digital data ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Optical computing ,Image processing ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Search engine ,law ,Electronic engineering ,Electrical and Electronic Engineering ,business ,Digital signal processing ,Beam splitter ,media_common - Abstract
An optical parallel processor is implemented for binary images with three cascaded bipolar-operational spatial light modulators that support the reversible readout and storage capabilities of binary images. All 16 Boolean operations are performed in real time according to the electric pulses. The programmable processor will serve for both optical digital signal processing and real-time image processing. >
- Published
- 1991
- Full Text
- View/download PDF
133. Tunable light source using a liquid-crystal Fabry-Perot interferometer
- Author
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Hiroyuki Tsuda, Katsuhiko Hirabayashi, Y. Tohmori, and T. Kurokawa
- Subjects
Range (particle radiation) ,Materials science ,Laser diode ,business.industry ,Physics::Optics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Interferometry ,Light source ,Optics ,Liquid crystal ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Fabry–Pérot interferometer ,Laser beams ,Voltage - Abstract
A tunable light source with a liquid-crystal Fabry-Perot interferometer (LC-FPI) tuning element that emits a laser beam with a tuning range of 41 nm has been constructed. Incorporating a multiple quantum well (MQW) laser diode with a phase control (PC) section enables the selection of almost all external modes. Stable single-mode emission is obtained for the region, except where the slope of the lasing wavelength versus applied voltage to the liquid crystal is quite large. >
- Published
- 1991
- Full Text
- View/download PDF
134. Operation characteristics of three-terminal hybrid structure with multiple-quantum-well reflection modulator and heterojunction phototransistor
- Author
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T. Kurokawa, C. Amano, and Matsuo Shinji
- Subjects
Materials science ,business.industry ,Optical computing ,Optical modulation amplitude ,Optical switch ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Optics ,Logic gate ,Optical transistor ,Optoelectronics ,Contrast ratio ,Electrical and Electronic Engineering ,Photonics ,business ,Quantum well - Abstract
The operation characteristics of optically controlled three-terminal gates consisting of a multiple quantum well (MQW) reflection modulator and a heterojunction phototransistor (HPT) are discussed. It is found that the photonic gates, in which both components are electrically connected in series and parallel, operate as NOR and OR gates, respectively. The photonic gates exhibit a high contrast ratio of more than 20 dB as well as optical gain. >
- Published
- 1991
- Full Text
- View/download PDF
135. Narrow-band tunable wavelength-selective filters of Fabry-Perot interferometers with a liquid crystal intracavity
- Author
-
Katsuhiko Hirabayashi, Hiroyuki Tsuda, and T. Kurokawa
- Subjects
Materials science ,business.industry ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Finesse ,Wavelength ,Full width at half maximum ,Optics ,Liquid crystal ,Astronomical interferometer ,Liquid crystal tunable filter ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Optical filter ,Fabry–Pérot interferometer - Abstract
Optimum designs for tunable wavelength-selective filters of Fabry-Perot interferometers with a liquid crystal intracavity are described. A nematic liquid crystal with index numbers 1.5506 and 1.4771 was used. Methods of aligning liquid crystal molecules were studied. The filters provide high finesse (150-410), high transmittance (20-70%), narrow transmission peak (FWHM: 0.17-0.35 nm), and a large shift (>50 nm) at a wavelength of 1.5 mu m. These filters have a potential to select over 50 channels in WDM. >
- Published
- 1991
- Full Text
- View/download PDF
136. The effect of intraportal administration of prostaglandin E1 on liver blood flow and liver function
- Author
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H, Inagaki, T, Kurokawa, T, Nonami, T, Miwa, A, Nakao, and H, Takagi
- Subjects
Adult ,Male ,Carcinoma, Hepatocellular ,Portal Vein ,Vasodilator Agents ,Liver Neoplasms ,Middle Aged ,Portal System ,Postoperative Complications ,Liver ,Liver Function Tests ,Hepatectomy ,Humans ,Female ,Alprostadil ,Ultrasonography, Doppler, Color ,Infusions, Intravenous ,Blood Flow Velocity ,Aged - Abstract
Prostaglandin E1 (PGE1) exerts a hepatic cytoprotective action directly and indirectly through enhancing hepatic blood flow. Although PGE1 is usually administered systemically, more than 60% of PGE1 is inactivated during only a single passage through the lung. By administering PGE1 intraportally the intrahepatic level of this drug can be increased effectively and liver dysfunction might be prevented. In this study, the effect of intraportal administration of PGE1 to patients who underwent hepatectomy was estimated.Twenty patients who underwent hepatectomy from January 1995 to December 1996 were divided into 2 groups, i.e., a PGE1 group (n=8) and a control group (n=12). Laboratory data and hepatic portal blood flow were examined before and after hepatectomy. In the PGE 1 group, PGE 1 was continuously infused at a dose of 120 microg/day for 5 days through a catheter inserted into the portal vein via the gastroepiploic vein.There was no difference in the post-operative change in aspartate aminotransferase (AST) or alanine aminotransferase (ALT) between the 2 groups. Elevation of total bilirubin was more significantly suppressed in the PG group than in the control group. Total branched-chain amino acids and the tyrosine ratio reached their peak on the 5th post-operative day (POD) and were significantly higher in the PG group. Post-operative portal blood flow was significantly increased in the PG group.Our results indicated that continuous intraportal administration of small doses of PGE1 is effective for the protection of hepatic function after hepatectomy.
- Published
- 1999
137. BDNF diminishes caspase-2 but not c-Jun immunoreactivity of neurons in retinal ganglion cell layer after transient ischemia
- Author
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T, Kurokawa, N, Katai, H, Shibuki, S, Kuroiwa, Y, Kurimoto, C, Nakayama, and N, Yoshimura
- Subjects
Retinal Ganglion Cells ,Cell Survival ,Proto-Oncogene Proteins c-jun ,Brain-Derived Neurotrophic Factor ,Caspase 2 ,Retinal Vessels ,Apoptosis ,Cell Count ,Recombinant Proteins ,Rats ,Rats, Sprague-Dawley ,Caspases ,Reperfusion Injury ,In Situ Nick-End Labeling ,Animals ,Female ,Neurons, Afferent ,Fluorescent Antibody Technique, Indirect - Abstract
Retinal ischemia-reperfusion injury induces apoptosis of retinal neurons. The purpose of this study was to examine the association of c-Jun, caspase-1, -2, and -3 immunoreactivities and neuronal apoptosis in the retinal ganglion cell layer (GCL) and to study the effects of intravitreal brain-derived neurotrophic factor (BDNF) on the expression of these gene products in a rat model of retinal ischemia-reperfusion injury.After 60 minutes of ischemia, eyes were enucleated after 3, 6, 12, 24, and 168 hours of reperfusion. The numbers of c-Jun-, caspase-1-, caspase-2-, caspase-3, and TdT-dUTP terminal nick-end labeling (TUNEL)-positive cells in the GCL were counted. Recombinant human BDNF (5 microg) or vehicle was injected intravitreally immediately after reperfusion. At 6, 24, and 168 hours, the numbers of immunoreactive cells in BDNF- and vehicle-treated groups were compared.Expression of c-Jun and caspase-2 was found in dying cells in flat-mounted retinas. The numbers of caspase-1- and caspase-3-positive cells were fewer than c-Jun- or caspase-2-positive cells. Cell death in the retinal GCL was suppressed by an intravitreal injection of BDNF. The numbers of TUNEL- and caspase-2-positive cells were lower in the BDNF-treated group at 6 hours after reperfusion (P0.01). The number of c-Jun-positive cells in the treated retinas was not altered by the treatment.Expression of c-Jun and caspase-2 is associated with neuronal cell apoptosis in the GCL. Suppression of caspase-2 expression may explain the neuroprotective effects of BDNF.
- Published
- 1999
138. Hoxb-5 is expressed in gill arch 5 during pharyngeal arch development of flounder Paralichthys olivaceus embryos
- Author
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T, Suzuki, A S, Srivastava, and T, Kurokawa
- Subjects
Gills ,Homeodomain Proteins ,Branchial Region ,Genes, Homeobox ,Animals ,Gene Expression Regulation, Developmental ,Flounder ,Zebrafish Proteins ,In Situ Hybridization - Abstract
Hox genes are expressed in domains with clear anterior borders exhibiting 3'--5' hierarchy in hindbrain and in the pharyngeal area commonly in vertebrate embryos. Teleost embryos form seven pharyngeal arches, the mandibular arch, hyoid arch and the gill arches 1-5. We previously reported that, in Japanese flounder (Paralichthys olivaceus) embryos, Hoxd-4 is expressed from rhombomere 7 to the spinal cord in the central nervous system and at gill arches 2-5. At present, the hierarchy of Hox genes at gill arches 3-5 of teleost fish is unclear. Here, we investigated the expression domains of Hoxb-5 in the flounder embryo by whole-mount in situ hybridization to gain insight into the Hox code at gill arches. The initial signal indicating Hoxb-5 expression was identified in the spinal cord at hatching, corresponding with the prim-5 stage of zebrafish. Then, intense signals were detected from the anterior part of the spinal cord and from the posterior part of the pharyngeal area at 36 h after hatching. By serially sectioning the hybridized embryos, it was found that signal in the pharyngeal area came from the most posterior gill arch 5. Therefore, it is speculated that Hoxb-5 functions in regional identification of gill arch 5 in this teleost.
- Published
- 1999
139. The therapeutic effect of proton pump inhibitors on Helicobacter pylori-positive gastric ulcers
- Author
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T. Kurokawa, Takashi Joh, Kenji Tsuchida, Y. Yokoyama, Makoto Itoh, M Sasakii, and Kyoji Seno
- Subjects
Adult ,Male ,medicine.medical_specialty ,Patient Dropouts ,medicine.drug_class ,Spirillaceae ,Lansoprazole ,Pharmaceutical Science ,Proton-pump inhibitor ,Ranitidine ,Gastroenterology ,2-Pyridinylmethylsulfinylbenzimidazoles ,Helicobacter Infections ,Internal medicine ,medicine ,Humans ,Helicobacter ,Stomach Ulcer ,Risk factor ,Nizatidine ,Aged ,Pharmacology ,biology ,Helicobacter pylori ,business.industry ,Stomach ,Therapeutic effect ,Proton Pump Inhibitors ,Middle Aged ,biology.organism_classification ,Anti-Ulcer Agents ,Famotidine ,digestive system diseases ,medicine.anatomical_structure ,Treatment Outcome ,Histamine H2 Antagonists ,Multivariate Analysis ,Female ,business ,Omeprazole ,medicine.drug - Abstract
The aim of the present study was to elucidate the risk factors that could delay gastric ulcer healing when either a proton pump inhibitor or an H2-receptor antagonist is used for gastric ulcer treatment. Endoscopically-diagnosed gastric ulcer patients (216 men and 96 women, mean age: 57 ± 13 years) were investigated. All patients were consecutively recruited and randomly assigned to receive H2-receptor antagonist (n = 196) or proton pump inhibitor (n = 116) treatment for eight weeks. Chi-squared tests and multivariate analysis to determine factors influencing ulcer healing were used to analyse the patients profiles, endoscopic findings, and Helicobacter pylori-infection status. In the H2-receptor antagonist group, the most important risk factor was a large ulcer size (> 2 cm diam.), followed by a linear shape of the ulcer, undermining tendency of ulcer, previous history of gastric ulcer, and H. pylori infection. In the proton pump inhibitor group, linear shape of the ulcer was the only significant risk factor for slow ulcer healing; other factors, including H. pylori infection, were insignificant. These results indicate that ulcer morphology may be the most important information for predicting ulcer healing, and that H. pylori infection does not delay gastric ulcer healing when proton pump inhibitor treatment is used.
- Published
- 1999
140. [A case of familial adenomatous polyposis with mesenteric fibromatosis]
- Author
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K, Abe, S, Tanaka, S, Suemaru, H, Kawamura, M, Kurome, Y, Miyake, T, Kumagi, M, Oumoto, M, Tamaru, M, Umeda, T, Kurokawa, and R, Haba
- Subjects
Adult ,Male ,Neoplasms, Multiple Primary ,Adenomatous Polyposis Coli ,Colonic Neoplasms ,Humans ,Fibromatosis, Abdominal ,Mesentery ,Peritoneal Neoplasms - Published
- 1999
141. Blood loss and ICG clearance as best prognostic markers of post-hepatectomy liver failure
- Author
-
T, Nonami, A, Nakao, T, Kurokawa, H, Inagaki, Y, Matsushita, J, Sakamoto, and H, Takagi
- Subjects
Adult ,Aged, 80 and over ,Indocyanine Green ,Male ,Carcinoma, Hepatocellular ,Liver Neoplasms ,Blood Loss, Surgical ,Middle Aged ,Prognosis ,Survival Rate ,Postoperative Complications ,Hepatectomy ,Humans ,Female ,Liver Failure ,Aged - Abstract
Hepatic failure after hepatic resection is a lethal complication. Various factors affecting the occurrence of hepatic failure were examined.The subjects were 315 patients who underwent hepatic resection for hepatocellular carcinoma during the 11-year period between 1985 and 1995. Univariate analyses of 14 variables were performed among living and dead patients after hepatic resection. With the significant prognostic variables obtained in the multivariate analysis, the predicted probability of death (PPD) was calculated for each patient.There were 291 survivors and 24 patients with post-operative liver failure. Among the factors showing statistical or near significance in the univariate analysis, KICG and blood loss were disclosed to be factors independently correlating with survival. PPD was calculated for each patient according to the following equation: PPD = 1/Exp(1.6766 - 0.0004394 x blood loss + 16.69 x KICG) + 1. Assessing the goodness-of-fit model by Hosmer-Lemeshow test indicated the model seemed to fit quite well.Minimizing the blood loss during hepatic resection is important to avoid post-operative liver failure. Careful hemostatic procedure is necessary for patients with unexpected massive blood loss during hepatic resection so as to prevent post-operative bleeding.
- Published
- 1999
142. [In relation to present status of children (adults) with severe motor and intellectual disabilities]
- Author
-
T, Kurokawa
- Subjects
Adult ,Movement Disorders ,Intellectual Disability ,Humans ,Multiple Birth Offspring ,Child - Published
- 1999
143. The role of extended radical procedures in advanced gallbladder cancer
- Author
-
T, Kurokawa, T, Nonami, A, Nakao, N, Okuda, A, Harada, and H, Takagi
- Subjects
Adult ,Aged, 80 and over ,Male ,Middle Aged ,Survival Rate ,Lymphatic Metastasis ,Hepatectomy ,Humans ,Lymph Node Excision ,Cholecystectomy ,Female ,Gallbladder Neoplasms ,Aged ,Follow-Up Studies ,Neoplasm Staging - Abstract
Owing to recent advances in diagnostic and surgical techniques, aggressive operations for advanced gallbladder carcinoma are becoming more safe. However, the role of a radical operation in terms of long-term survival remains controversial. In this study, we reviewed our experience with gallbladder carcinoma and the literature to clarify the present status of this strategy.So far in our department, we have treated 88 patients with gallbladder carcinoma and resection was performed in 46 of them. Stages, operative procedures, results of pathologic examinations and the outcome of the resected cases were reviewed.Only 6 of the 46 patients belonged to the early stage (stage I and II in Nevin staging system, or stage I in TNM staging system) and had a good prognosis. Cholecystectomy with regional lymph node resection was performed in 13 patients. In other patients, more radical procedures including adjacent organ resection were performed according to the spread of the cancer. Major hepatectomy and pancreatoduodenectomy were additionally performed on 8 and 6 patients, respectively. Portal vein resection and reconstruction were performed in 3 patients. The survival rate in advanced cases was poor, but we had 5 long-term (more than 4 years) survivors among 40 patients in the advanced stages. Moreover, one patient undergoing a combination of extended right lobectomy of the liver, pancreato-duodenectomy with portal vein resection and extended node resection of the paraaortic nodes, survived for 3 years and 3 months until she died of another disease.The prognosis is still not good in patients with advanced gallbladder carcinoma even if radical resection is performed. However, a number of our patients who underwent radical surgery survived a long time.
- Published
- 1999
144. [Acute myelocytic leukemia and plasmacytoma secondary to chemotherapy and radiotherapy in a long-term survivor of small cell lung cancer]
- Author
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K, Fukunishi, T, Kurokawa, A, Takeshita, K, Nariyama, Y, Egashira, Y, Shibayama, K, Kamei, T, Oue, S, Hashimoto, Y, Fukuda, K Y, Min, and N, Ohsawa
- Subjects
Male ,Lung Neoplasms ,Esophageal Neoplasms ,Radiotherapy ,Survival ,Neoplasms, Second Primary ,Combined Modality Therapy ,Neoplasms, Multiple Primary ,Leukemia, Myeloid, Acute ,Antineoplastic Combined Chemotherapy Protocols ,Carcinoma, Squamous Cell ,Humans ,Carcinoma, Small Cell ,Aged ,Plasmacytoma - Abstract
A 68-year-old man was given a diagnosis of lung cancer of the right upper lobe (small cell carcinoma, T 4 N 2 M 0, stage IIIB) in February 1991. The tumor diminished after chemotherapy and radiotherapy. In February 1992, a partial resection of the lower lobe of the right lung was performed because of the appearance of a metastatic tumor. In September 1994, squamous cell carcinoma developed in the lower part of the esophagus, but disappeared after radiotherapy. In February 1998, a diagnosis of myelodysplastic syndrome was made. Two months later, the patient had an attack of acute myelocytic leukemia and died of cardiac tamponade. An autopsy determined that both the lung cancer and esophageal cancer had disappeared. Acute myelocytic leukemia and plasmacytoma of lymph nodes in the irradiated area were confirmed. These were regarded as secondary malignancies induced by chemotherapy and radiotherapy.
- Published
- 1999
145. Caspaselike proteases activated in apoptotic photoreceptors of Royal College of Surgeons rats
- Author
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N, Katai, T, Kikuchi, H, Shibuki, S, Kuroiwa, J, Arai, T, Kurokawa, and N, Yoshimura
- Subjects
Blotting, Western ,Caspase 1 ,Retinal Degeneration ,Caspase 2 ,Apoptosis ,Caspase Inhibitors ,Rats, Mutant Strains ,Rats ,Enzyme Activation ,Rats, Sprague-Dawley ,Coumarins ,Caspases ,In Situ Nick-End Labeling ,Animals ,Indicators and Reagents ,Enzyme Inhibitors ,Fluorescent Antibody Technique, Indirect ,Oligopeptides ,Photoreceptor Cells, Vertebrate - Abstract
To study the role of caspase-like proteases, especially roles of more extensively characterized caspase-1 and caspase-2, in apoptotic photoreceptor cell degeneration in Royal College of Surgeons (RCS) rats.Both RCS and Sprague-Dawley rats were used. Cryosections of the retinas at various postnatal times were immunostained with antibodies against caspase-1 (interleukin-1beta-converting enzyme, ICE) and caspase-2 (Nedd2/Ich-1). Double staining with TdT-dUTP terminal nick-end labeling (TUNEL), propidium iodide, and the antibodies was also performed. To evaluate the time course of protein expression, western blot analysis was carried out. The temporal profile of caspase-like protease activity was studied using a fluorogenic tetrapeptide substrate, acetyl-tyrosyl-valyl-alanyl-aspartic acid alpha (4-methyl-coumaryl-7-amide) (Ac-YVAD-MCA). Intravitreal injection of a caspase-1 inhibitor, acetyl-tyrosyl-valyl-alanyl-aspartic-aldehyde (Ac-YVAD-CHO), at postnatal days 21 (P21) and P26 was performed to see if this caused a decrease in apoptotic cell number at P28.TUNEL-positive photoreceptors of RCS rats stained strongly with antibodies against caspase-1 and caspase-2. Double staining studies revealed that caspase-1 and caspase-2 were coexpressed in apoptotic cells. Western blot analysis showed that active forms of caspase-1-like and caspase-2-like proteases were upregulated at P28, concurrent with the peak in TUNEL-positive cells. The enzymatic activity of caspase-1-like protease was elevated in RCS rat retinas at P28, and the inhibitor of caspase-1 transiently reduced the number of the apoptotic photoreceptors.Activation of caspase-like proteases plays an important role in photoreceptor apoptosis of RCS rats.
- Published
- 1999
146. Mechanism and prevention of ischemia-reperfusion injury
- Author
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T Kurokawa and H Takagi
- Subjects
Transplantation ,business.industry ,medicine.medical_treatment ,Microcirculation ,Ischemia ,Liver transplantation ,medicine.disease ,Proinflammatory cytokine ,Liver Transplantation ,Pathogenesis ,Anesthesia ,Reperfusion Injury ,Parenchyma ,medicine ,Animals ,Humans ,Surgery ,business ,Reperfusion injury ,Liver Circulation - Abstract
ISCHEMIA-REPERFUSION injury remains an important clinical consideration in liver transplantation. Severe damage associated with organ preservation and reperfusion leads to primary nonfunction of the graft, which accounts for approximately 10% of early graft loss necessitating retransplantation. Early investigations focused on changes of parenchymal cells in ischemic injury. Now many of the problems have been resolved by the modern cold preservation technique, including development of a new preservation solution. More recently, various factors that regulate microcirculation of the organ and toxic factors such as free radicals or inflammatory cytokines, which are generated during ischemia and reperfusion, have been documented.
- Published
- 1999
147. Gene transfer with cationic lipid into human hepatocellular carcinoma in nude mice
- Author
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T, Miwa, N, Emi, T, Nonami, T, Kurokawa, K, Yoshikawa, A, Nakao, and H, Takagi
- Subjects
Quaternary Ammonium Compounds ,Mice ,Mice, Inbred BALB C ,Liver Neoplasms, Experimental ,Lac Operon ,Gene Transfer Techniques ,Tumor Cells, Cultured ,Animals ,Humans ,Mice, Nude ,Genetic Therapy ,Neoplasm Transplantation - Abstract
Using a cationic lipid, gene transfection into the tumor of a human hepatocellular carcinoma model in nude mice was attempted in order to explore the possibility of its use in gene therapy.A DNA-lipid complex was made by combining the cationic lipid distearyldimethyl ammonium bromide (DDAB) with pCMV sPORT expressing the reporter gene LacZ. The expression of this complex was first investigated in vitro against the human hepatocellular carcinoma cell line Li7HM. It was then injected directly into a hepatocellular carcinoma model tumor created by implanting Li7HM into the liver of BALB/c nu/nu mice, and the expression of LacZ was histologically evaluated.LacZ gene was expressed in Li7HM in vitro with the optimized DNA-lipid complex. Cell toxicity was not a problem. Expression of LacZ was also seen in the mouse hepatocellular model tumor into which the complex had been injected, indicating successful gene transfection with this method.Direct injection of a DNA-lipid complex into a mouse hepatocellular carcinoma model tumor is a safe and simple method of gene transfection, proving this to be a viable method of transfer for use in gene therapy.
- Published
- 1999
148. Clinical significance of alpha-fetoprotein mRNA during perioperative period in HCC
- Author
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N, Okuda, A, Nakao, S, Takeda, K, Oshima, N, Kanazumi, T, Nonami, T, Kurokawa, and H, Takagi
- Subjects
Adult ,Male ,Carcinoma, Hepatocellular ,Portal Vein ,Reverse Transcriptase Polymerase Chain Reaction ,Liver Neoplasms ,Middle Aged ,Prognosis ,Biomarkers, Tumor ,Humans ,Female ,Postoperative Period ,RNA, Messenger ,alpha-Fetoproteins ,Neoplasm Recurrence, Local ,Aged - Abstract
The presence of alpha-fetoprotein (AFP)mRNA in the peripheral blood of patients with HCC suggested that carcinoma cells still existed. We investigated the influence of an alternation of human AFPmRNA perioperatively detected in peripheral blood in matters of recurrence, prognosis and operative performance.Thirty-three patients with HCC were enrolled for this study. AFPmRNA in peripheral blood before the operation, and on 1, 3, 7, 14, 21 and 28 post-operative days was examined by means of the reverse-transcriptase polymerase chain reaction (RT-PCR).In 18 of 33 patients (54.5%) with HCC, AFPmRNA was detected in peripheral blood pre-operatively. Ten of 22 (45.4%) who were detected with AFPmRNA in peripheral blood during the perioperative period were diagnosed with intrahepatic recurrence or distant metastasis within 12 months post-operatively. In contrast, 10 (90.8%) of 11 patients who were not detected with AFPmRNA in peripheral blood anytime during hospitalization were diagnosed as free of intrahepatic recurrence or distant metastases within 9 months after the operation.These results suggested that an alternation of AFPmRNA from HCC patients' peripheral blood during the perioperative period by means of this technique may be a practical tool in the detection of early recurrence or distant metastases after surgery.
- Published
- 1999
149. Interleukin-1 alpha induced cyclooxygenase-2 expression in bone-derived endothelial cells
- Author
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T, Nakagawa, N, Fujita, T, Oh-Hara, T, Kurokawa, K, Nakamura, and T, Tsuruo
- Subjects
Mice, Inbred BALB C ,Receptors, Interleukin-1 ,Transfection ,Dinoprostone ,Gene Expression Regulation, Enzymologic ,Cell Line ,Isoenzymes ,Mice ,Transformation, Genetic ,Cyclooxygenase 2 ,Prostaglandin-Endoperoxide Synthases ,Animals ,Bone Remodeling ,Endothelium, Vascular ,Femur ,RNA, Messenger ,Interleukin-1 - Abstract
Histological studies have suggested that vascular endothelial cells in bone are members of a complex network that regulates bone development and remodeling by producing soluble factors or by mediating cell-cell adhesion. To clarify the role of bone-derived endothelial cell lines (BDECs) in bone remodeling, we established several clones of BDECs from the femurs of BALB/c mice after transformation with the SV40 virus. Then we examined the response of these clones to interleukin-1alpha (IL-1alpha). IL-1alpha is known to induce bone resorption in part by increasing the expression of cyclooxygenase-2 (COX-2) that is associated with the production of PGE2 in osteoblast-lineage cells. Treating the primary and established BDECs with IL-1alpha induced COX-2 mRNA expression. A transcriptional activation assay revealed that the treatment with IL-1alpha increased COX-2 promoter activity in a dose-dependent manner, and IL-1alpha promoted COX-2 protein expression in BDECs. Treatment with IL-1alpha promoted PGE2 production from BDECs in a dose-dependent manner. These results indicate that IL-1alpha stimulates PGE2 synthesis largely by inducing BDECs to express COX-2. Because PGE2 stimulates bone resorption, these vascular endothelial cells, as well as osteoblast cells, play important roles in bone remodeling.
- Published
- 1999
150. Remission of idiopathic thrombocytopenic purpura after femoral lengthening. Clinical case followed for 5 years
- Author
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R, Murashima, K, Nakamura, T, Matsushita, and T, Kurokawa
- Subjects
Adult ,Fracture Healing ,Purpura, Thrombocytopenic, Idiopathic ,Bone Transplantation ,Platelet Count ,Remission, Spontaneous ,Accidents, Traffic ,Fracture Fixation, Intramedullary ,Radiography ,Fractures, Open ,Bone Lengthening ,Osteogenesis ,Fractures, Ununited ,Humans ,Female ,Femoral Fractures ,Follow-Up Studies - Abstract
We report on a patient with chronic idiopathic thrombocytopenic purpura (ITP) who went into remission after femoral lengthening. Although it is possible that spontaneous remission (frequency 5%-10%) of chronic ITP coincided with the femoral lengthening, limb lengthening could also have caused the thrombocytosis. This case suggests a close relationship between osteogenesis and hematopoiesis during regenerate bone formation. Limb lengthening can therefore be defined as the formation not only of bone and soft tissue but also of hematopoietic tissue.
- Published
- 1999
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