342 results on '"S., Imagawa"'
Search Results
2. Residual Magnetic Field Induced by Superconducting Magnets of Large Helical Device
- Author
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S. Imagawa and K. Takahata
- Subjects
NbTi ,General Physics and Astronomy ,General Materials Science ,Superconducting magnet ,Cable-in-conduit conductor ,Magnetization ,Residual magnetic field - Abstract
The residual magnetic field was measured to investigate its source for the Large Helical Device, the superconducting magnet system of which consists of two Helical Coils (HCs), two Inner Vertical (IV) coils, two Inner Shaping (IS) coils, and two Outer Vertical (OV) coils. NbTi cable-in-conduit conductors were adopted for the IV, IS, and OV coils. Firstly, Hall probes were installed at five periodic positions on the mid-plane of the inner cylinder of the cryostat. Since the residual field was changed by around 0.1 mT at all the positions during the warm-up of the superconducting coils, a major part of the residual field had to be induced by magnetization of the coils. In the next campaign (cool-down, plasma experiment, and warm-up), the Hall probes were moved to the five different vertical positions in order to measure the distribution of the residual field. Calculation of the residual field has been carried out under the assumption that NbTi filaments in each conductor are magnetized in the same direction as the field at the center of the conductor during excitation. From comparison between the measured and calculated values, we conclude that the residual field from the coils that had been excited to high currents should be reduced by around 35%, due to the self-field in strands in the conductor. The best fitted critical current densities of the IV and IS coils are 1.31 and 2.81 × 1010 A/m2, respectively, which are consistent with the field dependence obtained from the magnetization curve of each strand.
- Published
- 2023
3. Measurement of Decay Time Constant of Shielding Current in ITER-TF Joint Samples
- Author
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Suguru Takada, Shinji Hamaguchi, K. Takahata, S. Imagawa, H. Kajitani, K. Matsui, T. Obana, N. Koizumi, Hirotaka Chikaraishi, and Y. Onodera
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History ,Decay time ,Materials science ,Nuclear engineering ,Electromagnetic shielding ,Current (fluid) ,Constant (mathematics) ,Joint (geology) ,Computer Science Applications ,Education - Abstract
Joint sample tests have been carried out as a qualification test for ITER Toroidal Field (TF) coils. The joint sample comprises two short TF conductors that have “twin-box” joint terminals at both ends. The lower joint is a testing part that is a full size joint of the TF coils. Hall probes are attached on the lower joint box at around the center of the external field coil of the test facility. The magnetic field induced by shielding currents in the joint can be estimated from the difference between the measured magnetic field strength and the magnetic field generated by the external field coil. The magnetic field by the shielding currents during shut-off of the external field coil from -1.0 T is evaluated for six samples. The decay time constants of the shielding currents are gradually elongated with decrease of the shielding currents in all the samples. In comparison with simulation results, it is considered that the main shielding current flows in superconducting cables in the two conductors with crossing the jointed plane and that the joint resistance is decreased at low total current.
- Published
- 2021
4. Methicillin-resistant staphylococcus aureus: colonization and development of infection in patients with haematological disorders
- Author
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Kiyohiko Hatake, Akiyoshi Miwa, N. Komatu, Shotaro Hagiwara, R. Sasaki, Kazuo Muroi, Yoshida M, S. Miura, S. Imagawa, and Shinobu Sakamoto
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Staphylococcus aureus ,medicine.medical_specialty ,Microbiological culture ,Microbial Sensitivity Tests ,Biology ,medicine.disease_cause ,Blood Urea Nitrogen ,Risk Factors ,Internal medicine ,Lower respiratory tract infection ,medicine ,Cholinesterases ,Humans ,In patient ,Colonization ,Retrospective Studies ,Retrospective cohort study ,Hematology ,General Medicine ,Middle Aged ,Staphylococcal Infections ,biochemical phenomena, metabolism, and nutrition ,Prognosis ,bacterial infections and mycoses ,medicine.disease ,Hematologic Diseases ,Thrombocytopenia ,Methicillin-resistant Staphylococcus aureus ,Immunology ,Methicillin Resistance ,Haematological disorders - Abstract
A retrospective study of 53 patients with haematological disorders whose bacterial cultures were positive for methicillin-resistant Staphylococcus aureus (MRSA), was performed to analyse the risk factors for MRSA infection, and the prognostic factors. Sixteen patients showed colonization by MRSA but never developed infection(C), 16 showed colonization and subsequent infection(C-I), while 21 had MRSA infection at the time of first culture (I). Poor performance status, thrombocytopenia, increased serum urea nitrogen and decreased serum cholinesterase were more prominent in (I) than (C) + (C-I). The risk factors associated with the development of infection from colonization were age and serum cholinesterase. In addition, lower respiratory tract infection as a type of infection, non-remission status of the haematological malignancy and an inappropriate antibiotic therapy were associated with a poor prognosis for MRSA infection.
- Published
- 2009
5. Stress and strain measurement of the large helical device during coil excitation
- Author
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A Nishimura, H Tamura, S Imagawa, T Satow, S Satoh, O Motojima, and the LHD group
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Tokamak ,Materials science ,Mechanical Engineering ,Superconducting magnet ,Mechanics ,Magnetic field ,law.invention ,Nuclear physics ,Large Helical Device ,Nuclear Energy and Engineering ,law ,Electromagnetic coil ,Eddy current ,General Materials Science ,Deformation (engineering) ,Excitation ,Civil and Structural Engineering - Abstract
The large helical device (LHD), which has a large superconducting magnet system, has been constructed and the magnetic field at the plasma axis reached to 2.9 T in the third cycle operation in 1999. To carry out the strain measurement without temperature rise by eddy current, slow ramp rate of the magnetic field was employed and the data acquisition system worked continuously during the coil excitation. The results obtained in the experiments showed that the deformation behavior of the cryogenic support structure could be explained qualitatively and it was confirmed that the FEM analysis gave good results in comparing with the stresses measured. Also, it is clarified that the strain measurement will give valuable information on the deformation and the stress condition even at cryogenic temperature, in high vacuum and under high magnetic field, and it is possible to evaluate the soundness of the cryogenic structure.
- Published
- 2001
6. Overview of LHD experiments
- Author
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M. Fujiwara, K. Kawahata, N. Ohyabu, O. Kaneko, A. Komori, H. Yamada, N. Ashikawa, L.R. Baylor, S.K. Combs, P.C. deVries, M. Emoto, A. Ejiri, P.W. Fisher, H. Funaba, M. Goto, D. Hartmann, K. Ida, H. Idei, S. Iio, K. Ikeda, S. Inagaki, N. Inoue, M. Isobe, S. Kado, K. Khlopenkov, T. Kobuchi, A.V. Krasilnikov, S. Kubo, R. Kumazawa, F. Leuterer, Y. Liang, J.F. Lyon, S. Masuzaki, T. Minami, J. Miyajima, T. Morisaki, S. Morita, S. Murakami, S. Muto, T. Mutoh, Y. Nagayama, N. Nakajima, Y. Nakamura, H. Nakanishi, K. Narihara, K. Nishimura, N. Noda, T. Notake, S. Ohdachi, Y. Oka, S. Okajima, M. Okamoto, M. Osakabe, T. Ozaki, R.O. Pavlichenko, B.J. Peterson, A. Sagara, K. Saito, S. Sakakibara, R. Sakamoto, H. Sanuki, H. Sasao, M. Sasao, K. Sato, M. Sato, T. Seki, T. Shimozuma, M. Shoji, H. Sugama, H. Suzuki, M. Takechi, Y. Takeiri, N. Tamura, K. Tanaka, K. Toi, T. Tokuzawa, Y. Torii, K. Tsumori, K.Y. Watanabe, T. Watanabe, T. Watari, I. Yamada, S. Yamaguchi, S. Yamamoto, M. Yokoyama, N. Yoshida, Y. Yoshimura, Y.P. Zhao, R. Akiyama, K. Haba, M. Iima, J. Kodaira, T. Takita, T. Tsuzuki, K. Yamauchi, H. Yonezu, H. Chikaraishi, S. Hamaguchi, S. Imagawa, A. Iwamoto, S. Kitagawa, Y. Kubota, R. Maekawa, T. Mito, K. Murai, A. Nishimura, K. Takahata, H. Tamura, S. Yamada, N. Yanagi, K. Itoh, K. Matsuoka, K. Ohkubo, I. Ohtake, S. Satoh, T. Satow, S. Sudo, S. Tanahashi, K. Yamazaki, Y. Hamada, and O. Motojima
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Nuclear and High Energy Physics ,Materials science ,Tokamak ,Thermonuclear fusion ,Plasma ,Condensed Matter Physics ,law.invention ,Ion ,law ,Beta (plasma physics) ,Atomic physics ,Magnetohydrodynamics ,Scaling ,Stellarator - Abstract
During the first two years of the LHD experiment the following results have been achieved: (i) higher Te (Te(0) = 4.4 keV at ne = 5.3 × 1018 m-3 and Pabs = 1.8 MW); (ii) higher confinement (τE = 0.3 s, Te(0) = 1.1 keV at ne = 6.5 × 1019 m-3 and Pabs = 2.0 MW); (iii) higher stored energy, Wpdia = 880 kJ at B = 2.75 T. High performance plasmas have been realized in the inward shifted magnetic axis configuration (R = 3.6 m) where helical symmetry is recovered and the particle orbit properties are improved by a trade-off of MHD stability properties due to the appearance of a magnetic hill. Energy confinement was systematically higher than that predicted by the International Stellarator Scaling 95 by up to a factor of 1.6 and was comparable with the ELMy H mode confinement capability in tokamaks. This confinement improvement is attributed to configuration control (inward shift of the magnetic axis) and to the formation of a high edge temperature. The average beta value achieved reached 2.4% at B = 1.3 T, the highest beta value ever obtained in a helical device, and so far no degradation of confinement by MHD phenomena has been observed. The inward shifted configuration has also led to successful ICRF minority ion heating. ICRF powers up to 1.3 MW were reliably injected into the plasma without significant impurity contamination, and a plasma with a stored energy of 200 kJ was sustained for 5 s by ICRF alone. As another important result, long pulse discharges of more than 1 min were successfully achieved separately with an NBI heating of 0.5 MW and with an ICRF heating of 0.85 MW.
- Published
- 2001
7. Actuator control to suppress disturbances for 8 cm DVD-RAM video camera recorder
- Author
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M. Suzuki, J. Ohya, H. Ono, and S. Imagawa
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Engineering ,business.industry ,Acoustics ,Feed forward ,Video camera ,Shock (mechanics) ,law.invention ,Vibration ,Acceleration ,RAM drive ,law ,Media Technology ,DVD-RAM ,Electrical and Electronic Engineering ,Actuator ,business ,Computer hardware - Abstract
A new actuator control technique for an 8 cm DVD-RAM drive, used for a video camera recorder, was developed. The new technique consists of the acceleration feed forward control (AFFC) and the velocity feed back control (VFBC). Suppressing external disturbances, such as the vibration or the shock made it possible for the drive to be used practically inside the video camera.
- Published
- 2001
8. Design and construction of helical coils for LHD
- Author
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S Imagawa, S Masuzaki, N Yanagi, S Yamaguichi, T Satow, J Yamamoto, O Motojima, and LHD Group
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Quantitative Biology::Biomolecules ,Materials science ,Mechanical Engineering ,Mechanical engineering ,Insulator (electricity) ,Fusion power ,law.invention ,Conductor ,Magnetic field ,Nuclear magnetic resonance ,Rigidity (electromagnetism) ,Nuclear Energy and Engineering ,law ,Electromagnetic coil ,General Materials Science ,Electrical conductor ,Stellarator ,Civil and Structural Engineering - Abstract
Helical coils for LHD are pool-cooled superconducting coils. In order to produce a fine magnetic surface, highly accurate manufacturing tolerances within ±2 mm and high rigidity against large electro-magnetic forces are required. Additionally, high current densities of over 50 A mm−2 are necessary to keep enough distance between the helical coil and plasma. The helical coil is designed to enhance cryogenic stability by optimizing the wetted surface fraction of each conductor in considering both the magnetic field and stress in the insulator between conductors. For attaining highly accurate helical winding and cryogenic stability, composite conductors with pure aluminum stabilizers were developed and directly wound on highly accurate thick cases. The actual winding was carried out on-site from January 1995 to May 1996. After that, the top covers of the case were set on the coils and welded very carefully. The entire assembly was installed into an outer supporting shell.
- Published
- 1998
9. Positive and negative regulation of the erythropoietin gene
- Author
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Yasusada Miura, S Imagawa, and T Izumi
- Subjects
Messenger RNA ,Oligonucleotide ,Negative regulatory element ,Cell Biology ,Biology ,Biochemistry ,Molecular biology ,Regulatory sequence ,Erythropoietin ,Transcription (biology) ,Translational regulation ,medicine ,Transcriptional regulation ,Molecular Biology ,medicine.drug - Abstract
In order to investigate positive and negative regulatory elements of the erythropoietin (Epo) gene, synthetic oligonucleotides were designed to control Epo transcription by means of an antigen strategy. We devised a new method for detecting regulatory elements of genes that have a weak promoter. Synthetic oligonucleotides were incubated with Hep3B cells in the presence or absence of CoCl2 or hypoxia. To exclude the effect of translational regulation, Epo mRNA concentration was determined by competitive polymerase chain reaction. The addition of antisense oligonucleotide for CACCC elements decreased the production of Epo mRNA in a dose-dependent fashion when cells were stimulated by CoCl2 or hypoxia. In contrast, the addition of antisense oligonucleotide for the GATA element caused a dose-dependent stimulation of Epo mRNA production either in the presence or absence of CoCl2 or hypoxia. Triple helix formation was revealed by electrophoresis. CACCC elements were demonstrated to be positive regulatory elements of the Epo gene, whereas the GATA element was a negative regulatory element. Furthermore, by gel mobility shift assays, we demonstrated evidence for the presence of factors in Hep3B cell nuclear extract that specifically bind to CACCC or GATA elements. Based on these observations, we presented the possibility that triple helix formation could serve as a novel means for transcriptional regulation of the gene.
- Published
- 1994
10. Design analysis of electromagnetic forces on the Large Helical Device
- Author
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S. Imagawa, H. Tamura, K. Yamazaki, T. Satow, J. Yamamoto, O. Motojima, and null LHD Design Group
- Subjects
Physics ,Quantitative Biology::Biomolecules ,Design analysis ,Mechanical Engineering ,Physics::Medical Physics ,Mechanics ,Conductor ,Large Helical Device ,Rigidity (electromagnetism) ,Nuclear magnetic resonance ,Nuclear Energy and Engineering ,Electromagnetic coil ,General Materials Science ,Superconducting Coils ,Civil and Structural Engineering - Abstract
A calculation of the electromagnetic forces was carried out to design the supporting structure and the coil package. LHD has one pair of helical coils and three pairs of poloidal coils, all of which are superconducting coils. Because of the large electromagnetic force, the helical coils are fixed to a cylindrical supporting structure that is called the shell support. From the comparison between three types of methods to support the poloidal coils is found that the most suitable is that with the poloidal coils fixed firmly to the shell support in all directions. When considering the rigidity of the poloidal coils, the maximum stress of the shell support is smallest with this type. The forces on the electrical insulators of the helical coils are estimated by calculating the electromagnetic forces on each conductor and summing them. The maximum loads on the insulators between turns and between layers are 159 and 116 MPa, respectively. They occur in the center area of the coil cross section.
- Published
- 1993
11. Radial build between helical coil and plasma in the Large Helical Device
- Author
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N. Ohyabu, K. Yamazaki, Hantao Ji, S. Imagawa, H. Kaneko, S. Morimoto, N. Noda, T. Satow, J. Yamamoto, O. Motojima, and null LHD Design Group
- Subjects
Quantitative Biology::Biomolecules ,Materials science ,Mechanical Engineering ,Divertor ,Torus ,Field strength ,Plasma ,Radius ,Large Helical Device ,Nuclear magnetic resonance ,Nuclear Energy and Engineering ,Physics::Plasma Physics ,Electromagnetic coil ,General Materials Science ,Atomic physics ,Current density ,Civil and Structural Engineering - Abstract
The Large Helical Device (LHD) is a heliotron/torsatron-type confinement device (B = 4 T, R = 3.9 m) equipped with a helical divertor. In the LHD configuration, the plasma region is shifted inwards approximately a third of the plasma minor radius relative to the center of the two pairing helical coils, thus making the distance between the coil center and the edge plasma small, 328 mm on the small major radius side of the torus. Within this space, many components must be installed, such as the superconducting helical coil (163), its coil can (45), the thermal shield (30), the vacuum gap (35), the plasma vacuum vessel (15), the first wall (25) (the numbers in the parentheses are allocated radial space in mm for the respective components). Effective edge plasma control by the divertor requires a space of more than 15 mm between the plasma and the first wall. To meet the above space requirement, the thickness of the helical coil is designed to be as small as possible, yet the coil current density and maximum field strength are within the limits of reliable coil operation.
- Published
- 1993
12. Structural design of the cryostat for the LHD
- Author
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H. Tamura, A. Nishimura, S. Imagawa, T. Satow, J. Yamamoto, O. Motojima, and null LHD Design Group
- Subjects
Cryostat ,Toroid ,Materials science ,Atmospheric pressure ,Mechanical Engineering ,Mechanics ,Finite element method ,law.invention ,Magnetic field ,Stress field ,Large Helical Device ,Nuclear Energy and Engineering ,law ,Eddy current ,General Materials Science ,Civil and Structural Engineering - Abstract
The Large Helical Device (LHD) will be operated under various loads, such as strong electromagnetic forces, atmospheric pressure, and thermal stress. The outer vessel of the cryostat has a toroidal shape and is the largest component of the LHD. The designed maximum pressure of the vessel is 0.1 MPa inward and 0.01 MPa outward. Since the cross section of the outer vessel is not circular, the presence of unbalanced atmospheric pressure requires carefully designed studies of the rigidity of the cryostat. The poloidal cross section of the vessel is designed as a bell-shape, of which the bottom is a flat plate of 150 mm and the top has a major radius of 4 m, the minor radius is 2 m, with a thickness of 50 mm, by the finite element method using ANSYS. In this case, the maximum deformation appears at the center of the bottom flat plate; its value is 1.7 mm when stainless steel is used. The poloidal cross section of the outer vessel of the cryostat is desirable to have a symmetric circular shape which increases the mechanical stiffness and reduces the unbalanced magnetic field due to the eddy current during experiments. However, from an engineering point of view, the bottom is required to have the shape of a flat plate to have working space for inner components. We analyzed the stress field and deformation of the outer vessel under atmospheric pressure by using a finite element analysis code to pursue the optimized shape and thickness of the body.
- Published
- 1993
13. Regulatory elements of the erythropoietin gene
- Author
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S Imagawa, MA Goldberg, J Doweiko, and HF Bunn
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Immunology ,Cell Biology ,Hematology ,Biochemistry - Abstract
Because the human hepatoma cell line Hep3B produces erythropoietin (Epo) in a regulated fashion, it can be used to investigate the cis- acting regulatory elements of the Epo gene. Comparison of primate and mouse sequences shows strong homology not only in the coding sequence but also within the 5′ flanking region, the first intron, and the 3′ flanking region. These portions of the Epo gene were inserted 5′ and 3′ to a reporter gene, human growth hormone (GH). 5A is a 1,192-base pair (bp) HindIII-Xbal fragment that extends from 378 bp 5′ to the cap site through the first intron. To obviate the problem of false initiation of translation from the Epo ATG start codon, this site was changed to TAG by site-directed mutagenesis. 3A is a 255-bp Accl-BglII fragment that extends 67 bp upstream from the Epo termination codon and covers most of the 3′ noncoding region of homology. The plasmid DNAs were transfected by electroporation into Hep3B cells with RSVCAT as an internal standard to correct for transfection efficiency. One aliquot of cells was exposed to 50 mumol/L CoCl2 or to 1% O2. At the end of the incubations, GH and Epo were measured in the cell media and the cell pellet was assayed for CAT. Production of GH was stimulated 1.7-fold by cobalt or hypoxia. Furthermore, addition of 3A to the GH gene, irrespective of orientation, stimulated GH production 2.6-fold with CoCl2 and 2.3-fold with hypoxia. Stable cell lines were produced by cotransfection of the above constructions, along with the selectable marker pSV-Neo. In two clones, exposure to hypoxia resulted in much more marked (16-fold) induction of GH. Stimulus of both GH and Epo production by hypoxia was partially abrogated by carbon monoxide. These results demonstrate the presence of promoter and enhancer elements within the human Epo gene that are appropriately responsive to hypoxia and cobalt.
- Published
- 1991
14. Performance of upgraded cooling system for LHD helical coils
- Author
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S. Hamaguchi, S. Imagawa, T. Obana, N. Yanagi, S. Moriuchi, H. Sekiguchi, K. Oba, T. Mito, O. Motojima, T. Okamura, T. Semba, S. Yoshinaga, H. Wakisaka, J. G. Weisend, John Barclay, Susan Breon, Jonathan Demko, Michael DiPirro, J. Patrick Kelley, Peter Kittel, Arkadiy Klebaner, Al Zeller, Mark Zagarola, Steven Van Sciver, Andrew Rowe, John Pfotenhauer, Tom Peterson, and Jennifer Lock
- Subjects
Quantitative Biology::Biomolecules ,business.industry ,Nuclear engineering ,Physics::Medical Physics ,Electrical engineering ,chemistry.chemical_element ,Cryogenics ,Superconducting magnet ,Physics::Fluid Dynamics ,Subcooling ,Large Helical Device ,chemistry ,Heat exchanger ,Physics::Atomic and Molecular Clusters ,Water cooling ,Physics::Atomic Physics ,Lambda point refrigerator ,business ,Helium - Abstract
Helical coils of the Large Helical Device (LHD) are large scale superconducting magnets for heliotron plasma experiments. The helical coils had been cooled by saturated helium at 4.4 K, 120 kPa until 2005. An upgrade of the cooling system was carried out in 2006 in order to improve the cryogenic stability of the helical coils and then it has been possible to supply the coils with subcooled helium at 3.2 K, 120 kPa. A designed mass flow of the supplied subcooled helium is 50 g/s. The subcooled helium is generated at a heat exchanger in a saturated helium bath. A series of two centrifugal cold compressors with gas foil bearing is utilized to lower the helium pressure in the bath. The supplied helium temperature is regulated by rotational speed of the cold compressors and power of a heater in the bath. The mass flow of the supplied helium is also controlled manually by a supply valve and its surplus is evaporated by ten heaters at the outlet above the coils. In the present study, the performance of the cooli...
- Published
- 2007
15. Finite element analysis of the cold end recovery current of aluminum stabilized composite conductor in a finite bias field
- Author
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S. Imagawa
- Subjects
Superconductivity ,Resistive touchscreen ,Materials science ,Magnetoresistance ,Condensed matter physics ,Mechanics ,Electric current ,Current (fluid) ,Finite element method ,Magnetic field ,Conductor - Abstract
The cold end recovery current is important for superconducting coils which are designed to satisfy the cryostable condition. Magnetoresistivity of a composite conductor made of a pure aluminum stabilizer and a copper sheath is enhanced by a Hall current flowing in the cross-section of the conductor. In order to reduce the Hall current, a resistive layer around the pure aluminum is effective. However, this resistive layer disturbs the current transfer between superconducting strands and the aluminum stabilizer, and excess resistance may deteriorate the cryogenic stability. A finite element method is applicable to evaluate its effect. In order to solve the propagating process of a normal zone, dynamic calculation is necessary because of strong effects of the slow current diffusion into the pure aluminum. Nevertheless, static calculation is applicable to evaluate the recovery current in the case of a normal-zone stagnating in a finite bias magnetic field, such as short sample tests. The calculations become very simple by fixing the length of normal zone, and the recovery current can be evaluated from the temperature at the end of the normal zone. The results of calculations for various resistive layers show that the recovery current becomes the highest for the fairly high resistance, and this method is useful to evaluate the effect of the finite size of bias field.
- Published
- 2002
16. All-trans-retinoic acid treatment for chemotherapy-resistant acute adult T-cell leukemia
- Author
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M, Toshima, T, Nagai, T, Izumi, T, Tarumoto, M, Takatoku, S, Imagawa, N, Komatsu, and K, Ozawa
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Leukemia, T-Cell ,Drug Resistance, Neoplasm ,Acute Disease ,Humans ,Antineoplastic Agents ,Female ,Tretinoin ,Middle Aged - Abstract
We report a case in which treatment with all-trans-retinoic acid (ATRA) improved the clinical features of a 47-year-old female patient with acute adult T-cell leukemia (ATL). The patient was first treated several times with combination chemotherapy. but the number of ATL cells increased and other clinical manifestations progressed. ATRA 60 mg was then administered daily. ATRA treatment dramatically improved the patient's clinical features. In vitro examination revealed that ATRA inhibited the growth of ATL cells from the patient. These findings suggest that ATRA may be a useful treatment for patients with chemotherapy-resistant acute ATL.
- Published
- 2001
17. N(G)-monomethyl-L-arginine inhibits erythropoietin gene expression by stimulating GATA-2
- Author
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T, Tarumoto, S, Imagawa, K, Ohmine, T, Nagai, M, Higuchi, N, Imai, N, Suzuki, M, Yamamoto, and K, Ozawa
- Subjects
Binding Sites ,omega-N-Methylarginine ,Base Sequence ,Recombinant Fusion Proteins ,Molecular Sequence Data ,DNA ,Nitric Oxide ,DNA-Binding Proteins ,GATA2 Transcription Factor ,Mice ,NG-Nitroarginine Methyl Ester ,Gene Expression Regulation ,Mutation ,Tumor Cells, Cultured ,Animals ,Humans ,Enzyme Inhibitors ,Hypoxia ,Luciferases ,Promoter Regions, Genetic ,Cyclic GMP ,Erythropoietin ,Protein Binding ,Transcription Factors - Abstract
N(G)-monomethyl-L-arginine (L-NMMA) has been reported to be elevated in uremic patients. Based on the hypothesis that the pathogenesis of the anemia of renal disease might be due to the perturbation of transcription factors of the erythropoietin (Epo) gene by L-NMMA, the present study was designed to investigate the effect of L-NMMA on Epo gene expression through the GATA transcription factor. L-NMMA caused decreased levels of NO, cyclic guanosine monophosphate (cGMP), and Epo protein in Hep3B cells. L-NAME (analogue of L-NMMA) also inhibited Epo production in anemic mice. Transfection of the Epo promoter-luciferase gene into Hep3B cells revealed that L-NMMA inhibited the Epo promoter activity. However, L-NMMA did not inhibit the Epo promoter activity when mutated Epo promoter (GATA to TATA) was transfected, and L-NMMA did not affect the enhancer activity. Electrophoretic mobility shift assays demonstrated the stimulation of GATA binding activity by L-NMMA. However, L-NMMA had no effect on the binding activity of hepatic nuclear factor-4, COUP-TF1, hypoxia-inducing factor-1, or NF-kappaB. Furthermore, cGMP inhibited the L-NMMA-induced GATA binding activity. L-NMMA also increased GATA-2 messenger RNA expression. These results demonstrate that L-NMMA suppresses Epo gene expression by up-regulation of the GATA transcription factor and support the hypothesis that L-NMMA is one of the candidate substances that underlie the pathogenesis of renal anemia. (Blood. 2000;96:1716-1722)
- Published
- 2000
18. A de novo philadelphia chromosome-positive acute mixed-lineage leukemia with both major and minor BCR/ABL mRNA transcripts
- Author
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T, Tarumoto, S, Imagawa, K, Ohmine, A, Mano, T, Nagai, M, Takatoku, K, Muroi, K, Hatake, and K, Ozawa
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Adult ,Gene Rearrangement ,Male ,Histocytochemistry ,Reverse Transcriptase Polymerase Chain Reaction ,Remission Induction ,Fusion Proteins, bcr-abl ,Bone Marrow Cells ,Burkitt Lymphoma ,Translocation, Genetic ,Blotting, Southern ,Leukemia, Myeloid, Acute ,Antineoplastic Combined Chemotherapy Protocols ,Humans ,Philadelphia Chromosome ,RNA, Messenger ,Immunoglobulin Heavy Chains ,Peroxidase - Abstract
A patient with a Philadelphia chromosome (Ph)-positive acute mixed-lineage leukemia (AMLL) expressing both major and minor BCR/ABL mRNA transcripts is described. Phenotypic analysis of the leukemic blasts revealed positivity for both myeloid and B-cell lineages. Southern blot analysis showed a rearrangement of the immunoglobulin heavy chain (IgH) gene. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis showed the expression of both major and minor BCR/ABL mRNA transcripts. To our knowledge, this is the first report of AMLL expressing both major and minor BCR/ABL mRNA transcripts and rearrangement of the IgH gene.
- Published
- 2000
19. Autologous peripheral blood stem cell transplantation for adults with B-lineage acute lymphoblastic leukemia: a pilot study
- Author
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Kazuo Muroi, Minoru Yoshida, S Imagawa, Norio Komatsu, R Kuribara, Tatsuya Suzuki, Kiyohiko Hatake, Chizuru Kawano, Yasusada Miura, Youichi Amemiya, Hiroshi Tomizuka, Tetsuya Otsuki, Keiya Ozawa, and Tohru Izumi
- Subjects
Adult ,Male ,Cancer Research ,medicine.medical_specialty ,Vincristine ,Adolescent ,medicine.medical_treatment ,Pilot Projects ,Ranimustine ,Hematopoietic stem cell transplantation ,Transplantation, Autologous ,Antineoplastic Combined Chemotherapy Protocols ,Granulocyte Colony-Stimulating Factor ,medicine ,Humans ,Etoposide ,Chemotherapy ,business.industry ,Remission Induction ,Hematopoietic Stem Cell Transplantation ,Hematology ,Total body irradiation ,Middle Aged ,Burkitt Lymphoma ,Combined Modality Therapy ,Hematopoietic Stem Cell Mobilization ,Surgery ,Transplantation ,Oncology ,Female ,business ,Busulfan ,medicine.drug - Abstract
We conducted a pilot study on autologous peripheral blood stem cell transplantation (PBSCT) for 11 adults with B-lineage acute lymphoblastic leukemia (ALL) in first complete remission (CR) or even in those with more advanced stages. All patients achieved CR by induction therapy, of whom 10 were treated with anthracycline, vincristine and prednisolone-based regimens. After consolidation therapy, all patients except one received high-dose cytarabine followed by granulocyte colony-stimulating factor (G-CSF) administration to collect PBSCs. Ten patients received busulfan 4 mg/kg for 4 days, etoposide 20 mg/kg for 3 days and ranimustine 200 mg/m2 for 2 days as a conditioning regimen. One received a regimen consisting of etoposide, cyclophosphamide and total body irradiation. From day 1, G-CSF was given intravenously, and no additional chemotherapy was administered. At the median follow-up time of 30.8 months, four of six patients with standard-risk B-lineage ALL survived within the range of 19.7 to 85.4 months without relapse. In contrast, only one of five with high-risk B-lineage ALL survived for 36.3 months without relapse. Autologous PBSCT as post-remission therapy may prolong CR in adults with standard-risk B-lineage ALL.
- Published
- 2000
20. [Two cases of acute myelogenous leukemia complicated with fatal gastrointestinal tract bleeding after treatment with idarubicin and cytarabine]
- Author
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T, Nagashima, T, Izumi, K, Muroi, A, Miyasato, M, Uchida, S, Imagawa, N, Komatsu, M, Yoshida, K, Hatake, Y, Miura, and K, Ozawa
- Subjects
Adult ,Male ,Leukemia, Myeloid, Acute ,Antibiotics, Antineoplastic ,Fatal Outcome ,Bone Marrow ,Humans ,Female ,Middle Aged ,Gastrointestinal Hemorrhage ,Idarubicin - Abstract
We describe herein two newly diagnosed patients with acute myelogenous leukemia (AML), who were treated twice with an idarubicin hydrochloride (IDR)-containing regimen as a response-orientated induction therapy. Both patients had severe gastrointestinal tract hemorrhage complications at their nadir. The two patients were as follows: a 35-year-old male, FAB-M4, and a 47-year-old female, FAB-M0. They received the same induction chemotherapy (IDR 12 mg/m2 for four days and cytarabine 100 mg/m2 for ten days). No response (NR) was obtained in either, so they underwent the same regimen again. During the period of myelosuppression, they developed severe gastrointestinal hemorrhage. One died of sepsis, and the other of acute respiratory distress syndrome without a recovery in bone marrow. The fetal gastrointestinal tract complications may have been due to severe myelosuppression and mucosal damage in these patients. Careful observation will be needed to prevent such severe complications after the treatment with IDR.
- Published
- 2000
21. [Low-dose prednisolone therapy for idiopathic thrombocytopenic purpura]
- Author
-
K, Ohmine, T, Izumi, K, Muroi, R, Shimizu, S, Imagawa, N, Komatsu, R, Sasaki, K, Hatake, Y, Miura, and K, Ozawa
- Subjects
Purpura, Thrombocytopenic, Idiopathic ,Prednisolone ,Azathioprine ,Anti-Inflammatory Agents ,Quality of Life ,Splenectomy ,Humans ,Length of Stay ,Combined Modality Therapy ,Immunosuppressive Agents - Abstract
Prednisolone (PSL) is widely used for the treatment of idiopathic thrombocytopenic purpura (ITP). We compared the effects of a relatively low dose (0.5 mg/kg/day, LD group) of PSL and the conventional dose (1.0 mg/kg/day, CD group) on 59 ITP patients. Twenty-six patients were treated with low-dose PSL, and 23 patients with the conventional dose. No statistically significant difference was observed in the complete remission rates for the LD group (35%) and the CD group (39%). However, the mean duration of hospitalization was significantly (p0.001) shorter for LD group patients than for patients in the CD group (20 days versus 50 days, respectively). In conclusion, low-dose PSL may be as effective as the conventional dose and capable of reducing the cost of hospitalization, thus, improving the quality of life for patients with ITP.
- Published
- 2000
22. [Erythropoietin and hypoxia responsive system]
- Author
-
S, Imagawa
- Subjects
omega-N-Methylarginine ,Transcription, Genetic ,Basic Helix-Loop-Helix Leucine Zipper Transcription Factors ,Nuclear Proteins ,Anemia ,Genetic Therapy ,Hypoxia-Inducible Factor 1, alpha Subunit ,Phosphoproteins ,Event-Related Potentials, P300 ,DNA-Binding Proteins ,Gene Expression Regulation ,Hepatocyte Nuclear Factor 4 ,Animals ,Humans ,Kidney Failure, Chronic ,Hypoxia-Inducible Factor 1 ,Hypoxia ,Erythropoietin ,Transcription Factors - Published
- 1999
23. [Retrospective analysis of elderly patientsor = 60 years of age with acute leukemia]
- Author
-
M, Tabata, M, Yoshida, T, Izumi, C, Kawano, R, Kuribara, M, Toshima, K, Omine, M, Takatoku, M, Uchida, K, Kirito, A, Miyazato, H, Takahashi, M, Hoshino, Y, Terui, H, Tomizuka, T, Otsuki, R, Shimizu, J, Tsunoda, K, Muroi, Y, Furukawa, Y, Amemiya, S, Imagawa, N, Komatsu, T, Suzuki, and Y, Miura
- Subjects
Male ,Mercaptopurine ,Prednisolone ,Daunorubicin ,Cytarabine ,DNA ,Middle Aged ,Precursor Cell Lymphoblastic Leukemia-Lymphoma ,Leukemia, Myeloid, Acute ,Methotrexate ,Vincristine ,Myelodysplastic Syndromes ,Antineoplastic Combined Chemotherapy Protocols ,Granulocyte Colony-Stimulating Factor ,Humans ,Female ,Aclarubicin ,Cyclophosphamide ,Aged ,Retrospective Studies - Abstract
A retrospective analysis was performed on 76 consecutive elderly patients with acute leukemia aged 60 years or more (48 men, 28 women). Forty patients were 60-69 years old, 28 were 70-79 years old and 8 wereor = 80 years old. There were 55 patients with acute myelogenous leukemia (AML), 13 acute lymphoblastic leukemia (ALL) and 8 AML from myelodysplastic syndrome (MDS/AML). Patients were treated with the JALSG protocol, CAG regimen, or low-dose Ara-C regimen for AML, and DVP/M-CHOP protocol for ALL. The complete remission (CR) rates were 52.7% (29 of 55) in AML, 61.5% (8 of 13) in ALL, and 0% in MDS/AML. The median CR durations were 226, 85, 0 days, and the median survivals were 204, 177, 99 days, respectively. CR rates were 65.3% for the JALSG protocol, 62.5% for the CAG regimen and 25.0% for low-dose Ara-C regimen. According to age, CR was obtained 62.5% in patients aged 60-69 years and 33.3% in patients over 70 years old. Our results indicated that patients aged 60-69 years should be treated with intensive chemotherapy.
- Published
- 1998
24. Erythropoietin gene expression by hydrogen peroxide
- Author
-
S, Imagawa, M, Yamamoto, M, Ueda, and Y, Miura
- Subjects
Vitamin K ,Gene Expression ,Humans ,Hydrogen Peroxide ,Hypoxia ,Promoter Regions, Genetic ,Erythropoietin ,Cells, Cultured ,Transcription Factors - Abstract
We examined the effect of H2O2 on the regulation of the human erythropoietin (Epo) gene through the GATA sequence in the Epo promoter in Hep3B cells. The addition of exogenous H2O2 in Hep3B cells inhibited hypoxia-induced Epo production of mRNA as assessed by competitive polymerase chain reaction (PCR) and protein by EIA. Likewise, menadione, which increased production of endogenous H2O2, inhibited hypoxia-induced Epo production in Hep3B cells. Furthermore, the expression of the human GATA (hGATA) transcription factor was increased dose-dependently by the addition of H2O2 or menadione in Hep3B cells as assessed by gel mobility shift assay. We concluded that H2O2 inhibits Epo gene expression, because it enhanced the expression of the hGATA transcription factor. Our findings support the hypothesis that GATA is a transcription factor for the Epo gene acting through the oxygen sensor.
- Published
- 1996
25. Philadelphia chromosome-negative cells with trisomy 8 after busulfan and interferon treatment of Ph1-positive chronic myelogenous leukemia
- Author
-
T, Izumi, S, Imagawa, K, Hatake, Y, Miura, T, Ariyama, J, Inazawa, and T, Abe
- Subjects
Male ,Leukemia, Myelogenous, Chronic, BCR-ABL Positive ,Humans ,Interferon-alpha ,Antineoplastic Agents ,Trisomy ,Middle Aged ,Antineoplastic Agents, Alkylating ,Busulfan ,Combined Modality Therapy ,Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative ,Chromosomes, Human, Pair 8 - Abstract
A 48-year-old Japanese man with Philadelphia chromosome (Ph1)-positive chronic myelogenous leukemia (CML) was treated with busulfan followed by interferon-alpha (IFN-alpha). Ten months after IFN-alpha treatment, Ph1(-) cells with trisomy 8 were detected by the conventional banding technique and fluorescence in situ hybridization (FISH) analysis. Add(Y)(q12) was also found in Ph1(-) cells with trisomy 8. Although Ph1(+) cells disappeared after the treatment with IFN-alpha, Ph1(-) cells with trisomy 8 did not. We summarize four previous case reports of Ph1(+) CML developing Ph1(-) cells with trisomy 8. All four patients had received busulfan and IFN-alpha. These drugs may be related to the ontogenesis of Ph1(-) cells with trisomy 8, but the significance of Ph1(-) cells with trisomy 8 is not known, and further observation is needed.
- Published
- 1996
26. [A case of acute promyelocytic leukemia (APL) with myeloblastoma in the oral cavity developing after receiving all-trans retinoic acid (ATRA)]
- Author
-
T, Izumi, K, Hatake, S, Imagawa, M, Yoshikda, M, Ohta, R, Sasaki, A, Miwa, T, Suda, S, Sakamoto, and Y, Miura
- Subjects
Adult ,Leukemia, Promyelocytic, Acute ,Administration, Oral ,Humans ,Female ,Mouth Neoplasms ,Tretinoin ,Blast Crisis - Abstract
A 44-year-old woman was diagnosed as having acute promyelocytic leukemia (APL) in April 1988. On her first admission, chromosomal translocation (15; 17), +8, and +12 was detected. When she was readmitted to our hospital with the second relapse in May 1990, t(3; 13) and +8 was detected, instead of t(15;17). Complete remission was re-achieved with VP-16, MIT, and BHAC, but the third relapse occurred in September 1990. After obtaining informed consent, she was given etretinate 40 mg per day orally for 17 days, without any effect on leukemia. She was then given all-trans retinoic acid (ATRA) 60 mg per day orally for 29 days. Although a mild granulocytic recovery was observed, no sufficient hematological recovery was obtained (minor response). Besides common side effects of ATRA, such as dry skin and hypertriglycedemia, she had a myeloblastoma in the oral cavity, but it is unknown whether the symptom was a complication of ATRA therapy or not.
- Published
- 1994
27. Positive and negative regulation of the erythropoietin gene
- Author
-
S, Imagawa, T, Izumi, and Y, Miura
- Subjects
Binding Sites ,Base Sequence ,Molecular Sequence Data ,Oligonucleotides ,Nuclear Proteins ,Cobalt ,In Vitro Techniques ,Cell Line ,DNA-Binding Proteins ,Enhancer Elements, Genetic ,Gene Expression Regulation ,Humans ,Nucleic Acid Conformation ,RNA, Messenger ,Hypoxia ,Promoter Regions, Genetic ,Erythropoietin ,DNA Primers - Abstract
In order to investigate positive and negative regulatory elements of the erythropoietin (Epo) gene, synthetic oligonucleotides were designed to control Epo transcription by means of an antigen strategy. We devised a new method for detecting regulatory elements of genes that have a weak promoter. Synthetic oligonucleotides were incubated with Hep3B cells in the presence or absence of CoCl2 or hypoxia. To exclude the effect of translational regulation, Epo mRNA concentration was determined by competitive polymerase chain reaction. The addition of antisense oligonucleotide for CACCC elements decreased the production of Epo mRNA in a dose-dependent fashion when cells were stimulated by CoCl2 or hypoxia. In contrast, the addition of antisense oligonucleotide for the GATA element caused a dose-dependent stimulation of Epo mRNA production either in the presence or absence of CoCl2 or hypoxia. Triple helix formation was revealed by electrophoresis. CACCC elements were demonstrated to be positive regulatory elements of the Epo gene, whereas the GATA element was a negative regulatory element. Furthermore, by gel mobility shift assays, we demonstrated evidence for the presence of factors in Hep3B cell nuclear extract that specifically bind to CACCC or GATA elements. Based on these observations, we presented the possibility that triple helix formation could serve as a novel means for transcriptional regulation of the gene.
- Published
- 1994
28. [Multiple myeloma with hemolytic anemia and thrombocytopenia]
- Author
-
K, Muroi, S, Imagawa, T, Suda, E, Kajii, Y, Otuka, I, Sakurabayashi, Y, Amemiya, S, Sakamoto, and Y, Miura
- Subjects
Anemia, Hemolytic ,Immunoglobulin G ,Humans ,Female ,Middle Aged ,Multiple Myeloma ,Thrombocytopenia - Abstract
We report a 59 year old female patient who was diagnosed as having IgG kappa myeloma with hemolytic anemia and thrombocytopenia simultaneously. Although M-protein was suspected to contribute to the hemolysis, the IgG purified from the patient's serum did not bind to red blood cells. Therefore, massive non-specific binding of M-protein to blood cells might contribute to high levels of red blood cell-associated IgG and platelet-associated IgG in the patient.
- Published
- 1991
29. Regulation of the erythropoietin gene in Hep 3B cells
- Author
-
M A, Goldberg, S, Imagawa, R K, Strair, and H F, Bunn
- Subjects
Hemeproteins ,Oxygen ,Liver Neoplasms, Experimental ,Gene Expression Regulation ,Metals ,Dactinomycin ,Tumor Cells, Cultured ,Animals ,RNA, Messenger ,Regulatory Sequences, Nucleic Acid ,Erythropoietin - Published
- 1991
30. [Staphylococcus aureus sepsis in patients with hematological malignancies: increase in MRSA sepsis]
- Author
-
M, Itoh, M, Yoshida, H, Kurata, S, Imagawa, M, Hoshino, J, Tsunoda, H, Ema, S, Tsunoda, T, Suzuki, and N, Komatsu
- Subjects
Adult ,Aged, 80 and over ,Male ,Staphylococcus aureus ,Leukemia ,Minocycline ,Middle Aged ,Staphylococcal Infections ,Prognosis ,Chloramphenicol ,Vancomycin ,Sepsis ,Humans ,Female ,Methicillin Resistance ,Aged - Abstract
From January 1978 to August 1990, Staphylococcus aureus bacteremia (SAB) were identified in 31 patients with hematological malignancies at Jichi Medical School hospital. Mortality due to SAB was 48.4% (15/31). Of the variables analyzed, four factors were significantly associated with a poor prognosis; elderly age (p = 0.015), high granulocyte count (more than 500/microliters) (p = 0.015), presence of DIC (p = 0.011) and presence of pneumonia (p = 0.023). The incidence of methicillin-resistant SAB was 32.3% (10/31) and the first patient developed in 1985. Although not statistically significant, there was a trend of higher mortality for methicillin-resistant SAB (70%) than for methicillin-sensitive SAB (38.1%). Most strains of methicillin-resistant Staphylococcus aureus were sensitive to minocycline, chloramphenicol and vancomycin.
- Published
- 1991
31. Extension of the high-ion-temperature regime in the Large Helical Device
- Author
-
M., Yokoyama, K., Nagaoka, M., Yoshinuma, Y., Takeiri, K., Ida, S., Morita, O., Kaneko, T., Seki, H., Kasahara, T., Mutoh, Y., Oka, K., Tsumori, M., Osakabe, K., Ikeda, K., Tanaka, H., Funaba, S., Matsuoka, S., Masuzaki, J., Miyazawa, R., Sakamoto, H., Yamada, K., Kawahata, N., Ohyabu, S., Imagawa, A., Komori, S., Sudo, O., Motojima, and Experimental Group, LHD
- Subjects
Physics ,plasma confinement ,Fusion ,Hydrogen ,Ambipolar diffusion ,chemistry.chemical_element ,Plasma ,Condensed Matter Physics ,Thermal diffusivity ,plasma transport processes ,Ion ,Large Helical Device ,plasma beam injection heating ,chemistry ,hydrogen ,Electric field ,plasma flow ,stellarators ,Atomic physics ,plasma temperature - Abstract
High-ion-temperature (exceeding 5 keV) hydrogen plasmas have been successfully produced in the Large Helical Device [Iiyoshi et al., Nucl. Fusion 39, 1245 (1999); Motojima et al., Nucl. Fusion 47, S668 (2007)] with the ion heat confinement improvement in the core region. The experimental ion heat diffusivity at the core region is found to be almost independent of the ion temperature, T_i (even decreasing as T_i increases). The neoclassical (NC) ripple transport is suppressed by the ambipolar radial electric field, E_r (
- Published
- 2008
32. 4P-1069 Natural killer T cells accelerate atherogenesis in mice
- Author
-
N. Ishimori, T. Zaman, D. Goto, T. Mishima, Y. Nakai, K. Watano, A. Kitabatake, S. Fujii, T. Furumoto, S. Imagawa, and J. Dong
- Subjects
Immunology ,Internal Medicine ,General Medicine ,Biology ,Cardiology and Cardiovascular Medicine ,Natural killer T cell - Published
- 2003
33. 2P-0402 Hypofibrinolysis and cardiac perivascular fibrosis observed during the development of diabetes in obese mice: Beneficial role of angiotensin converting enzyme (ACE) inhibitor
- Author
-
A. Kitabatake, B.E. Sobel, S. Fujii, T. Furumoto, Y. Nakai, D. Jie, T. Mishima, A.K.M.T. Zaman, S. Imagawa, and D. Goto
- Subjects
medicine.medical_specialty ,biology ,business.industry ,Angiotensin-converting enzyme ,General Medicine ,medicine.disease ,Endocrinology ,Diabetes mellitus ,Internal medicine ,ACE inhibitor ,Internal Medicine ,medicine ,biology.protein ,Cardiology and Cardiovascular Medicine ,business ,Perivascular fibrosis ,medicine.drug ,Obese Mice - Published
- 2003
34. 4P-1075 Induction of plasminogen activator inhibitor-1 by interleukin-6 is attenuated by HMG-CoA reductase inhibitor: Potential link between atherothrombosis and statins
- Author
-
T. Kaneko, T. Furomoto, J. Dong, D. Goto, S. Imagawa, S. Fujii, and A. Kitabatake
- Subjects
chemistry.chemical_compound ,biology ,Chemistry ,Plasminogen activator inhibitor-1 ,HMG-CoA reductase ,Internal Medicine ,biology.protein ,General Medicine ,Pharmacology ,Cardiology and Cardiovascular Medicine ,Interleukin 6 - Published
- 2003
35. Effect of Nerve Growth Factor and Dibutyryl Cyclic AMP on Biopterin and Catecholamine Levels of PC12h Pheochromocytoma Cells
- Author
-
Reiko Matsumoto, S. Yamada, S. Onozawa, S. Imagawa, M. Nakamura, and N. Nakanishi
- Subjects
medicine.medical_specialty ,Crystallography ,Clinical Biochemistry ,Biopterin ,Dibutyryl Cyclic AMP ,medicine.disease ,Biochemistry ,Pheochromocytoma ,chemistry.chemical_compound ,Nerve growth factor ,Endocrinology ,chemistry ,QD901-999 ,Internal medicine ,Catecholamine ,medicine ,Molecular Medicine ,medicine.drug - Published
- 1991
36. Interleukin-6 and Tumor Necrosis Factor-α in Patients with Obstructive Sleep Apnea-Hypopnea Syndrome.
- Author
-
S. Imagawa, Y. Yamaguchi, K. Ogawa, N. Obara, N. Suzuki, M. Yamamoto, and T. Nagasawa
- Subjects
- *
SLEEP apnea syndromes , *PATIENTS , *VASCULAR endothelial growth factors , *GROWTH factors , *APNEA , *SLEEP disorders - Abstract
Background: In previous studies, significantly elevated levels of vascular endothelial growth factor (VEGF) have been reported in patients with severe obstructive sleep apnea-hypopnea syndrome (OSAHS). On the other hand, plasma tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) have been significantly higher in mild sleep apneics than in normal controls. However, this study included a small number of patients and milder cases of OSAHS. Objectives andMethods: To assess the involvement of IL-6 and TNF-α in VEGF increases in patients with severe OSAHS, serum levels of IL-6 and TNF-α were determined in patients with severe OSAHS (n = 110) and compared to those of controls (n = 45) using an enzyme-linked immunosorbent assay. Results: No significant increase in IL-6 or TNF-α was detected in the present study cohort. However, the body mass index was significantly correlated with the severity of the apnea-hypopnea index. Conclusions: These data suggest that the elevation in VEGF is not directly related to IL-6 or TNF-α levels. However, the question of whether VEGF is the cause or the result of OSAHS remains to be determined. Further studies are needed to clarify the role of IL-6 and TNF-α in the pathogenesis of OSAHS, in which obesity should be entered as an independent factor.Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
37. Radiologic changes in knee joints before and after synovectomy
- Author
-
O. Hasegawa, S. Imagawa, and Y. Nagayama
- Subjects
medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Medicine ,Synovectomy ,business ,Surgery - Published
- 1974
38. A Tecnique and Results of Anterior Decompression and Interbody Fusion for Spondylotic Myelopathy of Cervical Spine
- Author
-
Y. Murakami, S. Saka, T. Nakazaki, T. Sumida, Itsushi Baba, N. Okamoto, and S. Imagawa
- Subjects
Vertebral body ,medicine.medical_specialty ,business.industry ,Spondylotic myelopathy ,Medicine ,Anterior decompression ,Subtotal Resection ,Posterior Longitudinal Ligament Ossification ,business ,Cervical spine ,Surgery - Abstract
The operative results and technique of 18 cases with cervical spondylotic myelopathy are described.The operative technique which we had underwent since in 1968 is subtotal resection of the affected vertebral body and most of the patients in this series had functionally excellent results. The technique for posterior longitudinal ligament calcification is described in details.
- Published
- 1978
39. Regulation of the Erythropoietin Gene
- Author
-
M A Goldberg, H F Bunn, and S Imagawa
- Subjects
Regulation of gene expression ,medicine.medical_specialty ,Kidney ,medicine.medical_treatment ,In situ hybridization ,Biology ,Hypoxia (medical) ,Cell biology ,Endocrinology ,medicine.anatomical_structure ,Cytokine ,Erythropoietin ,hemic and lymphatic diseases ,Internal medicine ,Gene expression ,medicine ,medicine.symptom ,medicine.drug ,Hormone - Abstract
In man and other mammals the red cell mass is regulated by the hormone erythropoietin (Epo). This glycoprotein is produced in the fetal liver1 and the adult kidney2 in response to hypoxia. The hormone travels to hematopoietic tissues where it stimulates the proliferation and differentiation of erythroid progenitor cells. Recent in situ hybridization suggests that in the kidney Epo mRNA is localized in a subset of peritubular cells3,4. The site of Epo production in the liver remains uncertain. In addition, little is understood about the mechanism by which hypoxia leads to the increased expression of the Epo gene.
- Published
- 1989
40. Beta-2-microglobulin concentration in cerebrospinal fluid--monitoring of malignant lymphoma in the central nervous system
- Author
-
S, Imagawa, Y, Aoki, H, Ninomiya, Y, Yoda, and T, Abe
- Subjects
Lymphoma ,Brain Neoplasms ,Humans ,Prognosis ,beta 2-Microglobulin - Published
- 1985
41. Oxygen sensing and erythropoietin gene regulation
- Author
-
M A, Goldberg, S, Imagawa, P S, Dunning, and H F, Bunn
- Subjects
Hemeproteins ,Oxygen ,Carcinoma, Hepatocellular ,Gene Expression Regulation ,Metals ,Genes, Regulator ,Liver Neoplasms ,Tumor Cells, Cultured ,Humans ,Hypoxia ,Erythropoietin - Published
- 1989
42. The effect of recombinant erythropoietin on intracellular free calcium in erythropoietin-responsive cells
- Author
-
S, Imagawa, B R, Smith, R, Palmer-Crocker, and H F, Bunn
- Subjects
Cytoplasm ,Cell Separation ,In Vitro Techniques ,Flow Cytometry ,Recombinant Proteins ,Colony-Forming Units Assay ,Mice ,Animals ,Calcium ,Erythropoiesis ,Egtazic Acid ,Erythropoietin ,Calcimycin ,Spleen - Abstract
We have investigated whether recombinant erythropoietin (r-Epo) elicits a change in intracellular free calcium (IFC) in purified Epo-responsive cells in spleens of mice treated with phenylhydrazine. Colony-forming units (CFU-E) were prepared by negative selection through immunologic panning. Anti-Forssman, Mac-1, Ia, and HSA antibodies were used to eliminate nonhematopoietic progenitors. After two pannings, 29 +/- 1.5% (mean +/- 1 SD) of the recovered cells were CFU-E. IFC was measured by labeling cells with the fluorescent dye Indo-1 and analyzing them on a flow cytometer from 15 seconds to 30 minutes after the addition of agonist. At each step of the panning procedure, there was no effect of r-Epo (0 to 10 U/mL) on IFC even in the larger cells that are predominantly CFU-E. As a positive control, calcium ionophore (A23187) significantly increased IFC in greater than 90% of the spleen cells enriched in CFU-E. During growth of CFU-E in methylcellulose, the calcium ionophore did not affect the r-Epo-dependent formation of erythroid colonies. EGTA inhibited the formation of erythroid colonies. This inhibition appeared to be the result of a toxic effect of the chelator because the colony growth could not be restored when Ca2+ was added to the cultures in the presence of the EGTA. We conclude that the biologic action of Epo on responsive erythroid cells does not depend on acute changes in IFC.
- Published
- 1989
43. Symbrachydactyly: review of 50 cases and definition
- Author
-
S, Imagawa
- Subjects
Adult ,Fingers ,Male ,Adolescent ,Thumb ,Child, Preschool ,Humans ,Abnormalities, Multiple ,Female ,Middle Aged ,Child ,Hand Deformities, Congenital ,Pectoralis Muscles - Published
- 1980
44. Regulation of the erythropoietin gene
- Author
-
S, Imagawa, M A, Goldberg, and H F, Bunn
- Subjects
Hemeproteins ,Carcinoma, Hepatocellular ,Recombinant Fusion Proteins ,Liver Neoplasms ,Regulatory Sequences, Nucleic Acid ,Cell Hypoxia ,Mice ,Gene Expression Regulation ,Genes ,Liver ,Cations ,Sequence Homology, Nucleic Acid ,Tumor Cells, Cultured ,Animals ,Humans ,Erythropoietin - Published
- 1989
45. Symbrachydactyly: pathogenesis of 5-fluorouracil induced model in mice
- Author
-
S, Imagawa
- Subjects
Disease Models, Animal ,Mice ,Pregnancy ,Abnormalities, Drug-Induced ,Animals ,Female ,Fluorouracil ,Syndactyly - Published
- 1980
46. [A case of IgG-Bence Jones protein kappa type multiple myeloma complicated by adult Fanconi syndrome and osteomalacia]
- Author
-
S, Imagawa, H, Ninomiya, Z B, Wang, M, Nakazawa, H, Nakamura, Y, Yoda, and A, Ohno
- Subjects
Immunoglobulin kappa-Chains ,Osteomalacia ,Humans ,Female ,Immunoglobulin Light Chains ,Middle Aged ,Fanconi Syndrome ,Multiple Myeloma ,Bence Jones Protein - Published
- 1984
47. [Experiences with the clinical use of Segontin in coronary disease]
- Author
-
I, OHIRA, M, HAGIWARA, T, UMEZONO, T, TSUCHIYA, S, IMAGAWA, and K, MATSUOKA
- Subjects
Cardiotonic Agents ,Vasodilator Agents ,Prenylamine ,Coronary Disease ,Diuretics ,Anti-Arrhythmia Agents - Published
- 1962
48. [STUDIES ON GASTRIC CANCER]
- Author
-
S, YAMADA, I, OHIRA, T, HISADA, M, HAGIWARA, S, SHIMIZU, N, KATO, T, UMEZONO, F, KUTSUMI, T, TSUCHIYA, S, IMAGAWA, T, MATSUOKA, and S, TERAOKA
- Subjects
Proteinuria ,Japan ,Stomach Neoplasms ,Tuberculin Test ,Biopsy ,Cytodiagnosis ,Neoplasms ,Endopeptidases ,Humans ,Endoscopy ,Cholecystography ,Diet - Published
- 1964
49. Performance of the LHD cryogenic system during cooling and excitation tests
- Author
-
T., Mito, R., Maekawa, A., Twamoto, S., Imagawa, K., Takahata, S., Yamada, N., Yanagi, A., Nishimura, H., Tamura, H., Chikaraishi, S., Hamaguchi, T., Baba, S., Moriuchi, K., Oba, H., Sekiguchi, I., Otake, T., Satow, Y., Nakamura, S., Satoh, O., Motojima, and Group, LHD
- Subjects
Quantitative Biology::Biomolecules ,Materials science ,Steady state ,Liquid helium ,Nuclear engineering ,Physics::Medical Physics ,Cryogenics ,Superconducting magnet ,Condensed Matter Physics ,Helium-3 refrigerator ,Electronic, Optical and Magnetic Materials ,law.invention ,Nuclear magnetic resonance ,Electromagnetic coil ,law ,Electrical and Electronic Engineering ,Lambda point refrigerator ,Excitation - Abstract
Performance of the LHD cryogenic system in the first year's operation was described making importance on the recovery process after the normal transition of the helical coils. During the excitation tests of the LHD superconducting coils up to 2.75 T, the normal zone propagation was observed in the helical coil and the emergency shut-off of the coil power supplies was carried out. 2,700 l of liquid helium evaporated from the helical coils. The coils and the helium refrigerator were separated automatically and the helium refrigerator could keep its steady state operation. After the pressure and flow rate of the recovery gas from the helical coils were settled down to the normal state, the coils were connected to the helium refrigerator and the cooling was restarted. The system could return to the steady state in which coil excitation is enabling, by only three and a half hours.
50. Improvement in Cryogenic Stability of the Model Coil of the LHD Helical Coil with Lower Temperatures
- Author
-
S., Imagawa, N., Yanagi, S., Hamaguchi, and T., Mito
Catalog
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