27 results on '"J. Okayama"'
Search Results
2. First test results for the ITER central solenoid model coil
- Author
-
T. Kato, H. Tsuji, T. Ando, Y. Takahashi, H. Nakajima, M. Sugimoto, T. Isono, N. Koizumi, K. Kawano, M. Oshikiri, K. Hamada, Y. Nunoya, K. Matsui, T. Shinba, Y. Tsuchiya, G. Nishijima, H. Kubo, E. Hara, H. Hanawa, K. Imahashi, K. Ootsu, Y. Uno, T. Oouchi, J. Okayama, T. Kawasaki, M. Kawabe, S. Seki, K. Takano, Y. Takaya, F. Tajiri, A. Tsutsumi, T. Nakanura, H. Wakabayashi, K. Nishii, N. Hosogane, M. Matsukawa, Y. Miura, T. Terakado, J. Okano, K. Shimada, M. Yamashita, K. Arai, T. Ishigouoka, A. Ninomiya, K. Okuno, D. Bessete, H. Takigami, N. Martovetsky, P. Michael, M. Takayasu, M. Ricci, R. Zanino, L. Savoldi, G. Zahn, A. Martinez, and R. Maix
- Subjects
Tokamak ,Materials science ,Thermonuclear fusion ,Mechanical Engineering ,Nuclear engineering ,Solenoid ,Fusion power ,Nuclear reactor ,law.invention ,Magnetic field ,Conductor ,Nuclear physics ,Nuclear Energy and Engineering ,law ,Electromagnetic coil ,General Materials Science ,Civil and Structural Engineering - Abstract
The largest pulsed superconducting coils ever built, the Central Solenoid (CS) Model Coil and Central Solenoid Insert Coil were successfully developed and tested by international collaboration under the R&D activity of the International Thermonuclear Experimental Reactor (ITER), demonstrating and validating the engineering design criteria of the ITER Central Solenoid coil. The typical achievement is to charge the coil up to the operation current of 46 kA, and the maximum magnetic field to 13 T with a swift rump rate of 0.6 T/s without quench. The typical stored energy of the coil reached during the tests was 640 MJ that is 21 times larger than any other superconducting pulsed coils ever built. The test have shown that the high current cable in conduit conductor technology is indeed applicable to the ITER coils and could accomplish all the requirements of current sharing temperature, AC losses, ramp rate limitation, quench behavior and 10 000-cycle operation.
- Published
- 2001
- Full Text
- View/download PDF
3. Test Results of ITER Model Coil. 13 T-640 MJ Nb3Sn Pulse Coil
- Author
-
Junji Inagaki, Kazuya Hamada, Gen Nihijima, Nicolai Martovetsky, Yoshihiko Nunoya, Osamu Ohsaki, Shuiti Seki, J. Okayama, Andre Martinez, Laura Savoldi, Hiroatsu Kubo, Mario Ricci, Yasuhide Uno, Masaru Kawabe, H. Hanawa, Fujio Tajiri, Takashi Kato, Hiroshi Tsuji, Tohru Shinba, Tadatoshi Tamiya, Tatsuya Shimizu, Phillip Michael, Takahiro Nakamura, Makoto Sugimoto, Tuneaki Terakado, T. Ohuchi, Toshinari Ando, Tadao Hiyama, Takeshi Omine, Fumiake Tsutsumi, Kenji Nishii, Norikiyo Koizumi, Kiyoshi Okuno, Yoshikazu Takahashi, H. Wakabayashi, Yoshinori Tsuchiya, Kiichi Ootsu, Tutomu Kawasaki, H. Takigami, Mamoru Shimada, Katsumi Kawano, Makoto Takayasu, Katsutoshi Takano, Takaaki Isono, K. Imahashi, Roberto Zanino, M. Oshikiri, Takeomi Hirohara, Denis Bessette, Yuushi Miura, Kunihiro Matsui, Hideo Nakajima, Saburo Ikeda, Katsuya Kuramochi, G. Zahn, and Y. Takaya
- Subjects
Materials science ,Test facility ,Fabrication ,Thermonuclear fusion ,Electromagnetic coil ,Nuclear engineering ,Stored energy ,Time constant ,Voltage ,Leakage (electronics) - Abstract
In the project for the International Thermonuclear Experimental Reactor (ITER), a Central Solenoid (CS) model coil was developed to demonstrate the feasibility of the coil design and fabrication procedure. The model coil was installed in the test facility at JAERI, Naka, and a performance test is being carried out. The cool-down was completed without cold He leakage at the beginning of April 2000. We could charge the model coil up to the nominal current of 46kA without quenching in the first DC charging test. The model coil could generate the maximum field of 13T, and the stored energy was 640MJ. A manual dump test was also performed with the time constant of 5.3s from the nominal current. A maximum voltage of 4.8kV appeared in the coil during the dump test, and no damage was found after the test. In the pulse operation test, the coil could be ramped up to the nominal current in 26s, with the maximum ramping rate of 0.5T/s. The target ramping rate of 0.4T/s was satisfied. The test results are described in this paper.
- Published
- 2000
- Full Text
- View/download PDF
4. Test Results of the SMES Model Coil. Cool-down and Thermal Characteristics
- Author
-
Tadao Hiyama, S. Sekiguchi, M. Taneda, Toru Minemura, T. Ohuchi, Ichiro Takano, Tsutomu Kawasaki, Katsumi Kawano, Satoshi Hanai, K. Imahashi, Takashi Satow, F. Tajiri, Takashi Kato, Takataro Hamajima, Toshihiro Kusunose, T. Honda, Hiroshi Tsuji, Y. Takaya, Kimiyuki Shinoda, Yoshihiro Wachi, Takaaki Isono, Takashi Himeno, Kazuya Hamada, Kiichi Ootsu, J. Okayama, and Tsukasa Wada
- Subjects
Pressure drop ,Bellows ,Materials science ,Electromagnetic coil ,Nuclear engineering ,Refrigerator car ,Solenoid ,Superconducting magnetic energy storage ,Electrical conductor ,Conductor - Abstract
A model coil of a superconducting magnetic energy storage (SMES) device, which is a forced-cooled Nb-Ti coil, has been fabricated and a performance test at cryogenic temperatures has been carried out. The SMES model coil is composed of 4 dual pancakes and its total weight is 4.5t. The applied conductors are cable-in-conduit conductors cooled by supercritical helium (SHe) at 4.5K and 0.7MPa. SHe is supplied to the SMES model coil and the structure by a reciprocating bellows pump. The test facility is located at the International Thermonuclear Experimental Reactor (ITER) common test facility, was constructed for the testing of an ITER central solenoid model coil. In the experiments, cool-down was finished within 10 days under controlled temperature differences in the SMES model coil. During cool-down and 4.5K operation, pressure drop characteristics of the conductor were measured and the friction factor estimated. The pressure drop characteristics of the SMES model coil were in good agreement with those of the previous cable-in-conduit conductor. During static operation without current, the heat load and refrigerator operation conditions were measured. The heat load of the SMES model coil is 7.5W, which is within the expected value.
- Published
- 1998
- Full Text
- View/download PDF
5. Development and Performance Test Results of 50kA Vapor-cooled Current Lead for ITER
- Author
-
H. Hanawa, Y. Takaya, Tomonobu Ito, Katsutoshi Takano, T. Honda, A. Terasawa, Yoshikazu Takahashi, Masayuki Konno, Tadao Hiyama, K. Azuma, Yasuhiro Uno, Yoshihiko Nunoya, Takashi Kato, Toshiaki Uehara, S. Sekiguchi, Takaaki Isono, Kiichi Ootsu, Kazuya Hamada, F. Tajiri, Kunihiro Matsui, Masanobu Taneda, M. Oshikiri, Masanobu Nozawa, Shinichi Nose, Yukio Yasukawa, Norikiyo Koizumi, Toshio Uede, I. Watanabe, Hideo Nakajima, K. Imahashi, Makoto Sugimoto, T. Ohuchi, T. Kawasaki, Toshinari Ando, H. Wakabayashi, Katsumi Kawano, Hiroshi Tsuji, Kiyoshi Takita, Ikuo Itoh, J. Okayama, and S. Seki
- Subjects
Thermonuclear fusion ,Materials science ,chemistry ,Electromagnetic coil ,Nuclear engineering ,chemistry.chemical_element ,Solenoid ,Current (fluid) ,Lead (electronics) ,Cooling channel ,Helium ,Volumetric flow rate - Abstract
JAERI has developed 50kA current leads for the International Thermonuclear Experimental Reactor (ITER). The Center Solenoid (CS) Model Coil program is under way by means of international collaboration in ITER-EDA. The CS model coil is being developed for ITER CS coil and is for demonstration for ITER construction. The performance test of the CS model coil will be carried out at the JAERI ITER common test facility (CTF). The current lead consists of the vertical lead and the connection lead. The vertical lead is a vapor-cooled type and has a cable-in-conduit geometry. The vertical lead was designed with a heat leak of 1.2W/kA at a helium flow rate of 0.06g/(s·kA). The measured heat leak satisfied the designed value. The connection lead was made from copper pipe soldered with NbTi supreconducting wires. The pipe was stabilized by the supreconducting wires and a cooling channel. The current lead was operated up to 60kA. The design and the performance test results of 50kA current leads are reported. The results meet the specifications for the CS model coil test and for the ITER real machine.
- Published
- 1998
- Full Text
- View/download PDF
6. Construction and Commissioning Test Results of the Test Facility for the ITER CS Model Coil
- Author
-
T. Kawasaki, Y. Takaya, Takashi Kato, T. Ito, T. Ando, Kazuhiko Nishida, Kazuya Hamada, Katsutoshi Takano, Yoshihiko Nunoya, Norikiyo Koizumi, K. Imahashi, K. Kawano, J. Okayama, Hajime Nakajima, S. Sckiguchi, H. Matsui, Hirokazu Tsuji, H. Wakabayashi, K. Ohotsu, Yoshikazu Takahashi, T. Honda, F. Tajiri, Takaaki Isono, M. Oshikiri, T. Ohuchi, Susumu Shimamoto, Masayoshi Sugimoto, Masataka Nishi, Y. Uno, S. Scki, H. Hanawa, and Tadao Hiyama
- Subjects
Fabrication ,Thermonuclear fusion ,Materials science ,Test facility ,Nuclear engineering ,General Engineering ,Iter tokamak ,Cryogenics ,Superconducting magnet ,Physics::Plasma Physics ,Electromagnetic coil ,Condensed Matter::Superconductivity ,Computer Science::Programming Languages ,Circuit breaker - Abstract
So as to demonstrate the superconducting magnet technology to be developed for construction of the International Thermonuclear Experimental Reactor (ITER), model coils were designed and are now bei...
- Published
- 1996
- Full Text
- View/download PDF
7. Construction of ITER common test facility for CS model coil
- Author
-
Y. Uno, S. Sekiguchi, Tadao Hiyama, Susumu Shimamoto, Hideo Nakajima, T. Ohuchi, T. Honda, T. Isono, K. Hamada, Y. Takaya, Masayoshi Sugimoto, H. Hanawa, Masataka Nishi, Kazuhiko Nishida, K. Nunoya, K. Ohtsu, M. Oshikiri, T. Ando, K. Imahashi, T. Kawasaki, K. Takano, K. Kawano, Norikiyo Koizumi, Y. Takahashi, Hirokazu Tsuji, H. Wakabayashi, Takeshi Kato, F. Tajiri, S. Seki, J. Okayama, and H. Matsui
- Subjects
Physics ,Nuclear magnetic resonance ,Electromagnetic coil ,Nuclear engineering ,Solenoid ,Vacuum chamber ,Superconducting magnet ,Cryopump ,Cryogenics ,Electrical and Electronic Engineering ,Fusion power ,Pulsed power ,Electronic, Optical and Magnetic Materials - Abstract
Japan Atomic Energy Research Institute is constructing the International Thermonuclear Experimental Reactor common test facility for the Central Solenoid Model Coil which is around 180 tons, a forced-flow cooled magnet with the maximum pulsed operation of 2 T/s and generates the rated magnetic field of 13 T at 48 kA with stored energy of 668 MJ. The test facility consists of a coil vacuum chamber, a cryogenic system with the 5-kW refrigerator and 500-g/s cryogenic pump, two pairs of 50-kA current leads, two DC power supplies (50 kA and 60 kA) and two JT-60 pulsed power supplies (50 kA, /spl plusmn/4.5 kV and /spl plusmn/40 kA, /spl plusmn/1.5 kV). The facility will be demonstrating the refrigeration and operation of a fusion pulsed magnet and the design and construction will accumulate experience towards the construction of ITER.
- Published
- 1996
- Full Text
- View/download PDF
8. Effects of cyclic pulsed operation on the coil performance in the Nb/sub 3/Sn Demo poloidal coil (DPC-EX)
- Author
-
Masayoshi Sugimoto, Masataka Nishi, A. Miyake, H. Wakabayashi, S. Seki, Y. Takahashi, Hirokazu Tsuji, Norikiyo Koizumi, Toshiyuki Takahashi, K. Yamamoto, M. Oshikiri, K. Kawano, K. Imahashi, F. Wuchner, F. Tajiri, Takeshi Kato, T. Ouchi, Hideo Nakajima, B. Turck, Y. Kon, F. Hosono, Yukio Yasukawa, Kiyoshi Okuno, K. Outsu, H. Tsukamoto, T. Ando, J. Okayama, T. Isono, H. Hanawa, Tadao Hiyama, H. Ebisu, T. Kawasaki, Y. Takaya, Y. Wadayama, T. Sasaki, Makoto Takayasu, K. Hamada, S. Iwamoto, and Koji Yoshida
- Subjects
Materials science ,Electromagnet ,Iter tokamak ,Superconducting magnet ,Electronic, Optical and Magnetic Materials ,law.invention ,Nuclear magnetic resonance ,law ,Electromagnetic coil ,Electrical equipment ,Current sharing ,Magnet ,Electrical and Electronic Engineering ,Composite material ,Alternating current - Abstract
The effect of cyclic pulsed operation on the coil performance was studied from the electrical and mechanical points of view in the second experiment of the Nb/sub 3/Sn Demo Poloidal Coil (DPC-EX). Current sharing temperatures, ac losses, displacements, and strains were measured before and after cyclic pulsed operation, which consisted of about 350 cycles. No degradation of the electrical and mechanical performance of the DPC-EX was observed in the range of these cycles. >
- Published
- 1994
- Full Text
- View/download PDF
9. Test results of the DPC-TJ: electromagnetic performance
- Author
-
Hideo Nakajima, F. Tajiri, M. Oshikiri, F. Hosono, Yoshikazu Takahashi, T. Fujioka, Katsumi Kawano, J. Okayama, Masahiro Seki, Hiroshi Tsuji, H. Mukai, Yoshihiro Wachi, Takaaki Isono, Takashi Kato, Kiyoshi Okuno, Masataka Nishi, T. Ohuchi, Toshinari Ando, Michitaka Ono, Mamoru Shimada, Tadao Hiyama, H. Hiue, H. Hanawa, and Makoto Sugimoto
- Subjects
Physics ,Nuclear physics ,Thermonuclear fusion ,Test facility ,Electromagnetic coil ,General Physics and Astronomy ,General Materials Science ,Average current ,Critical current ,Fusion power ,Superconducting Coils - Abstract
The DPC-TJ coil experiment was successfully carried out at the Japan Atomic Research Institute (JAERI) in 1991. This coil was developed by Toshiba and JAERI in collaboration to demonstrate the realization of superconducting coils for fusion with a high average current density of 40 A mm −2 . The DPC-TJ coil was charged up to its rated current of 24 kA (40 A mm −2 ) at 7.6 T without quench in the DPC test facility. Thereafter electromagnetic performance was tested by measuring I c and T cs values, and the critical current at 12 T was estimated at 41 kA. Many electromagnetic results were obtained, which are necessary for the design of future fusion machines such as the International Thermonuclear Experimental Reactor (ITER).
- Published
- 1993
- Full Text
- View/download PDF
10. Charging test results of the DPC-TJ, a high-current-density large superconducting coil for fusion machines
- Author
-
H. Ishida, Y. Kamiyauchi, H. Ebisu, A. Miyake, M. Oshikiri, Hajime Nakajima, Masayoshi Sugimoto, T. Sasaki, Masataka Nishi, H. Ohuchi, J.R. Armstrong, K. Kawano, H. Mukai, F. Tajiri, Y. Takaya, T. Ando, Yoshihiro Wachi, Y. Kon, Masami Seki, Takeshi Kato, Norikiyo Koizumi, T. Fujioka, J. Okayama, S. Iwamoto, Susumu Shimamoto, H. Hanawa, K. Koizumi, Koji Yoshida, Tadao Hiyama, Kiyoshi Okuno, T. Ohuchi, Eisuke Tada, Y. Sanada, T. Hamajima, Mamoru Shimada, F. Hosono, Y. Takahashi, Hirokazu Tsuji, Takaaki Isono, H. Hiue, and M. Ono
- Subjects
Physics ,Superconductivity ,Fusion ,Thermonuclear fusion ,Tokamak ,Nuclear engineering ,Superconducting magnet ,Fusion power ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Nuclear magnetic resonance ,law ,Electromagnetic coil ,Electrical and Electronic Engineering ,Current density - Abstract
The authors describe the electromagnetic results and the quench phenomena of the DPC-TJ large cable-in-conduit Nb/sub 3/Sn coil experiment which took place in the summer of 1991. The DPC-TJ coil was developed by Toshiba and JAERI in collaboration to demonstrate the realization of (NbTi)/sub 3/Sn superconducting coils for fusion with high average current density of 40 A/mm/sup 2/. The coil was charged up to its rated current of 24 kA (40 A/mm/sup 2/) at 7.6 T without quench in the DPC test facility. Thereafter, the electromagnetic performance was tested by measuring I/sub c/ and T/sub cs/, and the critical current at 12 T was estimated to be 41 kA. The quench phenomena of the DPC-TJ coil were also tested by measuring normal-zone propagation velocity to get the protection design. In these experiments, very slow and very fast propagation were observed. Many other electromagnetic results were also obtained, which are necessary for the design of fusion machines such as International Thermonuclear Experimental Reactor. >
- Published
- 1993
- Full Text
- View/download PDF
11. Test results of the toroidal model pancake for ITER/FER toroidal field coils
- Author
-
M. Sugimoto, F. Hosono, T. Isono, N. Koizumi, K. Yoshida, T. Ando, Y. Takahashi, M. Nishi, K. Okuno, H. Nakajima, H. Tsukamoto, T. Kato, K. Kawano, T. Hiyama, H. Hiue, S. Iwamoto, A. Miyake, T. Sasaki, H. Ebisu, T. Takahashi, K. Yamamoto, Y. Yasukawa, H. Hanawa, M. Oshikiri, S. Seki, F. Tajiri, M. Seki, T. Ouchi, J. Okayama, and H. Tsuji
- Subjects
Pressure drop ,Tokamak ,Toroid ,Materials science ,Nuclear engineering ,Toroidal field ,Superconducting magnet ,Fusion power ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Conductor ,Nuclear magnetic resonance ,law ,Electromagnetic coil ,Electrical and Electronic Engineering - Abstract
Development of a hollow cooling monolithic (TMC-FF) conductor has been carried out by Japan Atomic Energy Research Institute (JAERI) since 1988. Manufacture of the toroidal model pancake (TMP) made of the TMC-FF conductor was completed in August, 1991, after trial manufacturing and verification tests. Experiments on the TMP started in January, 1992, in the Demo Poloidal Coil (DPC) test facility. Results of cooldown, pressure drop, stability, and mechanical performance of the TMP are presented. >
- Published
- 1993
- Full Text
- View/download PDF
12. Test Results of the DPC-TJ-Electromagnetic Performance
- Author
-
T. Ohuchi, Toshinari Ando, H. Hanawa, Michitaka Ono, Masahiro Seki, Masataka Nishi, Katsumi Kawano, Mamoru Shimada, Yoshihiro Wachi, Takaaki Isono, Tadao Hiyama, Hideo Nakajima, H. Mukai, H. Hiue, Hiroshi Tsuji, Makoto Sugimoto, T. Fujioka, J. Okayama, F. Tajiri, M. Oshikiri, Kiyoshi Okuno, Takashi Kato, F. Hosono, and Yoshikazu Takahashi
- Subjects
Physics ,Thermonuclear fusion ,Test facility ,Electromagnetic coil ,Realizability ,Nuclear engineering ,Average current ,Critical current ,Current (fluid) ,Superconducting Coils - Abstract
The DPC-TJ coil experiment took place successfully at the Japan Atomic Energy Research Institute (JAERI) in 1991. This coil was developed by Toshiba and JAERI in collaboration to demonstrate the realizability of superconducting coils for fusion with high average current density of 40A/mm2. The DPC-TJ was charged up to its rated current of 24kA (40A/mm2) at 7.6T without quench in the DPC test facility. Thereafter the electromagnetic performances were tested by measuring Ic and Tcs, and the critical current at 12T was estimated 41kA. Many electromagnetic results were obtained, which are necessary for the design of the next fusion machines like International Thermonuclear Experimental Reactor (ITER).
- Published
- 1992
- Full Text
- View/download PDF
13. Behavior of off-flavour Compounds in the Raw Water of Lake Biwa and Its Treatment
- Author
-
J. Okayama, M. Nishikawa, T. Negoro, and M. Ando
- Subjects
Powdered activated carbon treatment ,Waste management ,Off-flavour ,business.industry ,Water supply ,Portable water purification ,Pulp and paper industry ,Geosmin ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Environmental science ,2-Methylisoborneol ,Raw water ,business ,Filtration - Abstract
A few, off-flavour problems are occurring every year conceming the water supply system of Kyoto City, Japan. In our research three species of filamentous blue-green algae have been identified as playing important roles in producing geosmin and 2-methylisoborneol (MIB) in Lake Biwa. These odorous compounds were found being stored in trichomes mainly, so the majority of those compounds can be removed from water during rapid sand filtration. In our water supply system, water purification has been executed based on the above pri nciple and we are obtaining favorable for removing those off-flavour troubles.
- Published
- 1991
- Full Text
- View/download PDF
14. Ramp-rate limitation test results of the Nb/sub 3/Sn Demo Poloidal Coil (DPC-EX)
- Author
-
M. Nishi, H. Nakajima, T. Ando, T. Hiyama, Y. Takahashi, K. Okuno, K. Yoshida, T. Kato, K. Kawano, T. Isono, M. Sugimoto, N. Koizumi, K. Hamada, T. Sasaki, K. Imahashi, S. Iwamoto, H. Ebisu, T. Ouchi, K. Ohtsu, J. Okayama, M. Oshikiri, T. Kawasaki, S. Seki, S. Sekiguchi, T. Takahashi, Y. Takaya, F. Tajiri, H. Tsukamoto, H. Hanawa, F. Hosono, A. Miyake, Y. Yasukawa, K. Yamamoto, H. Wakabayashi, Y. Wadayama, and H. Tsuji
- Subjects
Superconductivity ,Quantitative Biology::Biomolecules ,Fusion ,Materials science ,business.industry ,Nuclear engineering ,Physics::Medical Physics ,Electrical engineering ,Superconducting magnet ,Conductor ,Magnetic field ,chemistry.chemical_compound ,chemistry ,Electromagnetic coil ,Niobium-tin ,business ,Electrical conductor - Abstract
As a high-field pulse-poloidal test coil in the development program of superconducting coils for fusion machines, a 1 m-inner diameter superconducting coil named DPC-EX wound with 10 kA Nb/sub 3/Sn cable-in-conduit forced-cooled conductor was fabricated and its various performances were investigated. In its second test, the ramp-rate limitation phenomenon, i.e. the dependence of the coil current at quench on the current ramp speed, was studied in detail and a lot of important data for the design of large pulse coils were achieved.
- Published
- 2002
- Full Text
- View/download PDF
15. Progress of the ITER central solenoid model coil programme
- Author
-
S. Egorov, Laura Savoldi, J. Okano, S. Seki, Yoshihiko Nunoya, T. Shimizu, Takashi Kato, G. Bevilacqua, T. Tamiya, Katsutoshi Takano, T. Ando, Masamichi Yamashita, H. Wakabayashi, Katsumi Kawano, Roberto Zanino, A. Martinez, R. J. Jayakumar, T. Terakado, J. Okayama, K. Shimada, E. Hara, K. Arai, Rui Vieira, K. Nishii, Norikiyo Koizumi, Joseph Minervini, T. Omine, A. Ninomiya, Kunihiro Matsui, K. Imahashi, Denis Bessette, Hirotaka Kubo, Richard J. Thome, Yoshikazu Takahashi, R. Manahan, T. Shimba, M. Ricci, Hideo Nakajima, Kiyoshi Okuno, Y. Uno, M. Oshikiri, F. Tajiri, H. Hanawa, T. Ohuchi, Philip C. Michael, T. Kawasaki, Yoshinori Tsuchiya, T. Nakamura, Nicolai Martovetsky, Hirokazu Tsuji, T. Ishigooka, W. Herz, Ettore Salpietro, Tadao Hiyama, Gen Nishijima, K. Ohtsu, Yukitoshi Miura, G. Zahn, N. Mitchell, M. Kawabe, M. Matsukawa, Makoto Takayasu, J. Harada, Makoto Sugimoto, F. Tsutsumi, Y. Takaya, K. Kuramochi, N. Hosogane, G. Vecsey, M. Huguet, Takaaki Isono, and R.K. Maix
- Subjects
Nuclear and High Energy Physics ,Materials science ,Electromagnetic coil ,Nuclear engineering ,Stored energy ,Iter tokamak ,Solenoid ,Condensed Matter Physics ,Operation temperature ,Superconducting Coils - Abstract
The world's largest pulsed superconducting coil was successfully tested by charging up to 13 T and 46 kA with a stored energy of 640 MJ. The ITER central solenoid (CS) model coil and CS insert coil were developed and fabricated through an international collaboration, and their cooldown and charging tests were successfully carried out by international test and operation teams. In pulsed charging tests, where the original goal was 0.4 T/s up to 13 T, the CS model coil and the CS insert coil achieved ramp rates to 13 T of 0.6 T/s and 1.2 T/s, respectively. In addition, the CS insert coil was charged and discharged 10 003 times in the 13 T background field of the CS model coil and no degradation of the operational temperature margin directly coming from this cyclic operation was observed. These test results fulfilled all the goals of CS model coil development by confirming the validity of the engineering design and demonstrating that the ITER coils can now be constructed with confidence.
- Published
- 2001
16. A Bi-directional pattern antenna using short-tapered slot antenna
- Author
-
Hiroyuki Arai, Nobuhiro Kuga, and J. Okayama
- Subjects
Engineering ,Coaxial antenna ,business.industry ,Acoustics ,Antenna measurement ,Electrical engineering ,Slot antenna ,Antenna factor ,Antenna rotator ,business ,Monopole antenna ,Antenna efficiency ,Radiation pattern - Abstract
An array antenna consisting of short-tapered slot antennas that are placed parallel to a metallic palate is proposed. The antenna utilizes chokes to suppress mutual coupling since currents on the ground plane concentrate around the taper edge. Antenna characteristics are examined through FDTD analysis and experiments.
17. Postpartum acute adrenal insufficiency of early-onset Sheehan syndrome: A case series study in a single center.
- Author
-
Ishikawa S, Ishikawa H, Sato M, Nagasawa A, Suzuki Y, Okayama J, Nakada E, Omoto A, Shozu M, and Koga K
- Subjects
- Pregnancy, Female, Humans, Adult, Retrospective Studies, Postpartum Period, Acute Disease, Postpartum Hemorrhage epidemiology, Postpartum Hemorrhage etiology, Postpartum Hemorrhage therapy, Hyponatremia complications, Adrenal Insufficiency complications, Adrenal Insufficiency diagnosis, Adrenal Insufficiency epidemiology, Hypopituitarism complications, Hypopituitarism diagnosis
- Abstract
Aim: To identify the symptoms and relevant factors associated with acute adrenal insufficiency of early-onset Sheehan syndrome., Methods: We retrospectively reviewed the charts of 125 women admitted to our intensive care unit because of postpartum hemorrhage between January 2011 and December 2021. Three women developed acute adrenal insufficiency. We investigated the total blood loss, shock status, consciousness level upon arrival, and intensive care provided to the women. We also analyzed the symptoms and laboratory data that led to the diagnosis of acute adrenal insufficiency. Continuous variables were presented by median (minimum-maximum)., Results: The medians and ranges of age, total blood loss, and shock index [heart rate/systolic blood pressure] on admission were 33.1 (17.2-45.3) years, 3351 (595-20 260) g, and 0.94 (0.55-2.94), respectively. Seven women were older than 40 years, 28 experienced >5000 g blood loss, 17 had shock index >1.5, 27 had impaired consciousness upon arrival, and 15 underwent hysterectomy. Women who developed acute adrenal insufficiency were <40 years old and had a bleeding volume of over 5000 g, impaired consciousness upon arrival, and had undergone hysterectomy. They had experienced lactation failure, presented with hyponatremia-related symptoms on postpartum days 8-9, experienced general malaise, headache, and impaired consciousness, and showed severe hyponatremia., Conclusions: Massive postpartum hemorrhage over 5000 g, impaired consciousness upon arrival, and hysterectomy as a hemostatic measure were relevant factors associated with acute adrenal insufficiency of early-onset Sheehan syndrome. Hyponatremia-related symptoms occurring after lactation failure are indicative of the onset of acute adrenal insufficiency., (© 2023 Japan Society of Obstetrics and Gynecology.)
- Published
- 2024
- Full Text
- View/download PDF
18. Single-nucleotide polymorphism array and fluorescence in situ hybridization analysis to decode the cytogenetic profile of atypical partial hydatidiform moles diagnosed by short tandem repeat polymorphism analysis.
- Author
-
Suzuki Y, Usui H, Katayama E, Sato A, Nakamura N, Nakada E, Omoto A, Okayama J, Sato M, Nagasawa A, Hirosawa A, Shozu M, and Koga K
- Subjects
- Humans, Female, Pregnancy, Adult, Uterine Neoplasms genetics, Uterine Neoplasms diagnosis, Uterine Neoplasms pathology, Middle Aged, Hydatidiform Mole genetics, Hydatidiform Mole diagnosis, Hydatidiform Mole pathology, Microsatellite Repeats genetics, Polymorphism, Single Nucleotide, In Situ Hybridization, Fluorescence methods
- Abstract
Accurate diagnosis of partial hydatidiform moles (PHMs) is crucial for improving outcomes of gestational trophoblastic neoplasia. The use of short tandem repeat (STR) polymorphism analysis to distinguish between PHM and hydropic abortuses is instrumental; however, its diagnostic power has not been comprehensively assessed. Herein, we evaluated the diagnostic efficacy of STR in differentiating between PHM and hydropic abortus, thus providing an opportunity for early measurement of human chorionic gonadotropin for PHMs. We reviewed charts of STR polymorphism analysis performed on fresh villous specimens and patient blood samples using a commercial kit for 16 loci. The genetic classification of 79 PHMs was confirmed. STR was reliable in differentiating PHMs when at least 15 loci were available. Typically, PHMs are characterized by their triploidy, including two paternal and one maternal haploid contribution. In our sample, seven PHMs lacked the three-allelic loci, requiring fluorescence in situ hybridization (FISH) analysis to investigate imbalanced biparental conceptus and single-nucleotide polymorphism array analysis to reveal cytogenetic details. Of these PHMs, two, three, and one were identified as androgenetic/biparental mosaics (diploids), monospermic diandric monogynic triploids, and a typical dispermic diandric monogynic triploid, respectively. The remaining case was monospermic origin, but its ploidy details could not be available. Therefore, STR differentiated PHM from a biparental diploid abortus in most cases. However, PHM diagnosis may be compromised when STR is used as the sole method for cases displaying distinct cytogenetic patterns lacking the three-allelic loci, including androgenetic/biparental mosaicism. Therefore, FISH should be considered to confirm the diagnosis., (© 2024 Wiley Periodicals LLC.)
- Published
- 2024
- Full Text
- View/download PDF
19. Inter-agency collaboration factors affecting multidisciplinary workers' ability to identify child maltreatment.
- Author
-
Okato A, Hashimoto T, Tanaka M, Saito N, Endo M, Okayama J, Ichihara A, Eshima S, Handa S, Senda M, Sato Y, Watanabe H, Nakazato M, and Iyo M
- Subjects
- Adult, Child, Female, Humans, Intersectoral Collaboration, Japan, Leadership, Male, Middle Aged, Personnel Loyalty, Surveys and Questionnaires, Child Abuse prevention & control, Child Protective Services
- Abstract
Objectives: This study aimed to clarify the factors of successful inter-agency collaboration that affect multidisciplinary workers' abilities to identify child maltreatment. A questionnaire-based survey was conducted; the contents of the questionnaire included the Collaboration Evaluation Scale we developed and the workers' abilities to identify child maltreatment. In total, 277 individuals from various agencies in Japan participated in this study. To examine the factors of successful inter-agency collaboration affecting workers' awareness of child maltreatment, we used hierarchical multiple regression analysis., Results: The analysis showed the positive effect of "commitment with loyalty" on the workers' awareness of child maltreatment-related information in all fields (β = .18-.31, p < .05), the effect of "strong leadership" on information about maltreated children and the home environment (β = .18, p < .05; β = .16, p < .05, respectively), and the effect of "resources" on the information about mothers' information during pregnancy and of fathers' feelings towards their children during the perinatal period (β = .17, p < .05; β = .22, p < .01, respectively). In conclusion, commitment with loyalty, strong leadership, and resources are factors of successful inter-agency collaboration that affects the ability of multidisciplinary workers to recognize signs of child maltreatment.
- Published
- 2020
- Full Text
- View/download PDF
20. The Effect of Grandmothers' Presence on the Provision of Multidisciplinary Perinatal Support for Pregnant and Postpartum Women with Psychosocial Problems.
- Author
-
Ogawa M, Hashimoto T, Tanaka M, Tachibana M, Seki R, Sato A, Okayama J, Endo M, Saito N, Sato Y, Watanabe H, Nakazato M, Mori E, Shozu M, and Iyo M
- Abstract
Background: Pregnant and postpartum women with psychosocial problems are prone to face limited or absent perinatal functional support from biological grandmothers due to familial dysfunction. The study aimed to investigate whether the involvement and presence of biological maternal grandmothers providing practical support for their pre/postnatal daughters (ie, pregnant women) during the perinatal period may influence the number of support services provided by multidisciplinary agencies, including child consultation centers and municipal offices., Participants and Methods: This is a retrospective cohort study based on the medical records of all pregnant women with psychosocial problems that visited, gave birth, and received intervention from the hospital-based child protection unit at the Chiba University Hospital between February 2018 to March 2019. The primary outcome was to identify whether there was a difference in the number of multidisciplinary agencies providing perinatal support between pregnant women with and without the presence of functional support from biological maternal grandmothers during the perinatal period., Results: We identified 114 pregnant and postpartum women with psychosocial problems. Seventy-six of these participants (66.7%) had functional support from their biological maternal grandmothers during the perinatal period, and 38 participants (33.3%) did not. The number of agencies involved with participants who lacked functional support was significantly higher than participants with functional support ( t (55.14) = 2.98, p < 0.01). This finding was consistent among pregnant and postpartum primipara participants (n = 70) (t(68) = 3.87, p < 0.001), but not multipara (n = 44)., Conclusion: The findings indicate that the presence and functional support of biological maternal grandmothers influence the support that is needed from multidisciplinary perinatal support systems by pregnant and postpartum women with psychosocial problems. Primipara mothers without support from their own mothers may need greater multidisciplinary support., Competing Interests: In accordance with Dove press policy and the authors’ ethical obligation as researchers, we are reporting that Dr. Hashimoto reported personal fees from research support of a clinical trial that the Signant Health company manages. Dr. Iyo received consultant fees from Janssen, Eli Lilly, Otsuka, and Meiji Seika Pharma and reports honoraria from Janssen, Eli Lilly, Otsuka, Meiji Seika Pharma, Astellas, Dainippon Sumitomo, Ono, Mochida, MSD, Eisai, Daiichi-Sankyo, Novartis, Teijin, Shionogi, Hisamitsu, and Asahi Kasei. The other authors report no potential conflicts of interest in this work., (© 2019 Ogawa et al.)
- Published
- 2019
- Full Text
- View/download PDF
21. Removal of retained products of conception showing marked vascularity without uterine artery embolization: Two case reports.
- Author
-
Usui H, Sato A, Okayama J, Suzuki Y, Omoto A, and Shozu M
- Subjects
- Adult, Female, Humans, Pregnancy, Abortion, Incomplete surgery, Hydatidiform Mole surgery, Laminaria, Obstetric Surgical Procedures methods, Uterine Neoplasms surgery
- Abstract
Retained products of conception with marked vascularity can cause massive postabortal or post-partum bleeding. Uterine artery embolization is effective for uterus preservation but does not assure fertility preservation. Thus, the optimal treatment for retained products of conception with marked vascularity is uncertain. Here, we report two cases of retained products of conception with marked vascularity: one early abortion and one hydatidiform mole, which were successfully resolved by dilation and removal of the retained products, without uterine artery embolization. We pretreated the cervical dilation using two or more laminaria tents and named this technique the 'maximum laminaria procedure'. We observed that the vascularity disappeared just after the laminaria tents were removed, and subsequently, we could remove the retained products with minimal bleeding, without uterine artery embolization. This protocol might become a standard treatment for retained products of conception with marked vascularity., (© 2018 Japan Society of Obstetrics and Gynecology.)
- Published
- 2018
- Full Text
- View/download PDF
22. Hospital-based child protection teams that care for parents who abuse or neglect their children recognize the need for multidisciplinary collaborative practice involving perinatal care and mental health professionals: a questionnaire survey conducted in Japan.
- Author
-
Okato A, Hashimoto T, Tanaka M, Tachibana M, Machizawa A, Okayama J, Endo M, Senda M, Saito N, and Iyo M
- Abstract
Background: Child abuse and/or neglect is a serious issue, and in many cases, parents are the perpetrators. Hospital-based child protection teams (CPTs) play pivotal roles in the management of not only abused and/or neglected children but also of their parents; this is generally conducted through multidisciplinary practice. The aim of this study is to survey hospital-based CPT members to determine the professions they perceive to be most applicable to participation in CPTs., Participants and Methods: The participants were members of CPTs affiliated with hospitals that had pediatric emergency departments and which were located in Chiba Prefecture; specifically, 114 CPT members from 23 hospitals responded to this survey. The two main questionnaire items concerned are as follows: 1) each respondent's evaluation of conducting assessments, providing support, and implementing multidisciplinary collaborative practice in the treatment of abusive and negligent parents, and 2) each CPT member's opinion on the professions that are most important for CPT activities. An exploratory factor analysis (EFA) was performed to explore the factor structure of the data, and a correlation analysis was performed using the result obtained., Results: The EFA returned two factors: multidisciplinary collaborative practice (α = 0.84) and assessment and support (α = 0.89). A correlational analysis showed that multidisciplinary collaborative practice had a positive correlation for obstetricians ( r = 0.315, p = 0.001), neonatologists ( r = 0.261, p = 0.007), midwives ( r = 0.248, p = 0.011), and psychiatrists ( r = 0.194, p = 0.048); however, assessment and support was only significantly correlated with midwives ( r = 0.208, p = 0.039)., Conclusion: This study showed that hospital-based CPT members highly evaluate multidisciplinary collaborative practice for the management of abusive and/or negligent parents, and they believe that, in addition to pediatric physicians and nurses, perinatal care and mental health professionals are the most important participants in advanced CPT activities., Competing Interests: Disclosure Dr. Hashimoto reported personal fees from research support of a clinical trial that the bracket global company manages. Dr. Iyo received consultant fees from Janssen, Eli Lilly, Otsuka, and Meiji Seika Pharma and reports honoraria from Janssen, Eli Lilly, Otsuka, Meiji Seika Pharma, Astellas, Dainippon Sumitomo, Ono, Mochida, MSD, Eisai, Daiichi-Sankyo, Novartis, Teijin, Shionogi, Hisamitsu, and Asahi Kasei. The authors report no other conflicts of interest in this work.
- Published
- 2018
- Full Text
- View/download PDF
23. Tubal pregnancy associated with additional conception in a contralateral tube.
- Author
-
Ishikawa H, Kiyokawa T, Okayama J, Usui H, and Shozu M
- Subjects
- Adult, Female, Humans, Laparoscopy, Pregnancy, Salpingectomy, Embryo Transfer, Fallopian Tubes surgery, Fertilization in Vitro, Pregnancy, Tubal surgery
- Abstract
Pregnancy of unknown location is defined as empty endometrial cavity despite positive pregnancy test, and often develops as overt intrauterine or ectopic pregnancy. The pathophysiology of persistent pregnancy of unknown location, however, which involves continuous low serum human chorionic gonadotropin without any visible implantation site, is unknown. We report a case of left tubal pregnancy associated with additional conception in the contralateral tube. Left tubal pregnancy was suspected in a 40-year-old nulligravid woman after two embryo transfers following in vitro fertilization. Laparoscopic bilateral salpingectomy was performed for bilateral hydrosalpinx. Products from an additional conception were identified in the right tube. Short tandem repeat analysis using genomic DNA from resected specimens indicated two conceptions of different origin. The extra conception identified on microscopy may indicate one pathogenesis of persistent pregnancy of unknown location. Salpingectomy of the contralateral tube with hydrosalpinx is an option to prevent persistent occult pregnancy., (© 2015 Japan Society of Obstetrics and Gynecology.)
- Published
- 2015
- Full Text
- View/download PDF
24. Efficacy of transient treatment with FK506 in the early phase on cyclophosphamide-induced bone marrow chimerism and transplant tolerance across MHC barriers.
- Author
-
Okayama J, Ko S, Kanehiro H, Kanokogi H, and Nakajima Y
- Subjects
- Animals, Bone Marrow Cells drug effects, Bone Marrow Cells immunology, Graft vs Host Disease drug therapy, Graft vs Host Disease immunology, Graft vs Host Disease prevention & control, Heart Transplantation immunology, Lymphocyte Culture Test, Mixed, Rats, Rats, Inbred BN, Rats, Inbred Lew, Survival Rate, Transplantation, Homologous immunology, Cyclophosphamide pharmacology, Immunosuppressive Agents pharmacology, Major Histocompatibility Complex immunology, Tacrolimus pharmacology, Transplantation Chimera immunology, Transplantation Tolerance drug effects
- Abstract
Background: The use of mixed allogeneic bone marrow chimerism to induce donor-specific transplantation tolerance has been extensively demonstrated. In the present study, we assessed the effect of combined use of a short course of FK506 and a single-dose cyclophosphamide (CYP) on the induction of tolerance and development of GVHD after allogeneic BMT., Materials and Methods: Lewis rat (RT1(l)) recipients received BMT from Brown Norway (RT1(n)) donors on the next day after injection of CYP at a dose of 200 mg/kg. The recipients were further treated with no FK506 (n = 8), 0.3 mg/kg/day FK506 on days 10-16 (n = 6), or the same dose of FK506 on days 0-6 (n = 6). In a subgroup of animals, heterotopic heart transplantation was performed to investigate transplantation tolerance., Results: Six of eight recipient rats that did not receive FK506 died of severe GVHD, while high levels of chimerism were induced. Recipients of FK506 in the later phase developed mild transient GVHD around 2 to 3 weeks after BMT and recovered thereafter; however, the level of chimerism was significantly decreased (2.8 +/- 2.3% on day 100). Treatment with FK506 in the early phase completely prevented the development of GVHD and induced stable allogeneic chimerism in the long-term (13.8 +/- 8.3% on day 100). These recipients with stable chimerism accepted subsequent BN heart allografts indefinitely (>200 days x 5), while rejecting third-party (BUF) heart allografts by day 12., Conclusions: Early transient FK506 promotes the induction of stable bone marrow chimerism without GVHD after BMT with CYP pretreatment. The timing of treatment with FK506 is critical with a view to preventing GVHD and inducing stable long-lasting chimerism.
- Published
- 2006
- Full Text
- View/download PDF
25. Efficacy of auxiliary partial orthotopic liver transplantation for cure of hemophilia in a canine hemophilia A model.
- Author
-
Ko S, Tanaka I, Kanokogi H, Kanehiro H, Okayama J, Ori J, Shima M, Yoshioka A, Giles A, and Nakajima Y
- Subjects
- Animals, Bilirubin blood, Biomarkers blood, Disease Models, Animal, Dogs, Feasibility Studies, Graft Survival, Liver Transplantation physiology, Male, Transplantation, Homologous, Factor VIII analysis, Hemophilia A surgery, Liver Transplantation methods
- Abstract
Metabolic liver disease can be cured by orthotopic liver transplantation. Some successful cases of whole or partial liver transplantation have been reported. Because liver function in these recipients is normal save for the production of the responsive metabolic factor, auxiliary partial orthotopic liver transplantation (APOLT) may produce a benefit. However, no experimental model of APOLT for metabolic liver diseases has been reported. We established a canine APOLT model to evaluate the clinical feasibility and efficacy of APOLT to cure hemophilia. The donor normal beagle dog was used to establish an APOLT model. A left lobe partial liver graft taken from the donor was orthotopically transplanted to the recipient after resection of the native left lobe preserving the native right lobe. Recipients showed no atrophy and comparable blood flow in both the graft and the native liver at the time of exploration after APOLT. Thus, APOLT was performed from a normal donor to a recipient with hemophilia A. In this recipient, blood factor VIII activity markedly increased after APOLT and was maintained for 7 weeks. No episode of bleeding was seen during the observation. In conclusion, a canine APOLT model was successfully established as evidenced by sustained production of factor VIII in a hemophilia recipient. These findings suggest the clinical feasibility and efficacy of APOLT for metabolic liver diseases.
- Published
- 2005
- Full Text
- View/download PDF
26. Bone marrow chimerism and tolerance induced by single-dose cyclophosphamide.
- Author
-
Okayama J, Ko S, Kanehiro H, Kanokogi H, Hisanaga M, Ohashi K, Sho M, Nagao M, Ikeda N, Kanamura T, Akashi S, and Nakajima Y
- Subjects
- Animals, Cyclophosphamide immunology, Heart Transplantation immunology, Immunosuppressive Agents immunology, Major Histocompatibility Complex immunology, Models, Animal, Rats, Rats, Inbred Lew, Transplantation Tolerance immunology, Bone Marrow Transplantation immunology, Cyclophosphamide pharmacology, Immunosuppressive Agents pharmacology, Transplantation Chimera immunology, Transplantation Tolerance drug effects
- Abstract
Background: Establishment of hematopoietic chimerism is the most stable strategy for donor-specific tolerance. Safer pretreatment regimens are needed for clinical application. We evaluated the efficacy of a simple protocol using cyclophosphamide (CYP) on induction of chimerism and organ transplant tolerance across major histocompatibility complex (MHC) barriers in the rat., Materials and Methods: Bone marrow cells from BN (RT1(n)) donors were infused to LEW (RT1(l)) recipients on day 0 after a single injection of CYP at various doses on day -1. Donor-derived hematopoietic chimerism was evaluated by flowcytometry. The recipients received BN or third party (BUF) heart allografts on day 100., Results: While pretreatment with 200 mg/kg of CYP induced high levels of hematopoietic chimerism, six of eight recipients died of severe graft-versus-host-disease (GVHD). CYP at dose of 150 mg/kg induced 36.5 +/- 24.1% of donor-derived chimerism on day 10, and sustained macrochimerism was seen until day 100 without GVHD. Pretreatment with 100 mg/kg of CYP resulted in only transient chimerism (4.8 +/- 5.2%) which disappeared by day 20. In the recipients with 50 mg/kg of CYP, donor bone marrow cells were rapidly rejected and no chimerism was observed. The recipients with 150 mg/kg of CYP accepted BN heart allografts (>100 days x 5), while rejecting BUF allografts by day 12 (n = 4). BN heart allografts were rejected in the recipients with 100 (MST: 57 days, n = 5) and 50 mg/kg (MST: 7 days, n = 5) of CYP., Conclusions: A single dose of CYP can induce hematopoietic chimerism across MHC-barriers. The dose of 150 mg/kg seems to be optimal to induce organ transplant tolerance without developing GVHD.
- Published
- 2004
- Full Text
- View/download PDF
27. Immune responses of graft mesenteric lymph node in small bowel transplantation.
- Author
-
Kanokogi H, Ko S, Kanehiro H, Hisanaga M, Tatekawa Y, Kanamura T, Okayama J, and Nakajima Y
- Subjects
- Animals, Antibody Formation, Antigens, CD, Apoptosis, B7-1 Antigen drug effects, B7-2 Antigen, Cytokines genetics, Graft Survival, Histocompatibility Antigens Class I metabolism, Intestine, Small pathology, Lymph Nodes metabolism, Lymph Nodes pathology, Lymph Nodes physiopathology, Male, Membrane Glycoproteins antagonists & inhibitors, Phenotype, RNA, Messenger metabolism, Rats, Rats, Inbred BN, Rats, Inbred Lew, Tissue Donors, Intestine, Small transplantation, Lymph Nodes immunology, Mesentery
- Abstract
Background: The high proportions of lymphoid tissues are thought to be one of the underlying factors inducing severe allograft rejection following small bowel transplantation. Mesenteric lymph nodes (MLN) contained in the intestinal graft are not only a source of donor-derived professional antigen-presenting cells, but also offer a field for immune interaction between donor and host cells. We investigated immune responses in graft MLNs with or without FK506 to develop a novel strategy to control small bowel allograft rejection., Materials and Methods: Heterotopic small bowel transplantations were performed from Brown Norway donors to Lewis recipients. Changes in population of lymphocytes, expressions of costimulatory molecules, apoptosis, and cytokine profiles in graft MLNs were evaluated., Results: The increase in apoptotic cells and cytokine responses relating to rejection in the graft MLNs developed prior to those in graft jejunum. While donor lymphocytes in graft MLNs were rapidly replaced to host-derived lymphocytes independent of FK treatment, increase in CD8(+) T cells in host population was seen only in recipients without FK506 treatment. The expressions of B7 molecules on donor cells in graft MLNs were significantly lower in the recipients with FK treatment., Conclusions: Immune responses in graft MLNs have significant impact on the outcome of the small bowel allograft. Apoptosis of graft MLN cells was well correlated with and ahead of progression of acute rejection. Modulation of costimulatory molecules on donor-derived MLN cells in the allograft and specific suppression of host CD8(+) T cells are possible ways to control severe rejection after allogeneic small bowel transplantation.
- Published
- 2004
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.