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Horimoto Y, Hayashi E, Ito Y, Iida A, Hibino H, Inagaki A, Tajima T, Fukagawa K, Okita K, Yasui K, Nanbu I, Anan C, Uematsu N, Katada E, Matsukawa N, Kabasawa H. Dopaminergic performances in patients with parkinsonism — A combination study of dopamine transporter SPECT, dopamine synthesis and receptor pet. J Neurol Sci 2017. [DOI: 10.1016/j.jns.2017.08.733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Parmentier FD, Cazimajou T, Sekine Y, Hibino H, Irie H, Glattli DC, Kumada N, Roulleau P. Quantum Hall effect in epitaxial graphene with permanent magnets. Sci Rep 2016; 6:38393. [PMID: 27922114 PMCID: PMC5138823 DOI: 10.1038/srep38393] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 11/08/2016] [Indexed: 11/09/2022] Open
Abstract
We have observed the well-kown quantum Hall effect (QHE) in epitaxial graphene grown on silicon carbide (SiC) by using, for the first time, only commercial NdFeB permanent magnets at low temperature. The relatively large and homogeneous magnetic field generated by the magnets, together with the high quality of the epitaxial graphene films, enables the formation of well-developed quantum Hall states at Landau level filling factors v = ±2, commonly observed with superconducting electro-magnets. Furthermore, the chirality of the QHE edge channels can be changed by a top gate. These results demonstrate that basic QHE physics are experimentally accessible in graphene for a fraction of the price of conventional setups using superconducting magnets, which greatly increases the potential of the QHE in graphene for research and applications.
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Affiliation(s)
- F D Parmentier
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette cedex, France
| | - T Cazimajou
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette cedex, France
| | - Y Sekine
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa, Japan
| | - H Hibino
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa, Japan
| | - H Irie
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa, Japan
| | - D C Glattli
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette cedex, France
| | - N Kumada
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa, Japan
| | - P Roulleau
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette cedex, France
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3
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Wang S, Sekine Y, Suzuki S, Maeda F, Hibino H. Photocurrent generation of a single-gate graphene p-n junction fabricated by interfacial modification. Nanotechnology 2015; 26:385203. [PMID: 26334952 DOI: 10.1088/0957-4484/26/38/385203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A back-gate graphene p-n junction was achieved by selective interfacial modification of a chemical vapor deposition (CVD)-grown graphene field effect transistor (FET). Silane self-assembled monolayer (SAM) patterns were used to fabricate uniform p- and n-doped regions and a sharp p-n junction in the graphene FET channel. A gate-dependent photocurrent response was observed at the graphene p-n junction, and exhibited a maximum signal between two Dirac point voltages of SAM-doped graphene regions. A spatial photocurrent map shows that the photocurrent generated at the junction region was much larger than that from graphene/electrode junctions under the same incident laser power. This single-peak characteristic photocurrent in CVD graphene is dominated by the photothermoelectric contribution, and is highly sensitive to the power of incident laser. The SAM interfacial modification method provides a feasible route for the fabrication of efficient graphene-based photodetectors.
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Affiliation(s)
- S Wang
- NTT Basic Research Laboratories, NTT Corporation, Atsugi, Kanagawa 243-0198, Japan
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Kumada N, Parmentier FD, Hibino H, Glattli DC, Roulleau P. Shot noise generated by graphene p-n junctions in the quantum Hall effect regime. Nat Commun 2015; 6:8068. [PMID: 26337067 PMCID: PMC5426518 DOI: 10.1038/ncomms9068] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/13/2015] [Indexed: 11/11/2022] Open
Abstract
Graphene offers a unique system to investigate transport of Dirac Fermions at p–n junctions. In a magnetic field, combination of quantum Hall physics and the characteristic transport across p–n junctions leads to a fractionally quantized conductance associated with the mixing of electron-like and hole-like modes and their subsequent partitioning. The mixing and partitioning suggest that a p–n junction could be used as an electronic beam splitter. Here we report the shot noise study of the mode-mixing process and demonstrate the crucial role of the p–n junction length. For short p–n junctions, the amplitude of the noise is consistent with an electronic beam-splitter behaviour, whereas, for longer p–n junctions, it is reduced by the energy relaxation. Remarkably, the relaxation length is much larger than typical size of mesoscopic devices, encouraging using graphene for electron quantum optics and quantum information processing. Dirac fermions at a p–n junction can exhibit a wide variety of unusual properties. Here, the authors investigate the dynamics of such fermions in a graphene junction using shot noise measurements and demonstrate the crucial role of junction length.
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Affiliation(s)
- N Kumada
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198, Japan.,Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS URA 2464), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - F D Parmentier
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS URA 2464), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - H Hibino
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198, Japan
| | - D C Glattli
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS URA 2464), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - P Roulleau
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS URA 2464), CEA Saclay, F-91191 Gif-sur-Yvette, France
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Kumada N, Roulleau P, Roche B, Hashisaka M, Hibino H, Petković I, Glattli DC. Resonant edge magnetoplasmons and their decay in graphene. Phys Rev Lett 2014; 113:266601. [PMID: 25615366 DOI: 10.1103/physrevlett.113.266601] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Indexed: 06/04/2023]
Abstract
We investigate resonant edge magnetoplasmons (EMPs) and their decay in graphene by high-frequency electronic measurements. From EMP resonances in disk shaped graphene, we show that the dispersion relation of EMPs is nonlinear due to interactions, giving rise to the intrinsic decay of EMP wave packets. We also identify extrinsic dissipation mechanisms due to interaction with localized states in bulk graphene from the decay time of EMP wave packets. We indicate that, owing to the linear band structure and the sharp edge potential, EMP dissipation in graphene can be lower than that in GaAs systems.
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Affiliation(s)
- N Kumada
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198, Japan and Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS URA 2464), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - P Roulleau
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS URA 2464), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - B Roche
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS URA 2464), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - M Hashisaka
- Department of Physics, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8551, Japan
| | - H Hibino
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198, Japan
| | - I Petković
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS URA 2464), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - D C Glattli
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS URA 2464), CEA Saclay, F-91191 Gif-sur-Yvette, France
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Shimano R, Yumoto G, Yoo JY, Matsunaga R, Tanabe S, Hibino H, Morimoto T, Aoki H. Quantum Faraday and Kerr rotations in graphene. Nat Commun 2013; 4:1841. [DOI: 10.1038/ncomms2866] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 04/12/2013] [Indexed: 12/27/2022] Open
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Kumada N, Tanabe S, Hibino H, Kamata H, Hashisaka M, Muraki K, Fujisawa T. Plasmon transport in graphene investigated by time-resolved electrical measurements. Nat Commun 2013; 4:1363. [PMID: 23322051 PMCID: PMC3562445 DOI: 10.1038/ncomms2353] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 12/03/2012] [Indexed: 11/08/2022] Open
Abstract
Plasmons, which are collective charge oscillations, could provide a means of confining electromagnetic field to nanoscale structures. Recently, plasmonics using graphene have attracted interest, particularly because of the tunable plasmon dispersion, which will be useful for tunable frequency in cavity applications. However, the carrier density dependence of the dispersion is weak (proportional to n(1/4)) and it is difficult to tune the frequency over orders of magnitude. Here, by exploiting electronic excitation and detection, we carry out time-resolved measurements of a charge pulse travelling in a plasmon mode in graphene corresponding to the gigahertz range. We demonstrate that the plasmon velocity can be changed over two orders of magnitude by applying a magnetic field B and by screening the plasmon electric field with a gate metal; at high B, edge magnetoplasmons, which are plasmons localized at the sample edge, are formed and their velocity depends on B, n and the gate screening effect.
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Affiliation(s)
- N Kumada
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan.
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Abstract
Various physical properties of epitaxial graphene grown on SiC(0001) are studied. First, the electronic transport in epitaxial bilayer graphene on SiC(0001) and quasi-free-standing bilayer graphene on SiC(0001) is investigated. The dependences of the resistance and the polarity of the Hall resistance at zero gate voltage on the top-gate voltage show that the carrier types are electron and hole, respectively. The mobility evaluated at various carrier densities indicates that the quasi-free-standing bilayer graphene shows higher mobility than the epitaxial bilayer graphene when they are compared at the same carrier density. The difference in mobility is thought to come from the domain size of the graphene sheet formed. To clarify a guiding principle for controlling graphene quality, the mechanism of epitaxial graphene growth is also studied theoretically. It is found that a new graphene sheet grows from the interface between the old graphene sheets and the SiC substrate. Further studies on the energetics reveal the importance of the role of the step on the SiC surface. A first-principles calculation unequivocally shows that the C prefers to release from the step edge and to aggregate as graphene nuclei along the step edge rather than be left on the terrace. It is also shown that the edges of the existing graphene more preferentially absorb the isolated C atoms. For some annealing conditions, experiments can also provide graphene islands on SiC(0001) surfaces. The atomic structures are studied theoretically together with their growth mechanism. The proposed embedded island structures actually act as a graphene island electronically, and those with zigzag edges have a magnetoelectric effect. Finally, the thermoelectric properties of graphene are theoretically examined. The results indicate that reducing the carrier scattering suppresses the thermoelectric power and enhances the thermoelectric figure of merit. The fine control of the Fermi energy position is thought to be key for the practical use of graphene as a thermoelectric material, which could be achieved with epitaxial graphene. All of these results reveal that epitaxial graphene is physically interesting.
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Affiliation(s)
- H Kageshima
- NTT Basic Research Laboratories, Nippon Telegraph and Telephone Corporation, Atsugi, Kanagawa, Japan.
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Ida T, Goto T, Hibino H. Particle statistics in ϕ- and ω-scan powder diffraction intensity measurements. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311082961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Koyama S, Midorikawa A, Suzuki A, Hibino H, Kawamura M. A new type of prosopagnosia? A brain-damaged patient who can recognize faces but cannot discriminate races. J Vis 2010. [DOI: 10.1167/6.6.681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Watanabe T, Sasaki Y, Nanez JE, Koyama S, Mukai I, Hibino H, Tootell RB. Psychophysics and fMRI reveal V1 as the locus of passive learning. J Vis 2010. [DOI: 10.1167/2.7.557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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13
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Mukai I, Hibino H, Watanabe T. The likelihood of motion capture is more strongly determined by the degree of color contrast of adjacent gratings than by the degree of luminance contrast. J Vis 2010. [DOI: 10.1167/1.3.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Abstract
The microscopic structural and electrical properties of few-layer graphene grown on an SiC substrate were characterized by low-energy electron microscopy, transmission electron microscopy and scanning probe microscopy measurements of local conductance. The double-layer graphene sheet was confirmed to be continuous across the atomic steps on the buried SiC substrate surface, and the measured local conductance was clearly modified in the vicinity of the steps. The conductance decreased (slightly increased) at the lower (upper) side of the steps, suggesting deformation-induced strain is the origin of the conductance modification. From the contact force dependence of the conductance images, the effective contact areas for both nanogap-probe and point-probe measurements were estimated.
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Affiliation(s)
- M Nagase
- NTT Basic Research Laboratories, Nippon Telegraph and Telephone Corporation, 3-1, Morinosato-wakamiya, Atsugi, Kanagawa 243-0198, Japan.
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15
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Abstract
The uncertainty in measured diffraction intensities caused by particle statistics, which originates from the limited number of crystallites satisfying the diffraction condition, has been evaluated by a step-scan measurement about the rotation angle of a specimen-spinning attachment of a laboratory powder X-ray diffractometer. The residual statistical variance of the spinner-scan intensity data, after subtraction of periodic drift and variance caused by counting statistics, was assigned to the variance caused by particle statistics. Particle statistics for a standard Si powder (NIST SRM640c) and three size fractions (nominally 3–7, 8–12 and 18–22 µm in Stokes diameter) of quartz powder separated by a sedimentation method have been analysed by scanning electron microscopy (SEM) and the spinner-scan method using a powder X-ray diffractometer. It has been confirmed that the observed ratio of the squared diffraction-peak intensity to the variance caused by particle statistics is proportional to the multiplicity of reflections predicted by the crystal structure. The spinner-scan intensity data for the standard Si powder (NIST SRM640c), the effective particle diameter of which was estimated at 5.6 µm by SEM image analysis, was used as the standard for crystallite-size evaluation of quartz powder based on analysis of spinner-scan data. The effective crystallite diameters of the three quartz powder samples have been estimated at 6.5 (2), 11.7 (2) and 22.8 (2) µm by the analysis of the spinner-scan data, while the effective particle diameters evaluated by SEM image analysis are 7.1, 12 and 25 µm, respectively. Other possible applications of the analysis of particle statistics based on the spinner-scan method are also discussed.
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Nagase M, Hibino H, Kageshima H, Yamaguchi H. In-plane conductance measurement of graphene nanoislands using an integrated nanogap probe. Nanotechnology 2008; 19:495701. [PMID: 21730681 DOI: 10.1088/0957-4484/19/49/495701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The in-plane conductance of individual graphene nanoislands thermally grown on SiC substrate was successfully measured using an integrated nanogap probe without lithographic patterning. A Pt nanogap electrode with a 30 nm gap integrated on the cantilever tip of a scanning probe microscope enables us to image a conductance map of graphene nanoislands with nanometer resolution. Single- and double-layer graphene islands are clearly distinguished in the conductance image. The size dependence of the conductance of the nanoislands suggests that the band gap opening is due to the lateral confinement effect.
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Affiliation(s)
- M Nagase
- NTT Basic Research Laboratories, Nippon Telegraph and Telephone Corporation, 3-1, Morinosato-wakamiya, Atsugi, Kanagawa 243-0198, Japan
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Ishizawa N, Kondo S, Hibino H, Nakano H. Phase transition in Gd 3RuO 7and Tb 3RuO 7at elevated temperatures. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308083566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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18
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Ida T, Oya A, Hibino H. Statistical properties of measured X-ray intensities affected by counting loss of detection system. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308093653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Ida T, Hibino H. Symmetrization of diffraction peak profiles measured with a high-resolution synchrotron X-ray powder diffractometer. J Appl Crystallogr 2006. [DOI: 10.1107/s0021889805040318] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The asymmetry of diffraction peak profiles observed with a high-resolution synchrotron powder X-ray diffractometer has been successfully removed by a double deconvolution method. In the first step, the asymmetry caused by the axial divergence aberration of the diffractometer is removed by a whole-pattern deconvolution method based on ana prioritheoretical model for the aberration. In the second step, the residual asymmetry, the origin of which can be ascribed to the aberrations of the beamline optics, is also removed by a whole-pattern deconvolution method, based on an empirical model derived from the analysis of experimental diffraction peak profiles of a standard Si powder (NIST SRM640b). The beamline aberration has been modelled by the convolution of a pseudo-Voigt or Voigt function with an exponential distribution function. It has been found that the angular dependence of the asymmetry parameter in the exponential function is almost proportional to tanθ, which supports the idea that the residual asymmetry should be ascribed mainly to the intrinsic asymmetry in the spectroscopic distribution of the source X-ray supplied by the beamline optics of the synchrotron facility. Recently developed procedures of whole-pattern deconvolution have been improved to treat the singularity of the instrumental function in the measured angular range. Formulae for the whole-pattern deconvolution based on the Williamson–Hall-type dependence of the width parameter of the instrumental function have also been developed. The method was applied to the diffraction intensity data of a standard ZnO powder sample (NIST SRM674) measured with a high-resolution powder diffractometer on beamline BL4B2at the Photon Factory. The structure parameters of ZnO were refined from the integrated peak intensities, which were extracted by an individual profile fitting method applying symmetric profile models. The refined structure parameters coincide fairly well with those obtained from single-crystal data.
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Lesage F, Hibino H, Hudspeth AJ. Association of beta-catenin with the alpha-subunit of neuronal large-conductance Ca2+-activated K+ channels. Proc Natl Acad Sci U S A 2003; 101:671-5. [PMID: 14701909 PMCID: PMC327206 DOI: 10.1073/pnas.0307681100] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The association of Ca(2+)-activated K(+) channels with voltage-gated Ca(2+) channels at the presynaptic active zones of hair cells, photoreceptors, and neurons contributes to rapid repolarization of the membrane after excitation. Ca(2+) channels have been shown to bind to a large set of synaptic proteins, but the proteins interacting with Ca(2+)-activated K(+) channels remain unknown. Here, we report that the large-conductance Ca(2+)-activated K(+) channel of the chicken's cochlear hair cell interacts with beta-catenin. Yeast two-hybrid assays identified the S10 region of the K(+) channel's alpha-subunit and the ninth armadillo repeat and carboxyl terminus of beta-catenin as necessary for the interaction. An antiserum directed against the alpha-subunit specifically coprecipitated beta-catenin from brain synaptic proteins. beta-Catenin is known to associate with the synaptic protein Lin7/Velis/MALS, whose interaction partner Lin2/CASK also binds voltage-gated Ca(2+) channels. beta-Catenin may therefore provide a physical link between the two types of channels at the presynaptic active zone.
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Affiliation(s)
- F Lesage
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10021, USA
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Ida T, Shimazaki S, Hibino H, Toraya H. Diffraction peak profiles from spherical crystallites with lognormal size distribution. J Appl Crystallogr 2003. [DOI: 10.1107/s0021889803011580] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
An efficient and accurate method to evaluate the theoretical diffraction peak profiles from spherical crystallites with lognormal size distribution (SLN profile) is presented. Precise results can be obtained typically by an eight-term numerical integral for any values of the parameters, by applying an appropriate substitution of the variable to the integral formula. The calculated SLN profiles have been verified by comparison with those calculated by inverse Fourier transform from the exact analytical solution of the Fourier-transformed SLN profile. It has been found that the shape of the SLN profile strongly depends on the variance of size distribution. When the logarithmic standard deviation ω of the size distribution is close to 0.76, the SLN profile becomes close to a Lorentzian profile, and `super-Lorentzian' profiles are predicted for larger values of ω, as has been concluded by Popa & Balzar [J. Appl. Cryst.(2002),35, 338–346]. The intrinsic diffraction peak profiles of an SiC powder sample obtained by deconvolution of the instrumental function have certainly shown `super-Lorentzian' line profiles, and they are well reproduced by the SLN profile for the value ω = 0.93.
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Toraya H, Hibino H, Ida T, Kuwano N. Quantitative basis for the rocking-curve measurement of preferred orientation in polycrystalline thin films. J Appl Crystallogr 2003. [DOI: 10.1107/s0021889803003145] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
A quantitative basis for the rocking-curve measurement of the preferred orientation in polycrystalline thin films is presented. Gaussian functions are used for modeling the density distribution of the normals to the crystal plane around the normal to the specimen surface. An intensity formula for the rocking curve is derived from the kinematical theory applied to the case of asymmetric Bragg reflection. The density distribution is determined by the least-squares fit of a theoretical rocking curve to the observed curve, and a volume fraction of crystallites, whose normals to the crystal plane are present within a defined angular range, can be obtained from it. AlN and Au polycrystalline thin films were used for testing the present procedure. Parameter values of the model function, refined using both synchrotron radiation and laboratory X-rays, agree well with each other within the experimental errors although these intensity data sets were collected under different experimental conditions in instrumentation and wavelength. A distribution of depth-dependent preferred orientation in the AlN thin film was revealed by using double-layer and multiple-layer models. A very small degree of preferred orientation in Au thin films could also be measured. Parallel-beam optics and integrated intensities instead of peak height intensities are important for reliable rocking curve measurement.
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Abstract
A method to remove the effects of instrumental aberrations from the whole powder diffraction pattern measured with a high-resolution synchrotron powder diffractometer is presented. Two types of asymmetry in the peak profiles caused by (i) the axial-divergence aberration of the diffractometer (diffractometer aberration) and (ii) the aberration of the monochromator and focusing optics on the beamline (beamline aberration) are both taken into account. The method is based on the whole-pattern deconvolution by Fourier technique combined with the abscissa-scale transformation appropriate for each instrumental aberration. The experimental powder diffraction data of LaB6(NIST SRM660) measured on beamline BL-4B2at the Photon Factory in Tsukuba have been analysed by the method. The formula of the scale transformation for the diffractometer aberration hasa prioribeen derived from the instrumental function with geometric parameters of the optics. The strongly deformed experimental peak profiles at low diffraction angles have been transformed to sharp peak profiles with less asymmetry by the deconvolution of the diffractometer aberration. The peak profiles obtained by the deconvolution of the diffractometer aberration were modelled by an asymmetric model profile function synthesized by the convolution of the extended pseudo-Voigt function and an asymmetric component function with an empirical asymmetry parameter, which were linearly dependent on the diffraction angle. Fairly symmetric peak profiles have been obtained by further deconvolution of the empirically determined asymmetric component of the beamline aberration.
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Hibino H, Pironkova R, Onwumere O, Rousset M, Charnet P, Hudspeth AJ, Lesage F. Direct interaction with a nuclear protein and regulation of gene silencing by a variant of the Ca2+-channel beta 4 subunit. Proc Natl Acad Sci U S A 2003; 100:307-12. [PMID: 12518067 PMCID: PMC140959 DOI: 10.1073/pnas.0136791100] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The beta subunits of voltage-gated Ca(2+) channels are known to be regulators of the channels' gating properties. Here we report a striking additional function of a beta subunit. Screening of chicken cochlear and brain cDNA libraries identified beta(4c), a short splice variant of the beta(4) subunit. Although beta(4c) occurs together with the longer isoforms beta(4a) or beta(4b) in the brain, eye, heart, and lung, the cochlea expresses exclusively beta(4c). The association of beta(4c) with the Ca(2+)-channel alpha(1) subunit has slight but significant effects on the kinetics of channel activation and inactivation. Yeast two-hybrid and biochemical assays revealed that beta(4c) interacts directly with the chromo shadow domain of chromobox protein 2heterochromatin protein 1gamma (CHCB2HP1gamma), a nuclear protein involved in gene silencing and transcriptional regulation. Coexpression of this protein specifically recruits beta(4c) to the nuclei of mammalian cells. Furthermore, beta(4c) but not beta(4a) dramatically attenuates the gene-silencing activity of chromobox protein 2heterochromatin protein 1gamma. The beta(4c) subunit is therefore a multifunctional protein that not only constitutes a portion of the Ca(2+) channel but also regulates gene transcription.
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Affiliation(s)
- H Hibino
- The Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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Yanagisawa A, Hibino H, Nomura N, Yamamoto H. Unprecedented .gamma.-selective nucleophilic substitution reaction of allylmetal reagents: a new cross-coupling of diphenyl phosphates with allylic Grignard reagents. J Am Chem Soc 2002. [DOI: 10.1021/ja00066a088] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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26
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Hibino H, Pironkova R, Onwumere O, Vologodskaia M, Hudspeth AJ, Lesage F. RIM binding proteins (RBPs) couple Rab3-interacting molecules (RIMs) to voltage-gated Ca(2+) channels. Neuron 2002; 34:411-23. [PMID: 11988172 PMCID: PMC2151925 DOI: 10.1016/s0896-6273(02)00667-0] [Citation(s) in RCA: 213] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Ca(2+) influx through voltage-gated channels initiates the exocytotic fusion of synaptic vesicles to the plasma membrane. Here we show that RIM binding proteins (RBPs), which associate with Ca(2+) channels in hair cells, photoreceptors, and neurons, interact with alpha(1D) (L type) and alpha(1B) (N type) Ca(2+) channel subunits. RBPs contain three Src homology 3 domains that bind to proline-rich motifs in alpha(1) subunits and Rab3-interacting molecules (RIMs). Overexpression in PC12 cells of fusion proteins that suppress the interactions of RBPs with RIMs and alpha(1) augments the exocytosis triggered by depolarization. RBPs may regulate the strength of synaptic transmission by creating a functional link between the synaptic-vesicle tethering apparatus, which includes RIMs and Rab3, and the fusion machinery, which includes Ca(2+) channels and the SNARE complex.
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Affiliation(s)
| | | | | | | | - A. J. Hudspeth
- Address for correspondence: Dr. A. J. Hudspeth, Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, Box 314, The Rockefeller University, 1230 York Avenue, New York NY 10021-6399 USA, Telephone: 212/327-7351; Facsimile: 212/327-7352; E-mail:
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27
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Nielsen JF, Pelz JP, Hibino H, Hu CW, Tsong IS. Enhanced terrace stability for preparation of step-free Si(001)-(2 x 1) surfaces. Phys Rev Lett 2001; 87:136103. [PMID: 11580609 DOI: 10.1103/physrevlett.87.136103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2001] [Indexed: 05/23/2023]
Abstract
We show that depositing Si while annealing patterned Si(001)-(2 x 1) substrates at sublimation temperatures enhances terrace stability, permitting larger step-free areas to be produced in a given time than possible by annealing alone. We confirm this enhanced terrace stability using real-time low-energy electron microscopy observations, and quantitative microscopic modeling of step dynamics. Our measurements can be used to estimate the lateral variation in adatom concentration across large terraces, and to estimate an adatom diffusion length lambda approximately 10-30 microm at 1000 degrees C.
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Affiliation(s)
- J F Nielsen
- Department of Physics, Ohio State University, Columbus, Ohio 43210, USA
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28
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Abstract
A formula of the instrumental function for a high-resolution synchrotron X-ray diffractometer, equipped with a flat crystal analyser and a set of Soller slits for limiting the axial divergence of the diffracted beam, has been derived. The formula incorporates the effects of (i) the axial divergence of the diffracted beam limited by the Soller slits, (ii) the Bragg angle of the flat crystal analyser, and (iii) the tilt angle defined as the deviation of the normal direction of the analyser face from the goniometer plane. The model profile function given by the convolution of a Lorentzian function with the instrumental function has been applied to fit the experimental diffraction peak profiles of standard Si powder (NIST SRM640b) measured with a high-resolution synchrotron X-ray diffractometer, MDS, on beamline BL4B2 at the Photon Factory in Tsukuba. The convolution has been calculated by applying an efficient algorithm for numerical integration. The profile function reproduces not only the experimental profiles measured with a well aligned crystal analyser, but also significantly distorted profiles arising from misalignment of the analyser, withRpvalues within 1.4%, by varying only the instrumental parameter for the tilt angle. It is suggested that further convolution with a Gaussian distribution is practically not necessary for the model instrumental function to fit the data collected with MDS. More rapid computation can be achieved by applying an analytical formula of the profile function, when the tilt angle of the crystal analyser is within about 0.2°.
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Hibino H, Tani K, Sugiyama H, Suzuki S, Wu MS, Izawa K, Hase H, Nakazaki Y, Tanabe T, Ooi J, Izeki T, Tojo A, Saitoh I, Tanioka Y, Asano S. Haematopoietic progenitor cells from the common marmoset as targets of gene transduction by retroviral and adenoviral vectors. Eur J Haematol 2001; 66:272-80. [PMID: 11380607 DOI: 10.1034/j.1600-0609.2001.066004272.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
To establish a new non-human primate model for human cytokine and gene therapy, we characterized lymphocytes and haematopoietic progenitor cells of the small New World monkey, the common marmoset. We first assessed the reactions of marmoset bone marrow (BM) and peripheral blood (PB) cells to mouse anti-human monoclonal antibodies (mAbs) for the purpose of isolating marmoset lymphocytes and haematopoietic progenitor cells. Both cell fractions stained with CD4 and CD8 mAbs were identified as lymphocytes by cell proliferation assay and morphological examination. Myeloid-specific mAbs such as CD14 and CD33 did not react with marmoset BM and PB cells. No available CD34 and c-kit mAbs could be used to purify the marmoset haematopoietic progenitor cells. Furthermore, we studied the in vitro transduction of the bacterial beta-galactosidase (LacZ) gene into CFU-GM derived from marmoset BM using retroviral and adenoviral vectors. The transduction efficiency was increased by using a mixed culture system consisting of marmoset BM stromal cells and retroviral producer cells. It was also possible to transduce LacZ gene into marmoset haematopoietic progenitor cells with adenoviral vectors as well as retroviral vectors. The percentage of adenovirally transduced LacZ-positive clusters was 15% at day 4 (multiplicity of infection=200), but only 1-2% at day 14. The differential use of viral vector systems is to be recommended in targeting different diseases. Our results suggested that marmoset BM progenitor cells were available to examine the transduction efficiency of various viral vectors in vitro.
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Affiliation(s)
- H Hibino
- Department of Hematology/Oncology, Institute of Medical Science, The University of Tokyo, Central Institute for Experimental Animals Laboratories Inc., Kawasaki, Kanagawa, Japan
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30
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Abstract
Line shapes of theKα1–Kα2doublet beam reflected from a parabolic graded multilayer (PGM) were analysed by ray tracing and rocking-curve measurements using an Si(400) flat single crystal. The integrated intensity and the intensity ratio ofKα2toKα1of the reflected beam vary with the angle of incidence at the PGM. The rates of these variations are considered to increase with increasing spectral resolution of the PGM. TheKα1andKα2beams are reflected from the PGM in slightly different directions. Therefore, the angular separation between theKα1andKα2peaks of the observed diffraction profile of a sample becomes smaller than that calculated from the two wavelengths forKα1andKα2when the PGM and the sample are arranged in the (+−) setting, andvice versawhen they are in the (++) setting. The magnitude of the shift of the angular separation is close to the experimental uncertainty in the determination of the peak positions when the PGM consists of W/Si bilayers, whereas it is estimated to be three times as large when a PGM of high spectral resolution is used.
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Wu MS, Tani K, Sugiyama H, Hibino H, Izawa K, Tanabe T, Nakazaki Y, Ishii H, Ohashi J, Hohjoh H, Iseki T, Tojo A, Nakamura Y, Tanioka Y, Tokunaga K, Asano S. MHC (major histocompatibility complex)-DRB genes and polymorphisms in common marmoset. J Mol Evol 2000; 51:214-22. [PMID: 11029066 DOI: 10.1007/s002390010083] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
A New World monkey, the common marmoset (Callithrix jacchus), will be used as a preclinical animal model to study the feasibility of cell and gene therapy targeting immunological and hematological disorders. For elucidating the immunogenetic background of common marmoset to further studies, in the present study, polymorphisms of MHC-DRB genes in this species were examined. Twenty-one Caja-DRB exon 2 alleles, including seven new ones, were detected by means of subcloning and the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) methods followed by nucleotide sequencing. Based on the alignment of these allele sequences, we designed two pairs of specific primers and established a PCR-SSCP method for DNA-based histocompatibility typing of the common marmoset. According to the family segregation data and phylogenetic analyses, we presumed that Caja-DRB alleles could be classified into five different loci. Southern blotting analysis also supported the existence of multiple DRB loci. The patterns of nucleotide substitutions suggests that positive selection operates in the antigen-recognition sites of Caja-DRB genes.
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Affiliation(s)
- M S Wu
- Division of Molecular Therapy, Advanced Clinical Research Center (ACRC), The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
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Hibino H, Inanobe A, Tanemoto M, Fujita A, Doi K, Kubo T, Hata Y, Takai Y, Kurachi Y. Anchoring proteins confer G protein sensitivity to an inward-rectifier K(+) channel through the GK domain. EMBO J 2000; 19:78-83. [PMID: 10619846 PMCID: PMC1171779 DOI: 10.1093/emboj/19.1.78] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Anchoring proteins cluster receptors and ion channels at postsynaptic membranes in the brain. They also act as scaffolds for intracellular signaling molecules including synGAP and NO synthase. Here we report a new function for intracellular anchoring proteins: the regulation of synaptic ion channel function. A neuronal G protein-gated inwardly rectifying K(+) channel, Kir3.2c, can not be activated either by M(2)-muscarinic receptor stimulation or by G(betagamma) overexpression. When coexpressed with SAP97, a member of the PSD/SAP anchoring protein family, the channel became sensitive to G protein stimulation. Although the C-terminus of Kir3. 2c bound to the second PDZ domain of SAP97, functional analyses revealed that the guanylate kinase (GK) domain of SAP97 is crucial for sensitization of the Kir3.2c channel to G protein stimulation. Furthermore, SAPAP1/GKAP, which binds specifically to the GK domain of membrane-associated guanylate kinases, prevented the SAP97-induced sensitization. The function of a synaptic ion channel can therefore be controlled by a network of various intracellular proteins.
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Affiliation(s)
- H Hibino
- Departments of Pharmacology II, Graduate School of Medicine, Osaka University, 2-2, Yamada-oka, Suita, Osaka 565-0871, Japan
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Tomobe YI, Morizawa K, Tsuchida M, Hibino H, Nakano Y, Tanaka Y. Dietary docosahexaenoic acid suppresses inflammation and immunoresponses in contact hypersensitivity reaction in mice. Lipids 2000; 35:61-9. [PMID: 10695925 DOI: 10.1007/s11745-000-0495-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This study was designed to examine the immunomodulatory effects of dietary docosahexaenoic acid (DHA) in the absence of eicosapentaenoic acid (EPA). We investigated the effects of feeding dietary DHA ethyl ester (DHA-Et) (97% pure) at levels of 4.8 wt% of the total diet and of feeding EPA ethyl ester (EPA-Et) (99% pure) at 4.8 wt% on the inflammatory response in the challenge phase of the contact hypersensitivity reaction (CHR) in the ears of mice sensitized with 2,4-dinitro-1-fluorobenzene (DNFB). The effect of DHA-Et on T lymphocytes at the CHR site was examined using anti-CD4 antibodies. Furthermore, we examined the cytokines formed at the CHR site on the mRNA level. It was found that 24 h after the challenge, DHA-Et but not EPA-Et reduced the ear swelling. Infiltration of inflammatory cells, in particular, CD4-positive T lymphocytes, into the ears in the challenge phase of CHR was observed. DHA-Et reduced the infiltration of CD4-positive T lymphocytes into the ears. DHA-Et also decreased the expression of interferon-gamma, interleukin (IL)-6, IL-1beta, and IL-2 mRNA in ears. These observations suggest that DHA, but not EPA, may exert an antiinflammatory and immunosuppressive effect. The immunosuppressive effectiveness of fish oil may be attributed mainly to DHA.
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Affiliation(s)
- Y I Tomobe
- Tsukuba Research Laboratory, NOF Corporation, Ibaraki, Japan
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Inanobe A, Horio Y, Fujita A, Tanemoto M, Hibino H, Inageda K, Kurachi Y. Molecular cloning and characterization of a novel splicing variant of the Kir3.2 subunit predominantly expressed in mouse testis. J Physiol 1999; 521 Pt 1:19-30. [PMID: 10562331 PMCID: PMC2269641 DOI: 10.1111/j.1469-7793.1999.00019.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
1. One of the features of weaver mutant mice is male infertility, which suggests that Kir3.2, a G-protein-gated inwardly rectifying K+ channel subunit, may be involved in spermatogenesis. Therefore, we have characterized the Kir3.2 isoform in mouse testis using immunological, molecular biological and electrophysiological techniques. 2. Testicular membrane contained a protein that was recognized by the antibody specific to the C-terminus of Kir3.2c (aG2C-3). Its molecular mass was approximately 45 kDa, which was smaller than that of Kir3.2c ( approximately 48 kDa). The immunoprecipitant obtained from testis with aG2C-3 contained a single band of the 45 kDa protein, which could not be detected by the antibody to the N-terminus common to the known Kir3.2 isoforms (aG2N-2). 3. A novel alternative splicing variant of Kir3.2, designated Kir3.2d, was isolated from a mouse testis cDNA library. The cDNA had an open reading frame encoding 407 amino acids, whose molecular mass was calculated to be approximately 45 kDa. Kir3.2d was 18 amino acids shorter than Kir3.2c at its N-terminal end, which was the only difference between the two clones. The 18 amino acid region possesses the epitope for aG2N-2. 4. In heterologous expression systems of both Xenopus oocytes and mammalian cells (HEK 293T), Kir3.2d either alone or with Kir3.1 exhibited G-protein-gated inwardly rectifying K+ channel activity. 5. Prominent Kir3.2d immunoreactivity in the testis was detected exclusively in the acrosomal vesicles of spermatids, while Kir3.1 immunoreactivity was diffuse in the spermatogonia and spermatocytes. These results indicate the possibility that the testicular variant of Kir3.2, Kir3. 2d, may assemble to form a homomultimeric G-protein-gated K+ channel and be involved in the development of the acrosome during spermiogenesis.
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Affiliation(s)
- A Inanobe
- Department of Pharmacology II, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
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Hibino H, Horio Y, Fujita A, Inanobe A, Doi K, Gotow T, Uchiyama Y, Kubo T, Kurachi Y. Expression of an inwardly rectifying K(+) channel, Kir4.1, in satellite cells of rat cochlear ganglia. Am J Physiol 1999; 277:C638-44. [PMID: 10516093 DOI: 10.1152/ajpcell.1999.277.4.c638] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Satellite cells are glial cells wrapped around somata of sensory and autonomic ganglion neurons. Neither their functional roles nor electrical properties have been fully clarified so far. Using immunohistochemistry, we found that inwardly rectifying K(+) channel subunit Kir4.1 (also called Kir1.2 or K(AB)-2) was expressed prominently in the satellite cells of cochlear ganglia. The Kir4.1 immunoreactivity was localized specifically at the myelin sheaths of satellite cells wrapping the somata of the ganglion neurons. Developmental expression of Kir4.1 in satellite cells paralleled development of the action potential in the auditory nerve. These results suggest that this channel in satellite cells may be responsible for the regulation of K(+) extruded from the ganglion neurons during excitation.
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Affiliation(s)
- H Hibino
- Department of Pharmacology II, Faculty of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
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Abstract
Since the first identification of an association between mutations in the connexin26 (Cx26) gene and autosomal recessive non-syndromic deafness it has been shown that several mutations in this gene cause recessive, sporadic, and dominant non-syndromic deafness. Three novel mutations in the Cx26 gene were identified in four of 20 Japanese families with autosomal recessive non-syndromic deafness. Seven of 40 chromosomes contained a 233delC allele, while Tyr136Stop (408C-->A) and Gly45Glu (134G-->A) were detected in two of 40 chromosomes, respectively. These mutations were not found in chromosomes in cases of sporadic congenital deafness (0/60) or in control groups (0/100). This indicates that 27.5% (11/40 chromosomes) of cases of autosomal recessive non-syndromic deafness among the Japanese are caused by mutations in the Cx26 gene.
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Affiliation(s)
- Y Fuse
- Department of Otolaryngology, Osaka University Medical School, Suita, Japan
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37
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Hibino H, Tani K, Ikebuchi K, Wu MS, Sugiyama H, Nakazaki Y, Tanabe T, Takahashi S, Tojo A, Suzuki S, Tanioka Y, Sugimoto Y, Nakahata T, Asano S. The common marmoset as a target preclinical primate model for cytokine and gene therapy studies. Blood 1999; 93:2839-48. [PMID: 10216078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Nonhuman primate models are useful to evaluate the safety and efficacy of new therapeutic modalities, including gene therapy, before the inititation of clinical trials in humans. With the aim of establishing safe and effective approaches to therapeutic gene transfer, we have been focusing on a small New World monkey, the common marmoset, as a target preclinical model. This animal is relatively inexpensive and easy to breed in limited space. First, we characterized marmoset blood and bone marrow progenitor cells (BMPCs) and showed that human cytokines were effective to maintain and stimulate in culture. We then examined their susceptibility to transduction by retroviral vectors. In a mixed culture system containing both marmoset stromal cells and retroviral producer cells, the transduction efficiency into BMPCs and peripheral blood progenitor cells (PBPCs) was 12% to 24%. A series of marmosets then underwent transplantation with autologous PBPCs transduced with a retroviral vector carrying the multidrug resistance 1 gene (MDR1) and were followed for the persistence of these cells in vivo. Proviral DNA was detectable by polymerase chain reaction (PCR) in peripheral blood granulocytes and lymphocytes in the recipients of gene transduced progenitors up to 400 days posttransplantation. To examine the function of the MDR1 gene in vivo, recipient maromsets were challenged with docetaxel, an MDR effluxed drug, yet the overall level of gene transfer attained in vivo (<1% in peripheral blood granulocytes) was not sufficient to prevent the neutropenia induced by docetaxel treatment. Using this model, we safely and easily performed a series of in vivo studies in our small animal center. Our results show that this small nonhuman primate, the common marmoset, is a useful model for the evaluation of gene transfer methods targeting hematopoietic stem cells.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/analysis
- ATP Binding Cassette Transporter, Subfamily B, Member 1/biosynthesis
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- Animals
- Bone Marrow Cells/cytology
- Callithrix
- Cells, Cultured
- Cytokines/pharmacology
- Cytokines/therapeutic use
- DNA, Viral/analysis
- Disease Models, Animal
- Docetaxel
- Gene Transfer Techniques
- Genetic Therapy/methods
- Genetic Vectors
- Granulocyte Colony-Stimulating Factor/pharmacology
- Granulocytes/physiology
- Granulocytes/virology
- Hematopoietic Stem Cell Transplantation
- Hematopoietic Stem Cells/cytology
- Hematopoietic Stem Cells/drug effects
- Hematopoietic Stem Cells/physiology
- Humans
- Lymphocytes/physiology
- Lymphocytes/virology
- Paclitaxel/analogs & derivatives
- Paclitaxel/pharmacology
- Polymerase Chain Reaction
- Retroviridae
- Stromal Cells/cytology
- Taxoids
- Transplantation, Autologous
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Affiliation(s)
- H Hibino
- Departments of Hematology/Oncology and Clinical Oncology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
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Inanobe A, Yoshimoto Y, Horio Y, Morishige KI, Hibino H, Matsumoto S, Tokunaga Y, Maeda T, Hata Y, Takai Y, Kurachi Y. Characterization of G-protein-gated K+ channels composed of Kir3.2 subunits in dopaminergic neurons of the substantia nigra. J Neurosci 1999; 19:1006-17. [PMID: 9920664 PMCID: PMC6782136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
G-protein-gated K+ (KG) channels generate slow inhibitory postsynaptic potentials in the brain. Current opinion suggests that neuronal KG channels are heterotetramers of Kir3.1 and Kir3.2. In substantia nigra (SN), however, mRNA of Kir3.1 does not express, whereas that of Kir3.2 clearly does. Therefore, we have characterized the KG channels containing Kir3.2 subunits in SN using biochemical and immunological techniques. We found that they were composed of only Kir3.2 subunits and did not contain significant amounts of either Kir3.1 or Kir3.3. Furthermore, at least some of the KG channels in SN were assemblies of the splicing variants Kir3. 2a and Kir3.2c. The channels were localized specifically at the postsynaptic membrane on the dendrites of dopaminergic neurons. Kir3. 2c, but not Kir3.2a, could bind a PDZ domain-containing protein, PSD-95. The heterologously expressed KG channels composed of Kir3.2a plus Kir3.2c or Kir3.2a alone were activated by G-protein stimulation, but expression of Kir3.2c alone was not. This study reveals that the Kir3.2 splicing variants play distinct roles in the control of function and localization of some of the KG channels in dopaminergic neurons of SN.
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Affiliation(s)
- A Inanobe
- Department of Pharmacology II, Faculty of Medicine and Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
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Abstract
Phosphatidylcholine (PC), especially dilinoleoyl-PC, has been reported to be effective in preventing hepatic fibrosis in chronically alcohol-fed baboons. Continuous hepatic inflammation predisposes the structure of the liver to fibrosis. Since n-3 polyunsaturated fatty acids (PUFA) have been shown to exhibit an anti-inflammatory effect, we tested the hypothesis that n-3 PUFA PC as a dietary supplement has a beneficial effect on chronic liver disease susceptible to fibrosis. Salmon roe phospholipids, 90% of which are PC, were extracted and encapsulated. Almost a third of the PC fatty acids were docosahexaenoic acid (22:6 n3) and 10% were eicosapentanoic acid (20:5 n3). About 1600 mg/day of the phospholipids was administered for six months to six chronic liver disease patients, four with hepatitis B infection (three with cirrhosis, one with chronic hepatitis), one with hepatitis C virus cirrhosis and one with alcoholic cirrhosis. There was no change in the results of blood chemistry studies related to liver function, except in globulin, which decreased from 3.80 g/dl to 3.67 g/dl (p < 0.05). Among the lipid parameters, HDL-cholesterol, apolipoprotein A-I and apolipoprotein E increased significantly. Although this was a small trial, n-3 PUFA PC may be beneficial in the treatment of chronic liver diseases.
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Affiliation(s)
- H Hayashi
- Department of Internal Medicine, Yokohama Red Cross Hospital, Japan
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Shimane M, Tani K, Hibino H, Setoyama M, Takahashi S, Tojo A, Yodoi J, Asano S. Significant expression of G-CSF-induced gene-1 (GIG-1) protein in myeloid cells and NK cells. J Leukoc Biol 1999; 65:109-16. [PMID: 9886253 DOI: 10.1002/jlb.65.1.109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The granulocyte colony-stimulating factor (G-CSF)-induced gene, GIG-1, was originally cloned from G-CSF-stimulated bone marrow mononuclear cells obtained from a patient with chronic myelogenous leukemia (CML). We have characterized the GIG-1 gene and its protein product. Expression of GIG-1 mRNA was elevated by treatment with G-CSF in normal bone marrow mononuclear cells, as well as in some cases of blast cells obtained from patients with acute myelogenous leukemia (AML) and CML. Western blot analysis with anti-GIG-1 peptide antiserum showed the molecular mass of GIG-1 product was about 17 kDa. Immunostaining of the hematopoietic cells demonstrated that GIG-1 product was mainly localized to the cytoplasm of both myeloid and natural killer (NK) cells. These results suggested that GIG-1 protein is an integral component that is accumulated during the differentiation of myeloid cells toward the stage of mature neutrophils. Expression of GIG-1 gene in mature neutrophils was tightly regulated and reactivation of GIG-1 gene by G-CSF in mature neutrophils may represent a compensation process for the protein lost through the activation of these cells, thus implying an important role for this protein in host defense mechanisms.
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MESH Headings
- Antigens, CD34/blood
- Blotting, Western
- Bone Marrow Cells/metabolism
- Fetal Blood/cytology
- Fetal Blood/metabolism
- Flow Cytometry
- Humans
- Immunohistochemistry
- Killer Cells, Natural/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myeloid, Acute/metabolism
- Membrane Proteins/biosynthesis
- Membrane Proteins/genetics
- Poly(A)-Binding Proteins
- Proteins
- RNA, Messenger/metabolism
- RNA-Binding Proteins/biosynthesis
- RNA-Binding Proteins/genetics
- T-Cell Intracellular Antigen-1
- Tumor Cells, Cultured
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Affiliation(s)
- M Shimane
- Hematology and Oncology, Institute of Medical Science, University of Tokyo, Japan
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41
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Okada H, Watanabe T, Niki M, Takano H, Chiba N, Yanai N, Tani K, Hibino H, Asano S, Mucenski ML, Ito Y, Noda T, Satake M. AML1(-/-) embryos do not express certain hematopoiesis-related gene transcripts including those of the PU.1 gene. Oncogene 1998; 17:2287-93. [PMID: 9811459 DOI: 10.1038/sj.onc.1202151] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The AML1 and PEBP2beta/CBFbeta genes encode the DNA-binding and non-binding subunits, respectively, of the heterodimeric transcription factor, PEBP2/CBF. Targeting each gene results in an almost identical phenotype, namely the complete lack of definitive hematopoiesis in the fetal liver on embryonic day 11.5 (E11.5). We examined and compared the expression levels of various hematopoiesis-related genes in wild type embryos and in embryos mutated for AML1 or PEBP2beta/CBFbeta. The RNAs were prepared from the yolk sacs of E9.5 embryos, from the aorta-gonad- mesonephros regions of E11.5 embryos and from the livers of E11.5 embryos and RT-PCR was performed to detect various gene transcripts. Transcripts were detected for most of the hematopoiesis-related genes that encode transcription factors, cytokines and cytokine receptors, even in tissues from homozygously targeted embryos. On the other hand, PU.1 transcripts were never detected in any tissue of AML1(-/-) or PEBP2beta/CBFbeta(-/-) embryos. In addition, transcripts for the Vav, flk-2/flt-3, M-CSF receptor, G-CSF receptor and c-Myb genes were not detected in certain tissues of the (-/-) embryos. The results suggest that the expression of a particular set of hematopoiesis-related genes is closely correlated with the PEBP2/CBF function.
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Affiliation(s)
- H Okada
- Department of Cell Biology, Cancer Institute, Tokyo, Japan
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42
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Omura T, Yan J, Zhong B, Wada M, Zhu Y, Tomaru M, Maruyama W, Kikuchi A, Watanabe Y, Kimura I, Hibino H. The P2 protein of rice dwarf phytoreovirus is required for adsorption of the virus to cells of the insect vector. J Virol 1998; 72:9370-3. [PMID: 9765491 PMCID: PMC110363 DOI: 10.1128/jvi.72.11.9370-9373.1998] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intact particles of rice dwarf phytoreovirus adsorbed to and entered monolayer-cultured cells of the insect vector Nephotettix cincticeps and multiplied within the cells. Particles that lacked the P2 protein neither attached to nor infected such cells. Furthermore, P2-free particles obtained from a transmission-competent isolate of the virus were unable to infect insect vectors that had been allowed to feed on these virus particles through a membrane. However, when such virus particles were injected into insects via a glass capillary tube they successfully infected the insects, which became able to transmit the virus. These results support the hypothesis that, while P2-free particles can neither interact with nor infect cells in the intestinal tract of the insect vector, they do retain the ability to infect such cells when physically introduced into the hemolymph by injection.
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Affiliation(s)
- T Omura
- National Agriculture Research Center, Tsukuba, Ibaraki 305, Japan.
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43
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Nakazaki Y, Tani K, Lin ZT, Sumimoto H, Hibino H, Tanabe T, Wu MS, Izawa K, Hase H, Takahashi S, Tojo A, Azuma M, Hamada H, Mori S, Asano S. Vaccine effect of granulocyte-macrophage colony-stimulating factor or CD80 gene-transduced murine hematopoietic tumor cells and their cooperative enhancement of antitumor immunity. Gene Ther 1998; 5:1355-62. [PMID: 9930341 DOI: 10.1038/sj.gt.3300726] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
To develop immunogene therapy targeting minimal residual hematopoietic tumor cells in patients, we transduced murine GM-CSF or CD80 gene into murine WEHI 3B myelomonocytic leukemia and EL-4 thymic lymphoma cells using retroviral vectors and evaluated their effects on inducing antitumor responses in syngeneic host mice. Subcutaneously injected GM-CSF- and CD80 gene-transduced WEHI 3B (GMCSF/WEHI/3.2 or CD80/WEHI/1.8, respectively) cells lost their original tumorigenicity in immunocompetent syngeneic mice. Results from tumor inoculation experiments using athymic nude mice suggested that the rejection of GMCSF/WEHI/3.2 in immunocompetent mice depended fully on T cells and that of CD80/WEHI 1.8 depended partly on T cells and partly on NK cells. In both WEHI 3B and EL-4 models, irradiated GM-CSF gene-transduced cells provided strong immuno-protection against wild-type cells, but irradiated CD80 gene-transduced cells did not. A remarkably high cooperative effect was obtained when irradiated GMCSF/EL-4 and CD80/EL-4 were inoculated together. These results suggested that the tumor vaccine effect is efficiently enhanced by GM-CSF gene transduction and CD80 gene transduction induces some protective antitumor immunity in co-operation with GM-CSF gene transduction.
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Affiliation(s)
- Y Nakazaki
- Department of Hematology/Oncology, University of Tokyo, Japan
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44
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Hibino H, Minamoto K, Suzuki S, Ukai T. Michael addition reactions of some nucleobases to 1-(4,6-O-benzylidene-2,3-didehydro-2,3-dideoxy-3-nitro-beta-D- hexopyran osyl) uracil. Nucleic Acids Symp Ser 1998:41-2. [PMID: 9585989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Michael addition of cytosine, N4-dimethyl-aminomethylidene-cytosine, uracil and thymine to the nitroolefin (2) generated in situ from 1-(4,6-O-benzylidene-3-deoxy-3-nitro-beta-D-glucopyranosyl)-uracil (1) gave the corresponding 2-(N1-pyrimidinyl)-2,3-dideoxy-3-nitro-beta-D-glucopyranosides (3-6). Compound 3 was also obtainable from 4.
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Affiliation(s)
- H Hibino
- Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Japan
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45
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Sumimoto H, Tani K, Nakazaki Y, Tanabe T, Hibino H, Wu MS, Izawa K, Hamada H, Asano S. Superiority of interleukin-12-transduced murine lung cancer cells to GM-CSF or B7-1 (CD80) transfectants for therapeutic antitumor immunity in syngeneic immunocompetent mice. Cancer Gene Ther 1998; 5:29-37. [PMID: 9476964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Interleukin-12 (IL-12) is a heterodimeric cytokine that consists of p40 and p35 subunits. IL-12 has been regarded as a potent inducer of host antitumor immunity through interferon-gamma (IFN-gamma) production and development of Th1 helper T cells from Th0 cells. Here, we demonstrate the immunomodulatory actions of an IL-12-transduced murine lung cancer cell line, Lewis lung carcinoma (LLC) (LLC/IL12) cells, in syngeneic C57BL/6 mice. We also report on their therapeutic potency. Three LLC/IL12 cells producing different levels of IL-12 were cloned and found to have diminished tumorigenicity in C57BL/6 mice depending on their level of IL-12 production. In vivo depletion assay demonstrated that the loss of tumorigenicity of LLC/IL12 depended on both CD4+ and CD8+ T cells, and that natural killer (NK) cells were involved, especially in the early phase of immunity. The strong systemic antitumor immunity against challenge with wild type LLC (LLC/wt) cells was also induced by LLC/IL12 cells. The systemic antitumor memory was found to be dependent mainly on the CD4+ T-cell subset. 51Cr-release assay revealed that the killer activity consisted of a specific killer activity directed at the parental LLC/wt cells and a nonspecific killer activity directed at both LLC/wt and syngeneic EL-4 thymoma cells. In addition, LLC/IL12 apparently had a much stronger antitumor effect against the established LLC/wt tumor than LLC transduced with B7-1 or GM-CSF cDNA. IL-12 can be considered an efficient candidate molecule for immunogene therapy for lung cancer in this experimental system.
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Affiliation(s)
- H Sumimoto
- Department of Hematology/Oncology, the Institute of Medical Science, the University of Tokyo, Japan
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46
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Sumimoto H, Tani K, Nakazaki Y, Tanabe T, Hibino H, Hamada H, Azuma M, Asano S. GM-CSF and B7-1 (CD80) co-stimulatory signals co-operate in the induction of effective anti-tumor immunity in syngeneic mice. Int J Cancer 1997; 73:556-61. [PMID: 9389572 DOI: 10.1002/(sici)1097-0215(19971114)73:4<556::aid-ijc17>3.0.co;2-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
B7-1 (CD80) co-stimulatory molecule gene-transduced Lewis lung carcinoma (LLC) cells (LLC/B7 cells) resulted in remarkable loss of tumorigenicity in syngeneic C57BL/6 mice (87.5% rejection) compared to B7-negative, wild-type LLC (LLC/wt) cells (0% rejection). However, mice that had rejected LLC/B7 cells developed almost no systemic immunity protective against challenge with wild-type tumor cells after 4 weeks (11.8% rejection). Enhancement of MHC class I (H-2Kb) expression of LLC/B7 cells with in vitro interferon-gamma treatment did not result in enhancement of protective immunity. In vivo depletion assay revealed that abrogation of tumorigenicity in LLC/B7 depended on CD8+ T cells but not on CD4+ T cells. However, vaccination of C57BL/6 mice with irradiated LLC cells transduced with GM-CSF (LLC/GM) led to the induction of potent, specific immunity against challenge with the LLC/wt cells after 2 weeks (80.8% rejection). Next, we established a double transfectant of LLC cells expressing both B7-1 and GM-CSF (LLC/GM + B7). The tumorigenicity of these clonal cells was also remarkably suppressed (90% rejection) to the same degree as LLC/B7, whereas that of LLC/GM was not suppressed (0% rejection). Interestingly, mice that had rejected LLC/GM+B7 cells developed enhanced protective immunity against challenge with LLC/wt cells after 4 weeks (55.6% rejection) compared to the results of LLC/B7 cells (11.8%). To evaluate whether co-expression of GM-CSF and B7-1 enabled the tumor cells to activate cytotoxic T cells more efficiently than B7-1 alone, we performed an in vitro killing assay. We found that immunization with LLC/GM+B7 cells resulted in a 3-fold stronger cytotoxic response than that with LLC/B7. Our data indicate that co-transfection of the B7-1 co-stimulatory molecule and GM-CSF genes may be more effective for the induction of stronger protective immunity in this experimental system.
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Affiliation(s)
- H Sumimoto
- Department of Hematology/Oncology, Institute of Medical Science, University of Tokyo, Japan
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47
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Ishii M, Horio Y, Tada Y, Hibino H, Inanobe A, Ito M, Yamada M, Gotow T, Uchiyama Y, Kurachi Y. Expression and clustered distribution of an inwardly rectifying potassium channel, KAB-2/Kir4.1, on mammalian retinal Müller cell membrane: their regulation by insulin and laminin signals. J Neurosci 1997; 17:7725-35. [PMID: 9315894 PMCID: PMC6793902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Inwardly rectifying potassium (K+) channels (Kir) in Müller cells, the dominant glial cells in the retina, are supposed to be responsible for the spatial buffering action of K+ ions. The molecular properties and subcellular localization of Müller cell Kir channels in rat and rabbit retinas were examined by using electrophysiological, molecular biological, and immunostaining techniques. Only a single population of Kir channel activity, the properties of which were identical to those of KAB-2/Kir4.1 expressed in HEK293T cells, could be recorded from endfoot to the distal portion of Müller cells. Consistently, Northern blot, in situ hybridization, and RT-PCR analyses indicated expression of Kir4. 1 in Müller cells per se. The Kir4.1 immunoreactivity was distributed in clusters throughout Müller cell membrane. The Kir4.1 expression in Müller cells disappeared promptly after culturing. When the dissociated Müller cells were cultured on laminin-coated dishes in the presence of insulin, Kir4.1 immunoreactivity was detected in a clustered manner on the cell membrane. Because insulin and laminin exist in the surrounding of Müller cells in the retina, these substances possibly may be physiological regulators of expression and distribution of Kir4.1 in Müller cells in vivo.
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Affiliation(s)
- M Ishii
- Department of Pharmacology II, Faculty of Medicine, Osaka University, Osaka 565, Japan
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48
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Hibino H, Horio Y, Inanobe A, Doi K, Ito M, Yamada M, Gotow T, Uchiyama Y, Kawamura M, Kubo T, Kurachi Y. An ATP-dependent inwardly rectifying potassium channel, KAB-2 (Kir4. 1), in cochlear stria vascularis of inner ear: its specific subcellular localization and correlation with the formation of endocochlear potential. J Neurosci 1997; 17:4711-21. [PMID: 9169531 PMCID: PMC6573344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Cochlear endolymph has a highly positive potential of approximately +80 mV. This so-called endocochlear potential (EP) is essential for hearing. Although pivotal roles of K+ channels in the formation of EP have been suggested, the types and distribution of K+ channels in cochlea have not been characterized. Because EP was depressed by vascular perfusion of Ba2+, an inhibitor of inwardly rectifying K+ (Kir) channels, but not by either 4-aminopyridine or tetraethylammonium, we examined the expression of Kir channel subunits in cochlear stria vascularis, the tissue that is supposed to play the central role in the generation of positive EP. Of 11 members of the Kir channel family examined with reverse transcription-PCR, we could detect only expression of KAB-2 (Kir4.1) mRNA in stria vascularis. KAB-2 immunoreactivity was specifically localized at the basolateral membrane of marginal cells but not in either basal or intermediate cells. Developmental expression of KAB-2 in marginal cells paralleled formation of EP. Furthermore, deaf mutant mice (viable dominant spotting; WV/WV) expressed no KAB-2 in their marginal cells. These results suggest that KAB-2 in marginal cells may be critically involved in the generation of positive EP.
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Affiliation(s)
- H Hibino
- Department of Pharmacology II, Faculty of Medicine, Osaka University, Osaka 565, Japan
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49
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Niki M, Okada H, Takano H, Kuno J, Tani K, Hibino H, Asano S, Ito Y, Satake M, Noda T. Hematopoiesis in the fetal liver is impaired by targeted mutagenesis of a gene encoding a non-DNA binding subunit of the transcription factor, polyomavirus enhancer binding protein 2/core binding factor. Proc Natl Acad Sci U S A 1997; 94:5697-702. [PMID: 9159135 PMCID: PMC20841 DOI: 10.1073/pnas.94.11.5697] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The Pebpb2 gene encodes a non-DNA binding subunit of the heterodimeric transcription factor, polyomavirus enhancer binding protein 2/core binding factor (PEBP2/CBF), and is rearranged in inversion of chromosome 16 associated with human acute myeloid leukemia. To investigate its physiological function, Pebpb2 was mutated by a targeting strategy to generate a null mutant. The homozygous mutation in mice proved lethal in embryos around embryonic day 12.5, apparently due to massive hemorrhaging in the central nervous system. In addition, definitive hematopoiesis in the liver was severely impaired. The observed phenotype was indistinguishable from that reported for homozygous disruption of AML1, which encodes a DNA binding subunit of PEBP2/CBF. Thus, the results indicate that the two subunits function together as a heterodimeric PEBP2/CBF in vivo and that PEBP2/CBF plays an essential role in the development of definitive hematopoiesis.
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Affiliation(s)
- M Niki
- Department of Molecular Immunology, Institute of Development, Aging, and Cancer, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980, Japan
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50
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Horio Y, Hibino H, Inanobe A, Yamada M, Ishii M, Tada Y, Satoh E, Hata Y, Takai Y, Kurachi Y. Clustering and enhanced activity of an inwardly rectifying potassium channel, Kir4.1, by an anchoring protein, PSD-95/SAP90. J Biol Chem 1997; 272:12885-8. [PMID: 9148889 DOI: 10.1074/jbc.272.20.12885] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
An inwardly rectifying potassium channel predominantly expressed in glial cells, Kir4.1/KAB-2, has a sequence of Ser-Asn-Val in its carboxyl-terminal end, suggesting a possible interaction with an anchoring protein of the PSD-95 family. We examined the effects of PSD-95 on the distribution and function of Kir4.1 in a mammalian cell line. When Kir4.1 was expressed alone, the channel immunoreactivity was distributed homogeneously. In contrast, when co-expressed with PSD-95, prominent clustering of Kir4.1 in the cell membrane occurred. Kir4.1 was co-immunoprecipitated with PSD-95 in the co-expressed cells. Glutathione S-transferase-fusion protein of COOH terminus of Kir4.1 bound to PSD-95. These interactions disappeared when the Ser-Asn-Val motif was deleted. The magnitude of whole-cell Kir4.1 current was increased by 2-fold in cells co-expressing Kir4.1 and PSD-95 compared with cells expressing Kir4. 1 alone. SAP97, another member of the PSD-95 family, showed similar effects on Kir4.1. Furthermore, we found that Kir4.1 as well as SAP97 distributed not diffusely but clustered in retinal glial cells. Therefore, PSD-95 family proteins may be a physiological regulator of the distribution and function of Kir4.1 in glial cells.
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Affiliation(s)
- Y Horio
- Department of Pharmacology II, Faculty of Medicine, Osaka University, Suita, Osaka 565, Japan
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