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Yamaguchi H, Hayakawa S, Ma N, Shimizu H, Okawa K, Zhang Q, Yang L, Kahl D, La Cognata M, Lamia L, Abe K, Beliuskina O, Cha S, Chae K, Cherubini S, Figuera P, Ge Z, Gulino M, Hu J, Inoue A, Iwasa N, Kim A, Kim D, Kiss G, Kubono S, La Commara M, Lattuada M, Lee E, Moon J, Palmerini S, Parascandolo C, Park S, Phong V, Pierroutsakou D, Pizzone R, Rapisarda G, Romano S, Spitaleri C, Tang X, Trippella O, Tumino A, Zhang N, Lam Y, Heger A, Jacobs A, Xu S, Ma S, Ru L, Liu E, Liu T, Hamill C, Murphy ASJ, Su J, Fang X, Kwag M, Duy N, Uyen N, Kim D, Liang J, Psaltis A, Sferrazza M, Johnston Z, Li Y. RIB induced reactions: Studying astrophysical reactions with low-energy RI beam at CRIB. EPJ WEB OF CONFERENCES 2023. [DOI: 10.1051/epjconf/202327501015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Astrophysical reactions involving radioactive isotopes (RI) often play an important role in high-temperature stellar environments. The experimental studies on the reaction rates for those are still limited mainly due to the technical difficulties in producing high-quality RI beams. A direct measurement of those reactions would be still challenging in many cases, however, we can make a reliable evaluation of the reaction rates by an indirect method or by studying the resonance prorerties. Here we ntroduce recent examples of experimental studies on such RI-involving astrophysical reactions, performed at Center for Nuclear Study, the University of Tokyo, using the low-energy RI beam separator CRIB. One is for the neutron-induced destruction reactions of 7Be in the Big-Bang nucleosynthesis, and the other is the study on the 22Mg(α, p) reaction relevant in X-ray bursts, which was performed with the resonant scattering method from the inverse reaction channel.
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Claiborne D, Detwiler Z, Okawa K, Bateson T, Chen T, Scadden D, Boutwell C, Allen T. OP 6.4 – 00096 High-efficiency CRISPR/Cas9-mediated disruption of ccr5 in human hematopoietic stem progenitor cells generates HIV-refractory immune systems. J Virus Erad 2022. [DOI: 10.1016/j.jve.2022.100249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Yamaguchi H, Hayakawa S, Ma N, Shimizu H, Okawa K, Yang L, Kahl D, La Cognata M, Lamia L, Abe K, Beliuskina O, Cha S, Chae K, Cherubini S, Figuera P, Ge Z, Gulino M, Hu J, Inoue A, Iwasa N, Kim A, Kim D, Kiss G, Kubono S, La Commara M, Lattuada M, Lee E, Moon J, Palmerini S, Parascandolo C, Park S, Phong VH, Pierroutsakou D, Pizzone R, Rapisarda G, Romano S, Spitaleri C, Tang X, Trippella O, Tumino A, Zhang N, Lam Y, Heger A, Jacobs A, Xu S, Ma S, Ru L, Liu E, Liu T, Hamill C, St J. Murphy A, Su J, Fang X, Kwag M, Duy N, Uyen N, Kim D, Liang J, Psaltis A, Sferrazza M, Johnston Z, Li Y. Experimental studies on astrophysical reactions at the low-energy RI beam separator CRIB. EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202226003003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Experimental studies on astrophysical reactions involving radioactive isotopes (RI) often accompany technical challenges. Studies on such nuclear reactions have been conducted at the low-energy RI beam separator CRIB, operated by Center for Nuclear Study, the University of Tokyo. We discuss two cases of astrophysical reaction studies at CRIB; one is for the 7Be+n reactions which may affect the primordial 7Li abundance in the Big-Bang nucleosynthesis, and the other is for the 22Mg(α, p) reaction relevantin X-raybursts.
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Morii Y, Fujimoto S, Nakahara R, Okawa K, Senaha H, Fujiwara K, Tsubaki M, Matzno S, Takegami M, Shimomura K, Nishida S. Effect of proton pump inhibitors on the development of hypomagnesemia induced by panitumumab. DIE PHARMAZIE 2022; 77:81-84. [PMID: 35209968 DOI: 10.1691/ph.2022.1988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Panitumumab, a therapeutic agent for unresectable advanced/recurrent colorectal cancer, is a human IgG2 monoclonal antibody that binds to and inhibits the activity of the epidermal growth factor receptor (EGFR). The onset of hypomagnesemia is a known side effect of anti-EGFR inhibitors, including panitumumab, and it is thought that inhibition of reabsorption of Mg in renal tubules is one of the causes. In addition, recent reports have shown that long-term administration of proton pump inhibitors (PPIs) reduces serum magnesium levels. Therefore, in this study, 102 patients who received oral PPIs treated with panitumumab were classified into a PPI combination group and a PPI non-combination group, and the effect of PPIs on the development of grade 2 or higher hypomagnesemia was investigated. The incidence of hypomagnesemia in the PPI combination group (46.9%, 15/32) was higher than that in the PPI non-combination group (25.7%, 18/70). A comparison of the backgrounds of the two groups of patients showed a significant difference in serum albumin levels. PPI administration was significantly associated with panitumumab-induced hypomagnesemia development when adjusted for known risk factors, serum albumin level, renal function, and oral magnesium oxide tablets in Cox proportional hazards regression analysis (hazard ratio 2.09; 95% confidence interval 1.03-4.22; P =0.040). These results indicate that detailed monitoring of serum magnesium levels is recommended for patients treated with panitumumab and co-administration of PPIs.
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Okada T, Tsushima R, Taya S, Saito E, Takagi W, Sogo M, Ugawa S, Nosaka K, Takahashi M, Okawa K, Sakane K, Miyoshi T, Ito H, Doi M. Feasibility and safety of early initiation of a PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor in patients with acute myocardial infarction undergoing primary PCI. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.3340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Recent ESC/EAS Guidelines for the management of dyslipidemia stated that the treatment goal of LDL cholesterol (LDL-C) in very high-risk patients is less than 55mg/dl. PCSK9 inhibitors in addition to strong statins could be a useful strategy for rapid and aggressive lowering of LDL-C. However, the feasibility and safety of early initiation of a PCSK9 inhibitor for AMI patients undergoing primary PCI remain unclear.
Objectives
We examined the effects of early initiation of a PCSK9 inhibitor, evolocumab, on lipid profile and inflammatory markers and its safety in AMI patients undergoing primary PCI.
Methods
This study is a single center, randomized, controlled trial involving 102 patients hospitalized for AMI. The patients were randomly assigned 1:1 to the evolocumab group and the control group. Evolocumab (140 mg) was subcutaneously injected within 24 hours after PCI and then every two weeks. All patients received pitavastatin (2mg/day) in addition to the allocated treatment. The primary endpoints were changes in lipid profile and inflammatory markers from baseline to 4 weeks.
Results
102 patients were enrolled between October 2017 and December 2019. 89 patients were ST-segment elevation myocardial infarction (STEMI), 13 patients were non-STEMI. Primary PCI was successfully performed in all patients. 76 patients were statin-naïve. 2 patients were excluded from analyses because they died severe heart failure in acute phase. Finally, 100 patients (evolocumab; n=51 and control; n=49) were analyzed. Baseline LDL-C was 121.6±30.3 mg/dl in the evolocumab group and 124.7±33.6 mg in the control group. Change in LDL-C from the baseline to 4 weeks was −92.4±32.4 mg/dl (−75%) in the evolocumab group and −44.8±32.1 mg/dl (−33.1%) in the control group (mean difference; 47.6mg/dl, 95% CI; 34.8 to 60.4 mg/dl, p<0.001). LDL-C <70mg/dl at 4 weeks was achieved in 96.0% of the evolocumab group as compared with 26.5% of the control group. Further, in the evolocumab group. LDL <55mg/dl was achieved in 92.1% at 2 weeks and 92.1% at 4 weeks. Regarding inflammatory markers, there were no significant difference in change in high-sensitivity C-reactive protein (p=0.49) and tumor necrosis factor-alpha (p=0.63) between two groups even after adjustment of baseline value. No adverse event associated with evolocumab was observed during this study.
Conclusion
In patients with AMI undergoing primary PCI, early initiation of evolocumab rapidly reduced LDL-C without no adverse event, and achieved LDL-C<55mg/dl in most patients within 2 weeks. Early administration of a PCSK9 inhibitor combined with a strong statin could be a feasible and safe treatment for AMI patients undergoing PCI.
Funding Acknowledgement
Type of funding source: None
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Amagai Y, Shimazaki T, Okawa K, Kawae T, Fujiki H, Kaneko NH. Precise absolute Seebeck coefficient measurement and uncertainty analysis using high-Tc superconductors as a reference. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:014903. [PMID: 32012567 DOI: 10.1063/1.5122226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 12/17/2019] [Indexed: 06/10/2023]
Abstract
The intrinsic properties of superconductors enable the direct determination of the absolute Seebeck coefficient at low temperature due to the disappearance of the Seebeck effect to obey the Meissner effect. We report a precision absolute Seebeck coefficient measurement for the fine Pt sample determined using the high-Tc YBa2Cu3O7-x (YBCO) superconductor as a reference and an analysis of the measurement uncertainty. To make a precision measurement and aid in the verification of the uncertainty components, we developed a cryostat system that enables temperature control in a stable manner. The expected performance of the reference superconductor yielded a zero value well below Tc, which was validated by a superconductor-superconductor thermocouple experiment. Uncertainty analysis shows that the main limiting factor for this measurement is the accuracy of the temperature difference measurement using the resistance temperature sensors, along with its analog noise. We obtained values of S = 5.6 ± 0.2 µV/K with a relative expanded uncertainty of 3% at 80 K and precisely compared the Pt value with that determined by the high-Tc Bi2Sr2Ca2Cu3O8+δ (Bi-2223) superconductor, which has a higher Tc. We found that there was no difference between the Seebeck coefficient values obtained from the YBCO and Bi-2223 references up to its Tc within the expanded measurement uncertainties of 0.3 µV/K (2σ). These results provide accurate validation that the high-Tc superconductor is a useful reference up to the liquid nitrogen temperature.
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Clark OJ, Neat MJ, Okawa K, Bawden L, Marković I, Mazzola F, Feng J, Sunko V, Riley JM, Meevasana W, Fujii J, Vobornik I, Kim TK, Hoesch M, Sasagawa T, Wahl P, Bahramy MS, King PDC. Fermiology and Superconductivity of Topological Surface States in PdTe_{2}. PHYSICAL REVIEW LETTERS 2018; 120:156401. [PMID: 29756894 DOI: 10.1103/physrevlett.120.156401] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/17/2018] [Indexed: 05/12/2023]
Abstract
We study the low-energy surface electronic structure of the transition-metal dichalcogenide superconductor PdTe_{2} by spin- and angle-resolved photoemission, scanning tunneling microscopy, and density-functional theory-based supercell calculations. Comparing PdTe_{2} with its sister compound PtSe_{2}, we demonstrate how enhanced interlayer hopping in the Te-based material drives a band inversion within the antibonding p-orbital manifold well above the Fermi level. We show how this mediates spin-polarized topological surface states which form rich multivalley Fermi surfaces with complex spin textures. Scanning tunneling spectroscopy reveals type-II superconductivity at the surface, and moreover shows no evidence for an unconventional component of its superconducting order parameter, despite the presence of topological surface states.
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Bahramy MS, Clark OJ, Yang BJ, Feng J, Bawden L, Riley JM, Marković I, Mazzola F, Sunko V, Biswas D, Cooil SP, Jorge M, Wells JW, Leandersson M, Balasubramanian T, Fujii J, Vobornik I, Rault JE, Kim TK, Hoesch M, Okawa K, Asakawa M, Sasagawa T, Eknapakul T, Meevasana W, King PDC. Ubiquitous formation of bulk Dirac cones and topological surface states from a single orbital manifold in transition-metal dichalcogenides. NATURE MATERIALS 2018; 17:21-28. [PMID: 29180775 DOI: 10.1038/nmat5031] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 10/13/2017] [Indexed: 05/12/2023]
Abstract
Transition-metal dichalcogenides (TMDs) are renowned for their rich and varied bulk properties, while their single-layer variants have become one of the most prominent examples of two-dimensional materials beyond graphene. Their disparate ground states largely depend on transition metal d-electron-derived electronic states, on which the vast majority of attention has been concentrated to date. Here, we focus on the chalcogen-derived states. From density-functional theory calculations together with spin- and angle-resolved photoemission, we find that these generically host a co-existence of type-I and type-II three-dimensional bulk Dirac fermions as well as ladders of topological surface states and surface resonances. We demonstrate how these naturally arise within a single p-orbital manifold as a general consequence of a trigonal crystal field, and as such can be expected across a large number of compounds. Already, we demonstrate their existence in six separate TMDs, opening routes to tune, and ultimately exploit, their topological physics.
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Iwaya K, Kohsaka Y, Okawa K, Machida T, Bahramy MS, Hanaguri T, Sasagawa T. Full-gap superconductivity in spin-polarised surface states of topological semimetal β-PdBi 2. Nat Commun 2017; 8:976. [PMID: 29042547 PMCID: PMC5730620 DOI: 10.1038/s41467-017-01209-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 08/24/2017] [Indexed: 12/05/2022] Open
Abstract
A bulk superconductor possessing a topological surface state at the Fermi level is a promising system to realise long-sought topological superconductivity. Although several candidate materials have been proposed, experimental demonstrations concurrently exploring spin textures and superconductivity at the surface have remained elusive. Here we perform spectroscopic-imaging scanning tunnelling microscopy on the centrosymmetric superconductor β-PdBi2 that hosts a topological surface state. By combining first-principles electronic-structure calculations and quasiparticle interference experiments, we determine the spin textures at the surface, and show not only the topological surface state but also all other surface bands exhibit spin polarisations parallel to the surface. We find that the superconducting gap fully opens in all the spin-polarised surface states. This behaviour is consistent with a possible spin-triplet order parameter expected for such in-plane spin textures, but the observed superconducting gap amplitude is comparable to that of the bulk, suggesting that the spin-singlet component is predominant in β-PdBi2.Although several materials have been proposed as topological superconductors, spin textures and superconductivity at the surface remain elusive. Here, Iwaya et al. determine the spin textures at the surface of a superconductor β-PdBi2 and find the superconducting gap opening in all spin-polarised surface states.
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Takahashi M, Okawa K, Himoto A, Akai H, Hara S, Matsuo N, Sudo Y, Sogo M, Ugawa S, Okada T, Nosaka K, Sakane K, Doi M. P2700Fatal risk of warfarin in asian very elderly patients with atrial fibrillation in direct oral anti-coagulant era. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx502.p2700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Okawa K, Miyoshi T, Hara S, Matuo N, Sogo M, Okada T, Ugawa S, Nosaka K, Takahashi M, Sakane K, Doi M, Morita H, Ito H. P873Differences in endothelial dysfunction induced by paroxysmal and persistent atrial fibrillation: insights from the restoration of sinus rhythm with catheter ablation. Europace 2017. [DOI: 10.1093/ehjci/eux151.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Inoue M, Taguchi J, Okawa K, Inada K, Shiomi H, Koike I, Murai T, Iwata H, Iwabuchi M, Higurashi M, Tatewaki K, Ohta S. EP-1744: Evaluation of the clinical accuracy of the robotic respiratory tracking system. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32995-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sakano M, Okawa K, Kanou M, Sanjo H, Okuda T, Sasagawa T, Ishizaka K. Topologically protected surface states in a centrosymmetric superconductor β-PdBi2. Nat Commun 2015; 6:8595. [PMID: 26460338 PMCID: PMC4633943 DOI: 10.1038/ncomms9595] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/08/2015] [Indexed: 11/22/2022] Open
Abstract
The topological aspects of electrons in solids can emerge in real materials, as represented by topological insulators. In theory, they show a variety of new magneto-electric phenomena, and especially the ones hosting superconductivity are strongly desired as candidates for topological superconductors. While efforts have been made to develop possible topological superconductors by introducing carriers into topological insulators, those exhibiting indisputable superconductivity free from inhomogeneity are very few. Here we report on the observation of topologically protected surface states in a centrosymmetric layered superconductor, β-PdBi2, by utilizing spin- and angle-resolved photoemission spectroscopy. Besides the bulk bands, several surface bands are clearly observed with symmetrically allowed in-plane spin polarizations, some of which crossing the Fermi level. These surface states are precisely evaluated to be topological, based on the Z2 invariant analysis in analogy to three-dimensional strong topological insulators. β-PdBi2 may offer a solid stage to investigate the topological aspect in the superconducting condensate. Materials possessing topologically non-trivial electronic surface states are predicted to host exotic Majorana fermion excitations in the superconducting state. Here, the authors demonstrate the existence of topologically-protected surface states in the centrosymmetric layered superconductor β-PdBi2.
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Dohi M, Miyata H, Doi K, Okawa K, Motomura N, Takamoto S, Yaku H. The off-pump technique in redo coronary artery bypass grafting reduces mortality and major morbidities: propensity score analysis of data from the Japan Cardiovascular Surgery Database. Eur J Cardiothorac Surg 2014; 47:299-307; discussion 307-8. [DOI: 10.1093/ejcts/ezu081] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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Dohi M, Doi K, Miyata H, Motomura N, Ohira S, Kawajiri H, Yamamoto T, Watanabe T, Okawa K, Takamoto S, Yaku H. 231 * THE OFF-PUMP TECHNIQUE REDUCED MORTALITY AND MAJOR MORBIDITIES IN REDO CORONARY ARTERY BYPASS GRAFTING: A PROPENSITY SCORE ANALYSIS FROM A JAPANESE CARDIOVASCULAR SURGERY DATABASE. Interact Cardiovasc Thorac Surg 2013. [DOI: 10.1093/icvts/ivt372.231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Ueda H, Nakashima Y, Hosoi K, Ichimura K, Takeda H, Kigure S, Takahashi S, Okawa K, Imai T. Initial Simulation Results of GAMMA 10 as NBI Driven Neutron Source. FUSION SCIENCE AND TECHNOLOGY 2013. [DOI: 10.13182/fst13-a16940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Inoue M, Shiomi H, Iwata H, Koike I, Okawa K, Senda M, Inada K, Tatewaki K, Yokota N. Estimation of Clinical Error With Respiratory Motion Tracking of the Image Guided Robotic Radiosurgery System. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.1959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Inoue M, Shiomi H, Okawa K, Senda M, Inada K, Koshi T, Yokota N, Iwata H, Sato K. SU-E-T-584: The Accuracy of the Respiratory Motion Tracking with Robotic Radiosurgery System. Med Phys 2011. [DOI: 10.1118/1.3612546] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Inoue M, Okawa K, Tatewaki K, Sato K, Koike I, Shiomi H. Retrospective Study for the Dosimetric Effects from Residual Target Motion with Image Guided Robotic Radiotherapy. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Urakawa I, Yamazaki Y, Shimada T, Iijima K, Hasegawa H, Okawa K, Fujita T, Fukumoto S, Yamashita T. The Antisenescence Protein Klotho Is Necessary for FGF23-Induced Phosphaturia. J Am Soc Nephrol 2007; 18:663-669. [PMID: 37001014 DOI: 10.1681/01.asn.0000926868.48235.3d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
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Satou M, Hoshikawa R, Sato Y, Okawa K. An in vitro study of long-term potentiation in the carp (Cyprinus carpio L.) olfactory bulb. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2005; 192:135-50. [PMID: 16328534 DOI: 10.1007/s00359-005-0056-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2005] [Revised: 08/30/2005] [Accepted: 09/01/2005] [Indexed: 10/25/2022]
Abstract
Long-term potentiation (LTP) of synaptic transmission is considered a cellular mechanism for neural plasticity and memory formation. Previously, we showed that in the carp olfactory bulb, LTP occurs at the dendrodendritic mitral-to-granule cell synapse following tetanic electrical stimulation applied to the olfactory tract, and suggested that it is involved in the process of olfactory memory formation. As a first step towards understanding mechanisms underlying plasticity at this synapse, we examined the effects of various drugs (glutamate and GABA receptor agonists and antagonists, noradrenaline, and drugs affecting cAMP signaling) on dendrodendritic mitral-to-granule cell synaptic transmission in an in vitro preparation. Two forms of LTP are involved: a postsynaptic form (tetanus-evoked LTP) and a presynaptic form. The postsynaptic form is evoked at the granule cell dendrite following tetanic olfactory tract stimulation and is suppressed by the NMDA receptor antagonist, D-AP5, enhanced by noradrenaline, and occluded by the metabotropic glutamate receptor agonist, trans-ACPD. The presynaptic form occurs at the mitral cell dendrite following blockade of the GABA(A) receptor by picrotoxin and bicuculline, or via activation of cAMP signaling by forskolin and 8-Br-cAMP.
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Yoshimoto H, Fukushige T, Yonezawa T, Sakai Y, Okawa K, Iwamatsu A, Sone H, Tamai Y. Pyruvate decarboxylase encoded by the PDC1 gene contributes, at least partially, to the decarboxylation of alpha-ketoisocaproate for isoamyl alcohol formation in Saccharomyces cerevisiae. J Biosci Bioeng 2005; 92:83-5. [PMID: 16233064 DOI: 10.1263/jbb.92.83] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2001] [Accepted: 04/24/2001] [Indexed: 11/17/2022]
Abstract
Isoamyl alcohol is an important flavor component of yeast-fermented alcoholic beverages. To identify the enzyme and gene involved in the decarboxylation of alpha-ketoisocaproate (alpha-KIC) for isoamyl alcohol formation, the enzyme was partially purified and analyzed by mass spectrometry. The pyruvate decarboxylase encoded by the PDC1 gene was considered a likely candidate enzyme. Genetic analysis showed that the activity of alpha-KIC decarboxylase and production of isoamyl alcohol partially decreased in a pdc1 null mutant and increased in a transformant with a multi-copy plasmid carrying the PDC1 gene. These results indicate that pyruvate decarboxylase encoded by the PDC1 gene contributes, at least partially, to the decarboxylation of alpha-KIC for isoamyl alcohol formation.
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Nakazawa N, Okawa K, Sato T, Enei H, Harashima S. Mass mating method in combination with G418- and aureobasidin A-resistance markers for efficient selection of hybrids from homothallic strains in Saccharomyces cerevisiae. J Biosci Bioeng 2005; 88:468-71. [PMID: 16232646 DOI: 10.1016/s1389-1723(00)87660-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/1999] [Accepted: 08/10/1999] [Indexed: 10/18/2022]
Abstract
We have developed a mass mating method using the spore suspensions of homothallic yeasts of Saccharomyces cerevisiae in combination with dominant selective drug resistance markers, Tn601(903) against geneticin and AUR1-C against aureobasidin A for the selection of the hybrids. To examine the effectiveness of these markers in the mass mating method, each marker was introduced into a homothallic wine yeast. Using a mixed culture of spore suspensions from the resultant transformants, many hybrids were screened by the drug resistance markers. This method is more practical than the spore-to-spore mating method because it does not require the use of a micromanipulator and many hybrids are obtained at one time. The resultant hybrids could be utilized for industrial brewing because plasmids, which are used to confer resistance markers, are easily eliminated from the hybrids by cultivation in a medium without drugs. We propose that the mass mating method using spore suspensions in combination with dominant selective geneticin- and aureobasidin A-resistance markers is useful for the selection of hybrids from industrial homothallic yeasts.
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Ogawa Y, Ono T, Wakata Y, Okawa K, Tagami H, Shibahara KI. Histone variant macroH2A1.2 is mono-ubiquitinated at its histone domain. Biochem Biophys Res Commun 2005; 336:204-9. [PMID: 16129414 DOI: 10.1016/j.bbrc.2005.08.046] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Accepted: 08/03/2005] [Indexed: 11/21/2022]
Abstract
Histone macroH2A1.2 (macroH2A) is an unusual histone H2A variant with a large non-histone macrodomain at its carboxyl terminal. MacroH2A1.2 is enriched in facultative heterochromatin, including inactivated X chromosomes in mammalian females and senescence-associated heterochromatin foci. We show here that a small population of macroH2A1.2 is mono-ubiquitinated in human HeLa cells. Mass spectrometry analysis revealed that the specific targeting sites for the mono-ubiquitination are Lys115 and Lys116 of the histone domain. A corresponding Lys119 conserved in histone H2A is also mono-ubiquitinated by Ring protein in the polycomb group complex. We suggest that the mono-ubiquitination of macroH2A1.2 and histone H2A has similar or synergistic implications, but that the multiple ubiquitination sites in macroH2A1.2 might confer a variety of functions upon macroH2A1.2 to modulate chromatin states.
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Yokoyama T, Egami K, Miyamoto M, Watanabe H, Hasegawa H, Iida S, Suzuki S, Nakamura Y, Okawa K, Hagiwara N, Takashima Y, Yoshioka M, Tajiri T, Onda M. Percutaneous and laparoscopic approaches of radiofrequency ablation treatment for liver cancer. ACTA ACUST UNITED AC 2003; 10:425-7. [PMID: 14714162 DOI: 10.1007/s00534-002-0830-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2002] [Accepted: 12/17/2002] [Indexed: 10/26/2022]
Abstract
BACKGROUND/PURPOSE Radiofrequency ablation (RFA) and microwave coagulation therapy (MCT) have been gaining acceptance as a standard method in the management strategy of liver cancer, for reasons of minimally invasive techniques and effective results. We present our experience of RFA and MCT in patients with liver cancer, and analyze retrospectively the advantages and disadvantages of both of the percutaneous and laparoscopic approaches. METHODS Thirty-two consecutive patients (23 men and 9 women) with 19 hepatocellular carcinomas (HCC), 12 metastatic liver cancers, and recurrent cholangiocellular carcinoma (CCC), were enrolled in this study. Out of these 32 patients, as a prior laparotomy, 19 underwent hepatectomy, colectomy, gastrectomy or cholecystectomy, and 15 were treated with the laparoscopic approach, 17 treated with the percutaneous approach, and 2 treated with the combined approach of those two. All of these procedures were carried out under general anesthesia with ultrasound guidance. Seven and 30 days after these procedures, an assessment helical computed tomography was done. RESULTS No sign of the residual tissues was noted in all patients except only one case. CONCLUSIONS The percutaneous approach was thought to be a more practical and less invasive method regardless previous laparotomy. For the laparoscopic approach, tumors located at the hepatic surface or margin were preferable candidates.
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