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Takagi H, Hari Y, Nakashima K, Kuno T, Ando T. Mortality after transcatheter versus surgical aortic valve replacement: an updated meta-analysis of randomised trials. Neth Heart J 2020; 28:320-333. [PMID: 32166571 PMCID: PMC7270388 DOI: 10.1007/s12471-020-01378-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Background To determine whether transcatheter aortic valve implantation (TAVI) improves early (30-day) and midterm (1-year) mortality compared with surgical aortic valve replacement (SAVR), we performed an updated meta-analysis of all the currently available randomised controlled trials (RCTs). Methods To identify all RCTs providing both 30-day and 1‑year mortality after TAVI versus SAVR, PubMed and ClinicalTrials.gov were searched up to and including July 2019. A risk difference (RD) and its 95% confidence interval were generated using data of prespecified outcomes in both the TAVI and SAVR groups. Study-specific estimates were pooled using inverse variance-weighted averages of RDs in the random-effects model. Results We identified seven eligible high-quality RCTs including a total of 7631 as-treated patients. Pooled analyses demonstrated significantly lower 30-day (RD −0.60%; p = 0.046) and 1‑year all-cause mortality (RD −1.12%; p = 0.03) after TAVI than after SAVR. No funnel plot asymmetry was detected for 30-day and 1‑year mortality. Meta-regression analyses indicated that RDs of 30-day and 1‑year mortality between TAVI and SAVR were not modulated by mean Society of Thoracic Surgeons Predicted Risk of Mortality score. Bleeding complications at 30 days and 1 year and stage 2/3 acute kidney injury at 30 days were significantly less frequent after TAVI than after SAVR, whereas major vascular complications and new permanent pacemaker implantation at 30 days and 1 year were significantly more frequent after TAVI than after SAVR. Conclusion The best evidence from the present meta-analysis of all the currently available RCTs suggests that TAVI may reduce 30-day and 1‑year all-cause mortality compared with SAVR. Electronic supplementary material The online version of this article (10.1007/s12471-020-01378-1) contains supplementary material, which is available to authorized users.
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Nakamura H, Huang D, Merz J, Khalaf E, Ostrovsky P, Yaresko A, Samal D, Takagi H. Robust weak antilocalization due to spin-orbital entanglement in Dirac material Sr 3SnO. Nat Commun 2020; 11:1161. [PMID: 32127524 PMCID: PMC7054336 DOI: 10.1038/s41467-020-14900-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 02/11/2020] [Indexed: 11/17/2022] Open
Abstract
The presence of both inversion (P) and time-reversal (T) symmetries in solids leads to a double degeneracy of the electronic bands (Kramers degeneracy). By lifting the degeneracy, spin textures manifest themselves in momentum space, as in topological insulators or in strong Rashba materials. The existence of spin textures with Kramers degeneracy, however, is difficult to observe directly. Here, we use quantum interference measurements to provide evidence for the existence of hidden entanglement between spin and momentum in the antiperovskite-type Dirac material Sr3SnO. We find robust weak antilocalization (WAL) independent of the position of EF. The observed WAL is fitted using a single interference channel at low doping, which implies that the different Dirac valleys are mixed by disorder. Notably, this mixing does not suppress WAL, suggesting contrasting interference physics compared to graphene. We identify scattering among axially spin-momentum locked states as a key process that leads to a spin-orbital entanglement.
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Takagi H, Yamane K, Matsui M, Suzuki S, Ito K. Pathotypes and Drug Susceptibility of Escherichia coli Isolated from Companion Dogs in Japan. Jpn J Infect Dis 2020; 73:253-255. [PMID: 32009053 DOI: 10.7883/yoken.jjid.2019.122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Considering the possibility that Escherichia coli carried by companion dogs could infect owners and human society, we investigated their pathogenicity and drug resistance. E. coli was isolated from stool samples of companion dogs (n = 90) to examine the O-serogroup, virulence genes, and drug susceptibility. The age of dogs ranged from 4 months to 16 years, and they were mainly treated with cefalexin, enrofloxacin, or amoxicillin. A total of 69 samples were positive for E. coli (76% of examined dogs), and the most common O-serogroup was O18 (n = 13). Nine diarrheagenic E. coli, including enteropathogenic E. coli (n = 3), enteroaggregative E. coli (n = 1), and astA-carrying E. coli (n = 5), were isolated. In addition, we isolated 28 E. coli strains resistant to at least one of six antimicrobials, including cephalothin (CET), ceftazidime (CAZ), cefotaxime (CTX), chloramphenicol (CP), fosfomycin (FOM), and norfloxacin (NLFX). The resistance pattern was as follows: CET, n = 16; NLFX, n = 3; CET/CP (resistance to both CET and CP), n = 1; CET/NLFX, n = 1; CET/CAZ/CTX, n = 3; CET/CTX/NLFX, n = 2; CET/CP/NLFX, n = 1; and CET/CAZ/CTX/NLFX, n = 1. Moreover, ten E. coli isolates were found to produce extended-spectrum β-lactamase (ESBL), including AmpC (n = 4; OUT, O18, O74, and O166), CTX-M-1 (n = 1; O25), CTX-M-9 (n = 4; OUT, O18, O18, and O125), and AmpC/CTX-M-9 (n = 1; OUT) groups. The AmpC-producing E. coli strains included enteropathogenic and astA-carrying E. coli. Our results showed that the human-infectious diarrheagenic E. coli was isolated from some dogs, and some strains exhibited ESBL. Therefore, future studies are needed to investigate the possibility of transmission of these E. coli strains to humans.
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Katoh N, Kataoka Y, Saeki H, Hide M, Kabashima K, Etoh T, Igarashi A, Imafuku S, Kawashima M, Ohtsuki M, Fujita H, Arima K, Takagi H, Chen Z, Shumel B, Ardeleanu M. Efficacy and safety of dupilumab in Japanese adults with moderate-to-severe atopic dermatitis: a subanalysis of three clinical trials. Br J Dermatol 2019; 183:39-51. [PMID: 31564057 PMCID: PMC7384164 DOI: 10.1111/bjd.18565] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2019] [Indexed: 12/15/2022]
Abstract
Background Dupilumab, a human monoclonal antibody, blocks the shared receptor unit for interleukin‐4 and interleukin‐13. International phase II and III studies have evaluated the efficacy and safety of dupilumab in adults with moderate‐to‐severe atopic dermatitis (AD), but the effects of dupilumab in Japanese patients have not been reported. Objectives To evaluate the efficacy and safety of dupilumab in Japanese patients with moderate‐to‐severe AD. Methods We analysed the efficacy and safety of dupilumab in the Japanese cohorts of a 16‐week, phase IIb dose‐finding trial (AD‐1021; NCT01859988); a 16‐week, phase III, placebo‐controlled monotherapy trial (LIBERTY AD SOLO 1; NCT02277743) and a 52‐week, phase III, placebo‐controlled study of dupilumab with topical corticosteroids (LIBERTY AD CHRONOS; NCT02260986). Results Twenty‐seven, 106 and 117 Japanese patients were enrolled in AD‐1021, SOLO 1 and CHRONOS, respectively. Baseline disease severity was numerically higher in the Japanese cohort than in the overall study population. Generally, dupilumab significantly improved signs and symptoms of AD, including pruritus and patient quality of life, compared with placebo in the Japanese cohort, consistent with the overall study population. The combined safety profile of dupilumab in the Japanese cohort was similar to that in the total study populations; dupilumab was associated with an increased incidence of injection‐site reactions and conjunctivitis compared with placebo. Dupilumab was associated with rapid reduction in thymus and activation‐regulated chemokine and gradual IgE reductions. Conclusions Dupilumab alone or with topical corticosteroids improved signs and symptoms of AD, had an acceptable safety profile, and suppressed biomarkers of type 2 inflammation compared with placebo in Japanese adult patients with moderate‐to‐severe AD. What's already known about this topic? Differences in atopic dermatitis (AD) pathology have been reported between Asian and Western populations, in which distinct helper T‐cell activation profiles have been observed. International clinical studies in adults with moderate‐to‐severe AD have evaluated the efficacy and safety of dupilumab, which blocks interleukin‐4 and interleukin‐13, key molecules in type 2 inflammation. The effects of dupilumab in Japanese patients specifically have not yet been reported.
What does this study add? Dupilumab alone or with topical corticosteroids improved signs and symptoms of AD and had an acceptable safety profile compared with placebo in Japanese patients with moderate‐to‐severe AD. The effects were comparable with those observed in the overall study population. Reported immunological differences in AD pathology in Asian patients may be secondary to type 2 immune activation.
Plain language summary available online Respond to this article
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Takagi H, Zhao S, Muto S, Mine H, Watanabe M, Ozaki Y, Okabe N, Hasegawa T, Shio Y, Aoki M, Tan C, Shimoyama S, Nakamura K, Inano A, Suzuki H. P1.03-23 Delta-Like 1 Homolog (DLK1) Expression in Non-Small-Cell Lung Cancer and the Development of Radioimmunotherapy Targeting DLK1. J Thorac Oncol 2019. [DOI: 10.1016/j.jtho.2019.08.875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Watanabe M, Higashi T, Mine H, Takagi H, Ozaki Y, Muto S, Okabe N, Hasegawa T, Shio Y, Sugimoto K, Chiba H, Suzuki H. P2.06-20 Characterization of Claudin15 as a New Diagnostic Marker for Malignant Pleural Mesotheliomas. J Thorac Oncol 2019. [DOI: 10.1016/j.jtho.2019.08.1638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Grissonnanche G, Legros A, Badoux S, Lefrançois E, Zatko V, Lizaire M, Laliberté F, Gourgout A, Zhou JS, Pyon S, Takayama T, Takagi H, Ono S, Doiron-Leyraud N, Taillefer L. Giant thermal Hall conductivity in the pseudogap phase of cuprate superconductors. Nature 2019; 571:376-380. [DOI: 10.1038/s41586-019-1375-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/26/2019] [Indexed: 11/09/2022]
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Takagi H, Sakamoto J, Sasagawa T. Long-term treatment of endometriosis with dienogest for up to five years. CLIN EXP OBSTET GYN 2019. [DOI: 10.12891/ceog4720.2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Suzuki H, Gretarsson H, Ishikawa H, Ueda K, Yang Z, Liu H, Kim H, Kukusta D, Yaresko A, Minola M, Sears JA, Francoual S, Wille HC, Nuss J, Takagi H, Kim BJ, Khaliullin G, Yavaş H, Keimer B. Spin waves and spin-state transitions in a ruthenate high-temperature antiferromagnet. NATURE MATERIALS 2019; 18:563-567. [PMID: 30911120 DOI: 10.1038/s41563-019-0327-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 02/26/2019] [Indexed: 06/09/2023]
Abstract
Ruthenium compounds serve as a platform for fundamental concepts such as spin-triplet superconductivity1, Kitaev spin liquids2-5 and solid-state analogues of the Higgs mode in particle physics6,7. However, basic questions about the electronic structure of ruthenates remain unanswered, because several key parameters (including Hund's coupling, spin-orbit coupling and exchange interactions) are comparable in magnitude and their interplay is poorly understood, partly due to difficulties in synthesizing large single crystals for spectroscopic experiments. Here we introduce a resonant inelastic X-ray scattering (RIXS)8,9 technique capable of probing collective modes in microcrystals of 4d electron materials. We observe spin waves and spin-state transitions in the honeycomb antiferromagnet SrRu2O6 (ref. 10) and use the extracted exchange interactions and measured magnon gap to explain its high Néel temperature11-16. We expect that the RIXS method presented here will enable momentum-resolved spectroscopy of a large class of 4d transition-metal compounds.
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Takayama T, Yaresko AN, Takagi H. Monoclinic SrIrO 3-a Dirac semimetal produced by non-symmorphic symmetry and spin-orbit coupling. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:074001. [PMID: 30523949 DOI: 10.1088/1361-648x/aaf68a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
SrIrO3 crystallizes in a monoclinic structure of distorted hexagonal perovskite at ambient pressure. The transport measurements show that the monoclinic SrIrO3 is a low-carrier density semimetal, as in the orthorhombic perovskite polymorph. The electronic structure calculation indicates a semimetallic band structure with Dirac bands at two high-symmetry points of Brillouin zone only when spin-orbit coupling is incorporated, suggesting that the semimetallic state is produced by the strong spin-orbit coupling. We argue that the Dirac bands are protected by the non-symmorphic symmetry of lattice.
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Michon B, Girod C, Badoux S, Kačmarčík J, Ma Q, Dragomir M, Dabkowska HA, Gaulin BD, Zhou JS, Pyon S, Takayama T, Takagi H, Verret S, Doiron-Leyraud N, Marcenat C, Taillefer L, Klein T. Thermodynamic signatures of quantum criticality in cuprate superconductors. Nature 2019; 567:218-222. [PMID: 30760922 DOI: 10.1038/s41586-019-0932-x] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 12/17/2018] [Indexed: 11/09/2022]
Abstract
The three central phenomena of cuprate (copper oxide) superconductors are linked by a common doping level p*-at which the enigmatic pseudogap phase ends and the resistivity exhibits an anomalous linear dependence on temperature, and around which the superconducting phase forms a dome-shaped area in the phase diagram1. However, the fundamental nature of p* remains unclear, in particular regarding whether it marks a true quantum phase transition. Here we measure the specific heat C of the cuprates Eu-LSCO and Nd-LSCO at low temperature in magnetic fields large enough to suppress superconductivity, over a wide doping range2 that includes p*. As a function of doping, we find that Cel/T is strongly peaked at p* (where Cel is the electronic contribution to C) and exhibits a log(1/T) dependence as temperature T tends to zero. These are the classic thermodynamic signatures of a quantum critical point3-5, as observed in heavy-fermion6 and iron-based7 superconductors at the point where their antiferromagnetic phase comes to an end. We conclude that the pseudogap phase of cuprates ends at a quantum critical point, the associated fluctuations of which are probably involved in d-wave pairing and the anomalous scattering of charge carriers.
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Horio M, Hauser K, Sassa Y, Mingazheva Z, Sutter D, Kramer K, Cook A, Nocerino E, Forslund OK, Tjernberg O, Kobayashi M, Chikina A, Schröter NBM, Krieger JA, Schmitt T, Strocov VN, Pyon S, Takayama T, Takagi H, Lipscombe OJ, Hayden SM, Ishikado M, Eisaki H, Neupert T, Månsson M, Matt CE, Chang J. Three-Dimensional Fermi Surface of Overdoped La-Based Cuprates. PHYSICAL REVIEW LETTERS 2018; 121:077004. [PMID: 30169083 DOI: 10.1103/physrevlett.121.077004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Indexed: 06/08/2023]
Abstract
We present a soft x-ray angle-resolved photoemission spectroscopy study of overdoped high-temperature superconductors. In-plane and out-of-plane components of the Fermi surface are mapped by varying the photoemission angle and the incident photon energy. No k_{z} dispersion is observed along the nodal direction, whereas a significant antinodal k_{z} dispersion is identified for La-based cuprates. Based on a tight-binding parametrization, we discuss the implications for the density of states near the van Hove singularity. Our results suggest that the large electronic specific heat found in overdoped La_{2-x}Sr_{x}CuO_{4} cannot be assigned to the van Hove singularity alone. We therefore propose quantum criticality induced by a collapsing pseudogap phase as a plausible explanation for observed enhancement of electronic specific heat.
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Kato M, Kito K, Kubo A, Takagi H. P1479Effects of preoperative exercise training on safety and exercise capacity in patients with abdominal aortic aneurysm: a meta-analysis of randomised controlled trials. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.p1479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ota K, Takahashi K, Agishi T, Sonda T, Oka T, Ueda S, Amemiya H, Shiramizu T, Okazaki H, Akiyama N, Hasegawa A, Kawamura T, Takagi H, Ueno A. Multicentre trial of ABO-incompatible kidney transplantation. Transpl Int 2018. [DOI: 10.1111/tri.1992.5.s1.40] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Matsuyama K, Tokuzumi M, Takahashi T, Shu E, Takagi H, Hashimoto T, Seishima M. Elevated serum eosinophil cationic protein and transforming growth factor-α levels in a patient with pemphigus vegetans. Clin Exp Dermatol 2018; 43:917-920. [DOI: 10.1111/ced.13670] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2017] [Indexed: 12/31/2022]
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Takagi H, Sasagawa T, Osaka Y. Confirmation of menopause based on changes in follicle-stimulating hormone levels in patients who were administered dienogest. CLIN EXP OBSTET GYN 2018. [DOI: 10.12891/ceog4029.2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Tatemoto K, Nozaki Y, Tsuda R, Kaneko S, Tomura K, Furuno M, Ogasawara H, Edamura K, Takagi H, Iwamura H, Noguchi M, Naito T. Endogenous protein and enzyme fragments induce immunoglobulin E-independent activation of mast cells via a G protein-coupled receptor, MRGPRX2. Scand J Immunol 2018; 87:e12655. [PMID: 29484687 DOI: 10.1111/sji.12655] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 02/20/2018] [Indexed: 12/31/2022]
Abstract
Mast cells play a central role in inflammatory and allergic reactions by releasing inflammatory mediators through 2 main pathways, immunoglobulin E-dependent and E-independent activation. In the latter pathway, mast cells are activated by a diverse range of basic molecules (collectively known as basic secretagogues) through Mas-related G protein-coupled receptors (MRGPRs). In addition to the known basic secretagogues, here, we discovered several endogenous protein and enzyme fragments (such as chaperonin-10 fragment) that act as bioactive peptides and induce immunoglobulin E-independent mast cell activation via MRGPRX2 (previously known as MrgX2), leading to the degranulation of mast cells. We discuss the possibility that MRGPRX2 responds various as-yet-unidentified endogenous ligands that have specific characteristics, and propose that MRGPRX2 plays an important role in regulating inflammatory responses to endogenous harmful stimuli, such as protein breakdown products released from damaged or dying cells.
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Matt CE, Sutter D, Cook AM, Sassa Y, Månsson M, Tjernberg O, Das L, Horio M, Destraz D, Fatuzzo CG, Hauser K, Shi M, Kobayashi M, Strocov VN, Schmitt T, Dudin P, Hoesch M, Pyon S, Takayama T, Takagi H, Lipscombe OJ, Hayden SM, Kurosawa T, Momono N, Oda M, Neupert T, Chang J. Direct observation of orbital hybridisation in a cuprate superconductor. Nat Commun 2018; 9:972. [PMID: 29511188 PMCID: PMC5840306 DOI: 10.1038/s41467-018-03266-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 02/01/2018] [Indexed: 11/19/2022] Open
Abstract
The minimal ingredients to explain the essential physics of layered copper-oxide (cuprates) materials remains heavily debated. Effective low-energy single-band models of the copper–oxygen orbitals are widely used because there exists no strong experimental evidence supporting multi-band structures. Here, we report angle-resolved photoelectron spectroscopy experiments on La-based cuprates that provide direct observation of a two-band structure. This electronic structure, qualitatively consistent with density functional theory, is parametrised by a two-orbital (\documentclass[12pt]{minimal}
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\begin{document}$$d_{z^2}$$\end{document}dz2) tight-binding model. We quantify the orbital hybridisation which provides an explanation for the Fermi surface topology and the proximity of the van-Hove singularity to the Fermi level. Our analysis leads to a unification of electronic hopping parameters for single-layer cuprates and we conclude that hybridisation, restraining d-wave pairing, is an important optimisation element for superconductivity. The essential physics of cuprate superconductors is often described by single-band models. Here, Matt et al. report direct observation of a two-band electronic structure in La-based cuprates.
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Yokoyama M, Oka T, Takagi H, Kojima H, Okabe T, Nagano T, Tohya Y, Sato H. A Proposal for a Structural Model of the Feline Calicivirus Protease Bound to the Substrate Peptide under Physiological Conditions. Front Microbiol 2017; 8:1383. [PMID: 28790989 PMCID: PMC5524728 DOI: 10.3389/fmicb.2017.01383] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 07/10/2017] [Indexed: 11/30/2022] Open
Abstract
Feline calicivirus (FCV) protease functions to cleave viral precursor proteins during productive infection. Previous studies have mapped a protease-coding region and six cleavage sites in viral precursor proteins. However, how the FCV protease interacts with its substrates remains unknown. To gain insights into the interactions, we constructed a molecular model of the FCV protease bound with the octapeptide containing a cleavage site of the capsid precursor protein by homology modeling and docking simulation. The complex model was used to screen for the substrate mimic from a chemical library by pharmacophore-based in silico screening. With this structure-based approach, we identified a compound that has physicochemical features and arrangement of the P3 and P4 sites of the substrate in the protease, is predicted to bind to FCV proteases in a mode similar to that of the authentic substrate, and has the ability to inhibit viral protease activity in vitro and in the cells, and to suppress viral replication in FCV-infected cells. The complex model was further subjected to molecular dynamics simulation to refine the enzyme-substrate interactions in solution. The simulation along with a variation study predicted that the authentic substrate and anti-FCV compound share a highly conserved binding site. These results suggest the validity of our in silico model for elucidating protease-substrate interactions during FCV replication and for developing antivirals.
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Arimura K, Takagi H, Uto T, Fukaya T, Nakamura T, Choijookhuu N, Hishikawa Y, Yamashita Y, Sato K. Crucial role of plasmacytoid dendritic cells in the development of acute colitis through the regulation of intestinal inflammation. Mucosal Immunol 2017; 10:957-970. [PMID: 27848952 DOI: 10.1038/mi.2016.96] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 09/23/2016] [Indexed: 02/04/2023]
Abstract
Disruption of intestinal homeostasis can lead to inflammatory bowel diseases endowed susceptibility genes and environmental factors affecting intestinal accumulation and activation of colitogenic phagocytes. Plasmacytoid dendritic cells (pDCs) are immune cells that had been proposed to control innate and adaptive immunity through the massive secretion of type I interferon (IFN-I). However, the contribution of pDCs to the progression of intestinal inflammation remains unclear. Here we show a critical role of pDCs in the initiation of acute colonic inflammation using T-cell-independent acute colitis model with a selective ablation of pDCs. Although pDCs accumulated in the inflamed colon upon mucosal injury, deficiency of pDCs attenuated the development of acute colitis independent of IFN-I signaling, accompanied by the diminished colonic production of proinflammatory cytokines. Furthermore, deficiency of pDCs impaired the mobilization of colitogenic phagocytes into the inflamed colon possibly mediated by the abrogated mucosal production of C-C chemokine receptor 2 ligand. Thus, our findings highlight a critical role of pDCs in the induction of the colonic inflammation that regulates the colonic accumulation of inflammatory phagocytes leading to the initiation and exacerbation of acute colitis, and they may serve a key role in controlling gut mucosal immune homeostasis.
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Kitamoto T, Takai-Todaka R, Kato A, Kanamori K, Takagi H, Yoshida K, Katayama K, Nakanishi A. Viral Population Changes during Murine Norovirus Propagation in RAW 264.7 Cells. Front Microbiol 2017; 8:1091. [PMID: 28663743 PMCID: PMC5471328 DOI: 10.3389/fmicb.2017.01091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 05/30/2017] [Indexed: 12/23/2022] Open
Abstract
Laboratory adaptation of viruses is an essential technique for basic virology research, including the generation of attenuated vaccine strains, although the principles of cell adaptation remain largely unknown. Deep sequencing of murine norovirus (MuNoV) S7 during serial passages in RAW264.7 cells showed that the frequencies of viral variants were altered more dynamically than previously reported. Serial passages of the virus following two different multiplicity of infections gave rise to distinct haplotypes, implying that multiple cell-adaptable sequences were present in the founder population. Nucleotide variants lost during passage were assembled into a viral genome representative of that prior to cell adaptation, which was unable to generate viral particles upon infection in cultured cells. In addition, presence of the reconstructed genome interfered with production of infectious particles from viruses that were fully adapted to in vitro culture. Although the key nucleotide changes dictating cell adaptation of MuNoV S7 viral infection are yet to be elucidated, our results revealed the elaborate interplay among selected sequences of viral variants better adapted to propagation in cell culture. Such knowledge will be instrumental in understanding the processes necessary for the laboratory adaptation of viruses, especially to those without relevant cell culture systems.
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Lu YF, Kono H, Larkin TI, Rost AW, Takayama T, Boris AV, Keimer B, Takagi H. Zero-gap semiconductor to excitonic insulator transition in Ta 2NiSe 5. Nat Commun 2017; 8:14408. [PMID: 28205553 PMCID: PMC5316885 DOI: 10.1038/ncomms14408] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 12/25/2016] [Indexed: 11/24/2022] Open
Abstract
The excitonic insulator is a long conjectured correlated electron phase of narrow-gap semiconductors and semimetals, driven by weakly screened electron–hole interactions. Having been proposed more than 50 years ago, conclusive experimental evidence for its existence remains elusive. Ta2NiSe5 is a narrow-gap semiconductor with a small one-electron bandgap EG of <50 meV. Below TC=326 K, a putative excitonic insulator is stabilized. Here we report an optical excitation gap Eop ∼0.16 eV below TC comparable to the estimated exciton binding energy EB. Specific heat measurements show the entropy associated with the transition being consistent with a primarily electronic origin. To further explore this physics, we map the TC–EG phase diagram tuning EG via chemical and physical pressure. The dome-like behaviour around EG∼0 combined with our transport, thermodynamic and optical results are fully consistent with an excitonic insulator phase in Ta2NiSe5. The nature of an insulating phase in Ta2NiSe5 is an open question. Here, Lu et al. report transport, thermodynamic and optical evidences being fully consistent with an excitonic insulator phase in this material.
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Ohba M, Oka T, Ando T, Arahata S, Ikegaya A, Takagi H, Ogo N, Owada K, Kawamori F, Wang Q, Saif LJ, Asai A. Discovery and Synthesis of Heterocyclic Carboxamide Derivatives as Potent Anti-norovirus Agents. Chem Pharm Bull (Tokyo) 2017; 64:465-75. [PMID: 27150478 DOI: 10.1248/cpb.c16-00001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There is an urgent need for structurally novel anti-norovirus agents. In this study, we describe the synthesis, anti-norovirus activity, and structure-activity relationship (SAR) of a series of heterocyclic carboxamide derivatives. Heterocyclic carboxamide 1 (50% effective concentration (EC50)=37 µM) was identified by our screening campaign using the cytopathic effect reduction assay. Initial SAR studies suggested the importance of halogen substituents on the heterocyclic scaffold and identified 3,5-di-boromo-thiophene derivative 2j (EC50=24 µM) and 4,6-di-fluoro-benzothiazole derivative 3j (EC50=5.6 µM) as more potent inhibitors than 1. Moreover, their hybrid compound, 3,5-di-bromo-thiophen-4,6-di-fluoro-benzothiazole 4b, showed the most potent anti-norovirus activity with a EC50 value of 0.53 µM (70-fold more potent than 1). Further investigation suggested that 4b might inhibit intracellular viral replication or the late stage of viral infection.
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Shibata T, Sakamoto J, Osaka Y, Neyatani N, Fujita S, Oka Y, Takagi H, Mori H, Fujita H, Tanaka Y, Sasagawa T. Myeloperoxidase in blood neutrophils during normal and abnormal menstrual cycles in women of reproductive age. Int J Lab Hematol 2016; 39:169-174. [PMID: 28013526 DOI: 10.1111/ijlh.12599] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/22/2016] [Indexed: 11/30/2022]
Abstract
INTRODUCTION We previously reported that granulocyte colony-stimulating factor (G-CSF) plays a critical role in ovulation, suggesting that neutrophils may maintain ovulation. We assessed myeloperoxidase (MPO), a major and specific enzyme of neutrophils, in women with abnormal and normal menstrual cycles to clarify the relationship between MPO and ovulation. METHODS We analyzed MPO activity in blood neutrophils of women with abnormal menstrual cycles (indicative of anovulation, n = 12) and age- and body mass index-matched normal menstrual cycles (indicative of ovulation, n = 24) using two parameters as a marker of MPO, Neut X and mean peroxidase index (MPXI). RESULTS MPO of women with abnormal menstrual cycles was significantly lower than that of women with normal menstrual cycles [Neut X: 62.6 ± 1.1 (mean ± standard error of the mean) vs. 66.2 ± 0.3, P = 0.009; MPXI: -0.54 ± 1.66 vs. 4.91 ± 0.53, P = 0.008]. Among women with normal menstrual cycles, MPO was highest in the follicular phase (Neut X: 67.0 ± 0.3; P = 0.033). CONCLUSION The difference in MPO between women with abnormal and normal menstrual cycles and the upregulation of MPO before ovulation suggest that neutrophils and MPO are closely related to ovulation.
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