1
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Jung HJ, Park BH, Kim SH, Hong SC. Integrating magnetic tweezers and single-molecule FRET: A comprehensive approach to studying local and global conformational changes simultaneously. Methods Enzymol 2024; 694:167-189. [PMID: 38492950 DOI: 10.1016/bs.mie.2024.01.007] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
This chapter presents the integration of magnetic tweezers with single-molecule FRET technology, a significant advancement in the study of nucleic acids and other biological systems. We detail the technical aspects, challenges, and current status of this hybrid technique, which combines the global manipulation and observation capabilities of magnetic tweezers with the local conformational detection of smFRET. This innovative approach enhances our ability to analyze and understand the molecular mechanics of biological systems. The chapter serves as our first formal documentation of this method, offering insights and methodologies developed in our laboratory over the past decade.
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Affiliation(s)
- Hae Jun Jung
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, Korea
| | - Beom-Hyeon Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, Korea
| | - Sook Ho Kim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, Korea; College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, Korea.
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2
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Park C, Lim JM, Hong SC, Cho M. Monitoring the synthesis of neutral lipids in lipid droplets of living human cancer cells using two-color infrared photothermal microscopy. Chem Sci 2024; 15:1237-1247. [PMID: 38274065 PMCID: PMC10806728 DOI: 10.1039/d3sc04705a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/25/2023] [Indexed: 01/27/2024] Open
Abstract
There has been growing interest in the functions of lipid droplets (LDs) due to recent discoveries regarding their diverse roles. These functions encompass lipid metabolism, regulation of lipotoxicity, and signaling pathways that extend beyond their traditional role in energy storage. Consequently, there is a need to examine the molecular dynamics of LDs at the subcellular level. Two-color infrared photothermal microscopy (2C-IPM) has proven to be a valuable tool for elucidating the molecular dynamics occurring in LDs with sub-micrometer spatial resolution and molecular specificity. In this study, we employed the 2C-IPM to investigate the molecular dynamics of LDs in both fixed and living human cancer cells (U2OS cells) using the isotope labeling method. We investigated the synthesis of neutral lipids occurring in individual LDs over time after exposing the cells to excess saturated fatty acids while simultaneously comparing inherent lipid contents in LDs. We anticipate that these research findings will reveal new opportunities for studying lesser-known biological processes within LDs and other subcellular organelles.
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Affiliation(s)
- Chanjong Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science Seoul 02841 Korea
- Department of Chemistry, Korea University Seoul 02841 Korea
| | - Jong Min Lim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science Seoul 02841 Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science Seoul 02841 Korea
- Department of Physics, Korea University Seoul 02841 Korea
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science Seoul 02841 Korea
- Department of Chemistry, Korea University Seoul 02841 Korea
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3
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Park JS, Lee IB, Moon HM, Hong SC, Cho M. Long-term cargo tracking reveals intricate trafficking through active cytoskeletal networks in the crowded cellular environment. Nat Commun 2023; 14:7160. [PMID: 37963891 PMCID: PMC10645962 DOI: 10.1038/s41467-023-42347-7] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 09/29/2023] [Indexed: 11/16/2023] Open
Abstract
A eukaryotic cell is a microscopic world within which efficient material transport is essential. Yet, how a cell manages to deliver cellular cargos efficiently in a crowded environment remains poorly understood. Here, we used interferometric scattering microscopy to track unlabeled cargos in directional motion in a massively parallel fashion. Our label-free, cargo-tracing method revealed not only the dynamics of cargo transportation but also the fine architecture of the actively used cytoskeletal highways and the long-term evolution of the associated traffic at sub-diffraction resolution. Cargos frequently run into a blocked road or experience a traffic jam. Still, they have effective strategies to circumvent those problems: opting for an alternative mode of transport and moving together in tandem or migrating collectively. All taken together, a cell is an incredibly complex and busy space where the principle and practice of transportation intriguingly parallel those of our macroscopic world.
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Affiliation(s)
- Jin-Sung Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Korea
| | - Il-Buem Lee
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Korea
| | - Hyeon-Min Moon
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Korea.
- Department of Physics, Korea University, Seoul, Korea.
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Korea.
- Department of Chemistry, Korea University, Seoul, Korea.
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4
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Park C, Lim JM, Hong SC, Cho M. Two-color infrared photothermal microscopy. Analyst 2023; 148:2395-2402. [PMID: 37132454 DOI: 10.1039/d3an00042g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Infrared photothermal microscopy is an infrared (IR) imaging technique that enables non-invasive, non-destructive, and label-free investigations at the sub-micrometer scale. It has been applied in various research areas targeting pharmaceutical and photovoltaic materials as well as biomolecules in living systems. Despite its potency in observing biomolecules in living organisms, its practical application for cytological research has been restricted by the deficiency of molecular information from the IR photothermal signal, due to the narrow spectral width of a quantum cascade laser that is one of the most preferred IR excitation light sources for current IR photothermal imaging (IPI) techniques. Here, we address this issue by bringing modulation-frequency multiplexing into IR photothermal microscopy for developing a two-color IR photothermal microscopy technique. We demonstrate that the two-color IPI technique can be used to obtain the IR microscopic images of two discrete IR absorption bands and to distinguish two different chemical species in live cells with a sub-micrometer spatial resolution. We anticipate that the more general multi-color IPI technique and its use for metabolic studies of live cells could be realized by extending the present modulation-frequency multiplexing method.
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Affiliation(s)
- Chanjong Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, 02841, Republic of Korea.
- Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea
| | - Jong Min Lim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, 02841, Republic of Korea.
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, 02841, Republic of Korea.
- Department of Physics, Korea University, Seoul, 02841, Republic of Korea
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, 02841, Republic of Korea.
- Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea
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5
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Žambochová K, Lee IB, Park JS, Hong SC, Cho M. Axial profiling of interferometric scattering enables an accurate determination of nanoparticle size. Opt Express 2023; 31:10101-10113. [PMID: 37157566 DOI: 10.1364/oe.480337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Interferometric scattering (iSCAT) microscopy has undergone significant development in recent years. It is a promising technique for imaging and tracking nanoscopic label-free objects with nanometer localization precision. The current iSCAT-based photometry technique allows quantitative estimation for the size of a nanoparticle by measuring iSCAT contrast and has been successfully applied to nano-objects smaller than the Rayleigh scattering limit. Here we provide an alternative method that overcomes such size limitations. We take into account the axial variation of iSCAT contrast and utilize a vectorial point spread function model to uncover the position of a scattering dipole and, consequently, the size of the scatterer, which is not limited to the Rayleigh limit. We found that our technique accurately measures the size of spherical dielectric nanoparticles in a purely optical and non-contact way. We also tested fluorescent nanodiamonds (fND) and obtained a reasonable estimate for the size of fND particles. Together with fluorescence measurement from fND, we observed a correlation between the fluorescent signal and the size of fND. Our results showed that the axial pattern of iSCAT contrast provides sufficient information for the size of spherical particles. Our method enables us to measure the size of nanoparticles from tens of nanometers and beyond the Rayleigh limit with nanometer precision, making a versatile all-optical nanometric technique.
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6
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Kim SE, Hong SC. Two Opposing Effects of Monovalent Cations on the Stability of i-Motif Structure. J Phys Chem B 2023; 127:1932-1939. [PMID: 36811958 DOI: 10.1021/acs.jpcb.2c07069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
At acidic pH, cytosine-rich single-stranded DNA can be folded into a tetraplex structure called i-motif (iM). In recent studies, the effect of monovalent cations on the stability of iM structure has been addressed, but a consensus about the issue has not been reached yet. Thus, we investigated the effects of various factors on the stability of iM structure using fluorescence resonance energy transfer (FRET)-based analysis for three types of iM derived from human telomere sequences. We confirmed that the protonated cytosine-cytosine (C:C+) base pair is destabilized as the concentration of monovalent cations (Li+, Na+, K+) increases and that Li+ has the greatest tendency of destabilization. Intriguingly, monovalent cations would play an ambivalent role in iM formation by making single-stranded DNA flexible and pliant for an iM structure. In particular, we found that Li+ has a notably greater flexibilizing effect than Na+ and K+. All taken together, we conclude that the stability of iM structure is controlled by the subtle balance of the two counteractive effects of monovalent cations: electrostatic screening and disruption of cytosine base pairing.
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Affiliation(s)
- Sung Eun Kim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Korea, Department of Physics, Korea University, Seoul 02841, Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Korea, Department of Physics, Korea University, Seoul 02841, Korea
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7
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Jung HJ, Park BH, Kim SH, Hong SC. Single-Molecule Methods to Study Z-DNA Mechanics and Dynamics. Methods Mol Biol 2023; 2651:85-103. [PMID: 36892761 DOI: 10.1007/978-1-0716-3084-6_6] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
Single-molecule methods are powerful in revealing physical and mechanobiological details about biological phenomena. Here, we describe the single-molecule methods applied to study mechanical properties of Z-DNA and dynamics of the B-Z transition.
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Affiliation(s)
- Hae Jun Jung
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, South Korea
| | - Beom-Hyeon Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, South Korea
| | - Sook Ho Kim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, South Korea. .,College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, South Korea.
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8
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Moon HM, Park JS, Lee IB, Kang YI, Jung HJ, An D, Shin Y, Kim MJ, Kim HI, Song JJ, Kim J, Lee NK, Hong SC. Cisplatin fastens chromatin irreversibly even at a high chloride concentration. Nucleic Acids Res 2021; 49:12035-12047. [PMID: 34865121 PMCID: PMC8643659 DOI: 10.1093/nar/gkab922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 02/27/2021] [Revised: 09/12/2021] [Accepted: 09/28/2021] [Indexed: 12/17/2022] Open
Abstract
Cisplatin is one of the most potent anti-cancer drugs developed so far. Recent studies highlighted several intriguing roles of histones in cisplatin's anti-cancer effect. Thus, the effect of nucleosome formation should be considered to give a better account of the anti-cancer effect of cisplatin. Here we investigated this important issue via single-molecule measurements. Surprisingly, the reduced activity of cisplatin under [NaCl] = 180 mM, corresponding to the total concentration of cellular ionic species, is still sufficient to impair the integrity of a nucleosome by retaining its condensed structure firmly, even against severe mechanical and chemical disturbances. Our finding suggests that such cisplatin-induced fastening of chromatin can inhibit nucleosome remodelling required for normal biological functions. The in vitro chromatin transcription assay indeed revealed that the transcription activity was effectively suppressed in the presence of cisplatin. Our direct physical measurements on cisplatin-nucleosome adducts suggest that the formation of such adducts be the key to the anti-cancer effect by cisplatin.
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Affiliation(s)
- Hyeon-Min Moon
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea.,Department of Physics, Korea University, Seoul 02841, Korea
| | - Jin-Sung Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea
| | - Il-Buem Lee
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea.,Department of Physics, Korea University, Seoul 02841, Korea
| | - Young-Im Kang
- Department of Physics, Korea University, Seoul 02841, Korea
| | - Hae Jun Jung
- Department of Physics, Korea University, Seoul 02841, Korea
| | - Dongju An
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Yumi Shin
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Min Ji Kim
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Hugh I Kim
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Ji-Joon Song
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Jaehoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Nam-Kyung Lee
- Department of Physics, Sejong University, Seoul 05006, Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea.,Department of Physics, Korea University, Seoul 02841, Korea
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9
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Kim SH, Jung HJ, Lee IB, Lee NK, Hong SC. Sequence-dependent cost for Z-form shapes the torsion-driven B-Z transition via close interplay of Z-DNA and DNA bubble. Nucleic Acids Res 2021; 49:3651-3660. [PMID: 33744929 PMCID: PMC8053131 DOI: 10.1093/nar/gkab153] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 02/19/2021] [Accepted: 02/27/2021] [Indexed: 02/06/2023] Open
Abstract
Despite recent genome-wide investigations of functional DNA elements, the mechanistic details about their actions remain elusive. One intriguing possibility is that DNA sequences with special patterns play biological roles, adopting non-B-DNA conformations. Here we investigated dynamics of thymine-guanine (TG) repeats, microsatellite sequences and recurrently found in promoters, as well as cytosine–guanine (CG) repeats, best-known Z-DNA forming sequence, in the aspect of Z-DNA formation. We measured the energy barriers of the B–Z transition with those repeats and discovered the sequence-dependent penalty for Z-DNA generates distinctive thermodynamic and kinetic features in the torque-induced transition. Due to the higher torsional stress required for Z-form in TG repeats, a bubble could be induced more easily, suppressing Z-DNA induction, but facilitate the B–Z interconversion kinetically at the transition midpoint. Thus, the Z-form by TG repeats has advantages as a torsion buffer and bubble selector while the Z-form by CG repeats likely behaves as torsion absorber. Our statistical physics model supports quantitatively the populations of Z-DNA and reveals the pivotal roles of bubbles in state dynamics. All taken together, a quantitative picture for the transition was deduced within the close interplay among bubbles, plectonemes and Z-DNA.
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Affiliation(s)
- Sook Ho Kim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841 Korea.,Department of Physics, Korea University, Seoul, 02841 Korea.,GRI-TPC International Research Center, Sejong University, Seoul, 05006 Korea
| | - Hae Jun Jung
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841 Korea.,Department of Physics, Korea University, Seoul, 02841 Korea
| | - Il-Buem Lee
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841 Korea.,Department of Physics, Korea University, Seoul, 02841 Korea
| | - Nam-Kyung Lee
- Department of Physics and Astronomy, Sejong University, Seoul, 05006 Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841 Korea.,Department of Physics, Korea University, Seoul, 02841 Korea
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10
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Lerner E, Barth A, Hendrix J, Ambrose B, Birkedal V, Blanchard SC, Börner R, Sung Chung H, Cordes T, Craggs TD, Deniz AA, Diao J, Fei J, Gonzalez RL, Gopich IV, Ha T, Hanke CA, Haran G, Hatzakis NS, Hohng S, Hong SC, Hugel T, Ingargiola A, Joo C, Kapanidis AN, Kim HD, Laurence T, Lee NK, Lee TH, Lemke EA, Margeat E, Michaelis J, Michalet X, Myong S, Nettels D, Peulen TO, Ploetz E, Razvag Y, Robb NC, Schuler B, Soleimaninejad H, Tang C, Vafabakhsh R, Lamb DC, Seidel CA, Weiss S. FRET-based dynamic structural biology: Challenges, perspectives and an appeal for open-science practices. eLife 2021; 10:60416. [PMID: 33779550 PMCID: PMC8007216 DOI: 10.7554/elife.60416] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 02/09/2021] [Indexed: 12/18/2022] Open
Abstract
Single-molecule FRET (smFRET) has become a mainstream technique for studying biomolecular structural dynamics. The rapid and wide adoption of smFRET experiments by an ever-increasing number of groups has generated significant progress in sample preparation, measurement procedures, data analysis, algorithms and documentation. Several labs that employ smFRET approaches have joined forces to inform the smFRET community about streamlining how to perform experiments and analyze results for obtaining quantitative information on biomolecular structure and dynamics. The recent efforts include blind tests to assess the accuracy and the precision of smFRET experiments among different labs using various procedures. These multi-lab studies have led to the development of smFRET procedures and documentation, which are important when submitting entries into the archiving system for integrative structure models, PDB-Dev. This position paper describes the current ‘state of the art’ from different perspectives, points to unresolved methodological issues for quantitative structural studies, provides a set of ‘soft recommendations’ about which an emerging consensus exists, and lists openly available resources for newcomers and seasoned practitioners. To make further progress, we strongly encourage ‘open science’ practices.
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Affiliation(s)
- Eitan Lerner
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, and The Center for Nanoscience and Nanotechnology, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Anders Barth
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Jelle Hendrix
- Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre and Biomedical Research Institute (BIOMED), Hasselt University, Diepenbeek, Belgium
| | - Benjamin Ambrose
- Department of Chemistry, University of Sheffield, Sheffield, United Kingdom
| | - Victoria Birkedal
- Department of Chemistry and iNANO center, Aarhus University, Aarhus, Denmark
| | - Scott C Blanchard
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Richard Börner
- Laserinstitut HS Mittweida, University of Applied Science Mittweida, Mittweida, Germany
| | - Hoi Sung Chung
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States
| | - Thorben Cordes
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Timothy D Craggs
- Department of Chemistry, University of Sheffield, Sheffield, United Kingdom
| | - Ashok A Deniz
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, United States
| | - Jiajie Diao
- Department of Cancer Biology, University of Cincinnati School of Medicine, Cincinnati, United States
| | - Jingyi Fei
- Department of Biochemistry and Molecular Biology and The Institute for Biophysical Dynamics, University of Chicago, Chicago, United States
| | - Ruben L Gonzalez
- Department of Chemistry, Columbia University, New York, United States
| | - Irina V Gopich
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Howard Hughes Medical Institute, Baltimore, United States
| | - Christian A Hanke
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Gilad Haran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Nikos S Hatzakis
- Department of Chemistry & Nanoscience Centre, University of Copenhagen, Copenhagen, Denmark.,Denmark Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sungchul Hohng
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, Republic of Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science and Department of Physics, Korea University, Seoul, Republic of Korea
| | - Thorsten Hugel
- Institute of Physical Chemistry and Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Antonino Ingargiola
- Department of Chemistry and Biochemistry, and Department of Physiology, University of California, Los Angeles, Los Angeles, United States
| | - Chirlmin Joo
- Department of BioNanoScience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands
| | - Achillefs N Kapanidis
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, United Kingdom
| | - Harold D Kim
- School of Physics, Georgia Institute of Technology, Atlanta, United States
| | - Ted Laurence
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, United States
| | - Nam Ki Lee
- School of Chemistry, Seoul National University, Seoul, Republic of Korea
| | - Tae-Hee Lee
- Department of Chemistry, Pennsylvania State University, University Park, United States
| | - Edward A Lemke
- Departments of Biology and Chemistry, Johannes Gutenberg University, Mainz, Germany.,Institute of Molecular Biology (IMB), Mainz, Germany
| | - Emmanuel Margeat
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Universitié de Montpellier, Montpellier, France
| | | | - Xavier Michalet
- Department of Chemistry and Biochemistry, and Department of Physiology, University of California, Los Angeles, Los Angeles, United States
| | - Sua Myong
- Department of Biophysics, Johns Hopkins University, Baltimore, United States
| | - Daniel Nettels
- Department of Biochemistry and Department of Physics, University of Zurich, Zurich, Switzerland
| | - Thomas-Otavio Peulen
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States
| | - Evelyn Ploetz
- Physical Chemistry, Department of Chemistry, Center for Nanoscience (CeNS), Center for Integrated Protein Science Munich (CIPSM) and Nanosystems Initiative Munich (NIM), Ludwig-Maximilians-Universität, München, Germany
| | - Yair Razvag
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, and The Center for Nanoscience and Nanotechnology, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nicole C Robb
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Benjamin Schuler
- Department of Biochemistry and Department of Physics, University of Zurich, Zurich, Switzerland
| | - Hamid Soleimaninejad
- Biological Optical Microscopy Platform (BOMP), University of Melbourne, Parkville, Australia
| | - Chun Tang
- College of Chemistry and Molecular Engineering, PKU-Tsinghua Center for Life Sciences, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, China
| | - Reza Vafabakhsh
- Department of Molecular Biosciences, Northwestern University, Evanston, United States
| | - Don C Lamb
- Physical Chemistry, Department of Chemistry, Center for Nanoscience (CeNS), Center for Integrated Protein Science Munich (CIPSM) and Nanosystems Initiative Munich (NIM), Ludwig-Maximilians-Universität, München, Germany
| | - Claus Am Seidel
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Shimon Weiss
- Department of Chemistry and Biochemistry, and Department of Physiology, University of California, Los Angeles, Los Angeles, United States.,Department of Physiology, CaliforniaNanoSystems Institute, University of California, Los Angeles, Los Angeles, United States
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11
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Park JS, Lee IB, Moon HM, Ryu JS, Kong SY, Hong SC, Cho M. Fluorescence-Combined Interferometric Scattering Imaging Reveals Nanoscale Dynamic Events of Single Nascent Adhesions in Living Cells. J Phys Chem Lett 2020; 11:10233-10241. [PMID: 33206530 DOI: 10.1021/acs.jpclett.0c02103] [Citation(s) in RCA: 2] [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: 06/11/2023]
Abstract
Focal adhesions (FAs) are dynamic protein nanostructures that form mechanical links between cytoskeletal actin fibers and the extracellular matrix. Here, we demonstrate that interferometric scattering (iSCAT) microscopy, a high-speed and time-unlimited imaging technique, can uncover the real-time dynamics of nanoscopic nascent adhesions (NAs). The high sensitivity and stability of the iSCAT signal enabled us to trace the whole life span of each NA spontaneously nucleated under a lamellipodium. Such high-throughput and long-term image data provide a unique opportunity for statistical analysis of adhesion dynamics. Moreover, we directly revealed that FAs play critical roles in both the extrusion of filopodia as nucleation sites on the leading edge and the one-dimensional transport of cargos along cytoskeletal fibers as fiber docking sites. These experimental results show that iSCAT is a sensitive tool for tracking real-time dynamics of nanoscopic objects involved in endogenous and exogenous biological processes in living cells.
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Affiliation(s)
- Jin-Sung Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea
| | - Il-Buem Lee
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea
| | - Hyeon-Min Moon
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea
| | - Jin-Sun Ryu
- Center for Breast Cancer, National Cancer Center, Goyang 10408, Korea
| | - Sun-Young Kong
- Division of Translational Science, National Cancer Center, Goyang 10408, Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea
- Department of Physics, Korea University, Seoul 02841, Korea
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea
- Department of Chemistry, Korea University, Seoul 02841, Korea
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12
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Lee IB, Moon HM, Park JS, Zambochova K, Hong SC, Cho M. Three-dimensional interferometric scattering microscopy via remote focusing technique. Opt Lett 2020; 45:2628-2631. [PMID: 32356833 DOI: 10.1364/ol.386172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
Interferometric scattering (iSCAT) microscopy enables us to track nm-sized objects with high spatial and temporal resolutions and permits label-free imaging of biomolecules. Its superb sensitivity, however, comes at a cost by several downsides, such as slow three-dimensional imaging and limited vertical tracking. Here, we propose a new method, Remote Focusing-iSCAT (RF-iSCAT) microscopy, to visualize a volume specimen by imaging sections at different depths without translation of either the objective lens or sample stage. We demonstrate the principle of RF-iSCAT by determining the z-position of submicrometer beads by translating the reference mirror instead. RF-iSCAT features an unprecedentedly long range of vertical tracking and permits fast but vibration-free vertical scanning. We anticipate that RF-iSCAT would enhance the utility of iSCAT for dynamics study.
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13
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Lee IB, Park JS, Moon HM, Zambochova K, Kim KH, Joo JH, Ryu JS, Kong SY, Hong SC, Cho M. Interferometric Scattering Microscopy to Characterize Nanometric Objects and Subcellular Structures: Towards Fast 3D Imaging at Nanoscale. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.945] [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: 10/25/2022] Open
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14
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Kim SH, Lim SH, Lee AR, Kwon DH, Song HK, Lee JH, Cho M, Johner A, Lee NK, Hong SC. Unveiling the pathway to Z-DNA in the protein-induced B-Z transition. Nucleic Acids Res 2019; 46:4129-4137. [PMID: 29584891 PMCID: PMC5934635 DOI: 10.1093/nar/gky200] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [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: 10/10/2017] [Accepted: 03/13/2018] [Indexed: 12/31/2022] Open
Abstract
Left-handed Z-DNA is an extraordinary conformation of DNA, which can form by special sequences under specific biological, chemical or physical conditions. Human ADAR1, prototypic Z-DNA binding protein (ZBP), binds to Z-DNA with high affinity. Utilizing single-molecule FRET assays for Z-DNA forming sequences embedded in a long inactive DNA, we measure thermodynamic populations of ADAR1-bound DNA conformations in both GC and TG repeat sequences. Based on a statistical physics model, we determined quantitatively the affinities of ADAR1 to both Z-form and B-form of these sequences. We also reported what pathways it takes to induce the B–Z transition in those sequences. Due to the high junction energy, an intermediate B* state has to accumulate prior to the B–Z transition. Our study showing the stable B* state supports the active picture for the protein-induced B–Z transition that occurs under a physiological setting.
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Affiliation(s)
- Sook Ho Kim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, South Korea.,Department of Physics, Korea University, Seoul 02841, South Korea
| | - So-Hee Lim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, South Korea.,Department of Chemistry, Korea University, Seoul 02841, South Korea
| | - Ae-Ree Lee
- Department of Chemistry and RINS, Gyeongsang National University, Jinju 52828, South Korea
| | - Do Hoon Kwon
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, South Korea.,Department of Life Sciences, Korea University, Seoul 02841, South Korea
| | - Hyun Kyu Song
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, South Korea.,Department of Life Sciences, Korea University, Seoul 02841, South Korea
| | - Joon-Hwa Lee
- Department of Chemistry and RINS, Gyeongsang National University, Jinju 52828, South Korea
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, South Korea.,Department of Chemistry, Korea University, Seoul 02841, South Korea
| | - Albert Johner
- Institute Charles Sadron, CNRS 23 rue du Loess 67034, Strasbourg cedex 2, France.,Department of Physics, Sejong University, Seoul 05006, South Korea
| | - Nam-Kyung Lee
- Institute Charles Sadron, CNRS 23 rue du Loess 67034, Strasbourg cedex 2, France.,Department of Physics, Sejong University, Seoul 05006, South Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, South Korea.,Department of Physics, Korea University, Seoul 02841, South Korea
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15
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Hummel T, Whitcroft KL, Andrews P, Altundag A, Cinghi C, Costanzo RM, Damm M, Frasnelli J, Gudziol H, Gupta N, Haehne A, Holbrook E, Hong SC, Hornung D, Hüttenbrink KB, Kamel R, Kobayashi M, Konstantinidis I, Landis BN, Leopold DA, Macchi A, Miwa T, Moesges R, Mullol J, Mueller CA, Ottaviano G, Passali GC, Philpott C, Pinto JM, Ramakrishnan VJ, Rombaux P, Roth Y, Schlosser RA, Shu B, Soler G, Stjärne P, Stuck BA, Vodicka J, Welge-Luessen A. Position paper on olfactory dysfunction. Rhinology 2018. [PMID: 29528615 DOI: 10.4193/rhino16.248] [Citation(s) in RCA: 366] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Background Olfactory dysfunction is an increasingly recognised condition, associated with reduced quality of life and major
health outcomes such as neurodegeneration and death. However, translational research in this field is limited by heterogeneity in methodological approach, including definitions of impairment, improvement and appropriate assessment techniques. Accordingly, effective treatments for smell loss are limited. In an effort to encourage high quality and comparable work in this field, among others, we propose the following ideas and recommendations. Whilst the full set of recommendations are outlined in the main document, points include the following:
• Patients with suspected olfactory loss should undergo a full examination of the head and neck, including rigid nasal endoscopy
with small diameter endoscopes.
• Subjective olfactory assessment should not be undertaken in isolation, given its poor reliability.
• Psychophysical assessment tools used in clinical and research settings should include reliable and validated tests of odour
threshold, and/or one of odour identification or discrimination.
• Comprehensive chemosensory assessment should include gustatory screening.
• Smell training can be helpful in patients with olfactory loss of several aetiologies. Conclusions We hope the current manuscript will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency and generalisability of work in this field.
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16
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Taivansaikhan P, Tsevelmaa T, Rhim SH, Hong SC, Odkhuu D. Inducing and manipulating magnetization in 2D zinc-oxide by strain and external voltage. J Phys Condens Matter 2018; 30:145802. [PMID: 29485107 DOI: 10.1088/1361-648x/aab283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Two-dimensional (2D) structures that exhibit intriguing magnetic phenomena such as perpendicular magnetic anisotropy and its switchable feature are of great interests in spintronics research. Herein, the density functional theory studies reveal the critical impacts of strain and external gating on vacancy-induced magnetism and its spin direction in a graphene-like single layer of zinc oxide (ZnO). In contrast to the pristine and defective ZnO with an O-vacancy, the presence of a Zn-vacancy induces significant magnetic moments to its first neighboring O and Zn atoms due to the charge deficit. We further predict that the direction of magnetization easy axis reverses from an in-plane to perpendicular orientation under a practically achievable biaxial compressive strain of only ~1-2% or applying an electric field by means of the charge density modulation. This magnetization reversal is mainly driven by the strain- and electric-field-induced changes in the spin-orbit coupled d states of the first-neighbor Zn atom to a Zn-vacancy. These findings open interesting prospects for exploiting strain and electric field engineering to manipulate magnetism and magnetization orientation of 2D materials.
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Affiliation(s)
- P Taivansaikhan
- Department of Physics, Incheon National University, Incheon 22012, Republic of Korea
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17
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Park JS, Lee IB, Moon HM, Joo JH, Kim KH, Hong SC, Cho M. Label-free and live cell imaging by interferometric scattering microscopy. Chem Sci 2018; 9:2690-2697. [PMID: 29732052 PMCID: PMC5914294 DOI: 10.1039/c7sc04733a] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [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: 11/02/2017] [Accepted: 02/08/2018] [Indexed: 11/21/2022] Open
Abstract
Despite recent remarkable advances in microscopic techniques, it still remains very challenging to directly observe the complex structure of cytoplasmic organelles in live cells without a fluorescent label.
Despite recent remarkable advances in microscopic techniques, it still remains very challenging to directly observe the complex structure of cytoplasmic organelles in live cells without a fluorescent label. Here we report label-free and live-cell imaging of mammalian cell, Escherischia coli, and yeast, using interferometric scattering microscopy, which reveals the underlying structures of a variety of cytoplasmic organelles as well as the underside structure of the cells. The contact areas of the cells attached onto a glass substrate, e.g., focal adhesions and filopodia, are clearly discernible. We also found a variety of fringe-like features in the cytoplasmic area, which may reflect the folded structures of cytoplasmic organelles. We thus anticipate that the label-free interferometric scattering microscopy can be used as a powerful tool to shed interferometric light on in vivo structures and dynamics of various intracellular phenomena.
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Affiliation(s)
- Jin-Sung Park
- Center for Molecular Spectroscopy and Dynamics , Institute for Basic Science , Seoul 02841 , Korea
| | - Il-Buem Lee
- Center for Molecular Spectroscopy and Dynamics , Institute for Basic Science , Seoul 02841 , Korea.,Department of Physics , Korea University , Seoul 02841 , Korea .
| | - Hyeon-Min Moon
- Center for Molecular Spectroscopy and Dynamics , Institute for Basic Science , Seoul 02841 , Korea.,Department of Physics , Korea University , Seoul 02841 , Korea .
| | - Jong-Hyeon Joo
- Center for Molecular Spectroscopy and Dynamics , Institute for Basic Science , Seoul 02841 , Korea.,Department of Chemistry , Korea University , Seoul 02841 , Korea .
| | - Kyoung-Hoon Kim
- Center for Molecular Spectroscopy and Dynamics , Institute for Basic Science , Seoul 02841 , Korea.,Department of Physics , Korea University , Seoul 02841 , Korea .
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics , Institute for Basic Science , Seoul 02841 , Korea.,Department of Physics , Korea University , Seoul 02841 , Korea .
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics , Institute for Basic Science , Seoul 02841 , Korea.,Department of Chemistry , Korea University , Seoul 02841 , Korea .
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18
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Hummel T, Whitcroft KL, Andrews P, Altundag A, Cinghi C, Costanzo RM, Damm M, Frasnelli J, Gudziol H, Gupta N, Haehner A, Holbrook E, Hong SC, Hornung D, Hüttenbrink KB, Kamel R, Kobayashi M, Konstantinidis I, Landis BN, Leopold DA, Macchi A, Miwa T, Moesges R, Mullol J, Mueller CA, Ottaviano G, Passali GC, Philpott C, Pinto JM, Ramakrishnan VJ, Rombaux P, Roth Y, Schlosser RA, Shu B, Soler G, Stjärne P, Stuck BA, Vodicka J, Welge-Luessen A. Position paper on olfactory dysfunction. Rhinology 2017. [PMID: 28623665 DOI: 10.4193/rhin16.248] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Olfactory dysfunction is an increasingly recognised condition, associated with reduced quality of life and major health outcomes such as neurodegeneration and death. However, translational research in this field is limited by heterogeneity in methodological approach, including definitions of impairment, improvement and appropriate assessment techniques. Accordingly, effective treatments for smell loss are limited. In an effort to encourage high quality and comparable work in this field, among others, we propose the following ideas and recommendations. Whilst the full set of recommendations are outlined in the main document, points include the following: - Patients with suspected olfactory loss should undergo a full examination of the head and neck, including rigid nasal endoscopy with small diameter endoscopes. - Subjective olfactory assessment should not be undertaken in isolation, given its poor reliability. - Psychophysical assessment tools used in clinical and research settings should include reliable and validated tests of odour threshold, and/or one of odour identification or discrimination. - Comprehensive chemosensory assessment should include gustatory screening. - Smell training can be helpful in patients with olfactory loss of several aetiologies. CONCLUSIONS We hope the current manuscript will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency and generalisability of work in this field.
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Affiliation(s)
- T Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - K L Whitcroft
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - P Andrews
- UCL Ear Institute, Faculty of Brain Sciences, University College London, London, UK
| | - A Altundag
- Department of Otorhinolaryngoglogy, Istanbul Surgery Hospital, Istanbul, Turkey
| | - C Cinghi
- Department of Otolaryngology; Eskisehir Osmangazi University, Istanbul, Turkey
| | - R M Costanzo
- Smell and Taste Disorders Center, Department of Otolaryngology Head and Neck Surgery, VCU School of Medicine, Richmond, VA, USA
| | - M Damm
- Department of Otorhinolaryngology, Head and Neck Surgery, University of Cologne Medical Center, Cologne, Germany
| | - J Frasnelli
- Research Chair in Chemosensory Neuroanatomy, Department of Anatomy, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, QC, Canada
| | - H Gudziol
- Department of Otorhinolaryngology, University of Jena, Jena, Germany
| | - N Gupta
- Department of Otorhinolaryngology, University College of Medical Sciences and GTB Hospital, Delhi, India
| | - A Haehner
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - E Holbrook
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - S C Hong
- Department of Otorhinolaryngology, Konkuk University Medical Center, Hwayang-dong, Gwangjin-gu, Seoul, South Korea
| | - D Hornung
- Dept. of Biology, St. Lawrence University, Canton, NY, USA
| | | | - R Kamel
- Department of Otorhinolaryngology, Cairo University, Cairo, Egypt
| | - M Kobayashi
- Department of Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Mie, Japan
| | - I Konstantinidis
- Smell and Taste Clinic, Second Academic Otorhinolaryngology Department, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - B N Landis
- Department for ENT, Head and Neck Surgery, Bern University Hospital, Bern, Switzerland
| | - D A Leopold
- Division of Otorhinolaryngology-Head and Neck Surgery, Department of Surgery, University of Vermont Medical Center, Burlington, Vermont, USA
| | - A Macchi
- ENT Clinic, University of Insubria, ASST, sette laghi, Varese, Italy
| | - T Miwa
- Department of Otorhinolaryngology, Kanazawa Medical University, Uchinada, Kahoku, Ishikawa, Japan
| | - R Moesges
- Institute of Medical Statistics, Informatics and Epidemiology, University Hospital of Cologne, Cologne, Germany
| | - J Mullol
- Rhinology Unit and Smell Clinic, IDIBAPS, University of Barcelona, Barcelona, Catalonia, Spain
| | - C A Mueller
- Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria
| | - G Ottaviano
- Department of Neurosciences DNS, Otolaryngology Section, University, Padua, Italy
| | - G C Passali
- Head and Neck section, Department of Aging, Neurosciences, Head and Neck and Orthopedic; Catholic University of Sacred heart, A. Gemelli Hospital Foundation, Rome, Italy
| | - C Philpott
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - J M Pinto
- Section of Otolaryngology-Head and Neck Surgery, The University of Chicago Medicine and Biological Sciences, Chicago, IL, USA
| | - V J Ramakrishnan
- Departments of Otolaryngology and Neurosurgery, University of Colorado, Aurora, CO, USA
| | - P Rombaux
- Universite Catholique de Louvain, Institute of Neurosciences, Unit of Otorhinolaryngology, Brussels, Belgium
| | - Y Roth
- The Institute for Nose and Sinus Therapy and Clinical Investigations, Department of Otolaryngology - Head and Neck Surgery, Edith Wolfson Medical Center, Tel Aviv University Sackler Faculty of Medicine, Holon, Israel
| | - R A Schlosser
- Department of Otolaryngology, Head and Neck Surgery, Medical Univeristy of South Carolina, Charleston, SC, USA
| | - B Shu
- Department of Otolaryngology, Taipei Veterans General Hospital, National Yang Ming University School of Medicine Faculty of Medicine, Taipei, Taiwan
| | - G Soler
- Division of Otorhinolaryngology, Area of Smell and Taste, Hospital de Clinicas, University of Buenos Aires, Buenos Aires City, Argentina
| | - P Stjärne
- Section of Rhinology, Department of Otorhinolaryngology, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden
| | - B A Stuck
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Essen, University Duisburg-Essen, Germany
| | - J Vodicka
- Department of Otorhinolaryngology and Head and Neck Surgery, Hospital Pardubice, Faculty of Health Studies, University of Pardubice, Pardubice, Czech Republic
| | - A Welge-Luessen
- University Hospital Basel - Otorhinolaryngology, Basel, Switzerland
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19
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Cho GJ, Ahn KH, Kim LY, Hwang SY, Hong SC, Oh MJ, Kim HJ. Effect of relative humidity on preeclampsia. CLIN EXP OBSTET GYN 2017; 44:264-267. [PMID: 29746035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
PURPOSE OF INVESTIGATION The authors aimed to determine the relationship between meteorological variables and hypertension in pregnancy by using data from a national weather database. MATERIALS AND METHODS For this population-based observational study, the database of the Korea National Health Insurance (KNHI) Claims of the Health Insurance Review and Assessment Service (HIRA) and Korea Meteorological Administration was used. The 48,275 women with preeclampsia among 2,495,383 women who gave birth were included. Monthly meteorological factors and preeclampsia prevalence for five years were statistically analyzed. RESULTS Among temperature, relative humidity, sunlight duration, and rainfall, only relative humidity had a significant inverse correlation with the preeclampsia prevalence (p < 0.001). The other meteorological factors were not associated with preeclampsia. CONCLUSION Relative humidity may be a significant factor for of the development of preeclampsia. Further monitoring of weather parameters during the entire pregnancy period may be the best method for verifying the present results in the development of preeclampsia.
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20
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Hwang W, Lee IB, Hong SC, Hyeon C. Decoding Single Molecule Time Traces with Dynamic Disorder. PLoS Comput Biol 2016; 12:e1005286. [PMID: 28027304 PMCID: PMC5226833 DOI: 10.1371/journal.pcbi.1005286] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 01/11/2017] [Accepted: 12/07/2016] [Indexed: 12/11/2022] Open
Abstract
Single molecule time trajectories of biomolecules provide glimpses into complex folding landscapes that are difficult to visualize using conventional ensemble measurements. Recent experiments and theoretical analyses have highlighted dynamic disorder in certain classes of biomolecules, whose dynamic pattern of conformational transitions is affected by slower transition dynamics of internal state hidden in a low dimensional projection. A systematic means to analyze such data is, however, currently not well developed. Here we report a new algorithm—Variational Bayes-double chain Markov model (VB-DCMM)—to analyze single molecule time trajectories that display dynamic disorder. The proposed analysis employing VB-DCMM allows us to detect the presence of dynamic disorder, if any, in each trajectory, identify the number of internal states, and estimate transition rates between the internal states as well as the rates of conformational transition within each internal state. Applying VB-DCMM algorithm to single molecule FRET data of H-DNA in 100 mM-Na+ solution, followed by data clustering, we show that at least 6 kinetic paths linking 4 distinct internal states are required to correctly interpret the duplex-triplex transitions of H-DNA. We have developed a new algorithm to better decode single molecule data with dynamic disorder. Our new algorithm, which represents a substantial improvement over other methodologies, can detect the presence of dynamic disorder in each trajectory and quantify the kinetic characteristics of underlying energy landscape. As a model system, we applied our algorithm to the single molecule FRET time traces of H-DNA. While duplex-triplex transitions of H-DNA are conventionally interpreted in terms of two-state kinetics, slowly varying dynamic patterns corresponding to hidden internal states can also be identified from the individual time traces. Our algorithm reveals that at least 4 distinct internal states are required to correctly interpret the data.
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Affiliation(s)
- Wonseok Hwang
- Korea Institute for Advanced Study, Seoul, Republic of Korea
| | - Il-Buem Lee
- Department of Physics, Korea University, Seoul, Republic of Korea
| | - Seok-Cheol Hong
- Korea Institute for Advanced Study, Seoul, Republic of Korea
- Department of Physics, Korea University, Seoul, Republic of Korea
| | - Changbong Hyeon
- Korea Institute for Advanced Study, Seoul, Republic of Korea
- * E-mail:
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21
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Hong SC, Agarwal S, Wong P, Fraser MA, Chen I, Singh SS. The Role of TAP Block in Ob/Gyn. J Minim Invasive Gynecol 2016; 22:S120. [PMID: 27678632 DOI: 10.1016/j.jmig.2015.08.337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- S C Hong
- MIS Unit, KK Women's and Children's Hospital, Singapore, Singapore
| | - S Agarwal
- Department of Obstetrics and Gynaecology, MIS Unit, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - P Wong
- Department of Anesthesiology, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - M A Fraser
- Department of Medical Imaging, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - I Chen
- Department of Obstetrics and Gynaecology, MIS Unit, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - S S Singh
- Department of Obstetrics and Gynaecology, MIS Unit, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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22
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Kim MS, Jo KI, Yeon JY, Kim JS, Kim KH, Jeon P, Hong SC. Association between Postprocedural Infarction and Antiplatelet Drug Resistance after Coiling for Unruptured Intracranial Aneurysms. AJNR Am J Neuroradiol 2016; 37:1099-105. [PMID: 27056423 DOI: 10.3174/ajnr.a4777] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/19/2015] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND PURPOSE Procedure-related thromboembolism is a major limitation of coil embolization, but the relationship between thromboembolic infarction and antiplatelet resistance is poorly understood. The purpose of this study was to verify the association between immediate postprocedural thromboembolic infarction and antiplatelet drug resistance after endovascular coil embolization for unruptured intracranial aneurysm. MATERIALS AND METHODS This study included 338 aneurysms between October 2012 and March 2015. All patients underwent postprocedural MR imaging within 48 hours after endovascular coil embolization. Antiplatelet drug resistance was checked a day before the procedure by using the VerifyNow system. Abnormal antiplatelet response was defined as >550 aspirin response units and >240 P2Y12 receptor reaction units. In addition, we explored the optimal cutoff values of aspirin response units and P2Y12 receptor reaction units. The primary outcome was radiologic infarction based on postprocedural MR imaging. RESULTS Among 338 unruptured intracranial aneurysms, 134 (39.6%) showed diffusion-positive lesions on postprocedural MR imaging, and 32 (9.5%) and 105 (31.1%) had abnormal aspirin response unit and P2Y12 receptor reaction unit values, respectively. Radiologic infarction was associated with advanced age (65 years and older, P = .024) only with defined abnormal antiplatelet response (aspirin response units ≥ 550, P2Y12 receptor reaction units ≥ 240). P2Y12 receptor reaction unit values in the top 10th percentile (>294) were associated with radiologic infarction (P = .003). With this cutoff value, age (adjusted odds ratio, 2.29; 95% confidence interval, 1.28-4.08), P2Y12 receptor reaction units (>294; OR, 3.43; 95% CI, 1.53-7.71), and hyperlipidemia (OR, 2.05; 95% CI, 1.04-4.02) were associated with radiologic infarction in multivariate analysis. CONCLUSIONS Radiologic infarction after coiling for unruptured aneurysm was closely associated with age. Only very high P2Y12 receptor reaction unit values (>294) predicted postprocedural infarction. Further controlled studies are needed to determine the precise cutoff values, which could provide information regarding the optimal antiplatelet regimen for aneurysm coiling.
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Affiliation(s)
- M S Kim
- From the Departments of Neurosurgery (M.S.K., J.Y.Y., J.S.K., S.C.H.)
| | - K I Jo
- Department of Neurosurgery (K.I.J.), Hana General Hospital, Cheongju, Korea
| | - J Y Yeon
- From the Departments of Neurosurgery (M.S.K., J.Y.Y., J.S.K., S.C.H.)
| | - J S Kim
- From the Departments of Neurosurgery (M.S.K., J.Y.Y., J.S.K., S.C.H.)
| | - K H Kim
- Radiology (K.H.K., P.J.), Division of Interventional Neuroradiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - P Jeon
- Radiology (K.H.K., P.J.), Division of Interventional Neuroradiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - S C Hong
- From the Departments of Neurosurgery (M.S.K., J.Y.Y., J.S.K., S.C.H.)
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23
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Kwon AY, Lee NK, Hong SC, Fierling J, Johner A. Annealed random copolymer model of the B-Z transition in DNA: torsional responses. Biophys J 2016; 108:2562-2572. [PMID: 25992734 DOI: 10.1016/j.bpj.2015.03.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 03/10/2015] [Accepted: 03/17/2015] [Indexed: 11/26/2022] Open
Abstract
Both in vivo and in vitro, specific sequences in double-stranded DNA can adopt the left-handed Z-form when underwound. Recently, the B-Z transition of DNA has been studied in detail in magnetic tweezers experiments by several groups. We present a theoretical description of this transition, based on an annealed random copolymer model. The transition of a switchable sequence is discussed as a function of energetic and geometric parameters of the B- and Z-forms, of the applied boundary conditions, and of the characteristics of the B-Z interface. We address a possible torsional softening upon the B-Z transition. The model can be also applied to other biofilaments with annealed torsional/flexural degrees of freedom.
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Affiliation(s)
- Ah-Young Kwon
- Department of Physics, Sejong University, Seoul, South Korea
| | - Nam-Kyung Lee
- Department of Physics, Sejong University, Seoul, South Korea; Institute Charles Sadron, Centre National de la Recherche Scientifique, Strasbourg, France.
| | | | - Julien Fierling
- Institute Charles Sadron, Centre National de la Recherche Scientifique, Strasbourg, France
| | - Albert Johner
- Department of Physics, Sejong University, Seoul, South Korea; Institute Charles Sadron, Centre National de la Recherche Scientifique, Strasbourg, France
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Kwon AY, Nam GM, Johner A, Kim S, Hong SC, Lee NK. Competition between B-Z and B-L transitions in a single DNA molecule: Computational studies. Phys Rev E 2016; 93:022411. [PMID: 26986366 DOI: 10.1103/physreve.93.022411] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Indexed: 11/07/2022]
Abstract
Under negative torsion, DNA adopts left-handed helical forms, such as Z-DNA and L-DNA. Using the random copolymer model developed for a wormlike chain, we represent a single DNA molecule with structural heterogeneity as a helical chain consisting of monomers which can be characterized by different helical senses and pitches. By Monte Carlo simulation, where we take into account bending and twist fluctuations explicitly, we study sequence dependence of B-Z transitions under torsional stress and tension focusing on the interaction with B-L transitions. We consider core sequences, (GC)_{n} repeats or (TG)_{n} repeats, which can interconvert between the right-handed B form and the left-handed Z form, imbedded in a random sequence, which can convert to left-handed L form with different (tension dependent) helical pitch. We show that Z-DNA formation from the (GC)_{n} sequence is always supported by unwinding torsional stress but Z-DNA formation from the (TG)_{n} sequence, which are more costly to convert but numerous, can be strongly influenced by the quenched disorder in the surrounding random sequence.
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Affiliation(s)
- Ah-Young Kwon
- Institute of Fundamental Physics, Department of Physics, Sejong University, Seoul 143-743, Korea
| | - Gi-Moon Nam
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Albert Johner
- Institute of Fundamental Physics, Department of Physics, Sejong University, Seoul 143-743, Korea.,Institute Charles Sadron, Université de Strasbourg, CNRS UPR22, 23 rue du Loess 67034, Strasbourg cedex 2, France
| | - Seyong Kim
- Institute of Fundamental Physics, Department of Physics, Sejong University, Seoul 143-743, Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea.,Department of Physics, Korea University, Seoul 02841, Korea
| | - Nam-Kyung Lee
- Institute of Fundamental Physics, Department of Physics, Sejong University, Seoul 143-743, Korea.,Institute Charles Sadron, Université de Strasbourg, CNRS UPR22, 23 rue du Loess 67034, Strasbourg cedex 2, France
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25
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Hwang W, Lee IB, Hong SC, Hyeon C. Decoding Dynamic Disorder in Single Molecule Data. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.1048] [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: 10/22/2022] Open
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26
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Affiliation(s)
- Sung Eun Kim
- Department
of Physics, Korea University, Seoul 136-713, Republic of Korea
| | - Il-Buem Lee
- Department
of Physics, Korea University, Seoul 136-713, Republic of Korea
| | - Changbong Hyeon
- Korea Institute for Advanced Study, Seoul 130-722, Republic of Korea
| | - Seok-Cheol Hong
- Department
of Physics, Korea University, Seoul 136-713, Republic of Korea
- Korea Institute for Advanced Study, Seoul 130-722, Republic of Korea
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27
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Han SY, Ryu KJ, Ahn KH, Cho SB, Lee CH, Hong SC. Conservative treatment of uterine fistula with abdominal abscess after caesarean section. J OBSTET GYNAECOL 2014; 35:650-1. [PMID: 25496617 DOI: 10.3109/01443615.2014.987115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- S Y Han
- a Department of Obstetrics and Gynecology , College of Medicine, Korea University , Seoul , Republic of Korea
| | - K J Ryu
- a Department of Obstetrics and Gynecology , College of Medicine, Korea University , Seoul , Republic of Korea
| | - K H Ahn
- a Department of Obstetrics and Gynecology , College of Medicine, Korea University , Seoul , Republic of Korea
| | - S B Cho
- b Department of Radiology , College of Medicine, Korea University , Seoul , Republic of Korea
| | - C H Lee
- c Department of Science , University of Manitoba , Winnipeg , MB , Canada
| | - S C Hong
- a Department of Obstetrics and Gynecology , College of Medicine, Korea University , Seoul , Republic of Korea
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28
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Taivansaikhan P, Odkhuu D, Kwon OR, Tsogbadrakh N, Hong SC. Magnetism and magnetocrystalline anisotropy of 3dtransition metal monolayers on Pt(001): a density-functional study. J Nanosci Nanotechnol 2014; 14:9011-9013. [PMID: 25971000 DOI: 10.1166/jnn.2014.10078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We systematically investigate the effects of having Pt as a substrate and/or capping layer on the magnetism and magnetocrystalline anisotropy (MCA) of 3d transition metal (TMs; Cr, Mn, Fe, and Co) monolayers (MLs) by using a first-principles calculationl method. We found that Fe and Co MLs are ferromagnetic (FM) on a Pt(001) surface, but Mn and Cr MLs are antiferromagnetic (AFM). The magnetic moments are quite robust with additional Pt-capping. Furthermore, Pt-capping enhances the small perpendicular MCA (meV) of Fe/Pt(001) significantly to 4.44 meV. Our electronic structure analyses indicate that strong hybridization between Pt-5d and TM-3d orbitals plays a crucial role in determining magnetic ordering and MCA. For comparison we also calculated magnetism and MCA of 3d TM MLs on Ta(001) with and without Ta-capping.
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Shick AB, Hong SC, Maca F, Lichtenstein AI. Magnetic anisotropy energy and effective exchange interactions in Co intercalated graphene on Ir(1 1 1). J Phys Condens Matter 2014; 26:476003. [PMID: 25351898 DOI: 10.1088/0953-8984/26/47/476003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The electronic structure, magnetic moments, effective exchange interaction parameter and the magnetic anisotropy energy of [monolayer Co]/Ir(1 1 1) and Co intercalated graphene on Ir(1 1 1) are studied making use of the first-principles density functional theory calculations. A large positive magnetic anisotropy of 1.24 meV/Co is found for [monolayer Co]/Ir(1 1 1), and a high Curie temperature of 1190 K is estimated. These findings show the Co/Ir(1 1 1) system is a promising candidate for perpendicular ultra-high density magnetic recording applications. The magnetic moments, exchange interactions and the magnetic anisotropy are strongly affected by graphene. Reduction of the magnetic anisotropy and the Curie temperature are found for graphene/[monolayer Co]/Ir(1 1 1). It is shown that for graphene placed in the hollow-hexagonal positions over the monolayer Co, the magnetic anisotropy remains positive, while for the placements with one of the C atoms on the top of Co it becomes negative. These findings may be important for assessing the use of graphene for magnetic recording and magnetoelectronic applications.
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Affiliation(s)
- A B Shick
- Institute of Physics ASCR, Na Slovance 2, 18221 Prague, Czech Republic
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Shin MR, Kang SK, Kim YS, Lee SY, Hong SC, Kim EC. TNF-α and LPS activate angiogenesis via VEGF and SIRT1 signalling in human dental pulp cells. Int Endod J 2014; 48:705-16. [PMID: 25311745 DOI: 10.1111/iej.12396] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 10/08/2014] [Indexed: 01/05/2023]
Abstract
AIM To assess whether SIRT1 and VEGF are responsible for tumour necrosis factor-α (TNF-α) and lipopolysaccharide (LPS)-induced angiogenesis and to examine the molecular mechanism(s) of action in human dental pulp cells (HDPCs). METHODOLOGY Immortalized HDPCs obtained from Prof. Takashi Takata (Hiroshima University, Japan) were treated with LPS (1 μg mL(-1) ) and TNF-α (10 ng mL(-1) ) for 24 h. mRNA and protein levels were examined by RT-PCR and Western blotting, respectively. Migration and tube formation were examined in human umbilical vein endothelial cells (HUVECs). The data were analysed by one-way anova. Statistical analysis was performed at α = 0.05. RESULTS LPS and TNF-α upregulated VEGF and SIRT1 mRNA and protein levels. Inhibition of SIRT1 activity by sirtinol and SIRT1 siRNA or inhibition of the VEGF receptor by CBO-P11 significantly attenuated LPS + TNF-α-stimulated MMPs production in HDPCs, as well as migration and tube formation in HUVECs (P < 0.05). Furthermore, sirtinol, SIRT1 siRNA and CBO-P11 attenuated phosphorylation of Akt, extracellular signal-regulated kinase (ERK), p38 and c-Jun N-terminal kinase (JNK) and the nuclear translocation of NF-κB p65. Pre-treatment with inhibitors of p38, ERK, JNK, PI3K and NF-κB decreased LPS + TNF-α-induced VEGF and SIRT1 expression, MMPs activity in HDPCs and angiogenesis (P < 0.05) in HUVECs. CONCLUSIONS TNF-α and LPS led to upregulation of VEGF and SIRT1, and subsequent upregulation of MMP-2 and MMP-9 production, and promote angiogenesis via pathways involving PI3K, p38, ERK, JNK and NF-κB. The results suggest that inhibition of SIRT1 and VEGF might attenuate pro-inflammatory mediator-induced pulpal disease.
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Affiliation(s)
- M R Shin
- Department of Prosthodontics, Dongatn Sacred Heart Hospital, Hallym University, Dongtan, Korea
| | - S K Kang
- Department of Oral Medicine, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - Y S Kim
- Department of Oral and Maxillofacial Pathology, Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, Seoul, Korea
| | - S Y Lee
- Department of Oral and Maxillofacial Pathology, Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, Seoul, Korea
| | - S C Hong
- Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - E-C Kim
- Department of Oral and Maxillofacial Pathology, Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, Seoul, Korea
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Han SY, Ahn KH, Lee CH, Hong SC, Oh MJ, Kim HJ. Concomitant therapy with hysterectomy and arterial embolisation for postpartum uterine haemorrhage. J OBSTET GYNAECOL 2014; 35:424-5. [PMID: 25207796 DOI: 10.3109/01443615.2014.954100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- S Y Han
- Department of Obstetrics and Gynaecology, Korea University Medical Center, College of Medicine, Korea University , Seoul , South Korea
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Affiliation(s)
- Sung Eun Kim
- Department
of Physics, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 136-713, Republic of Korea
| | - Il-Buem Lee
- Department
of Physics, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 136-713, Republic of Korea
| | - Changbong Hyeon
- School
of Computational Sciences, Korea Institute for Advanced Study, 85
Hoegi-ro Dongdaemun-gu, Seoul 130-722, Republic of Korea
| | - Seok-Cheol Hong
- Department
of Physics, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 136-713, Republic of Korea
- School
of Computational Sciences, Korea Institute for Advanced Study, 85
Hoegi-ro Dongdaemun-gu, Seoul 130-722, Republic of Korea
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Kim SH, Lee NK, Lee JH, Hong SC. Z-DNA-Forming TG Repeats are Dynamic Mechanical Switches Sensitive to Tension and Torsion. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.440] [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: 11/16/2022] Open
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34
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Lee NK, Johner A, Lee IB, Hong SC. DNA triplex folding: moderate versus high salt conditions. Eur Phys J E Soft Matter 2013; 36:57. [PMID: 23749234 DOI: 10.1140/epje/i2013-13057-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 04/08/2013] [Indexed: 06/02/2023]
Abstract
Some specific sequences in duplex DNA can give rise to local formation of a triple helical DNA called triplex together with a separate strand. Recent single-molecule FRET experiments, performed on DNA strands designed to fold into a triplex, allow us to measure the folding and unfolding time distributions under neutral p H conditions. The average times of both processes are of the order of 1 s. The folding time is moderately sensitive to salt concentration. The average unfolding time is found to be nearly constant. Interestingly, the distributions of the unfolding time revealed heterogeneous kinetics at moderate salt concentration (∼ 10 mM), but not at high salt (∼ 100 mM). We relate this salt dependence to different folding paths and folded states, which are governed by the (salt-dependent) stiffness of the third single-stranded donor sequence. Finally we comment on the formation of intramolecular triplex named H-DNA in a torsionally constrained duplex under physiological salt conditions, which mimics the in vivo situation of triplex folding.
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Affiliation(s)
- Nam-Kyung Lee
- Department of Physics, Sejong University, 143-743, Seoul, South Korea.
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35
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Lee IB, Hong SC, Lee NK, Johner A. Kinetics of the triplex-duplex transition in DNA. Biophys J 2012; 103:2492-501. [PMID: 23260051 PMCID: PMC3525853 DOI: 10.1016/j.bpj.2012.10.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 09/16/2012] [Accepted: 10/24/2012] [Indexed: 11/28/2022] Open
Abstract
The kinetics of triplex folding/unfolding is investigated by the single-molecule fluorescence resonance energy transfer (FRET) technique. In neutral pH conditions, the average dwell times in both high-FRET (folded) and low-FRET (unfolded) states are comparable, meaning that the triplex is marginally stable. The dwell-time distributions are qualitatively different: while the dwell-time distribution of the high-FRET state should be fit with at least a double-exponential function, the dwell-time distribution of the low-FRET state can be fit with a single-exponential function. We propose a model where the folding can be trapped in metastable states, which is consistent with the FRET data. Our model also accounts for the fact that the relevant timescales of triplex folding/unfolding are macroscopic.
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Affiliation(s)
- Il-Buem Lee
- Department of Physics, Korea University, Seoul, South Korea
| | | | - Nam-Kyung Lee
- Department of Physics, Sejong University, Seoul, South Korea
| | - Albert Johner
- Institute Charles Sadron, Centre National de la Recherche Scientifique, Universite' de Strasbourg, Strasbourg, France
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36
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Hong SC, Lim YK, Chew SH, Chia YN, Yam KL. Case report of granular cell tumor of the vulva and review of current literature. Gynecol Oncol Case Rep 2012; 3:20-2. [PMID: 24371657 DOI: 10.1016/j.gynor.2012.10.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 10/30/2012] [Indexed: 12/11/2022]
Abstract
► We present four cases of benign granular cell tumours of the vulva managed between 1998 and 2001. ► We discuss the clinical and histopathological features of this condition. ► Treatment of this condition is primarily surgical.
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Affiliation(s)
- S C Hong
- Department of General Obstetrics and Gynaecology, KK Women's and Children's Hospital, Singapore
| | - Y K Lim
- Department of Gynaecological Oncology, KK Women's and Children's Hospital, Singapore
| | - S H Chew
- Department of Pathology and Laboratory Medicine, KK Women's and Children's Hospital, Singapore
| | - Y N Chia
- Department of Gynaecological Oncology, KK Women's and Children's Hospital, Singapore
| | - K L Yam
- Department of Gynaecological Oncology, KK Women's and Children's Hospital, Singapore
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Lim HK, Hong SC, Jung WS, Ahn KJ, Won WY, Hahn C, Kim IS, Lee CU. Automated segmentation of hippocampal subfields in drug-naïve patients with Alzheimer disease. AJNR Am J Neuroradiol 2012; 34:747-51. [PMID: 23042923 DOI: 10.3174/ajnr.a3293] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Although a few automated hippocampal subfield segmentation methods have been developed, there is no study on the effects of the diagnosis of Alzheimer disease on the hippocampal subfield volume with in vivo MR imaging. The aim of this study was to investigate hippocampal subfield volume differences between drug-naïve subjects with AD and healthy elderly controls by using an automated hippocampal subfield segmentation technique. MATERIALS AND METHODS Thirty-one drug-naïve subjects with AD and 33 group-matched healthy control subjects underwent 3T MR imaging, and hippocampal subfield volume was measured and compared between the groups. RESULTS Subjects with AD had significantly smaller volumes of the presubiculum, subiculum, CA2-3, and CA4 DG compared with healthy subjects (uncorrected, P<.001). In addition, we found significant positive correlations between the presubiculum and the subicular volumes and the MMSE-K and the CERAD-K verbal delayed recall scores in the AD group. CONCLUSIONS We are unaware of previous imaging studies of automated hippocampal subfield segmentation in AD. These structural changes in the hippocampal presubiculum, subiculum, and CA2-3 might be at the core of underlying neurobiologic mechanisms of hippocampal dysfunction and their relevance to verbal delayed recall impairments in AD.
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Affiliation(s)
- H K Lim
- Department of Psychiatry, Saint Vincent Hospital, and College of Medicine, Catholic University of Korea, Suwon, Korea
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Bae HS, Ahn KH, Oh MJ, Kim HJ, Hong SC. Postpartum uterine involution: sonographic changes in the endometrium between 2 and 6 weeks postpartum related to delivery mode and gestational age at delivery. Ultrasound Obstet Gynecol 2012; 39:727-728. [PMID: 22223478 DOI: 10.1002/uog.11069] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Kim SE, Lee IB, Hong SC. The Effect of the Oxygen Scavenging System on the pH of Buffered Sample Solutions: in the Context of Single-molecule Fluorescence Measurements. B KOREAN CHEM SOC 2012. [DOI: 10.5012/bkcs.2012.33.3.958] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Park JS, Kim SH, Lee NK, Lee KJ, Hong SC. In situ analysis of cisplatin binding to DNA: the effects of physiological ionic conditions. Phys Chem Chem Phys 2012; 14:3128-33. [PMID: 22286168 DOI: 10.1039/c2cp23551j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Platinum-based anti-cancer drugs form a major family of cancer chemotherapeutic agents. Cisplatin, the first member of the family, remains a potent anti-cancer drug and exhibits its clinical effect by inducing local DNA kinks and subsequently interfering with DNA metabolism. Although its mechanism is reasonably well understood, effects of intracellular ions on cisplatin activity are left to be elucidated because cisplatin binding to DNA, thus its drug efficacy, is modified by various ions. One such issue is the effect of carbonate ions: cisplatin binding to DNA is suppressed under physiological carbonate conditions. Here, we examined the role of common cellular ions (carbonate and chloride) by measuring cisplatin binding in relevant physiological buffers via a DNA micromanipulation technique. Using two orthogonal single-molecule methods, we succeeded in detecting hidden monofunctional adducts (kink-free, presumably clinically inactive form) and clearly showed that the major effect of carbonates was to form such adducts and to prevent them from converting to bifunctional adducts (kinked, clinically active). The chloride-rich environment also led to the formation of monofunctional adducts. Our approach is widely applicable to the study of the transient behaviours of various drugs and proteins that bind to DNA in different modes depending on various physical and chemical factors such as tension, torsion, ligands, and ions.
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Affiliation(s)
- Jin-Sung Park
- Center for Cell Dynamics and Department of Physics, Korea University, Anam, Seongbuk, Seoul, 136-713, Korea
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Lee I, Hong SC, Toseland C. Single-Molecule Study of RecG Activity at a 3-way DNA Junction. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.1549] [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: 11/30/2022] Open
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Hong SC, MacGuidwin A, Gratton C. Soybean aphid and soybean cyst nematode interactions in the field and effects on soybean yield. J Econ Entomol 2011; 104:1568-74. [PMID: 22066186 DOI: 10.1603/ec11084] [Citation(s) in RCA: 6] [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] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
How above- and belowground plant pests interact with each other and how these interactions affect productivity is a relatively understudied aspect of crop production. Soybean cyst nematode, Heterodera glycines Ichinohe, a root parasite of soybean, Glycine max (L.) Merr., is the most threatening pathogen in soybean production and soybean aphid, Aphis glycines Matsumura, an aboveground phloem-feeding insect that appeared in North America in 2000, is the key aboveground herbivore of soybean in the midwestern United States. Now, both soybean aphid and soybean cyst nematode co-occur in soybean-growing areas in the Upper Midwest. The objectives of this study were to examine aphid colonization patterns and population growth on soybean across a natural gradient of nematode density (range, approximately 900 and 27,000 eggs per 100 cm3 soil), and to investigate the effect of this pest complex on soybean productivity. Alate (winged) soybean aphid colonization of soybean was negatively correlated to soybean cyst nematode egg density (r = -0.363, P = 0.0095) at the end of July, at the onset of peak alate colonization. However, both a manipulative cage study and openly colonized plants showed that soybean cyst nematode density below ground was unrelated to variation in aphid population growth (r approximately -0.01). Based on regression analyses, soybean aphids and cyst nematodes had independent effects on soybean yield through effects on different yield components. High soybean cyst nematode density was associated with a decline in soybean yield (kg ha(-1)), whereas increasing soybean aphid density (both alate and apterous) significantly decreased seed weight (g 100 seeds(-1)).
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Affiliation(s)
- S C Hong
- Department of Entomology, University of Wisconsin-Madison; 237 Russell Labs, 1630 Linden Dr., Madison, WI 53706, USA
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Hong SC, Lau MSK, Yam PKL. Ectopic pregnancy in previous Caesarean section scar. Singapore Med J 2011; 52:e115-e117. [PMID: 21731980] [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: 05/31/2023]
Abstract
We report two cases of Caesarean scar pregnancies that were managed surgically. The first case was a 33-year-old woman who presented at 21 weeks of gestation with lower abdominal pain. An exploratory laparotomy was performed as she was hypotensive and had a drastic drop in haemoglobin level. Intraoperatively, a ruptured scar ectopic pregnancy with placenta percreta was found. A hysterectomy was performed in view of uncontrolled haemorrhage. The second case was a 30-year-old woman who presented with irregular per vaginal spotting without abdominal pain. Ultrasonography revealed a gestational sac at a previous Caesarean scar, with interval increase in size and development of a yolk sac. On laparoscopy, the diagnosis of scar pregnancy was confirmed, and the gestational sac and surrounding myometrium were excised. Our case report shows that early diagnosis of scar pregnancy is important, as timely intervention can prevent life-threatening complications and preserve fertility.
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Affiliation(s)
- S C Hong
- Department of General Obstetrics and Gynaecology, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899.
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Hong SC, Donaldson J, Gratton C. Soybean cyst nematode effects on soybean aphid preference and performance in the laboratory. Environ Entomol 2010; 39:1561-9. [PMID: 22546453 DOI: 10.1603/en10091] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Herbivores on plants frequently interact via shared resources. Studies that have examined performance of herbivores in the presence of other herbivores, however, have often focused on above-ground feeding guilds and relatively less research has examined interactions between below- and above-ground consumers. We examine how soybean aphid, Aphis glycines (Matsumura) an above-ground phloem-feeding herbivore, interacts with a below-ground plant parasite, soybean cyst nematode, Heterodera glycines (Ichinohe) through their shared host plant, soybean (Glycine max L). Laboratory experiments evaluated the preference of alate (flight-capable) soybean aphids toward plants either infected with soybean cyst nematode or uninfected controls in a simple choice arena. Alate soybean aphids preferred uninfected soybean over soybean cyst nematode-infected plants: 48 h after the releases of alate aphids in the center of the arena, 67% more aphids were found on control soybean compared with nematode infected plants. No-choice feeding assays were also conducted using clip cages and apterous (flight-incapable) aphids to investigate effect of soybean cyst nematode infection of soybean on aphid performance. These studies had mixed results: in one set of experiments overall aphid population growth at 7 d was not statistically different between control and soybean cyst nematode-infected plants. A different experiment using a life-table analysis found that apterous aphids feeding on soybean cyst nematode-infected plants had significantly greater finite rate of increase (λ), intrinsic rate of increase (r(m)), and net reproductive rate (R(o)) compared with aphids reared on uninfected (control) soybean plants. We conclude that the below-ground herbivore, soybean cyst nematode, primarily influences soybean aphid behavior rather than performance.
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Affiliation(s)
- S C Hong
- Department of Entomology, University of Wisconsin/Madison, 237 Russell Labs, 1630 Linden Drive, Madison, WI 53706, USA
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Affiliation(s)
- K S Hong
- Department of Neurosurgery, Samsung Medical Centre, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Kangnam-Gu, Seoul 135-710 Korea
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Lee NK, Park JS, Johner A, Obukhov S, Hyon JY, Lee KJ, Hong SC. Investigation of the elasticity of a cisplatin-DNA adduct via single-molecule measurements and bimodal modeling. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 79:041921. [PMID: 19518270 DOI: 10.1103/physreve.79.041921] [Citation(s) in RCA: 8] [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] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Indexed: 05/27/2023]
Abstract
Cisplatin has been known as an anticancer drug for a long time. It is therapeutically active upon binding to DNA. A double-bound cisplatin bends DNA into a localized kink. We model the elastic properties of cisplatin-DNA adducts at moderate tension (<6 pN). It is shown that from the mechanical point of view the action of cisplatin can be revealed by reduced persistence length. We derived two expressions for the persistence length, which apply in the linear-response and the strong-force regimes, respectively. Experimental data for DNA adducts stretched by magnetic tweezers are consistently fitted by these expressions. This allows us to estimate the degree of platination at various salt concentrations.
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Affiliation(s)
- Nam-Kyung Lee
- Department of Physics, Institute of Fundamental Physics, Sejong University, Seoul 143-743, Korea.
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Lee NK, Park JS, Johner A, Obukhov S, Hyon JY, Lee KJ, Hong SC. Elasticity of cisplatin-bound DNA reveals the degree of cisplatin binding. Phys Rev Lett 2008; 101:248101. [PMID: 19113672 DOI: 10.1103/physrevlett.101.248101] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2008] [Indexed: 05/27/2023]
Abstract
Cisplatin was incidentally discovered to suppress cell division and became one of the most successful antitumor drugs. It is therapeutically active upon binding to DNA and locally kinking it. We demonstrate that after a bimodal modeling, the degree of platination of a single DNA molecule can be consistently and reliably estimated from elasticity measurements performed with magnetic tweezers. We predicted and measured for the first time two separate persistence lengths of kinked DNA at high and low tensions. We also directly observed that the degree of platination of DNA strongly depends on the concentration of sodium chloride as required for cisplatin's intracellular activity. Our study shows that micromanipulation techniques accurately reveal the degree of chemical modification of DNA which can be used for a new type of structure-sensitive biosensors.
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Affiliation(s)
- Nam-Kyung Lee
- Institute of Fundamental Physics, Department of Physics, Sejong University, Seoul 143-743, Korea
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Hong SC, Lee JH, Chi HS, Lee CK, Nah SS, Kim YG, Oh JS, Moon HB, Yoo B. Systemic lupus erythematosus complicated by acquired von Willebrand’s syndrome. Lupus 2008; 17:846-8. [DOI: 10.1177/0961203308089429] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Haematological abnormalities are common in systemic lupus erythematosus (SLE). In some cases of acquired von Willebrand syndrome (AvWS), von Willebrand disease (vWD) is associated with autoimmune or lymphoproliferative disorders. In this study, we describe a 36-year-old woman with SLE and AvWS. The patient was referred to our hospital because of easy bruisability and recurrent vaginal bleeding. She had no history of bleeding tendency and no family history of bleeding diathesis, but she had a history of recurrent arthralgia, photosensitivity and sicca symptoms. Tests for antinuclear, anti–double stranded DNA, anticardiolipin and anti–β2-glycoprotein I antibodies were all positive. Analysis of haemostatic parameters showed complete absence of von Willebrand factor ristocetin cofactor (vWF:Rco), von Willebrand antigen (vWF:Ag) and ristocetin-induced platelet aggregation (RIPA). Electrophoretic analysis of plasma showed a complete absence of high–molecular weight vWF multimer. The presence of antibody to vWF was detected by enzyme linked immunosorbent assay (ELISA). Treatment with corticosteroids improved SLE symptoms and corrected bleeding diasthesis. Also, the multimeric patterns of vWF became normalised and anti–vWF antibody disappeared. These findings indicated that this patient had SLE associated with AvWS, which was ameliorated by corticosteroid treatment.
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Affiliation(s)
- SC Hong
- Division of Rheumatology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - JH Lee
- Division of Hematology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - HS Chi
- Department of Laboratory Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - CK Lee
- Division of Rheumatology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - SS Nah
- Division of Rheumatology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - YG Kim
- Division of Rheumatology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - JS Oh
- Division of Rheumatology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - HB Moon
- Division of Rheumatology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - B Yoo
- Division of Rheumatology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
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Shin YK, Yoon IY, Han EK, No YM, Hong MC, Yun YD, Jung BK, Chung SH, Choi JB, Cyn JG, Lee YJ, Hong SC. Prevalence of narcolepsy-cataplexy in Korean adolescents. Acta Neurol Scand 2008; 117:273-8. [PMID: 17922892 DOI: 10.1111/j.1600-0404.2007.00930.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [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: 11/30/2022]
Abstract
BACKGROUND Narcolepsy typically begins between adolescence and early adulthood causing severe neuropsychiatric impairments, but few prevalence studies are available on adolescent narcoleptics. In the present study, we investigated the prevalence of narcolepsy-cataplexy in adolescents. METHODS In total 20,407 students, aged 14-19 years, participated in this study. Ullanlinna Narcolepsy Scale (UNS) was applied to all subjects and those with a UNS score of > or =14 were contacted by phone for semi-structured interview. Subjects then suspected of having narcolepsy participated in a laboratory investigation, which included polysomnography and HLA typing, or were interviewed in detail by telephone. RESULTS Three subjects were finally diagnosed as narcolepsy with cataplexy and seven subjects might be diagnosed as narcolepsy without cataplexy. Among three narcoleptics with cataplexy, two subjects were HLA-DQB1*0602 and DRB1*1501 positive, but one subject had no test of HLA typing. The prevalence of narcolepsy with cataplexy in Korean adolescence was thus determined to be 0.015% (95% confidence interval = 0.0-0.0313%). CONCLUSION This epidemiologic study is the first of its type on adolescent narcolepsy to use the International Classification of Sleep Disorders, 2nd edition (ICSD-2) diagnostic criteria. Considering those cases with an onset after adolescence were not included, the prevalence of narcolepsy with cataplexy determined in the present study is comparable with that of other studies in adults.
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Affiliation(s)
- Y K Shin
- Department of Psychiatry, St Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
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Kim HM, Jeong BH, Hyon JY, An MJ, Seo MS, Hong JH, Lee KJ, Kim CH, Joo T, Hong SC, Cho BR. Two-photon fluorescent turn-on probe for lipid rafts in live cell and tissue. J Am Chem Soc 2008; 130:4246-7. [PMID: 18331041 DOI: 10.1021/ja711391f] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report a new two-photon fluorescence turn-on probe 6-[(E)-3-oxo-1-dodecenyl]-2-[N-methyl-N-(carboxymethyl)amino]naphthalene (CL2) that is designed specifically for visualizing lipid rafts in living cells and tissues. This probe emits much brighter two-photon excited fluorescence in lipid rafts than in non-raft domains and allows direct visualization of the lipid rafts in the live cells and pyramidal neuron layer of the CA1 region at a depth of 100-250 mum in live tissues using two-photon microscopy.
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Affiliation(s)
- Hwan Myung Kim
- Department of Chemistry, National Creative Research Initiative Center for Cell Dynamics, Department of Physics, Biomicrosystems Technology Program, Korea University, 1-Anamdong, Seoul, 136-701, Korea
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