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Harrison DE, Strong R, Reifsnyder P, Rosenthal N, Korstanje R, Fernandez E, Flurkey K, Ginsburg BC, Murrell MD, Javors MA, Lopez-Cruzan M, Nelson JF, Willcox BJ, Allsopp R, Watumull DM, Watumull DG, Cortopassi G, Kirkland JL, Tchkonia T, Choi YG, Yousefzadeh MJ, Robbins PD, Mitchell JR, Acar M, Sarnoski EA, Bene MR, Salmon A, Kumar N, Miller RA. Astaxanthin and meclizine extend lifespan in UM-HET3 male mice; fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate do not significantly affect lifespan in either sex at the doses and schedules used. GeroScience 2024; 46:795-816. [PMID: 38041783 PMCID: PMC10828146 DOI: 10.1007/s11357-023-01011-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 11/07/2023] [Indexed: 12/03/2023] Open
Abstract
In genetically heterogeneous (UM-HET3) mice produced by the CByB6F1 × C3D2F1 cross, the Nrf2 activator astaxanthin (Asta) extended the median male lifespan by 12% (p = 0.003, log-rank test), while meclizine (Mec), an mTORC1 inhibitor, extended the male lifespan by 8% (p = 0.03). Asta was fed at 1840 ± 520 (9) ppm and Mec at 544 ± 48 (9) ppm, stated as mean ± SE (n) of independent diet preparations. Both were started at 12 months of age. The 90th percentile lifespan for both treatments was extended in absolute value by 6% in males, but neither was significant by the Wang-Allison test. Five other new agents were also tested as follows: fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate. None of these increased lifespan significantly at the dose and method of administration tested in either sex. Amounts of dimethyl fumarate in the diet averaged 35% of the target dose, which may explain the absence of lifespan effects. Body weight was not significantly affected in males by any of the test agents. Late life weights were lower in females fed Asta and Mec, but lifespan was not significantly affected in these females. The male-specific lifespan benefits from Asta and Mec may provide insights into sex-specific aspects of aging.
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Affiliation(s)
- David E Harrison
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA.
| | - Randy Strong
- Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center, San Antonio, TX, USA
- Education, and Clinical Center, Geriatric Research, San Antonio, TX, USA
- Research Service, South Texas Veterans Health Care System, San Antonio, TX, USA
- Department of Pharmacology, The University of Texas Health Science Center, San Antonio, TX, USA
| | - Peter Reifsnyder
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Nadia Rosenthal
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Ron Korstanje
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Elizabeth Fernandez
- Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center, San Antonio, TX, USA
- Education, and Clinical Center, Geriatric Research, San Antonio, TX, USA
- Department of Pharmacology, The University of Texas Health Science Center, San Antonio, TX, USA
| | - Kevin Flurkey
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Brett C Ginsburg
- Department of Psychiatry, The University of Texas Health Science Center, San Antonio, TX, USA
| | - Meredith D Murrell
- Department of Psychiatry, The University of Texas Health Science Center, San Antonio, TX, USA
| | - Martin A Javors
- Department of Psychiatry, The University of Texas Health Science Center, San Antonio, TX, USA
| | - Marisa Lopez-Cruzan
- Department of Psychiatry, The University of Texas Health Science Center, San Antonio, TX, USA
| | - James F Nelson
- Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center, San Antonio, TX, USA
- Department of Physiology, The University of Texas Health Sciences Center, San Antonio, TX, USA
| | - Bradley J Willcox
- John A. Burns School of Medicine, University of Hawai'I at Mānoa, Honolulu, HI, USA
| | - Richard Allsopp
- John A. Burns School of Medicine, University of Hawai'I at Mānoa, Honolulu, HI, USA
| | | | | | - Gino Cortopassi
- Department of Molecular Biosciences, University of California, Davis, CA, USA
| | | | | | | | | | | | | | - Murat Acar
- Department of Basic Medical Sciences, School of Medicine, Koç University, 34450, Istanbul, Turkey
| | - Ethan A Sarnoski
- Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Michael R Bene
- Department of Molecular Medicine, The University of Texas Health Sciences Center, San Antonio, TX, USA
| | - Adam Salmon
- Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center, San Antonio, TX, USA
- Education, and Clinical Center, Geriatric Research, San Antonio, TX, USA
- Research Service, South Texas Veterans Health Care System, San Antonio, TX, USA
- Department of Molecular Medicine, The University of Texas Health Sciences Center, San Antonio, TX, USA
| | - Navasuja Kumar
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Richard A Miller
- Department of Pathology and Geriatrics Center, University of Michigan, Ann Arbor, MI, USA
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Lin J, Unge J, Gonen T. Unraveling the Structure of Meclizine Dihydrochloride with MicroED. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306435. [PMID: 38044280 PMCID: PMC10853755 DOI: 10.1002/advs.202306435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 11/15/2023] [Indexed: 12/05/2023]
Abstract
Meclizine (Antivert, Bonine) is a first-generation H1 antihistamine used in the treatment of motion sickness and vertigo. Despite its wide medical use for over 70 years, its crystal structure and the details of protein-drug interactions remained unknown. Single-crystal X-ray diffraction (SC-XRD) is previously unsuccessful for meclizine. Today, microcrystal electron diffraction (MicroED) enables the analysis of nano- or micro-sized crystals that are merely a billionth the size needed for SC-XRD directly from seemingly amorphous powder. In this study, MicroED to determine the 3D crystal structure of meclizine dihydrochloride is used. Two racemic enantiomers (R/S) are found in the unit cell, which is packed as repetitive double layers in the crystal lattice. The packing is made of multiple strong N-H-Cl- hydrogen bonding interactions and weak interactions like C-H-Cl- and pi-stacking. Molecular docking reveals the binding mechanism of meclizine to the histamine H1 receptor. A comparison of the docking complexes between histamine H1 receptor and meclizine or levocetirizine (a second-generation antihistamine) shows the conserved binding sites. This research illustrates the combined use of MicroED and molecular docking in unraveling elusive drug structures and protein-drug interactions for precision drug design and optimization.
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Affiliation(s)
- Jieye Lin
- Department of Biological ChemistryUniversity of California615 Charles E. Young Drive SouthLos AngelesCA90095USA
| | - Johan Unge
- Department of Biological ChemistryUniversity of California615 Charles E. Young Drive SouthLos AngelesCA90095USA
| | - Tamir Gonen
- Department of Biological ChemistryUniversity of California615 Charles E. Young Drive SouthLos AngelesCA90095USA
- Department of PhysiologyUniversity of California615 Charles E. Young Drive SouthLos AngelesCA90095USA
- Howard Hughes Medical InstituteUniversity of CaliforniaLos AngelesCA90095USA
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3
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Mertens AM, Schenk HC, Volk HA. Current definition, diagnosis, and treatment of canine and feline idiopathic vestibular syndrome. Front Vet Sci 2023; 10:1263976. [PMID: 37808104 PMCID: PMC10556701 DOI: 10.3389/fvets.2023.1263976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 09/07/2023] [Indexed: 10/10/2023] Open
Abstract
Idiopathic vestibular syndrome (IVS) is one of the most common neurological disorders in veterinary medicine. However, its diagnosis and treatment varies between publications. The aim of the current study was to gather experts' opinion about IVS definition, diagnosis, and treatment. An online-survey was used to assess neurology specialists' opinion about the definition, diagnosis and treatment of IVS. The study demonstrated that the definition, diagnosis, and treatment of IVS are largely consistent worldwide, with the EU prioritising less frequently advanced imaging and more often otoscopy to rule out other diseases. IVS was defined by most specialists as an acute to peracute, improving, non-painful peripheral vestibular disorder that often affects cats of any age and geriatric dogs. Regarding diagnosis, a detailed neurological examination and comprehensive blood tests, including thyroid values, blood pressure, and otoscopic examination, was seen as crucial. A thorough workup may also involve MRI and CSF analysis to rule out other causes of vestibular dysfunction. Treatment of IVS typically involved intravenous fluid therapy and the use of an antiemetic, with maropitant once daily being the preferred choice among specialists. Antinausea treatment was considered, however, only by a handful specialists. This survey-based study provides valuable insights from neurology experts and highlights areas that require further research to bridge the gap between theory and practice.
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Affiliation(s)
- Anna Morgana Mertens
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
- Department of Neurology/Neurosurgery, Tierklinik Lüneburg, Lüneburg, Germany
| | | | - Holger Andreas Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
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4
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Lin J, Unge J, Gonen T. Unraveling the Structure of Meclizine Dihydrochloride with MicroED. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.05.556418. [PMID: 37786674 PMCID: PMC10541648 DOI: 10.1101/2023.09.05.556418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Meclizine (Antivert, Bonine) is a first-generation H1 antihistamine used in the treatment of motion sickness and vertigo. Despite its wide medical use for over 70 years, its crystal structure and the details of protein-drug interactions remained unknown. In this study, we used microcrystal electron diffraction (MicroED) to determine the three-dimensional (3D) crystal structure of meclizine dihydrochloride directly from a seemingly amorphous powder. Two racemic enantiomers (R/S) were found in the unit cell, which packed as repetitive double layers in the crystal lattice. The packing was made of multiple strong N-H⋯Cl- hydrogen bonding interactions and weak interactions like C-H⋯Cl- and pi-stacking. Molecular docking revealed the binding mechanism of meclizine to the histamine H1 receptor. A comparison of the docking complexes between histamine H1 receptor and meclizine or levocetirizine (a second-generation antihistamine) showed the conserved binding sites. This research illustrates the combined use of MicroED and molecular docking in unraveling protein-drug interactions for precision drug design and optimization.
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Affiliation(s)
- Jieye Lin
- Department of Biological Chemistry, University of California, Los Angeles, 615 Charles E. Young Drive South, Los Angeles, California 90095, United States
| | - Johan Unge
- Department of Biological Chemistry, University of California, Los Angeles, 615 Charles E. Young Drive South, Los Angeles, California 90095, United States
| | - Tamir Gonen
- Department of Biological Chemistry, University of California, Los Angeles, 615 Charles E. Young Drive South, Los Angeles, California 90095, United States
- Department of Physiology, University of California, Los Angeles, 615 Charles E. Young Drive South, Los Angeles, California 90095, United States
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
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5
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Liu J, Xiao Y, Hao J, Shen Q. Copper-Catalyzed Trifluoromethylation of (Hetero)aryl Boronic Acid Pinacol Esters with YlideFluor. Org Lett 2023; 25:1204-1208. [PMID: 36779647 DOI: 10.1021/acs.orglett.3c00206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
A copper-catalyzed trifluoromethylation of (hetero)arylboronic acid pinacol esters with YlideFluor for the preparation of trifluoromethylated (hetero)arenes was described. The reaction conditions are mild and compatible with a broad range of functional groups. Heteroaryl boronic acid pinacol esters could also be trifluoromethylated in high yields. Application of this protocol for trifluoromethylation of drug and OLED molecules was demonstrated.
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Affiliation(s)
- Jing Liu
- Department of Chemistry, Shanghai University, 99 Shangda Road, Shanghai 200444, P. R. China.,Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, P. R. China
| | - Yisa Xiao
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, P. R. China
| | - Jian Hao
- Department of Chemistry, Shanghai University, 99 Shangda Road, Shanghai 200444, P. R. China
| | - Qilong Shen
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, P. R. China
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Viola P, Marcianò G, Casarella A, Pisani D, Astorina A, Scarpa A, Siccardi E, Basile E, De Sarro G, Gallelli L, Chiarella G. The Pharmacological Treatment of Pediatric Vertigo. CHILDREN 2022; 9:children9050584. [PMID: 35626761 PMCID: PMC9139449 DOI: 10.3390/children9050584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/09/2022] [Accepted: 04/15/2022] [Indexed: 12/25/2022]
Abstract
Vertigo in children is a challenging topic. The lack of dedicated trials, guidelines and papers causes inhomogeneity in the treatment of vertigo in children. Meniere’s disease, migraine equivalents, vestibular neuritis, paroxysmal positional benign vertigo (BPPV), persistent postural-perceptual dizziness (PPPD) and motion sickness may affect children with various degrees of incidence and clinical severity compared to adults. Several drugs are proposed for the management of these conditions, even if their use is subordinated to the child’s age. In this review, we summarize the existing evidence related to the use of drugs for this clinical condition in children as a start point for new trials, stating the urgent need for international guidelines.
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Affiliation(s)
- Pasquale Viola
- Unit of Audiology, Regional Centre of Cochlear Implants and ENT Diseases, Department of Experimental and Clinical Medicine, Magna Graecia University, 88100 Catanzaro, Italy; (P.V.); (D.P.); (A.A.)
| | - Gianmarco Marcianò
- Clinical Pharmacology and Pharmacovigilance Unit, Department of Health Science, School of Medicine, University of Catanzaro, Mater Domini Hospital, 88100 Catanzaro, Italy; (G.M.); (A.C.); (E.B.); (G.D.S.); (L.G.)
| | - Alessandro Casarella
- Clinical Pharmacology and Pharmacovigilance Unit, Department of Health Science, School of Medicine, University of Catanzaro, Mater Domini Hospital, 88100 Catanzaro, Italy; (G.M.); (A.C.); (E.B.); (G.D.S.); (L.G.)
| | - Davide Pisani
- Unit of Audiology, Regional Centre of Cochlear Implants and ENT Diseases, Department of Experimental and Clinical Medicine, Magna Graecia University, 88100 Catanzaro, Italy; (P.V.); (D.P.); (A.A.)
| | - Alessia Astorina
- Unit of Audiology, Regional Centre of Cochlear Implants and ENT Diseases, Department of Experimental and Clinical Medicine, Magna Graecia University, 88100 Catanzaro, Italy; (P.V.); (D.P.); (A.A.)
| | - Alfonso Scarpa
- Department of Medicine and Surgery, University of Salerno, 84081 Baronissi, Italy;
| | | | - Emanuele Basile
- Clinical Pharmacology and Pharmacovigilance Unit, Department of Health Science, School of Medicine, University of Catanzaro, Mater Domini Hospital, 88100 Catanzaro, Italy; (G.M.); (A.C.); (E.B.); (G.D.S.); (L.G.)
| | - Giovambattista De Sarro
- Clinical Pharmacology and Pharmacovigilance Unit, Department of Health Science, School of Medicine, University of Catanzaro, Mater Domini Hospital, 88100 Catanzaro, Italy; (G.M.); (A.C.); (E.B.); (G.D.S.); (L.G.)
- Research Center FAS@UMG, Department of Health Science, Magna Graecia University, 88100 Catanzaro, Italy
| | - Luca Gallelli
- Clinical Pharmacology and Pharmacovigilance Unit, Department of Health Science, School of Medicine, University of Catanzaro, Mater Domini Hospital, 88100 Catanzaro, Italy; (G.M.); (A.C.); (E.B.); (G.D.S.); (L.G.)
- Research Center FAS@UMG, Department of Health Science, Magna Graecia University, 88100 Catanzaro, Italy
- Medifarmagen SRL, Department of Health Science, Magna Graecia University, 88100 Catanzaro, Italy
| | - Giuseppe Chiarella
- Unit of Audiology, Regional Centre of Cochlear Implants and ENT Diseases, Department of Experimental and Clinical Medicine, Magna Graecia University, 88100 Catanzaro, Italy; (P.V.); (D.P.); (A.A.)
- Correspondence: ; Tel.: +39-0961364-7124
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Expanding horizons of achondroplasia treatment: current options and future developments. Osteoarthritis Cartilage 2022; 30:535-544. [PMID: 34864168 DOI: 10.1016/j.joca.2021.11.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/23/2021] [Accepted: 11/28/2021] [Indexed: 02/02/2023]
Abstract
Activating mutations in the FGFR3 receptor tyrosine kinase lead to most prevalent form of genetic dwarfism in humans, the achondroplasia. Many features of the complex function of FGFR3 in growing skeleton were characterized, which facilitated identification of therapy targets, and drove progress toward treatment. In August 2021, the vosoritide was approved for treatment of achondroplasia, which is based on a stable variant of the C-natriuretic peptide. Other drugs may soon follow, as several conceptually different inhibitors of FGFR3 signaling progress through clinical trials. Here, we review the current achondroplasia therapeutics, describe their mechanisms, and illuminate motivations leading to their development. We also discuss perspectives of curing achondroplasia, and options for repurposing achondroplasia drugs for dwarfing conditions unrelated to FGFR3.
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Abstract
PURPOSE OF REVIEW Motion sickness is an ancient phenomenon that affects many people. Nausea, vomiting, disorientation, sweating, fatigue, and headache are just few of the many signs and symptoms that are commonly experienced during an episode of motion sickness. In the present review, we will provide an overview of the current research trends and topics in the domain of motion sickness, including theoretical considerations, physiological and neural mechanisms, individual risk factors, and treatment options, as well as recommendations for future research directions. RECENT FINDINGS More recently, motion sickness has been in the focus of attention in the context of two global technological trends, namely automated vehicles and virtual reality. Both technologies bear the potential to revolutionize our daily lives in many ways; however, motion sickness is considered a serious concern that threatens their success and acceptance. The majority of recent research on motion sickness focuses on one of these two areas. SUMMARY Aside from medication (e.g. antimuscarinics, antihistamines), habituation remains the most effective nonpharmacological method to reduce motion sickness. A variety of novel techniques has been investigated with promising results, but an efficient method to reliably prevent or minimize motion sickness has yet to emerge.
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Affiliation(s)
- Behrang Keshavarz
- KITE-Toronto Rehabilitation Institute, University Health Network
- Department of Psychology, Ryerson University, Toronto, Canada
| | - John F Golding
- Department of Psychology, School for Social Sciences, University of Westminster, London, United Kingdom
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Ku KB, Shin HJ, Kim HS, Kim BT, Kim, SJ, Kim C. Repurposing Screens of FDA-Approved Drugs Identify 29 Inhibitors of SARS-CoV-2. J Microbiol Biotechnol 2020; 30:1843-1853. [PMID: 33203821 PMCID: PMC9728307 DOI: 10.4014/jmb.2009.09009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/09/2020] [Accepted: 11/09/2020] [Indexed: 01/08/2023]
Abstract
COVID-19, caused by the novel coronavirus SARS-CoV-2, has spread globally and caused serious social and economic problems. The WHO has declared this outbreak a pandemic. Currently, there are no approved vaccines or antiviral drugs that prevent SARS-CoV-2 infection. Drugs already approved for clinical use would be ideal candidates for rapid development as COVID-19 treatments. In this work, we screened 1,473 FDA-approved drugs to identify inhibitors of SARS-CoV-2 infection using cell-based assays. The antiviral activity of each compound was measured based on the immunofluorescent staining of infected cells using anti-dsRNA antibody. Twenty-nine drugs among those tested showed antiviral activity against SARS-CoV-2. We report this new list of inhibitors to quickly provide basic information for consideration in developing potential therapies.
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Affiliation(s)
- Keun Bon Ku
- Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Hye Jin Shin
- Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Hae Soo Kim
- Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Bum-Tae Kim
- Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Seong-Jun Kim,
- Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea,S-J.Kim Phone: +82-42-860-7477 E-mail:
| | - Chonsaeng Kim
- Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea,Corresponding authors C.Kim Phone: +82-42-860-7491 E-mail:
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10
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Optokinetic stimulation induces vertical vergence, possibly through a non-visual pathway. Sci Rep 2020; 10:15544. [PMID: 32968160 PMCID: PMC7511321 DOI: 10.1038/s41598-020-72646-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 08/26/2020] [Indexed: 11/19/2022] Open
Abstract
Vertical vergence is generally associated with one of three mechanisms: vestibular activation during a head tilt, induced by vertical visual disparity, or as a by-product of ocular torsion. However, vertical vergence can also be induced by seemingly unrelated visual conditions, such as optokinetic rotations. This study aims to investigate the effect of vision on this latter form of vertical vergence. Eight subjects (4m/4f) viewed a visual scene in head erect position in two different viewing conditions (monocular and binocular). The scene, containing white lines angled at 45° against a black background, was projected at an eye-screen distance of 2 m, and rotated 28° at an acceleration of 56°/s2. Eye movements were recorded using a Chronos Eye-Tracker, and eye occlusions were carried out by placing an infrared-translucent cover in front of the left eye during monocular viewing. Results revealed vergence amplitudes during binocular viewing to be significantly lower than those seen for monocular conditions (p = 0.003), while torsion remained unaffected. This indicates that vertical vergence to optokinetic stimulation, though visually induced, is visually suppressed during binocular viewing. Considering that vertical vergence is generally viewed as a vestibular signal, the findings may reflect a visually induced activation of a vestibular pathway.
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11
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Wibble T, Engström J, Pansell T. Visual and Vestibular Integration Express Summative Eye Movement Responses and Reveal Higher Visual Acceleration Sensitivity than Previously Described. Invest Ophthalmol Vis Sci 2020; 61:4. [PMID: 32392313 PMCID: PMC7405760 DOI: 10.1167/iovs.61.5.4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose Acceleration plays a great impact on the vestibular system, but is attributed little influence over vision. This study aims to explore how visual and vestibular acceleration affect roll-plane oculomotor responses, including their addiative effect. Methods Seated in a mechanical sled, 13 healthy volunteers (7 men, 6 women; mean age 25 years) were exposed to a series of visual (VIS) optokinetic, vestibular (VES) whole-body, and combined (VIS + VES) rotations. This was carried out at two acceleration intensities. Subjects wore a video-based eye tracker, enabling analysis of torsional and skewing eye movement responses, which were used to evaluate the individual response to each trial. The tracker also contained accelerometers allowing head tracking. Results Both ocular torsion and vertical skewing were sensitive to acceleration intensities for VES and VIS + VES. For VIS only, skewing exhibited such a response. An increased acceleration yielded a decreased torsion-skewing ratio for VIS, explained by the change in skewing, but remained unchanged for VES and VIS + VES. Torsion exhibited particularly reliable summative effect, yielding a relative contribution of 32% VIS and 75% VES during low acceleration, and 19% and 85%, respectively, during high acceleration. Conclusions The change in the skewing response to different intensities indicates that the visual system is more sensitive to visual accelerations than previously described. Eye movements showed reliable summative effects, indicating a robust visual-vestibular integration that indicates their integrative priorities for each acceleration, with the visual system being more involved during low accelerations. Such objective quantifications could hold clinical utility when assessing sensory mismatch in vertiginous patients.
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Wibble T, Engström J, Verrecchia L, Pansell T. The effects of meclizine on motion sickness revisited. Br J Clin Pharmacol 2020; 86:1510-1518. [PMID: 32077140 PMCID: PMC7373708 DOI: 10.1111/bcp.14257] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 01/21/2020] [Accepted: 01/22/2020] [Indexed: 01/13/2023] Open
Abstract
AIMS Antihistamines make up the first line of treatments against motion-sickness. Still, their efficacy and specific mechanism have come into question. The aim of this study was to investigate the effect of meclizine on motion-sensitivity. METHODS This study was carried out as a triple-blinded randomized trial involving 12 healthy subjects who were exposed to (i) vestibular (VES), (ii) visual (VIS) and (iii) visual-vestibular (VIS+VES) stimulations in the roll plane. Subjects were divided into 2 groups by stratified randomization, receiving either meclizine or a placebo. Stimulations were carried out before, and after, drug administration, presented at 2 intensity levels of 14 and 28°/s2 . Eye movements were tracked, and torsional slow-phase velocities, amplitudes and nystagmus beats were retrieved. Subjects initially graded for their motion-sickness susceptibility. RESULTS Susceptibility had no effect on intervention outcome. Despite large variations, repeated ANOVAS showed that meclizine led to a relative increase in torsional velocity compared to placebo during vestibular stimulation for both intensities: 2.36 (7.65) from -0.01 (4.17) during low intensities, and 2.61 (6.67) from -3.49 (4.76) during high. The visual-vestibular stimuli yielded a decrease during low acceleration, -0.40 (3.87) from 3.75 (5.62), but increased during high, 3.88 (6.51) from -3.88 (8.55). CONCLUSIONS Meclizine had an inhibitory effect on eye movement reflexes for low accelerations during VIS+VES trials. This indicates that meclizine may not primarily work through sensory-specific mechanisms, but rather on a more central level. Practically, meclizine shows promise in targeting motion-sickness evoked by everyday activities, but its use may be counterproductive in high-acceleration environments.
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Affiliation(s)
- Tobias Wibble
- Department of Clinical Neuroscience, Division of Ophthalmology and Vision, Marianne Bernadotte Centre, Karolinska Institutet, Stockholm, Sweden.,St Erik Eye Hospital, Stockholm, Sweden
| | - Johanna Engström
- Department of Clinical Neuroscience, Division of Ophthalmology and Vision, Marianne Bernadotte Centre, Karolinska Institutet, Stockholm, Sweden
| | - Luca Verrecchia
- Department of Clinical Neuroscience, Division of Ophthalmology and Vision, Marianne Bernadotte Centre, Karolinska Institutet, Stockholm, Sweden.,The Hearing and Balance Clinic, The Karolinska University Hospital, Stockholm, Sweden
| | - Tony Pansell
- Department of Clinical Neuroscience, Division of Ophthalmology and Vision, Marianne Bernadotte Centre, Karolinska Institutet, Stockholm, Sweden.,St Erik Eye Hospital, Stockholm, Sweden
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