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Memon H, Ong J, Waisberg E, Panzo N, Sarker P, Zaman N, Tavakkoli A, Lee AG. Biophysics of ophthalmic medications during spaceflight: Principles of ocular fluid dynamics and pharmacokinetics in microgravity. LIFE SCIENCES IN SPACE RESEARCH 2024; 42:53-61. [PMID: 39067991 DOI: 10.1016/j.lssr.2024.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 04/11/2024] [Accepted: 04/29/2024] [Indexed: 07/30/2024]
Abstract
As spaceflight becomes increasingly accessible and expansive to humanity, it is becoming ever more essential to consider the treatment of various eye diseases in these challenging environments. This paper delves into the increasing fascination with interplanetary travel and its implications for health management in varying environments. It specifically discusses the pharmacological management of ocular diseases, focusing on two key delivery methods: topical eye drops and intravitreal injections. The paper explores how microgravity impacts the administration of these treatments, a vital aspect in understanding drug delivery in space. An extensive analysis is presented on the pharmacokinetics of eye medications, examining the interaction between pharmaceuticals and ocular tissues in zero gravity. The goal of the paper is to bridge the understanding of fluid dynamics, microgravity and the human physiological systems to pave the way for innovative solutions faced by individuals in microgravity.
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Affiliation(s)
- Hamza Memon
- Texas A&M School of Medicine, Bryan, TX, United States
| | - Joshua Ong
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Ethan Waisberg
- Department of Ophthalmology, University of Cambridge, Cambridge, United Kingdom
| | | | - Prithul Sarker
- Human-Machine Perception Laboratory, Department of Computer Science and Engineering, University of Nevada, Reno, Reno, Nevada, United States
| | - Nasif Zaman
- Human-Machine Perception Laboratory, Department of Computer Science and Engineering, University of Nevada, Reno, Reno, Nevada, United States
| | - Alireza Tavakkoli
- Human-Machine Perception Laboratory, Department of Computer Science and Engineering, University of Nevada, Reno, Reno, Nevada, United States
| | - Andrew G Lee
- Texas A&M School of Medicine, Bryan, TX, United States; Center for Space Medicine, Baylor College of Medicine, Houston, Texas, United States; Department of Ophthalmology, Blanton Eye Institute, Houston Methodist Hospital, Houston, Texas, United States; The Houston Methodist Research Institute, Houston Methodist Hospital, Houston, Texas, United States; Departments of Ophthalmology, Neurology, and Neurosurgery, Weill Cornell Medicine, New York, New York, United States; Department of Ophthalmology, University of Texas Medical Branch, Galveston, Texas, United States; University of Texas MD Anderson Cancer Center, Houston, Texas, United States; Department of Ophthalmology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, United States.
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2
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Lidberg KA, Jones-Isaac K, Yang J, Bain J, Wang L, MacDonald JW, Bammler TK, Calamia J, Thummel KE, Yeung CK, Countryman S, Koenig P, Himmelfarb J, Kelly EJ. Modeling cellular responses to serum and vitamin D in microgravity using a human kidney microphysiological system. NPJ Microgravity 2024; 10:75. [PMID: 38982119 PMCID: PMC11233620 DOI: 10.1038/s41526-024-00415-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 06/24/2024] [Indexed: 07/11/2024] Open
Abstract
The microgravity environment aboard the International Space Station (ISS) provides a unique stressor that can help understand underlying cellular and molecular drivers of pathological changes observed in astronauts with the ultimate goals of developing strategies to enable long- term spaceflight and better treatment of diseases on Earth. We used this unique environment to evaluate the effects of microgravity on kidney proximal tubule epithelial cell (PTEC) response to serum exposure and vitamin D biotransformation capacity. To test if microgravity alters the pathologic response of the proximal tubule to serum exposure, we treated PTECs cultured in a microphysiological system (PT-MPS) with human serum and measured biomarkers of toxicity and inflammation (KIM-1 and IL-6) and conducted global transcriptomics via RNAseq on cells undergoing flight (microgravity) and respective controls (ground). Given the profound bone loss observed in microgravity and PTECs produce the active form of vitamin D, we treated 3D cultured PTECs with 25(OH)D3 (vitamin D) and monitored vitamin D metabolite formation, conducted global transcriptomics via RNAseq, and evaluated transcript expression of CYP27B1, CYP24A1, or CYP3A5 in PTECs undergoing flight (microgravity) and respective ground controls. We demonstrated that microgravity neither altered PTEC metabolism of vitamin D nor did it induce a unique response of PTECs to human serum, suggesting that these fundamental biochemical pathways in the kidney proximal tubule are not significantly altered by short-term exposure to microgravity. Given the prospect of extended spaceflight, more study is needed to determine if these responses are consistent with extended (>6 months) exposure to microgravity.
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Affiliation(s)
- Kevin A Lidberg
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
- RayzeBio, San Diego, CA, USA
| | | | - Jade Yang
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Jacelyn Bain
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Lu Wang
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - James W MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Theo K Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Justina Calamia
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Kenneth E Thummel
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Catherine K Yeung
- Department of Pharmacy, University of Washington, Seattle, WA, USA
- Kidney Research Institute, Seattle, WA, USA
| | | | - Paul Koenig
- BioServe Space Technologies, University of Colorado, Boulder, CO, USA
| | | | - Edward J Kelly
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA.
- Kidney Research Institute, Seattle, WA, USA.
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3
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Binneboessel S, Gerdes N, Baertschi M, Kaya S, Geerling G, Kelm M, Jung C. Changes in Ocular Perfusion and Pressure Changes in Gravitational Alteration Contribute to Spaceflight-Associated Neuro-Ocular Syndrome. Arterioscler Thromb Vasc Biol 2024; 44:1716-1718. [PMID: 38721708 DOI: 10.1161/atvbaha.124.320720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Affiliation(s)
- Stephan Binneboessel
- Department of Cardiology, Pulmonology, and Vascular Medicine, University Hospital and Medical Faculty (S.B., N.G., M.K., C.J.), Heinrich-Heine University, Germany
| | - Norbert Gerdes
- Department of Cardiology, Pulmonology, and Vascular Medicine, University Hospital and Medical Faculty (S.B., N.G., M.K., C.J.), Heinrich-Heine University, Germany
- Cardiovascular Research Institute Duesseldorf (CARID), Medical Faculty (N.G., M.K., C.J.), Heinrich-Heine University, Germany
| | | | - Sema Kaya
- Department of Ophthalmology, University Hospital and Medical Faculty (S.K., G.G.), Heinrich-Heine University, Germany
| | - Gerd Geerling
- Department of Ophthalmology, University Hospital and Medical Faculty (S.K., G.G.), Heinrich-Heine University, Germany
| | - Malte Kelm
- Department of Cardiology, Pulmonology, and Vascular Medicine, University Hospital and Medical Faculty (S.B., N.G., M.K., C.J.), Heinrich-Heine University, Germany
- Cardiovascular Research Institute Duesseldorf (CARID), Medical Faculty (N.G., M.K., C.J.), Heinrich-Heine University, Germany
| | - Christian Jung
- Department of Cardiology, Pulmonology, and Vascular Medicine, University Hospital and Medical Faculty (S.B., N.G., M.K., C.J.), Heinrich-Heine University, Germany
- Cardiovascular Research Institute Duesseldorf (CARID), Medical Faculty (N.G., M.K., C.J.), Heinrich-Heine University, Germany
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4
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Wu F, Du H, Overbey E, Kim J, Makhijani P, Martin N, Lerner CA, Nguyen K, Baechle J, Valentino TR, Fuentealba M, Bartleson JM, Halaweh H, Winer S, Meydan C, Garrett-Bakelman F, Sayed N, Melov S, Muratani M, Gerencser AA, Kasler HG, Beheshti A, Mason CE, Furman D, Winer DA. Single-cell analysis identifies conserved features of immune dysfunction in simulated microgravity and spaceflight. Nat Commun 2024; 15:4795. [PMID: 38862487 PMCID: PMC11166937 DOI: 10.1038/s41467-023-42013-y] [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: 12/06/2022] [Accepted: 09/27/2023] [Indexed: 06/13/2024] Open
Abstract
Microgravity is associated with immunological dysfunction, though the mechanisms are poorly understood. Here, using single-cell analysis of human peripheral blood mononuclear cells (PBMCs) exposed to short term (25 hours) simulated microgravity, we characterize altered genes and pathways at basal and stimulated states with a Toll-like Receptor-7/8 agonist. We validate single-cell analysis by RNA sequencing and super-resolution microscopy, and against data from the Inspiration-4 (I4) mission, JAXA (Cell-Free Epigenome) mission, Twins study, and spleens from mice on the International Space Station. Overall, microgravity alters specific pathways for optimal immunity, including the cytoskeleton, interferon signaling, pyroptosis, temperature-shock, innate inflammation (e.g., Coronavirus pathogenesis pathway and IL-6 signaling), nuclear receptors, and sirtuin signaling. Microgravity directs monocyte inflammatory parameters, and impairs T cell and NK cell functionality. Using machine learning, we identify numerous compounds linking microgravity to immune cell transcription, and demonstrate that the flavonol, quercetin, can reverse most abnormal pathways. These results define immune cell alterations in microgravity, and provide opportunities for countermeasures to maintain normal immunity in space.
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Grants
- R01 MH117406 NIMH NIH HHS
- T32 AG000266 NIA NIH HHS
- This work was supported in part through funds derived from the Buck Institute for Research on Aging (D.A.W., D.F.), and the Huiying Memorial Foundation (D.A.W.). T.V. and J.B. are funded by a T32 NIH fellowship grant (NIA T32 AG000266). C.E.M. thanks the Scientific Computing Unit (SCU) at WCM, the WorldQuant Foundation, NASA (NNX14AH50G, NNX17AB26G, 80NSSC22K0254, NNH18ZTT001N-FG2, 80NSSC22K0254, NNX16AO69A), the National Institutes of Health (R01MH117406), and LLS (MCL7001-18, LLS 9238-16).
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Affiliation(s)
- Fei Wu
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Huixun Du
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Eliah Overbey
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10021, USA
| | - JangKeun Kim
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Priya Makhijani
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
- Department of Immunology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Nicolas Martin
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Chad A Lerner
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Khiem Nguyen
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Jordan Baechle
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | | | | | | | - Heather Halaweh
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Shawn Winer
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada
| | - Cem Meydan
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Francine Garrett-Bakelman
- Department of Medicine, University of Virginia, Charlottesville, VA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Nazish Sayed
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Simon Melov
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Masafumi Muratani
- Transborder Medical Research Center, University of Tsukuba, Ibaraki, 305-8575, Japan
- Department of Genome Biology, Faculty of Medicine, University of Tsukuba, Ibaraki, 305-8575, Japan
| | | | | | - Afshin Beheshti
- Blue Marble Space Institute of Science, Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94043, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Christopher E Mason
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10021, USA.
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10021, USA.
- WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medicine, New York, NY, 10021, USA.
- The Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA.
| | - David Furman
- Buck Institute for Research on Aging, Novato, CA, 94945, USA.
- Stanford 1000 Immunomes Project, Stanford University School of Medicine, Stanford, CA, USA.
- Institute for Research in Translational Medicine, Universidad Austral, CONICET, Pilar, Buenos Aires, Argentina.
| | - Daniel A Winer
- Buck Institute for Research on Aging, Novato, CA, 94945, USA.
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, 90089, USA.
- Department of Immunology, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Division of Cellular & Molecular Biology, Toronto General Hospital Research Institute (TGHRI), University Health Network, Toronto, ON, M5G 1L7, Canada.
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5
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Park J, Overbey EG, Narayanan SA, Kim J, Tierney BT, Damle N, Najjar D, Ryon KA, Proszynski J, Kleinman A, Hirschberg JW, MacKay M, Afshin EE, Granstein R, Gurvitch J, Hudson BM, Rininger A, Mullane S, Church SE, Meydan C, Church G, Beheshti A, Mateus J, Mason CE. Spatial multi-omics of human skin reveals KRAS and inflammatory responses to spaceflight. Nat Commun 2024; 15:4773. [PMID: 38862494 PMCID: PMC11166909 DOI: 10.1038/s41467-024-48625-2] [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: 11/26/2022] [Accepted: 04/26/2024] [Indexed: 06/13/2024] Open
Abstract
Spaceflight can change metabolic, immunological, and biological homeostasis and cause skin rashes and irritation, yet the molecular basis remains unclear. To investigate the impact of short-duration spaceflight on the skin, we conducted skin biopsies on the Inspiration4 crew members before (L-44) and after (R + 1) flight. Leveraging multi-omics assays including GeoMx™ Digital Spatial Profiler, single-cell RNA/ATAC-seq, and metagenomics/metatranscriptomics, we assessed spatial gene expressions and associated microbial and immune changes across 95 skin regions in four compartments: outer epidermis, inner epidermis, outer dermis, and vasculature. Post-flight samples showed significant up-regulation of genes related to inflammation and KRAS signaling across all skin regions. These spaceflight-associated changes mapped to specific cellular responses, including altered interferon responses, DNA damage, epithelial barrier disruptions, T-cell migration, and hindered regeneration were located primarily in outer tissue compartments. We also linked epithelial disruption to microbial shifts in skin swab and immune cell activity to PBMC single-cell data from the same crew and timepoints. Our findings present the inaugural collection and examination of astronaut skin, offering insights for future space missions and response countermeasures.
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Affiliation(s)
- Jiwoon Park
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
| | - Eliah G Overbey
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
| | - S Anand Narayanan
- Department of Nutrition & Integrative Physiology, Florida State University, Tallahassee, FL, USA
| | - JangKeun Kim
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
| | - Braden T Tierney
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
| | - Namita Damle
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | - Deena Najjar
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | - Krista A Ryon
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | - Jacqueline Proszynski
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | - Ashley Kleinman
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | - Jeremy Wain Hirschberg
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | - Matthew MacKay
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | - Evan E Afshin
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | - Richard Granstein
- Department of Dermatology, Weill Cornell Medicine, New York, NY, USA
| | - Justin Gurvitch
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | | | | | | | | | - Cem Meydan
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
| | - George Church
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Afshin Beheshti
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Blue Marble Space Institute of Science, Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | | | - Christopher E Mason
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA.
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA.
- The Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
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6
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Sampige R, Ong J, Waisberg E, Zaman N, Sarker P, Tavakkoli A, Lee AG. XR-SANS: a multi-modal framework for analyzing visual changes with extended reality (XR) in Spaceflight Associated Neuro-Ocular Syndrome (SANS). Eye (Lond) 2024:10.1038/s41433-024-03147-5. [PMID: 38802484 DOI: 10.1038/s41433-024-03147-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 04/30/2024] [Accepted: 05/10/2024] [Indexed: 05/29/2024] Open
Affiliation(s)
- Ritu Sampige
- School of Medicine, Baylor College of Medicine, Houston, TX, USA.
| | - Joshua Ong
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI, USA.
| | - Ethan Waisberg
- Department of Ophthalmology, University of Cambridge, Cambridge, MA, USA
| | - Nasif Zaman
- Human-Machine Perception Laboratory, Department of Computer Science and Engineering, University of Nevada, Reno, Reno, NV, USA
| | - Prithul Sarker
- Human-Machine Perception Laboratory, Department of Computer Science and Engineering, University of Nevada, Reno, Reno, NV, USA
| | - Alireza Tavakkoli
- Human-Machine Perception Laboratory, Department of Computer Science and Engineering, University of Nevada, Reno, Reno, NV, USA
| | - Andrew G Lee
- Center for Space Medicine, Baylor College of Medicine, Houston, TX, USA
- Department of Ophthalmology, Blanton Eye Institute, Houston Methodist Hospital, Houston, TX, USA
- Departments of Ophthalmology, Neurology, and Neurosurgery, Weill Cornell Medicine, New York, NY, USA
- Department of Ophthalmology, University of Texas Medical Branch, Galveston, TX, USA
- University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Texas A&M College of Medicine, Bryan, TX, USA
- Department of Ophthalmology, The University of Iowa Hospitals and Clinics, Iowa City, IA, USA
- The Houston Methodist Research Institute, Houston Methodist Hospital, Houston, TX, USA
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7
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Rezaei S, Seyedmirzaei H, Gharepapagh E, Mohagheghfard F, Hasankhani Z, Karbasi M, Delavari S, Aarabi MH. Effect of spaceflight experience on human brain structure, microstructure, and function: systematic review of neuroimaging studies. Brain Imaging Behav 2024:10.1007/s11682-024-00894-7. [PMID: 38777951 DOI: 10.1007/s11682-024-00894-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2024] [Indexed: 05/25/2024]
Abstract
Spaceflight-induced brain changes have been commonly reported in astronauts. The role of microgravity in the alteration of the brain structure, microstructure, and function can be tested with magnetic resonance imaging (MRI) techniques. Here, we aim to provide a comprehensive overview of Spaceflight studies exploring the potential role of brain alterations identified by MRI in astronauts. We conducted a search on PubMed, Web of Science, and Scopus to find neuroimaging correlates of spaceflight experience using MRI. A total of 20 studies (structural MRI n = 8, diffusion-based MRI n = 2, functional MRI n = 1, structural MRI and diffusion-weighted MRI n = 6, structural MRI and functional MRI n = 3) met our inclusion criteria. Overall, the studies showed that regardless of the MRI techniques, mission duration significantly impacts the human brain, prompting the inclusion of various brain regions as features in the analyses. After spaceflight, notable alterations were also observed in the superior occipital gyrus and the precentral gyrus which show alterations in connectivity and activation during spaceflight. The results provided highlight the alterations in brain structure after spaceflight, the unique patterns of brain remodeling, the challenges in drawing unified conclusions, and the impact of microgravity on intracranial cerebrospinal fluid volume.
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Affiliation(s)
- Sahar Rezaei
- Clinical Research Development Unit of Tabriz Valiasr Hospital, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Nuclear Medicine, Medical School, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Homa Seyedmirzaei
- Sports Medicine Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Esmaeil Gharepapagh
- Department of Nuclear Medicine, Medical School, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Fateme Mohagheghfard
- Department of para Medicine, Medical School, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Zahra Hasankhani
- Department of para Medicine, Medical School, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahsa Karbasi
- Department of radiology, Medical School, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sahar Delavari
- Institute for the Developing Mind, Children's Hospital Los Angeles, Keck School of Medicine at the University of Southern California, Los Angeles, CA, USA
| | - Mohammad Hadi Aarabi
- Padova Neuroscience Center (PNC), University of Padova, Padova, Italy.
- Department of Neuroscience, University of Padova, Padova, Italy.
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8
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Rudolf AM, Hood WR. Mitochondrial stress in the spaceflight environment. Mitochondrion 2024; 76:101855. [PMID: 38403094 DOI: 10.1016/j.mito.2024.101855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 02/12/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024]
Abstract
Space is a challenging environment that deregulates individual homeostasis. The main external hazards associated with spaceflight include ionizing space radiation, microgravity, isolation and confinement, distance from Earth, and hostile environment. Characterizing the biological responses to spaceflight environment is essential to validate the health risks, and to develop effective protection strategies. Mitochondria energetics is a key mechanism underpinning many physiological, ecological and evolutionary processes. Moreover, mitochondrial stress can be considered one of the fundamental features of space travel. So, we attempt to synthesize key information regarding the extensive effects of spaceflight on mitochondria. In summary, mitochondria are affected by all of the five main hazards of spaceflight at multiple levels, including their morphology, respiratory function, protein, and genetics, in various tissues and organ systems. We emphasize that investigating mitochondrial biology in spaceflight conditions should become the central focus of research on the impacts of spaceflight on human health, as this approach will help resolve numerous challenges of space health and combat several health disorders associated with mitochondrial dysfunction.
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Affiliation(s)
- Agata M Rudolf
- Department of Biological Sciences, Auburn University, Auburn, AL, USA; Space Technology Centre, AGH University of Science and Technology, Krakow, Poland.
| | - Wendy R Hood
- Department of Biological Sciences, Auburn University, Auburn, AL, USA
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9
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Munster DW, Lewandowski BE, Nelson ES, Prabhu RK, Myers JG. Modeling the impact of thoracic pressure on intracranial pressure. NPJ Microgravity 2024; 10:46. [PMID: 38600142 PMCID: PMC11006658 DOI: 10.1038/s41526-024-00385-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 03/13/2024] [Indexed: 04/12/2024] Open
Abstract
A potential contribution to the progression of Spaceflight Associated Neuro-ocular Syndrome is the thoracic-to-spinal dural sac transmural pressure relationship. In this study, we utilize a lumped-parameter computational model of human cerebrospinal fluid (CSF) systems to investigate mechanisms of CSF redistribution. We present two analyses to illustrate potential mechanisms for CSF pressure alterations similar to those observed in microgravity conditions. Our numerical evidence suggests that the compliant relationship between thoracic and CSF compartments is insufficient to solely explain the observed decrease in CSF pressure with respect to the supine position. Our analyses suggest that the interaction between thoracic pressure and the cardiovascular system, particularly the central veins, has greater influence on CSF pressure. These results indicate that future studies should focus on the holistic system, with the impact of cardiovascular changes to the CSF pressure emphasized over the sequestration of fluid in the spine.
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Affiliation(s)
- Drayton W Munster
- NASA Glenn Research Center, 21000 Brookpark Road, Cleveland, OH, 44135, USA.
| | - Beth E Lewandowski
- NASA Glenn Research Center, 21000 Brookpark Road, Cleveland, OH, 44135, USA
| | - Emily S Nelson
- NASA Glenn Research Center, 21000 Brookpark Road, Cleveland, OH, 44135, USA
| | - R K Prabhu
- Universities Space Research Association, 21000 Brookpark Road, Cleveland, OH, 44135, USA
| | - Jerry G Myers
- NASA Glenn Research Center, 21000 Brookpark Road, Cleveland, OH, 44135, USA
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van Oosterhout WPJ, Perenboom MJL, Terwindt GM, Ferrari MD, Vein AA. Frequency and Clinical Features of Space Headache Experienced by Astronauts During Long-Haul Space Flights. Neurology 2024; 102:e209224. [PMID: 38478846 PMCID: PMC11033988 DOI: 10.1212/wnl.0000000000209224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 12/23/2023] [Indexed: 04/24/2024] Open
Abstract
BACKGROUND AND OBJECTIVES Few anecdotal cases and 1 small retrospective study during short-duration space missions suggest that headache may occur early in flight, as part of the space motion syndrome. Whether headaches may also occur at later stages of space flights is unknown. We aimed to prospectively characterize the incidence, timing, clinical features, and management of space headaches during long-duration flights. METHODS We prospectively evaluated the occurrence, characteristics, and evolution of space headaches and the effects of treatment and countermeasures during long-haul flights with onboard questionnaires and correlated them with prevailing temperature, pressure, and ambient O2 and CO2 levels, measured within the International Space Station. In addition, we analyzed retrospective headache data from a different astronaut cohort. Headache data were reported using descriptive statistics and correlation data with intraindividual logistic regression models. Astronauts were included through (inter)national aerospace organizations. RESULTS In the prospective study, 22/24 (91.7%) astronauts (mean ± SD age: 46.6 ± 6.5 years, 95.8% male) experienced ≥1 episode of headache during a total of 3,596 space days. A total of 378 episodes were reported (median 9; range 1-128) with detailed information on 189. Phenotypically, 170/189 (89.9%) episodes were tension-type headache (TTH) and 19/189 (10.1%) were migraine. Episodes in the first week differed from those in later periods in terms of phenotype (migraine 12/51 [23.5%] vs 7/138 [5.1%]; TTH 39/51 [86.5%] vs 131/138 [94.9%]; overall p = 0.0002) and accompanying symptoms: nausea: 17.6% vs 6.9%, p = 0.05; vomiting: 9.8% vs 0.7%, p = 0.005; nasal congestion: 52.9% vs 29.7%, p = 0.004; facial edema: 41.2% vs 1.4%, p < 0.001; and duration (p = 0.001). Severity and treatments were similar: acute antiheadache medication: 55.6%; other medication: 22.4%; and alternative treatments: 41.1%. Headache occurrence was not associated with temperature or ambient pressure/levels of O2 and CO2 (all p > 0.05). In the retrospective study, 23/42 (54.8%) astronauts (43.5 ± 7.2 years, 90.5% male) reported experiencing ≥1 headache episode during mission. Nasal congestion was the most common (8/33; 24.2%) accompanying symptom. Seventeen of 42 astronauts have been previously described. DISCUSSION Astronauts during space flights frequently experience headaches. These most often have characteristics of TTHs but sometimes have migrainous features, particularly during the first week of flight in astronauts without a history of recurrent headaches before or after the space flight.
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Affiliation(s)
- Willebrordus P J van Oosterhout
- From the Department of Neurology (W.P.J.v.O., M.J.L.P., G.M.T., M.D.F., A.A.V.), Leiden University Medical Center; and Department of Neurology (W.P.J.v.O.), Zaans Medical Center, Zaandam, the Netherlands
| | - Matthijs J L Perenboom
- From the Department of Neurology (W.P.J.v.O., M.J.L.P., G.M.T., M.D.F., A.A.V.), Leiden University Medical Center; and Department of Neurology (W.P.J.v.O.), Zaans Medical Center, Zaandam, the Netherlands
| | - Gisela M Terwindt
- From the Department of Neurology (W.P.J.v.O., M.J.L.P., G.M.T., M.D.F., A.A.V.), Leiden University Medical Center; and Department of Neurology (W.P.J.v.O.), Zaans Medical Center, Zaandam, the Netherlands
| | - Michel D Ferrari
- From the Department of Neurology (W.P.J.v.O., M.J.L.P., G.M.T., M.D.F., A.A.V.), Leiden University Medical Center; and Department of Neurology (W.P.J.v.O.), Zaans Medical Center, Zaandam, the Netherlands
| | - Alla A Vein
- From the Department of Neurology (W.P.J.v.O., M.J.L.P., G.M.T., M.D.F., A.A.V.), Leiden University Medical Center; and Department of Neurology (W.P.J.v.O.), Zaans Medical Center, Zaandam, the Netherlands
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11
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Mehare A, Chakole S, Wandile B. Navigating the Unknown: A Comprehensive Review of Spaceflight-Associated Neuro-Ocular Syndrome. Cureus 2024; 16:e53380. [PMID: 38435236 PMCID: PMC10907968 DOI: 10.7759/cureus.53380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 01/31/2024] [Indexed: 03/05/2024] Open
Abstract
Spaceflight-associated neuro-ocular syndrome (SANS) is a complex and multifaceted condition that affects astronauts during and after their missions in space. This comprehensive review delves into the various aspects of SANS, providing a thorough understanding of its definition, historical context, clinical presentation, epidemiology, diagnostic techniques, preventive measures, and management strategies. Various ocular and neurological symptoms, including visual impairment, optic disc edema, choroidal folds, retinal changes, and increased intracranial pressure, characterize SANS. While microgravity is a primary driver of SANS, other factors like radiation exposure, genetic predisposition, and environmental conditions within spacecraft contribute to its development. The duration of space missions is a significant factor, with longer missions associated with a higher incidence of SANS. This review explores the diagnostic criteria and variability in SANS presentation, shedding light on early detection and management challenges. The epidemiology section provides insights into the occurrence frequency, affected astronauts' demographics, and differences between long-term and short-term missions. Diagnostic tools, including ophthalmological assessments and imaging techniques, are crucial in monitoring astronaut health during missions. Preventive measures are vital in mitigating the impact of SANS. Current strategies, ongoing research in prevention methods, lifestyle and behavioral factors, and the potential role of artificial gravity are discussed in detail. Additionally, the review delves into interventions, potential pharmacological treatments, rehabilitation, and long-term management considerations for astronauts with SANS. The conclusion underscores the importance of continued research in SANS, addressing ongoing challenges, and highlighting unanswered questions. With the expansion of human space exploration, understanding and managing SANS is imperative to ensure the health and well-being of astronauts during long-duration missions. This review is a valuable resource for researchers, healthcare professionals, and space agencies striving to enhance our knowledge and address the complexities of SANS.
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Affiliation(s)
- Abhidnya Mehare
- Obstetrics and Gynecology, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Swarupa Chakole
- Community Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Bhushan Wandile
- Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
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12
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Kermorgant M, Chedmail T, Varenne F, Bareille MP, Beck A, Billette de Villemeur R, Fournié P, Grondin L, Hélissen O, Membrives C, Nasr N, Pavy-Le Traon A, Soler V. Neuro-ophthalmological changes in healthy females exposed to a 5-day dry immersion: a pilot study. NPJ Microgravity 2024; 10:4. [PMID: 38212301 PMCID: PMC10784282 DOI: 10.1038/s41526-024-00344-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 01/01/2024] [Indexed: 01/13/2024] Open
Abstract
After exposure to microgravity, astronauts undergo microgravity-induced thoraco-cephalic fluid shift, which may lead to ocular changes called "spaceflight associated neuro-ocular syndrome" (SANS). The onset of SANS may be multifactorial, including a potential elevation in intracranial pressure. Moreover, little is known about the impact of spaceflight on SANS in women due to the fact that fewer female astronauts have spent time in long-term missions. The objective is to determine whether similar ophthalmological changes occur in healthy women after short-term exposure to microgravity. The auto-refractometer was used to determine objective refraction. The best corrected distance visual acuity was assessed with a Monoyer chart. The ocular axial length was assessed using optical biometry. The applanation tonometry was used to determine intraocular pressure. Peripapillary retinal nerve fibre layer thickness (pRNFLT), macular total retinal thickness, and ganglion cell complex (GCC) were measured using optical coherence tomography. Ocular axial length is reduced after DI. pRNFL is thickest after DI specifically in the temporal, temporal-inferior, and nasal-inferior quadrants. Macular total retinal at the inferior quadrant of the 6-mm ring is thickest after DI. Global GCC is thinnest after DI. In this study, 5 days of DI induces slight but significant ophthalmological changes in women. However, these subtle changes do not correspond to criteria defined in SANS.
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Affiliation(s)
- Marc Kermorgant
- UMR INSERM U1297, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
| | - Thibault Chedmail
- Department of Ophthalmology, University Hospital of Toulouse, Toulouse, France
| | - Fanny Varenne
- Department of Ophthalmology, University Hospital of Toulouse, Toulouse, France
| | | | - Arnaud Beck
- Institute for Space Medicine and Physiology (MEDES), Toulouse, France
| | | | - Pierre Fournié
- Department of Ophthalmology, University Hospital of Toulouse, Toulouse, France
| | - Lisa Grondin
- Department of Ophthalmology, University Hospital of Toulouse, Toulouse, France
| | - Ophélie Hélissen
- UMR INSERM U1297, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
| | | | - Nathalie Nasr
- UMR INSERM U1297, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
- Department of Neurology, University Hospital of Toulouse, Toulouse, France
| | - Anne Pavy-Le Traon
- UMR INSERM U1297, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France.
- Department of Neurology, University Hospital of Toulouse, Toulouse, France.
| | - Vincent Soler
- Department of Ophthalmology, University Hospital of Toulouse, Toulouse, France.
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Kelly E, Lindberg K, Jones-Isaac K, Yang J, Bain J, Wang L, MacDonald J, Bammler T, Calamia J, Thummel K, Yeung C, Countryman S, Koenig P, Himmelfarb J. Impact of microgravity on a three-dimensional microphysiologic culture of the human kidney proximal tubule epithelium: cell response to serum and vitamin D. RESEARCH SQUARE 2023:rs.3.rs-3778779. [PMID: 38196580 PMCID: PMC10775397 DOI: 10.21203/rs.3.rs-3778779/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
The microgravity environment aboard the International Space Station (ISS) provides a unique stressor that can help understand underlying cellular and molecular drivers of pathological changes observed in astronauts with the ultimate goals of developing strategies to enable long-term spaceflight and better treatment of diseases on Earth. We used this unique environment to evaluate the effects of microgravity on kidney proximal tubule epithelial cell (PTEC) response to serum exposure and vitamin D biotransformation capacity. To test if microgravity alters the pathologic response of the proximal tubule to serum exposure, we treated PTECs cultured in a microphysiological system (PT-MPS) with human serum and measured biomarkers of toxicity and inflammation (KIM-1 and IL-6) and conducted global transcriptomics via RNAseq on cells undergoing flight (microgravity) and respective controls (ground). We also treated 3D cultured PTECs with 25(OH)D3 (vitamin D) and monitored vitamin D metabolite formation, conducted global transcriptomics via RNAseq, and evaluated transcript expression of CYP27B1, CYP24A1, or CYP3A5 in PTECs undergoing flight (microgravity) and respective ground controls. We demonstrated that microgravity neither altered PTEC metabolism of vitamin D nor did it induce a unique response of PTECs to human serum, suggesting that these fundamental biochemical pathways in the kidney proximal tubule are not significantly altered by short-term exposure to microgravity. Given the prospect of extended spaceflight, more study is needed to determine if these responses are consistent with extended (> 6 month) exposure to microgravity.
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Kazmi S, Farajdokht F, Meynaghizadeh-Zargar R, Sadigh-Eteghad S, Pasokh A, Farzipour M, Farazi N, Hamblin MR, Mahmoudi J. Transcranial photobiomodulation mitigates learning and memory impairments induced by hindlimb unloading in a mouse model of microgravity exposure by suppression of oxidative stress and neuroinflammation signaling pathways. Brain Res 2023; 1821:148583. [PMID: 37717889 DOI: 10.1016/j.brainres.2023.148583] [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: 04/05/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/19/2023]
Abstract
Prolonged microgravity exposure causes cognitive impairment. Evidence shows that oxidative stress and neuroinflammation are involved in the causation. Here, we explore the effectiveness of transcranial near-infrared photobiomodulation (PBM) on cognitive deficits in a mouse model of simulated microgravity. 24 adult male C57BL/6 mice were assigned into three groups (8 in each); control, hindlimb unloading (HU), and HU + PBM groups. After surgery to fit the suspension fixing, the animals were housed either in HU cages or in their normal cage for 14 days. The mice in the HU + PBM group received PBM (810 nm laser, 10 Hz, 8 J/cm2) once per day for 14 days. Spatial learning and memory were assessed in the Lashley III maze and hippocampus tissue samples were collected to assess oxidative stress markers and protein expression of brain-derived neurotrophic factor (BDNF), nuclear factor erythroid 2-related factor 2 (Nrf2), Sirtuin 1 (Sirt1), and Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Behavioral testing showed that the PBM-treated animals had a shorter latency time to find the target and fewer errors than the HU group. PBM decreased hippocampal lipid peroxidation while increasing antioxidant defense systems (glutathione peroxidase, superoxide dismutase, and total antioxidant capacity) compared to HU mice. PBM increased protein expression of Sirt1, Nrf2, and BDNF while decreasing NF-κB compared to HU mice. Our findings suggested that the protective effect of PBM against HU-induced cognitive impairment involved the activation of the Sirt1/Nrf2 signaling pathway, up-regulation of BDNF, and reduction of neuroinflammation and oxidative stress in the hippocampus.
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Affiliation(s)
- Sareh Kazmi
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Fereshteh Farajdokht
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Physiology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Saeed Sadigh-Eteghad
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amir Pasokh
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Pharmaceutical Sciences, Division of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Mohammad Farzipour
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Narmin Farazi
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Michael R Hamblin
- Laser Research Centre, Faculty of Health Science, University of Johannesburg, Doornfontein 2028, South Africa; Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Javad Mahmoudi
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
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15
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Ax T, Ganse B, Fries FN, Szentmáry N, de Paiva CS, March de Ribot F, Jensen SO, Seitz B, Millar TJ. Dry eye disease in astronauts: a narrative review. Front Physiol 2023; 14:1281327. [PMID: 37929210 PMCID: PMC10620524 DOI: 10.3389/fphys.2023.1281327] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 10/03/2023] [Indexed: 11/07/2023] Open
Abstract
Long-duration spaceflight can have adverse effects on human health. One of the most common ocular conditions experienced by astronauts is dry eye disease (DED). Symptoms of DED include feelings of eye irritation, eye strain, foreign body sensation and blurred vision. Over 30% of International Space Station expedition crew members reported irritation and foreign body sensation. We reviewed the current literature on the prevalence and mechanisms of DED in astronauts and its potential implications for long-duration spaceflight, including the influence of environmental factors, such as microgravity and fluid shift on tear film physiology in space. DED has negative effects on astronaut performance, which is why there is a need for further research into the pathophysiology and countermeasures. As an in-flight countermeasure, neurostimulation seems to be among the most promising options.
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Affiliation(s)
- Timon Ax
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
- School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Bergita Ganse
- Werner Siemens-Endowed Chair for Innovative Implant Development (Fracture Healing), Departments and Institutes of Surgery, Saarland University, Homburg/Saar, Germany
- Department of Trauma, Hand and Reconstructive Surgery, Departments and Institutes of Surgery, Saarland University, Homburg/Saar, Germany
| | - Fabian N. Fries
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg/Saar, Germany
| | - Nóra Szentmáry
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg/Saar, Germany
| | - Cintia S. de Paiva
- Ocular Surface Center, Department of Ophthalmology, Baylor College of Medicine, Cullen Eye Institute, Houston, TX, United States
| | | | - Slade O. Jensen
- School of Medicine, Western Sydney University, Sydney, NSW, Australia
- Antimicrobial Resistance and Mobile Elements Group, Ingham Institute of Applied Medical Research, Sydney, NSW, Australia
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
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16
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Lanéelle D, Ogoh S, Trihan JE, Bailey DM, Normand H. Selective elevation in external carotid artery flow during acute gravitational transition to microgravity during parabolic flight. Am J Physiol Heart Circ Physiol 2023; 325:H665-H672. [PMID: 37565259 DOI: 10.1152/ajpheart.00341.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/19/2023] [Accepted: 08/03/2023] [Indexed: 08/12/2023]
Abstract
This study sought to determine to what extent acute exposure to microgravity (0 G) and related increases in central blood volume (CBV) during parabolic flight influence the regional redistribution of intra and extra cranial cerebral blood flow (CBF). Eleven healthy participants performed during two parabolic flights campaigns aboard the Airbus A310-ZERO G aircraft. The response of select variables for each of the 15 parabolas involving exposure to both 0 G and hypergravity (1.8 G) were assessed in the seated position. Mean arterial blood pressure (MAP) and heart rate (HR) were continuously monitored and used to calculate stroke volume (SV), cardiac output ([Formula: see text]), and systemic vascular resistance (SVR). Changes in CBV were measured using an impedance monitor. Extracranial flow through the internal carotid, external carotid, and vertebral artery ([Formula: see text]ICA, [Formula: see text]ECA, and [Formula: see text]VA), and intracranial blood velocity was measured by duplex ultrasound. When compared with 1-G baseline condition, 0 G increased CBV (+375 ± 98 mL, P = 0.004) and [Formula: see text] (+16 ± 14%, P = 0.024) and decreased SVR (-7.3 ± 5 mmHg·min·L-1, P = 0.002) and MAP (-13 ± 4 mmHg, P = 0.001). [Formula: see text]ECA increased by 43 ± 46% in 0 G (P = 0.030), whereas no change was observed for CBF, [Formula: see text]ICA, or [Formula: see text]VA (P = 0.102, P = 0.637, and P = 0.095, respectively).NEW & NOTEWORTHY Our findings demonstrate that in microgravity there is a selective increase in external carotid artery blood flow whereas global and regional cerebral blood flow remained preserved. To what extent this reflects an adaptive, neuroprotective response to counter overperfusion remains to be established.
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Affiliation(s)
- Damien Lanéelle
- INSERM UMRS-1075, COMETE, GIP Cyceron, University of Caen Normandy, Caen, France
- Department of Vascular Medicine, University Hospital of Caen Normandy, Caen, France
| | - Shigehiko Ogoh
- Department of Biomedical Engineering, Toyo University, Kawagoe, Japan
| | | | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Glamorgan, United Kingdom
| | - Hervé Normand
- INSERM UMRS-1075, COMETE, GIP Cyceron, University of Caen Normandy, Caen, France
- Department of Clinical Physiology, University Hospital of Caen Normandy, Caen, France
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Ong J, Waisberg E, Masalkhi M, Kamran SA, Lowry K, Sarker P, Zaman N, Paladugu P, Tavakkoli A, Lee AG. Artificial Intelligence Frameworks to Detect and Investigate the Pathophysiology of Spaceflight Associated Neuro-Ocular Syndrome (SANS). Brain Sci 2023; 13:1148. [PMID: 37626504 PMCID: PMC10452366 DOI: 10.3390/brainsci13081148] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/24/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023] Open
Abstract
Spaceflight associated neuro-ocular syndrome (SANS) is a unique phenomenon that has been observed in astronauts who have undergone long-duration spaceflight (LDSF). The syndrome is characterized by distinct imaging and clinical findings including optic disc edema, hyperopic refractive shift, posterior globe flattening, and choroidal folds. SANS serves a large barrier to planetary spaceflight such as a mission to Mars and has been noted by the National Aeronautics and Space Administration (NASA) as a high risk based on its likelihood to occur and its severity to human health and mission performance. While it is a large barrier to future spaceflight, the underlying etiology of SANS is not well understood. Current ophthalmic imaging onboard the International Space Station (ISS) has provided further insights into SANS. However, the spaceflight environment presents with unique challenges and limitations to further understand this microgravity-induced phenomenon. The advent of artificial intelligence (AI) has revolutionized the field of imaging in ophthalmology, particularly in detection and monitoring. In this manuscript, we describe the current hypothesized pathophysiology of SANS and the medical diagnostic limitations during spaceflight to further understand its pathogenesis. We then introduce and describe various AI frameworks that can be applied to ophthalmic imaging onboard the ISS to further understand SANS including supervised/unsupervised learning, generative adversarial networks, and transfer learning. We conclude by describing current research in this area to further understand SANS with the goal of enabling deeper insights into SANS and safer spaceflight for future missions.
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Affiliation(s)
- Joshua Ong
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI 48105, USA
| | | | - Mouayad Masalkhi
- University College Dublin School of Medicine, Belfield, Dublin 4, Ireland
| | - Sharif Amit Kamran
- Human-Machine Perception Laboratory, Department of Computer Science and Engineering, University of Nevada, Reno, NV 89512, USA
| | | | - Prithul Sarker
- Human-Machine Perception Laboratory, Department of Computer Science and Engineering, University of Nevada, Reno, NV 89512, USA
| | - Nasif Zaman
- Human-Machine Perception Laboratory, Department of Computer Science and Engineering, University of Nevada, Reno, NV 89512, USA
| | - Phani Paladugu
- Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Alireza Tavakkoli
- Human-Machine Perception Laboratory, Department of Computer Science and Engineering, University of Nevada, Reno, NV 89512, USA
| | - Andrew G. Lee
- Center for Space Medicine, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Ophthalmology, Blanton Eye Institute, Houston Methodist Hospital, Houston, TX 77030, USA
- The Houston Methodist Research Institute, Houston Methodist Hospital, Houston, TX 77030, USA
- Departments of Ophthalmology, Neurology, and Neurosurgery, Weill Cornell Medicine, New York, NY 10065, USA
- Department of Ophthalmology, University of Texas Medical Branch, Galveston, TX 77555, USA
- University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Texas A&M College of Medicine, Bryan, TX 77030, USA
- Department of Ophthalmology, The University of Iowa Hospitals and Clinics, Iowa City, IA 50010, USA
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Mu Y, Wei D, Yao L, Xu X, Li S, Cao R, Chen T, Zhang Z. Choroidal circulation disturbance is an initial factor in outer retinal degeneration in rats under simulated weightlessness. Front Physiol 2023; 14:1198862. [PMID: 37546536 PMCID: PMC10397408 DOI: 10.3389/fphys.2023.1198862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 07/07/2023] [Indexed: 08/08/2023] Open
Abstract
Objective: Microgravity contributes to ocular injury yet the underlying mechanism remains unclear. This study aims to elucidate the mechanism behind choroidal circulation disorder and outer retinal degeneration in rats with simulated weightlessness. Methods: Optical coherence tomography angiography (OCTA) was used to evaluate choroidal circulation and retinal morphological alterations in rats with weightlessness simulation. Electroretinogram and transmission electron microscopy were used to examine the ultrastructure and function of the choroid and outer retina. Furthermore, histological and terminal deoxynucleotidyl transferase deoxyuridine dUTP nick-end labeling (TUNEL) staining was used to monitor retinal morphology. Western blotting was performed to analyze the expressions of blood-retinal outer barrier function-related proteins (Cx43, ZO-1, and occludin). Results: The choroidal thickening was observed from the fourth week of simulated weightlessness (p < 0.05), and choroidal capillary density started to decline by the fifth week (p < 0.05). Transmission electron microscopy revealed that the choroidal vessels were open and operating well by the fourth week. However, most of the mitochondria within the vascular endothelium underwent mild swelling, and by the fifth week, the choroidal vessels had various degrees of erythrocyte aggregation, mitochondrial swelling, and apoptosis. Additionally, ERG demonstrated a decline in retinal function beginning in the fifth week (p < 0.05). TUNEL staining revealed a significantly higher apoptotic index in the outer nuclear layer of the retina (p < 0.05). At the sixth week weeks of simulated weightlessness, OCTA and hematoxylin and eosin (HE) staining of retinal sections revealed that the outer nuclear layer of the retina started to become thin (p < 0.05). Results from western blotting revealed that Cx43, ZO-1, and occludin exhibited decreased expression (p < 0.05). Conclusion: Based on our findings in a rat model of simulated weightlessness, choroidal circulation disturbance induced by choroidal congestion is the initial cause of outer retinal degeneration. Blood-retinal barrier disruption is significant in this process.
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Affiliation(s)
- Yuxue Mu
- Aerospace Clinical Medical Center, School of Aerospace Medicine, Air Force Medical University, Xi’an, China
- Department of Aviation Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Dongyu Wei
- Aerospace Clinical Medical Center, School of Aerospace Medicine, Air Force Medical University, Xi’an, China
| | - Lilingxuan Yao
- The Third Regiment, School of Basic Medicine, Air Force Medical University, Xi’an, China
| | - Xinyue Xu
- Aerospace Clinical Medical Center, School of Aerospace Medicine, Air Force Medical University, Xi’an, China
| | - Shaoheng Li
- Aerospace Clinical Medical Center, School of Aerospace Medicine, Air Force Medical University, Xi’an, China
| | - Ruidan Cao
- Aerospace Clinical Medical Center, School of Aerospace Medicine, Air Force Medical University, Xi’an, China
- Department of Aviation Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Tao Chen
- Aerospace Clinical Medical Center, School of Aerospace Medicine, Air Force Medical University, Xi’an, China
- Department of Aviation Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Zuoming Zhang
- Aerospace Clinical Medical Center, School of Aerospace Medicine, Air Force Medical University, Xi’an, China
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Jagtap S, Kumar A, Mahale B, Dixit J, Kalange AE, Kanawade R, Gangal S, Vidyasagar P. Response of cardiac pulse parameters in humans at various inclinations via 360° rotating platform for simulated microgravity perspective. NPJ Microgravity 2023; 9:54. [PMID: 37463938 DOI: 10.1038/s41526-023-00301-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 07/02/2023] [Indexed: 07/20/2023] Open
Abstract
On the Earth, the human body is designed and adapted to function under uniform gravitational acceleration. However, exposure to microgravity or weightlessness as experienced by astronauts in space causes significant alterations in the functioning of the human cardiovascular system. Due to limitations in using real microgravity platforms, researchers opted for various ground-based microgravity analogs including head-down tilt (HDT) at fixed inclination. However, in the present study, an investigation of response of various cardiac parameters and their circulatory adaptation in 18 healthy male subjects was undertaken by using an indigenously developed 360° rotating platform. Cardiac pulse was recorded from 0° to 360° in steps of 30° inclination using piezoelectric pulse sensor (MLT1010) and associated cardiac parameters were analyzed. The results showed significant changes in the pulse shape while an interesting oscillating pattern was observed in associated cardiac parameters when rotated from 0° to 360°. The response of cardiac parameters became normal after returning to supine posture indicating the ability of the cardiovascular system to reversibly adapt to the postural changes. The observed changes in cardiac parameters at an inclination of 270°, in particular, were found to be comparable with spaceflight studies. Based on the obtained results and the proposed extended version of fluid redistribution mechanism, we herewith hypothesize that the rotation of a subject to head down tilt inclination (270°) along with other inclinations could represent a better microgravity analog for understanding the cumulative cardiac response of astronauts in space, particularly for short duration space missions.
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Affiliation(s)
- Sagar Jagtap
- Department of Physics, Haribhai V. Desai College, Pune, MS, 411002, India.
| | - Ajay Kumar
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, MS, 411008, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| | - Bhoopesh Mahale
- Department of Electronics, Savitribai Phule Pune University, Pune, MS, 411007, India
| | - Jyotsana Dixit
- Department of Microbiology, Savitribai Phule Pune University, Pune, MS, 411007, India
| | - Ashok E Kalange
- Department of Physics, Tuljaram Chaturchand College, Baramati, Dist., Pune, 413102, MS, India
| | - Rajesh Kanawade
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, MS, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Shashikala Gangal
- Department of Electronics, Savitribai Phule Pune University, Pune, MS, 411007, India
| | - Pandit Vidyasagar
- Department of Physics, Savitribai Phule Pune University, Pune, MS, 411007, India.
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20
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Corydon TJ, Schulz H, Richter P, Strauch SM, Böhmer M, Ricciardi DA, Wehland M, Krüger M, Erzinger GS, Lebert M, Infanger M, Wise PM, Grimm D. Current Knowledge about the Impact of Microgravity on Gene Regulation. Cells 2023; 12:cells12071043. [PMID: 37048115 PMCID: PMC10093652 DOI: 10.3390/cells12071043] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 03/24/2023] [Accepted: 03/25/2023] [Indexed: 03/31/2023] Open
Abstract
Microgravity (µg) has a massive impact on the health of space explorers. Microgravity changes the proliferation, differentiation, and growth of cells. As crewed spaceflights into deep space are being planned along with the commercialization of space travelling, researchers have focused on gene regulation in cells and organisms exposed to real (r-) and simulated (s-) µg. In particular, cancer and metastasis research benefits from the findings obtained under µg conditions. Gene regulation is a key factor in a cell or an organism’s ability to sustain life and respond to environmental changes. It is a universal process to control the amount, location, and timing in which genes are expressed. In this review, we provide an overview of µg-induced changes in the numerous mechanisms involved in gene regulation, including regulatory proteins, microRNAs, and the chemical modification of DNA. In particular, we discuss the current knowledge about the impact of microgravity on gene regulation in different types of bacteria, protists, fungi, animals, humans, and cells with a focus on the brain, eye, endothelium, immune system, cartilage, muscle, bone, and various cancers as well as recent findings in plants. Importantly, the obtained data clearly imply that µg experiments can support translational medicine on Earth.
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Affiliation(s)
- Thomas J. Corydon
- Department of Biomedicine, Aarhus University, Hoegh Guldbergs Gade 10, 8000 Aarhus, Denmark
- Department of Ophthalmology, Aarhus University Hospital, Palle Juul-Jensens Blvd. 99, 8200 Aarhus, Denmark
- Correspondence: ; Tel.: +45-28-992-179
| | - Herbert Schulz
- Department of Microgravity and Translational Regenerative Medicine, Medical Faculty, University Hospital Magdeburg, Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
- Clinic for Plastic, Aesthetic and Hand Surgery, Medical Faculty, University Hospital Magdeburg, Otto von Guericke University, Leipziger Straße 44, 39120 Magdeburg, Germany
- Research Group ‘Magdeburger Arbeitsgemeinschaft für Forschung unter Raumfahrt-und Schwerelosigkeitsbedingungen’ (MARS), Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Peter Richter
- Gravitational Biology Group, Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Sebastian M. Strauch
- Postgraduate Program in Health and Environment, University of Joinville Region, Joinville 89219-710, SC, Brazil
| | - Maik Böhmer
- Institute for Molecular Biosciences, Johann Wolfgang Goethe Universität, 60438 Frankfurt am Main, Germany
| | - Dario A. Ricciardi
- Institute for Molecular Biosciences, Johann Wolfgang Goethe Universität, 60438 Frankfurt am Main, Germany
| | - Markus Wehland
- Department of Microgravity and Translational Regenerative Medicine, Medical Faculty, University Hospital Magdeburg, Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
- Clinic for Plastic, Aesthetic and Hand Surgery, Medical Faculty, University Hospital Magdeburg, Otto von Guericke University, Leipziger Straße 44, 39120 Magdeburg, Germany
- Research Group ‘Magdeburger Arbeitsgemeinschaft für Forschung unter Raumfahrt-und Schwerelosigkeitsbedingungen’ (MARS), Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Marcus Krüger
- Department of Microgravity and Translational Regenerative Medicine, Medical Faculty, University Hospital Magdeburg, Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
- Research Group ‘Magdeburger Arbeitsgemeinschaft für Forschung unter Raumfahrt-und Schwerelosigkeitsbedingungen’ (MARS), Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Gilmar S. Erzinger
- Postgraduate Program in Health and Environment, University of Joinville Region, Joinville 89219-710, SC, Brazil
| | - Michael Lebert
- Gravitational Biology Group, Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Manfred Infanger
- Department of Microgravity and Translational Regenerative Medicine, Medical Faculty, University Hospital Magdeburg, Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
- Clinic for Plastic, Aesthetic and Hand Surgery, Medical Faculty, University Hospital Magdeburg, Otto von Guericke University, Leipziger Straße 44, 39120 Magdeburg, Germany
- Research Group ‘Magdeburger Arbeitsgemeinschaft für Forschung unter Raumfahrt-und Schwerelosigkeitsbedingungen’ (MARS), Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Petra M. Wise
- Department of Microgravity and Translational Regenerative Medicine, Medical Faculty, University Hospital Magdeburg, Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
- Research Group ‘Magdeburger Arbeitsgemeinschaft für Forschung unter Raumfahrt-und Schwerelosigkeitsbedingungen’ (MARS), Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
- The Saban Research Institute, Children’s Hospital Los Angeles, University of Southern California, 4650 Sunset Blvd, Los Angeles, CA 90027, USA
| | - Daniela Grimm
- Department of Biomedicine, Aarhus University, Hoegh Guldbergs Gade 10, 8000 Aarhus, Denmark
- Department of Microgravity and Translational Regenerative Medicine, Medical Faculty, University Hospital Magdeburg, Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
- Clinic for Plastic, Aesthetic and Hand Surgery, Medical Faculty, University Hospital Magdeburg, Otto von Guericke University, Leipziger Straße 44, 39120 Magdeburg, Germany
- Research Group ‘Magdeburger Arbeitsgemeinschaft für Forschung unter Raumfahrt-und Schwerelosigkeitsbedingungen’ (MARS), Otto von Guericke University, Universitätsplatz 2, 39106 Magdeburg, Germany
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21
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Brent MB. Pharmaceutical treatment of bone loss: From animal models and drug development to future treatment strategies. Pharmacol Ther 2023; 244:108383. [PMID: 36933702 DOI: 10.1016/j.pharmthera.2023.108383] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/18/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023]
Abstract
Animal models are fundamental to advance our knowledge of the underlying pathophysiology of bone loss and to study pharmaceutical countermeasures against it. The animal model of post-menopausal osteoporosis from ovariectomy is the most widely used preclinical approach to study skeletal deterioration. However, several other animal models exist, each with unique characteristics such as bone loss from disuse, lactation, glucocorticoid excess, or exposure to hypobaric hypoxia. The present review aimed to provide a comprehensive overview of these animal models to emphasize the importance and significance of investigating bone loss and pharmaceutical countermeasures from perspectives other than post-menopausal osteoporosis only. Hence, the pathophysiology and underlying cellular mechanisms involved in the various types of bone loss are different, and this might influence which prevention and treatment strategies are the most effective. In addition, the review sought to map the current landscape of pharmaceutical countermeasures against osteoporosis with an emphasis on how drug development has changed from being driven by clinical observations and enhancement or repurposing of existing drugs to today's use of targeted anti-bodies that are the result of advanced insights into the underlying molecular mechanisms of bone formation and resorption. Moreover, new treatment combinations or repurposing opportunities of already approved drugs with a focus on dabigatran, parathyroid hormone and abaloparatide, growth hormone, inhibitors of the activin signaling pathway, acetazolamide, zoledronate, and romosozumab are discussed. Despite the considerable progress in drug development, there is still a clear need to improve treatment strategies and develop new pharmaceuticals against various types of osteoporosis. The review also highlights that new treatment indications should be explored using multiple animal models of bone loss in order to ensure a broad representation of different types of skeletal deterioration instead of mainly focusing on primary osteoporosis from post-menopausal estrogen deficiency.
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Affiliation(s)
- Mikkel Bo Brent
- Department of Biomedicine, Aarhus University, Denmark, Wilhelm Meyers Allé 3, 8000 Aarhus C, Denmark.
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22
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Freeborn TJ, Critcher S, Hooper G. Segmental Tissue Resistance of Healthy Young Adults during Four Hours of 6-Degree Head-Down-Tilt Positioning. SENSORS (BASEL, SWITZERLAND) 2023; 23:2793. [PMID: 36904995 PMCID: PMC10006931 DOI: 10.3390/s23052793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
(1) Background: One effect of microgravity on the human body is fluid redistribution due to the removal of the hydrostatic gravitational gradient. These fluid shifts are expected to be the source of severe medical risks and it is critical to advance methods to monitor them in real-time. One technique to monitor fluid shifts captures the electrical impedance of segmental tissues, but limited research is available to evaluate if fluid shifts in response to microgravity are symmetrical due to the bilateral symmetry of the body. This study aims to evaluate this fluid shift symmetry. (2) Methods: Segmental tissue resistance at 10 kHz and 100 kHz was collected at 30 min intervals from the left/right arm, leg, and trunk of 12 healthy adults over 4 h of 6° head-down-tilt body positioning. (3) Results: Statistically significant increases were observed in the segmental leg resistances, first observed at 120 min and 90 min for 10 kHz and 100 kHz measurements, respectively. Median increases were approximately 11% to 12% for the 10 kHz resistance and 9% for the 100 kHz resistance. No statistically significant changes in the segmental arm or trunk resistance. Comparing the left and right segmental leg resistance, there were no statistically significant differences in the resistance changes based on the side of the body. (4) Conclusions: The fluid shifts induced by the 6° body position resulted in similar changes in both left and right body segments (that had statistically significant changes in this work). These findings support that future wearable systems to monitor microgravity-induced fluid shifts may only require monitoring of one side of body segments (reducing the hardware needed for the system).
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Affiliation(s)
- Todd J. Freeborn
- Department of Electrical and Computer Engineering, College of Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Shelby Critcher
- Department of Electrical and Computer Engineering, College of Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Gwendolyn Hooper
- Capstone College of Nursing, The University of Alabama, Tuscaloosa, AL 35487, USA
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23
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Griffith JL, Cluff K, Downes GM, Eckerman B, Bhandari S, Loflin BE, Becker R, Alruwaili F, Mohammed N. Wearable Sensing System for NonInvasive Monitoring of Intracranial BioFluid Shifts in Aerospace Applications. SENSORS (BASEL, SWITZERLAND) 2023; 23:985. [PMID: 36679781 PMCID: PMC9860908 DOI: 10.3390/s23020985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/20/2022] [Accepted: 01/11/2023] [Indexed: 06/17/2023]
Abstract
The alteration of the hydrostatic pressure gradient in the human body has been associated with changes in human physiology, including abnormal blood flow, syncope, and visual impairment. The focus of this study was to evaluate changes in the resonant frequency of a wearable electromagnetic resonant skin patch sensor during simulated physiological changes observed in aerospace applications. Simulated microgravity was induced in eight healthy human participants (n = 8), and the implementation of lower body negative pressure (LBNP) countermeasures was induced in four healthy human participants (n = 4). The average shift in resonant frequency was -13.76 ± 6.49 MHz for simulated microgravity with a shift in intracranial pressure (ICP) of 9.53 ± 1.32 mmHg, and a shift of 8.80 ± 5.2097 MHz for LBNP with a shift in ICP of approximately -5.83 ± 2.76 mmHg. The constructed regression model to explain the variance in shifts in ICP using the shifts in resonant frequency (R2 = 0.97) resulted in a root mean square error of 1.24. This work demonstrates a strong correlation between sensor signal response and shifts in ICP. Furthermore, this study establishes a foundation for future work integrating wearable sensors with alert systems and countermeasure recommendations for pilots and astronauts.
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Affiliation(s)
- Jacob L. Griffith
- Department of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USA
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Kim Cluff
- Department of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USA
| | - Grant M. Downes
- Department of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USA
- Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66045, USA
| | - Brandon Eckerman
- Department of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USA
| | - Subash Bhandari
- Department of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USA
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14850, USA
| | - Benjamin E. Loflin
- Department of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USA
- Department of Orthopaedic Surgery, Indiana University, Indianapolis, IN 46202, USA
| | - Ryan Becker
- Department of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USA
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Fayez Alruwaili
- Department of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USA
- Department of Biomedical Engineering, Rowan University, Glassboro, NJ 08028, USA
| | - Noor Mohammed
- Department of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USA
- Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA
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24
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Computational modeling of orthostatic intolerance for travel to Mars. NPJ Microgravity 2022; 8:34. [PMID: 35945233 PMCID: PMC9363491 DOI: 10.1038/s41526-022-00219-2] [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: 01/17/2022] [Accepted: 07/15/2022] [Indexed: 11/12/2022] Open
Abstract
Astronauts in a microgravity environment will experience significant changes in their cardiopulmonary system. Up until now, there has always been the reassurance that they have real-time contact with experts on Earth. Mars crew however will have gaps in their communication of 20 min or more. In silico experiments are therefore needed to assess fitness to fly for those on future space flights to Mars. In this study, we present an open-source controlled lumped mathematical model of the cardiopulmonary system that is able simulate the short-term adaptations of key hemodynamic parameters to an active stand test after being exposed to microgravity. The presented model is capable of adequately simulating key cardiovascular hemodynamic changes—over a short time frame—during a stand test after prolonged spaceflight under different gravitational conditions and fluid loading conditions. This model can form the basis for further exploration of the ability of the human cardiovascular system to withstand long-duration space flight and life on Mars.
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25
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Arshad I, Ferrè ER. Express: Cognition in Zero Gravity: Effects of Non-Terrestrial Gravity on Human Behaviour. Q J Exp Psychol (Hove) 2022; 76:979-994. [PMID: 35786100 PMCID: PMC10119906 DOI: 10.1177/17470218221113935] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As humanity prepares for deep space exploration, understanding the impact of spaceflight on bodily physiology is critical. While the effects of non-terrestrial gravity on the body are well established, little is known about its impact on human behaviour and cognition. Astronauts often describe dramatic alterations in sensorimotor functioning, including orientation, postural control and balance. Changes in cognitive functioning as well as in socio-affective processing have also been observed. Here we have reviewed the key literature and explored the impact of non-terrestrial gravity across three key functional domains: sensorimotor, cognition, and socio-affective processing. We have proposed a neuroanatomical model to account for the effects of non-terrestrial gravity in these domains. Understanding the impact of non-terrestrial gravity on human behaviour has never been more timely and it will help mitigate against risks in both commercial and non-commercial spaceflight.
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Affiliation(s)
- Iqra Arshad
- Department of Psychology, Royal Holloway University of London, Egham, UK 3162
| | - Elisa Raffaella Ferrè
- Department of Psychological Sciences, Birkbeck University of London, London, UK 3162
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26
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Man J, Graham T, Squires-Donelly G, Laslett AL. The effects of microgravity on bone structure and function. NPJ Microgravity 2022; 8:9. [PMID: 35383182 PMCID: PMC8983659 DOI: 10.1038/s41526-022-00194-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 03/04/2022] [Indexed: 12/22/2022] Open
Abstract
Humans are spending an increasing amount of time in space, where exposure to conditions of microgravity causes 1–2% bone loss per month in astronauts. Through data collected from astronauts, as well as animal and cellular experiments conducted in space, it is evident that microgravity induces skeletal deconditioning in weight-bearing bones. This review identifies contentions in current literature describing the effect of microgravity on non-weight-bearing bones, different bone compartments, as well as the skeletal recovery process in human and animal spaceflight data. Experiments in space are not readily available, and experimental designs are often limited due to logistical and technical reasons. This review introduces a plethora of on-ground research that elucidate the intricate process of bone loss, utilising technology that simulates microgravity. Observations from these studies are largely congruent to data obtained from spaceflight experiments, while offering more insights behind the molecular mechanisms leading to microgravity-induced bone loss. These insights are discussed herein, as well as how that knowledge has contributed to studies of current therapeutic agents. This review also points out discrepancies in existing data, highlighting knowledge gaps in our current understanding. Further dissection of the exact mechanisms of microgravity-induced bone loss will enable the development of more effective preventative and therapeutic measures to protect against bone loss, both in space and possibly on ground.
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Affiliation(s)
- Joey Man
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Clayton, Victoria, 3168, Australia. .,Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, 3800, Australia. .,Space Technology Future Science Platform, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, Victoria, 3168, Australia.
| | - Taylor Graham
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Clayton, Victoria, 3168, Australia.,Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, 3800, Australia
| | - Georgina Squires-Donelly
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Clayton, Victoria, 3168, Australia.,Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, 3800, Australia
| | - Andrew L Laslett
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Clayton, Victoria, 3168, Australia. .,Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, 3800, Australia. .,Space Technology Future Science Platform, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, Victoria, 3168, Australia.
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27
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Feola AJ, Girkin CA, Ethier CR, Samuels BC. A Potential Role of Acute Choroidal Expansion in Nonarteritic Anterior Ischemic Optic Neuropathy. Invest Ophthalmol Vis Sci 2022; 63:23. [PMID: 35481840 PMCID: PMC9055550 DOI: 10.1167/iovs.63.4.23] [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] [Indexed: 11/24/2022] Open
Abstract
Purpose Nonarteritic anterior ischemic optic neuropathy (NAION) has been associated with a thickened choroid at the optic nerve head (ONH). Here, we use computational modeling to better understand how choroidal expansion and choroidal geometry influence tissue deformation within the ONH relative to intraocular pressure (IOP) and intracranial pressure (ICP) effects. Methods Using a model of the posterior eye that included the sclera, peripapillary sclera, annular ring, pia mater, dura mater, neural tissues, Bruch's membrane, choroid, and lamina cribrosa, we examined how varying material properties of ocular tissues influenced ONH deformations under physiological and supra-physiological, or “pathological,” conditions. We considered choroidal expansion (c. 35 µL of expansion), elevated IOP (30 mm Hg), and elevated ICP (20 mm Hg), and calculated peak strains in the ONH relative to a baseline condition representing an individual in the upright position. Results Supra-physiological choroidal expansion had the largest impact on strains in the prelaminar neural tissue. In addition, compared to a tapered choroid, a “blunt” choroid insertion at the ONH resulted in higher strains. Elevated IOP and ICP caused the highest strains within the lamina cribrosa and retrolaminar neural tissue, respectively. Conclusions Acute choroidal expansion caused large deformations of the ONH and these deformations were impacted by choroid geometry. These results are consistent with the concept that compartment syndrome due to the choroid geometry and/or expansion at the ONH contributes to NAION. Prolonged deformations due to supra-physiological loading may induce a mechanobiological response or ischemia, highlighting the potential impact of choroidal expansion on biomechanical strains in the ONH.
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Affiliation(s)
- Andrew J Feola
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Atlanta, Georgia, United States.,Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, GA, United States
| | - Christopher A Girkin
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - C Ross Ethier
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, GA, United States
| | - Brian C Samuels
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama, United States
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28
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Wostyn P, Gibson CR, Mader TH. The odyssey of the ocular and cerebrospinal fluids during a mission to Mars: the "ocular glymphatic system" under pressure. Eye (Lond) 2022; 36:686-691. [PMID: 34373611 PMCID: PMC8956714 DOI: 10.1038/s41433-021-01721-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 07/10/2021] [Accepted: 07/26/2021] [Indexed: 02/07/2023] Open
Abstract
A significant proportion of the astronauts who spend extended periods in microgravity develop ophthalmic abnormalities including optic disc edema, globe flattening, chorioretinal folds, and hyperopic refractive error shifts. A constellation of these neuro-ophthalmic findings has been termed "spaceflight-associated neuro-ocular syndrome". Understanding this syndrome is currently a top priority for NASA, especially in view of future long-duration missions (e.g., Mars missions). The recent discovery of an "ocular glymphatic system" can potentially help to unlock mechanisms underlying microgravity-induced optic disc edema. Indeed, a major paradigm shift is currently occurring in our understanding of transport of fluids and solutes through the optic nerve following the recent discovery of an optic nerve glymphatic pathway for influx of cerebrospinal fluid. In addition, the recent identification of an entirely new glymphatic pathway for efflux of ocular fluid may have profound implications for fluid dynamics in the eye. Observations pertaining to this ocular glymphatic pathway provide critical new insights into how intracranial pressure can alter basic fluid transport in the eye. We believe that these novel findings have the potential to be game changers in our understanding of the pathogenesis of optic disc edema in astronauts. In the present review, we integrate these new insights with findings on the intracranial and neuro-ophthalmologic effects of microgravity in one coherent conceptual framework. Further studies in this area of investigation could not only provide exciting new insights into the mechanisms underlying microgravity-induced optic disc edema but also offer opportunities to develop countermeasure strategies.
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Affiliation(s)
- Peter Wostyn
- Department of Psychiatry, PC Sint-Amandus, Beernem, Belgium
| | - Charles Robert Gibson
- Coastal Eye Associates, Webster, TX USA ,grid.481680.30000 0004 0634 8729KBR, NASA Space Medicine Operations Division, Houston, TX USA
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29
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Mhatre SD, Iyer J, Puukila S, Paul AM, Tahimic CGT, Rubinstein L, Lowe M, Alwood JS, Sowa MB, Bhattacharya S, Globus RK, Ronca AE. Neuro-consequences of the spaceflight environment. Neurosci Biobehav Rev 2021; 132:908-935. [PMID: 34767877 DOI: 10.1016/j.neubiorev.2021.09.055] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 08/03/2021] [Accepted: 09/28/2021] [Indexed: 12/17/2022]
Abstract
As human space exploration advances to establish a permanent presence beyond the Low Earth Orbit (LEO) with NASA's Artemis mission, researchers are striving to understand and address the health challenges of living and working in the spaceflight environment. Exposure to ionizing radiation, microgravity, isolation and other spaceflight hazards pose significant risks to astronauts. Determining neurobiological and neurobehavioral responses, understanding physiological responses under Central Nervous System (CNS) control, and identifying putative mechanisms to inform countermeasure development are critically important to ensuring brain and behavioral health of crew on long duration missions. Here we provide a detailed and comprehensive review of the effects of spaceflight and of ground-based spaceflight analogs, including simulated weightlessness, social isolation, and ionizing radiation on humans and animals. Further, we discuss dietary and non-dietary countermeasures including artificial gravity and antioxidants, among others. Significant future work is needed to ensure that neural, sensorimotor, cognitive and other physiological functions are maintained during extended deep space missions to avoid potentially catastrophic health and safety outcomes.
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Affiliation(s)
- Siddhita D Mhatre
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; KBR, Houston, TX, 77002, USA; COSMIAC Research Center, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Janani Iyer
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Universities Space Research Association, Columbia, MD, 21046, USA
| | - Stephanie Puukila
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Universities Space Research Association, Columbia, MD, 21046, USA; Flinders University, Adelaide, Australia
| | - Amber M Paul
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Universities Space Research Association, Columbia, MD, 21046, USA
| | - Candice G T Tahimic
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; KBR, Houston, TX, 77002, USA; Department of Biology, University of North Florida, Jacksonville, FL, 32224, USA
| | - Linda Rubinstein
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Universities Space Research Association, Columbia, MD, 21046, USA
| | - Moniece Lowe
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Blue Marble Space Institute of Science, Seattle, WA, 98154, USA
| | - Joshua S Alwood
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Marianne B Sowa
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Sharmila Bhattacharya
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Ruth K Globus
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - April E Ronca
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Wake Forest Medical School, Winston-Salem, NC, 27101, USA.
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30
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The effects of real and simulated microgravity on cellular mitochondrial function. NPJ Microgravity 2021; 7:44. [PMID: 34750383 PMCID: PMC8575887 DOI: 10.1038/s41526-021-00171-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 10/07/2021] [Indexed: 11/22/2022] Open
Abstract
Astronauts returning from space shuttle missions or the International Space Station have been diagnosed with various health problems such as bone demineralization, muscle atrophy, cardiovascular deconditioning, and vestibular and sensory imbalance including visual acuity, altered metabolic and nutritional status, and immune system dysregulation. These health issues are associated with oxidative stress caused by a microgravity environment. Mitochondria are a source of reactive oxygen species (ROS). However, the molecular mechanisms through which mitochondria produce ROS in a microgravity environment remain unclear. Therefore, this review aimed to explore the mechanism through which microgravity induces oxidative damage in mitochondria by evaluating the expression of genes and proteins, as well as relevant metabolic pathways. In general, microgravity-induced ROS reduce mitochondrial volume by mainly affecting the efficiency of the respiratory chain and metabolic pathways. The impaired respiratory chain is thought to generate ROS through premature electron leakage in the electron transport chain. The imbalance between ROS production and antioxidant defense in mitochondria is the main cause of mitochondrial stress and damage, which leads to mitochondrial dysfunction. Moreover, we discuss the effects of antioxidants against oxidative stress caused by the microgravity environment space microgravity in together with simulated microgravity (i.e., spaceflight or ground-based spaceflight analogs: parabolic flight, centrifugal force, drop towers, etc.). Further studies should be taken to explore the effects of microgravity on mitochondrial stress-related diseases, especially for the development of new therapeutic drugs that can help increase the health of astronauts on long space missions.
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31
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Mlinar T, Jaki Mekjavic P, Royal JT, Valencic T, Mekjavic IB. Intraocular pressure during handgrip exercise: The effect of posture and hypercapnia in young males. Physiol Rep 2021; 9:e15035. [PMID: 34665531 PMCID: PMC8525324 DOI: 10.14814/phy2.15035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 08/10/2021] [Accepted: 08/22/2021] [Indexed: 11/25/2022] Open
Abstract
PURPOSE As part of our investigations of intraocular pressure (IOP) as a potential contributing factor to the spaceflight-associated neuro-ocular syndrome using the 6° head-down tilt (6°HDT) bed rest experimental model, we compared the effect of rest and isometric exercise in prone and supine 6°HDT positions on IOP with that observed in the seated position. METHODS Ten male volunteers (age = 22.5 ± 3.1 yrs) participated in six interventions. All trials comprised a 10-min rest period, a 3-min isometric handgrip exercise at 30% of participant's maximum, and a 10-min recovery period. The trials were conducted under normocapnic (NCAP) or hypercapnic (FI CO2 = 0.01; HCAP) conditions, the latter mimicking the ambient conditions on the International Space Station. IOP, systolic and diastolic pressures, and heart rate (HR) were measured during the trials. RESULTS Isometric exercise-induced elevations in HR and mean arterial blood pressure. IOP in the prone 6°HDT position was significantly higher (p < 0.001) compared to IOP in supine 6°HDT position and seated trials at all time points. IOP increased with exercise only in a seated HCAP trial (p = 0.042). No difference was observed between trials in NCAP and HCAP. IOP in the prone 6°HDT position was constantly elevated above 21 mmHg, the lower limit for clinical ocular hypertension. CONCLUSIONS IOP in the prone 6°HDT position was similar to IOP reported in astronauts upon entering microgravity, potentially indicating that prone, rather than supine 6°HDT position might be a more suitable experimental analog for investigating the acute ocular changes that occur in microgravity.
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Affiliation(s)
- Tinkara Mlinar
- Department of Automation, Biocybernetics and RoboticsJozef Stefan InstituteLjubljanaSlovenia
- Jozef Stefan International Postgraduate SchoolLjubljanaSlovenia
| | - Polona Jaki Mekjavic
- Department of Automation, Biocybernetics and RoboticsJozef Stefan InstituteLjubljanaSlovenia
- Eye HospitalUniversity Medical CentreLjubljanaSlovenia
- Faculty of MedicineUniversity of LjubljanaLjubljanaSlovenia
| | - Joshua T. Royal
- Department of Automation, Biocybernetics and RoboticsJozef Stefan InstituteLjubljanaSlovenia
- Jozef Stefan International Postgraduate SchoolLjubljanaSlovenia
| | - Tamara Valencic
- Department of Automation, Biocybernetics and RoboticsJozef Stefan InstituteLjubljanaSlovenia
| | - Igor B. Mekjavic
- Department of Automation, Biocybernetics and RoboticsJozef Stefan InstituteLjubljanaSlovenia
- Department of Biomedical Physiology and KinesiologySimon Fraser UniversityBurnabyBritish ColumbiaCanada
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32
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Chen W, Chen ZQ, Xiang Y, Deng CH, Zhang H, Wang JM. Analogs of microgravity: the function of Schlemm's canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjects. Int J Ophthalmol 2021; 14:1419-1423. [PMID: 34540620 DOI: 10.18240/ijo.2021.09.19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 12/02/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the ocular outcomes and to elucidate possible mechanisms underlying intraocular pressure (IOP) change following the head-down tilt (HDT) test. METHODS The study included 21 participants at the Department of Ophthalmology of Tongji Hospital. Subjects received the test of I-care tonometry, enhanced depth imaging optical coherence tomography and heart rate variability (HRV) analysis before and after 15min HDT test. The lumen area of Schlemm's canal (SCAR), IOP, HRV were calculated. RESULTS IOP increased significantly after 20° head down position from 14.0±3.0 to 17.0±3.3 mm Hg (P<0.001). SCAR decreased from 13449.0±5454.9 µm2 at sitting condition to 9576.6±4130.9 µm2 post 15min HDT test. High frequency (HF) indices increased significantly from 1462±865 Hz at baseline to 2128±824 Hz. Heart rate (HR) decreased significantly from 76±11.48 to 70±11.52 bpm after the HDT. The linear regression analysis showed that the difference of HF and SCAR significantly correlated with each other during the HDT (R2 =20%, P=0.04). CONCLUSION These outcomes perform the first evidence of the activation of autonomic nervous system of HDT may cause the collapse of Schlemm's canal lumen, which in turn leading to the increased IOP.
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Affiliation(s)
- Wei Chen
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Zhi-Qi Chen
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Yan Xiang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Chao-Hua Deng
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Hong Zhang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Jun-Ming Wang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
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33
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Verma A, Bacci T, Sarraf D, Freund KB, Sadda SR. Vortex Vein Imaging: What Can It Tell Us? Clin Ophthalmol 2021; 15:3321-3331. [PMID: 34408390 PMCID: PMC8364369 DOI: 10.2147/opth.s324245] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 07/23/2021] [Indexed: 11/23/2022] Open
Abstract
This review article summarizes the patho-anatomy of the vortex veins, the major drainage channels for the choroid, and describes the various pathways of diseases associated with vortex vein abnormalities. This report also details the technical advancements to image the vortex veins, such as ultra-widefield indocyanine green angiography, which are critical to elucidate the importance of the vortices in various retino-choroidal disorders. Future applications of these advanced imaging systems to better understand the role of the vortex veins in health and disease are also discussed.
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Affiliation(s)
- Aditya Verma
- Doheny Eye Institute, Los Angeles, CA, USA.,Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Tommaso Bacci
- Vitreous Retina Macula Consultants of New York, New York, NY, USA.,Department of Ophthalmology, New York University Grossman School of Medicine, New York, NY, USA
| | - David Sarraf
- Stein Eye Institute, David Geffen School of Medicine at University of California, Los Angeles, CA, 90095, USA
| | - K Bailey Freund
- Vitreous Retina Macula Consultants of New York, New York, NY, USA.,Department of Ophthalmology, New York University Grossman School of Medicine, New York, NY, USA
| | - SriniVas R Sadda
- Doheny Eye Institute, Los Angeles, CA, USA.,Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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34
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Kermorgant M, Sadegh A, Geeraerts T, Varenne F, Liberto J, Roubelat FP, Bataille N, Bareille MP, Beck A, Godard B, Golemis A, Nasr N, Arvanitis DN, Hélissen O, Senard JM, Pavy-Le Traon A, Soler V. Effects of Venoconstrictive Thigh Cuffs on Dry Immersion-Induced Ophthalmological Changes. Front Physiol 2021; 12:692361. [PMID: 34335300 PMCID: PMC8317025 DOI: 10.3389/fphys.2021.692361] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/10/2021] [Indexed: 11/13/2022] Open
Abstract
Neuro-ophthalmological changes named spaceflight associated neuro-ocular syndrome (SANS) reported after spaceflights are important medical issues. Dry immersion (DI), an analog to microgravity, rapidly induces a centralization of body fluids, immobilization, and hypokinesia similar to that observed during spaceflight. The main objectives of the present study were 2-fold: (1) to assess the neuro-ophthalmological impact during 5 days of DI and (2) to determine the effects of venoconstrictive thigh cuffs (VTC), used as a countermeasure to limit headward fluid shift, on DI-induced ophthalmological adaptations. Eighteen healthy male subjects underwent 5 days of DI with or without VTC countermeasures. The subjects were randomly assigned into two groups of 9: a control and cuffs group. Retinal and optic nerve thickness were assessed with spectral-domain optical coherence tomography (OCT). Optic nerve sheath diameter (ONSD) was measured by ocular ultrasonography and used to assess indirect changes in intracranial pressure (ICP). Intraocular pressure (IOP) was assessed by applanation tonometry. A higher thickness of the retinal nerve fiber layer (RNFL) in the temporal quadrant was observed after DI. ONSD increased significantly during DI and remained higher during the recovery phase. IOP did not significantly change during and after DI. VTC tended to limit the ONSD enlargement but not the higher thickness of an RNFL induced by DI. These findings suggest that 5 days of DI induced significant ophthalmological changes. VTC were found to dampen the ONSD enlargement induced by DI.
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Affiliation(s)
- Marc Kermorgant
- INSERM DR Midi-Pyrénées Limousin, Institute of Cardiovascular and Metabolic Diseases (I2MC) UMR1297, University Hospital of Toulouse, Toulouse, France
| | - Ayria Sadegh
- Department of Ophthalmology, University Hospital of Toulouse, Toulouse, France
| | - Thomas Geeraerts
- Department of Anaesthesiology and Critical Care, University Hospital of Toulouse, Toulouse, France
| | - Fanny Varenne
- Department of Ophthalmology, University Hospital of Toulouse, Toulouse, France
| | - Jérémy Liberto
- Department of Ophthalmology, University Hospital of Toulouse, Toulouse, France
| | | | - Noémie Bataille
- Department of Ophthalmology, University Hospital of Toulouse, Toulouse, France
| | | | - Arnaud Beck
- Institute for Space Medicine and Physiology (MEDES), Toulouse, France
| | - Brigitte Godard
- Institute for Space Medicine and Physiology (MEDES), Toulouse, France
| | - Adrianos Golemis
- Institute for Space Medicine and Physiology (MEDES), Toulouse, France
| | - Nathalie Nasr
- INSERM DR Midi-Pyrénées Limousin, Institute of Cardiovascular and Metabolic Diseases (I2MC) UMR1297, University Hospital of Toulouse, Toulouse, France.,Department of Neurology, University Hospital of Toulouse, Toulouse, France
| | - Dina N Arvanitis
- INSERM DR Midi-Pyrénées Limousin, Institute of Cardiovascular and Metabolic Diseases (I2MC) UMR1297, University Hospital of Toulouse, Toulouse, France
| | - Ophélie Hélissen
- INSERM DR Midi-Pyrénées Limousin, Institute of Cardiovascular and Metabolic Diseases (I2MC) UMR1297, University Hospital of Toulouse, Toulouse, France
| | - Jean-Michel Senard
- INSERM DR Midi-Pyrénées Limousin, Institute of Cardiovascular and Metabolic Diseases (I2MC) UMR1297, University Hospital of Toulouse, Toulouse, France.,Department of Clinical Pharmacology, University Hospital of Toulouse, Toulouse, France
| | - Anne Pavy-Le Traon
- INSERM DR Midi-Pyrénées Limousin, Institute of Cardiovascular and Metabolic Diseases (I2MC) UMR1297, University Hospital of Toulouse, Toulouse, France.,Department of Neurology, University Hospital of Toulouse, Toulouse, France
| | - Vincent Soler
- Department of Ophthalmology, University Hospital of Toulouse, Toulouse, France
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Spaide RF, Gemmy Cheung CM, Matsumoto H, Kishi S, Boon CJF, van Dijk EHC, Mauget-Faysse M, Behar-Cohen F, Hartnett ME, Sivaprasad S, Iida T, Brown DM, Chhablani J, Maloca PM. Venous overload choroidopathy: A hypothetical framework for central serous chorioretinopathy and allied disorders. Prog Retin Eye Res 2021; 86:100973. [PMID: 34029721 DOI: 10.1016/j.preteyeres.2021.100973] [Citation(s) in RCA: 122] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/11/2021] [Accepted: 05/15/2021] [Indexed: 12/19/2022]
Abstract
In central serous chorioretinopathy (CSC), the macula is detached because of fluid leakage at the level of the retinal pigment epithelium. The fluid appears to originate from choroidal vascular hyperpermeability, but the etiology for the fluid is controversial. The choroidal vascular findings as elucidated by recent optical coherence tomography (OCT) and wide-field indocyanine green (ICG) angiographic evaluation show eyes with CSC have many of the same venous patterns that are found in eyes following occlusion of the vortex veins or carotid cavernous sinus fistulas (CCSF). The eyes show delayed choroidal filling, dilated veins, intervortex venous anastomoses, and choroidal vascular hyperpermeability. While patients with occlusion of the vortex veins or CCSF have extraocular abnormalities accounting for the venous outflow problems, eyes with CSC appear to have venous outflow abnormalities as an intrinsic phenomenon. Control of venous outflow from the eye involves a Starling resistor effect, which appears to be abnormal in CSC. Similar choroidal vascular abnormalities have been found in peripapillary pachychoroid syndrome. However, peripapillary pachychoroid syndrome has intervortex venous anastomoses located in the peripapillary region while in CSC these are seen to be located in the macular region. Spaceflight associated neuro-ocular syndrome appears to share many of the pathophysiologic problems of abnormal venous outflow from the choroid along with a host of associated abnormalities. These diseases vary according to their underlying etiologies but are linked by the venous decompensation in the choroid that leads to significant vision loss. Choroidal venous overload provides a unifying concept and theory for an improved understanding of the pathophysiology and classification of a group of diseases to a greater extent than previous proposals.
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Affiliation(s)
- Richard F Spaide
- Vitreous, Retina, Macula Consultants of New York, New York, NY, USA.
| | | | - Hidetaka Matsumoto
- Department of Ophthalmology, Gunma University Graduate School of Medicine, Japan.
| | | | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands.
| | - Elon H C van Dijk
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands.
| | | | | | | | | | | | | | - Jay Chhablani
- University of Pittsburgh, UPMC Eye Center, Pittsburgh, PA, USA.
| | - Peter M Maloca
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.
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36
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Takács E, Barkaszi I, Czigler I, Pató LG, Altbäcker A, McIntyre J, Cheron G, Balázs L. Persistent deterioration of visuospatial performance in spaceflight. Sci Rep 2021; 11:9590. [PMID: 33953237 PMCID: PMC8100295 DOI: 10.1038/s41598-021-88938-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/19/2021] [Indexed: 12/01/2022] Open
Abstract
Although human adaptation to spaceflight has been studied for decades, little is known about its long-term effects on brain and behavior. The present study investigated visuospatial performance and associated electrophysiological responses in astronauts before, during, and after an approximately half-year long mission to the International Space Station. Here we report findings demonstrating that cognitive performance can suffer marked decrements during spaceflight. Astronauts were slower and more error-prone on orbit than on Earth, while event-related brain potentials reflected diminished attentional resources. Our study is the first to provide evidence for impaired performance during both the initial (~ 8 days) and later (~ 50 days) stages of spaceflight, without any signs of adaptation. Results indicate restricted adaptability to spaceflight conditions and calls for new research prior to deep space explorations.
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Affiliation(s)
- Endre Takács
- Institute of Cognitive Neuroscience and Psychology, ELKH Research Centre for Natural Sciences, Budapest, 1117, Hungary.,Institute of Psychology, Eötvös Loránd University, Budapest, 1075, Hungary.,Doctoral School of Psychology, Eötvös Loránd University, Budapest, 1075, Hungary
| | - Irén Barkaszi
- Institute of Cognitive Neuroscience and Psychology, ELKH Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - István Czigler
- Institute of Cognitive Neuroscience and Psychology, ELKH Research Centre for Natural Sciences, Budapest, 1117, Hungary.,Institute of Psychology, Eötvös Loránd University, Budapest, 1075, Hungary
| | - Lívia Gabriella Pató
- Institute of Cognitive Neuroscience and Psychology, ELKH Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - Anna Altbäcker
- Institute of Cognitive Neuroscience and Psychology, ELKH Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - Joseph McIntyre
- Centre de Neurophysique, Physiology, Et Pathology, Centre National de La Recherche Scientifique, Université Paris Descartes, 75270, Paris Cedex 06, France.,Health Division, Tecnalia Research and Innovation, 20009, Donostia-San Sebastian, Spain.,Ikerbasque Science Foundation, 48009, Bilbao, Spain
| | - Guy Cheron
- Laboratory of Neurophysiology Movement Biomechanics, ULB Neuroscience Institute, Université Libre de Bruxelles, 1070, Anderlecht, Belgium.,Laboratory of Electrophysiology, Université de Mons, 7000, Mons, Belgium
| | - László Balázs
- Institute of Cognitive Neuroscience and Psychology, ELKH Research Centre for Natural Sciences, Budapest, 1117, Hungary.
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37
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Malyugin BE, Koloteva MI, Pozdeyeva NA, Morozova TA, Sychova DV, Pikusova SM, Mashkov DA. [Effects of artificial gravity on perimetry results]. Vestn Oftalmol 2021; 137:26-33. [PMID: 33881260 DOI: 10.17116/oftalma202113702126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The active exploration of space requires minimizing negative effects induced by weightlessness (microgravity). Risk reduction can be achieved with the use of artificial gravity created by short-radius centrifuge (SRC). Short-radius centrifuge causes redistribution of body liquids towards the caudal portion of the body imitating a vertical human pose. Presently, studying the safety of this prevention method for the human body in general, and for the visual system in particular, is one of the priority tasks of space medicine. PURPOSE To study the effects of artificial gravity on the perimetry measurements of the eye. MATERIAL AND METHODS The study included 9 volunteers (men) aged 31.2±6 years (from 25 to 40 years). Each man was subjected to three rotations on SRC. The operative factor in the tests was overloads in the «head-pelvis» direction. Rotations were carried out in three different modes with varying maximum overload value at the feet level of up to 2.0; 2.4; 2.9 G. Pulsar-perimetry was carried out before and 1-2 hours after the rotations estimating the mean threshold of retinal photosensitivity Mean Sensitivity (MS), mean loss of sensitivity Mean Defect (MD), square root of Loss Variance (sLV); the Bebie curve; additionally, cluster analysis was performed. RESULTS Mean threshold of retinal photosensitivity, mean loss of photosensitivity, square root of Loss Variance by Pulsar-perimetry before (MS=22.75 dB; MD= -0.6 dB; sLV=1.5) and after rotations on SRC (in Mode 1: 23.4; -0.2; 1.5, Mode 2: 23.2; -0.4; 1.4 and Mode 3: 23.5; -0.8; 1.4 respectively) did not change significantly. No adverse phenomena were detected in the eyes. CONCLUSIONS There were no significant changes in the visual fields of the test subjects after rotations in three different modes according to Pulsar-perimetry data, which gives reason to tentatively conclude that using SCR in these modes is safe for the visual sensory system. According to preliminary data, this method can be successfully used to reduce the risk of long-term space flights and prevent unwanted phenomena caused by weightlessness.
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Affiliation(s)
- B E Malyugin
- S.N. Fedorov National Medical Research Center «MNTK «Eye Microsurgery», Moscow, Russia
| | - M I Koloteva
- Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - N A Pozdeyeva
- Cheboksary branch of the S.N. Fedorov National Medical Research Center «MNTK «Eye Microsurgery», Cheboksary, Russia.,Postgraduate Doctors' Training Institute, Cheboksary, Russia
| | - T A Morozova
- Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - D V Sychova
- Postgraduate Doctors' Training Institute, Cheboksary, Russia
| | - S M Pikusova
- Postgraduate Doctors' Training Institute, Cheboksary, Russia
| | - D A Mashkov
- Medical technical association «Stormoff» LLC, Krasnogorsk, Russia
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38
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Marshall-Goebel K, Macias BR, Laurie SS, Lee SMC, Ebert DJ, Kemp DT, Miller A, Greenwald SH, Martin DS, Young M, Hargens AR, Levine BD, Stenger MB. Mechanical countermeasures to headward fluid shifts. J Appl Physiol (1985) 2021; 130:1766-1777. [PMID: 33856253 DOI: 10.1152/japplphysiol.00863.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Head-to-foot gravitationally induced hydrostatic pressure gradients in the upright posture on Earth are absent in weightlessness. This results in a relative headward fluid shift in the vascular and cerebrospinal fluid compartments and may underlie multiple physiological consequences of spaceflight, including the spaceflight-associated neuro-ocular syndrome. Here, we tested three mechanical countermeasures [lower body negative pressure (LBNP), venoconstrictive thigh cuffs (VTC), and impedance threshold device (ITD) resistive inspiratory breathing] individually and in combination to reduce a posture-induced headward fluid shift as a ground-based spaceflight analog. Ten healthy subjects (5 male) underwent baseline measures (seated and supine postures) followed by countermeasure exposure in the supine posture. Noninvasive measurements included ultrasound [internal jugular veins (IJV) cross-sectional area, cardiac stroke volume, optic nerve sheath diameter, noninvasive IJV pressure], transient evoked otoacoustic emissions (OAE; intracranial pressure index), intraocular pressure, choroidal thickness from optical coherence tomography imaging, and brachial blood pressure. Compared with the supine posture, IJV area decreased 48% with application of LBNP [mean ratio: 0.52, 95% confidence interval (CI): 0.44-0.60, P < 0.001], 31% with VTC (mean ratio: 0.69, 95% CI: 0.55-0.87, P < 0.001), and 56% with ITD (mean ratio: 0.44, 95% CI: 0.12-1.70, P = 0.46), measured at end-inspiration. LBNP was the only individual countermeasure to decrease the OAE phase angle (Δ -12.9 degrees, 95% CI: -25 to -0.9, P = 0.027), and use of combined countermeasures did not result in greater effects. Thus, LBNP, and to a lesser extent VTC and ITD, represents promising headward fluid shift countermeasures but will require future testing in analog and spaceflight environments.NEW & NOTEWORTHY As a weightlessness-induced headward fluid shift is hypothesized to be a primary factor underlying several physiological consequences of spaceflight, countermeasures aimed at reversing the fluid shift will likely be crucial during exploration-class spaceflight missions. Here, we tested three mechanical countermeasures individually and in various combinations to reduce a posture-induced headward fluid shift as a ground-based spaceflight analog.
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Affiliation(s)
| | | | | | | | | | - David T Kemp
- University College London Ear Institute, London, United Kingdom
| | | | | | | | | | - Alan R Hargens
- Department of Orthopaedic Surgery, UC San Diego Medical Center, University of California, San Diego, California
| | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, UT Southwestern, Dallas, Texas
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Lee JK, Koppelmans V, Pasternak O, Beltran NE, Kofman IS, De Dios YE, Mulder ER, Mulavara AP, Bloomberg JJ, Seidler RD. Effects of Spaceflight Stressors on Brain Volume, Microstructure, and Intracranial Fluid Distribution. Cereb Cortex Commun 2021; 2:tgab022. [PMID: 34296167 PMCID: PMC8152913 DOI: 10.1093/texcom/tgab022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/02/2021] [Accepted: 03/26/2021] [Indexed: 11/25/2022] Open
Abstract
Astronauts are exposed to elevated CO2 levels onboard the International Space Station. Here, we investigated structural brain changes in 11 participants following 30-days of head-down tilt bed rest (HDBR) combined with 0.5% ambient CO2 (HDBR + CO2) as a spaceflight analog. We contrasted brain changes observed in the HDBR + CO2 group with those of a previous HDBR sample not exposed to elevated CO2. Both groups exhibited a global upward shift of the brain and concomitant intracranial free water (FW) redistribution. Greater gray matter changes were seen in the HDBR + CO2 group in some regions. The HDBR + CO2 group showed significantly greater FW decrements in the posterior cerebellum and the cerebrum than the HDBR group. In comparison to the HDBR group, the HDBR + CO2 group exhibited greater diffusivity increases. In half of the participants, the HDBR + CO2 intervention resulted in signs of Spaceflight Associated Neuro-ocular Syndrome (SANS), a constellation of ocular structural and functional changes seen in astronauts. We therefore conducted an exploratory comparison compared between subjects that did and did not develop SANS and found asymmetric lateral ventricle enlargement in the SANS group. These results enhance our understanding of the underlying mechanisms of spaceflight-induced brain changes, which is critical for promoting astronaut health and performance.
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Affiliation(s)
- Jessica K Lee
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL 32611, USA
| | - Vincent Koppelmans
- Department of Psychiatry, University of Utah, Salt Lake City, UT 84108, USA
| | - Ofer Pasternak
- Deparments of Psychiatry and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | - Edwin R Mulder
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | | | | | - Rachael D Seidler
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL 32611, USA
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Ong J, Lee AG, Moss HE. Head-Down Tilt Bed Rest Studies as a Terrestrial Analog for Spaceflight Associated Neuro-Ocular Syndrome. Front Neurol 2021; 12:648958. [PMID: 33841315 PMCID: PMC8032981 DOI: 10.3389/fneur.2021.648958] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 03/01/2021] [Indexed: 01/16/2023] Open
Abstract
Astronauts who undergo prolonged periods of spaceflight may develop a unique constellation of neuro-ocular findings termed Spaceflight Associated Neuro-Ocular Syndrome (SANS). SANS is a disorder that is unique to spaceflight and has no terrestrial equivalent. The prevalence of SANS increases with increasing spaceflight duration and although there have been residual, structural, ocular changes noted, no irreversible or permanent visual loss has occurred after SANS, with the longest spaceflight to date being 14 months. These microgravity-induced findings are being actively investigated by the United States' National Aeronautics Space Administration (NASA) and SANS is a potential obstacle to future longer duration, manned, deep space flight missions. The pathophysiology of SANS remains incompletely understood but continues to be a subject of intense study by NASA and others. The study of SANS is of course partially limited by the small sample size of humans undergoing spaceflight. Therefore, identifying a terrestrial experimental model of SANS is imperative to facilitate its study and for testing of preventative measures and treatments. Head-down tilt bed rest (HDTBR) on Earth has emerged as one promising possibility. In this paper, we review the HDTBR as an analog for SANS pathogenesis; the clinical and imaging overlap between SANS and HDTBR studies; and potential SANS countermeasures that have been or could be tested with HDTBR.
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Affiliation(s)
- Joshua Ong
- University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Andrew G Lee
- Department of Ophthalmology, Houston Methodist Hospital, Houston, TX, United States.,Baylor College of Medicine and the Center for Space Medicine, Houston, TX, United States.,The Houston Methodist Research Institute, Houston Methodist Hospital, Houston, TX, United States.,Departments of Ophthalmology, Neurology, and Neurosurgery, Weill Cornell Medicine, New York, NY, United States.,Department of Ophthalmology, University of Texas Medical Branch, Galveston, TX, United States.,University of Texas MD Anderson Cancer Center, Houston, TX, United States.,Texas A and M College of Medicine, Bryan, TX, United States.,Department of Ophthalmology, The University of Iowa Hospitals and Clinics, Iowa City, IA, United States
| | - Heather E Moss
- Departments of Ophthalmology, Stanford University, Palo Alto, CA, United States.,Departments of Neurology & Neurosciences, Stanford University, Palo Alto, CA, United States
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Du J, Cui J, Yang J, Wang P, Zhang L, Luo B, Han B. Alterations in Cerebral Hemodynamics During Microgravity: A Literature Review. Med Sci Monit 2021; 27:e928108. [PMID: 33446627 PMCID: PMC7814510 DOI: 10.12659/msm.928108] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Most reported neurological symptoms that happen after exposure to microgravity could be originated from alterations in cerebral hemodynamics. The complicated mechanisms involved in the process of hemodynamics and the disparate experimental protocols designed to study the process may have contributed to the discrepancies in results between studies and the lack of consensus among researchers. This literature review examines spaceflight and ground-based studies of cerebral hemodynamics and aims to summarize the underlying physiological mechanisms that are altered in cerebral hemodynamics during microgravity. We reviewed studies that were published before July 2020 and sought to provide a comprehensive summary of the physiological or pathological theories of hemodynamics and to arrive at firm conclusions from incongruous results that were reported in those related articles. We give plausible explanations of inconsistent results on factors including intracranial pressure, cerebral blood flow, and cerebrovascular autoregulation. Although there are no definitive data to confirm how cerebral hemodynamics changes during microgravity, every discrepancy in results was interpreted by existing theories, which were derived from physiological and pathological processes. We conclude that microgravity-induced alterations of hemodynamics at the brain level are multifaceted. Factors including duration, partial pressures of carbon dioxide, and individual adaptability contribute to this process and are unpredictable. With a growing understanding of this hemodynamics model, additional factors will likely be considered. Aiming for a full understanding of the physiological and/or pathological changes of hemodynamics will enable researchers to investigate its cellular and molecular mechanisms in future studies, which are desperately needed.
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Affiliation(s)
- Jichen Du
- Department of Neurology, Aerospace Center Hospital, Beijing, China (mainland)
| | - Jiangbo Cui
- Aerospace Clinic Academy, Peking University Health Science Center, Beijing, China (mainland)
| | - Jing Yang
- Department of Neurology, Aerospace Center Hospital, Beijing, China (mainland)
| | - Peifu Wang
- Department of Neurology, Aerospace Center Hospital, Beijing, China (mainland)
| | - Lvming Zhang
- Department of Neurology, Aerospace Center Hospital, Beijing, China (mainland)
| | - Bin Luo
- Department of Neurology, Aerospace Center Hospital, Beijing, China (mainland)
| | - Bailin Han
- Department of Neurology, Aerospace Center Hospital, Beijing, China (mainland)
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Hibernation as a Tool for Radiation Protection in Space Exploration. Life (Basel) 2021; 11:life11010054. [PMID: 33466717 PMCID: PMC7828799 DOI: 10.3390/life11010054] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/29/2020] [Accepted: 01/11/2021] [Indexed: 02/08/2023] Open
Abstract
With new and advanced technology, human exploration has reached outside of the Earth's boundaries. There are plans for reaching Mars and the satellites of Jupiter and Saturn, and even to build a permanent base on the Moon. However, human beings have evolved on Earth with levels of gravity and radiation that are very different from those that we have to face in space. These issues seem to pose a significant limitation on exploration. Although there are plausible solutions for problems related to the lack of gravity, it is still unclear how to address the radiation problem. Several solutions have been proposed, such as passive or active shielding or the use of specific drugs that could reduce the effects of radiation. Recently, a method that reproduces a mechanism similar to hibernation or torpor, known as synthetic torpor, has started to become possible. Several studies show that hibernators are resistant to acute high-dose-rate radiation exposure. However, the underlying mechanism of how this occurs remains unclear, and further investigation is needed. Whether synthetic hibernation will also protect from the deleterious effects of chronic low-dose-rate radiation exposure is currently unknown. Hibernators can modulate their neuronal firing, adjust their cardiovascular function, regulate their body temperature, preserve their muscles during prolonged inactivity, regulate their immune system, and most importantly, increase their radioresistance during the inactive period. According to recent studies, synthetic hibernation, just like natural hibernation, could mitigate radiation-induced toxicity. In this review, we see what artificial hibernation is and how it could help the next generation of astronauts in future interplanetary missions.
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Rasmussen JC, Kwon S, Pinal A, Bareis A, Velasquez FC, Janssen CF, Morrow JR, Fife CE, Karni RJ, Sevick-Muraca EM. Assessing lymphatic route of CSF outflow and peripheral lymphatic contractile activity during head-down tilt using near-infrared fluorescence imaging. Physiol Rep 2021; 8:e14375. [PMID: 32097544 PMCID: PMC7058174 DOI: 10.14814/phy2.14375] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 01/27/2020] [Indexed: 12/04/2022] Open
Abstract
Evidence overwhelmingly suggests that the lymphatics play a critical role in the clearance of cerebrospinal fluid (CSF) from the cranial space. Impairment of CSF outflow into the lymphatics is associated with a number of pathological conditions including spaceflight‐associated neuro‐ocular syndrome (SANS), a problem that limits long‐duration spaceflight. We used near‐infrared fluorescence lymphatic imaging (NIRFLI) to dynamically visualize the deep lymphatic drainage pathways shared by CSF outflow and disrupted during head‐down tilt (HDT), a method used to mimic the cephalad fluid shift that occurs in microgravity. After validating CSF clearance into the lymph nodes of the neck in swine, a pilot study was conducted in human volunteers to evaluate the effect of gravity on the flow of lymph through these deep cervical lymphatics. Injected into the palatine tonsils, ICG was imaged draining into deep jugular lymphatic vessels and subsequent cervical lymph nodes. NIRFLI was performed under HDT, sitting, and supine positions. NIRFLI shows that lymphatic drainage through pathways shared by CSF outflow are dependent upon gravity and are impaired under short‐term HDT. In addition, lymphatic contractile rates were evaluated from NIRFLI following intradermal ICG injections of the lower extremities. Lymphatic contractile activity in the legs was slowed in the gravity neutral, supine position, but increased under the influence of gravity regardless of whether its force direction opposed (sitting) or favored (HDT) lymphatic flow toward the heart. These studies evidence the role of a lymphatic contribution in SANS.
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Affiliation(s)
- John C Rasmussen
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Sunkuk Kwon
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Amanda Pinal
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Alexander Bareis
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Fred C Velasquez
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Christopher F Janssen
- Center for Laboratory Animal Medicine and Care, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - John R Morrow
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Caroline E Fife
- Department of Geriatrics, Baylor College of Medicine, Houston, TX, USA.,The Wound Care Clinic, CHI St. Luke's Health, The Woodlands Hospital, The Woodlands, TX, USA
| | - Ron J Karni
- Department of Otorhinolaryngology, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Eva M Sevick-Muraca
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine at The University of Texas Health Science Center at Houston, Houston, TX, USA
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Willey JS, Britten RA, Blaber E, Tahimic CG, Chancellor J, Mortreux M, Sanford LD, Kubik AJ, Delp MD, Mao XW. The individual and combined effects of spaceflight radiation and microgravity on biologic systems and functional outcomes. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, TOXICOLOGY AND CARCINOGENESIS 2021; 39:129-179. [PMID: 33902391 PMCID: PMC8274610 DOI: 10.1080/26896583.2021.1885283] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Both microgravity and radiation exposure in the spaceflight environment have been identified as hazards to astronaut health and performance. Substantial study has been focused on understanding the biology and risks associated with prolonged exposure to microgravity, and the hazards presented by radiation from galactic cosmic rays (GCR) and solar particle events (SPEs) outside of low earth orbit (LEO). To date, the majority of the ground-based analogues (e.g., rodent or cell culture studies) that investigate the biology of and risks associated with spaceflight hazards will focus on an individual hazard in isolation. However, astronauts will face these challenges simultaneously Combined hazard studies are necessary for understanding the risks astronauts face as they travel outside of LEO, and are also critical for countermeasure development. The focus of this review is to describe biologic and functional outcomes from ground-based analogue models for microgravity and radiation, specifically highlighting the combined effects of radiation and reduced weight-bearing from rodent ground-based tail suspension via hind limb unloading (HLU) and partial weight-bearing (PWB) models, although in vitro and spaceflight results are discussed as appropriate. The review focuses on the skeletal, ocular, central nervous system (CNS), cardiovascular, and stem cells responses.
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Affiliation(s)
| | | | - Elizabeth Blaber
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute
| | | | | | - Marie Mortreux
- Department of Neurology, Harvard Medical School, Beth Israel Deaconess Medical Center
| | - Larry D. Sanford
- Department of Radiation Oncology, Eastern Virginia Medical School
| | - Angela J. Kubik
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute
| | - Michael D. Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University
| | - Xiao Wen Mao
- Division of Biomedical Engineering Sciences (BMES), Department of Basic Sciences, Loma Linda University
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45
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Vyas RJ, Young M, Murray MC, Predovic M, Lim S, Jacobs NM, Mason SS, Zanello SB, Taibbi G, Vizzeri G, Parsons-Wingerter P. Decreased Vascular Patterning in the Retinas of Astronaut Crew Members as New Measure of Ocular Damage in Spaceflight-Associated Neuro-ocular Syndrome. Invest Ophthalmol Vis Sci 2020; 61:34. [PMID: 33372980 PMCID: PMC7774106 DOI: 10.1167/iovs.61.14.34] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 11/11/2020] [Indexed: 02/04/2023] Open
Abstract
Purpose Ocular structural and functional changes, collectively termed spaceflight-associated neuro-ocular syndrome (SANS), have been described in astronauts undergoing long-duration missions in the microgravity environment of the International Space Station. We tested the hypothesis that retinal vascular remodeling, particularly by smaller vessels, mediates the chronic headward fluid shifts associated with SANS. Methods As a retrospective study, arterial and venous patterns extracted from 30° infrared Heidelberg Spectralis retinal images of eight crew members acquired before and after six-month missions were analyzed with NASA's recently released VESsel GENeration Analysis (VESGEN) software. Output parameters included the fractal dimension and overall vessel length density that was further classified into large and small vascular branching generations. Vascular results were compared with SANS-associated clinical ocular measures. Results Significant postflight decreases in Df, Lv, and in smaller but not larger vessels were quantified in 11 of 16 retinas for arteries and veins (P value for Df, Lv, and smaller vessels in all 16 retinas were ≤0.033). The greatest vascular decreases occurred in the only retina displaying clinical evidence of SANS by choroidal folds and optic disc edema. In the remaining 15 retinas, decreases in vascular density from Df and Lv ranged from minimal to high by a custom Subclinical Vascular Pathology Index. Conclusions Together with VESGEN, the Subclinical Vascular Pathology Index may represent a new, useful SANS biomarker for advancing the understanding of SANS etiology and developing successful countermeasures for long duration space exploration in microgravity, although further research is required to better characterize retinal microvascular adaptations.
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Affiliation(s)
- Ruchi J. Vyas
- SGT Incorporated, NASA Ames Research Center, Mountain View, California, United States
| | | | - Matthew C. Murray
- Ames Blue Marble Space Institute of Science, NASA Ames Research Center, Mountain View, California, United States
| | - Marina Predovic
- Ames Blue Marble Space Institute of Science, NASA Ames Research Center, Mountain View, California, United States
| | - Shiyin Lim
- Ames Blue Marble Space Institute of Science, NASA Ames Research Center, Mountain View, California, United States
| | - Nicole M. Jacobs
- Ames Blue Marble Space Institute of Science, NASA Ames Research Center, Mountain View, California, United States
| | - Sara S. Mason
- MEI Technologies, NASA Johnson Space Center, Houston, Texas, United States
| | | | - Giovanni Taibbi
- Department of Ophthalmology and Visual Sciences, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States
| | - Gianmarco Vizzeri
- Department of Ophthalmology and Visual Sciences, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States
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46
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Lee C, Rohr J, Sass A, Sater S, Zahid A, Macias B, Stenger MB, Samuels BC, Martin BA, Oshinski JN, Ethier CR. In vivo estimation of optic nerve sheath stiffness using noninvasive MRI measurements and finite element modeling. J Mech Behav Biomed Mater 2020; 110:103924. [PMID: 32957219 DOI: 10.1016/j.jmbbm.2020.103924] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 12/21/2022]
Abstract
The optic nerve sheath (ONS) is biomechanically important. It is acted on by tension due to ocular movements, and by fluid shifts and/or alterations in intracranial pressure (ICP) in human disease, specifically in pathologies leading to intracranial hypertension. It has also been hypothesized that the ONS is acted on by altered ICP in astronauts exposed chronically to microgravity. However, a non-invasive method to quantify ONS biomechanical properties is not presently available; knowledge of such properties is desirable to allow characterization of the biomechanical forces exerted on the optic nerve head and other ocular structures due to the ONS. Thus, the primary objective of this study was to characterize the biomechanical properties (stiffness) of the human ONS in vivo as a necessary step towards investigating the role of ICP in various conditions, including Spaceflight Associated Neuro-ocular Syndrome (SANS). We acquired non-invasive magnetic resonance imaging (MRI) scans of ostensibly healthy subjects (n = 18, age = 30.4 ± 11.6 [mean ± SD] years) during supine and 15-degree head-down-tilt (HDT) postures, and extracted ONS contours from these scans. We then used finite element modeling to quantify ONS expansion due to postural changes and an inverse approach to estimate ONS stiffness. Using this non-invasive procedure, we estimated an in vivo ONS stiffness of 39.2 ± 21.9 kPa (mean ± SD), although a small subset of individuals had very stiff ONS that precluded accurate estimates of their stiffness values. ONS stiffness was not correlated with age and was higher in males than females.
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Affiliation(s)
- Chanyoung Lee
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Jesse Rohr
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - Austin Sass
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - Stuart Sater
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - Arslan Zahid
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
| | - Brandon Macias
- Cardiovascular and Vision Laboratory, KBR, Houston, TX, USA
| | | | - Brian C Samuels
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Bryn A Martin
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - John N Oshinski
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
| | - C Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
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Mekjavic IB, Amoaku W, Mlinar T, Jaki Mekjavic P. Hypercapnia augments resistive exercise-induced elevations in intraocular pressure in older individuals. Exp Physiol 2020; 105:641-651. [PMID: 32034962 DOI: 10.1113/ep088236] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 02/07/2020] [Indexed: 12/13/2022]
Abstract
NEW FINDINGS What is the central question of this study? Astronauts on-board the International Space Station (ISS) perform daily exercises designed to prevent muscle atrophy and bone demineralization: what is the effect of resistive exercise performed by subjects while exposed to the same level of hypercapnia as on the ISS on intraocular pressure (IOP)? What is the main finding and its importance? The static exercise-induced elevation in IOP during 6° prone head-down tilt (simulating the headward shift of body fluids in microgravity) is augmented by hypercapnia and exceeds the ocular hypertension threshold. ABSTRACT The present study assessed the effect of 6° head-down (establishing the cephalad fluid displacement noted in astronauts in microgravity) prone (simulating the effect on the eye) tilt during rest and exercise (simulating exercise performed by astronauts to mitigate the sarcopenia induced by unloading of weight-bearing limbs), in normocapnic and hypercapnic conditions (the latter simulating conditions on the International Space Station) on intraocular pressure (IOP). Volunteers (mean age = 57.8 ± 6 years, n = 10) participated in two experimental sessions, each comprising: (i) 10 min rest, (ii) 3 min static handgrip exercise (30% max), and (iii) 2 min recovery, inspiring either room air (NCAP) or a hypercapnic mixture (1% CO2 , HCAP). We measured IOP in the right eye, cardiac output (CO), stroke volume (SV), heart rate (HR) and mean arterial pressure (MAP) at regular intervals. Baseline IOP in the upright seated position while breathing room air was 14.1 ± 2.9 mmHg. Prone 6° head-down tilt significantly (P < 0.01) elevated IOP in all three phases of the NCAP (rest: 27.0 ± 3.7 mmHg; exercise: 32.2 ± 4.8 mmHg; recovery: 27.4 ± 4.0 mmHg) and HCAP (rest: 27.3 ± 4.3 mmHg; exercise: 34.2 ± 6.0 mmHg; recovery: 29.1 ± 5.8 mmHg) trials, with hypercapnia augmenting the exercise-induced elevation in IOP (P < 0.01). CO, SV, HR and MAP were significantly increased during handgrip dynamometry, but there was no effect of hypercapnia. The observed IOP measured during prone 6° HDT in all phases of the NCAP and HCAP trials exceeded the threshold pressure defining ocular hypertension. The exercise-induced increase in IOP is exacerbated by hypercapnia.
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Affiliation(s)
- Igor B Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Jamova 39, Ljubljana, SI-1000, Slovenia.,Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, V51 1S6, Canada
| | - Winfried Amoaku
- Nottingham Eye Research Centre, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Tinkara Mlinar
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Jamova 39, Ljubljana, SI-1000, Slovenia.,International Postgraduate School Jozef Stefan, Jamova 39, Ljubljana, SI-1000, Slovenia
| | - Polona Jaki Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Jamova 39, Ljubljana, SI-1000, Slovenia.,Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, Ljubljana, SI-1000, Slovenia.,Faculty of Medicine, University of Ljubljana, Vrazov trg 2, Ljubljana, SI-1000, Slovenia
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48
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Lee JK, Koppelmans V, Riascos RF, Hasan KM, Pasternak O, Mulavara AP, Bloomberg JJ, Seidler RD. Spaceflight-Associated Brain White Matter Microstructural Changes and Intracranial Fluid Redistribution. JAMA Neurol 2020; 76:412-419. [PMID: 30673793 DOI: 10.1001/jamaneurol.2018.4882] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Importance Spaceflight results in transient balance declines and brain morphologic changes; to our knowledge, the effect on brain white matter as measured by diffusion magnetic resonance imaging (dMRI), after correcting for extracellular fluid shifts, has not been examined. Objective To map spaceflight-induced intracranial extracellular free water (FW) shifts and to evaluate changes in brain white matter diffusion measures in astronauts. Design, Setting and Participants We performed retrospective, longitudinal analyses on dMRI data collected between 2010 and 2015. Of the 26 astronauts' dMRI scans released by the National Aeronautics and Space Administration Lifetime Surveillance of Astronaut Health, 15 had both preflight and postflight dMRI scans and were included in the final analyses. Data were analyzed between 2015 and 2018. Interventions or Exposures Seven astronauts completed a space shuttle mission (≤30 days) and 8 completed a long-duration International Space Station mission (≤200 days). Main Outcomes and Measures The dMRI scans were acquired for clinical monitoring; in this retrospective analysis, we analyzed brain FW and white matter diffusion metrics corrected for FW. We also obtained scores from computerized dynamic posturography tests of balance to assess brain-behavior associations. Results Of the 15 astronauts included, the median (SD) age was 47.2 (1.5) years; 12 were men, and 3 were women. We found a significant, widespread increase in FW volume in the frontal, temporal, and occipital lobes from before spaceflight to after spaceflight. There was also a significant decrease in FW in the posterior aspect of the vertex. All FW changes were significant and ranged from approximately 2.5% to 4.0% across brain regions. We observed white matter changes in the right superior and inferior longitudinal fasciculi, the corticospinal tract, and cerebellar peduncles. All white matter changes were significant and ranged from approximately 0.75% to 1.25%. Spaceflight mission duration was associated with cerebellar white matter change, and white matter changes in the superior longitudinal fasciculus were associated with the balance changes seen in the astronauts from before spaceflight to after spaceflight. Conclusions and Relevance Free water redistribution with spaceflight likely reflects headward fluid shifts occurring in microgravity as well as an upward shift of the brain within the skull. White matter changes were of a greater magnitude than those typically seen during the same period with healthy aging. Future, prospective assessments are required to better understand the recovery time and behavioral consequences of these brain changes.
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Affiliation(s)
- Jessica K Lee
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville
| | | | - Roy F Riascos
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center, Houston
| | - Khader M Hasan
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center, Houston
| | - Ofer Pasternak
- Departments of Psychiatry and Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | | | - Jacob J Bloomberg
- National Aeronautics and Space Administration Johnson Space Center, Houston, Texas
| | - Rachael D Seidler
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville.,Department of Neurology, University of Florida, Gainesville
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Sidi M, Aminu M. Sonographic evaluation of the optic nerve sheath diameter and anterior chamber depth of the eye among apparently healthy adults in Kano, Nigeria. WEST AFRICAN JOURNAL OF RADIOLOGY 2020. [DOI: 10.4103/wajr.wajr_3_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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From international ophthalmology to space ophthalmology: the threats to vision on the way to Moon and Mars colonization. Int Ophthalmol 2019; 40:775-786. [PMID: 31722052 DOI: 10.1007/s10792-019-01212-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/28/2019] [Indexed: 12/29/2022]
Abstract
PURPOSE To report the ophthalmological risks of space travel. METHODS The literature about the effect of microgravity and cosmic radiation on the human eye has been reviewed, focusing on the so-called "spaceflight related neuro-ocular syndrome (SANS)", and possible remedies. RESULTS The eye is the major candidate to suffer from the adverse space conditions, so much so that SANS is the main concern of the National Aeronautics and Space Administration (NASA). SANS, that affects astronauts engaged in long-duration spaceflights, is characterized by optic nerve head swelling, flattening of the posterior region of the scleral shell, choroidal folds, retinal cotton wool spots, and hyperopic shift. Even if it seems related to an increased volume of the cerebrospinal fluid in the brain and the optic nerve sheaths, its pathogenesis is still unclear. In addition, cataract is related to the effect of galactic cosmic rays on the lens. Centrifuges, pressurizing chambers, and mechanical counter-pressure suits have been advanced to counteract the upward fluid shift responsible for the SANS syndrome. Shields with a high content of hydrogen, magnetic shielding systems, and wearable radiation shielding devices are under study to mitigate the exposure to galactic cosmic rays. CONCLUSIONS Since 1961, the year of the first manned mission outside the Earth, history has shown that the human being may venture in space. Yet, visual impairment is the top health risk for long-duration spaceflight. Effective remediation is mandatory in anticipation of long space missions and Moon and Mars colonization.
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