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Wright CS, Lewis KJ, Semon K, Yi X, Reyes Fernandez PC, Rust K, Prideaux M, Schneider A, Pederson M, Deosthale P, Plotkin LI, Hum JM, Sankar U, Farach-Carson MC, Robling AG, Thompson WR. Deletion of the auxiliary α2δ1 voltage sensitive calcium channel subunit in osteocytes and late-stage osteoblasts impairs femur strength and load-induced bone formation in male mice. J Bone Miner Res 2024; 39:298-314. [PMID: 38477790 DOI: 10.1093/jbmr/zjae010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 12/03/2023] [Accepted: 12/27/2023] [Indexed: 03/14/2024]
Abstract
Osteocytes sense and respond to mechanical force by controlling the activity of other bone cells. However, the mechanisms by which osteocytes sense mechanical input and transmit biological signals remain unclear. Voltage-sensitive calcium channels (VSCCs) regulate calcium (Ca2+) influx in response to external stimuli. Inhibition or deletion of VSCCs impairs osteogenesis and skeletal responses to mechanical loading. VSCC activity is influenced by its auxiliary subunits, which bind the channel's α1 pore-forming subunit to alter intracellular Ca2+ concentrations. The α2δ1 auxiliary subunit associates with the pore-forming subunit via a glycosylphosphatidylinositol anchor and regulates the channel's calcium-gating kinetics. Knockdown of α2δ1 in osteocytes impairs responses to membrane stretch, and global deletion of α2δ1 in mice results in osteopenia and impaired skeletal responses to loading in vivo. Therefore, we hypothesized that the α2δ1 subunit functions as a mechanotransducer, and its deletion in osteocytes would impair skeletal development and load-induced bone formation. Mice (C57BL/6) with LoxP sequences flanking Cacna2d1, the gene encoding α2δ1, were crossed with mice expressing Cre under the control of the Dmp1 promoter (10 kb). Deletion of α2δ1 in osteocytes and late-stage osteoblasts decreased femoral bone quantity (P < .05) by DXA, reduced relative osteoid surface (P < .05), and altered osteoblast and osteocyte regulatory gene expression (P < .01). Cacna2d1f/f, Cre + male mice displayed decreased femoral strength and lower 10-wk cancellous bone in vivo micro-computed tomography measurements at the proximal tibia (P < .01) compared to controls, whereas Cacna2d1f/f, Cre + female mice showed impaired 20-wk cancellous and cortical bone ex vivo micro-computed tomography measurements (P < .05) vs controls. Deletion of α2δ1 in osteocytes and late-stage osteoblasts suppressed load-induced calcium signaling in vivo and decreased anabolic responses to mechanical loading in male mice, demonstrating decreased mechanosensitivity. Collectively, the α2δ1 auxiliary subunit is essential for the regulation of osteoid-formation, femur strength, and load-induced bone formation in male mice.
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Affiliation(s)
- Christian S Wright
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, Indiana University, Indianapolis, IN 46202, United States
- Indiana Center for Musculoskeletal Health, Indianapolis, IN 46202, United States
| | - Karl J Lewis
- Department of Biomedical Engineering, Cornell University, Ithaca, NY 14850, United States
| | - Katelyn Semon
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, Indiana University, Indianapolis, IN 46202, United States
- Department of Anatomy & Cell Biology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States
| | - Xin Yi
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, Indiana University, Indianapolis, IN 46202, United States
- Indiana Center for Musculoskeletal Health, Indianapolis, IN 46202, United States
| | - Perla C Reyes Fernandez
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, Indiana University, Indianapolis, IN 46202, United States
- Indiana Center for Musculoskeletal Health, Indianapolis, IN 46202, United States
| | - Katie Rust
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, Indiana University, Indianapolis, IN 46202, United States
| | - Matthew Prideaux
- Indiana Center for Musculoskeletal Health, Indianapolis, IN 46202, United States
| | - Artur Schneider
- Department of Physiology, College of Osteopathic Medicine, Marian University, Indianapolis, IN 46202, United States
| | - Molly Pederson
- School of Science, Indiana University-Purdue University, Indianapolis, IN 46202, United States
| | - Padmini Deosthale
- Department of Anatomy & Cell Biology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States
| | - Lilian I Plotkin
- Indiana Center for Musculoskeletal Health, Indianapolis, IN 46202, United States
- Department of Anatomy & Cell Biology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States
| | - Julia M Hum
- Department of Physiology, College of Osteopathic Medicine, Marian University, Indianapolis, IN 46202, United States
| | - Uma Sankar
- Indiana Center for Musculoskeletal Health, Indianapolis, IN 46202, United States
- Department of Anatomy & Cell Biology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States
| | - Mary C Farach-Carson
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, University of Texas, Health Science Center, Houston, TX 78712, United States
| | - Alexander G Robling
- Indiana Center for Musculoskeletal Health, Indianapolis, IN 46202, United States
- Department of Anatomy & Cell Biology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States
| | - William R Thompson
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, Indiana University, Indianapolis, IN 46202, United States
- Indiana Center for Musculoskeletal Health, Indianapolis, IN 46202, United States
- Department of Anatomy & Cell Biology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States
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Buettmann EG, Chlebek C, Lockard CA, Clayton SW, Lewis KJ, Collins KH. Post or perish? Social media strategies for disseminating orthopedic research. J Orthop Res 2023; 41:1643-1652. [PMID: 37163368 PMCID: PMC10524931 DOI: 10.1002/jor.25588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 04/07/2023] [Accepted: 05/01/2023] [Indexed: 05/12/2023]
Abstract
Social media usage, particularly Twitter, among scientists in academia has increased in recent years. However, Twitter's use in scholarly post-publication dissemination of orthopaedic research and musculoskeletal advocacy remains low. To enhance usage of Twitter among musculoskeletal researchers, this article reviews data supporting the professional benefits of using the platform to disseminate scholarly works. Next, we provide a linear workflow for Tweet curation, discuss the importance of data-driven decision making behind tweet curation and posting, and propose new guidelines for professional Twitter usage. Since this workflow may not eliminate all the identified barriers and new institutionalized shifts in policies regarding curation and consumption of social media on Twitter, we also briefly introduce and explore using other social media platforms. We hope this information will be persuasive and compelling to those in the orthopedic research field and be broadly applicable to others in related scientific fields who wish to disseminate findings and engage a public audience on social media. In addition, we encourage the Orthopedic Research Society (ORS) and Journal of Orthopedic Research (JOR) communities to take advantage of the many tools curated by the Wiley editorial office and the ORS social media committee to increase dissemination of their scholarly works online. Twitter and social media can assist in accomplishing our mission of creating a world without musculoskeletal limitations via the timely dissemination of orthopedic information. However, this can only be accomplished if the orthopedic research community has a unified and strong online presence actively engaged in orthopaedic research findings and news.
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Affiliation(s)
- Evan G. Buettmann
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA
| | - Carolyn Chlebek
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME
| | - Carly A. Lockard
- Stephens Family Clinical Research Institute, Carle Foundation Hospital, Urbana, IL
| | - Sade W. Clayton
- Department of Orthopedic Surgery, Washington University in St. Louis, St. Louis, MO
| | - Karl J. Lewis
- Department of Biomedical Engineering, Cornell University. Ithaca, NY
| | - Kelsey H. Collins
- Department of Orthopedic Surgery, Washington University in St. Louis, St. Louis, MO
- Shriners Hospitals for Children, St. Louis, MO
- Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA
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Lewis KJ, Boorman-Padgett JF, Castaneda M, Spray DC, Thi MM, Schaffler MB. A Fluorescent Intravital Imaging Approach to Study Load-Induced Calcium Signaling Dynamics in Mouse Osteocytes. J Vis Exp 2023. [PMID: 36912542 DOI: 10.3791/64366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023] Open
Abstract
Bone tissue is exquisitely sensitive to differences in mechanical load magnitude. Osteocytes, dendritic cells that form a syncytium throughout the bone, are responsible for the mechanosensory function of bone tissue. Studies employing histology, mathematical modeling, cell culture, and ex vivo bone organ cultures have greatly advanced the understanding of osteocyte mechanobiology. However, the fundamental question of how osteocytes respond to and encode mechanical information at the molecular level in vivo is not well understood. Intracellular calcium concentration fluctuations in osteocytes offer a useful target for learning more about acute bone mechanotransduction mechanisms. Here, we report a method for studying osteocyte mechanobiology in vivo, combining a mouse strain with a fluorescently genetically encoded calcium indicator expressed in osteocytes with an in vivo loading and imaging system to directly detect osteocyte calcium levels during loading. This is achieved with a three-point bending device that can deliver well-defined mechanical loads to the third metatarsal of living mice while simultaneously monitoring fluorescently indicated calcium responses of osteocytes using two-photon microscopy. This technique allows for direct in vivo observation of osteocyte calcium signaling events in response to whole bone loading and is useful in the endeavor to reveal mechanisms in osteocyte mechanobiology.
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Affiliation(s)
- Karl J Lewis
- Meinig School of Biomedical Engineering, Cornell University;
| | | | - Macy Castaneda
- Sibley School of Mechanical and Aerospace Engineering, Cornell University
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine
| | - Mia M Thi
- Department of Orthopaedic Surgery, Albert Einstein College of Medicine; Department of Molecular Pharmacology, Albert Einstein College of Medicine
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Reyes Fernandez PC, Wright CS, Masterson AN, Yi X, Tellman TV, Bonteanu A, Rust K, Noonan ML, White KE, Lewis KJ, Sankar U, Hum JM, Bix G, Wu D, Robling AG, Sardar R, Farach-Carson MC, Thompson WR. Gabapentin Disrupts Binding of Perlecan to the α 2δ 1 Voltage Sensitive Calcium Channel Subunit and Impairs Skeletal Mechanosensation. Biomolecules 2022; 12:biom12121857. [PMID: 36551284 PMCID: PMC9776037 DOI: 10.3390/biom12121857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/04/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Our understanding of how osteocytes, the principal mechanosensors within bone, sense and perceive force remains unclear. Previous work identified "tethering elements" (TEs) spanning the pericellular space of osteocytes and transmitting mechanical information into biochemical signals. While we identified the heparan sulfate proteoglycan perlecan (PLN) as a component of these TEs, PLN must attach to the cell surface to induce biochemical responses. As voltage-sensitive calcium channels (VSCCs) are critical for bone mechanotransduction, we hypothesized that PLN binds the extracellular α2δ1 subunit of VSCCs to couple the bone matrix to the osteocyte membrane. Here, we showed co-localization of PLN and α2δ1 along osteocyte dendritic processes. Additionally, we quantified the molecular interactions between α2δ1 and PLN domains and demonstrated for the first time that α2δ1 strongly associates with PLN via its domain III. Furthermore, α2δ1 is the binding site for the commonly used pain drug, gabapentin (GBP), which is associated with adverse skeletal effects when used chronically. We found that GBP disrupts PLN::α2δ1 binding in vitro, and GBP treatment in vivo results in impaired bone mechanosensation. Our work identified a novel mechanosensory complex within osteocytes composed of PLN and α2δ1, necessary for bone force transmission and sensitive to the drug GBP.
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Affiliation(s)
- Perla C. Reyes Fernandez
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN 46202, USA
| | - Christian S. Wright
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN 46202, USA
| | - Adrianna N. Masterson
- Department of Chemistry and Chemical Biology, School of Science, Indiana University, Indianapolis, IN 46202, USA
| | - Xin Yi
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN 46202, USA
| | - Tristen V. Tellman
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
| | - Andrei Bonteanu
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
- Department of Bioengineering, George R. Brown School of Engineering, Rice University, Houston, TX 77005, USA
| | - Katie Rust
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN 46202, USA
| | - Megan L. Noonan
- Department of Medical and Molecular Genetics, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Kenneth E. White
- Department of Medical and Molecular Genetics, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Karl J. Lewis
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Uma Sankar
- Department of Anatomy, Cell Biology and Physiology, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Julia M. Hum
- Division of Biomedical Science, College of Osteopathic Medicine, Marian University, Indianapolis, IN 46222, USA
| | - Gregory Bix
- Departments of Neurosurgery and Neurology, School of Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Danielle Wu
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
- Department of Bioengineering, George R. Brown School of Engineering, Rice University, Houston, TX 77005, USA
| | - Alexander G. Robling
- Department of Anatomy, Cell Biology and Physiology, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Rajesh Sardar
- Department of Chemistry and Chemical Biology, School of Science, Indiana University, Indianapolis, IN 46202, USA
| | - Mary C. Farach-Carson
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
- Department of Bioengineering, George R. Brown School of Engineering, Rice University, Houston, TX 77005, USA
| | - William R. Thompson
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN 46202, USA
- Department of Anatomy, Cell Biology and Physiology, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
- Division of Biomedical Science, College of Osteopathic Medicine, Marian University, Indianapolis, IN 46222, USA
- Correspondence:
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5
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Affiliation(s)
- Karl J Lewis
- Meinig School of Biomedical Engineering, Cornell University Weill Hall, 237 Tower Road Ithaca NY 14853
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Lewis KJ. Osteocyte calcium signaling - A potential translator of mechanical load to mechanobiology. Bone 2021; 153:116136. [PMID: 34339908 DOI: 10.1016/j.bone.2021.116136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/25/2021] [Accepted: 07/27/2021] [Indexed: 10/20/2022]
Abstract
Osteocytes are embedded dendritic bone cells; by virtue of their position in bone tissue, ability to coordinate bone building osteoblasts and resorbing osteoclasts, and sensitivity to tissue level mechanical loading, they serve as the resident bone mechanosensor. The mechanisms osteocytes use to change mechanical loading into biological signals that drive tissue level changes has been well studied over the last 30 years, however the ways loading parameters are encoded at the cellular level are still not fully understood. Calcium signaling is a first messenger signal exhibited by osteocytes in response to mechanical forces. A body of work interrogating the mechanisms of osteocyte calcium signaling exists and is presently expanding, presenting the opportunity to better understand the relationship between calcium signaling characteristics and tuned osteocyte responses to tissue level strain features (e.g. magnitude, duration, frequency). This review covers the history of osteocyte load induced calcium signaling and highlights potential cellular mechanisms used by osteocytes to turn details about loading parameters into biological events.
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Affiliation(s)
- Karl J Lewis
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States of America.
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Lewis KJ, Cabahug-Zuckerman P, Boorman-Padgett JF, Basta-Pljakic J, Louie J, Stephen S, Spray DC, Thi MM, Seref-Ferlengez Z, Majeska RJ, Weinbaum S, Schaffler MB. Estrogen depletion on In vivo osteocyte calcium signaling responses to mechanical loading. Bone 2021; 152:116072. [PMID: 34171514 PMCID: PMC8316427 DOI: 10.1016/j.bone.2021.116072] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 06/15/2021] [Accepted: 06/20/2021] [Indexed: 11/27/2022]
Abstract
Microstructural adaptation of bone in response to mechanical stimuli is diminished with estrogen deprivation. Here we tested in vivo whether ovariectomy (OVX) alters the acute response of osteocytes, the principal mechanosensory cells of bone, to mechanical loading in mice. We also used super resolution microscopy (Structured Illumination microscopy or SIM) in conjunction with immunohistochemistry to assess changes in the number and organization of "osteocyte mechanosomes" - complexes of Panx1 channels, P2X7 receptors and CaV3 voltage-gated Ca2+ channels clustered around αvβ3 integrin foci on osteocyte processes. Third metatarsals bones of mice expressing an osteocyte-targeted genetically encoded Ca2+ indicator (DMP1-GCaMP3) were cyclically loaded in vivo to strains from 250 to 3000 με and osteocyte intracellular Ca2+ signaling responses were assessed in mid-diaphyses using multiphoton microscopy. The number of Ca2+ signaling osteocytes in control mice increase monotonically with applied strain magnitude for the physiological range of strains. The relationship between the number of Ca2+ signaling osteocytes and loading was unchanged at 2 days post-OVX. However, it was altered markedly at 28 days post-OVX. At loads up to 1000 με, there was a dramatic reduction in number of responding (i.e. Ca2+ signaling) osteocytes; however, at higher strains the numbers of Ca2+ signaling osteocytes were similar to control mice. OVX significantly altered the abundance, make-up and organization of osteocyte mechanosome complexes on dendritic processes. Numbers of αvβ3 foci also staining with either Panx 1, P2X7R or CaV3 declined by nearly half after OVX, pointing to a loss of osteocyte mechanosomes on the dendritic processes with estrogen depletion. At the same time, the areas of the remaining foci that stained for αvβ3 and channel proteins increased significantly, a redistribution of mechanosome components suggesting a potential compensatory response. These results demonstrate that the deleterious effects of estrogen depletion on skeletal mechanical adaptation appear at the level of mechanosensation; osteocytes lose the ability to sense small (physiological) mechanical stimuli. This decline may result at least partly from changes in the structure and organization of osteocyte mechanosomes, which contribute to the distinctive sensitivity of osteocytes (particularly their dendritic processes) to mechanical stimulation.
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Affiliation(s)
- Karl J Lewis
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Pamela Cabahug-Zuckerman
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - James F Boorman-Padgett
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Jelena Basta-Pljakic
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Joyce Louie
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Samuel Stephen
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Mia M Thi
- Orthopaedic Surgery, Albert Einstein College of Medicine, Bronx, NY, United States of America; Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Zeynep Seref-Ferlengez
- Orthopaedic Surgery, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Robert J Majeska
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Sheldon Weinbaum
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Mitchell B Schaffler
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America.
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Alliston T, Foucher KC, Frederick B, Hernandez CJ, Iatridis JC, Kozloff KM, Lewis KJ, Liu XS, Mercer DM, Ochia R, Queen RM, Rimnac CM, van der Meulen MCH, Westendorf JJ. The importance of diversity, equity, and inclusion in orthopedic research. J Orthop Res 2020; 38:1661-1665. [PMID: 32267012 DOI: 10.1002/jor.24685] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/25/2020] [Accepted: 04/01/2020] [Indexed: 02/04/2023]
Affiliation(s)
- Tamara Alliston
- Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, California
| | - Kharma C Foucher
- Department of Kinesiology and Nutrition, University of Illinois, Chicago, Illinois
| | | | - Christopher J Hernandez
- Nancy E. and Peter C. Meinig School of Biomedical Engineering and Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York
| | - James C Iatridis
- Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York City, New York
| | - Kenneth M Kozloff
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan
| | - Karl J Lewis
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - X Sherry Liu
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Deana M Mercer
- Department of Orthopaedics and Rehabilitation, The University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Ruth Ochia
- Department of Bioengineering, Temple University, Philadelphia, Pennsylvania
| | - Robin M Queen
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia
| | - Clare M Rimnac
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Marjolein C H van der Meulen
- Nancy E. and Peter C. Meinig School of Biomedical Engineering and Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York
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9
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Lewis KJ, Yi X, Wright CS, Pemberton EZ, Bullock WA, Thompson WR, Robling AG. The mTORC2 Component Rictor Is Required for Load-Induced Bone Formation in Late-Stage Skeletal Cells. JBMR Plus 2020; 4:e10366. [PMID: 32666017 PMCID: PMC7340445 DOI: 10.1002/jbm4.10366] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 03/17/2020] [Indexed: 12/14/2022] Open
Abstract
Bone relies on mechanical cues to build and maintain tissue composition and architecture. Our understanding of bone cell mechanotransduction continues to evolve, with a few key signaling pathways emerging as vital. Wnt/β‐catenin, for example, is essential for proper anabolic response to mechanical stimulation. One key complex that regulates β‐catenin activity is the mammalian target of rapamycin complex 2 (mTORc2). mTORc2 is critical for actin cytoskeletal reorganization, an indispensable component in mechanotransduction in certain cell types. In this study, we probed the impact of the mTORc2 signaling pathway in osteocyte mechanotransduction by conditionally deleting the mTORc2 subunit Rictor in Dmp1‐expressing cells of C57BL/6 mice. Conditional deletion of the Rictor was achieved using the Dmp1–Cre driver to recombine Rictor floxed alleles. Rictor mutants exhibited a decrease in skeletal properties, as measured by DXA, μCT, and mechanical testing, compared with Cre‐negative floxed littermate controls. in vivo axial tibia loading conducted in adult mice revealed a deficiency in the osteogenic response to loading among Rictor mutants. Histological measurements of osteocyte morphology indicated fewer, shorter cell processes in Rictor mutants, which might explain the compromised response to mechanical stimulation. In summary, inhibition of the mTORc2 pathway in late osteoblasts/osteocytes leads to decreased bone mass and mechanically induced bone formation. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Karl J Lewis
- Department of Anatomy & Cell Biology Indiana University School of Medicine Indianapolis IN USA
| | - Xin Yi
- Department of Physical Therapy Indiana University School of Health & Human Sciences Indianapolis IN USA
| | - Christian S Wright
- Department of Physical Therapy Indiana University School of Health & Human Sciences Indianapolis IN USA
| | - Emily Z Pemberton
- Department of Anatomy & Cell Biology Indiana University School of Medicine Indianapolis IN USA
| | - Whitney A Bullock
- Department of Anatomy & Cell Biology Indiana University School of Medicine Indianapolis IN USA
| | - William R Thompson
- Department of Physical Therapy Indiana University School of Health & Human Sciences Indianapolis IN USA.,Indiana Center for Musculoskeletal Health Indianapolis IN USA
| | - Alexander G Robling
- Department of Anatomy & Cell Biology Indiana University School of Medicine Indianapolis IN USA.,Indiana Center for Musculoskeletal Health Indianapolis IN USA.,Department of Biomedical Engineering Indiana University-Purdue University at Indianapolis Indianapolis IN USA.,Richard L. Roudebush VA Medical Center Indianapolis IN USA
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Dutta B, Gitaitis RD, Lewis KJ, Langston DB. A New Report of Xanthomonas cucurbitae Causing Bacterial Leaf Spot of Watermelon in Georgia, USA. Plant Dis 2013; 97:556. [PMID: 30722235 DOI: 10.1094/pdis-10-12-0908-pdn] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In June 2012, watermelon leaves (Citrullus lanatus (Thunb.) Matsum. & Nakai) were observed with angular, necrotic spots with chlorotic halos in a field in Telfair County, GA. The field exhibited 20 to 25% disease incidence with no observable symptoms on fruits. Isolations were made from foliar lesions of 30 leaves onto yeast extract-dextrose-CaCO3 (YDC) agar medium (3). Yellow-pigmented, Xanthomonas-like colonies were observed after 48-h incubation at 28°C from 100% of the samples. Bacteria harvested were gram-negative, oxidase-negative, indole-negative, hydrolyzed starch and esculin, and formed pits on crystal violet pectate and carboxymethyl cellulose media. The bacterial isolates did not produce nitrites from nitrates but produced hypersensitive reactions on tobacco upon inoculation with 1 × 108 colony-forming units (CFU)/ml. These characteristics are typical of members of the Xanthomonas campestris group. The genus Xanthomonas was confirmed using conventional PCR with genus-specific primers RST2 (5'AGGCCCTGGAAGGTGCCCTGGA3') and RST3 (5'ATCGCACTGCGTACCGCGCGCGA3'), which produced an 840-bp band. Universal primers fD1 and rD1 (1) were used to amplify the 16S rRNA gene from four isolates and amplified products were sequenced and BLAST searched in GenBank. The nucleotide sequences of the isolates showed 97 to 98% similarity to X. cucurbitae (Accessions AB680438.1 and Y10760), X. campestris (HQ256868.1), X. arboricola (JF835910.1), X. oryzae pv. oryzicola (CP003057.1) and X. campestris pv. raphani (CP002789.1). PCR amplification and sequencing of the atpD gene (ATP synthase, 720 bp) showed 99% similarity with X. cucurbitae when BLAST searched in GenBank (HM568911.1). X. cucurbitae was not present in the database of BIOLOG (Biolog, Hayward, CA); therefore, substrate utilization tests of three isolates were compared with substrate utilization patterns of Xanthomonas groups reported by Vauterin et al. (4). The watermelon isolates displayed 93.7, 89.5, and 89.5% similarity with the reported BIOLOG metabolic profiles of X. campestris, X. cucurbitae, and X. hortorum, respectively, of Xanthomonas groups 15, 8, and 2. However, none of the isolates were amplified using a conventional PCR assay with X. campestris pv. campestris and X. campestris pv. raphani-specific primers (2), indicating a closer relationship with X. cucurbitae. When 2-week old watermelon seedlings cv. Crimson sweet (n = 4/isolate/experiment) were inoculated by spraying with a suspension of 1 × 108 CFU/ml, 100% of the seedlings developed symptoms (water soaked angular lesions that developed into necrotic spots) 14 days after planting under greenhouse conditions (~30°C and ~70% RH). Ten control plants inoculated with sterile water remained asymptomatic. Bacterial colonies were reisolated from symptomatic seedlings that showed similar characteristics to those described above. The identity of isolated colonies was confirmed by amplifying and sequencing the 16S rRNA gene, which showed 97 to 98% similarity to X cucurbitae accessions in GenBank. To our knowledge, this is the first report of X. cucurbitae on watermelon in Georgia since the 1950s. References: (1) Y. Besancon et al. Biotechnol. Appl. Biochem. 20:131, 1994. (2) Leu et al. Plant Pathol. Bull. 19:137, 2010. (3) N. W. Schaad et al. Laboratory Guide for Identification of Plant Pathogenic Bacteria, 3rd ed. APS Press. St. Paul, MN, 2001. (4) Vauterin et al. Int. J. Syst. Bacteriol. 45:472, 1995.
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Affiliation(s)
- B Dutta
- Department of Plant Pathology, University of Georgia, Tifton, 31793
| | - R D Gitaitis
- Department of Plant Pathology, University of Georgia, Tifton, 31793
| | - K J Lewis
- Department of Plant Pathology, University of Georgia, Tifton, 31793
| | - D B Langston
- Department of Plant Pathology, University of Georgia, Tifton, 31793
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Abstract
Dothistroma septosporum has caused a serious needle blight epidemic in the lodgepole pine forests in northwest British Columbia over the past several years. Although ascocarps had been observed in British Columbia, nothing was known about the contribution of sexual reproduction, gene flow and long-distance dispersal to the epidemic. Amplified fragment length polymorphism and mating-type markers in 19 sites were used to generate population and reproductive data. Overall, evidence suggests a mixed mode of reproduction. Haplotypic diversity was high, with 79 unique and 56 shared haplotypes (possible clones) identified from 192 fungal isolates. Overall, mating-type segregation did not differ significantly from 1:1; however, random mating was rejected in most populations in the index of association and parsimony tree-length permutation analyses using the full data set and, when using clone-corrected data sets, more of the smaller populations showed random mating. Two of the smaller populations consistently showed random mating for both tests using both clone-corrected and noncorrected data. High gene flow is suggested by no differentiation between 14 of the 19 sites, several of which came from young plantations where the pathogen was not likely present prior to the current outbreak. The remaining five sites showed some level of divergence, possibly due to historic separation and endemic pathogen populations. Results indicate a high evolutionary potential and long-distance dispersal in this pathogen, important to consider in future forest management.
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Affiliation(s)
- A L Dale
- Natural Resources and Environmental Studies Institute, University of Northern British Columbia, 3333 University Way, Prince George, BC V2N 4Z9, Canada.
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Nischwitz C, Langston D, Sanders HF, Torrance R, Lewis KJ, Gitaitis RD. First Report of Colletotrichum gloeosporioides Causing 'Twister Disease' of Onion (Allium cepa) in Georgia. Plant Dis 2008; 92:974. [PMID: 30769746 DOI: 10.1094/pdis-92-6-0974c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In the fall of 2007, onion seedlings with twisted and distorted leaves were observed in seedbeds in multiple fields in the Vidalia onion region of Georgia. Tests for viruses and bacteria were negative and chemical injury was deemed improbable because of disease distribution in the fields. Upon further investigation, fungal fruiting bodies were observed on the outside sheath of a few of the seedlings. Symptomatic plants were cut into 1-cm segments and surface sterilized in 70% ethanol for 3 min. After rinsing in sterile water, the segments were placed onto potato dextrose agar amended with tetracycline. The fungus isolated from symptomatic plants fit the description of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. Conidia were aseptate, cylindrical, and hyaline. Sequencing of the internal transcribed spacer region and a BLAST search in GenBank (99% sequence similarity to C. gloeosporioides accessions) confirmed the identification. Ten onion seedlings were spray inoculated with a suspension of 1 × 107 spores/ml until runoff, and four seedlings were inoculated with water as negative controls. Plants were bagged for 12 h to maintain high relative humidity. Five plants were placed in the greenhouse and five plants placed in a growth chamber at 22°C. All plants inoculated with C. gloeosporioides developed distorted and twisted leaves 3 weeks after inoculation in the growth chamber and 5 weeks after inoculation in the greenhouse. Night time temperatures in the greenhouse (15°C) were lower than those in the growth chamber (22°C). Seedlings inoculated with water showed no symptoms. The fungus was reisolated from symptomatic plants. C. gloeosporioides has been reported to cause a disease called twister on onion in tropical regions (1). The fall of 2007 was unusually warm with maximum temperatures reaching 26°C during the day. The pathogen is present on many crops in the United States, but to our knowledge, this is the first report of C. gloeosporioides causing twister disease of onion in the United States. In Nigeria and Brazil, yield losses as much as 100% were observed in fields with infected onions (1). The impact of infection on the growth of the transplants and subsequent yield in Vidalia onions is currently unknown. References: (1) J. P. Hill. Compendium of Onion and Garlic Diseases. 2nd ed. The American Phytopathological Society, St. Paul, MN, 2008.
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Affiliation(s)
- C Nischwitz
- Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton 31793-0748
| | - D Langston
- Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton 31793-0748
| | - H F Sanders
- Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton 31793-0748
| | - R Torrance
- Tattnall Cooperative Extension Service, Reidsville, GA 30453
| | - K J Lewis
- Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton 31793-0748
| | - R D Gitaitis
- Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton 31793-0748
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Abstract
The purpose of this paper is to review potential novel functional pathways by which estradiol and estrogenic compounds elicit biological responses in mammals. We will limit our approach to those novel functions suggested by phenotypes associated with estrogen receptor-alpha (ER alpha) gene mutations and polymorphisms. The study of these pathways has been greatly aided by the availability of ER alpha-minus mice, which lack classic biological responses to estradiol. In addition, the availability of an ER alpha-minus human family, aromatase-minus human families, and in the near future an aromatase-minus mouse model will allow correlations of novel phenotypes with the lack of active ER alpha protein. The ER alpha-minus mice can potentially be used to characterize in depth novel clinical phenotypes that link the functions of estrogens with sexual maturation, cardiovascular disease, osteoporosis, diabetes, and cancer.
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Affiliation(s)
- J A Taylor
- Department of Biochemistry, University of Missouri, Columbia 65211, USA
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Lewis KJ, Irwin WJ, Akhtar S. Development of a sustained-release biodegradable polymer delivery system for site-specific delivery of oligonucleotides: characterization of P(LA-GA) copolymer microspheres in vitro. J Drug Target 1998; 5:291-302. [PMID: 9713978 DOI: 10.3109/10611869808995882] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Development of a Sustained-Release Biodegradable Polymer Delivery System for Site-Specific Delivery of Oligonucleotides: Characterization of P(LA-GA) Copolymer Microspheres In Vitro Antisense oligodeoxynucleotides (ODNs) can selectively inhibit individual gene expression provided they gain access to and remain stable at the target site for a sufficient period of time. Biodegradable sustained-release delivery systems may facilitate site-specific delivery and also prevent degradation of ODNs by nucleases whilst delivering the nucleic acid in a controlled manner to the desired site of action. In this study, we have characterized biodegradable poly (lactide-co-glycolide) (P(LA-GA)) 50:50 microspheres for the potential delivery of antisense oligonucleotides in vivo. Phosphodiester (PO) oligonucleotides complementary to either c-myc proto-oncogene or the tat gene in HIV-RNA were adequately incorporated within P(LA-GA) microspheres with entrapment efficiencies up to 60% depending on particles size. In vitro release profiles of antisense nucleic acids from 10-20 microm size microspheres over 56 days in physiological buffer were triphasic. Profiles were characterised by an initial burst effect during the first 48 hours (phase 1) of release followed by a more sustained release (phase 2) with an additional increased release (phase 3) being observed after 25 days which corresponded with bulk degradation of the copolymer matrix. The release profiles were influenced by microsphere size, copolymer molecular weight, ODN loading, ODN length and by the pH of release medium used. The serum stability of PO ODNs was significantly improved when entrapped within P(LA-GA) microspheres and the hybridization capability, as assessed by duplex melting (Tm) measurements, of released ODN was not impaired by the double-emulsion microsphere fabrication procedure used. Thus, P(LA-GA) microspheres appear to be promising candidates for improving site-specific delivery profiles for ODNs and are worthy of further evaluation in vivo.
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Affiliation(s)
- K J Lewis
- Pharmaceutical Sciences Institute, Aston University, Birmingham, UK
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Abstract
The therapeutic efficacy of tacrine, atropine and glycopyrrolate alone or in combination with the oxime HI-6 against soman was evaluated in anaesthetized rats. Arterial blood pressure, heart rate, respiratory frequency and body temperature were monitored in vivo. Blood cholinesterases were determined after each drug or soman challenge. At the lowest concentration tested (2.5 mg kg-1), tacrine was effective in improving the survivability of the rat by a factor of 2.6 (protection ratio), whereas the protection by atropine or glycopyrrolate was either insignificant or only marginally effective (protection ratio ranged from 1.0 to 1.9). In combination with HI-6, atropine increased the ratio to 4.6. In contrast, tacrine with HI-6 failed to improve the efficacy of the regimen, while glycopyrrolate plus HI-6 showed only slight improvement. The four physiological parameters monitored were relatively constant during the time course of the experiment in both the control and those with drug therapy. The more noticeable changes occurred toward the end of the experiment when sufficient amount of soman was injected to cause lethality. Death of the animal was usually preceded by a surge of arterial blood pressure and heart rate and a decrease in respiratory frequency. These physiological parameters rapidly deteriorated to zero just before the animal died. Blood and plasma cholinesterases were significantly inhibited after the animal received a relatively small dose of soman (20 micrograms kg-1) and were almost completely inactivated after the lethal dose of soman was administered. However, these changes of enzyme activity did not correspond well with the survivability of the rat. The inclusion of HI-6 with the three antimuscarinics appeared to be capable of protecting some cholinesterases against soman.
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Affiliation(s)
- W M Lau
- Aeronautical and Maritime Research Laboratory, Defence Science and Technology Organization, Department of Defence, Melbourne, Victoria, Australia
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Abstract
Insulin-like growth factor I (IGF-I) at concentrations of 40 ng/ml is lipogenic in ovine adipose tissue slices in vitro. Neither human IGF-II (hIGF-II) or rat IGF-II (rIGF-II) [multiplication-stimulating activity (MSA)] is lipogenic at similar concentrations. However, when present at lower concentrations recombinant human IGF-I (rhIGF-I) (400 pg/ml), hIGF-II (0.4 pg/ml), and MSA (40 pg/ml) were lipolytic. As IGF-II appeared more potent than IGF-I in promoting lipolysis, this effect may be mediated via the type 2 IGF receptor. The lipolytic effect of GH may be partly due to the actions of IGFs released locally.
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Affiliation(s)
- K J Lewis
- Department of Biological Sciences, University of Waikato, Hamilton, New Zealand
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Lewis KJ. Much ado about car parking--a radical solution realised. Hosp Health Serv Rev 1985; 81:172-6. [PMID: 10272315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Lewis KJ. The delivery of prevention in a general dental practice. Dent Update 1981; 8:405-6, 409-12, 414-5. [PMID: 6951780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Abstract
When formalin-sterilized dialyzers were rinsed by our standard technique (similar to that used in many other dialysis centres) undesirable concentrations of formaldehyde were found in the dialyzers at the start of dialysis. When the technique was modified by passing part of the saline through the blood compartment immediately before connection and discarding the saline left in the dialyzer at the time of connection, the concentration of formaldehyde infused into the patient fell below 2 micrograms/ml. However, the dialyzers still contained up to 13 mg of formaldehyde which leached slowly from the dialyzer during simulated dialysis. Some residual formaldehyde was found in several components of the dialyzer but the great majority was contained in the cellulose membrane.
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Lewis KJ, Dewar PJ, Ward MK, Kerr DN. Formation of anti-N-like antibodies in dialysis patients: effect of different methods of dialyzer rinsing to remove formaldehyde. Clin Nephrol 1981; 15:39-43. [PMID: 6971198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Use of formalin to sterilize dialyzers is known to be responsible for the formation of anti-N-like antibody in long-term hemodialysis patients. Patients dialyzed as in-patients using formalin were found to be completely free of anti-N-like antibody, while among those on home dialysis, there was a high prevalence (31%) and incidence. The hospital patients were found to be receiving concentrations of formaldehyde less than 1 microgram/ml while those on home dialysis received 3-13 micrograms/ml. This is offered as an explanation for the absence of anti-N-antibody in patients using formalin-sterilized dialyzers.
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Barber TL, Walton TE, Lewis KJ. Efficacy of trivalent inactivated encephalomyelitis virus vaccine in horses. Am J Vet Res 1978; 39:621-5. [PMID: 646197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Twenty-nine horses were vaccinated with a trivalent (Venezuelan, eastern, and western) inactivated equine encephalomyelitis virus vaccine. The vaccine purchased for this study was the only one licensed and commercially available in May, 1975. Plaque-neutralizing and hemagglutinin-inhibiting antibodies in response to each of the 3 equine encephalomyelitis viruses were determined after vaccination. Horses had rising levels of plaque-neutralizing and hemagglutinin-inhibiting antibodies shortly after injection with the 1st and 2nd doses of the vaccine (given 3 weeks apart) and were refractory to challenge of immunity with virulent homologous virus at 3, 8, and 12 months after vaccination. After 12 months, 8 horses were revaccinated; maximum antigenic stimulation was achieved with the 1st dose of the 2nd series of vaccinations.
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Lewis KJ, Doyle MD. Nutrient intake and weight response of women on weight-control diets. J Am Diet Assoc 1970; 56:119-25. [PMID: 5412059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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