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Blaker CL, Ashton DM, Hartnell N, Little CB, Clarke EC. Tendon biomechanical properties are altered by storage duration but not freeze-thaw temperatures or cycles. J Orthop Res 2024; 42:1180-1189. [PMID: 38245841 DOI: 10.1002/jor.25783] [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: 08/29/2023] [Revised: 12/11/2023] [Accepted: 12/24/2023] [Indexed: 01/22/2024]
Abstract
Tendon allograft and xenograft processing often involves one or more steps of freezing and thawing. As failure strength is an important graft consideration, this study aimed to evaluate effects on failure properties when varying freeze-thaw conditions. Kangaroo tendons, a potential xenograft source, were used to evaluate changes in ultimate tensile strength (UTS), failure strain and elastic modulus after exposure to different freezer-storage temperatures (-20°C vs. -80°C), storage durations (1, 3, 6, 9, or 12 months), number of freeze-thaw cycles (1, 2, 3, 4, 5, or 10), or freeze-thaw temperature ranges (including freezing in liquid nitrogen to thawing at 37°C). Tendons stored for 6 or more months had significantly increased UTS and elastic modulus compared with 1 or 3 months of storage. This increase occurred irrespective of the freezing temperature (-20°C vs. -80°C) or the number of freeze-thaw cycles (1 vs. 10). In contrast, UTS, failure strain and the elastic modulus were no different between storage temperatures, number of freeze-thaw cycles and multiple freeze-thaw cycles across a range of freeze and thaw temperatures. Common freeze-thaw protocols did not negatively affect failure properties, providing flexibility for graft testing, storage, transportation and decellularisation procedures. However, the change in properties with the overall storage duration has implications for assessing the consistent performance of grafts stored for short versus extended periods of time (<6 months vs. >6 months), and the interpretation of data obtained from tissues of varying or unknown storage durations.
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Affiliation(s)
- Carina L Blaker
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Faculty of Medicine and Health, The University of Sydney and the Northern Sydney Local Health District, Sydney, New South Wales, Australia
- Sydney Musculoskeletal Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Dylan M Ashton
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Faculty of Medicine and Health, The University of Sydney and the Northern Sydney Local Health District, Sydney, New South Wales, Australia
- Sydney Musculoskeletal Health, The University of Sydney, Sydney, New South Wales, Australia
| | | | - Christopher B Little
- Sydney Musculoskeletal Health, The University of Sydney, Sydney, New South Wales, Australia
- Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Faculty of Medicine and Health, The University of Sydney and the Northern Sydney Local Health District, Sydney, New South Wales, Australia
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Faculty of Medicine and Health, The University of Sydney and the Northern Sydney Local Health District, Sydney, New South Wales, Australia
- Sydney Musculoskeletal Health, The University of Sydney, Sydney, New South Wales, Australia
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Clarke EC. Considerations for Glycoprotein Production. Methods Mol Biol 2024; 2762:329-351. [PMID: 38315375 DOI: 10.1007/978-1-0716-3666-4_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
This chapter is intended to provide insights for researchers aiming to choose an appropriate expression system for the production of recombinant glycoproteins. Producing glycoproteins is complex, as glycosylation patterns are determined by the availability and abundance of specific enzymes rather than a direct genetic blueprint. Furthermore, the cell systems often employed for protein production are evolutionarily distinct, leading to significantly different glycosylation when utilized for glycoprotein production. The selection of an appropriate production system depends on the intended applications and desired characteristics of the protein. Whether the goal is to produce glycoproteins mimicking native conditions or to intentionally alter glycan structures for specific purposes, such as enhancing immunogenicity in vaccines, understanding glycosylation present in the different systems and in different growth conditions is essential. This chapter will cover Escherichia coli, baculovirus/insect cell systems, Pichia pastoris, as well as different mammalian cell culture systems including Chinese hamster ovary (CHO) cells, human endothelial kidney (HEK) cell lines, and baby hamster kidney (BHK) cells.
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Affiliation(s)
- Elizabeth C Clarke
- Center for Global Health, Division of Infectious Diseases, Department of Internal Medicine, University of New Mexico, Albuquerque, NM, USA.
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Haubruck P, Heller R, Blaker CL, Clarke EC, Smith SM, Burkhardt D, Liu Y, Stoner S, Zaki S, Shu CC, Little CB. Streamlining quantitative joint-wide medial femoro-tibial histopathological scoring of mouse post-traumatic knee osteoarthritis models. Osteoarthritis Cartilage 2023; 31:1602-1611. [PMID: 37716405 DOI: 10.1016/j.joca.2023.07.013] [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: 08/07/2022] [Revised: 07/03/2023] [Accepted: 07/26/2023] [Indexed: 09/18/2023]
Abstract
OBJECTIVES Histological scoring remains the gold-standard for quantifying post-traumatic osteoarthritis (ptOA) in animal models, allowing concurrent evaluation of numerous joint tissues. Available systems require scoring multiple sections/joint making analysis laborious and expensive. We investigated if a single section allowed equivalent quantitation of pathology in different joint tissues and disease stages, in three ptOA models. METHOD Male 10-12-week-old C57BL/6 mice underwent surgical medial-meniscal-destabilization, anterior-cruciate-ligament (ACL) transection, non-invasive-ACL-rupture, or served as sham-surgical, non-invasive-ACL-strain, or naïve/non-operated controls. Mice (n = 12/group) were harvested 1-, 4-, 8-, and 16-week post-intervention. Serial sagittal toluidine-blue/fast-green stained sections of the medial-femoro-tibial joint (n = 7/joint, 84 µm apart) underwent blinded scoring of 40 histology-outcomes. We evaluated agreement between single-slide versus entire slide-set maximum or median scores (weighted-kappa), and sensitivity/specificity of single-slide versus median/maximum to detect OA pathology. RESULTS A single optimal mid-sagittal section showed excellent agreement with median (weighted-kappa 0.960) and maximum (weighted-kappa 0.926) scores. Agreement for individual histology-outcomes was high with only 19/240 median and 15/240 maximum scores having a weighted-kappa ≤0.4, the majority of these (16/19 and 11/15) in control groups. Statistically-significant histology-outcome differences between ptOA models and their controls detected with the entire slide-set were reliably reproduced using a single slide (sensitivity >93.15%, specificity >93.10%). The majority of false-negatives with single-slide scoring were meniscal and subchondral bone histology-outcomes (89%) and occurred in weeks 1-4 post-injury (84%). CONCLUSION A single mid-sagittal slide reduced the time needed to score diverse histopathological changes by 87% without compromising the sensitivity or specificity of the analysis, across a variety of ptOA models and time-points.
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Affiliation(s)
- Patrick Haubruck
- Centre for Orthopaedics, Trauma Surgery and Spinal Cord Injury, Trauma and Reconstructive Surgery, Heidelberg University Hospital, D-69118 Heidelberg, Germany; Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
| | - Raban Heller
- Centre for Orthopaedics, Trauma Surgery and Spinal Cord Injury, Trauma and Reconstructive Surgery, Heidelberg University Hospital, D-69118 Heidelberg, Germany; Institute for Experimental Endocrinology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt Universität zu Berlin, Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany; Bundeswehr Hospital Berlin, Clinic of Traumatology and Orthopaedics, D-10115 Berlin, Germany
| | - Carina L Blaker
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia; Murray Maxwell Biomechanics Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
| | - Susan M Smith
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
| | - Daniel Burkhardt
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
| | - Yolanda Liu
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
| | - Shihani Stoner
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
| | - Sanaa Zaki
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia; Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Australia
| | - Cindy C Shu
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
| | - Christopher B Little
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Institute of Bone and Joint Research, Faculty of Medicine and Health University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia.
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Ashton DM, Blaker CL, Hartnell N, Haubruck P, Hefferan SA, Little CB, Clarke EC. Challenging the Perceptions of Human Tendon Allografts: Influence of Donor Age, Sex, Height, and Tendon on Biomechanical Properties. Am J Sports Med 2023; 51:768-778. [PMID: 36594505 DOI: 10.1177/03635465221143385] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND The use of allograft tendons has increased for primary and revision anterior cruciate ligament reconstruction, but allograft supply is currently limited to a narrow range of tendons and donors up to the age of 65 years. Expanding the range of donors and tendons could help offset an increasing clinical demand. PURPOSE To investigate the effects of donor age, sex, height, and specific tendon on the mechanical properties of a range of human lower leg tendons. STUDY DESIGN Descriptive laboratory study. METHODS Nine tendons were retrieved from 39 fresh-frozen human cadaveric lower legs (35 donors [13 female, 22 male]; age, 49-99 years; height, 57-85 inches [145-216 cm]) including: Achilles tendon, tibialis posterior and anterior, fibularis longus and brevis, flexor and extensor hallucis longus, plantaris, and flexor digitorum longus. Tendons underwent tensile loading to failure measuring cross-sectional area (CSA), maximum load, strain at failure, ultimate tensile strength, and elastic modulus. Results from 332 tendons were analyzed using mixed-effects linear regression, accounting for donor age, sex, height, and weight. RESULTS Mechanical properties were significantly different among tendons and were substantially greater than the effects of donor characteristics. Significant effects of donor sex, age, and height were limited to specific tendons: Achilles tendon, tibialis posterior, and tibialis anterior. All other tendons were unaffected. The Achilles tendon was most influenced by donor variables: greater CSA in men (β = 15.45 mm2; Šidák adjusted P < .0001), decreased maximum load with each year of increased age (β = -17.20 N per year; adjusted P = .0253), and increased CSA (β = 1.92 mm2 per inch; adjusted P < .0001) and maximum load (β = 86.40 N per inch; adjusted P < .0001) with each inch of increased height. CONCLUSION Mechanical properties vary significantly across different human tendons. The effects of donor age, sex, and height are relatively small, are limited to specific tendons, and affect different tendons uniquely. The findings indicate that age negatively affected only the Achilles tendon (maximum load) and challenge the exclusion of donors aged >65 years across all tendon grafts. CLINICAL RELEVANCE The findings support including a broader range of tendons for use as allografts for anterior cruciate ligament reconstruction and reviewing the current exclusion criterion of donors aged >65 years.
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Affiliation(s)
- Dylan M Ashton
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute; Northern Sydney Local Health District; Sydney Musculoskeletal Health, Faculty of Medicine and Health, University of Sydney, St Leonards, Australia
| | - Carina L Blaker
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute; Northern Sydney Local Health District; Sydney Musculoskeletal Health, Faculty of Medicine and Health, University of Sydney, St Leonards, Australia
| | | | - Patrick Haubruck
- Heidelberg Trauma Research Group, Centre for Orthopaedics, Trauma Surgery and Spinal Cord Injury, Trauma and Reconstructive Surgery, Heidelberg University Hospital, Heidelberg, Germany.,Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute; Northern Sydney Local Health District; Sydney Musculoskeletal Health, Faculty of Medicine and Health, University of Sydney, St Leonards, Australia
| | - Samantha A Hefferan
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute; Northern Sydney Local Health District; Sydney Musculoskeletal Health, Faculty of Medicine and Health, University of Sydney, St Leonards, Australia
| | - Christopher B Little
- Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute; Northern Sydney Local Health District; Sydney Musculoskeletal Health, Faculty of Medicine and Health, University of Sydney, St Leonards, Australia
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Fowler A, Ye C, Clarke EC, Pascale JM, Peabody DS, Bradfute SB, Frietze KM, Chackerian B. A method for mapping the linear epitopes targeted by the natural antibody response to Zika virus infection using a VLP platform technology. Virology 2023; 579:101-110. [PMID: 36623351 PMCID: PMC9904412 DOI: 10.1016/j.virol.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/21/2022] [Accepted: 01/03/2023] [Indexed: 01/05/2023]
Abstract
Zika virus (ZIKV), a mosquito-borne pathogen, is associated with neurological complications in adults and congenital abnormalities in newborns. There are no vaccines or treatments for ZIKV infection. Understanding the specificity of natural antibody responses to ZIKV could help inform vaccine efforts. Here, we used a technology called Deep Sequence-Coupled Biopanning to map the targets of the human antibody responses to ZIKV infection. A bacteriophage virus-like particle (VLP) library displaying overlapping linear peptides derived from the ZIKV polyprotein was generated. The library was panned using IgG from 23 ZIKV-infected patients from Panama and deep sequencing identified common targets of anti-ZIKV antibodies within the ZIKV envelope glycoprotein. These included epitopes within the fusion loop within domain II and four epitopes within domain III. Additionally, we showed that VLPs displaying selected epitopes elicited antibodies that bound to native ZIKV envelope protein but failed to prevent infection in a mouse challenge model.
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Affiliation(s)
- Alexandra Fowler
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA.
| | - Chunyan Ye
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA
| | - Elizabeth C Clarke
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA
| | | | - David S Peabody
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA
| | - Steven B Bradfute
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA
| | - Kathryn M Frietze
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA
| | - Bryce Chackerian
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA.
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Little CB, Zaki S, Blaker CL, Clarke EC. Animal models of osteoarthritis. Bone Joint Res 2022; 11:514-517. [PMID: 35909339 PMCID: PMC9396918 DOI: 10.1302/2046-3758.118.bjr-2022-0217.r1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Cite this article: Bone Joint Res 2022;11(8):514–517.
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Affiliation(s)
- Christopher B. Little
- Raymond Purves Bone and Joint Research Laboratories, Kolling Institute, Faculty of Medicine and Health, University of Sydney and Northern Sydney Local Health District, Sydney, Australia
| | - Sanaa Zaki
- Raymond Purves Bone and Joint Research Laboratories, Kolling Institute, Faculty of Medicine and Health, University of Sydney and Northern Sydney Local Health District, Sydney, Australia
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, Australia
| | - Carina L. Blaker
- Murray Maxwell Biomechanics Laboratory, Kolling Institute, Faculty of Medicine and Health, University of Sydney and Northern Sydney Local Health District, Sydney, Australia
| | - Elizabeth C. Clarke
- Murray Maxwell Biomechanics Laboratory, Kolling Institute, Faculty of Medicine and Health, University of Sydney and Northern Sydney Local Health District, Sydney, Australia
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Clarke EC, Nofchissey RA, Ye C, Bradfute SB. The iminosugars celgosivir, castanospermine and UV-4 inhibit SARS-CoV-2 replication. Glycobiology 2021; 31:378-384. [PMID: 32985653 PMCID: PMC7543591 DOI: 10.1093/glycob/cwaa091] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/23/2020] [Accepted: 09/24/2020] [Indexed: 12/17/2022] Open
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic poses an unprecedented challenge for health care and the global economy. Repurposing drugs that have shown promise in inhibiting other viral infections could allow for more rapid dispensation of urgently needed therapeutics. The Spike protein of SARS-CoV-2 is extensively glycosylated with 22 occupied N glycan sites and is required for viral entry. In other glycosylated viral proteins, glycosylation is required for interaction with calnexin and chaperone-mediated folding in the endoplasmic reticulum, and prevention of this interaction leads to unfolded viral proteins and thus inhibits viral replication. As such, we investigated two iminosugars, celgosivir, a prodrug of castanospermine, and UV-4, or N-(9-methoxynonyl)-1-deoxynojirimycin, a deoxynojirimycin derivative. Iminosugars are known inhibitors of the α-glucosidase I and II enzymes and were effective at inhibiting authentic SARS-CoV-2 viral replication in a cell culture system. Celgosivir prevented SARS-CoV-2-induced cell death and reduced viral replication and Spike protein levels in a dose-dependent manner in culture with Vero E6 cells. Castanospermine, the active form of celgosivir, was also able to inhibit SARS-CoV-2, confirming the canonical castanospermine mechanism of action of celgosivir. The monocyclic UV-4 also prevented SARS-CoV-2-induced death and reduced viral replication after 24 h of treatment, although the reduction in viral copies was lost after 48 h. Our findings suggest that iminosugars should be urgently investigated as potential SARS-CoV-2 inhibitors.
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Affiliation(s)
- Elizabeth C Clarke
- MSC10 5550 Department of Internal Medicine, 1 University of New Mexico Albuquerque, NM, 87131, USA
| | - Robert A Nofchissey
- MSC10 5550 Department of Internal Medicine, 1 University of New Mexico Albuquerque, NM, 87131, USA
| | - Chunyan Ye
- MSC10 5550 Department of Internal Medicine, 1 University of New Mexico Albuquerque, NM, 87131, USA
| | - Steven B Bradfute
- MSC10 5550 Department of Internal Medicine, 1 University of New Mexico Albuquerque, NM, 87131, USA
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Blaker CL, Zaki S, Little CB, Clarke EC. Long-term Effect of a Single Subcritical Knee Injury: Increasing the Risk of Anterior Cruciate Ligament Rupture and Osteoarthritis. Am J Sports Med 2021; 49:391-403. [PMID: 33378213 DOI: 10.1177/0363546520977505] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Rupture of the anterior cruciate ligament (ACL) is a well-known risk factor for the development of posttraumatic osteoarthritis (PTOA), but patients with the "same injury" can have vastly different trajectories for the onset and progression of disease. Minor subcritical injuries preceding the critical injury event may drive this disparity through preexisting tissue pathologies and sensory changes. PURPOSE To investigate the role of subcritical injury on ACL rupture risk and PTOA through the evaluation of pain behaviors, joint mechanics, and tissue structural change in a mouse model of knee injury. STUDY DESIGN Controlled laboratory study. METHODS Ten-week-old male C57BL/6J mice were allocated to naïve control and subcritical knee injury groups. Injury was induced by a single mechanical compression to the right hindlimb, and mice were evaluated using joint histopathology, anteroposterior joint biomechanics, pain behaviors (mechanical allodynia and hindlimb weightbearing), and isolated ACL tensile testing to failure at 1, 2, 4, or 8 weeks after injury. RESULTS Subcritical knee injury produced focal osteochondral lesions in the patellofemoral and lateral tibiofemoral compartments with no resolution for the duration of the study (8 weeks). These lesions were characterized by focal loss of proteoglycan staining, cartilage structural change, chondrocyte pathology, microcracks, and osteocyte cell loss. Injury also resulted in the rapid onset of allodynia (at 1 week), which persisted over time and reduced ACL failure load (P = .006; mean ± SD, 7.91 ± 2.01 N vs 9.37 ± 1.01 N in naïve controls at 8 weeks after injury), accompanied by evidence of ACL remodeling at the femoral enthesis. CONCLUSION The present study in mice establishes a direct effect of a single subcritical knee injury on the development of specific joint tissue pathologies (osteochondral lesions and progressive weakening of the ACL) and allodynic sensitization. These findings demonstrate a predisposition for secondary critical injuries (eg, ACL rupture) and an increased risk of PTOA onset and progression (structurally and symptomatically). CLINICAL RELEVANCE Subcritical knee injuries are a common occurrence and, based on this study, can cause persistent sensory and structural change. These findings have important implications for the understanding of risk factors of ACL injury and subsequent PTOA, particularly with regard to prevention and management strategies following an often underreported event.
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Affiliation(s)
- Carina L Blaker
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, Northern Clinical School, University of Sydney, St Leonards, Australia.,Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, Northern Clinical School, University of Sydney, St Leonards, Australia
| | - Sanaa Zaki
- Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, Northern Clinical School, University of Sydney, St Leonards, Australia.,Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Camperdown, Australia
| | - Christopher B Little
- Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, Northern Clinical School, University of Sydney, St Leonards, Australia
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, Northern Clinical School, University of Sydney, St Leonards, Australia
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Blaker CL, Ashton DM, Doran N, Little CB, Clarke EC. Sex- and injury-based differences in knee biomechanics in mouse models of post-traumatic osteoarthritis. J Biomech 2020; 114:110152. [PMID: 33285491 DOI: 10.1016/j.jbiomech.2020.110152] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/21/2020] [Accepted: 11/23/2020] [Indexed: 01/14/2023]
Abstract
Sex and joint injury are risk factors implicated in the onset and progression of osteoarthritis (OA). In mouse models of post-traumatic OA (ptOA), the pathogenesis of disease is notably impacted by sex (often worse in males) and injury model (e.g. meniscal versus ligament injury). Increasing ptOA progression and severity is often associated with greater relative instability of the joint but few studies have directly quantified changes in joint mechanics after injury and compared outcomes across multiple models in both male and female mice. Passive anterior-posterior knee biomechanics were evaluated in 10-week-old, male and female C57BL/6J mice. PtOA injury models included destabilisation of the medial meniscus (DMM), anterior cruciate ligament transection (ACLT) or mechanical rupture (ACLR), and combined DMM and ACLT (DMM + ACLT). Sham operated and non-operated controls (NOC) were included for baseline comparisons. The test apparatus loaded hindlimbs at 60° flexion between ± 1 N at 0.5 mm/s (build specifications available for download: https://doi.org/10.17632/z754455x3c.1). Measures of joint laxity (range of motion, neutral zone) and stiffness were calculated. Joint laxity was comparable between male and female mice while joint stiffness was greater in females (P ≤ 0.002, correcting for body-mass and injury-model). Anterior-posterior joint mechanics were minimally altered by DMM but significantly affected by loss of the ACL (P < 0.001), with equivalent changes between ACL-injury models despite different injury mechanisms and adjacent meniscal damage. These findings suggest that despite the important role of joint injury; sex- and model-specific differences in ptOA progression and severity are not primarily driven by altered anterior-posterior knee biomechanics.
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Affiliation(s)
- Carina L Blaker
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, University of Sydney, St. Leonards, New South Wales, Australia; Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, University of Sydney, St. Leonards, New South Wales, Australia
| | - Dylan M Ashton
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, University of Sydney, St. Leonards, New South Wales, Australia
| | - Nathan Doran
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, University of Sydney, St. Leonards, New South Wales, Australia; School of Biomedical Engineering, University of New South Wales, Kensington, New South Wales, Australia
| | - Christopher B Little
- Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, University of Sydney, St. Leonards, New South Wales, Australia
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, University of Sydney, St. Leonards, New South Wales, Australia.
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Bradfute SB, Ye C, Clarke EC, Kumar S, Timmins GS, Deretic V. Ambroxol and Ciprofloxacin Show Activity Against SARS-CoV2 in Vero E6 Cells at Clinically-Relevant Concentrations. bioRxiv 2020:2020.08.11.245100. [PMID: 32817934 PMCID: PMC7430564 DOI: 10.1101/2020.08.11.245100] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We studied the activity of a range of weakly basic and moderately lipophilic drugs against SARS CoV2 in Vero E6 cells, using Vero E6 survival, qPCR of viral genome and plaque forming assays. No clear relationship between their weakly basic and hydrophobic nature upon their activity was observed. However, the approved drugs ambroxol and ciprofloxacin showed potent activity at concentrations that are clinically relevant and within their known safety profiles, and so may provide potentially useful agents for preclinical and clinical studies in COVID-19.
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Affiliation(s)
- Steven B Bradfute
- Center for Global Health, Department of Internal Medicine, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Chunyan Ye
- Center for Global Health, Department of Internal Medicine, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Elizabeth C Clarke
- Center for Global Health, Department of Internal Medicine, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Suresh Kumar
- Autophagy, Inflammation and Metabolism (AIM) Center, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- Department of Microbiology and Molecular Genetics, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Graham S Timmins
- Autophagy, Inflammation and Metabolism (AIM) Center, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Vojo Deretic
- Autophagy, Inflammation and Metabolism (AIM) Center, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- Department of Microbiology and Molecular Genetics, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
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11
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Clarke EC, Bradfute S. The impact of glycoyslation on filovirus vaccine immunogenicity in mice. The Journal of Immunology 2020. [DOI: 10.4049/jimmunol.204.supp.247.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Filoviruses are highly virulent pathogens which cause severe hemorrhagic fevers, including Ebola virus disease (EVD). There is currently an ongoing large outbreak in the Democratic Republic of Congo, and while investigational vaccines have been used in trials during the outbreak, there are no licensed vaccines to EVD, or the related Marburg virus disease (MVD). The glycoproteins of filoviruses are the only virally expressed proteins on the virion surface and are required for receptor binding and as such, they are the main candidate vaccine antigen. A major component of the glycoprotein are the N- and O-linked glycans, but these glycans vary in number, distribution and type depending on the cell type producing the glycoprotein. Both mammalian and insect cell lines are commonly used to produce filovirus proteins used in vaccine development, but produce proteins with very different glycosylation. Here, we describe the impact of the filovirus glycoprotein glycans on the immunogenicity of the transmembrane-deleted glycoprotein (GPdTM) vaccine in mice using insect-produced, mammalian-produced, and deglycosylated filovirus glycoproteins. Results suggest differences in antibody titer and T cell epitopes induced between glycoproteins with different glycosylation patterns. Studies are underway to test how these changes affect survival against live virus challenge with mouse-adapted Ebola and Marburg.
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12
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Taha ME, Schneider K, Clarke EC, O'Briain DE, Smith MM, Cunningham G, Cass B, Young AA. A Biomechanical Comparison of Different Suture Materials Used for Arthroscopic Shoulder Procedures. Arthroscopy 2020; 36:708-713. [PMID: 31727418 DOI: 10.1016/j.arthro.2019.08.048] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 08/18/2019] [Accepted: 08/20/2019] [Indexed: 02/02/2023]
Abstract
PURPOSE To evaluate the viscoelastic properties of 4 commercially available cord-like sutures and 2 commercially available suture tapes when subjected to physiological loads, as well as to compare them with each other and to identify the clinically most desirable combination of suture material properties. METHODS Six suture materials (Ethibond, FiberWire, FiberTape, Orthocord, Ultrabraid, and Ultratape) underwent creep testing (n = 7, 60 N, 10 minutes) to determine specimen stiffness, initial elongation at 60 N of load, static creep (during 10 minutes of loading), and relaxed elongation (material recovery 3 minutes after removal of load). Furthermore, cyclic testing (n = 7, 10-45 N, 0.5 Hz, 500 cycles) was carried out to determine dynamic creep, peak-to-peak displacement, and relaxed elongation. Mechanical testing was conducted on a material testing machine in 37°C phosphate-buffered saline solution. RESULTS FiberTape showed the greatest stiffness (23.9 ± 3.2 N/mm, P < .001), the smallest amounts of static (0.38 ± 0.10 mm, P < .001) and dynamic (0.16 ± 0.09 mm, P = .003) creep, and the smallest peak-to-peak displacement (0.20 ± 0.02 mm, P < .001). FiberTape and FiberWire showed the smallest initial elongation (1.17 ± 0.17 mm and 1.63 ± 0.25 mm, respectively; P < .001). Ultrabraid showed the greatest relaxed elongation, both statically (4.73 ± 0.73 mm, P < .001) and dynamically (4.18 ± 0.83 mm, P = .002). CONCLUSIONS FiberTape consistently displayed less creep, greater stiffness, and less extensibility than the other suture types. Ultrabraid showed the largest amount of relaxed elongation on both static and dynamic testing. CLINICAL RELEVANCE When considering high stiffness in combination with low initial extension and low static creep to be ideal parameters to achieve optimal initial construct stability and considering low dynamic creep in combination with low peak-to-peak displacement to be ideal conditions for the repetitive loading of the construct during the healing process, tapes seem to be superior to cord-like sutures for performing rotator cuff repair.
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Affiliation(s)
- Mohy E Taha
- Division of Orthopaedics and Trauma Surgery, Basel University Hospital, Basel, Switzerland
| | - Kerstin Schneider
- Department of Paediatric Orthopaedics, Schulthess Clinic Zurich, Zurich, Switzerland.
| | | | - David E O'Briain
- Department of Orthopaedic Service, University Hospital Waterford, Waterford, Ireland
| | - Margaret M Smith
- Raymond Purves Research Labs, University of Sydney, Sydney, Australia
| | - Gregory Cunningham
- Shoulder Center, Hirslanden Clinique la Colline, Geneva, Switzerland; Division of Orthopaedics and Trauma Surgery, University of Geneva, Geneva, Switzerland
| | - Benjamin Cass
- Sydney Shoulder Research Institute, Sydney, Australia
| | - Allan A Young
- Sydney Shoulder Research Institute, Sydney, Australia
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13
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Clarke EC, Bradfute SB. The use of mice lacking type I or both type I and type II interferon responses in research on hemorrhagic fever viruses. Part 1: Potential effects on adaptive immunity and response to vaccination. Antiviral Res 2020; 174:104703. [DOI: 10.1016/j.antiviral.2019.104703] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 12/10/2019] [Accepted: 12/20/2019] [Indexed: 12/25/2022]
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14
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Kunamneni A, Clarke EC, Ye C, Bradfute SB, Durvasula R. Generation and Selection of a Panel of Pan-Filovirus Single-Chain Antibodies using Cell-Free Ribosome Display. Am J Trop Med Hyg 2020; 101:198-206. [PMID: 31074409 PMCID: PMC6609206 DOI: 10.4269/ajtmh.18-0658] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Filoviruses, which include ebolaviruses and marburgvirus, can cause outbreaks of highly lethal hemorrhagic fever. This disease causes significant morbidity and mortality in humans and non-human primates, with human fatality rates reaching 90% during some outbreaks. Currently, there is lack of licensed vaccines or antivirals for these viruses. Since early symptoms of filovirus infection mimic more common diseases, there is a strong unmet public health and biodefense need for broad-spectrum filovirus rapid diagnostics. We have generated a panel of mouse single-chain Fv-antibodies (scFvs) to filovirus glycoproteins (GPs) using cell-free ribosome display and determined their cross-reactivity profiles to all known filovirus species. Two scFvs (4-2 and 22-1) were able to detect all known Ebolavirus and Marburgvirus species. This is the first report on ribosome display scFvs that can detect a broad set of filovirus GPs, which demonstrates the potential for use in diagnostics.
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Affiliation(s)
- Adinarayana Kunamneni
- Department of Medicine, Loyola University Medical Center, Chicago, Illinois.,Department of Internal Medicine, Center for Global Health, University of New Mexico, Albuquerque, New Mexico
| | - Elizabeth C Clarke
- Department of Internal Medicine, Center for Global Health, University of New Mexico, Albuquerque, New Mexico
| | - Chunyan Ye
- Department of Internal Medicine, Center for Global Health, University of New Mexico, Albuquerque, New Mexico
| | - Steven B Bradfute
- Department of Internal Medicine, Center for Global Health, University of New Mexico, Albuquerque, New Mexico
| | - Ravi Durvasula
- Department of Internal Medicine, Center for Global Health, University of New Mexico, Albuquerque, New Mexico.,Department of Medicine, Loyola University Medical Center, Chicago, Illinois
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15
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Blaker CL, Clarke EC, Little CB. Adding insult to injury: synergistic effect of combining risk-factors in models of post-traumatic osteoarthritis. Osteoarthritis Cartilage 2019; 27:1731-1734. [PMID: 31276817 DOI: 10.1016/j.joca.2019.06.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 06/25/2019] [Indexed: 02/02/2023]
Affiliation(s)
- C L Blaker
- Murray Maxwell Biomechanics Laboratory, St Leonards, NSW, Australia
| | - E C Clarke
- Murray Maxwell Biomechanics Laboratory, St Leonards, NSW, Australia
| | - C B Little
- Raymond Purves Bone and Joint Research Laboratory, Royal North Shore Hospital, Kolling Institute and Institute of Bone and Joint Research, University of Sydney, St Leonards, NSW, Australia.
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16
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Graham DJ, Clitherow HDS, Singh HP, Clarke EC, Smith BJ, Tonkin MA. The Effect of Extensor Tendon Adhesions on Finger Motion. J Hand Surg Am 2019; 44:903.e1-903.e5. [PMID: 30733099 DOI: 10.1016/j.jhsa.2018.12.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 04/26/2018] [Revised: 10/24/2018] [Accepted: 12/19/2018] [Indexed: 02/02/2023]
Abstract
PURPOSE To quantify the amount and pattern of finger range of motion loss at the metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints with a simulated extensor tendon adhesion at the level of the proximal phalanx or metacarpal. METHODS In 10 cadaveric specimens, traction sutures were placed in the forearm extensor digitorum communis and flexor digitorum profundus tendons of the middle and ring fingers. Active motion was simulated by suspending weights from the traction sutures via pulleys. The angles of the MCP, PIP, and DIP joints were measured at the position of maximum flexion and extension. Extensor tendon adhesions were simulated alternately at the proximal phalanx and metacarpal levels of the middle and ring fingers, using suture anchors. Repeat measurements were taken using the same amount of force. RESULTS There was an average total loss of flexion of 38° and of extension of 6° with a proximal phalanx adhesion, with a greater contribution of flexion loss at the PIP joint. The loss of flexion was 17° and of extension was 50° with a metacarpal adhesion, with a loss of extension mostly at the MCP joint. CONCLUSIONS The results of this study identified clear patterns of motion loss that are associated with isolated simulated adhesions in different locations along the extensor mechanism. The greatest motion loss occurred at the joint immediately distal to the simulated adhesion. CLINICAL RELEVANCE Although extrapolation of these findings to clinical relevance remains unclear, the ability to predict the level of adhesion by the pattern of motion restriction may allow for a targeted tenolysis procedure. This would reduce the amount of soft tissue dissection required, which in turn, could be expected to reduce the degree of repeat adhesion formation.
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Affiliation(s)
- David J Graham
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, Sydney, Australia
| | - Harry D S Clitherow
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, Sydney, Australia
| | - Harvinder P Singh
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, Sydney, Australia
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Kolling Institute of Medical Research, University of Sydney, Sydney, Australia
| | - Belinda J Smith
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, Sydney, Australia
| | - Michael A Tonkin
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, Sydney, Australia.
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17
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Choi RK, Smith MM, Smith S, Little CB, Clarke EC. Functionally distinct tendons have different biomechanical, biochemical and histological responses to in vitro unloading. J Biomech 2019; 95:109321. [DOI: 10.1016/j.jbiomech.2019.109321] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 08/02/2019] [Accepted: 08/15/2019] [Indexed: 01/29/2023]
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18
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Jones CF, Clarke EC. Engineering approaches to understanding mechanisms of spinal column injury leading to spinal cord injury. Clin Biomech (Bristol, Avon) 2019; 64:69-81. [PMID: 29625748 DOI: 10.1016/j.clinbiomech.2018.03.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 02/16/2018] [Accepted: 03/24/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND The mechanical interactions occurring between the spinal column and spinal cord during an injury event are complex and variable, and likely have implications for the clinical presentation and prognosis of the individual. METHODS The engineering approaches that have been developed to better understand spinal column and cord interactions during an injury event are discussed. These include injury models utilising human and animal cadaveric specimens, in vivo anaesthetised animals, finite element models, inanimate physical systems and combinations thereof. FINDINGS The paper describes the development of these modelling approaches, discusses the advantages and disadvantages of the various models, and the major outcomes that have had implications for spinal cord injury research and clinical practice. INTERPRETATION The contribution of these four engineering approaches to understanding the interaction between the biomechanics and biology of spinal cord injury is substantial; they have improved our understanding of the factors contributing to the spinal column disruption, the degree of spinal cord deformation or motion, and the resultant neurological deficit and imaging features. Models of the injury event are challenging to produce, but technological advances are likely to improve these models and, consequently, our understanding of the mechanical context in which the biological injury occurs.
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Affiliation(s)
- Claire F Jones
- Spinal Research Group, Centre for Orthopaedics and Trauma Research, Adelaide Medical School, The University of Adelaide, Australia; School of Mechanical Engineering, The University of Adelaide, Australia
| | - Elizabeth C Clarke
- Institute for Bone and Joint Research, Kolling Institute, Sydney Medical School, University of Sydney, Australia.
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19
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Donald S, Niu R, Jones CW, Smith BJ, Clarke EC, Lawson RD. Reply to "Citation Accuracy Regarding the Influence of Compression on Fracture Healing". J Hand Surg Am 2018; 43:e13. [PMID: 30077232 DOI: 10.1016/j.jhsa.2018.05.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 05/21/2018] [Indexed: 02/02/2023]
Affiliation(s)
- Simon Donald
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia
| | - Rui Niu
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia
| | - Christopher W Jones
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia
| | - Belinda J Smith
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Kolling Institute, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Richard D Lawson
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia
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20
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Bolsterlee B, Finni T, D'Souza A, Eguchi J, Clarke EC, Herbert RD. Three-dimensional architecture of the whole human soleus muscle in vivo. PeerJ 2018; 6:e4610. [PMID: 29682414 PMCID: PMC5910694 DOI: 10.7717/peerj.4610] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/22/2018] [Indexed: 12/19/2022] Open
Abstract
Background Most data on the architecture of the human soleus muscle have been obtained from cadaveric dissection or two-dimensional ultrasound imaging. We present the first comprehensive, quantitative study on the three-dimensional anatomy of the human soleus muscle in vivo using diffusion tensor imaging (DTI) techniques. Methods We report three-dimensional fascicle lengths, pennation angles, fascicle curvatures, physiological cross-sectional areas and volumes in four compartments of the soleus at ankle joint angles of 69 ± 12° (plantarflexion, short muscle length; average ± SD across subjects) and 108 ± 7° (dorsiflexion, long muscle length) of six healthy young adults. Microdissection and three-dimensional digitisation on two cadaveric muscles corroborated the compartmentalised structure of the soleus, and confirmed the validity of DTI-based muscle fascicle reconstructions. Results The posterior compartments of the soleus comprised 80 ± 5% of the total muscle volume (356 ± 58 cm3). At the short muscle length, the average fascicle length, pennation angle and curvature was 37 ± 8 mm, 31 ± 3° and 17 ± 4 /m, respectively. We did not find differences in fascicle lengths between compartments. However, pennation angles were on average 12° larger (p < 0.01) in the posterior compartments than in the anterior compartments. For every centimetre that the muscle-tendon unit lengthened, fascicle lengths increased by 3.7 ± 0.8 mm, pennation angles decreased by −3.2 ± 0.9° and curvatures decreased by −2.7 ± 0.8 /m. Fascicles in the posterior compartments rotated almost twice as much as in the anterior compartments during passive lengthening. Discussion The homogeneity in fascicle lengths and inhomogeneity in pennation angles of the soleus may indicate a functionally different role for the anterior and posterior compartments. The data and techniques presented here demonstrate how DTI can be used to obtain detailed, quantitative measurements of the anatomy of complex skeletal muscles in living humans.
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Affiliation(s)
- Bart Bolsterlee
- Neuroscience Research Australia (NeuRA), Sydney, New South Wales, Australia.,University of New South Wales, Sydney, New South Wales, Australia
| | - Taija Finni
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Arkiev D'Souza
- Neuroscience Research Australia (NeuRA), Sydney, New South Wales, Australia.,University of New South Wales, Sydney, New South Wales, Australia
| | - Junya Eguchi
- Neuroscience Research Australia (NeuRA), Sydney, New South Wales, Australia.,University of New South Wales, Sydney, New South Wales, Australia
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Institute for Bone and Joint Research, Kolling Institute of Medical Research, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Robert D Herbert
- Neuroscience Research Australia (NeuRA), Sydney, New South Wales, Australia.,University of New South Wales, Sydney, New South Wales, Australia
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21
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Donald SM, Niu R, Jones CW, Smith BJ, Clarke EC, Lawson RD. Effects of Removal and Reinsertion of Headless Compression Screws. J Hand Surg Am 2018; 43:139-145. [PMID: 29137829 DOI: 10.1016/j.jhsa.2017.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 08/30/2017] [Accepted: 10/02/2017] [Indexed: 02/02/2023]
Abstract
PURPOSE This study investigates the loss of compression when 3 commonly used headless compression screws are backed out (reversed), and assesses the ability to re-establish compression with screws of greater diameter. METHODS Two investigators tested 3 screw designs (Acutrak 2, Synthes HCS, Medartis SpeedTip CCS) in 2 diameters and lengths. Each design had 10 test cycles in a polyurethane foam bone model with compression recorded using a washer load cell. A 28-mm screw of the narrower diameter was inserted until 2 mm recessed and then reversed 30°, 60°, 90°, 180°, 270°, 360°, and 720°. After this the screw was removed completely and a 24-mm screw of greater diameter inserted until recessed 2 mm with the compressive force again recorded. RESULTS All screws showed an immediate, statistically significant loss of compression at 30° of reversing. The Acutrak 2 Micro screw demonstrated not only the greatest mean compressive force, but also the fastest compressive loss. Insertion of the shorter screw of greater diameter was associated with re-establishment of compression to levels comparable with the original screw. CONCLUSIONS This study reaffirms the importance of establishing the correct screw length before insertion due to the immediate loss of compression with reversal of these devices. CLINICAL RELEVANCE If a headless compression screw penetrates the far joint surface, the screw should be completely removed and replaced with a shorter screw of greater diameter.
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Affiliation(s)
- Simon M Donald
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia
| | - Rui Niu
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia
| | - Christopher W Jones
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia
| | - Belinda J Smith
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Kolling Institute, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Richard D Lawson
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia.
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22
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Lloyd RA, Fletcher DF, Clarke EC, Bilston LE. Chiari malformation may increase perivascular cerebrospinal fluid flow into the spinal cord: A subject-specific computational modelling study. J Biomech 2017; 65:185-193. [DOI: 10.1016/j.jbiomech.2017.10.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/07/2017] [Accepted: 10/15/2017] [Indexed: 10/18/2022]
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23
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Clarke EC, Collar AL, Ye C, Caì Y, Anaya E, Rinaldi D, Martinez B, Yarborough S, Merle C, Theisen M, Wada J, Kuhn JH, Bradfute SB. Production and Purification of Filovirus Glycoproteins in Insect and Mammalian Cell Lines. Sci Rep 2017; 7:15091. [PMID: 29118454 PMCID: PMC5678155 DOI: 10.1038/s41598-017-15416-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 10/26/2017] [Indexed: 01/10/2023] Open
Abstract
Filoviruses are highly virulent pathogens capable of causing severe disease. The glycoproteins of filoviruses are the only virally expressed proteins on the virion surface and are required for receptor binding. As such, they are the main candidate vaccine antigen. Despite their virulence, most filoviruses are not comprehensively characterized, and relatively few commercially produced reagents are available for their study. Here, we describe two methods for production and purification of filovirus glycoproteins in insect and mammalian cell lines. Considerations of expression vector choice, modifications to sequence, troubleshooting of purification method, and glycosylation differences are all important for successful expression of filovirus glycoproteins in cell lines. Given the scarcity of commercially available filovirus glycoproteins, we hope our experiences with possible difficulties in purification of the proteins will facilitate other researchers to produce and purify filovirus glycoproteins rapidly.
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Affiliation(s)
- Elizabeth C Clarke
- Center for Global Health, Division of Infectious Diseases, Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Amanda L Collar
- Center for Global Health, Division of Infectious Diseases, Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Chunyan Ye
- Center for Global Health, Division of Infectious Diseases, Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Yíngyún Caì
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, 21702, USA
| | - Eduardo Anaya
- Department of Pathology, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Derek Rinaldi
- Department of Pathology, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Britney Martinez
- Undergraduate Pipeline Network, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Sarah Yarborough
- Undergraduate Pipeline Network, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | | | | | - Jiro Wada
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, 21702, USA
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, 21702, USA
| | - Steven B Bradfute
- Center for Global Health, Division of Infectious Diseases, Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico, 87131, USA.
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24
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Blaker CL, Little CB, Clarke EC. Joint loads resulting in ACL rupture: Effects of age, sex, and body mass on injury load and mode of failure in a mouse model. J Orthop Res 2017; 35:1754-1763. [PMID: 27601010 DOI: 10.1002/jor.23418] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/29/2016] [Indexed: 02/04/2023]
Abstract
Anterior cruciate ligament (ACL) tears are a common knee injury with a known but poorly understood association with secondary joint injuries and post-traumatic osteoarthritis (OA). Female sex and age are known risk factors for ACL injury but these variables are rarely explored in mouse models of injury. This study aimed to further characterize a non-surgical ACL injury model to determine its clinical relevance across a wider range of mouse specifications. Cadaveric and anesthetized C57BL/6 mice (9-52 weeks of age) underwent joint loading to investigate the effects of age, sex, and body mass on ACL injury mechanisms. The ACL injury load (whole joint load required to rupture the ACL) was measured from force-displacement data, and mode of failure was assessed using micro-dissection and histology. ACL injury load was found to increase with body mass and age (p < 0.001) but age was not significant when controlling for mass. Sex had no effect. In contrast, the mode of ACL failure varied with both age and sex groups. Avulsion fractures (complete or mixed with mid-substance tears) were common in all age groups but the proportion of mixed and mid-substance failures increased with age. Females were more likely than males to have a major avulsion relative to a mid-substance tear (p < 0.01). This data compliments studies in human cadaveric knees, and provides a basis for determining the severity of joint injury relative to a major ACL tear in mice, and for selecting joint loading conditions in future experiments using this model. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1754-1763, 2017.
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Affiliation(s)
- Carina L Blaker
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Sydney Medical School Northern, University of Sydney, St. Leonards, New South Wales, 2065, Australia.,Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Sydney Medical School Northern, University of Sydney, St. Leonards, New South Wales, 2065, Australia
| | - Christopher B Little
- Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Sydney Medical School Northern, University of Sydney, St. Leonards, New South Wales, 2065, Australia
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute, Sydney Medical School Northern, University of Sydney, St. Leonards, New South Wales, 2065, Australia
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Blaker CL, Clarke EC, Little CB. Using mouse models to investigate the pathophysiology, treatment, and prevention of post-traumatic osteoarthritis. J Orthop Res 2017; 35:424-439. [PMID: 27312470 DOI: 10.1002/jor.23343] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 06/14/2016] [Indexed: 02/04/2023]
Abstract
Post-traumatic osteoarthritis (PTOA) is defined by its development after joint injury. Factors contributing to the risk of PTOA occurring, the rate of progression, and degree of associated disability in any individual, remain incompletely understood. What constitutes an "OA-inducing injury" is not defined. In line with advances in the traumatic brain injury field, we propose the scope of PTOA-inducing injuries be expanded to include not only those causing immediate structural damage and instability (Type I), but also those without initial instability/damage from moderate (Type II) or minor (Type III) loading severity. A review of the literature revealed this full spectrum of potential PTOA subtypes can be modeled in mice, with 27 Type I, 6 Type II, and 4 Type III models identified. Despite limitations due to cartilage anatomy, joint size, and bio-fluid availability, mice offer advantages as preclinical models to study PTOA, particularly genetically modified strains. Histopathology was the most common disease outcome, cartilage more frequently studied than bone or synovium, and meniscus and ligaments rarely evaluated. Other methods used to examine PTOA included gene expression, protein analysis, and imaging. Despite the major issues reported by patients being pain and biomechanical dysfunction, these were the least commonly measured outcomes in mouse models. Informative correlations of simultaneously measured disease outcomes in individual animals, was rarely done in any mouse PTOA model. This review has identified knowledge gaps that need to be addressed to increase understanding and improve prevention and management of PTOA. Preclinical mouse models play a critical role in these endeavors. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:424-439, 2017.
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Affiliation(s)
- Carina L Blaker
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Level 10, Kolling Institute B6, Northern Sydney Local Health District, Sydney Medical School Northern, University of Sydney, The Royal North Shore Hospital, St. Leonards, New South Wales, 2065, Australia.,Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Sydney Medical School Northern, University of Sydney, St. Leonards, New South Wales, 2065, Australia
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Level 10, Kolling Institute B6, Northern Sydney Local Health District, Sydney Medical School Northern, University of Sydney, The Royal North Shore Hospital, St. Leonards, New South Wales, 2065, Australia
| | - Christopher B Little
- Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Sydney Medical School Northern, University of Sydney, St. Leonards, New South Wales, 2065, Australia
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Smith MM, Clarke EC, Little CB. Considerations for the design and execution of protocols for animal research and treatment to improve reproducibility and standardization: "DEPART well-prepared and ARRIVE safely". Osteoarthritis Cartilage 2017; 25:354-363. [PMID: 27816577 DOI: 10.1016/j.joca.2016.10.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/11/2016] [Accepted: 10/20/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To review the factors in experimental design that contribute to poor translation of pre-clinical research to therapies for patients with osteoarthritis (OA) and how this might be improved. METHODS Narrative review of the literature, and evaluation of the different stages of design conduct and analysis of studies using animal models of OA to define specific issues that might reduce quality of evidence and how this can be minimised. RESULTS Preventing bias and improving experimental rigour and reporting are important modifiable factors to improve translation from pre-clinical animal models to successful clinical trials of therapeutic agents. Despite publication and adoption by many journals of guidelines such as Animals in Research: Reporting In Vivo Experiments (ARRIVE), experimental animal studies published in leading rheumatology journals are still deficient in their reporting. In part, this may be caused by researchers first consulting these guidelines after the completion of experiments, at the time of publication. This review discusses factors that can (1) bias the outcome of experimental studies using animal models of osteoarthritis or (2) alter the quality of evidence for translation. We propose a checklist to consult prior to starting experiments; in the Design and Execution of Protocols for Animal Research and Treatment (DEPART). CONCLUSIONS Following DEPART during the design phase will enable completion of the ARRIVE checklist at the time of publication, and thus improve the quality of evidence for inclusion of experimental animal research in meta-analyses and systematic reviews: "DEPART well-prepared and ARRIVE safely".
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Affiliation(s)
- M M Smith
- Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute (University of Sydney), Level 10, Kolling Building, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
| | - E C Clarke
- Murray Maxwell Biomechanics Laboratory, Institute of Bone and Joint Research, Kolling Institute (University of Sydney), Level 10, Kolling Building, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
| | - C B Little
- Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute (University of Sydney), Level 10, Kolling Building, Royal North Shore Hospital, St Leonards, NSW 2065, Australia.
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Collar AL, Clarke EC, Anaya E, Merrill D, Yarborough S, Anthony SM, Kuhn JH, Merle C, Theisen M, Bradfute SB. Comparison of N- and O-linked glycosylation patterns of ebolavirus glycoproteins. Virology 2016; 502:39-47. [PMID: 27984785 DOI: 10.1016/j.virol.2016.12.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/06/2016] [Accepted: 12/07/2016] [Indexed: 11/18/2022]
Abstract
Ebolaviruses are emerging pathogens that cause severe and often fatal viral hemorrhagic fevers. Four distinct ebolaviruses are known to cause Ebola virus disease in humans. The ebolavirus envelope glycoprotein (GP1,2) is heavily glycosylated, but the precise glycosylation patterns of ebolaviruses are largely unknown. Here we demonstrate that approximately 50 different N-glycan structures are present in GP1,2 derived from the four pathogenic ebolaviruses, including high mannose, hybrid, and bi-, tri-, and tetra-antennary complex glycans with and without fucose and sialic acid. The overall N-glycan composition is similar between the different ebolavirus GP1,2s. In contrast, the amount and type of O-glycan structures varies widely between ebolavirus GP1,2s. Notably, this O-glycan dissimilarity is also present between two variants of Ebola virus, the original Yambuku variant and the Makona variant responsible for the most recent Western African epidemic. The data presented here should serve as the foundation for future ebolaviral entry and immunogenicity studies.
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Affiliation(s)
- Amanda L Collar
- Center for Global Health, Division of Infectious Diseases, Department of Internal Medicine, University of New Mexico, Albuquerque, NM, USA
| | - Elizabeth C Clarke
- Center for Global Health, Division of Infectious Diseases, Department of Internal Medicine, University of New Mexico, Albuquerque, NM, USA
| | - Eduardo Anaya
- Department of Pathology, University of New Mexico, Albuquerque, NM, USA
| | - Denise Merrill
- Center for Global Health, Division of Infectious Diseases, Department of Internal Medicine, University of New Mexico, Albuquerque, NM, USA
| | - Sarah Yarborough
- Undergraduate Pipeline Network, University of New Mexico, Albuquerque, NM, USA
| | - Scott M Anthony
- Department of Microbiology, University of Iowa, Iowa City, IA, USA
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Fort Detrick, Frederick, MD, USA
| | | | | | - Steven B Bradfute
- Center for Global Health, Division of Infectious Diseases, Department of Internal Medicine, University of New Mexico, Albuquerque, NM, USA.
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Clarke EC, Fletcher DF, Bilston LE. Sustained high-pressure in the spinal subarachnoid space while arterial expansion is low may be linked to syrinx development. Comput Methods Biomech Biomed Engin 2016; 20:457-467. [DOI: 10.1080/10255842.2016.1243665] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Elizabeth C. Clarke
- Murray Maxwell Biomechanics Laboratory, Institute for Bone and Joint Research, Kolling Institute of Medical Research, Sydney Medical School – Northern, University of Sydney, Sydney, Australia
| | - David F. Fletcher
- School of Chemical and Biomolecular Engineering, University of Sydney, Sydney, Australia
| | - Lynne E. Bilston
- Neuroscience Research Australia, and Prince of Wales Clinical School, UNSW Medicine, University of New South Wales, Sydney, Australia
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Borzelleca JF, Clarke EC, Condie LW. Short-Term Toxicity (1 and 10 Days) of Cadmium Chloride in Male and Female Rats: Gavage and Drinking Water. ACTA ACUST UNITED AC 2016. [DOI: 10.3109/10915818909019561] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Male and female Sprague-Dawley-derived rats received CdCl2 by gavage at doses of 25, 51, 107, and 225 mg CdCl2 per kg body weight per day for 1 or 10 consecutive days or in drinking solutions at concentrations of 13–323 mg CdCl2 per liter for 10 consecutive days. There were appropriate controls. In the 1 day study in males only, an apparent treatment-related but not statistically significant decrease in body weight was reported; spleen weights and ratios were significantly lower and lung weights and ratios were significantly higher (in the highest dose only). Dose-dependent mortality was observed in the 10 day gavage study. Body weight gain was depressed in a dose-dependent manner in both males and females. Weights and/or ratios of brain, liver, spleen, lungs, thymus, kidneys, and testes of treated males were depressed in a dose-dependent manner. In females, weights and/or ratios of liver, spleen, thymus, and kidneys were depressed in a dose-dependent manner. Focal necrotic changes in renal tubular epithelium and tubular degeneration were reported in males and females. Testicular and hepatic histopathologic changes (testicular atrophy and necrosis and hepatic necrosis) were also reported in males. In the drinking water study, males demonstrated dose-dependent decreases in body weight gain and weight and/or ratios of liver, spleen, thymus, and kidneys. There were no significant compound-related effects in females, although liver weights and ratios were lower. There were no compound-related histopathologic effects.
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Affiliation(s)
- Joseph F. Borzelleca
- Department of Pharmacology and Toxicology Medical College of Virginia Richmond, VA 23293
| | - Elizabeth C. Clarke
- Department of Pharmacology and Toxicology Medical College of Virginia Richmond, VA 23293
| | - L. W. Condie
- Department of Pharmacology and Toxicology Medical College of Virginia Richmond, VA 23293
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Choi RK, Smith MM, Martin JH, Clarke JL, Dart AJ, Little CB, Clarke EC. Chondroitin sulphate glycosaminoglycans contribute to widespread inferior biomechanics in tendon after focal injury. J Biomech 2016; 49:2694-2701. [PMID: 27316761 DOI: 10.1016/j.jbiomech.2016.06.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 05/28/2016] [Accepted: 06/01/2016] [Indexed: 11/24/2022]
Abstract
Both mechanical and structural properties of tendon change after injury however the causal relationship between these properties is presently unclear. This study aimed to determine the extent of biomechanical change in post-injury tendon pathology and whether the sulphated glycosaminoglycans (glycosaminoglycans) present are a causal factor in these changes. Equine superficial digital flexor tendons (SDF tendons) were surgically-injured in vivo (n=6 injured, n=6 control). Six weeks later they were harvested and regionally dissected into twelve regions around the lesion (equal medial/lateral, proximal/distal). Glycosaminoglycans were removed by enzymatic (chondroitinase) treatment. Elastic modulus (modulus) and ultimate tensile strength (UTS) were measured under uniaxial tension to failure, and tendon glycosaminoglycan content was measured by spectrophotometry. Compared to healthy tendons, pathology induced by the injury decreased modulus (-38%; 95%CI -49% to -28%; P<0.001) and UTS (-38%; 95%CI -48% to -28%; P<0.001) and increased glycosaminoglycan content (+52%; 95%CI 39% - 64%; P<0.001) throughout the tendon. Chondroitinase-mediated glycosaminoglycan removal (50%; 95%CI 21-79%; P<0.001) in surgically-injured pathological tendons caused a significant increase in modulus (5.6MPa/µg removed; 95%CI 0.31-11; P=0.038) and UTS (1.0MPa per µg removed; 95%CI 0.043-2; P=0.041). These results demonstrate that the chondroitin/dermatan sulphate glycosaminoglycans that accumulate in pathological tendon post-injury are partly responsible for the altered biomechanical properties.
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Affiliation(s)
- Rachel K Choi
- Murray Maxwell Biomechanics Laboratory (Institute of Bone and Joint Research), Kolling Institute, Royal North Shore Hospital (Sydney Medical School, University of Sydney), St Leonards, New South Wales, Australia; Raymond Purves Bone and Joint Research Laboratories (Institute of Bone and Joint Research), Kolling Institute, Royal North Shore Hospital (Sydney Medical School, University of Sydney), St Leonards, New South Wales, Australia
| | - Margaret M Smith
- Raymond Purves Bone and Joint Research Laboratories (Institute of Bone and Joint Research), Kolling Institute, Royal North Shore Hospital (Sydney Medical School, University of Sydney), St Leonards, New South Wales, Australia
| | - Joshua H Martin
- Murray Maxwell Biomechanics Laboratory (Institute of Bone and Joint Research), Kolling Institute, Royal North Shore Hospital (Sydney Medical School, University of Sydney), St Leonards, New South Wales, Australia
| | - Jillian L Clarke
- Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales, Australia
| | - Andrew J Dart
- Research and Clinical Training Unit, University Veterinary Teaching Hospital, University of Sydney, Camden, New South Wales, Australia
| | - Christopher B Little
- Raymond Purves Bone and Joint Research Laboratories (Institute of Bone and Joint Research), Kolling Institute, Royal North Shore Hospital (Sydney Medical School, University of Sydney), St Leonards, New South Wales, Australia.
| | - Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory (Institute of Bone and Joint Research), Kolling Institute, Royal North Shore Hospital (Sydney Medical School, University of Sydney), St Leonards, New South Wales, Australia
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Langbart MJ, Glezos CM, Smith BJ, Clarke EC, Lawson RD, Tonkin MA. A2 pulley integrity and the strength of flexor tendon repair: a biomechanical study in a chicken model. Hand Surg 2015; 20:11-17. [PMID: 25609269 DOI: 10.1142/s021881041550001x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
PURPOSE This study assesses the influence of A2 pulley integrity on the strength of the repair. METHOD Part 1- The flexor digitorum profundus (FDP) tendons of 72 Cobb chicken feet were severed and repaired in the region of the A2 pulley using a modified Kessler core suture and an epitendinous suture. The A2 pulley was either left intact, divided for 50% of its length, or divided in its entirety. The distal interphalangeal joint was fixed at a position of 20°, 40° or 60° of joint flexion. The load to failure, integrity of the A2 pulley and the site of tendon failure were analysed. Part 2- A further 32 chicken feet were used to exclude the effects of freezing and thawing on results and to analyse differences when using a core suture only. RESULTS No difference in failure load between any of the test groups or subgroups was identified. The integrity of the A2 pulley was preserved in all specimens. The most common cause of failure was distal suture pull-out. DISCUSSION This study does not demonstrate that release of the A2 pulley provides an advantage in increasing tendon repair strength. Division of 50% of the A2 pulley does not predispose to pulley rupture. Flexor tendon repair strength did not alter with distal interphalangeal joint flexion between 20° and 60°. CLINICAL RELEVANCE The findings of this study do not support division of the A2 pulley to prevent flexor tendon repair failure if repair methods of appropriate strength are utilised.
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Affiliation(s)
- Marc J Langbart
- Department of Hand Surgery and Peripheral Nerve Surgery, Royal North Shore Hospital, Australia
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Lau NSS, Gorrie CA, Chia JY, Bilston LE, Clarke EC. Severity of spinal cord injury in adult and infant rats after vertebral dislocation depends upon displacement but not speed. J Neurotrauma 2013; 30:1361-73. [PMID: 23617630 DOI: 10.1089/neu.2012.2725] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Spinal cord injury (SCI) is less common in children than in adults, but in children it is generally more severe. Spinal loading conditions (speed and displacement) are also thought to affect SCI severity, but the relationship between these parameters is not well understood. This study aimed to investigate the effects of vertebral speed and displacement on the severity of SCI in infants and adults using a rodent model of vertebral dislocation. Thoracolumbar vertebral dislocation was induced in anaesthetized infant rats (∼30 g, 13-15 days postnatal, n=40) and adult rats (∼250 g, n=57). The 12th thoracic vertebra was secured, whereas the first lumbar vertebra was dislocated laterally. Dislocation speed and magnitude were varied independently and scaled between adults and infants (Adults: 100-250mm/s, 4-10mm; Infants: 40-100mm/s, 1.6-4mm). At 5 h post-injury, rats were euthanized and spinal cords harvested. Spinal cord sections were stained to detect hemorrhage (hematoxylin and eosin) and axonal injury (β-amyloid precursor protein). For each millimeter increase in vertebral displacement, normalized hemorrhage volume increased by 1.9×10(-3) mm(3) (p=0.028) and normalized area of axonal injury increased by 2.2×10(-1)mm(2) (p<0.001). Normalized hemorrhage volume was 3.3×10(-3) mm(3) greater for infants than for adults (p<0.001). Magnitude of dislocation was found to have a different effect on the normalized area of axonal injury in adults than in infants (p=0.003). Speed of dislocation was not found to have a significant effect on normalized hemorrhage volume (p=0.427) or normalized area of axonal injury (p=0.726) independent of displacement for the range of speeds tested. The findings of this study suggest that both age and amount of spinal motion are key factors in the severity of acute SCI.
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Affiliation(s)
- Ngee-Soon Stephen Lau
- Neuroscience Research Australia, and Prince of Wales Clinical School, The University of New South Wales, Sydney, New South Wales, Australia
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Clarke EC, Fletcher DF, Stoodley MA, Bilston LE. Computational fluid dynamics modelling of cerebrospinal fluid pressure in Chiari malformation and syringomyelia. J Biomech 2013; 46:1801-9. [PMID: 23769174 DOI: 10.1016/j.jbiomech.2013.05.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 04/10/2013] [Accepted: 05/20/2013] [Indexed: 02/03/2023]
Abstract
The pathogenesis of syringomyelia in association with Chiari malformation (CM) is unclear. Studies of patients with CM have shown alterations in the CSF velocity profile and these could contribute to syrinx development or enlargement. Few studies have considered the fluid mechanics of CM patients with and without syringomyelia separately. Three subject-specific CFD models were developed for a normal participant, a CM patient with syringomyelia and a CM patient without syringomyelia. Model geometries, CSF flow rate data and CSF velocity validation data were collected from MRI scans of the 3 subjects. The predicted peak CSF pressure was compared for the 3 models. An extension of the study performed geometry and flow substitution to investigate the relative effects of anatomy and CSF flow profile on resulting spinal CSF pressure. Based on 50 monitoring locations for each of the models, the CM models had significantly higher magnitude (p<0.01) peak CSF pressure compared with normal. When using the same CSF input flow waveform, changing the upper spinal geometry changed the magnitude of the CSF pressure gradient, and when using the same upper spinal geometry, changing the input flow waveform changed the timing of the peak pressure. This study may assist in understanding syringomyelia mechanisms and relative effects of CSF velocity profile and spinal geometry on CSF pressure.
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Affiliation(s)
- Elizabeth C Clarke
- Murray Maxwell Biomechanics Laboratory, Kolling Institute of Medical Research, Sydney Medical School, University of Sydney, Level 10, Kolling Building 6, RNS Hospital, St Leonards, NSW 2065, Australia.
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Clarke EC, Stoodley MA, Bilston LE. Changes in temporal flow characteristics of CSF in Chiari malformation Type I with and without syringomyelia: implications for theory of syrinx development. J Neurosurg 2013; 118:1135-40. [PMID: 23495878 DOI: 10.3171/2013.2.jns12759] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The pathogenesis of syringomyelia in association with Chiari malformation Type I (CM-I) is unclear. Studies of patients with CM-I have shown alterations in the CSF velocity profile using cardiac-gated cine phase-contrast MRI, and computational simulations have demonstrated that temporal features of the CSF pulse could contribute to syrinx development or enlargement. Few studies have reported temporal characteristics of the CSF profile, and few studies have reported on CM-I patients with and without syringomyelia separately. This study was performed to determine whether specific temporal features of the CSF flow profile may underlie the development or enlargement of a syrinx in patients with CM-I. METHODS Ten healthy volunteers and 18 patients with CM-I with (8 patients) and without (10 patients) syringomyelia were studied using cardiac-gated cine phase-contrast MRI, measuring the maximum CSF velocities in the cranial and caudal directions, the timing of these maximums relative to the cardiac cycle time, the timing of caudal flow onset, timing of cranial flow onset, and the duration of caudal flow. RESULTS The caudal CSF flow was significantly faster (p ≤ 0.01) and earlier (p < 0.02) in patients without syringomyelia than in healthy volunteers and patients with syringomyelia. There were no significant differences in the CSF velocities between patients with syringomyelia and healthy volunteers. Patients with CM-I who had syringomyelia had a significantly later start of caudal CSF flow (p < 0.01) and earlier maximum cranial velocity (p = 0.03) than healthy volunteers, but the relative durations of caudal and cranial flow were not significantly different between any of the groups. CONCLUSIONS The significantly earlier arrival and earlier peak velocity of caudal CSF flow may underlie the development of syringomyelia in patients with CM-I, and after a syrinx develops the CSF flow profile appears to stabilize.
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Affiliation(s)
- Elizabeth C Clarke
- The Kolling Institute of Medical Research, Sydney Medical School, The University of Sydney
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Diong JH, Herbert RD, Harvey LA, Kwah LK, Clarke JL, Hoang PD, Martin JH, Clarke EC, Bilston LE, Gandevia SC. Passive mechanical properties of the gastrocnemius after spinal cord injury. Muscle Nerve 2012; 46:237-45. [DOI: 10.1002/mus.23356] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kwah LK, Herbert RD, Harvey LA, Diong J, Clarke JL, Martin JH, Clarke EC, Hoang PD, Bilston LE, Gandevia SC. Passive mechanical properties of gastrocnemius muscles of people with ankle contracture after stroke. Arch Phys Med Rehabil 2012; 93:1185-90. [PMID: 22502803 DOI: 10.1016/j.apmr.2012.02.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 01/18/2012] [Accepted: 02/13/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVE To investigate the mechanisms of contracture after stroke by comparing passive mechanical properties of gastrocnemius muscle-tendon units, muscle fascicles, and tendons in people with ankle contracture after stroke with control participants. DESIGN Cross-sectional study. SETTING Laboratory in a research institution. PARTICIPANTS A convenience sample of people with ankle contracture after stroke (n=20) and able-bodied control subjects (n=30). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Stiffness and lengths of gastrocnemius muscle-tendon units, lengths of muscle fascicles, and tendons at specific tensions. RESULTS At a tension of 100N, the gastrocnemius muscle-tendon unit was significantly shorter in participants with stroke (mean, 436mm) than in able-bodied control participants (mean, 444mm; difference, 8mm; 95% confidence interval [CI], 0.2-15mm; P=.04). Muscle fascicles were also shorter in the stroke group (mean, 44mm) than in the control group (mean, 50mm; difference, 6mm; 95% CI, 1-12mm; P=.03). There were no significant differences between groups in the mean stiffness or length of the muscle-tendon units and fascicles at low tension, or in the mean length of the tendons at any tension. CONCLUSIONS People with ankle contracture after stroke have shorter gastrocnemius muscle-tendon units and muscle fascicles than control participants at high tension. This difference is not apparent at low tension.
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Affiliation(s)
- Li Khim Kwah
- George Institute for Global Health, Sydney, NSW, Australia
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Herbert RD, Clarke J, Kwah LK, Diong J, Martin J, Clarke EC, Bilston LE, Gandevia SC. In vivo passive mechanical behaviour of muscle fascicles and tendons in human gastrocnemius muscle-tendon units. J Physiol 2011; 589:5257-67. [PMID: 21825027 DOI: 10.1113/jphysiol.2011.212175] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Ultrasound imaging was used to measure the length of muscle fascicles in human gastrocnemius muscles while the muscle was passively lengthened and shortened by moving the ankle. In some subjects the muscle belly 'buckled' at short lengths. When the gastrocnemius muscle-tendon unit was passively lengthened from its shortest in vivo length by dorsiflexing the ankle, increases in muscle-tendon length were not initially accompanied by increases in muscle fascicle lengths (fascicle length remained constant), indicating muscle fascicles were slack at short muscle-tendon lengths. The muscle-tendon length at which slack is taken up differs among fascicles: some fascicles begin to lengthen at very short muscle-tendon lengths whereas other fascicles remain slack over a large range of muscle-tendon lengths. This suggests muscle fascicles are progressively 'recruited' and contribute sequentially to muscle-tendon stiffness during passive lengthening of the muscle-tendon unit. Even above their slack lengths muscle fascicles contribute only a small part (<~30%) of the total change in muscle-tendon length. The contribution of muscle fascicles to muscle-tendon length increases with muscle length. The novelty of this work is that it reveals a previously unrecognised phenomenon (buckling at short lengths), posits a new mechanism of passive mechanical properties of muscle (recruitment of muscle fascicles), and confirms with high-resolution measurements that the passive compliance of human gastrocnemius muscle-tendon units is due largely to the tendon. It would be interesting to investigate if adaptations of passive properties of muscles are associated with changes in the distribution of muscle lengths at which fascicles fall slack.
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Affiliation(s)
- Robert D Herbert
- The George Institute for Global Health, Camperdown NSW 2050, Australia.
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Abstract
OBJECTIVE Motor vehicle crashes are the leading cause of serious spinal injury in most developed nations. However, since these injuries are rare, systematic analyses of the crash factors that are predictive of spinal injury have rarely been performed. This study aimed to use a population-reference crash sample to identify crash factors associated with moderate to severe spinal injury, and how these vary with occupant age. METHODS The US National Automotive Sampling System Crashworthiness Data System (NASS) data for 1993-2007 were analysed using logistic regression to identify crash factors associated with Abbreviated Injury Scale (AIS)2+ spinal injury among restrained vehicle passengers. RESULTS Risk of moderate or severe spinal injury (AIS2+) was associated with higher severity crashes (OR=3.5 (95% CI 2.6 to 4.6)), intrusion into an occupant's seating position (OR=2.7 (95% CI 1.9 to 3.7)), striking a fixed object rather than another car (OR=1.7 (95% CI 1.3 to 2.1)), and use of a shoulder-only belt (OR=2.7 (95% CI 1.5 to 4.8)). Older occupants (65 years or older) were at higher risk of spinal injury than younger adults in frontal, side and rollover crashes. Children under 16 were at a lower risk of spinal injury than adults in all crash types except frontal crashes. CONCLUSIONS While the risk of serious spinal injury in motor vehicle crashes is low, these injuries are more common in crashes of higher severity or into fixed objects, and in the presence of intrusion. There are elevated risks of spinal injury for older occupants compared with younger adults, which may reflect changes in biomechanical tolerances with age. Children appear to be at lower risk of serious spinal injury than adults except in frontal crashes.
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Clarke EC, Cheng S, Bilston LE. The mechanical properties of neonatal rat spinal cord in vitro, and comparisons with adult. J Biomech 2009; 42:1397-1402. [PMID: 19442976 DOI: 10.1016/j.jbiomech.2009.04.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 04/06/2009] [Accepted: 04/07/2009] [Indexed: 11/25/2022]
Abstract
A number of studies have investigated the mechanical properties of adult spinal cord under tension, however it is not known whether age has an effect on these properties. This is of interest to those aiming to understand the clinical differences between adults and children with spinal cord injury (e.g. severity and recovery), and those developing experimental or computational models for paediatric spinal cord injury. Entire spinal cords were freshly harvested from neonatal rats (14 days) and tested in vitro under uniaxial tension at a range of strain rates (0.2, 0.02, 0.002/s) to a range of strains (2%, 3.5%, 5%), with relaxation responses being recorded for 15 min. These mechanical properties were compared to previously reported data from similar experiments on adult rat spinal cords, and the peak stress and the stress after 15 min of relaxation were found to be significantly higher for spinal cords from adults than neonates (p<0.001). A non-linear viscoelastic model was developed and was observed to adequately predict the mechanical behaviour of this tissue. The model developed in this study may be of use in computational models of paediatric spinal cord. The significant differences between adult and neonatal spinal cord properties may explain the higher initial severity of spinal cord injury in children and may have implications for the development of experimental animal models for paediatric spinal cord injury, specifically for those aiming to match the injury severity with adult experimental models.
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Affiliation(s)
- Elizabeth C Clarke
- Prince of Wales Medical Research Institute, University of New South Wales, Randwick, NSW 2031, Sydney, Australia.
| | - Shaokoon Cheng
- Prince of Wales Medical Research Institute, University of New South Wales, Randwick, NSW 2031, Sydney, Australia
| | - Lynne E Bilston
- Prince of Wales Medical Research Institute, University of New South Wales, Randwick, NSW 2031, Sydney, Australia.
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Clarke EC, Bilston LE. Contrasting biomechanics and neuropathology of spinal cord injury in neonatal and adult rats following vertebral dislocation. J Neurotrauma 2008; 25:817-32. [PMID: 18627258 DOI: 10.1089/neu.2007.0379] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Clinically, spinal cord injuries (SCI) in infants are different from SCIs in adults. SCI is rarer in infants, and the most common types of associated spinal column injury are different for adults and infants. Initially, infants tend to have higher injury severities and mortality; however, young survivors of SCI typically have greater and more rapid functional recovery. The objective of this study was to contrast the biomechanics and neuropathology of SCI in adult and neonatal rats to investigate these differences. Thoracolumbar vertebrae of anaesthetized rats were dislocated laterally (T12 held stationary and L1 displaced laterally, with T13 between these levels) by 10 mm at 250 mm/sec in adults and by 4 mm at 100 mm/sec in neonates (13-15 days), and rats were euthanized 6 h later. Spinal cord sections were stained to detect hemorrhage (with hematoxylin and eosin [H&E]), axonal injury (with beta-amyloid precursor protein [betaAPP]), and neuronal nuclei (with NeuN). Maximum load was significantly higher in adults (25.7 +/- 2.4N) than neonates (11.0 +/- 2.4N; p < 0.001). Adult and neonatal hemorrhage volumes were not significantly different for either the raw or normalized data sets (p = 0.064 for normalized dataset). Un-normalized axonal injury densities were similar for adults and neonates, but normalized axonal injury density was significantly higher in neonates (p < 0.001). Reduction of NeuN immunoreactivity was significantly lower in neonates, for both un-normalized (p < 0.004) and normalized (p < 0.001) data sets. The findings of this study may explain the different common types of spinal column injury associated with SCI, and the greater initial severity of SCI in infants.
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Affiliation(s)
- Elizabeth C Clarke
- Department of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia
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Clarke EC, Choo AM, Liu J, Lam CK, Bilston LE, Tetzlaff W, Oxland TR. Anterior fracture-dislocation is more severe than lateral: a biomechanical and neuropathological comparison in rat thoracolumbar spine. J Neurotrauma 2008; 25:371-83. [PMID: 18373485 DOI: 10.1089/neu.2007.0421] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
ABSTRACT Fracture-dislocation is one of the most common causes of spinal cord injury (SCI) in human adults, yet it is not widely studied experimentally. Clinical studies have found that anterior fracture-dislocation occurs more commonly and produces greater neurological deficit than lateral fracture-dislocation. However, the effect of loading direction on SCI neuropathology has not been investigated experimentally and the reasons behind these clinical differences are not known. Thoracolumbar vertebrae T12-L1 of anaesthetized rats were dislocated anteriorly or laterally by 9 mm at 220 mm/sec. Spinal cord sections from animals euthanized at 1, 3, and 6 h post-injury, were stained with hematoxylin and eosin (H&E) to detect hemorrhage, the pathologic accumulation of beta-amyloid precursor protein (betaAPP) in white matter axons, and degenerating neurons (Fluoro-Jade and loss of NeuN) in the gray matter. The vertebral fracture load and maximum load were similar for both directions of dislocation; however, vertebral fracture occurred at 4.3 mm (+/-1.5 mm SD) during anterior dislocation compared to 1.1 mm (+/-0.7 mm SD) during lateral dislocation (p < 0.001). betaAPP accumulation and reduction of NeuN immunoreactivity (IR) were greatest along a diagonal band across the spinal cord angled at 45 degrees to the direction of loading (in different planes for each loading direction). Hemorrhage volume (p < 0.05), betaAPP-IR, and reduction of NeuN-IR (p < 0.05 in ventral horns) were more pronounced following anterior dislocation. In addition, there was a different spatial distribution of axonal damage for each direction of dislocation. The findings of this study may explain the greater severity of anterior fracture-dislocation observed clinically and reinforces the need to experimentally model differing human SCIs.
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Affiliation(s)
- Elizabeth C Clarke
- Department of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia
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Cheng S, Clarke EC, Bilston LE. Rheological properties of the tissues of the central nervous system: a review. Med Eng Phys 2008; 30:1318-37. [PMID: 18614386 DOI: 10.1016/j.medengphy.2008.06.003] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 05/23/2008] [Accepted: 06/01/2008] [Indexed: 10/21/2022]
Abstract
Knowledge of the biomechanical properties of central nervous system (CNS) tissues is important for understanding mechanisms and thresholds for injury, and aiding development of computer or surrogate models of these tissues. Many investigations have been conducted to estimate the properties of CNS tissues including under shear, compressive and tensile loading, however there is much variability in this body of literature, making it difficult to separate the material properties from effects that result from a given experimental protocol. This review summarises previous studies of brain and spinal cord properties; discussing their main findings and points of difference, and displays the reported data on comparable scales. Additionally, based on the observed effects of methodological choices on reported tissue properties, recommendations for future studies of brain and spinal cord properties are made.
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Affiliation(s)
- Shaokoon Cheng
- Prince of Wales Medical Research Institute, University of New South Wales, Barker Street, Randwick, Sydney, NSW, 2031, Australia
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Abstract
Mechanical deformation of a peripheral nerve can evoke action potentials in sensory and motor axons. The generation of these impulses with brief stimuli (<0.5 s) and their relationship to the deformation conditions have not been systematically studied in human subjects. Controlled compression stimuli over a range of amplitudes, durations, and loading rates were delivered to the ulnar nerve at the medial epicondyle in awake human subjects. Compound muscle action potentials were recorded from the first dorsal interosseous muscle. Subjects rated the magnitude of evoked paresthesias. Mechanically evoked motor and sensory responses varied linearly with the magnitude (P < 0.001) and rate of deformation (P < 0.01), but not the duration, and occurred only during the compression phase. Cutaneous axons had lower mechanical thresholds than motor axons. We relate these findings to the viscoelastic properties of peripheral nerves and differences in biophysical properties of cutaneous and motor axons.
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Affiliation(s)
- Elizabeth C Clarke
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia.
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44
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Affiliation(s)
- C Merrick
- Employment Nursing Advisory Service, Health and Safety Executive, Sheffield, UK
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O'Hara TM, Sheppard MA, Clarke EC, Borzelleca JF, Gennings C, Condie LW. A CCl4/CHCl3 interaction study in isolated hepatocytes: non-induced and phenobarbital-pretreated cells. J Appl Toxicol 1991; 11:147-54. [PMID: 2061553 DOI: 10.1002/jat.2550110214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 12/30/2022]
Abstract
The purpose of this study was to evaluate an isolated hepatocyte model for predicting the in vivo hepatotoxicity of carbon tetrachloride (CCl4) and chloroform (CHCl3), alone and in combination. Response surface methodology (RSM) was used to analyze and describe the data. The interaction was evaluated for % initial K+ (cell injury) and % LDH leakage (cell death) in non-induced (untreated) and phenobarbital-pretreated suspended hepatocytes. CCl4 and CHCl3 were delivered alone and in combination in dimethyl sulfoxide (DMSO) to suspended hepatocytes. The maximum observed no-effect level (MONEL) for CCl4 in non-induced cells was 1.0 mM (LDH and K+). In induced cells, the MONEL was 0.25 mM (K+) and 0.5 mM (LDH). The MONEL for CHCl3 in non-induced cells was 5.0 mM (LDH and K+) and in induced cells was 0.5 mM (K+) and 1.0 mM (LDH). Phenobarbital pretreatment enhanced the toxicity of both CCl4 and CHCl3, alone and in combination. RSM analysis of the % initial K+ and % LDH for CCl4 and CHCl3 in combination in noninduced and induced cells showed a greater than additive interaction. The isolated hepatocyte model appears to be a promising system for evaluating the toxicity of chemical mixtures and predicting their in vivo effects.
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Affiliation(s)
- T M O'Hara
- Dept. of Pharmacology and Toxicology, Medical College of Virginia, Richmond 23298
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O'Hara TM, Borzelleca JF, Clarke EC, Sheppard MA, Condie LW. A CCl4/CHCl3 interaction study in isolated hepatocytes: selection of a vehicle. Fundam Appl Toxicol 1989; 13:605-15. [PMID: 2612791] [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] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Emulphor, ethanol, and dimethyl sulfoxide (DMSO) were evaluated as vehicles in studying the toxicity of CCl4 and CHCl3 in isolated hepatocytes. The appropriateness of the vehicle was determined by evaluating the following parameters: solubility of CCl4 and CHCl3 in the vehicle, cell injury (intracellular K+), cell death (LDH leakage), and lack of interaction (protection or enhanced toxicity) with CCl4 and CHCl3. The relative toxicity of the vehicles according to maximum no effect levels (v/v) was: emulphor (0.125%) greater than ethanol (1.0%) greater than DMSO (5.0%). Emulphor at toxic levels was inadequate to dissolve enough CCl4 to evaluate in this system. Ethanol (5.0, 2.5, 1.0, 0.5%) was more toxic than DMSO and interacted with both CCl4 and CHCl3 to enhance toxicity. DMSO (15.0, 5.0, 2.5%) did not significantly alter the toxicity of CCl4 and CHCl3; no interaction. These data suggest that DMSO should be the vehicle for evaluating the toxicity of CCl4 and CHCl3 and their mechanisms of action in the isolated hepatocyte.
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Affiliation(s)
- T M O'Hara
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298
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Allardice JT, Clarke EC, Jones RD. A study of the prevalence of epistaxis and respiratory symptoms in carpet backwinders. J Soc Occup Med 1983; 33:36-41. [PMID: 6687481 DOI: 10.1093/occmed/33.1.36] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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48
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Clarke EC. City Scavengering in Boston. Public Health Pap Rep 1879; 5:24-31. [PMID: 19600012 PMCID: PMC2272152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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