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Zhou S, Xiao C, Fan L, Yang J, Ge R, Cai M, Yuan K, Li C, Crawford RW, Xiao Y, Yu P, Deng C, Ning C, Zhou L, Wang Y. Injectable ultrasound-powered bone-adhesive nanocomposite hydrogel for electrically accelerated irregular bone defect healing. J Nanobiotechnology 2024; 22:54. [PMID: 38326903 PMCID: PMC10851493 DOI: 10.1186/s12951-024-02320-y] [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: 12/10/2023] [Accepted: 01/26/2024] [Indexed: 02/09/2024] Open
Abstract
The treatment of critical-size bone defects with irregular shapes remains a major challenge in the field of orthopedics. Bone implants with adaptability to complex morphological bone defects, bone-adhesive properties, and potent osteogenic capacity are necessary. Here, a shape-adaptive, highly bone-adhesive, and ultrasound-powered injectable nanocomposite hydrogel is developed via dynamic covalent crosslinking of amine-modified piezoelectric nanoparticles and biopolymer hydrogel networks for electrically accelerated bone healing. Depending on the inorganic-organic interaction between the amino-modified piezoelectric nanoparticles and the bio-adhesive hydrogel network, the bone adhesive strength of the prepared hydrogel exhibited an approximately 3-fold increase. In response to ultrasound radiation, the nanocomposite hydrogel could generate a controllable electrical output (-41.16 to 61.82 mV) to enhance the osteogenic effect in vitro and in vivo significantly. Rat critical-size calvarial defect repair validates accelerated bone healing. In addition, bioinformatics analysis reveals that the ultrasound-responsive nanocomposite hydrogel enhanced the osteogenic differentiation of bone mesenchymal stem cells by increasing calcium ion influx and up-regulating the PI3K/AKT and MEK/ERK signaling pathways. Overall, the present work reveals a novel wireless ultrasound-powered bone-adhesive nanocomposite hydrogel that broadens the therapeutic horizons for irregular bone defects.
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Affiliation(s)
- Shiqi Zhou
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, China
| | - Cairong Xiao
- School of Materials Science and Engineering, National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, Guangdong, 510641, China
| | - Lei Fan
- Department of Orthopedic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Jinghong Yang
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, China
| | - Ruihan Ge
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, China
| | - Min Cai
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, China
| | - Kaiting Yuan
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, China
| | - Changhao Li
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, China
| | - Ross William Crawford
- Institute of Health and Biomedical Innovation & Australia-China Centre for Tissue Engineering and Regenerative Medicine, Centre for Biomedical Technologies, Queensland University of Technology, Queensland, 4059, Australia
| | - Yin Xiao
- School of Medicine and Dentistry & Menzies Health Institute Queensland, Griffith University, Queensland, 4111, Australia
| | - Peng Yu
- School of Materials Science and Engineering, National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, Guangdong, 510641, China
| | - Chunlin Deng
- School of Materials Science and Engineering, National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, Guangdong, 510641, China
| | - Chengyun Ning
- School of Materials Science and Engineering, National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, Guangdong, 510641, China.
| | - Lei Zhou
- Guangzhou Key Laboratory of Spine Disease Prevention and Treatment, Department of Spine Surgery, The Third Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, 510150, China.
| | - Yan Wang
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, China.
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Brown CP, Oloyede A, Crawford RW, Thomas GER, Price AJ, Gill HS. Acoustic, mechanical and near-infrared profiling of osteoarthritic progression in bovine joints. Phys Med Biol 2012; 57:547-59. [DOI: 10.1088/0031-9155/57/2/547] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [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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Schrobback K, Malda J, Crawford RW, Upton Z, Leavesley DI, Klein TJ. Effects of oxygen on zonal marker expression in human articular chondrocytes. Tissue Eng Part A 2012; 18:920-33. [PMID: 22097912 DOI: 10.1089/ten.tea.2011.0088] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Articular cartilage is organized in depth zones with phenotypically distinct subpopulations of chondrocytes that are exposed to different oxygen tensions. Despite growing evidence of the critical role for oxygen in chondrogenesis, little is known about its effect on chondrocytes from different zones. This study evaluates zonal marker expression of human articular chondrocytes from different zones under various oxygen tensions. Chondrocytes isolated from full-thickness, superficial, and middle/deep cartilage from knee replacement surgeries were expanded and redifferentiated under hypoxic (5% O(2)) or normoxic (20% O(2)) conditions. Differentiation under hypoxia increased expression of hypoxia-inducible factors 1alpha and 2alpha and accumulation of extracellular matrix, particularly in middle/deep chondrocytes, and favored re-expression of proteoglycan 4 by superficial chondrocytes compared with middle/deep cells. Zone-dependent expression of clusterin varied with culture duration. These results demonstrate that zonal chondrocytes retain important phenotypic differences during in vitro cultivation, and that these characteristics can be improved by altering the oxygen environment. However, transcript levels for pleiotrophin, cartilage intermediate layer protein, and collagen type X were similar between zones, challenging their reliability as zonal markers for tissue-engineered cartilage from osteoarthritis patients. Key factors including oxygen tension and cell source should be considered to prescribe zone-specific properties to tissue-engineered cartilage.
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Affiliation(s)
- Karsten Schrobback
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia.
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Smith BN, Lee AJC, Timperley AJ, Whitehouse SL, Crawford RW. The effect of the Rim Cutter on cement pressurization and penetration on cemented acetabular fixation in total hip arthroplasty: an in vitro study. Proc Inst Mech Eng H 2010; 224:1133-40. [PMID: 21053777 DOI: 10.1243/09544119jeim651] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Rim Cutter (Stryker Orthopedics, Mahwah, New Jersey) is a tool designed to cut a ledge inside the rim of the acetabulum, onto which a precisely trimmed, cemented, flanged cup can be fitted. The aim was to investigate the effect of the Rim Cutter on the intra-acetabular cement mantle pressure and the depth of cement penetration during cup insertion. The study had two parts. In the first part, hemi-pelvis models were fitted with pressure sensors. Pressure in the acetabulum was measured on insertion of a conventional cemented flanged cup with and without the use of a Rim Cutter to prepare the rim of the acetabulum. The second part assessed cement penetration when the same cups were inserted into a foam shell model. The shell was mounted in a jig and had holes drilled in it; the distance that cement penetrated into the holes was measured. A significant increase in cement pressure at the apex (p = 0.04) and the rim (p = 0.004) is seen when the Rim Cutter is used. Cement penetration in the Rim Cutter group was significantly increased at the rim of the acetabulum (p = 0.003). Insertion of a flanged cup after the acetabulum is prepared with the Rim Cutter leads to a significant increase in cement pressure and penetration during cup insertion in vitro when compared with conventional flanged cups.
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Affiliation(s)
- B N Smith
- Gold Coast Hospital, Gold Coast Queensland, Australia
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5
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Costain DJ, Crawford RW. Fresh-frozen vs. irradiated allograft bone in orthopaedic reconstructive surgery. Injury 2009; 40:1260-4. [PMID: 19486972 DOI: 10.1016/j.injury.2009.01.116] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2008] [Revised: 12/22/2008] [Accepted: 01/19/2009] [Indexed: 02/02/2023]
Abstract
The use of allograft bone is increasingly common in orthopaedic reconstruction procedures. The optimal method of preparation of allograft bone is subject of great debate. Proponents of fresh-frozen graft cite improved biological and biomechanical characteristics relative to irradiated material, whereas fear of bacterial or viral transmission warrants some to favour irradiated graft. Careful review of the literature is necessary to appreciate the influence of processing techniques on bone quality. Whereas limited clinical trials are available to govern the selection of appropriate bone graft, this review presents the argument favouring the use of fresh-frozen bone allograft as compared to irradiated bone.
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Affiliation(s)
- D J Costain
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
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Brown CP, Bowden JC, Rintoul L, Meder R, Oloyede A, Crawford RW. Diffuse reflectance near infrared spectroscopy can distinguish normal from enzymatically digested cartilage. Phys Med Biol 2009; 54:5579-94. [DOI: 10.1088/0031-9155/54/18/015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [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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Lewis D, Lutton C, Wilson LJ, Crawford RW, Goss B. Low cost polymer intramedullary nails for fracture fixation: a biomechanical study in a porcine femur model. Arch Orthop Trauma Surg 2009; 129:817-22. [PMID: 19172285 DOI: 10.1007/s00402-009-0819-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Whilst intramedullary nailing is a commonly accepted technique for lower limb fracture fixation, the cost of nails can be prohibitive in hospitals in developing nations. In these institutions bone cement has found many off label applications, that whilst are effective do not meet manufacturers guidelines. The aim of this study was to examine the biomechanics of one such application, fracture fixation using a bone cement intramedullary nail. MATERIALS AND METHODS Five porcine femurs underwent a mid-shaft osteotomy and were fixed using a nail made from antibiotic simplex bone cement. The torsional and flexural stiffness and shear modulus of these constructs were compared to five intact porcine femurs. RESULTS The bone cement intramedullary nail was able to achieve relative stability in both torsion, with a mean shear modulus of 0.17 GPa and in flexion with a mean flexural stiffness of 358 N/mm. This corresponds to 47 and 22% of the respective measurements in the intact femurs. The mean ultimate flexural strength of fracture/nail constructs was 936 +/- 350 N, which is 20% of the ultimate flexural strength of an intact porcine femur (4,820 +/- 698 N). CONCLUSION Intramedullary nails made from bone cement were able to provide sufficient promise in this situation to warrant further investigation for their applicability as a low cost alternative for use in developing countries.
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Affiliation(s)
- D Lewis
- AOSpine Reference Centre, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
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Brown CP, Nguyen TC, Moody HR, Crawford RW, Oloyede A. Assessment of common hyperelastic constitutive equations for describing normal and osteoarthritic articular cartilage. Proc Inst Mech Eng H 2009; 223:643-52. [DOI: 10.1243/09544119jeim546] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
With the aim of providing information for modelling joint and limb systems, widely available constitutive hyperelastic laws are evaluated in this paper for their ability to predict the mechanical responses of normal and osteoarthritic articular cartilage. Load—displacement data from mechanical indentation were obtained for normal and osteoarthritic cartilage at 0.1 s−1 and 0.025 s−1 and converted to the stress—stretch ratio. The data were then fitted to the ArrudA—Boyce, Mooney—Rivlin, neo-Hookean, Ogden, polynomial, and Yeoh hyperelastic laws in the MATLAB environment. Although each of the hyperelastic laws performed satisfactorily at the higher rate of loading, their ability to fit experimental data at the lower loading rate varied considerably. For the preferred models, coefficients were provided for stiff, soft, and average tissues to represent normal and degraded tissue at high and low loading rates. The present authors recommend the use of the Mooney—Rivlin or the Yeoh models for describing both normal and degraded articular cartilage, with the Mooney—Rivlin model providing the best compromise between accuracy and required computational power.
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Affiliation(s)
- C P Brown
- School of Engineering Systems, Queensland University of Technology, Brisbane, Australia
| | - T C Nguyen
- School of Engineering Systems, Queensland University of Technology, Brisbane, Australia
| | - H R Moody
- School of Engineering Systems, Queensland University of Technology, Brisbane, Australia
| | - R W Crawford
- School of Engineering Systems, Queensland University of Technology, Brisbane, Australia
| | - A Oloyede
- School of Engineering Systems, Queensland University of Technology, Brisbane, Australia
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9
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Abstract
This paper is a sequel to previously published findings showing that mechanical indentation alone cannot clearly discriminate between normal and degraded articular cartilage. Consequently, the structural elasticity potential ℜc = ɛr/ σi, which combines indentation stress σi with near-instantaneous rebound ɛr following unloading, is hypothesized as a potential cartilage assessment parameter, which arguably measures the integrity of the collagen fibre—proteoglycan entrapment system. To establish the validity of our hypothesis, samples of normal intact, artificially degraded, and osteoarthritic bovine cartilage were subjected to quasi-static compression at 0.1 s−1 and 0.025 s−1 to 30 per cent strain and then unloaded. A significant reduction in recovery was observed for artificially and naturally degraded samples in the first 5 s following unloading ( p<0.01). The structural elasticity potential provided a considerable improvement over the results obtained using the individual indentation and rebound parameters to distinguish between paired normal and artificially degraded samples and indicated a high statistical significance of p<0.005 when applied to the differentiation of normal and osteoarthritic samples.
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Affiliation(s)
- C P Brown
- Institute of Health and Biomechanical Innovation, Faculty of Built Environment and Engineering, Queensland University of Technology, Brisbane, Australia
| | - R W Crawford
- Institute of Health and Biomechanical Innovation, Faculty of Built Environment and Engineering, Queensland University of Technology, Brisbane, Australia
| | - A Oloyede
- Institute of Health and Biomechanical Innovation, Faculty of Built Environment and Engineering, Queensland University of Technology, Brisbane, Australia
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Beldiman M, Xiao Y, Crawford RW, Oloyede A. Cell response in mixtures of surfactant-culture medium--towards a systemic approach to cell-based treatments for focal osteoarthritis. Biosystems 2008; 94:209-14. [PMID: 18721858 DOI: 10.1016/j.biosystems.2008.05.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Accepted: 05/21/2008] [Indexed: 11/25/2022]
Abstract
Osteoarthritis (OA), the most common form of arthritis is a degenerative joint disease, which causes severe long-term pain and physical disability. It is becoming more important to improve diagnosis and understanding of the disease process and subsequently develop new intervention to delay or even reverse the disease progress. Our study was designed to combine two relatively novel treatment techniques, autologous chondrocyte transplantation (ACT) and proposed application of medical remedies based on surface-active phospholipids. To this end we exposed chondrocyte to culture environments with mixtures of culture medium and phospholipid solutions. Following various culture periods, cell survival and well-being were determined by measuring proliferation and assessing morphological features, and comparing these with the behaviour of cells grown in classical which were not mixed with surfactant, i.e., control culture medium. Scanning electron microscopy and light microscopy demonstrate that the cells exposed to mixtures with surfactant were as healthy as those in the control environment with polygonal morphology, while proliferation assay indicated a noticeably higher level of proliferation over similar periods, for cells cultured in media that was mixed with surfactants. Also, the cells in media with unsaturated surfactants responded better than those cultured in mixtures containing saturated surfactant.
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Affiliation(s)
- M Beldiman
- Queensland University of Technology, Institute of Health and Biomedical Innovation, GPO Box 2434, Brisbane, Queensland 4001, Australia
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Brown CP, Hughes SW, Crawford RW, Oloyede A. Joint laminate degradation assessed by reflected ultrasound from the cartilage surface and osteochondral junction. Phys Med Biol 2008; 53:4123-35. [PMID: 18612178 DOI: 10.1088/0031-9155/53/15/008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The ability to quantify and qualify the progression of joint degeneration is becoming increasingly important in surgery. This paper examines the patterns of relative ultrasound reflection from normal, artificially and naturally degraded cartilage-on-bone, particularly investigating the potential of the ratio of reflection coefficients from the surface and osteochondral junction in distinguishing normal from osteoarthritic tissue. To this end, the reflection coefficients from the articular surface and osteochondral junction of normal cartilage-on-bone samples were calculated and compared to samples after the removal of proteoglycans, disruption of the collagen meshwork, delipidization of the articular surface and mechanical abrasion. Our results show that the large variation across normal and degraded joint samples negates the use of an isolated bone reflection measurement and to a lesser extent, an isolated surface reflection. The relative surface to bone reflections, calculated as a ratio of reflection coefficients, provided a more consistent and statistically significant (p < 0.001) method for distinguishing each type of degradation, especially osteoarthritic degradation, and due to the complementary relationship between surface and bone reflections was found to be an effective method for distinguishing degraded from normal tissue in the osteoarthritic joint, independent of the site of initiation of the osteoarthritic process.
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Affiliation(s)
- C P Brown
- School of Engineering Systems, IHBI, QUT, Brisbane, Australia
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12
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Whitehouse SL, Crawford RW, Learmonth ID. Validation for the reduced Western Ontario and McMaster Universities Osteoarthritis Index function scale. J Orthop Surg (Hong Kong) 2008; 16:50-3. [PMID: 18453660 DOI: 10.1177/230949900801600113] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [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] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To assess the criterion validity, repeatability, and the missing value protocol of the reduced Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function scale ('reduced scale'). METHODS Three separate studies were performed: a cross-over study to compare the full- and reduced-scale scores in 66 UK patients for validity, a test-retest study for repeatability in 103 Australian patients, and a study for the missing value protocol of the reduced-scale questionnaire. RESULTS There was no significant difference between scores for the full- and reduced-scale questionnaires in both cross-over and test-retest studies. For the missing value protocol of the reduced-scale questionnaire, when 3 or more of the 7 items were missing, the patient's response was regarded as invalid and the sub-scale score was eliminated from further analysis; when 2 or fewer items were missing, the mean value of the sub-scale was substituted for the missing values. CONCLUSIONS The reduced-scale questionnaire retains excellent validity and repeatability. Its use is recommended along with the original pain dimension in studies of total joint replacement.
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Affiliation(s)
- S L Whitehouse
- Orthopaedic Research Unit, Queensland University of Technology, Prince Charles Hospital, Chermside, Australia.
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de Visser SK, Crawford RW, Pope JM. Structural adaptations in compressed articular cartilage measured by diffusion tensor imaging. Osteoarthritis Cartilage 2008; 16:83-9. [PMID: 17625926 DOI: 10.1016/j.joca.2007.05.013] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 05/26/2007] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To demonstrate the use of diffusion tensor magnetic resonance micro-imaging to observe adaptations of collagen fibres to mechanical compression in articular cartilage. METHODS Spin-echo and diffusion tensor images (156x156microm in-plane resolution, 2mm slice thickness) of bovine cartilage were obtained at a magnetic field of 7.0T in relaxed and compressed states. The parameters determined were: T2, maximum and mean diffusivity, direction of the maximum diffusion eigenvector and fractional anisotropy of diffusion. RESULTS A correlation was found between the compressive strain applied to the cartilage and the change in both magnitude and direction of the maximum diffusivity. Compression resulted in a decrease in both the maximum and mean eigenvalues, particularly in the surface and transitional zones, while the change in orientation of the eigenvectors corresponding to maximum diffusion was greatest in the transitional region. In this region, the average orientation of the principal eigenvectors with respect to the normal to the articular surface increased by up to 40 degrees, indicating that the collagen fibre bundles were oriented more parallel to the surface when compressed. CONCLUSIONS Diffusion tensor imaging can be used to monitor the changes in the direction of the collagen fibres due to compression. It may form the basis of a new non-invasive approach to functional evaluation of cartilage, with potential applications in the diagnosis and treatment of osteoarthritis.
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Affiliation(s)
- S K de Visser
- School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
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Moody HR, Brown CP, Bowden JC, Crawford RW, McElwain DLS, Oloyede AO. In vitro degradation of articular cartilage: does trypsin treatment produce consistent results? J Anat 2007; 209:259-67. [PMID: 16879604 PMCID: PMC2100317 DOI: 10.1111/j.1469-7580.2006.00605.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
It is common practice in laboratories to create models of degraded articular cartilage in vitro and use these to study the effects of degeneration on cartilage responses to external stimuli such as mechanical loading. However, there are inconsistencies in the reported action of trypsin, and there is no guide on the concentration of trypsin or the time to which a given sample can be treated so that a specific level of proteoglycan depletion is achieved. This paper argues that before any level of confidence can be established in comparative analysis it is necessary to first obtain samples with similar properties. Consequently, we examine the consistency of the outcome of the artificial modification of cartilage relative to the effects of the common enzyme, trypsin, used in the process of in vitro proteoglycan depletion. The results demonstrate that for a given time and enzyme concentration, the action of trypsin on proteoglycans is highly variable and is dependent on the initial distribution and concentration of proteoglycans at different depths, the intrinsic sample depth, the location in the joint space and the medium type, thereby sounding a note of caution to researchers attempting to model a proteoglycan-based degeneration of articular cartilage in their experimental studies.
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Affiliation(s)
- H R Moody
- School of Engineering Systems, Queensland University of Technology, Australia
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15
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Abstract
Clinical experience shows that removal of the Exeter long-stem femoral component (220 mm, 240 mm, 260 mm) of total hip arthroplasty is extremely difficult, often requiring splitting of the femur. To identify the reason for this, measurements of stem geometry and force required to pull the stems out of the cement mantle were conducted on three original Exeter long-stem and one standard femoral components. All implants required an initial force of approximately 4 kN for release from the cement. The long-stem components then required much larger forces and hence much higher expenditure of energy to pull them clear of the cement. This was attributed to the reverse taper seen on the nominally cylindrical distal section of the long-stem components. Following re-design of the manufacturing process to ensure the taper continued to the implant's distal tip, four further implants were tested. These demonstrated the requirement for initial cement release but then required no further energy expenditure similar to the standard stem. This study clearly demonstrated that the original difficulty in removing these long stems was owing to the manufacturing process resulting in a reverse taper on the distal stem. The adoption of recommended manufacturing changes to ensure the taper continues to the distal tip removed this difficulty.
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Affiliation(s)
- G A Tevelen
- School of Engineering Systems and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
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16
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de Jong M, Ray M, Crawford S, Whitehouse SL, Crawford RW. Platelet and leukocyte activation in salvaged blood and the effect of its reinfusion on the circulating blood. Clin Orthop Relat Res 2007; 456:238-42. [PMID: 17119458 DOI: 10.1097/blo.0b013e31802dc4ba] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Postoperative wound drainage reinfusion reduces the frequency of homologous blood transfusion. The salvaged blood is depleted of coagulation factors but may contain platelets and leukocytes which are activated, and therefore potentially procoagulant. We ascertained the degree of activation of platelets and leukocytes in salvaged blood and asked whether their infusion produced any measurable effect on patients' coagulation system. We prospectively randomized 24 patients who had total knee arthroplasties to reinfusion of salvaged autologous blood (n = 12) or a standard drain with no reinfusion (n = 12). Analysis of the salvaged blood showed marked activation of platelets as shown by their expression of P-selectin, CD40 ligand, and Factor V/Va, and as increased numbers of platelet-derived microparticles. After reinfusion there was no measurable effect on activation markers of circulating platelets or leukocytes but there was a decrease in platelet count in the reinfused group compared with the control group. Levels of prothrombin fragment F1 + 2 (suggesting thrombin formation) increased in the reinfused group compared with control group, possibly indicating activation of coagulation systemically. The platelets and leukocytes in salvaged blood are markedly activated and their reinfusion causes a decrease in platelet count in the recipient and a possible increase in thrombin generation potentially favoring thrombosis.
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Affiliation(s)
- M de Jong
- Orthopaedic Department, Queensland Health Pathology Service, The Prince Charles Hospital, Rode Road, Chermside Queensland, Australia
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Abstract
A number of navigation systems used for total knee replacement surgery currently require the insertion of a distal femoral reference sensor pin, which is placed anterior to posterior just superior to the level of the knee joint. There is potential for the posterior neurovascular bundle to be damaged during the insertion of this sensor device. The aim of this cadaveric study was to identify the structures at risk during insertion of the distal femoral sensor, and determine whether a safe zone for insertion could be identified. Sixteen cadaveric lower limbs (8 pairs) were studied. In each knee Steinman pins were passed from anterior to posterior, 5 cm proximal to the level of the femoral articular cartilage, directly AP and angled at 30 degrees passing medially or laterally. All pins that were passed directly from anterior to posterior and from lateral to medial passed within 5 mm of a major neurovascular structure, while 62.5% of pins passing from medial to lateral passed within 5 mm of a major neurovascular structure. The popliteal vessels and the sciatic nerve are at risk of injury from a navigation pin or drill placed in the distal femur during knee navigation. Caution should be exercised in passing these pins and alternate methods of fixing femoral sensors should be considered.
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Affiliation(s)
- D C Marchant
- The Prince Charles Hospital, Brisbane, Queensland, Australia
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Ray MJ, Crawford SA, Crawford RW, Jabur MK, Walters DL. Increased CD40 ligand expression on platelets is associated with cardiovascular events after total hip arthroplasty. J Thromb Haemost 2006; 4:695-7. [PMID: 16460462 DOI: 10.1111/j.1538-7836.2006.01816.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Marchant DC, Rimmington DP, Crawford RW, Whitehouse SL, McGuire J. An algorithm for locating the center of the ankle joint in knee navigation surgery. Comput Aided Surg 2005; 10:45-9. [PMID: 16199381 DOI: 10.3109/10929080500230536] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The primary aim of computer-assisted knee arthroplasty is to improve the alignment of the implanted prostheses. Accurate component alignment is dependent on the establishment of accurate anatomical reference points. Current techniques for establishing the center of the ankle joint, especially in the coronal plane, rely solely on clinical judgment in relation to the position of the center of the ankle joint. The aim of this study was to determine if an algorithm could be developed, based on establishing the most prominent points on the medial and lateral malleoli on 3D CT scans, to accurately and reproducibly establish the position of the center of the ankle joint. To determine this, images of 20 ankles were obtained and axial, coronal, and sagittal 2D reconstructions were manipulated on a workstation. Two observers independently performed relevant measurements and calculations. The calculated data was found to be reproducible with a very small standard deviation in each plane. This algorithm is able to provide accurate measurements of the ankle joint in knee navigation surgery. Caution must be exercised in anatomically abnormal ankles, as the calculations of the ankle center were found to be significantly different.
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Affiliation(s)
- D C Marchant
- The Prince Charles Hospital, Brisbane, Queensland, Australia
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20
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Abmayr S, Crawford RW, Chamberlain JS. Characterization of ARC, apoptosis repressor interacting with CARD, in normal and dystrophin-deficient skeletal muscle. Hum Mol Genet 2003; 13:213-21. [PMID: 14645204 DOI: 10.1093/hmg/ddh018] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Duchenne muscular dystrophy is an X-linked recessive disorder, primarily characterized by progressive muscle weakness and wasting. The disease results from the absence of dystrophin, however the precise molecular mechanisms leading to muscle pathology are poorly understood. Dystrophic muscles undergo increased oxidative stress and altered calcium homeostasis, which may contribute to myofiber loss by triggering both necrosis and apoptosis. Recent studies have identified ARC (apoptosis repressor with caspase recruitment domain) as an abundant protein in human muscle that can inhibit both hypoxia and caspase-8-induced apoptosis as well as protect cells from oxidative stress. To explore a potential role for ARC in protecting muscle fibers from dystrophic breakdown, we have cloned and characterized murine ARC and studied its expression in normal and dystrophic mouse muscle. ARC is expressed at high levels in striated muscle and displays fiber-type restricted expression patterns. ARC expression levels are normal in dystrophic mdx mice, although the intracellular localization pattern of ARC is slightly altered compared with normal muscles. Overexpression of ARC in transgenic mdx mice failed to alleviate the dystrophic pathology in skeletal muscles, suggesting that misregulation of the molecular pathways regulated by ARC does not significantly contribute to myofiber death.
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Affiliation(s)
- S Abmayr
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA
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Abstract
Much evidence supports the hypothesis that surface-active phospholipid (SAPL), which imparts the thin hydrophobic outermost lining to the normal articular surface, is the boundary lubricant reducing friction to remarkably low levels. We review this evidence and further hypothesize that SAPL produced in type B synoviocytes will also lubricate prostheses after implantation. This could explain why implanted hips display far less wear than hips in simulated wear trials do, even using protein as the lubricant whereas rougher surfaces can be tolerated in vivo. We introduce the concept that a deficiency of SAPL might explain the selective failure of prostheses just as osteoarthritic articular surfaces are deficient. This, in turn, leads to the replenishment of SAPL, as tested in OA, and the concept of prelubricating prostheses before implantation.
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Affiliation(s)
- B A Hills
- Mater Children's Hospital and Department of Medicine university of Queensland, Queensland University ot Technology, Brisbane, Australia
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Dellorusso C, Crawford RW, Chamberlain JS, Brooks SV. Tibialis anterior muscles in mdx mice are highly susceptible to contraction-induced injury. J Muscle Res Cell Motil 2002; 22:467-75. [PMID: 11964072 DOI: 10.1023/a:1014587918367] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Skeletal muscles of patients with Duchenne muscular dystrophy (DMD) and mdx mice lack dystrophin and are more susceptible to contraction-induced injury than control muscles. Our purpose was to develop an assay based on the high susceptibility to injury of limb muscles in mdx mice for use in evaluating therapeutic interventions. The assay involved two stretches of maximally activated tibialis anterior (TA) muscles in situ. Stretches of 40% strain relative to muscle fiber length were initiated from the plateau of isometric contractions. The magnitude of damage was assessed one minute later by the deficit in isometric force. At all ages (2-19 months), force deficits were four- to seven-fold higher for muscles in mdx compared with control mice. For control muscles, force deficits were unrelated to age, whereas force deficits increased dramatically for muscles in mdx mice after 8 months of age. The increase in susceptibility to injury of muscles from older mdx mice did not parallel similar adverse effects on muscle mass or force production. The in situ stretch protocol of TA muscles provides a valuable assay for investigations of the mechanisms of injury in dystrophic muscle and to test therapeutic interventions for reversing DMD.
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Affiliation(s)
- C Dellorusso
- Department of Human Genetics, University of Michigan, Ann Arbor 48109-2007, USA
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Crawford RW, Psychoyios V, Gie G, Ling R, Murray D. Incomplete cement mantles in the sagittal femoral plane: an anatomical explanation. Acta Orthop Scand 1999; 70:596-8. [PMID: 10665725 DOI: 10.3109/17453679908997848] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The influence of operative technique on the formation of incomplete cement mantles in the sagittal plane has been rarely considered in the literature. In this article, we discuss the influence of the anatomy of the proximal femur on the formation of incomplete cement mantles and discuss how their incidence can be reduced by correct component positioning.
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Affiliation(s)
- R W Crawford
- Nuffield Department Orthopaedic Surgery, Oxford, Headington, UK
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Crawford RW, Evans M, Ling RS, Murray DW. Fluid flow around model femoral components of differing surface finishes: in vitro investigations. Acta Orthop Scand 1999; 70:589-95. [PMID: 10665724 DOI: 10.3109/17453679908997847] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We studied fluid flow at the stem-cement interface of bonded and debonded, polished and rough model femoral components. In a first series of experiments, fluid flow along the interface between bone cement and well-fixed model femoral components, differing in surface finish, and in shape, was measured. Fluid migration along the bone-cement interface of rough stems (Ra 3 microm) was greater than that on polished stems (p < 0.001). This was true of cylindrical and conical tapered stems. On stems with the same surface finish, shape did not influence fluid migration. In a second series of experiments, fluid flow along the stem-cement interface of 5 highly polished and 10 rough-finished (5 of Ra approximately 1.5 microm and 5 of Ra approximately 3 microm), debonded, tapered circular stems was measured. None of the rough stems could prevent fluid flow along the stem-cement interface. Polished tapered stems sealed the interface and, after 48 hrs of continuous pressure, no fluid flow was observed. This difference in the ability to seal the stem-cement interface between rough and polished stems was significant (p < 0.001). The difference in fluid migration along the stem-cement interface of rough and polished stems which we observed offers a plausible explanation of the occurrence of osteolysis distal to the articulation of cemented THR in the presence of cement mantle defects. It may also explain why osteolysis is uncommon with polished double-tapered stems.
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Affiliation(s)
- R W Crawford
- Oxford Orthopaedic Engineering Centre, Headington, UK
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Psychoyios V, Crawford RW, O'Connor JJ, Murray DW. Wear of congruent meniscal bearings in unicompartmental knee arthroplasty: a retrieval study of 16 specimens. J Bone Joint Surg Br 1998; 80:976-82. [PMID: 9853488 DOI: 10.1302/0301-620x.80b6.8176] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Many designs of unicompartmental knee replacement show early and mid-term failure due to polyethylene wear. We studied the wear rate of congruent polyethylene meniscal bearings retrieved from failed Oxford unicompartmental knee replacements. We examined 16 bearings, 0.8 to 12.8 years after implantation, measuring their thickness and comparing it with that of 14 unused bearings. The mean rate of penetration, which included the effects of wear at both upper and lower surfaces, was 0.036 mm per year (maximum 0.08). Bearings as thin as 3.5 mm wore no faster than thicker models, but ten with evidence of impingement had greater wear. The six bearings with no impingement showed a mean rate of penetration of 0.01 mm per year. In unicompartmental knee replacement, careful implantation of fully congruous meniscal bearings can avoid failure due to polyethylene wear.
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Crawford RW, Gie GA, Ling RS, Murray DW. Diagnostic value of intra-articular anaesthetic in primary osteoarthritis of the hip. J Bone Joint Surg Br 1998; 80:279-81. [PMID: 9546460 DOI: 10.1302/0301-620x.80b2.8299] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We investigated 42 patients who were being considered for primary total hip arthroplasty (THA), but in whom it was uncertain whether the hip was the source of their pain. They were given an injection of local anaesthetic into the joint space. Of 33 patients who gained pain relief from their injection, 32 subsequently had successful THA. The remaining patient has not had surgery. The intra-articular injection of local anaesthetic is thus at least 96% sensitive. Of the nine patients who had no or only minimal pain relief from injection, one has had an unsuccessful THA, three have been successfully treated for other conditions and five have unresolved pain for which no organic basis has been established. We believe that the injection of local anaesthetic into the hip is a reliable test, with low morbidity. In difficult cases it will aid in the clarification of the cause of pain which possibly arises from the hip.
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Affiliation(s)
- R W Crawford
- Princess Elizabeth Orthopaedic Hospital, Exeter, England, UK
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27
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Abstract
We investigated 15 patients with painful hip arthroplasties using intra-articular injection of bupivicaine. Fourteen had pain relief and 13 of them were subsequently found to have loosening of one or both components. The relief of pain after total hip arthroplasty by intra-articular injection of bupivicaine indicates that a satisfactory result is probable after revision surgery with refixation of the components.
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Affiliation(s)
- R W Crawford
- Princess Elizabeth Orthopaedic Hospital, Exeter, UK
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Wylie GD, Finger SE, Crawford RW. Toxicity of municipal wastewater effluents contaminated by pentachlorophenol in Southwest Missouri. Environ Pollut 1990; 64:43-53. [PMID: 15092306 DOI: 10.1016/0269-7491(90)90094-s] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/1989] [Accepted: 11/08/1989] [Indexed: 05/24/2023]
Abstract
Toxicity of effluents from two sewage treatment plants in Joplin, Missouri, was tested using Ceriodaphnia dubia and Pimephales promelas. No test organisms survived in effluents from either plant, in effluents diluted with water from Turkey Creek (the receiving stream), or in water from Turkey Creek. Mortality was complete in all but the most dilute treatments of effluents, in which reconstituted water was used as the diluent. High concentrations of pentachlorophenol (130-970 microg liter(-1)) in effluents and the receiving stream likely caused mortality during the 7-day tests. Detectable concentrations of other phenolic compounds indicated the presence in Turkey Creek of other toxic by-products of pentachlorophenol manufacture. This study demonstrated the utility of biological tests of whole effluents to determine toxicity of wastewater effluents.
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Affiliation(s)
- G D Wylie
- US Fish and Wildlife Service, National Fisheries Contaminant Research Center, Columbia, Missouri 65201, USA
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30
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Crawford RW, Brand HR, Wong CM, Gregg HR, Hoffman PA, Enke CG. Instrument database system and application to mass spectrometry/mass spectrometry. Anal Chem 1984; 56:1121-7. [PMID: 6742440 DOI: 10.1021/ac00271a015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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McCulloch CE, Crawford RW, Angus MJ, Glasser FP, Rahman AA. Sorption of radiocesium by active silica. Health Phys 1984; 46:1095-1100. [PMID: 6327573 DOI: 10.1097/00004032-198405000-00009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Cement and cement components have previously been shown to exhibit negligible sorption for cesium. Pyrogenic silica has been examined as an additive to cement materials for its ability to reduce the leachability of cesium and to provide a host material with permanent sorption sites. The incorporation of silica into cement composites can also improve the physical characteristics and strength of these materials as long ages. At neutral pH values, there is significant sorption of cesium by silica, but in high pH regimes, such as occur in cement environments, initial sorption is enhanced but this high level of sorption is followed by a gradual release of Cs. This apparent desorption is due to the consumption of SiO2 by Ca(OH)2 to form products which have little sorption potential for cesium. If, however, sufficient SiO2 is added to the system initially such that an excess remains after satisfying the demands of the Ca(OH)2 reaction, permanent sorption sites for cesium may be created.
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Jersild RA, Crawford RW. The distribution and mobility of anionic sites on the brush border of intestinal absorptive cells. Am J Anat 1978; 152:287-305. [PMID: 677051 DOI: 10.1002/aja.1001520303] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Drewinko B, Wallace B, Flores C, Crawford RW, Trujillo JM. Computerized hematology: operation of a high-volume hematology laboratory. Am J Clin Pathol 1977; 67:64-76. [PMID: 831456 DOI: 10.1093/ajcp/67.1.64] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Operation of automated hematology testing, on-line to a laboratory-dedicated computer, is described. The computer stores, retrieves and monitors the results of two Model S Sr. Coulter Counters, three Technicon platelet counters, one Electra 600-D, and six leukocyte differential consoles, which are interphased to the computer. All other hematology tests are batch-entered via the keyboard of cathode-ray tubes. The computer generates specimen labels, worksheets, and lists of incomplete tests, monitors all on-line instruments, and performs all the calculations used in the procedures of quality control. Results are available instantaneously on cathod-ray tubes strategically located in patient-related areas throughout the institution. These can be obtained as all of the results for a given day or as cumulative summaries or histogram-type plots of results for a given day.
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Zeigerman JH, Honigman FH, Crawford RW. Inflammatory mammary cancer during pregnancy and lactation. Report of a case. Obstet Gynecol 1968; 32:373-5. [PMID: 4316074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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