Guinea Pig Knee Research Articles

Synovial inflammation plays a greater role in post-traumatic osteoarthritis compared to idiopathic osteoarthritis in the Hartley guinea pig knee

BackgroundThe objective of this study was to evaluate the extent of stromal cell-derived factor-1’s (SDF-1) involvement in the pathogenesis of idiopathic versus post-traumatic OA by comparing differences in synovial membrane morphology, SDF-1 synovial fluid (SF) concentrations, and matrix metalloproteinase-13 (MMP-13) SF concentrations.MethodsThirty-six 3-month-old Hartley guinea pigs were obtained and divided into 6 groups. Upon sacrifice, India Ink staining was used to evaluate gross morphology, Safranin O/Fast green staining was used to assess cartilage damage, H/E staining was employed to visualize the synovium, and SF samples were obtained for biochemical analyses. Sandwich ELISA was used to quantify the SF concentrations of SDF-1 and MMP-13.Results12 month-old, idiopathic OA guinea pigs and 5.5 month-old ACLT animals had comparable cartilage damage when evaluated by the Modified Mankin Score. SDF-1 and MMP-13 concentrations were not statistically different between the two groups. The synovial membrane of the 5.5 month ACLT group had severe synovitis compared to the idiopathic OA group.ConclusionIn this study, it was found that synovial inflammation, independent of cartilage morphology, SDF-1 concentration, and MMP-13 concentration, was markedly different between idiopathic and post-traumatic OA. These results highlight the differing morphological and biochemical profiles of post-traumatic versus idiopathic osteoarthritis and calls for a more thorough examination of the sole of the synovial membrane in the pathogenesis of post-traumatic osteoarthritis.

'Iron accumulation' gene expression profile in obese hartley guinea pig knee joints is associated with more severe osteoarthritis

'Iron accumulation' gene expression profile in obese hartley guinea pig knee joints is associated with more severe osteoarthritis

Cartilage Imaging using HR Propagation-Based Phase-contrast CT in a Guinea Pig Knee Joint Model of Different Age Groups

Cartilage Imaging using HR Propagation-Based Phase-contrast CT in a Guinea Pig Knee Joint Model of Different Age Groups

Accuracy of ultrasound-guided intra-articular injections in guinea pig knees.

Objective Dunkin Hartley guinea pigs, a commonly used animal model of osteoarthritis, were used to determine if high frequency ultrasound can ensure intra-articular injections are accurately positioned in the knee joint.MethodsA high-resolution small animal ultrasound system with a 40 MHz transducer was used for image-guided injections. A total of 36 guinea pigs were anaesthetised with isoflurane and placed on a heated stage. Sterile needles were inserted directly into the knee joint medially, while the transducer was placed on the lateral surface, allowing the femur, tibia and fat pad to be visualised in the images. B-mode cine loops were acquired during 100 µl. We assessed our ability to visualise 1) important anatomical landmarks, 2) the needle and 3) anatomical changes due to the injection. ResultsFrom the ultrasound images, we were able to visualise clearly the movement of anatomical landmarks in 75% of the injections. The majority of these showed separation of the fat pad (67.1%), suggesting the injections were correctly delivered in the joint space. We also observed dorsal joint expansion (23%) and patellar tendon movement (10%) in a smaller subset of injections.ConclusionThe results demonstrate that this image-guided technique can be used to visualise the location of an intra-articular injection in the joints of guinea pigs. Future studies using an ultrasound-guided approach could help improve the injection accuracy in a variety of anatomical locations and animal models, in the hope of developing anti-arthritic therapies.Cite this article: Bone Joint Res 2015;4:1–5.

Superoxide dismutase downregulation in osteoarthritis progression and end-stage disease

BackgroundOxidative stress is proposed as an important factor in osteoarthritis (OA).ObjectiveTo investigate the expression of the three superoxide dismutase (SOD) antioxidant enzymes in OA.MethodsSOD expression was determined by real-time PCR...

Comparison of differential biomarkers of osteoarthritis with and without posttraumatic injury in the Hartley guinea pig model

The objective was to compare biomarkers of articular cartilage metabolism in synovial fluid from Hartley guinea pig knees, with and without anterior cruciate ligament transection (ACLT), to establish whether detectable differences in biomarker levels exist between primary and secondary osteoarthritis (OA). Synovial fluid lavages and knees were obtained from 3-month (control group) and 12-month (primary OA group) animals. Another group of animals (posttraumatic OA group) underwent unilateral ACLT at 3 months, and samples were obtained 9 months postsurgery. Synovial fluid concentrations of stromal cell-derived-factor (SDF-1), collagen fragments (C2C), proteoglycan (GAG), lubricin, matrix metalloproteinase-13 (MMP-13), and Interleukin-1 (IL-1beta) were evaluated. Cartilage damage was assessed via histology. The highest concentrations of C2C and SDF-1 in synovial fluid were found in the posttraumatic OA group, moderate concentrations were found in the primary OA group, and low concentrations in the control group. GAG release in synovial fluid was similar to C2C and SDF-1. The lubricin concentrations were significantly lower in ACLT joints than either the control or 12-month primary OA groups, but not between the control and primary OA groups. Higher levels of MMP-13 and IL-1beta were detected in the joints of the posttraumatic OA group as compared to the control or primary OA groups. Histology revealed greatest OA damage in the posttraumatic OA group, followed by moderate and minimal damage in primary OA and control groups, respectively. This study indicates that the biomarkers and progression of OA may differ in the Hartley guinea pig models with and without posttraumatic OA.

Collagen fibril disruption occurs early in primary guinea pig knee osteoarthritis

A major barrier inhibiting the discovery of structural modifying agents for osteoarthritis (OA) is an incomplete understanding of early disease events. Herein, we investigated the time course of collagen II cleavage and fibril disruption in the well-validated Hartley guinea pig model of spontaneous OA of the knee. Knee joints of 46 male Hartley guinea pigs were analyzed at 3 weeks, 2, 4, 7, 10, 12, and 18 months of age for histological severity of OA, cartilage collagen fibril disruption by semi-quantitative polarized light microscopy, and expression of type II collagen degradation biomarkers, 9A4 and Coll2-1, by immunohistochemistry. In addition, serum biomarkers specific for collagen II degradation, CTX-II, C2C, and Coll2-1 were quantified. Collagen fibril disruption and expression of the collagenase-generated cleavage neoepitope, 9A4, were observed as early as 2 months of age, despite the appearance of histological OA at 4 months of age. Only serum Coll2-1 increased coincident with the early disruption of the collagen fibril between 3 weeks and 7 months, in contrast to serum C2C, which did not change significantly or correlate with histological severity. Inversely, CTX-II declined dramatically from 3 weeks to 4 months and remaining low thereafter, coincident with growth plate turnover. Collagenase cleavage and disruption of the type II collagen network are early OA disease events in this model, preceding histological evidence of proteoglycan loss. The markedly different serum profiles of collagen II-related biomarkers during the early stages of disease development suggest compartmental segregation and temporal regulation of collagen degrading enzymes.

Transglutaminase 2 is a marker of chondrocyte hypertrophy and osteoarthritis severity in the Hartley guinea pig model of knee OA

The transglutaminase (TG) isoenzyme TG2, which catalyzes protein cross-linking via transamidation, influences healing phenotype in multiple forms of tissue injury. Moreover, TG2 knockout suppresses cartilage destruction but promotes osteophyte formation in instability-induced mouse knee osteoarthritis (OA). TG2 is marker of growth plate chondrocyte hypertrophy. Moreover, TG2 secreted by chondrocytes acts in part by promoting chondrocyte maturation to hypertrophy, a differentiation state linked with MMP-13 expression and disease progression in OA. Moreover, glucosamine, which is currently under investigation as an OA therapy, binds and inhibits TG2. Here, we examined TG2 as a potential marker of cartilage hypertrophy in the spontaneous guinea pig model of OA. Synovial fluid ELISA and cartilage Immunohistochemistry and quantitative Reverse transcription-polymerase chain reaction (RT-PCR), were used to examine TG2 expression and TG transamidation-catalyzed isopeptide bonds. TG isopeptide bonds and TG2 were most abundant in articular cartilage in early knee OA. TG2 expression was robust at sites of early but not established osteophytes. Synovial fluid TG2 correlated with knee OA total histological score (r=0.47, P=0.01), as did medial tibial plateau cartilage TG2 mRNA (r=1.0, P=0.003). At 12 months of age, medial tibial plateau cartilage TG2 mRNA expression rose markedly in association with elevated type X collagen, as well as ADAMTS-5, and MMP-13 expression, changes not shared in age-matched Strain 13 guinea pigs that are less susceptible to knee OA. Hartley guinea pig knee TG2 expression associates with enhanced articular chondrocyte hypertrophy and is a biomarker of OA severity.

Extrinsic and Intrinsic Innervation of the Guinea Pig Knee Joint: Toward an Animal Model for Manipulative Therapy

Objectives Besides spinal conditions, knee joint problems are one of the most common ailments of the musculoskeletal system. Problems with the knee can be classified into (1) poor mechanics, (2) traumatic injury, and (3) arthritic changes. All these problems can produce pain. Conservative treatment such as chiropractic manipulative therapy can be helpful in alleviating some of the pain. The present study was carried out to investigate the extrinsic and intrinsic innervation of the knee joint of the guinea pig in the hope of shedding light on future study of the underlying mechanism of chiropractic manipulative therapy on knee joint pain conditions. Methods A total of 16 guinea pigs were used in the present study. Microdissection was performed to reveal the gross anatomy of nerve innervation. Histology and immunohistochemistry were also performed to identify nerve endings and immunoreactive fibers in different articular tissues. Results Gross dissection revealed the general pattern of guinea pig knee joint innervation. By using gold chloride preparations, various kinds of nerves and terminals or endings were identified in these tissues. Immunohistochemistry also revealed immunoreactivities in nerve fibers in different joint tissues. Conclusions The distribution of the different nerve endings showed a characteristic pattern in different articular tissues. They were considered to be mechanoreceptors (types I, II, and III) and pain receptors (type IV). The structural characteristics and distribution patterns of the different types of nerve endings suggest that the roles of the different nerve endings vary in different parts of the articular tissues.

Wnt/β-catenin signaling stimulates matrix catabolic genes and activity in articular chondrocytes: its possible role in joint degeneration

A fine balance between anabolic and catabolic mechanisms maintains extracellular matrix homeostasis in articular cartilage, and shifts toward degradation are associated with joint conditions such as osteoarthritis. To test the possible involvement, relevance and significance of the Wnt/β-catenin-signaling pathway in those catabolic shifts, rabbit articular chondrocyte cultures were subjected to experimental activation of β-catenin signaling by Wnt3A treatment or forced expression of constitutive-active β-catenin (CA-β-catenin). Both interventions provoked strong gelatinase activity and stimulated gene expression of matrix metalloprotease-3 and -13 and a disintegrin-like and metalloprotease with thrombospondin motif (ADAMTS)-4 and -5 proteases. Furthermore, Wnt3A treatment additively enhanced the effects of intereukin-1β, a well-known catabolic culprit of proteoglycan matrix loss. To determine whether Wnt/β-catenin signaling is associated with age-associated osteoarthritic changes in articular cartilage in vivo, we analyzed the presence and intracellular distribution of β-catenin in a spontaneous guinea pig osteoarthritis model. Healthy articular chondrocytes in young guinea pig knees contained barely detectable levels of β-catenin. In contrast, the protein was highly abundant in osteoarthritic-like chondrocytes present in older guinea pig joints, and was localized not only in the cytoplasm but also the nucleus, a clear reflection of activated Wnt signaling. These and other data suggest that Wnt/β-catenin signaling is a powerful stimulator of chondrocyte matrix catabolic action and may be part of mechanisms leading to excessive remodeling and degradation of cartilage matrix in age-associated joint pathologies.

Knee cartilage thickness measurements using MRI: a 4½-month longitudinal study in the meniscectomized guinea pig model of OA

The aim of this study was to follow, over a 4(1/2)-month period, the medial tibia cartilage thickness on a meniscectomy (MNX) guinea pig osteoarthritis (OA) model and to compare with control animals, using three-dimensional high-resolution magnetic resonance imaging (3D HR-MRI). MRI experimentations were performed in vivo at 7 T on guinea pig knee joints. 3D HR-MR images were acquired in 60 controls (SHAM) and 45 osteoarthritic animals (MNX) at four time-points (15, 45, 90 and 135 days) after surgery. Medial tibial cartilage thickness was measured from MRI images using in-house dedicated 3D software followed by a statistical analysis. At each time-point 15 SHAM and 15 MNX animals were sacrificed for histomorphometric assessments. No significant difference of mean cartilage thickness between the groups was found at early stage (D45) using MRI; however, significant differences were found between the groups at D90 (P<0.001) and D135 (P<0.001). Histomorphometry data confirmed the pathological status of the animals and was well correlated with MRI at D15 (r=0.79, P<0.01), D45 (r=0.67, P<0.01), and D135 (r=0.39, P<0.05) for SHAM, and at D45 (r=0.63, P<0.01), and D135 (r=0.81, P<0.01) for MNX. Medial tibial cartilage measurement based on HR-MR images enables the monitoring of longitudinal cartilage thickness changes. This technique showed significant differences between SHAM and MNX as from D90 after surgery. It could be used as a noninvasive and reproducible tool to monitor therapeutic response in this OA model.

Frictional properties of Hartley guinea pig knees with and without proteolytic disruption of the articular surfaces

To apply a pendulum technique to detect changes in the coefficient of friction of the articular cartilage of the intact guinea pig tibiofemoral joint after proteolytic disruption. Twenty-two hind limbs were obtained from 11 3-month old Hartley guinea pigs. Twenty knees were block-randomized to one of two treatment groups receiving injections of: (1) alpha-chymotrypsin (to disrupt the superficial layer of the articular surface) or (2) saline (sham; to control for the effects of the intra-articular injection). The legs were mounted in a pendulum where the knee served as the fulcrum. The decay in pendulum amplitude as a function of oscillation number was first recorded and the coefficient of friction of the joint was determined from these data before injection. Ten microliters of either isotonic saline or 1 Unit/microL alpha-chymotrypsin was then injected into the intra-articular joint space and incubated for 2h. The pendulum test was repeated. Changes in the coefficient of friction between the sham and alpha-chymotrypsin joints were compared. One additional pair of knees was used for histological study of the effects of the injections. Treatment with alpha-chymotrypsin significantly increased the coefficient of friction of the guinea pig knee by 74% while sham treatment decreased it by 8%. Histological sections using Gomori trichrome stain verified that the lamina splendens was damaged following treatment with alpha-chymotrypsin and not following saline treatment. Treatment with alpha-chymotrypsin induces mild cartilage surface damage and increases the coefficient of friction in the Hartley guinea pig knee.

Chondrocyte calcium-sensing receptor expression is up-regulated in early guinea pig knee osteoarthritis and modulates PTHrP, MMP-13, and TIMP-3 expression

Growth plate chondrocytes up-regulate calcium-sensing receptor (CaR) expression as they mature to hypertrophy. In cells other than chondrocytes, extracellular calcium-sensing via the CaR functions partly to promote expression of parathyroid hormone-related protein (PTHrP), a critical regulator of endochondral development. Moreover, PTHrP is up-regulated in human osteoarthritis (OA) and surgically induced rabbit OA cartilages and may promote both chondrocyte proliferation and osteophyte formation therein. Hence, we examined chondrocyte CaR-mediated calcium-sensing in OA pathogenesis. We studied spontaneous knee OA in male Hartley guinea pigs. We also evaluated cultured bovine knee chondrocytes and immortalized human articular chondrocytes (CH-8 cells), employing the CaR calcimimetic agonist NPS R-467 or altering physiologic extracellular calcium (1.8 mM). Immunohistochemistry revealed that CaR expression became up-regulated in the superficial zone at 4 months of age in the guinea pig medial tibial plateau cartilage as early OA developed. CaR expression later became up-regulated in the middle zone. PTHrP content, measured by immunoassay, was significantly increased in the medial tibial plateau cartilage as OA developed and progressed. In cultured chondrocytic cells, CaR-mediated extracellular calcium-sensing, stimulated by the calcimimetic NPS R-467, induced PTHrP and matrix metalloproteinase (MMP)-13 expression and suppressed expression of tissue inhibitor of metalloproteinase (TIMP)-3 dose-dependently, effects shared by elevated extracellular calcium (3 mM). Extracellular calcium-sensing appeared essential for PTHrP and interleukin (IL)-1 to induce MMP-13 and for PTHrP 1-34 to suppress TIMP-3 expression. Chondrocyte CaR expression becomes up-regulated early in the course of spontaneous guinea pig knee OA. Chondrocyte CaR-mediated extracellular calcium-sensing promotes PTHrP expression, modulates the effects of PTHrP and IL-1, and promotes MMP-13 expression and TIMP-3 depletion. Our results implicate up-regulated extracellular calcium-sensing via the CaR as a novel mediator of OA progression.

Mediation of spontaneous knee osteoarthritis by progressive chondrocyte ATP depletion in Hartley guinea pigs

Because articular chondrocytes reside in a hypoxic milieu, anaerobic glycolysis is central in generating ATP to support chondrocyte matrix synthesis and viability, with mitochondrial oxidative phosphorylation possibly providing physiologic reserve ATP generation. Nitric oxide (NO) potently suppresses mitochondrial oxidative phosphorylation. Because enhanced cartilage NO generation occurs in osteoarthritis (OA), we systematically tested for mitochondrial dysfunction in the pathogenesis of OA. We assessed chondrocytes for ATP depletion and for in situ changes in mitochondrial ultrastructure prior to and during the evolution of spontaneous knee OA in male Hartley guinea pigs, a model in which chondrocalcinosis also supervenes. Spontaneous NO release from knee cartilage samples in organ culture doubled between ages 2 months and 8 months as knee OA developed. Concomitantly, chondrocyte intracellular ATP levels declined by approximately 50%, despite a lack of mitochondrial ultrastructure abnormalities in knee chondrocytes. As ATP depletion progressed with aging in knee chondrocytes, an increased ratio of lactate to pyruvate was observed, consistent with an adaptive augmentation of glycolysis to mitochondrial dysfunction. Furthermore, we observed progressive elevation of chondrocyte ATP-scavenging nucleotide pyrophosphatase/phosphodiesterase (NPP) activity and extracellular levels of the NPP enzymatic end product inorganic pyrophosphate (PPi), which stimulate chondrocalcinosis. Profound chondrocyte ATP depletion develops in association with heightened NO generation in guinea pig knee OA. Increased NPP activity and concordant increases in extracellular PPi, which are strongly associated with human aging-associated degenerative arthropathy and directly stimulate chondrocalcinosis, may be primarily driven by chondrocyte ATP depletion. Our findings implicate a decreased mitochondrial bioenergetic reserve as a pathogenic factor in both degenerative arthropathy and chondrocalcinosis in aging.

Cartilage mechanics in the guinea pig model of osteoarthritis studied with an osmotic loading method

Objective: To determine the material properties of articular cartilage in the Hartley guinea pig model of spontaneous osteoarthritis. Methods: Cartilage-bone samples from the medial femoral condyle and tibial plateau of 12 month-old guinea pig knees were subjected to osmotic loading. Site-matched swelling strains and fixed charge density values were used in a triphasic theoretical model for cartilage swelling to determine the modulus of the cartilage solid matrix. The degree of cartilage degeneration was assessed in adjacent tissue sections using a semi-quantitative histological grading scheme. Results: Decreased values for both moduli and surface zone fixed charge density were associated with increasing grades of cartilage degeneration. Decreases in moduli reflect damage to the collagen matrix, which give rise to greater swelling strains. Conclusion: Histological evidence of cartilage degeneration was associated with impaired cartilage mechanics in the aging Hartley guinea pig.

Tumour necrosis factor alpha up-regulates protein kinase R (PKR)-activating protein (PACT) and increases phosphorylation of PKR and eukaryotic initiation factor 2-alpha in articular chondrocytes.

Our previous analysis of the genes regulated in cartilage at the onset of spontaneous osteoarthritis in the guinea pig knee revealed up-regulation of the gene for protein kinase R (PKR)-activating protein (PACT), which encodes the cellular activator of the protein kinase, PKR. PACT and PKR are upstream components of a number of signal transduction and gene transcription pathways used by pro-inflammatory cytokines. We have investigated the role of PACT and PKR in articular cartilage degradation using cytokine treatment of bovine primary chondrocytes and cartilage explants. Tumour necrosis factor alpha increased expression of PACT protein after 3 h of treatment. Furthermore, increased phosphorylation of PKR and eukaryotic initiation factor 2-alpha was observed. The known role of PKR in cytokine-induced signalling pathways, together with our data showing cytokine regulation of PACT and PKR in chondrocytes, reveals a novel mechanism of cartilage degradation that may be important in the pathogenesis of arthritic diseases.

Osmotic loading to determine the intrinsic material properties of guinea pig knee cartilage

Few methods exist to study cartilage mechanics in small animal joints due to the difficulties associated with handling small tissue samples. In this study, we apply an osmotic loading method to quantify the intrinsic material properties of articular cartilage in small animal joints. Cartilage samples were studied from the femoral condyle and tibial plateau of two-month old guinea pigs. Swelling strains were measured using confocal fluorescence scanning microscopy in samples subjected to osmotic loading. A histochemical staining method was developed and calibrated for quantification of negative fixed charge density in guinea pig cartilage. Site-matched swelling strain data and fixed charge density values were then used with a triphasic theoretical model for cartilage swelling to determine the uniaxial modulus of the cartilage solid matrix. Moduli obtained in this study (7.2 MPa femoral condyle; 10.8 MPa, tibial plateau) compare well with previously reported values for the tensile moduli of human and other animal cartilages determined from uniaxial tension experiments. This study provides the first available data for material properties and fixed charge density in cartilage from the guinea pig knee and suggests a promising method for tracking changes in cartilage mechanics in small animal models of degeneration.

Effect of load on articular cartilage matrix and the development of guinea-pig osteoarthritis

Objective To study the biochemical changes in the early development of primary guinea-pig knee osteoarthritis (OA) and its dependence on load.Methods Load distribution was modified with below-knee amputation or femur valgus osteotomy in 9-month-old guinea-pigs. Soft tissue sham operated animals served as controls. The composition of uncalcified and calcified articular cartilage at the medial and lateral tibial condyle was studied by analysing small and large proteoglycans (PG) by gel electrophoresis and sulfation pattern with high-performance liquid chromatography. Collagen concentration was also determined.Results The articular surfaces with a presumed higher load after surgery had a slight, but consistent, higher water content. Decreased load—on the ipsilateral medial condyle after femur osteotomy, and on the ipsilateral medial and lateral condyles following tibia amputation—was associated with an increased concentration of PGs, while this concentration decreased in condyles with increased load. Collagen concentration followed a similar pattern in the osteotomy group. In the amputated animals collagen concentration went down in all condyles, regardless of change of load. The aggregability and proportion of large and small PGs, the concentration of hyaluronan and the sulfation pattern of chondroitin sulfate was not affected by load. No consistent changes in PG, collagen or HA concentration, HA aggregability or sulfation pattern were seen in the calcified cartilage.Conclusions Primary guinea-pig knee OA is a reproducible model similar to human OA. It develops slowly and biochemical changes seem to appear before the morphological lesions become evident. The biochemical events are affected by load redistribution and correlate closely to morphological changes. These changes eventually result in a cartilage devoid in aggrecan, as also has been demonstrated in advanced human OA. All of this makes primary guinea-pig OA a suitable model for studying early OA changes.

ONO-4817, an orally active matrix metalloproteinase inhibitor, prevents lipopolysaccharide-induced proteoglycan release from the joint cartilage in guinea pigs.

To evaluate the effect of a newly developed inhibitor of matrix metalloproteinases (MMPs), ONO-4817, on the degradation of cartilage in the guinea pig arthritis model. 42 guinea pigs were used in the arthritis model. Lipopolysaccharide (LPS) was injected into guinea pig knee joints. The content of proteoglycan released in synovial cavity was measured as a marker of cartilage degradation. ONO-4817, dexamethasone or indomethacin were administered orally to the animals. ONO-4817 showed a broad inhibitory activity against MMPs except MMP-1 and MMP-7. The oral administration of ONO-4817 dose-dependently suppressed the release of proteoglycan from the cartilage of the knee joints. This study suggests the possibility that a novel MMP inhibitor, ONO-4817 may have a therapeutic utility for MMP-related diseases.

Immunoelectron microscopy of matrix molecules in the guinea pig knee during early stages of osteoarthritis

International Journal of Experimental PathologyVolume 79, Issue 5 p. A49-A50 Immunoelectron microscopy of matrix molecules in the guinea pig knee during early stages of osteoarthritis R.D. YOUNG, R.D. YOUNG Connective Tissue Biology Laboratories, School of Molecular & Medical Biosciences, University of Wales, Cardiff, UKSearch for more papers by this authorA. VAUGHAN-THOMAS, A. VAUGHAN-THOMAS Connective Tissue Biology Laboratories, School of Molecular & Medical Biosciences, University of Wales, Cardiff, UKSearch for more papers by this authorV.C. DUANCE, V.C. DUANCE Connective Tissue Biology Laboratories, School of Molecular & Medical Biosciences, University of Wales, Cardiff, UKSearch for more papers by this author R.D. YOUNG, R.D. YOUNG Connective Tissue Biology Laboratories, School of Molecular & Medical Biosciences, University of Wales, Cardiff, UKSearch for more papers by this authorA. VAUGHAN-THOMAS, A. VAUGHAN-THOMAS Connective Tissue Biology Laboratories, School of Molecular & Medical Biosciences, University of Wales, Cardiff, UKSearch for more papers by this authorV.C. DUANCE, V.C. DUANCE Connective Tissue Biology Laboratories, School of Molecular & Medical Biosciences, University of Wales, Cardiff, UKSearch for more papers by this author First published: 16 May 2002 https://doi.org/10.1046/j.1365-2613.1998.t01-18-750408.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume79, Issue5October 1998Pages A49-A50 RelatedInformation