Resorbable electrospun polydioxanone fibres modify the behaviour of cells from both healthy and diseased human tendons.

Chronic tendinopathy in an active and ageing population represents an increasing burden to healthcare systems. Rotator cuff tendinopathy alone accounts for approximately 70 % of all shoulder pain. Tendinopathic tissue has a disorganised extracellular matrix, altered vasculature, and infiltration of fibroblasts and inflammatory cells. This altered biology may contribute to the limited success of surgical repair strategies. Electrospun resorbable scaffolds can potentially enhance endogenous repair mechanisms by influencing the tissue microenvironment. Polydioxanone (PDO) has an established safety profile in patients. We compared the response of healthy and diseased human tendon cells to electrospun PDO fibres using live cell imaging, proliferation, flow cytometry, and gene expression studies. Within 4 h of initial contact with electrospun PDO, healthy tendon cells underwent a marked transformation; elongating along the fibres in a fibre density dependent manner. Diseased tendon cells initially responded at a slower rate, but ultimately underwent a similar morphological change. Electrospun fibres increased the proliferation rate of diseased tendon cells and increased the ratio of type I:IIIcollagenmRNA expression. Flow cytometry revealed decreased expression of CD106, a marker of mesenchymal stem cells, and increased expression of CD10 on healthy versus diseased tendon cells. PDO electrospun scaffolds further promoted CD106negCD10pos expression of healthy tendon cells. Despite their behavioural differences, both healthy and diseased human tendon cells responded to electrospun PDO fibres. This encourages further work establishing their efficacy in augmenting surgical repair of diseased tendons.

Dickkopf-3 is upregulated in osteoarthritis and has a chondroprotective role.

OBJECTIVE: Dickkopf-3 (Dkk3) is a non-canonical member of the Dkk family of Wnt antagonists and its upregulation has been reported in microarray analysis of cartilage from mouse models of osteoarthritis (OA). In this study we assessed Dkk3 expression in human OA cartilage to ascertain its potential role in chondrocyte signaling and cartilage maintenance. METHODS: Dkk3 expression was analysed in human adult OA cartilage and synovial tissues and during chondrogenesis of ATDC5 and human mesenchymal stem cells. The role of Dkk3 in cartilage maintenance was analysed by incubation of bovine and human cartilage explants with interleukin-1ß (IL1ß) and oncostatin-M (OSM). Dkk3 gene expression was measured in cartilage following murine hip avulsion. Whether Dkk3 influenced Wnt, TGFß and activin cell signaling was assessed in primary human chondrocytes and SW1353 chondrosarcoma cells using qRT-PCR and luminescence assays. RESULTS: Increased gene and protein levels of Dkk3 were detected in human OA cartilage, synovial tissue and synovial fluid. DKK3 gene expression was decreased during chondrogenesis of both ATDC5 cells and humans MSCs. Dkk3 inhibited IL1ß and OSM-mediated proteoglycan loss from human and bovine cartilage explants and collagen loss from bovine cartilage explants. Cartilage DKK3 expression was decreased following hip avulsion injury. TGFß signaling was enhanced by Dkk3 whilst Wnt3a and activin signaling were inhibited. CONCLUSIONS: We provide evidence that Dkk3 is upregulated in OA and may have a protective effect on cartilage integrity by preventing proteoglycan loss and helping to restore OA-relevant signaling pathway activity. Targeting Dkk3 may be a novel approach in the treatment of OA.

The response of tenocytes to commercial scaffolds used for rotator cuff repair.

Surgical repairs of rotator cuff tears have high re-tear rates and many scaffolds have been developed to augment the repair. Understanding the interaction between patients' cells and scaffolds is important for improving scaffold performance and tendon healing. In this in vitro study, we investigated the response of patient-derived tenocytes to eight different scaffolds. Tested scaffolds included X-Repair, Poly-Tape, LARS Ligament, BioFiber (synthetic scaffolds), BioFiber-CM (biosynthetic scaffold), GraftJacket, Permacol, and Conexa (biological scaffolds). Cell attachment, proliferation, gene expression, and morphology were assessed. After one day, more cells attached to synthetic scaffolds with dense, fine and aligned fibres (X-Repair and Poly-Tape). Despite low initial cell attachment, the human dermal scaffold (GraftJacket) promoted the greatest proliferation of cells over 13 days. Expression of collagen types I and III were upregulated in cells grown on non-cross-linked porcine dermis (Conexa). Interestingly, the ratio of collagen I to collagen III mRNA was lower on all dermal scaffolds compared to synthetic and biosynthetic scaffolds. These findings demonstrate significant differences in the response of patient-derived tendon cells to scaffolds that are routinely used for rotator cuff surgery. Synthetic scaffolds promoted increased cell adhesion and a tendon-like cellular phenotype, while biological scaffolds promoted cell proliferation and expression of collagen genes. However, no single scaffold was superior. Our results may help understand the way that patients' cells interact with scaffolds and guide the development of new scaffolds in the future.

A gene expression study of normal and damaged cartilage in anteromedial gonarthrosis, a phenotype of osteoarthritis.

OBJECTIVE: To identify osteoarthritis (OA) relevant genes and pathways in damaged and undamaged cartilage isolated from the knees of patients with anteromedial gonarthrosis (AMG) - a specific form of knee OA. DESIGN: Cartilage was obtained from nine patients undergoing unicompartmental knee replacement (UKR) for AMG. AMG provides a spatial representation of OA progression; showing a reproducible and histologically validated pattern of cartilage destruction such that damaged and undamaged cartilage from within the same knee can be consistently isolated and examined. Gene expression was analysed by microarray and validated using real-time PCR. RESULTS: Damaged and undamaged cartilage showed distinct gene expression profiles. 754 genes showed significant up- or down-regulation (non-False discovery rate (FDR) P < 0.05) with enrichment for genes involved in cell signalling, Extracellular Matrix (ECM) and inflammatory response. A number of genes previously unreported in OA showed strongly altered expression including RARRES3, ADAMTSL2 and DUSP10. Confirmation of genes previously identified as modulated in OA was also obtained e.g., SFRP3, MMP3 and IGF1. CONCLUSIONS: This is the first study to examine a common and consistent phenotype of OA to allow direct comparison of damaged and undamaged cartilage from within the same joint compartment. We have identified specific gene expression profiles in damaged and undamaged cartilage and have determined relevant genes and pathways in OA progression. Importantly this work also highlights the necessity for phenotypic and microanatomical characterization of cartilage in future studies of OA pathogenesis and therapeutic development.

CT angiograms for lower GI bleeding: the experience of a large UK teaching hospital.

INTRODUCTION: The clinical presentation of lower gastrointestinal bleeding (LGIB) is variable in severity, cause and potential investigations. The British Society of Gastroenterology recently published LGIB guidelines, recommending CT angiography (CT-A) for haemodynamically unstable patients, defined by shock index (SI) greater than 1. The aim of this study was to assess the use and role of CT-A in diagnosing LGIB, by assessing the pickup rate of active LGIB defined by contrast extravasation or 'blush' and to determine any association between positive CT-A with various patient and clinical characteristics. METHODS: A retrospective analysis was carried out of 4 years of LGIB admissions. Demographics, inpatient observations and use of blood products were acquired. Vital signs nearest the time of CT-A plus abnormal vital signs preceding imaging were used to calculate SI, Age SI, National Early Warning Score 2 (NEWS2) and Standardised Early Warning Score (SEWS). A consultant gastrointestinal radiologist further reviewed all consultant-reported scans. RESULTS: In total, 930 patients were admitted with LGIB. Median age was 71 years and 51% were male; 179 (19.2%) patients received red blood cell transfusion and 93 patients (10%) underwent CT-A, who were older and were likely to be hypotensive and receive red cell transfusions. Following exclusions, 92 CT-As were included in the analysis. Nine (9.8%) were positive. Univariate analysis showed no association between positive CT-A and any scoring system. A multivariate analysis, including age and gender, showed association between both NEWS2 and SEWS scores with positive CT-A. CONCLUSION: In our analysis of the typical LGIB population, CT-A has shown relatively low pick up rate of active bleeding. CT-A clearly has a role in the investigation of LGIB, but selection remains challenging.

CT angiograms for lower GI bleeding: the experience of a large UK teaching hospital.

INTRODUCTION: The clinical presentation of lower gastrointestinal bleeding (LGIB) is variable in severity, cause and potential investigations. The British Society of Gastroenterology recently published LGIB guidelines, recommending CT angiography (CT-A) for haemodynamically unstable patients, defined by shock index (SI) greater than 1. The aim of this study was to assess the use and role of CT-A in diagnosing LGIB, by assessing the pickup rate of active LGIB defined by contrast extravasation or 'blush' and to determine any association between positive CT-A with various patient and clinical characteristics. METHODS: A retrospective analysis was carried out of 4 years of LGIB admissions. Demographics, inpatient observations and use of blood products were acquired. Vital signs nearest the time of CT-A plus abnormal vital signs preceding imaging were used to calculate SI, Age SI, National Early Warning Score 2 (NEWS2) and Standardised Early Warning Score (SEWS). A consultant gastrointestinal radiologist further reviewed all consultant-reported scans. RESULTS: In total, 930 patients were admitted with LGIB. Median age was 71 years and 51% were male; 179 (19.2%) patients received red blood cell transfusion and 93 patients (10%) underwent CT-A, who were older and were likely to be hypotensive and receive red cell transfusions. Following exclusions, 92 CT-As were included in the analysis. Nine (9.8%) were positive. Univariate analysis showed no association between positive CT-A and any scoring system. A multivariate analysis, including age and gender, showed association between both NEWS2 and SEWS scores with positive CT-A. CONCLUSION: In our analysis of the typical LGIB population, CT-A has shown relatively low pick up rate of active bleeding. CT-A clearly has a role in the investigation of LGIB, but selection remains challenging.

Cytokines in tendon disease: A Systematic Review.

OBJECTIVES: Emerging evidence indicates that tendon disease is an active process with inflammation that is critical to disease onset and progression. However, the key cytokines responsible for driving and sustaining inflammation have not been identified. METHODS: We performed a systematic review of the literature using MEDLINE (U.S. National Library of Medicine, Bethesda, Maryland) in March 2017. Studies reporting the expression of interleukins (ILs), tumour necrosis factor alpha (TNF-α) and interferon gamma in diseased human tendon tissues, and animal models of tendon injury or exercise in comparison with healthy control tissues were included. RESULTS: IL-1ß, IL-6, IL-10, and TNF-α are the cytokines that have been most frequently investigated. In clinical samples of tendinopathy and tendon tears, the expression of TNF-α tended not to change but IL-6 increased in tears. Healthy human tendons showed increased IL-6 expression after exercise; however, IL-10 remained unchanged. Animal tendon injury models showed that IL-1ß, IL-6, and TNF-α tend to increase from the early phase of tendon healing. In animal exercise studies, IL-1ß expression showed a tendency to increase at the early stage after exercise, but IL-10 expression remained unchanged with exercise. CONCLUSIONS: This review highlights the roles of IL-1ß, IL-6, IL-10, and TNF-α in the development of tendon disease, during tendon healing, and in response to exercise. However, there is evidence accumulating that suggests that other cytokines are also contributing to tendon inflammatory processes. Further work with hypothesis-free methods is warranted in order to identify the key cytokines, with subsequent mechanistic and interaction studies to elucidate their roles in tendon disease development.Cite this article: W. Morita, S. G. Dakin, S. J. B. Snelling, A. J. Carr. Cytokines in tendon disease: A Systematic Review. Bone Joint Res 2017;6:656-664. DOI: 10.1302/2046-3758.612.BJR-2017-0112.R1.

The influence of tumour microenvironmental factors on the efficacy of cisplatin and novel platinum(IV) complexes.

The chemotherapeutic drug cisplatin is an important treatment for many types of solid tumours, in particular non-small cell lung cancer (NSCLC). Platinum(IV) complexes offer several advantages to cisplatin due to their requirement for reduction to the active platinum(II) form to elicit cytotoxicity. This should minimise non-specific effects and facilitate higher amounts of the active complexes reaching the target DNA. Hypoxia and a quiescent cell population are features of the tumour microenvironment known to lead to resistance to many chemotherapeutic agents. It is unclear how these microenvironmental factors will impact on the efficacy of novel platinum(IV) complexes. Consequently, the cytotoxicities of several platinum drugs were determined in monolayer and tumour spheroid cultures derived from NSCLC lines. Platinum(IV) reduction potential correlated well with cytotoxicity. The complex containing a chloro axial ligand demonstrated the greatest potency and the drug with the hydroxy ligand was the least effective. Although drug cytotoxicity was not enhanced under hypoxic conditions, both cisplatin and the platinum(IV) complexes retained full potency. In addition, all of the platinum drugs retained the ability to evoke apoptosis in quiescent cells. In summary, unlike many anticancer drugs, the platinum(IV) complexes retain cytotoxic potency under resistance-inducing tumour microenvironmental conditions and warrant further investigation as more selective alternatives to current platinum-based therapy for the treatment of solid tumours.

Radiographic changes in elbow dysplasia following ulnar osteotomy--a case report and review of the literature.

This case report describes the results of bilateral elbow arthrotomy and a unilateral ulnar osteotomy in a 10-month-old dog with bilateral elbow dysplasia. Fragmented coronoid processes were removed from both joints via bilateral medial arthrotomies. On the right side an ulnar osteotomy was also performed using a caudolateral approach. Bilateral flexed lateral elbow radiographs taken before surgery and 5 months postoperatively were assessed for changes in osteophyte size on the anconeal process, caudal epicondylar ridge and radial head. Osteophytes on the anconeal process and caudal epicondylar ridge disappeared over the postoperative period in the joint that received an ulnar osteotomy. In the contralateral joint the size of the oesteophytes on the anconeal process and caudal epicondylar ridge increased in size during the same period.

A retrospective study of unilateral arytenoid lateralisation in the treatment of laryngeal paralysis in 100 dogs (1992-2000).

OBJECTIVE: To determine the effectiveness of unilateral arytenoid lateralisation as a surgical treatment for laryngeal paralysis in dogs. DESIGN: The case records of 100 dogs that received a unilateral arytenoid lateralisation for laryngeal paralysis between 1992 and 2000 were reviewed. The results of questionnaires on surgical outcome, formulated for the animal owner and the referring veterinarian, were analysed. Information obtained for dogs under 10 kg and dogs over 10 kg was analysed separately. RESULTS: The Labrador Retriever was the most commonly affected breed. The male:female ratio was 1.56:1 and the average age of presentation was 9.9 years. The most common month in which surgery was performed was October. The majority of owners (87.7%) felt that their dog's quality of life was improved in the 6 months after surgery. Thirty-three percent of dogs revisited the referring clinic with a respiratory problem following unilateral arytenoid lateralisation, and 10.7% of dogs were reported as having a post-surgical complication associated with the procedure. Following surgery, dogs under 10 kg revisited the referring veterinarian with a respiratory complication more often than dogs over 10 kg. Significantly fewer owners of dogs under 10 kg than owners of dogs over 10 kg felt that their dogs quality of life was improved by surgery (55% versus 93%). CONCLUSION: The majority of owners surveyed reported that unilateral arytenoid lateralisation had improved the quality of their dog's life during the first 6 postoperative months. Owner dissatisfaction with the results of surgery and the reported rate of re-presentation (for respiratory disease) may be higher for small (< 10 kg) dogs. A prospective study comparing the results of unilateral arytenoid lateralisation surgery in large and small dogs may be worthwhile in the future.

A retrospective review of antebrachial angular and rotational limb deformity correction in dogs using intraoperative alignment and type 1b external fixation.

AIM: The aim of this study was to report the outcome of acute antebrachial angular and rotational limb deformity (AARLD) correction using a standard radial ostectomy, an unarticulated type 1b external skeletal fixator (ESF) and intra-operative alignment with no pre-operative planning. METHODS: A retrospective evaluation was performed of dogs with carpal valgus, radial procurvatum and rotational deformity of the forelimb. All 39 cases presented and were treated surgically at a referral hospital in Melbourne, Australia, between September 2008 and March 2012. Surgical correction involved a standard closing cuneiform radial ostectomy, distal ulnar ostectomy and application of an unarticulated type 1b ESF. The method used intra-operative limb alignment and did not use pre-operative planning. Outcome was assessed via client phone interviews in all cases. Five cases were evaluated post-operatively using centre of rotation and angulation (CORA) methodology. RESULTS: As reported by owners of the 39 cases following surgery, limb function was excellent in 26 (67%), good in 12 (31%) cases and acceptable in one (2.5%) case. Frame tolerance was reported as good in 24 (62%), acceptable in 14 (36%) cases and poor in one (2.5%) case. Limb appearance was reported as straight in 25 (64%) cases and mildly rotated in 14 (36%) cases. In five cases that were evaluated, post-operative frontal and sagittal plane alignment ranged from 0-3.1° and 9.1-12.2°, respectively, and distal CORA was corrected to <6.1°. These were within the normal reported reference ranges. Pin tract infections were reported in seven (18%) cases CONCLUSIONS AND CLINICAL RELVANCE: This study suggests that the described technique may be an effective practice for the correction of AARLD that provides good clinical results, based on client assessment. The effectiveness of this technique was further supported by the five cases that underwent objective radiographic assessment. The technique is simpler than techniques that use extensive pre-operative planning, uses a smaller inventory and is easily applicable in companion animal practice.

Ventral fixation of chronic atlanto-occipital luxation in a dog.

A 4·5-year-old male Australian Kelpie was presented for evaluation of ambulatory tetraparesis and neck pain of five weeks duration. Atlanto-occipital luxation was diagnosed by computed tomography. The joint was unstable following closed reduction, and a ventral surgical approach to the cranial cervical spine and occiput permitted manual reduction and stabilisation of the atlanto-occipital joint. The thickened joint capsule and articular cartilage were removed to promote AO arthrodesis. Eight cortical screws, inserted into the occipital condyles and C1, were embedded in polymethylmethacrylate to stabilise the atlanto-occipital articulation. The dog recovered uneventfully after it was placed in a neck brace and rested for six weeks. Neurologic examination at six weeks was normal and the dog returned to normal farm work 12 weeks after surgery.

Allelic expression analysis suggests that cis-acting polymorphism of FRZB expression does not contribute to osteoarthritis susceptibility.

OBJECTIVE: The FRZB gene codes for secreted frizzled-related protein 3 (sFRP3), a soluble antagonist of wnt signalling that is required for maintaining cartilage integrity. Two common single nucleotide polymorphisms (SNPs) that code for the substitution of conserved arginine residues have previously been identified in FRZB and found to be associated with osteoarthritis (OA). Functional studies revealed that the arginine substitutions lead to a loss-of-function of sFRP3 activity. We set out to assess whether cis-acting polymorphism in the regulation of FRZB expression exists, as this may be an additional mechanism through which sFRP3 activity could be modulated. METHODS: RNA was extracted from the articular cartilage chondrocytes of 25 individuals who had undergone joint replacement for OA and who were heterozygous for one of the two FRZB SNPs. Allelic output was measured by single base extension in to the SNPs and deviations from the expected 1:1 pattern were assessed using the Mann-Whitney U test. RESULTS: Differential allelic expression was observed in six of the 25 individuals. However, the average fold difference in allelic expression in the six was only 1.19. CONCLUSIONS: The presence of a small degree of differential allelic expression in a low proportion (24%) of the individuals studied suggests that polymorphism in FRZB cis-acting regulatory elements can be discounted as a major factor that could influence the development of OA.

Genetic association analysis of LRCH1 as an osteoarthritis susceptibility locus.

OBJECTIVE: A genetic association with knee osteoarthritis (OA) of a single nucleotide polymorphism (SNP) in intron 1 of the LRCH1 gene was recently reported in a UK Caucasian case-control sample and confirmed in a Newfoundland Caucasian sample. Our objective was to assess whether the SNP was associated with OA in our large UK Caucasian sample. METHODS: The SNP was genotyped in 1521 cases that had undergone elective joint replacement of the hip (1098 cases), of the knee (340 cases) or of the hip and knee (83 cases) due to end-stage primary OA. The SNP was also genotyped in 736 controls of similar ages in the cases. RESULTS: There was no significant difference (all P-values >0.05) in genotype or allele frequencies between our cases and our controls. There was also no significant difference when the cases were stratified by sex, by joint replaced or by sex combined with joint replaced. CONCLUSION: Our data on 2257 individuals implies that the LRCH1 intron 1 SNP is not a risk factor for OA aetiology of the knee or of the hip in our UK Caucasian sample.

Ceftazidime or gentamicin plus benzylpenicillin in neonates less than forty-eight hours old.

A clinical trial was conducted to assess the value of ceftazidime as a first-line antibiotic in a neonatal intensive care unit. Fifty-five infants less than 48 h old with suspected sepsis were randomly treated with ceftazidime or penicillin and gentamicin. A full septic screen was performed in all infants before treatment. Treatment was stopped after 48 h if cultures were sterile. A further 22 infants more than 48 h old, with clinical evidence of sepsis, were treated with ceftazidime in an open trial. Ceftazidime proved effective against all but two of the septicaemias. A group D beta-haemolytic streptococcus and a coagulase-negative staphylococcus proved resistant, but were also resistant to penicillin and gentamicin. No adverse response to ceftazidime was noted, and the incidence of later candidiasis was similar to that after other broad-spectrum antibiotic combinations. The avoidance of gentamicin assay in the ceftazidime group was an advantage in this age group.