Search

The purpose of this study is to determine whether age-related changes to tendon matrix molecules can be detected using Raman spectroscopy. Raman spectra were collected from human Achilles (n = 8) and tibialis anterior (n = 8) tendon tissue excised from young (17 ± 3 years) and old (72 ± 7 years) age groups. Normalised Raman spectra underwent principal component analysis (PCA), to objectively identify differences between age groups and tendon types. Certain Raman band intensities were correlated with levels of advanced glycation end-product (AGE) collagen crosslinks, quantified using conventional destructive biochemistry techniques. Achilles and tibialis anterior tendons in the old age group demonstrated significantly higher overall Raman intensities and fluorescence levels compared to young tendons. PCA was able to distinguish young and old age groups and different tendon types. Raman intensities differed significantly for several bands, including those previously associated with AGE crosslinks, where a significant positive correlation with biochemical measures was demonstrated. Differences in Raman spectra between old and young tendon tissue and correlation with AGE crosslinks provides the basis for quantifying age-related chemical modifications to tendon matrix molecules in intact tissue. Our results suggest that Raman spectroscopy may provide a powerful tool to assess tendon health and vitality in the future.

Energy storing tendons such as the human Achilles and equine superficial digital flexor tendon (SDFT) are prone to injury, with incidence increasing with ageing. The interfascicular matrix (IFM), which binds tendon fascicles, plays a key role in energy storing tendon mechanics, and ageing alterations to the IFM negatively impact tendon function. While the mechanical role of the IFM in tendon function is well-established, the biological role of IFM-resident cell populations remains to be elucidated. Therefore, the aim of this study was to identify IFM-resident cell populations and establish how these populations are affected by ageing. Cells from young and old SDFTs were subjected to single cell RNA-sequencing, and immunolabelling for markers of each resulting population used to localise cell clusters. Eleven cell clusters were identified, including tenocytes, endothelial cells, mural cells and immune cells. One tenocyte cluster localised to the fascicular matrix, whereas nine clusters localised to the IFM. Interfascicular tenocytes and mural cells were preferentially affected by ageing, with differential expression of genes related to senescence, dysregulated proteostasis and inflammation. This is the first study to uncover the importance of the IFM niche for a diverse range of cell populations, and to identify age-related alterations specific to IFM-localised cells.

Tendon consists of highly aligned collagen-rich fascicles surrounded by interfascicular matrix (IFM). Some tendons act as energy stores to improve locomotion efficiency, but such tendons commonly obtain debilitating injuries. In equine tendons, energy storing is achieved primarily through specialisation of the IFM. However, no studies have investigated IFM structure-function specialisation in human tendons. Here, we compare the human positional anterior tibial tendon and energy storing Achilles tendons, testing the hypothesis that the Achilles tendon IFM has specialised composition and mechanical properties, which are lost with ageing. Data demonstrate IFM specialisation in the energy storing Achilles, with greater elasticity and fatigue resistance than in the positional anterior tibial tendon. With ageing, alterations occur predominantly to the proteome of the Achilles IFM, which are likely responsible for the observed trends towards decreased fatigue resistance. Knowledge of these key energy storing specialisations and their changes with ageing offers crucial insight towards developing treatments for tendinopathy. Statement of significance Developing effective therapeutics or preventative measures for tendon injury necessitates the understanding of healthy tendon function and mechanics. By establishing structure-function relationships in human tendon and determining how these are affected by ageing, potential targets for therapeutics can be identified. In this study, we have used a combination of mechanical testing, immunolabelling and proteomics analysis to study structure-function specialisations in human tendon. We demonstrate that the interfascicular matrix is specialised for energy storing in the Achilles tendon, and that its proteome is altered with ageing, which is likely responsible for the observed trends towards decreased fatigue resistance. Knowledge of these key energy storing specialisations and their changes with ageing offers crucial insight towards developing treatments and preventative approaches for tendinopathy., Graphical abstract Image, graphical abstract

Human Achilles tendon is composed of three smaller sub-tendons and exhibits non-uniform internal displacements, which decline with age and after injury, suggesting a potential role in the development of tendinopathies. Studying internal sliding behaviour is therefore important but difficult in human Achilles tendon. Here we propose the equine deep digital flexor tendon (DDFT) and its accessory ligament (AL) as a model to understand the sliding mechanism. The AL-DDFT has a comparable sub-bundle structure, is subjected to high and frequent asymmetric loads and is a natural site of injury similar to human Achilles tendons. Equine AL-DDFT were collected and underwent whole tendon level (n=7) and fascicle level (n=7) quasi-static mechanical testing. Whole tendon level testing was performed by sequentially loading through the proximal AL and subsequently through the proximal DDFT and recording regional strain in the free structures and joined DDFT and AL. Fascicle level testing was performed with focus on the inter-sub-bundle matrix between the two structures at the junction. Our results demonstrate a significant difference in the regional strain between the joined DDFT and AL and a greater transmission of force from the AL to the DDFT than vice versa. These results can be partially explained by the mechanical properties and geometry of the two structures and by differences in the properties of the interfascicular matrices. In conclusion, this tendon model successfully demonstrates that high displacement discrepancy occurs between the two structures and can be used as an easy-access model for studying intra-tendinous shear mechanics at the sub-tendon level. STATEMENT OF SIGNIFICANCE: Our study provides a naturally occurring and easily accessible equine model to study the complex behaviour of sub-tendons within the human Achilles tendon, which is likely to play a critical role in the pathogenesis of tendon disease. Our results demonstrate that the difference in material stiffness between the equine AL and DDFT stems largely from differences in the inter-fascicular matrix and furthermore that differences in strain are maintained in distal parts of the tightly joined structure. Furthermore, our results suggest that distribution of load between sub-structures is highly dependent on the morphological relationship between them; a finding that has important implications for understanding Achilles tendon mechanical behaviour, injury mechanisms and rehabilitation.

Our objective was to investigate the effectiveness of booster sessions after self-management interventions as a means of maintaining self-management behaviours in the treatment of chronic musculoskeletal pain. We searched MEDLINE, EMBASE, Science Citation Index, Cochrane Central Register of Controlled Trials, and PsychINFO. Two authors independently identified eligible trials and collected data. We calculated the odds ratio for the analyses of dichotomous data and standardised mean differences (SMDs) with 95% confidence interval (CI) for continuous variables. Our search identified 14 studies with a total of 1695 patients. All studies were at high risk of bias and provided very low quality evidence. For the primary outcomes, booster sessions had no evidence of an effect on improving patient-reported outcomes on physical function (SMD -0.13, 95% CI -0.32 to -0.06; P = 0.18), pain-related disability (SMD -0.16, 95% CI -0.36 to 0.03; P = 0.11), and pain self-efficacy (SMD 0.15, 95% CI -0.07 to 0.36; P = 0.18). For the secondary outcomes, booster sessions caused a significant reduction in patient-reported pain catastrophising (SMD -0.42, 95% CI -0.64 to -0.19; P = 0.0004) and no evidence of an effect on patient-reported pain intensity, depression, coping, or treatment adherence. There is currently little evidence that booster sessions are an effective way to prolong positive treatment effects or improve symptoms of long-term musculoskeletal conditions after self-management interventions. However, the studies were few with high heterogeneity, high risk of bias, and overall low quality of evidence. Our review argues against including booster sessions routinely to self-management interventions for the purpose of behaviour maintenance.

The unique structure of the Achilles tendon, combining three smaller sub-tendons, enhances movement efficiency by allowing individual control from connected muscles. This requires compliant interfaces between sub-tendons, but compliance decreases with age and may account for increased injury frequency. Current understanding of sub-tendon sliding and its role in the whole Achilles tendon function is limited. Here we show changing the degree of sliding greatly affects the tendon mechanical behaviour. Our in vitro testing discovered distinct sub-tendon mechanical properties in keeping with their mechanical demands. In silico study based on measured properties, subject-specific tendon geometry, and modified sliding capacity demonstrated age-related displacement reduction similar to our in vivo ultrasonography measurements. Peak stress magnitude and distribution within the whole Achilles tendon is affected by individual tendon geometries, the sliding capacity between sub-tendons, and different muscle loading conditions. These results suggest clinical possibilities to identify patients at risk and design personalised rehabilitation protocols.

The accumulation of advanced glycation end‐products is a fundamental process that is central to age‐related decline in musculoskeletal tissues and locomotor system function and other collagen‐rich tissues. However, although computational studies of advanced glycation end‐product cross‐links could be immensely valuable, this area remains largely unexplored given the limited availability of structural parameters for the derivation of force fields for Molecular Dynamics simulations. In this article, we present the bonded force constants, atomic partial charges and geometry of the arginine‐lysine cross‐links DOGDIC, GODIC, and MODIC. We have performed in vacuo Molecular Dynamics simulations to validate their implementation against quantum mechanical frequency calculations. A DOGDIC advanced glycation end‐product cross‐link was then inserted into a model collagen fibril to explore structural changes of collagen and dynamics in interstitial water. Unlike our previous studies of glucosepane, our findings suggest that intra‐collagen DOGDIC cross‐links furthers intra‐collagen peptide hydrogen‐bonding and does not promote the diffusion of water through the collagen triple helices.

Mature connective tissues demonstrate highly specialised properties, remarkably adapted to meet their functional requirements. Tissue adaptation to environmental cues can occur throughout life and poor adaptation commonly results in injury. However, the temporal nature and drivers of functional adaptation remain undefined. Here, we explore functional adaptation and specialisation of mechanically loaded tissues using tendon; a simple aligned biological composite, in which the collagen (fibre phase) and surrounding predominantly non-collagenous matrix (matrix phase) can be interrogated independently. Using an equine model of late development, we report the first phase-specific analysis of biomechanical, structural and compositional changes seen in functional adaptation, demonstrating adaptation occurs postnatally, following mechanical loading, and is almost exclusively localised to the non-collagenous matrix phase. These novel data redefine adaptation in connective tissue, highlighting the fundamental importance of non-collagenous matrix and suggesting that regenerative medicine strategies should change focus from the fibrous to the non-collagenous matrix phase of tissue.

Background: Despite the availability of medium-to-high-dose inhaled corticosteroid-and-long-acting beta agonist (ICS-LABA) combination therapies, some adult patients with asthma remain uncontrolled. This can impact patients’ health-related quality of life (HRQoL), the magnitude of which is currently unknown. Aims: This study aimed to identify and summarize the literature on the humanistic burden in asthma patients who are inadequately controlled on medium-to-high-dose ICS-LABA therapy. Methods: Systematic searches were conducted in MEDLINE, Embase, and the National Health Service’s Economic Evaluation Databases to identify studies published from 1/1/2009-3/20/2019. Methods followed PRISMA guidelines. Observational studies were included and data on humanistic outcomes are presented here. Results: The searches identified 7,496 records, of which 22 studies reporting humanistic outcomes met the criteria for inclusion. Moderate burden was indicated by both mean baseline Asthma Quality of Life Questionnaire scores (n=19) and baseline St. George’s Respiratory Questionnaire total score (n=2); the former ranged from 3.0 to >5.0 while the latter ranged from 45.9 (SD: 2.1) to 53.2 (95% CI: 8.9, 85.0). High burden among patients with severe uncontrolled asthma was evident as measured by the EuroQol Five Dimensions (EQ-5D) questionnaire in selected studies. Baseline EQ-5D-3L (n=4) scores ranged from 0.48 (SD: 0.36) to 0.59 (SD: 0.25). Scores from the 36-item Short Form (SF-36) tool also indicated HRQoL burden in one study. Conclusions: The results suggest that the humanistic burden for adults with asthma remains high despite the availability of efficacious therapies. Method: GSK [HO-18-17246].

The lack of clinical detection tools at the molecular level hinders our progression in preventing age-related tendon pathologies. Raman spectroscopy can rapidly and non-invasively detect tissue molecular compositions and has great potential for in vivo applications. In biological tissues, a highly fluorescent background masks the Raman spectral features and is usually removed during data processing, but including this background could help age differentiation since fluorescence level in tendons increases with age. Therefore, we conducted a stepwise analysis of fluorescence and Raman combined spectra for better understanding of the chemical differences between young and old tendons. Spectra were collected from random locations of vacuum-dried young and old equine tendon samples (superficial digital flexor tendon (SDFT) and deep digital flexor tendon (DDFT), total n = 15) under identical instrumental settings. The fluorescence-Raman spectra showed an increase in old tendons as expected. Normalising the fluorescence-Raman spectra further indicated a potential change in intra-tendinous fluorophores as tendon ages. After fluorescence removal, the pure Raman spectra demonstrated between-group differences in CH2 bending (1450 cm&minus, 1) and various ring-structure and carbohydrate-associated bands (1000&ndash, 1100 cm&minus, 1), possibly relating to a decline in cellular numbers and an accumulation of advanced glycation end products in old tendons. These results demonstrated that Raman spectroscopy can successfully detect age-related tendon molecular differences.

Injuries to the intra-articular knee joint ligament (anterior cruciate ligament (ACL)) together with the extra-articular medial collateral ligament (MCL) result in significant joint instability, pain and immobility for the affected individual. Moderate endurance type exercise has been shown to increase ligament strength, however little is known on the effect of short-term high intensity exercise regimes such as treadmill training on the ACL and MCL and whether they may be beneficial to the extracellular matrix (ECM) structure of these ligaments. This study aimed to identify the effect of short-term high intensity exercise on the proteome of the rat ACL and MCL using mass spectrometry. Sprague Dawley male rats (n=12) were split into equal groups of control and exercise animals, which were subjected to high intensity training and followed by proteomic analysis of the ACL and MCL. Knee joint and ligament health was assessed using OARSI scoring or using a validated histological scoring system. Histopathological analyses demonstrated no significant changes in the ACL, MCL or cartilage of the knee joint, indicating that the exercise regime used in this study did not have substantial impact on tissue structure and health of several tissues within the rat knee joint. Some proteins were found to be significantly more abundant in the ACL in the exercised group than the control group. However, no proteins with a significantly different expression were identified between MCL control and MCL exercised groups. The majority of proteins expressed at higher levels in the ACL exercise group were cytoskeletal proteins, ribosomal proteins and enzymes. Several matrisomal proteins were also more abundant such as collagen proteins and proteoglycans in ACL exercise group. In conclusion, our results indicate that short-term high intensity exercise has an impact on ACL ECM protein expression, with the majority of differential expressed proteins being cellular proteins such as actins, ribosomal and heat shock proteins, indicative of metabolic and molecular responses. Further study is necessary to determine the impact of these short-term changes on ligament structure and function.

There are limited published data on the burden of moderate/severe uncontrolled asthma.We conducted a systematic literature review to better understand the impact of moderate-to-severe asthma in the US, the UK, Germany, France, Italy, Spain, Canada, Japan, and Australia in terms of prevalence, clinical measures, health-related quality of life (HRQoL) and economic burden, for patients whose asthma is uncontrolled despite inhaled corticosteroid/long-acting βThe prevalence of uncontrolled asthma among patients with moderate/severe disease varied but was as high as 100% in some subgroups. Patients with uncontrolled asthma generally had poor lung function (mean/median pre-bronchodilator forced expiratory volume in 1 second [FEVOur findings suggest that significant unmet needs exist for patients with uncontrolled asthma despite the availability of ICS/LABA therapy. Novel treatments are needed to help reduce the burden to patients, healthcare systems and society.

Background Queenie’s Roadshow is an engagement project targeted at local schools and nurseries. Pupils receive a free presentation from the hospice’s Community Fundraiser and our mascot, Queenie. The presentation gives pupils the opportunity to learn about the invaluable work that is carried out by the hospice and their wider services. In July, schools will hold a fundraising activity or event during their Sports Day. This is the first year in which the Roadshow has run, and whilst the focus is on engaging with local schools and nurseries to increase awareness of hospice work, dying and bereavement, it is estimated that there will be an income of approximately £1,000. Aim The aim is engagement with local schools and nurseries to develop long-lasting relationships. This will help build Compassionate Communities and increase fundraising activities. Methods Social media marketing. This reached 1,274 people, 75 of which engaged with the Facebook post. Traditional marketing via written request (to those who had consented) to schools and nurseries did not result in any engagement. Results Results are anecdotal at this point as the campaign is ongoing. Children have been curious and excited to engage and have conversations. This is beginning to increase awareness. To this point, six schools/nurseries are signed up to the campaign. Conclusion We believe that by utilising our mascot effectively we will not only develop long-lasting relationships with our local schools, but we will also raise awareness and knowledge of our hospice in a way that enables conversations about dying and bereavement with young people. We can use these experiences as building blocks within the development of Compassionate Communities as well as benefitting from fundraising activity by each school/nursery.

Background Queenscourt recognises the importance of raising awareness of hospice care and Compassionate Communities amongst the local population and dispel the myth that hospices are gloomy places where people go to die. Aims We believe passionately about normalising conversation about death and dying and have engaged with a local Girlguiding (North West England) unit to work collaboratively on producing a Queenscourt Challenge Badge. Methods Queenscourt community fundraiser initially liaised with the Guide Leader to ascertain which age groups would be involved and if any subjects were ‘off limits’. It was agreed that ALL sections should be involved from Rainbows, aged five to Rangers aged eighteen; no age group was excluded. The Queenscourt Challenge badge will incorporate all five essential elements (Girlguiding). The community fundraiser and clinical staff considered some key elements of hospice care: themes included are: therapies, nutrition, volunteering, medicine and treatments, pets as therapy, clergy, importance of the environment and gardens and Transport and fundraising, to name a few. Results An afternoon has been arranged when the Guides will visit the hospice, there will be numerous ‘stations’ set up around the hospice demonstrating the above, the Guides will have to engage with staff and undertake certain hospice related challenges appropriate to their age and topic. Conclusion Working collaboratively with a local Girlguiding group has opened up the perception of hospice care to a whole new group of young people. We hope to continue this work with more Girlguiding units across our locality promoting our work around Compassionate Communities, one of our key strategic objectives. The work has also improved professional relationships between clinical and corporate teams within the hospice, each becoming more aware of each other’s professional roles and responsibilities.

Background The multi-professional team identified the need to provide a more structured programme of support for carers. Aim To provide a bespoke programme of support and advice to carers of patients from any services provided across the organisation, based on requirements following individual holistic assessment. This would be delivered either in a group setting or individually as appropriate. Methods Carers were identified and the carers programme was explained to them with an invitation to attend for a personal carer’s assessment. The programme is co-ordinated by the Day Services Sister. A five-week programme is implemented, with approximately six carers attending one day a week for five consecutive weeks. Carers from patients on the inpatient unit were often unable to complete the programme but were encouraged to attend when possible. Carers accessed therapy services, social worker was available for support and advice, catering staff provided information about nourishing the whole person. Hand massage and anxiety management sessions were provided as is lunch. Care shifts were provided for patients at home by Queenscourt at Home thus enabling the carers to attend. Conclusion Evaluations have exceeded expectations. We expected carers to be disappointed when the programme ended, however, many of them have formed support groups of their own and arranged to meet regularly. Carers feel empowered with more knowledge and skills, and many realise that taking time out for themselves should be seen as a necessity and not a guilty pleasure. Other comments include ‘don’t feel so alone any more’ and ‘I feel well cared for myself’. We will continue to run the programme and adapt it as necessary according to evaluations.

Background Similar to Lights of Love (or Light Up A Life) at Christmas, the Forget Me Not appeal is an increasingly popular spring fundraising appeal in UK hospices. In May/June, supporters are invited to make a donation in memory of someone they love, and Forget Me Not flowers are usually displayed in the hospice grounds. In addition, many hospices invite their supporters to attend a remembrance event. In recent years, we have seen income for this appeal steadily decreasing, and needed a way to rejuvenate the appeal. Aims To generate additional unrestricted income by extending the reach of the appeal using digital tools and engaging new supporters. Methods In 2019, in addition to the traditional direct mailing sent to previous supporters of the appeal, a new virtual forget-me-not meadow was created in partnership with an online fundraising platform – there were no upfront costs, making this a risk-free option for our hospice. The page allowed supporters to make an online donation to dedicate a virtual flower, share a photo of their loved one and leave a personal message in celebration of their life. They could then share their dedication with friends and family using social media. The appeal was promoted by direct mail, press, email and social media (paid and organic). Results Final results are not yet known. At the time of writing, the appeal is still live. However, after two weeks, we have already seen: 55.4% increase in online donations; 8 new donors acquired to this point. Conclusion We believe that using digital technology and introducing virtual giving has been a very cost-effective way to attract new support and donations.

Background It was recognised there was a gap in companionship and empathic support for certain patients in hospital approaching end of life. Aim Queenscourt in Hospital, an extension of Queenscourt Outside Volunteer Service, is launched to provide comfort and companionship for patients in hospital who are in the last hours to days of life, and whose families are absent or need support to take a short break. Method Volunteers are recruited with previous health and social care experience and who are available at very short notice to respond to patient’s changing condition. Volunteers are aligned with the hospice’s vision and values. A bespoke training programme was put in place to prepare, educate and allay any potential anxieties and fears. Results Patients eligible to benefit from service are identified by members of the Queenscourt Supportive and Specialist Palliative Care Services working in hospital. Volunteers may read quietly, provide gentle hand massage or may just simply be present. Volunteers may escalate a patient’s needs and concerns to the ward staff if unsettled. Volunteers are fully debriefed following each shift and consequently report feeling empowered and valued for having made a difference. Challenges around hospital policies and procedures were overcome by liaising between HR departments, and open communication. Conclusion Queenscourt delivers compassionate and emotional support to patients and their families across all settings. Our new volunteers in hospital are an integral part of this. By enlisting the support of volunteers, patients in hospital who are reaching the end of their lives have an empathic presence and companion by their side. We aim to support more people dying in hospital and communicate with secondary care colleagues ensuring all professional boundaries are respected. Training and support of volunteers ensures retention and continuation of a worthwhile service.

Background Throughout the ages, human subjects have selected horse breeds for their locomotor capacities. Concurrently, tissue properties may have diversified because of specific requirements of different disciplines. Objectives The aim of this study was to compare the biomechanical properties of tendons with different functions between equine breeds traditionally selected for racing or sport. Study design This study used ex vivo tendons and compared the mechanical properties of the common digital extensor tendon (CDET) and superficial digital flexor tendon (SDFT) between racehorses (Thoroughbred [TB]) and sports horses (Friesian Horse [FH], Warmblood [WB]). Methods The SDFT and CDET of FH (n = 12), WBs (n = 12) and TBs (n = 8) aged 3-12 years were harvested. The cross sectional area (cm2 ), maximal load (N), ultimate strain (%), ultimate stress (MPa) and elastic modulus (MPa) were determined and tested for significant differences between the breeds (P Results The SDFT from WB horses had a significantly lower elastic modulus than TB horses and failed at a higher strain and load than both FHs and TBs. The mechanical properties of the CDET did not differ between breeds. In agreement with previous studies, the CDET failed at a higher stress and had a higher elastic modulus than the SDFT and, for the WB group of horses only, failed at a significantly lower strain. Interestingly, the mode of failure differed between breeds, particularly with respect to the FHs. Main limitations The exercise history of horses used in this study was unknown and the age-range was relatively large; both these factors may have influenced the absolute properties reported in this study. Conclusions This study shows for the first time that mechanical properties of the SDFT differ between breeds. These properties are likely to be related to selection for high-speed vs. an extravagant elastic gait and may be an important indicator of performance ability. The Summary is available in Spanish - see Supporting Information.

The extracellular matrix (ECM) provides the environment for many cells types within the body and, in addition to the well recognised role as a structural support, influences many important cell process within the body. As a result, age-related changes to the proteins of the ECM have far reaching consequences with the potential to disrupt many different aspects of homeostasis and healthy function. The proteins collagen and elastin are the most abundant in the ECM and their ability to function as a structural support and provide mechanical stability results from the formation of supra-molecular structures. Collagen and elastin have a long half-life, as required by their structural role, which leaves them vulnerable to a range of post-translational modifications. In this chapter the role of the ECM is discussed and the component proteins introduced. Major age-related modifications including glycation, carbamylation and fragmentation and the impact these have on ECM function are reviewed.

Background Specialist palliative care services (SPCS) often develop within organisations providing care in community, hospital and hospice. Even in their own geographical area, patients may meet at least three separate specialist teams – all working slightly differently, with individual telephone numbers and sets of guidelines – in addition to tertiary centre specialist teams. Aim To provide a single, seamless, SPCS for patients, families and their associated health professionals. Method A recent community services tendering process had threatened to destroy at a stroke, a successful, longstanding plan to keep community and hospital SPCS integrated through five local health service reorganisations/TUPE transfers. Negotiation, opportunity and creativity allowed the final pieces of the jigsaw to slot into place. Palliative care nurse specialists (PCNS), admin staff and consultants (NHS contract retained) transferred under TUPE arrangements, enabling the formation of a single integrated SPCS working across all settings. Results A single telephone numbered, Hospice Central Access Hub, takes all clinical calls from patients registered with the integrated SPCS, their families and health professionals – manned 7/7, from 9–5. A full service operates during the week, and a doctor, PCNS, Transform facilitator and admin support share weekend work across all settings. At night clinical calls are directed to the inpatient unit who access the doctor on call if required. Conclusion Wholly integrated services means patients have ONE – number to ring, team to speak to, joined up service, set of guidelines and bereavement service. The team receive the SAME – development training, uniform, support, and access to assistance. ONE single multidisciplinary team meeting discusses all new referrals to the whole service, documented on ONE single electronic patient record with mobile access for clinical staff with no duplication. There is much to do and many ideas for further development, but with a new improved road to travel.

Background Recruiting and retaining therapists has been challenging and expensive, with few therapists with specialist palliative care knowledge and skills and many choosing to practise within their own area of expertise. Agency staff were utilised and although knowledgeable and professional, didn’t take ownership of the role and cost was prohibitive. We needed to be innovative in order to develop, recruit and retain therapy staff and ensure that the wider therapy workforce gains palliative care knowledge. We have a proven track record developing roles from within and excellent collaborative working with the local NHS Hospital Trust. Aims To ensure the organisation evolves to meet the needs of the local population (NICE guidelines for care of the dying, 2015; Ambitions for palliative and end of life care, 2015) and give therapists the experience of working in a specialist palliative care organisation for a defined period, enabling them to utilise their new found skills in practice when returning to the hospital, ultimately providing a wider recruitment pool in future. Methods Formal discussions between hospice clinical leads and head of therapy services in the local NHS Trust to determine interest and costings for a mutually beneficial collaboration. Proposal paper presented to hospice Board of Trustees for discussion and approval. Results Approval given for the hospice to form part of the wider NHS Trust therapy rotation programme. Therapists rotated to the hospice would be supported and mentored by the hospice therapy lead and clinical team. Conclusion We continue to strengthen relationships working collaboratively with the hospital trust and sharing good practice, not only are we creating a workforce with experience, specialist knowledge and skills in palliative care for recruitment purposes for the future, but those therapists who have spent time at the hospice are utilising their new skills in their general practice, undertaking audit and education sessions, so benefiting every patient they care for, wherever that may be.

Background Increasing workload of palliative care social worker recognised. Employed by hospice but funding for post shared by hospice, local authority and Clinical Commissioning Group with responsibility to attend meetings, training and supervision away from hospice base. Aims In order to facilitate a timely discharge to preferred place of care, we need to be able to respond and meet the demands of the complex and challenging needs of patients and improve the accessibility of social work advice to patients and their families in a timely manner. Methods Empower existing staff in a developmental role by recognising ambition, skills and knowledge in a current staff member, whilst acknowledging limitations of this and respecting specialist social worker role. Shadowing of palliative care social worker on ward rounds, outpatient clinic and day services; communication skills training undertaken. Developing existing knowledge for application of Continuing Healthcare Funding and placements with further training planned for benefits and welfare advice. Work closely with social work administration support. Results Access to social work advice from health professional at time suitable to patient and family means no waiting. Discussions and administration around discharge planning can be commenced in a timely way and followed up with specialist input from social worker. Better use of health professional skills; palliative care social worker can undertake joint discharge planning visits with appropriate members of team allowing patient to tell their story only once, more timely discharge. It releases time to care for RGNs who have social work support team available as resource. Conclusion By empowering experienced staff member who has a sound knowledge base of palliative care and the introduction of new skills and training, patients have services readily accessible to them. The specialist palliative care social worker is now able to concentrate on complex issues whilst being supported from a more knowledgeable team than before.

Background In 2015 the local NHS Integrated Care Organisation put community services out to tender across two NHS Clinical Commissioning Groups (CCGs), a population of 235,000. This included specialist palliative care team (SPCT) for hospital and community and Consultants. The SPCT were an integral part of the local integrated service, the risks to patients and families of not having a seamless service would be detrimental. In 2016 two individual providers won the contract; one private and one NHS. Both approached us independently suggesting they subcontract SPCT to the hospice. Aims Hospice to employ SPCT under terms of two separate subcontracts, one private, one NHS, ensuring patients and families receive seamless care wherever they are. Methods Sub-contract required Board approval, considering risks and benefits to hospice reputation, including public perception of hospice ‘funding’ private healthcare. Learning curve for Directors in projecting five year costings with no knowledge of current costs, ensuring no financial risk to charity, and legalities around contracts. Results Agreeing the specification and quality data was time consuming. Numerous bureaucratic executive layers through which to proceed for approval, and efforts to ensure that the service was fully funded for the duration of the subcontract to avoid risk to charity. Conclusion A year later the SPCT fully integrated in hospice with no financial risk to charity as fully funded. Hospice corporate uniform supplied so visible immediately as hospice employee, all one team raises awareness for income generation. Ability to be creative with roles and working patterns ensuring seven day clinical and admin cover, and implementation of development roles within team.

The computational study of advanced glycation end-product cross- links remains largely unexplored given the limited availability of bonded force constants and equilibrium values for molecular dynamics force fields. In this article, we present the bonded force constants, atomic partial charges and equilibrium values of the arginine-lysine cross-links DOGDIC, GODIC and MODIC. The Hessian was derived from a series of ab initio quantum mechanical electronic structure calculations and from which a complete set of force constant and equilibrium values were generated using our publicly available software, ForceGen. Short in vacuo molecular dynamics simulations were performed to validate their implementation against quantum mechanical frequency calculations.

The computational study of advanced glycation end-product cross- links remains largely unexplored given the limited availability of bonded force constants and equilibrium values for molecular dynamics force fields. In this article, we present the bonded force constants, atomic partial charges and equilibrium values of the arginine-lysine cross-links DOGDIC, GODIC and MODIC. The Hessian was derived from a series of ab initio quantum mechanical electronic structure calculations and from which a complete set of force constant and equilibrium values were generated using our publicly available software, ForceGen. Short in vacuo molecular dynamics simulations were performed to validate their implementation against quantum mechanical frequency calculations.

The extracellular matrix (ECM) provides the environment for many cells types within the body and, in addition to the well recognised role as a structural support, influences many important cell process within the body. As a result, age-related changes to the proteins of the ECM have far reaching consequences with the potential to disrupt many different aspects of homeostasis and healthy function. The proteins collagen and elastin are the most abundant in the ECM and their ability to function as a structural support and provide mechanical stability results from the formation of supra-molecular structures. Collagen and elastin have a long half-life, as required by their structural role, which leaves them vulnerable to a range of post-translational modifications. In this chapter the role of the ECM is discussed and the component proteins introduced. Major age-related modifications including glycation, carbamylation and fragmentation and the impact these have on ECM function are reviewed.

The extracellular matrix (ECM) undergoes progressive age-related stiffening and loss of proteolytic digestibility due to an increase in concentration of advanced glycation end products (AGEs). The most abundant AGE, glucosepane, accumulates in collagen with concentrations over 100 times greater than all other AGEs. Detrimental collagen stiffening properties are believed to play a significant role in several age-related diseases such as osteoporosis and cardiovascular disease. Currently little is known of the potential location of covalently cross-linked glucosepane formation within collagen molecules; neither are there reports on how the respective cross-link sites affect the physical and biochemical properties of collagen. Using fully atomistic molecular dynamics simulations (MD) we have identified six sites where the formation of a covalent intra-molecular glucosepane cross-link within a single collagen molecule in a fibrillar environment is energetically favourable. Identification of these favourable sites enables us to align collagen cross-linking with experimentally observed changes to the ECM. For example, formation of glucosepane was found to be energetically favourable within close proximity of the Matrix Metalloproteinase-1 (MMP1) binding site, which could potentially disrupt collagen degradation., Highlights • We conduct fully atomistic molecular dynamics simulation of fibrillar collagen. • Glucosepane cross-link formation is energetically favourable at six positions. • Positions identified are within key collagen biomolecule sites. • Positioning of sites may have a significant effect on tissue function and integrity.

Advancing age is a well-known risk factor for tendon disease. Energy-storing tendons [e.g., human Achilles, equine superficial digital flexor tendon (SDFT)] are particularly vulnerable and it is thought that injury occurs following an accumulation of micro-damage in the extracellular matrix (ECM). Several authors suggest that age-related micro-damage accumulates due to a failure of the aging cell population to maintain the ECM or an imbalance between anabolic and catabolic pathways. We hypothesized that ageing results in a decreased ability of tendon cells to synthesize matrix components and matrix-degrading enzymes, resulting in a reduced turnover of the ECM and a decreased ability to repair micro-damage. The SDFT was collected from horses aged 3-30 years with no signs of tendon injury. Cell synthetic and degradative ability was assessed at the mRNA and protein levels. Telomere length was measured as an additional marker of cell ageing. There was no decrease in cellularity or relative telomere length with increasing age, and no decline in mRNA or protein levels for matrix proteins or degradative enzymes. The results suggest that the mechanism for age-related tendon deterioration is not due to reduced cellularity or a loss of synthetic functionality and that alternative mechanisms should be considered.

A large number of crystallographic protein structures include ligands, small molecules and post-translational modifications. Atomic bond force values for computational atomistic models of post-translational or non-standard amino acids, metal binding active sites, small molecules and drug molecules are not readily available in most simulation software packages. We present ForceGen, a Java tool that extracts the bond stretch and bond angle force values and equilibrium values from the Hessian of a Gaussian vibrational frequency analysis. The parameters are compatible with force fields derived using the second order tensor of the Hessian. The output is formatted with the Gromacs topology in mind. This study further demonstrates the use of ForceGen over the quantum mechanically derived structures of a small organic solvent, a naturally occurring protein crosslink derived from two amino acids following post-translational modification and the amino acid ligands of a zinc ion. We then derive Laplacian bond orders to understand how the resulting force values relate back to the quantum mechanical model. The parameterisation of the organic solvent, toluene, was verified using Molecular Mechanics simulations. The structural data from the simulation compared well with the quantum mechanical structure and the system density compared well with experimental values. Electronic supplementary material The online version of this article (10.1007/s00894-017-3530-6) contains supplementary material, which is available to authorized users.

Aim Volunteers ensure high quality experience for hospice attendees. Building on existing practice and promoting future excellence, a volunteer workforce was trained to support patients and families in end of life (EoL) choices, in own home/hospital, particularly if alone. Volunteers, aligned to hospice vision and values, complement and ‘fill gaps’ in existing services. Approach A review of day/‘at home’ patients, revealed those ‘well enough’ for discharge from specialist palliative care (SPC) input, who would still benefit from regular hospice support for self/family. A willing, confident, flexible, health and social care experienced, volunteer team, able to respond to changing demand, recruited to work unsupervised in people’s homes. A bespoke training programme, addressed expressed anxieties, role clarity, boundaries and communication skills. Volunteer Outside Service (VOS) co-ordinated by Hospice at Home, ideally placed to promote initiative whilst identifying/assessing potential patients. Patients seamlessly allocated volunteer visits and SPC as condition dictates. Uniformed volunteers, with lone worker devices, start and finish from hospice, with current patient information to avoid ‘surprises’ on arrival at patients’ home, undertake light household duties; provide listening ear/read; make meals; not expected to undertake personal/clinical care; have clear guidelines to follow if encounter difficulties and appropriately debriefed on return. Results 10–14 volunteers made 500 home/hospital VOS visits. Volunteers report feeling valued and fulfilled, privileged to be involved in lives of people at an important time and proud of making a difference. Hospice staff report, that despite required time and support, they have integrated well into existing team providing companionship and practical support. Conclusion Volunteers, integral to package of care, meet complex and challenging patient and family needs. Younger volunteers are needed, due to the demographic profile of the current volunteer workforce. The plan is to support more people dying in hospital and we continue to communicate with secondary care colleagues to ensure professional boundaries are respected. Volunteer training and retention, ensures continuity of a reportedly worthwhile valuable service.

Aim Experienced, qualified and unqualified, hospice nurses desire career progression which is limited within the hospice environment. Time and money is invested in education to deliver high quality palliative care. For nurses to then take those skills elsewhere leaves a huge gap in our workforce. An NHS post is the usual route to becoming a Palliative Care Nurse Specialist (PCNS). If experienced Health Care Assistants (HCA) want to progress they are currently required to attend university to gain an academic qualification and for many this would prove challenging. Approach Local hospices’ professional development was scoped, but revealed no specific models and new roles were bespoke. Two local roles were developed; Hospice Nurse Specialist (HNS), and HCA Therapy Assistant (TA). Roles were clearly defined, with robust job descriptions and person specifications, scope of practice agreed, required skills, competences and boundaries established. Result The skilled HNS provides continuity of care for patients and a visible presence provides a vital link between nursing and medical professionals. It has led to a more streamlined admission process for the patient and following completion of the non-medical prescribing module, the HNS works autonomously wherever the patient presents, allowing medical staff to focus on patients with more specialist complex needs. The TA role presented its own challenges as there is no national specifically defined pathway to follow. Specific competencies were developed including input from community equipment suppliers, wheelchair services and by shadowing various therapy teams within hospital and community setting. Conclusion This has been a successful ‘dip of the toe in the water’ for role development. Future development includes an accredited academic module in Specialist Palliative and End of Life Care, in partnership with the local university and investigating the role of apprenticeships for hospice Healthcare Support Workers and Assistant Practitioners.

Background As a small hospice, whose only research activity had been individual staff undertaking Masters degrees or local university collaborative service evaluation, opportunity of a national multicentre trial of short specialist palliative care intervention (SSPCI) in advanced neurological disease (AND) was exciting and daunting. The local neurological centre identified suitable patients, explained, consented, randomised and undertook research questionnaires. The hospice delivered intervention, following required training for involved staff. Method Collation staff/patient comments about study involvement. Results Staff reported pride at being involved with high calibre institutions; anxious and keen to get it right; initially saw trial patients as different and lacked confidence assessing and evaluating their care; positive experience following patient (with long standing diagnoses, and excellent existing care/support at home) from admission to discharge; keen to demonstrate impact of SSPCI in AND patients; having named clinical lead nurse responsible for overall supervision of study proved beneficial and necessary; challenges talking to patients with long standing diagnoses about preferred place of care and future care planning. Patients reported feeling proud to take part; initial reluctance to attend hospice due to pre conceived ideas, but all now state look forward to coming. One participant decided participating was not for him and withdrew. Conclusion Significant multiprofessional staff time and effort involved in delivering intervention – more than expected for a similar number of usual referrals. Staff recognised the vital importance of thorough initial clinical assessment on admission; used some new educational and inspirational outcome measures; further educated in whole ‘research process’ and realise importance of adhering to strict requirements; frustrated that unable to signpost patients elsewhere for support at end of interventions due to lack of available resources and/or funding.

Tendon injury is thought to involve both damage accumulation within the matrix and an accompanying cell response. While several studies have characterized cell and matrix response in chronically injured tendons, few have assessed the initial response of tendon to overload-induced damage. In this study, we assessed cell response to cyclic loading. Fascicle bundles from the equine superficial digital flexor tendon were exposed to cyclic loading in vitro, designed to mimic a bout of high-intensity exercise. Changes in cell morphology and protein-level alterations in markers of matrix inflammation and degradation were investigated. Loading resulted in matrix damage, which was accompanied by cells becoming rounder. The inflammatory markers cyclooxygenase-2 and interleukin-6 were increased in loaded samples, as were matrix metalloproteinase-13 and the collagen degradation marker C1,2C. These results indicate upregulation of inflammatory and degradative pathways in response to overload-induced in vitro, which may be initiated by alterations in cell strain environment because of localized matrix damage. This provides important information regarding the initiation of tendinopathy, suggesting that inflammation may play an important role in the initial cell response to tendon damage. Full understanding of the early tenocyte response to matrix damage is critical in order to develop effective treatments for tendinopathy.

BACKGROUND Increasing mutant huntingtin (mHTT) clearance through the autophagy pathway may be a way to treat Huntington's disease (HD). Tools to manipulate and measure autophagy flux in brain in vivo are not well established. OBJECTIVE To examine the in vivo pharmacokinetics and pharmacodynamics of the lysosomal inhibitor chloroquine (CQ) and the levels of selected autophagy markers to determine usefulness of CQ as a tool to study autophagy flux in brain. METHODS Intraperitoneal injections of CQ were administered to WT and HD(Q175/Q175) mice. CQ levels were measured by LC-MS/MS in WT brain, muscle and blood at 4 to 24 hours after the last dose. Two methods of tissue preparation were used to detect by Western blot levels of the macroautophagy markers LC3 II and p62, the chaperone mediated autophagy receptor LAMP-2A and the late endosome/lysosomal marker RAB7. RESULTS Following peripheral administration, CQ levels were highest in muscle and declined rapidly between 4 and 24 hours. In the brain, CQ levels were greater in the cortex than striatum, and levels persisted up to 24 hours post-injection. CQ treatment induced changes in LC3 II and p62 that were variable across regions and tissue preparations. HD(Q175/Q175) mice exposed to CQ had variable but diminished levels of LC3 II, p62 and LAMP-2A, and increased levels of RAB7. Higher levels of mHTT were found in the membrane compartment of CQ treated HD mice. CONCLUSION Our findings suggest that the response of brain to CQ treatment, a blocker of autophagy flux, is variable and not as robust as it has been demonstrated in vitro, suggesting that CQ treatment has limitations for modulating autophagy flux in vivo. Alternative methods, compounds, and technologies need to be developed to further investigate autophagy flux in vivo, especially in the brain.

Collagen glycation, and in particular the formation of advanced glycation end-product (AGE) crosslinks, plays a central role in the ageing process and in many of the long-term complications of diabetes. Glucosepane, the most abundant and relevant AGE crosslink, has been suggested to increase the stiffness of tissue and reduce its solubility, although no evidence is available concerning the mechanisms. We have used a combination of computational and experimental techniques to study a collagen-rich tissue with a relatively simple organisation to further our understanding of the impact of glucosepane on the structural and physical properties of collagen fibrils. Our work shows that glucosepane levels increase dramatically in aged tendon tissue and are associated with the reduced density of collagen packing and increased porosity to water molecules. Our studies provide the basis to understand many of the tissue dysfunctions associated with ageing and diabetes across a range of different tissues types., Highlights • Levels of the advanced glycation end-product glucosepane increase in human tendon with increasing chronological age. • Glucosepane results in a less tightly held helical structure in the collagen molecule and increased porosity to water. • Water content is higher in Achilles and anterior tibialis tendon tissue from older individuals compared to young people. • The denaturation temperature of collagen increases in the older age group suggesting a more highly cross-linked structure. • The enthalpy of collagen denaturation decreases in older donors suggesting molecules are less confined within the fibril.

Age-related tendinopathy is common in both humans and horses; the initiation and progression of which is similar between species. The majority of tendon injuries occur to high-strain energy storing tendons, such as the human Achilles tendon and equine superficial digital flexor (SDFT). By contrast, the low-strain positional human anterior tibialis tendon and equine common digital extensor (CDET) are rarely injured. It has previously been established that greater extension occurs at the fascicular interface in the SDFT than in the CDET; this may facilitate the large strains experienced during locomotion in the SDFT without damage occurring to the fascicles. This study investigated the alterations in whole tendon, fascicle and interfascicular mechanical properties in the SDFT and CDET with increasing age. It was hypothesised that the amount of sliding at the fascicular interface in the SDFT would decrease with increasing horse age, whereas the properties of the interface in the CDET would remain unchanged with ageing. Data support the hypothesis; there were no alterations in the mechanical properties of the whole SDFT or its constituent fascicles with increasing age. However, there was significantly less sliding at the fascicular interface at physiological loads in samples from aged tendons. There was no relationship between fascicle sliding and age in the CDET. The increase in stiffness of the interfascicular matrix in aged SDFT may result in the fascicles being loaded at an earlier point in the stress strain curve, increasing the risk of damage. This may predispose aged tendons to tendinopathy.

The collagen protein provides tensile strength to the extracellular matrix in addition to localising cells, proteins and protein cofactors. Collagen is susceptible to a build up of glycation modifications as a result of an exceptionally long half-life. Glucosepane is a collagen cross-linking advanced glycation end product; the structural and mechanical effects of glucosepane are still the subjects of much debate. With the prospect of an ageing population, the management and treatment of age-related diseases is becoming a pressing concern. One area of interest is the isolation of hydrated glucosepane, which has yet to be reported at an atomistic level. This study presents a series of glucosepane-water complexes within an implicit aqueous environment. Electronic structure calculations were performed using density functional theory and a high level basis set. Hydrogen bonds between glucosepane and explicit water were identified by monitoring changes to covalent bonds, calculating levels of electron donation from Natural Bonding Orbital analysis and the detection of bond critical points. Hydrogen bond strength was calculated using second-order perturbation calculations. The combined results suggest that glucosepane is very hydrophilic, with the imidazole feature being energetically more attractive to water than either hydroxyl group, although all hydrogen bonds, regardless of bond strength, were electrostatic in nature. Our results are in growing support of an earlier hypothesis that cross-links may result in an increase in interstitial water retention, which would permit the collagen fibril to swell, thereby potentially affecting the tensile and compression properties and biological function of connective tissues.

The zinc-dependent Matrix Metalloproteinases (MMPs) found within the extracellular matrix (ECM) of vertebrates are linked to pathological processes such as arthritis, skin ulceration and cancer. Although a general backbone proteolytic mechanism is understood, crystallographic data continue to suggest an active site that is too narrow to encompass the respective substrate. We present a fully parameterised Molecular Dynamics (MD) study of the structural properties of an MMP-1-collagen crystallographic structure (Protein Data Bank - 4AUO), followed by an exploration of the free energy surface of a collagen polypeptide chain entering the active site, using a combined meta-dynamics and umbrella sampling (MDUS) approach. We conclude that the interactions between MMP-1 and the collagen substrate are in good agreement with a number of experimental studies. As such, our unrestrained MD simulations and our MDUS results, which indicate an energetic barrier for a local uncoiling and insertion event, can inform future investigations of the collagen-peptide non-bonded association steps with the active site prior to proteolytic mechanisms. The elucidation of such free energy barriers provides a better understanding of the role of the enzyme in the ECM and is important in the design of future MMP inhibitors.

Tendon functional competence and structural integrity rely on homeostasis of tendon cell metabolism and extracellular matrix macromolecules. The clear link between tendinopathies and increasing age suggests a slow change to tendon homeostasis, which increases susceptibility to damage. Despite this well evidenced association between increasing age and tendon damage, changes to tendon mechanical properties with ageing are not clear with different studies reporting conflicting results. More recent research suggests that age-related changes occur at specific sub-structure locations and may be overlooked by measuring properties of the whole tendon. In this chapter we review changes to tendon mechanical properties, structure and composition. Mechanisms speculated to contribute to tendon change with age such as cellular senescence, ageing stem cell population, reactive oxygen species and formation of advanced glycation end-product crosslinks are discussed. Understanding age-related changes to tendon homeostasis are key to understanding increased incidence of tendon injuries in the ageing population.

Tendons transfer force from muscle to bone. Specific tendons, including the equine superficial digital flexor tendon (SDFT), also store and return energy. For efficient function, energy-storing tendons need to be more extensible than positional tendons such as the common digital extensor tendon (CDET), and when testedin vitrohave a lower modulus and failure stress, but a higher failure strain. It is not known how differences in matrix organization contribute to distinct mechanical properties in functionally different tendons. We investigated the properties of whole tendons, tendon fascicles and the fascicular interface in the high-strain energy-storing SDFT and low-strain positional CDET. Fascicles failed at lower stresses and strains than tendons. The SDFT was more extensible than the CDET, but SDFT fascicles failed at lower strains than CDET fascicles, resulting in large differences between tendon and fascicle failure strain in the SDFT. At physiological loads, the stiffness at the fascicular interface was lower in the SDFT samples, enabling a greater fascicle sliding that could account for differences in tendon and fascicle failure strain. Sliding between fascicles prior to fascicle extension in the SDFT may allow the large extensions required in energy-storing tendons while protecting fascicles from damage.

P>Reasons for performing study:Damage to the flexor tendons, particularly the superficial digital flexor tendon (SDFT), is one of the most common musculoskeletal injuries sustained by horses competing in all disciplines. Our previous work has shown that SDFTs from different individuals show a wide variation in mechanical strengths; this is important clinically as it may relate to predisposition to injury. The high mechanical strength of tendon relies on the correct orientation of collagen molecules within fibrils and stabilisation by the formation of chemical cross-links between collagen molecules. It is not known whether the variation in SDFT mechanical properties between individuals relates to differences in collagen cross-link levels.Hypothesis:Enzyme-derived, intermolecular cross-linking of tendon collagen correlates with mechanical properties of the SDFT.Methods:SDFTs were collected from 38 horses and mechanically tested to failure. Structural and material properties were calculated from the load/deformation plot and cross-sectional area for each tendon. Following mechanical testing, pyrrolic cross-link levels were measured using a spectrophotometric assay for Ehrlich's reactivity and pyridinoline levels were quantified by HPLC. Cross-link levels were correlated with mechanical properties and statistical significance tested using a Pearson's correlation test.Results:Pyrrole cross-link levels showed a significant positive correlation with ultimate stress (P = 0.004), yield stress (P = 0.003) and elastic modulus (P = 0.018) of the tendons, despite being a minor cross-link in these tendons. There was no significant correlation of mechanical properties with either hydroxylysyl- or lysyl-pyridinoline levels.Conclusions:Given the low absolute levels of pyrrole, we suggest that the correlation with high mechanical strength is through an indirect mechanism. Understanding the nature of the relationships between pyrrole cross-links, other matrix characteristics and tendon material properties may allow development of strategies to identify horses at risk from tendon injury and be of value in informing training practices.

In human athletes, conditioning, training and competition are commenced before skeletal maturity. Yet in equine athletics, racing of young (age 2 years) horses remains contentious. Tendon injury persists as major causes of wastage in equine athletes. Minimising injury and associated welfare issues could involve a radical approach to the timing and implementation of conditioning and training. Tendons were examined from Thoroughbreds, Dutch Warmblood foals, working horses and also a group of wild horses to evaluate effects of age, function and exercise. Gross mechanical properties did not differ significantly with age or exercise, but showed a high variance within each group. Mechanical properties of tendon tissue showed significant differences as a function of age and location. The collagen fibril crimp angle and length showed a regional reduction in the central core with exercise and age, with a synergistic effect. Regional differences in collagen fibril diameter were seen in long-term exercised older horses, but not in short-term exercised, or younger, horses. The higher proportion of small fibrils in the central region of the long-term exercised horses did not correlate with new collagen formation and therefore appear to result from disassembly of the larger diameter fibrils. Fibril diameter distributions were influenced by exercise regimens in the growing foal. Changes in molecular composition occurred in longer-term exercise and older horses, in the centre of the tendon, with higher levels of type III collagen and changes in glycosaminoglycan (GAG) content. Cartilage Oligomeric Matrix Protein (COMP) levels also appear to be modulated by age, function and superimposition of exercise. These changes were all exacerbated with age and exercise, suggesting appropriate exercise in young horses may lead to a lower incidence of injury than in older horses. An hypothesis is advanced that immature tendon can respond to exercise while mature tendon has limited, if any, ability to do so. These findings support potentially controversial earlier conditioning and racing of younger, rather than older, equine athletes.