Dissertations / Theses on the topic 'Tendine'

Introduzione L’attività fisica moderata seguita da improvvisa interruzione può influenzare le caratteristiche biologiche del tendine. Lo scopo del lavoro è stato quello di valutare l’attività cellulare, le caratteristiche istologiche, istomorfometriche e microstrutturali del tendine patellare e della sua entesi in condizioni di non allenamento (sedentarietà), allenamento ed improvviso arresto dell’attività fisica. E’ stato ipotizzato che un’iniezione peri-tendinea di acido ialuronico nelle settimane successive all’improvviso arresto dell’attività fisica potesse mantenere l’integrità strutturale e biologica del tendine patellare. Materiali e Metodi 24 ratti Sprague Dawley maschi di 8 settimane sono stati suddivisi in tre gruppi, allenati per 10 settimane, fino a 60-80% VO2max. I ratti sono stati suddivisi in tre gruppi: Non Allenati (6), Allenati (6), Disallenati (12). A 6 dei 12 ratti del gruppo Detrained, è stata praticata un’infiltrazione peri-tendinea a nel tendine patellare destro di 300 μl di acido ialuronico, mentre nei rimanenti 6, è stata praticata l’infiltrazione con soluzione fisiologica. I tendini rotulei espiantati sono stati valutati con coltura cellulare, valutazione biologica molecolare, valutazioni morfologiche microstrutturali, proliferazione, conta ed attività cellulare. Risultati I risultati in vitro hanno evidenziato vitalità e conta cellulare simili fra i Gruppi Trained e Detrained-HA con un incremento significativo del metabolismo cellulare rispetto agli altri Gruppi. La cellularità ha mostrato valori maggiori nei Gruppi Non Allenati e Detrained-NaCl ove si è osservata una biosintesi del collagene III superiore ai Gruppi Trained e Detrained-HA. Contrariamente, la produzione di collagene I e II presentava valori maggiori nei Gruppi Trained e Detrained-HA suggerendo una superiore efficienza tessutale e metabolica di questi ultimi. Conclusioni Questi risultati confermano che l’allenamento ed il suo improvviso arresto hanno effetti sulla struttura tendinea patellare di ratto e che l’iniezione peritendinea di acido ialuronico nel periodo di inattività ha effetti significativi su metabolismo cellulare e sul tendine rispetto al trattamento con soluzione fisiologica.
Introduction Different conditions may alter tendon characteristics. Clinical evidence suggests that tendon injuries are more frequent in athletes that change type, intensity and duration of training. Aim of the study was the assessment of training and especially detraining on the patellar tendon (PT) and its enthesis. We also hypotized that peri-tendineous injection with Ialuronic acid in detrained rats could prevent structural tendon integrity. Materials and Methods: 24 male adult Sprague-Dawley rats were divided into 3 groups: 18 rats were trained on a treadmill for 10 weeks. Of these, 6 rats were euthanized immediately after training (trained group), 12 were caged without exercise for 4 weeks before being injected in peri patellar tendon tissue, 1 group with Ialuronic acid (de-trained HA group) and the other with Saline solution and then euthanized (de-trained Saline group). The remaining 6 rats used as controls (untrained rats). Patellar tendons were evaluated with cellular coltures, molecular biological evaluation, microstructural morphologic evaluation, cellular proliferation, cellular number and activity. Results In vitro results showed cells vitality and number similar between Trained and Detrained-HA groups with an increased significance cellular methabolism vs the others groups. Cellularity showed better values in Non Trained and Detrained-NaCl Groups where we saw superior collagen III biosinthesis vs Trained and Detrained-HA Groups. On the other side Collagen I and II showed better values in Trained and Detrained-HA suggesting a better tissue activity of Detrained-HA Group. Conclusion Sudden interruption of physical activity has a negative effect on tendons and peri-tendineous patellar injection with Ialuronic Acid can represent a protective tendon therapy after a sudden detraining period.

Introduzione L’attività fisica moderata seguita da improvvisa interruzione può influenzare le caratteristiche biologiche del tendine. Lo scopo del lavoro è stato quello di valutare l’attività cellulare, le caratteristiche istologiche, istomorfometriche e microstrutturali del tendine patellare e della sua entesi in condizioni di non allenamento (sedentarietà), allenamento ed improvviso arresto dell’attività fisica. E’ stato ipotizzato che un’iniezione peri-tendinea di acido ialuronico nelle settimane successive all’improvviso arresto dell’attività fisica potesse mantenere l’integrità strutturale e biologica del tendine patellare. Materiali e Metodi 24 ratti Sprague Dawley maschi di 8 settimane sono stati suddivisi in tre gruppi, allenati per 10 settimane, fino a 60-80% VO2max. I ratti sono stati suddivisi in tre gruppi: Non Allenati (6), Allenati (6), Disallenati (12). A 6 dei 12 ratti del gruppo Detrained, è stata praticata un’infiltrazione peri-tendinea a nel tendine patellare destro di 300 μl di acido ialuronico, mentre nei rimanenti 6, è stata praticata l’infiltrazione con soluzione fisiologica. I tendini rotulei espiantati sono stati valutati con coltura cellulare, valutazione biologica molecolare, valutazioni morfologiche microstrutturali, proliferazione, conta ed attività cellulare. Risultati I risultati in vitro hanno evidenziato vitalità e conta cellulare simili fra i Gruppi Trained e Detrained-HA con un incremento significativo del metabolismo cellulare rispetto agli altri Gruppi. La cellularità ha mostrato valori maggiori nei Gruppi Non Allenati e Detrained-NaCl ove si è osservata una biosintesi del collagene III superiore ai Gruppi Trained e Detrained-HA. Contrariamente, la produzione di collagene I e II presentava valori maggiori nei Gruppi Trained e Detrained-HA suggerendo una superiore efficienza tessutale e metabolica di questi ultimi. Conclusioni Questi risultati confermano che l’allenamento ed il suo improvviso arresto hanno effetti sulla struttura tendinea patellare di ratto e che l’iniezione peritendinea di acido ialuronico nel periodo di inattività ha effetti significativi su metabolismo cellulare e sul tendine rispetto al trattamento con soluzione fisiologica.
Introduction Different conditions may alter tendon characteristics. Clinical evidence suggests that tendon injuries are more frequent in athletes that change type, intensity and duration of training. Aim of the study was the assessment of training and especially detraining on the patellar tendon (PT) and its enthesis. We also hypotized that peri-tendineous injection with Ialuronic acid in detrained rats could prevent structural tendon integrity. Materials and Methods: 24 male adult Sprague-Dawley rats were divided into 3 groups: 18 rats were trained on a treadmill for 10 weeks. Of these, 6 rats were euthanized immediately after training (trained group), 12 were caged without exercise for 4 weeks before being injected in peri patellar tendon tissue, 1 group with Ialuronic acid (de-trained HA group) and the other with Saline solution and then euthanized (de-trained Saline group). The remaining 6 rats used as controls (untrained rats). Patellar tendons were evaluated with cellular coltures, molecular biological evaluation, microstructural morphologic evaluation, cellular proliferation, cellular number and activity. Results In vitro results showed cells vitality and number similar between Trained and Detrained-HA groups with an increased significance cellular methabolism vs the others groups. Cellularity showed better values in Non Trained and Detrained-NaCl Groups where we saw superior collagen III biosinthesis vs Trained and Detrained-HA Groups. On the other side Collagen I and II showed better values in Trained and Detrained-HA suggesting a better tissue activity of Detrained-HA Group. Conclusion Sudden interruption of physical activity has a negative effect on tendons and peri-tendineous patellar injection with Ialuronic Acid can represent a protective tendon therapy after a sudden detraining period.

The following thesis is a summa of several research projects and insights around the tendon tissue: first the pathophysiology has been discussed, then the nutraceuticals as prevention strategy. Follows a deep discussion about the role of growth factors in tendon physiology and pathology, finding in the PRP (platelet rich plasma) and PRFM (platelet rich fibrin matrix) a novel and interesting therapy. It has been investigated through a preclinical study comparing and ex vivo model and a quantitative and qualitative assay to identify how the different growth factors may be involved in the tissue repair. At last, a clinical part (diagnostics) has been investigated presenting the results of a study on Achilles tendon evaluated with a novel ultrasound device, the real time elahstosonography: normal achilles tendon of health volunteers has been compared with ruptured ones undergone surgery to assess structural and biomechanics differences.

Con la presente tesi si intende descrivere il progetto di ricostruzione della struttura multiscala del tendine di Achille, esplicando le varie fasi che conducono alla realizzazione di uno scaffold artificiale. Alla struttura tendinea, infatti, è affidata un’importante funzione meccanica: essa permette la trasmissione delle forze dal muscolo all’osso per garantire il movimento del corpo. Eventuali lesioni tendinee comportano gravi problematiche motorie, accentuate dal fatto che tale tessuto non ha la capacità di rigenerazione spontanea; per questo l’ingegneria tissutale ha ricercato alternative alla sua ricostruzione.

L'ingegneria tissutale è progredita notevolmente negli ultimi anni, ma la ricostruzione del tessuto tendineo resta ancora oggi una sfida, per la sua complessa struttura multiscala e le proprietà meccaniche che possiede in virtù del suo ruolo di raccordo tra ossa e muscoli. Nel presente lavoro di tesi si descrive la realizzazione, reticolazione e caratterizzazione di supporti porosi tridimensionali elettrofilati, pensati per la rigenerazione del tessuto tendineo.

Ogni anno nel mondo vengono segnalati più di 33 milioni di infortuni muscoloscheletrici, con significative ripercussioni socio-economiche in termini di ore di lavoro perse e spese economiche conseguenti. Essi costituiscono una delle più frequenti diagnosi in campo ortopedico, rappresentando oltre il 30% di tutte le diagnosi nelle visite muscoloscheletriche effettuate ogni anno. Al giorno d’oggi si conoscono numerose strategie per il trattamento dei tendini danneggiati. Tra queste, gli interventi chirurgici prevedono l’innesto di materiali biologici o sintetici all’interno del sito danneggiato, costituendo una strategia semplice e rapida se paragonati al processo di guarigione naturale; tuttavia, essi hanno dei limiti che possono portare a un insuccesso del trattamento. L’ingegneria tissutale costituisce un promettente approccio da applicare quando la guarigione naturale o la sostituzione chirurgica falliscono. Attualmente, differenti tipologie di cellule e di biomateriali vengono utilizzati per disegnare sostituti tissutali ingegnerizzati. In particolare, gli scaffold possono essere realizzati con biomateriali di origine sintetica o biologica e attraverso diverse tecniche di fabbricazione. Tra queste il cell-electrospinning ha raggiunto un elevato livello di interesse nel campo della medicina rigenerativa. Esso è basato sulla normale tecnica di elettrofilatura, ma aggiunge il vantaggio di poter incapsulare le cellule nelle micro/nanofibre. Grazie a questa tecnica è quindi possibile ricreare in maniera più fedele l’ambiente della matrice extracellulare, preservando e promuovendo la normale attività cellulare. Nonostante ciò, esistono ancora diversi limiti da superare prima che i costrutti tissutali tendinei possano essere utilizzati in ambito clinico. Studi futuri che integrano diversi materiali e tecniche di produzione potranno quindi essere di supporto per il trattamento delle patologie tendinee.

In veterinary as well as human medicine the tenodesmic lesions play a great interest because of their high incidence, the difficult wound healing and therefore an incomplete full functional recover with long periods of inactivity. The therapeutical protocols recently used in the treatment of these lesions are not able to reach a real “restitutio ad integrum”. In sport horses, tendon and ligament injuries are a frequent cause of lameness and entail long periods of rest. Often the healing process does not achieve a complete recovery of the functional and morphologic characteristics of these structures, especially if the entity of the lesion is severe. In equine medicine, there is a continuous research of therapies that enhance a correct regeneration of the injured tissue, stimulating the physiological response on a molecular and cellular level, with the aim of improving the quality of the healing response. The ultimate aim of current research is to obtain a total recovery of the animal’s athletic performance, meanwhile reducing the risk of relapses. During recent years great attention has been focused on verifying the possibility of using Platelet Rich Plasma (PRP) as a treatment for musculoskeletal lesions in the horse: platelet rich plasma contains a high concentration of platelets, which, once activated, are able to secrete a great quantity of growth factors. For years it has been proven that growth factors enhance the healing response of tissues. In this thesis it will be described two clinical studies and one experimental research approach carried out in the Department of Clinical Science in collaboration with the Laboratory of Anatomy of the Department of Experimental Veterinary Sciences of the University of Padova, the Istituto Zooprofilattico della Lombardia e dell’Emilia Romagna of Brescia, the Clinica dell’Ippodromo of Merano and veterinary doctor. Aim of the first clinical study has been to evacuate the clinical effectiveness of intralesional ultrasonographic injections of autologous platelet rich plasma for the treatment of tendon and ligament injuries was evaluated in 9 horses. In all the horses treated (100%) no side effects, local or systemic, were recorded following the injection of platelet rich plasma. In all cases, successive ultrasonographic evaluations, performed at regular intervals, confirmed the favourable progression of the tissue’s healing process with a correct re-alignment of the new fibres. In all cases, the formation of scar tissue or of adherences between the damaged tendon or ligament and the adjacent tissues was not reported. At the end of the rehabilitation period (9-12 months) 7 of the 9 horses treated (77.7%) returned to competition, displaying athletic performances that are comparable to the ones reached before the occurrence of injury. The second clinical study had the aim to evaluate if a combined use of platelet rich plasma and autologous mesenchimal stem cells could determine a better effect on tissutal regenerative response. The use of mesenchimal stem cells is very promising in the veterinary field since their potency has been documented in the tissue engineering research. Recently, several studies proposed the use of platelet rich plasma as a matrix for the application of mesenchmal stem cells knowing that platelets might induce multipotent cells thanks to the great amount of growth factors delivered by these cells. Indeed platelet growth factors showed the ability to differentiate stem cells towards the proper fate and to induce angiogenesis. The combination of platelet rich plasma and stem cells should improve the quality of the regenerative response of the tissue. Our study has been conducted on a group of 17 horses affected by tenodesmic lesions. The combined association of platelet rich plasma and mesenchimal stem cells did not cause collateral side effects; the follow up, evidenced by clinical and ecographic observations, showed an amelioration of the subjects injuries. At the end of the reabilitation period 13 of 17 horses returned to the sport activity and no sign of scar or adherences were observed at the level of new formed tissue. The results obtained from these two clinical studies substain the use of platelet rich plasma as a therapeutic useful tool since is preparation is easy and allow a better tissutal regeneration without the formation of a scar. Moreover, the combined use of platelet rich plasma and mesenchimal stem cells resulted to be very promising for ameliorate tenodesmic lesions. Overall it has been shown that platelet rich plasma could be very effective both alone or in combination with mesenchimal stem cells at the tissue level although did not shorten the rehabiitation period. In the experimental approach used in our study we observed the effect the use of platelet rich plasma and platelet rich plasma in association with mesenchimal stem cells in sheep. The tendon of sheep was experimentally injured and after the treatment animals were sacrificed in order to evalute also histologically the treated tissues. The positive results of this research allowed to obatin new information about the early regenerative response in lesions treated with platelet rich plasma and platelet rich plasma associated with mesenchimal stem cells. The latter study will shed light on the real efficacy of novel treatments on injured tendons that recently are becoming very popular also in the vetetinary medicine.
In medicina umana e veterinaria le patologie teno-desmiche rivestono grande interesse per l’elevata incidenza con cui si verificano, per la difficoltà di ottenere una guarigione completa con un pieno recupero funzionale delle strutture coinvolte e perché comportano lunghi periodi di inattività. I protocolli terapeutici attualmente utilizzati nel trattamento di queste patologie sono lontani dalla potenzialità di una reale “restitutio ad integrum”. Nel cavallo utilizzato per fini sportivi le lesioni dei tendini e dei legamenti rappresentano la principale causa di zoppia e comportano lunghi periodi di riposo; spesso il processo di guarigione non porta ad un completo recupero delle caratteristiche funzionali e morfologiche di queste strutture, soprattutto se l'entità della lesione è grave. Per tale ragione vi è una continua ricerca di terapie in grado di migliorare la rigenerazione corretta del tessuto danneggiato, stimolando la risposta fisiologica a livello molecolare e cellulare con l'obiettivo di ottimizzare la qualità della risposta riparativa. Il fine delle attuali ricerche è quello di ottenere un recupero totale delle prestazioni atletiche degli animali riducendo al minimo il rischio di recidive. Negli ultimi anni grande attenzione è stata posta nel valutare la possibilità di utilizzare il concentrato piastrinico (PRP) come trattamento per le lesioni muscolo-scheletriche del cavallo: il PRP infatti contiene un'alta concentrazione di piastrine, che, nella loro forma attiva, sono in grado di secernere una grande quantità di fattori di crescita. Già da alcuni decenni infatti è stato dimostrato che i fattori di crescita sono in grado di migliorare la risposta di guarigione dei tessuti. In questa tesi verranno illustrati due studi clinici ed uno sperimentale realizzati presso il Dipartimento di Scienze Cliniche dell’Università di Padova in collaborazione con il laboratorio di Anatomia del Dipartimento di Scienze Sperimentali Veterinarie, l’Istituto Zooprofilattico della Lombardia e dell’Emilia Romagna di Brescia, la Clinica dell’Ippodromo di Merano e veterinari liberi professionisti. Scopo del primo studio è stato di valutare l'efficacia clinica dell’iniezione intralesionale ecoguidata di PRP autologo per il trattamento di lesioni tenodesmiche in 9 cavalli. In tutti i cavalli trattati non sono stati registrati effetti collaterali, né locali né sistemici dopo l'iniezione di PRP. Nei diversi soggetti le valutazioni cliniche ed ecografiche eseguite ad intervalli regolari hanno confermato la progressione favorevole del processo di guarigione del tessuto con un corretto ri-allineamento delle fibre neoformate. In nessun caso è stata rilevata la formazione di tessuto cicatriziale o di aderenze tra il tendine danneggiato ed i tessuti adiacenti. Al termine del periodo di riabilitazione (9-12 mesi) 7 dei 9 cavalli trattati (77.7%) sono tornati alle competizioni, con prestazioni atletiche paragonabili a quelle raggiunte prima del verificarsi del danno tissutale. Il secondo studio clinico si è posto invece l’obiettivo di valutare se un utilizzo combinato di PRP e di cellule staminali mesenchimali autologhe potesse determinare un miglior effetto sinergico sul meccanismo dei guarigione tissutale. L’utilizzo delle cellule staminali come strumento per la riparazione tissutale costituisce un’importante prospettiva di ricerca in clinica veterinaria. Sempre con maggior interesse ci si avvicina alle prospettive terapeutiche basate sulla capacità rigenerativa e riparativa di organi e tessuti che le cellule staminali offrono, come la capacità di auto-replicazione e di proliferazione illimitata. La capacità differenziativa di tali cellule ha reso soprattutto nell’ultimo decennio le MSCs una componente potenzialmente promettente nel campo dell’ingegneria tissutale. Recentemente diversi studi hanno proposto l’utilizzo di concentrato piastrinico, sia nella sua forma liquida che in quella gelatinosa, come matrice per l’applicazione di cellule staminali, con l’obiettivo che le piastrine debitamente attivate potessero liberare i diversi fattori di crescita necessari per la differenziazione delle cellule multipotenti. I fattori di crescita liberati dalle piastrine infatti hanno dimostrato di possedere la capacità di favorire la differenziazione delle cellule staminali verso il destino cellulare e di promuovere l’angiogenesi. L’associazione delle cellule mesenchimali con i fattori di crescita piastrinici permette di accelerare l’impianto e la crescita in vivo delle cellule impiantate. Il nostro studio è stato effettuato in un gruppo di 17 cavalli purosangue inglesi affetti da lesioni teno-desmiche. Anche in questo secondo gruppo di cavalli, il protocollo terapeutico scelto non ha evidenziato effetti collaterali locali né sistemici. Il follow up rilevato, in termini di valutazione clinica ed ecografica, ha evidenziato un soddisfacente miglioramento dei soggetti. Non sono state osservati fenomeni cicatriziali né aderenze a livello del tessuto neoformato ed al termine della fase di riabilitazione 13 dei 17 cavalli trattati (76.5%) sono tornati all’attività sportiva con buoni risultati e senza manifestare recidive. I risultati ottenuti durante questi due studi clinici vanno a sostenere l’utilizzo a scopo terapeutico del PRP nel trattamento di lesioni tenodesmiche: infatti PRP non ha causato effetti collaterali locali o sistemici o la comparsa di segni di rigetto, inoltre può essere ottenuto in breve tempo e quindi utilizzato sul paziente in anestesia locale. Inoltre, il PRP ha dimostrato di essere una terapia promettente, in quanto migliora la rigenerazione dei tessuti, favorendo la formazione di tessuto sano e funzionale, invece di tessuto cicatriziale. L’utilizzo combinato di PRP e MSC, sulla base delle valutazioni cliniche, ecografiche e dei risultati ottenuti a breve e a lungo termine risulta essere molto promettente nel trattamento delle lesioni tenodesmiche del purosangue inglese. Comparando i risultati ottenuti nei due studi clinici, possiamo osservare un effettivo apporto benefico del PRP sia da solo che in associazione alle MSCs sia in termini di miglioramento clinico dei soggetti sia in termini di riduzione dei casi di recidiva rispetto ai trattamenti convenzionali. Rimane di fondamentale importanza il protocollo riabilitativo dei cavalli, che deve tener conto dei lunghi tempi di recupero associati alla guarigione del tessuto: i trattamenti studiati nel nostro lavoro, sembrano apportare effettivamente un’ottimale stimolo per la guarigione tissutale per quanto riguarda le caratteristiche del tessuto neoformato ma non consente di accorciare i tempi di recupero dei soggetti trattati. Un importante aspetto di questo progetto è stato infine quello di verificare, in vivo ed in animali sperimentali, l’efficacia da un punto di vista clinico, ecografico ed istologico, dell’applicazione di PRP da solo o in associazione a MSCs autologhe. Questo protocollo è stato utilizzato nel trattamento di lesioni tendinee sperimentalmente indotte nella pecora: uno degli obiettivi che ci siamo posti è di cercare di comprendere maggiormente la reale efficacia di questi trattamenti attraverso approfondimenti istologici ed immunoistochimici dei tessuti trattati. L'esito positivo di tale ricerca, confermato dai rilievi clinici, ecografici ed istologici ha permesso di ottenere maggiori informazioni sull’andamento del processo di guarigione di lesioni trattate con PRP e con PRP e MSCs nel breve periodo. Tale studio potrà quindi gettare le basi per aumentare la casistica e la numerosità sperimentale nell'applicazione di nuove terapie, volte a migliorare sia il tipo che le caratteristiche della guarigione, che sembrano riscuotere, secondo quando riportato in letteratura, risultati sempre più promettenti.

This research project focused on study of adult stromal cells derived from equine and canine mesenchymal tissue and the application of these cell sources in musculoskeletal injuries, particularly in tendon repair. Adult MSCs gained general attention in both human and veterinary medicine, however despite the advances in this field, much studies are needed in order to better understand MSCs behavior. With this goal the following research project focused on: - A comprehensive characterization and study in vitro of mesenchymal stromal cells derived from peripheral blood of horses (ePB-MSCs) and from adipose tissue of dog (cA-MSCs). Moreover the possibility to cryopreserve these cells in the long-term period and the delivery methods of both ePB-MSCs and cA-MSCs in the short-term period was verified. - The use of MSCs from peripheral blood and from adipose tissue in the tendon regeneration process was investigated in two different work: the use of adipose tissue derived MSCs in the re-cellularization of a human biocompatible scaffold, and the use of MSCs derived from ovine peripheral blood injected in experimental tendon lesions of the deep digital flexor tendon (DDFT) in a ovine model. The full characterization of both ePB-MSCs and cA-MSCs was achieved using FACS sorting in order to identify the Cluster of Differentiation (CD) expression on the surface of these cells, by the study of population doubling time (PDT), the analysis of telomerase enzyme presence by Real Time PCR, and the alkaline phosphatase positivity. The differentiative potential of both ePB-MSCs and cA-MSCs was assessed by the in vitro induction of these cells into osteo, muscular and adipogenic lineages and verified by expression of tissue specific gene, like PPAR-y, Desmin, and Osteopontin (SPP-1). The same characterization and differentiative potential were then verified on ePB-MSCs and cA-MSCs after 1 year. Results obtained from this study furnished novel information on adult MSCs and confirmed the possibility to cryopreserve these cells in the long-term period for their potential applications in clinical field. The study on delivery of both ePB-MSCs and cA-MSCs in the short-term period, performed by exposing cells to different media, time and temperature, lead to the conclusion that cells could be delivered in PBS at room temperature no longer than 9-12 hrs; cells were also monitored for CD expression, for apoptotic resistance and ß-galactosidase activity during different time intervals. The second challenge of this research project was on study of regeneration capability of adult MSCs derived from peripheral blood and from adipose tissue in tendon pathologies. A first work was performed using MSCs derived from human lipoaspirate in order to recellularize a human tendon scaffold to be used as insert in full-thickness lesions of flexor hand tendons. A previous re-cellularization was successfully obtained using Tris solution and enzymatic digestion, and the absence of native genonic DNA were assessed by standard PCR. Moreover a good protocol for re-cellularization was obtained, using a collagen matrix gel, which helped a good penetration of stromal cells inside the biocompatible scaffold. Secondly a comparation study among the effect of PB-MSCs, platelet rich plasma (PRP) or combination of both on tendon healing was performed using ovine model. Experimental lesions were made using collagenase 1A injection in the left deep digital flexor tendon (DDFT) of 18 Bergamasca sheep, using the right DDFT as internal control (lesioned, not treated). Sheep were further divided in two groups, the first euthanized after 1 month and the second after 4 months, and tendon were then analyzed by histological and immunohistochemical assays. Results obtained after 4 months showed a significant difference between the treated tendon of all group respect to the relative internal control (lesioned, not treated); notably after 4 months the group that received the treatment with MSCs alone or in combination with PRP, showed significant improvement of the healing process respect to PRP treated group, becoming similar to the normal healthy tendons.
Il seguente progetto di ricerca ha avuto l’obiettivo di studiare in modo approfondito le cellule stromali adulte derivate da sangue periferico di cavallo e da tessuto adiposo di cane e successivamente verificare le loro potenzialità applicative nelle patologie muscolo-scheletriche, in modo particolare nella rigenerazione tendinea. Negli ultimi anni le cellule stromali adulte di derivazione mesenchimale hanno sollevato l’attenzione della comunità scientifica sia in medicina umana che veterinaria, per la potenzialità che possono rivestire nel trattamento di patologie che a tutt’oggi non trovano completa risoluzione clinica. Tuttavia nonostante i notevoli progressi fatti in questo campo di ricerca, ulteriori approfondimenti sono necessari per comprendere del tutto i diversi meccanismi delle cellule stromali adulte sia in vivo che in vitro. Questo studio ha avuto la finalità di: - Effettuare una completa ed esaustiva caratterizzazione delle cellule staminali adulte isolate a partire da sangue periferico di cavallo (ePB-MSCs) e da tessuto adiposo di cane (cA-MSCs). È stata poi indagata la possibilità di criopreservare entrambi i tipi di cellule per un anno, ed infine è stato studiato l’effetto di parametri ritenuti importanti nell’influenzare la vitalità cellulare durante la spedizione delle cellule nel breve periodo evitando il congelamento. - Indagare l’uso di cellule stromali isolate da sangue periferico e da tessuto adiposo nella rigenerazione tendinea in due diversi studi: il primo con l’obiettivo di ottenere la ricellularizzazione di uno scaffold tendineo precedentemente decellularizzato, il secondo con l’obiettivo di verificare il contributo alla rigenerazione tendinea in vivo di cellule stromali isolate da sangue periferico di pecora, immesse in lesioni sperimentali indotte con collagenasi 1A. Per l’ottenimento di una completa caratterizzazione di entrambe le ePB-MSCs e le cA-MSC è stato utilizzato il FACS sorting per analizzare l’espressione dei cluster di differenziamento (CD) presenti sulla membrana cellulare di queste cellule, inoltre è stato effettuato lo studio del tempo di duplicazione cellulare (PDT) e la positività alla fosfatasi alcalina. La potenzialità differenziativa delle ePB-MSCs e delle cA-MSCs è stata verificata mediante l’induzione al differenziamento in vitro di queste cellule verso tessuto osseo, muscolare e adiposo, e successiva verifica dell’espressione di specifici geni, quali la PPAR-y la Desmina e l’ostopontina (SPP-1) mediante PCR. Gli stessi esperimenti effettuati per definire la caratterizzazione di entrambe le ePB-MSCs e le cA-MSCs sono stati effettuati dopo un anno di criopreservazione delle stesse, concludendo che le caratteristiche di staminalità non cambiano nelle cellule stromali adulte di entrambe le specie dopo congelamento. É stata effettuata un’indagine sull’effetto che diversi mezzi di coltura, tempo e temperatura hanno sulla sopravvivenza di entrambe le ePB-MSCs e le cA-MSCs durante la spedizione nel breve periodo. Le cellule stromali di entrambe le specie sono state analizzate per l’espressione dei cluster di differenziamento, per la presenza di resistenza all’attività apoptotica e per la positività alla beta- galattosidasi. I risultati ottenuti hanno portato alla conclusione che le cellule stromali adulte possono essere spedite in soluzione salina (PBS) a temperatura ambiente per non più di 9-12 ore. Il secondo obiettivo di questo progetto di ricerca è stato finalizzato all’applicazione delle cellule stromali isolate da sangue periferico e da tessuto adiposo nella rigenerazione tendinea. Il primo lavoro effettuato ha previsto l’utilizzo di MSCs derivate da lipoaspirato umano per la ricellularizzazione di uno scaffold tendineo umano con la finalità di utilizzarlo nelle lesioni totali dei tendini flessori della mano. Lo scaffold biocompatibile è stato in precedenza decellularizzato grazie all’utilizzo di soluzioni detergenti ed enzimatiche. L’assenza di residuale materiale genomico è stata verificata tramite PCR. Questo studio ha permesso di mettere appunto una tecnica di ricellularizzazione efficiente che, avvalendosi dell’ausilio di una matrice gelificante di collagene, ha garantito una buona penetrazione cellulare all’interno della matrice dello scaffold. Il secondo lavoro effettuato sulla rigenerazione tendinea, ha avuto la finalità di paragonare l’effetto di tre diversi trattamenti (cellule stromali derivate da sangue periferico di pecora (sPB-MSCs), sPB-MSCs + platelet rich plasma (PRP), e PRP) sulla rigenerazione tendinea a 1 mese e a 4 mesi dopo lesione sperimentalmente indotta sul tendine flessore profondo delle falangi di pecora (DDFT). Dopo eutanasia delle pecore a 1 e 4 mesi i tendini sono stati analizzati tramite analisi istologica e immunoistochimica; i risultati ottenuti dopo 4 mesi hanno evidenziato una differenza significativa nel grado di riparazione tissutale tra tutti i gruppi di pecore trattate e i loro rispettivi controlli interni (lesionati, non trattati). Inoltre le pecore che hanno ricevuto il trattamento con sPB-MSCs hanno dimostrato avere il migliore processo riparativo tendineo rispetto al gruppo di pecore trattato solo con PRP per tutti i parametri istologici valutati, risultando molto più simili al tendine sano usato come controllo positivo.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Nesta pesquisa foram investigados aspectos anatômicos e biométricos da face flexora dos dígitos de 20 novilhas mestiças da raça Nelore, com idades entre 24 e 36 meses, criadas em sistema extensivo. O material foi proveniente de matadouro sob Fiscalização do Serviço de Inspeção Oficial e mantido sob congelamento a -18°C até o momento da dissecação. Após tricotomia e limpeza das regiões distais ao metacarpo e metatarso, as faces palmar e plantar dos dígitos foram dissecadas in natura e as estruturas anatômicas identificadas e medidas com auxílio de paquímetro universal. As mensurações foram feitas em milímetros (mm) e incluíram o comprimento, a largura e a espessura das estruturas anatômicas digitais. A técnica de dissecação in natura foi considerada útil para a execução deste estudo e as estruturas identificadas e mensuradas incluíram os ligamentos acessórios distais dos paradígitos, ligamentos anulares palmares e plantares, bainha digital tendínea, ligamentos anulares proximais e distais, ligamentos interdigitais distais, tendões flexores digitais superficiais e profundos e a manica flexoria. Os dados biométricos obtidos indicam diferenças (p≤0,05) entre membros, antímeros e dígitos, especialmente nas estruturas anatômicas localizadas distalmente. Devido à escassez de estudos biométricos sobre o assunto, os achados deste trabalho podem servir como valores de referência para a faixa etária de novilhas avaliadas e contribuir em pesquisas morfológicas futuras
In the present work anatomic and biometric studies of the distal aspect in the flexor aspect of digits were carried out for 20 cross-breed heifer of Nelore breed aging around 24-36 months raised in an extensive regiment. The materials came from shamble under the Official Fiscalization of Inspect Service and were kept under freezing at -18°C until dissection. After the clipper and cleaning the distal areas, from metacarpus to metatarsus, the structures were dissected and measured by using a universal caliper rule (mm) on length (proximal-distal), widht (abaxial-axial) and thickness (dorso-palmar or dorso-plantar). The dissected structures included the paradigits distal accessories ligaments, palmar and plantar annular ligaments and tendon digital sheath, proximal and distal annular ligaments, interdigital distal ligament, superficial digital flexor tendon and deep digital flexor tendon and manica flexoria. The measured data indicate differences (p≤0,05) among the limb, right, left and respective digits mainly in the more distal analyzed structures. Due to scarcity of biometric studies about this topic, the data found in this work might be useful as a reference for the analyzed group, as well in the anatomic detailed structures which are essential to understanding many of the pathological process of locomotor apparatus in cattle

Tendons function to transmit the forces generated by muscle to bone, resulting in movement of a joint. However some tendons have more specialized functions. Functionally distinct tendons have differences in tissue composition that relate to differences in function. However, it is unclear whether functionally distinct tendons also behave differently following injury. This study aims to investigate the normal characteristics of ovine forelimb extensor tendons and the changes that occur following injury using a combination of histological and gene expression analysis. The lateral digital extensor tendon (LDET) and two branches of the common digital extensor tendons (CDET) in the forelimb of 6 sheep were collected to study normal extensor tendon characteristics. In another 6 sheep, the LDET and two branches of the CDET were transected and harvested 8 weeks later to evaluate the characteristics of injured extensor tendons. In the third group of 6 sheep, the LDET and two branches of the CDET were harvested 8 weeks after partial transection of the superficial digital flexor tendon (SDFT) in the same limb to evaluate the effects of tendinopathy of the SDFT on the normal extensor tendon characteristics. Samples were assessed using histology and gene expression. The results demonstrate that there are gene expression differences between the extensor tendons in the ovine forelimb and the changes in the ovine extensor tendons following surgery are similar to that of other tendons studied including the “energy storing” tendons. Partial transection of the SDFT had no effect on the extensor tendons.

Introducción: Determinar la asociación entre el ángulo de inclinación del tendón patelar (AITP) y la presencia de dolor anterior de rodilla (DAR), así como conocer la prevalencia de DAR en deportistas universitarios. Material y métodos: Estudio de corte transversal en 143 deportistas universitarios. La presencia de DAR se detectó usando la Anterior Knee Pain Scale de Kujala y se calculó el AITP analizando una fotografía de ambas piernas con el programa Kinovea ®. Cada rodilla se consideró como una muestra. La razón de prevalencia entre el DAR y el AITP se calculó usando regresión de Poisson robusta. Resultados: Se evaluaron 143 sujetos, por tanto, 286 rodillas, donde 176 (61.5%) presentaban DAR. El AITP se clasificó en cuartiles. Para el análisis se unió el segundo y tercer cuartil, por lo que se obtuvo un cuartil medio (9°y 14°).Se encontró que un AITP menor a 9° tiene 1,34 (IC95%; 1,09-1,65) más probabilidad de tener DAR, y un AITP mayor a 14° tiene 1,35 (IC95%; 1,09-1,69) más probabilidades. Conclusiones: Los deportistas con un AIPT menor a 9° o mayor a 14° tienen mayor probabilidad de presentar DAR. Se recomienda que el profesional considere el ángulo de inclinación del tendón patelar en su evaluación.
Introduction: To determine the association between patellar tendon angle (AITP) and the presence of anterior knee pain (DAR) and the prevalence of DAR in college athletes. Materials and methods: Cross-sectional study of college athletes. The presence of DAR was detected using the Anterior Knee Pain Scale by Kujala and AITP was calculated by analyzing a photograph of both legs with Kinovea program ®. Each knee was considered as a sample. The prevalence ratio between the DAR and the AITP was calculated using Poisson regression robust Results: 143 subjects were evaluated, therefore, 286 knees, where 176 (61.5%) had anterior knee pain (DAR). The AITP was ranked in quartiles. To analyze was joined second and third quartile so was obtained a midquartile (9° and 14°). It was found that AITP fewer than 9° is 1.34 (95% CI, 1.09 - 1.65) more likely to have DAR, and AITP greater than 14° is 1.35 (95% CI; 1,09- 1.69) more likely. Conclusions: Athletes with AITP fewer than 9 ° or greater than 14 ° are more likely to have DAR. It is recommended that the professional considers the inclination patellar tendon angle in the evaluation

Um dos recursos mais utilizados no processo de reparo de lesões tendíneas é o laser que demonstrou ter resultados satisfatórios quando se buscam efeitos antiinflamatório e cicatrizante. No entanto, por requerer uma tecnologia de alto custo, um outro tipo de fototerapia vem sendo buscado, como o diodo emissor de luz, LED. Porém, o número de pesquisas realizadas para a determinação segura de seus efeitos terapêuticos ainda é muito pequeno, inviabilizando uma proposta de protocolo para adoção do LED. Um outro recurso também utilizado durante a reabilitação de lesões tendíneas, é o ultra-som pulsado de baixa intensidade (LIPUS). Trabalhos realizados até o momento mostram alterações satisfatórias quanto à deposição e alinhamento das fibras de colágeno. Este estudo objetiva testar comparativamente a eficácia da aplicação de LEDs 630 nm e 830 nm em relação à terapia laser de baixa intensidade (LILT), com laser de 685 nm e 830 nm, e à terapia com LIPUS em tendão calcâneo parcialmente lesado. Foram utilizados 56 ratos Wistar, submetidos à lesão mecânica parcial do tendão calcâneo. A análise da evolução do processo foi realizada através da microscopia de polarização. Os resultados mostraram uma real eficácia dos tratamentos com LEDs e lasers, e uma ineficácia do tratamento à base de US. Nosso estudo sugere que uma boa organização e um bom alinhamento das fibras de colágeno são conseguidos no processo de reparo de lesões tendíneas através de aplicações à base de LED 880 nm e laser 630 nm, os quais se mostraram mais eficazes. No entanto, outras pesquisas na área se fazem necessárias para uma determinação segura e eficaz dos protocolos de tratamento utilizando essa modalidade de fototerapia.
Laser is one of the most effective resources of treatment for tendinous injury when anti-inflammatory and cicatrizing effects are wanted. However, it is considered an expensive treatment and so, an alternative and cheaper light therapy as effective as it has been searched and the light emitting diodes, LEDs, are a promising candidate for it. Results from the studies already done have been useful to predict the possible effects of LED on the injured tissues, but are not enough to establish a treatment protocol that guarantees its recommendation as a substitute therapeutic tool for tendinous injury treatment. Another promising resource for tendinous injury healing is the ultra-sound of low intensity (LIPUS). Studies done until the present moment have shown satisfactory results when deposition and alignments of collagens fibers are wanted. The aim of this study was to compare the effects of laser, light emitting diodes (LEDs) and ultra-sound of low intensity on the treatment of Achilles tendon of albino rats, Wistar lineage, exposed to mechanical trauma. The experimental model consisted of a partial mechanical lesion of the right Achilles tendon of 56 rats, which were divided in 6 groups, 5 with 10 animals and one, the control group, with 6. One hour after the lesion, the injured animals received the respective applications of laser, LED or US, and the same procedure was repeated each 24 h. The healing process and the deposition were evaluated by analyze of the alignment of collagens fibers through polarization microscopy. The results showed a real efficiency of treatments based on LEDs and lasers, but the treatment based on US was inefficient. Applications of laser at 830 and LED 880 nm were more efficient when the aim is a good organization and alignment of the collagen fibers on tendon healing. However more research is needed for a safety and more efficient determination of a protocol.

Fibrotic diseases account for an estimated 45% of the total number of deaths in the developed world (Wynn 2007). Tendons are an excellent model for studying the dysregulated response which leads to fibrosis, as tendons have an organized, parallel matrix, in which tissue defects could easily be distinguished. Wong et al. (2006b) demonstrated the presence of a bell-shaped region around sutures in tendons that was devoid of cells in histological sections. The mechanisms of the formation of this acellular zone, that was also noted in cornea and cartilage (Matsuda et al. 1999; Hunziker and Stähli 2008), were unknown. It was hypothesized that the acellular zone was formed by cell death and that suturing caused alterations to the extracellular matrix of sutured regions of tendon, which made the acellular zone refractory to cellular re-population. The acellular zone was tracked in sutured tendons for up to a year to determine the temporal properties of the acellular zone. Electron microscopic and time lapse studies were carried out to determine if the acellular zone formed by cell migration or cell death. Microarray analysis was conduced to confirm this and to reveal potential molecular targets for future studies. The extracellular matrix of sutured tendons was studied by electron, atomic, scanning and polarized light microscopy and mechanical measurements were obtained using nanoindentation. It was concluded that the acellular zone formed within 24 hours and persisted for up to a year. Tension and size of the suture's grasp were also shown to be important for acellular zone formation. Cell death was the main effector of acellular zone formation. Microarray analysis showed evidence of upregulation of inflammatory mediators and programmed necrosis pathways. The sutured extracellular matrix was denser, more disorganized and had a lower Young's modulus than unsutured regions of the same tendon. These differences in the properties of the extracellular matrix of sutured tendons may be the cause of the persistence of the acellular zone.

Degenerative disorders of the rotator cuff tendons account for nearly 75% of all shoulder pain, causing considerable pain and morbidity. Given the strong correlation between age and tendinopathy, and unprecedented population aging, these disorders will become increasingly prevalent. Improved understanding of tendon degeneration will guide the development of future diagnostic and treatments, and is therefore urgently needed. However, the aetiology and pathology of rotator cuff tendinopathy remain unclear. The complicated mechanical environment of the rotator cuff is hypothesised to influence the susceptibility of the tendons to degeneration and tearing. Studies have reported biological adaptations in torn cuff tendons indicative of increased compressive loading within the tendon. The material adaptations of healthy and degenerative cuff tendons are largely unreported but will provide further insight into the role of the mechanical environment in rotator cuff aetiology and pathology. This thesis examined the material adaptations of healthy and diseased tendons to explore the role of mechanical loading in rotator cuff pathology. The material adaptations of healthy animal tendons, and healthy and delaminated human cadaveric rotator cuff tendons, in response to different loading environments were characterised. The effects of age, tears, steroid injection and subacromial decompression surgery on the structural adaptations of human cuff tendons were also studied, as was the effect of tendon cell proliferation on the mechanical properties and degradation behaviour of collagen scaffolds. Loading environment significantly affected the structural adaptations of healthy tendons. Regions exposed to compressive and shear strains exhibited thinner fibres, shorter crimp lengths and thinner, less aligned fibrils compared with regions exposed to tensile strains alone. In healthy rotator cuff tendons, the inhomogeneous loading environment produced topographically inhomogeneous structural adaptations. The tendons of a delaminated rotator cuff exhibited less topographical variation in properties and thinner, less aligned fibrils compared with healthy cuff tendons. Torn cuff tendons exhibited thinner fibrils and shorter crimp lengths compared with control samples. These adaptations were identifiable early in the disease progression, and neither steroid injection nor subacromial decompression surgery significantly influenced these adaptations at seven weeks post‐treatment. Significant correlations between decreasing dimensions and increasing tear size were found when age was included as a confounding factor, reflecting the importance of age and tear size in determining the material properties of tendons. Tendon cell proliferation influenced the mechanical properties and degradation behaviour of the collagen scaffolds, emphasising the integral role of cells in the functional adaptation of biological materials. These results demonstrate the effect of mechanical environment on the material adaptations of tendons. They also indicate the importance of the complicated mechanical environment experienced by the rotator cuff tendons in predisposing the tendons to degeneration and tearing. The observed material adaptations of degenerative and torn tendons suggest that rotator cuff pathology is associated with increased levels of compressive and/or shear strains within the tendon. These changes begin early in the disease progression and neither steroid injection nor sub‐acromial decompression surgery are capable of reversing the changes in the timeframe investigated. These findings highlight the urgent clinical need for pre‐rupture diagnostic techniques for the detection of early pathological changes in the rotator cuff. They also emphasize the requirement for new intervention strategies that restore the healthy mechanical environment and reverse early pathological adaptations in order to prevent catastrophic failure of the tendons.

The human Achilles tendon is the strongest tendon in the body, but it is also the tendon most prone to developing tendinopathy. Tendinopathy is a clinical term used to describe tendon pathology that presents clinically as a painful, thickened tendon with altered mechanical behaviour. The main conservative treatment for tendinopathy is exercise, typically in the form of calf muscle contractions. However calf exercises are likely to impose very different stresses and strains on the tendons of different individuals as a result of inter-subject variability in tendon geometry, tendon material properties, muscle mechanical properties and muscle activation patterns. Although there are reports of global stress and strain experienced by the Achilles tendon during voluntary contractions in the literature, little is known about the local stress and strain within the tendon. It is important to understand the local mechanical behaviour in tendon tissue because mechanical loading is a critical stimulus to tendon adaptation via localised mechano-biological pathways. Musculoskeletal tissues including tendons, are reported to have an optimal range in which mechanical loading produces positive tissue adaptation (an anabolic effect), with either too much or too little mechanical loading having a detrimental (catabolic) effect. Clinical efficacy of exercise-based training and rehabilitation for the Achilles tendon could be enhanced if an “optimal” loading stimulus is provided to the tendon. The general aim of this thesis was to investigate the influence of subject-specific tendon geometry and material properties on mechanical stress and damage in living free Achilles tendons with and without tendinopathy during submaximal, isometric loading. A methodological pipeline was developed to generate individualised finite element models of the living free Achilles tendon (n = 8 healthy, n = 8 tendinopathic). Subject-specific polynomial finite element meshes were rendered based on freehand three-dimensional ultrasound scans of the free tendon. Subject-specific material properties were obtained from numerical optimisation by minimising the difference between experimental measures of longitudinal strain under load and modelled strains. The tendon was defined as an incompressible, homogeneous and hyper-elastic material and implemented in CMISS. CMISS is a finite element software based on polynomial basis functions which can accommodate large deformation based of coarse polynomial meshes. Finite element analyses were subsequently conducted to determine the strain, stress and damage criteria within the tendon based on force boundary conditions obtained from the subject-specific experimentally measured ankle plantarflexor torque. The first study used three-dimensional ultrasound based measures of in-vivo free Achilles tendon geometry in conjunction with finite element analysis to determine the effects of subject-specific versus generic geometries and material properties on the stress distribution within the living tendon during a submaximal isometric contraction. The mean (SD) lengths, volumes and cross-sectional areas of the tendons at rest were 62 ± 13 mm, 3617 ± 984 mm³ and 58 ± 11 mm², respectively. The measured tendon strain at 70% maximum voluntary contraction was 5.9 ± 1.3%. Generic geometry was represented by the average mesh and generic material properties were taken from the literature. Local stresses were subsequently computed for all combinations of subject-specific and generic geometry and material properties. For a given geometry, changing from generic to subject-specific material properties had little effect on the stress distribution in the tendon. In contrast, changing from generic to subject-specific geometry had a 26-fold greater effect on tendon stress distribution. Overall, these findings highlight a strong variability between individual tendons and indicate that the tendon geometry has a greater influence on the stress distribution than the tendon material properties. Achilles tendon mechanical properties and geometry are altered in Achilles tendinopathy. The purpose of the second study was to determine the relative contributions of altered mechanical properties and geometry to free Achilles tendon stress distribution during a sub-maximal contraction in tendinopathic relative to healthy tendons. The average resting CSA of the free tendon was on average 35% greater for the tendinopathic tendons. At the same tensile force, the tendinopathic tendons experienced a strain of 7.1 ± 2.9% compared to 5.9 ± 1.3% for controls. The mean Young’s modulus for tendinopathic tendons was 40% of the corresponding control value. Finite element analyses revealed that tendinopathic tendons experience 24% less stress at submaximal loading compared to healthy tendons. The lower tendon stress in tendinopathy was due to a greater influence of tendon CSA, which alone reduced tendon stress by 30%, compared to Young’s modulus, which alone increased tendon stress by 8%. These findings suggest that the greater tendon CSA observed in tendinopathy compensates for the substantially lower Young’s modulus, and thereby protects pathological tendon against excessive stress. The purpose of the final study was to determine how tendinopathic alterations in Achilles tendon geometry and material properties affect damage load and location. Tendon damage load was assessed at a theoretical damage strain of 12%. The subject-specific damage load was found significantly higher for the healthy tendon (12.5 ± 5.0 kN) compared to the tendinopathic tendon (5.7 ± 1.5 kN). A 59% decrease in the damage load was observed when the average material properties of the healthy tendon were replaced with average tendinopathic material properties while retaining the average healthy tendon geometry. Damage load increased by 23% when the average healthy geometry was replaced by average tendinopathic geometry while retaining average healthy material properties. A substantial variation in damage location was observed across all tendons. Overall findings of this study suggest that tendinopathic alterations in material properties are more influential than corresponding alterations in tendon geometry in determining the load required to cause tendon damage. This thesis has demonstrated the feasibility of using a finite element modelling approach to investigate stress distributions in the Achilles tendons based on in-vivo, subject-specific measures of three-dimensional tendon geometry and tendon mechanical properties. Stress patterns in the Achilles tendon were found to differ substantially between individuals. Generic training and rehabilitation programs for the Achilles tendon are therefore likely to result in very different tendon stresses and strains between individuals. The general findings of this thesis point to the need for personalised training and rehabilitation for the Achilles tendon that takes account of the substantial variation in tendon geometry and material properties between individuals to ensure an optimal loading stimulus is provided that maximises positive tissue adaptation for healthy and tendinopathic tendons.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School Allied Health Sciences
Griffith Health
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Les étirements sont aujourd'hui une pratique courante dans les milieux sportifs et de réadaptation. Ils sont habituellement recommandés dans le but de contribuer à la prévention des blessures (Willson et al. 1991 ;Pope et al. 2000), à l’amélioration de la performance sportive lorsque celle-ci nécessite une amplitude articulaire importante (Heyters, 1985 ;Hortobagyi et al. 1985) et à la récupération de la mobilité articulaire dans le cadre d’un programme de réadaptation (Magnusson et al. 1996b). Ces méthodes, qui se sont développées ces dernières années, font classiquement appel à l’étirement passif et aux étirements neurofacilités (PNF), présentés initialement par Kabat (1958). Plus récemment, un intérêt particulier a été porté au travail musculaire excentrique. Des études ont montré que celui-ci permettait également d’augmenter l’amplitude articulaire (Willson et al. 1991 ;Nelson et Bandy, 2004).

Dans une première partie de ce travail, il nous a semblé intéressant de comparer les effets de l’étirement passif à ceux des étirements PNF par "contracté-relâché" et "contracté de l’antagoniste". Si les modalités d'application de chaque étirement sont différentes, elles présentent un intérêt majeur. De fait, elles permettent de faire varier les conditions d'allongement des différentes structures du système myotendineux, en modulant l'activité volontaire des musculatures agoniste ou antagoniste. En effet, si l’étirement passif s'effectue sans activation volontaire, l’étirement par "contracté-relâché" consiste à faire précéder l'étirement passif, d'une contraction volontaire maximale isométrique de la musculature agoniste. L’étirement par "contracté de l’antagoniste" associe à l'allongement de la musculature agoniste, une contraction volontaire maximale de la musculature antagoniste. Si de nombreuses études s'intéressent encore actuellement à caractériser leurs effets respectifs, elles ont déjà permis de montrer que ceux-ci avaient au moins deux origines distinctes, l'une neurophysiologique et l'autre mécanique (Taylor et al. 1990 ;Hutton, 1993). Au plan neurophysiologique, il est bien accepté que ces méthodes induisent une modulation de l'activité réflexe tonique facilitant le relâchement musculaire et par conséquent l’amplitude articulaire (Guissard et al. 1988 ;2001). Il est également bien admis que l’importance de ces effets sur la musculature est variable selon la méthode employée (Guissard et Duchateau, 2006). Au plan mécanique, des études menées chez l’animal ont montré que l’étirement passif modifie les caractéristiques viscoélastiques des tissus (Taylor et al. 1990), et de fait favorise l’allongement des tissus myotendineux (McHugh et al. 1992). Chez le sujet humain, plusieurs expérimentations ont montré que l’étirement par "contracté-relâché" permet d’obtenir un allongement myotendineux et un gain d’amplitude articulaire plus important que par étirement passif (Moore et Hutton, 1980). D’autres études ont montré que l’étirement par "contracté de l’antagoniste" permet de majorer encore les gains obtenus par l’étirement "contracté-relâché" (Osternig et al. 1990). Une première question posée dans ce travail est de savoir si la contribution des processus neurophysiologiques et mécaniques se traduit d’une manière spécifique sur le rapport de compliance des tissus de l’unité myotendineuse. Le développement de techniques d’investigation, telles que l’échographie, permet désormais d’observer le comportement de l’unité myotendineuse, d’une manière non invasive (Fukunaga et al. 1992 ;Herbert et Gandevia, 1995 ;Kuno et Fukunaga, 1995 ;Maganaris et al. 1998). Elle permet ainsi d’étudier les effets d’un étirement ou d’une contraction (Fukunaga et al. 1996) sur le rapport de compliance des structures musculaires et des tissus tendineux.

S’il était intéressant d’étudier la spécificité de ces trois méthodes d’étirement classiques par rapport à leurs effets sur les tissus myotendineux, il nous paraissait pertinent d’observer celle d’un travail musculaire excentrique. En effet, la particularité de celui-ci est de soumettre l’unité myotendineuse préalablement activée, à un allongement. En réadaptation, le travail excentrique est généralement proposé dans le but d’améliorer plus rapidement la symptomatologie d’une tendinopathie (Stanish et al. 1986 ;Alfredson et al. 1998). Des études récentes ont indiqué qu’il peut également être proposé pour augmenter l'amplitude articulaire (Nelson et Bandy, 2004). Toutefois, ses effets sur les tissus myotendineux ne sont pas clairement définis dans la littérature. Chez l’animal, Heinemeier et al. (2007) ont comparé les effets d’un entraînement en contractions concentriques et excentriques sur les tissus de l’unité myotendineuse. Leurs résultats indiquent que si les tissus tendineux sont sensibles aux deux modes de contraction pour leurs effets favorisant la synthèse de collagène, les structures musculaires sont spécifiquement sensibles au mode excentrique. Chez le sujet humain, Crameri et al. (2004) ont observé une série de contractions excentriques d’intensité maximale augmente la synthèse de collagène au sein de l’ensemble des tissus de l’unité myotendineuse. Ces résultats montrent que les effets de ce travail ne se limitent pas aux tissus tendineux, tels que certains protocoles thérapeutiques le suggéraient, et que le tissu musculaire doit désormais être associé à la discussion des effets de ce travail musculaire. Dans ce contexte, la deuxième question que nous avons posée est de savoir si l’étirement de l’unité myotendineuse préalablement activée, telle que se caractérise une contraction excentrique, modifie le rapport de compliance des tissus myotendineux par rapport aux méthodes classiques. Autrement dit, si l’étirement de l’unité myotendineuse activée favorise spécifiquement l’allongement de l’un des tissus de l’unité myotendineuse.

Dans une troisième partie, il nous a paru intéressant d'étudier le comportement à l’étirement de l’unité myotendineuse, dont la compliance était modifiée suite à une désadaptation à long terme. L’hypertonie spastique, qui caractérise une majorité de sujets parétiques spastiques, est généralement caractérisée par une augmentation anormale des résistances opposées à l'étirement passif (Carey et Burghart, 1993). L’origine de ces résistances peut être attribuée à des adaptations tant neurophysiologiques (Pierrot-Deseilligny et Mazières, 1985) que mécaniques et structurelles des tissus de l'unité myotendineuse (Berger et al. 1984 ;Tardieu et al. 1989). Il n’existe pourtant pas encore dans la littérature de consensus les définissant clairement (Fridén et Lieber, 2003). En outre, l’étude récente de Lieber et Fridén (2002) a mis en évidence des modifications de l’architecture des muscles fléchisseurs du carpe. Contrairement à ce qui est généralement proposé au sujet de la longueur des fascicules spastiques (Tardieu et al. 1982), Lieber et Fridén (2002) n’ont pas mis en évidence de raccourcissement de ces derniers. Ainsi, l’hypothèse de Tardieu et al. (1982), selon laquelle le raccourcissement des fascicules est à l’origine de l’augmentation des résistances à l’allongement, ne peut plus être soutenue. Il nous paraissait ainsi intéressant d’associer, à l’observation du comportement des fascicules, celui des tissus tendineux, dans le but de déterminer si l’une de ces deux structures présente des caractéristiques particulières, susceptibles d’expliquer le développement plus important de ces résistances à l’allongement. La troisième question que nous avons posée dans ce travail est de savoir comment se caractérise, à l’étirement, le rapport de compliance des tissus musculaire et tendineux dans un contexte de spasticité.

Outre le fait que la réponse à ces différentes questions soit fondamentale pour mieux comprendre et spécifier la pratique des méthodes d’étirement, l’objectif de notre travail est non seulement de mettre en évidence le tissu dont l’allongement est spécifiquement favorisé par l’une ou l’autre méthode, mais également de contribuer à différencier celui qui limite l’étirement global du système myotendineux. Dans ce contexte, il sera intéressant de pouvoir recommander la pratique d’une méthode particulière, en fonction des besoins spécifiques de chacun.

Doctorat en Sciences de la motricité
info:eu-repo/semantics/nonPublished

Tendinopathies are painful tendon conditions of presumably multifactorial genesis. In tendinosis, as in Achilles tendinosis, there is apart from pain also morphological changes which are described as degenerative with no signs of inflammation. The exact mechanisms behind these conditions are still, to a large extent, unknown. Pain, being the foremost impairing symptom, leads us to the hypothesis that nerves are deeply involved in the symptoms and processes of Achilles tendinosis. Locally produced nerve signal substances may also be involved in the processes. Knowledge of the innervation patterns within the tendon and knowledge on a possible local nerve signal substance production are therefore of utmost importance. There is a lack of information on these aspects. The specific aims of this thesis were 1) to investigate the innervation patterns regarding general, sensory, cholinergic and sympathetic innervations, and 2) to examine for the possible occurrence of a production of nerve signal substances and a presence of receptors related to these in the tendon cells, the tenocytes. Painfree normal and tendinosis Achilles tendons were examined. Immunohistochemistry, using antibodies against the general nerve marker PGP9.5, the synthesizing enzymes for acetylcholine (choline acetyltransferase; ChAT), and catecholamines (tyrosine hydroxylase; TH), the vesicular acetylcholine transporter (VAChT), neuropeptide Y (NPY), substance P and calcitonin gene-related peptide, was applied. Immunohistochemistry was also used for the delineation of muscarinic (M2R), adrenergic (α1-AR) and NPY-ergic (Y1 and Y2) receptors. To detect mRNA for TH and ChAT, in situ hybridization was used. In normal Achilles tendons, as well as in the tendinosis tendons, there was a very scanty innervation within the tendon tissue proper, the main general, sensory and sympathetic innervations being found in the paratendinous loose connective tissue. Interestingly, the tenocytes showed immunoreactions for ChAT, VAChT, TH, M2R, α1-AR and Y1R. The reactions were clearly more observable in tendons of tendinosis patients than in those of controls. The tenocytes of tendinosis patients also displayed mRNA reactions for ChAT and TH. Nevertheless, all tenocytes in the tendinosis specimens did not show these reactions. Immunoreactions for α1-AR, M2R and Y1R were also seen for blood vessel walls. The present thesis shows that there is a very limited innervation within tendon tissue proper, whilst there is a substantial innervation in the paratendinous loose connective tissue. It also gives evidence for an occurrence of production of catecholamines and acetylcholine in tenocytes, especially for tendinosis tendons. Furthermore, that ACh, catecholamines and NPY can have effects on these, as well as on blood vessels, via the receptors observed. The observations suggest that Achilles tendon tissue, whilst containing a very scarce innervation, exhibits autocrine/paracrine cholinergic/catecholaminergic/NPY-ergic effects that are upregulated in tendinosis. These findings are of great importance as the results of such effects may mimic processes that are known to occur in tendinosis. That includes effects related to proliferation and angiogenesis, and blood vessel and collagen regulating effects. In conclusion, within the Achilles tendon there is a very scarce innervation, whilst there appears to be a marked local production of nerve signal substances in Achilles tendinosis, namely in the tenocytes, the cells also harbouring receptors for these substances. The observations give a new insight into how the tendon tissue of the Achilles tendon is influenced by signal substances and may give options for new treatments of Achilles tendinosis.

Les lesions du tendon flechisseur superficiel du doigt (fsd) constituent l'une des dominantes de la pathologie locomotrice chez le cheval. Ces lesions affectent surtout la region metacarpienne du tendon ; elles sont difficiles a traiter et leurs recidives sont frequentes. Notre etude a consiste, dans un premier temps, a evaluer les variations locales (segmentaires) des proprietes mecaniques sur 10 tendons fsd sains. Les valeurs ainsi obtenues (valeurs de reference) ont ete ensuite confrontees a celles obtenues sur 8 tendons fsd pathologiques, porteurs de lesions spontanees documentees histologiquement. L'objectif etait de preciser les consequences mecaniques de ces lesions tendineuses afin d'ameliorer l'evaluation de leur pronostic. Les 18 tendons, sains et pathologiques, ont ete soumis a des tests en traction jusqu'a rupture (1 mm. S#-#1). Le long de chaque tendon, 8 aiguilles munies de marqueurs ont ete implantees de facon a delimiter 7 segments dont l'aire de section a ete determinee par echographie. Chaque test a ete filme et la mesure des allongements segmentaires a ete effectuee a partir des enregistrements video digitalises. Pour chaque image, la force correspondante a ete enregistree. A partir de ces donnees, la longueur initiale de chaque segment, sa deformation et sa contrainte ont ete determinees. Le polynome du 3eme degre qui s'ajuste le mieux a la courbe contrainte-deformation ainsi obtenue a ete calcule par approximation des moindres carres. Le module d'elasticite (emax) a ete evalue comme le maximum de la derivee de ce polynome. Il s'est avere que si les proprietes mecaniques intrinseques d'un tendon fsd sain sont relativement homogenes sur toute la longueur de celui-ci, dans un tendon lese, les sites qui sont les plus fragiles sont les segments immediatement adjacents a la lesion ; or, ce sont aussi les sites les plus frequents de rupture experimentale et ceux au niveau desquels surviennent generalement les recidives, en clinique

Un des problèmes majeurs contribuant à la réduction de la mobilité chez la personne âgée est la hausse de l’occurrence des chutes. La capacité à maintenir l’équilibre ou la stabilité posturale a été précédemment associée à la structure et aux propriétés mécaniques des tendons du membre inférieur. Cette étude fut menée afin d’évaluer les effets de l’intensité d’entrainement et de l’âge sur les changements de l’architecture tendineuse et ses propriétés mécaniques ainsi que sur les adaptations musculaires du membre inférieur. Ce projet avait ainsi pour objectif de comparer les effets de deux conditions d’entrainement pour un volume équivalent (intensité modérée (55% d’une répétition maximale (1RM) vs élevée (80% de 1RM)) sur deux groupes musculaires différents (quadriceps vs triceps sural), sur les adaptations des tendons d’Achille et patellaire associés aux adaptations de ces groupes musculaires respectifs. Enfin, le dernier objectif de cette étude était de montrer si des changements de la balance posturale et de la capacité de mouvement pouvaient s’expliquer par les évolutions de l’architecturale et de propriétés mécaniques des structures musculaires et tendineuses avec l’âge. Dix hommes jeunes (Age : 24.8 ± 3.6) et 27 séniors (Age : 69.9 ± 4.5) sédentaires ont été recrutés et ont participé à un programme d’entrainement en résistance de 12 semaines (3 fois/semaine) sur les muscles du triceps sural et du quadriceps. Le groupe de jeunes (n=10) ainsi qu’un groupe de séniors (n=13) ont participé à un programme d’entrainement modéré correspondant à 55% de 1RM, tandis qu’un deuxième groupe de seniors s’est vu imposer une intensité d’entrainement de 80% de 1RM (n=14). Chaque groupe a reçu exactement le même volume d'entraînement sur les muscles quadriceps et triceps sural en utilisant des machines de musculation guidées : la presse à jambes, l'extension des jambes et la machine à mollets assis. Afin de pouvoir obtenir les paramètres nécessaires à cette étude, l’utilisation d’ergomètres, d’images échographiques et IRM et d’un système de capture de mouvement ont été nécessaires. En comparant deux populations de jeunes et de séniors, cette étude a ainsi permis de quantifier une diminution de la force, couplée ou non suivant le tendon considéré à une diminution des propriétés intrinsèques du matériau tendineux. L’obtention de l’architecture musculaire a permis de construire les courbes d’évolutions de la section de chacun des muscles du quadriceps et du triceps sural pour les populations jeunes et séniors. Les deux conditions d’entrainement nous ont permis de mettre en évidence une amélioration des propriétés mécaniques des tendons d’Achille et patellaire, et plus sensiblement le tendon d’Achille, sur les deux populations jeunes et séniors sans toutefois observer de gain supplémentaire pour une intensité élevée. Des gains similaires suite à la période d’entrainement ont pu être observés chez les séniors sur les volumes des muscles du triceps sural et du quadriceps sans distinction de l’intensité considérée. L’analyse du mouvement nous a permis de mettre en évidence l’amélioration de la stabilité posturale et une évolution de la stratégie de flexion du tronc lors d’un lever de chaise suite à l’entrainement chez les séniors sans bénéfice supplémentaire entre une intensité modérée et élevée. De plus, les effets de l’âge sur les propriétés mécaniques des tendons ont pu être corrélés avec les performances liées aux exercices de stabilité posturale, de saut et de lever de chaise. Ce travail a donc permis de quantifier les effets de l’âge sur les capacités musculaires, tendineuses et de mouvement. Cette étude nous a également permis de mettre en évidence un seuil d’intensité d’entrainement (55% de 1RM) à partir duquel les personnes âgées ne semblent pas montrer de gain additionnel pour les systèmes musculaires et tendineux. Ce travail permet donc de proposer une optimisation de l’activité physique prescrite à la personne âgée ou vieillissante
The ability to maintain balance has previously been associated with the structure and mechanical properties of the tendons of the lower limb. In order to evaluate the effects of training intensity (moderate vs. high intensity) and age on changes in tendon architecture (Achilles and patellar) and its mechanical properties, 10 young men and 27 sedentary seniors participated in a 12-week resistance training program (3 times/week) on the muscles of the triceps surae (TS) an quadriceps (QF). The young group and a senior group participated in a moderate training program corresponding to 55% of IRM (maximum repetition), while a second group of seniors received a training intensity of 80% of IRM. Each group received the same volume of training on the TS and QF muscles using guided weight machines. The use of ergometers, ultrasound and MRI images and a motion capture system were required. A decrease in strength, coupled or not depending on the tendon under consideration, and a decrease in the properties of the tendon material have been quantified with age. Evolution curves of each of the QF and TS muscles for both populations were constructed. The two training conditions showed an improvement in the mechanical properties of the Achilles and patellar tendons, and more significantly the Achilles, on both populations without any additional gain for a high intensity. Similar gains after training between the two intensities could be observed in seniors on muscle volumes. The improvement of postural stability and an evolution of the strategy during a chair lift were observed in seniors without any additional benefit between the two training intensities. This made it possible to quantify the effects of age on muscle, tendon and movement abilities by highlighting a threshold of training intensity (55% of IRM) from which seniors do not seem to show any additional gain. This work therefore makes it possible to propose an optimization of the physical activity prescribed to the elderly person

Les tendons sont une forme unique de tissu conjonctif au sein du système musculosquelettique. Le développement, l’homéostasie et la réparation du tendon reposent sur des combinaisons de paramètres moléculaires et aussi mécaniques, régulant la production et l’assemblage des fibres de collagène. Notre objectif est de comprendre quelles sont les voies de mécanotransduction impliquées dans la différentiation tendineuse, via deux (co-)facteurs de transcription : EGR1 et YAP. Nous avons montré que l’expression du gène de tendon SCX, de EGR1 et l'activité de YAP sont réduites dans les tendons de membres de fœtus de poulet immobilisés. De plus, la reprise des contractions musculaires entraîne une reprise de l’expression des gènes de tendon comparable à celle des fœtus jamais immobilisés. La mécanobiologie du tendon a été étudiée avec des constructions cellulaires en 3-dimensions (3D) en gel de fibrine ou de collagène, faits de cellules souches mésenchymateuses. La perte de tension de ces constructions a induit une chute de l’expression de Egr1, des gènes de tendon et de l’activité de YAP. Une surexpression de Egr1 dans les constructions 3D en gel de fibrine sans tension a empêché la chute d’expression des gènes de tendon. L’activité de YAP et l’expression de Scx ont augmenté en étirant les constructions en gel de collagène. L’inactivation de l’activité de YAP par traitement à la verteporfin (VTPF) a induit une diminution de l’expression des gènes de tendon, qui n’a pas été restaurée lorsque ces constructions traitées ont été étirées. Ensemble, ces résultats montrent l’importance de YAP et EGR1 en aval des signaux mécaniques pour réguler la différentiation des cellules du tendon
Tendons are unique forms of connective tissue of the musculoskeletal system. Tendon development, homeostasis and repair rely on specific combinations of mechanical and molecular factors regulating the production and assembly of collagen fibers. Our objective is to decipher the mechanotransduction pathways underlying tendon cell differentiation, through the activity of two transcription (co-)factors, EGR1 and YAP. We showed that the expression of the tendon gene SCX, the mechanosensitive gene EGR1 and YAP activity were downregulated in limb tendons of immobilized chicken fetuses. Restored muscle contraction after immobilization led to a recovery of tendon gene expression. Tendon mechanobiology was studied in vitro in fibrin- or collagen-based 3-dimensional (3D) constructs made of mesenchymal stem cells and mimicking tendon formation. Tension release in fibrin and collagen 3D-constructs induced a drop of the expression of Egr1, tendon genes and YAP activity. Overexpression of Egr1 was able to prevent the downregulation of tendon gene expression in de-tensioned fibrin 3D-constructs. YAP activity was upregulated in dynamically stretched collagen 3D-constructs and was paired with the expression of the tendon gene Scx. Chemical knock-down of YAP activity with Verteporfin (VTPF) treatment showed a decrease in the expression of YAP target genes and the tendon genes. Besides, dynamic stretch applied on VTPF-treated constructs did not restore tendon gene expression, conforting the role of YAP as an intracellular relay of mechanical cues in tendon cells. Altogether, these results highlight the importance of EGR1 and YAP downstream of mechanical forces during tendon cell differentiation

L'interfaccia tendine-osso, definita entesi, presenta una complessa organizzazione strutturale e una composizione multi-scalare mantenuta da un contesto cellulare eterogeneo, cosicchè per i chirurghi ortopedici il trattamento del distacco del tendine o dello strappo dall'inserimento osseo rimane tuttora una sfida. La comprensione limitata della biologia dell'entesi ha finora ostacolato lo sviluppo di nuove opzioni di trattamento per migliorarne la rigenerazione. Imitare la struttura e la composizione dei tessuti naturali rappresenta ancora un grande ostacolo da superare, seppur in presenza di progressi costanti. In questo elaborato, si valutano criticamente le attuali strategie di ingegneria dei tessuti dell'interfaccia tendine-osso attraverso l'uso di segnali biologici, biochimici o biofisici, che alla fine devono essere combinati in sofisticati sistemi di gradiente. Vengono descritte le specifiche cellulari, gli ambienti colturali e l'impiego di fattori di crescita. Si considerano inoltre aspetti legati alla progettazione di biomateriali appropriati per sostenere i carichi meccanici rilevanti.

Para avaliar a eficácia do laser de arsenito de gálio em acelerar a cicatrização tendínea em cavalos PSI de corrida com lesão no tendão flexor digital superficial, foram realizados dois experimentos, primeiro (E1) com 14 casos clínicos onde as lesões foram decorrentes do esporte em um dos membros torácicos, o segundo (E2) com cinco casos experimentais, onde as lesões foram induzidas com colagenase em ambos os membros torácicos. No E1, após a detecção da lesão no tendão flexor digital superficial por exame ultra-sonográfico, todos os animais receberam antiinflamatório não esteróide associado à dimetilsulfóxido por via intravascular, crioterapia no local da lesão, e caminharam ao passo duas vezes ao dia por 15 minutos durante os 30 dias de acompanhamento. Os membros tratados pertenceram a onze animais que receberam uma sessão diária de laser de arsenito de gálio na dose de 20 J/cm2, realizadas durante 10 dias consecutivos, após término do antiinflamatório e da crioterapia. Os membros controle pertenceram a três animais, os quais não foram tratados com laser. No E2, após identificação das lesões, foram escolhidos aleatoriamente um membro torácico controle e outro a ser tratado por laser em cada animal. Da mesma forma, estes animais foram mantidos a passo e receberam o mesmo protocolo de laserterapia que os membros tratados do E1. Todos os membros foram avaliados através de exames ultra-sonográficos, utilizando-se como parâmetros o paralelismo das fibras tendíneas em corte longitudinal; a ecogenicidade, a área do tendão, a área da lesão e a porcentagem de ocupação da lesão em corte transversal. No E1, os membros controle não apresentaram diferença significativa (P>0,05) nos parâmetros avaliados entre os dias 0 e 30. Nos membros tratados, a área do tendão também não apresentou diferença significativa (P>0,05) entre os dias analisados, porém houve diminuição muito significativa nos escores de ecogenicidade e paralelismo (P<0,001), assim como diminuição no tamanho da lesão (P<0,05) e na porcentagem de ocupação da lesão (P<0,05). No E2 também não houve diferença significativa entre os dias em todos os critérios avaliados nos membros controles (P>0,05). Nos membros tratados a ecogenicidade, o paralelismo e o tamanho do tendão, não sofreram alterações significativas (P>0,05) entre os dias avaliados, porém o tamanho da lesão (P<0,05) e a porcentagem de ocupação da lesão (P<0,01) apresentaram diminuição significativa. O laser de arsenito de gálio na dose de 20 J/cm2 mostrou-se eficaz em acelerar a reparação da lesão tendínea nos membros tratados em relação aos membros controle, tanto no grupo de casos clínicos quanto no grupo experimental, quando comparados aos 30 dias do aparecimento da lesão. Esses resultados sugerem a participação positiva do laser de arsenito de gálio nos resultados e a validação do mesmo no tratamento da tendinite do flexor digital superficial de cavalos Puro Sangue Inglês de corrida.
This study conducted two trials to evaluate the efficacy of Gallium Arsenide Laser in the speed of the healing process of superficial digital flexor tendon (SDFT) lesions in thoroughbred horses. One trial group (T1) comprises 14 horses with lesions, which resulted from the sport, in the SDFT in one of the front limbs. The other trial group (T2) was formed by five horses that had lesions induced in both front limbs by collagenase injection. In the T1, after the detection of the lesion in the SDFT by ultrasonography all horses were treated by intravenous injection, once a day, over five days, with an association of two AINS: phenylbutazone and dimethylsulfoxide. Cryotherapy was also applied on the affected tendon (three times a day over five days) and the horses were kept in stalls and allowed controlled exercise (hand-walked twice daily for 15 minutes) during the 30 days of the study. The treated limbs belong to 11 horses that received laser sessions once a day for ten days at a dosage of 20J/cm2. These sessions started after the AINS association and cryotherapy. The control limbs belong to the other three horses that received the same treatment, except by the laser sessions. In the T2, after the detection of the lesion, a limb from each horse was randomly chosen to be the control limb and the other limb was treated by laser. These horses were also kept in stall under controlled exercise and the treated limb was under the same laser protocol that T1. All horses were evaluated by two ultrasonographic exams with a 30-day interval. The parameters evaluated were: the fiber alignment, the echogenicity, the tendon area, the lesion area and the proportion of the cross sectional area involved. In the T1, the control limbs showed no significant difference (p>0,05) in the echogenicity, the fiber alignment, the tendon area, the lesion area or the proportion of the cross sectional area involved, between the day 0 and 30. The treated limb, didn´t show any significant difference of the tendon area, but showed a significant difference on the echogenicity (P<0,001), the fiber alignment (P<0,001), the lesion area (P<0,05) and the proportion of the cross sectional area involved (P<0,05). In the T2, only one limb received the laser treatment, the other limb acted as a control. The control limbs showed no significant difference (P>0,05) in the echogenicity, the fiber alignment, the tendon area, the lesion area and the proportion of the cross sectional area involved between the day 0 and 30. The treated limbs showed no significant difference (P>0,05) in the echogenicity, the fiber alignment and the tendon area, but showed significant difference in the lesion area (P<0,05) and the proportion of the cross sectional area involved (P<0,01). The treatment dose of 20J/cm2 of gallium arsenide laser was efficient in speeding the healing process of SDFT lesions of the laser treated limbs in both groups (T1 and T2), when compared with the control limbs, at 30 days of the onset of the lesion. The group which lesions occurred due to the sport (T1) had a better response to the treatment than the group which lesions were induced by collagenasis (T2). The limbs treated by laser showed a positive response which validates the use of the Gallium Arsenide laser for the treatment of tendinitis in the Superficial Digital Flexor in race horses.

Les tendinopathies sont fréquentes et entraînent une diminution de la qualité de la vie à long terme. Les connaissances des événements physiopathologiques suivant un traumatisme tendineux sont toutefois parcimonieuses. Conséquemment, peu ou pas de stratégies thérapeutiques permettent d’en accélérer le processus de réparation. Le but de cette thèse était donc d’explorer les mécanismes cellulaires et le rôle de différents régulateurs potentiels de la réaction inflammatoire dans la réparation des tendons. Dans un premier temps, nous avons mis au point un modèle de blessure tendineuse aiguë consistant en l’injection de collagénase dans le tendon d’Achille de rats. Nous avons observé, par marquages immunohistochimiques, que les neutrophiles étaient les premières cellules à infiltrer le site de la lésion, suivis des macrophages. Nous avons également remarqué, dans un second projet que l’injection de collagénase, une métalloprotéinase, dans le tendon, induisait une altération des propriétés mécaniques des tendons de rats, et que l’administration d’un anti-inflammatoire non stéroïdien n’affectait pas significativement cette perte fonctionnelle, probablement en raison d’un effet anti-inflammatoire localisé en périphérie des faisceaux tendineux. En utilisant le même modèle expérimental, nous avons ensuite étudié le rôle d’un médiateur central de la physiopathologie tendineuse : p53. L’inhibition pharmacologique de la transactivation des gènes cibles de p53, par une molécule appelée pifithrin-α, a diminué l’accumulation des cellules inflammatoires dans le tendon blessé. Cet effet anti-inflammatoire n’était pas associé à une diminution de la perte fonctionnelle en phase aiguë, mais retardait la guérison de la blessure tendineuse. Puisque les stratégies anti-inflammatoires ne diminuent pas le déficit fonctionnel en phase inflammatoire, nous avons finalement testé le dogme voulant que les cellules inflammatoires pouvaient causer des dommages non spécifiques à la matrice des tendons. L’injection intra tendineuse de carraghénine a induit une accumulation massive de cellules inflammatoires. Cependant, cette réaction n’était pas associée à une altération des propriétés biomécaniques ni à une diminution du contenu en collagène des tendons. En conclusion, nos résultats ont permis d’accroître les connaissances de la séquence physiopathologique suivant un traumatisme tendineux et jettent un doute sur les effets délétères de l’inflammation suivant un traumatisme aigu.
Tendinopathies show a high prevalence and can alter the quality of life for many years. Nevertheless, the pathophysiology of tendinopathies is not well characterized and it may explain the lack of effective treatments to accelerate tendon healing. This thesis was therefore dedicated to the study the role of potential regulators of the pathophysiological sequence following tendon trauma. In a first project we set up an experimental model of acute tendon injury where collagenase was injected into the Achilles tendon of rats. This procedure induces a classical sequence of accumulation of leukocytes where neutrophils accumulate massively 24 hours following the injection of collagenase, followed by macrophages on day 3. We also showed, in a second project, that injection of collagenase reduces the load to failure by more than 50% 3 days post trauma. Moreover, administration of diclofenac, a non-steroidal anti-inflammatory drug, did not rescue tendons from that loss of mechanical strength, presumably because the anti-inflammatory effect was located in the paratenon and not in the core of the tendon where the load-resisting collagen bundles are located. In a third project we studied the role of p53, a putative regulator of the inflammatory process and extracellular matrix homeostasis, on the pathophysiological sequence following an acute tendon trauma. Transactivation inhibition of p53 reduced the accumulation of neutrophils and macrophages in the entire tendon. This anti-inflammatory effect was not associated to a rescue of the mechanical properties and even delayed the onset of healing. In view of the evidence that anti-inflammatory strategies failed to rescue tendons from functional loss, we challenged the dogma that the inflammatory process could induce non-specific damages to the tendon extracellular matrix. Intra-tendinous injection of carrageenan induced a massive accumulation of inflammatory cells. However this was neither associated to a reduction of tendons’ collagen content nor to a reduction of the load to failure. In conclusion, we identified new mediators and mechanisms of the pathophysiology of tendons. Our results challenge the concept that inflammatory cells strictly play deleterious effects following tendon trauma.

Nitric oxide is a small free radical generated by family of enzymes, the nitric oxide synthases. In a series of experiments performed over the last 15 years we showed that nitric oxide is induced by all three isoforms of nitric oxide synthase during tendon healing and that it plays a crucial beneficial role in restoring tendon function. In normal tendon we found very little nitric oxide synthase activity while in injured rat and human tendons nitric oxide synthase activity was expressed in healing fibroblasts in a temporal fashion. In healing rat Achilles tendon fibroblasts the first isoform to be expressed was endothelial nitric oxide synthase (eNOS), followed by inducible nitric oxide synthase (iNOS), and then brain or neuronal nitric oxide synthase (bNOS). Systemic inhibition of nitric oxide synthase activity decreased the cross sectional area and mechanical properties of the healing rodent Achilles tendons. Addition of nitric oxide via NO-flurbiprofen or NO-paracetamol enhanced rat Achilles tendon healing. Addition of nitric oxide to cultured human tendon cells via chemical means and via adenoviral transfection enhanced collagen synthesis, suggesting that one mechanism for the beneficial of nitric oxide on tendon healing might be via matrix synthesis. The final part of the work involved three randomized, double-blind clinical trials which evaluated the efficacy of nitric oxide donation via a patch in the management of the tendinopathy. In all three clinical trials there was a significant positive beneficial effect of nitric oxide donation to the clinical symptoms and function of patients with Achilles tendinopathy, tennis elbow and Achilles tendonitis.

Ad oggi, non esistono tecniche standard in grado di rigenerare e sostituire efficacemente il tessuto tendineo e legamentoso. Tra le varie tecniche proposte per la produzione di scaffolds, l’elettrofilatura è sicuramente la più promettente. Lo scopo di questo lavoro di tesi è stato quello di caratterizzare le prestazioni meccaniche cicliche di scaffold elettrofilati bioriassorbibili e la loro interazione con fibroblasti umani se coltivati in condizioni statiche o dinamiche. I test meccanici hanno riportato caratteristiche meccaniche simili a tendini e legamenti. L’analisi morfologica ha confermato una disposizione fisiologica dei fibroblasti coltivati sugli scaffolds. I campioni proposti in questo studio risultano perciò promettenti per futuri test in vivo di rigenerazione del tessuto tendineo e legamentoso. Efficient strategies to replace and regenerate tendons and ligaments are still not effective. Among the different techniques proposed in literature, electrospinning is the most promising one for scaffolds productions, due to its ability to produce fibers with nanometric diameters. For this reason, electrospinning allows to mimic the extracellular matrix and hierarchical structure of tendinous and ligamentous tissue. The aim of this study was to provide a cyclic mechanical characterization of electrospun bioresorbable scaffolds, and to determine their influence over human fibroblasts morphology, when cultured in dynamic ad static conditions. The mechanical characterization has demonstrated that scaffolds had a mechanical behavior similar to tendons and ligaments one. The morphological investigation showed that fibroblasts seeded on the scaffolds had a similar morphology to the one of the fibroblasts grown on real tendons/ligaments. The specimens proposed in this study showed promising properties for future in-vivo tests for tendons/ligaments regeneration.

Název diplomové práce ?Vývojové tendence současné rodiny? napovídá, že se studie zabývá charakteristikou rodiny v současnosti. Úvodem definuje pojem ?rodina?, vymezuje její smysl a sleduje soubor činností a opatření státu, která směřují k podpoře rodinných funkcí. Analyzuje vliv rodinné politiky na úroveň plodnosti a porodnosti. V rámci tématu manželství pojednává o volbě životního partnera, dochází k zamyšlení se nad motivy, které vedou pár k rozhodnutí vstoupit do vztahu manželského. Prostřednictvím časových řad a využitím komparativní metody analyzuje sňatečnost v České republice. Hodnotí proměny rodinného života. Sleduje nesezdaná soužití a pojednává o okolnostech, jež byly důvodem pro rozhodnutí páru žít společně, aniž by uzavřeli sňatek. Dále se práce zabývá diferenciací rolí v rodině (tzn. k jakým změnám vnitřní struktury rodiny dochází). Závěrečná kapitola je věnována analýze rozpadu rodiny a jeho vlivu na vývoj jednotlivce.

L’ingegneria dei tessuti biologici è una branca di ricerca applicata in via di sviluppo, definita dallo Scientific Committee on Medicinal Products and Medical Devices della Commissione Europea come la realizzazione di sostituti dei tessuti biologici mediante impiego di cellule seminate a bordo di strutture di supporto e fatte maturare in apparati di coltura specializzati. La progettazione di questi costrutti avviene dunque attraverso l’utilizzo di tre importanti componenti: cellule, scaffolds e bioreattori. Lo scopo di questo lavoro di tesi è di presentare i recenti progressi dell’ingegneria nell’ambito della rigenerazione del tessuto tendineo. Viene descritta quindi la struttura e la funzione dei tendini, per poi analizzare le principali cause di lesione e le principali terapie attualmente disponibili. Viene quindi considerata l'opzione offerta dall’ingegneria tessutale. Per questo si analizza in dettaglio uno studio effettuato da Rinoldi C. e riguardante la fabbricazione di uno scaffold 3D multistrato che è stato quindi sottoposto a stimolazione meccanica e biochimica per l'induzione del fenotipo desiderato. L’effetto sinergico della stimolazione meccanica e biochimica, viene osservato in termini di incremento di proliferazione, vitalità e allineamento cellulare, e del differenziamento tenogenico. I risultati ottenuti suggeriscono che le strategie proposte hanno margine per un impiego clinico dei sostituti ingegnerizzati del tessuto tendineo

Tendon disorders are hugely burdensome to individuals, costly on a societal level, and are being compounded by the increasingly ageing population. These chronic and often disabling conditions are poorly understood and lacking in an effective long-term treatment. Recently, attempts to elucidate the underlying mechanisms of tendon diseases in order to improve their prognosis have arrived at a key hypothesis: it is posited that the various tendons found throughout the body have unique properties, unique responses to disease-causing stimuli, and in turn therefore, different responses to the therapies being applied. It is possible this is why individual therapies are simultaneously effective in specific patient groups, and disappointingly ineffective in others. The theme of distinct tendon phenotypes is central to this thesis. This body of work explores the hypothesis that functionally distinct tendons respond differently to changes in their loading environment, first by assessing properties developed in vivo in response to a surgically-induced injury of an equine tendon, and then the properties of ovine tendons developed in response to their distinct in vivo functions. It continues by then developing and applying in vitro loading environments, where more precisely controlled loading is used to understand how tendons with highly energy-storing functions may differ from simply positional tendons, at rest and under various loading conditions. The scope of the results span multiple levels, from cells and tissues, to the functional mechanical properties of multiple tendons and disease phenotypes, in order to better understand how these influence each other. This broad approach helps to try and unify work which has previously been isolated by discipline, and more accurately contextualise previous and future work to better understand tendon phenotypes. The key findings of this thesis are: A focal tendon injury in the horse's energy-storing superficial digital exor tendon disrupted healthy relationships (e.g. biomechanics-glycosaminoglycans), and caused widespread increases in chondroitin/dermatan sulfate glycosaminoglycan levels, which were partially responsible for the concomitant reductions in modulus and ultimate tensile strength. A subsequent study of three functionally distinct ovine tendon types showed higher biomechanical properties of the medial branch of the common digital extensor tendon, a positional tendon, when compared to its energy-storing counterparts, and distinct responses to stress-deprivation, with regards to loss of glycosaminoglycans and biomechanical properties. The underpinning gene expression and immunohistochemistry results suggest that despite broad similarities between the tendon types, differences also exist at baseline and in response to stress-deprivation. When cyclic loading ± compression loading were applied identically to those functionally distinct ovine tendons for 10 days, there was a convergence between the tendons in terms of gene expression and histological appearances, but not biochemical properties. Together, these results show there are differences between tendon types in baseline phenotype and mechanical properties and their response to perturbations in normal loading environments. By improving our understanding of the heterogeneity of tendons found throughout the body and their unique responses, this thesis takes a step along the pathway towards more targeted treatment and improved outcomes for tendon disorders.

Le mouvement Nouvelle tendance (NT) est un groupe international d’artistes formé pendantles années soixante (1961 - 1973) autour d’un programme d’expositions de la Galerie d’ArtContemporain (Galerija suvremene umjetnosti) de Zagreb. Au cours de son existence, lemouvement NT a rassemblé presque deux cents artistes et plusieurs groupes tels que GRAV,T, N, Zero, Equipo 57, Dvizhenije, MID etc. La première étape de ce mouvement jusqu’en 1968est caractérisée par l’abstraction géometrique et l’art lumino-cinétique tandis que dans laseconde partie (1968 -1973), Nouvelle tendance ouvre le chapitre de l’art numérique
New Tendancy movement (NT) is an international group of artists united in the sixties(1961 - 1973) around the exhibition programme at the Gallery of Contemporary Art (Galerijasuvremene umjetnosti) in Zagreb. During its existence, the movement gathered around twohundred artists and differents groups such as GRAV, T, N, Zero, Equipo 57, Dvizhenije, MID etc.The first phase of the movement that lasted until 1968 was characterized by the geometricabstraction and lumino-kinetic art. During the second phase, New Tendancy opened thechapter of numerical arts

La tesi si articola in tre capitoli. Il primo dà conto del dibattito sorto attorno alla problematica dell’inquadramento della previdenza complementare nel sistema costituzionale dell’art. 38 Cost. che ha diviso la dottrina tra quanti hanno voluto ricondurre tale fenomeno al principio di libertà della previdenza privata di cui all’ art. 38, comma 5, Cost. e quanti lo hanno invece collocato al 2° comma della stessa norma, sulla base di una ritenuta identità di funzioni tra previdenza pubblica e previdenza complementare. Tale ultima ricostruzione in particolare dopo la c.d. Riforma “Amato” è culminata nella giurisprudenza della Corte Costituzionale, che ha avuto modo di pronunciarsi sulla questione con una serie di pronunce sulla vicenda del c.d. “contributo sul contributo” e su quella della subordinazione dei requisiti di accesso alle prestazioni pensionistiche complementari alla maturazione dei requisiti previsti dal sistema obbligatorio. Il capitolo successivo si occupa della verifica della attualità e della coerenza dell’impostazione della Corte Costituzionale alla luce dell’evoluzione della disciplina dei fondi pensione. Nel terzo capitolo, infine, vengono affrontate alcune questioni aperte in relazione ai c.d. fondi pensione “preesistenti” suscettibili di sollevare preoccupazioni circa la necessità di garantire le aspettative e i diritti dei soggetti iscritti.
The dissertation consists of three chapters. The first one gives account of the debate about the problems of the arrangement of complementary social security in the constitutional system of the article 38 of the Constitution, which has divided the scholarship between those who want to trace the phenomenon back to the principle of the liberty of private social security in article 38, comma 5, of the Constitution, and on the other hand those who have arranged it at comma 2 of the same article, on the basis of an assumed identity of functions between public and complementary social security. This final reconstruction, above all after the so-called Reform “Amato” has culminated in the jurisprudence of the Supreme Court, which has pronounced itself about the problem with a series of verdicts in regard to the affair of the so-called “contribution of the contribution” e to the one of the subordination of the access criteria for the complementary pension services to the maturity of the provided criteria of the compulsory system. The next chapter regards the verification of the up-to-dateness and consistency of the position of the Supreme Court in the light of the evolution of the subject of pension funds. In the third chapter, ultimately, will be tackled several open questions on the topic of the so-called “pre-existing” pension funds susceptible to rise concerns regarding the necessity to guaranty the expectations and the rights of their members.

La tesi si articola in tre capitoli. Il primo dà conto del dibattito sorto attorno alla problematica dell’inquadramento della previdenza complementare nel sistema costituzionale dell’art. 38 Cost. che ha diviso la dottrina tra quanti hanno voluto ricondurre tale fenomeno al principio di libertà della previdenza privata di cui all’ art. 38, comma 5, Cost. e quanti lo hanno invece collocato al 2° comma della stessa norma, sulla base di una ritenuta identità di funzioni tra previdenza pubblica e previdenza complementare. Tale ultima ricostruzione in particolare dopo la c.d. Riforma “Amato” è culminata nella giurisprudenza della Corte Costituzionale, che ha avuto modo di pronunciarsi sulla questione con una serie di pronunce sulla vicenda del c.d. “contributo sul contributo” e su quella della subordinazione dei requisiti di accesso alle prestazioni pensionistiche complementari alla maturazione dei requisiti previsti dal sistema obbligatorio. Il capitolo successivo si occupa della verifica della attualità e della coerenza dell’impostazione della Corte Costituzionale alla luce dell’evoluzione della disciplina dei fondi pensione. Nel terzo capitolo, infine, vengono affrontate alcune questioni aperte in relazione ai c.d. fondi pensione “preesistenti” suscettibili di sollevare preoccupazioni circa la necessità di garantire le aspettative e i diritti dei soggetti iscritti.
The dissertation consists of three chapters. The first one gives account of the debate about the problems of the arrangement of complementary social security in the constitutional system of the article 38 of the Constitution, which has divided the scholarship between those who want to trace the phenomenon back to the principle of the liberty of private social security in article 38, comma 5, of the Constitution, and on the other hand those who have arranged it at comma 2 of the same article, on the basis of an assumed identity of functions between public and complementary social security. This final reconstruction, above all after the so-called Reform “Amato” has culminated in the jurisprudence of the Supreme Court, which has pronounced itself about the problem with a series of verdicts in regard to the affair of the so-called “contribution of the contribution” e to the one of the subordination of the access criteria for the complementary pension services to the maturity of the provided criteria of the compulsory system. The next chapter regards the verification of the up-to-dateness and consistency of the position of the Supreme Court in the light of the evolution of the subject of pension funds. In the third chapter, ultimately, will be tackled several open questions on the topic of the so-called “pre-existing” pension funds susceptible to rise concerns regarding the necessity to guaranty the expectations and the rights of their members.

Pierre de Coubertin (1863-1937), father of the modem Olympics believed that sport was about 'making men1', a test of 'arete' or virtue, the ability to make the most of your physical gifts through will, wisdom, courage, self-control, and through moral maturity as evidenced in the notion of fair play. He believed that Olympism was primarily a forum to demonstrate characterological excellence rather than physical and that it offered the opportunity for others to observe the qualities that accompanied greatness in men. The aim of this. thesis is to take up this opportunity, to explore the personal characteristics, more specifically, the personalities, that enable those who achieve this highest mantle of sporting excellence and which differentiate them from the many others identified as having the potential to do so. What has emerged through triangulation of data from several studies of Olympians and potential Olympians, using both quantitative and qualitative methodologies, speaks to both personality structure and processes. Firstly, many elite sportsmen and women seem to have a personality structure operating in the sporting domain that is quite different from that operating in their non-sporting life - that is, they have a sporting personality and a non-sporting, or life personality - different 'contextual selves'. Secondly, that success at the highest level seems crucially dependent upon the dispositional propensity to survive chronic stress and its acute corollaries. Thirdly, that there is more than one dispositional pathway with the power to ameliorate the potentially debilitating affects of these stressors - indeed there are even characteristics that seem to enable stress to become a formative experience. Two quite different stress- adaptive forces identified in this series of studies are hardiness (or openness) in one's approach to the sporting endeavour and mental toughness in the face of pressure or adversity. Both hardiness and mental toughness seem to be related to resilience but each relates differentially to traits such as optimism, commitment and need for control, among others. Mental toughness itself seems to take two forms: for some individuals such stress endurance is driven by a high need for achievement (Type I); for others it is more the result of energy associated with the directed, adaptive, expression of psychological vulnerabilities such as high anxiety (Type II). In some cases such expression may involve conscious or unconscious defense mechanisms to protect the individual from a full awareness of the pressures they are confronting. However, such defenses also seem to constitute an Achilles' heel once at the elite sporting level. In the absence of hard-won resilience, such psychological vulnerabilities seem to increasingly compromise further achievement. Finally, personality in this population seems to be an emergenic, dynamic force. A significant challenge in adapting to stress seems to be sustaining a balance adaptive forces identified in this series of studies are hardiness (or openness) in one's approach to the sporting endeavour and mental toughness in the face of pressure or adversity. Both hardiness and mental toughness seem to be related to resilience but each relates differentially to traits such as optimism, commitment and need for control, among others. Mental toughness itself seems to take two forms: for some individuals such stress endurance is driven by a high need for achievement (Type I); for others it is more the result of energy associated with the directed, adaptive, expression of psychological vulnerabilities such as high anxiety (Type II). In some cases such expression may involve conscious or unconscious defense mechanisms to protect the individual from a full awareness of the pressures they are confronting. However, such defenses also seem to constitute an Achilles' heel once at the elite sporting level. In the absence of hard-won resilience, such psychological vulnerabilities seem to increasingly compromise further achievement. Finally, personality in this population seems to be an emergenic, dynamic force. A significant challenge in adapting to stress seems to be sustaining a balance between the tendency toward growth (or self-actualisation) and the need for recovery (or systemic homeostasis through tension reduction). In seeking to understand the role of the Olympian personality as a complex, dynamic entity, a new framework is presented - one which merges two divergent psychological traditions, trait personology and personcentred personality theories - uniquely drawing together the key structural and process elements of elite sporting personality. Evaluation of this framework is begun. Implications for the practice of psychology in sport are discussed as are the implications for the wider study of human exceptionality. between the tendency toward growth (or self-actualisation) and the need for recovery (or systemic homeostasis through tension reduction). In seeking to understand the role of the Olympian personality as a complex, dynamic entity, a new framework is presented - one which merges two divergent psychological traditions, trait personology and personcentred personality theories - uniquely drawing together the key structural and process elements of elite sporting personality. Evaluation of this framework is begun. Implications for the practice of psychology in sport are discussed as are the implications for the wider study of human exceptionality. 1 Coubertin was referring to 'men' in the literal sense however throughout this dissertation, gender terms will be used interchangeably except where clearly stated. It is the observation of the author after more than a decade working with Olympians, that gender is not a particularly salient psychological characteristic in this sphere. This is also an impression offered by elite sporting coaches such as Richard Charlesworth, an Olympian himself and coach of female Olympian hockey players for nearly a decade (Charlesworth, 2001).

La fonctionnalité de l’appareil locomoteur repose en grande partie sur l’intégrité du tendon, essentiellement composé de fibres de collagènes de types I et III, dont la désorganisation participe à la tendinite de fatigue. Les microtraumatismes subis par les tendons des chevaux athlètes au cours d’entraînements intensifs provoquent, à long terme, une altération des fibres collagéniques. Cette pathologie conduit le plus souvent à l’arrêt prématuré de la carrière sportive du cheval. Cette étude vise à identifier les biomarqueurs précoces de la lésion tendineuse de fatigue chez le cheval. Des expérimentations in vivo tendant à mimer cette affection ont permis de mieux connaître la physiopathologie du tendon et de caractériser des marqueurs moléculaires des stades précoces de la tendinite. Deux modèles d’induction de lésions, chirurgical et «mixte», ont été développés afin se rapprocher du processus physiopathologique spontané. Après induction mécanique chirurgicale de lésions, des biopsies des tendons ont été réalisées et soumises à des mesures de l’expression des gènes et des protéines extra- et intracellulaires, montrant une modification de toutes les molécules étudiées intervenant dans le remodelage de la MEC. Une surexpression des collagènes de types I et III et de la ténascine-C est démontrée dans le tendon lésé, ainsi qu’une désorganisation progressive de la structure du tendon. L’étude sur les facteurs de transcription a révélé que scléraxis semble être un marqueur plus tardif. Ces recherches nous ont permis d’approfondir les connaissances sur la tendinite de fatigue in vivo chez le cheval, tant sur les aspects physiologiques que moléculaires et biochimiques. Elles s'inscrivent dans une démarche de développement d'une sonde moléculaire optique, spécifique d'un marqueur précoce de la tendinite, afin de détecter les lésions de la façon la plus précoce qui soit, avant l'acquisition de lésions irréparables, afin de développer des thérapies qui seront adaptées à l'avenir en clinique vétérinaire, et humaine à postériori. Ainsi, nos recherches ont permis de mettre en évidence de nouveaux marqueurs dans les conditions de tendinite de fatigue
The functionality of the musculoskeletal system is largely based on the integrity of the tendon, mainly composed of types I and III collagens fibrils, whose disorganization takes a great part in the fatigue tendinitis. Microtraumas exerted on the tendons of race horses during intensive training lead to long-term impairments resulting in fatigue tendinitis. This condition often leads to premature termination of the sport career of the horse. The goal of this study was to characterize early biomarkers of the fatigue tendon injury in horse. Experiments were designed to mimic this pathology by inducing fatigue tendinitis in vivo in horse through a surgery technique and the data led to a better knowledge of the pathophysiology of the tendon and to characterize molecular markers of tendinitis at early stages. Two models of induction of lesions, surgical and "mixed", have been developed to closer to the spontaneous pathophysiological process. After surgical induction of mechanical lesions, tendon biopsies were collected and were subjected to evaluation of gene and protein expressions of different extra-and intracellular proteins, showing a modification of the molecules studied involved in ECM remodeling. Overexpression of types I and III collagens and tenascin -C is observed in injured tendon and a progressive disorganization of the tendon structure. The study of transcription factors revealed that scleraxis seems to be a late tendinitis marker. Therefore, this research allowed us to extend our knowledge on the fatigue tendinitis in both physiological and pathological situations, through biochemical, molecular and cellular approaches. This study was carried out in order to develop an optical molecular marker probe relevant of the earliest stages of tendinitis, leading to the detection as early as possible micro-lesions before they become unrepairable, with the objective especially to promote appropriate therapies in veterinary or human clinic a posteriori. Thus, our research has highlighted new markers of the horse fatigue tendinitis

La ecografía es una técnica ampliamente utilizada para evaluar las lesiones tendinosas en los caballos, hasta este momento no se ha realizado ningún estudio sobre la ecogenicidad y el área de los tendones flexores y ligamentos de la zona metacarpiana del Pura Raza Español (P.R.E). El objetivo de nuestro estudio es determinar el área y la ecogenicidad de los tendones flexores y ligamentos de la zona del metacarpo, y determinar si tiene algún efecto la edad, el sexo, la extremidad y la zona de corte a ecografiar sobre estos parámetros en el caballo PRE.De este trabajo podemos concluir que la edad y la zona del metacarpo donde se realiza el examen tienen un efecto tanto en la ecogenicidad como en el área. Mientras que la extremidad sólo influye en los valores del área. Sin embargo, no se encontró ninguna diferencia entre machos y hembras ni en la ecogenicidad ni en los valores del área.
The ultrasonographic assessment of tendon injuries can be based on several criteria. The purposes of this study were to establish normal values for CSA and ME of flexor tendons and ligaments of the metacarpal region of Andalusian horses; to determine the normal relation between the different tendons and ligaments; to determine the normal relation between the male and female for each tendon and ligament; to determine the normal relation between the left and right limbs for each tendon and ligament and to determine the normal relation between different age (young, adult and senile) for each tendon and ligament.In conclusion, this work suggests that the age and level have an effect on CSA and ME of the tendons and ligaments. The limb has also an effect on CSA of each tendon and ligament. Differences in CSA or ME of each tendon were not found between males and females.