References of "LE GOFF, Caroline"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailTendon lesion and platelet-rich plasma (PRP) injection: rat model
Kaux, Jean-François ULg; Drion, Pierre ULg; Renouf, Julien et al

in Annual Congress of the RBSPRM (2010, December 03)

Introduction: For a few years, the positive effect of platelets on the healing process of different tissues (skin, bones...) was demonstrated. In fact platelets contain lots of growth factors which can be ... [more ▼]

Introduction: For a few years, the positive effect of platelets on the healing process of different tissues (skin, bones...) was demonstrated. In fact platelets contain lots of growth factors which can be release locally and enhance the healing process. Thus the aim of our experiment was to ascertain by an original mechanical measure whether the use of PRP was of interest for accelerating the healing process of rats’ Achilles tendons after surgical induced lesion. Methods: Ninety rats’ Achilles tendons were sectioned. Forty-two rats beneficed of a PRP injection in situ. After 5, 15 and 30 days, 15 rats of both groups were euthanized after tendon sampling which were immediately submitted to a biomechanical tensile test until tendon rupture, using an original method of measurement (“cryo-jaw”). Histological and biochemical analyses were made as well as a quantification of collagen with an original procedure (quantification of the “greys” on histological cross-sections). Results: Tendons in the PRP group were more resistant to rupture than those in the control group. Histological findings showed in this group an increase of collagen proliferation and better collagen fibres reorganization. However, we did not find any biochemical difference neither in term of encoding gene expression for type III collagen, matrix metalloprotease 9 and tenomodulin. Conclusion: Our animal study demonstrated that an injection of PRP could accelerate the tendons healing process and improve its quality. [less ▲]

Detailed reference viewed: 73 (13 ULg)
Full Text
Peer Reviewed
See detailIntrinsic modification of tendon structure after concentric or excentric training
Kaux, Jean-François ULg; Drion, Pierre ULg; Besançon, Benoît et al

Poster (2010, November 25)

Introduction: It is well known that eccentric training is a successful way of treating chronic tendinopathy. Although clinical results are very positive, beneficial morphological and histological effects ... [more ▼]

Introduction: It is well known that eccentric training is a successful way of treating chronic tendinopathy. Although clinical results are very positive, beneficial morphological and histological effects have not yet been elucidated. The aim of our experiment was to determine if there exist any intrinsic modifications in a tendon trained in concentric or eccentric modes, in a rat model, using an original method of measurement (cryo-jaws). Methods: 18 rats were divided into 3 groups: 6 for the control group, without physical restraint; 12 for a training of1 hour, 3 times a week, for 5 weeks, at a speed of 17m/min (1km/h), on a inclined treadmill: 6 rats running uphill at +15° for the concentric effort (group C) and 6 rats running downhill at -15° for the eccentric effort (group E). After this training period, the Achilles, patellar and tricipital tendons of both limbs were surgically removed in all 18 rats. Tendons taken from five rats of each group were subjected to a tensile test up to rupture using a “cryo” jaw. Tendons of the remaining rat of each group were subjected to a histological study. Results: The results showed significant changes in group E only: (1) an increase of the force required to rupture the patellar and tricipital tendons; (2) an improvement of the ratio between the force necessary to rupture the tricipital tendon and the body mass of the rats; (3) an increase of the surface area of the section of the tricipital tendon. No significant change was observed as far as constraint was concerned between groups. Histologically, we saw, in the group E, more peripheral blood vessels and a greater proportion of collagen. Conclusion: This study showed that the mechanical properties of tendon tissue are enhanced by eccentric training. Tendons become stronger, the amount of collagen increases and there is probably more interaction between collagen fibers (mechanotransduction). [less ▲]

Detailed reference viewed: 72 (8 ULg)
Full Text
Peer Reviewed
See detailTendon lesion and VEGF-111 injection
Kaux, Jean-François ULg; Drion, Pierre ULg; Libertiaux, Vincent ULg et al

Poster (2010, November 25)

Introduction: Tendon lesion is one of the most frequent pathology in sports and by physical workers. This pathology often becomes chronic. For this reason, it is of interest to develop new treatments ... [more ▼]

Introduction: Tendon lesion is one of the most frequent pathology in sports and by physical workers. This pathology often becomes chronic. For this reason, it is of interest to develop new treatments. Injection of platelet-rich plasma (PRP) seems to be a promising one by releasing growth factors (GF) locally. Among all the GF released by activated platelets, the vascular endothelial growth factor-A (VEGF-A) is known to induce positive effects on vascular function and angiogenesis, and could be implicated in the healing process of tendons. Recently, a novel VEGF-A isoform was identified, the VEGF-111, a biologically active and proteolysis-resistant VEGF-A isoform, also known to present beneficial effects on ischemic diseases. This prompted us to evaluate whether VEGF-111 would have a therapeutic interest within the framework of the tendon pathology. Methods: 60 Rats were divided into 2 groups: A: control (no injection), B: VEGF-111 treatment. A 5mm defect was surgically induced in rat Achilles tendon after resection of plantaris tendon. Rats received a local injection of VEGF-111 (100ng) in situ after the surgery and were placed in their cages without immobilization. After 5, 15 and 30 days, the traumatized Achilles tendons of 10 rats of both groups were removed and dissected during their healing process. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. Rats were then euthanized. Statistical analyses were made with an ANOVA. Values are significant when p-value is below 0.05. Results: Our results showed that the developed force necessary to induce tendon rupture during biomechanical tensile test was greater for tendons which had received an injection of 100ng of VEGF-111. These results were already noticed from day 5 onwards. The ratio between force and weight increased with time in both groups, but this ratio was greater for tendons which had been submitted to an injection of VEGF111. The surface area of the section of the tendons increased between 5 and 15 days followed by a stabilization. After 30 days, sections in both groups were similar. Thus, the constraint was similar after 5 and 15 days but was better for VEGF111 group after one month. Discussion - Conclusion: This experimentation has shown that a 100ng injection of VEGF-111 stimulated tendon healing process as suggested by the increased force needed to break tendons during its healing process and the increased of constraint in comparison with the control group. Other experimentations with different concentration of VEGF111 are now in process. Acknowledgement : This experimentation was partially financed by “Standard de Liège 2007” and “Lejeune-Lechien 2008” grants. [less ▲]

Detailed reference viewed: 46 (12 ULg)
Full Text
Peer Reviewed
See detailTendon lesion and platelet-rich plasma (PRP) injection
Kaux, Jean-François ULg; Drion, Pierre ULg; Renouf, Julien et al

Poster (2010, November 25)

Introduction: For a few years, the positive effects of platelets on the healing process of different tissues (skin, bones...) were demonstrated. In fact platelets contain lots of growth factors which can ... [more ▼]

Introduction: For a few years, the positive effects of platelets on the healing process of different tissues (skin, bones...) were demonstrated. In fact platelets contain lots of growth factors which can be release locally and enhance the healing process. Thus the aim of our experiment was to ascertain by an original mechanical measure whether the use of PRP was of interest for accelerating the healing process of rats’ Achilles tendons after surgical induced lesion. Methods: A 5mm defect was surgically induced in 90 rats’ Achilles tendon. Rats were divided into 2 groups of 45: (A) control (no treatment) and (B) PRP treatment. Rats of group B received a PRP injection in situ after the surgery. Afterwards, rats of both groups were placed in their cages without immobilization. After 5, 15 and 30 days, 10 traumatized Achilles tendons of each group were dissected and removed. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. After that, transcriptomic analyses were made on the tendon samples, to study the expression of type III collagen, matrix metalloproteases and tenomodulin. A hydroxyproline dosage was finally realised to quantify the collagen in the tendon during its healing process. Tendons of the 15 remaining rats of each group were subjected to a histological study, respectively at day 5, 15 and 30 (5 rats for each time). Results: We demonstrated that (1) the stress (F) during biomechanical tensile test up to tendon rupture was significantly greater for tendons which had been submitted to an injection of PRP compared to the control group; (2) the surface (S) area of the section of the tendon was greater in the PRP group during the 15 first days, but this section was similar after 30 days in the 2 groups; (3) the ration F/weight of the rat was significantly greater in the PRP group at each time; (4) constrain was similar after the 15 first days but was significantly greater in the PRP group after 30 days. Histological study showed that PRP could enhance cells proliferation, angiogenesis and collagen organisation. Our biochemical analyses did not explain beneficial effects of PRP. Indeed, there was no significant difference between the expressions of different studied genes. Conclusion: Our animal study demonstrated that an injection of PRP could accelerate the tendons healing process and improve its quality. [less ▲]

Detailed reference viewed: 54 (11 ULg)
Full Text
Peer Reviewed
See detailInfluence du mode de contraction sur le tendon : modèle animal
Kaux, Jean-François ULg; Drion, Pierre ULg; Besançon, Benoît et al

in 3ème Congrès Commun SFMS - SFTS (2010, October 01)

Introduction : Les tendinopathies sont fréquentes et touchent aussi bien les membres supérieurs que les membres inférieurs. La rééducation excentrique constitue une thérapeutique de choix dans le ... [more ▼]

Introduction : Les tendinopathies sont fréquentes et touchent aussi bien les membres supérieurs que les membres inférieurs. La rééducation excentrique constitue une thérapeutique de choix dans le traitement des tendinopathies. Malgré les résultats favorables en clinique, les effets morphologiques et biochimiques n’ont pas encore été élucidés. Matériel et méthodes : Dix-huit rats de souche Sprague-Dawley adultes ont été répartis en trois groupes : 6 témoins (groupe T) qui ne sont soumis à aucune contrainte physique ; 6 soumis à un effort concentrique (groupe C), course en montée ; 6 soumis à un effort excentrique (groupe E), course en descente. Les 12 rats des groupes C et E ont dû courir sur un tapis roulant incliné à +15° (groupe C) ou -15° (groupe E) à une vitesse de 17m/min (1km/h) pendant une heure à raison de trois séances par semaine pendant 5 semaines. Au terme de l’entraînement, les tendons achilléens, rotuliens et tricipitaux ont été prélevés bilatéralement. Les tendons de cinq rats de chaque groupe ont bénéficié d’une évaluation biomécanique (test de traction à l’aide de mors type « cryo-jaws »). Les tendons du sixième rat de chaque groupe ont permis l’étude histologique (coloration à l’hématoxyline-éosine et trichrome de Masson). Résultats : Le groupe E présente une augmentation de la tension de rupture des tendons rotuliens (29 ,5% ; p=0,047) et tricipitaux (72% ; p=0,018), une amélioration du rapport Force/Masse pour le tendon tricipital (54% ; p=0,043) ainsi qu’une augmentation de la section tendineuse tricipitale (74% ; p=0,008). Aucune variation pour aucun des tendons entre les groupes n’est relevée pour le paramètre contrainte (=Force/Section). Histologiquement, les tendons du groupe E se caractérisent par une plus grande quantité de vaisseaux sanguins périphériques ainsi qu’une plus grande proportion de collagène. Conclusion : Cette étude démontre que les propriétés mécaniques du tendon sont améliorées après un entraînement excentrique. Le tendon plus résistant augmente sa quantité de collagène et probablement les interactions entre les fibres de collagène. [less ▲]

Detailed reference viewed: 104 (14 ULg)
Full Text
Peer Reviewed
See detailInjection de concentrés plaquettaires et régénération tendineuse : modèle animal
Kaux, Jean-François ULg; Drion, Pierre ULg; Renouf, Julien et al

in 3ème Congrès Commun SFMS - SFTS (2010, October 01)

Introduction : La régénération tendineuse en traumatologie du sport demeure un processus actuellement difficile à gérer et de nouvelles voies thérapeutiques sont en cours d’exploration. La littérature ... [more ▼]

Introduction : La régénération tendineuse en traumatologie du sport demeure un processus actuellement difficile à gérer et de nouvelles voies thérapeutiques sont en cours d’exploration. La littérature récente fait état d’effets bénéfiques sur la régénération tendineuse de concentrés plaquettaires (platelet-rich plasma ou PRP), administrés in situ, dus au relargage de facteurs de croissance par activation des plaquettes et à leur activité stimulante au cours de la cicatrisation. Dès lors, nous avons souhaité tester l’effet bénéfique de ce traitement sur des rats préalablement lésés au niveau de leur tendon d’Achille. Matériel et Méthode : Une section unilatérale du tendon d’Achille a été réalisée chez 60 rats Sprague Dawley adultes. De ces 60 rats, 30 ont subi une cicatrisation naturelle (rats contrôles) et 30 rats ont bénéficié d’une injection in situ de PRP le jour de la lésion. Diverses études biomécaniques, biochimiques et histologiques ont été réalisées sur ces tendons d’Achille en cours de cicatrisation à respectivement J5, J15 et J30 après lésion. Dix rats supplémentaires ont servi de témoins sains (sans lésion tendineuse). L’étude biomécanique appréciait la résistance maximale des tendons à la traction à l’aide de mors type « cryo-jaws ». L’étude histologique évaluait l’évolution cellulaire pendant la phase de cicatrisation. L’analyse transcriptomique étudiait l’expression de gènes codant pour le collagène de type III, les métalloprotéases matricielles (MMP-9) et la ténomoduline (TNMD), ainsi qu’un dosage d’hydroxyproline permettant d’évaluer la quantité de collagène présente dans le tendon au cours de la cicatrisation. Résultats : L’étude biomécanique démontre la meilleure résistance des tendons traités avec du PRP par rapport aux tendons contrôles à J5 (+19%), J15 (+30%) et significativement à J30 (+43%). L’étude histologique suggère qu’une injection de PRP stimule la prolifération cellulaire, favorise l’organisation tissulaire, stimule l’angiogenèse et la réorganisation architectural du collagène. L’étude biochimique ne permet pas d’expliquer les effets bénéfiques puisqu’il n’y a pas de différence dans l’expression des gènes des différentes molécules matricielles (collagène de type III, MMP-9 et TNMD) ni dans la quantité d’hydroxyproline qui s’accroit au cours du temps de la cicatrisation de façon similaire dans les deux groupes. Conclusion : L’injection de PRP améliore et accélère la cicatrisation tendineuse et augmente la résistance aux contraintes mécaniques du tendon en cours de cicatrisation. [less ▲]

Detailed reference viewed: 144 (18 ULg)
Full Text
Peer Reviewed
See detailLe VEGF-111 comme nouvel outil thérapeutique des lésions tendineuses
Kaux, Jean-François ULg; Drion, Pierre ULg; Libertiaux, Vincent ULg et al

in 3ème Congrès Commun SFMS - SFTS (2010, September 30)

Introduction : Les lésions tendineuses sont très fréquentes en traumatologie du sport et deviennent fréquemment chroniques. Pour ces raisons, de nouvelles thérapeutiques sont en cours de développement ... [more ▼]

Introduction : Les lésions tendineuses sont très fréquentes en traumatologie du sport et deviennent fréquemment chroniques. Pour ces raisons, de nouvelles thérapeutiques sont en cours de développement. Les injections de concentrés plaquettaires (platelet-rich plasma ou PRP) semblent constituer en ce sens une voie encourageante. Elles agissent par libération locale de divers facteurs de croissance parmi lesquels le VEGF-A (vascular endothelial growth factor-A), connu pour induire un effet positif sur la fonction vasculaire et l’angiogenèse, serait impliqué dans le processus cicatriciel des tendons. Récemment, une nouvelle isoforme du VEGF-A a été identifié : le VEGF-111. Celui-ci est une isoforme biologiquement active du VEGF-A, résistant à la protéolyse et aussi connu pour présenter un effet bénéfique sur les pathologies ischémiques. Pour ces raisons, nous avons pensé que le VEGF-111 pourrait avoir un intérêt thérapeutique pour les pathologies tendineuses. Matériel et méthode : 60 rats de souche Sprague-Dawley adultes ont été séparés en 2 groupes (A: groupe contrôle sans traitement et B: groupe traité par une injection de VEGF-111). Chez ces rats, un défaut de 5mm dans le tendon d’Achille a été réalisé après résection du tendon du plantaire grêle. Les 30 rats du groupe B ont alors bénéficié d’une injection in loco de 100ng de VEGF-111. Les rats ont été euthanasiés par groupe de 20 (10 du groupe A et 10 du groupe B) respectivement à J5, J15 et J30 et le tendon d’Achille en cours de régénération a été disséqué et prélevé. Une étude biomécanique de traction jusqu’à rupture a été réalisée à l’aide de mors type « cryo-jaw ». Résultats : L’analyse de nos résultats montre que la force nécessaire pour rompre le tendon lors du test de traction, était plus importante pour les tendons du groupe B. Ces résultats peuvent être observés dès le 5ème jour. Le rapport entre la force et la masse corporelle du rat augmente dans les 2 groupes avec le temps, mais cette augmentation est plus importante pour les tendons du groupe B. La surface de section du tendon de groupe B s’accroit plus rapidement entre les jours 5 et 15 et ensuite se stabilise. Après 30 jours, les sections tendineuses sont similaires dans les 2 groupes. Enfin, dans le groupe B, les contraintes nécessaires pour obtenir la rupture du tendon, en tenant compte de l’accroissement de sa section, sont similaires entre les jours 5 et 15 et augmentent après un mois. Conclusion : Cette expérience a démontré qu’une injection de 100ng de VEGF-111 stimulait le processus de cicatrisation tendineuse en augmentant la résistance du tendon et les contraintes nécessaires pour rompre celui-ci. D’autres expérimentations avec différentes concentrations de VEGF-111 sont actuellement en cours. [less ▲]

Detailed reference viewed: 76 (18 ULg)
Full Text
Peer Reviewed
See detailInfluence of the contraction mode on the tendon structure - Rat model
Kaux, Jean-François ULg; Drion, Pierre ULg; Besançon, Benoît et al

in 2nd Congress of European College of Sport & Exercise Physicians - Conference Brochure 2010: Abstracts and CVs (2010, September 09)

Introduction: Tendinopathies are common in sport and affect both upper and lower limbs. Eccentric rehabilitation is a successful way of treating them and now is becoming the “gold treatment”. Although ... [more ▼]

Introduction: Tendinopathies are common in sport and affect both upper and lower limbs. Eccentric rehabilitation is a successful way of treating them and now is becoming the “gold treatment”. Although clinical results are very favorable, beneficial morphological and histological effects have not yet been elucidated. The aim of our experiment was to determine if there exist any intrinsic modifications in a tendon trained in concentric or eccentric modes, in a rat model. Methods: 18 rats were divided into 3 groups: 6 for the control group, without physical restraint; 12 for a training of1 hour, 3 times a week, for 5 weeks, at a speed of 17m/min (1km/h), on a inclined treadmill: 6 rats running uphill at +15° for the concentric effort (group C) and 6 rats running downhill at -15° for the eccentric effort (group E). After this training period, the Achilles, patellar and tricipital tendons of both limbs were surgically removed in all 18 rats. Tendons taken from five rats of each group were subjected to a tensile test up to rupture using a “cryo” jaw. Tendons of the remaining rat of each group were subjected to a histological study. Results: The results showed significant changes in group E only: (1) an increase of the force required to rupture the patellar and tricipital tendons; (2) an improvement of the ratio between the force necessary to rupture the tricipital tendon and the body mass of the rats; (3) an increase of the surface area of the section of the tricipital tendon. No significant change was observed as far as constraint was concerned between groups. Histologically, we saw, in the group E, more peripheral blood vessels and a greater proportion of collagen. Conclusion: This study showed that the mechanical properties of tendon tissue are enhanced by eccentric training. Tendons become stronger, the amount of collagen increases and there is probably more interaction between collagen fibers (mechanotransduction). [less ▲]

Detailed reference viewed: 53 (7 ULg)
Full Text
Peer Reviewed
See detailVEGF-111 as a new therapeutic tool for tendon lesion
Kaux, Jean-François ULg; Drion, Pierre ULg; Libertiaux, Vincent ULg et al

in Osteoarthritis and Cartilage (2010, September), 18(Supplement 2), 22

Introduction: Tendon lesion is one of the most frequent pathology in sports and by physical workers. This pathology often becomes chronic. For this reason, it is of interest to develop new treatments ... [more ▼]

Introduction: Tendon lesion is one of the most frequent pathology in sports and by physical workers. This pathology often becomes chronic. For this reason, it is of interest to develop new treatments. Injection of platelet-rich plasma (PRP) seems to be a promising one by releasing growth factors (GF) locally. Among all the GF released by activated platelets, the vascular endothelial growth factor-A (VEGF-A) is known to induce positive effects on vascular function and angiogenesis, and could be implicated in the healing process of tendons. Recently, a novel VEGF-A isoform was identified, the VEGF-111, a biologically active and proteolysis-resistant VEGF-A isoform, also known to present beneficial effects on ischemic diseases. This prompted us to evaluate whether VEFF-111 would have a therapeutic interest within the framework of the tendon pathology. Methods: 60 Rats were divided into 2 groups: A: control (no injection), B: VEGF-111 treatment. A 5mm defect was surgically induced in rat Achilles tendon after resection of plantaris tendon. Rats received a local injection of VEGF-111 (100ng) in situ after the surgery and were placed in their cages without immobilization. After 5, 15 and 30 days, the traumatized Achilles tendons of 10 rats of both groups were removed and dissected during their healing process. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. Rats were then euthanized. Statistical analyses were made with an ANOVA. Values are significant when p-value is below 0.05. Results: Our results shown that the developed force necessary to induce tendon rupture during biomechanical tensile test was greater for tendons which had received an injection of 100ng of VEGF-111. These results were already noticed from day 5 onwards. The ratio between force and weight increased with time in both groups, but this ratio was greater for tendons which had been submitted to an injection of VEGF111. The surface area of the section of the tendons increased between 5 and 15 days followed by a stabilization. After 30 days, sections in both groups were similar. Thus, the constraint was similar after 5 and 15 days but was better for VEGF111 group after one month. Discussion - Conclusion: This experimentation has shown that a 100ng injection of VEGF-111 stimulated tendon healing process as suggested by the increased force needed to break tendons during its healing process and the increased of constraint in comparison with the control group. Other experimentations with different concentration of VEGF111 are now in process. Acknowledgement This experimentation was partially financed by “Standard de Liège 2007” and “Lejeune-Lechien 2008” grants. [less ▲]

Detailed reference viewed: 133 (27 ULg)
Full Text
Peer Reviewed
See detailPlatelet-Rich Plasma injection to improve tendon healing process
Kaux, Jean-François ULg; Drion, Pierre ULg; Renouf, Julien et al

in Osteoarthritis and Cartilage (2010, September), 18(Supplement 2), 221

Introduction It is well known that injured tendons do not heal easily. For example, tendinopathy is a condition which often becomes chronic in the case of bad or late management. Recently, several studies ... [more ▼]

Introduction It is well known that injured tendons do not heal easily. For example, tendinopathy is a condition which often becomes chronic in the case of bad or late management. Recently, several studies, essentially in vitro and, more recently, a few in clinical practice, have demonstrated the positive effects of platelets on the healing process of different tissues. In fact, platelets contain lots of growth factors which can be released after a local injection. These growth factors have the potentiality to enhance the tendon healing process, for example after rupture or tendinopathy. The aim of our experiment was to ascertain whether the use of Platelet-Rich Plasma (PRP) was of interest for accelerating the healing process of Achilles tendon after surgical induced lesion. Methods All experimental procedures and protocols used in this investigation / were reviewed and approved by the Institutional Animal Care and Use Committee of the University of Liège. 60 rats were divided into 2 groups: A: control (no injection) and B: PRP injection. A 5mm defect was surgically induced in the rats’ Achilles tendon after resection of plantaris tendon. Rats of group B received a PRP injection in situ after the surgery. Afterwards, rats of both groups were placed in their cages without immobilization. After 5, 15 and 30 days, the traumatized Achilles tendons of 10 rats of both groups were removed and dissected during their healing process. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. Rats were then euthanized. Statistical analyses were made with an ANOVA. Values are significant when p-value is below 0.05. Results We observed that the force necessary to induce tendon rupture during biomechanical tensile testing increased with time in both groups; that this force was greater for tendons which had been submitted to an injection of PRP. The ratio between force and weight increased with time in both groups; that this ratio was greater for tendons which had been submitted to an injection of PRP too. There is also a significant interaction between time and the group. The surface area of the section of the tendons increased between 5 and 15 days followed by a stabilization. After 30 days, sections in both groups were similar. Thus, the constraint was similar after 5 and 15 days but is significantly better for PRP group after one month. Discussion – Conclusion We demonstrated that the force necessary to induce tendon rupture during biomechanical tensile testing was greater for tendons which had been submitted to an injection of PRP. These results were observed and significant (p<0.05) from day 5 onwards. We observed too that the section of the tendon was the same in both groups after 30 days. Thus the quality of the healing tendon is better with an injection of PRP, as shown with the increase of the constraint until rupture. Acknowledgement This experimentation was partially financed by “Standard de Liège 2007” and “Lejeune-Lechien 2008” grants. [less ▲]

Detailed reference viewed: 253 (16 ULg)
Full Text
Peer Reviewed
See detailAssessment of high sensitive troponin T and I immunoassays in patients with acute chest
Le Goff, Caroline ULg; Garweg, Christophe ULg; Laurent, Terry et al

in Clinical Chemistry (2010, July), 56(S6), 127

Introduction: Cardiac troponin I and T are specific markers of myocardial injury that are widely used for the diagnosis of acute coronary syndrome (ACS). In acute chest pain without ST-segment elevation ... [more ▼]

Introduction: Cardiac troponin I and T are specific markers of myocardial injury that are widely used for the diagnosis of acute coronary syndrome (ACS). In acute chest pain without ST-segment elevation, they are used to differentiate unstable angina from non ST-segment elevation myocardial infarction (NSTEMI). Recently, troponin assays with higher analytical sensitivities became available to enable the detection of minor myocardial damage and identify individuals at higher risk for ACS. As a result of its high tissue-specificity, cardiac troponin T and I are cardio-specific, highly sensitive markers for myocardial damage. The aim of this study was to evaluate the new higher sensitive troponin (T and I) in patients with stable angina and acute chest pain without ST-segment elevation. Methods: Sixty subjects (mean age : 65.5± 11 years), were included: 20 healthy controls, 20 patients with stable angina, 9 with unstable angina (troponin-) and 18 patients with NSTEMI myocardial infarction (troponin+). The protocol was approved by the ethic committee of the University of Liège (Belgium). High sensitive troponin T (hsTnT) determination was realized on heparin plasma by electrochemiluminescence immunoassay on Modular E (Roche Diagnostic). Troponin I II (TnI II) is a chemiluminescent microparticle immunoassay for the quantitative determination of cardiac troponin-I in heparine plasma on the ARCHITECT i System (Abbott Diagnostic). The lower detection limit of these assays was 0.005μg/L for hsTnT and 0.01μg/L for TnI II. Stastistical analysis was performed using t test. P value <0.05 was considered significant. Results: HsTNT levels were 0.003(0.003, 0.004) [median baseline (1st, 3rd quartile)]ng/ml in controls, 0.0075 (0.00475, 0.014) ng/ml in stable angina, 0.011(0.006, 0.012) ng/ml in unstable angina and 0.3715 (0.1795, 1.00725) ng/ml in NSTEMI ACS. TnI II levels were 0 (0, 0.001) ng/ml in controls and in patients with stable angina, 0.07 (0.005, 0.014) ng/ml in unstable angina and 1.4475 (0.0407, 2.656) ng/ml in NSTEMI. HsTNT and TnI II levels were significantly increased in NSTEMI as compared to control subjects, patients with stable and unstable angina. TnI II levels were also increased in unstable angina as compared to controls. Conclusion: In our population, TnI II was more sensitive than hsTNT to detect minor myocardial damage in patients with unstable angina as compared to controls. Therefore, future studies will have to determine whether TnI II might contribute to better risk stratification and treatment strategy in this group of patients. [less ▲]

Detailed reference viewed: 123 (16 ULg)
Full Text
Peer Reviewed
See detailUse of clinical biology techniques in clinical practice: injections of platelet-rich plasma to heal tendon
Kaux, Jean-François ULg; Le Goff, Caroline ULg; Drion, Pierre ULg et al

in Clinical Chemistry (2010, July), 56(S6), 111

Introduction: A tendon is a tissue which does not heal easily. For example, tendinopathy is a condition which often becomes chronic in the case of bad or overdue management. Several studies, essentially ... [more ▼]

Introduction: A tendon is a tissue which does not heal easily. For example, tendinopathy is a condition which often becomes chronic in the case of bad or overdue management. Several studies, essentially in vitro and, more recently, a few in clinical practice, have demonstrated the positive effects of platelets on the healing process of tendons. A local injection of platelet–rich plasma (PRP), which releases many growth factors, has the potentiality to enhance the tendon healing process. The aim of our experiment was to ascertain whether the use of PRP could accelerate the healing process of an Achilles tendon after a surgically induced lesion. Methods (*): PRP was obtained from the blood of 12 Sprague Dawley rats by cardiac puncture under general anaesthesia until the heart stopped beating. Quantities of 1mL of anticoagulant, adenosine-citrate-dextrose-acid (ACD-A), were added immediately to each 4,5mL of blood. The blood was then centrifuged at 180g for 10 minutes. To improve platelet concentration of the PRP, the supernatant was centrifuged for a second time at 1000g for 10 minutes. The platelets were then collected using a gauge pipette. Cell and platelet counts were made by an auto-analyser. Platelet concentration was around 2.2 to 2.9 x106/mm³. A 5mm defect was surgically induced in the Achilles tendon of 60 rats. Rats were divided into 2 groups of 30: A: a control group (no injection) and B: with a PRP injection. The rats of group B received a PRP injection in situ 1 hour after the surgery on the site of the lesion of the Achilles tendon. Fifty micro-litres of PRP were injected in each rat of the PRP group. Platelets were activated by the local presence of collagen in the wound. Afterwards, the rats of both groups were placed in their cages without immobilization. After 5, 15 and 30 days, 10 rats of each group were euthanized. The traumatized Achilles tendon of each rat was dissected and removed. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a tensile machine with a “Cryo-jaw”. Results: We demonstrated that the force necessary to induce tendon rupture during biomechanical tensile testing was greater for tendons which had been submitted to an injection of PRP. These results were observed and significant (p<0.05) from day 5 onwards. Discussion: This experimentation showed that PRP injections could accelerate the tendon healing process and increase the force needed to break tendons in their healing process. This “accelerating” process can be observed and is significant (p<0.05) as early as day 5. Conclusion: PRP, by the local release of growth factors, would be a new therapeutic tool to accelerate tendon healing. Acknowledgement: This experimentation was partially financed by “Standard de Liège” and “Lejeune-Lechien” grants. (*) All experimental procedures and protocols used in this investigation were reviewed and approved by the Institutional Animal Care and Use Committee of the University of Liège. [less ▲]

Detailed reference viewed: 63 (16 ULg)
Full Text
Peer Reviewed
See detailNew use of VEGF in therapeutics: application in tendon lesions
Kaux, Jean-François ULg; Le Goff, Caroline ULg; Drion, Pierre ULg et al

in Clinical Chemistry (2010, July), 56(S6), 111

Introduction: As demonstrated in previous studies, mechanical overload, injury and inflammation, hypoxic condition or any combination of the above could lead to increased expression of VEGF in the tendon ... [more ▼]

Introduction: As demonstrated in previous studies, mechanical overload, injury and inflammation, hypoxic condition or any combination of the above could lead to increased expression of VEGF in the tendon. Thus, VEGF could participate in the healing of pathological tendons. Indeed, some authors are convinced that this neovascularization is the sign of a chronic tendinopathy while others plead in favour of it being a sign of healing processes. The VEGF111, which is a biologically active and proteolysis-resistant VEGF-A isoform, was recently identified. It is induced by ultraviolet B and genotoxic drugs. Experimentation shows that, in nude mice, tumors formed by HEK293 cells expressing VEGF111 develop a more widespread peritumoral neovascularisation than those expressing other VEGF isoforms. Good angiogenic activity and resistance to proteolysis makes VEGF111 a potential beneficial therapeutic option for ischemic diseases. The aim of our study was to determine whether if VEGF111 could have a therapeutic interest in the framework of tendinous pathology. Methods (*): A 5mm defect was surgically induced in Achilles tendon of 60 rats. Rats were divided into 2 groups of 30: A: a control group (no injection) and B: with a VEGF111 injection. The rats of group B received an injection of 100 ng of VEGF111 in situ 1 hour after surgery on the site of the tendon lesion. Afterwards, rats of both groups were placed in their cages without immobilization. After 5, 15 and 30 days, 10 rats of each group were euthanized. The traumatized Achilles tendon of each rat was dissected and removed. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a tensile machine with “Cryo-jaw”. Statistical analyses were made with an ANOVA. Results: A significant increase over time of the force necessary to induce tendon rupture was observed for tendons which had been submitted to an injection of VEGF111 (p=0.016). The force required to break the tendon is always greater for the VEGF111 group (p<0.05). Discussion: We demonstrated that the force necessary to induce the rupture of a rat’s Achilles tendon during biomechanical tensile testing was greater for tendons which had been submitted to an injection of VEGF111. Thus, this experimentation showed that VEGF111 injections could accelerate the tendon healing process and increase the force needed to break tendons in their healing process. Conclusion: VEGF111 could be a new therapy for tendon lesions. However, other experimentation using a rat model with different concentrations of VEGF111 should be made to ascertain the best concentration for this healing process. Acknowledgement: This experimentation was partially financed by “Standard de Liège” and “Lejeune-Lechien” grants. (*) All experimental procedures and protocols used in this investigation were reviewed and approved by the Institutional Animal Care and Use Committee of the University of Liège. [less ▲]

Detailed reference viewed: 74 (21 ULg)
Full Text
Peer Reviewed
See detailDoes echocardiographic stress test induced release of hsTnT and TnI II?
Le Goff, Caroline ULg; Laurent, Terry; Garweg, Christophe ULg et al

in Clinical Chemistry (2010, July), 56(S6), 128

Background: Cardiac troponins (cTn) are considered as the best biomarkers for detection of myocardial cell injury. In this study, cTnT and cTnI were measured by new commercially available high-sensitive ... [more ▼]

Background: Cardiac troponins (cTn) are considered as the best biomarkers for detection of myocardial cell injury. In this study, cTnT and cTnI were measured by new commercially available high-sensitive methods in patients undergoing brief exercise- or pharmacologicinduced stress. Our aim was to compare cTnT and cTnI levels before and after the stress tests, in the patients with or without reversible ischemia. Materials and Methods: Fifty patients (28 men and 22 women) underwent an echographic stress test (ST) for suspected ischemic heart disease. Of these 50 patients, 28 received pharmacological ST (dobutamine injection) and 22 dynamic ST (bicycle exercise). The patients were subdivided into two groups according to the presence or absence of documented transient reversible ischemia: 14 with reversible ischemia ( mean age: 67.71±9.66 y) and 36 without ischemia ( mean age: 63.17±11.72 y). In all patients, cTnT and cTnI concentrations were measured by high sensitive methods (hsTnT, Roche Diagnostics and TnI II, Abbott Diagnostics) on heparin plasma immediately before (T0) and after ST (T1).The lower detection limit of these assays was 0.005μg/L for hsTnT and 0.01μg/L for TnI II. The protocol was approved by the ethics committee of the University of Liège (Belgium). All patients gave informed consent. All statistical analyses were performed using Medcalc version 8.1 for Windows. P value <0.05 was regarded as statistically significant. Results: There was no significant difference between hsTnT concentrations at T0 and T1, neither in the whole patient group, nor in the subgroups of subjects who received pharmacological ST or dynamic ST. The same was true for TnI II. Although there was no change in hsTnT levels during test in ischemic and in non ischemic patients, the latter tend to demonstrate higher median T0 levels (25th, 75th percentiles) than the others [0.011 (0.007, 0.029) vs 0.007 (0.0047, 0.1125) ng/ml, p=0.09]. They also showed higher median T1 levels [0.014 (0.065, 0.03) vs 0.007 (0.003, 0.0102) ng/ml, p=0.08]. Higher TnI II levels were also recorded in ischemic patients as compared to non ischemic patients at T0[ 0.014 (0.0072; 0.0265) vs 0.005 (0.003; 0.01) ng/ml, p=0.08] and T1[ 0.013 (0.0085- 0.03) vs 0.006 (0.0035-0.008) ng/ml, p=0.08]. Also, TnI II levels did not change during test in both subgroups. Conclusions: Measurement of cardiac troponins by high sensitive methods did not allow to detect significant release of biomarkers from the heart during exercise-or pharmacologic-induced ST, even in patients who demonstrated reversible myocardial ischemia. The type of test – pharmacological or dynamic - was without effect. The patients with induced transient ischemia had however higher troponin T and I levels at baseline, this difference remaining during test. [less ▲]

Detailed reference viewed: 83 (9 ULg)
Full Text
Peer Reviewed
See detailConsequences of laparoscopy on liver ischemia during portal triad clamping in a swine model
Nsadi, Berthier; Pire, E.; Gilson, Nathalie ULg et al

in Acta Chirurgica Belgica (2010, April), 110

Detailed reference viewed: 34 (7 ULg)
Full Text
Peer Reviewed
See detailRelease of cardiac biomarkers after an intense physical exercise: preliminary results
Le Goff, Caroline ULg; Laurent, Terry; Chapelle, Jean-Paul ULg et al

Poster (2010, March 20)

Background: Over the past 2 decades, there has been a large interest in cardiac markers elevations, which are often seen following endurance sport events. These elevations were transient, with levels ... [more ▼]

Background: Over the past 2 decades, there has been a large interest in cardiac markers elevations, which are often seen following endurance sport events. These elevations were transient, with levels decreasing to pre-event concentrations within 24-48 hours. This might be explained by the relatively short half-life of studied markers, or water imbalance during and after the event. Therefore, the present preliminary study aimed to examine the increase in N-terminal pro-brain natriuretic peptide (NT-proBNP), highly sensitivity cardiac troponin T (hsTnT) and I (TnI II), myoglobin, creatine kinase muscle – brain (CK-MB), myeloperoxydase (MPO) and Highly sensitive C-reactive protein (hs-CRP) elevations after prolonged strenuous exercise . Materials and methods: Blood samples (EDTA plasma and heparinised plasma) were drawn at baseline, after 45, 90, 105, 165, 225, 285, 345, 690 and 1440 minutes in two healthy persons (29 year, trained 6 hours per week; 23 year, untrained). Each subjects runs at the maximal possibility during 2 hours. Results: For the untrained person, level of NT-proBNP exceeded the upper reference limits 12 hours after exercise but increased in all times. HsTnT and TnI II levels were upper the reference limit respectively 45 minutes and directly after exercise and increased up to 4 hours after exercise. We reported a decrease of these concentrations above the reference limits after 24 hours. Myoglobin increased after 45 minutes until 5 hours after exercises. It decreased after the 5th hour to be normalized 24 hours after exercise. CK-MB increased directly after the exercise and was upper the reference limits 165 minutes after the exercise. Level of MPO was very high just after exercise and decreased quickly in the following hours to be just upper the limit references 24 hours after exercise. HsCRP levels increased after 105 minutes and continued to increase after 24 hours. For the trained subject, we noted the same profile of increase of cardiac markers levels stayed but in the range of reference. Conclusion: These cases are extremely interesting. Indeed, this observation suggested a physiological counter regulatory process rather a simple increase of myocardial damage related to the intensity of exercise. In fact, for this moment, we do not know if the release of cardiac markers is physiological or pathological thus it must be studied. This preliminary study on endurance training suggested that intensively is determinants of the rate and the magnitude of subsequent cardiac marker release. These results suggested that an adaptation mechanism could exist. Benefits and possible long-term negative aspects of prolonged exercise should be evaluated with a more important population of athletes. [less ▲]

Detailed reference viewed: 51 (11 ULg)
Full Text
Peer Reviewed
See detailComparison between platelet-rich plasma (PRP) and vascular endothelial growth factor-111 (VEGF-111) as a therapeutic tool in tendon healing process
Kaux, Jean-François ULg; Drion, Pierre ULg; Libertiaux, Vincent ULg et al

Poster (2010, March 20)

Introduction In spite of the availability of various treatments for tendinopathy, this pathology often becomes chronic. For this reason, it is of interest to develop new treatments. Among them, the ... [more ▼]

Introduction In spite of the availability of various treatments for tendinopathy, this pathology often becomes chronic. For this reason, it is of interest to develop new treatments. Among them, the injection of platelet-rich plasma (PRP) seems to be a promising one. Indeed, several animal models have demonstrated that injection of blood platelets can initiate and stimulate tendon and ligament repair by releasing growth factors (GF) locally. Among all the GF released by activated platelets, the vascular endothelial growth factor-A (VEGF-A) is known to induce positive effects on vascular function and angiogenesis, and could be implicated in the healing process of tendons. Recently, a novel VEGF-A isoform was identified, the VEGF-111, a biologically active and proteolysis-resistant VEGF-A isoform, also known to present beneficial effects on ischemic diseases. This prompted us to evaluate whether VEFF-111 would have a therapeutic interest within the framework of the tendon pathology. Aim of the study: We hypothesized that the healing of ruptured Achilles tendons, which is the last stage of the Blazina’s classification, could be improved by injection of VEGF-111 that was compared to the potential effect of PRP injections using a rat model. Methods: A 5mm defect was surgically induced in rat Achilles tendon after resection of plantaris tendon. Rats were divided into 3 groups: A: control (no injection), B: PRP treatment and C: VEGF-111 treatment. Rats received a local injection of PRP (50µL) or VEGF-111 (100ng) in situ after the surgery and were placed in their cage without immobilization. After 5, 15 and 30 days, the rats were euthanized in each group. The traumatized Achilles tendon of each rat was removed and dissected during the healing process. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. Results: Our results show that developed force necessary to induce tendon rupture during biomechanical tensile test was more important for tendons which had received an injection of PRP or VEGF-111. Moreover, the tensile force necessary to break tendons is higher with PRP than with VEGF-111. These results were already noticed from day 5 onwards. Conclusion: This experimentation has shown that both PRP and VEGF-111 injections stimulated tendon healing process as suggested by the increased force needed to break tendons during its healing process. Furthermore, this acceleration of the cicatrisation process was more significant with PRP than with VEGF-111. This could be explained by the release from platelets of a “cocktail” of growth factors acting in synergy on the healing process. Acknowledgement This experimentation was partially financed by “Standard de Liège 2007” and “Lejeune-Lechien 2008” grants. [less ▲]

Detailed reference viewed: 109 (33 ULg)
Full Text
Peer Reviewed
See detailPlatelet-rich plasma (PRP) increases healing process of rats' Achilles tendons
Kaux, Jean-François ULg; Drion, Pierre ULg; Pascon, Frédéric ULg et al

Conference (2010, March 20)

Introduction Some tendinopathies (epicondylitis, jumper’s knee or Achilles tendinopathy) are frequently considered as rebel to “classic” treatments such as rest, orthotics, NSAIs, electrotherapy ... [more ▼]

Introduction Some tendinopathies (epicondylitis, jumper’s knee or Achilles tendinopathy) are frequently considered as rebel to “classic” treatments such as rest, orthotics, NSAIs, electrotherapy, physiotherapy, corticosteroid infiltrations, extracorporeal shock waves… Recently, several studies, essentially in vitro, demonstrated the positive effects of platelets on the healing process of different tissues: bones, muscles and tendons. Objectives The aim of our experiment was to ascertain whether the use of platelet-rich plasma (PRP) was of interest for accelerating the healing process of Achilles tendon after surgical induced lesion. Methods A 5mm defect was surgically induced in rat Achilles tendon after resection of plantaris tendon. Rats were divided into 2 groups: A: control (no injection) and B: PRP injection. Rats of group B received a PRP injection in situ after the surgery. Afterwards, rats of both groups were placed in their cage without immobilization. After 5, 15 and 30 days, rats were euthanized. The traumatized Achilles tendon of each rat was removed and dissected during this healing process. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. Results We demonstrated that the force necessary to induce tendon rupture during biomechanical tensile test study was more important for tendons which had been submitted to an injection of PRP. These results were noticed from day 5 onwards. Discussion – Conclusion This experimentation has shown that PRP injections could accelerate tendons healing process and increase the force needed to break tendons in their healing process. This “accelerating” process can be observed as early as day 5. Acknowledgement This experimentation was partially financed by “Standard de Liège 2007” and “Lejeune-Lechien 2008” grants. [less ▲]

Detailed reference viewed: 132 (36 ULg)
Full Text
Peer Reviewed
See detailGPS™ II and GPS™ III: comparison of obtained platelets concentrations
Kaux, Jean-François ULg; Le Goff, Caroline ULg; Renouf, Julien et al

Poster (2010, March 20)

Introduction: Recently, several researches, essentially in vitro, demonstrated the positive effects of platelets on healing process of different tissues: bones, muscles and tendons. The aim of this study ... [more ▼]

Introduction: Recently, several researches, essentially in vitro, demonstrated the positive effects of platelets on healing process of different tissues: bones, muscles and tendons. The aim of this study is to compare the obtained platelets concentration between the new GPS™ III and GPS™ II. Methods: Two blood samples of 52 mL were taken in 5 volunteers and transferred respectively in both GPS™ II and GPS™ III. These devices were centrifuged at 3200 RPM during 15 min. The platelet-rich plasma (PRP) was thus collected and transferred in 6 mL test tubes. Cells count was done using an analyser ABX Micros 60. Results and conclusion: Platelets concentrations were more important from 6.2 up to 9.2 times with GPS™ II and from 7.3 up to 8.3 times with GPS™ III compared to blood samples. Efficiency of the collected platelets was around 92% for GPS™ II and 96% for GPS™ III. Both techniques made it possible to collect platelets but, unfortunately, also a lot of red and white blood cells. None of these parameters showed any significant difference (p>0.05). Conflicts of interests: The 10 devices GPS™ II and GPS™ III were provided gracefully by the firm Biomet Biologics TTC. [less ▲]

Detailed reference viewed: 95 (16 ULg)
Full Text
Peer Reviewed
See detailComparaison des taux de BNP et de NT-proBNP chez des patients insuffisants rénaux pour prévenir l'insuffisance cardiaque
Le Goff, Caroline ULg; Kaux, Jean-François ULg; Bovy, Christophe ULg et al

in Biotribune Magazine (2010), 34

Background: The aim of the study is to compare the performances of BNP and NT-proBNP for diagnosing heart failure (HF) in a population of patients with high incidence of chronic renal insufficiency (CRI ... [more ▼]

Background: The aim of the study is to compare the performances of BNP and NT-proBNP for diagnosing heart failure (HF) in a population of patients with high incidence of chronic renal insufficiency (CRI, plasma creatinine > 1.5 mg/dl). Patients and methods: Ninety-eight patients were included in this study. BNP and NT-proBNP determinations were performed by an immunofluorescent assay (Biosite®) and by an electrochemiluminescence sandwich immuno assay (Roche Diagnostic®), respectively. Results and discussion: BNP and NTproBNP level are correlated in CRI and non CRI . Both assays are useful to rule out CRI pts suspected of HF. However, in renal failure pts, higher decision limits should be used for improving the positive predictive value of the assays. [less ▲]

Detailed reference viewed: 202 (8 ULg)