Didier Serteyn

Curcumin (diferuloylmethane), a yellow pigment in the spice turmeric has been used for centuries as a treatment for inflammatory diseases. Curcumin inhibits TNFα, blocks NfκB, modulates neutrophil reactivity, induces neutrophil apoptosis and inhibits the enzyme myeloperoxydase, which largely contributes to the “oxidative stress”. These properties could be very interesting to treat a lot of equine or camels pathologies when excessive neutrophils activation and mitochondrial dysfunction occur. However, Curcumin has a poor intestinal resorption and a low bioavailability The authors have developed a new patented hydrosoluble form of curcumin. This compound presented in vitro potent anti-oxidant properties such as: free radical scavenging, oxidative enzyme inhibition and improvement of mitochondrial function. The soluble form of curcumin administrated by inhalation is used with success in horses suffered from respiratory diseases especially inflammatory airway disease (IAD) and recurrent airway obstruction (RAO). Concerning the exercise induced pulmonary hemorrhage (EIPH), interesting results are observed due to the reduction of pulmonary inflammation and inhibition of neutrophils enzyme. The same indications can be expected for the prevention and the treatment of camel respiratory diseases including EIPH.

peer reviewedIntroduction: The enzymatic theory of equine laminitis is supported by enhanced Matrix MetalloProteinase-9 (MMP-9) activity in laminar tissues that could be attributed to neutrophil infiltration and activation during the development phase of the disease.1,2 We hypothesized the role of neutrophil elastase (NE) in the conversion of pro-MMP into active form and evaluated the possibility of this theory by comparing plasmatic equine NE between horses suffering from laminitis and healthy horses. Materials and Methods: NE was extracted from equine neutrophils (isolated from whole blood by gradient centrifugation), and purified by a double chromatographic step. Purified NE was used for the immunization of a guinea pig and a rabbit. At the end of immunization, animals were exsanguinated and the IgG purified by affinity chromatography. The anti-NE antibodies were used to develop and validate an ELISA technique for measuring NE in plasma from EDTA-blood samples. Mean normal blood value was established by measuring NE level in plasma from 37 healthy horses. Blood NE level was determined in the plasma of 29 horses suffering from acute laminitis and referred by the veterinarian to our equine clinic. The NE concentration was measured from blood collected either at the admission or within the first 4 days of hospitalization. Values from healthy and laminitis horses were transformed (natural logarithm) for the normality test and then compared by using an unpaired t-test. Significance was set at p<0.05. Results: Purified equine NE was characterized by enzymatic assay and its molecular weight was 29 KDa as determined by polyacrylamide gel electrophoresis. The immunoreactivity of the antibodies isolated from guinea pig and rabbit antisera was controlled by positive radial immunodiffusion. The ELISA was sensitive (lowest limit of detection: 0.56 ng/ml) and specific for measuring NE in plasma from EDTA-blood samples. The mean plasmatic NE value ± SD in healthy horses was 32.53±28 ng/ml. In horses suffering from laminitis the mean plasmatic value was 202±187.22 ng/ml, significantly different from the normal value (p<0.0001). Discussion: Increased mean level of NE in blood of laminitis horses traduces the systemic nature of laminitis with neutrophils recruitment, activation and degranulation. These results are in agreement with a previous study which demonstrated increased MPO concentrations in blood, laminar tissues and skin of induced laminitis horses during the development phase of the disease.3 Similarly elevation of MMP-9 level in the laminar tissues is accompanied by an increased blood concentration in horses developing laminitis.1,2 As for MPO, increased NE concentrations in blood of laminitis horses could have led to or derived from an infiltration of NE in laminar tissues. NE is a serine protease mainly involved in host defense and tissue remodeling4 but various serine proteases comprising the elastases are implicated in the activation of pro-MMP into active MMP.5 Thus, by its direct ability to degrade extracellular matrix protein and by activating MMP, NE could play an important role in the enzymatic pathway of laminitis by participating to the degradation of basement membrane and dermo-epidermic separation in the laminar tissues. This study contributes to better understanding of the exact pathogenesis of laminitis and may open the field for new treatment options. References: 1. Mungall BA, Pollitt CC: Zymographic analysis of equine laminitis. Histochem Cell Biol 112:467-472, 1999. 2. Loftus JP, Belknap JK, Black SJ: Matrix metalloproteinase-9 in laminae of black walnut extract treated horses correlates with neutrophil abundance. Vet Immunol Immunopathol, 113:267-276, 2006. 3. Riggs LM, Franck T, Moore JN, et al: Neutrophil myeloperoxidase measurements in plasma, laminar tissue, and skin of horses given black walnut extract. Am J Vet Res 68:81-86, 2007. 4. Chua F, Laurent GJ: Neutrophil elastase: mediator of extracellular matrix destruction and accumulation. Proc Am Thorac Soc 3:424-427, 2006. 5. Vissers MC, Winterbourn CC: Activation of human neutrophil gelatinase by endogenous serine proteinases. The Biochem J 249:327-331, 1988

peer reviewedBackground Morbidity and mortality related to general anaesthesia is higher in horses than in most other domestic animal species (Johnston et al. 2002). A multi-centre study showed that colic is the most common post-anaesthetic complication in horses (Senior et al. 2007). However, the reason for this has not been investigated. Many drugs used in equine anaesthesia may have an impact on intestinal motility, which may explain the high incidence of colic after non-abdominal surgery. Objectives The aim of the study was (1) to evaluate the impact of general anaesthesia on the motility of the gastrointestinal tract in horses undergoing non abdominal surgery and (2) to assess the feasibility of ultrasound as a simple tool for the evaluation of gastrointestinal motility. Methods Twenty-five horses hospitalized for elective procedures were studied before and after general anaesthesia consisting of acepromazine and xylazine premedication, and midazolam and ketamine induction followed by gaseous or total intravenous anaesthesia. Post-operative time points for ultrasonography and auscultation were immediately after the recovery, 2 to 4 h, 12 to 18 h and 24 h after it. Ultrasound imaging based on a previously established protocol (Busoni et al. 2011) was used to assess the size of the stomach, the diameter and the contractility of the duodenum, the diameter and the visibility of the jejunum and the presence or absence of peritoneal fluid. Abdominal auscultation in the post-operative period was also recorded. Statistical analysis was carried by ANOVA and Chi-Square tests. Results None of the horses showed signs of colic in the post-operative period. There was a significant decrease of gut sounds in the immediate postoperative period compared to pre-anaesthetic evaluation. Ultrasound analysis in the post-operative period revealed a smaller stomach, less duodenal contractions, more visualisation of the small intestine which had a greater diameter than pre-operatively. These values returned to normal towards the end of the 24h period. Conclusions The study showed that abdominal ultrasonography is a useful tool for the real-time evaluation of gastric and small intestinal dimensions and motility in the postoperative period. Smaller stomach, larger small intestinal diameter, and less small intestinal contractions suggest a reduced small intestinal motility after non-abdominal surgery in horses. Further studies should evaluate the sensitivity of the method, investigate the impact of different anaesthetic protocols and include a population of horses suffering from post-anaesthetic colic. References Johnston, G.M., Eastment, J.K., Wood, J.L.N., Taylor, P.M. (2002) The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of phases 1 and 2. Vet. Anaesth. Analg. 29, 159-170. Senior, J.M., Pinchbeck G.L., Allister R., Dugdale A.H.A.,Clark L., Clutton R.E., Coumbe K., Dyson S., Clegg P.D. (2007) Reported morbidities following 861 anaesthetics given at four equine hospitals. Vet Rec., 160, 407-408. Busoni, V., De Busscher, V., Lopez, D., Verwhilgen, D., Cassart, D. (2011) Evaluation of a protocol for fast localised abdominal sonography of horses (FLASH) admitted for colic. Vet Journal, 188, 77-82

Abstract:[en] Juvenile interphalangeal degenerative joint disease is frequently observed in ardenner horses. The aim of this study is to established a radiographic examination's protocol of the distal limb and to apply it to ardenner horses. This investigation method ...

Le present travail a porte sur l’evaluation des proprietes anti-inflammatoires et anticancereuses de Agelanthus dodoneifolius (Loranthaceae), communement appelee «gui africain». Cette plante hemiparasite est utilisee en medecine traditionnelle africaine pour le traitement de pathologies chroniques telles que l’asthme, l’hypertension, des gastroenterites et le cancer. Actuellement, les maladies chroniques representent un probleme mondial de sante publique. En effet, elles constituent la premiere cause de mortalite dans le monde surtout dans les pays a revenu faible ou intermediaire. Cette etude a ete realisee dans le but d’apporter une validation scientifique quant a certaines utilisations traditionnelles de Agelanthus dodoneifolius. Pour evaluer l’effet anti-inflammatoire de Agelanthus dodoneifolius, nous avons teste les differentes fractions de la plante sur la production des especes reactives de l’oxygene, la liberation et l’activite specifique de la myeloperoxydase (MPO), enzyme liberee par le neutrophile au cours de la phagocytose pour detruire les microorganismes. L’identification et la quantification des composes a ete faite grâce a une combinaison des methodes chromatographiques, spectrophotometriques et spectrometriques. L’activite anticancereuse de Agelanthus dodoneifolius a consiste, d’abord, a determiner l’effet d’inhibition de croissance de diverses fractions de la plante, de la quercetine ainsi que de ses derives sur des lignees cellulaires cancereuses. Nous avons ensuite determine les effets de la quercetine sur l’activite de plus de 300 kinases. Les resultats obtenus montrent qu’Agelanthus dodoneifolius est capable de moduler les activites biologiques des neutrophiles. En effet, le decocte aqueux et les fractions organiques de la plante inhibent de maniere dose-dependante la production des especes reactives de l’oxygene, la degranulation du neutrophile et l’activite specifique de la myeloperoxydase. Nous avons pu identifier et quantifier dix composes polyphenoliques dont quatre acides phenoliques : l’acide gallique, l’acide coumarique, l’acide chlorogenique et l’acide ellagique et six flavonoides : la quercetine, le kaempferol, la catechine, l’isoquercitrine ou quercetine 3-O-glucoside, la rutine et la miquelianine ou quercetine-3-O-glucuronide. Concernant l’activite anticancereuse, les resultats montrent que seules les fractions a l’ether diethylique et a l’acetate d’ethyle ont une activite antiproliferative. La quercetine a des effets inhibiteurs de croissance, cytostatiques et presente un large spectre d’activite sur plusieurs kinases surexprimees dans certains cancers. En conclusion, l’ensemble de ces resultats constitue des bases scientifiques qui pourraient justifier certaines utilisations traditionnelles de Agelanthus dodoneifolius. A notre connaissance, cette etude est la premiere a evaluer d’une part l’effet, in vitro, des differentes fractions de Agelanthus dodoneifolius sur des neutrophiles stimules et sur la MPO et d’autre part l’effet inhibiteur de croissance de lignees cellulaires cancereuses par certaines fractions de la plante. En outre, cette etude a permis pour la premiere fois d’identifier et de quantifier des composes polyphenoliques dans Agelanthus dodoneifolius. Les nombreuses proprietes de ces composes, notamment celles anti-inflammatoires et anticancereuses, peuvent expliquer en partie les resultats reportes dans ce travail.This work focused on evaluating anti-inflammatory and anticancer activities of Agelanthus dodoneifolius (Loranthaceae), commonly called "African mistletoe". This plant is used in African traditional medicine for the treatment of chronic conditions such as asthma, hypertension, gastroenteritis and cancer. Currently, chronic diseases are a global public health problem. Indeed, they are the leading cause of death worldwide, especially in countries with low and middle income.The study was conducted to provide scientific validation for some traditional uses of Agelanthus dodoneifolius.To characterize the anti-inflammatory activity of Agelanthus dodoneifolius, we tested the different fractions of the plant on reactive oxygen species production, release and the specific activity of myeloperoxidase, an enzyme released by neutrophils during phagocytosis to destroy microorganisms. The identification and quantification of compounds were made through a combination of chromatographic, spectrophotometric and spectrometric techniques. The anticancer activity of Agelanthus dodoneifolius consisted, first, to determine, the antiproliferative effect of fractions of the plant, quercetin and its derivatives on cancer cell lines. Then, we determined the effects of quercetin on the activity of more than 300 kinases.The results show that Agelanthus dodoneifolius is capable of modulating the biological activities of neutrophils. In fact, the decoction aqueous and organic fractions of the plant inhibited in a dose-dependent manner the production of reactive oxygen species,…

Resultat d'une etude menee a l'Universite de Liege, precisant la conduite a tenir lors du traitement d'une fracture par l'utilisation combinee d'une attelle de Thomas et d'une resine 1) selectionner les animaux a traiter selon le type de fracture ou lebovin (âge, sexe); 2) preparer l'animal pour l'intervention et fabriquer l'attelle adequate; 3) mettre en place l'attelle; 4) gerer la phase postoperatoire immediate et surveiller les complications a plus ou...

This retrospective study of 206 surgical colic cases shows the incidence of the different types of pathologies. The small intestine is concerned in 106 (51,5 %) cases with 102 (96 %) strangulation obstructions. The remaining 100 cases (48,5 %) are large intestine obstructions with 45 (45 %) strangulation obstructions. The global survival rate is of 51,5 %, of 42,2 % for small intestine and of 61 % for large intestine. A gravity and a shock score permit to define the prognosis before the decision for surgery. The incidence of the postoperative complications is higher (55,2 %) and the time for recovery is significantly longer for small intestinal pathologies than for large intestine affections. Shock and paralytic ileus are the most frequent complications accounting for 65 % of post operative mortalities. The survival rates are significantly different according to gravity and shock score. The time of recovery is also significantly different in function of the shock score. These findings show the importance of rapid diagnosis of the acute abdominal disease in order to improve the outcome.Peer reviewe

Introduction : Histone deacetylases (HDAC) is a family of eighteen enzymes, which modulates the acetylation level of histones and non-histone proteins to regulate gene expression and chromatin structure. Broad-spectrum inhibitors of these enzymes such as SAHA can inhibit tumor growth both in vitro and in vivo and are currently used as anti-cancer agents in clinic. For many years, we are investigating the specific role of individual HDAC members in cancer biology and we have recently demonstrated that specific depletion of HDAC5 using siRNA technology reduced cancer cells proliferation and survival1. Aims : The goal of this study is to further understand the molecular mechanisms of action of HDAC5 in cancer cells. Methods and results : Screening transcriptomic study demonstrated that HDAC5 depletion induces a down-regulation of NDUFB5, a subunit of the complex I of the mitochondrial respiratory chain through modulation of mRNA stability. HDAC5 depletion-induced NDUFB5 downregulation causes a significant increase of ROS production and induces uncoupled mitochondrial respiration. In addition, this HDAC5 depletion-induced mitochondrial dysfunction provokes metabolic adaptation associated with increased importance of glucose. Indeed, interference with glucose supply in HDAC5-depleted cancer cells significantly increases apoptotic cell death suggesting that glucose deprivation might be combined to HDAC5 inhibition as a therapeutic strategy to kill cancer cells. Conclusions : Our study demonstrated for the first time that specific HDAC5 inhibition induces alteration of NDUFB5 gene expression by altering mRNA stability and provides insight into a valuable experimental strategy for manipulation of specific HDAC5 inhibition and glucose metabolism in therapy against cancer. 1.Peixoto, P. et al. HDAC5 is required for maintenance of pericentric heterochromatin, and controls cell-cycle progression and survival of human cancer cells. Cell death and differentiation, 2012; 1-14

Introduction : Histone deacetylases (HDAC) is a family of eighteen enzymes, which modulates the acetylation level of histones and non-histone proteins to regulate gene expression and chromatin structure. Broad-spectrum inhibitors of these enzymes such as SAHA can inhibit tumor growth both in vitro and in vivo and are currently used as anti-cancer agents in clinic. For many years, we are investigating the specific role of individual HDAC members in cancer biology and we have recently demonstrated that specific depletion of HDAC5 using siRNA technology reduced cancer cells proliferation and survival1. Aims : The goal of this study is to further understand the molecular mechanisms of action of HDAC5 in cancer cells. Methods and results : Screening transcriptomic study demonstrated that HDAC5 depletion induces a down-regulation of NDUFB5, a subunit of the complex I of the mitochondrial respiratory chain through modulation of mRNA stability. HDAC5 depletion-induced NDUFB5 downregulation causes a significant increase of ROS production and induces uncoupled mitochondrial respiration. In addition, this HDAC5 depletion-induced mitochondrial dysfunction provokes metabolic adaptation associated with increased importance of glucose. Indeed, interference with glucose supply in HDAC5-depleted cancer cells significantly increases apoptotic cell death suggesting that glucose deprivation might be combined to HDAC5 inhibition as a therapeutic strategy to kill cancer cells. Conclusions : Our study demonstrated for the first time that specific HDAC5 inhibition induces alteration of NDUFB5 gene expression by altering mRNA stability and provides insight into a valuable experimental strategy for manipulation of specific HDAC5 inhibition and glucose metabolism in therapy against cancer. 1.Peixoto, P. et al. HDAC5 is required for maintenance of pericentric heterochromatin, and controls cell-cycle progression and survival of human cancer cells. Cell death and differentiation, 2012; 1-14

Introduction: Histone deacetylases (HDAC) is a family of eighteen enzymes which modulates the acetylation level of histones and non-histone proteins to regulate gene expression and chromatin structure. Broad spectrum inhibitors of these enzymes such as SAHA can inhibit tumor growth both in vitro and in vivo and are currently used as anti-cancer agents in clinic. For many years, we are investigating the specific role of individual HDAC members in cancer biology and we have recently demonstrated that depletion of HDAC5 using siRNA technology triggered cancer cells to both autophagy and apoptosis (ref papier). The study of autophagy in cancer is a new research field that has recently generated tremendous attention due to the recognition that autophagy can have either pro-survival or pro-death functions depending on its level of activation. In addition, more and more studies indicate that a complex relationship exists between autophagy and apoptosis, and that the interplay between these two processes determines whether a cell will live or die. Aims: The goal of this study is to further understand the role of autophagy induced by HDAC5 depletion. Current investigations include determining the molecular mechanisms by which HDAC5 depletion induces autophagy and exploring regulatory relationship between autophagy and apoptosis on cancer cell death in absence of HDAC5. Results: The set up of the autophagy in absence of HDAC5 was demonstrated by the conversion of LC3 and development of autophagosomes by electronic microscopy. Transcriptomic study demonstrated a deregulation of a set of genes involved in ROS detoxification in HDAC5 depleted cancer cells leading to significant increase of ROS levels. Further investigations showed that pretreatment with NAC, a ROS scavenger, effectively blocked the accumulation of ROS and autopahgy triggered by HDAC5 silencing. Moreover, HDAC5 depletion induces activation of JNK, and knockdown of JNK by siRNA inhibited ROS production and autophagy, but antioxidant NAC failed to block JNK activation induced by HDAC5 depletion indicating that JNK activation may be a upstream signaling of ROS and should be a core component in HDAC5 silencing-induced autophagic signaling pathway. Finally, blocking of autophagy induced by HDAC5 silencing with NAC or chloroquine and bafilomycin enhanced pro-apoptotic effect. Conclusion: Autophagy functions as a prosurvival mechanism to mitigate HDAC5 depletion-induced apoptotic cell death, suggesting that targeting autophagy might improve the therapeutic effects of specific HDAC5 inhibition

Intense exercice causes alterations in innate immune system functions and produces a systemic inflammatory reaction characterized by a neutrophil activation leading to an oxidative stress. Reactive oxygen species are mainly generated by activated neutrophils or by mitochondrial dysfunction. Recently, the links between inflammation and mitochondria were clearly demonstrated. Myeloperoxidase, a potent oxidative enzyme, released by activated neutrophils enters in the muscle cells and inhibits the mitochondrial electron transfer chain especially the complex 1. Strenuous exercises undertaken by horses (or camels) during endurance races induce a marked increase of myeloperoxidase and elastase plasma concentration. These enzymes could be responsible for tissue lesions observed in sport horses such as myopathy, tendinitis, fracture or degenerative joint disease. However, large differences exist between the horses for the similar level of exercise. Inflammatory airway disease is an important cause of poor performance in young Thoroughbred racehorses. Neutrophil percentage, myeloperoxidase concentration, haemosiderophage percentage and total bacterial numbers were significantly elevated in broncho alveaolar fluid in horses with exercise intolerance. As camels can be affected by exercise induced pulmonary hemorrhage or other respiratory diseases, we hypothesized that systemic and/or local inflammation leading to oxidative stress and mitochondrial dysfunction occur in this species.

Introduction: Equine joint infection is a life-threatening disorder. A presumptive diagnosis is commonly based on synovial fluid total and differential white blood cell counts together with total protein levels and is confirmed with a positive bacterial culture. However, cytological results are not always conclusive and up to 45% of the cultures may remain negative, depending on the method used. Efforts to define novel biomarkers for the discrimination of infectious and non-infectious joint disease, such as the synovial fluid D-dimer and serum amyloid A concentration and the neutrophil viability, were recently reported (Jacobsen et al., 2006; Wauters et al., 2010; Ribera et al., 2011). In the current study, myeloperoxidase (MPO), an anti-bacterial enzyme of the neutrophils involved in the production of reactive oxygen species, was evaluated as a candidate biomarker. Detection of MPO has rapidly gained importance in the diagnosis of equine gastro-intestinal, pulmonary and orthopaedic disease (Fietz et al., 2008). We therefore aimed to investigate the synovial fluid levels of both the total (= sum of enzymatically active and inactive fractions) MPO and enzymatically active MPO fraction in patients by immunological detection. Materials and methods: Four patient groups were included: (1) 29 healthy horses (29 joints), (2) 24 horses with OCD-caused synovitis (24 joints), (3) 16 horses with traumatic non-infectious synovitis (16 joints) and (4) 17 horses with culture confirmed infectious synovitis (19 joints). Diseased joint samples were obtained from client-owned horses, while healthy joints were obtained from slaughterhouse horses. Samples were collected in EDTA tubes after standard surgical preparation of the synoviocentesis sites. The total nucleated and differential cell count was performed with an automated blood counter prior to cell fraction isolation. Synovial fluid viscosity was therefore decreased with hyaluronidase before collecting the supernatants by 10 min centrifugation at 500 g at 4°C and storage at - 80°C prior to analysis. Total MPO was measured with a commercial horse-specific sandwich ELISA, while the active MPO fraction was monitored by the SIEFED (specific immunological extraction followed by enzymatic detection) technique, both according to the manufacturers’ recommendations but with adaptation of the dilution factor (Franck et al., 2005 and 2006). The ELISA and SIEFED methods resulted in skewed data that were evaluated through non-parametric statistical analysis (Kruskal-Wallis with Post-Hoc Dunn’s multiple comparison test). Results: Statistically significant differences were observed between patient groups for both total and active MPO (p < 0.0001). As illustrated in Figure 1 and 2, samples of infected joints contained significantly more MPO protein compared to samples from healthy horses (p < 0.001), OCD horses (p < 0.001) and horses diagnosed with severe traumatic non-infectious synovitis (p < 0.01). The same was true for the active MPO concentration but SIEFED determination also showed a significantly higher MPO value in traumatic non-infectious synovitis samples compared to the healthy control group (p < 0.01). Routine synovial fluid analysis results are shown in Table 1 for each patient group. No correlation was observed between the synovial fluid MPO concentrations and the total and differential nucleated cell counts and only a weak correlation could be observed with the synovial fluid total protein levels. Discussion: Synovial fluid total and active MPO levels are demonstrated to be higher in infected compared to either non-infected traumatic or OCD-related or healthy samples. Interestingly, the MPO concentration was not correlated with the synovial fluid cell counts or differentiation and therefore we suggest MPO might be a valuable biomarker to include in the diagnostic tool kit for infectious arthritis, particularly in these cases where synovial fluid cytological results are not conclusive for infectious synovitis. Both techniques (cytology and MPO determination) could therefore be used complementary to each other to predict more accurately whether a sample is infected. A larger clinical study should however still be undertaken to determine an MPO cut-off value that can be used in clinical circumstances. Results obtained for ELISA and SIEFED were comparable and thus only one of both techniques should be adapted for clinical use. Both techniques allow quasi immediate results, in contrast to bacterial culture, and are easy to perform. The potential of a customized low-cost one-sample ELISA for quick and easy reading (as in e.g. the “snap-foal” test) seems to favour determination of total MPO. Nevertheless, further research should first elucidate whether the level of active MPO could be correlated with other clinically interesting parameters such as joint damage and long-term outcome, as this would favour commercialisation of SIEFED detection compared to ELISA.

Cardiomyoplasty is a wrapping of an electrostimulated latissimus dorsi muscle flap around the heart for substitution and/or reinforcement. The surgical technique for reproducible cardiomyoplasties in the goat model is presented. The methods combine the direction of wrapping (clockwise, counter-clockwise) and the orientation of muscle fibers. A cardiomyoplasty model using right and left latissimus dorsi or left latissimus dorsi and pectoralis major as well as a split muscle technique are illustrated.

In locomotor biomechanics, three high groups of contraints are commonly encountared : pressure, traction and torsion. In supra-maximal conditions, all of these contraints would be responsible of some equine diseased locomotor systems. In order to understand better the contraints in the equine locomotor dynamics, some investigations have been carried out. Moreover, some measurement methods, based on the mechanics of Newton, have been performed. This review shows the different measurement techniques and introduces the mechanical basis that are compulsory for the understanding of the equine locomotor apparatus functioning.Peer reviewe

We are interested in a possible role of synoviocytes in the ROS production implicated in osteoarthritis, therefore we studied the response of a rabbit synoviocyte cell line (HIG-82) to variable oxygen tensions and the oxidant activity of these cells in response to stimuli. Synoviocytes were cultured at 5 and 21 % O2, their O2 consumption (cellular respiration, monitored with Clark electrode) was measured at 21% O2 and after anoxia, before and after stimulation with phorbol myristate acetate (PMA), and their oxidant response to PMA stimulation was quantified by measuring ethylene (gas chromatography) released when the substrate, alpha-keto-gamma-methylbutyric acid, is oxidised by the ROS produced by the cells. Cell growth was faster at 21 % O2 than at 5% O2, and microscopic observation revealed 2 cell populations: a few small round cells in suspension and many adherent cells. By oxymetry, we observed that a 106 synoviocytes suspension in 2 ml completely consumed O2 within 15 min, that anoxia (7 min) slightly slowed the respiration rate down and that PMA stimulation increased O2 consumption (150 % increase). The oxidant activity (ethylene production) of the cells was stimulated by PMA in a dose-dependent manner (10-9 to 10-7M) but the cell response was highly variable (from 150 to 1500 % increase) and was largely reduced by diphenyliodonium, an inhibitor of NADPH-oxidase and NO-synthase. The capacity to produce free radical species was confirmed for the small round cells by detection of an electron paramagnetic resonance (EPR) signal after stimulation. These results thus demonstrate a sensibility to O2 and an oxidant activity of synoviocytes at least related to ROS production by NADPH-oxidase activity