References of "Baise, Etienne"
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See detailEquine cadaver ligaments : A new promising source of stem cells
Shikh Al Sook, Mohamad Khir ULg; Gabriel, Annick ULg; Salouci, Moustafa et al

Poster (2015)

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See detailCharacterization of collagen fibrils after equine suspensory ligament injury: an ultrastructural and biochemical approach
Shikh Al Sook, Mohamad Khir ULg; Gabriel, Annick ULg; Salouci, Moustafa et al

in Veterinary Journal (2015)

Suspensory ligament (SL) injuries are an important cause of lameness in horses. The mechanical properties of connective tissue in normal and pathological ligaments are mainly related to the fibril ... [more ▼]

Suspensory ligament (SL) injuries are an important cause of lameness in horses. The mechanical properties of connective tissue in normal and pathological ligaments are mainly related to the fibril morphology, as well as the collagen content and types. The purpose of this study was to evaluate, using biochemical and ultrastructural approaches, the alterations in collagen fibrils after injury. Eight Warmblood horses with visible signs of injury in only one forelimb SL were selected and specimens were examined by transmission electron microscope (TEM). Collagen types I, III and V were purified by differential salt precipitation after collagen extraction with acetic acid containing pepsin. TEM revealed abnormal organization as well as alterations in the diameter and shape of fibrils after SL injury. The bands corresponding to types I, III and V collagen were assessed by densitometry after sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric analysis indicated that the proportions of type III and type V collagen were significantly higher (P <0.001) in damaged tissues compared to normal tissues with a mean increase of 20.9 and 17.3% respectively. Concurrently, a significant decrease (P <0.001) in type I collagen within damaged tissues was recorded with a mean decrease of 15.2%. These alterations could be the hallmark of a decrease in the tissue quality and mechanical properties of the ligament. This provides new insight for subsequent research on tissue regeneration that may lead to the development of future treatment strategies for SL injury. [less ▲]

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See detailLes nouveaux outils de diagnostic et de pronostic de la myopathie atypique
Habyarimana, Jean ULg; BOEMER, François ULg; Amory, Hélène ULg et al

in Proceeding de la 41ème Journée de la Recherche équine (2015)

In equines, ingestion of hypoglycin A, a toxin produced in the seeds (samaras) of sycamore maple (Acer pseudoplatanus) tree alters the energetic metabolism of muscle cells and results in atypical myopathy ... [more ▼]

In equines, ingestion of hypoglycin A, a toxin produced in the seeds (samaras) of sycamore maple (Acer pseudoplatanus) tree alters the energetic metabolism of muscle cells and results in atypical myopathy (AM). This alterations leads to a characteristic biochemical profile of acylcarnitines (AC) that enables to confirm the diagnosis of AM. This study aims at validating a methodology for the dosage of hypoglycin A in vegetal extracts but also in blood. In addition, the biochemical profile in AC has been determined in AM cases (5 survivors and 13 deceased) and in 5 horses suffering from exercise-induced myopathy. The AC profiles of these horses have been compared to the one of healthy horses (n = 35). This study showed that hypoglycin A was present in seeds and spring seedlings of sycamore and also in blood of AM cases horses. In addition, the establishment of AC profile contributes to the diagnostic and helps to assess the prognosis of AM cases. [less ▲]

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See detailCharacterization of collagen fibrils after equine suspensory ligament injury: an ultrastructural and biochemical approach
Shikh Al Sook, Mohamad Khir ULg; Gabriel, Annick ULg; Salouci, Moustafa et al

Poster (2014, October 19)

Suspensory ligament (SL) injuries are an important cause of lameness in horses. The mechanical properties of connective tissue in normal and pathological ligaments are mainly related to the fibril ... [more ▼]

Suspensory ligament (SL) injuries are an important cause of lameness in horses. The mechanical properties of connective tissue in normal and pathological ligaments are mainly related to the fibril morphology, as well as the collagen content and types. The purpose of this study was to evaluate, using biochemical and ultrastructural approaches, the alterations in collagen fibrils after injury. Eight Warmblood horses with visible signs of injury in only one forelimb SL were selected and specimens were examined by transmission electron microscope (TEM). Collagen types I, III and V were purified by differential salt precipitation after collagen extraction with acetic acid containing pepsin. TEM revealed abnormal organization as well as alterations in the diameter and shape of fibrils after SL injury. The bands corresponding to types I, III and V collagen were assessed by densitometry after sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric analysis indicated that the proportions of type III and type V collagen were significantly higher (P <0.001) in damaged tissues compared to normal tissues with a mean increase of 20.9 and 17.3% respectively. Concurrently, a significant decrease (P <0.001) in type I collagen within damaged tissues was recorded with a mean decrease of 15.2%. These alterations could be the hallmark of a decrease in the tissue quality and mechanical properties of the ligament. This provides new insight for subsequent research on tissue regeneration that may lead to the development of future treatment strategies for SL injury. [less ▲]

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See detailQuantitative Analysis of the Relative Abundance Changes Observed in Type I, III and V Collagen after Suspensory Ligament Injuries in Horses
Shikh Al Sook, Mohamad Khir ULg; Baise, Etienne ULg; Piret, Joëlle ULg et al

in Anatomia, Histologia, Embryologia (2014, July)

Introduction: The equine suspensory ligament (SL) injuries are an important cause of lameness in horses. Quantification of the relative abundance of the constitutive collagen types is essential to ... [more ▼]

Introduction: The equine suspensory ligament (SL) injuries are an important cause of lameness in horses. Quantification of the relative abundance of the constitutive collagen types is essential to investigate the differences between normal and injured tissues. The aim of this original study was to precisely determine the different collagen ratios both in injured and normal SL. This approach is a rational step towards understanding the intimate mechanisms of SL repair and regeneration at the molecular and histological levels. Methods: Five Warmblood horses with visible signs of injury in only one forelimb SL were selected. Specimens were obtained from the central core of lesions in damaged SLs and from the corresponding regions in other healthy SLs. Collagen types I, III and V were purified by differential salt precipitation after collagen extraction with acetic acid containing pepsin and they were examined by transmission electron microscopy. The bands corresponding to types I, III, and V collagen were assessed by densitometry after SDS-PAGE. SAS software (SAS Institute 2001) was used for all statistical analyses. Results: Based on ultrastructural observations, purified fibers of types I, III, and V collagens have been identified. The relative proportions of type III and type V collagen were significantly higher in the specimens‎ from damaged tissue compared with specimens from normal tissue (P < 0.001). These changes were concomitant with significant decrease in type I collagen in the injured tissue (P < 0.001). Conclusions: Our study showed that after SL injury, the relative abundance of the different collagen types is modified. These changes are the molecular hallmark of a decrease in tissue quality and mechanical properties of the ligament. It lays down the bases of subsequent researches on the tissue regeneration that may lead to the development of new treatment strategies for damaged tissues, particularly in the equine SL injuries. [less ▲]

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See detailIn vitro culture of seal muscle-derived satellite cells
Freichels, Astrid ULg; Baise, Etienne ULg; Jauniaux, Thierry ULg et al

Poster (2014, April)

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See detailContribution à l’étude de l’activité antivirale et du mécanisme moléculaire de la MX1 bovine
Baise, Etienne ULg

Doctoral thesis (2009)

Summary Type I interferons (IFNs a/b) induce the synthesis of many factors belonging to the innate immune system which is known to play an essential role as the first defence line against the viral ... [more ▼]

Summary Type I interferons (IFNs a/b) induce the synthesis of many factors belonging to the innate immune system which is known to play an essential role as the first defence line against the viral infection. Among these contributors, the MX protein (a member of the large GTPase family) along with the double stranded (ds) RNA dependent protein kinase R (PKR) and the 2’5’ oligoadenylate synthetase/Rnase L system, has been shown to be one of the most efficient among the murine and the human species. The bovine counterpart of the MX system was, at the beginning of this work, described at the sole gene level (the CDS sequence) but its functional capacity was still totally unexplored. Accordingly, our first aim was to assess the ability of the bovine GTPase we called boMX1 to inhibit viruses infecting cattle. A Vero cell line (V103) conditionally expressing the boMX1 was established. To proof the concept, we firstly tested the inhibition of a canonical virus on this field, the vesicular stomatitis virus (VSV) which was confirmed to be as sensitive to boMX1 as previously shown to MXA (Homo sapiens). In a second step, we focused our investigation on the activity of boMX1 against two Paramyxoviridae viruses, the boRSV and the boPI3, both of these being sensitive to IFNs as reported in the literature and furthermore confirmed by our previous in vitro experiments. Although boMX1 was expected to be the most important factor of the type I interferon resistance recorded against boPI3 and boRSV, our study has shown that the bovine protein was not able to block these viruses belonging to the Respirovirus genus. Conversely, the famous Orthomyxoviridae virus member, Influenza A was shown to be almost completely inhibited in cells expressing boMX1. The inhibitory potential of boMX1 was so strong it could only be measured upon the replacement of the low pathogenic H1N1 strain used in the first assays by the hypervirulent H7N7 one. In this case, the protection rate was as high as 108. Typically, the value found for the human counterpart MXA is in the range of 103 – 104 and according to our knowledge, none of the MX proteins investigated so far have never been shown to be so effective against Influenza A. In the wave of these results, the well-known avian H5N1 Influenza A strain has been tested in vitro and in vivo. All the data reinforced the concept of a very high anti-Influenza A activity for BoMX1. A such important antiviral effect appeared as an opportunity to initiate an experimental approach of the largely unknown underlying mechanism(s) of the MX antiviral activity. Our first objective was to identify the “primum movens” of the inhibition mechanism. Therefore, we followed the kinetic of the infection in V103 expressing or not the boMX1 during one single cycle. The evidence of an important activity of the bovine GTPase in the first hours post-infection led us to identify at the RNA level which replication step was the first to be blocked. Following the collected results, we adapted a primer extension method to quantify the genomic viral RNA (vRNA) early entry in the induced and non induced cell cultures. Finally, we tested a first interaction hypothesis between the boMX1 and a potential interacting protein sister. [less ▲]

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See detailFlow Cytometric Probing of Mitochondrial Function in Equine Peripheral Blood Mononuclear Cells
Cassart, Dominique ULg; Fett, Thomas ULg; Sarlet, Michaël ULg et al

in BMC Veterinary Research (2007), 3

BACKGROUND: The morphopathological picture of a subset of equine myopathies is compatible with a primary mitochondrial disease, but functional confirmation in vivo is still pending. The cationic dye JC-1 ... [more ▼]

BACKGROUND: The morphopathological picture of a subset of equine myopathies is compatible with a primary mitochondrial disease, but functional confirmation in vivo is still pending. The cationic dye JC-1 exhibits potential-dependent accumulation in mitochondria that is detectable by a fluorescence shift from green to orange. As a consequence, mitochondrial membrane potential can be optically measured by the orange/green fluorescence intensity ratio. A flow cytometric standardized analytic procedure of the mitochondrial function of equine peripheral blood mononuclear cells is proposed along with a critical appraisal of the crucial questions of technical aspects, reproducibility, effect of time elapsed between blood sampling and laboratory processing and reference values. RESULTS: The JC-1-associated fluorescence orange and green values and their ratio were proved to be stable over time, independent of age and sex and hypersensitive to intoxication with a mitochondrial potential dissipator. Unless time elapsed between blood sampling and laboratory processing does not exceed 5 hours, the values retrieved remain stable. Reference values for clinically normal horses are given. CONCLUSION: Whenever a quantitative measurement of mitochondrial function in a horse is desired, blood samples should be taken in sodium citrate tubes and kept at room temperature for a maximum of 5 hours before the laboratory procedure detailed here is started. The hope is that this new test may help in confirming, studying and preventing equine myopathies that are currently imputed to mitochondrial dysfunction. [less ▲]

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See detailMorphological alterations in oxidative muscles and mitochondrial structure associated with equine atypical myopathy
Cassart, Dominique ULg; Baise, Etienne ULg; Cherel, Yann et al

in Equine Veterinary Journal (2007), 39(1), 26-32

REASONS FOR PERFORMING STUDY: There is a lack of well documented studies about muscular lesions in equine atypical myopathy (EAM). <br /> <br />OBJECTIVES: To characterise morphopathological changes of ... [more ▼]

REASONS FOR PERFORMING STUDY: There is a lack of well documented studies about muscular lesions in equine atypical myopathy (EAM). <br /> <br />OBJECTIVES: To characterise morphopathological changes of striated muscles and myocardium, to progress understanding of this disease. <br /> <br />METHODS: Thirty-two horses age 0.5-7 years kept on pasture were referred for a sudden ataxia/myoglobinuria syndrome. Clinical examination (stiffness, muscle pain, muscle fasciculations, abnormal gait, recumbency, myoglobinuria, tachycardia, sweating) and plasma CPK, LDH and AST levels were consistent with extensive myonecrosis and, together with anamnestic data, with so-called 'equine atypical myopathy' (EAM), a disease of unknown aetiology reported since 1939. Macroscopic and microscopic (histology, histoenzymology, ultrastructure) lesions were evaluated. <br /> <br />RESULTS: Necropsic examination revealed large areas of muscle necrosis, the extent and severity of which varied between cases and muscles, but which were clearly more constant and severe in respiratory and postural muscles and in the myocardium. Histology highlighted a multifocal and monophasic process compatible with Zenker degeneration/necrosis that mostly and segmentally affected type 1 fibres. Histochemical evaluation revealed a weak and disorganised pattern of NADH tetrazolium reductase staining, the absence of calcium salts precipitates and a dramatic accumulation of lipid droplets. Ultrastructural examination often revealed fibres of which the sole modifications were altered mitochondria and sarcoplasmic lipidosis. <br /> <br />CONCLUSIONS: Taken together, the data suggest that a primary alteration of mitochondria should be considered, although secondary mitochondrial abnormalities have yet to be ruled out. <br /> <br />POTENTIAL RELEVANCE: The morphological features gathered here reveal that EAM shares most of the characteristics of toxic myopathies. [less ▲]

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See detailContribution of MX dynamin, oligoadenylate synthetase, and protein kinase R to anti-paramyxovirus activity of type-1 interferons in vitro
Leroy, M.; Baise, Etienne ULg; Pire, G. et al

in American Journal of Veterinary Research (2007), 68

OBJECTIVE: To determine the contribution of MX dynamin, oligoadenylate synthetase (OAS), and double-stranded RNA-dependent protein kinase R (PKR) to the antiviral effects of type 1 interferons (IFNs ... [more ▼]

OBJECTIVE: To determine the contribution of MX dynamin, oligoadenylate synthetase (OAS), and double-stranded RNA-dependent protein kinase R (PKR) to the antiviral effects of type 1 interferons (IFNs) against bovine parainfluenza-3 virus (PI-3V) infection of Vero cells. SAMPLE POPULATION: Vero cell cultures. PROCEDURES: PI-3V yield was first compared between control and transfected type 1 IFNs-incompetent Vero cells expressing recombinant OAS or MX proteins. Afterwards, phosphorylation of eukaryotic initiation factor 2 alpha (eIF2alpha) was used to scale the degree of PKR activation upon infection of Vero cells by PI-3V. RESULTS: Overexpression of OAS did not result in significantly decreased viral replication. Phosphorylated eIF2alpha forms, the hallmark of PKR activation, were not increased in IFNalpha-primed infected Vero cells. Although human MXA contributed to partial blockade of replication of bovine PI-3V, the antiviral effect was not as strong as that of IFNalpha. CONCLUSIONS AND CLINICAL RELEVANCE: The powerful anti-Paramyxovirus activity of type 1 IFNs is mediated by noncanonic pathways. [less ▲]

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See detailExpression of the interferon-alpha/beta-inducible bovine Mx1 dynamin interferes with replication of rabies virus
Leroy, Michael; Pire, Grégory; Baise, Etienne ULg et al

in Neurobiology of Disease (2006), 21(3), 515-521

Rabies is a fatal anthropozoonotic viral infection of the central nervous system that remains a serious public health problem in many countries. As several animal cases of spontaneous survival to ... [more ▼]

Rabies is a fatal anthropozoonotic viral infection of the central nervous system that remains a serious public health problem in many countries. As several animal cases of spontaneous survival to infection were reported and because type 1 interferons were shown to protect against the virus, it was suggested that innate resistance mechanisms exist. Among the antiviral proteins that are synthesized in response to interferon-alpha/beta stimulation, Mx proteins from several species are long known to block the replication of vesicular stomatitis virus (VSV). As both VSV and rabies virus belongs to the Rhabdoviridae family, this study was started with the aim to establish whether the anti-VSV activity of a mammalian Mx protein could be extended to rabies virus. This question was addressed by inoculating the virus onto a bovine Mx1 or human MxA-expressing Vero cell clone. Plaque formation was unambiguously blocked, and viral yields were reduced 100- to 1000-fold by bovine Mx1 expression for both SAG2 and SADB19 viral strains. In opposition, only SAG2 strain could be inhibited by the expression of human MxA protein. The effect of both proteins expression was then evaluated at the viral protein expression level. Again, boMx1 was able to repress protein expression in both strain, whereas only SAG2 proteins were inhibited in human MxA-expressing cells. These results suggest that protection conferred by interferon-alpha/beta against rabies could be, at least partially, attributable to the Mx pathway. Alternatively, bovine Mx1 could be unique in its ability to repress rabies virus which, if confirmed in vivo, would open an avenue for the development of new antirabies therapeutic strategies. [less ▲]

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See detailResistance of paramyxoviridae to type I interferon-induced Bos taurus Mx1 dynamin
Leroy, Michael; Baise, Etienne ULg; Pire, Grégory et al

in Journal of Interferon & Cytokine Research (2005), 25(4), 192-201

Typical targets of type I interferon (IFN)-induced antiviral Mx proteins known to date have been shown to share a common profile: single-stranded negative-sense RNA viruses. Among them, human MxA is known ... [more ▼]

Typical targets of type I interferon (IFN)-induced antiviral Mx proteins known to date have been shown to share a common profile: single-stranded negative-sense RNA viruses. Among them, human MxA is known to interfere with the replication of measles, human, and bovine parainfluenza-3 viruses (BoPi3V), that is, three members of the Paramyxoviridae family. Recently, bovine Mx1 protein (BoMx1) was included in the group of Mx proteins with authenticated antiviral potential, as it dramatically represses the replication of vesicular stomatitis virus (VSV). As replication in bovine cells of Pi3, respiratory syncytial (RS), and Sendai (Se) viruses, all members of the same family, is known to be reduced on IFN-alpha incorporation into the culture medium, it was hypothesized that the BoMx1 pathway possibly was involved, its antiviral spectrum thus probably extending to Paramyxoviridae. In this study, probing of BoMx1-inhibiting effects was carried out by infecting a transgenic Vero cell line that allows tightly regulated conditional expression of BoMx1 after doxycycline treatment with a wide array of Paramyxoviridae. Expressing and nonexpressing cells displayed similar viability, cytopathic effects (CPEs), and amounts of infectious virus yields, whatever the infecting virus or the multiplicity of infection (moi) imposed. It is, therefore, concluded that BoMx1 does not interfere with Paramyxoviridae. [less ▲]

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See detailCloning and characterisation of the primary structure of the sheep lymphocyte function-associated antigen-1 alpha subunit
Fett, Thomas ULg; Zecchinon, Laurent ULg; Baise, Etienne ULg et al

in Molecular Immunology (2005), 42(12), 1503-1508

The leukocyte integrins play a critical role in a number of cellular adhesive interactions during the immune response. The ovine cDNA encoding CD1 1a, the predominant a subunit of the beta(2)-integrin ... [more ▼]

The leukocyte integrins play a critical role in a number of cellular adhesive interactions during the immune response. The ovine cDNA encoding CD1 1a, the predominant a subunit of the beta(2)-integrin family, was sequenced and compared with the human, bovine and murine sequences. Despite some focal differences, it shares all the main characteristics of its known mammalian homologues. Along with the ovine CD18-encoding cDNA, which is available for a few months, the sequence data provided here will allow the Ovis aries beta(2)-integrin CD1 1a/CD18 (LEA-1, alpha(L)beta 2) expression in vitro as a tool to examine the specificities of inflammation in the ovine species. (c) 2005 Elsevier Ltd. All rights reserved. [less ▲]

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See detailMolecular characterization of the caprine (Capra hircus) lymphocyte function-associated antigen-1 alpha subunit
Fett, Thomas ULg; Zecchinon, Laurent ULg; Baise, Etienne ULg et al

in BMC Veterinary Research (2005)

Background: Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alpha L beta 2) is required for many cellular adhesive interactions during the immune response. Results: The Capra hircus CD11a ... [more ▼]

Background: Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alpha L beta 2) is required for many cellular adhesive interactions during the immune response. Results: The Capra hircus CD11a-encoding cDNA was sequenced and compared with its human, murine, rat, bovine and ovine counterparts. Despite some focal differences, it shares all the main characteristics of its known mammalian homologues. Conclusion: Therefore, along with the caprine CD18-encoding cDNA, which has been available for a few months, the sequence data revealed here will allow the Capra hircus LFA-1 expression in vitro as a tool to explore the specificities of inflammation in the caprine species. [less ▲]

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See detailClues for Differential Diagnosis of atypical myopathy
Votion, Dominique ULg; Amory, Hélène ULg; Sandersen, Charlotte ULg et al

in Proceeding of the Maastricht International Congress on Equine Medicine (MICEM) (2004, December)

Atypical myopathy (AM), also called “atypical myoglobinuria”, is a frequently and rapidly fatal myopathy of unknown origin occurring sporadically in grazing horses. As opposed to the exertional ... [more ▼]

Atypical myopathy (AM), also called “atypical myoglobinuria”, is a frequently and rapidly fatal myopathy of unknown origin occurring sporadically in grazing horses. As opposed to the exertional rhabdomyolysis syndrome (ERS), clinical signs of AM are not induced by exercise. The condition has been reported in several European countries including Belgium, France, Germany and Great Britain. Clinical signs of AM are characterised by muscular weakness, stiffness, recumbency, sweating and when urine is observed, myoglobinuria. These signs are characteristic but not pathognomonic of the disease; the differential diagnosis of sudden weakness, severe myopathy and/or unexpected death includes several neurogenic and myopathic disorders. The main pathologies that share clinical similarities with AM include the acute form of grass sickness (GS), acute piroplasmosis, botulism, ERS, the hyperkalemic periodic paresis (HPP), nutritional myopathy (NM; i.e. vitamin E and/or selenium deficiency), plants or drugs (i.e. ionophores intoxication) intoxication, tetanus and postanaesthesia myopathy. This report aims at reviewing key facts in history, clinical signs, clinical examination and laboratory findings that contribute towards the diagnosis of AM and/or invalidate the diagnosis of other pathologies. [less ▲]

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See detailAtypical Myopathy (Atypical Myoglobinuria)
Votion, Dominique ULg; Amory, Hélène ULg; Demoulin, Vincent ULg et al

in IVIS Reviews in Veterinary Medicine (2004)

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