Arterial head vascularization cartographies of normal metencephalic dogs using magnetic resonance angiography

in Anatomical Record : Advances in Integrative Anatomy and Evolutionary Biology (2011), 294

Morphological and histological studies of sheep’s brain

Poster (2010)

Introduction: The study of normal structures of the sheep’s brain is very important to understand pathological changes caused by the bluetongue virus in the fetus’s brain at various stages of the ... [more ▼]

Introduction: The study of normal structures of the sheep’s brain is very important to understand pathological changes caused by the bluetongue virus in the fetus’s brain at various stages of the gestation. Bluetongue is an arthropod-borne viral disease of domestic and wild ruminants. The serotype 8 is responsible for outbreaks in Northern Europe in 2006. This virus causes lesions in the brain of fetuses as hydrancephaly and porencephaly. The aim of this work is to improve knowledge of anatomy and histology of the central nervous system of the sheep. Methods: Seven heads of adult sheep and one from a fetus aged 4,5 months were used. All heads were first opened in the frontal area using bone’s saw and immerged in a formalin solution for 10 days. After a good fixation, the brains were extracted and sectioned. Transversal, frontal and sagittal sections were realized. The sections of two brains were stained with Berlin-blue and treated to be embedded in methylmetacrylate for gross morphology. The different parts of the 6 resting brains were then embedded in paraffin, cut and the histological sections were stained with haematoxylin/eosin, cresyl violet or by use of silver impregnation. Results: Gross morphological examination of the brains embedded in methylmetacrylate showed the detailed anatomy of the different parts. The staining with haematoxylin/eosin permitted to differentiate the grey matter, the different nucleus and the layers of cerebral and cerebellum cortex. The cresyl violet technique permitted to visualize the Nissl bodies and the silver impregnation revealed nerve fibers. In the fetus brain, blood vessels were very numerous in the brainstem, the cerebellum and the cerebrum. The grey matter was less organized and looser. Conclusion: This work establishes an anatomical and histological approach allowing future studies in ovine fetuses with and without brain lesions potentially caused by the bluetongue virus. [less ▲]

Study of brain vascularisation of normal dogs using angiographic magnetic resoinance techniques

Poster (2009)

Magnetic resonance imaging arteriography of canine normal brain: an anatomic study

Poster (2008)

Neuroimmune connections in jejunal and ileal Peyer's patches at various bovine ages: potential sites for prion neuroinvasion

in Cell & Tissue Research (2007), 329(1), 35-44

During preclinical stages of cattle orally infected with bovine spongiform encephalopathy (BSE), the responsible agent is confined to ileal Peyer's patches (IPP), namely in nerve fibers and in lymph ... [more ▼]

During preclinical stages of cattle orally infected with bovine spongiform encephalopathy (BSE), the responsible agent is confined to ileal Peyer's patches (IPP), namely in nerve fibers and in lymph follicles, before reaching the peripheral and central nervous systems. No infectivity has been reported in other bovine lymphoid organs, including jejunal Peyer's patches (JPP). To determine the potential sites for prion neuroinvasion in IPP, we analyzed the mucosal innervation and the interface between nerve fibers and follicular dendritic cells (FDC), two dramatic influences on neuroinvasion. Bovine IPP were studied at three ages, viz., newborn calves, calves less than 12 months old, and bovines older than 24 months, and the parameters obtained were compared with those of JPP. No differences in innervation patterns between IPP and JPP were found. The major difference observed was that, in calves of less than 12 months, IPP were the major mucosal-associated lymphoid organ that possessed a large number of follicles with extended FDC networks. Using a panel of antibodies, we showed that PP in 24-month-old bovines were highly innervated at various strategic sites assumed to be involved in the invasion and replication of the BSE pathogen: the suprafollicular dome, T cell area, and germinal centers. In PP in calves of less than 12 months old, no nerve fibers positive for the neurofilament markers NF-L (70 kDa) and NF-H (200 kDa) were observed in contact with FDC. Thus, in view of the proportion of these protein subunits present in neurofilaments, the innervation of the germinal centers can be said to be an age-dependent dynamic process. This variation in innervation might influence the path of neuroinvasion and, thus, the susceptibility of bovines to the BSE agent. [less ▲]

Morphology of the stifle menisci in dogs: preliminary study

in Slovenian Veterinary Research (2007), 44

Distribution of nerve fibres in bovine and human mucosal associated lymphoid tissues

Poster (2006, October)

Prion cell tropism varies significantly among animal species, depending on both the agent strain and host-specific factors. For example, prions show high lymphotropism in scrapie infected sheep and vCJD ... [more ▼]

Prion cell tropism varies significantly among animal species, depending on both the agent strain and host-specific factors. For example, prions show high lymphotropism in scrapie infected sheep and vCJD, but little, if any, in sCJD or BSE. In particular, the BSE strain is associated with significant PrP-res accumulation in tonsils, spleen and appendix in humans, whereas it is largely confined to the nervous system in infected cattle. Therefore, at least in the case of BSE and vCJD, it appears that host properties can influence the accumulation of the infectious agent in lymphoid organs. Mature FDC play an important role in prion pathogenesis, since neuroinvasion following peripheral challenge is significantly impaired in their absence. The proximity between these FDC and sympathetic nerve endings is known to affect the speed of prion neuroinvasion. In this study, we analysed the mucosal innervation and the interface between nerve fibres and FDC in bovine and human tonsils and in ileal and jejunal bovine Peyer’s patches using a panel of antibodies observed by confocal microscopy. Since differences in the innervation of lymphoid organs depending on age have been reported, we analysed three categories of bovine ages (new born calves, calves less than 12 months old and bovines older than 24 months) and two categories of human ages (patients less than 5 years old and patients older than 25 years). In both species, hypothetical ways of innervation by-passing germinal centre could be postulated: nerve fibres are widely distributed in antigens/cells traffic area (the lamina propria, the interfollicular zone, the suprafollicular dome in Peyer’s patches and the lymphoepithelial area in tonsils). We pointed out that, only in ileal and jejunal Peyer’s patches and in tonsils of bovines older than 24 months, nerve fibres are observed to be in contact with FDC. In contrast, in human tonsils, no nerve fibres established contact with FDC, whatever the age. Thus, innervation of germinal centres can be said to be an age-dependent dynamic process in bovines and a weak innervation of the secondary lymphoid organs could thus be a rate-limiting step to neuroinvasion in humans. This variation could influence the way of neuroinvasion and thus, the differences of susceptibility of bovines and humans to the BSE agent. [less ▲]

Etude des variables spirométriques et des mesures morphométriques des veaux croisés Blanc-Bleu Belge x Holsteins pie noire

in Annales de Médecine Vétérinaire (2004), 148(1), 39-46

The bovine species is highly susceptible to respiratory dis-eases. A previous experiment has shown that Belgian Blue and White calves have lower spiro-metric variables than Holstein calves. The first aim ... [more ▼]

The bovine species is highly susceptible to respiratory dis-eases. A previous experiment has shown that Belgian Blue and White calves have lower spiro-metric variables than Holstein calves. The first aim of this study was to measure the spirometric variables (peak inspiratory flow, peak expiratory flow, maximal tidal volume, maximal ventilation in 15 seconds and ventilatory reserve) of 18 crossed Belgian Blue x Holstein calves and of 32 Dual purpose calves by the lobelin test and to compare them with 19 Holstein calves and 22 Belgian Blue and White calves. The second aim was to test the correlation between some mor-phometrical parameters (chest girth, thoracic width, thoracic length, thoracic height, thoracic section and costal angle) and those spirometric variables. The spirometric variables of the crossed calves and of the Dual purpose calves are situated between the ones of the Belgian Blue and White and of the Holstein. There is a positive sig-nificant correlation between these parameters and the spirometric variables. The higher cor-relation is obtained with the chest girth. All these parameters are easier and quicker measura-ble, and at lower cost than the spirometric variables [less ▲]

La capacité ventilatoire des veaux Blanc-Bleu Belges : relation avec la résistance aux pathologies respiratoires

in Sixième Carrefour des Productions Animales : La Sélection Animale au Service de la Société (2001)

Les performances spirométriques ont un effet sur la morbidité, la mortalité et le coût des maladies respiratoires dans l'espèce bovine. Les veaux Blanc-Bleu Belge se distinguant des autres par de ... [more ▼]

Les performances spirométriques ont un effet sur la morbidité, la mortalité et le coût des maladies respiratoires dans l'espèce bovine. Les veaux Blanc-Bleu Belge se distinguant des autres par de meilleures performances spirométriques sont avantagés du point de vue fonctionnel respiratoire; ils sont plus résistants aux pathologies respiratoires. Parmi les variables, ce sont la capacité ventilatoire et la ventilation maximale qui sont les plus importantes pour améliorer la résistance aux maladies respiratoires. Ces variables sont héritables et cela sans diminution du gain de poids ni du développement musculaire de ces animaux [less ▲]

Effects of Dobutamine on Isovolumic and Ejection Phase Indices of Cardiac Contractility in Conscious Healthy Dogs

in Research in Veterinary Science (1998), 64(1, Jan-Feb), 45-50

The aim of this study was to determine cardiac contractility using indices derived from cardiac catheterisation in conscious healthy dogs during dobutamine infusion. Eight dogs were studied. An ECG was ... [more ▼]

The aim of this study was to determine cardiac contractility using indices derived from cardiac catheterisation in conscious healthy dogs during dobutamine infusion. Eight dogs were studied. An ECG was recorded together with left ventricular pressure and volume which were measured using a conductance catheter with an integrated microtip pressure sensor. Eight indices of left ventricular systolic performance were derived from these records. Measurements were realised under basal conditions and during an incremental dobutamine challenge. The maximal rate of rise in ventricular pressure (max dP/dt), max dP/dt divided by the developed pressure and the mean systolic ejection rate were the most sensitive indices to detect dobutamine induced changes in contractility with maximal percentage changes of 122+/-11 per cent, 130+/-7 per cent and 102+/-24 per cent respectively. Ejection fraction increased significantly during dobutamine infusion (maximal percentage change of 43+/-9 per cent) whereas the pre-ejection period (PEP) and the left ventricular ejection time (LVET) decreased significantly (maximal percentage change of -41+/-2 per cent and -28+/-3 per cent respectively). All these six indices were significantly correlated with each other. Conversely, the ratio PEP/LVET and the LVET corrected for heart rate dependency showed a maximal percentage change of only -10+/-1 per cent and -16+/-7 per cent, respectively, during the dobutamine infusion and were not significantly correlated with the other contractility indices. This study demonstrated the feasibility of the conductance method to determine cardiac contractility in conscious healthy dogs submitted to a pharmacological stress testing and provides control values for eight indices of left ventricular contractility during dobutamine infusion at increasing dosages. [less ▲]