Clinical, electroretinographic and histomorphometric evaluation of the retina in sheep with natural scrapie

Background: The retina is part of the diencephalon in a peripheral location and may be involved in prion diseases. Retinal function and structural changes were assessed in naturally scrapie-affected red face Manech ewes presenting the classical signs of the disease, and clinically healthy age-matched subjects for controls. Ophthalmic examination was done prior to electroretinography (ERG), which was carried out under conditions that allowed photopic and scotopic activities to be assessed. Histomorphometry of the inner and outer retinal layers was performed post-mortem, and retinas were also examined for evidence of abnormal prion protein (PrPSc) accumulation and glial fibrillary acidic protein (GFAP) upregulation as a marker of gliosis. Scrapie status was determined by examination of brain tissue Results: Ocular reflexes and ophthalmoscopy did not reveal any difference between scrapie affected and control animals. Although the light-and dark-adapted ERG responses of both rod-and cone-mediated functions had a similar waveform in scrapie-affected and control sheep, a significant reduction in the amplitude of the ERG a-and b-waves was observed in affected animals compared to controls. These functional alterations were correlated with a substantial loss of cells in the outer nuclear layer (ONL), lengthening and disorganization in photoreceptor segments, and substantial reduction in cellularity and thickness of the inner nuclear layer (INL). The degenerative changes in the INL and ONL were most marked in the central and paracentral areas of the scrapie retinas, and were accompanied in all scrapie retinas by PrPSc deposition in the ganglion cell and synaptic layers. GFAP immunoreactivity was mainly increased in the ganglion cell and inner plexiform layers. Conclusions: No appreciable fundoscopic changes were observed in the scrapie-affected ewes although reproducible changes in retinal function as measured by ERG were observed in these animals. The alterations in the receptoral and post-receptoral pathways corresponded to the degenerative lesions observed in the ONL and INL of the scrapie retinas. The retinal degeneration was associated with prion protein infectivity which presumably spread via the optic nerve

Détection immunohistochimique de p53 chez les animaux domestiques (étude méthodologique)

Les mutations du gène p53 sont les altérations génétiques les plus fréquentes des cancers chez l'homme. Ces mutations entraînent généralement une stabilité accrue de la protéine, rendant sa détection possible par immunohistochimie. Deux anticorps monoclonaux (DO-7 et PAb-240) et polyclonaux (CM-1 et Ab-7) ont été testés chez les animaux domestiques sur des carcinomes épidermoïdes (CE) dans toutes les espèces et des lésions précancéreuses chez le chien et le chat. Une immunoréactivité a été detectée avec les anticorps CM-1 et PAb-240, pour des CE félins, bovin, équin et ovin, ainsi que pour la kératose actinique féline. Aucun marquage n'a été obtenu pour l'anticorps Ab-7, et DO-7 n'a pas réagi dans les espèces féline et canine. L'immunodétection de p53 est donc possible dans les principales espèces domestiques, essentiellement avec les anticorps CM-1 et PAb-240. En outre, les altérations de p53 semblent être, comme chez l'homme, un phénomène précoce dans la cancérogenèse des CE félins.TOULOUSE3-BU Santé-Centrale (315552105) / SudocTOULOUSE-EN Vétérinaire (315552301) / SudocSudocFranceF

Genital form off pasteurellosis in breeding turkeys infected during artificial insemination and isolation off an unusual strain of <em>Pasteurella</em> <em>multocida.</em>

International audienceA genital and potentially fatal form of Pasteurella multocida infection was reported on two turkey-breeding farms on which birds were vaccinated against Pasteurella multocida. Both outbreaks were linked to the use of semen from young vaccinated toms with a history of respiratory pasteurellosis followed by treatment during rearing. Typing by agar gel immunodiffusion and rapid slide agglutination of P. multocida isolated from cloacal swabs was completed by multilocus sequence typing. Restriction enzyme analysis showed that that the isolates were clonal. They belonged to sequence type (ST) 30, described in chickens, cats, and ducks. This strain differed in sequence type from the ones used in the vaccine (ST8, ST60, ST53, and ST235), which might have limited its effectiveness. No contamination of the semen (n = 30) was found, suggesting fecal contamination during semen collection

Clinical, electroretinographic and histomorphometric evaluation of the retina in sheep with natural scrapie

Abstract Background The retina is part of the diencephalon in a peripheral location and may be involved in prion diseases. Retinal function and structural changes were assessed in naturally scrapie-affected red face Manech ewes presenting the classical signs of the disease, and clinically healthy age-matched subjects for controls. Ophthalmic examination was done prior to electroretinography (ERG), which was carried out under conditions that allowed photopic and scotopic activities to be assessed. Histomorphometry of the inner and outer retinal layers was performed post-mortem, and retinas were also examined for evidence of abnormal prion protein (PrPSc) accumulation and glial fibrillary acidic protein (GFAP) upregulation as a marker of gliosis. Scrapie status was determined by examination of brain tissue Results Ocular reflexes and ophthalmoscopy did not reveal any difference between scrapie affected and control animals. Although the light-and dark-adapted ERG responses of both rod-and cone-mediated functions had a similar waveform in scrapie-affected and control sheep, a significant reduction in the amplitude of the ERG a-and b-waves was observed in affected animals compared to controls. These functional alterations were correlated with a substantial loss of cells in the outer nuclear layer (ONL), lengthening and disorganization in photoreceptor segments, and substantial reduction in cellularity and thickness of the inner nuclear layer (INL). The degenerative changes in the INL and ONL were most marked in the central and paracentral areas of the scrapie retinas, and were accompanied in all scrapie retinas by PrPSc deposition in the ganglion cell and synaptic layers. GFAP immunoreactivity was mainly increased in the ganglion cell and inner plexiform layers. Conclusions No appreciable fundoscopic changes were observed in the scrapie-affected ewes although reproducible changes in retinal function as measured by ERG were observed in these animals. The alterations in the receptoral and post-receptoral pathways corresponded to the degenerative lesions observed in the ONL and INL of the scrapie retinas. The retinal degeneration was associated with prion protein infectivity which presumably spread via the optic nerve.</p

Colorectal Hamartomatous Polyposis and Ganglioneuromatosis in a Dog

International audienceA 5-month-old female Great Dane puppy was treated for hematochezia, tenesmus, and rectal prolapse by resection of a 10-cm-long segment of colon and rectum. Grossly, the colorectal segment had diffuse mucosal and submucosal thickening with multiple polypoid nodules. The histologic diagnosis was colorectal hamartomatous polyps with ganglioneuromatosis. Duplication of PTEN was detected by quantitative multiplex polymerase chain reaction testing. The presence of 2 hamartomatous colorectal lesions with PTEN mutation is similar to human Cowden syndrome

Un foyer de mammites aspergillaires dans un troupeau laitier caprin

National audienceCet article présente un foyer de mammite à Aspergillus fumigatus dans un troupeau de chèvres laitières. 17 animaux, sur un effectif de 150 chèvres en lactation, ont déclaré dans les 8 à 10 jours après la mise bas une atteinte mammaire avec hypertrophie, inflammation et induration de la glande, et une sécrétion lactée très réduite et aqueuse. Une importante atteinte de l’état général a été notée (hyperthermie, abattement, anorexie, amaigrissement rapide) et 5 animaux sont morts en 3 semaines. À l’examen nécropsique, on a observé une atteinte diffuse du parenchyme mammaire avec des nodules granulomateux à contenu nécrotique d’aspect très variable. Le diagnostic de certitude s’est appuyé sur la mise en évidence d’A. fumigatus en culture pure, à partir de plusieurs prélèvements de lait et de tissus, et sur l’examen anatomo-pathologique du parenchyme mammaire. Ce foyer d’aspergillose mammaire a probablement pour origine des conditions d’asepsie non maîtrisées, associées à un environnement hygiénique défavorable (paille moisie) lors d’une antibiothérapie intramammaire pratiquée au tarissement précéden

Un foyer de mammites aspergillaires dans un troupeau laitier caprin

National audienceCet article présente un foyer de mammite à Aspergillus fumigatus dans un troupeau de chèvres laitières. 17 animaux, sur un effectif de 150 chèvres en lactation, ont déclaré dans les 8 à 10 jours après la mise bas une atteinte mammaire avec hypertrophie, inflammation et induration de la glande, et une sécrétion lactée très réduite et aqueuse. Une importante atteinte de l’état général a été notée (hyperthermie, abattement, anorexie, amaigrissement rapide) et 5 animaux sont morts en 3 semaines. À l’examen nécropsique, on a observé une atteinte diffuse du parenchyme mammaire avec des nodules granulomateux à contenu nécrotique d’aspect très variable. Le diagnostic de certitude s’est appuyé sur la mise en évidence d’A. fumigatus en culture pure, à partir de plusieurs prélèvements de lait et de tissus, et sur l’examen anatomo-pathologique du parenchyme mammaire. Ce foyer d’aspergillose mammaire a probablement pour origine des conditions d’asepsie non maîtrisées, associées à un environnement hygiénique défavorable (paille moisie) lors d’une antibiothérapie intramammaire pratiquée au tarissement précéden

Edge passivation of shingled poly-Si/SiO

This work aims at the full recovery of efficiency losses induced by shingling double-side poly-Si/SiOx passivated contacts crystalline silicon solar cells. It focuses on thermally-activated Aluminium Oxide (AlOx) layers elaborated by thermal Atomic Layer Deposition (ALD) to passivate the edges of shingled cells cut by using the innovative “45° tilt squaring approach”. The whole procedure featuring high-temperature AlOx annealing led to very low cut-related performance losses. Indeed, the efficiency and FF of the passivated shingled cells surpassed the values obtained for the as-cut shingles by 0.5%abs and 2.6%abs, respectively. Approaches for further improvements are also discussed, particularly to overcome the short-circuit current density decrease observed for passivated shingles

Coupling hydrodynamic, geochemical and isotopic approaches to evaluate oxbow connection degree to the main stream and to adjunct alluvial aquifer

International audienceWetlands as oxbows play a fundamental socio-economic and environmental role. They behave as efficient tools in regards to hydrological and ecological concerns: they contribute to control rivers discharge (flood prevention and contribution to drought flow) as well as to manage water quality (excess nutrients retention) and they constitute refuge habitats for flora and fauna. They may so become more and more determinant as nature-based solutions in a near future. However, the establishment of complete and reliable functioning models is complicated by the different connection degrees that can present these specific wetlands to the main stream and to the adjunct alluvial aquifer. Moreover, monodisciplinary approaches usually conducted can underestimate or even neglect sources of water supply. The present study offers a multidisciplinary approach coupling hydrodynamic (surface water/groundwater levels), geochemical (T, EC, pH, major ions) and isotopic (delta H-2-delta O-18) characterization in order to properly assess the dynamic of these specific hydrosystems and so be able to establish a complete and reliable hydrodynamic conceptual model. The coupling approach has been tested on the Auzon Oxbow, one of the fluvial annexes of the Allier River (Massif Central, France). The resulting conceptual model testifies for connection degree higher that expected between the oxbow and both the main stream and alluvial aquifer. Indeed, a non-negligible supply of the oxbow by the alluvial groundwater is observed, especially in its downstream part. As this part of the oxbow is the site of its confluence to the Allier River, groundwater supply could have been underestimated. The geochemical approach shows that Allier River also supply the oxbow through the upstream paleochannel, result of a channel migration 30 years ago. Hydrodynamic and isotopic approaches complete the understanding showing that the paleochannel pathway is only active during high flow periods (from November to June). Based on these results, the strategic utility of the proposed approach to study oxbow's hydrosystems has been proved.Keyword

Caprine nodular thelitis due to Mycobacterium uberis: A series of 26 cases in 11 dairy goat farms in Western France

International audienceBovine Nodular Thelitis (BNT) is a granulomatous dermatitis of teat skin associated with acid-fast bacilli. A similar condition has been recorded in a dairy goat flock in France recently. The causative agent was shown to be related to the leprosy-causing bacilli Mycobacterium leprae and M. lepromatosis, then sequenced and named M. uberis. Following the initial report in goats, the aim of this study was to investigate new cases of Caprine Nodular Thelitis (CNT) in the same area to confirm the presence of M. uberis by molecular techniques and to get a better description of the clinical signs and of the affected flocks. Twenty-six animals (25 females and 1 male) from 11 flocks were included in the study. Lesions were located on the udder/teat skin (24/25), on the body skin (6/25) or on the scrotum skin (1/1). Udder skin lesions were circular, nodular and/or ulcerate covered with a crust and associated with supramammary lymph node enlargement. Body skin lesions were located at different parts of the body, showed large necrotizing ulcers with undetermined edges and were associated with regional lymph node enlargement. Histopathological results indicated granulomatous dermatitis and lymphadenitis of varying intensity with no acid-fast bacilli seen after Fite-Faraco staining. M. uberis DNA was amplified from 26 samples out of 47 (udder: 11/22; lymph node: 11/20; body: 4/5). The female goats were mostly older than 4 year of age and originated from breeding units characterized by large flock size and high proportion of goat in continuous lactation