Reemergence of cattle paramphistomiasis in France : Current review of epidemiology, pathophysiology and diagnosis

The prevalence of cattle paramphistomiasis is growing in France. This recent reemergence may be related to several factors: limited number of specific anthelmintics available, longevity and high prolificity of adult worms, decreasing prevalence liver fluke which increases the availability of the snails which act as intermediate hosts for paramphistomids, and extensification of cattle farming. Although clinical signs are not very typical, the pathogenicity of paramphistomiasis cannot be ignored, due to the risk of acute form due to immature worms (difficult to identify) and of recurrent bloating due to the mechanical effect of adult worms. However, the pathogenicity of paramphistomids is much milder than that of Fasciola hepatica. There is currently no immunological method available for this diagnosis; a clinical suspicion is confirmed by faecal egg counts (epg), but there is no formal correlation between their numbers and the parasite load.On constate un accroissement de la prévalence de la paramphistomose bovine en France. Cette récente réémergence peut être reliée à différents facteurs : le peu d'anthelminthiques spécifiques disponibles, la longévité et la forte prolificité des vers adultes, la chute de la prévalence de Fasciola hepatica permettant la plus grande disponibilité des limnées, hôtes intermédiaires, et enfin l'extensification de l'élevage. En dépit d'une symptomatologie peu spécifique, la pathogénicité de la paramphistomose ne doit pas être ignorée : risques de forme aiguë liée aux vers immatures -difficile à identifier- et de météorisation récurrente par l'effet mécanique des adultes. Cette pathogénicité est néanmoins bien moindre que celle de Fasciola hepatica. Aucun test sérologique n'est actuellement disponible : seul le diagnostic coproscopique avec comptage des oeufs (OPG) vient confirmer la suspicion clinique. Cependant, le niveau des OPG n'est pas formellement corrélé à la charge parasitaire

« The liver fluke wa tchdog » : Evaluation of control measures required in farm herds to control fasciolosis and initial results

The initial results obtained by the « Observatoire de la grande douve », or Liver Fluke Watchdog, in France offer an interesting platform for veterinary practitioners to set up formal programs to fight endemic diseases (parasitism, mastitis, neonatal gastroenteritis…). This experience has shown that breeders are indeed coming round to the idea of paying a consultancy fee, provided the advice is relevant and profitable. These therapeutic and prevention protocols, HACCP compliant, provide some insight on the health policy of the future. The example of fluke control illustrates the actions to promote : screening, risk factor identification, prescription of therapeutic and agronomic measures, and finally, control of the program’s efficacy. The initial results obtained in animal husbandry confirm the major benefits of this approach.Les premiers résultats de l'« Observatoire de la grande douve» offrent une plateforme intéressante aux vétérinaires praticiens pour l'élaboration de plans de lutte formalisés contre des maladies endémiques (parasitisme, mammites, gastro-entérites néonatales...). En effet, les éleveurs acceptent de plus en plus l'idée de rémunérer un conseil, sous réserve qu'il soit pertinent et rentable. Ces protocoles de traitement et de prévention, conformes à la méthode HACCP, laissent percevoir l'organisation de la politique sanitaire des années à venir. L'exemple de la maîtrise de la fasciolose illustre les actions à promouvoir: dépister, identifier les facteurs de risque, prescrire des mesures thérapeutiques et agronomiques, et enfin, contrôler l'efficacité du plan d'action. Les premiers résultats obtenus en élevage confirment l'intérêt majeur de cette démarche

Int J Mol Sci

The complement is a component of the innate immune system designed to fight infections and tissue- or age-related damages. Complement activation creates an inflammatory microenvironment, which enhances cell death. Excessive complement inflammatory activity has been linked to alterations in the structure and functions of the blood-brain barrier, contributing to a poor prognosis for Alzheimer's disease (AD). In the AD preclinical phase, individuals are often clinically asymptomatic despite evidence of AD neuropathology coupled with heightened inflammation. Considering the involvement of the complement system in the risk of developing AD, we hypothesize that inhibiting complement activation could reduce this inflammatory period observed even before clinical signs, thereby slowing down the onset/progression of AD. To validate our hypothesis, we injected complement inhibitor factor H into the brain of APP/PS1 AD mice at early or late stages of this pathology. Our results showed that the injection of factor H had effects on both the onset and progression of AD by reducing proinflammatory IL6, TNF-α, IL1β, MAC and amyloid beta levels. This reduction was associated with an increase in VGLUT1 and Psd95 synaptic transmission in the hippocampal region, leading to an improvement in cognitive functions. This study invites a reconsideration of factor H's therapeutic potential for AD treatment

Évolutions épidémiologiques et nouvelles contraintes dans la lutte contre les myiases ovines

Sheep myiasis : recent developments in epidemiology and novel constraints in control. The blowfly (Lucilia sericata), the fleshfly (Wohlfahrtia magnifica) and the nasal-bot fly (Oestrus ovis) are important pests for the sheep industry. Moreover, sporadic opthalmomyiasis cases due to O. ovis are reported in human beings worldwide. In the last 20 years, the epidemiology of ovine myiasis showed considerable evolution in France with a marked spreading of their geographical distribution. A large array of chemical compounds is still available to control these parasites in meat sheep. However, due to revised milk withdrawal times, many efficient chemical compounds are now forbidden in dairy sheep. In the same time, alternative methods to chemical treatments are still in their infancy. Therefore, the information towards sheep breeders and veterinarians is of critical importance to detect clinical cases as soon as possible and for the global survey of these parasitosis.Une myiase naso-sinusale à Oestrus ovis et deux myiases cutanées à Lucilia sericata et Wohlfahrtia magnifica constituent toujours une dominante pathologique des ovins au pâturage. De plus, la myiase naso-sinusale à Oestrus ovis est responsable de cas sporadiques d’ophtalmomyiase externe chez l’homme. Dans les dernières décennies, ces affections parasitaires ont connu des évolutions épidémiologiques importantes, gagnant de nouveaux territoires en France métropolitaine. Leur contrôle reste tout à fait réalisable en élevage ovin allaitant même s’il est contraignant, mais il s’est considérablement compliqué en élevage ovin laitier en raison d’interdictions réglementaires de l’utilisation de nombreuses molécules actives. En parallèle, les méthodes alternatives au traitement chimique restent très limitées. L’information des éleveurs et des vétérinaires est donc essentielle pour la détection précoce des cas et la surveillance de ces parasitoses.Jacquiet Philippe, Alzieu Jean-Pierre, Liénard Emmanuel, Grisez Chistelle, Prévot Françoise, Bergeaud Jean-Paul, Bouhsira Emilie, Franc Michel, Dorchies Philippe. Évolutions épidémiologiques et nouvelles contraintes dans la lutte contre les myiases ovines. In: Bulletin de l'Académie Vétérinaire de France tome 169 n°1, 2016. pp. 46-53

Partial Mural Cell Ablation Disrupts Coronary Vasculature Integrity and Induces Systolic Dysfunction

Background Although the critical role of pericytes in maintaining vascular integrity has been extensively demonstrated in the brain and the retina, little is known about their role in the heart. We aim to investigate structural and functional consequences of partial pericyte depletion (≈60%) in the heart of adult mice. Methods and Results To deplete pericytes in adult mice, we used platelet‐derived growth factor receptor β–Cre/ERT2; RosaDTA mice and compared their phenotype with that of control mice (RosaDTA) chosen among their littermates. Cardiac function was assessed via echocardiography and left ventricular catheterization 1 month after the first tamoxifen injection. We found mice depleted with pericytes had a reduced left ventricular ejection fraction and an increased end‐diastolic pressure, demonstrating both systolic and diastolic dysfunction. Consistently, mice depleted with pericytes presented a decreased left ventricular contractility and an increased left ventricular relaxation time (dP/dtmin). At the tissue level, mice depleted of pericytes displayed increased coronary endothelium leakage and activation, which was associated with increased CD45+ cell infiltration. Consistent with systolic dysfunction, pericyte depletion was associated with an increased expression of myosin heavy chain 7 and decreased expression of ATPase sarcoplasmic/endoplasmic reticulum Ca2+ transporting 2 and connexin 43. More important, coculture assays demonstrated, for the first time, that the decreased expression of connexin 43 is likely attributable to a direct effect of pericytes on cardiomyocytes. Besides, this study reveals that cardiac pericytes may undergo strong remodeling on injury. Conclusions Cardiac pericyte depletion induces both systolic and diastolic dysfunction, suggesting that pericyte dysfunction may contribute to the occurrence of cardiac diseases

Mensonges (1)

La vérité finit toujours par être inconnue. Victor Hug

First Expert Elicitation of Knowledge on Drivers of Emergence of Bovine Besnoitiosis in Europe

International audienceBovine besnoitiosis (BB) is a chronic and debilitating parasitic disease in cattle caused by the protozoan parasite Besnoitia besnoiti. South European countries are affected and have reported clinical cases of BB. However, BB is considered as emerging in other countries/regions of central, eastern and northern Europe. Yet, data on drivers of emergence of BB in Europe are scarce. In this study, fifty possible drivers of emergence of BB in cattle were identified. A scoring system was developed per driver. Then, the scoring was elicited from eleven recognized European experts to: (i) allocate a score to each driver, (ii) weight the score of drivers within each domain and (iii) weight the different domains among themselves. An overall weighted score was calculated per driver, and drivers were ranked in decreasing order of importance. Regression tree analysis was used to group drivers with comparable likelihoods to play a role in the emergence of BB in cattle in Europe. Finally, robustness testing of expert elicitation was performed for the seven drivers having the highest probability to play a key role in the emergence of BB: i.e., (i) legal/illegal movements of live animals from neighbouring/European Union member states or (ii) from third countries, (iii) risk of showing no clinical sign and silent spread during infection and post infection, (iv) as a consequence, difficulty to detect the emergence, (v) existence of vectors and their potential spread, (vi) European geographical proximity of the pathogen/disease to the country, and (vii) animal density of farms. Provided the limited scientific knowledge on the topic, expert elicitation of knowledge, multi-criteria decision analysis, cluster and sensitivity analyses are very important to prioritize future studies, e.g., the need for quantitative import risk assessment and estimation of the burden of BB to evidence and influence policymaking towards changing (or not) its status as a reportable disease, with prevention and control activities targeting, firstly, the top seven drivers. The present methodology could be applied to other emerging animal diseases

Ephrin-B1 regulates the adult diastolic function through a late postnatal maturation of cardiomyocyte surface crests

The rod-shaped adult cardiomyocyte (CM) harbors a unique architecture of its lateral surface with periodic crests, relying on the presence of subsarcolemmal mitochondria (SSM) with unknown role. Here, we investigated the development and functional role of CM crests during the postnatal period. We found in rodents that CM crest maturation occurs late between postnatal day 20 (P20) and P60 through both SSM biogenesis, swelling and crest-crest lateral interactions between adjacent CM, promoting tissue compaction. At the functional level, we showed that the P20-P60 period is dedicated to the improvement of relaxation. Interestingly, crest maturation specifically contributes to an atypical CM hypertrophy of its short axis, without myofibril addition, but relying on CM lateral stretching. Mechanistically, using constitutive and conditional CM-specific knock-out mice, we identified ephrin-B1, a lateral membrane stabilizer, as a molecular determinant of P20-P60 crest maturation, governing both the CM lateral stretch and the diastolic function, thus highly suggesting a link between crest maturity and diastole. Remarkably, while young adult CM-specific Efnb1 KO mice essentially exhibit an impairment of the ventricular diastole with preserved ejection fraction and exercise intolerance, they progressively switch toward systolic heart failure with 100% KO mice dying after 13 months, indicative of a critical role of CM-ephrin-B1 in the adult heart function. This study highlights the molecular determinants and the biological implication of a new late P20-P60 postnatal developmental stage of the heart in rodents during which, in part, ephrin-B1 specifically regulates the maturation of the CM surface crests and of the diastolic function

Crest maturation at the cardiomyocyte surface contributes to a new late postnatal development stage that controls the diastolic function of the adult heart

Abstract RATIONALE In addition to its typical rod-shape, the mammalian adult cardiomyocyte (CM) harbors a unique lateral membrane surface architecture with periodic crests, relying on the presence of subsarcolemmal mitochondria (SSM) the role of which is still unknown. OBJECTIVE To investigate the development and functional role of CM crests during the postnatal period. METHODS AND RESULTS Electron/confocal microscopy and western-blot of left ventricular tissues from rat hearts indicated a late CM surface crest maturation, between postnatal day 20 (P20) and P60, as shown by substantial SSM swelling and increased claudin-5 cell surface expression. The P20-P60 postnatal stage also correlates with an ultimate maturation of the T-Tubules and the intercalated disk. At the cellular level, we identified an atypical CM hypertrophy characterized by an increase in long- and short-axes without myofibril addition and with sarcomere lateral stretching, indicative of lateral stretch-based CM hypertrophy. We confirmed the P20-P60 hypertrophy at the organ level by echocardiography but also demonstrated a transcriptomic program after P20 targeting all the cardiac cell populations. At the functional level, using Doppler echocardiography, we found that the P20-P60 period is specifically dedicated to the improvement of relaxation. Mechanistically, using CM-specific knock-out mice, we identified ephrin-B1 as a determinant of CM crest maturation after P20 controlling lateral CM stretch-hypertrophy and relaxation. Interestingly, while young adult Efnb1 CMspe−/− mice essentially show a relaxation impairment with exercise intolerance, they progressively switch toward heart failure with 100% KO mice dying after 13 months. CONCLUSIONS This study highlights a new late P20-P60 postnatal developmental stage of the heart in rodents during which the CM surface crests mature through an ephrin-B1-dependant mechanism and regulate the diastolic function. Moreover, we demonstrate for the first time that the CM crest architecture is cardioprotective