Defective Innate Cell Response and Lymph Node Infiltration Specify Yersinia pestis Infection

Since its recent emergence from the enteropathogen Yersinia pseudotuberculosis, Y. pestis, the plague agent, has acquired an intradermal (id) route of entry and an extreme virulence. To identify pathophysiological events associated with the Y. pestis high degree of pathogenicity, we compared disease progression and evolution in mice after id inoculation of the two Yersinia species. Mortality studies showed that the id portal was not in itself sufficient to provide Y. pseudotuberculosis with the high virulence power of its descendant. Surprisingly, Y. pseudotuberculosis multiplied even more efficiently than Y. pestis in the dermis, and generated comparable histological lesions. Likewise, Y. pseudotuberculosis translocated to the draining lymph node (DLN) and similar numbers of the two bacterial species were found at 24 h post infection (pi) in this organ. However, on day 2 pi, bacterial loads were higher in Y. pestis-infected than in Y. pseudotuberculosis-infected DLNs. Clustering and multiple correspondence analyses showed that the DLN pathologies induced by the two species were statistically significantly different and identified the most discriminating elementary lesions. Y. pseudotuberculosis infection was accompanied by abscess-type polymorphonuclear cell infiltrates containing the infection, while Y. pestis-infected DLNs exhibited an altered tissue density and a vascular congestion, and were typified by an invasion of the tissue by free floating bacteria. Therefore, Y. pestis exceptional virulence is not due to its recently acquired portal of entry into the host, but is associated with a distinct ability to massively infiltrate the DLN, without inducing in this organ an organized polymorphonuclear cell reaction. These results shed light on pathophysiological processes that draw the line between a virulent and a hypervirulent pathogen

La Réserve de la biosphère de la mer d’Iroise: un SIG en milieu insulaire

The Mer d’Iroise Biosphere Reserve GIS covers the intertidal zone. A set of maps is proposed, based on the combination of two parameters which are essential to fauna zonation. ABSTRACTLe domaine maritime de la base de données de la Réserve de la Biosphère de la mer d’Iroise s’étend à la stratification biologique de l’estran. La combinaison de deux paramètres déterminants pour la répartition de la faune intertidale permet de réaliser une première synthèse cartographique.El sector marítimo de la base de datos de la Reserva de la Biosfera del Mar de Iroise abarca la estratificación biológica del estero. La combinación de dos parámetros determinantes en cuanto a la repartición de la fauna de la zona permite realizar una primera síntesis cartográfica. RESUMENGourmelon Françoise, Guinet Christophe, Jean Frédéric. La Réserve de la biosphère de la mer d’Iroise: un SIG en milieu insulaire. In: Mappemonde, 1993/4. Facettes de SIG. pp. 28-29

Étude in vitro et in vivo du pouvoir immunogène de trois protéines recombinantes d'échinocoques

Exprimées au stade protoscolex des échinocoques, EgA31, EgTrp et FABP1 sont des protéines candidates pour une préparation vaccinale contre Echinococcus granulosus, agent de l'hydatidose, et Echinococcus multilocularis, agent de l'echinococcose alvéolaire. Le but de ce travail a été d'étudier l'immunogénicité de ces protéines recombinantes dans deux modèles : (1) un modèle in vitro développé en alternative à l'expérimentation chez l'hôte définitif qui consiste en un système de co-culture de cellules leucocytaires et entérocytaires humaines. Ce modèle permet une première approche du profil cytokinique Th1/Th2 en réponse à un antigène, (2) un modèle in vivo, la souris BALB/c où les réponses cellulaires et humorales ont été analysées. Globalement, dans les deux modèles, EgA31, utilisée seule ou en association avec l'une et/ou l'autre des protéines recombinantes candidates, génère un forte réponse mixte Th1 et Th2LYON1-BU.Sciences (692662101) / SudocSudocFranceF

La Schynige Platte et son jardin alpin

Lemaire A, Dowsett-Lemaire Françoise, Guinet Camille. La Schynige Platte et son jardin alpin. In: La Terre et La Vie, Revue d'Histoire naturelle, tome 9, n°3, 1939. pp. 94-95

Abdominal Aortic Aneurysm Infected by Yersinia pseudotuberculosis

Infected aneurysms caused by Yersinia are very uncommon and are principally due to Yersinia enterocolitica. We describe the first case of an infected aneurysm caused by Yersinia pseudotuberculosis in an elderly patient with a history of atherosclerotic cardiovascular disease

Studies on project documentation and transmission and the battle against re-innovation

This communication relates preliminary findings of a study group which examined the process of creation of new outreach and informal education projects. The group is developing recommendations for the organization of the documentation and transmission of past experiences in the domain. Scientific outreach and informal education has a tendency to take on very familiar forms. Very diverse projects which appear different on the surface due to content and context are often organizationally and conceptually very similar. Currently, many volunteer projects are strictly local, “hand-crafted” by their organizers for a specific event or context, and documented only for the use of the operators of the event. This leads to “re-innovation”: because each event is created locally and in isolation from most of past experience, little development occurs and previous errors in conception and/or organization are reproduced. The communication discusses means of avoiding this tendency and exposes some promising dynamics underway in the French chemical community

Montagnes, développement durable et technologies d'information et de communication: Rapport 3 : TIC et développement des territoires de montagne : des infrastructures aux services

Rapport de recherche sur contrat industrie