Revisión y nuevas aportaciones a la fauna del yacimiento pliocénico de Vilacolum, Girona

En la presente nota se señala por vez primera la presencia de dos gasterópodos en el yacimiento pliocénico de Vilacolum (Girona), Bittium (s.s.), reticulatum DA COSTA y Scala (Hirtoscala) muricata Risso, este último citado por vez primera en el Neógeno español. Se acompaña de un catálogo actualizado de toda la fauna estudiada hasta el presente en dicho yacimiento ampliándose con especies hasta ahora no citadas de Crustáceos y Equínidos halladas por nosotros

Hallazgo de un ammonites cretácico en la isla volcánica de Fernando Poo

Fernando Poo es una isla volcánica perteneciente a una alineación de este origen que se extiende a lo largo de unos 900 km desde el Monte Camerún por las islas de Fernando Poo, Príncipe y Sao Tomé, hasta la de Annobón, ya al sur del Ecuador. La misma línea (le inestabilidad se desarrolla, en sentido opuesto hacia el interior del Continente Africano, al menos otros 1.000 km más. (...

Caracterización de terrenos de edad estampiense en Campins (Vallés Oriental)

Se da a conocer la presencia de dos yacimientos de mamíferos en los alrededores del pueblo de Campins, cuyo estudio permite caracterizar por primera vez la presencia de terrenos de edad Estampiense en la Cuenca del Vallés-Penedés. Los mamíferos encontrados pueden atribuirse al nivel bicronológico de Les Chapelins

Aportaciones al estudio del Mioceno marino de la comarca del Vallés

Con motivo de una intensa explotación a que se ven sometidas las arcillas que integran el Mioceno del Vallés, se han abierto a lo largo de la carretera de Sant Cugat a Sardanyola una serie de canteras ("terrals").Uno de ellos el de Can Xercavins, a medida que avanzaban los trabajos de extracción de arcilla, iba mostrando un magnífico corte que nosotros hemos aprovechado para estudiarlo ; en él aflora ampliamente el Mioceno marino del Vallés. En este corte hemos encontrado una abundante y bien conservada fauna lo que ha permitido su datación. Estos sedimentos marinos se hallan dispuestos en varios niveles que indentan en el Mioceno continental; ello es pues de un gran interés cronoestratigráfico por ser esta datación un nuevo jalón sobre el cual puede apoyarse la estratigrafía del Mioceno del Vallés

Perspectives on the Trypanosoma cruzi-host cell receptor interaction

Chagas disease is caused by the parasite Trypanosoma cruzi. The critical initial event is the interaction of the trypomastigote form of the parasite with host receptors. This review highlights recent observations concerning these interactions. Some of the key receptors considered are those for thromboxane, bradykinin, and for the nerve growth factor TrKA. Other important receptors such as galectin-3, thrombospondin, and laminin are also discussed. Investigation into the molecular biology and cell biology of host receptors for T. cruzi may provide novel therapeutic targets

Visual Genome-Wide RNAi Screening to Identify Human Host Factors Required for Trypanosoma cruzi Infection

The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical infection that affects millions of people in the Americas. Current chemotherapy relies on only two drugs that have limited efficacy and considerable side effects. Therefore, the development of new and more effective drugs is of paramount importance. Although some host cellular factors that play a role in T. cruzi infection have been uncovered, the molecular requirements for intracellular parasite growth and persistence are still not well understood. To further study these host-parasite interactions and identify human host factors required for T. cruzi infection, we performed a genome-wide RNAi screen using cellular microarrays of a printed siRNA library that spanned the whole human genome. The screening was reproduced 6 times and a customized algorithm was used to select as hits those genes whose silencing visually impaired parasite infection. The 162 strongest hits were subjected to a secondary screening and subsequently validated in two different cell lines. Among the fourteen hits confirmed, we recognized some cellular membrane proteins that might function as cell receptors for parasite entry and others that may be related to calcium release triggered by parasites during cell invasion. In addition, two of the hits are related to the TGF-beta signaling pathway, whose inhibition is already known to diminish levels of T. cruzi infection. This study represents a significant step toward unveiling the key molecular requirements for host cell invasion and revealing new potential targets for antiparasitic therapy

Eosinophil levels in the acute phase of experimental chagas' disease

Eosinophil dynamics, in bone marrow, blood and peritoneal exudate, of resistant C57B1/6 (C57) and susceptible A/Snell (A/Sn) mice was comparatively studied during the acute phase of infection by Trypanosoma cruzi Y strain. A decline was observed in bone marrow eosinophil levels in A/Sn, but not in C57 mice, soon after infection, those of the former remaining significantly below those of the latter up to the 4th day of infection. Bone marrow eosinophil levels of C57 mice declined subsequently to levels comparable to those of A/Sn mice, the number of these cells in this compartment remaining 50% those of non infected controls, in both strains, up to the end of the experiment on the 14th day of infection. The fluctuations in eosinophil levels in blood and peritoneal space were similar in both mice strains studied. Concomitantly with depletion of eosinophils in the marrow, depletion in blood and a marked rise of these cells in the peritoneal space, initial site of infection, occurred in both strains. The difference in eosinophil bone marrow levels, between C57 and A/Sn mice, observed in the first four days of infection, suggests a higher eosinopoiesis capacity of the former in this period, which might contribute to their higher resistance to T. cruzi infection