ABSTRACT
En el presente trabajo se estudiaron las vías de penetración del miracidio de Fasciola hepática (Linnaeus, 1758) dentro del hepatopáncreas de Lymnaea truncatula (Müller, 1774) y Lymnaea cubensis (Pfeiffer, 1839), en 2 moluscos obtenidos de las zonas endémicas de Fasciolosis de Rusia y de la República Mexicana respectivamente¹. El trayecto de la larva mostró la disolución de la sustancia intercelular y deformación de células epiteliales de los tejidos de los moluscos. A nivel citológico se observaron cambios en el epitelio lineal de cobertura de los ductos de la glándula digestiva y en el tejido conjuntivo del hepatopáncreas. Se observaron diferencias en las vías de penetración y afectación en las dos especies de moluscos estudiados, marcando así las diferencias de las condiciones ecológicas que prevalecen en cada zona geográfica.
The present work investigated the penetration pathways of Fasciola hepática (Linnaeus, 1758) into the hepatopancreas of Lymnaea truncatula (Muller, 1774) and Lymnaea cubensis (Pfeiffer, 1839), two mollusks obtained from Fasciolosis endemic areas in Russia and Mexico, respectively. The larval trajectory showed dissolution of intercellular substance and deformation of epithelial cells of mollusk's tissues. Cytological changes in the ductal epithelium of the digestive gland and in the connective tissue of hepatopancreas were found. Some differences in the penetration and damage pathways in the two species of mollusks studied were observed; thus highlighting the differences in the environmental conditions prevailing in each geographic area.
ABSTRACT
Paracoccidioides brasiliensis causes infection through inhalation by the host of airborne propagules from the mycelium phase of the fungus. This fungus reaches the lungs, differentiates into the yeast form and is then disseminated to virtually all parts of the body. Here we review the identification of differentially-expressed genes in host-interaction conditions. These genes were identified by analyzing expressed sequence tags (ESTs) from P. brasiliensis cDNA libraries. The P. brasiliensis was recovered from infected mouse liver as well as from fungal yeast cells incubated in human blood and plasma, mimicking fungal dissemination to organs and tissues and sites of infection with inflammation, respectively. In addition, ESTs from a cDNA library of P. brasiliensis mycelium undergoing the transition to yeast were previously analyzed. Together, these studies reveal significant changes in the expression of a number of genes of potential importance in the host-fungus interaction. In addition, the unique and divergent representation of transcripts when the cDNA libraries are compared suggests differential gene expression in response to specific niches in the host. This analysis of gene expression patterns provides details about host-pathogen interactions and peculiarities of sites within the host.