Browsing by Author "Fuentes, Eduardo"

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    Landscape change under indirect effects of human use: the Savanna of Central Chile
    (1989) Fuentes, Eduardo; Avilés, Reinaldo; Segura, Alejandro
    The Chilean Intermediate Depression to the north of Santiago has experienced a physiognomical transformation from a Prosopis chilensis woodland to an Acacia caven savanna. Today P. chilensis trees are scarce and belong mostly to the larger size classes. By contrast A. caven seems to reproduce frequently and its populations consist of individuals of all size classes. In this paper we document these changes and report the results of tests aimed at determining the causes of these physiognomical changes. We found that livestock, leporids, introduced Mediterranean forbs and agriculture account for differences in seed dispersal and survival of A. caven and P. chilensis, which can explain the documented changes in the Chilean landscape.
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    Microhabitat use by European rabbits (Oryctolagus cuniculus) in central Chile: Are adult and juvenile patterns the same?
    (1982) Simonetti, Javier A.; Fuentes, Eduardo
    Rabbits (Oryctolagus cuniculus) have been recently introduced to central Chile; adult rabbits have been previously reported to exhibit a release in their use of microhabitats due to lack of effective predation upon them. This paper shows that kittens and juvenile rabbits do not exhibit the same microhabitat use pattern as adults, in spite of the very low predation pressure upon them. These results suggest that small rabbits are ecologically comparable to native rodents.
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    Platelet Activation Is Triggered by Factors Secreted by Senescent Endothelial HMEC-1 Cells In Vitro
    (2020) Venturini, Whitney; Olate-Briones, Alexandra; Valenzuela, Claudio; Mendez, Diego; Fuentes, Eduardo; Cayo, Angel; Mancilla, Daniel; Segovia, Raul; Brown, Nelson E.; Moore-Carrasco, Rodrigo
    Aging is one of the main risk factors for the development of chronic diseases, with both the vascular endothelium and platelets becoming functionally altered. Cellular senescence is a form of permanent cell cycle arrest initially described in primary cells propagated in vitro, although it can also be induced by anticancer drugs and other stressful stimuli. Attesting for the complexity of the senescent phenotype, senescent cells synthesize and secrete a wide variety of bioactive molecules. This "senescence-associated secretory phenotype" (SASP) endows senescent cells with the ability to modify the tissue microenvironment in ways that may be relevant to the development of various physiological and pathological processes. So far, however, the direct role of factors secreted by senescent endothelial cells on platelet function remains unknown. In the present work, we explore the effects of SASP factors derived from senescent endothelial cells on platelet function. To this end, we took advantage of a model in which immortalized endothelial cells (HMEC-1) were induced to senesce following exposure to doxorubicin, a chemotherapeutic drug widely used in the clinic. Our results indicate that (1) low concentrations of doxorubicin induce senescence in HMEC-1 cells; (2) senescent HMEC-1 cells upregulate the expression of selected components of the SASP and (3) the media conditioned by senescent endothelial cells are capable of inducing platelet activation and aggregation. These results suggest that factors secreted by senescent endothelial cells in vivo could have a relevant role in the platelet activation observed in the elderly or in patients undergoing therapeutic stress.