Search

Copyright of Avances en PsicologÍa Latinoamericana is the property of Colegio Mayor de Nuestra Senora del Rosario and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Air pollution affects cities and countries all over the world. One of the most common air pollutants is particulate matter (PM10) which has a direct impact on people´s health (WHO, 2006). The concentration of this pollutant in the troposphere depends principally on weather conditions. This paper seeks to analyse variations in Bahía Blanca (Argentina) PM10 concentration over time by evaluating the relationship between physical and anthropogenic factors that may influence its dynamics. It was observed that variations in PM10 concentrations are related to both natu- ral and anthropogenic factors. Traffic flow and agroindustrial activities, mainly related to grain transport and storage, promote high pollutant concentrations. This is reflected by marked variations of PM10 concentrations throughout the day and between working and nonworking days. PM10 concentrations are affected by Northern, high speed winds, which cause clouds of dust and smoke very often. In addition, results from this investigation revealed that PM10 concentrations may be related to volcanic activity, as the eruption of the Puyehue- Caulle Range. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) possess unique paracrine and immunosuppressive properties, which make them useful candidates for cellular therapy. Here, we address how cellular senescence influences the therapeutic potential of human MSCs (hMSCs). Senescence was induced in bone marrow-derived hMSC cultures with gamma irradiation. Control and senescent cells were tested for their immunoregulatory activity in vitro and in vivo, and an extensive molecular characterization of the phenotypic changes induced by senescence was performed. We also compared the gene expression profiles of senescent hMSCs with a collection of hMSCs used in an ongoing clinical study of Graft Versus Host disease (GVHD). Our results show that senescence induces extensive phenotypic changes in hMSCs and abrogates their protective activity in a murine model of LPS-induced lethal endotoxemia. Although senescent hMSCs retain an ability to regulate the inflammatory response on macrophages in vitro, and, in part retain their capacity to significantly inhibit lymphocyte proliferation, they have a severely impaired migratory capacity in response to proinflammatory signals, which is associated with an inhibition of the AP-1 pathway. Additionally, expression analysis identified PLEC, C8orf48, TRPC4, and ZNF14, as differentially regulated genes in senescent hMSCs that were similarly regulated in those hMSCs which failed to produce a therapeutic effect in a GVHD trial. All the observed phenotypic alterations were confirmed in replicative-senescent hMSCs. In conclusion, this study highlights important changes in the immunomodulatory phenotype of senescent hMSCs and provides candidate gene signatures which may be useful to evaluate the therapeutic potential of hMSCs used in future clinical studies. S tem C ells 2014;32:1865-1877 [ABSTRACT FROM AUTHOR]