The many faces of Pluripotency: in vitro adaptations of a continuum of in vivo states

Pluripotency defines the propensity of a cell to differentiate into, and generate, all somatic, as well as germ cells. The epiblast of the early mammalian embryo is the founder population of all germ layer derivatives and thus represents the bona fide in vivo pluripotent cell population. The so-called pluripotent state spans several days of development and is lost during gastrulation as epiblast cells make fate decisions towards a mesoderm, endoderm or ectoderm identity. It is now widely recognized that the features of the pluripotent population evolve as development proceeds from the pre- to post-implantation period, marked by distinct transcriptional and epigenetic signatures. During this period of time epiblast cells mature through a continuum of pluripotent states with unique properties. Aspects of this pluripotent continuum can be captured in vitro in the form of stable pluripotent stem cell types. In this review we discuss the continuum of pluripotency existing within the mammalian embryo, using the mouse as a model, and the cognate stem cell types that can be derived and propagated in vitro. Furthermore, we speculate on embryonic stage-specific characteristics that could be utilized to identify novel, developmentally relevant, pluripotent states

Formal caregivers of older adults: reflection about their practice

OBJECTIVE To understand the job function of caregivers of older adults and contribute to the debate on the consolidation of this professional practice. METHODOLOGICAL PROCEDURES This is a descriptive, qualitative, and exploratory study. Four focal group sessions were performed in 2011 with 11 elderly companions, formal caregivers of older adults in the Programa Acompanhante de Idosos (Program for Caregivers of Older Adults), Sao Paulo, SP, Southeastern Brazil. These sessions, guided by a semi-structured script, were audio-recorded and fully transcribed. Data were analyzed using the Content Analysis technique, Thematic Modality. RESULTS In view of considering the caregivers of older adults as a new category of workers, it was difficult to define their duties. The elderly companions themselves as well as the care receivers, their families, and the professionals that comprised the team were unclear about their duties. The professional practice of these formal caregivers has been built on the basis of constant discussions and negotiations among them and other team members in Programa Acompanhante de Idosos during daily work. This was achieved via a recognition process of their job functions and by setting apart other workers’ exclusive responsibilities. CONCLUSIONS The delimitation of specific job functions for elderly companions is currently one of the greatest challenges faced by these workers to develop and consolidate their professional role as well as improve Programa Acompanhante de Idosos

A Sprouty4 reporter to monitor FGF/ERK signaling activity in ESCs and mice

The FGF/ERK signaling pathway is highly conserved throughout evolution and plays fundamental roles during embryonic development and in adult organisms. While a plethora of expression data exists for ligands, receptors and pathway regulators, we know little about the spatial organization or dynamics of signaling in individual cells within populations. To this end we developed a transcriptional readout of FGF/ERK activity by targeting a histone H2B-linked Venus fluorophore to the endogenous locus of Spry4, an early pathway target, and generated Spry4H2B-Venus embryonic stem cells (ESCs) and a derivative mouse line. The Spry4H2B-Venus reporter was heterogeneously expressed within ESC cultures and responded to FGF/ERK signaling manipulation. In vivo, the Spry4H2B-Venus reporter recapitulated the expression pattern of Spry4 and localized to sites of known FGF/ERK activity including the inner cell mass of the pre-implantation embryo and the limb buds, somites and isthmus of the post-implantation embryo. Additionally, we observed highly localized reporter expression within adult organs. Genetic and chemical disruption of FGF/ERK signaling, in vivo in pre- and post-implantation embryos, abrogated Venus expression establishing the reporter as an accurate signaling readout. This tool will provide new insights into the dynamics of the FGF/ERK signaling pathway during mammalian development