1,721,003 research outputs found
Morphological, immunohistochemical and ultrastructural characteristics of human dental pulp stem cells after neuronal and glial cell differentiation
No full textnot availabl
Morphological, immunohistochemical and ultrastructural characteristics of human dental pulp stem cells after neuronal and glial cell differentiation
No full textnot availabl
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Expression Pattern of Basal Markers in Human Dental Pulp Stem Cells and Tissue
Full text linkDental pulp stem cells (DPSC) have been characterized as a multipotent stem cell population, with the ability to differentiate into mesodermal and neural cell lineages. Although 'de novo' expression of neural markers after differentiation is mostly considered as proof of differentiation, expression of these markers in undifferentiated DPSC is not well described. Therefore, an immunocytochemical analysis was performed to evaluate the neural marker expression of undifferentiated human DPSC (hDPSC) in in vitro cultures. Undifferentiated hDPSC uniformly expressed neural markers β-III-tubulin, S100 protein and synaptophysin. A subset of the population showed a positive immune-reactivity for galactocerebroside, neurofilament and nerve growth factor receptor p75. Furthermore, the location of possible stem cell niches, present in young dental pulp tissue, was determined by means of immunohistochemistry based on mesenchymal and neural marker expression. The results demonstrated the presence of a perivascular niche and a second stem cell niche at the cervical area. In adult dental pulp, only a perivascular niche could be observed. Based on the expression of neural markers in naïve DPSC, it has to be taken into account that not only the marker expression upon neural differentiation must be analyzed, but an ultrastructural analysis of the morphological changes and functional studies must also be performed to confirm a successful differentiation.sponsorship: The authors of the manuscript are very grateful to Marc Jans and Jeanine Santermans for their dedicated technical assistance. A.B. received a postdoctoral grant from the Fonds voor Wetenschappelijk Onderzoek-Vlaanderen. (Fonds voor Wetenschappelijk Onderzoek-Vlaanderen)status: Publishe
Metallothionein: a possible new marker for human dental pulp stem cells
No full textHuman dental pulp stem cells (HDPSC’s) is a term used for the remaining mesenchymal stem cell population in adult teeth. It has already been described that these cells exhibit odontogenic capacities when these cells are explanted into immunocompromised mice. They create a dentin-pulp like complex and in this way their use in tissue engineering and tooth regeneration seems very promising. However, there is still a lack of specific markers to identify this cell type. In this study, we investigated the immunoreactivity of HDPSC’s for metallothionein (MT), a Cystein-rich, low molecular weight protein. MT has the capacity to bind both physiological (Zn, Cu, Se,...) and xenobiotic (Cd, Hg, Ag,...) heavy metals through the thiol group of its cysteine residues. Furthermore, the immunoreactivity fot MT was tested in human pulp tissue and human bone-marrow derived mesenchymal stem cells
Ultrastructural evidence for multi-lineage differentiation of human dental pulp stem cells
No full textMesenchymal stemm cells (MSCs) are one of the most promising stem cell types due to their availability and relatively simple requirements for in vitro expansion and genetic manipulation. Besides the well-characterized MSCs derived from bone marrow, there is growing eveidence suggesting that dental pulp and the umbilical cord matrix both contain a substantial amount of cells having propertes similar to those of MSCs. In order to assess the potential of dental pulp-derived MSCs(DPSC) and umbilical cord-derived MSCs(UCSC) in future clinical applications, it is essential to gain more insight into their differentiation capacity and to evaluate the tissues formed by these cells. In the present study, the morphological and ultrastructural characteristics of DPSC and UCSC induced towards osteogenic, adipogenic, and chondrogenic lineages were investigated. Cultured DPSC and UCSC showed a similar expression pattern of antigens characteristic of MSCs including CD105, CD29, CD44, CD146, and STRO-1. Under appropriate culture conditions, both DPSC and UCSC showed chondrogenic and osteogenic potential. Adipogenesis could be only partially induced in DPSC resulting in the de novo expression of fatty acid binding protein (FABP), whereas UCSC expressed FABP combined with a very high accumulation of lipid droplets in the cytoplasm. Our results demonstrate, at the biochemical and ultrastructural level, that DPSC display at least bilineage potential, whereas UCSC, which are developmentally more primitive cells, show trilineage potential. We emphasize that transmission electron microscopical analysis is useful to elucidate detailed structural information and provides indisputable evidence of differentiation. These findings highlight their potential therapeutic value for cell-based tissue engineering
Metallothionein: a possible new marker for human dental pulp stem cells
No full textHuman dental pulp stem cells (HDPSC’s) is a term used for the remaining mesenchymal stem cell population in adult teeth. It has already been described that these cells exhibit odontogenic capacities when these cells are explanted into immunocompromised mice. They create a dentin-pulp like complex and in this way their use in tissue engineering and tooth regeneration seems very promising. However, there is still a lack of specific markers to identify this cell type. In this study, we investigated the immunoreactivity of HDPSC’s for metallothionein (MT), a Cystein-rich, low molecular weight protein. MT has the capacity to bind both physiological (Zn, Cu, Se,...) and xenobiotic (Cd, Hg, Ag,...) heavy metals through the thiol group of its cysteine residues. Furthermore, the immunoreactivity fot MT was tested in human pulp tissue and human bone-marrow derived mesenchymal stem cells
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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