1,720,965 research outputs found
Expression of CD52 mRNA in the rat embryo
No full textCD52 is a leukocyte differentiation antigen first discovered in humans as expressed on the surface of lymphocytes,
monocytes and eosinophils. The human CD52 is found on chromosome 1, and two alleles are both known to be
reasonably common. A closely homologous gene has been identified in the cynomologous monkey and related
genes have been found in mouse, rat and dog. The role of CD52 in lymphocyte is still unclear but the anti-CD52
antibodies named CAMPATH-1 antibodies are largely used for therapy where depletion of lymphocytes is required.
In the past expression of the antigen on progenitors of leukocytes in bone marrow had been excluded, but recent
work indicates CD52 is highly expressed on cells with colony-forming and NOD/SCID (non-obese diabetic-severe
combined immunodeficiency)-engrafting capacities, both at the mRNA and membrane protein level. We have
investigated CD52 expression during development in rat embryos by in situ hybridization. We report here that
the antigen is highly expressed in the liver that is the major organ where multipotent hematopietic stem cells
differentiate but also in the splancnopleuric mesoderm, at early stages of embryo differentiation, where hematopietic
stem cells are suggested to arise. CD52+ cells were found in areas active in vasculogenesis at early embryo stages
and in the walls of the vessels in the liver at mid gestation. CD52+ cells were also found to emerge among c-Kit
positive cells
Identification of a novel, alpha2-fucosylation-dependent uptake system in highly proliferative cells.
No full textIn this paper we describe a new structure present in highly proliferative cells and absent in cells with normal growth potential. We used cultured bovine venular endothelial cells (CVEC) as examples of high proliferation, and dermal fibroblasts of a primary culture as examples of normal proliferation. The structure, consisting of tubules radiating from the nuclear region to the tips of cell protrusions, was revealed by its strong positivity to the fucose-binding lectin from Lotus (LTL) that prefers glycans with alpha-1,2-linked fucose. Another fucose-binding lectin that prefers glycans with alpha-1,6-linked fucose was instead found to localize glycans exclusively in Golgi complexes. LTL binding sites were also found at the surface of CVEC in a restricted region close to the nucleus. The role of alpha-1,2-linked fucose in forming or maintaining the tubules was confirmed by the fact that down-regulation of the fucosyltransferases FUT1 and FUT2 resulted in disappearance of the tubular structure. LTL also proved able to penetrate the cells through the tubular structures up to the nuclear region and to inhibit proliferation. Endostatin was also found to massively penetrate the cells in the tubular structures in control cells but not in FUT1/2 depleted cells. In cells of a first passage primary culture of dermal fibroblasts the tubular LTL-positive structure was absent as well as the LTL-positive sites at the external surface, and both fucose-binding lectins were found to exclusively localize glycans in Golgi complexes. Tubules were again found progressively in fibroblasts derived from repeated passages, where faster growing cells predominate. Disappearance of LTL-positivity in Golgi complexes paralleled appearance of LTL-positive tubules. The role of Golgi complexes in forming the tubules is discussed
A fucose-containing O-glycoepitope on bovine and human nucleolin
No full textIn this paper, we demonstrate the existence and localization
of fucosyl-containing O-glycoforms of nucleolin in cultured
bovine endothelial cells (CVEC) and malignant cultured
human A431 cells. The tool for this discovery was an
antibody raised against gp273, a glycoprotein ligand for the
sperm–egg interaction in the mollusc bivalve Unio elongatulus.
The function and immunological properties of gp273
mainly depend on clustered Lewis-like, fucose-containing
O-glycans. Here an anti-gp273 antibody was used to evaluate
whether glycoepitopes similar to those of gp273 are part
of potential ligands of selectins in endothelial cells.We found
that anti-gp273 strongly and exclusively interacted with a
110 kDa protein in CVEC and A431 tumor cells. After partial
purification, mass spectrometry identified the protein
as nucleolin. This was confirmed by comparing anti-gp273
and anti-nucleolin antibody immunoblotting after nucleolin
depletion.We confirmed that anti-gp273 binding to nuclear
and extranuclear nucleolin was against a fucose-containing
O-glycoepitope by immunoblot analysis of the protein after
chemically removing O-glycans and by lectin-blot analysis
of control and nucleolin-depleted samples. Using anti-gp273
IgG, we detected nucleolin on the plasma membrane and
cytoplasm. O-glycosylation may regulate the plethora of
functions in which nucleolin is involved
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
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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