1,720,990 research outputs found
Nuclear accumulation of c-myc mRNA in phytohaemagglutinin-activated T lymphocytes treated with anti-HLA class I monoclonal antibody
No full textAnti-HLA class I monoclonal antibody 01.65 inhibits the proliferative response of PHA-activated human T lymphocytes from peripheral blood mononuclear cells. The recruitment rate in the cell cycle is slack and the G1 and S phases are prolonged. Among the early events after PHA activation, only the calcium-dependent PKC activity appears to be modified: particulate PKC is completely depleted while cytosolic residual PKC is reduced by 80% after MAb 01.65 treatment. We have carried out in greater detail the study of c-myc gene regulation by MAb 01.65 and the results are as follows: (i) c-myc RNA transcription is normally initiated and finished, suggesting a post-transcriptional regulation of c-myc gene expression; (ii) no alteration in c-myc mRNA stability has been documented; (iii) steady-state levels of c-myc mRNA expression by Northern blot analysis and PCR amplification are decreased in the cytoplasmic compartment, while in the nuclear compartment they appear to be increased. Nuclear accumulation of mature mRNA after MAb 01.65 and PKC inhibitor (H7 and StSp) treatment appears to be the most probable mechanism involved. The possible implications of this are discussed
A polymorphism in the 5′ region of coagulation factor VII gene (F7) caused by an inserted decanucleotide
No full textWe describe a polymorphism in the 5' region of the coagulation factor VII (FVII) gene, originating from a decanucleotide (CCTATATCCT) insert present in the less frequent allele. This marker can be detected by restriction analysis of polymerase chain reaction products
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
Localization of cloned human DNA sequences and analysis of chromosomal alteration by in situ hybridization
No full textThe in situ hybridization technique was used for the localization on human chromosomes of single-copy and repeated sequences and, in addition, for the characterization of altered human chromosomes. Two anonymous clones, single or low-copy, obtained from a human X chromosome library were localized on the distal part of the long arm and in the paracentromeric region of X chromosome, respectively. A genomic fragment of the single-copy thyroglobulin (TG) gene was used to confirm the localization on the distal part of the long arm of chromosome 8. The localization and distribution on human chromosomes of the glyceraldehyde-3-phosphate dehydrogenase (GAPD) multigene family obtained by in situ hybridization and by somatic cell hybrids were compared. A phosphoglycerate kinase (PGK) c-DNA clone, which detects genic and pseudogenic sequences on the X chromosome, was used for the characterization of three small ring markers present in unrelated female patients
Adaptative value of a PKC-PKI55 feedback loop of inhibition that prevents the kinase's deregulation.
No full textA 168-bp amplification product was obtained in RT-PCR experiments using a degenerate oligonucleotide designed on a five-amino acid sequence of IN, a 7-kDa protein, previously characterized as a PKC inhibitor. It was included in the coding ORF of the 1530-bp-long IMAGE clone ID 38900 (accession numbers R51337 and R51448) that produces a translation product of 6.5 kDa. The translation of the ORF conceptual reading frame allowed the preparation of the synthetic protein PKI55, which was found to inhibit and degrade both untreated nPKC d isozymes and activated cPKC isozymes. The PKI55 gene is localized in chromosome 2q35. The Repeat Maskers output showed a 533-bp-long LTR32/ERVL segment that included the PKI55 coding sequence and a complete regulatory region. The coding sequence and the structure of PKI55 were detected in a brain cDNA of Macaca fascicularis (diverged from human lineages about 25 Myr ago). Three other human genes with over 60% identities with PKI55 were identified in three different loci (i.e., chromosomes 10, 15, and 20.) Synthesis of PKI55 was stimulated by PKC activation. A feedback loop of inhibition is established. When the PKCs are overactivated, PKI55 induces degradation of the enzyme and prevents the isozyme overexpression implicated in a number of important diseases including cancer, diabetes, and disorders of the immune system. The presence of the PKI55 sequence in Macaca fascicularis as well as in human chromosomes 10, 15, and 20 indicates a selective advantage for the PKI55 sequence and the adaptive value of the feedback mechanism
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
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