1,720,960 research outputs found
Intracerebroventricular interleukin-1 alpha increases immunocyte beta-endorphin concentrations in the rat:involvement of corticotropin releasing hormone and neurotransmitters
No full textThe opioid peptide β-endorphin (BE) is synthesized and secreted by the cells of the immune system and has been shown to participate in the modulation of immune responses, e.g. during stress. Interleukin-1 (IL-1) is a potent activator of the corticotropin-releasing hormone (CRH) system in the hypothalamus, and it has been shown to be involved in many stress responses, including immunosuppression. We studied the effect of centrally injected IL- 1α on immunocyte BE concentrations in the rat. IL-1α (1 ng/rat, intracerebroventricularly) significantly (P < 0.01) increased the concentrations of the peptide in splenocytes, lymph node cells, and peripheral blood mononuclear cells 2 and 24 h after treatment. Intracerebroventricular, but not iv, administration of 2 μg IL-1 receptor antagonist blocked the IL-1α-induced increase. These effects were also prevented by the intracerebroventricular administration of the CRH receptor antagonist α-helical CRH-(9-41). Treatment with 6-hydroxydopamine and 5,7- dihydroxytryptamine, which deplete the catecholaminergic or the serotoninergic systems, respectively, blocked the increase in BE induced by the cytokine. In contrast, hypophysectomy and treatment with indomethacin did not modify the effect of IL. The increase in immunocyte BE, therefore, seems to depend on the activation of CRH, catecholamines, and serotonin, but to be independent of activation of the hypothalamus-pituitary-adrenal-axis and prostaglandins. The immunocyte BE increase could be involved in the immunosuppression induced by central IL-1α
Benzodiazepine-induced chemotaxis is impaired in monocytes from patients with generalized anxiety disorders
No full textPeripheral benzodiazepine receptors (PBR) modulate chemotaxis and cytokine production of monocytes and lymphocytes. Since PBR are decreased in animal models of stress and in patients with anxiety disorders, in the present study we analyze the ability of monocytes obtained from patients suffering from generalized anxiety to migrate towards chemoattracting benzodiazepines. In these patients, the benzodiazepine-induced chemotaxis is completely abolished, while the response to the control chemoattractant formyl-leu-met-phe is still maintained. The chemotaxis responses are not restored after pharmacological treatment of the pathology. The decreased chemotactic response could be linked to a decreased number of PBR receptors present on monocytes of generalized anxiety disorder patients
Pharmacological modulation of neuropeptides in peripheral mononuclear cells
No full textThe concentrations of β-endorphin and cholecystokinin were measured in fresh resting peripheral mononuclear cells obtained from rats and human subjects in basal conditions and after different pharmacological treatments. Both in the human and the rat, β-endorphin concentrations in mononuclear cells increased after treatment with serotoninergic agonists, decreased after dopaminergic or GABAergic drugs, while the respective antagonists exerted the opposite effect. In vitro, serotoninergic and GABAergic compounds confirmed their roles in the modulation of β-endorphin in mononuclear cells. Cholecystokinin was never affected by the pharmacological treatments
Visualization of cholecystokinin receptors on a subset of human monocytes and in rat spleen
No full textDirect radioreceptor binding experiments and Scatchard analysis reveal CCK receptors on elutriator purified human peripheral blood monocytes, but not on purified human T cells. The monocyte receptors have a single class of high (0.1 nM) affinity binding sites. A structure-function analysis of monocyte binding by different CCK analogs correlates well with previously demonstrated chemotactic responses in monocytes and receptors in brain tissue. Biochemical cross-linking indicates that the monocyte CCK recognition molecule is comparable in molecular size to that in brain membranes. Utilizing a novel fluoresceinated Texas Red-CCK conjugate we have visualized that up to 20% of human peripheral monocytes bear receptors for CCK. A discrete and anatomically significant distribution of CCK receptors in rat spleen is shown by film autoradiography of tissue sections. A more detailed microscopic analysis identifies a dendritic population of monocyte-derived cells within the periarteriolar lymphocyte sheath (PALS) of the white pulp as the CCK receptor-bearing cell in spleen. The anatomical localization of receptor-bearing cells within the PALS region suggests a role for CCK in the antigen processing and sensitization phases of the immune response via regulatory effects of this peptide on a specific, local macrophage-related cell population
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
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