1,720,999 research outputs found
Electroconvulsive shock blocks the opioid-mediated inhibition of dopamine release in rat striatal slices
No full textDopamine release in striatal slices of rats previously submitted to electroconvulsive shock
No full textRelationship between stress and circulating levels of S100B protein
No full textIt has been proposed that S100B can be a marker for several pathological conditions including brain traumas, blood-brain barrier disruption, and ischemia. Because the hypothalamo-pituitary-adrenal axis is activated in these conditions, we investigated the role of glucocorticoids in the effects of stress on serum S100B. Restraint stress increased S100B levels in control and in adrenalectomized but not in corticosterone-injected rats. Adrenalectomy did not alter basal S100B. These results indicate a glucocorticoid-independent relationship between stress and S100B. (C) 2004 Elsevier B.V. All rights reserved
Effect of stress on hippocampal nociceptin expression in the rat
No full textNociceptin/orphanin FQ (N/OFQ) peptide and its receptor are not only ubiquitously expressed in mammalian brain and spinal cord but are also abundant in limbic structures, particularly in the hippocampus. The widespread distribution of N/OFQ reflects the broad spectrum of its biological actions such as nociception, food intake, spontaneous locomotor activity, and learning and memory processes. Since the hippocampus is involved in the control of adrenocortical activity, its role in stress-related phenomena is well characterized. In male Wistar rats, we first examined the effects of acute restraint stress (120 min) on the brain immunohistochemical localization of N/OFQ. The analysis carried out on sections obtained at the onset of stress revealed enhanced expression of N/OFQ in CA1, CA3, and the dentate gyrus as well as increased plasma corticosterone concentrations. Next, we examined whether endogenous glucocorticoid hormone plays a role in the modulation of hippocampal N/OFQ expression in response to stress. To this end, rats were injected with corticosterone (1 mg/kg) or subjected to restraint stress 1 week after adrenalectomy. Two hours after corticosterone administration, plasma glucocorticoid concentrations were comparable to those observed after restraint stress, while N/OFQ expression had significantly increased in all the hippocampal subfields examined. By contrast, in adrenalectomized rats, stress did not modify protein expression. These results confirm that stress can affect N/OFQ expression and that glucocorticoids may constitute hormonal mediators of this complex interplay
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
GENETIC POLYMORPHISM OF ANGIOTENSIN-CONVERTING ENZYME IS NOT ASSOCIATED WITH THE DEVELOPMENT OF PARKINSON’S DISEASE AND OF L-DOPA INDUCED ADVERSE EFFECTS
No full textSporadic Parkinson's disease (PD) is a frequent neurodegenerative movement disorder. Both environmental and genetic factors have been studied in the etiology of PD. Among genetic factors, increasing evidences suggest that deletion/insertion (D/I) gene polymorphism of the angiotensin I-converting enzyme (ACE) may be involved in the pathogenesis of PD and in the occurrence of the adverse effects of chronic L-dopa therapy. We investigated this hypothesis by evaluating the frequency of the ACE gene D/I polymorphism in 120 Italian PD patients and 132 controls. Out of the 120 PD patients, 91 were under chronic L-dopa treatment. Our results revealed no difference in ACE I/D genotype (?2=0.79, p=0.66) and allele (?2=0.34, p=0.56) frequencies between PD and controls. We also failed to observe any significant association with the occurrence of L-dopa-induced adverse effects in long-term treated PD patients, thereby excluding the presence of an association between ACE I/D genotypes and the genetic susceptibility to PD and the development of adverse effect of chronic L-dopa therapy
Differential expression of heat shock protein (HSP70) mRNAs in rat cells
No full textHeat shock treatment in PC12 cells induces the synthesis of two HSP70 transcripts of 2.55 and 3.05 kb in size, while only a 70-kDa protein is shown by SDS-PAGE. Using reverse transcription-polymerase chain reaction strategy, two mRNA species were amplified from heat-shocked PC12 cells and sequenced, Both cDNAs revealed the same open reading frame encoding a single predicted 641-amino-acid polypeptide of about 70 kDa. The two 3' untranslated regions of the two mRNAs were completely different in both length and composition. Expression of the mRNA of the two corresponding genes and that of another rat HSP70 family member was investigated in PC12, Rat1 cells, and lung fibroblasts. Northern blot analysis revealed that the 2.55- and the 3.05-kb related gene transcripts are differentially expressed in the rat cell lines tested, while the third member of the subfamily is not induced, The single-copy nature of the three genes is also confirmed by Southern blot analysis. (C) 1996 Academic Press, Inc
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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