1,720,975 research outputs found
The effect of alexithymia and depressive feelings on pain perception in somatoform pain disorder
No full textObjective: To investigate the relationship between alexithymia and depression and their influence on the subjective versus experimental pain perception in somatoform pain disorder. Methods: Three groups consisting of 40 patients with somatoform pain disorder, 40 patients with depression, and 40 healthy controls were matched. They completed questionnaires regarding alexithymia (TAS26) and depressive feelings (BDI-II). In addition, pain patients rated their subjective pain intensity (NRS). Quantitative sensory testings were conducted in all participants examining temperature (CPT, HPT) and mechanical (MPT, PPT) thresholds. Results: Analysis of variance showed that alexithymia was significantly increased in both patient groups compared to healthy controls, but with the highest amount in somatoform pain. Regression analyses confirmed that this finding was in part due to a high comorbidity of depressive feelings in both patient groups. We found a discrepancy between increased clinical pain ratings and elevated pressure pain thresholds, indicating a less intense mechanical pain perception in somatoform pain. Correlation analyses demonstrated a significant connection of subjective pain ratings and pressure pain thresholds with depressive feelings. Conclusion: Contrary to the results of other experimental pain studies on chronic muskuloskeletal pain syndromes, we could not confirm central sensitization in somatoform pain disorder. Our findings place the somatoform pain disorder more in the direction of affective disorder such as depression. These findings may improve a better understanding of the disease and also have direct therapeutic implications. The high occurrence of alexithymia and depressive feelings in somatoform pain should be considered in diagnostic and therapeutic regimens of these patients
Microarray analysis of Akt1 activation in transgenic mouse hearts reveals transcript expression profiles associated with compensatory hypertrophy and failure
No full textTo investigate molecular mechanisms involved in the development of cardiac hypertrophy and heart failure, we developed a tetracycline-regulated transgenic system to conditionally switch a constitutively active form of the Akt1 protein kinase on or off in the adult heart. Short-term activation (2 wk) of Akt1 resulted in completely reversible hypertrophy with maintained contractility. In contrast, chronic Akt1 activation (6 wk) induced extensive cardiac hypertrophy, severe contractile dysfunction, and massive interstitial fibrosis. The focus of this study was to create a transcript expression profile of the heart as it undergoes reversible Akt1-mediated hypertrophy and during the transition from compensated hypertrophy to heart failure. Heart tissue was analyzed before transgene induction, 2 wk after transgene induction, 2 wk of transgene induction followed by 2 days of repression, 6 wk after transgene induction, and 6 wk of transgene induction followed by 2 wk of repression. Acute overexpression of Akt1 (2 wk) leads to changes in the expression of 826 transcripts relative to noninduced hearts, whereas chronic induction (6 wk) led to changes in the expression of 1,611, of which 65% represented transcripts that were regulated during the pathological phase of heart growth. Another set of genes identified was uniquely regulated during heart regression but not growth, indicating that nonoverlapping transcription programs participate in the processes of cardiac hypertrophy and atrophy. These data define the gene regulatory programs downstream of Akt that control heart size and contribute to the transition from compensatory hypertrophy to heart failure. Copyright © 2006 the American Physiological Society
Impaired revascularization in a mouse model of type 2 diabetes is associated with dysregulation of a complex angiogenic-regulatory network
No full textObjective - Diabetes is a risk factor for the development of cardiovascular diseases associated with impaired angiogenesis or increased endothelial cell apoptosis. Methods and Results - Here it is shown that angiogenic repair of ischemic hindlimbs was impaired in Lepr db/db mice, a leptin receptor-deficient model of diabetes, compared with wild-type (WT) C57BL/6 mice, as evaluated by laser Doppler flow and capillary density analyses. To identify molecular targets associated with this disease process, hindlimb cDNA expression profiles were created from adductor muscle of Lepr db/db and WT mice before and after hindlimb ischemia using Affymetrix GeneChip Mouse Expression Set microarrays. The expression patterns of numerous angiogenesis-related proteins were altered in Lepr db/db versus WT mice after ischemic injury. These transcripts included neuropilin-1, vascular endothelia growth factor-A, placental growth factor, elastin, and matrix metalloproteinases implicated in blood vessel growth and maintenance of vessel wall integrity. Conclusion - These data illustrate that impaired ischemia-induced neovascularization in type 2 diabetes is associated with the dysregulation of a complex angiogenesis-regulatory network. © 2005 American Heart Association, Inc
Angiogenic-regulatory network revealed by molecular profiling heart tissue following Akt1 induction in endothelial cells
No full textAkt is a pivotal signaling molecule involved in the regulation of angiogenesis. In order to further elucidate the role of Akt1 in blood vessel development, a tetracycline-regulated transgenic system was utilized to conditionally activate Akt1 signaling in endothelial cells to examine transcript expression changes associated with angiogenesis in the heart. Induction of Akt1 over the course of 6 weeks led to a 33% increase in capillary density without affecting overall heart growth. Transcript expression profiles in the hearts were analyzed with an Affymetrix GeneChip Mouse Expression Set 430 2.0, which represents approximately 45,000 cDNAs and ESTs. A total of 248 transcripts were differentially expressed between transgenic and control mice (fold change >/<1.8; false discovery rate < 0.1; P < 0.01). A subset of these differentially expressed transcripts included angiogenic growth factors, cytokines, and extracellular matrix proteins. More specifically, these transcripts included VEGF-receptor2, neuropilin-1, and connective tissue growth factor, each of which is implicated in blood vessel growth and the maintenance of vessel wall integrity. Furthermore, these factors may be involved in an autocrine-regulatory feedback system, one believed to promote vessel growth. Knowledge of these and other targets could be used to treat ischemic heart disease, a disease whose broad spectrum of manifestations range from patients with only effort-induced angina without myocardial damage, through stages of myocardial ischemia that are associated with reversible and irreversible impairment in left ventricular function, to states of irreversible myocardial injury and necrosis resulting in congestive heart failure (CHF). © 2008 Springer Science+Business Media B.V
Impaired angiogenesis in glutathione peroxidase-1-deficient mice is associated with endothelial progenitor cell dysfunction
No full textSeveral vascular disease are characterized by elevated levels of reactive oxygen species (ROS). Vascular endothelium is protected from oxidant stress by expressing enzymes such as glutathione peroxidase type 1 (GPx-1). In this study, we investigated the effect of vascular oxidant stress on ischemia-induced neovascularization in a murine model of homozygous deficiency of GPx-1. GPx-1-deficient mice showed impaired revascularization following hindlimb ischemic surgery based on laser Doppler measurements of blood flow and capillary density in adductor muscle. GPx-1-deficient mice also showed an impaired ability to increase endothelial progenitor cell (EPC) levels in response to ischemic injury or subcutaneous administration of vascular endothelial growth factor protein. EPCs isolated from GPx-1-deficient mice showed a reduced ability to neutralize oxidative stress in vitro, which was associated with impaired migration toward vascular endothelial growth factor and increased sensitivity to ROS-induced apoptosis. EPCs isolated from GPx-1-deficient mice were impaired in their ability to promote angiogenesis in wild-type mice, whereas wild-type EPCs were effective in stimulating angiogenesis in GPx-1-deficient mice. These data suggest that EPC dysfunction is a mechanism by which elevated levels of ROS can contribute to vascular disease. © 2006 American Heart Association, Inc
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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