1,720,962 research outputs found
Cytokine modulation by endothelin-1 and possible therapeutic implications in systemic sclerosis
No full textSystemic sclerosis (SSc), also known as scleroderma, is an autoimmune disorder characterized by a progressive fibrosis which involves skin and internal organs, caused by microvascular damage. The earliest clinical sign of the disease is Raynauds Phenomenon, a vasospastic response to cold or stress stimuli, followed by the skin and organ involvement over time. This kind of vascular manifestation originates from the microvascular structural alteration, characterized by an abnormal myocyte cell proliferation, intima cell proliferation and adventitia fibrosis. The microvascular damage seems to be the consequence of the autoimmune attack to the endothelium, followed by inflammatory cascade and massive deposition of collagen. From the beginning of the disorder, serum Endothelin-1 (ET- 1) is found in very high concentration: this protein, today, is considered one of the most important mediators of scleroderma vascular alterations. Furthermore, many recent studies have shown that ET-1 is involved in the inflammatory and fibrotic processes, increasing the concentration of pro-fibrotic and pro-inflammatory cytokines. The aim of this review is to clarify the ET-1 role in SSc, in particular the relationship between ET-1 and cytokine expression, adding another element to the understanding of scleroderma disease
Evaluation of the effect of Bosentan treatment on proinflammatory cytokine serum levels in patients affected by Systemic Sclerosis
No full textSystemic sclerosis (SSc) is a connective tissue disease characterized by vascular and fibrotic changes in the skin and in internal organs. Endothelin-1 (ET-1) is a peptide that has a role in promoting both vascular injury and the fibrotic process in SSc; indeed, patients with systemic sclerosis have higher levels of ET-1 compared with healthy subjects. Moreover, ET-1 enhances expression of pro-inflammatory cytokines in animal model. Bosentan is a dual endothelin receptor antagonist approved for the treatment of pulmonary arterial hypertension and digital ulcers in scleroderma patients. In animal models and in vitro models, after treatment with Bosentan, a significant reduction of cytokine (TNF α, IFN γ,IL-8, IL-4) levels was observed. The aim of the study is to verify whether Bosentan treatment in SSc patients can reduce circulating cytokines levels. We enrolled 10 patients affected by SSc with digital ulcers and/or pulmonary hypertension, treated with Bosentan 125 mg twice daily. Patients were tested for cytokines and ET-1 level before treatment and after 12 months. The cytokines tested were IL-10, IL-2, IL-4, IL-5, IL-6, IL-8, GM-CSF, IFN-γ and TNF. Levels of ET-1, IL-10, IL-4, IL-5, GM-CSF and TNFalpha did not show consistent modification during treatment with Bosentan in respect to baseline, while IL-2, IL-6, IL-8 and IFN-γ were significantly decreased. Bosentan significantly reduced IL-2, IL-6, IL-8 and IFN- γ levels in SSc patients, probably slowing progression to fibrosis and vascular damage. This is the first report showing a decrease of profibrotic and proinflammatory cytokines levels in humans during treatment with Bosentan
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
Mapping trace contaminant emissions from a municipal waste incinerator
No full textTracers of environmental contamination generated by the emissions of a small municipal solid waste incinerator were measured in different environmental compartments. Concentrations of OCDD, Hg, As, Cd and Pb in soil and plant foliage mapped in the impacted area revealed a clear fingerprint. The levels of measured contaminants, however, were far from having a toxicological significance. Lichens, used as biological indicators of air quality, revealed a measurable degree of pollution generated by acid emissions only very partially due to the studied source
Preliminary data on butyltin residues in dolphins frequenting the Mediterranean coastal areas
No full textVariations 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
Accumulation of butyltin compounds in dolphins stranded along the Mediterranean coasts
No full textConcentrations of tributyltin (TBT) and its degradation products, monobutyltin (MBT) and dibutyltin (DBT), were determined in the liver and kidney of striped dolphins (Stenella coeruleoalba), bottlenose dolphins (Tursiops truncatus) and in a fetus of the common dolphin (Delphinus delphi) found stranded along the western Italian and Greek coasts in the period 1992-1994. Butyltin (BT) compounds were detected in almost all the samples analyzed and were higher in the kidney than in the liver. Total BT concentrations were 0.78-8.05 μg g-1wet wt in kidney and 0.015-1.02 μg g-1wet wt in liver of S. coeruloealba. Bottlenose dolphins had lower BT concentrations than striped dolphins. Although only one fetal sample was analyzed, it showed the highest BT concentrations of all. Unlike BT concentrations in the other adult dolphins, in the pregnant dolphin they were higher in the liver (4.35 μg g-1wet wt), suggesting that BTs are transferred from mother to fetus. No significant differences in BT concentrations were found between sexes. Of the breakdown products, DBT was predominant in most liver samples and MBT was more abundant in kidney. Although BT concentrations are known to be found in cetaceans inhabiting waters of developed countries, our observations strongly suggest that concentrations found in S. coeruleoalba were either similar to or higher than those reported for other Stenella species collected from coastal areas close to harbors or marinas. Copyright (C) 2000 John Wiley and Sons, Ltd
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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