1,720,976 research outputs found
Stimulation of endogenous adenosine release by oral administration of quercetin and resveratrol in man
No full textEpidemiological evidence indicates that moderate alcohol consumption is associated with a significant decrease in the incidence of certain cardiovascular disorders, which can lead to impaired quality of life and to death. However, there are no objective data suggesting a cause-effect relationship and detailed research based on definitive working hypotheses is needed. We tested two flavonoids in man and found that these substances can belong, at least in part, to a wine-dependent mechanism, which leads to increased adenosine plasma levels. If these results could be confirmed by analyzing all the possible influences leading to blood nucleoside increase, a hypothesis of diet-dependent cellular preconditioning could be discussed
Variations of peripheral markers of serotoninergic system in selected vascular patients
No full textBACKGROUND AND AIM: Serotonin (5-HT), a decarboxylated derivative of tryptophan, is synthesized in the enterochromaffin cells and released into blood stream to be incorporated into platelets. At the site of endothelial lesions, platelets aggregate and secrete 5-HT that presents several vascular actions involved in thrombosis and atherogenesis. In fact, 5-HT may induce vasoconstriction in the presence of endothelial injury, aggregation of platelets, and mitogenesis of arterial smooth muscle cells and endothelial cells. It may also contribute to the vascular inflammation associated with atherogenesis by increasing the synthesis of Interleukin-6 in vascular smooth muscle cells. We evaluated serotonin levels in plasma and platelets of patients with unstable angina and ischemic stroke, to identify an association between serotonin and atherosclerosis of coronary and cerebral arteries.
METHODS AND RESULTS: Twenty patients (14 men, 6 women, mean age 69 +/- 10 years) with unstable angina and 15 patients (7 men, 8 women, mean age 81 +/- 10 years) with ischemic stroke were included in the study. Twenty-four healthy subjects matched for age and sex constituted the control group. Blood samples were drawn in the morning to determine plasma and platelet concentrations of serotonin. In patients with unstable angina serotonin levels in platelets were significantly lower (p < 0.001) than those observed in controls, while serotonin concentrations in plasma did not significantly differ from those found in controls. In patients affected by stroke serotonin levels in plasma and in platelets did not significantly differ from those found in normal subjects.
CONCLUSIONS: Our findings may contribute to the knowledge to different mechanisms involved in the pathogenesis of cardiac and cerebral ischemia
Effects of Spa therapy on serum leptin and adiponectin levels in patients with knee osteoarthritis
No full textAdipocytokine, including leptin and adiponectin, may play an important role in the pathophysiology of osteoarthritis (OA). Spa therapy is one of the most commonly used non-pharmacological approaches for OA, but its mechanisms of action are not completely known. The aim of the present study was to assess whether spa therapy modified plasma levels of leptin and adiponectin in thirty patients with knee OA treated with a cycle of a combination of daily locally applied mud-packs and bicarbonate-sulphate mineral bath water. Leptin and adiponectin plasma levels were assessed at baseline and after 2 weeks, upon completion of the spa treatment period. The concentrations of leptin and adiponectin were measured by ELISA. At basal time, plasma leptin levels were significantly correlated with body mass index (BMI) and gender, but no significant correlation was found with patient age, duration of disease, radiographic severity of knee OA, VAS score or Lequesne index. There was no correlation between plasma adiponectin level and BMI, gender and age, duration of the disease, radiographic severity of knee OA and VAS score. A significant correlation of plasma adiponectin levels was found only with the Lequesne index. At the end of the mud-bath therapy cycle, serum leptin levels showed a slight but not significant increase, while a significant decrease (P < 0.05) in serum adiponectin levels was found. However, leptin and adiponectin concentrations after treatment were not correlated with other clinical parameters. In conclusion, our data show that spa therapy can modify plasma levels of the adipocytokines leptin and adiponectin, important mediators of cartilage metabolism. Whether this effect may play a potential role in OA needs further investigation
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
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