1,720,968 research outputs found
Paraoxonase activity in high density lipoproteins: a comparison between healthy and obese females
No full textJ Clin Endocrinol Metab. 2005 Mar;90(3):1728-33. Epub 2004 Dec 21.
Paraoxonase activity in high-density lipoproteins: a comparison between healthy and obese females.
Ferretti G, Bacchetti T, Moroni C, Savino S, Liuzzi A, Balzola F, Bicchiega V.
SourceIstituto di Biochimica, Facoltà di Medicina e Chirurgia, Università Politecnica delle Marche, Via Ranieri, 60131 Ancona, Italy. [email protected]
Abstract
Paraoxonase, an enzyme associated with high-density lipoprotein (HDL-PON), exerts a protective effect against oxidative damage of circulating cells and lipoproteins, modulates the susceptibility of HDL to atherogenic modifications such as glycation and homocysteinylation, and even exerts an antiinflammatory role. The aim of the present study was to investigate the relationship between lipoprotein oxidative stress and the activity of HDL-PON in healthy and obese subjects. Therefore, the activity of HDL-PON and the levels of lipid hydroperoxides in HDL and low-density lipoprotein (LDL) isolated from plasma of obese females (n = 12) and age-sex-matched controls (n = 31) were compared. Our results demonstrated for the first time that the activity of HDL-PON in obese subjects was significantly lower compared with that in controls (P < 0.001). Moreover, our results showed a significant increase in the levels of lipid hydroperoxides in HDL and LDL isolated from obese subjects (P < 0.001). The negative correlations established between HDL-PON activity and the levels of lipid hydroperoxides associated with HDL and LDL confirm the relationship between paraoxonase activity and lipid peroxidation of lipoproteins. Plasma levels of leptin correlated negatively with HDL-PON activity and positively with levels of lipid hydroperoxides in HDL and LDL of obese subjects, suggesting a relationship between leptin and oxidative damage of lipoproteins. In conclusion, our study demonstrated that the increase in oxidative stress in LDL and HDL of obese subjects is associated with a decrease in HDL-PON activity. The lower paraoxonase activity and the compositional changes in HDL and LDL could contribute to the greater risk of cardiovascular disease associated with obesity.
PMID:15613429[PubMed - indexed for MEDLINE
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Is serum uric acid a predictive factor of response to IFN-treatment in patients with chronic hepatitis C infection?
No full textSeveral factors, including metabolic profile, are predictive of response to standard antiviral therapy in patients with chronic hepatitis C. In a retrospective study, it was investigated whether uric acid, involved in metabolic syndrome, could be included. A total of 153 patients (56.2% males; mean age 45.7 +/- 11.3 years) treated with pegylated-interferon and ribavirin were included. Eighty-five were infected with hepatitis C virus (HCV) genotype 1 or 4 and 68 with genotype 2 or 3. Viral load was >1,000,000 IU/ml in 101, 4 in 15 and unknown in 57 patients. Mean serum uric acid was 5.05 +/- 1.3 mg/dl. Sustained virological response (negative serum HCV-RNA 6 months after treatment cessation) was achieved in 102 patients (67%). In the final logistic model, serum uric acid level > or =5.8 mg/dl (OR = 0.46; 95% CI: 0.30-0.62), viral load (OR = 0.29; 95% CI: 0.09-0.92) and HCV genotype (OR = 0.23; 95% CI: 0.09-0.60) were identified as the most important factors independently influencing clinical outcome. The prognostic role of serum uric acid was confirmed on the sub-sample reporting Ishak fibrosis score (OR = 0.49; 95% CI: 0.28-0.85). Serum uric acid level > or =5.8 mg/dl is predictive of poor response to HCV treatment. Prospective studies are needed to clarify the issue
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