1,721,071 research outputs found
Determinazione della velocità di eritrosedimentazione: comparazione fra i risultati ottenuti con il metodo di riferimento ICSH e con pipette monouso di plastica
No full textEffect of physiological concentration of tyrosol on normal and diabetic human erythrocytes under oxidative stress
No full textEffect of physiological concentration of phloridzin on normal and diabetic human erythrocytes under oxidative stress
No full textType 2 diabetes mellitus (T2DM) is the most prevalent metabolic disease affecting people all over the world. Recent studies hypothesize that oxidative stress, present inT2DM, plays a crucial role in suppression of insulin biosynthesis and in progression of insulin resistance (1); therefore an evaluation of the potential usefulness of dietary antioxidants in treatment for T2DM is required. Several in vitro studies on human erythrocytes (RBCs) show the antioxidant property of some polyphenols but in very high and far to in vivo reachable concentrations.
OBJECTIVES: evaluate the potential antioxidant effect of phloridzin (PRZ), a polyphenol present in apple (2), at in vivo-liked concentration, on RBCs membrane fluidity and on some membrane and cytosolic glycohydrolases activities indicated as a very sensitive markers of RBCs oxidative stress (3).
MATERIALS AND METHODS: RBCs (from health subjects and T2DM patients), preincubated with 1M of phloridzin, then stressed by a Xanthine/Xanthine oxidase system for 1 hour; were analysed for: a) membrane fluorescence anisotropy; b) cytosolic O-GlcNAcase and Hexosaminidase (Hex) activities; c) ß-D-glucuronidase (GCR) and Hex activities in plasma membrane.
RESULTS: a) decrease of membrane fluidity and an increment of membrane GCR activity in T2DM patients. b) no appreciable effect of PRZ on enzyme activities nor in membrane fluidity.
CONCLUSIONS: We don’t find, at in vivo concentration, the protective effect of PRZ against oxidative stress reported in previously studies in-vitro (2). Possible synergistic in vitro effects with other polyphenols and/or their derivative metabolites at physiological levels will be focused in further studies
O-GLcNACase as biomarker of antioxidant status in healty women under isoflavones supplementation
No full textConsumption of soy has been correlated to a lower incidence of chronic diseases, among which CVD characterized by a high oxidative stress, that has been partially attributed to isoflavone (IF) intake. We evaluated the antioxidant effects of 80 mg/d of total IF supplementation in 13 healthy women (age 29 ± 8) for 6 months followed by 2 months of suspension; blood samples were collected every two months (T=0, 1, 2, 3 and 4). Plasma concentrations of IF, RBC activities of O-GlcNAcase, considered good marker of cellular stress, and of cytosolic hesosaminidase (Hex-c), total plasma antioxidant capacity (Lag-time), RBC membrane fluidity (rs) and DNA oxidative damage (comet assay) were evaluated. Statistical analysis were performed by ANOVA for repeated measure (p<0.05).
IF plasma concentrations and Lag-time increased (p<0.05) according to dietary intervention and rs increased at T=2 vs. T=1 and T=4 (p<0.05). DNA damage (due to H2O2) significantly decreased during supplementation, with a significant inverse correlation with plasma IF concentration. OGlcNAcase and Hex-c activities did not change after 2 months of IF supplementation, while they increased at T=2 and T=3 vs. T=1 (p<0.05). Results suggest a positive effect of IF supplementation against oxidative stress and confirm previous studies indicating O-GlcNAcase as a good tool for monitoring antioxidant status
Effect of physiological concentration of caffeic acid on normal and diabetic human erythrocytes under oxidative stress
No full text
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
- …
