1,720,976 research outputs found
Eicosapentaenoic acid-rich oil supplementation activates PPAR-γ and delays skin wound healing in type 1 diabetic mice
No full textDelayed wound healing is a devastating complication of diabetes and supplementation with fish oil, a source of anti-inflammatory omega-3 (ω-3) fatty acids including eicosapentaenoic acid (EPA), seems an appealing treatment strategy. However, some studies have shown that ω-3 fatty acids may have a deleterious effect on skin repair and the effects of oral administration of EPA on wound healing in diabetes are unclear. We used streptozotocin-induced diabetes as a mouse model to investigate the effects of oral administration of an EPA-rich oil on wound closure and quality of new tissue formed. Gas chromatography analysis of serum and skin showed that EPA-rich oil increased the incorporation of ω-3 and decreased ω-6 fatty acids, resulting in reduction of the ω-6/ω-3 ratio. On the tenth day after wounding, EPA increased production of IL-10 by neutrophils in the wound, reduced collagen deposition, and ultimately delayed wound closure and impaired quality of the healed tissue. This effect was PPAR-γ-dependent. EPA and IL-10 reduced collagen production by fibroblasts in vitro. In vivo, topical PPAR-γ-blockade reversed the deleterious effects of EPA on wound closure and on collagen organization in diabetic mice. We also observed a reduction in IL-10 production by neutrophils in diabetic mice treated topically with the PPAR-γ blocker. These results show that oral supplementation with EPA-rich oil impairs skin wound healing in diabetes, acting on inflammatory and non-inflammatory cells
The use of gas chromatography to analyze compositional changes of fatty acids in rat liver tissue during pregnancy
No full textPregnancy leads to significant changes to the fatty acid composition of maternal tissues. Lipid profiles can be obtained via gas chromatography to allow identification and quantification of fatty acids in individual lipid classes among rats fed various high and low fat diets during pregnanc
Maternal high-fat diet in mice alters immune regulation and lung function in the offspring
No full textPUFA modulate immune function and have been associated with the risk of childhood atopy and asthma. We investigated the effect of maternal fat intake in mice on PUFA status, elongase and desaturase gene expression, inflammatory markers and lung function in the offspring. C57BL/6J mice (n 32) were fed either standard chow (C, 20·4 % energy as fat) or a high-fat diet (HFD, 39·9 % energy as fat) for 4 weeks prior to conception and during gestation and lactation. At 21 d of age, offspring were weaned onto either the HFD or C, generating four experimental groups: C/C, C/HF, HF/C and HF/HF. Plasma and liver fatty acid composition were measured by GC and gene expression by quantitative PCR. Lung resistance to methacholine was assessed. Arachidonic acid concentrations in offspring plasma and liver phospholipids were increased by HFD; this effect was greater in the post-natal HFD group. DHA concentration in offspring liver phospholipids was increased in response to HFD and was higher in the post-natal HFD group. Post-natal HFD increased hepatic fatty acid desaturase (FADS) 2 and elongation of very long-chain fatty acid 5 expression in male offspring, whereas maternal HFD elevated expression of FADS1 and FADS2 in female offspring compared with males. Post-natal HFD increased expression of IL-6 and C-C motif chemokine ligand 2 (CCL2) in perivascular adipose tissue. The HFD lowered lung resistance to methacholine. Excessive maternal fat intake during development modifies hepatic PUFA status in offspring through regulation of gene expression of enzymes that are involved in PUFA biosynthesis and modifies the development of the offspring lungs leading to respiratory dysfunction.</p
Recommended from our members
High dose fish oil supplements are more effective than oily fish in altering the number and function of extracellular vesicles in healthy human subjects: a randomized, double-blind, placebo-controlled, parallel trial
Full text linkBackground: N-3 polyunsaturated fatty acids (n-3 PUFAs) delivered by fish oil supplements alter the number and functions of circulating extracellular vesicles (EVs), but consumption of oily fish does not reproduce this effect.
Objective: To assess the effects of fish oil supplements and oily fish, at a level achievable in the diet, on EV numbers, composition and procoagulant activity in healthy human volunteers.
Methods: Forty-two healthy subjects were assigned to one of three treatment groups: (i) fish oil supplements plus white fish meals, (ii) control supplements plus oily fish meals or (iii) control supplements plus white fish meals for 12 weeks in a randomized, double-blind, placebo-controlled, parallel trial. Circulating EVs were enumerated and their procoagulant activity assessed using thrombin generation and fibrinolysis assays.
Results: Fish oil supplements decreased circulating EV numbers and reduced EV-stimulated thrombin generation, but the consumption of oily fish at half the dose of EPA had no effect on either EV number or thrombogenic capacity. Consumption of both oily fish and fish oil supplements increased the EPA and DHA contents of EVs and the proportion of EPA in circulating EVs was strongly associated with EV-stimulated thrombin generation.
Conclusions: The additional 1 g/d EPA delivered in the fish oil supplements is required to decrease the numbers and thrombogenic capacity of EVs, since oily fish at a level achievable in the diet had no effect. Increasing EPA intake beyond current guidelines for oily fish consumption may therefore be required for cardiovascular benefits relating to EVs
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
ω-3 polyunsaturated fatty acid supplementation improves postabsorptive and prandial protein metabolism in patients with chronic obstructive pulmonary Disease: a randomized clinical trial
No full textBackground: Disturbances in protein metabolism and impaired muscle health have been observed in chronic obstructive pulmonary disease (COPD). The ω-3 (n–3) PUFAs EPA and DHA are known for their anti-inflammatory and muscle health-enhancing properties. Objectives: We examined whether daily EPA + DHA supplementation can improve daily protein homeostasis in patients with COPD by reducing postabsorptive whole-body protein breakdown (PB) and enhancing the anabolic response to feeding in a dose-dependent way. Methods: Normal-weight participants with moderate to severe COPD (n = 32) received daily for 4 wk, according to a randomized double-blind placebo controlled 3-group design, a high dose (3.5 g, n = 10) of EPA + DHA, a low dose (2.0 g, n = 10) of EPA + DHA, or placebo (olive oil, n = 12) via gel capsules. At pre- and postintervention, stable isotope tracers were infused to assess postabsorptive netPB [postabsorptive PB – protein synthesis (PS)] and the anabolic response (prandial netPS = prandial PS-PB) to a protein meal. In addition, muscle mass and function were measured. Results: Plasma phosphatidylcholine EPA and DHA concentrations were higher after 4 wk of supplementation in both EPA + DHA groups (P < 0.004), and there was a trend toward higher values for plasma EPA after the high compared with the low dose of EPA + DHA (P = 0.065). Postabsorptive PB was lower after 4 wk of the high dose of EPA + DHA, whereas netPB was lower independent of the dose of EPA + DHA (low dose, P = 0.037; high dose, P = 0.026). Prandial netPS was increased only after the high dose of EPA + DHA (P = 0.03). Extremity lean mass but not muscle function was increased, independent of the EPA + DHA dose (P < 0.05). Conclusions: Daily n–3 PUFA supplementation for 4 wk induces a shift toward a positive daily protein homeostasis in patients with COPD in part in a dose-dependent way. Daily doses up to 3.5 g EPA and DHA are still well tolerated and lead to protein gain in these patients. This trial was registered at clinicaltrials.gov as NCT01624792.</p
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
- …
