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polymorphism and steatosis on liver function assessed by methacetin breath test
No full textBackground: MBOAT7 rs641738 variant is a risk factor for nonalcoholic fatty liver disease (NAFLD) and liver fibrosis, but the relationship between this polymorphism and early liver dysfunction remains uncertain.Methods: Eighty outpatients underwent blood analyses, liver imaging by ultrasound and acoustic radiation force impulse shear wave elastography and were genotyped for MBOAT7 (wild-type [WT], rs641738 heterozygous or homozygous) polymorphism using TaqMan assays.Results: NAFLD was confirmed in 53 patients. Portal uptake and hepatocyte microsomal metabolization of (C-13)-methacetin were explored by measuring (CO2)-C-13 appearance in exhaled air. The distribution of the MBOAT7 genotypes was comparable in subjects with or without NAFLD. The majority of subjects with or without NAFLD had fibrosis <= F1 but decreased portal extraction of (C-13)-methacetin, i.e. 78.6% in homozygous, 45.0% in heterozygous and 46.2% in WT for the MBOAT7 variant. Both substrate extraction and microsomal metabolization were mostly defective in the homozygous carriers. The extraction efficiency from portal blood flow was minimal in subjects with both homozygous rs641738 polymorphism and NAFLD, as compared to those with WT/heterozygous polymorphism, with or without NAFLD.Conclusions: The homozygous MBOAT7 rs641738 polymorphism per se is associated with a reduced extraction efficiency of (C-13)-methacetin from the portal flow pointing to subclinical liver dysfunction independently from liver fibrosis. Liver steatosis worsens (C-13)-methacetin extraction efficiency. We urge to better explore the mechanisms of interaction between external factors and multiple gene polymorphisms (including MBOAT7), paving the road to primary prevention and novel therapeutic strategies
The Potential of the Mediterranean Diet to Improve Mitochondrial Function in Experimental Models of Obesity and Metabolic Syndrome
Get PDFThe abnormal expansion of body fat paves the way for several metabolic abnormalities including overweight, obesity, and diabetes, which ultimately cluster under the umbrella of metabolic syndrome (MetS). Patients with MetS are at an increased risk of cardiovascular disease, morbidity, and mortality. The coexistence of distinct metabolic abnormalities is associated with the release of pro-inflammatory adipocytokines, as components of low-to-medium grade systemic inflammation and increased oxidative stress. Adopting healthy lifestyles, by using appropriate dietary regimens, contributes to the prevention and treatment of MetS. Metabolic abnormalities can influence the function and energetic capacity of mitochondria, as observed in many obesity-related cardio-metabolic disorders. There are preclinical studies both in cellular and animal models, as well as clinical studies, dealing with distinct nutrients of the Mediterranean diet (MD) and dysfunctional mitochondria in obesity and MetS. The term “Mitochondria nutrients” has been adopted in recent years, and it depicts the adequate nutrients to keep proper mitochondrial function. Different experimental models show that components of the MD, including polyphenols, plant-derived compounds, and polyunsaturated fatty acids, can improve mitochondrial metabolism, biogenesis, and antioxidant capacity. Such effects are valuable to counteract the mitochondrial dysfunction associated with obesity-related abnormalities and can represent the beneficial feature of polyphenols-enriched olive oil, vegetables, nuts, fish, and plant-based foods, as the main components of the MD. Thus, developing mitochondria-targeting nutrients and natural agents for MetS treatment and/or prevention is a logical strategy to decrease the burden of disease and medications at a later stage. In this comprehensive review, we discuss the effects of the MD and its bioactive components on improving mitochondrial structure and activity
Nonalcoholic Fatty Liver Disease (NAFLD). Mitochondria as Players and Targets of Therapies?
Get PDFNonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and represents the hepatic expression of several metabolic abnormalities of high epidemiologic relevance. Fat accumulation in the hepatocytes results in cellular fragility and risk of progression toward necroinflammation, i.e., nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and eventually hepatocellular carcinoma. Several pathways contribute to fat accumulation and damage in the liver and can also involve the mitochondria, whose functional integrity is essential to maintain liver bioenergetics. In NAFLD/NASH, both structural and functional mitochondrial abnormalities occur and can involve mitochondrial electron transport chain, decreased mitochondrial β-oxidation of free fatty acids, excessive generation of reactive oxygen species, and lipid peroxidation. NASH is a major target of therapy, but there is no established single or combined treatment so far. Notably, translational and clinical studies point to mitochondria as future therapeutic targets in NAFLD since the prevention of mitochondrial damage could improve liver bioenergetics
Liver fat accumulation more than fibrosis causes early liver dynamic dysfunction in patients with non-alcoholic fatty liver disease
No full textIntroduction: In Non-Alcoholic Fatty Liver Disease (NAFLD), events driving early hepatic dysfunction with respect to specific metabolic pathways are still poorly known.Methods: We enrolled 84 subjects with obesity and/or type 2 diabetes (T2D). FibroScan (R) served to assess NAFLD by controlled attenuation parameter (CAP), and fibrosis by liver stiffness (LS). Patients with LS above 7 kPa were excluded. APRI and FIB-4 were used as additional serum biomarkers of fibrosis. The stable-isotope dynamic breath test was used to assess the hepatic efficiency of portal extraction (as DOB15) and microsomal metabo-lization (as cPDR30) of orally-administered (13C)-methacetin.Results: NAFLD occurred in 45%, 65.9%, and 91.3% of normal weight, overweight, and obese subjects, respec-tively. Biomarkers of liver fibrosis were comparable across subgroups, and LS was higher in obese, than in normal weight subjects. DOB15 was 23.2 +/- 1.5%o in normal weight subjects, tended to decrease in overweight (19.9 +/- 1.0%o) and decreased significantly in obese subjects (16.9 +/- 1.3, P = 0.008 vs. normal weight). Subjects with NAFLD had lower DOB15 (18.7 +/- 0.9 vs. 22.1 +/- 1.2, P = 0.03) but higher LS (4.7 +/- 0.1 vs. 4.0 +/- 0.2 kPa, P = 0.0003) than subjects without NAFLD, irrespective of fibrosis. DOB15 (but not cPDR30) decreased with increasing degree of NAFLD (R =-0.26; P = 0.01) and LS (R =-0.23, P = 0.03). Patients with T2D showed increased rate of NAFLD than those without T2D but similar LS, DOB15 and cPDR30.Conclusions: Overweight, obesity and liver fat accumulation manifest with deranged portal extraction efficiency of methacetin into the steatotic hepatocyte. This functional alteration occurs early, and irrespective of significant fibrosis and presence of T2D
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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