1,721,016 research outputs found
Vinyl chloride and the liver: Misrepresentation of epidemiological evidence
No full textResearch Letter. Abstract not available
Effect of extracellular matrix on hepatic stellate cells response to bacterial endotoxins and integrin-linked kinase expression
No full text
''Plasma antioxidant levels in chronic cholestatic liver diseases''
Full text linkAbstract: Background: A predictable consequence of cholestasis is malabsorption of fat-soluble factors, (vitamins A, D, E, K) and other free radical scavengers, such as carotenoids. It has been suggested that oxygen-derived free radicals may be involved in the pathogenesis of chronic liver damage.
Aims: (i) To evaluate retinol, alpha-tocopherol and carotenoid plasma levels in two groups of patients with chronic cholestatic liver disease (primary biliary cirrhosis and primary sclerosing cholangitis); (ii) to compare the respective plasma levels with those of the general population; (iii) to correlate the plasma levels with disease severity.
Methods: A total of 105 patients with chronic cholestasis were included in the study: 86 with primary biliary cirrhosis (81 female, five male, mean age 55.5 +/- 11 years), 19 with primary sclerosing cholangitis (seven female, 12 male, mean age 35 +/- 11 years; six patients had associated inflammatory bowel disease); 105 sex- and age-matched subjects from the general population in the same geographical area (88 female, 17 male, mean age 51.3.5 +/- 10 years) served as controls. Carotenoids (lutein zeaxanthin, lycopene, beta-carotene, alpha-carotene, beta-cryptoxanthin), retinol and alpha-tocopherol were assayed by high-pressure liquid chromatography. A food frequency questionnaire was administered to each subject to evaluate the quality and the quantity of dietary compounds. Data were processed by analysis of variance and linear regression analysis, as appropriate.
Results: Both primary biliary cirrhosis and primary sclerosing cholangitis patients had significantly lower levels of retinol, alpha-tocopherol, total carotenoids, lutein, zeaxanthin, lycopene, alpha- and beta-carotene than controls (P < 0.0001). Among the cholestatic patients, no significant difference in the concentration of antioxidants was observed between primary biliary cirrhosis and primary sclerosing cholangitis subjects. Anti-oxidant plasma levels were not affected by the severity of the histological stage in primary biliary cirrhosis, but a negative correlation was found between total carotenoids and both alkaline phosphatase (ALP) and gammaglutamyl transpeptidase (GGT) (P < 0.013 and P < 0.018, respectively). Within the primary sclerosing cholangitis group, no correlation was found between total carotenoids and cholestatic enzymes. Nutritional intake in cholestatic patients was comparable to controls, including fruit and vegetable intake.
Conclusions: Although no clinical sign of deficiency is evident, plasma levels of antioxidants are low in cholestatic patients even in early stages of the disease. This is probably due to malabsorption of fat-soluble vitamins, as well as other mechanisms of hepatic release, suggesting the need for dietary supplementation
Verifica di teorie delle intenzioni tramite modelli di equazioni strutturali
No full textThe aims of this study are as follows: 1. to test the evaluative/affective model of attitude; 2. to test the validity of the theory of planned behaviour and of the self-regulation theory; 3. to test the hypothesis that the theory of self-regulation has a greater explicative power than that of the theory of planned behaviour. A sample of 201 male and female adults was examined, all of whom consumed alcoholic drinks, even moderately. The instrument used is a questionnaire; structural equation models were applied. The results indicate the validity of the evaluative/affective model and the greater heuristic power of the self-regulation theory
Effects of dietary fibre on the chemical-physiscal characteristics of pig faeces
No full textDublin, Ireland
No effect of endurance exercise on serum bilirubin in healthy athletes and with congenital hyperbilirubinemia (Gilbert's syndrome).
No full textTwenty male athletes, mean age 26 years, were studied by a work load test with cycle-ergometer, with increasing power output for 60 minutes until an intensity corresponding to 70% of the individual maximal heart rate was achieved. Ten of them had familial hyperbilirubinemia (Gilbert's syndrome) and ten had been considered as healthy controls. The diagnosis of Gilbert's syndrome was made using the following criteria: unconjugated hyperbilirubinemia, no systemic symptoms, no overt or clinically recognizable haemolysis, normal liver function tests. Blood levels of free fatty acids (FFA) showed a progressive significant increase after muscular exercise in both healthy and Gilbert's syndrome subjects (p < 0.001). The increase was more evident in controls compared to Gilbert's syndrome subjects (p < 0.05). Total and fractionated bilirubin showed no change in both groups. In conclusion, a competitive mechanism between bilirubin and FFA is probably responsible for the lower increase in plasma FFA in Gilbert's syndrome
Exposure to bacterial cell wall products triggers an inflammatory phenotype in hepatic stellate cells
No full textActivated hepatic stellate cells (HSCs) secrete extracellular matrix components during hepatic fibrosis, but recent studies have shown that HSCs can also release a variety of proinflammatory cytokines. Moreover, bacterial endotoxemia is not only associated with systemic complications in the late stages of liver failure but is also a direct cause of liver damage, activating resident inflammatory cells. In this study, we investigated whether HSCs can respond directly to bacterial cell wall products acquiring a new phenotype. RT-PCR and immunocytochemistry assays were used to show that murine HSCs expressed specific mRNA transcripts and proteins for LPS and lipoteichoic acid (LTA) receptor systems and peptidoglycan recognition proteins. Exposing HSCs to bacterial endotoxins led to phosphorylation of mitogen-activated protein kinase ERK1 and the development of a proinflammatory phenotype. After exposure to LPS, LTA, or N-acetyl muramyl peptide, transforming growth factor-beta1, IL-6, and monocyte chemoattractant protein-1 (MCP-1) mRNA specific transcripts and proteins increased significantly in HSCs, as assayed by quantitative real-time RT-PCR and ELISA. These LPS-mediated effects in HSCs were receptor dependent, because LPS-induced ERK1 phosphorylation, IL-6, and MCP-1 mRNA and protein level upregulation were significantly less pronounced in HSCs isolated from C3H/HeJ mice lacking Toll-like receptor 4. In conclusion, our results show that murine HSCs express functional receptors for bacterial endotoxins, and HSCs exposed to bacterial products develop a strong proinflammatory phenotype. We speculate that high levels of bacterial endotoxins in the portal vein may directly induce a proinflammatory phenotype in HSCs that contributes to liver damag
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
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