Search Results (4)

Background: Infection with hepatitis C virus (HCV) lowers serum cholesterol levels, which rapidly recover during therapy with direct-acting antivirals (DAAs). Serum cholesterol is also reduced in patients with liver cirrhosis. Studies investigating serum cholesterol in patients with chronic liver diseases are generally based on enzymatic assays providing total cholesterol levels. Hence, these studies do not account for the individual cholesteryl ester (CE) species, which have different properties according to acyl chain length and desaturation. Methods: Free cholesterol (FC) and 15 CE species were quantified by flow injection analysis high-resolution Fourier Transform mass spectrometry (FIA-FTMS) in the serum of 178 patients with chronic HCV before therapy and during treatment with DAAs. Results: Serum CEs were low in HCV patients with liver cirrhosis and, compared to patients without cirrhosis, proportions of CE 16:0 and 16:1 were higher whereas % CE 20:4 and 20:5 were reduced. FC levels were unchanged, and the CE/FC ratio was consequently low in cirrhosis. FC and CEs did not correlate with viral load. Four CE species were reduced in genotype 3 compared to genotype 1-infected patients. During DAA therapy, 9 of the 15 measured CE species, and the CE/FC ratio, increased. Relative to total CE levels, % CE 16:0 declined and % CE 18:3 was higher at therapy end. At this time, % CE 14:0, 16:0 and 16:1 were higher and % CE 20:4 and 22:6 were lower in the cirrhosis than the non-cirrhosis patients. Viral genotype associated changes of CEs disappeared at therapy end. Conclusions: The serum CE composition differs between patients with and without liver cirrhosis, and changes through the efficient elimination of HCV. Overall, HCV infection and cirrhosis are associated with a higher proportion of CE species with a lower number of carbon atoms and double bonds, reflecting a less-favorable CE profile. Full article

Dyslipidemia, metabolic disorders and/or obesity are postulated as risk factors for pancreatic ductal adenocarcinoma (PDAC). The majority of patients with these metabolic alterations have low density lipoproteins (LDLs) with increased susceptibility to become aggregated in the extracellular matrix (ECM). LDL aggregation can be efficiently inhibited by low-density lipoprotein receptor-related protein 1 (LRP1)-based peptides. The objectives of this work were: (i) to determine if aggregated LDLs affect the intracellular cholesteryl ester (CE)/free cholesterol (FC) ratio and/or the tumor pancreatic cell proliferation, using sphingomyelinase-modified LDL particles (Aggregated LDL, AgLDL); and (ii) to test whether LRP1-based peptides, highly efficient against LDL aggregation, can interfere in these processes. For this, we exposed human pancreatic cancer cell lines (PANC-1, RWP-1 and Capan-1) to native (nLDL) or AgLDLs in the absence or presence of LRP1-based peptides (DP3) or irrelevant peptides (IP321). Results of thin-layer chromatography (TLC) following lipid extraction indicate that AgLDLs induce a higher intracellular CE/FC ratio than nLDL, and that DP3 but not IP321 counteracts this effect. AgLDLs also increase PANC-1 cell proliferation, which is inhibited by the DP3 peptide. Our results indicate that AgLDL-induced intracellular CE accumulation plays a crucial role in the proliferation of pancreatic tumor cell lines. Peptides with anti-LDL aggregation properties may thus exhibit anti-tumor effects. Full article

The aim of this article is to assess the validity of the culturalist explanation of unsustainability by critically examining the social–cultural interpretation of the risks on which it is epistemologically based. First, we will explore the different ways in which the notion of Anthropocene is changing our perception of risks. Second, we will analyze the limits of the social–cultural explanation of risks relative to the global (non-linear) interdependence between human activities and environmental processes that defines the Anthropocene. Third, we will introduce the Chinese concept of Ecological Civilization and analyze its cultural foundations and culturalist assumptions. Finally, we will develop the practical consequences of this critic of the social-cultural interpretation of risks and of culturalist explanations of unsustainability. Full article

The use of a polymer electrolyte fuel cell (PEFC) with a Nafion membrane for isotopic separation of deuterium (D) was investigated. Mass analysis at the cathode side indicated that D diffused through the membrane and participated in an isotope exchange reaction. The exchange of D with protium (H) in H₂O was facilitated by a Pt catalyst. The anodic data showed that the separation efficiency was dependent on the D concentration in the source gas, whereby the water produced during the operation of the PEFC was more enriched in D as the D concentration of the source gas was increased. Full article