Search results for " radical"

Differential effects of oxidized LDL on apolipoprotein AI and B synthesis in HepG2 cells

2006

Oxidized low-density lipoproteins (Ox-LDL) are key elements in atherogenesis. Apolipoprotein AI (apoAI) is an active component of the antiatherogenic high-density lipoproteins (HDL). In contrast, plasma apolipoprotein B (apoB), the main component of LDL, is highly correlated with coronary risk. Our results, obtained in HepG2 cells, show that Ox-LDL, unlike native LDL, leads to opposite effects on apoB and apoAI, namely a decrease in apoAI and an increase in apoB secretion as evaluated by [(3)H]leucine incorporation and specific immunoprecipitation. Parallel pulse-chase studies show that Ox-LDL impaired apoB degradation, whereas apoAI degradation was increased and mRNA levels were decreased.…

Role of the cyclic AMP-dependent pathway in free radical-induced cholesterol accumulation in vascular smooth muscle cells.

2000

We have previously reported that free radical-treated vascular smooth muscle cells (SMC) lead to cholesterol accumulation in vitro. In the current study, we investigated the effects of oxidative stress on cyclic AMP concentration and cAMP-dependent enzymes involved in cholesterol homeostasis in A7r5 cells. Under our conditions of a mild oxidative stress, namely with no change in cell viability, we found that free radicals, initiated using azobis-amidinopropane dihydrochloride (AAPH), resulted in a dose-dependent decrease in cellular cAMP which was opposed by vitamin E preincubation. Although the addition of adenylate cyclase activators (carbacyclin and forskolin) increased cAMP levels it di…

Oxidative stress leads to cholesterol accumulation in vascular smooth muscle cells.

1999

The transformation of macrophages and smooth muscle cells into foam cells by modified low-density lipoproteins (LDL) is one of the key events of atherogenesis. Effects of free radicals have mainly been studied in LDL, and other than toxicity, data dealing with direct action of free radicals on cells are scarce. This study focused on the direct effects of free radicals on cholesterol metabolism of smooth muscle cells. A free radical generator, azobis-amidinopropane dihydrochloride, was used, and conditions for a standardized oxidative stress were set up in vascular smooth muscle cells. After free radical action, the cells presented an accumulation of cholesterol that appeared to be the resul…

Methyl Radical in Clathrate Silica Voids. The Peculiar Physisorption Features of the Guest-Host Molecular Dynamics Interaction.

2016

EPR line shape simulations of CH3/SiO2 clathrates and comparison to CH3/N2O and CH3/SiO2 experiments reveal the motional conditions of the CH3 radical up to the unusual regime of its stability, the high-temperature diffusional regime, at 300 K. In the low-temperature region, the CH3 in clathrates is found to rotate around the in-plane axes even at as low temperatures as 3.8 K. However, nonrotating methyls performing only libration about the C2-axes as well as around the C3-axis are also found, proving the existence of special sites in the clathrate voids that begin to accumulate a significant fraction of methyl radicals at temperatures below approximately 7 K. A distinctive feature in the s…

Oxysterols Incorporate in Primary Porcine Retinal Pigment Epithelial Cells and Induce Inflammation and Oxidative Stress

2006

International audience; Purpose: : Aging is associated with an accumulation of cholesterol in the Bruch’s membrane. Cholesterol is prone to undergo oxidation and to generate oxysterols that have cytotoxic properties. The aim of this study was to evaluate the effects of oxysterols on cell viability, oxidative stress and inflammation and to measure oxysterol incorporation in primary porcine retinal pigment epithelial (RPE) cell cultures. Methods: : Porcine RPE cells were incubated with oxysterols (24S–hydroxycholesterol, 24OH ; 25–hydroxycholesterol, 25OH and 7–ketocholesterol, 7K) (100µg, 50µM) for 24 and 48h. Cell viability was evaluated by measuring mitochondrial succinate dehydrogenase (S…

CCDC 1945945: Experimental Crystal Structure Determination

2019

Related Article: Suchithra Ashoka Sahadevan, Alexandre Abhervé, Noemi Monni, Pascale Auban-Senzier, Joan Cano, Francesc Lloret, Miguel Julve, Hengbo Cui, Reizo Kato, Enric Canadell, Maria Laura Mercuri, Narcis Avarvari|2019|Inorg.Chem.|58|15359|doi:10.1021/acs.inorgchem.9b02404

Grafting of polymer chains on the surface of carbon nanotubes via nitroxide radical coupling reaction

2016

Poly(butylene succinate)/MWCNTs nanocomposites with improved dispersion and with nanotubes embedded/immobilized into the polymer matrix were here prepared by an alternative "grafting to" method based on thenitroxide radical coupling reaction. Poly(butylene succinate) (PBS) was grafted on the surface of TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) modified multi-walled carbon nanotubes (MWCNTs) via a nitroxide radical coupling reaction. TEMPO functionalized MWCNTs (MWCNTs-g-TEMPO) were synthesized using the Cu(I)-catalyzed azide/alkyne click chemistry approach and the covalent bond of the nitroxide moieties onto the MWCNTs was confirmed via electron paramagnetic resonance (EPR) spectroscopy.…

Análisis ideológico-discursivo de la nueva derecha radical. El caso de Vox y el nativismo

2022

Durante las últimas décadas ha ido desarrollándose un nuevo auge de la ultraderecha a nivel mundial que está protagonizado por unas formaciones de derecha radical nacidas en el contexto sociopolítico actual y que persiguen unos intereses y emplean unos discursos populistas que no coinciden con las directrices profundamente antidemocráticas que seguían tradicionalmente las organizaciones que representaban este espacio del espectro ideológico desde los años treinta, pero que actualmente ha quedado dividido en dos grandes familias: la vieja y, en la que se centra este trabajo, la nueva. España, al igual que la mayoría de los países europeos, no se ha librado del auge de esta nueva familia, pue…

Review of Recanati’s “Literal Meaning”,

2005

La necesaria rehabilitación del sistema representativo en las propuestas de reforma democrática

2010

In the debates on deliberative democracy it’s a common idea that the defenders of this theory argue for the direct participation of the citizens in the political issues and for the transformation of our current representative devices. However, in this work I argue that this conception is misguided, and that it’s the minority who defends the direct participation. The majority of the writers acknowledges the necessity of a representative device, although based on different premises to the liberal system. The deliberative democracy supports a responsible and compromised citizenship, against the model of self interested citizenship.<br><br>En los debates sobre la democracia delibera…