98 research outputs found
Differences in Transcriptional Activation by the Two Allelic (L162V Polymorphic) Variants of PPARα after Omega-3 Fatty Acids Treatment
Omega-3 fatty acids (FAs) have the potential to regulate gene
expression via the peroxisome proliferator-activated receptor α (PPARα);
therefore, genetic variations in this gene may
impact its
transcriptional activity on target genes. It is hypothesized that
the transcriptional activity by wild-type L162-PPARα is enhanced
to a greater extent than the mutated variant (V162-PPARα) in the
presence of eicosapentaenoic acid (EPA), docosahexaenoic acid
(DHA) or a mixture of EPA:DHA. To examine the functional
difference of the two allelic variants on receptor activity,
transient co-transfections were performed in human hepatoma HepG2
cells activated with EPA, DHA and EPA:DHA mixtures. Results
indicate that the addition of EPA or DHA demonstrate potential to
increase the transcriptional activity by PPARα with respect to
basal level in both variants. Yet, the EPA:DHA mixtures enhanced
the transcriptional activity to a greater extent than individual
FAs indicating possible additive effects of EPA and DHA.
Additionally, the V162 allelic form of PPARα demonstrated
consistently lower transcriptional activation when incubated with
EPA, DHA or EPA:DHA mixtures than, the wild-type variant. In
conclusion, both allelic variants of the PPARα L162V are activated
by omega-3 FAs; however, the V162 allelic form displays a lower
transcriptional activity than the wild-type variant
N-3 polyunsaturated fatty acids stimulate bile acid detoxification in human cell models
Cholestasis is characterized by the accumulation of toxic bile acids (BAs) in liver cells. The present study aimed to evaluate the effects of n-3 polyunsaturated fatty acids (n-3 PUFAs), such as docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids, on BA homeostasis and toxicity in human cell models. The effects of EPA and/or DHA on the expression of genes involved in the maintenance of BA homeostasis were analyzed in human hepatoma (HepG2) and colon carcinoma (Caco-2) cells, as well as in primary culture of human intestinal (InEpC) and renal (RPTEC) cells. Extracellular BA species were quantified in culture media using LC-MS/MS. BA-induced toxicity was evaluated using caspase-3 and flow cytometry assays. Gene expression analyses of HepG2 cells reveal that n-3 PUFAs reduce the expression of genes involved in BA synthesis (CYP7A1, CYP27A1) and uptake (NTCP), while activating genes encoding metabolic enzymes (SULT2A1) and excretion transporters (MRP2, MRP3). N-3 PUFAs also generate a less toxic BA pool and prevent the BA-dependent activation of apoptosis in HepG2 cells. Conclusion. The present study reveals that n-3 PUFAs stimulate BA detoxification
Differences in metabolomic and transcriptomic profiles between responders and non-responders to an n-3 polyunsaturated fatty acids (PUFAs) supplementation
Studies have demonstrated large within-population heterogeneity in plasma triacylglycerol (TG) response to n-3 PUFA supplementation. The objective of the study was to compare metabolomic and transcriptomic profiles of responders and non-responders of an n-3 PUFA supplementation. Thirty subjects completed a 2-week run-in period followed by a 6-week supplementation with n-3 PUFA (3 g/d). Six subjects did not lower their plasma TG (+9 %) levels (non-responders) and were matched to 6 subjects who lowered TG (â41 %) concentrations (responders) after the n-3 PUFA supplementation. Pre-n-3 PUFA supplementation characteristics did not differ between the non-responders and responders except for plasma glucose concentrations. In responders, changes were observed for plasma hexose concentrations, docosahexaenoic acid, stearoyl-CoA-desaturase-18 ratio, and the extent of saturation of glycerophosphatidylcholine after n-3 PUFA supplementation; however, no change in these parameters was observed in non-responders. Transcriptomic profiles after n-3 PUFA supplementation indicate changes in glycerophospholipid metabolism in both subgroups and sphingolipid metabolism in non-responders. Six key genes in lipid metabolism: fatty acid desaturase 2, phospholipase A2 group IVA, arachidonate 15-lipoxygenase, phosphatidylethanolamine N-methyltransferase, monoglyceride lipase, and glycerol-3-phosphate acyltransferase, were expressed in opposing direction between subgroups. In sum, results highlight key differences in lipid metabolism of non-responders compared to responders after an n-3 PUFA supplementation, which may explain the inter-individual variability in plasma TG response
PPAR α
Hypolipidemic fibrates activate the peroxisome proliferator-activated receptor (PPAR) α to modulate lipid oxidation and metabolism. The present study aimed at evaluating how 3 PPARα agonists, namely, fenofibrate, gemfibrozil, and Wy14,643, affect bilirubin synthesis and metabolism. Human umbilical vein epithelial cells (HUVEC) and coronary artery smooth muscle cells (CASMC) were cultured in the absence or presence of the 3 activators, and mRNA, protein, and/or activity levels of the bilirubin synthesizing heme oxygenase- (HO-) 1 and biliverdin reductase (BVR) enzymes were determined. Human hepatocytes (HH) and HepG2 cells sustained similar treatments, except that the expression of the bilirubin conjugating UDP-glucuronosyltransferase (UGT) 1A1 enzyme and multidrug resistance-associated protein (MRP) 2 transporter was analyzed. In HUVECs, gemfibrozil, fenofibrate, and Wy14,643 upregulated HO-1 mRNA expression without affecting BVR. Wy14,643 and fenofibrate also caused HO-1 protein accumulation, while gemfibrozil and fenofibrate favored the secretion of bilirubin in cell media. Similar positive regulations were also observed with the 3 PPARα ligands in CASMCs where HO-1 mRNA and protein levels were increased. In HH and HepG2 cells, both UGT1A1 and MRP2 transcripts were also accumulating. These observations indicate that PPARα ligands activate bilirubin synthesis in vascular cells and metabolism in liver cells. The clinical implications of these regulatory events are discussed
AustĂ©ritĂ© versus protection sociale : comment garantir lâaccĂšs aux soins en Europe ?
Maria MelchiorMĂ©decins du Monde agit en Europe depuis 1986, et actuellement dans 14 pays diffĂ©rents Ă travers 160 programmes qui visent Ă aider des personnes vulnĂ©rables Ă accĂ©der Ă des soins et Ă leurs droits. Depuis 2004, lâassociation dĂ©veloppe un plaidoyer spĂ©cifique auprĂšs de divers acteurs europĂ©ens â le Parlement europĂ©en, la Commission europĂ©enne, lâAgence de surveillance sanitaire europĂ©enne ainsi que le Conseil de lâEurope â pour promouvoir lâaccĂšs aux soins de toutes les personnes ..
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 nonâcritically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (nâ=â257), ARB (nâ=â248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; nâ=â10), or no RAS inhibitor (control; nâ=â264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ supportâfree days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ supportâfree days among critically ill patients was 10 (â1 to 16) in the ACE inhibitor group (nâ=â231), 8 (â1 to 17) in the ARB group (nâ=â217), and 12 (0 to 17) in the control group (nâ=â231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ supportâfree days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
LANGSAD : former des formateurs
Barbier Marie-claude. LANGSAD : former des formateurs. In: Cahiers de l'APLIUT, volume 14, numéro 2, 1994. Vidéo. pp. 119-120
Henry Rider Haggard in Zululand: A Reluctant Imperialist?
This paper analyses Rider Haggardâs first major work, Cetywayo and his White Neighbours or Remarks on Recent Events in Zululand, Natal and the Transvaal, published in 1882, after six years in South Africa. Those years were crucial in the history of the country because of the two deadly conflicts fought by the British: the Anglo-Zulu War and the first Boer war, both marked by the traumatic defeats at Isandhlwana and Majuba Hill. On his return to England, Haggard decided to give an account of the events based on his own observations and perspective as an active witness. Though a supporter of British imperialism, Haggard criticized Britainâs political choices in Zululand at the time and tried to show that the principal cause of the conflicts was British ignorance of Zulu society. He blamed the arrival of Western civilisation for permanently compromising Zulu identity as its traders and missionaries brought with them evils which could no longer be eradicated. Torn between his admiration for the Zulu, which was to inspire him in his subsequent well-known works of fiction, and his belief that development of the colonies was essential for Britain, but also conscious that white domination was inescapable, he suggested a protectorate as being a lesser evil.Cet article analyse un essai publiĂ© en 1882 par Rider Haggard, Cetywayo and his White Neighbours or Remarks on Recent Events in Zululand, Natal and the Transvaal, aprĂšs un sĂ©jour de six annĂ©es en Afrique du Sud. AnnĂ©es cruciales dans lâhistoire du pays puisque sây dĂ©roulĂšrent deux conflits majeurs pour les Britanniques, la guerre anglo-zouloue et la premiĂšre guerre des Boers, ponctuĂ©s par les traumatisantes dĂ©faites dâIsandhlwana et de Majuba Hill. De retour en Angleterre, Haggard souhaite apporter sa version des faits tels quâil les avait vĂ©cus en tant que tĂ©moin participant. MĂȘme sâil soutient la prĂ©sence britannique en Afrique du sud, il se montre trĂšs critique des choix politiques de son pays pour le Zululand, considĂ©rant que les conflits rĂ©sultent dâune mĂ©connaissance des mĆurs zouloues. Il dĂ©nonce lâimpact nĂ©gatif de la civilisation occidentale qui, avec ses commerçants et ses missionnaires, a perverti Ă jamais lâidentitĂ© de ce peuple. PartagĂ© entre son admiration pour les Zoulous â qui allaient Ă plusieurs reprises lâinspirer dans ses romans futurs- et son adhĂ©sion Ă un nĂ©cessaire dĂ©veloppement des colonies, et surtout conscient de lâinĂ©luctabilitĂ© de la domination blanche, il suggĂšre que lâĂ©tablissement dâun protectorat britannique sur le pays serait un moindre mal
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