21 research outputs found

    Methyl donor deficiency impairs fatty acid oxidation through PGC-1α hypomethylation and decreased ER-α, ERR-α, and HNF-4α in the rat liver

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    BACKGROUND & AIMS: Folate and cobalamin are methyl donors needed for the synthesis of methionine, which is the precursor of S-adenosylmethionine, the substrate of methylation in epigenetic, and epigenomic pathways. Methyl donor deficiency produces liver steatosis and predisposes to metabolic syndrome. Whether impaired fatty acid oxidation contributes to this steatosis remains unknown.METHODS: We evaluated the consequences of methyl donor deficient diet in liver of pups from dams subjected to deficiency during gestation and lactation. RESULTS: The deprived rats had microvesicular steatosis, with increased triglycerides, decreased methionine synthase activity, S-adenosylmethionine, and S-adenosylmethionine/S-adenosylhomocysteine ratio. We observed no change in apoptosis markers, oxidant and reticulum stresses, and carnityl-palmitoyl transferase 1 activity, and a decreased expression of SREBP-1c. Impaired beta-oxidation of fatty acids and carnitine deficit were the predominant changes, with decreased free and total carnitines, increased C14:1/C16 acylcarnitine ratio, decrease of oxidation rate of palmitoyl-CoA and palmitoyl-L-carnitine and decrease of expression of novel organic cation transporter 1, acylCoA-dehydrogenase and trifunctional enzyme subunit alpha and decreased activity of complexes I and II. These changes were related to lower protein expression of ER-α, ERR-α and HNF-4α, and hypomethylation of PGC-1α co-activator that reduced its binding with PPAR-α, ERR-α, and HNF-4α. CONCLUSIONS: The liver steatosis resulted predominantly from hypomethylation of PGC1-α, decreased binding with its partners and subsequent impaired mitochondrial fatty acid oxidation. This link between methyl donor deficiency and epigenomic deregulations of energy metabolism opens new insights into the pathogenesis of fatty liver disease, in particular, in relation to the fetal programming hypothesis

    Side channel analysis of some hash based MACs:A response to SHA-3 requirements

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    The forthcoming NIST's Advanced Hash Standard (AHS) competition to select SHA-3 hash function requires that each candidate hash function submission must have at least one construction to support FIPS 198 HMAC application. As part of its evaluation, NIST is aiming to select either a candidate hash function which is more resistant to known side channel attacks (SCA) when plugged into HMAC, or that has an alternative MAC mode which is more resistant to known SCA than the other submitted alternatives. In response to this, we perform differential power analysis (DPA) on the possible smart card implementations of some of the recently proposed MAC alternatives to NMAC (a fully analyzed variant of HMAC) and HMAC algorithms and NMAC/HMAC versions of some recently proposed hash and compression function modes. We show that the recently proposed BNMAC and KMDP MAC schemes are even weaker than NMAC/HMAC against the DPA attacks, whereas multi-lane NMAC, EMD MAC and the keyed wide-pipe hash have similar security to NMAC against the DPA attacks. Our DPA attacks do not work on the NMAC setting of MDC-2, Grindahl and MAME compression functions. This talk outlines our results

    Book Review: Austin, Cleared for Takeoff: Aviators, Businessmen, and the Growth of an American City

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    At its widest point, Texas measures some 850 miles across. EI Paso, in the extreme west, is closer to Los Angeles than it is to Texarkana, sited near the state\u27s eastern boundary. Given the distances its citizens have to travel, Texas has always been attuned to transport technology. And people living in the capital, Austin, near the state\u27s center, have always been interested in finding rapid forms of travel to the far-flung cities and counties of the rest of the state. Thus, Ragsdale\u27s book touches on a highly relevant aspect of urban as well as regional history. Moreover, as national and international travel became accepted for business as well as pleasure, the role of airlines and airports serving Austin took on a growing immediacy

    Patients with inflammatory bowel disease are not at increased risk of covid-19: A large multinational cohort study

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    The impact of COVID-19 on inflammatory bowel disease (IBD) patients under pharmacological immunosuppression is still not clearly understood. We investigated the incidence of COVID-19 and the impact of immunosuppression and containment measures on the risk of SARS-CoV-2 infection in a large IBD cohort, from a multicenter cohort from 21st of February to 30th of June, 2020. Ninety-seven patients with IBD (43 UC, 53 CD, one unclassified IBD) and concomitant COVID-19 over a total of 23,879 patients with IBD were enrolled in the study. The cumulative incidence of SARS-CoV-2 infection in patients with IBD vs. the general population was 0.406% and 0.402% cases, respectively. Twenty-three patients (24%) were hospitalized, 21 (22%) had pneumonia, four (4%) were admitted to the Intensive Care Unit, and one patient died. Lethality in our cohort was 1% compared to 9% in the general population. At multivariable analysis, age > 65 years was associated with increased risk of pneumonia and hospitalization (OR 11.6, 95% CI 2.18–62.60; OR 5.1, 95% CI 1.10–23.86, respectively), treatment with corticosteroids increased the risk of hospitalization (OR 7.6, 95% CI 1.48–40.05), whereas monoclonal antibodies were associated with reduced risk of pneumonia and hospitalization (OR 0.1, 95% CI 0.04–0.52; OR 0.3, 95% CI 0.10–0.90, respectively). The risk of COVID-19 in patients with IBD is similar to the general population. National lockdown was effective in preventing infection in our cohort. Advanced age and treatment with corticosteroids impacted negatively on the outcome of COVID-19, whereas monoclonal antibodies did not seem to have a detrimental effect. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
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