495 research outputs found

    Sex Dimorphism of Nonalcoholic Fatty Liver Disease (NAFLD) in Pparg-Null Mice.

    Get PDF
    Men with nonalcoholic fatty liver disease (NAFLD) are more exposed to nonalcoholic steatohepatitis (NASH) and liver fibrosis than women. However, the underlying molecular mechanisms of NALFD sex dimorphism are unclear. We combined gene expression, histological and lipidomic analyses to systematically compare male and female liver steatosis. We characterized hepatosteatosis in three independent mouse models of NAFLD, ob/ob and lipodystrophic fat-specific (PpargF <sup>Δ/Δ</sup> ) and whole-body PPARγ-null (Pparg <sup>Δ/Δ</sup> ) mice. We identified a clear sex dimorphism occurring only in Pparg <sup>Δ/Δ</sup> mice, with females showing macro- and microvesicular hepatosteatosis throughout their entire life, while males had fewer lipid droplets starting from 20 weeks. This sex dimorphism in hepatosteatosis was lost in gonadectomized Pparg <sup>Δ/Δ</sup> mice. Lipidomics revealed hepatic accumulation of short and highly saturated TGs in females, while TGs were enriched in long and unsaturated hydrocarbon chains in males. Strikingly, sex-biased genes were particularly perturbed in both sexes, affecting lipid metabolism, drug metabolism, inflammatory and cellular stress response pathways. Most importantly, we found that the expression of key sex-biased genes was severely affected in all the NAFLD models we tested. Thus, hepatosteatosis strongly affects hepatic sex-biased gene expression. With NAFLD increasing in prevalence, this emphasizes the urgent need to specifically address the consequences of this deregulation in humans

    Phase field approach to optimal packing problems and related Cheeger clusters

    Full text link
    In a fixed domain of RN\Bbb{R}^N we study the asymptotic behaviour of optimal clusters associated to α\alpha-Cheeger constants and natural energies like the sum or maximum: we prove that, as the parameter α\alpha converges to the "critical" value (N−1N)+\Big (\frac{N-1}{N}\Big ) _+, optimal Cheeger clusters converge to solutions of different packing problems for balls, depending on the energy under consideration. As well, we propose an efficient phase field approach based on a multiphase Gamma convergence result of Modica-Mortola type, in order to compute α\alpha-Cheeger constants, optimal clusters and, as a consequence of the asymptotic result, optimal packings. Numerical experiments are carried over in two and three space dimensions

    Lipid-lowering and anti-thrombotic therapy in patients with peripheral arterial disease:European Atherosclerosis Society/European Society of Vascular Medicine Joint Statement

    Get PDF
    Patients with peripheral arterial disease (PAD) are at very high risk of cardiovascular events, but risk factor management is usually suboptimal. This Joint Task Force from the European Atherosclerosis Society and the European Society of Vascular Medicine has updated evidence on the management on dyslipidaemia and thrombotic factors in patients with PAD. Guidelines recommend a low-density lipoprotein cholesterol (LDLC) goal of more than 50% reduction from baseline and <1.4 mmol/L (<55 mg/dL) in PAD patients. As demonstrated by randomized controlled trials, lowering LDL-C not only reduces cardiovascular events but also major adverse limb events (MALE), including amputations, of the order of 25%. Addition of ezetimibe or a PCSK9 inhibitor further decreases the risk of cardiovascular events, and PCSK9 inhibition has also been associated with reduction in the risk of MALE by up to 40%. Furthermore, statin- based treatment improved walking performance, including maximum walking distance, and pain-free walking distance and duration. This Task Force recommends strategies for managing statin-associated muscle symptoms to ensure that PAD patients benefit from lipid-lowering therapy. Antiplatelet therapy, either daily clopidogrel 75 mg or the combination of aspirin 100 mg and rivaroxaban (2×2.5 mg) is also indicated to prevent cardiovascular events. Dual pathway inhibition (aspirin and rivaroxaban) may be considered following revascularization, taking into account bleeding risk. This Joint Task Force believes that adherence with these recommendations for lipid-lowering and antithrombotic therapy will improve the morbidity and mortality in patients with PAD

    Intestinal PPARÎł signalling is required for sympathetic nervous system activation in response to caloric restriction.

    Get PDF
    Nuclear receptor PPARÎł has been proven to affect metabolism in multiple tissues, and has received considerable attention for its involvement in colon cancer and inflammatory disease. However, its role in intestinal metabolism has been largely ignored. To investigate this potential aspect of PPARÎł function, we submitted intestinal epithelium-specific PPARÎł knockout mice (iePPARÎłKO) to a two-week period of 25% caloric restriction (CR), following which iePPARÎłKO mice retained more fat than their wild type littermates. In attempting to explain this discrepancy, we analysed the liver, skeletal muscle, intestinal lipid trafficking, and the microbiome, none of which appeared to contribute to the adiposity phenotype. Interestingly, under conditions of CR, iePPARÎłKO mice failed to activate their sympathetic nervous system (SNS) and increase CR-specific locomotor activity. These KO mice also manifested a defective control of their body temperature, which was overly reduced. Furthermore, the white adipose tissue of iePPARÎłKO CR mice showed lower levels of both hormone-sensitive lipase, and its phosphorylated form. This would result from impaired SNS signalling and possibly cause reduced lipolysis. We conclude that intestinal epithelium PPARÎł plays an essential role in increasing SNS activity under CR conditions, thereby contributing to energy mobilization during metabolically stressful episodes

    The prescribed mean curvature equation in weakly regular domains

    Get PDF
    We show that the characterization of existence and uniqueness up to vertical translations of solutions to the prescribed mean curvature equation, originally proved by Giusti in the smooth case, holds true for domains satisfying very mild regularity assumptions. Our results apply in particular to the non-parametric solutions of the capillary problem for perfectly wetting fluids in zero gravity. Among the essential tools used in the proofs, we mention a \textit{generalized Gauss-Green theorem} based on the construction of the weak normal trace of a vector field with bounded divergence, in the spirit of classical results due to Anzellotti, and a \textit{weak Young's law} for (Λ,r0)(\Lambda,r_{0})-minimizers of the perimeter.Comment: 23 pages, 1 figure --- The results on the weak normal trace of vector fields have been now extended and moved in a self-contained paper available at: arXiv:1708.0139

    Comprehensive Evaluation of Plasma 7-Ketocholesterol and Cholestan-3ÎČ,5α,6ÎČ-Triol in an Italian Cohort of Patients Affected by Niemann-Pick Disease due to NPC1 and SMPD1 Mutations

    Get PDF
    : Niemann-Pick C disease (NPCD) is a rare autosomal recessive neurovisceral disorder with a heterogeneous clinical presentation. Cholestan-3ÎČ,5α,6ÎČ-triol and 7-ketocholesterol have been proposed as biomarkers for the screening of NPCD. In this work, we assessed oxysterols levels in a cohort of Italian patients affected by NPCD and analyzed the obtained results in the context of the clinical, biochemical and molecular data. In addition, a group of patients affected by Niemann-Pick B disease (NPBD) were also analyzed. NPC patients presented levels of both oxysterols way above the cut off value, except for 5 siblings presenting the variant biochemical phenotype who displayed levels of 3ÎČ,5α,6ÎČ-triol below or just above the cut-off value; 2 of them presented also normal levels of 7-KC. Both oxysterols were extremely high in a patient presenting the neonatal systemic lethal phenotype. All NPB patients showed increased oxysterols levels. In conclusion, the reported LC-MS/MS assay provides a robust non-invasive screening tool for NPCD. However, false negative results can be obtained in patients expressing the variant biochemical phenotype. These data strengthen the concept that the results should always be interpreted in the context of the patients' clinical picture and filipin staining and/or genetic studies might still be undertaken in patients with normal levels of oxysterols if symptoms are highly suggestive of NPCD. Both oxysterols are significantly elevated in NPB patients; thus a differential diagnosis should always be performed in patients presenting isolated hepatosplenomegaly, a common clinical sign of both NPCD and NPBD

    Clinical epigenetics settings for cancer and cardiovascular diseases: real-life applications of network medicine at the bedside

    Get PDF
    Despite impressive efforts invested in epigenetic research in the last 50&nbsp;years, clinical applications are still lacking. Only a few university hospital centers currently use epigenetic biomarkers at the bedside. Moreover, the overall concept of precision medicine is not widely recognized in routine medical practice and the reductionist approach remains predominant in treating patients affected by major diseases such as cancer and cardiovascular diseases. By its’ very nature, epigenetics is integrative of genetic networks. The study of epigenetic biomarkers has led to the identification of numerous drugs with an increasingly significant role in clinical therapy especially of cancer patients. Here, we provide an overview of clinical epigenetics within the context of network analysis. We illustrate achievements to date and discuss how we can move from traditional medicine into the era of network medicine (NM), where pathway-informed molecular diagnostics will allow treatment selection following the paradigm of precision medicine

    Delphi consensus on the current clinical and therapeutic knowledge on Anderson-Fabry disease

    Get PDF
    BACKGROUND: Management of Anderson-Fabry disease (AFD) is contentious, particularly regarding enzyme replacement therapy (ERT). We report results of a Delphi consensus panel on AFD management. METHODS: A survey to gauge consensus among AFD experts was distributed online and responses were analysed. Statements on: 1) diagnosis; 2) when starting ERT; 3) management of ERT infusion and adverse reactions; and 4) follow-up/monitoring response to therapy and progression of disease were included. Responses without consensus were discussed with an enlarged panel and modified to reach consensus. RESULTS: 15 experts responded to the survey. After plenary discussion among the enlarged panel, consensus was reached on most statements. Key points were the use of a target organ biopsy to show Gb3 deposits in symptomatic women with negative molecular analysis, the need for ERT in symptomatic women and in all patients with persistent signs and symptoms±organ damage. It was agreed to assess vital signs before ERT administration and use a 0.2ΌL filter on infusion to reduce the risk of adverse reactions, that serum should be drawn prior to the first infusion for anti-agalsidase antibody analysis to have a baseline value if a subsequent adverse reaction appears, and that pre-medication is required in those with prior infusion reactions. Holter ECG monitoring, cardiac and brain MRI, renal parameters, and abdominal ultrasound were considered important for the assessment of disease progression and response at ERT. CONCLUSIONS: This consensus supplies guidance to healthcare providers on best practice in the management of patients with AFD and indicates a need for more guidanc

    Two examples of minimal Cheeger sets in the plane

    Get PDF
    We construct two minimal Cheeger sets in the Euclidean plane, i.e., unique minimizers of the ratio \u201cperimeter over area\u201d among their own measurable subsets. The first one gives a counterexample to the so- called weak regularity property of Cheeger sets, as its perimeter does not coincide with the 1-dimensional Hausdorff measure of its topological boundary. The second one is a kind of porous set, whose boundary is not locally a graph at many of its points, yet it is a weakly regular open set admitting a unique (up to vertical translations) nonparametric solution to the prescribed mean curvature equation, in the extremal case corresponding to the capillarity for perfectly wetting fluids in zero gravity
    • 

    corecore