611 research outputs found

    Binding and transport of gangliosides by prosaposin.

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    Delocalization power of global unitary operations on quantum information

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    We investigate how originally localized two pieces of quantum information represented by a tensor product of two unknown qudit states are delocalized by performing two-qudit global unitary operations. To characterize the delocalization power of global unitary operations on quantum information, we analyze the necessary and sufficient condition to deterministically relocalize one of the two pieces of quantum information to its original Hilbert space by using only LOCC. We prove that this LOCC one-piece relocalization is possible if and only if the global unitary operation is local unitary equivalent to a controlled-unitary operation. The delocalization power and the entangling power characterize different non-local properties of global unitary operations.Comment: 14 pages, 1 figur

    Generalized monogamy of contextual inequalities from the no-disturbance principle

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    In this paper we demonstrate that the property of monogamy of Bell violations seen for no-signaling correlations in composite systems can be generalized to the monogamy of contextuality in single systems obeying the Gleason property of no-disturbance. We show how one can construct monogamies for contextual inequalities by using the graph-theoretic technique of vertex decomposition of a graph representing a set of measurements into subgraphs of suitable independence numbers that themselves admit a joint probability distribution. After establishing that all the subgraphs that are chordal graphs admit a joint probability distribution, we formulate a precise graph-theoretic condition that gives rise to the monogamy of contextuality. We also show how such monogamies arise within quantum theory for a single four-dimensional system and interpret violation of these relations in terms of a violation of causality. These monogamies can be tested with current experimental techniques.Comment: 7 pages, 3 figure

    Acetylcholine induces fibrogenic effects via M2/M3 ACh receptors in NASH and in primary human hepatic stellate cells

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    BACKGROUND: The parasympathetic nervous system (PNS), via neurotransmitter Acetylcholine (ACh), modulates fibrogenesis in animal models. However, the role of ACh in human hepatic fibrogenesis is unclear. AIMS: We aimed to determine the fibrogenic responses of human hepatic stellate cells (hHSC) to ACh and the relevance of the PNS in hepatic fibrosis in patients with non-alcoholic steatohepatitis (NASH). METHODS: Primary hHSC were analysed for synthesis of endogenous ACh and acetylcholinesterase (AChE), and gene expression of choline acetyltransferase (ChAT) and muscarinic acetylcholine receptors (mAChR). Cell proliferation and fibrogenic markers were analysed in hHSC exposed to ACh, Atropine (Atrop), Mecamylamine (Mec), methoctramine and 4-Diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP). MAChR expression was analysed in human NASH scored for fibrosis. RESULTS: We observed that hHSC synthesise ACh and AChE, and express ChAT and M1-M5 mAChR. We also show that M2 was increased during NASH progression, while both M2 and M3 were found upregulated in activated hHSC. Furthermore, endogenous ACh is required for hHSC basal growth. Exogenous ACh resulted in hHSC hyperproliferation via mAChR and PI-3 K and MEK signalling pathways, as well as increased fibrogenic markers. CONCLUSION: We show that ACh regulates hHSC activation via M2 and M3 mAChR involving the PI-3 K and MEK pathways in vitro. Finally, we provide evidence that the PNS may be involved in human NASH fibrosis

    Hepatic rhythmicity of endoplasmic reticulum stress is disrupted in perinatal and adult mice models of high-fat diet-induced obesity

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    We investigated the regulation of hepatic ER stress in healthy liver and adult or perinatally programmed diet-induced non-alcoholic fatty liver disease (NAFLD). Female mice were fed either obesogenic or control diet before mating, during pregnancy and lactation. Post-weaning, offspring from each maternal group were divided into either obesogenic or control diet. At six months, offspring were sacrificed at 4-h intervals over 24 h. Offspring fed obesogenic diets developed NAFLD phenotype, and the combination of maternal and offspring obesogenic diets exacerbated this phenotype. UPR signalling pathways (IREα, PERK, ATF6) and their downstream regulators showed different basal rhythmicity, which was modified in offspring exposed to obesogenic diet and maternal programming. The double obesogenic hit increased liver apoptosis measured by TUNEL staining, active caspase-3 and phospho-JNK and GRP78 promoter methylation levels. This study demonstrates that hepatic UPR is rhythmically activated. The combination of maternal obesity (MO) and obesogenic diets in offspring triggered altered UPR rhythmicity, DNA methylation and cellular apoptosis

    Amphiregulin activates human hepatic stellate cells and is upregulated in non alcoholic steatohepatitis

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    Amphiregulin (AR) involvement in liver fibrogenesis and hepatic stellate cells (HSC) regulation is under study. Non-alcoholic fatty liver disease (NAFLD) and its more severe form non-alcoholic steatohepatitis (NASH) may progress to cirrhosis and hepatocellular cancer (HCC). Our aim was to investigate ex vivo the effect of AR on human primary HSC (hHSC) and verify in vivo the relevance of AR in NAFLD fibrogenesis. hHSC isolated from healthy liver segments were analyzed for expression of AR and its activator, TNF- converting enzyme (TACE). AR induction of hHSC proliferation and matrix production was estimated in the presence of antagonists. AR involvement in fibrogenesis was also assessed in a mouse model of NASH and in humans with NASH. hHSC time dependently expressed AR and TACE. AR increased hHSC proliferation through several mitogenic signaling pathways such as EGFR, PI3K and p38. AR also induced marked upregulation of hHSC fibrogenic markers and reduced hHSC death. AR expression was enhanced in the HSC of a murine model of NASH and of severe human NASH. In conclusion, AR induces hHSC fibrogenic activity via multiple mitogenic signaling pathways, and is upregulated in murine and human NASH, suggesting that AR antagonists may be clinically useful anti-fibrotics in NAFLD

    Occurrence and impact of delayed cerebral ischemia after coiling and after clipping in the International Subarachnoid Aneurysm Trial (ISAT)

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    Delayed cerebral ischemia (DCI) is an important cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). We studied differences in incidence and impact of DCI as defined clinically after coiling and after clipping in the International Subarachnoid Aneurysm Trial. We calculated odds ratios (OR) for DCI for clipping versus coiling with logistic regression analysis. With coiled patients without DCI as the reference group, we calculated ORs for poor outcome at 2 months and 1 year for coiled patients with DCI and for clipped patients without, and with DCI. With these ORs, we calculated relative excess risk due to Interaction (RERI). Clipping increased the risk of DCI compared to coiling in the 2,143 patients OR 1.24, 95% confidence interval (95% CI 1.01–1.51). Coiled patients with DCI, clipped patients without DCI, and clipped patients with DCI all had higher risks of poor outcome than coiled patients without DCI. Clipping and DCI showed no interaction for poor outcome at 2 months: RERI 0.12 (95% CI −1.16 to 1.40) or 1 year: RERI −0.48 (95% CI −1.69 to 0.74). Only for patients treated within 4 days, coiling and DCI was associated with a poorer outcome at 1 year than clipping and DCI (RERI −2.02, 95% CI −3.97 to −0.08). DCI was more common after clipping than after coiling in SAH patients in ISAT. Impact of DCI on poor outcome did not differ between clipped and coiled patients, except for patients treated within 4 days, in whom DCI resulted more often in poor outcome after coiling than after clipping

    Calcified Plaques in Patients With Acute Coronary Syndromes

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    OBJECTIVES: This study conducted detailed analysis of calcified culprit plaques in patients with acute coronary syndromes (ACS). BACKGROUND: Calcified plaques as an underlying pathology in patients with ACS have not been systematically studied. METHODS: From 1,241 patients presenting with ACS who had undergone pre-intervention optical coherence tomography imaging, 157 (12.7%) patients were found to have a calcified plaque at the culprit lesion. Calcified plaque was defined as a plaque with superficial calcification at the culprit site without evidence of ruptured lipid plaque. RESULTS: Three distinct types were identified: eruptive calcified nodules, superficial calcific sheet, and calcified protrusion (prevalence of 25.5%, 67.4%, and 7.1%, respectively). Eruptive calcified nodules were frequently located in the right coronary arteries (44.4%), whereas superficial calcific sheet was most frequently found in the left anterior descending coronary arteries (68.4%) (p = 0.012). Calcification index (mean calcification arc × calcification length) was greatest in eruptive calcified nodules, followed by superficial calcific sheet, and smallest in calcified protrusion (median 3,284.9 [interquartile range (IQR): 2,113.3 to 5,385.3] vs. 1,644.3 [IQR: 1,012.4 to 3,058.7] vs. 472.5 [IQR: 176.7 to 865.2]; p < 0.001). The superficial calcific sheet group had the highest peak post-intervention creatine kinase values among the groups (eruptive calcified nodules vs. superficial calcific sheet vs. calcified protrusion: 241 [IQR: 116 to 612] IU/l vs. 834 [IQR: 141 to 3,394] IU/l vs. 745 [IQR: 69 to 1,984] IU/l; p = 0.032). CONCLUSIONS: Three distinct types of calcified culprit plaques are identified in patients with ACS. Superficial calcific sheet, which is frequently located in the left anterior descending coronary artery, is the most prevalent type and is also associated with greatest post-intervention myocardial damage. (Identification of Predictors for Coronary Plaque Erosion in Patients With Acute Coronary Syndrome; NCT03479723).status: publishe
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