324 research outputs found

    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

    Clinical Prognostic Factors in Patients With Metastatic Adrenocortical Carcinoma Treated With Second Line Gemcitabine Plus Capecitabine Chemotherapy

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    Gemcitabine plus Capecitabine (Gem/Cape) is a frequently adopted second line chemotherapy for metastatic adrenocortical carcinoma (ACC), but only a minority of patients is destined to obtain a clinical benefit. The identification of baseline predictive factors of efficacy is relevant. We retrospectively analyzed clinical data from 50 consecutive patients with metastatic progressing ACC treated between 2011 and 2019. Patients received intravenous Gemcitabine and oral Capecitabine on a metronomic schedule. Previous mitotane therapy was maintained. Clinical benefit (partial response + stable disease) at 4 months was 30%, median progression-free survival (PFS) and disease-specific survival (DSS) from Gem/Cape start were 3 and 8 months, respectively. Among clinical variables evaluated before the start of Gem/Cape, presence of ECOG performance status ≥1 [HR 6.93 95% confidence interval (CI) 0.03–0.54, p.004] and neutrophil-to-lymphocyte ratio (NLR) ≥5 [HR 3.88, 95% (CI) 0.81–0.90, p.003] were independent indicators of poor PFS at multivariate analysis. Conversely, surgery of primary tumor, the presence of lung or lymph-node metastases, blood mitotane level, anemia, and the Advanced Lung cancer Inflammation index (ALI) failed to be independently associated. This study confirms that the Gem/Cape schedule is modestly active in heavily pretreated ACC patients (28% received at least two previous chemotherapy lines). NLR and performance status (PS) are easily available clinical parameters that are helpful to identify patients not likely to derive significant advantage from Gem/Cape chemotherapy

    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

    Effective connectivity reveals strategy differences in an expert calculator

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    Mathematical reasoning is a core component of cognition and the study of experts defines the upper limits of human cognitive abilities, which is why we are fascinated by peak performers, such as chess masters and mental calculators. Here, we investigated the neural bases of calendrical skills, i.e. the ability to rapidly identify the weekday of a particular date, in a gifted mental calculator who does not fall in the autistic spectrum, using functional MRI. Graph-based mapping of effective connectivity, but not univariate analysis, revealed distinct anatomical location of “cortical hubs” supporting the processing of well-practiced close dates and less-practiced remote dates: the former engaged predominantly occipital and medial temporal areas, whereas the latter were associated mainly with prefrontal, orbitofrontal and anterior cingulate connectivity. These results point to the effect of extensive practice on the development of expertise and long term working memory, and demonstrate the role of frontal networks in supporting performance on less practiced calculations, which incur additional processing demands. Through the example of calendrical skills, our results demonstrate that the ability to perform complex calculations is initially supported by extensive attentional and strategic resources, which, as expertise develops, are gradually replaced by access to long term working memory for familiar material

    Labor Productivity - The Use of Staffing Guides and Other Productivity Methods in U.S. Hotels: A Survey Study

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    This paper examines the issue of labor productivity in hotels. It elaborates on various measurement methods used by American hoteliers including staffing guides, with a special focus on productivity standards. Advantages of physical, financial and mixed methods such as percentage methods, revenue per employee, value-added, Data Envelope Analysis and Stochastic Frontier Analysis are discussed. While the use of percentages and staffing guides were found to be commonplace, results revealed that some fairly stable standards were already in place in the surveyed hotels. Results also revealed that at least in the surveyed companies, few hoteliers attempted to monitor or improve revenue per employee, focusing instead on physical labor inputs and outputs or simple labor percentages

    Evaluando el progreso de la eficiencia con tecnología en una cadena de hoteles española

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    This paper analyzes the changes in the total factor productivity index of a Spanish hotel chain in the period from 2007 to 2010 with the purpose of identifying efficiency patterns for the chain in a period of financial crisis. The data envelopment analysis (DEA) Malmquist productivity index was used to estimate productivity change in 38 hotels of the AC chain. Results reveal AC hotels’ efficiency trends and, therefore, their competitiveness in the recession period; they also show the changes experienced in these hotels’ total productivity and its components: technological and efficiency changes. Positive efficiency changes were due to positive technical efficiency rather than technological efficiency. The recession period certainly influenced the performance of AC Hotels, which focused on organizational changes rather than investing in technology.Este artigo analisa as mudanças no fator total de produtividade de uma cadeia de hotéis na Espanha, no período de 2007-2010, com o propósito de identificar os padrões da cadeia em um período de crise financeira. O índice data envelopment analysis (DEA) Malmquist de produtividade foi usado para estimar a mudança da produtividade nos 38 hotéis da AC Cadeia de Hotéis. Os resultados revelaram as tendências de eficiência e competitividade da AC Hotéis em um período de recessão, bem como as mudanças vivenciadas na produtividade total e, consequentemente, em seus componentes de eficiência e tecnológicos. O período de recessão influenciou, sem dúvida, o comportamento da AC Hotéis, que buscou mais mudanças organizacionais do que tecnológicas.Este artículo analiza los cambios del índice de productividad del factor total de una cadena de hoteles españoles en el periodo de 2007 hasta 2010, con el propósito de identificar patrones de eficiencia para la cadena en un periodo de crisis financiera. El índice de productividad data envelopment analysis (DEA) Malmquist fue utilizado para estimar el cambio de productividad en 38 hoteles de la cadena AC. Los resultados revelan las tendencias de la eficiencia de los hoteles AC y, por lo tanto, su competitividad en el periodo de recisión; ellos también demuestran los cambios experimentados en la productividad total de eses hoteles y sus componentes: cambios de eficiencia y tecnológicos. Cambios de eficiencia positivos se debieron más bien a eficiencias técnicas positivas que a eficiencias tecnológicas. El periodo de recesión ciertamente ha influenciado los Hoteles AC, que enfocaron más en los cambios organizacionales que en invirtiendo en tecnología

    Smart technologies for personalized experiences: a case study in the hospitality domain

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    Recent advances in the field of technology have led to the emergence of innovative technological smart solutions providing unprecedented opportunities for application in the tourism and hospitality industry.With intensified competition in the tourism market place, it has become paramount for businesses to explore the potential of technologies, not only to optimize existing processes but facilitate the creation of more meaningful and personalized services and experiences. This study aims to bridge the current knowledge gap between smart technologies and experience personalization to understand how smart mobile technologies can facilitate personalized experiences in the context of the hospitality industry. By adopting a qualitative case study approach, this paper makes a two-fold contribution; it a) identifies the requirements of smart technologies for experience creation, including information aggregation, ubiquitous mobile connectedness and real time synchronization and b) highlights how smart technology integration can lead to two distinct levels of personalized tourism experiences. The paper concludes with the development of a model depicting the dynamic process of experience personalization and a discussion of the strategic implications for tourism and hospitality management and research

    Adiponectin Upregulates Prolyl-4-Hydroxylase α1 Expression in Interleukin 6-Stimulated Human Aortic Smooth Muscle Cells by Regulating ERK 1/2 and Sp1

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    Adiponectin is an anti-atherogenic adipokine that inhibits the development of plaque by mechanisms that are not completely understood. Extracellular matrix (ECM) may have a role in the pathogenesis of atherosclerosis. We explored the effect and mechanisms of adiponectin on the synthesis of prolyl-4-hydroxylase (P4H) in interleukin 6 (IL-6)-stimulated human aortic smooth muscle cells (HASMCs). P4Hα1 mRNA level was quantified by RT-PCR, the protein levels of phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) and P4Hα1 were quantified by western blot analysis, and activation of specific protein 1 (Sp1) was determined by electrophoretic mobility shift assay and subcellular localization of Sp1 by immunofluorescence analysis. Adiponectin significantly increased P4Hα1 mRNA and protein levels in IL-6-stimulated HASMCs in a dose- and time-dependent manner. As well, ERK1/2 and Sp1 played a crucial role in the effect of adiponectin upregulating P4Hα1 expression in IL-6-stimulated HASMCs. Adiponectin abrogated the effects of IL-6 on collagen III level, which may indicate that P4Hα1 is essential for folding the procollagen polypeptide chains into stabilized collagen. Adiponectin attenuates IL-6–inhibited P4Hα1 synthesis and stabilizes collagen formation in HASMCs through a Sp1-ERK1/2-P4Hα1-dependent pathway

    Globally prevalent PfMDR1 mutations modulate Plasmodium falciparum susceptibility to artemisinin-based combination therapies

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    Antimalarial chemotherapy, globally reliant on artemisinin-based combination therapies (ACTs), is threatened by the spread of drug resistance in Plasmodium falciparum parasites. Here we use zinc-finger nucleases to genetically modify the multidrug resistance-1 transporter PfMDR1 at amino acids 86 and 184, and demonstrate that the widely prevalent N86Y mutation augments resistance to the ACT partner drug amodiaquine and the former first-line agent chloroquine. In contrast, N86Y increases parasite susceptibility to the partner drugs lumefantrine and mefloquine, and the active artemisinin metabolite dihydroartemisinin. The PfMDR1 N86 plus Y184F isoform moderately reduces piperaquine potency in strains expressing an Asian/African variant of the chloroquine resistance transporter PfCRT. Mutations in both digestive vacuole-resident transporters are thought to differentially regulate ACT drug interactions with host haem, a product of parasite-mediated haemoglobin degradation. Global mapping of these mutations illustrates where the different ACTs could be selectively deployed to optimize treatment based on regional differences in PfMDR1 haplotypes.This work was funded in part by the National Institutes of Health (R01 AI50234, AI124678 and AI109023) and a Burroughs Wellcome Fund Investigator in Pathogenesis of Infectious Diseases award to D.A.F. This research also received funding from the Portuguese Fundacao para a Ciencia e Tecnologia (FCT), cofunded by Programa Operacional Regional do Norte (ON.2-O Novo Norte); from the Quadro de Referencia Estrategico Nacional (QREN) through the Fundo Europeu de Desenvolvimento Regional (FEDER) and from the Projeto Estrategico - LA 26 - 2013-2014 (PEst-C/SAU/LA0026/2013). M.I.V. is the recipient of a postdoctoral fellowship from FCT/Ministerio da Ciencia e Ensino Superior, Portugal-MCES (SFRH/BPD/76614/2011). A.M.L. was supported by an Australian National Health and Medical Research Council (NHMRC) Overseas Biomedical Fellowship (585519). R.E.M. was supported by an NHMRC RD Wright Biomedical Fellowship (1053082). A.C.U. was supported by an Irving scholarship from Columbia University. We thank Dr Andrea Ecker for her help with plasmid design and Pedro Ferreira for his expert help with Fig. 6.info:eu-repo/semantics/publishedVersio
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