253 research outputs found

    High precision prediction for Mh in the MSSM

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    37th International Conference on High Energy Physics (ICHEP).The new particle discovered at the LHC can be interpreted as the lightest CP-even Higgs boson of the Minimal Supersymmetric Standard Model (MSSM), where M denotes its mass. The experimental precision of this mass has reached the level below ~ 500 MeV. In the MSSM M can directly be predicted from the other parameters of the model. The accuracy of this prediction should at least match the one of the experimental result. The relatively high mass value of about 125 GeV has led to many investigations where the scalar top quarks are in the multi-TeV range. We review the recent improvement in the prediction for M in the MSSM that has been reached by combining the existing fixed-order result, comprising the full one-loop and leading and subleading two-loop corrections, with a resummation of the leading and subleading logarithmic contributions from the scalar top sector to all orders.Peer Reviewe

    The hidden hedgehog of the pituitary: hedgehog signaling in development, adulthood and disease of the hypothalamic-pituitary axis

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    Hedgehog signaling plays pivotal roles in embryonic development, adult homeostasis and tumorigenesis. However, its engagement in the pituitary gland has been long underestimated although Hedgehog signaling and pituitary embryogenic development are closely linked. Thus, deregulation of this signaling pathway during pituitary development results in malformation of the gland. Research of the last years further implicates a regulatory role of Hedgehog signaling in the function of the adult pituitary, because its activity is also interlinked with homeostasis, hormone production, and most likely also formation of neoplasms of the gland. The fact that this pathway can be efficiently targeted by validated therapeutic strategies makes it a promising candidate for treating pituitary diseases. We here summarize the current knowledge about the importance of Hedgehog signaling during pituitary development and review recent data that highlight the impact of Hedgehog signaling in the healthy and the diseased adult pituitary gland

    Has the Revolution in Scholarly Communication Lived Up to Its Promise?

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    In the late 1990s the need for an overhaul in the approach to scholarly publishing was recognized. A drastic change would revise the economic model on which publishing was based, give authors rights to their own works in open access repositories and enable consumers across the world to access scholarly materials, building a flow of valuable information for the common good. The revolution has yet to materialize, though small but welcome achievements have been made. The open access business model has gained a foothold with the Public Library of Science (PLoS), and scientists receiving grants through the National Institutes of Health must submit manuscripts to the PubMed Central digital archive. Several universities mandate that faculty members deposit their scholarly articles in institutional repositories, and the Compact for Open Access Publishing Equity promotes open publishing by supporting authors. Librarians are both part of the problem and part of the solution. Instead of worrying about paying rising subscription fees, they could use their position to influence authors to take advantage of open access channels despite publish-or-perish pressures. Recent legislative and presidential initiatives, geared to disseminating publicly funded research, may be effective in moving open access closer to transforming the traditional system of scholarly communication

    FeynHiggs: status and prospects

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    Trabajo presentado a la 23rd International Conference on Supersymmetry and Unification of Fundamental Interactions, celebrada en Lake Tahoe, California (US) del 23 al 29 de agosto de 2015.We review the status and the prospects for (N)MSSM Higgs precision calculations, as incorporated into the code FeynHiggs.Peer Reviewe

    Effects of orally administered fumonisin B1 (FB1), partially hydrolysed FB1, hydrolysed FB1 and N-(1-deoxy-D-fructos-1-yl) FB1 on the sphingolipid metabolism in rats

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    Fumonisin B1 (FB1) is a Fusarium mycotoxin frequently occurring in maize-based food and feed. Alkaline processing like nixtamalisation of maize generates partially and fully hydrolysed FB1 (pHFB1 and HFB1) and thermal treatment in the presence of reducing sugars leads to formation of N-(1-deoxy-D-fructos- 1-yl) fumonisin B1 (NDF). The toxicity of these metabolites, in particular their effect on the sphingolipid metabolism, is either unknown or discussed controversially.We produced high purity FB1, pHFB1a+b, HFB1 and NDF and fed them to male Sprague Dawley rats for three weeks. Once a week, urine and faeces samples were collected over 24 h and analysed for fumonisin metabolites as well as for the sphinganine (Sa) to sphingosine (So) ratio by validated LCā€“MS/MS based methods. While the latter was significantly increased in the FB1 positive control group, the Sa/So ratios of the partially and fully hydrolysed fumonisins were indifferent from the negative control group. Although NDF was partly cleaved during digestion, the liberated amounts of FB1 did not raise the Sa/So ratio. These results show that the investigated alkaline and thermal processing products of FB1 were, at the tested concentrations, non-toxic for rats, and suggest that according food processing can reduce fumonisin toxicity for humans

    Oncogenic Transformation by Inhibitor-Sensitive and -Resistant EGFR Mutants

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    BACKGROUND: Somatic mutations in the kinase domain of the epidermal growth factor receptor tyrosine kinase gene EGFR are common in lung adenocarcinoma. The presence of mutations correlates with tumor sensitivity to the EGFR inhibitors erlotinib and gefitinib, but the transforming potential of specific mutations and their relationship to drug sensitivity have not been described. METHODS AND FINDINGS: Here, we demonstrate that EGFR active site mutants are oncogenic. Mutant EGFR can transform both fibroblasts and lung epithelial cells in the absence of exogenous epidermal growth factor, as evidenced by anchorage-independent growth, focus formation, and tumor formation in immunocompromised mice. Transformation is associated with constitutive autophosphorylation of EGFR, Shc phosphorylation, and STAT pathway activation. Whereas transformation by most EGFR mutants confers on cells sensitivity to erlotinib and gefitinib, transformation by an exon 20 insertion makes cells resistant to these inhibitors but more sensitive to the irreversible inhibitor CL-387,785. CONCLUSION: Oncogenic transformation of cells by different EGFR mutants causes differential sensitivity to gefitinib and erlotinib. Treatment of lung cancers harboring EGFR exon 20 insertions may therefore require the development of alternative kinase inhibition strategies

    Different Response of Ptch Mutant and Ptch Wildtype Rhabdomyosarcoma Toward SMO and PI3K Inhibitors

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    Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma with poor prognosis. RMS frequently show Hedgehog (HH) pathway activity, which is predominantly seen in the embryonal subtype (ERMS). They also show activation of Phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) signaling. Here we compared the therapeutic effectiveness and the impact on HH target gene expression of Smoothened (SMO) antagonists with those of the PI3K inhibitor pictilisib in ERMS with and without mutations in the HH receptor Patched1 (PTCH). Our data demonstrate that growth of ERMS showing canonical Hh signaling activity due to Ptch germline mutations is efficiently reduced by SMO antagonists. This goes along with strong downregulation of the Hh target Gli1. Likewise Ptch mutant tumors are highly responsive toward the PI3K inhibitor pictilisib, which involves modulation of AKT and caspase activity. Pictilisib also modulates Hh target gene expression, which, however, is rather not correlated with its antitumoral effects. In contrast, sporadic ERMS, which usually express HH target genes without having PTCH mutation, apparently lack canonical HH signaling activity. Thus, stimulation by Sonic HE (SHH) or SAG (Smoothened agonist) or inhibition by SMO antagonists do not modulate HH target gene expression. In addition, SMO antagonists do not provoke efficient anticancer effects and rather exert off-target effects. In contrast, pictilisib and other PI3K/AKT/mTOR inhibitors potently inhibit cellular growth. They also efficiently inhibit HH target gene expression. However, of whether this is correlated with their antitumoral effects it is not clear. Together, these data suggest that PI3K inhibitors are a good and reliable therapeutic option for all ERMS, whereas SMO inhibitors might only be beneficial for ERMS driven by PTCH mutations
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