1,975 research outputs found

    Ds→η,η′D_s \rightarrow \eta, \eta' semileptonic decay form factors with disconnected quark loop contributions

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    We calculate for the first time the form factors of the semi-leptonic decays of the DsD_s meson to η\eta and η′\eta^\prime using lattice techniques. As a by-product of the calculation we obtain the masses and leading distribution amplitudes of the η\eta and η′\eta^\prime mesons. We use Nf=2+1N_f=2+1 non-perturbatively improved clover fermions on configurations with a lattice spacing a∼0.075a\sim 0.075 fm. We are able to obtain clear signals for relevant matrix elements, using several noise reduction techniques, both for the connected and disconnected contributions. This includes a new method for reducing the variance of pseudoscalar disconnected two-point functions. At zero momentum transfer, we obtain for the scalar form factors, ∣f0Ds→η∣=0.564(11)|f_0^{D_s\to \eta}|=0.564(11) and ∣f0Ds→η′∣=0.437(18)|f_0^{D_s\to \eta'}|=0.437(18) at Mπ≈470 MeVM_\pi\approx 470\, {\rm MeV}, as well as ∣f0Ds→η∣=0.542(13)|f_0^{D_s\to \eta}|=0.542(13) and ∣f0Ds→η′∣=0.404(25)|f_0^{D_s\to \eta'}|=0.404(25) at Mπ≈370 MeVM_\pi\approx 370\, {\rm MeV}, where the errors are statistical only.Comment: 26 pages 28 figures; v2: a phenomenological analysis added, title changed slightly, minor typos correcte

    Toll-like receptor stimulation induces higher TNF-alpha secretion in peripheral blood mononuclear cells from patients with hyper IgE syndrome

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    Hyper IgE syndromes (HIES) are primary immunodeficiency disorders of unknown pathogenesis. Patients are typically affected with `cold' abscesses of the skin, recurrent cyst-forming pneumonia, chronic mucocutaneous candidiasis and other less frequent features such as progressive skeletal abnormalities. Defective signaling in the Toll-like receptor (TLR) pathways has been suggested as a responsible pathologic mechanism, however, in previous reports, 10 patients revealed no defect in inflammatory cytokine responses to different TLR ligands. Here, we report the increase in pro-inflammatory cytokines TNF-alpha and IL-8, following TLR2 and TLR4 stimulation in a larger cohort of 25 additional patients with HIES, and provide a meta-analysis of the TLR data in HIES. Copyright (C) 2008 S. Karger AG, Basel

    Functional display of heterotetrameric human protein kinase CK2 on Escherichia coli: a novel tool for drug discovery

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    Background: Human protein kinase CK2 represents a novel therapeutic target for neoplastic diseases. Inhibitors are in need to explore the druggability and the therapeutic options of this enzyme. A bottleneck in the search for new inhibitors is the availability of the target for testing. Therefore an assay was developed to provide easy access to CK2 for discovery of novel inhibitors. Results: Autodisplay was used to present human CK2 on the surface of Escherichia coli. Heterotetrameric CK2 consists of two subunits, α and β, which were displayed individually on the surface. Co-display of CK2α and CK2β on the cell surface led to the formation of functional holoenzyme, as demonstrated by NaCl dependency of enzymatic activity, which differs from that of the catalytic subunit CK2α without β. In addition interaction of CK2α and CK2β at the cell surface was confirmed by co-immunoprecipitation assays. Surface displayed CK2 holoenzyme enabled an easy IC50 value determination. The IC50 values for the known CK2 inhibitors TBB and Silmitasertib were determined to be 50 and 3.3 nM, respectively. Conclusion: Surface-displayed CK2α and CK2β assembled on the cell surface of E. coli to an active tetrameric holoenzyme. The whole-cell CK2 autodisplay assay as developed is suitable for inhibition studies. Furthermore, it can be used to determine quantitative CK2 inhibition data such as IC50 values. In summary, this is the first report on the functional surface display of a heterotetrameric enzyme on E. coli.<br

    Multimodal Treatment Eliminates Cancer Stem Cells and Leads to Long-Term Survival in Primary Human Pancreatic Cancer Tissue Xenografts.

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    Copyright: 2013 Hermann et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.PURPOSE: In spite of intense research efforts, pancreatic ductal adenocarcinoma remains one of the most deadly malignancies in the world. We and others have previously identified a subpopulation of pancreatic cancer stem cells within the tumor as a critical therapeutic target and additionally shown that the tumor stroma represents not only a restrictive barrier for successful drug delivery, but also serves as a paracrine niche for cancer stem cells. Therefore, we embarked on a large-scale investigation on the effects of combining chemotherapy, hedgehog pathway inhibition, and mTOR inhibition in a preclinical mouse model of pancreatic cancer. EXPERIMENTAL DESIGN: Prospective and randomized testing in a set of almost 200 subcutaneous and orthotopic implanted whole-tissue primary human tumor xenografts. RESULTS: The combined targeting of highly chemoresistant cancer stem cells as well as their more differentiated progenies, together with abrogation of the tumor microenvironment by targeting the stroma and enhancing tissue penetration of the chemotherapeutic agent translated into significantly prolonged survival in preclinical models of human pancreatic cancer. Most pronounced therapeutic effects were observed in gemcitabine-resistant patient-derived tumors. Intriguingly, the proposed triple therapy approach could be further enhanced by using a PEGylated formulation of gemcitabine, which significantly increased its bioavailability and tissue penetration, resulting in a further improved overall outcome. CONCLUSIONS: This multimodal therapeutic strategy should be further explored in the clinical setting as its success may eventually improve the poor prognosis of patients with pancreatic ductal adenocarcinoma

    Recent advances in cardio-oncology:a report from the 'Heart Failure Association 2019 and World Congress on Acute Heart Failure 2019'

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    While anti-cancer therapies, including chemotherapy, immunotherapy, radiotherapy, and targeted therapy, are constantly advancing, cardiovascular toxicity has become a major challenge for cardiologists and oncologists. This has led to an increasing demand of cardio-oncology units in Europe and a growing interest of clinicians and researchers. The Heart Failure 2019 meeting of the Heart Failure Association of the European Society of Cardiology in Athens has therefore created a scientific programme that included four dedicated sessions on the topic along with several additional lectures. The major points that were discussed at the congress included the implementation and delivery of a cardio-oncology service, the collaboration among cardio-oncology experts, and the risk stratification, prevention, and early recognition of cardiotoxicity. Furthermore, sessions addressed the numerous different anti-cancer therapies associated with cardiotoxic effects and provided guidance on how to treat cancer patients who develop cardiovascular disease before, during, and after treatment

    Mutations in NSUN2 Cause Autosomal- Recessive Intellectual Disability

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    With a prevalence between 1 and 3%, hereditary forms of intellectual disability (ID) are among the most important problems in health care. Particularly, autosomal-recessive forms of the disorder have a very heterogeneous molecular basis, and genes with an increased number of disease-causing mutations are not common. Here, we report on three different mutations (two nonsense mutations, c.679C>T [p.Gln227∗] and c.1114C>T [p.Gln372∗], as well as one splicing mutation, g.6622224A>C [p.Ile179Argfs∗192]) that cause a loss of the tRNA-methyltransferase-encoding NSUN2 main transcript in homozygotes. We identified the mutations by sequencing exons and exon-intron boundaries within the genomic region where the linkage intervals of three independent consanguineous families of Iranian and Kurdish origin overlapped with the previously described MRT5 locus. In order to gain further evidence concerning the effect of a loss of NSUN2 on memory and learning, we constructed a Drosophila model by deleting the NSUN2 ortholog, CG6133, and investigated the mutants by using molecular and behavioral approaches. When the Drosophila melanogaster NSUN2 ortholog was deleted, severe short-term-memory (STM) deficits were observed; STM could be rescued by re-expression of the wild-type protein in the nervous system. The humans homozygous for NSUN2 mutations showed an overlapping phenotype consisting of moderate to severe ID and facial dysmorphism (which includes a long face, characteristic eyebrows, a long nose, and a small chin), suggesting that mutations in this gene might even induce a syndromic form of ID. Moreover, our observations from the Drosophila model point toward an evolutionarily conserved role of RNA methylation in normal cognitive development

    Monocyte mitochondrial dysfunction, inflammaging, and inflammatory pyroptosis in major depression

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    BACKGROUND: The macrophage theory of depression states that macrophages play an important role in Major Depressive Disorder (MDD). METHODS: MDD patients (N = 140) and healthy controls (N = 120) participated in a cross-sectional study investigating the expression of apoptosis/growth and lipid/cholesterol pathway genes (BAX, BCL10, EGR1, EGR2, HB-EGF, NR1H3, ABCA1, ABCG1, MVK, CD163, HMOX1) in monocytes (macrophage/microglia precursors). Gene expressions were correlated to a set of previously determined and reported inflammation-regulating genes and analyzed with respect to various clinical parameters. RESULTS: MDD monocytes showed an overexpression of the apoptosis/growth/cholesterol and the TNF genes forming an inter-correlating gene cluster (cluster 3) separate from the previously described inflammation-related gene clusters (containing IL1 and IL6). While upregulation of monocyte gene cluster 3 was a hallmark of monocytes of all MDD patients, upregulation of the inflammation-related clusters was confirmed to be found only in the monocytes of patients with childhood adversity. The latter group also showed a downregulation of the cholesterol metabolism gene MVK, which is known to play an important role in trained immunity and proneness to inflammation. CONCLUSIONS: The upregulation of cluster 3 genes in monocytes of all MDD patients suggests a premature aging of the cells, i.e. mitochondrial apoptotic dysfunction and TNF "inflammaging", as a general feature of MDD. The overexpression of the IL-1/IL-6 containing inflammation clusters and the downregulation of MVK in monocytes of patients with childhood adversity indicates a shift in this condition to a more severe inflammation form (pyroptosis) of the cells, additional to the signs of premature aging and inflammaging

    EphA2- and HDAC-Targeted Combination Therapy in Endometrial Cancer

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    Endometrial cancer is the most frequent malignant tumor of the female reproductive tract but lacks effective therapy. EphA2, a receptor tyrosine kinase, is overexpressed by various cancers including endometrial cancer and is associated with poor clinical outcomes. In preclinical models, EphA2-targeted drugs had modest efficacy. To discover potential synergistic partners for EphA2-targeted drugs, we performed a high-throughput drug screen and identified panobinostat, a histone deacetylase inhibitor, as a candidate. We hypothesized that combination therapy with an EphA2 inhibitor and panobinostat leads to synergistic cell death. Indeed, we found that the combination enhanced DNA damage, increased apoptosis, and decreased clonogenic survival in Ishikawa and Hec1A endometrial cancer cells and significantly reduced tumor burden in mouse models of endometrial carcinoma. Upon RNA sequencing, the combination was associated with downregulation of cell survival pathways, including senescence, cyclins, and cell cycle regulators. The Axl-PI3K-Akt-mTOR pathway was also decreased by combination therapy. Together, our results highlight EphA2 and histone deacetylase as promising therapeutic targets for endometrial cancer
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