597 research outputs found

    Three-dimensional interactions analysis of the anticancer target c-src kinase with its inhibitors

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    Src family kinases (SFKs) constitute the biggest family of non-receptor tyrosine kinases considered as therapeutic targets for cancer therapy. An aberrant expression and/or activation of the proto-oncogene c-Src kinase, which is the oldest and most studied member of the family, has long been demonstrated to play a major role in the development, growth, progression and metastasis of numerous human cancers, including colon, breast, gastric, pancreatic, lung and brain carcinomas. For these reasons, the pharmacological inhibition of c-Src activity represents an effective anticancer strategy and a few compounds targeting c-Src, together with other kinases, have been approved as drugs for cancer therapy, while others are currently undergoing preclinical studies. Nevertheless, the development of potent and selective inhibitors of c-Src aimed at properly exploiting this biological target for the treatment of cancer still represents a growing field of study. In this review, the co-crystal structures of c-Src kinase in complex with inhibitors discovered in the past two decades have been described, highlighting the key ligand–protein interactions necessary to obtain high potency and the features to be exploited for addressing selectivity and drug resistance issues, thus providing useful information for the design of new and potent c-Src kinase inhibitors

    Interleukin-2 promoter activation in T-cells expressing activated Ha-ras.

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    Antigen triggering of the T-cell receptor results in an accumulation of activated GTP-bound p21ras protein. To assess the role of ras protein in T-cell activation we have cotransfected the murine thymoma line EL4 with a construct capable of expressing a constitutively active, oncogenic form of Ha-ras and a reporter construct containing the human interleukin-2 promoter fused upstream of the bacterial gene for chloramphenicol acetyltransferase. We show that the ras oncoprotein contributes to interleukin-2 promoter activation. Its pattern of synergism with a calcium ionophore or the lymphokine interleukin-1 indicates that it replaces a signal mediated by protein kinase C. Interleukin-2 promoter activity in the presence of ras oncoprotein was inhibited by H7, a potent inhibitor of protein kinase C, but not by HA1004, an inhibitor of cyclic nucleotide-dependent kinase, suggesting that protein kinase C mediates the ras effect. In addition, we show that in these cells, expression of activated ras results in activation of a synthetic promoter containing several copies of an NF kappa B binding site

    When Do People Trust Their Social Groups?

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    Trust facilitates cooperation and supports positive outcomes in social groups, including member satisfaction, information sharing, and task performance. Extensive prior research has examined individuals' general propensity to trust, as well as the factors that contribute to their trust in specific groups. Here, we build on past work to present a comprehensive framework for predicting trust in groups. By surveying 6,383 Facebook Groups users about their trust attitudes and examining aggregated behavioral and demographic data for these individuals, we show that (1) an individual's propensity to trust is associated with how they trust their groups, (2) smaller, closed, older, more exclusive, or more homogeneous groups are trusted more, and (3) a group's overall friendship-network structure and an individual's position within that structure can also predict trust. Last, we demonstrate how group trust predicts outcomes at both individual and group level such as the formation of new friendship ties.Comment: CHI 201

    Cyclosporin A blocks calcium-dependent pathways of gene activation

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    We have used an interleukin-2 (IL-2) promoter-CAT fusion gene to study activation of IL-2 gene expression by IL-1, phytohemagglutinin (PHA), phorbol myristate acetate (PMA), and calcium ionophore in the murine thymoma line EL4 and the human lymphoma line Jurkat. The two cell lines respond differently to combinations of these stimuli. IL-1 in combination with suboptimal concentration of PMA induced chloramphenicol acetyltransferase (CAT) activity in EL4. In Jurkat cells, IL-1 failed to synergize with PMA or PHA. Cotransfection with the IL-2/CAT gene and a construct capable of expressing murine T-cell type IL-1 receptors converted Jurkat cells to IL-1 responsiveness. IL-1 in combination with PHA but not with PMA resulted in induction of CAT activity in these cells. Induction of IL-2/CAT activity by all stimuli in both cell lines was blocked by the presence of EGTA in the culture medium. EGTA did not inhibit IL-1/PMA activation of an SV40 early promoter-CAT fusion gene in either EL4 or Jurkat cells; therefore, calcium was not required for IL-1 or PMA signal transduction. Jurkat cells were shown to differ from EL4 in their requirement for calcium mobilization. Two different calcium-dependent pathways of gene activation were distinguished, both of which were blocked by the immunosuppressive drug cyclosporin A

    Investigation of fennel protein extracts by shot-gun Fourier transform ion cyclotron resonance mass spectrometry

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    A rapid shot-gun method by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) is proposed for the characterization of fennel proteins. After enzymatic digestion with trypsin, few microliters of extract were analyzed by direct infusion in positive ion mode. A custom-made non-redundant fennel-specific proteome database was derived from the well-known NCBI database; additional proteins belonging to recognized allergenic sources (celery, carrot, parsley, birch, and mugwort) were also included in our database, since patients hypersensitive to these plants could also suffer from fennel allergy. The peptide sequence of each protein from that derived list was theoretically sequenced to produce calculated m/z lists of possible m/z ions after tryptic digestions. Then, by using a home-made Matlab algorithm, those lists were matched with the experimental FT-ICR mass spectrum of the fennel peptide mixture. Finally, Peptide Mass Fingerprint searches confirmed the presence of the matched proteins inside the fennel extract with a total of 70 proteins (61 fennel specific and 9 allergenic proteins)

    Natural based products for cleaning copper and copper alloys artefacts

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    Copper alloys objects can deteriorate their conservation state through irreversible corrosion. Since in the cultural heritage field every artefact is unique and any loss irreplaceable, solutions for conservation are needed. Hence, there is the necessity to stop the corrosion process with a suitable cleaning and conservation process to avoid further degradation processes without changing its morphological aspect. Chelating solutions are commonly used in chemical cleaning, mainly sodium salts of ethylenediaminetetraacetic acid (EDTA). However, it is resistant to water purification procedures and is not biodegradable. The goal of this study was to see if applying an ecologically friendly chelating agent as an alternative to EDTA cleaning procedures for cultural heritage was suitable. In this study were chosen six natural-based chelators that could be a new green non-toxic alternative to EDTA in corrosion-inhibiting properties. They were tested for cleaning copper artefacts exposed to atmospheric environment in polluted areas. The study considered four amino acids, a glucoheptonate (CSA) and an industrial green chelator (GLDA). The effectiveness was tested on corrosion copper compounds and on laboratory corroded copper sheets. Finally, the cleaning efficacy was tested on four Roman coins and a modern copper painting. To define the cleaning efficacy, surface analytical investigations have been carried out by means ICP-OES, UV-VIS, µ-Raman, spectro-colorimetry, XRD and FTIR. Among the amino acids, alanine was the most effective, showing an unaltered noble patina and a good effective copper recovery from corrosion patinas

    Discovery of monoacylglycerol lipase (MAGL) inhibitors based on a pharmacophore-guided virtual screening study

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    Monoacylglycerol lipase (MAGL) is an important enzyme of the endocannabinoid system that catalyzes the degradation of the major endocannabinoid 2-arachidonoylglycerol (2-AG). MAGL is associated with pathological conditions such as pain, inflammation and neurodegenerative diseases like Parkinson's and Alzheimer's disease. Furthermore, elevated levels of MAGL have been found in aggressive breast, ovarian and melanoma cancer cells. Due to its different potential therapeutic implications, MAGL is considered as a promising target for drug design and the discovery of novel small-molecule MAGL inhibitors is of great interest in the medicinal chemistry field. In this context, we developed a pharmacophore-based virtual screening protocol combined with molecular docking and molecular dynamics simulations, which showed a final hit rate of 50% validating the reliability of the in silico workflow and led to the identification of two promising and structurally different reversible MAGL inhibitors, VS1 and VS2. These ligands represent a valuable starting point for structure-based hit-optimization studies aimed at identifying new potent MAGL inhibitors

    Intranasal Oxytocin Modulates Decision-Making Depending on Outcome Predictability-A Randomized Within-Subject Controlled Trial in Healthy Males.

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    Oxytocin (OT) has been extensively studied with regard to its socio-cognitive and -behavioral effects. Its potential as a therapeutic agent is being discussed for a range of neuropsychiatric conditions. However, there is limited evidence of its effects on non-social cognition in general and decision-making in particular, despite the importance of these functions in neuropsychiatry. Using a crossover/within-subject, blinded, randomized design, we investigated for the first time if intranasal OT (24 IU) affects decision-making differently depending on outcome predictability/ambiguity in healthy males. The Iowa Gambling Task (IGT) and the Cambridge Risk Task (CRT) were used to assess decision-making under low outcome predictability/high ambiguity and under high outcome probability/low ambiguity, respectively. After administration of OT, subjects performed worse and exhibited riskier performance in the IGT (low outcome predictability/high ambiguity), whereas they made borderline-significant less risky decisions in the CRT (high outcome probability/low ambiguity) as compared to the control condition. Decision-making in healthy males may therefore be influenced by OT and adjusted as a function of contextual information, with implications for clinical trials investigating OT in neuropsychiatric conditions

    A regularity class for the roots of nonnegative functions

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    We investigate the regularity of the positive roots of a non-negative function of one-variable. A modified H\"older space Fβ\mathcal{F}^\beta is introduced such that if f∈Fβf\in \mathcal{F}^\beta then fα∈Cαβf^\alpha \in C^{\alpha \beta}. This provides sufficient conditions to overcome the usual limitation in the square root case (α=1/2\alpha = 1/2) for H\"older functions that f1/2f^{1/2} need be no more than C1C^1 in general. We also derive bounds on the wavelet coefficients of fαf^\alpha, which provide a finer understanding of its local regularity.Comment: 12 page
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