328 research outputs found

    Entanglement-enhanced probing of a delicate material system

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    Quantum metrology uses entanglement and other quantum effects to improve the sensitivity of demanding measurements. Probing of delicate systems demands high sensitivity from limited probe energy and has motivated the field's key benchmark-the standard quantum limit. Here we report the first entanglement-enhanced measurement of a delicate material system. We non-destructively probe an atomic spin ensemble by means of near-resonant Faraday rotation, a measurement that is limited by probe-induced scattering in quantum-memory and spin-squeezing applications. We use narrowband, atom-resonant NOON states to beat the standard quantum limit of sensitivity by more than five standard deviations, both on a per-photon and per-damage basis. This demonstrates quantum enhancement with fully realistic loss and noise, including variable-loss effects. The experiment opens the way to ultra-gentle probing of single atoms, single molecules, quantum gases and living cells.Comment: 7 pages, 8 figures; Nature Photonics, advance online publication, 16 December 201

    The steroid sulfatase inhibitor COUMATE attenuates rather than enhances access of dehydroepiandrosterone sulfate to the brain in the mouse

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    Intraperitoneal injection of adult male mice with the neuroactive steroid dehydroepiandrosterone sulfate (DHEAS) at 1 and 40 mg/kg caused dose-dependent increases in the concentration of both this compound and its corresponding free steroid DHEA in brain within 1 h of injection. Pretreatment of these animals for 24 h with the steroid sulfatase inhibitor COUMATE at a dose (10 mg/kg, p.o.) shown previously to cause almost complete inhibition of this enzyme in liver and brain was expected to increase the amount of the DHEAS dose reaching the brain. Surprisingly however, the increases in brain concentrations of DHEAS and DHEA after injection of DHEAS i.p. were attenuated by pretreatment with COUMATE. The results suggest that the arylsulfamate based steroid sulfatase inhibitors such as COUMATE interfere with the influx of the DHEAS anion into the brain

    The Complete Genome Sequence of Escherichia coli EC958: A High Quality Reference Sequence for the Globally Disseminated Multidrug Resistant E. coli O25b:H4-ST131 Clone

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    Escherichia coli ST131 is now recognised as a leading contributor to urinary tract and bloodstream infections in both community and clinical settings. Here we present the complete, annotated genome of E. coli EC958, which was isolated from the urine of a patient presenting with a urinary tract infection in the Northwest region of England and represents the most well characterised ST131 strain. Sequencing was carried out using the Pacific Biosciences platform, which provided sufficient depth and read-length to produce a complete genome without the need for other technologies. The discovery of spurious contigs within the assembly that correspond to site-specific inversions in the tail fibre regions of prophages demonstrates the potential for this technology to reveal dynamic evolutionary mechanisms. E. coli EC958 belongs to the major subgroup of ST131 strains that produce the CTX-M-15 extended spectrum β-lactamase, are fluoroquinolone resistant and encode the fimH30 type 1 fimbrial adhesin. This subgroup includes the Indian strain NA114 and the North American strain JJ1886. A comparison of the genomes of EC958, JJ1886 and NA114 revealed that differences in the arrangement of genomic islands, prophages and other repetitive elements in the NA114 genome are not biologically relevant and are due to misassembly. The availability of a high quality uropathogenic E. coli ST131 genome provides a reference for understanding this multidrug resistant pathogen and will facilitate novel functional, comparative and clinical studies of the E. coli ST131 clonal lineage

    SAMMSON fosters cancer cell fitness by concertedly enhancing mitochondrial and cytosolic translation

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    Synchronization of mitochondrial and cytoplasmic translation rates is critical for the maintenance of cellular fitness, with cancer cells being especially vulnerable to translational uncoupling. Although alterations of cytosolic protein synthesis are common in human cancer, compensating mechanisms in mitochondrial translation remain elusive. Here we show that the malignant long non-coding RNA (lncRNA) SAMMSON promotes a balanced increase in ribosomal RNA (rRNA) maturation and protein synthesis in the cytosol and mitochondria by modulating the localization of CARF, an RNA-binding protein that sequesters the exo-ribonuclease XRN2 in the nucleoplasm, which under normal circumstances limits nucleolar rRNA maturation. SAMMSON interferes with XRN2 binding to CARF in the nucleus by favoring the formation of an aberrant cytoplasmic RNA-protein complex containing CARF and p32, a mitochondrial protein required for the processing of the mitochondrial rRNAs. These data highlight how a single oncogenic lncRNA can simultaneously modulate RNA-protein complex formation in two distinct cellular compartments to promote cell growth

    The Wnt Receptor Ryk Reduces Neuronal and Cell Survival Capacity by Repressing FOXO Activity During the Early Phases of Mutant Huntingtin Pathogenicity

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    The Wnt receptor Ryk is an evolutionary-conserved protein important during neuronal differentiation through several mechanisms, including γ-secretase cleavage and nuclear translocation of its intracellular domain (Ryk-ICD). Although the Wnt pathway may be neuroprotective, the role of Ryk in neurodegenerative disease remains unknown. We found that Ryk is up-regulated in neurons expressing mutant huntingtin (HTT) in several models of Huntington's disease (HD). Further investigation in Caenorhabditis elegans and mouse striatal cell models of HD provided a model in which the early-stage increase of Ryk promotes neuronal dysfunction by repressing the neuroprotective activity of the longevity-promoting factor FOXO through a noncanonical mechanism that implicates the Ryk-ICD fragment and its binding to the FOXO co-factor β-catenin. The Ryk-ICD fragment suppressed neuroprotection by lin-18/Ryk loss-of-function in expanded-polyQ nematodes, repressed FOXO transcriptional activity, and abolished β-catenin protection of mutant htt striatal cells against cell death vulnerability. Additionally, Ryk-ICD was increased in the nucleus of mutant htt cells, and reducing γ-secretase PS1 levels compensated for the cytotoxicity of full-length Ryk in these cells. These findings reveal that the Ryk-ICD pathway may impair FOXO protective activity in mutant polyglutamine neurons, suggesting that neurons are unable to efficiently maintain function and resist disease from the earliest phases of the pathogenic process in HD. © 2014 Tourette et al

    Insulin/IGF and Sex Hormone Axes in Human Endometrium and Associations with Endometrial Cancer Risk Factors

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    Given an ordered set of points and an ordered set of geometric objects in the plane, we are interested in finding a non-crossing matching between point-object pairs. In this paper, we address the algorithmic problem of determining whether a non-crossing matching exists between a given point-object pair. We show that when the objects we match the points to are finite point sets, the problem is NP-complete in general, and polynomial when the objects are on a line or when their size is at most 2. When the objects are line segments, we show that the problem is NP-complete in general, and polynomial when the segments form a convex polygon or are all on a line. Finally, for objects that are straight lines, we show that the problem of finding a min-max non-crossing matching is NP-complete. © 2012 Elsevier B.V.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Resolving the neural circuits of anxiety

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    Although anxiety disorders represent a major societal problem demanding new therapeutic targets, these efforts have languished in the absence of a mechanistic understanding of this subjective emotional state. While it is impossible to know with certainty the subjective experience of a rodent, rodent models hold promise in dissecting well-conserved limbic circuits. The application of modern approaches in neuroscience has already begun to unmask the neural circuit intricacies underlying anxiety by allowing direct examination of hypotheses drawn from existing psychological concepts. This information points toward an updated conceptual model for what neural circuit perturbations could give rise to pathological anxiety and thereby provides a roadmap for future therapeutic development.National Institute of Diabetes and Digestive and Kidney Diseases (U.S.) (NIH Director’s New Innovator Award DP2-DK-102256-01)National Institute of Mental Health (U.S.) (NIH) R01-MH102441-01)JPB Foundatio

    A genetic cause of Alzheimer disease: mechanistic insights from Down syndrome

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    Down syndrome, caused by an extra copy of chromosome 21, is associated with a greatly increased risk of early onset Alzheimer disease. It is thought that this risk is conferred by the presence of three copies of the gene encoding amyloid precursor protein (APP), an Alzheimer risk factor, although the possession of extra copies of other chromosome 21 genes may also play a role. Further study of the mechanisms underlying the development of Alzheimer disease in Down syndrome could provide insights into the mechanisms that cause dementia in the general population

    Raltitrexed (Tomudex) administration in patients with relapsed metastatic colorectal cancer after weekly irinotecan/5-Fluorouracil/Leucovorin chemotherapy

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    PURPOSE: The present study aimed at evaluating the efficacy of Raltitrexed, a specific thymidilate synthase inhibitor, in patients with advanced colorectal cancer (ACC) in relapse (>8 weeks) after a prior response or disease stabilization to first-line chemotherapy combination with lrinotecan+5-Fluorouracil (5-FU)+Leucovorin (LV). METHODS: Twenty-five patients with metastatic ACC entered; 17 males/8 females, median age 61 (range: 47–70), median Karnovsky PS: 80 (70–90), and sites of metastases; liver: 21, lung: 4, lymph nodes: 7, peritoneal: 5 and a life expectancy of at least 3 months, were entered in the present pilot study. All patients had progressed after prior chemotherapy with lrinotecan+5-FU+LV. Raltitrexed was administered at a dose of 3 mg/m(2) i.v. every 21 days. RESULTS: Three patients (12%) achieved a partial response (PR), 8 (32%) had stable disease (SD), and the remaining 14 (56%) developed progressive disease (PD). Median time-to-progression (TTP) was 5.5 months (range, 2–8.5), and median overall survival (OS) 8 months (range, 4.0–12.5). Toxicity was generally mild; it consisted mainly of myelosuppression; neutropenia grade 1–2: 52%-grade 3: 28%, and anemia grade 1–2 only: 36%. Mild mucositis grade 1–2 occured in 13.5% of patients and was the principal non-hematologic toxicity. CONCLUSION: Response to treatment with Raltitrexed is limited in patients with ACC failing after an initial response or non-progression to the weekly lrinotecan+5-FU+LV combination. However, it appears that a limited number of patients with PR/SD may derive clinical benefit, but final proof would require a randomized study

    Bevacizumab plus FOLFIRI or FOLFOX in chemotherapy-refractory patients with metastatic colorectal cancer: a retrospective study

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    <p>Abstract</p> <p>Background</p> <p>The anti-VEGF antibody bevacizumab associated with an irinotecan or oxaliplatin-based chemotherapy was proved to be superior to the chemotherapy alone in first or second line treatment of metastatic colorectal cancer (mCRC). However, it was reported to have no efficacy in 3<sup>rd </sup>or later-line, alone or with 5FU. The aim of this study was to evaluate the activity of bevacizumab combined with FOLFIRI or FOLFOX in mCRC who have failed prior chemotherapy with fluoropyrimidine plus irinotecan and/or oxaliplatin.</p> <p>Methods</p> <p>Thirty one consecutive patients treated between May 2005 and October 2006 were included in this retrospective study. All of them have progressed under a chemotherapy with fluoropyrimidine plus irinotecan and/or oxaliplatin and received bevacizumab (5 mg/kg) in combination with FOLFIRI or simplified FOLFOX4 every 14 days.</p> <p>Results</p> <p>Ten patients (32.2%) had an objective response (1 CR, 9 PR) and 12 (38.8%) were stabilized. The response and disease control rates were 45.4% and 100% when bevacizumab was administered in 2<sup>nd </sup>or 3<sup>rd </sup>line and 25% and 55% in 4<sup>th </sup>or later line respectively (p = 0.024 and p = 0.008). Among the patients who had previously received the same chemotherapy than that associated with bevacizumab (n = 28) the overall response rate was 35.7% and 39.3% were stabilized. Median progression free survival (PFS) and overall survival (OS) were of 9.7 and 18.4 months respectively. Except a patient who presented a hypertension associated reversible posterior leukoencephalopathy syndrome, tolerance of bevacizumab was acceptable. A rectal bleeding occurred in one patient, an epistaxis in five. Grade 1/2 hypertension occurred in five patients.</p> <p>Conclusion</p> <p>This study suggests that bevacizumab combined with FOLFOX or FOLFIRI may have the possibility to be active in chemorefractory and selected mCRC patients who did not receive it previously.</p
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