920 research outputs found

    Variability of alkaloid content in Papaver somniferum L.

    Get PDF
    A total of 300 accessions of opium poppy (Papaver somniferum L., Papaveraceae) of the IPK genebank collection from nearly all over the world were cultivated under field conditions in Gatersleben for morphological and phytochemical characterisation. Altogether 35 morphological and agronomic characters were collected for all accessions. Determination of chromosome numbers with flow cytometry showed that the accessions of subspecies setigerum are tetraploid whereas all accessions of the other subspecies are diploid. Composition and content of the five main alkaloids (morphine, codeine, thebaine, papaverine and noscapine) were analysed by high performance liquid chromatography (HPLC). Total alkaloid content varied between 683.32 and 25,034.84 μg/g dry matter (first year) and 1,799.49 and 25,338.55 μg/g dry matter in the second year of cultivation. There is a highly significant correlation between total content of alkaloids and morphine in both years (r=0.926/P=0.000; r=0.918/P=0.000). In contrast, the other four main alkaloids show less or no correlation with each other or the total alkaloid content. This analysis demonstrated that the amount and composition of the main alkaloids are highly variable. Additionally, there is no important correlation between morphological characters and alkaloid content. So it is not possible to use these characters as a prediction tool of alkaloid content during breeding process

    TCRαβ/CD3 disruption enables CD3-specific antileukemic T cell immunotherapy

    Get PDF
    T cells engineered to express chimeric antigen receptors (CARs) against B cell antigens are being investigated as cellular immunotherapies. Similar approaches designed to target T cell malignancies have been hampered by the critical issue of T-on-T cytotoxicity, whereby fratricide or self-destruction of healthy T cells prohibits cell product manufacture. To date, there have been no reports of T cells engineered to target the definitive T cell marker, CD3 (3CAR). Recent improvements in gene editing now provide access to efficient disruption of such molecules on T cells, and this has provided a route to generation of 3CAR, CD3-specific CAR T cells. T cells were transduced with a lentiviral vector incorporating an anti-CD3ε CAR derived from OKT3, either before or after TALEN-mediated disruption of the endogenous TCRαβ/CD3 complex. Only transduction after disrupting assembly of TCRαβ/CD3 yielded viable 3CAR T cells, and these cultures were found to undergo self-enrichment for 3CAR+TCR-CD3- T cells without any further processing. Specific cytotoxicity against CD3ε was demonstrated against primary T cells and against childhood T cell acute lymphoblastic leukemia (T-ALL). 3CAR T cells mediated potent antileukemic effects in a human/murine chimeric model, supporting the application of cellular immunotherapy strategies against T cell malignancies. 3CAR provides a bridging strategy to achieve T cell eradication and leukemic remission ahead of conditioned allogeneic stem cell transplantation

    Re-structuring lentiviral vectors to express genomic RNA via cap-dependent translation

    Get PDF
    Lentiviral (LV) vectors based on human immunodeficiency virus type I (HIV-1) package two copies of their single-stranded RNA into vector particles. Normally, this RNA genome is reverse transcribed into a double-stranded DNA provirus that integrates into the cell genome, providing permanent gene transfer and long-term expression. Integration-deficient LV vectors have been developed to reduce the frequency of genomic integration and thereby limit their persistence in dividing cells. Here, we describe optimization of a reverse-transcriptase-deficient LV vector, which enables direct translation of LV RNA genomes upon cell entry, for transient expression of vector payloads as mRNA without a DNA intermediate. We have engineered a novel LV genome arrangement in which HIV-1 sequences are removed from the 5′ end, to enable ribosomal entry from the 5′ 7-methylguanylate cap for efficient translation of the vector payload. We have shown that this LV-mediated mRNA delivery platform provides transient transgene expression in vitro and in vivo. This has a potential application in gene and cell therapy scenarios requiring temporary payload expression in cells and tissues that can be targeted with pseudotyped LV vectors

    A stock-flow cohort model of the national car fleet

    Get PDF
    Purpose Various regulatory and fiscal policy instruments are in force to reduce the amount of greenhouse gases and local pollutants emitted by private cars. The incentives operate primarily—or exclusively—on the newest generation of cars. But how fast will technological developments affecting new vehicle models penetrate into the car fleet? The speed at which the adverse effects of private car use will be mitigated through the normal vehicle renewal process, or through an accelerated one, carries considerable interest. Suitable modelling tools are needed. This paper aims to demonstrate the usefulness and flexibility of a bottom-up stock-flow modelling approach to private car fleet forecasting and policy analysis. Methods In the BIG model of the Norwegian automobile fleet, the annual stocks and flows characterising the car fleet are specified as matrices of 682 mutually exclusive and exhaustive cells, formed by cross-tabulations between 22 vehicle segments and 31 age classes. New car registrations follow from a disaggregate generic discrete choice model based on two decades of complete sales data for individual passenger car models. Results Example projections are presented onto the 2050 horizon under a low carbon fiscal policy scenario as well as a business-as-usual scenario. The fiscal policy is seen to make a large difference in terms of long term fuel consumption and CO2 emissions. Conclusions Stock-flow cohort modelling of the automobile fleet is a powerful and handy tool for policy analysis. Even quite simple and straightforward accounting relations may provide important insights into the dynamics of fleet development. It is possible to incorporate, into the stock-flow modelling framework, interesting and useful behavioural relations, explaining aggregate automobile ownership and travel demand, scrapping and survival rates, or consumer choice in the market for new cars

    Status of the LUX Dark Matter Search

    Full text link
    The Large Underground Xenon (LUX) dark matter search experiment is currently being deployed at the Homestake Laboratory in South Dakota. We will highlight the main elements of design which make the experiment a very strong competitor in the field of direct detection, as well as an easily scalable concept. We will also present its potential reach for supersymmetric dark matter detection, within various timeframes ranging from 1 year to 5 years or more.Comment: 4 pages, in proceedings of the SUSY09 conferenc

    Near-field interactions between metal nanoparticle surface plasmons and molecular excitons in thin-films: part I: absorption

    Get PDF
    In this and the following paper (parts I and II, respectively), we systematically study the interactions between surface plasmons of metal nanoparticles (NPs) with excitons in thin-films of organic media. In an effort to exclusively probe near-field interactions, we utilize spherical Ag NPs in a size-regime where far-field light scattering is negligibly small compared to absorption. In part I, we discuss the effect of the presence of these Ag NPs on the absorption of the embedding medium by means of experiment, numerical simulations, and analytical calculations, all shown to be in good agreement. We observe absorption enhancement in the embedding medium due to the Ag NPs with a strong dependence on the medium permittivity, the spectral position relative to the surface plasmon resonance frequency, and the thickness of the organic layer. By introducing a low index spacer layer between the NPs and the organic medium, this absorption enhancement is experimentally confirmed to be a near field effect In part II, we probe the impact of the Ag NPs on the emission of organic molecules by time-resolved and steady-state photoluminescence measurements

    Automated manufacturing of chimeric antigen receptor T cells for adoptive immunotherapy using CliniMACS prodigy

    Get PDF
    Novel cell therapies derived from human T lymphocytes are exhibiting enormous potential in early-phase clinical trials in patients with hematologic malignancies. Ex vivo modification of T cells is currently limited to a small number of centers with the required infrastructure and expertise. The process requires isolation, activation, transduction, expansion and cryopreservation steps. To simplify procedures and widen applicability for clinical therapies, automation of these procedures is being developed. The CliniMACS Prodigy (Miltenyi Biotec) has recently been adapted for lentiviral transduction of T cells and here we analyse the feasibility of a clinically compliant T-cell engineering process for the manufacture of T cells encoding chimeric antigen receptors (CAR) for CD19 (CAR19), a widely targeted antigen in B-cell malignancies. Using a closed, single-use tubing set we processed mononuclear cells from fresh or frozen leukapheresis harvests collected from healthy volunteer donors. Cells were phenotyped and subjected to automated processing and activation using TransAct, a polymeric nanomatrix activation reagent incorporating CD3/CD28-specific antibodies. Cells were then transduced and expanded in the CentriCult-Unit of the tubing set, under stabilized culture conditions with automated feeding and media exchange. The process was continuously monitored to determine kinetics of expansion, transduction efficiency and phenotype of the engineered cells in comparison with small-scale transductions run in parallel. We found that transduction efficiencies, phenotype and function of CAR19 T cells were comparable with existing procedures and overall T-cell yields sufficient for anticipated therapeutic dosing. The automation of closed-system T-cell engineering should improve dissemination of emerging immunotherapies and greatly widen applicability

    The AMANDA Neutrino Telescope

    Full text link
    With an effective telescope area of order 10410^4 m2^2 for TeV neutrinos, a threshold near \sim50 GeV and a pointing accuracy of 2.5 degrees per muon track, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe early results on the calibration of natural deep ice as a particle detector as well as on AMANDA's performance as a neutrino telescope.Comment: 12 pages, Latex2.09, uses espcrc2.sty and epsf.sty, 13 postscript files included. Talk presented at the 18th International Conference on Neutrino Physics and Astrophysics (Neutrino 98), Takayama, Japan, June 199
    corecore