6,485 research outputs found

    Requirement of endogenous tumor necrosis factor/cachectin for recovery from experimental peritonitis

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    By intrasplenic immunization we raised a rat mAb (mAb V1q; IgG2a, kappa) with a potent neutralizing activity against natural mouse TNF (1 microgram/ml mAb V1q/100 U/ml TNF). mAb V1q was used to study the role of endogenous TNF in experimental peritonitis induced by sublethal cecal ligation and puncture. mAb V1q persisted for over 5 days in the serum of mice injected with 100 micrograms of the antibody and, therefore, proved useful for in vivo experiments. As little as 20 micrograms mAb V1q/mouse prevented lethal shock of the animals by 400 micrograms LPS/mouse. In sublethal cecal ligation and puncture i.p. injection of mAb V1q directly and up to 8 h after induction of experimental peritonitis lead to death of the animals within 1 to 3 days. The lethal effect of mAb V1q was compensated by injection of recombinant mouse TNF. Similar mAb V1q effects as in immunocompetent mice were shown in severe combined immune deficiency mice deficient of mature functional B and T cells. Taken together, these data suggest that during the early phase of peritonitis endogenous TNF may stimulate nonlymphoid cells such as granulocytes, macrophages, platelets, and fibroblasts to ingest bacteria and to localize inflammation, respectively. These beneficial effects of TNF may determine survival. Thus, our data may have implications for the therapeutic management of a beginning peritonitis

    Induction of IL 2 receptor expression and cytotoxicity of thymocytes by stimulation with TCF1

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    We investigated the role of T cell cytotoxicity inducing factor 1 (TCF1) in the induction of a cytotoxic T cell response. We found that help-deficient thymocyte cultures supplied with saturating amounts of purified IL 2 did not develop CTL in a 5-day culture. The expression of cytotoxicity was dependent on the addition of TCF1 derived from the T cell hybridoma K15. TCF1 also induced proliferation of thymocytes in the presence of IL 2. Only the PNA- thymocyte subpopulation responded to TCF1 with proliferation and cytotoxicity in the presence of IL 2. The monokine IL 1 also induced proliferation in this subpopulation but failed to induce cytotoxicity. IL 1 was further distinguished from TCF1 by inhibition of IL 1-induced but not TCF1-induced proliferation by anti-IL 1 antibodies. In addition, using anti-IL 2 receptor antibodies (AMT 13), we showed that TCF1 in the presence of IL 2 substantially increased IL 2 receptor expression in thymocytes. IL 1 had the same effect on induction of IL 2 receptor expression as TCF1. Because some effects of IL 1 and TCF1 are distinct and some overlap, we discuss whether IL 1 and TCF1 induce different subsets of PNA- thymocytes

    Determination of the angle gamma using B -> D* V modes

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    We propose a method to determine the angle γ=arg(Vub)\gamma=arg(V_{ub}), using the BDVB\to D^*V (V=K,ρV=K^*, \rho) modes. The DD^* is considered to decay to DπD \pi. An interference of the BD0VB \to D^{*0}V and BD0ˉVB \to \bar {D^{*0}}V amplitudes is achieved by looking at a common final state ff, in the subsequent decays of D0/D0ˉD^0/\bar{D^0}. A detailed analysis of the angular distribution, allows determination, not only of γ\gamma and Vub|V_{ub}|, but also all the hadronic amplitudes and strong phases involved. No prior knowledge of doubly Cabibbo suppressed branching ratios of DD are required. Large CP violating asymmetries (30\sim30 % for γ=30o\gamma=30^o) are possible if D0ˉf\bar{D^0} \to f is doubly Cabbibo suppressed, while D0fD^0 \to f is Cabbibo allowed, for decays of B+B^+ or B0B^0.Comment: 12 Pages Revte

    ILC Beam Energy Measurement by means of Laser Compton Backscattering

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    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered γ\gamma-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitive detectors operating in a large radiation environment. Several options for high spatial resolution detectors are discussed. Simulation studies support the use of an infrared or green laser and quartz fiber detectors to monitor the backscattered photons and edge electrons. Employing a cavity monitor, the beam particle position downstream of the magnet can be recorded with submicrometer precision. Such a scheme provides a feasible and promising method to access the incident beam energy with precisions of 10410^{-4} or better on a bunch-to-bunch basis while the electron and positron beams are in collision.Comment: 47 pages, 26 figures, version as accepted by Nucl. Instr. Meth. A after improvement

    On the distortion of twin building lattices

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    We show that twin building lattices are undistorted in their ambient group; equivalently, the orbit map of the lattice to the product of the associated twin buildings is a quasi-isometric embedding. As a consequence, we provide an estimate of the quasi-flat rank of these lattices, which implies that there are infinitely many quasi-isometry classes of finitely presented simple groups. In an appendix, we describe how non-distortion of lattices is related to the integrability of the structural cocycle

    Dynamics within the CD95 death-inducing signaling complex decide life and death of cells

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    CD95-mediated apoptotic and NF-κB signaling were described by a simple kinetic model. We used a model reduction technique to reduce the number of reactions from 92 to 23 while maintaining a good model fit.p43-FLIP, which is generated at the CD95 DISC by procaspase-8 cleavage, was found to be the link between the CD95 DISC and the NF-κB pathway. P43-FLIP interacts with the IKK complex and leads to its activation.The CD95 DISC complex acts as a signal processor that diverges signals into the apoptotic and NF-κB pathways depending on the amounts of specific DISC proteins.Life/death decisions in CD95 signaling are determined by c-FLIPL and procaspase-8 in a non-linear way

    Engineering a C-Phase quantum gate: optical design and experimental realization

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    A two qubit quantum gate, namely the C-Phase, has been realized by exploiting the longitudinal momentum (i.e. the optical path) degree of freedom of a single photon. The experimental setup used to engineer this quantum gate represents an advanced version of the high stability closed-loop interferometric setup adopted to generate and characterize 2-photon 4-qubit Phased Dicke states. Some experimental results, dealing with the characterization of multipartite entanglement of the Phased Dicke states are also discussed in detail.Comment: accepted for publication on EPJ

    Human impact on the hydroenvironment of Lake Parishan, SW Iran, through the late Holocene

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    A multiproxy record from Lake Parishan, SW Iran, shows human impact on the lake and its catchment over the last 4000 years. The Parishan record provides evidence of changes in lake hydrology, from ostracod, diatom and isotope analyses, that are directly linked to human activity in the catchment; recorded by pollen and charcoal and supported by regional archaeological and historical data. The lake ostracod fauna is particularly sensitive to human induced catchment alterations and allow us to identify changes in catchment hydrology that are due to more than a simple change in precipitation: evaporation state. Oxygen isotope data from endogenic carbonates follow these faunal changes but also displays a longer trend to more positive values through the period, coincident with regional patterns of water balance for the late Holocene in the eastern Mediterranean

    Rational design of biosafe crop resistance to a range of nematodes using RNA interference

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    Double stranded RNA (dsRNA) molecules targeting two genes have been identified that suppress economically important parasitic nematode species of banana. Proteasomal Alpha Subunit 4 (pas-4) and Actin-4 (act-4) were identified from a survey of sequence databases and cloned sequences for genes conserved across four pests of banana, Radopholus similis, Pratylenchus coffeae, Meloidogyne incognita and Helicotylenchus multicinctus. These four species were targeted with dsRNAs containing exact 21 nucleotide matches to the conserved regions. Potential off-target effects were limited by comparison to Caenorhabditis, Drosophila, rat, rice and Arabidopsis genomes. In vitro act-4 dsRNA treatment of R. similis suppressed target gene expression by 2.3 fold, nematode locomotion by 66 ± 4% and nematode multiplication on carrot discs by 49 ± 5%. The best transgenic carrot hairy root lines expressing act-4 or pas-4 dsRNA reduced transcript message abundance of target genes in R. similis by 7.9 fold and 4 fold and nematode multiplication by 94 ± 2% and 69 ± 3%, respectively. The same act-4 and pas-4 lines reduced P. coffeae target transcripts by 1.7 and 2 fold and multiplication by 50 ± 6% and 73 ± 8%. Multiplication of M. incognita on the pas-4 lines was reduced by 97 ± 1% and 99 ± 1% while target transcript abundance was suppressed 4.9 and 5.6 fold. There was no detectable RNAi effect on non-target nematodes exposed to dsRNAs targeting parasitic nematodes. This work defines a framework for development of a range of non-protein defences to provide broad resistance to pests and pathogens of crops
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