129 research outputs found

    Observers can always generate nonlocal correlations without aligning measurements by covering all their bases

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    Quantum theory allows for correlations between the outcomes of distant measurements that are inconsistent with any locally causal theory, as demonstrated by the violation of a Bell inequality. Typical demonstrations of these correlations require careful alignment between the measurements, which requires distant parties to share a reference frame. Here, we prove, following a numerical observation by Shadbolt et al., that if two parties share a Bell state and each party randomly chooses three orthogonal measurements, then the parties will always violate a Bell inequality. Furthermore, we prove that this probability is highly robust against local depolarizing noise, in that small levels of noise only decrease the probability of violating a Bell inequality by a small amount. We also show that generalizing to N parties increases the robustness against noise. These results improve on previous ones that only allowed a high probability of violating a Bell inequality for large numbers of parties.Comment: 4 pages, 2 figures. v2: updated reference. v3: published versio

    Improved hematopoiesis in anemic Sl/Sld mice by splenectomy and therapeutic transplantation of a hematopoietic microenvironment

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    The ability of a clonal hematopoiesis-supportive bone-marrow stromal cell line GBlneor to engraft and alter the microenvironment-induced anemia of Sl/Sld mice was studied. Prior to stromal cell transplantation, Sl/Sld mice received 1 Gy total body irradiation (TBI) and 13 Gy to the right hind limb. Two months after intravenous (IV) injection of 5 x 10(5) GBlneor cells, 54.4% +/- 17.0% donor origin (G418r) colony-forming cells were recovered from the right hind limb of Sl/Sld mice. Long-term bone marrow cultures (LTBMCs) established from GBlneor-transplanted mice produced 189.5 CFU-GEMM-forming progenitors/flask over 10 weeks compared with 52.7 +/- 6.2 CFU-GEMM forming progenitors/flask from irradiated nontransplanted Sl/Sld mice. A partial correction of macrocytic anemia was detected 2 months after GBlneor transplantation in splenectomized, irradiated Sl/Sld mice (HgB 7.2 +/- 0.4 g/dL; MCV 68.3 +/- 7.0 fL) compared to splenectomized, irradiated, nontransplanted Sl/Sld mice (HgB 5.5 +/- 1.1 g/dL; MCV 76 +/- 8.5 fL) or control Sl/Sld mice (HgB 5.4 +/- 0.5 g/dL; MCV 82.4 +/- 1.3 fL). Mean RBC volume distribution analysis showed a 2.5-fold increase in percentage of peripheral blood RBCs with MCV less than or equal to 45 fL and confirmed reduction of the MCV in splenectomized-GBlneor-transplanted mice compared to control Sl/Sld mice. A hematopoiesis-suppressive clonal stromal cell line derived from LTBMCs of Sl/Sld mice (Sldneor) engrafted as effectively (43.5% +/- 1.2% G418r CFU-F/limb) as did GBlneor cells (38.3% +/- 0.16% G418r CFU-F/limb) to the irradiated right hind limbs of C57Bl/6 mice. LTBMCs established after 2 or 6 months from Sldneor-transplanted mice showed decreased hematopoiesis (182 +/- 12 [2 months] and 3494.3 +/- 408.1 [6 months] CFU-GEMM forming progenitors/flask over 10 weeks) compared to those established from GBlneor-transplanted mice (5980 +/- 530 [2 months] and 7728 +/- 607, [6 months] CFU-GEMM progenitors forming/flask). Thus, transplantation of clonal bone-marrow stromal cell lines in vivo can stably transfer their physiologic properties to normal or mutant mice

    Strategies for Discovery of Small Molecule Radiation Protectors and Radiation Mitigators

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    Mitochondrial targeted radiation damage protectors (delivered prior to irradiation) and mitigators (delivered after irradiation, but before the appearance of symptoms associated with radiation syndrome) have been a recent focus in drug discovery for (1) normal tissue radiation protection during fractionated radiotherapy, and (2) radiation terrorism counter measures. Several categories of such molecules have been discovered: nitroxide-linked hybrid molecules, including GS-nitroxide, GS-nitric oxide synthase inhibitors, p53/mdm2/mdm4 inhibitors, and pharmaceutical agents including inhibitors of the phosphoinositide-3-kinase pathway and the anti-seizure medicine, carbamazepine. Evaluation of potential new radiation dose modifying molecules to protect normal tissue includes: clonogenic radiation survival curves, assays for apoptosis and DNA repair, and irradiation-induced depletion of antioxidant stores. Studies of organ specific radioprotection and in total body irradiation-induced hematopoietic syndrome in the mouse model for protection/mitigation facilitate rational means by which to move candidate small molecule drugs along the drug discovery pipeline into clinical development

    Dissociation of opsonized particle phagocytosis and respiratory burst activity in an Epstein-Barr virus-infected myeloid cell line

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    A continuous tissue culture cell line (Karpas line 120), derived from a patient with acute myeloblastic leukemia, not only demonstrates myeloblastic morphology and in vitro expression of several myeloid- specific biochemical markers but also contains Epstein-Barr virus (EBV) nuclear antigen. The present studies demonstrate EBV-genome-specific DNA within the total cellular DNA by molecular hybridization, thus establishing the presence of stable viral genome integration. The cells demonstrate complex coordinated myeloid functions including ingestion, degranulation, and respiratory burst activity. Line 120 cells show a respiratory burst (superoxide and hydrogen peroxide generation and hexosemonophosphate shunt activity) in response to soluble (phorbol myristate acetate) and particulate (latex beads) stimuli, as do normal granulocytes. They ingest complement-opsonized particles (lipopolysaccharide-oil droplets, zymosan, and bacteria), and degranulate in response to them. However, unlike normal granulocytes, the line 120 cells do not demonstrate respiratory burst activity in response to these complementopsonized particles. The dissociation between ingestion of complement-opsonized particles and activation of oxygen-dependent bactericidal activity severely impairs bacterial killing as compared with normal polymorphonuclear phagocytes

    The HSP90 Inhibitor Ganetespib Radiosensitizes Human Lung Adenocarcinoma Cells

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    The molecular chaperone HSP90 is involved in stabilization and function of multiple client proteins, many of which represent important oncogenic drivers in NSCLC. Utilization of HSP90 inhibitors as radiosensitizing agents is a promising approach. The antitumor activity of ganetespib, HSP90 inhibitor, was evaluated in human lung adenocarcinoma (AC) cells for its ability to potentiate the effects of IR treatment in both in vitro and in vivo. The cytotoxic effects of ganetespib included; G2/M cell cycle arrest, inhibition of DNA repair, apoptosis induction, and promotion of senescence. All of these antitumor effects were both concentration- and time-dependent. Both pretreatment and post-radiation treatment with ganetespib at low nanomolar concentrations induced radiosensitization in lung AC cells in vitro. Ganetespib may impart radiosensitization through multiple mechanisms: such as down regulation of the PI3K/Akt pathway; diminished DNA repair capacity and promotion of cellular senescence. In vivo, ganetespib reduced growth of T2821 tumor xenografts in mice and sensitized tumors to IR. Tumor irradiation led to dramatic upregulation of β-catenin expression in tumor tissues, an effect that was mitigated in T2821 xenografts when ganetespib was combined with IR treatments. These data highlight the promise of combining ganetespib with IR therapies in the treatment of AC lung tumors

    Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene Therapy

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    Radiation-induced DNA damage is a precursor to mutagenesis and cytotoxicity. During radiotherapy, exposure of healthy tissues can lead to severe side effects. We explored the potential of mitochondrial SOD (MnSOD) gene therapy to protect esophageal, pancreatic and bone marrow cells from radiation-induced genomic instability. Specifically, we measured the frequency of homologous recombination (HR) at an integrated transgene in the Fluorescent Yellow Direct Repeat (FYDR) mice, in which an HR event can give rise to a fluorescent signal. Mitochondrial SOD plasmid/liposome complex (MnSOD-PL) was administered to esophageal cells 24 h prior to 29 Gy upper-body irradiation. Single cell suspensions from FYDR, positive control FYDR-REC, and negative control C57BL/6NHsd (wild-type) mouse esophagus, pancreas and bone marrow were evaluated by flow cytometry. Radiation induced a statistically significant increase in HR 7 days after irradiation compared to unirradiated FYDR mice. MnSOD-PL significantly reduced the induction of HR by radiation at day 7 and also reduced the level of HR in the pancreas. Irradiation of the femur and tibial marrow with 8 Gy also induced a significant increase in HR at 7 days. Radioprotection by intraesophageal administration of MnSOD-PL was correlated with a reduced level of radiation-induced HR in esophageal cells. These results demonstrate the efficacy of MnSOD-PL for suppressing radiation-induced HR in vivo.National Institutes of Health (U.S.) (NIH Grant R01-CA83876-8)National Institute of Allergy and Infectious Diseases (U.S.) (NIH grant U19A1068021)National Institutes of Health (U.S.) (Grant T32-ES07020)United States. Dept. of Energy (DOE DE-FG01-04ER04)National Institutes of Health (U.S.) (NIH P01-CA26735

    Gene Therapy for Systemic or Organ Specific Delivery of Manganese Superoxide Dismutase

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    Manganese superoxide dismutase (MnSOD) is a dominant component of the antioxidant defense system in mammalian cells. Since ionizing irradiation induces profound oxidative stress, it was logical to test the effect of overexpression of MnSOD on radioresistance. This task was accomplished by introduction of a transgene for MnSOD into cells in vitro and into organs in vivo, and both paradigms showed clear radioresistance following overexpression. During the course of development and clinical application of using MnSOD as a radioprotector, several prominent observations were made by Larry Oberley, Joel Greenberger, and Michael Epperly which include (1) mitochondrial localization of either manganese superoxide dismutase or copper/zinc SOD was required to provide optimal radiation protection; (2) the time required for optimal expression was 12–18 h, and while acceptable for radiation protection, the time delay was impractical for radiation mitigation; (3) significant increases in intracellular elevation of MnSOD activity were required for effective radioprotection. Lessons learned during the development of MnSOD gene therapy have provided a strategy for delivery of small molecule SOD mimics, which are faster acting and have shown the potential for both radiation protection and mitigation. The purpose of this review is to summarize the current status of using MnSOD-PL and SOD mimetics as radioprotectors and radiomitigators

    Gene Therapy for Systemic or Organ Specific Delivery of Manganese Superoxide Dismutase

    No full text
    Manganese superoxide dismutase (MnSOD) is a dominant component of the antioxidant defense system in mammalian cells. Since ionizing irradiation induces profound oxidative stress, it was logical to test the effect of overexpression of MnSOD on radioresistance. This task was accomplished by introduction of a transgene for MnSOD into cells in vitro and into organs in vivo, and both paradigms showed clear radioresistance following overexpression. During the course of development and clinical application of using MnSOD as a radioprotector, several prominent observations were made by Larry Oberley, Joel Greenberger, and Michael Epperly which include (1) mitochondrial localization of either manganese superoxide dismutase or copper/zinc SOD was required to provide optimal radiation protection; (2) the time required for optimal expression was 12–18 h, and while acceptable for radiation protection, the time delay was impractical for radiation mitigation; (3) significant increases in intracellular elevation of MnSOD activity were required for effective radioprotection. Lessons learned during the development of MnSOD gene therapy have provided a strategy for delivery of small molecule SOD mimics, which are faster acting and have shown the potential for both radiation protection and mitigation. The purpose of this review is to summarize the current status of using MnSOD-PL and SOD mimetics as radioprotectors and radiomitigators
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