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Find video protocols related to scientific articles indexed in Pubmed.
Revealing the halide effect on the kinetics of the aerobic oxidation of Cu(i) to Cu(ii).
Chem. Commun. (Camb.)
PUBLISHED: 11-20-2014
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In situ infrared (IR) and X-ray absorption near-edge structure (XANES) spectroscopic investigations reveal that different halide ligands have distinct effects on the aerobic oxidation of Cu(i) to Cu(ii) in the presence of TMEDA (tetramethylethylenediamine). The iodide ligand gives the lowest rate and thus leads to the lowest catalytic reaction rate of aerobic oxidation of hydroquinone to benzoquinone. Further DFT calculations suggest that oxidation of CuI-TMEDA involves a side-on transition state, while oxidation of CuCl-TMEDA involves an end-on transition state which has a lower activation energy.
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Cu(II)/Cu(I)-Synergistic Cooperation to Lead the Alkyne C-H Activation.
J. Am. Chem. Soc.
PUBLISHED: 11-11-2014
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An efficient alkyne C-H activation procedure has been well studied which indicated that a Cu(II)/Cu(I) synergistic co-operation might be involved. In situ Raman spectroscopy was engaged to study kinetic behavior, drawing the conclusion that Cu(II) didn't participate in the rate determining step. IR and X-ray absorption spectroscopy evidence were provided for structural information, indicating that Cu(II) alone couldn't accelerate the reduction procedure by simply coordinating with C-C triple bond to activate the terminal alkynes; meanwhile, X-band EPR spectra and solubility showed that Cu(I) and Cu(II) could affect the complication environment of each other. A distinctive Cu(I)-Cu(II) synergistic cooperation intermediate was proposed for the putative mechanism.
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Tetrahedral Sn-silsesquioxane: synthesis, characterization and catalysis.
Chem. Commun. (Camb.)
PUBLISHED: 11-01-2014
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A tetrahedral stannasilsesquioxane complex was synthesized as a racemic mixture using Sn(O(i)Pr)4 and silsesquioxanediol, and its structure was confirmed with X-ray crystallography, NMR, and EXAFS. The complex was a Lewis acid, and both anti and syn-binding with Lewis bases were possible with the formation of octahedral Sn complexes. It was also a Lewis acid catalyst active for epoxide ring opening and hydride transfer.
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Synergistic Interaction of Vancomycin with Different Antibiotics in Escherichia coli: Trimethoprim and Nitrofurantoin Display Strong Synergies with Vancomycin in Wild-type E.coli.
Antimicrob. Agents Chemother.
PUBLISHED: 10-29-2014
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Gram-negative bacteria are normally resistant to the antibiotic vancomycin (VAN), which cannot significantly penetrate the outer membrane. We used Escherichia coli mutants that are partially sensitive to VAN to study synergies between VAN and 10 other antibiotics representing 6 different functional categories. We detected strong synergies with VAN and nitrofurantoin (NIT) and with VAN and trimethoprim (TMP), and moderate synergies with other drugs, such as aminoglycosides. These synergies are powerful enough to show activity of VAN in wild-type E. coli at concentrations of VAN as low as 6.25 ?g/ml. This suggests that a very small percentage of exogenous VAN does enter E. coli, but normally has insignificant effects on growth inhibition or cell killing. We used the results of pair-wise interactions with VAN and the other 10 antibiotics tested to place VAN into a functional category of its own, as previously defined by Yeh, Tschumi and Kishony (1).
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Oesophageal perforation in a neonate during transoesophageal echocardiography for cardiac surgery.
Cardiol Young
PUBLISHED: 09-10-2014
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Oesophageal perforation is a rarely reported complication of transoesophageal echocardiography in infants. This case involves a 3.1-kg neonate with Trisomy 21, atrioventricular septal defect, and hypoplastic aortic arch undergoing aortic arch advancement and pulmonary artery banding. A paediatric transoesophageal echocardiography probe was placed intraoperatively causing a contained false passage from the oesophagus below the cricopharyngeus muscle with extension into the left posterior mediastinum. The perforation healed within 2 weeks without permanent sequelae after conservative medical management.
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Notch signaling at later stages of NK cell development enhances KIR expression and functional maturation.
J. Immunol.
PUBLISHED: 08-29-2014
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The Notch signaling pathway plays a substantial role in human NK cell development. However, the role of Notch on killer Ig-like receptor (KIR) upregulation and acquisition of effector function has not been explored. To evaluate how Notch influences terminal differentiation, cord blood-derived NK cells or sorted peripheral blood NK cells were cultured with IL-15 for 7 d with inhibitory or activating Notch signals. Inhibition of Notch signaling significantly decreased KIR expression, whereas activation enhanced it. Overexpression of activated Notch on cord blood-derived NK cells resulted in a 2-fold increase in KIR expression, indicating that Notch signaling plays a direct, cell-intrinsic role in KIR regulation. Moreover, Notch-mediated KIR expression on NK cells is regulated through cis inhibition by delta-like ligand 1. Notch signaling also enhances CD16 upregulation that precedes KIR expression. Concomitant with the upregulation of KIR and CD16, Notch signaling induces increased cytolytic effector capacity and cytokine secretion, even in posttransplant samples in which NK cell function is inherently defective. Given these attributes of Notch signaling, we propose that Notch agonists may enhance NK cell maturation and tumor killing in a posttransplant setting.
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Assignment of the oxidation states of Zr and Co in a highly reactive heterobimetallic Zr/Co complex using X-ray absorption spectroscopy (XANES).
Dalton Trans
PUBLISHED: 08-11-2014
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The reduced heterobimetallic complex (THF)Zr(MesNP(i)Pr2)3CoN2 (1) has been examined along with a series of structurally similar reference compounds using X-ray absorption near edge structure (XANES) spectroscopy. Complex 1 has been shown to be highly reactive, often via one-electron pathways that might be expected for a d(1) Zr(III) complex. However, the presence of two strongly interacting metals in complex 1 renders the assignment of oxidation states ambiguous. Both Zr and Co K-edge XANES spectra reveal that the most accurate description of complex 1 is that of a Zr(IV)/Co(-I) zwitterion. Electronic structure calculations support this assignment.
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Isolation of the Copper Redox Steps in the Standard Selective Catalytic Reduction on Cu-SSZ-13.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 07-09-2014
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Operando X-ray absorption experiments and density functional theory (DFT) calculations are reported that elucidate the role of copper redox chemistry in the selective catalytic reduction (SCR) of NO over Cu-exchanged SSZ-13. Catalysts prepared to contain only isolated, exchanged Cu(II) ions evidence both Cu(II) and Cu(I) ions under standard SCR conditions at 473?K. Reactant cutoff experiments show that NO and NH3 together are necessary for Cu(II) reduction to Cu(I) . DFT calculations show that NO-assisted NH3 dissociation is both energetically favorable and accounts for the observed Cu(II) reduction. The calculations predict in?situ generation of Brønsted sites proximal to Cu(I) upon reduction, which we quantify in separate titration experiments. Both NO and O2 are necessary for oxidation of Cu(I) to Cu(II) , which DFT suggests to occur by a NO2 intermediate. Reaction of Cu-bound NO2 with proximal NH4 (+) completes the catalytic cycle. N2 is produced in both reduction and oxidation half-cycles.
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Current challenges in health economic modeling of cancer therapies: a research inquiry.
Am Health Drug Benefits
PUBLISHED: 07-04-2014
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The demand for economic models that evaluate cancer treatments is increasing, as healthcare decision makers struggle for ways to manage their budgets while providing the best care possible to patients with cancer. Yet, after nearly 2 decades of cultivating and refining techniques for modeling the cost-effectiveness and budget impact of cancer therapies, serious methodologic and policy challenges have emerged that question the adequacy of economic modeling as a sound decision-making tool in oncology.
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Structure-kinetic relationship study of organozinc reagents.
Chem. Commun. (Camb.)
PUBLISHED: 06-25-2014
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Phenylzinc reagents prepared from various zinc halides show distinct kinetic features in the palladium-catalyzed Negishi-type oxidative coupling reaction, in which the phenylzinc reagent prepared from ZnI2 gives the highest rate. In situ infrared and X-ray absorption spectroscopy studies show that the higher reaction rate was observed for longer Zn-C bond distances.
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Adsorbate-induced structural changes in 1-3 nm platinum nanoparticles.
J. Am. Chem. Soc.
PUBLISHED: 06-24-2014
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We investigated changes in the Pt-Pt bond distance, particle size, crystallinity, and coordination of Pt nanoparticles as a function of particle size (1-3 nm) and adsorbate (H2, CO) using synchrotron radiation pair distribution function (PDF) and X-ray absorption spectroscopy (XAS) measurements. The ?1 nm Pt nanoparticles showed a Pt-Pt bond distance contraction of ?1.4%. The adsorption of H2 and CO at room temperature relaxed the Pt-Pt bond distance contraction to a value close to that of bulk fcc Pt. The adsorption of H2 improved the crystallinity of the small Pt nanoparticles. However, CO adsorption generated a more disordered fcc structure for the 1-3 nm Pt nanoparticles compared to the H2 adsorption Pt nanoparticles. In situ XANES measurements revealed that this disorder results from the electron back-donation of the Pt nanoparticles to CO, leading to a higher degree of rehybridization of the metal orbitals in the Pt-adsorbate system.
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NK cells in therapy of cancer.
Crit Rev Oncog
PUBLISHED: 06-19-2014
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Natural killer (NK) cells recognize targets stressed by malignant transformation or infection and can be long-lived. They become educated by interacting with major histocompatibility antigen (MHC) class I molecules to gain function to kill targets and produce cytokines. In the clinic, haploidentical NK cells can be adoptively transferred to treat cancer. Persistence and in vivo expansion of NK cells depends on lymphodepleting chemotherapy to make space and induce release of endogenous IL-15. In vivo expansion is also enhanced by cytokine administration but IL-2 has the down side of stimulating CD25hi regulatory T cells (Tregs). Other limitations to NK-cell therapy include poor in vivo survival and lack of specificity. Bispecific or trispecific killer engagers that target CD16 on NK cells to enhance recognition of tumor antigens, and desintegrin and metalloproteinase 17 (ADAM17) inhibition that prevents CD16 shedding after NK-cell activation should promote enhanced killing of cancer with specificity. These are exciting times; more than 35 years after NK cells were initially described, we are exploiting their capacity for clinical therapy.
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Low-temperature carbon monoxide oxidation catalysed by regenerable atomically dispersed palladium on alumina.
Nat Commun
PUBLISHED: 06-02-2014
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Catalysis by single isolated atoms of precious metals has attracted much recent interest, as it promises the ultimate in atom efficiency. Most previous reports are on reducible oxide supports. Here we show that isolated palladium atoms can be catalytically active on industrially relevant ?-alumina supports. The addition of lanthanum oxide to the alumina, long known for its ability to improve alumina stability, is found to also help in the stabilization of isolated palladium atoms. Aberration-corrected scanning transmission electron microscopy and operando X-ray absorption spectroscopy confirm the presence of intermingled palladium and lanthanum on the ?-alumina surface. Carbon monoxide oxidation reactivity measurements show onset of catalytic activity at 40 °C. The catalyst activity can be regenerated by oxidation at 700 °C in air. The high-temperature stability and regenerability of these ionic palladium species make this catalyst system of potential interest for low-temperature exhaust treatment catalysts.
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Transcriptional regulation of Munc13-4 expression in cytotoxic lymphocytes is disrupted by an intronic mutation associated with a primary immunodeficiency.
J. Exp. Med.
PUBLISHED: 05-19-2014
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Autosomal recessive mutations in UNC13D, the gene that encodes Munc13-4, are associated with familial hemophagocytic lymphohistiocytosis type 3 (FHL3). Munc13-4 expression is obligatory for exocytosis of lytic granules, facilitating cytotoxicity by T cells and natural killer (NK) cells. The mechanisms regulating Munc13-4 expression are unknown. Here, we report that Munc13-4 is highly expressed in differentiated human NK cells and effector CD8(+) T lymphocytes. A UNC13D c.118-308C>T mutation, causative of FHL3, disrupted binding of the ETS family member ELF1 to a conserved intronic sequence. This mutation impairs UNC13D intron 1 recruitment of STAT4 and the chromatin remodeling complex component BRG1, diminishing active histone modifications at the locus. The intronic sequence acted as an overall enhancer of Munc13-4 expression in cytotoxic lymphocytes in addition to representing an alternative promoter encoding a novel Munc13-4 isoform. Mechanistically, T cell receptor engagement facilitated STAT4-dependent Munc13-4 expression in naive CD8(+) T lymphocytes. Collectively, our data demonstrates how chromatin remodeling within an evolutionarily conserved regulatory element in intron 1 of UNC13D regulates the induction of Munc13-4 expression in cytotoxic lymphocytes and suggests that an alternative Munc13-4 isoform is required for lymphocyte cytotoxicity. Thus, mutations associated with primary immunodeficiencies may cause disease by disrupting transcription factor binding.
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Discovery of highly selective alkyne semihydrogenation catalysts based on first-row transition-metallated porous organic polymers.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 05-07-2014
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Five different first-row transition metal precursors (V(III) , Cr(III) , Mn(II) , Co(II) , Ni(II) ) were successfully incorporated into a catechol porous organic polymer (POP) and characterized using ATR-IR and XAS analysis. The resulting metallated POPs were then evaluated for catalytic alkyne hydrogenation using high-throughput screening techniques. All POPs were unexpectedly found to be active and selective catalysts for alkyne semihydrogenation. Three of the metallated POPs (V, Cr, Mn) are the first of their kind to be active single-site hydrogenation catalysts. These results highlight the advantages of using a POP platform to develop new catalysts which are otherwise difficult to achieve through traditional heterogeneous and homogeneous routes.
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Expansion and homing of adoptively transferred human natural killer cells in immunodeficient mice varies with product preparation and in vivo cytokine administration: implications for clinical therapy.
Biol. Blood Marrow Transplant.
PUBLISHED: 05-01-2014
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Natural killer (NK) cell efficacy correlates with in vivo proliferation, and we hypothesize that NK cell product manipulations may optimize this endpoint. Xenotransplantation was used to compare good manufacturing practice (GMP) grade freshly activated NK cells (FA-NK) and ex vivo expanded NK cells (Ex-NK). Cells were infused into NOD scid IL2 receptor gamma chain knockout (NSG) mice followed by IL-2, IL-15, or no cytokines. Evaluation of blood, spleen, and marrow showed that persistence and expansion was cytokine dependent, IL-15 being superior to IL-2. Cryopreservation and immediate infusion resulted in less cytotoxicity and fewer NK cells in vivo, and this could be rescued in FA-NK by overnight culture and testing the next day. Marked differences in the kinetics and homing of FA-NK versus Ex-NK were apparent: FA-NK cells preferentially homed to spleen and persisted longer after cytokine withdrawal. These data suggest that cryopreservation of FA-NK and Ex-NK is detrimental and that culture conditions profoundly affect homing, persistence, and expansion of NK cells in vivo. The NSG mouse model is an adjuvant to in vitro assays before clinical testing.
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Donor killer cell Ig-like receptor B haplotypes, recipient HLA-C1, and HLA-C mismatch enhance the clinical benefit of unrelated transplantation for acute myelogenous leukemia.
J. Immunol.
PUBLISHED: 04-18-2014
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Killer cell Ig-like receptors (KIRs) interact with HLA class I ligands to regulate NK cell development and function. These interactions affect the outcome of unrelated donor hematopoietic cell transplantation (HCT). We have shown previously that donors with KIR B versus KIR A haplotypes improve the clinical outcome for patients with acute myelogenous leukemia by reducing the incidence of leukemic relapse and improving leukemia-free survival (LFS). Both centromeric and telomeric KIR B genes contribute to the effect, but the centromeric genes are dominant. They include the genes encoding inhibitory KIRs that are specific for the C1 and C2 epitopes of HLA-C. We used an expanded cohort of 1532 T cell-replete transplants to examine the interaction between donor KIR B genes and recipient class I HLA KIR ligands. The relapse protection associated with donor KIR B is enhanced in recipients who have one or two C1-bearing HLA-C allotypes, compared with C2 homozygous recipients, with no effect due to donor HLA. The protective interaction between donors with two or more, versus none or one, KIR B motifs and recipient C1 was specific to transplants with class I mismatch at HLA-C (RR of leukemia-free survival, 0.57 [0.40-0.79]; p = 0.001) irrespective of the KIR ligand mismatch status of the transplant. The survival advantage and relapse protection in C1/x recipients compared with C2/C2 recipients was similar irrespective of the particular donor KIR B genes. Understanding the interactions between donor KIR and recipient HLA class I can be used to inform donor selection to improve outcome of unrelated donor hematopoietic cell transplantation for acute myelogenous leukemia.
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Clearance of acute myeloid leukemia by haploidentical natural killer cells is improved using IL-2 diphtheria toxin fusion protein.
Blood
PUBLISHED: 04-09-2014
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Haploidentical natural killer (NK) cell infusions can induce remissions in some patients with acute myeloid leukemia (AML) but regulatory T-cell (Treg) suppression may reduce efficacy. We treated 57 refractory AML patients with lymphodepleting cyclophosphamide and fludarabine followed by NK cell infusion and interleukin (IL)-2 administration. In 42 patients, donor NK cell expansion was detected in 10%, whereas in 15 patients receiving host Treg depletion with the IL-2-diphtheria fusion protein (IL2DT), the rate was 27%, with a median absolute count of 1000 NK cells/?L blood. IL2DT was associated with improved complete remission rates at day 28 (53% vs 21%; P = .02) and disease-free survival at 6 months (33% vs 5%; P < .01). In the IL2DT cohort, NK cell expansion correlated with higher postchemotherapy serum IL-15 levels (P = .002), effective peripheral blood Treg depletion (<5%) at day 7 (P < .01), and decreased IL-35 levels at day 14 (P = .02). In vitro assays demonstrated that Tregs cocultured with NK cells inhibit their proliferation by competition for IL-2 but not for IL-15. Together with our clinical observations, this supports the need to optimize the in vivo cytokine milieu where adoptively transferred NK cells compete with other lymphocytes to improve clinical efficacy in patients with refractory AML. This study is registered at clinicaltrials.gov, identifiers: NCT00274846 and NCT01106950.
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In vitro metabolism of 3,4-methylenedioxymethamphetamine in human hepatocytes.
J Anal Toxicol
PUBLISHED: 03-28-2014
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Users of the illicit drug, 3,4-methylenedioxymethamphetamine (MDMA), show signs of neurotoxicity. However, the precise mechanism of neurotoxicity caused by use of MDMA has not yet been elucidated. Synthetic glutathione (GSH) conjugates of MDMA are transported into the brain by the GSH transporter and subsequently produce neurotoxicity. The objective of this research is to show direct evidence of the formation of GSH adducts of MDMA in human hepatocytes. High-performance liquid chromatography coupled with tandem mass spectrometry was utilized to examine in vitro incubations of MDMA with cryopreserved human hepatocytes. The use of hydrophilic liquid chromatography in combination with linear ion trap mass spectrometry permitted the identification of two possible GSH metabolites. Enhanced product ion scans of m/z = 499 and 487 amu of extracts from hepatocytes treated with 1.0 mM MDMA show a distinct fragmentation pattern (m/z 194.2, 163, 135, 105), suggesting the formation of MDMA-GSH conjugate, MDMA-SG and 3,4-dihydroxymethamphetamine-SG. The formation of an MDMA-GSH conjugate was further supported by the apparent lack of the same fragmentation pattern from hepatocyte samples without MDMA treatment. The results generated from this study yield valuable qualitative and quantitative information about the neurotoxic thioether metabolites formed from MDMA in humans.
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Patient and procedural characteristics for successful and failed immediate tracheal extubation in the operating room following cardiac surgery in infancy.
Paediatr Anaesth
PUBLISHED: 03-26-2014
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Immediate extubation in the operating room after congenital heart surgery is practiced with rising frequency at many cardiac institutions to decrease costs and complications. Infants less than one year of age are also increasingly selected for this 'fast track'. However, factors for patient selection, success, or failure of this practice have not been well defined in this population, yet are critical for patient safety.
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CD16xCD33 bispecific killer cell engager (BiKE) activates NK cells against primary MDS and MDSC CD33+ targets.
Blood
PUBLISHED: 03-20-2014
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Myelodysplastic syndromes (MDS) are stem cell disorders that can progress to acute myeloid leukemia. Although hematopoietic cell transplantation can be curative, additional therapies are needed for a disease that disproportionally afflicts the elderly. We tested the ability of a CD16xCD33 BiKE to induce natural killer (NK) cell function in 67 MDS patients. Compared with age-matched normal controls, CD7(+) lymphocytes, NK cells, and CD16 expression were markedly decreased in MDS patients. Despite this, reverse antibody-dependent cell-mediated cytotoxicity assays showed potent degranulation and cytokine production when resting MDS-NK cells were triggered with an agonistic CD16 monoclonal antibody. Blood and marrow MDS-NK cells treated with bispecific killer cell engager (BiKE) significantly enhanced degranulation and tumor necrosis factor-? and interferon-? production against HL-60 and endogenous CD33(+) MDS targets. MDS patients had a significantly increased proportion of immunosuppressive CD33(+) myeloid-derived suppressor cells (MDSCs) that negatively correlated with MDS lymphocyte populations and CD16 loss on NK cells. Treatment with the CD16xCD33 BiKE successfully reversed MDSC immunosuppression of NK cells and induced MDSC target cell lysis. Lastly, the BiKE induced optimal MDS-NK cell function irrespective of disease stage. Our data suggest that the CD16xCD33 BiKE functions against both CD33(+) MDS and MDSC targets and may be therapeutically beneficial for MDS patients.
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Functional NK cell repertoires are maintained through IL-2R? and Fas ligand.
J. Immunol.
PUBLISHED: 03-14-2014
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Acquisition of a functional NK cell repertoire, known as education or licensing, is a complex process mediated through inhibitory receptors that recognize self. We found that NK cells containing self-killer Ig-like receptors for cognate HLA ligand in vivo were less susceptible to apoptosis. In vitro IL-15 withdrawal showed that uneducated NK cells upregulated Bim and Fas. Conversely, educated NK cells upregulated Fas ligand (FasL) under these conditions. Induction of cell death and Bim expression on uneducated cells correlated with increased IL-2R? expression. Overexpression and knockdown studies showed that higher IL-2R? limits NK cell survival in a novel manner that is independent from the role of IL-2 in activation-induced cell death. To study the role of FasL in induction of IL-2R?(hi) NK cell death, a coculture assay with FasL-blocking Abs was used. IL-15 withdrawal led to FasL-dependent killing of IL-2R?(hi) NK cells by more educated IL-2R?(lo) NK cells. Finally, CMV reactivation induces a potent long-lasting population of licensed NK cells with enhanced survival. These findings show that education-dependent NK cell survival advantages and killing of uneducated NK cells result in the maintenance of a functional repertoire, which may be manipulated to exploit NK cells for cancer immunotherapy.
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Deoxycytidine deaminase-deficient Escherichia coli strains display acute sensitivity to cytidine, adenosine, and guanosine and increased sensitivity to a range of antibiotics, including vancomycin.
J. Bacteriol.
PUBLISHED: 03-14-2014
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We show here that deoxycytidine deaminase (DCD)-deficient mutants of Escherichia coli are hypersensitive to killing by exogenous cytidine, adenosine, or guanosine, whereas wild-type cells are not. This hypersensitivity is reversed by exogenous thymidine. The mechanism likely involves the allosteric regulation of ribonucleotide reductase and severe limitations of the dTTP pools, resulting in thymineless death, the phenomenon of cell death due to thymidine starvation. We also report here that DCD-deficient mutants of E. coli are more sensitive to a series of different antibiotics, including vancomycin, and we show synergistic killing with the combination of vancomycin and cytidine. One possibility is that a very low, subinhibitory concentration of vancomycin enters Gram-negative cells and that this concentration is potentiated by chromosomal lesions resulting from the thymineless state. A second possibility is that the metabolic imbalance resulting from DCD deficiency affects the assembly of the outer membrane, which normally presents a barrier to drugs such as vancomycin. We consider these findings with regard to ideas of rendering Gram-negative bacteria sensitive to drugs such as vancomycin.
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A therapeutic trial of decitabine and vorinostat in combination with chemotherapy for relapsed/refractory acute lymphoblastic leukemia.
Am. J. Hematol.
PUBLISHED: 03-06-2014
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DNA hypermethylation and histone deacetylation are pathways of leukemia resistance. We investigated the tolerability and efficacy of decitabine and vorinostat plus chemotherapy in relapse/refractory acute lymphoblastic leukemia (ALL). Decitabine (15 mg/m(2) iv) and vorinostat (230 mg/m(2) PO div BID) were given days 1-4 followed by vincristine, prednisone, PEG-asparaginase, and doxorubicin. Genome wide methylation profiles were performed in 8 matched patient bone marrow (BM) samples taken at day 0 and day 5 (postdecitabine). The median age was 16 (range, 3-54) years. All patients had a prior BM relapse, with five relapsing after allogeneic transplant. The most common nonhematological toxicities possibly related to decitabine or vorinostat were infection with neutropenia (grade 3; n?=?4) and fever/neutropenia (grade 3, n?=?4; grade 4, n?=?1). Of the 13 eligible patients, four achieved complete remission without platelet recovery (CRp), two partial response (PR), one stable disease (SD), one progressive disease (PD), two deaths on study and three patients who did not have end of therapy disease evaluations for an overall response rate of 46.2% (CRp?+?PR). Following decitabine, significant genome-wide hypo-methylation was observed. Comparison of clinical responders with nonresponders identified methylation profiles of clinical and biological relevance. Decitabine and vorinostat followed by re-Induction chemotherapy was tolerable and demonstrated clinical benefit in relapsed patients with ALL. Methylation differences were identified between responders and nonresponders indicating interpatient variation, which could impact clinical outcome. This study was registered at www.clinicaltrials.gov as NCT00882206.
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The biology of NK cells and their receptors affects clinical outcomes after hematopoietic cell transplantation (HCT).
Immunol. Rev.
PUBLISHED: 02-13-2014
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Natural killer (NK) cells were first identified for their capacity to reject bone marrow allografts in lethally irradiated mice without prior sensitization. Subsequently, human NK cells were detected and defined by their non-major histocompatibility complex (MHC)-restricted cytotoxicity toward transformed or virally infected target cells. Karre et al. later proposed 'the missing self hypothesis' to explain the mechanism by which self-tolerant cells could kill targets that had lost self MHC class I. Subsequently, the receptors that recognize MHC class I to mediate tolerance in the host were identified on NK cells. These class I-recognizing receptors contribute to the acquisition of function by a dynamic process known as NK cell education or licensing. In the past, NK cells were assumed to be short lived, but more recently NK cells have been shown to mediate immunologic memory to secondary exposures to cytomegalovirus infection. Because of their ability to lyse tumors with aberrant MHC class I expression and to produce cytokines and chemokines upon activation, NK cells may be primed by many stimuli, including viruses and inflammation, to contribute to a graft-versus-tumor effect. In addition, interactions with other immune cells support the therapeutic potential of NK cells to eradicate tumor and to enhance outcomes after hematopoietic cell transplantation.
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In situ optical and structural studies on photoluminesence quenching in CdSe/CdS/Au heterostructures.
J. Am. Chem. Soc.
PUBLISHED: 02-03-2014
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We report here detailed in situ studies of nucleation and growth of Au on CdSe/CdS nanorods using synchrotron SAXS technique and time-resolved spectroscopy. We examine structural and optical properties of CdSe/CdS/Au heterostructures formed under UV illumination. We compare the results for CdSe/CdS/Au heterostructures with the results of control experiments on CdSe/CdS nanorods exposed to gold precursor under conditions when no such heterostructures are formed (no UV illumination). Our data indicate similar photoluminescence (PL) quenching and PL decay profiles in both types of samples. Via transient absorption and PL, we show that such behavior is consistent with rapid (faster than 3 ps) hole trapping by gold-sulfur sites at the surface of semiconductor nanoparticles. This dominant process was overlooked in previous end-point studies on semiconductor/metal heterostructures.
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Clinical utility of natural killer cells in cancer therapy and transplantation.
Semin. Immunol.
PUBLISHED: 01-22-2014
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Natural killer (NK) cells recognize deranged cells that display stress receptors or loss of major histocompatibility complex (MHC) class I. During development, NK cells become "licensed" only after they encounter cognate human leukocyte antigen (HLA) class I, leading to the acquisition of effector function. NK cells can be exploited for cancer therapy in several ways. These include targeting with monoclonal antibodies alone or combined with ex vivo and in vivo NK cell activation to facilitate adoptive immunotherapy using donor-derived NK cell products to induce graft-vs-tumor effects. In the adoptive transfer setting, persistence and in vivo expansion requires lymphodepleting chemotherapy to prevent rejection and provide homeostatic cytokines (such as IL-15) that activate NK cells. IL-15 has the advantage of avoiding regulatory T-cell expansion. Clinical applications are currently being tested. To enhance in vivo expansion, IL-2 has been used at low doses. However, low dose administration also leads to the stimulation of regulatory T cells. Monoclonal antibodies and bispecific killer engagers (BiKEs) may enhance specificity by targeting CD16 on NK cells to tumor antigens. Inhibition of CD16 shedding may also promote enhanced cytotoxicity. Future strategies include exploiting favorable donor immunogenetics or ex vivo expansion of NK cells from blood, progenitors, or pluripotent cells. Comparative clinical trials are needed to test these approaches.
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Direct observation of reduction of Cu(II) to Cu(I) by terminal alkynes.
J. Am. Chem. Soc.
PUBLISHED: 01-10-2014
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X-ray absorption spectroscopy and in situ electron paramagnetic resonance evidence were provided for the reduction of Cu(II) to Cu(I) species by alkynes in the presence of tetramethylethylenediamine (TMEDA), in which TMEDA plays dual roles as both ligand and base. The structures of the starting Cu(II) species and the obtained Cu(I) species were determined as (TMEDA)CuCl2 and [(TMEDA)CuCl]2 dimer, respectively.
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Retrospective database analysis of clinical outcomes and costs for treatment of abnormal uterine bleeding among women enrolled in US Medicaid programs.
Clinicoecon Outcomes Res
PUBLISHED: 01-01-2014
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Women with abnormal uterine bleeding (AUB) may be treated surgically with hysterectomy or global endometrial ablation (GEA), an outpatient procedure. We compared the costs and clinical outcomes of these surgical procedures for AUB among women in Medicaid programs.
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Cost-effectiveness of Telaprevir combination therapy for chronic hepatitis C.
PLoS ONE
PUBLISHED: 01-01-2014
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To explore the expected long-term health and economic outcomes of telaprevir (TVR) plus peginterferon alfa-2a and ribavirin (PR), a regimen that demonstrated substantially increased sustained virologic response (SVR) compared with PR alone in adults with chronic genotype 1 hepatitis C virus (HCV) and compensated liver disease in the Phase III studies ADVANCE (treatment-naïve patients) and REALIZE (relapsers, partial responders, and null responders to previous PR treatment).
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Millifluidics for Chemical Synthesis and Time-resolved Mechanistic Studies.
J Vis Exp
PUBLISHED: 12-12-2013
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Procedures utilizing millifluidic devices for chemical synthesis and time-resolved mechanistic studies are described by taking three examples. In the first, synthesis of ultra-small copper nanoclusters is described. The second example provides their utility for investigating time resolved kinetics of chemical reactions by analyzing gold nanoparticle formation using in situ X-ray absorption spectroscopy. The final example demonstrates continuous flow catalysis of reactions inside millifluidic channel coated with nanostructured catalyst.
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Therapeutic applications: natural killer cells in the clinic.
Hematology Am Soc Hematol Educ Program
PUBLISHED: 12-10-2013
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Natural killer (NK) cells recognize targets stressed by malignant transformation or infection (particularly CMV). We now know that NK cells can be long-lived and remember past exposures. They become educated by interaction with MHC class I molecules to gain potent function to kill targets and produce cytokines. In the clinical setting, haploidentical NK cells can be transferred adoptively to treat cancer. Persistence and in vivo expansion of NK cells depends on lymphodepleting chemotherapy to make space for the release of endogenous IL-15. In vivo expansion is also enhanced by cytokine administration. IL-2 has been used at low doses to stimulate NK cells in vivo, but has the down side of stimulating CD25(hi) regulatory T cells. IL-15 is now being tested and has the advantage of avoiding inhibitory regulatory T cell stimulation. In refractory acute myeloid leukemia, leukemia clearance is correlated with the persistence and in vivo expansion of NK cells after adoptive transfer. Limitations to NK cell therapy include poor in vivo survival and lack of specificity. Monoclonal antibodies and bispecific or trispecific killer engagers to target CD16 on NK cells to enhance recognition of various tumor antigens and ADAM17 inhibition to prevent CD16 shedding after NK cell activation should promote enhanced killing of cancer with specificity. Future strategies to exploit favorable donor immunogenetics or to expand NK cells ex vivo from blood, progenitors, or pluripotent progenitors may overcome immune barriers of adoptive transfer and comparative clinical trials will be needed to test these approaches.
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Robust ZFN-mediated genome editing in adult hemophilic mice.
Blood
PUBLISHED: 10-01-2013
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Monogenic diseases, including hemophilia, represent ideal targets for genome-editing approaches aimed at correcting a defective gene. Here we report that systemic adeno-associated virus (AAV) vector delivery of zinc finger nucleases (ZFNs) and corrective donor template to the predominantly quiescent livers of adult mice enables production of high levels of human factor IX in a murine model of hemophilia B. Further, we show that off-target cleavage can be substantially reduced while maintaining robust editing by using obligate heterodimeric ZFNs engineered to minimize unwanted cleavage attributable to homodimerization of the ZFNs. These results broaden the therapeutic potential of AAV/ZFN-mediated genome editing in the liver and could expand this strategy to other nonreplicating cell types.
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Stabilization of copper catalysts for liquid-phase reactions by atomic layer deposition.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 09-19-2013
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Atomic layer deposition (ALD) of an alumina overcoat can stabilize a base metal catalyst (e.g., copper) for liquid-phase catalytic reactions (e.g., hydrogenation of biomass-derived furfural in alcoholic solvents or water), thereby eliminating the deactivation of conventional catalysts by sintering and leaching. This method of catalyst stabilization alleviates the need to employ precious metals (e.g., platinum) in liquid-phase catalytic processing. The alumina overcoat initially covers the catalyst surface completely. By using solid state NMR spectroscopy, X-ray diffraction, and electron microscopy, it was shown that high temperature treatment opens porosity in the overcoat by forming crystallites of ?-Al2 O3 . Infrared spectroscopic measurements and scanning tunneling microscopy studies of trimethylaluminum ALD on copper show that the remarkable stability imparted to the nanoparticles arises from selective armoring of under-coordinated copper atoms on the nanoparticle surface.
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A Reusable Unsupported Rhenium Nanocrystalline Catalyst for Acceptorless Dehydrogenation of Alcohols through ?-C-H Activation.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 08-31-2013
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Rhenium nanocrystalline particles (Re NPs), of 2 nm size, were prepared from NH4 ReO4 under mild conditions in neat alcohol. The unsupported Re NPs convert secondary and benzylic alcohols to ketones and aldehydes, respectively, through catalytic acceptorless dehydrogenation (AD). The oxidant- and acceptor-free neat dehydrogenation of alcohols to obtain dihydrogen gas is a green and atom-economical process for making carbonyl compounds. Secondary aliphatic alcohols give quantitative conversion and yield. Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Re K-edge X-ray absorption near-edge structure (XANES), and X-ray absorption fine structure (EXAFS) data confirmed the characterization of the Re NPs as metallic rhenium with surface oxidation to rhenium(IV) oxide (ReO2 ). Isotope labeling experiments revealed a novel ?-CH activation mechanism for AD of alcohols.
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Proceedings from the National Cancer Institutes Second International Workshop on the Biology, Prevention, and Treatment of Relapse after Hematopoietic Stem Cell Transplantation: Part I. Biology of relapse after transplantation.
Biol. Blood Marrow Transplant.
PUBLISHED: 08-24-2013
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In the National Cancer Institutes Second Workshop on the Biology, Prevention, and Treatment of Relapse after Hematopoietic Stem Cell Transplantation, the Scientific/Educational Session on the Biology of Relapse discussed recent advances in understanding some of the host-, disease-, and transplantation-related contributions to relapse, emphasizing concepts with potential therapeutic implications. Relapse after hematopoietic stem cell transplantation (HSCT) represents tumor escape, from the cytotoxic effects of the conditioning regimen and from immunologic control mediated by reconstituted lymphocyte populations. Factors influencing the biology of the therapeutic graft-versus-malignancy (GVM) effect-and relapse-include conditioning regimen effects on lymphocyte populations and homeostasis, immunologic niches, and the tumor microenvironment; reconstitution of lymphocyte populations and establishment of functional immune competence; and genetic heterogeneity within the malignancy defining potential for clonal escape. Recent developments in T cell and natural killer cell homeostasis and reconstitution are reviewed, with implications for prevention and treatment of relapse, as is the application of modern genome sequencing to defining the biologic basis of GVM, clonal escape, and relapse after HSCT.
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Upper body central venous catheters in pediatric cardiac surgery.
Paediatr Anaesth
PUBLISHED: 08-20-2013
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A central venous catheter located in the jugular or subclavian vein provides rapid, reliable vascular access for pediatric heart surgery. However, intravascular catheters are associated with vessel injury. Stenosis or thrombosis of central veins in the upper body can lead to superior vena cava syndrome with markedly elevated venous pressures in the head and neck, causing facial swelling and headaches. This complication may be especially serious for patients with superior cavopulmonary (Glenn) or total cavopulmonary (Fontan) circulation. The authors hypothesized that upper body central line placement would be associated with a low risk of venous thrombosis or stenosis.
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Synthesis of porous carbon supported palladium nanoparticle catalysts by atomic layer deposition: application for rechargeable lithium-O2 battery.
Nano Lett.
PUBLISHED: 08-14-2013
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In this study, atomic layer deposition (ALD) was used to deposit nanostructured palladium on porous carbon as the cathode material for Li-O2 cells. Scanning transmission electron microscopy showed discrete crystalline nanoparticles decorating the surface of the porous carbon support, where the size could be controlled in the range of 2-8 nm and depended on the number of Pd ALD cycles performed. X-ray absorption spectroscopy at the Pd K-edge revealed that the carbon supported Pd existed in a mixed phase of metallic palladium and palladium oxide. The conformality of ALD allowed us to uniformly disperse the Pd catalyst onto the carbon support while preserving the initial porous structure. As a result, the charging and discharging performance of the oxygen cathode in a Li-O2 cell was improved. Our results suggest that ALD is a promising technique for tailoring the surface composition and structure of nanoporous supports in energy storage devices.
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A review of childhood and adolescent craniopharyngiomas with particular attention to hypothalamic obesity.
Pediatr. Neurol.
PUBLISHED: 06-28-2013
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Although craniopharyngiomas are considered "benign" neoplasms by the World Health Organization classification, these tumors may create significant morbidity and mortality in patients. Hypothalamic obesity is a frequent complication of craniopharyngiomas and is refractory to current management options.
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Comparison of x-ray films and low-dose computed tomographic scans: demonstration of asbestos-related changes in 2760 nuclear weapons workers screened for lung cancer.
J. Occup. Environ. Med.
PUBLISHED: 06-22-2013
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Increased availability and technical improvements of computed tomographic (CT) scanning encourages its use for detecting asbestos-related disease. We compared low-dose scans and x-ray films in 2760 workers potentially exposed to asbestos, to assess their ability to detect interstitial lung disease (ILD) and pleural thickening (PT).
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Isolation and characterization of canine natural killer cells.
Vet. Immunol. Immunopathol.
PUBLISHED: 06-14-2013
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NK cells are non-T, non-B lymphocytes that kill target cells without previous activation. The immunophenotype and function of these cells in humans and mice are well defined, but canine NK cells remain incompletely characterized. Our objectives were to isolate and culture canine peripheral blood NK cells, and to define their immunophenotype and killing capability. PBMC were obtained from healthy dogs and T cells were depleted by immunomagnetic separation. The residual cells were cultured in media supplemented with IL-2, IL-15 or both, or with mouse embryonic liver (EL) feeder cells. Non-T, non-B lymphocytes survived and expanded in these cultures. IL-2 was necessary and sufficient for survival; the addition of IL-15 was necessary for expansion, but IL-15 alone did not support survival. Culture with EL cells and IL-2 also fostered survival and expansion. The non-T, non-B lymphocytes uniformly expressed CD45, MHC I, and showed significant cytotoxic activity against CTAC targets. Expression of MHC II, CD11/18 was restricted to subsets of these cells. The data show that cells meeting the criteria for NK cells in other species, i.e., non-T, non-B lymphocytes with cytotoxic activity, can be expanded from canine PBMC by T-cell depletion and culture with cytokines or feeder cells.
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Toward eliminating HLA class I expression to generate universal cells from allogeneic donors.
Blood
PUBLISHED: 06-05-2013
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Long-term engraftment of allogeneic cells necessitates eluding immune-mediated rejection, which is currently achieved by matching for human leukocyte antigen (HLA) expression, immunosuppression, and/or delivery of donor-derived cells to sanctuary sites. Genetic engineering provides an alternative approach to avoid clearance of cells that are recognized as "non-self" by the recipient. To this end, we developed designer zinc finger nucleases and employed a "hit-and-run" approach to genetic editing for selective elimination of HLA expression. Electro-transfer of mRNA species coding for these engineered nucleases completely disrupted expression of HLA-A on human T cells, including CD19-specific T cells. The HLA-A(neg) T-cell pools can be enriched and evade lysis by HLA-restricted cytotoxic T-cell clones. Recognition by natural killer cells of cells that had lost HLA expression was circumvented by enforced expression of nonclassical HLA molecules. Furthermore, we demonstrate that zinc finger nucleases can eliminate HLA-A expression from embryonic stem cells, which broadens the applicability of this strategy beyond infusing HLA-disparate immune cells. These findings establish that clinically appealing cell types derived from donors with disparate HLA expression can be genetically edited to evade an immune response and provide a foundation whereby cells from a single donor can be administered to multiple recipients.
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Targeting natural killer cells to acute myeloid leukemia in vitro with a CD16 x 33 bispecific killer cell engager and ADAM17 inhibition.
Clin. Cancer Res.
PUBLISHED: 05-20-2013
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The graft versus leukemia effect by natural killer (NK) cells prevents relapse following hematopoietic stem cell transplantation. We determined whether a novel bispecific killer cell engager (BiKE) signaling through CD16 and targeting CD33 could activate NK cells at high potency against acute myelogenous leukemia (AML) targets.
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Prevention of Graft-versus-Host Disease by Adoptive T Regulatory Therapy Is Associated with Active Repression of Peripheral Blood Toll-Like Receptor 5 mRNA Expression.
Biol. Blood Marrow Transplant.
PUBLISHED: 05-12-2013
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Acute graft-versus-host disease (GVHD) occurs in 40% to 60% of recipients of partially matched umbilical cord blood transplantation (UCBT). In a phase I study, adoptive transfer of expanded CD4(+)CD25(+)Foxp3(+) natural regulatory T cells (nTregs) resulted in a reduced incidence of grade II-IV acute GVHD. To investigate potential mechanisms responsible for the reduced GVHD risk, we analyzed peripheral blood mononuclear cell mRNA expression of a tolerance gene set previously identified in operation- tolerant kidney transplant recipients, comparing healthy controls and patients who received nTregs and those who did not receive nTregs with and without experiencing GVHD. Samples from patients receiving nTregs regardless of GVHD status showed increased expression of Foxp3 expression, as well as B cell-related tolerance marker. This was correlated with early B cell recovery, predominately of naïve B cells, and nearly normal T cell reconstitution. CD8(+) T cells showed reduced signs of activation (HLA-DR(+) expression) compared with conventionally treated patients developing GVHD. In contrast, patients with GVHD had significantly increased TLR5 mRNA expression, whereas nTreg-treated patients without GVHD had reduced TLR5 mRNA expression. We identified Lin(-)HLADR(-)CD33(+)CD16(+) cells and CD14(++)CD16(-) monocytes as the main TLR5 producers, especially in samples of conventionally treated patients developing GVHD. Taken together, these data reveal interesting similarities and differences between tolerant organ and nTreg-treated hematopoietic stem cell transplantation recipients.
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Multitissue molecular, genomic, and developmental effects of the Deepwater Horizon oil spill on resident Gulf killifish (Fundulus grandis).
Environ. Sci. Technol.
PUBLISHED: 05-09-2013
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The Deepwater Horizon oil rig disaster resulted in crude oil contamination along the Gulf coast in sensitive estuaries. Toxicity from exposure to crude oil can affect populations of fish that live or breed in oiled habitats as seen following the Exxon Valdez oil spill. In an ongoing study of the effects of Deepwater Horizon crude oil on fish, Gulf killifish ( Fundulus grandis ) were collected from an oiled site (Grande Terre, LA) and two reference locations (coastal MS and AL) and monitored for measures of exposure to crude oil. Killifish collected from Grande Terre had divergent gene expression in the liver and gill tissue coincident with the arrival of contaminating oil and up-regulation of cytochrome P4501A (CYP1A) protein in gill, liver, intestine, and head kidney for over one year following peak landfall of oil (August 2011) compared to fish collected from reference sites. Furthermore, laboratory exposures of Gulf killifish embryos to field-collected sediments from Grande Terre and Barataria Bay, LA, also resulted in increased CYP1A and developmental abnormalities when exposed to sediments collected from oiled sites compared to exposure to sediments collected from a reference site. These data are predictive of population-level impacts in fish exposed to sediments from oiled locations along the Gulf of Mexico coast.
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Heterodimeric Bispecific Single-Chain Variable-Fragment Antibodies Against EpCAM and CD16 Induce Effective Antibody-Dependent Cellular Cytotoxicity Against Human Carcinoma Cells.
Cancer Biother. Radiopharm.
PUBLISHED: 04-23-2013
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Abstract A heterodimeric bispecific biological recombinant drug was synthesized by splicing DNA fragments from two fully humanized single-chain variable-fragment (scFV) antibody fragments forming a novel drug simultaneously recognizing the CD16 natural killer (NK) cell marker and the cancer marker epithelial cell adhesion molecule (EpCAM). The drug precipitously enhanced the killing of human carcinomas of the prostate, breast, colon, head, and neck even at very low effector:target ratios. The drug EpCAM16 rendered even nonactivated NK cell-proficient killers and activated them to kill via degranulation and cytokine production. Studies show that bispecific antibodies can be used to induce proficient killing of the carcinoma targets that ordinarily are resistant to NK-mediated killing. Apparently, the innate immune system can be effectively recruited to kill cancer cells using the bispecific antibody platform and EpCAM targeting.
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Synthesis and electrochemical reactivity of molybdenum dicarbonyl supported by a redox-active ?-diimine ligand.
Inorg Chem
PUBLISHED: 04-11-2013
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Low-valent molybdenum dicarbonyl complexes with a diazabutadiene [(mes)DAB(R); [ArN?C(R)C(R)?NAr]; Ar = 2,4,6-trimethylphenyl (mes), R = H or CH3] ligand have been synthesized and fully characterized. The title complexes exhibit elongated DAB C-N and shortened C-C bond lengths over the free ligand and other zerovalent molybdenum complexes of DAB. Compared to known examples theoretically described as iminato ?-radicals (L(•-)), the oxidation state assignment fits a molybdenum(II) description. However, Mo K-edge X-ray absorption spectroscopy indicates that the complexes are best described as molybdenum(0). This example demonstrates that caution should be exercised in assigning the oxidation state based on structural parameters alone. Cyclic voltammetry studies reveal an electrochemical-chemical process that has been identified by in situ Fourier transform infrared spectroelectrochemistry as cis-to-trans isomerization.
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A case of inflammatory nonscarring alopecia associated with the tyrosine kinase inhibitor nilotinib.
JAMA Dermatol
PUBLISHED: 04-05-2013
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Nilotinib, a recently approved multitargeted tyrosine kinase inhibitor targeting the BCR-Abl translocation involved in chronic myelogenous leukemia, reportedly produces alopecia according to the package insert, but clinical and histologic descriptions of the alopecia are lacking.
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Influence of the metal (Al, Cr, and Co) and substituents of the porphyrin in controlling reactions involved in copolymerization of propylene oxide and carbon dioxide by porphyrin metal(III) complexes. 3. Cobalt chemistry.
Inorg Chem
PUBLISHED: 04-04-2013
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A series of cobalt(III) complexes LCoX, where L = 5,10,15,20-tetraphenylporphyrin (TPP), 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (TFPP), and 2,3,7,8,12,13,17,18-octaethylporphyirn (OEP) and X = Cl or acetate, has been investigated for homopolymerization of propylene oxide (PO) and copolymerization of PO and CO2 to yield polypropylene oxide (PPO) and polypropylene carbonate (PPC) or propylene carbonate (PC), respectively. These reactions were carried out both with and without the presence of a cocatalyst, namely, 4-dimethylaminopyridine (DMAP) or PPN(+)Cl(-) (bis(triphenylphosphine)iminium chloride). The PO/CO2 copolymerization process is notably faster than PO homopolymerization. With ionic PPN(+)Cl(-) cocatalyst the TPPCoOAc catalyst system grows two chains per Co center and the presence of excess [Cl(-)] facilitates formation of PC by two different backbiting mechanisms during copolymerization. Formation of PPC is dependent on both [Cl(-)] and the CO2 pressure employed (1-50 bar). TPPCoCl and PO react to form TPPCo(II) and ClCH2CH(Me)OH, while with DMAP, TPPCoCl yields TPPCo(DMAP)2(+)Cl(-). The reactions and their polymers and other products have been monitored by various methods including react-IR, FT-IR, GPC, ESI, MALDI TOF, EXAFS, and NMR ((1)H, (13)C{(1)H}) spectroscopy. Notable differences are seen in these reactions with previous studies of (porphyrin)M(III) complexes (M = Al, Cr) and of the (salen)M(III) complexes where M = Cr, Co.
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Double-blind, randomized study evaluating the glycemic and anti-inflammatory effects of subcutaneous LY2189102, a neutralizing IL-1? antibody, in patients with type 2 diabetes.
Diabetes Care
PUBLISHED: 03-20-2013
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Inflammation is associated with pancreatic ?-cell apoptosis and reduced insulin sensitivity. Literature suggests that interleukin (IL)-1? may contribute to the pathogenesis of type 2 diabetes mellitus (T2DM). This study aimed to determine the efficacy, safety, and tolerability of LY2189102, a neutralizing IL-1? antibody, in T2DM patients.
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Ligand-stabilized and atomically precise gold nanocluster catalysis: a case study for correlating fundamental electronic properties with catalysis.
Chemistry
PUBLISHED: 02-15-2013
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We present results from our investigations into correlating the styrene-oxidation catalysis of atomically precise mixed-ligand biicosahedral-structure [Au25(PPh3)10(SC12H25)5Cl2](2+) (Au25-bi) and thiol-stabilized icosahedral core-shell-structure [Au25(SCH2CH2Ph)18](-) (Au25-i) clusters with their electronic and atomic structure by using a combination of synchrotron radiation-based X-ray absorption fine-structure spectroscopy (XAFS) and ultraviolet photoemission spectroscopy (UPS). Compared to bulk Au, XAFS revealed low Au-Au coordination, Au-Au bond contraction and higher d-band vacancies in both the ligand-stabilized Au clusters. The ligands were found not only to act as colloidal stabilizers, but also as d-band electron acceptor for Au atoms. Au25-bi clusters have a higher first-shell Au coordination number than Au25-i, whereas Au25-bi and Au25-i clusters have the same number of Au atoms. The UPS revealed a trend of narrower d-band width, with apparent d-band spin-orbit splitting and higher binding energy of d-band center position for Au25-bi and Au25-i. We propose that the differences in their d-band unoccupied state population are likely to be responsible for differences in their catalytic activity and selectivity. The findings reported herein help to understand the catalysis of atomically precise ligand-stabilized metal clusters by correlating their atomic or electronic properties with catalytic activity.
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Epigenetic regulation of NK cell differentiation and effector functions.
Front Immunol
PUBLISHED: 02-11-2013
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Upon maturation, natural killer (NK) cells acquire effector functions and regulatory receptors. New insights suggest a considerable functional heterogeneity and dynamic regulation of receptor expression in mature human NK cell subsets based on different developmental axes. Such processes include acquisition of lytic granules as well as regulation of cytokine production in response to exogenous cytokine stimulation or target cell interactions. One axis is regulated by expression of inhibitory receptors for self-MHC class I molecules, whereas other axes are less well defined but likely are driven by different activating receptor engagements or cytokines. Moreover, the recent identification of long-lived NK cell subsets in mice that are able to expand and respond rapidly following a secondary viral challenge suggest previously unappreciated plasticity in the programming of NK cell differentiation. Here, we review advances in our understanding of mature NK cell development and plasticity with regards to regulation of cellular function. Furthermore, we highlight some of the major questions that remain pertaining to the epigenetic changes that underlie the differentiation and functional specialization of NK cells and the regulation of their responses.
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Hypothesis driven single nucleotide polymorphism search (HyDn-SNP-S).
DNA Repair (Amst.)
PUBLISHED: 02-08-2013
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The advent of complete-genome genotyping across phenotype cohorts has provided a rich source of information for bioinformaticians. However the search for SNPs from this data is generally performed on a study-by-study case without any specific hypothesis of the location for SNPs that are predictive for the phenotype. We have designed a method whereby very large SNP lists (several gigabytes in size), combining several genotyping studies at once, can be sorted and traced back to their ultimate consequence in protein structure. Given a working hypothesis, researchers are able to easily search whole genome genotyping data for SNPs that link genetic locations to phenotypes. This allows a targeted search for correlations between phenotypes and potentially relevant systems, rather than utilizing statistical methods only. HyDn-SNP-S returns results that are less data dense, allowing more thorough analysis, including haplotype analysis. We have applied our method to correlate DNA polymerases to cancer phenotypes using four of the available cancer databases in dbGaP. Logistic regression and derived haplotype analysis indicates that ~80SNPs, previously overlooked, are statistically significant. Derived haplotypes from this work link POLL to breast cancer and POLG to prostate cancer with an increase in incidence of 3.01- and 9.6-fold, respectively. Molecular dynamics simulations on wild-type and one of the SNP mutants from the haplotype of POLL provide insights at the atomic level on the functional impact of this cancer related SNP. Furthermore, HyDn-SNP-S has been designed to allow application to any system. The program is available upon request from the authors.
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In vivo assessment of absorbable knotless barbed suture for single layer gastrotomy and enterotomy closure.
Vet Surg
PUBLISHED: 02-01-2013
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To compare the performance of an absorbable barbed suture device to absorbable monofilament suture after single layer, appositional gastrotomy and enterotomy closure.
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An Arabidopsis cell wall proteoglycan consists of pectin and arabinoxylan covalently linked to an arabinogalactan protein.
Plant Cell
PUBLISHED: 01-31-2013
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Plant cell walls are comprised largely of the polysaccharides cellulose, hemicellulose, and pectin, along with ?10% protein and up to 40% lignin. These wall polymers interact covalently and noncovalently to form the functional cell wall. Characterized cross-links in the wall include covalent linkages between wall glycoprotein extensins between rhamnogalacturonan II monomer domains and between polysaccharides and lignin phenolic residues. Here, we show that two isoforms of a purified Arabidopsis thaliana arabinogalactan protein (AGP) encoded by hydroxyproline-rich glycoprotein family protein gene At3g45230 are covalently attached to wall matrix hemicellulosic and pectic polysaccharides, with rhamnogalacturonan I (RG I)/homogalacturonan linked to the rhamnosyl residue in the arabinogalactan (AG) of the AGP and with arabinoxylan attached to either a rhamnosyl residue in the RG I domain or directly to an arabinosyl residue in the AG glycan domain. The existence of this wall structure, named ARABINOXYLAN PECTIN ARABINOGALACTAN PROTEIN1 (APAP1), is contrary to prevailing cell wall models that depict separate protein, pectin, and hemicellulose polysaccharide networks. The modified sugar composition and increased extractability of pectin and xylan immunoreactive epitopes in apap1 mutant aerial biomass support a role for the APAP1 proteoglycan in plant wall architecture and function.
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Intraperitoneal delivery of human natural killer cells for treatment of ovarian cancer in a mouse xenograft model.
Cytotherapy
PUBLISHED: 01-30-2013
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There is an urgent need for novel therapeutic strategies for relapsed ovarian cancer. Dramatic clinical anti-tumor effects have been observed with interleukin (IL)-2 activated natural killer (NK) cells; however, intravenous delivery of NK cells in patients with ovarian cancer has not been successful in ameliorating disease. We investigated in vivo engraftment of intraperitoneally (IP) delivered NK cells in an ovarian cancer xenograft model to determine if delivery mode can affect tumor cell killing and circumvent lack of NK cell expansion.
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Evidence that YycJ is a novel 5-3 double-stranded DNA exonuclease acting in Bacillus anthracis mismatch repair.
DNA Repair (Amst.)
PUBLISHED: 01-27-2013
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The most important system for correcting replication errors that survive the built in editing system of DNA polymerase is the mismatch repair (MMR) system. We have identified a novel mutator strain yycJ in Bacillus anthracis. Mutations in the yycJ gene result in a spontaneous mutator phenotype with a mutational frequency and specificity comparable to that of MMR-deficient strains such as those with mutations in mutL or mutS. YycJ was annotated as a metallo-?-lactamase (M?L) super family member with unknown activity. In this study we carried out a biochemical characterization of YycJ and demonstrated that a recombinant YycJ protein possesses a 5-3 exonuclease activity at the 5 termini and at nicks of double-stranded DNA. This activity requires a divalent metal cofactor Mn2+ and is stimulated by 5-phosphate ends of duplex DNA. The mutagenesis of conserved amino acid residues revealed that in addition to the five M?L family conserved motifs, YycJ appears to have its specific motifs that can be used to distinguish YycJ from other closely related M?L family members. A phylogenetic survey showed that putative YycJ homologs are present in several bacterial phyla as well as in members of the Methanomicrobiales and Thermoplasmales from Archaea. We propose that YycJ represents a new group of M?L fold exonucleases, which is likely to act in the recognition of MMR entry point and subsequent removal of the mismatched base in certain MutH-less bacterial species.
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Lineage relationships of human interleukin-22-producing CD56+ ROR?t+ innate lymphoid cells and conventional natural killer cells.
Blood
PUBLISHED: 01-17-2013
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Human interleukin (IL)-22-producing ROR?t(+) innate lymphoid cells (ILC22) and conventional natural killer (cNK) cells are present in secondary lymphoid tissues. Both have an immunophenotype corresponding to stage III NK progenitors (CD56(+/-)CD117(high)CD94(-)). Using an in vitro differentiation and primary human tissues, we investigated their developmental relationships. cNK cells showed a CD56(+)CD117(+)CD7(+/-)LFA-1(high) phenotype and expressed surface receptors, cytokines, and transcription factors found on mature cNK cells. In contrast, ILC22 cells were contained within the CD56(+)CD117(high)CD94(-)CD7(-)LFA-1(-) fraction and produced IL-22, IL-8, and granulocyte macrophage colony stimulating factor. Although ILC22 cells expressed NKp44 and CD161, they lacked most other NK receptors and NK-associated transcription factors (T-bet and Eomes) and were incapable of interferon-? production or cytotoxic responses. Most purified CD56(+)CD117(+)CD7(+/-)LFA-1(-) remained as ILC22 cells and never became cNK cells. In the absence of IL-15, CD34(+) cells showed a complete block in cNK differentiation and instead gave rise to a CD56(+) population of ILC22 cells. Conversely, in the absence of IL-7 and stem cell factor, cNK cells were generated but ILC22 cells showed minimal differentiation. Although human ILC22 cells and cNK progenitors have a phenotype that overlaps with stage III NK progenitors, they have unique cytokine requirements and can be distinguished by LFA-1 expression.
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A six-carbon 10?-electron aromatic system supported by group 3 metals.
Nat Commun
PUBLISHED: 01-10-2013
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Aromaticity is a fundamental concept with implications spanning all the chemical sciences. Hückels (4n+2)?-electron rule is the standard criterion to determine aromaticity and it applies well to neutral arenes as well as to charged species such as the cyclopentadienyl anion, the cyclooctatetraene dianion and the cycloheptatrienyl cation (tropylium). In the series of all-carbon aromatic compounds, no example of a benzene tetraanion, which is theoretically a 6C, 10?-electron aromatic system, has been reported although heteroatom analogues of such a system, known as electron-rich aromatics, have been studied in detail for a long time. Here we present the isolation of the first tetraanionic-substituted benzene as a ligand coordinated to group 3 metals. The nature of the substituted benzene tetraanion and the aromaticity of the 6C, 10?-electron system were established by X-ray crystallographic studies, multi-nuclei nuclear magnetic resonance spectroscopy, X-ray absorption spectroscopy and density functional theory calculations.
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Harvest: a web-based biomedical data discovery and reporting application development platform.
AMIA Summits Transl Sci Proc
PUBLISHED: 01-01-2013
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Biomedical researchers share a common challenge of making complex data understandable and accessible. This need is increasingly acute as investigators seek opportunities for discovery amidst an exponential growth in the volume and complexity of laboratory and clinical data. To address this need, we developed Harvest, an open source framework that provides a set of modular components to aid the rapid development and deployment of custom data discovery software applications. Harvest incorporates visual representations of multidimensional data types in an intuitive, web-based interface that promotes a real-time, iterative approach to exploring complex clinical and experimental data. The Harvest architecture capitalizes on standards-based, open source technologies to address multiple functional needs critical to a research and development environment, including domain-specific data modeling, abstraction of complex data models, and a customizable web client.
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Cytomegalovirus reactivation after allogeneic transplantation promotes a lasting increase in educated NKG2C+ natural killer cells with potent function.
Blood
PUBLISHED: 12-16-2011
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During mouse cytomegalovirus (CMV) infection, a population of Ly49H(+) natural killer (NK) cells expands and is responsible for disease clearance through the induction of a "memory NK-cell response." Whether similar events occur in human CMV infection is unknown. In the present study, we characterized the kinetics of the NK-cell response to CMV reactivation in human recipients after hematopoietic cell transplantation. During acute infection, NKG2C(+) NK cells expanded and were potent producers of IFN?. NKG2C(+) NK cells predominately expressed killer cell immunoglobulin-like receptor, and self-killer cell immunoglobulin-like receptors were required for robust IFN? production. During the first year after transplantation, CMV reactivation induced a more mature phenotype characterized by an increase in CD56(dim) NK cells. Strikingly, increased frequencies of NKG2C(+) NK cells persisted and continued to increase in recipients who reactivated CMV, whereas these cells remained at low frequency in recipients without CMV reactivation. Persisting NKG2C(+) NK cells lacked NKG2A, expressed CD158b, preferentially acquired CD57, and were potent producers of IFN? during the first year after transplantation. Recipients who reactivated CMV also expressed higher amounts of IFN?, T-bet, and IL-15R? mRNA transcripts. Our findings support the emerging concept that CMV-induced innate memory-cell populations may contribute to malignant disease relapse protection and infectious disease control long after transplantation.
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Low absorption vitreous carbon reactors for operando XAS: a case study on Cu/Zeolites for selective catalytic reduction of NO(x) by NH3.
Phys Chem Chem Phys
PUBLISHED: 12-09-2011
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We describe the use of vitreous carbon as an improved reactor material for an operando X-ray absorption spectroscopy (XAS) plug-flow reactor. These tubes significantly broaden the operating range for operando experiments. Using selective catalytic reduction (SCR) of NO(x) by NH(3) on Cu/Zeolites (SSZ-13, SAPO-34 and ZSM-5) as an example reaction, we illustrate the high-quality XAS data achievable with these reactors. The operando experiments showed that in Standard SCR conditions of 300 ppm NO, 300 ppm NH(3), 5% O(2), 5% H(2)O, 5% CO(2) and balance He at 200 °C, the Cu was a mixture of Cu(I) and Cu(II) oxidation states. XANES and EXAFS fitting found the percent of Cu(I) to be 15%, 45% and 65% for SSZ-13, SAPO-34 and ZSM-5, respectively. For Standard SCR, the catalytic rates per mole of Cu for Cu/SSZ-13 and Cu/SAPO-34 were about one third of the rate per mole of Cu on Cu/ZSM-5. Based on the apparent lack of correlation of rate with the presence of Cu(I), we propose that the reaction occurs via a redox cycle of Cu(I) and Cu(II). Cu(I) was not found in in situ SCR experiments on Cu/Zeolites under the same conditions, demonstrating a possible pitfall of in situ measurements. A Cu/SiO(2) catalyst, reduced in H(2) at 300 °C, was also used to demonstrate the reactors operando capabilities using a bending magnet beamline. Analysis of the EXAFS data showed the Cu/SiO(2) catalyst to be in a partially reduced Cu metal-Cu(I) state. In addition to improvements in data quality, the reactors are superior in temperature, stability, strength and ease of use compared to previously proposed borosilicate glass, polyimide tubing, beryllium and capillary reactors. The solid carbon tubes are non-porous, machinable, can be operated at high pressure (tested at 25 bar), are inert, have high material purity and high X-ray transmittance.
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In vivo assessment of an absorbable and nonabsorbable knotless barbed suture for laparoscopic single-layer enterotomy closure: a clinical and biomechanical comparison against nonbarbed suture.
J Laparoendosc Adv Surg Tech A
PUBLISHED: 12-02-2011
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Laparoscopic intracorporeal suturing and knot tying is a complex skill that requires repeated deliberate practice to master. A novel self-anchoring barbed suture material that does not require knot tying can eliminate knot failure and reduce operating time. The goal of this study was to compare the in vivo efficacy of two novel knotless barbed sutures (absorbable and nonabsorbable) for use with the Endo Stitch™ device (Covidien), against conventional suture (Endo Stitch device with Polysorb™ suture; Covidien) for laparoscopic closure of viscerotomies in canine stomach, jejunum, and colon.
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Callous and unemotional traits and social cognitive processes in a sample of community-based aggressive youth.
Int J Offender Ther Comp Criminol
PUBLISHED: 11-25-2011
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Psychopathic traits are associated with violent, aggressive behaviors and recidivism in adulthood. To increase positive treatment outcomes, it is arguably beneficial to identify and treat psychopathy as early as possible. Furthermore, because research shows that the effectiveness of behavior modification is likely to be affected by the social information-processing patterns of aggressive children, it is important to understand the relationship between conduct-disordered traits and social cognitions. The results of this study showed that callous/unemotional traits in a community-based sample of behavior-disordered youth (57 male, 19 female; 10-19 years of age; 63% African American) significantly predicted values in obtaining a tangible reward and getting into trouble or being punished. However, callous/unemotional traits, impulsivity/conduct problems, and narcissism failed to predict positive expectations regarding receiving a tangible reward, reducing aversive treatment, and demonstration of dominance. Implications for these results are presented.
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The mini mobile environmental monitoring unit: a novel bio-assessment tool.
J Environ Monit
PUBLISHED: 11-22-2011
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This paper introduces a new bio-assessment tool, the mini-mobile environmental monitoring unit (MMU). The MMU is a portable, lightweight, energy-efficient, miniaturized laboratory that provides a low-flow system for on-site exposure of aquatic animals to local receiving waters in a protected, controllable environment. Prototypes of the MMU were tested twice in week-long studies conducted during the summers of 2008 and 2009, and in a 12-day study in 2010. In 2008, fathead minnows and polar organic chemical integrative samplers (POCIS) were deployed downstream from the Hastings, Nebraska wastewater treatment plant (WWTP), a waterway known to contain estrogenic contaminants in biologically active concentrations. In 2009, minnows and POCIS were deployed downstream, upstream and within the Grand Island, Nebraska WWTP, a site where the estrogenic contaminants had been detected, but were found at levels below those necessary to directly impact fish. In 2010, an advanced prototype was tested at the Sauk Center, Minnesota WWTP to compare its performance with that of traditional fish exposure methods including caged fish and static-renewal laboratory testing of effluent. Results from the prototype illustrate the capabilities of the MMU and offer an inexpensive monitoring tool to integrate the effects of pollutant sources with temporally varying composition and concentration.
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Use of allogeneic NK cells for cancer immunotherapy.
Immunotherapy
PUBLISHED: 11-19-2011
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Controversy exists as to the role that the immune system plays in cancer therapy. While the immune system has been proposed to scavenge the body to prevent microscopic transformation from forming cancer, it has been difficult to mount its potential of shrinking established tumors. NK cells are components of the innate immune system. They can recognize targets without prior sensitization, making them ideal candidates to manipulate for therapeutic use against cancer. Initially, autologous NK cells were directed against tumors but it was realized that NK cells that recognize self cells are inhibited. More encouraging advances have been made with allogeneic NK cell therapy in clinical trials to overcome this limitation. In this article, we present developments in NK cell adoptive immunotherapy for hematologic and solid tumor malignancies.
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Cutting edge: microRNA-181 promotes human NK cell development by regulating Notch signaling.
J. Immunol.
PUBLISHED: 11-14-2011
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MicroRNAs (miRs) have recently been identified as important regulators of gene expression at the posttranscriptional level. Although it has clearly been established that miRs influence the ontogeny of several immune cell lineages, the role of individual miRs during NK cell development has not been described. In this study, we show that miR-181 expression levels have a profound impact on the development of human NK cells from CD34(+) hematopoietic progenitor cells and IFN-? production in primary CD56(+) NK cells. We also demonstrate that nemo-like kinase (NLK), an inhibitor of Notch signaling, is a target of miR-181 in NK cells, and knockdown of NLK mirrors the developmental effect of miR-181 overexpression. We conclude that miR-181 promotes NK cell development, at least in part, through the suppression of NLK, providing an important link between miRs and Notch signaling.
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Blocking IL-21 signaling ameliorates xenogeneic GVHD induced by human lymphocytes.
Blood
PUBLISHED: 11-10-2011
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In rodent graft-versus-host disease (GVHD) models, anti-IL-21 neutralizing mAb treatment ameliorates lethality and is associated with decreases in Th1 cytokine production and gastrointestinal tract injury. GVHD prevention was dependent on the in vivo generation of donor-inducible regulatory T cells (Tregs). To determine whether the IL-21 pathway might be targeted for GVHD prevention, skin and colon samples obtained from patients with no GVHD or grade 2 to 4 GVHD were analyzed for IL-21 protein expression. By immunohistochemistry staining, IL-21 protein-producing cells were present in all gastrointestinal tract samples and 54% of skin samples obtained from GVHD patients but not GVHD-free controls. In a human xenogeneic GVHD model, human IL-21-secreting cells were present in the colon of GVHD recipients and were associated with elevated serum IL-21 levels. A neutralizing anti-human IL-21 mAb given prophylactically significantly reduced GVHD-associated weight loss and mortality, resulting in a concomitant increase in Tregs and a decrease in T cells secreting IFN-? or granzyme B. Based on these findings, anti-IL-21 mAb could be considered for GVHD prevention in the clinic.
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Tackling antibiotic resistance.
Nat. Rev. Microbiol.
PUBLISHED: 11-02-2011
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The development and spread of antibiotic resistance in bacteria is a universal threat to both humans and animals that is generally not preventable but can nevertheless be controlled, and it must be tackled in the most effective ways possible. To explore how the problem of antibiotic resistance might best be addressed, a group of 30 scientists from academia and industry gathered at the Banbury Conference Centre in Cold Spring Harbor, New York, USA, from 16 to 18 May 2011. From these discussions there emerged a priority list of steps that need to be taken to resolve this global crisis.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.