386 research outputs found

    Molecular mechanism of poly(ADP-ribosyl)ation by PARP1 and identification of lysine residues as ADP-ribose acceptor sites

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    Poly(ADP-ribose) polymerase 1 (PARP1) synthesizes poly(ADP-ribose) (PAR) using nicotinamide adenine dinucleotide (NAD) as a substrate. Despite intensive research on the cellular functions of PARP1, the molecular mechanism of PAR formation has not been comprehensively understood. In this study, we elucidate the molecular mechanisms of poly(ADP-ribosyl)ation and identify PAR acceptor sites. Generation of different chimera proteins revealed that the amino-terminal domains of PARP1, PARP2 and PARP3 cooperate tightly with their corresponding catalytic domains. The DNA-dependent interaction between the amino-terminal DNA-binding domain and the catalytic domain of PARP1 increased Vmax and decreased the Km for NAD. Furthermore, we show that glutamic acid residues in the auto-modification domain of PARP1 are not required for PAR formation. Instead, we identify individual lysine residues as acceptor sites for ADP-ribosylation. Together, our findings provide novel mechanistic insights into PAR synthesis with significant relevance for the different biological functions of PARP family member

    Framing and visual type: Effect on future Zika vaccine uptake intent

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    Introduction: The Zika virus is associated with the birth defect microcephaly, and while a vaccine was not available in early- 2017, several were under development. This study’s purpose was to identify effective communication strategies to promote uptake of a new vaccine, particularly among women of reproductive age.Design and methods: In order to study the effects of Zika message framing (gain vs. loss) and visual type (photo vs. infographic) on future Zika vaccine uptake intent, a 2×2 between-subjects experiment was performed via an online survey in 2017 among 339 U.S. women of reproductive age (18-49 years). Participants were exposed to one of four messages, all resembling Instagram posts: gain-framed vs. loss-framed infographic, and gain-framed vs. loss-framed photo. These messages were followed by questions about Zika vaccine uptake intent as well as intermediate psychosocial variables that could lead to intent. Results: There was no interaction between framing and visual type (P=0.116), and there was no effect for framing (P=0.185) or visual type (P=0.724) on future Zika vaccine uptake intent, which is likely indicative of insufficient dosage of the intervention. However, when focusing on intermediate psychosocial constructs that are known to influence behavior and intent, gain-framed messages were more effective in increasing subjective norms (P=0.005) as related to a future Zika vaccine, as well as perceived benefits (P=0.016) and self-efficacy (P=0.032). Conclusions: Gain-framed messages seem to be more effective than loss-framed messages to increase several constructs that could, in turn, affect future Zika vaccine uptake intent. This is a novel finding since, traditionally, loss-framed messages are considered more beneficial in promoting vaccine-related health behaviors

    Lipid layers on polyelectrolyte multilayer supports

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    The mechanism of formation of supported lipid layers from phosphatidylcholine and phosphatidylserine vesicles in solution on polyelectrolyte multilayers was studied by a variety of experimental techniques. The interaction of zwitterionic and acidic lipid vesicles, as well as their mixtures, with polyelectrolyte supports was followed in real time by micro-gravimetry. The fabricated lipid–polyelectrolyte composite structures on top of multilayer coated colloidal particles were characterized by flow cytometry and imaging techniques. Lipid diffusion over the macroscopic scale was quantified by fluorescence recovery after photobleaching, and the diffusion was related to layer connectivity. The phospholipid–polyelectrolyte binding mechanism was investigated by infrared spectroscopy. A strong interaction of polyelectrolyte primary amino groups with phosphate and carboxyl groups of the phospholipids, leading to dehydration, was observed. Long-range electrostatic attraction was proven to be essential for vesicle spreading and rupture. Fusion of lipid patches into a homogeneous bilayer required lateral mobility of the lipids on the polyelectrolyte support. The binding of amino groups to the phosphate group of the zwitterionic lipids was too weak to induce vesicle spreading, but sufficient for strong adsorption. Only the mixture of phosphatidylcholine and phosphatidylserine resulted in the spontaneous formation of bilayers on polyelectrolyte multilayers. The adsorption of phospholipids onto multilayers displaying quarternary ammonium polymers produced a novel 3D lipid polyelectrolyte structure on colloidal particles.<br/

    Futteraufnahmeverhalten von Sauen und Ferkeln in freien Abferkelsystemen

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    BeifĂŒtterung wĂ€hrend der SĂ€ugezeit ist eine wichtige Maßnahme, um die Ferkel auf das Absetzen vorzubereiten und geringe Milchleistungen der Muttersau auszugleichen. An 917 Ferkeln wurde erhoben, wann, wie hĂ€ufig und wo (Ferkelfressplatz oder Sauentrog) in zwei freien Abferkelsystemen (Einzelhaltung) und einer GruppensĂ€ugebucht die Jungtiere Festfutter aufnehmen. Ab dem 17. (±1,8) Lebenstag der Ferkel wurde beigefĂŒttert, relevante Mengen wurden ab dem 29. Lebenstag (Einzelhaltung) bzw. dem 35. Lebenstag (GruppensĂ€ugen) aufgenommen. Am Beginn der BeifĂŒtterungsphase blieben die Ferkel ĂŒberwiegend fĂŒr weniger als eine Minute Dauer am Fressplatz. Erst am Ende der Versuchsperiode blieben sie fĂŒr fĂŒnf bis zehn Minuten. Über alle Buchtentypen hinweg wurden Ferkel annĂ€hernd gleich hĂ€ufig am Sauentrog beobachtet wie am speziell dafĂŒr ausgestalteten Fressplatz der Ferkel. Dieser wurde im GruppensĂ€ugen am besten genutzt. In diesem System war auch die Futteraufnahme der Ferkel am höchsten. Die Ergebnisse sollen zur Entwicklung eines noch besser an die BedĂŒrfnisse der Tiere angepassten Fressplatzes beitragen

    Incidence of erythropoietin antibody-mediated pure red cell aplasia: the Prospective Immunogenicity Surveillance Registry (PRIMS)

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    Background: Subcutaneous administration of Eprex(Âź) (epoetin alfa) in patients with chronic kidney disease (CKD) was contraindicated in the European Union between 2002 and 2006 after increased reports of anti-erythropoietin antibody-mediated pure red cell aplasia (PRCA). The Prospective Immunogenicity Surveillance Registry (PRIMS) was conducted to estimate the incidence of antibody-mediated PRCA with subcutaneous administration of a new coated-stopper syringe presentation of Eprex(Âź) and to compare this with the PRCA incidence with subcutaneous NeoRecormon(Âź) (epoetin beta) and Aranesp(Âź) (darbepoetin alfa). Methods: PRIMS was a multicentre, multinational, non-interventional, parallel-group, immunogenicity surveillance registry. Adults with CKD receiving or about to initiate subcutaneous Eprex(Âź), NeoRecormon(Âź) or Aranesp(Âź) for anaemia were enrolled and followed for up to 3 years. Unexplained loss or lack of effect (LOE), including suspected PRCA, was reported, with antibody testing for confirmation of PRCA. Results: Of the 15 333 patients enrolled, 5948 received Eprex(Âź) (8377 patient-years) and 9356 received NeoRecormon(Âź)/Aranesp(Âź) (14 286 patient-years). No treatment data were available for 29 patients. Among 23 patients with LOE, five cases of PRCA were confirmed (Eprex(Âź), n = 3; NeoRecormon(Âź), n = 1; Aranesp(Âź), n = 1). Based on exposed time, PRCA incidence was 35.8/100 000 patient-years (95% CI 7.4-104.7) for Eprex(Âź) versus 14.0/100 000 patient-years (95% CI 1.7-50.6) for NeoRecormon(Âź)/Aranesp(Âź). The incidence of PRCA with Eprex(Âź) was not significantly different versus comparator ESAs (rate ratio: 2.56; 95% CI 0.43-15.31). An analysis based on observed time produced similar findings. Conclusion: This large, prospective registry demonstrates that PRCA is rare with subcutaneous administration of either the new coated-stopper syringe presentation of Eprex(Âź), or NeoRecormon(Âź) or Aranesp(Âź).This study was funded by Janssen, Pharmaceutical Companies of Johnson & Johnson

    Analysis of the cell surface layer ultrastructure of the oral pathogen Tannerella forsythia

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    The Gram-negative oral pathogen Tannerella forsythia is decorated with a 2D crystalline surface (S-) layer, with two different S-layer glycoprotein species being present. Prompted by the predicted virulence potential of the S-layer, this study focused on the analysis of the arrangement of the individual S-layer glycoproteins by a combination of microscopic, genetic, and biochemical analyses. The two S-layer genes are transcribed into mRNA and expressed into protein in equal amounts. The S-layer was investigated on intact bacterial cells by transmission electron microscopy, by immune fluorescence microscopy, and by atomic force microscopy. The analyses of wild-type cells revealed a distinct square S-layer lattice with an overall lattice constant of 10.1 ± 0.7 nm. In contrast, a blurred lattice with a lattice constant of 9.0 nm was found on S-layer single-mutant cells. This together with in vitro self-assembly studies using purified (glyco)protein species indicated their increased structural flexibility after self-assembly and/or impaired self-assembly capability. In conjunction with TEM analyses of thin-sectioned cells, this study demonstrates the unusual case that two S-layer glycoproteins are co-assembled into a single S-layer. Additionally, flagella and pilus-like structures were observed on T. forsythia cells, which might impact the pathogenicity of this bacterium

    Defining a sustainable development target space for 2030 and 2050

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    With the establishment of the sustainable development goals (SDGs), countries worldwide agreed to a prosperous, socially inclusive, and environmentally sustainable future for all. This ambition, however, exposes a critical gap in science-based insights, namely on how to achieve the 17 SDGs simultaneously. Quantitative goal-seeking scenario studies could help explore the needed systems' transformations. This requires a clear definition of the "target space." The 169 targets and 232 indicators used for monitoring SDG implementation cannot be used for this; they are too many, too broad, unstructured, and sometimes not formulated quantitatively. Here, we propose a streamlined set of science-based indicators and associated target values that are quantifiable and actionable to make scenario analysis meaningful, relevant, and simple enough to be transparent and communicable. The 36 targets are based on the SDGs, existing multilateral agreements, literature, and expert assessment. They include 2050 as a longer-term reference point. This target space can guide researchers in developing new sustainable development pathways

    The Dynamic Library

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    "The Dynamic Library presents essays in translation from an interdisciplinary symposium on the classification and organization of knowledge held at Sitterwerk, St.Gallen in Switzerland. Home to over 25,000 volumes on art, architecture, design, and photography, the Sitterwerk’s Kunstbibliothek (art library) began with the bequest of book collector and connoisseur Daniel Rohner (1948–2007). The question of how to systematically organize this idiosyncratic collection into a publicly accessible library was a fundamental concern, and a solution was found in a dynamic system of organization powered by RFID technology, which relies on digital tracking. The essays gathered in The Dynamic Library contextualize the Sitterwerk’s associative classification system amid artistic and historical systems of order while pointing to future methods for incorporating subjectivity and serendipity into the organization of knowledge." -- Publisher's website
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