65 research outputs found

    Формування органів управління кінематографа в Україні (1919)

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    У статті розглядається процес створення та діяльність органів управління кінематографа в перші роки функціонування радянської влади в Україні.В статье рассматривается процесс создания и деятельность органов управления кинематографа в первые годы функционирования советской власти в Украине.The process of creating and functioning of the cinematography authorities in the early years of the Soviet Union in Ukraine is examined in the article

    Imaging biomarker roadmap for cancer studies.

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    Imaging biomarkers (IBs) are integral to the routine management of patients with cancer. IBs used daily in oncology include clinical TNM stage, objective response and left ventricular ejection fraction. Other CT, MRI, PET and ultrasonography biomarkers are used extensively in cancer research and drug development. New IBs need to be established either as useful tools for testing research hypotheses in clinical trials and research studies, or as clinical decision-making tools for use in healthcare, by crossing 'translational gaps' through validation and qualification. Important differences exist between IBs and biospecimen-derived biomarkers and, therefore, the development of IBs requires a tailored 'roadmap'. Recognizing this need, Cancer Research UK (CRUK) and the European Organisation for Research and Treatment of Cancer (EORTC) assembled experts to review, debate and summarize the challenges of IB validation and qualification. This consensus group has produced 14 key recommendations for accelerating the clinical translation of IBs, which highlight the role of parallel (rather than sequential) tracks of technical (assay) validation, biological/clinical validation and assessment of cost-effectiveness; the need for IB standardization and accreditation systems; the need to continually revisit IB precision; an alternative framework for biological/clinical validation of IBs; and the essential requirements for multicentre studies to qualify IBs for clinical use.Development of this roadmap received support from Cancer Research UK and the Engineering and Physical Sciences Research Council (grant references A/15267, A/16463, A/16464, A/16465, A/16466 and A/18097), the EORTC Cancer Research Fund, and the Innovative Medicines Initiative Joint Undertaking (grant agreement number 115151), resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007-2013) and European Federation of Pharmaceutical Industries and Associations (EFPIA) companies' in kind contribution

    Efficient synthesis of protein mimics by sequential native chemical ligation

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    Synthetic mimics of protein surfaces have the potential to become inhibitors of protein-protein interactions or even synthetic vaccines. However, the synthesis of these complicated molecular constructs is still difficult. Here we describe an efficient and versatile synthesis of protein mimics containing up to three different cyclic peptides. Using a sequential native chemical ligation strategy, peptide loops containing a thioester handle were introduced onto a triazacyclophane scaffold bearing orthogonal protected cysteine residues

    Scaffolded multiple cyclic peptide libraries for protein mimics by native chemical ligation

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    The accessibility to collections, libraries and arrays of cyclic peptides is increasingly important since cyclic peptides may provide better mimics of the loop-like structures ubiquitously present in and - especially - on the surface of proteins. The next important step is the preparation of libraries of ensembles of scaffolded cyclic peptides, which upon screening may lead to promising protein mimics. Here we describe the synthesis of a tri-cysteine containing scaffold as well as the simultaneous native chemical ligation of three cyclic peptides thereby affording a clean library of multiple cyclic peptides on this scaffold, representing potential mimics of gp120. Members of this collection of protein mimics showed a decent inhibition of the gp120-CD4 interaction

    Synthese en toepassing van een lipofiel aminozuurderivaat voor het verbeteren van de membraanaffiniteit van antimicrobiële peptiden

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    OBJECTIVE: To increase the potential of membrane-acting peptides as possible novel drug-like compounds by increasing lipophilicity and thereby enhancing membrane affinity. DESIGN: An Fmoc-protected enantiomerically pure lipophilic amino acid (Fmoc-Lad-OH), which contains a nine carbon atom hydrophobic side chain, was designed. Fmoc-Lad-OH can be introduced into any peptide sequence using standard solid phase peptide synthesis to increase the lipophilicity of a peptide without sacrificing important polar segments of a peptide like for instance the N and C-termini. The antimicrobial decapeptide anoplin was chosen as a model peptide to test the hypothesis. METHODS: Fmoc-Lad-OH was prepared via organic synthesis and incorporated into the anoplin peptide sequence using solid-phase peptide synthesis followed by reversed-phase HPLC purification. Biological activity was evaluated using microtiter dilution bacterial growth assays, haemolytic assays and membrane vesicle leakage experiments. RESULTS: All three lipophilic analogues show a dramatic increase in antimicrobial activity: up to 4-8 times better for Escherichia coli (Gram-negative] and over one order of magnitude for Staphylococcus aureus (Gram-positive) compared to anoplin. Although the haemolytic activity was increased for the lipophilic analogues, the concentration at which 50% lysis will occur (EC50) was still one order of magnitude higher than the determined MICs. In the membrane vesicle leakage experiments the lipophilic analogues showed a higher lytic activity than anoplin, in agreement with the observed MIC values. CONCLUSION: Introduction of Lad into anoplin clearly showed a positive effect, which suggests that Fmoc-Lad-OH could be used as a general approach to increase membrane affinity of membrane-acting peptides

    Synthese en toepassing van een lipofiel aminozuurderivaat voor het verbeteren van de membraanaffiniteit van antimicrobiële peptiden

    No full text
    OBJECTIVE: To increase the potential of membrane-acting peptides as possible novel drug-like compounds by increasing lipophilicity and thereby enhancing membrane affinity. DESIGN: An Fmoc-protected enantiomerically pure lipophilic amino acid (Fmoc-Lad-OH), which contains a nine carbon atom hydrophobic side chain, was designed. Fmoc-Lad-OH can be introduced into any peptide sequence using standard solid phase peptide synthesis to increase the lipophilicity of a peptide without sacrificing important polar segments of a peptide like for instance the N and C-termini. The antimicrobial decapeptide anoplin was chosen as a model peptide to test the hypothesis. METHODS: Fmoc-Lad-OH was prepared via organic synthesis and incorporated into the anoplin peptide sequence using solid-phase peptide synthesis followed by reversed-phase HPLC purification. Biological activity was evaluated using microtiter dilution bacterial growth assays, haemolytic assays and membrane vesicle leakage experiments. RESULTS: All three lipophilic analogues show a dramatic increase in antimicrobial activity: up to 4-8 times better for Escherichia coli (Gram-negative] and over one order of magnitude for Staphylococcus aureus (Gram-positive) compared to anoplin. Although the haemolytic activity was increased for the lipophilic analogues, the concentration at which 50% lysis will occur (EC50) was still one order of magnitude higher than the determined MICs. In the membrane vesicle leakage experiments the lipophilic analogues showed a higher lytic activity than anoplin, in agreement with the observed MIC values. CONCLUSION: Introduction of Lad into anoplin clearly showed a positive effect, which suggests that Fmoc-Lad-OH could be used as a general approach to increase membrane affinity of membrane-acting peptides

    Synthesis, antimicrobial activity, and membrane permeabilizing properties of C-terminally modified nisin conjugates accessed by CuAAC

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    Functionalization of the lantibiotic nisin with fluorescent reporter molecules is highly important for the understanding of its mode of action as a potent antimicrobial peptide. In addition to this, multimerization of nisin to obtain multivalent peptide constructs and conjugation of nisin to bioactive molecules or grafting it on surfaces can be attractive methods for interference with bacterial growth. Here, we report a convenient method for the synthesis of such nisin conjugates and show that these nisin derivatives retain both their antimicrobial activity and their membrane permeabilizing properties. The synthesis is based on the Cu(I)-catalyzed alkyne–azide cycloaddition reaction (CuAAC) as a bioorthogonal ligation method for large and unprotected peptides in which nisin was C-terminally modified with propargylamine and subsequently efficiently conjugated to a series of functionalized azides. Two fluorescently labeled nisin conjugates together with a dimeric nisin construct were prepared while membrane insertion as well as antimicrobial activity were unaffected by these modifications. This study shows that C-terminal modification of nisin does not deteriorate biological activity in sharp contrast to N-terminal modification and therefore C-terminally modified nisin analogues are valuable tools to study the antibacterial mode of action of nisin. Furthermore, the ability to use stoichiometric amounts of the azide containing molecule opens up possibilities for surface tethering and more complex multivalent structures

    Strong inhibition of cholera toxin B subunit by affordable, polymer-based multivalent inhibitors

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    Cholera is a potentially fatal bacterial infection that affects a large number of people in the developing countries. It is caused by the cholera toxin (CT), an AB5 toxin secreted by Vibrio cholera. The toxin comprises of a toxic A-subunit and a pentameric B-subunit that binds to the intestinal cell surface. Several monovalent and multivalent inhibitors of the toxin have been synthesized but are too complicated and expensive for practical use in developing countries. Meta-nitrophenyl α-galactoside (MNPG) is a known promising ligand for CT and here mono- and multivalent compounds based on MNPG were synthesized. We present the synthesis of MNPG in greatly improved yields and its use while linked to a multivalent scaffold. We used economical polymers as multivalent scaffolds, namely polyacrylamide, dextran and hyperbranched polyglycerols (hPGs). Copper catalyzed alkyne azide cycloaddition reaction (CuAAC) produced the inhibitors that were tested in an ELISA-type assay and an intestinal organoid swelling inhibition assay. The inhibitory properties varied widely depending on the type of polymer and the most potent conju-gates showed IC50 values in the nanomolar range

    Information analysis policy-instrument database

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    What is current environmental policy? What instruments is the government using? What environmental problems and target groups are these instruments aiming at? What is the effectiveness of policy instruments? What factors determine the effectiveness? These important questions play a central role in determining all RIVM products. To facilitate the environmental planning process, an information system will be added as a policy-instrument database to the current model infrastructure (like RIM+, target-group models, GOALBASE and environmental quality models) to describe current and environmental policy. This report describes all the aspects of such a policy-instrument database.Wat is het huidige milieubeleid? Welke instrumenten zet de overheid in om milieuproblemen aan te pakken? Op welke doelgroepen grijpen die instrumenten aan? Wat is de effectiviteit van die instrumenten? Welke factoren zijn van invloed op de effectiviteit van instrumenten? Belangrijke vragen, die in alle MilieuPlanBureauproducten steeds weer een centrale rol spelen. Om het beantwoorden van deze vragen te faciliteren, wordt het huidige MPB-instrumentarium (RIM+, doelgroepmodellen, GOALBASE, MK-modellen, etc) uitgebreid met een informatiesysteem waarin het huidige en voorgenomen milieubeleid is beschreven. Dit rapport beschrijft alle aspecten van een informatiesysteem voor het beschrijven van het milieubeleid: de instrumentendatabas
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