27 research outputs found

    De la prohibición al uso crítico de smartphones en clase

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    Frente a la prohibición existente en mucho centros educativos ante el uso de terminales móviles, el presente trabajo propone una serie de actividades que integran el uso de dichos dispositivos como herramienta principal de aprendizaje. Promoviendo así el carácter lúdico de la enseñanza de las ciencias experimentales y aumentando la motivación e interés del alumnado. La propuesta didáctica se sitúa en la asignatura de biología y geología del tercer curso de educación secundaria, concretamente en la unidad que abarca el tema de la nutrición humana

    A Replicative In Vitro Assay for Drug Discovery against Leishmania donovani.

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    The protozoan parasite Leishmania donovani is the causative agent of visceral leishmaniasis, a disease potentially fatal if not treated. Current available treatments have major limitations, and new and safer drugs are urgently needed. In recent years, advances in high-throughput screening technologies have enabled the screening of millions of compounds to identify new antileishmanial agents. However, most of the compounds identified in vitro did not translate their activities when tested in in vivo models, highlighting the need to develop more predictive in vitro assays. In the present work, we describe the development of a robust replicative, high-content, in vitro intracellular L. donovani assay. Horse serum was included in the assay media to replace standard fetal bovine serum, to completely eliminate the extracellular parasites derived from the infection process. A novel phenotypic in vitro infection model has been developed, complemented with the identification of the proliferation of intracellular amastigotes measured by EdU incorporation. In vitro and in vivo results for miltefosine, amphotericin B, and the selected compound 1 have been included to validate the assay

    New compound sets identified from high throughput phenotypic screening against three kinetoplastid parasites:an open resource

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    Using whole-cell phenotypic assays, the GlaxoSmithKline high-throughput screening (HTS) diversity set of 1.8 million compounds was screened against the three kinetoplastids most relevant to human disease, i.e. Leishmania donovani, Trypanosoma cruzi and Trypanosoma brucei. Secondary confirmatory and orthogonal intracellular anti-parasiticidal assays were conducted, and the potential for non-specific cytotoxicity determined. Hit compounds were chemically clustered and triaged for desirable physicochemical properties. The hypothetical biological target space covered by these diversity sets was investigated through bioinformatics methodologies. Consequently, three anti-kinetoplastid chemical boxes of ~200 compounds each were assembled. Functional analyses of these compounds suggest a wide array of potential modes of action against kinetoplastid kinases, proteases and cytochromes as well as potential host–pathogen targets. This is the first published parallel high throughput screening of a pharma compound collection against kinetoplastids. The compound sets are provided as an open resource for future lead discovery programs, and to address important research questions.The support and funding of Tres Cantos Open Lab Foundation is gratefully acknowledgedPeer reviewe

    Metabolic clustering analysis as a strategy for compound selection in the drug discovery pipeline for leishmaniasis

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    A lack of viable hits, increasing resistance, and limited knowledge on mode of action is hindering drug discovery for many diseases. To optimize prioritization and accelerate the discovery process, a strategy to cluster compounds based on more than chemical structure is required. We show the power of metabolomics in comparing effects on metabolism of 28 different candidate treatments for Leishmaniasis (25 from the GSK Leishmania box, two analogues of Leishmania box series, and amphotericin B as a gold standard treatment), tested in the axenic amastigote form of Leishmania donovani. Capillary electrophoresis–mass spectrometry was applied to identify the metabolic profile of Leishmania donovani, and principal components analysis was used to cluster compounds on potential mode of action, offering a medium throughput screening approach in drug selection/prioritization. The comprehensive and sensitive nature of the data has also made detailed effects of each compound obtainable, providing a resource to assist in further mechanistic studies and prioritization of these compounds for the development of new antileishmanial drugs

    Unravelling the rate of action of hits in the Leishmania donovani box using standard drugs amphotericin B and miltefosine

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    In recent years, the neglected diseases drug discovery community has elected phenotypic screening as the key approach for the identification of novel hit compounds. However, when this approach is applied, important questions related to the mode of action for these compounds remain unanswered. One of such questions is related to the rate of action, a useful piece of information when facing the challenge of prioritising the most promising hit compounds. In the present work, compounds of the "Leishmania donovani box" were evaluated using a rate of action assay adapted from a replicative intracellular high content assay recently developed. The potency of each compound was determined every 24 hours up to 96 hours, and standard drugs amphotericin B and miltefosine were used as references to group these compounds according to their rate of action. Independently of this biological assessment, compounds were also clustered according to their minimal chemical scaffold. Comparison of the results showed a complete correlation between the chemical scaffold and the biological group for the vast majority of compounds, demonstrating how the assay was able to bring information on the rate of action for each chemical series, a property directly linked to the mode of action. Overall, the assay here described permitted us to evaluate the rate of action of the "Leishmania donovani box" using two of the currently available drugs as references and, also, to propose a number of fast-acting chemical scaffolds present in the box as starting points for future drug discovery projects to the wider scientific community. The results here presented validate the use of this assay for the determination of the rate of action early in the discovery process, to assist in the prioritisation of hit compounds

    Identification of novel bromodomain inhibitors of Trypanosoma cruzi bromodomain factor 2 ( Tc BDF2) using a fluorescence polarization-based high-throughput assay

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    Bromodomains are structural folds present in all eukaryotic cells that bind to other proteins recognizing acetylated lysines. Most proteins with bromodomains are part of nuclear complexes that interact with acetylated histone residues and regulate DNA replication, transcription, and repair through chromatin structure remodeling. Bromodomain inhibitors are small molecules that bind to the hydrophobic pocket of bromodomains, interfering with the interaction with acetylated histones. Using a fluorescent probe, we have developed an assay to select inhibitors of the bromodomain factor 2 of Trypanosoma cruzi (TcBDF2) using fluorescence polarization. Initially, a library of 28,251 compounds was screened in an endpoint assay. The top 350-ranked compounds were further analyzed in a dose-response assay. From this analysis, seven compounds were obtained that had not been previously characterized as bromodomain inhibitors. Although these compounds did not exhibit significant trypanocidal activity, all showed bona fide interaction with TcBDF2 with dissociation constants between 1 and 3 µM validating these assays to search for bromodomain inhibitors

    Structure Guided Design and Synthesis of a Pyridazinone Series of Trypanosoma cruzi Proteasome Inhibitors

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    There is an urgent need for new treatments for Chagas disease, a parasitic infection which mostly impacts South and Central America. We previously reported on the discovery of GSK3494245/DDD01305143, a preclinical candidate for visceral leishmaniasis which acted through inhibition of the Leishmania proteasome. A related analogue, active against Trypanosoma cruzi, showed suboptimal efficacy in an animal model of Chagas disease, so alternative proteasome inhibitors were investigated. Screening a library of phenotypically active analogues against the T. cruzi proteasome identified an active, selective pyridazinone, the development of which is described herein. We obtained a cryo-EM co-structure of proteasome and a key inhibitor and used this to drive optimization of the compounds. Alongside this, optimization of the absorption, distribution, metabolism, and excretion (ADME) properties afforded a suitable compound for mouse efficacy studies. The outcome of these studies is discussed, alongside future plans to further understand the series and its potential to deliver a new treatment for Chagas disease.</p

    Pottery technology of levels IV and III in Kobaederra site (Cortézubi, Bizkaia). Supply and modification of raw material

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    RESUMEN: El estudio tecnológico del material cerámico requiere de la aplicación de técnicas de análisis arqueométrico que permitan un acercamiento a su mineralogía y composición química, con la fi nalidad de identifi car las etapas de su secuencia de elaboración. Este artículo presenta el análisis tecnológico de la cerámica neolítica documentada en los niveles inferiores del yacimiento de Kobaederra (Cortézubi, Bizkaia), a partir de su análisis mineralógico (petrografía y difracción de rayos X, DRX) y geoquímico (microscopio electrónico de barrido-espectómetro de dispersión de energía, MEB-EDS). Su objetivo es discriminar las potenciales áreas de aprovisionamiento de las materias primas y su modifi cación mediante la adición de desgrasantes. Por último, se discuten las implicaciones de los resultados obtenidos en relación con el resto de las evidencias arqueológicas disponibles para los niveles IV y III de Kobaederra.ABSRTACT: The technological study of ceramic materials requires the application of archaeometric analytical techniques to approach both their mineralogy and chemical composition, with the aim of identifying steps in their production sequence. This paper presents the technological analysis of the Neolithic pottery documented in the lower levels of the Kobaederra site (Cortézubi, Bizkaia) on the basis of their mineralogical (petrography and X-ray diffraction, XRD) and geochemical (SEM-EDS) analysis. Its goal is to discriminate the possible areas of raw materials supply and their modifi cation through the addition of tempers. Finally, the implications of the results in relation to the rest of available archaeological evidences from the IV and the III levels of the Kobaederra site are discussed
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