1,721,030 research outputs found
Histone Deacetylase Inhibitors as Multitarget Ligands: New Players in Alzheimer's Disease Drug Discovery?
No full textHistone deacetylase inhibitors (HDACIs) are responsible forcontrolling gene expression by modulating the acetylationstatus of histone proteins. Furthermore, they modulate the ac-tivity of cytoplasmic non-histone proteins. Due to the involve-ment of HDACs in neurodevelopment, memory formation, andcognitive processes, HDACIs have been suggested as innova-tive agents for the treatment of neurodegenerative disorderssuch as Alzheimer’s disease (AD). Given their mechanisms ofaction and the complex nature of AD, HDACIs have been pro-posed for the design of novel multitarget ligands (MTLs). Tothis aim, the fragment responsible for HDAC inhibition hasbeen coupled with other structures that are able to provideadditional biological actions, such as antioxidant activity or theinhibition of phosphodiesterase 5, transglutaminase 2, and gly-cogen synthase kinase 3b. Herein we discuss recent efforts todesign HDACI-based MTLs as potential disease-modifying enti-ties
Perspectives in Designing Multifunctional Molecules in Antipsychotic Drug Discovery
No full textPreclinical Research A novel and promising approach to overcome the limits of single-target therapy is represented by the multitarget approach. This strategy aims to simultaneously modulate several targets involved in the pathophysiology of a multifactorial disease, with the potential to enhance therapeutic effectiveness and improve drug safety. Although there has been a marked growth in the design of multitarget drugs (MTDs) in the last years in the context of anti-Alzheimer and anti-cancer drug discovery, a parallel expansion was not observed in antipsychotic drugs, even that for psychiatric disorders there is a cogent medical need for new treatments. The discovery of new MTDs is a challenging task and we will describe the main strategies that have been developed over the years for the design of multifunctional molecules in antipsychotic drug discovery. In particular, we will focus on the few available MTDs based on the design of selective serotonin re-uptake inhibitors, used as antidepressants and in the treatment of schizophrenia
Direct determination of GSK-3β activity and inhibition by UHPLC-UV-vis diode arrays detector (DAD)
No full textAltered GSK-3β activity can contribute to a number of pathological processes including Alzheimer's disease (AD). Indeed, GSK-3β catalyzes the hyperphosphorylation of tau protein by transferring a phosphate moiety from ATP to the protein substrate serine residue causing the formation of the toxic insoluble neurofibrillary tangles; for this reason it represents a key target for the development of new therapeutic agents for AD treatment. Herein we describe a new selective UHPLC methodology developed for the direct characterization of GSK-3β kinase activity and for the determination of its inhibition, which could be crucial in AD drug discovery. The UHPLC-UV (DAD) based method was validated for the very fast determination of ATP as reactant and ADP as product, and applied for the analysis of the enzymatic reaction between a phosphate primed peptide substrate (GSM), resembling tau protein sequence, ATP and GSK-3β, with/without inhibitors. Analysis time was ten times improved, when compared with previously published chromatographic methods. The method was also validated by determining enzyme reaction kinetic constants (KM and vmax) for GSM and ATP and by analyzing well known GSK-3β inhibitors. Inhibition potency (IC50) values for SB-415286 (81 ± 6 nM) and for Tideglusib (251 ± 17 nM), found by the newly developed UHPLC method, were in good agreement with the luminescence method taken as independent reference method. Further on, the UHPLC method was applied to the elucidation of Tideglusib mechanism of action by determining its inhibition constants (Ki). In agreement with literature data, Tideglusib resulted a GSM competitive inhibitor, whereas SB-415286 was found inhibiting GSK-3β in an ATP competitive manner. This method was applied to the determination of the potency of a new lead compound and was found potentially scalable to inhibitor screening of large compounds collections
Isothiocyanate synthetic analogs: biological activities, structure-activity relationships and synthetic strategies.
No full textSulforaphane is a natural product that is constantly under biological investigation for its unique biological properties. This naturally occurring isothiocyanate (ITC) and its analogs are the main components of cruciferous vegetables, such as cauliflower, watercress, broccoli, cabbage, Brussels sprouts, widely used as chemopreventive agents. Due to their interesting biological profiles, natural ITCs have been exploited as starting point to develop new synthetic analogs. The present mini-review briefly highlights the most important biological actions of selected new synthetic ITCs focusing on their structure-activity relationships and related synthetic strategies
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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