1,720,961 research outputs found
Using a systems approach to identify the mechanism of action of correctors
No full textTese de doutoramento, Biologia (Biologia de Sistemas), Universidade de Lisboa, Faculdade de Ciências, 2018Cystic Fibrosis (CF), the most common life-shortening genetic disorder among Caucasians, is caused by mutations in the gene encoding the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, an ion channel expressed at the apical membrane of epithelial cells. High-throughput screens (HTS) identified several novel molecules potentially targeting the underlying CFTR defect but only for some patients: potentiator VX-770 (Ivacaftor/Kalydeco), for subjects bearing G551D and other gating mutations, the combination corrector/potentiator VX-809 (Lumacaftor)/VX-770 (Orkambi) for F508del-homozygous patients and another similar combination VX-661 (Tezacaftor)/VX-770 is under approval. The main objective of this PhD work was to study new compounds that correct the basic CF defect, by rescuing CFTR protein traffic and function, focusing both on individual responses of CF patients with different CFTR mutations to these new drugs, and their mechanism of action. Chapter 1 focusses on the measurement of functional responses on human bronchial epithelial cells (HBE’s) derived from CF lung explants bearing different CFTR mutations to VX-809 namely: A561E, N1303K, G542X and Y1092X. Our data showed a positive response of A561E/A561E to VX-809 and F508del/Y1092X but not F508del/G542X. In Chapter 2, we evaluated the efficacy of CFTR modulators (correctors/potentiators) in physiologically relevant tissues, namely rectal biopsies, intestinal organoids, (HBE’s) and human nasal epithelial cells (HNE’s), from CF patients with rare CFTR mutations. Data obtained here showed that neither R560S nor H1079P-could not be rescued by any of the CFTR modulators, but 3849+10kbC>T and R334W and c.120del23-CFTR were rescued by VX-770 alone or with VX-809. In Chapter 3 we evaluated the efficacy of two novel CFTR correctors (B9, E12) in primary HBE cells, and three novel compounds E-act mimics (C2, C5, and C7) as enhancers of alternative Cl- channel TMEM16A in human intestinal organoids. In Chapter 4 (final) we assessed the effect of CFTR modulators and their possible additivity with F508del-CFTR genetic revertants 4RK, R1070W, and G550E to understand the mechanism of action of small molecule correctors and another variant diacidic ER exit code DD/AA in CFBE mCherry cells expressing these varinats by Ussing chamber analysis with or without CFTR modulators. Our data show that C18 and VX-661 and low temperature (But not VX-809) rescued DD/AA to the cell surface and genetic revertants restore the channel function without any CFTR modulator. Altogether, results from this work bring new insights into how the CFTR genotype may influence CFTR function and response to CFTR modulators and how each patient should be assessed individually for the responsiveness to the CFTR modulators towards personalized therapeutics
Using a systems approach to identify the mechanism of action of correctors
No full textTese de doutoramento, Biologia (Biologia de Sistemas), Universidade de Lisboa, Faculdade de Ciências, 2018Cystic Fibrosis (CF), the most common life-shortening genetic disorder among Caucasians, is caused by mutations in the gene encoding the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, an ion channel expressed at the apical membrane of epithelial cells. High-throughput screens (HTS) identified several novel molecules potentially targeting the underlying CFTR defect but only for some patients: potentiator VX-770 (Ivacaftor/Kalydeco), for subjects bearing G551D and other gating mutations, the combination corrector/potentiator VX-809 (Lumacaftor)/VX-770 (Orkambi) for F508del-homozygous patients and another similar combination VX-661 (Tezacaftor)/VX-770 is under approval. The main objective of this PhD work was to study new compounds that correct the basic CF defect, by rescuing CFTR protein traffic and function, focusing both on individual responses of CF patients with different CFTR mutations to these new drugs, and their mechanism of action. Chapter 1 focusses on the measurement of functional responses on human bronchial epithelial cells (HBE’s) derived from CF lung explants bearing different CFTR mutations to VX-809 namely: A561E, N1303K, G542X and Y1092X. Our data showed a positive response of A561E/A561E to VX-809 and F508del/Y1092X but not F508del/G542X. In Chapter 2, we evaluated the efficacy of CFTR modulators (correctors/potentiators) in physiologically relevant tissues, namely rectal biopsies, intestinal organoids, (HBE’s) and human nasal epithelial cells (HNE’s), from CF patients with rare CFTR mutations. Data obtained here showed that neither R560S nor H1079P-could not be rescued by any of the CFTR modulators, but 3849+10kbC>T and R334W and c.120del23-CFTR were rescued by VX-770 alone or with VX-809. In Chapter 3 we evaluated the efficacy of two novel CFTR correctors (B9, E12) in primary HBE cells, and three novel compounds E-act mimics (C2, C5, and C7) as enhancers of alternative Cl- channel TMEM16A in human intestinal organoids. In Chapter 4 (final) we assessed the effect of CFTR modulators and their possible additivity with F508del-CFTR genetic revertants 4RK, R1070W, and G550E to understand the mechanism of action of small molecule correctors and another variant diacidic ER exit code DD/AA in CFBE mCherry cells expressing these varinats by Ussing chamber analysis with or without CFTR modulators. Our data show that C18 and VX-661 and low temperature (But not VX-809) rescued DD/AA to the cell surface and genetic revertants restore the channel function without any CFTR modulator. Altogether, results from this work bring new insights into how the CFTR genotype may influence CFTR function and response to CFTR modulators and how each patient should be assessed individually for the responsiveness to the CFTR modulators towards personalized therapeutics
Using a systems approach to identify the mechanism of action of correctors
No full textTese de doutoramento, Biologia (Biologia de Sistemas), Universidade de Lisboa, Faculdade de Ciências, 2018Cystic Fibrosis (CF), the most common life-shortening genetic disorder among Caucasians, is caused by mutations in the gene encoding the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, an ion channel expressed at the apical membrane of epithelial cells. High-throughput screens (HTS) identified several novel molecules potentially targeting the underlying CFTR defect but only for some patients: potentiator VX-770 (Ivacaftor/Kalydeco), for subjects bearing G551D and other gating mutations, the combination corrector/potentiator VX-809 (Lumacaftor)/VX-770 (Orkambi) for F508del-homozygous patients and another similar combination VX-661 (Tezacaftor)/VX-770 is under approval. The main objective of this PhD work was to study new compounds that correct the basic CF defect, by rescuing CFTR protein traffic and function, focusing both on individual responses of CF patients with different CFTR mutations to these new drugs, and their mechanism of action. Chapter 1 focusses on the measurement of functional responses on human bronchial epithelial cells (HBE’s) derived from CF lung explants bearing different CFTR mutations to VX-809 namely: A561E, N1303K, G542X and Y1092X. Our data showed a positive response of A561E/A561E to VX-809 and F508del/Y1092X but not F508del/G542X. In Chapter 2, we evaluated the efficacy of CFTR modulators (correctors/potentiators) in physiologically relevant tissues, namely rectal biopsies, intestinal organoids, (HBE’s) and human nasal epithelial cells (HNE’s), from CF patients with rare CFTR mutations. Data obtained here showed that neither R560S nor H1079P-could not be rescued by any of the CFTR modulators, but 3849+10kbC>T and R334W and c.120del23-CFTR were rescued by VX-770 alone or with VX-809. In Chapter 3 we evaluated the efficacy of two novel CFTR correctors (B9, E12) in primary HBE cells, and three novel compounds E-act mimics (C2, C5, and C7) as enhancers of alternative Cl- channel TMEM16A in human intestinal organoids. In Chapter 4 (final) we assessed the effect of CFTR modulators and their possible additivity with F508del-CFTR genetic revertants 4RK, R1070W, and G550E to understand the mechanism of action of small molecule correctors and another variant diacidic ER exit code DD/AA in CFBE mCherry cells expressing these varinats by Ussing chamber analysis with or without CFTR modulators. Our data show that C18 and VX-661 and low temperature (But not VX-809) rescued DD/AA to the cell surface and genetic revertants restore the channel function without any CFTR modulator. Altogether, results from this work bring new insights into how the CFTR genotype may influence CFTR function and response to CFTR modulators and how each patient should be assessed individually for the responsiveness to the CFTR modulators towards personalized therapeutics
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
