1,721,013 research outputs found
A streamlined tandem affinity purification of His-MBP-SpyCas9, without buffer exchange, suitable for in vitro cleavage applications
Full text linkWe present a streamlined protocol for the purification of recombinant doubly-tagged His-MBP-SpyCas9 protein utilizing a dual affinity chromatography approach whereby the elution volume from immobilized metal ion affinity chromatography (IMAC) is loaded directly onto maltose-binding protein (MBP) affinity chromatography. This protocol, by optimizing the buffer composition throughout the process, eliminates the need for buffer exchanges thereby reducing the risk of protein precipitation. The purification process, from bacterial harvest to final product, can be completed within a single working day. The purified Cas9 protein is suitable for in vitro cleavage assays as validated using sgRNA/complementary dsDNA-reporter oligonucleotides. In fact, the elution buffer from the MBP binding column is suitable for storage and the purified protein can be stored/aliquoted at -20 °C after the addition of glycerol, to be used directly in vitro cleavage assays without additional processing
Infarct-like myocarditis with coronary vasculitis and aneurysm formation caused by epstein–barr virus infection
Full text linkMyocardial infection by Epstein–Barr virus (EBV) may manifest with inflammatory cardiomyopathy, coronary syndrome X, and rarely with infarct-like myocarditis. The aim of the report is to describe a case of myocardial EBV infection causing acute myocarditis with heart failure, necrotizing coronary vasculitis, and multiple left ventricular (LV) aneurysms. A 67-year-old woman presented with fever, chest pain, and heart failure. She underwent non-invasive cardiac studies including electrocardiography, 2D-echocardiography, cardiac magnetic resonance, hematochemical exams with Troponin T determination, and invasive studies including cardiac catheterization, coronary angiography, and LV endomyocardial biopsy. Five endomyocardial samples were processed for histology and immunohistochemistry for inflammatory cells characterization and detection of viral antigens. Two additional frozen samples were evaluated by real-time polymerase chain reaction for the presence of cardiotropic viral genomes. Routine laboratory tests revealed the presence of elevated white blood cells (17 000 103/μL) and increased Troponin T. Electrocardiogram showed sinus tachycardia with ST elevation in V2–V5. Two-dimensional echocardiography showed normal LV dimension with reduced LV contractility (LVEF = 40%) with mild pericardial effusion. Cardiac magnetic resonance revealed the presence of a micro-aneurism in the inferior LV wall, a diffuse oedematous imbibition of LV myocardium suggested by hyper-intensity of T2 mapping, and increased fibrosis as suggested by areas of late gadolinium enhancement signals. Coronary arteries were normal while several micro-aneurysms were observed at LV angiography. At histology, a lymphocytic myocarditis with necrotizing coronary vasculitis sustained by a positive real-time polymerase chain reaction for EBV, detectable in cardiomyocytes and inflamed intramural vessels by positive immunohistochemistry for EBV latent membrane protein 1 antigen, was observed. Myocardial EBV infection is an unusual cause of acute heart failure and cardiac aneurysms, increasing the risk of electrical instability, cardiac perforation, and sudden death
Gas6 anti-apoptotic signaling requires NF-kappa B activation
No full textThe growth arrest-specific 6 gene product Gas6 is a growth and survival factor related to protein S. Gas6 is the ligand of Axl receptor tyrosine kinase; upon binding to its receptor Gas6 activates the phosphatidylinositol 3-OH kinase (PI3K) and its downstream targets S6K and Akt. Gas6 anti-apoptotic signaling was previously shown to require functional PI3K and Akt and to involve Bad phosphorylation in serum-starved NIH 3T3 cells. Here we demonstrate that Gas6 induces a rapid and transient increase in nuclear NF-κB binding activity coupled to transcription activation from NF-κB-responsive promoters and increase in Bcl-xL protein level. Gas6 survival function is impaired in cells lacking p65/RelA and in NIH 3T3 cells transfected with a dominant negative IκB, indicating that NF-κB activation plays a central role in promoting survival in this system. Moreover, NF-κB activation can be blocked by a dominant negative Akt and by wortmannin, an inhibitor of PI3K, thus suggesting that NF-κB activation is a downstream event with respect to PI3K and Akt, as already described for other growth factors. In addition, we show that glycogen synthase kinase 3, which is phosphorylated in response to Gas6, can physically associate with NFKB1/p105 in living cells and can phosphorylate it in vitro. Furthermore, Gas6 treatment is coupled to a decrease in p105 protein level. Altogether these data suggest the involvement of NF-κB and glycogen synthase kinase 3 in Gas6 anti-apoptotic signaling and unveil a possible link between these survival pathways
Arrhythmic phenotype of myocarditis sustained by a prominent infiltration of conduction tissue
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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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