1,721,187 research outputs found
Proteolytic cleavage by neutrophil elastase converts inactive storage proforms to antibacterial bactenecins.
No full textBacS and Bac7, antibiotics of the bactenecin (proline/arginine-rich peptide) family, are stored as
proforms in the large granules of bovine neutrophils [Zanetti, M., Litteri, L., Gennaro, R.,
Horstmann, H. and Romeo, D. (1990) J. Cell Bid. I l l , 1363-13711. These proforms have been
purified to homogeneity from granule extracts by immunoaffinity and reverse-phase chromatography.
While mature bactenecins efficiently kill Escherichia coli, Klebsiella pneumoniae and Salmonella
typhimurium with minimal inhibitory concentrations of 6- 12 pg/ml, proBac5 and proBac7 do not
affect the growth of the same microorganisms, even at 500 pg/ml. Previous investigations have
suggested that the conversion of probactenecins into mature antimicrobial peptides is catalyzed by a
neutral serine protease stored in the azurophil granules. Purified proBac5 and proBac7 were thus
treated with elastase, cathepsin G or proteinase 3, which constitute the pool of neutral serine
proteases of the azurophils, and the reaction products were identified by Western blot analysis, mass
spectrometry, and N-terminal sequence analysis. Of the three proteases, only elastase is able to
catalyze the stepwise cleavage of probactenecins into the corresponding mature fieptides, which have
the same mass, N-terminal sequence and antibiotic activity of authentic BacS and Bac7. These results
point to the importance of cooperation between azurophils and large granules in mounting a defense
reaction
The release of superoxide anion from granulocytes: Effect of inhibitors of anion permeability.
No full textGeneration of superoxide anion (O2−) by phagocytizing bovine blood granulocytes and extracellular release of the anion were simultaneously assayed by measuring oxygen consumption and O2−-dependent ferricytochrome c reduction. O2− release, but not generation, was markedly inhibited by 4-acetamido-4′-isothiocyano-stilbene-2,2′-disulfonate and by 1-anilino-8-naphtalene sulfonate, with an I50 of about 50 μM. Inhibition of O2− release was also observed when a portion of NaCl in the cell suspending medium was replaced by NaNO3 or NaSCN or Na salicylate, with the anions acting in the following order of potency: salicylate > SCN− > NO3−
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
The Pooled Diagnostic Accuracy of Neuroimaging, General Movements, and Neurological Examination for Diagnosing Cerebral Palsy Early in High-Risk Infants: A Case Control Study.
No full textINTRODUCTION:
Clinical guidelines recommend using neuroimaging, Prechtls' General Movements Assessment (GMA), and Hammersmith Infant Neurological Examination (HINE) to diagnose cerebral palsy (CP) in infancy. Previous studies provided excellent sensitivity and specificity for each test in isolation, but no study has examined the pooled predictive power for early diagnosis.
METHODS:
We performed a retrospective case-control study of 441 high-risk infants born between 2003 and 2014, from three Italian hospitals. Infants with either a normal outcome, mild disability, or CP at two years, were matched for birth year, gender, and gestational age. Three-month HINE, GMA, and neuroimaging were retrieved from medical records. Logistic regression was conducted with log-likelihood and used to determine the model fit and Area Under the Curve (AUC) for accuracy.
RESULTS:
Sensitivity and specificity for detecting CP were 88% and 62% for three-month HINE, 95% and 97% for absent fidgety GMs, and 79% and 99% for neuroimaging. The combined predictive power of all three assessments gave sensitivity and specificity values of 97.86% and 99.22% (PPV 98.56%, NPV 98.84%).
CONCLUSION:
CP can be accurately detected in high-risk infants when these test findings triangulate. Clinical implementation of these tools is likely to reduce the average age when CP is diagnosed, and intervention is started
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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