1,721,034 research outputs found
Smoke and viral infection cause cilia loss detectable by bronchoalveolar lavage cytology and dynein ELISA
No full textThe purpose of this study was to quantitate cilia loss following airway epithelial cell injury. Two models of airway injury were used: (1) Ex vivo acute cigarette smoke exposure model: Bovine lungs, obtained directly after slaughter, were ventilated with air or cigarette smoke for 5 min followed immediately by bronchoalveolar lavage (BAL). The bronchi were examined histologically and bronchial and alveolar fractions of BAL fluid were examined for cell counts, cell differentials, and cilia dynein concentrations using a specific 13S dynein ELISA. Smoke exposure resulted in a marked loss of ciliated cells from the bronchial luminal surface (2,364 +/- 351 versus 11,090 +/- 542 ciliated cells/mm2; p = 0.0001), a comparable increase in ciliated cells in the bronchial BAL fraction (0.90 x 10(6) cells/mm3 versus 0.15 x 10(6) cells/mm3; p = 0.0003) and a significant increase in bronchial fluid dynein concentrations (24.5 +/- 6.0 micrograms/ml versus 8.9 +/- 2.2 micrograms/ml; p = 0.03) compared with that in air-exposed lungs. The dynein concentrations strongly correlated with the absolute number of ciliated cells recovered in the bronchial lavage (r = 0.80; p < 0.0001). (2) In vivo viral infection model: Healthy cattle underwent bronchoscopy 3 days before and 7 days after inoculation with bovine respiratory syncytial virus (BRSV). BAL fluid was examined as in the first model. Following BRSV inoculation, airway exfoliation of ciliated cells and squamous metaplasia were observed histologically, bronchial ciliated cell counts doubled (0.011 +/- 0.003 x 10(6) cells/mm3 versus 0.026 +/- 0.006 x 10(6) cells/mm3; p = 0.002) and bronchial dynein concentrations increased threefold (2.2 +/- 1.0 micrograms/ml versus 7.2 +/- 1.9 micrograms/ml; p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS
Efficacy and safety of once-daily aclidinium in chronic obstructive pulmonary disease.
Full text linkBACKGROUND: The long-term efficacy and safety of aclidinium bromide, a novel, long-acting muscarinic antagonist, were investigated in patients with moderate to severe chronic obstructive pulmonary disease (COPD).
METHODS: In two double-blind, 52-week studies, ACCLAIM/COPD I (n=843) and II (n=804), patients were randomised to inhaled aclidinium 200 μg or placebo once-daily. Patients were required to have a post-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity ratio of ≤70% and FEV1<80% of the predicted value. The primary endpoint was trough FEV1 at 12 and 28 weeks. Secondary endpoints were health status measured by St George's Respiratory Questionnaire (SGRQ) and time to first moderate or severe COPD exacerbation.
RESULTS: At 12 and 28 weeks, aclidinium improved trough FEV1 versus placebo in ACCLAIM/COPD I (by 61 and 67 mL; both p<0.001) and ACCLAIM/COPD II (by 63 and 59 mL; both p<0.001). More patients had a SGRQ improvement≥4 units at 52 weeks with aclidinium versus placebo in ACCLAIM/COPD I (48.1% versus 39.5%; p=0.025) and ACCLAIM/COPD II (39.0% versus 32.8%; p=0.074). The time to first exacerbation was significantly delayed by aclidinium in ACCLAIM/COPD II (hazard ratio [HR] 0.7; 95% confidence interval [CI] 0.55 to 0.92; p=0.01), but not ACCLAIM/COPD I (HR 1.0; 95% CI 0.72 to 1.33; p=0.9). Adverse events were minor in both studies.
CONCLUSION: Aclidinium is effective and well tolerated in patients with moderate to severe COPD
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
Severity of lung injury in cyclooxygenase-2-deficient mice is dependent on reduced prostaglandin E-2 production
No full textLevels of prostaglandin E-2 (PGE(2)), a potent inhibitor of fibroblast function, are decreased in the lungs of patients with pulmonary fibrosis, which has been shown to be because of limited expression of cyclooxygenase-2 (COX-2). To further investigate the relative importance of COX-2 and PGE2 in the development of fibrosis we have used a selective COX-2 inhibitor and COX-2-deficient ((-/-) and (+/-)) mice in studies of bleomycin-induced lung fibrosis. We demonstrate in wild-type mice that bleomycin-induced. p lung PGE(2) production is predominantly COX-2 mediated. Furthermore, COX-2(+/-) mice show limited induction of PGE2 and an enhanced fibrotic response with increased lung collagen content compared with wild-type mice after bleomycin injury (P < 0.001). In contrast, COX-2(-/-) mice show increased levels of lung PGE(2), compared with wild-type mice after injury (P < 0.05), because of compensatory up-regulation of COX-1, which appears to be associated with macrophage/monocytes but not fibroblasts derived from these mice. COX-2(-/-) mice show an enhanced and persistent inflammatory response to bleomycin, however the fibrotic response to injury was unaltered compared with wild-type animals. These data provide further direct evidence for the importance of up-regulating COX-2 and PGE(2) expression in protecting against the development of fibrosis after lung injury
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