1,720,960 research outputs found
Cromoglycate and Nedocromil: Influence on Airway Reactivity
No full textAlthough basic mechanisms of bronchial hyper-responsiveness (BHR)
are still incompletely understood, inflammation of airways is likely
to play a fundamental role in modulating BHR in patients with
asthma. The involvement of several inflammatory cells (eosinophils,
mast cells, lymphocytes, neutrophils, macrophages and platelets) and
of bioactive mediators secreted by these cells in the pathogenesis
of asthma is well documented. Sodium cromoglycate and nedocromil
sodium are two pharmacological agents which have anti-allergic and
anti-inflammatory properties. Their clinical effectiveness in mild
to moderate asthma, and the capacity to reduce BHR under different
natural and experimental conditions, make them valuable drugs for
maintenance therapy in patients with asthma
Reliability of salivary theophylline concentration monitoring in children with bronchial asthma following the administration of different drug formulations.
No full textThe applicability and reliability of the clinical usefulness of monitoring salivary theophylline concentrations as a predictive measure of serum concentrations was evaluated in a total of 59 children with asthma, divided in four groups. Three pharmacological preparations of oral theophylline (aqueous, alcoholic and slow release) were evaluated after single administration (groups 1-3); slow release theophylline was also tested in a steady state of metabolism in children under chronic therapy with the drug (group 4). Although a good correlation between theophylline concentrations in serum and saliva was observed in each group, the wide range of variability in serum levels predicted from salivary levels (20-60%) appears to limit the usefulness of this approach. The salivary measurements of theophylline may be useful as a general guide in management of patients, or in assessment of compliance
Evaluation of the effect of food on the absorption of sustained-release theophylline and comparison of two methods for serum theophylline analysis.
No full textFifteen healthy volunteers took part in a study to investigate the effect of food on the bioavailability of a slow-release formulation of theophylline. Serum theophylline levels were measured every two hours for ten hours after a single oral dose of 500 mg of theophylline. Serum levels were significantly higher after the dose was taken on an empty stomach; however, serum levels were significantly higher 10 hours later when the dose was taken after a standard meal. Despite these differences, eating had no overall effect on theophylline bioavailability. Two analytic methods for measuring serum levels of theophylline were compared, and it was found that fluorometry could measure lower levels and was therefore more precise than an enzyme immunoassay method, which is probably due to the complete automation and reduced interference of bilirubin and hemoglobin
Effects of allergen exposure-avoidance on inflammation in asthmatic children.
No full textInflammation of the airways has long been known to be the classic pathologic feature of asthmatics who have died in status asthmaticus (1, 2). However, it has recently been appreciated, from studies of bronchial lavage and bronchial biopsies, that inflammatory changes are present in even mildly symptomatic adult patients (3). Experimental evidence has linked the induction of bronchial hyperresponsiveness (BHR) to the presence of inflammation (4-7). The recognition of allergic airways inflammation, as a cause of both transient and persistent airway hyperresponsiveness, has led to increased appreciation of
importance of atopy in the pathogenesis of asthma (4-8). Recently, it has been shown that eosinophil counts in lavage fluid are correlated with histamine reactivity in children (9) as well as in adults (3).
Furthermore, ultrastructural examination of the airways of two asthmatic children undergoing open lung biopsy during clinical remission showed features similar to lung tissue from two children who had died in status asthmaticus with the exception of a larger number of submucosal eosinophils and more extensivedenudation ofthe epithelium in fatal asthma
(10). Evidence from these findings suggest that airways-inflammation may play a role also in asthmatic children. This hypothesis can be further supported by studies which have shown that allergen avoidance can improve BHR and asthma symptoms both in adults (11-12) and children (13-15) with asthma.
Because of the importance of better understanding the correlation of allergen exposure with BHR and inflammation we evaluated changes in BHR and serum markers of inflammation when allergic asthmatic children sensitive to house dust mites moved from an environment rich in allergens (sea level) to an environment free from mites at a high altitude
(Istituto Pi0 XII, Misurina 1756111) (16-17) and back again to sea level. The migration of asthmatic children from sea level to the alpine environment and back again, offers a natural allergen exposureavoidance-exposure challenge model
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
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