1,720,980 research outputs found
Late asthmatic reactions, airway inflammation and chronic asthma in TDI sensitized subjects.
No full textSensitized subjects may develop symptoms of asthma after exposure to isocyanates in their place of work. After challenge with isocyanates in the laboratory, sensitized subjects develop immediate, late and dual asthmatic reactions. We speculated that toluene diisocyanate (TDI) might cause late asthmatic reactions and increase bronchial responsiveness by causing an acute inflammatory reaction in the airways, and that airway inflammation may be responsible for persistence of occupational asthma induced by isocyanates. To test these hypotheses, we examined sensitized subjects during asthmatic reactions induced by exposure to toluene diisocyanate in the laboratory. We observed that late and dual, but not early, asthmatic reactions are associated with a transient increase of bronchial responsiveness which is associated with an acute inflammatory reaction of the airways characterized by an increase of neutrophils followed by eosinophils, by an increase of leukotriene B4 and albumin in bronchoalveolar lavage fluid, and that all these effects are inhibited by steroids. Longitudinal studies suggest that the majority of subjects with occupational asthma continue to have persistent asthma months and years after the cessation of exposure, and the results of our studies combined with the results of studies performed by others suggest that the persistence of asthma may be related to the persistence of airway inflammation
Presynaptic alpha 2-adrenergic stimulation leads to growth hormone release in the dog
No full textIn previous studies we have shown that the alpha 2 -adrenergic receptor agonist clonidine (CLON) releases growth hormone (GH) in conscious dogs, an effect abolished by the selective alpha 2-receptor antagonist yohimbine (YOH) and by reserpine, but not by the alpha 1-receptor antagonist prazosin (1). In the present work intravenous (iv) administration of CLON in conscious dogs evoked a dose-related rise in plasma GH at doses of 2-8 /micrograms/Kg, but not at 16 and 32 /micrograms/Kg. Acute pretreatment with the selective inhibitor of norepinephrine (NE) synthesis, DU-18288, or with a potent antagonist of presynaptic alpha 2-receptors, mianserin abolished the GH rise induced by CLON (4 /micrograms/Kg iv). In contrast, a 10-day-pretreatment with YOH greatly enhanced the GH-releasing effect of CLON (2 /micrograms/Kg iv). In all these data indicate that in the dog: 1) CLON induces GH release via activation of alpha 2-adrenergic receptors; 2) these receptors are likely located on presynaptic sites [experiments with reserpine (1), DU-18288, mianserin, dose-response curve with CLON 2-32/micrograms/kg iv]; 3) the adrenergic receptors involved in GH release exhibit supersensitivity upon (YOH-induced) chronic pharmacologic denervation. In view of the inhibitory action of presynaptic alpha 2-adrenergic receptors (autoreceptors) on NE function, it may be envisioned that in the dog noradrenergic activation is inhibitory and not stimulatory to GH release
Late asthmatic reactions, airway inflammation and chronic asthma in toluene-diisocyanate-sensitized subjects.
No full textTo determine the importance of airway inflammation for exacerbation and prognosis of asthma induced by toluene diisocyanate (TDI), we first examined sensitized subjects during asthmatic reactions induced by exposure to TDI in the laboratory. We observed that late and dual, but not early, asthmatic reactions induced by TDI are accompanied by a transient increase of airway responsiveness, bronchoalveolar neutrophilia followed by eosinophilia and by an increase of LTB4 and albumin in bronchoalveolar lavage fluid. All these effects were prevented by pretreatment with prednisone. In addition, we examined the lung pathology of 1 sensitized subject who died after exposure at work. The pathologic features of fatal asthma induced by TDI and of chronic asthma induced by TDI suggest the importance of inflammation for the exacerbation and prognosis of the disease
Neutrophils and asthma.
No full textThe importance of inflammation in asthma has been recognized for a long time and recently proved in man and animal models. All inflammatory cells are probably involved in exacerbations of asthma. Neutrophils in particular are present in the airways during and after the spontaneous asthma attacks in man and during asthmatic reactions and airway hyperresponsiveness induced experimentally in man and animals. Depletion of neutrophils prevents these effects and repletion with neutrophils reconstitutes them. Moreover, the supernatant from stimulated human neutrophils causes transient hyperresponsiveness. However, neutrophils are not increased in stable asthmatics with hyperreactive airways and are not involved in airway hyperresponsiveness induced experimentally in some animals (e.g. guinea-pigs). The studies reviewed suggest that neutrophils may be involved in the transient increases of airway responsiveness associated with exacerbations of asthma, but not in the long-lasting hyperresponsiveness of stable asthmatics
Bronchial epithelium and asthma.
No full textThe bronchial epithelium has a number of mechanical functions, including mucociliary clearance and protection against noxious agents. It may also modulate the function of the underlying smooth muscle by metabolism and regulation of mediators and the production of relaxant or constrictor substances, and regulate the activation and differentiation of lymphocytes and mast cells by releasing chemotactic factors and cytokines. It is possible that epithelial structural and functional abnormalities may lead via several mechanisms to increased bronchial responsiveness in asthmatic subjects
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
AIUTO AL SUICIDIO, AUTODETERMINAZIONE, DIRITTI FONDAMENTALI: UNO SFORZO DI SINTESI
No full textIL CONTRIBUTO RIPRODUCE LA RELAZIONE DI SINTESI SVOLTA AL TERMINE DEL CONVEGNO I CUI ATTI SONO STATI RACCOLTI NEL VOLUME OMONIMO, RIPRECCORENDO L'APPROCCIO METOLODOGICO E INTERDISCIPLINARE DELL'INCONTRO, CON UNA SITENSI PER "MODELLI" DELLE DIVERSE DISCIPLINE NEI PAESI CONSIDERATI E CONCLUDENDOSI CON LA PROBLEMATICA DELL'ORDINAMENTO ITALIANO
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