ABSTRACT
The aim of this study was to investigate the role of particle number, total surface area, mass and surface chemical groups in (K(f,c)) changes. The lung effects of four different fine (110 nm) and ultrafine (24 nm) polystyrene particles have been tested in an isolated perfused rabbit lung model. Pulmonary microvascular permeability (K(f,c)) modifications were measured in response to intratracheal particle challenge. Polystyrene particles, mainly located in alveolar spaces and macrophages, induced a K(f,c) increase that was related to the total surface area and number of particles rather than to the instilled mass. Moreover, the positively charged amine-modified polystyrene particles were more effective in the K(f,c) response than the negatively charged carboxylate-modified polystyrene particles. We concluded that particle number and diameter that mathematically equally determined total surface area do not have the same importance in explaining the biological effects observed and that particle number could be an alternative to total surface area to describe the particle exposure. Furthermore, surface properties of polystyrene particles need to be considered to investigate the microvascular permeability changes measured in our model.
Subject(s)
Capillary Permeability/drug effects , Lung/blood supply , Microcirculation/drug effects , Polystyrenes/toxicity , Animals , In Vitro Techniques , Intubation, Intratracheal , Lung/pathology , Particle Size , Perfusion , Polystyrenes/administration & dosage , Rabbits , Surface PropertiesABSTRACT
The purpose of this work was to investigate the role of tachykinins in cough induced by citric acid (0.8 M) in pigs. With this object, we have studied the effect of citric acid on substance P content in the tracheo-bronchial tree and the effects of substance P and of tachykinin receptor antagonists on citric acid-induced cough. Citric acid exposure significantly increased substance P concentration in both broncho-alveolar and tracheal lavage fluids, while it decreased significantly the substance P content in tracheal mucosa. Substance P did not elicit cough, but significantly potentiated the citric acid-induced cough frequency. Tachykinin NK(1), NK(2) or NK(3) receptor antagonists, SR 140333 (nolpitantium), SR 48968 (saredutant) and SR 142801 (osanetant), respectively, significantly inhibited citric acid-induced cough. The same inhibitory effect of tachykinin receptor antagonists was observed, when substance P was nebulised before citric acid challenge. We conclude that citric acid induces in pigs a release of substance P in the tracheo-bronchial tree, which plays a sensitising role on the cough reflex. The involvement of tachykinin NK(1), NK(2), NK(3) receptors are also demonstrated in this reflex.
Subject(s)
Citric Acid/administration & dosage , Cough/prevention & control , Piperidines/pharmacology , Receptors, Tachykinin/antagonists & inhibitors , Substance P/drug effects , Animals , Benzamides/pharmacology , Cough/chemically induced , Cough/physiopathology , Female , Lung/drug effects , Lung/metabolism , Male , Neurokinin-1 Receptor Antagonists , Quinuclidines/pharmacology , Receptors, Neurokinin-1/metabolism , Receptors, Neurokinin-2/antagonists & inhibitors , Receptors, Neurokinin-2/metabolism , Receptors, Neurokinin-3/antagonists & inhibitors , Receptors, Neurokinin-3/metabolism , Receptors, Tachykinin/metabolism , Reflex/drug effects , Reflex/physiology , Substance P/metabolism , Substance P/physiology , Swine, MiniatureABSTRACT
Neisseria sicca, although considered a harmless saprophyte, has been recognised as an etiologic agent in three cases of pneumonitis, and rare cases of endocarditis, meningitis, and osteomyelitis, particularly in immunocompromised hosts. We report the case of a 76-year-old man with a community-acquired pneumonia, in whom both sputum samples and bronchial secretions obtained with bronchoscopic protected catheter brush grew pure culture of N. sicca with abundant polymorphonuclear neutrophils. Dramatic clinical improvement only occurred after initiation of an appropriate antibiotherapy according to susceptibility spectrum of the isolated N. sicca. Bronchiectasis underlying lesions were disclosed by computed tomography. N. sicca should be added to the list of commensal organisms able to cause pulmonary infection. Moreover, the association of N. sicca and bronchiectasis has never been published.
Subject(s)
Bronchiectasis/complications , Neisseria , Pneumonia/microbiology , Aged , Anti-Bacterial Agents/therapeutic use , Bronchiectasis/diagnostic imaging , Humans , Male , Pneumonia/complications , Pneumonia/drug therapy , Tomography, X-Ray ComputedSubject(s)
Biomarkers, Tumor/analysis , Carcinoma, Small Cell/enzymology , Lung Neoplasms/enzymology , Phosphopyruvate Hydratase/analysis , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Small Cell/drug therapy , Female , Humans , Lung Neoplasms/drug therapy , Middle AgedABSTRACT
A Zairese patient with an extensive ulceration on the left foot due to Mycobacterium ulcerans was successfully treated with antibiotics and Debrisan. The diagnosis and treatment are discussed.
