Search results for "Respiratory tract diseases"
showing 10 items of 1015 documents
Electrophysiological brainstem investigations in obstructive sleep apnoea syndrome.
1996
Phasic inspiratory genioglossus activity prevents pharyngeal airway collapse in healthy subjects during sleep and is diminished or absent in obstructive sleep apnoea syndrome (OSAS), thus leading to pharyngeal obstruction. Case reports of OSAS after pontomedullary lesions indicate that impaired inspiratory genioglossal activity may result from brainstem lesions. We therefore investigated brainstem functions in 18 awake patients with OSAS using brainstem auditory evoked potentials, blink reflex, masseter reflex, masseter inhibitory reflex (in 11 of 18 patients), magnetic evoked potentials of the tongue and electrooculography with vestibular testing. Fifteen of 18 patients showed no electroph…
Airway Responsiveness to Inhaled Acetaldehyde in Subjects with Allergic Rhinitis: Relationship to Methacholine Responsiveness
2002
<i>Background:</i> Asthmatic subjects have an exaggerated airway response to inhaled acetaldehyde, but no information is available on airway responsiveness to this bronchoconstrictor agent in subjects with allergic rhinitis. <i>Objective:</i> The aim of this study was to determine the effect of inhaled acetaldehyde on lung function in nonasthmatic subjects with allergic rhinitis. <i>Methods:</i> A total of 78 adults (43 subjects with allergic rhinitis, 16 asthmatics and 19 healthy subjects) were challenged with increased concentrations of acetaldehyde and methacholine. The response to each bronchoconstrictor agent was measured by the provocative concentra…
Exhaled Nitric Oxide and Bronchial Responsiveness to Adenosine 5′-Monophosphate in Subjects With Allergic Rhinitis
2002
Study objectives: To determine differences in exhaled nitric oxide (ENO) between subjects with allergic rhinitis with and without increased responsiveness to direct and indirect bronchoconstrictor agents. Study design: Cross-sectional study with the order of challenge tests randomized. Setting: Specialist allergy unit in a university hospital. Patients: Thirty-eight subjects without asthma with allergic rhinitis and 10 healthy nonatopic control subjects. Measurements and results: Participants were challenged with increasing concentrations of adenosine 5monophosphate (AMP) and methacholine. ENO was measured with the singleexhalation method. A positive response to both bronchoconstrictor agen…
Baroreflex control of heart rate during sleep in severe obstructive sleep apnoea: effects of acute CPAP
2006
Baroreflex control of heart rate during sleep (baroreflex sensitivity; BRS) has been shown to be depressed in obstructive sleep apnoea (OSA), and improved after treatment with continuous positive airway pressure (CPAP). Whether CPAP also acutely affects BRS during sleep in uncomplicated severe OSA is still debatable. Blood pressure was monitored during nocturnal polysomnography in 18 patients at baseline and during first-time CPAP application. Spontaneous BRS was analysed by the sequence method, and estimated as the mean sequence slope. CPAP did not acutely affect mean blood pressure or heart rate but decreased cardiovascular variability during sleep. Mean BRS increased slightly during CPAP…
Adjustable maintenance dosing with budesonide/formoterol in a single inhaler provides effective asthma symptom control at a lower dose than fixed mai…
2004
Asthma guidelines suggest a stepwise approach to maintenance pharmacological treatment of persistent asthma until control is attained, and a 3 month review of the fixed maintenance dosing for step-up or step-down adjustment. This 12-week study compared the efficacy and safety of budesonide/formoterol in a single inhaler (Symbicort Turbuhaler 160/4.5 or 80/4.5 microg) given as adjustable maintenance or fixed maintenance dosing. Patients (n = 2358) were randomised to budesonide/formoterol fixed maintenance dosing (two inhalations bid) or adjustable maintenance dosing (two inhalation bid; stepping up to four inhalations bid if asthma worsened for a maximum of 14 days; stepping down to two inha…
Spontaneous interleukin 2 release of bronchoalveolar lavage cells in sarcoidosis is a codeterminator of prognosis
1996
There is mounting evidence that activated interleukin 2 (IL-2)-releasing lymphocytes play a central role in the immunopathogenesis of sarcoidosis by directing inflammatory reactions and granuloma formation. In the context that a significant proportion of these cells accumulates in the lung and releases mediators, we hypothesized that different immunologically defined stages of sarcoidosis can be identified. A cohort of 89 sarcoidosis patients was allocated to four groups according to the following criteria: stage A, a low number of bronchoalveolar lavage (BAL) lymphocytes (20%) without IL-2 release (1 unit/ml in BAL cell culture supernatant); stage B, BAL lymphocytes20%, with IL-2 release (…
Extracellular matrix composition in COPD
2012
Extracellular matrix (ECM) composition has an important role in determining airway structure. We postulated that ECM lung composition of chronic obstructive pulmonary disease (COPD) patients differs from that observed in smoking and nonsmoking subjects without airflow obstruction. We determined the fractional areas of elastic fibres, type-I, -III and -IV collagen, versican, decorin, biglycan, lumican, fibronectin and tenascin in different compartments of the large and small airways and lung parenchyma in 26 COPD patients, 26 smokers without COPD and 16 nonsmoking control subjects. The fractional area of elastic fibres was higher in non-obstructed smokers than in COPD and nonsmoking controls…
High-Resolution Computed Tomographic Evaluation of Airway Distensibility and the Effects of Lung Inflation on Airway Caliber in Healthy Subjects and …
2001
The effects of a deep inspiration (DI) in individuals with asthma differ from those observed in healthy subjects. It has been postulated that the beneficial effect of lung inflation is mediated by airway stretch. One hypothesis to explain the defects in the function of lung inflation in asthma is that a DI may be unable to stretch the airways. This may result from attenuation of the tethering forces between the airways and the surrounding parenchyma. In the current study, we used high-resolution computed tomography (HRCT) to examine the ability of a DI to distend the airways of subjects with asthma (n = 10) compared with healthy subjects (n = 9) at baseline and after increasing airway tone …
Airway neutrophilia in COPD is not associated with increased neutrophil survival
2006
Neutrophilic airway inflammation is a prominent feature of chronic obstructive pulmonary disease (COPD) and correlates with disease severity. The mechanisms that determine the extent of neutrophilia could involve increased influx or prolonged survival of neutrophils. The aim of the study was to assess whether neutrophil pro-survival mechanisms are increased in the airways of subjects with COPD owing to the presence of anti-apoptotic factors in the bronchial lining fluid. Induced sputum samples were collected from 20 subjects with stable COPD, 14 healthy smokers and 14 healthy controls. Quantification of apoptotic neutrophils was based on typical morphological cell changes. Anti-apoptotic, p…
Oxygen Radical Production by Alveolar Inflammatory Cells in Idiopathic Pulmonary Fibrosis
1990
Idiopathic pulmonary fibrosis (IPF) is a chronic inflammatory interstitial lung disease characterized by the accumulation of alveolar macrophages (AMs) and neutrophils in the lower respiratory tract, parenchymal cell injury, and fibrosis of the alveolar structure. Reactive oxygen intermediates (ROI) are claimed to be a major cause of tissue damage in IPF; however, the source of ROI has not been unequivocally identified. AMs, as well as neutrophils, are capable of releasing these agents. The contributions of these possible sources are not known. To address this question, we evaluated the spontaneous and stimulated (PMA or zymosan) ROI release of total bronchoalveolar cells and isolated AMs i…