The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Surfactant proteins (SP)-A and SP-D are collagen-like glycoproteins belonging to the "collectin" class of C-type lectins, which are primarily synthesized in type II cells. Recent studies reported the possibility of local production of SP-A and SP-D in the airways, but the amounts of surfactant proteins in patients with bronchial asthma have not been studied. The composition of surfactant proteins in mild, stable asthmatics in the first lavage as bronchial lavage (BL) and the second and third lavages consecutively as alveolar lavages (AL) were therefore, analysed separately. ⋯ The levels of SP-A correlated with those of fucose in patients with bronchial asthma (r=0.849, p<0.01). The observations in the present study suggested that surfactant protein A may be secreted from the airways with allergic inflammation in a different manner from the alveoli. The increased levels of surfactant proteins A and D may play a protective role in an allergic inflammation in the pathogenesis of bronchial asthma.
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Clinical Trial Controlled Clinical Trial
Airway inflammation in patients with symptoms suggesting asthma but with normal lung function.
The hypothesis that eosinophilic airway inflammation is present in many patients presenting with respiratory symptoms suggestive of asthma but with normal lung function was tested. Thirty-six consecutive patients presenting with these features were studied. Twenty-five asthmatics and 43 healthy volunteers served as control groups. ⋯ Four (13%) patients had developed asthma and another 10 (32%) had become free of symptoms. Using lung function measurements and induced sputum analyses, a group of patients with symptoms suggestive of asthma and signs of eosinophilic airway inflammation but without enough airflow variability to be diagnosed as asthmatics were detected. They seemed to respond favourably to inhaled beclomethasone dipropionate treatment.
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Epidemiological studies indicate that the prevalence of "wheeze" is very high in early childhood. However, it is clear that parents and clinicians frequently use the term "wheeze" for a range of audible respiratory noises. The commonest audible sounds originating from the lower airways in infancy are ruttles, which differ from classical wheeze in that the sound is much lower in pitch, with a continuous rattling quality and lacking any musical features. ⋯ The acoustic signals were analysed using a fast fourier transformation technique (Respiratory Acoustics Laboratory Environment programme). The acoustic properties of the two noises were shown to be quite distinct, the classical wheeze being characterized by a sinusoidal waveform with one or more distinct peaks in the power spectrum display; the ruttle is represented by an irregular nonsinusoidal waveform with diffuse peaks in the power spectrum and with increased sound intensity at a frequency of <600 Hz. It is important for clinicians and epidemiologists to recognize that there are distinct types of audible respiratory noise in early life with characteristic acoustic properties.
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Common colds are associated with exacerbations of chronic obstructive pulmonary disease (COPD). However, the role of the common cold virus (human rhinovirus) in the production of symptoms and lower airway inflammation at COPD exacerbation is unknown. Thirty three patients with moderate-to-severe COPD were seen at baseline, when the number of chest infections in the previous year was noted, and acutely at COPD exacerbation. ⋯ Median baseline sputum interleukin-6 levels rose from 90.2 to 140.3 pg x mL(-1) at exacerbation (p=0.005); the change was greater in the presence of rhinovirus infection (p=0.008). Rhinovirus infection can be detected at chronic obstructive pulmonary disease exacerbation. This is associated with elevation of lower airway interleukin-6 levels, which may mediate lower airway symptom expression during chronic obstructive pulmonary disease exacerbations.
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Volume and time dependence of respiratory system mechanics in normal anaesthetized paralysed humans.
The purpose of the present investigation was to assess the effect of large tidal volumes and mean lung volumes on the viscoelastic properties of the respiratory system in normal humans; and to verify if in this case the results could be satisfactorily described by a simple linear viscoelastic model of the respiratory system. Twenty-eight subjects (7 females), aged 14-28 yrs, were studied before orthopaedic surgery on the lower limbs. ⋯ It was found that the interrupter conductance increased linearly with lung volume over a larger range than used previously; and the viscoelastic resistance and time constant did not change over the entire range of tidal volumes and end-expiratory pressures studied. In conclusion, in normal anaesthetized, paralysed subjects a simple linear viscoelastic model satisfactorily described the viscoelastic behaviour of the respiratory system over the whole range of volume studied.