Revue des maladies respiratoires
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The aim of mineralogical analysis of lung tissue, bronchoalveolar lavage (BAL) and sputum is to characterize individuals' exposure to asbestos fibres by identifying markers of this; asbestos bodies (AB) and uncoated fibres. The techniques of mineralogical analysis, habitually used to identify AB and uncoated fibres, are respectively optical microscopy (OM) and analytical electronic microscopy (EM). Correlations between levels of retention of AB in lung tissue, BAL and sputum have been established and validated threshold values indicating a high probability of significant exposure exist. ⋯ Mineralogical analysis is not suitable for use in routine medical screening but it can be considered when a source of exposure is not evident from the questionnaire since a positive analysis of BAL or of sputum is highly specific and thus useful to confirm an important retention of asbestos in the lung, which justifies medical follow-up. A negative result does not exclude previous significant asbestos exposure (frequent false negatives occur especially in sputum and biopersistence of chrysotile is lower than for amphiboles). Thus it can be a complementary tool for the assessment of asbestos exposure but its use imposes conditions for the collection and handling of samples.
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Congenital lung lesions comprise a broad spectrum of various malformations including congenital cystic adenomatoid malformation (CCAM), bronchopulmonary sequestration (BPS), congenital lobar emphysema, bronchial atresia and bronchogenic cyst. This review aims at the description of their natural history, and of the underlying pathophysiological mechanisms. ⋯ Prospective follow-up of operated and unoperated children would complete our knowledge about the natural history of these lesions. The contribution of experimental models has led to advances in the understanding of pathogenic mechanisms. Further studies are needed to identify the factors initiating the malformative process.
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COPD is characterized by airflow limitation that is not fully reversible. Changes in the structure and function of the small airways (less than 2mm diameter) are now recognized to play a major pathophysiological and mechanical role in airflow limitation in COPD. There is, therefore, a need for technology to quantify small airways disease. ⋯ These functional tests are promising solutions for small airways assessment. FOT has the advantage of being a simple method, requiring only the passive cooperation of the subject.
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Intrapulmonary Percussion Ventilation (IPV) was designed to promote airway clearance, to recruit areas of lung and to improve pulmonary gas exchange. Its principle is to administer bursts of small tidal volume at high frequency. This article describes IPV devices, especially the Phasitron(®), which provides a dynamic interface between the pneumatic source of gas and the patient. ⋯ In patients with restrictive pulmonary disease but without ventilatory autonomy, IPV is expected to improve gas exchange. The frequency of percussion will be slower (80-200 cycles/min) but the proximal airway pressure may reach 40cm H(2)O. During the sessions, the frequency may be modified to alternate from a percussive pattern (high frequencies promoting the mobilization of secretions) to a ventilatory pattern (slow frequencies encouraging alveolar ventilation and clearance of secretions).
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Review Comparative Study
[Diaphragm and skeletal muscle dysfunction in COPD].
Chronic obstructive pulmonary disease (COPD) is often accompanied by skeletal muscle alterations, resulting in enhanced morbidity and mortality. ⋯ The current review introduces the alterations observed in the quadriceps and diaphragm in the context of COPD and suggests possible signaling pathways involved in the development of muscle dysfunction.