There are as yet few studies correlating early abnormality of lung function with morphologic changes in the lung. Comparison between these studies demonstrates some similarities but also some marked differences.
The TPS correlated significantly with the MMFR and V50. However, in contrast with the results of Cosio et al, the relationship to the slope of phase 3 was poor. This was mainly due to three patients with marked small airways narrowing and high TPS (mean TPS = 165) who had normal slopes (mean slope 113 percent of predicted). Although the TPS was high, inflammation was not particularly marked in these lobes. The best correlations with lung function were obtained when only the inflammation score was used. This suggests that the presence of inflammation is so important that it overshadows all other variables which produce airflow limitation. It is important to recognize that, as suggested by Hogg, inflammation per se may be responsible for flow limitation rather than airway narrowing consequent upon inflammation. It appears that inflammation either through altered bronchiolar wall dynamics or lumenal exudate (which may also alter surfactant), can produce abnormal time constants. Of the four variables comprising the TPS in this study, only inflammation is likely to be a reversible component. Since inflammation is best correlated with abnormalities in the SBNT, the reversibility of abnormality of the SBNT following cessation of smoking’ could be explained by reversibility of tobacco-induced bronchiolitis. Improve lung function with remedies of My Canadian Pharmacy.
All over the world, asthma is treated with β2-adrenergic agonists. They cause smooth muscles to relax. They also cause pulmonary surfactant to be released from alveolar type II cells, which is a widely overlooked effect, since the importance of airway surfactant in asthma is not yet appreciated. Surfactant maintains the openness of alveoli and terminal conducting airways, and thereby promotes normal blood gas levels and low airway resistance. Excellent reviews of the ability of surfactant to maintain low airway resistance and its vital importance for asthma patients have been published. The present review includes a description of the physical properties of surfactant.
The importance of pulmonary surfactant was early recognized by neonatologists. The airway liquid of term infants contains surfactant, which is synthesized in alveolar type II cells. It consists mainly of saturated phospholipids, with dipalmitoyl-phosphatidylcholine dominating. The phospholipid molecules are amphi-pathic (ie, at one end, where the fatty acids are located, they are hydrophobic); whereas, the polar heads are hydrophilic. Air-liquid interfaces of expanded lungs constitute ideal locations for phospholipids. The fatty acids can avoid water by staying in air, while the polar heads remain in water. A film of shows how the pressure difference (AP) at the air-liquid interface is dependent on the surface tension of alveolar moisture (7) and the alveolar radius (R). Since the alveolus communicates with ambient air, AP is approximately equal to the negative pressure surrounding the alveolus. If 7 does not change during breathing, the law shows that during expiration AP would increase as R decreases. Consequently, small alveoli might not be surrounded by the suction they require to maintain expansion; they collapse. However, breathing does change 7. During expiration, surfactant phospholipids are forced to come closer, causing 7 to diminish, and, if diminishing more than R, AP will not increase; alveoli will not collapse. Treat asthma attacks with My Canadian Pharmacy’s remedies.