Differentiated bronchiolar epithelium in alveolar ducts
of rats exposed to ozone for 20 months.
3] toxicity, particularly in the vicinity of the alveolar duct where interstitial inflammatory cells accumulate, the anatomical target of air pollutants in both children and dogs residing in Mexico City (Calderon-Garciduenas et al.
We have found an association between chronic exposures to severe urban air pollution and a significant increase in abnormal CXRs and lung CTs, suggestive of a bronchiolar, peribronchiolar, and/or alveolar duct inflammatory process, in clinically healthy children with no risk factors for lung disease.
In the three groups of rats, approximately 81-85% of the particulate material was located in alveolar and alveolar duct lumens either within macrophages or extracellularly.
Thus, the tendency of the rat to retain particles primarily in macrophages located in alveolar and alveolar duct lumens is not only seen in low-exposure groups but also when macrophage-mediated clearance is overloaded.
In the controls, the interstitial compartments with the greatest amount of particulate material were the alveolar and alveolar duct septa; the interlobular, intersegmental, and perivascular connective tissue; and the pleura.
These mice progressively accumulated soot, primarily in alveolar macrophages, and septal fibrosis and bronchiolization of alveolar ducts were observed in areas of soot accumulation.
The changes involve terminal bronchioles, respiratory bronchioles, and alveolar ducts.
44) Histologically, organizing pneumonia is characterized by plugs of granulation tissue, composed of fibroblasts within a myxoid or edematous stroma, which are located within bronchiolar lumens, alveolar ducts, and associated alveolar airspaces (Figure 9).
Lying within the bronchiolar lumen and also within adjacent alveolar ducts and alveoli, there are collections of macrophages containing finely granular brown cytoplasmic pigment (Figure 10).
For example, in some patients, especially heavy smokers, anthracotic pigment may be identified along alveolar ducts and respiratory bronchioles; however, there is typically less pigment deposition and less airway fibrosis than in patients with mineral dust-associated bronchiolitic diseases.
The extent of centrilobular nodules correlated with the number of macrophages in respiratory bronchioles and with chronic inflammation of respiratory bronchioles, whereas the extent of ground-glass opacity correlated with the amount of macrophage accumulation in the alveoli and alveolar ducts