Columnar epithelium in both the trachea and bronchiole
was intact, thus providing adequate columnar epithelial cells for evaluation.
Our data also show marked differences between particle retention and remodeling in the first-, second-, and third-generation respiratory bronchioles
. The major site of impact and injury appeared to be the terminal bronchiole
and adjacent first-generation respiratory bronchioles
, with progressive decrease in both retention of particles and injury in the second- and third-generation respiratory bronchioles
The lesion consists of sharply circumscribed areas containing a mixture of emphysema and dense, distinctively hyaline paucicellular interstitial fibrosis that often appears to radiate from the region of a respiratory bronchiole
to the pleura (Figure 1, A).
(68,71,72) Histologically, bronchiolar lumen contain purulent exudative material and sloughed bronchiolar mucosal cellular debris and variable amounts of mucus, and bronchiole
mucosa and walls contain a mixed neutrophilic infiltrate and chronic inflammatory cell infiltrate made up predominantly of lymphocytes and plasma cells.
Such criteria were; alveolar generation, thickening in interalveolar septum, capillary hyperemia, hemorrhage, inflammatory cell infiltration, terminal bronchiole
structure, terminal bronchiole
debris, respiratory bronchiole
wall structure, respiratory wall debris, alveolar structure and edema in vascular wall.
For instance, one study found that treating mice with oral antibiotics led to increased degeneration of the bronchiole
epithelium and a higher risk of death after infection with influenza.
Further, animal toxicological studies are inconclusive, failing to report significant effects on the deep lung portion (i.e., the area of the bronchiole
) in the test animals (Holebs) despite exposure to very high diacetyl concentrations.
Bridging fibrosis is essentially a more florid form of peribronchiolar fibrosis in which fibrosis spreads in the interstitium between a bronchiole
and another bronchiole
or, more often, between a bronchiole
and an interlobular septum or a bronchiole
and an area of subpleural fibrosis (Figures 2, A, and 3).
RAC was counted by drawing a perpendicular from geometric centre of bronchiole
to nearest connective tissue septum on 10 fields in each case.
Among the cases, abnormal terminal bronchioles
and pulmonary vessels showing features of peribronchiolitis and perivasculitis appeared as thickening in the wall of terminal bronchiole
and in the wall of pulmonary vessels due to lymphocytic infiltration (Figure-4).
And emphysema is defined anatomically: permanent enlargement of air spaces distal to the terminal bronchiole
with alveolar septae destruction.
Trachea and lung (including bronchus, bronchiole
, and pulmonary alveoli) from 3 animals per species were examined.