Hyperplasia Of Bronchiolar Epithelium Research Articles

Sex differences in vanadium inhalation effects in non-ciliated bronchiolar cells.

The non-ciliated bronchiolar cell (NCBC) is responsible for the defense of the lung and responds to negative stimuli such as exposure to toxic pro-oxidant substances, which triggers the hyperproduction and hypersecretion of mucins and CC16 protein. The literature demonstrates that physiological and pathological responses in the lung can be influenced by the organism's sex. The objective of this report was to evaluate response differences to vanadium (V) inhalation in male and female CD-1 mice. Mice were exposed to V for four weeks. Hyperplasia of bronchiolar epithelium, small inflammatory foci and sloughing of the NCBC were observed, without changes between sexes and throughout the exposure time. Mucosecretory metaplasia was found in both males and females, however it was more drastic in males. The expression of CC16 increased in both sexes. This study demonstrated a different susceptibility between male and female mice exposed to V inhalation regarding mucosecretory metaplasia.

Pathogenesis and Immunogenicity of Bovine Adenovirus Type 3 in Cotton Rats (Sigmodon hispidus)

Intranasal inoculation of cotton rats (Sigmodon hispidus) with 108 PFU of bovine adenovirus type 3 (BAd3) resulted in limited virus replication in the lung and trachea. Histopathological changes in the lungs were characterized by necrosis and hyperplasia of bronchiolar epithelium, eosinophilic intranuclear inclusions, pneumocyte type II hyperplasia in the alveoli, and mild peribronchiolar and perivascular lymphocytic infiltration. Immunohistochemically, viral antigens were observed more frequently in bronchiolar epithelial cells than in alveolar cells in cotton rat lung sections stained using a rabbit anti-BAd3 serum. Bronchiolar epithelial changes, intranuclear inclusion bodies, type II pneumocyte proliferation, peribronchiolar infiltration, and immunohistological staining were maximum at Day 3 or Day 4 postinoculation, whereas perivascular infiltration was first observed at Day 8 postinoculation. In addition to the histological study of the pathogenesis of BAd3 infection, we monitored the BAd3-specific immune response in cotton rats. Anti-BAd3 IgG and virus neutralizing antibodies were detected in sera, whereas anti-BAd3 IgA antibodies were found in the sera, lung, and nasal washes. Our results suggest that the cotton rat can serve as a useful small-animal model for investigating the pathogenesis of BAd3 infection, as well as immune responses to BAd3 recombinant virus vaccines.

Alveolar cell hyperplasia in the lungs of smoking dogs

Hyperplasia of bronchiolar epithelium was observed in the lung parenchyma of 14 smoking dogs. Besides the increased number of cell layers in the bronchiolar epithelium, there was a virtual absence of glycogen in the cell cytoplasm. Sheetlike arrangements of squamous cells containing an abundance of tonofilament bundles were found lining alveoli. Type II cells were found adjacent to, and sometimes extending over the squamous cells. In all cases, a proliferation of type II cells was found in the alveolar epithelium, almost completely lining some alveoli. Acinarlike structures also lined by many type II cells were sometimes found near the pleura. Microinvasions of cytoplasmic processes into the underlying connective tissue often occurred through defects in the basal lamina. In some type II cells an unusual content of RER was observed. It possessed electron dense banding ≈ 180 Å wide with a repeat at intervals of ≈ 540 Å and was found in narrow cisternae and in bulbous dilatations of the cisternae of the RER. Fibrogranular material of the same appearance and periodicity was also found in the perinuclear space in some cells. Type II cells are further implicated as a reserve cell or stem cell in metaplastic alterations.

Verminous pneumonia in East African antelopes

An extremely high incidence of verminous pneumonia was observed in antelopes of the sub-family Alcelaphinae (wildebeest, topi, Coke's hartebeest) and the sub-family Antilopinae (impala, Grant's gazelle, Thomson's gazelle) which were shot and examined in an area bordering the Serengeti National Park in northern Tanzania, East Africa. The lungs of these animals were infested with one or more of 5 different lungworm species of the family Protostrongylidae, which produced two different gross types of lesions. Protostrongylus etoshai, Protostrongylus gazellae, Pneumostrongylus calcaratus and Pneumostrongylus cornigerus caused lesions confined to the superficial or marginal parts of the lung lobes, whereas Protostrongylus africanus formed nodules embedded deeply and distributed irregularly in the lung parenchyma. Despite the obvious gross pathologic differences, there were only minimal microscopic differences in the lungs of the antelopes infected with the different parasites. The typical microscopic lesion was characterized by extensive alveolar and bronchiolar accumulations of ova, larvae and adult parasites; infiltrations of mononuclear cells, eosinophils and neutrophils; bronchiectasis; and hyperplasia of bronchiolar epithelium. Alveolar emphysema, atelectasis and fibrosis were observed in some animals.