Temporal and spatial distribution of ciliogenesis in the tracheobronchial airways of mice.

Little is known about ciliogenesis as it proceeds through the entire airway tree, from the trachea to the terminal bronchioles, especially during the postnatal period. The purpose of this study was to define the spatial and temporal (prenatal and postnatal) pattern of normal cilia development in the mouse. Three airway generations representing the entire airway tree were examined: trachea, lobar bronchi, and terminal bronchiole.

Repeated episodes of ozone inhalation amplifies the effects of allergen sensitization and inhalation on airway immune and structural development in Rhesus monkeys.

Twenty-four infant rhesus monkeys (30 days old) were exposed to 11 episodes of filtered air (FA), house dust mite allergen aerosol (HDMA), ozone (O3), or HDMA + O3 (5 days each followed by 9 days of FA). Ozone was delivered for 8 h/day at 0.5 ppm.

Detection of viral infection in the respiratory tract of virus antibody free mice: advantages of high-resolution imaging for respiratory toxicology.

Using a highly sensitive membrane permeability assay, a viral infection was discovered in the lungs of virus antibody free (VAF) Swiss-Webster mice purchased for respiratory toxicology studies. The assay is based on the uptake of a charged fluorescent compound by cells lacking an intact plasma membrane. Lungs from 74% of the untreated animals from a single vendor tested positive for injury in this assay.

Repeated episodes of ozone inhalation attenuates airway injury/repair and release of substance P, but not adaptation.

To determine the impact of repeated episodes of ozone exposure on physiologic adaptation, epithelial injury/repair, and tracheal substance P levels, adult rats were subjected to episodes of ozone (5 days, 1 ppm, 8 h/day) followed by 9 days of filtered air for four cycles. Rats were sampled on days 1 and 5 of each episode and 9 days after day 5 of episodes 1, 2, and 4. One hour before being euthanized each rat was injected with 5-bromo-2'-deoxyuridine to label proliferating cells.