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Acute ozone (O3) exposure in humans produces changes in pulmonary function that attenuate with repeated exposure. This phenomenon, termed adaptation, has been produced in unanesthetized rats. Rats exposed to O3 (0, 0.35, 0.5, or 1.0 ppm) for 2.25 h for 5 consecutive days showed an increased frequency of breathing and a decreased tidal volume on Days 1 and 2(More)
ular for lung endothelial cells, is disrupted by the toxic effect of chronic cigarette smoke in genetically susceptible patients, thus resulting in centrilobular emphysema. Specifically, we hypothesize that disappearance of lung alveoli resulting in centrilobular emphysema occurs by apoptosis after decreased expression or activity of lung vascular(More)
Ozone uptake was assessed in awake, spontaneously breathing Fischer-344 Sprague-Dawley, and Long-Evans rats and Hartley guinea pigs to provide data on the dosimetry of O3 in small laboratory animals. This information is needed for extrapolation of O3 toxicity data from experimental animals to man. Breathing measurements and O3 exposure data were obtained(More)
AbstructA basic criterion that determines the behavior of an active power filter is the method of calculating the reference current. There are many ways of generating this reference, but the methods are generally complex and hard to tune. This paper describes a simple and effective method for calculating the reference current, necessary to feed a shunt(More)
We investigated the role of Th1 or Th2 cells in airway hyperresponsiveness (AHR), because both IFN-gamma and IL-4 and IL-5-producing CD4 T cells have been identified in the airways of asthmatics. After transfer of in vitro-generated TCR transgenic Th1 or Th2 cells and exposure to inhaled Ag, Th2 cells induced AHR and airway eosinophilia, whereas Th1 cells(More)
Phosgene inhalation causes a severe noncardiogenic pulmonary edema characterized by an influx of neutrophils into the lung. To study the role of neutrophils in lung injury and mortality after phosgene, we investigated the effects of leukocyte depletion with cyclophosphamide, inhibiting the generation of the chemotaxin leukotriene B4 with the 5-lipoxygenase(More)
Ozone, a lower-airway irritant, produces fatigue, lethargy, and increased respiratory rates in several species, including man. Ammonia, an upper-airway irritant, produces burning of the eyes, nose, and throat, and a decrease in respiratory rate. The effects of exposure to these two prototypical irritants were examined to see if behavioral changes during and(More)
Ozone (O3) adaptation is a well-known, but poorly understood phenomenon that has been demonstrated in humans and laboratory animals. This study examined pulmonary function and bronchoalveolar lavage fluid (BALF) parameters in O3-adapted F-344 rats to explore possible mechanisms of adaptation. Of particular interest was ascorbic acid (AA), an antioxidant(More)
Three separate experiments were performed to evaluate how the topography of a behavioral response and its consequences influence the behavioral effects produced by ozone (O3) exposure. The first experiment measured the responding of food-deprived rats working to obtain intermittent delivery of small pellets of food by completing an active response, wheel(More)
We have previously shown that rats dosed intratracheally with indium trichloride (InCl3) develop severe lung damage and fibrosis. However, it is not clear what pulmonary effects would result following accidental occupational exposure to low concentrations of indium by inhalation. The present study uses a model of acute lung injury based on single 1-hr(More)