摘要:

Nasal, tracheal and bronchoalveolar injuries resulting from acute ozone exposure of rats were investigated by permeability changes.99mTc‐labeled diethylenetriaminepen‐taacetate (DPTA) and125l‐labeled bovine serum albumin (BSA) were selectively instilled into localized airway regions of anesthetized rats exposed to 0.8 ppm O3or clean air for 2 h. Transmucosal transfer of the radiolabeled tracers was detected by counting the radioactivity in blood samples collected at short postinstillation time intervals. Permeability measurements were made on d 0, 1, and 2 after O3exposure to analyze the extent and persistence of tissue injury in the nasal, tracheal, and bronchoalveolar regions. Normal mucosal permeability was low in nose, intermediate in bronchoalveolar zone, and high in trachea. The O3‐related injury, reflected by elevated permeability, was substantial in the trachea and bronchoalveolar zone but was minimal in the nose immediately after the exposure. Abnormal permeability persisted for less than 24 h in the trachea but for more than 24 h in the bronchoalveolar zone. The results are consistent with the properties of O3of causing greater injury in the smaller airways and the alveolar zone than in the trachea.

ISSN:0098-4108    

DOI:10.1080/15287398609530822

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Although photochemical air pollutants are believed to be associated with respiratory illness, there is also a need to consider their possible effects on postnatal lung maturation. The purpose of this study was to determine whether the maturation of lungs of young beagle dogs might be altered by an inhalation exposure to ozone that represents a severe 5‐d episode of photochemical oxidant air pollution. Exposures were at 6 wk of age to purified air, 1 or 2 ppm ozone for 4 hid on 5 consecutive days. After holding for 6 wk in clean air, lungs were removed and weighed, and the left lung was fixed both by inflation at 30 cm pressure and immersion using buffered formalin. Histologic sections were used for morphometric measurements. Statistical analysis showed that the mean linear intercept (inversely related to lung surface area) was greater than controls (up to about 5%) in the 7 ppm ozone‐exposed group. This effect was not seen at 2 ppm ozone, apparently due to large variations in mean linear intercept. No significant differences were seen in body weight, chest girth, lung weight, or volumes of the fixed, inflated lungs. It is concluded that if anatomic maturation of the lung was retarded by this brief regimen of ozone exposure, the effect was small and not likely to have major health consequences.

ISSN:0098-4108    

DOI:10.1080/15287398609530823

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The biologic interactions of potentially fibrogenic agents commonly occurring as environmental pollutants remain to be rigorously characterized. Two agents that produce pulmonary fibrosis were selected for this study. Separate groups of male Sprague‐Dawley rats were intratracheally instilled with 0, 2, 12, and 50 mg silica and then either sham‐exposed or exposed to 0.8 ppm ozone 6 h/d, 5 d/w, for 37 exposure days. Interaction was not detected between silica and ozone in the development of pulmonary fibrosis as determined by quantitative biochemical indices (hydroxypro‐line and lysyl oxidase) or by histopathologic examination of the lungs. Thus, environmentally relevant levels of ozone appear unlikely to affect the progression of a concurrent silicotic lesion.

ISSN:0098-4108    

DOI:10.1080/15287398609530824

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Strain A/J mice were exposed by inhalation for 6 h/d, 5 d/wk, for 6 mo to carbon disulfide, 1,2‐dibromoethane, ethylene oxide, naphthalene, nitrogen dioxide, or vinyl chloride. Significant increases in pulmonary adenoma formation were observed following exposure to 300 ppm carbon disulfide; 20 and 50 ppm 1,2‐dibromoethane; 70 and 200 ppm ethylene oxide; 10 ppm nitrogen dioxide; and 50, 200, and 500 ppm vinyl chloride comapred to control animals. Repeated studies with 1,2‐dibromoethane, ethylene oxide, and vinyl chloride gave similarly significant results. Exposure of mice to 30 ppm naphthalene did not elicit a significant adenoma response. Histopathological examination of lungs from animals in these studies revealed multiple alveolar adenomas. Results from earlier studies with these chemicals, using strain A mice and Swiss mice, and bioassay information with rats and mice were compared with these data. These results provide further information for the validation of thisin vivomodel as a tool for predicting oncogenic potential following chemical exposure.

ISSN:0098-4108    

DOI:10.1080/15287398609530825

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

TOXICOLOGY AND THE NEWBORN. Edited byS. KacewandM. J. Reasor, Elsevier, Amsterdam, 1984, 291 pp., $76.00

ISSN:0098-4108    

DOI:10.1080/15287398609530826

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0098-4108    

DOI:10.1080/15287398609530811

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor