ABSTRACT
Through a simulated flightline exposure protocol, Fischer 344 rats (F344) were subjected to an aerosol/vapor mix of the military jet fuel, JP-8. Previous studies with this model of lung injury have revealed significant increases in pulmonary resistance, increased alveolar clearance of 99mTcDTPA, and a decrease in bronchoalveolar lavage fluid (BALF) concentration of the neuropeptide substance P (SP). Exposures to JP-8 were nose-only and for one hour daily. Six groups of Fischer 344 rats were exposed for 7, 28, or 56 days at two JP-8 concentrations (low dose = 469-520 mg/m3/hr, high dose = 814-1263 mg/m3/hr). Exposed groups were matched with longitudinal controls. In response to JP-8 inhalation, exposure animals demonstrated a dose-dependent as well as duration-determined reduction in BALF SP concentration. Both JP-8 concentrations caused significant pathological changes in lower pulmonary structures.
Subject(s)
Hydrocarbons/toxicity , Lung Diseases/chemically induced , Lung Diseases/enzymology , Neprilysin/physiology , Petroleum/toxicity , Administration, Inhalation , Aircraft , Animals , Bronchi/drug effects , Bronchi/pathology , Bronchoalveolar Lavage Fluid/chemistry , Epithelium/pathology , Lung Diseases/pathology , Male , Rats , Rats, Inbred F344 , Substance P/metabolism , Substance P/physiology , Tachykinins/physiology , Time FactorsABSTRACT
In a simulated military flight-line exposure protocol, the effects of JP-8 jet fuel exposure on lung epithelial permeability were evaluated in male Fischer 344 rats (F344). Exposures were nose-only and for one hour daily. Groups were exposed for 7, 28, and 56 days. A protocol for administering a low dose (500mg/m3/hr) and a high dose (813-1094mg/m3/hr) of JP-8 jet fuel was used. Longitudinal sham-exposure groups (no jet fuel) for 7, 28, and 56 days were included in the protocol. Lung epithelial permeability was measured by clearance of technetium-labeled diethylenetriamine pentaacetate (99mTcDTPA, molecular weight = 492 daltons, physical half-life = 6.02 hours). The percent clearance of 99mTcDTPA per minute was calculated. Alveolar epithelial clearance for JP-8-exposed rats was dependent on both exposure concentration and duration. It was noted that at low-dose exposure concentrations alveolar epithelial clearance of 99mTcDTPA returned to low levels (LD56 = 1.09% per min; LC56 = 0.98% per min), suggesting recovery as evidenced by microscopic exam. The corresponding 56-day high-dose group (n = 10) had a significantly higher (p < 0.05) value of 2.25% per minute. The 28-day low-dose (n = 15) and high-dose (n = 20) groups had clearance values that were significantly increased from their longitudinal control group (n = 17). The alveolar epithelial permeability values were 2.51, 1.95, and 1.20, respectively. The seven-day longitudinal control, low-dose, and high-dose groups had alveolar permeability values of 1.57, 2.16, and 2.07, respectively. The lung histology correlated with the clearance values. Electron micrographs showed that all groups had interstitial edema resulting from endothelial damage. There was apparent thickening of the alveolar septa, and alveolar macrophages were activated in all groups. Lung permeability data, as determined by 99mTcDTPA alveolar clearance, indicated that lung injuries peaked at 28 days of jet fuel exposure, and this finding corresponded with the histology data. There was a discrepancy in the seven-day group between the number of cells and the 99mTcDTPA clearance values. The HD7 group had a total cell count significantly higher than all other groups, but the 99mTcDTPA clearance values in that group were not significantly different from that of any other group.
Subject(s)
Environmental Exposure/adverse effects , Kerosene/adverse effects , Lung Diseases/chemically induced , Pulmonary Alveoli/drug effects , Aircraft , Animals , Longitudinal Studies , Lung/drug effects , Lung/ultrastructure , Lung Diseases/pathology , Lymphocyte Activation , Lymphocyte Count , Male , Metabolic Clearance Rate/drug effects , Microscopy, Electron , Pulmonary Alveoli/metabolism , Rats , Rats, Inbred F344 , Time FactorsABSTRACT
The assessment of pulmonary function in infants and children with lung disease can add substantially to their diagnosis and management. This article is a practical review of techniques such as peak flow measurement and spirometry which can be performed in the home or office setting. More complex methods such as airway challenge and infant lung function testing techniques also are discussed.
Subject(s)
Lung Diseases/diagnosis , Respiratory Function Tests , Child , Child, Preschool , Humans , Infant , Lung Diseases/physiopathologyABSTRACT
OBJECTIVE: To describe the varied characteristics seen in patients with cystic fibrosis who develop chronic abscess formation secondary to unrecognized appendicitis. DESIGN: Patient series. SETTING: Cystic Fibrosis Care Centers in Columbus, Ohio, and Tucson, Ariz. PARTICIPANTS: Five patients with cystic fibrosis who developed chronic abdominal abscesses secondary to occult appendicitis are described. Two patients developed fistula formation with purulent fluid drainage before diagnosis. One patient developed an extensive psoas abscess. Another presented with prolonged fever of unknown origin. These patients were identified by retrospective review of the past 20-year experience at two Cystic Fibrosis Care Centers. CONCLUSIONS: Development of chronic abdominal abscess related to unrecognized appendicitis is a rare but important complication in patients with cystic fibrosis. Prompt diagnosis depends on physician familiarity with the varied presentations of this entity. Diagnostic abdominal computed tomography and/or ultrasonography should particularly be considered when patients with cystic fibrosis present with pain, mass, or drainage from the right flank; prolonged fever; a limp; or failure of suspected meconium ileus equivalent syndrome to respond promptly to cathartic measures.
