Hyperoxia activates NF-kappaB and increases TNF-alpha and IFN-gamma gene expression in mouse pulmonary lymphocytes.

Hyperoxia-associated production of reactive oxygen species leads to neutrophil infiltration into the lungs and increased pulmonary proinflammatory cytokine expression. However, the initial events induced by hyperoxia, and leading to acute inflammatory lung injury, remain incompletely characterized. To explore this issue, we examined nuclear transcriptional regulatory factor (NF-kappaB and NF-IL-6) activation and cytokine expression in the lungs following 12 to 48 h of hyperoxia exposure. No increases in cytokine (IL-1beta, IL-6, IL-10, TGF-beta, TNF-alpha, IFN-gamma) expression nor in NF-kappaB activation were found after 12 h of hyperoxia. Following 24 h of hyperoxia, NF-kappaB activation and increased levels of TNF-alpha mRNA were present in pulmonary lymphocytes. By 48 h of hyperoxia, amounts of IFN-gamma and TNF-alpha protein as well as mRNA were increased in the lungs, and NF-kappaB continued to show activation, even though no histologic abnormalities were present. These results show that hyperoxia activates NF-kappaB in the lungs before any increase in proinflammatory cytokine protein occurs, and suggest that NF-kappaB activation may represent an initial event in the proinflammatory sequence induced by hyperoxia.

Safety and efficacy of nebulized racemic epinephrine in conjunction with oral dexamethasone and mist in the outpatient treatment of croup.

STUDY OBJECTIVE: To identify patients with croup who after treatment with nebulized racemic epinephrine, oral dexamethasone, and mist may be safely discharged home after a period of observation. DESIGN: Prospective interventional. SETTING: Urban children's hospital emergency department. PARTICIPANTS: Children with croup who received racemic epinephrine for the treatment of stridor at rest. INTERVENTIONS: After treatment with .5 mL racemic epinephrine, .6 mg/kg dexamethasone PO, and mist, patients who were assessed as being safe for discharge after 3 hours of observation were discharged home and contacted for 48-hour follow-up. RESULTS: Fifty-five patients with croup were treated with racemic epinephrine. Thirty patients (55%) had sustained responses and were discharged home after 3 hours of observation. No recurrence of respiratory distress and no return visits for medical care were reported (95% confidence interval, 0% to 8.0%). CONCLUSION: Patients with croup who are treated with racemic epinephrine, oral dexamethasone, and mist may be safely discharged home if the patient is assessed as ready for discharge after 3 hours of observation.

Radioisotope-assisted diagnosis of traumatic rupture of the diaphragm.

Traumatic rupture of the diaphragm is usually not diagnosed early after injury. We hypothesized that the diagnostic yield could be improved by injecting 50 uC of Tc99m macroaggregated albumin in 300 ml of normal saline solution and using simple scintillation counting. Thirty dogs were divided into four groups, anesthetized, and mechanically ventilated. In all groups, counting was done bilaterally 5 cm from the midline at the sternal notch and at 8, 16, 24, 32, 40, 48, and 56 cm below that level immediately and at 10, 20, and 30 min after instillation of the nuclide. In group I, the nuclide was instilled through a left thoracostomy tube, and counting was done with the dogs in reversed Trendelenberg position. In group II, blunt diaphragmatic rupture was simulated before instillation of the nuclide, and counting was done as in group I. In group III, the nuclide was instilled through a standard peritoneal lavage catheter, and counting was done with the dogs in Trendelenberg position. In group IV, blunt diaphragmatic rupture was simulated, nuclide was instilled, and counting was done as in group III. In each dog, there was no significant difference in the counts per minute (cpm) taken immediately and at 10, 20, and 30 min after instillation. In group I, radioactivity was concentrated in the areas adjacent to the diaphragm. In group II, radioactivity was concentrated at the sites lowest in the abdomen where the mean cpm differed significantly (p = .034) from group I.(ABSTRACT TRUNCATED AT 250 WORDS)