Search

Objective: To determine if emergency department utilization for pediatric respiratory illness varies across small geographic jurisdictions within a large urban city., Design: A retrospective analysis of Maryland Health Services Cost Review Commission Emergency Department discharge data., Setting/patients: All non-neonatal, Baltimore City residents <18 years old with valid diagnoses admitted and discharged from emergency departments (ED) in the state of Maryland from April 1, 1997 to December 31, 2000 (n=245,339)., Main Outcome Measures: Crude and adjusted ED visit rates for asthma, upper and lower respiratory illnesses (per 1000 population). To evaluate the effect of geography on pediatric ED visit rates, odds of an asthma ED visit, URI, or LRI vs. non-respiratory ED visit were compared across regions of the city., Results: We determined that residential areas with high ED utilization rates for upper and lower respiratory illnesses, as well as non-respiratory illnesses correlate with regions of high ED utilization for asthma, even after adjusting for race, gender and age of the population. The regions with high odds ratios that an ED visit was for asthma were different from those with high ORs for URI and LRI after also controlling for poverty., Conclusions: This suggests that poverty accounts for high utilization of the ED in urban settings, but suggests that environmental exposures that increase the risk of ED care for asthma differ from those that lead to URI and LRI.

Epithelial Cl(-) channels mediate Cl(-) and fluid secretion in the lung. In cystic fibrosis, aberrant Cl(-) secretion is one of the major causes for lung fluid imbalance. Regulation of Cl(-) channels is therefore an important issue in the lung. IFN-gamma regulates Na(+) and Cl(-) channels and fluid transport in the lung, but the mechanisms involved in these regulations are not clear. In expression studies, we found that IFN-gamma increased ClC-2 transcripts in Calu-3 cells. Studies of the promoter identified a minimal promoter which interacts with transcription factors Sp1 and Sp3. However, reporter gene assays showed that IFN-gamma did not activate the promoter. Instead, IFN-gamma significantly increased ClC-2 transcript stability. Using Ussing chamber experiments, we demonstrate that IFN-gamma activates a pH-regulated and Cd(2+)-sensitive short circuit current, characteristic properties of the ClC-2 Cl(-) channel. These data suggest that IFN-gamma activates ClC-2 channel activity in lung epithelial cells via mRNA stabilization.