Preemptive use of high-dose fluticasone for virus-induced wheezing in young children.

BACKGROUND: Although virus-induced wheezing is common in preschool-age children, optimal management remains elusive. We examined the efficacy and safety of preemptive treatment with high-dose fluticasone in reducing the severity of recurrent virus-induced wheezing in children. METHODS: We randomly assigned 129 children who were 1 to 6 years of age to receive 750 microg of fluticasone propionate (ex-valve [manufacturer-measured] dose) or placebo twice daily, beginning at the onset of an upper respiratory tract infection and continuing for a maximum of 10 days, over a period of 6 to 12 months. The primary outcome was rescue oral corticosteroid use. Secondary outcomes included symptoms, use of beta(2)-agonists, acute care visits, hospitalizations, discontinuation of the study drug, change in growth and bone mineral density, basal cortisol level, and adverse events. RESULTS: Over a median period of 40 weeks, 8% of upper respiratory tract infections in the fluticasone group led to treatment with rescue systemic corticosteroids, as compared with 18% in the placebo group (odds ratio, 0.49; 95% confidence interval [CI], 0.30 to 0.83). Children who were treated with fluticasone, as compared with those who were given placebo, had smaller mean (+/-SD) gains from baseline in height (6.23+/-2.62 cm [unadjusted value]; z score, -0.19 +/-0.42 vs. 6.56+/-2.90 cm [unadjusted value]; z score, 0.00+/-0.48; difference between groups in z score from baseline to end point, -0.24 [95% CI, -0.40 to -0.08]) and in weight (1.53+/-1.17 kg [unadjusted value]; z score, -0.15+/-0.48 vs. 2.17+/-1.79 kg [unadjusted value]; z score, 0.11+/-0.43; difference between groups in z score from baseline to end point, -0.26 [95% CI, -0.41 to -0.09]). There were no significant differences between the groups in basal cortisol level, bone mineral density, or adverse events. CONCLUSIONS: In preschool-age children with moderate-to-severe virus-induced wheezing, preemptive treatment with high-dose fluticasone as compared with placebo reduced the use of rescue oral corticosteroids. Treatment with fluticasone was associated with a smaller gain in height and weight. Given the potential for overuse, this preventive approach should not be adopted in clinical practice until long-term adverse effects are clarified. (ClinicalTrials.gov number, NCT00238927.)

The Pediatric Respiratory Assessment Measure: a valid clinical score for assessing acute asthma severity from toddlers to teenagers.

OBJECTIVE: To determine the performance characteristics of the Preschool Respiratory Assessment Measure (PRAM) in preschool and school-aged children with acute asthma. STUDY DESIGN: In a prospective cohort study, we examined the validity, responsiveness, and reliability of the PRAM in children aged 2 to 17 years with acute asthma. The study involved more than 100 nurses and physicians who recorded the PRAM on triage, after initial bronchodilation, and at disposition. Predictive validity and responsiveness were examined using disposition as outcome. RESULTS: The PRAM was recorded in 81% (n = 782) of patients at triage. The PRAM at triage and after initial bronchodilation showed a strong association with admission (r = 0.4 and 0.5, respectively; P < .0001), thus supporting its ability to distinguish across severity levels. The responsiveness coefficient of 0.7 indicated good ability to identify change after bronchodilation. The PRAM showed good internal consistency (Cronbach alpha = 0.71) and inter-rater reliability (r = 0.78) for all patients and across all age groups. CONCLUSIONS: Good performance characteristics were observed in all age groups, making the PRAM an attractive score for assessing asthma severity and response to treatment.

Cell-type-specific pathways of neurotensin endocytosis.

The neurotensin receptor subtype 1 (NTS1) is a G-protein-coupled receptor (GPCR) mediating a large number of central and peripheral effects of neurotensin. Upon stimulation, NTS1 is rapidly internalized and targeted to lysosomes. This process depends on the interaction of the phosphorylated receptor with beta-arrestin. Little is known about other accessory endocytic proteins potentially involved. Here, we investigated the involvement of dynamin, amphiphysin, and intersectin in the internalization of NTS1 receptor-ligand complexes in transfected COS-7 and HEK 293 cells, by using the transferrin receptor as an internal control for the constitutive endocytic pathway. We found that NTS1 endocytosis was not only arrestin-dependent, but also dynamin-dependent in both COS-7 and HEK 293 cells, whereas internalization of the transferrin receptor was independent of arrestin but required dynamin. Overexpression of the SH3 domain of amphiphysin II had no effect on receptor internalization in either cell type. By contrast, overexpression of full-length intersectin or of its SH3 domain (but not of its EH domain) inhibited NTS1 internalization in COS-7 but not in HEK 293 cells. This difference between COS-7 and HEK 293 cells was not attributable to differences in endogenous intersectin levels between the two cell lines. Indeed, the same constructs inhibited transferrin endocytosis equally well in COS-7 and HEK 293 cells. However, immunogold electron microscopy revealed that internalized NTS1 receptors were associated with clathrin-coated pits in COS-7 cells but with smooth vesicles in HEK 293 cells, suggesting that NTS1 internalization proceeds via different endocytic pathways in these two cell types.