Wheeze is an unreliable endpoint for bronchial methacholine challenges in preschool children.

BACKGROUND: Onset of wheeze is the endpoint often used in the determination of a positive bronchial challenge test (BCT) in young children who cannot perform spirometry. We sought to assess several clinical endpoints at the time of a positive BCT in young children with recurrent wheeze compared to findings in school-aged children with asthma. METHODS: Positive BCT was defined in: (1) preschool children (n = 22) as either persistent cough, wheeze, fall in oxygen saturation (SpO2 ) of ≥5%, or ≥50% increase in respiratory rate (RR) from baseline; and (2) school-aged children (n = 22) as the concentration of methacholine (MCh) required to elicit a 20% decline in FEV1 (PC20 ). RESULTS: All preschool children (mean age 3.4 years) had a positive BCT (median provocative MCh concentration 1.25 mg/ml [IQR, 0.62, 1.25]). Twenty (91%) school-aged children (mean age 11.3 years) had a positive BCT (median PC20 1.25 mg/ml [IQR, 0.55, 2.5]). At the time of the positive BCT, the mean fall in SpO2 (6.9% vs. 3.8%; p = .001) and the mean % increase in RR (61% vs. 22%; p < .001) were greater among preschool-aged than among school-aged children. A minority of children developed wheeze at time of positive BCT (23% preschool- vs. 15% school-aged children; p = .5). CONCLUSIONS: The use of wheeze as an endpoint for BCT in preschool children is unreliable, as it rarely occurs. The use of clinical endpoints, such as ≥25% increase in RR or fall in SpO2 of ≥3%, captured all of our positive BCT in preschool children, while minimizing undue respiratory distress.

Oral food challenges in children with a diagnosis of food allergy.

OBJECTIVE: To assess the outcome of oral food challenges in patients placed on elimination diets based primarily on positive serum immunoglobulin E (IgE) immunoassay results. STUDY DESIGN: This is a retrospective chart review of 125 children aged 1-19 years (median age, 4 years) evaluated between January 2007 and August 2008 for IgE-mediated food allergy at National Jewish Health and who underwent an oral food challenge. Clinical history, prick skin test results, and serum allergen-specific IgE test results were obtained. RESULTS: The data were summarized for food avoidance and oral food challenge results. Depending on the reason for avoidance, 84%-93% of the foods being avoided were returned to the diet after an oral food challenge, indicating that the vast majority of foods that had been restricted could be tolerated at discharge. CONCLUSIONS: In the absence of anaphylaxis, the primary reliance on serum food-specific IgE testing to determine the need for a food elimination diet is not sufficient, especially in children with atopic dermatitis. In those circumstances, oral food challenges may be indicated to confirm food allergy status.

Determination of ethoxyquin by high-performance liquid chromatography with fluorescence detection and its application to the survey of residues in food products of animal origin.

An analytical method using HPLC with fluorescence detection (HPLC-FL) has been developed and applied for the survey of residue levels of ethoxyquin in a variety of food products of animal origin. HPLC was performed using a silica octadecylsilane column, butylhydroxytoluene-acetonitrile-water (0.05 + 800 + 200, v/v/v) mobile phase, and detection at excitation and emission wavelengths of 370 and 415 nm, respectively. HPLC/MS was used to confirm whether a chromatographic peak was ethoxyquin. The LOQ of the foods was 0.01 microg/g, except for pig fat and cow's milk, and the RSD (n=6) at 0.1 microg/mL of the standard solution was 1.12%. The accuracy of the calculated data of the standard solution was within the range of 94.0 to 101.2%. Recoveries of ethoxyquin from the food products of cattle, pigs, chickens, and salmon were more than 71.0% with an RSD of < 9.3%, except for chicken liver at different concentration levels, including the lower LOQ, the maximum residue limit (MRL), and in some tissues, twice the MRL. Residue levels of ethoxyquin in 33 commercially available food products of animal origin that were purchased on the west side of the Tokyo metropolitan area were surveyed. Contents of ethoxyquin residues in three chicken fat samples by the HPLC-FL method were 0.08, 0.03, and 0.04 microg/g, all less than the MRL (5 microg/g).

Approaching Current and New Drug Therapies for Pediatric Asthma.

As new therapies for pediatric asthma are approved by the Food and Drug Administration, clinicians should be aware of their benefits and limitations. Accompanying these therapies are potential obstacles, including the delivery of inhaled therapies and age-specific issues regarding implementation and adherence. New insights are being added to well-established controller medications, including inhaled corticosteroids and long-acting ß-agonists, while new medications previously approved in adults, including tiotropium and biologics, are now being evaluated for use in children. These drugs can be useful additive therapies to treat patients who are currently not responding to guidelines-based therapy.

The Atopic Dermatitis Quickscore (ADQ): validation of a new parent-administered atopic dermatitis scoring tool.

BACKGROUND: Atopic dermatitis (AD) severity is assessed using relatively elaborate scoring systems administered by health care practitioners; modification for parent assessment or self-assessment is limited. For ongoing home-based evaluation of pediatric AD treatment and outcomes, a quick, easy-to-use, parent-administered scoring tool is essential. OBJECTIVE: To evaluate the validity and responsiveness to change of the Atopic Dermatitis Quickscore (ADQ) compared with the established, widely used Scoring Atopic Dermatitis Severity Index (SCORAD). METHODS: The ADQ was developed for parent report and was validated against the SCORAD. The SCORAD assesses percentage of body surface area involved, intensity of a "representative area," pruritus, and insomnia. The ADQ assesses involvement and pruritus of 7 body parts. Sixty-eight children entering a pediatric day treatment program for moderate to severe AD were recruited. Skin severity was scored at admission by a physician assistant using the SCORAD and by a parent using the ADQ. Pearson correlations of the 2 scales were assessed. RESULTS: The ADQ total score correlates with the SCORAD total score (r = 0.64, P < .001). The ADQ pruritus score correlates with the SCORAD pruritus score (r = 0.62, P < .001). Correlation at the end of treatment was also seen for ADQ and SCORAD total and pruritus scores (r = 0.39, P = .02, and r = 0.66, P < .001, respectively). Responsiveness of both scales to change in skin condition was demonstrated, with significant decreases in total and pruritus scores (P < .001). CONCLUSIONS: The parent-administered ADQ takes 5 minutes to complete. Scores from the ADQ and the SCORAD are well correlated and are responsive to changes in skin condition, supporting the validity of the ADQ.

Rings-on-a-string chain structure in DNA.

Using fluorescence microscopy (FM), which permits the observation of single molecules, we found that a pearling structure is generated on a single long DNA molecule upon the addition of a gemini (dimeric) surfactant. This pearling structure was further investigated by performing atomic force microscopy measurements on the same DNA molecules as observed by FM. These observations revealed that the pearling structure is composed of many rings that are interconnected by elongated coil parts along a single DNA molecule, i.e., rings-on-a-string structure. The mechanism of the formation of such an intrachain segregated structure in terms of microphase separation on a single polyelectrolyte chain is discussed.

Nonspecificity induces chiral specificity in the folding transition of giant DNA.

The all-or-none type DNA folding transition from a coil to globule can be differentiated by the chirality of the triamines. The fluorescent microscope observation on single DNA molecules makes it clear that the tripeptides obtained from naturally occurring basic amino acids (l-lysine or l-arginine) can compact DNA molecules at concentrations lower than those from d-isomers. Nanometer-sized beads are found in the AFM images on the folded DNA molecule.