ABSTRACT
Background: Cysteinyl leukotrienes have been shown to play an important role in the pathogenesis of asthma. The effect of the leukotriene receptor antagonist, montelukast, on bronchial hyperreactivity (BHR) as measured by the methacholine challenge test in school children has not been reported. Objective: To determine the effect of montelukast (Singulairâ) on BHR measured by methacholine challenge and lung function tests in Thai asthmatic children aged 6-13 years. Materials and methods: This was a randomized, double-blind, placebo-controlled, crossover study performed in 29 mild to moderate persistent asthmatic children aged 6-13 years. Each child received crossover treatment with 6 weeks of montelukast (5 mg/day) and 6 weeks of placebo separated by a two-week washout period. Results: The improvement of FEV1 and FEV1/FVC after 6 weeks of treatment was significantly higher in montelukast group compared to those of placebo group (p<0.05). After 6 weeks of treatment, mean (+ SEM) PC was 20 in the placebo group (5.7 + 1.41 mg/ml) which was lower than in montelukast group (6.8 + 1.74 mg/ml) but there was no significant difference (p=0.79). Conclusion: Montelukast significantly improved FEV1 and FEV1/FVC but not BHR in mild to moderate persistent asthmatic children aged 6-13 years after the 6 weeks of treatment.
ABSTRACT
Background: Different mattress materials may affect the accumulation of allergens. Objective: To compare the amount of group 1 dust mite allergens (Der p1 + Der f1) on mattresses made of different kinds of materials before and after use. Methods: Sixty new mattresses made of kapok, synthetic fiber, coconut fiber and sponge-like polyurethane, were placed in the house officers’ dormitory at Siriraj hospital, Thailand. The dust samples were collected before (0), 1, 2, 3, 6, 9 and 12 months after the mattresses were used. Group 1 dust mite allergens were analyzed using two-site monoclonal antibody ELISA. Results: Der f1 made up 86.7 % of group 1 allergens found in the matress dust. After the 2nd month, only the mean level in sponge-like polyurethane mattress was under 2 µg/g dust (sensitized level). At the 6th month, the mean levels were 13.1 in coconut, 21.7 in kapok and 17.3 µg/g dust in synthetic fiber, all of which were more than 10 µg/g dust (symptomatic level). At the 9th month, the level in sponge-like polyurethane mattress was increased to 11.2 µg/g. At 12th month the level in coconut fiber, sponge-like polyurethane synthetic fiber and kapok mattresses were 20.2, 22.4, 28.9 and 32.2 µg/g dust respectively. Conclusions: The accumulation rate in kapok and synthetic mattresses was significantly higher than coconut and sponge-like polyurethane mattresses. The mean level of group 1 mite allergens exceeded 10 µg/g dust after the 6th month of use in coconut fiber, kapok and synthetic fiber and at the 9th month in sponge-like polyurethane mattress.