Combination drug therapy for the prevention of exercise-induced bronchoconstriction in children.

BACKGROUND: Sequential administration of a beta-agonist and cromolyn or nedocromil before exercise is recommended for patients whose symptoms are not controlled by beta-agonists alone; however, this practice reduces compliance. OBJECTIVE: To evaluate the effectiveness of a new pre-combined aerosol formulation (salbutamol and nedocromil) in preventing exercise-induced bronchoconstriction and to compare it to salbutamol alone. METHODS: Twelve children with asthma were studied in a double-blind, double-dummy, randomized, crossover, placebo-controlled design to compare the protective effect of salbutamol and a new pre-combined salbutamol/nedocromil formulation against exercise-induced bronchoconstriction. The drugs were delivered by a metered-dose inhaler (salbutamol, 200 microg; salbutamol/nedocromil, 200 microg/4 mg; placebo, 2 puffs) 20 minutes before exercise. RESULTS: Both active drugs were significantly more protective than placebo but there was no difference between them. Complete protection was obtained in 12/12, 10/12, and 1/12 subjects for the salbutamol/nedocromil combination, salbutamol alone and placebo, respectively. CONCLUSIONS: Although inhaled beta-agonists alone are highly efficacious in preventing exercise-induced bronchoconstriction, a minority of patients exists for whom a combined treatment with salbutamol and nedocromil is advantageous. This group may represent a subpopulation of subjects who release more, or different, mediators in response to exercise.

Salmeterol in exercise-induced bronchoconstriction in asthmatic children: comparison of two doses.

Since the optimal dose of salmeterol in asthmatic children has not yet been clearly defined, we compared the efficacy and duration of the protective effect of two doses of salmeterol (25 and 50 micrograms) against exercise-induced bronchoconstriction. Twelve children (aged 7-14 yrs) with asthma were studied in a double-blind, cross-over, placebo-controlled design. On three separate days, exercise tests were performed 1 h and 12 h after administration of the drug. Pulmonary function measurements were performed before drug inhalation, before every exercise test and 1, 5, 10, 15 and 30 min after the end of exercise. The response was expressed as maximal decrease in forced expiratory volume in one second (FEV1). Both doses of salmeterol provided significant bronchodilation for up to 12 h, with no difference between them. Maximal exercise-induced decrease in FEV1 (% fall) 1 h after pretreatment was (mean +/- SD) 35 +/- 16, 10 +/- 10 and 4 +/- 3% for placebo, 25 and 50 micrograms salmeterol, respectively. At 12 h after pretreatment these values were 31 +/- 14, 19 +/- 12 and 15 +/- 13%, respectively. Individual protection against exercise-induced bronchoconstriction at 1 and 12 h did not vary between the dosages (p < 0.05), even though the protection obtained by 25 micrograms at 12 h was no longer significant versus placebo. We conclude that 25 micrograms of inhaled salmeterol provides equally effective long-lasting bronchodilation and acute protection against exercise-induced bronchoconstriction as 50 micrograms, and may be a suitable dose for most asthmatic children.

Gamma delta T lymphocytes in mumps meningitis patients.

Flowcytometric analysis on T-cell subpopulations in the blood and cerebrospinal fluid (CSF) of 10 children with mumps meningitis (MM) revealed that the proportion of lymphocytes which bore the gamma delta T-cell receptor for antigen was significantly higher in CSF than in autologous and heterologous blood samples. gamma delta T-cell values in CSF of MM patients were also significantly higher than those calculated in CSF specimens from nine children with non-inflammatory neurological disorders. Whether and how the expanded CSF gamma delta T-lymphocyte subset, either CD8+ or double-negative (CD4-/CD8-), contributes to the eradication of mumps virus infection from the central nervous system represents a central focus of our ongoing research.

Cromolyn versus nedocromil: duration of action in exercise-induced asthma in children.

Cromolyn sodium (10 mg), nedocromil sodium (4 mg), and placebo, all delivered by a metered dose inhaler, were compared in their efficacy and duration of action in preventing exercise-induced asthma in children. After a screening test was performed, 13 patients with asthma performed standard exercise tests 20 minutes and 140 minutes after drug inhalation in a randomized, double-blind, crossover study. Both drugs were significantly more protective than placebo after 20 minutes, but no significant difference was seen between cromolyn sodium and nedocromil sodium. No difference between active drugs and placebo was found 140 minutes after inhalation. At these clinically recommended doses both cromolyn sodium and nedocromil sodium provide equal protection against exercise-induced asthma, and the duration of action of both lasts for less than 2 hours.

CD26 and CD31 surface antigen expression on human colostral T cells.

The expression levels of CD26 and CD31 surface antigens, two adhesion/activation molecules with helper and suppressor activities, respectively, were found to be significantly higher on human colostral T cells (CD3+) than in autologous peripheral blood samples. These findings provide further phenotypical evidence that immune system T lymphocytes are compartmentalized in the mammary gland late in pregnancy and during lactation. The question of whether these overexpanded T lymphocyte populations in breast milk modulate in situ, either by enhancing or suppressing, the cellular and/or humoral immune response of the suckling infant remains to be answered. Additional studies are, therefore, needed to explore this intriguing field concerning the immunology of the colostrum.