Biomedical subjects

Harold S Nelson

Publications and source records attributed to Harold S Nelson.

39 records · Page 3Linked to original sources

PubMed2002

A comparison of methods for assessing hypothalamic-pituitary-adrenal (HPA) axis activity in asthma patients treated with inhaled corticosteroids.

Suppression of the hypothalamic-pituitary-adrenal (HPA) axis is an accepted indicator of potential side effects from inhaled corticosteroids. Although cortisol monitoring is frequently used to detect changes in HPA axis activity, the optimal method for identifying the subset of asthma patients on inhaled steroids who experience severe cortisol suppression of potential clinical significance has not been established. The objective of this study was to compare several methods for assessing HPA axis activity in asthma patients taking inhaled corticosteroids. After screening, 153 patients with mild to moderate asthma were randomly assigned to receive inhaled fluticasone propionate (110, 220, 330, or 440 microg bid), flunisolide (500 microg or 1000 microg bid), or one of two control regimens (prednisone or placebo) for 21 days. Salivary (8 a.m.) and urinary (24-h) cortisol determinations were compared against 22-hour area under the serum cortisol concentration-time curve (AUC0-22 h) measured at baseline and on day 21. Comparisons were also made against 8 a.m. serum cortisol. A significant positive correlation was found between AUC0-22 h of serum cortisol and 8 a.m. serum cortisol level (r = 0.5140; p = 0.0001). The AUC0-22 h of serum cortisol was weakly correlated with 24-hour urinary cortisol levels, both corrected (r = 0.4388; p = 0.0001) and uncorrected (r = 0.3511; p = 0.0001) for creatinine excretion. The 8 a.m. salivary cortisol level correlated positively with the 8 a.m. serum cortisol level (r = 0.5460; p = 0.0001). Salivary cortisol was both sensitive and specific for the detection of a 50% decline in AUC0-22 h of serum cortisol. Cortisol reductions of this magnitude have been observed following repeated use of inhaled steroids. Because it is noninvasive, salivary cortisol measurement offers distinct advantages as a screening method for detecting pronounced HPA axis suppression in asthma patients receiving corticosteroid therapy.

Administration, Inhalation↗

PubMedDate not supplied

Mast cell inhibitor R112 is well tolerated and affects prostaglandin D2 but not other mediators, symptoms, or nasal volumes in a nasal challenge model of allergic rhinitis.

Understanding of the role played by mast cells in allergic rhinitis (AR) has led to the development of novel therapies. The aim of this study was to determine the safety and tolerability of R112, an inhibitor of the tyrosine kinase Syk, in an allergen challenge model of AR. We also examined the effects of R112 on symptoms, mediator release, and nasal airway volumes. This double-blinded, randomized, placebo-controlled, crossover trial enrolled 20 out-of-season volunteers with AR. One intranasal dose of R112 or vehicle was administered and followed by an allergen challenge. In addition to safety monitoring, symptoms; changes in histamine, tryptase, and prostaglandin D2 (PGD2) content of nasal secretions; and acoustic rhinometry were determined over a 15-minute period. R112 was well tolerated. Adverse events were similar between treatments. Five minutes after allergen instillation, PGD2 was decreased when subjects received R112 compared with vehicle (93.4 +/- 23.0 pg/mL versus 171.6 +/- 23.0 pg/mL; p = 0.03), and this correlated with rhinorrhea (p = 0.05). However, at 10 minutes, changes in PGD2, tryptase, and histamine were not significant (46.8 +/- 9.2 pg/mL versus 68.6 +/- 9.2 pg/mL, p = 0.1; 9.5 +/- 2.7 ng/mL versus 16.6 +/- 2.9 ng/mL, p = 0.09; and 1.5 +/- 1.6 ng/mL versus 3.5 +/- 1.6 ng/mL, p = 0.4). No differences were found in symptoms or in acoustic rhinometry between treatment groups. Single-dose R112 appears safe and significantly reduces PGD2 but not histamine or tryptase release in response to allergen challenge in subjects with AR.

Adult↗

PubMedDate not supplied

Pairwise comparison of levalbuterol versus racemic albuterol in the treatment of moderate-to-severe asthma.

The object of this study is a post hoc pairwise comparison of levalbuterol versus racemic albuterol for asthma in a multicenter, double-blind, randomized, placebo-controlled clinical trial. The participants are patients > or =12 years of age (n = 362) with FEV1 45-70% of predicted. The patients received nebulized levalbuterol (0.63 or 1.25 mg), racemic albuterol (1.25 or 2.5 mg), or placebo t.i.d. for 4 weeks. The primary endpoints, published in Nelson HS, Bensch G, Pleskow WW, et al. Improved bronchodilation with levalbuterol compared with racemic albuterol in patients with asthma. J Allergy Clin Immunol 102:943-952, 1998, included comparisons of active treatments with placebo and of the combined levalbuterol with the combined racemic albuterol groups for pulmonary function and rescue medication use. After the first dose, levalbuterol 1.25 mg produced a significantly greater increase in the mean peak change in FEV1 compared with both doses of racemic albuterol (p < 0.03) in all patients and in those with more severe asthma. Levalbuterol 1.25 mg also produced a significantly greater (p < 0.05) mean area under the curve (AUC) of the FEV1 versus time plot (AUC FEV1) compared with all other treatments after the first dose in all patients and in the subset with more severe disease, illustrating better overall improvement in FEV1. Active treatment groups demonstrated significant improvements compared with the placebo group (p < 0.05), except for AUC FEV1 in the racemic albuterol 1.25-mg group at week 4. Levalbuterol in the absence of the (S)-isomer provided greater bronchodilation than the same quantity of (R)-albuterol delivered as the racemate. These data suggest that (S)-albuterol may compromise the efficacy of (R)-albuterol.

Administration, Inhalation↗