A dual CysLT1/2 antagonist attenuates allergen-induced airway responses in subjects with mild allergic asthma.

BACKGROUND: The cysteinyl leukotrienes (cysLTs) play a key role in the pathophysiology of asthma. In addition to functioning as potent bronchoconstrictors, cysLTs contribute to airway inflammation through eosinophil and neutrophil chemotaxis, plasma exudation, and mucus secretion. We tested the activity of the dual cysLT1/2 antagonist, ONO-6950, against allergen-induced airway responses. METHODS: Subjects with documented allergen-induced early (EAR) and late asthmatic response (LAR) were randomized in a three-way crossover study to receive ONO-6950 (200 mg) or montelukast (10 mg) or placebo q.d. on days 1-8 of the three treatment periods. Allergen was inhaled on day 7 two hours postdose, and forced expiratory volume in 1 s (FEV1 ) was measured for 7 h following challenge. Sputum eosinophils and airway hyperresponsiveness were measured before and after allergen challenge. The primary outcome was the effect of ONO-6950 vs placebo on the EAR and LAR. RESULTS: Twenty-five nonsmoking subjects with mild allergic asthma were enrolled and 20 subjects completed all three treatment periods per protocol. ONO-6950 was well tolerated. Compared to placebo, ONO-6950 significantly attenuated the maximum % fall in FEV1 and area under the %FEV1 /time curve during the EAR and LAR asthmatic responses (P < 0.05) and allergen-induced sputum eosinophils. There were no significant differences between ONO-6950 and montelukast. CONCLUSIONS: Attenuation of EAR, LAR, and airway inflammation is consistent with cysLT1 blockade. Whether dual cysLT1/2 antagonism offers additional benefit for treatment of asthma requires further study.

Evaluating control of breathing utilizing an on-line microcomputer.

This paper describes a system that was designed to evaluate ventilatory responses to hypercapnia, airway occlusion pressure (P100), as well as measuring ventilatory drive and timing. Parameters measured include minute ventilation (VE), breathing rate (f), tidal volume (VT), inspiratory time (TI), fractional inspiratory time (TI/TTot), mean inspiratory flow (VT/TI), and end tidal partial pressure of carbon dioxide (PETCO2). These measurements allow for a thorough analysis of abnormalities of neural and neuromuscular ventilatory drive. The system's architecture was based primarily on currently available microcomputer components designed for the IEEE 696 bus.

Effect of thoracentesis on arterial oxygen tension.

The acute effects of thoracentesis on arterial oxygenation were observed in 19 studies on 17 patients. Arterial blood samples were obtained prior to, immediately after, and 1 h after thoracentesis. Unpredictable changes in the arterial oxygen tension, ranging from -22 to +19 mm Hg were found immediately following thoracentesis. It was concluded that significant hypoxemia may result from thoracentesis due to aberration of ventilation-perfusion relationships. It is further suggested that oxygen therapy be routinely administered during and immediately after the procedure.

Dose ranging study of mometasone furoate (Nasonex) in seasonal allergic rhinitis.

BACKGROUND: Topical nasal corticosteroids are rapidly gaining acceptance as first-line therapy for seasonal allergic rhinitis, but there is a desire for effective corticosteroids with an improved safety profile over existing products. OBJECTIVE: A multicenter, double-blind dose ranging study was conducted to compare the activity and tolerance of four doses of mometasone furoate nasal spray (tradename Nasonex) and placebo in adult patients with seasonal allergic rhinitis. METHODS: Four hundred eighty patients with seasonal allergic rhinitis were enrolled and randomized to receive mometasone furoate nasal spray 50 micrograms (n = 96), 100 micrograms (n = 95), 200 micrograms (n = 98) or 800 micrograms (n = 95), or placebo vehicle (n = 95) once daily for 28 days. RESULTS: All of the doses of mometasone furoate nasal spray showed activity in reducing the severity of rhinitis. The 200-microgram dose reduced total nasal symptom scores and total symptom scores throughout the study (P < .05 versus placebo vehicle). The 50-microgram dose and the 100-microgram dose showed less consistent activity at early timepoints (days 3 and 7), while the 800 microgram dose did not provide significant additional benefits over the 200-microgram dose. All dose levels were well tolerated CONCLUSION: The results of this trial indicate that 200 micrograms once daily is the optimum dose of mometasone furoate nasal spray for the treatment of seasonal allergic rhinitis.