RATIONALE In a guinea pig model of allergic asthma, using perfused tracheal preparations ex vivo, we demonstrated that L-arginine limitation due to increased arginase activity underlies a deficiency of bronchodilating nitric oxide (NO) and airway hyperresponsiveness (AHR) after the allergen-induced early and late asthmatic reaction. OBJECTIVES Using the same animal model, we investigated the ...

BACKGROUND Asthma has been associated with eosinophil activation, measured in serum, sputum, bronchoalveolar lavage (BAL) fluid, and urine. A whole blood automated method was developed to assess eosinophil and neutrophil activity in terms of peroxidase content and cell morphology using the Bayer haematology analyser. The method was applied to an in vitro stimulation model when fMLP was added to...

We have measured the competitive antagonistic effect of chlorpheniramine in bronchi of 8 normal and 12 asthmatic subjects. Classical pharmacological theory states that the degree of competitive antagonism depends only upon 1) antagonist concentration at the receptor, and 2) receptor affinity. Delivery and affinity also influence agonist responsiveness, but measurement of bronchial antagoni...

In asthmatic subjects there is a pronounced diurnal variation in bronchial responsiveness. If this phenomenon is due to variation in factors that control drug delivery, then it should be paralleled by a similar variation in competitive antagonist blockade. In order to study this possibility, we performed the methacholine challenge test and after 45 minutes, administered atropine by inhalat...

INTRODUCTION  Changes in the respiratory system of asthmatics are also due to the mechanical disadvantage caused by the increased airway resistance. OBJECTIVE  The study aims to evaluate the respiratory muscle strength and nutritional status of asthmatic children. METHOD  This is a prospective descriptive and transversal study with 50 children aged 7 to 12 years, who were placed into 2 grou...

Chitinase inhibitors have chemotherapeutic potential as fungicides, pesticides, and antiasthmatics. Argifin, a natural product cyclopentapeptide, competitively inhibits family 18 chitinases in the nanomolar to micromolar range and shows extensive substrate mimicry. In an attempt to map the active fragments of this large natural product, the cyclopentapeptide was progressively dissected down to ...