Aerosolised hyaluronic acid prevents exercise-induced bronchoconstriction, suggesting novel hypotheses on the correction of matrix defects in asthma.

Hyaluronic acid (HA), a biopolymer, member of the family of the glycosaminoglicanes (GAGs) is one of the major natural components of the connective amorphous matrix. The lungs, together with skin and intestine, contain >50% of HA of the body: it provides to several biologic functions and presents the unique capacity to link and retain a particularly relevant number of water molecules. Since other GAGs have been proven to be provided with anti-asthmatic properties and HA has been employed with positive results by intra-tracheal instillation in experimental models of lung emphysema and COPD, we have explored the efficacy of the pre-administered aerosol of HA (compared to placebo) in preventing in asthmatic patients the bronchoconstriction induced by a challenge test such as that obtained with muscular exercise. In a randomised, cross-over, single-blind study design, saline as placebo (P) or HA have been administered by aerosol, in two non-consecutive days, 30 min prior to the beginning of the challenge (10 min free running), to 14 patients (13-36 years old; 7 teenagers, 7 young adults; 11 males, 3 females; 12 allergic, 2 non-allergic), all suffering from mild bronchial asthma. The bronchoconstrictive effect induced by the muscular exercise has been relevant and statistically significant. With the P pre-treatment, the average FEV1 measured 5 min after the end of exercise was reduced by 36.14% from the baseline FEV1. Pre-treatment with HA determined a partial but clear-cut protection of the FEV1 impairment due to the challenge: the average post-challenge FEV1 resulted to be 12.43% less than the pre-challenge baseline value. No significant difference was observed in the level of HA protection in the subgroup of teenagers when compared to that of young adults. The protection induced by HA, when compared with P, resulted particularly significant by the statistical point of view (p < 0.0001). We conclude that aerosol HA administration significantly reduces the bronchial hyper-reactivity to muscular exercise in asthmatics. Such effect could be attributed to the correction of the pathological remodelling, one of the main features of asthma: a correction which could be attributed to the unique physicochemical properties of this major component of the loose connective amorphous matrix of the airways, which is undoubtedly involved in the remodelling process.

Protein profile of Helicobacter pylori strains by isoelectrofocusing in patients affected by chronic gastritis.

BACKGROUND: To understand if relapse, following antimicrobial treatment was due to re-infection or to recrudescence. METHODS: Fifty patients with dyspepsia were studied prospectively. They were followed up by endoscopy and biopsy of antral mucosa before and after treatment with anti-microbial therapy. Gel isoelectrofocusing was used to characterize protein profile of Hp. RESULTS: At baseline 40 patients were affected by chronic gastritis associated with Hp. At the end of treatment 75% patients given omeprazole, amoxicillin and clarithromycin were Hp infected: 43% showed the same protein profile and 57% different. CONCLUSIONS: Our data suggest that the relapse is due to recrudescence or to reinfection.

Efficacy and tolerability of nimesulide in asthmatic patients intolerant to aspirin.

Inflammation of the airways accompanied by eosinophil infiltration appears to play a fundamental role in the pathogenesis of bronchial asthma. Therefore, anti-inflammatory agents (at present corticosteroids, cromoglycate and nedocromil) are the first-line treatment for this condition. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin (acetylsalicylic acid) and indomethacin, however, have never been used in this setting, mainly for fear of adverse effects (e.g. severe obstructive reactions); these can occur, in a consistent number of patients as a consequence (according to the most widely accepted theory) of inhibition of prostaglandin synthesis. In a double-blind crossover placebo-controlled study involving 20 aspirin-sensitive patients with asthma, we found that oral nimesulide 100mg was well tolerated both clinically and functionally (no significant changes in forced expiratory volume in 1 second and specific airway resistance after drug intake). In a more recent study, we observed a mild obstructive reaction (easily controlled with inhaled bronchodilators) after oral administration of nimesulide 400mg to 3 patients who had previously tolerated a 100mg dose. On the basis of clinical experience, nimesulide (unlike most other NSAIDs) in the recommended doses appears to be well tolerated in aspirin-sensitive asthmatic patients. Furthermore, this distinctive anti-inflammatory agent might provide a novel approach to the treatment of bronchial asthma.

Tolerance of guaiacolic ester of acetylsalicylic acid by patients with aspirin-asthma.

The effects of oral administration of the guaiacolic ester of acetylsalicylic acid (ASA-G) on the ventilatory function were studied by means of a body plethysmograph, in a group of nine ASA-asthmatic patients. No differences in specific airway resistance were observed between ASA-G and placebo. It is concluded that ASA-G is tolerated by patients with ASA-induced asthma.

Aspects of bronchial reactivity to prostaglandins and aspirin in asthmatic patients.

The behaviour of bronchial reactivity to PGF2alpha was studied in asthmatic patients under various experimental conditions. Premedication with aminophylline, i.v., and, to a lesser extent, with DSCG afforded a partial protection, while beclomethasone dipropionate was inactive under this point of view. Diftalone, a new non-steroid anti-inflammatory agent, was well tolerated in 9 aspirin-intolerant asthmatic patients, and did not modify the bronchial response to PGF2alpha which was found to be generally lower then that of other aspirin-tolerant asthmatic patients. PGE 1-2 and DSCG prevented the bronchospasm induced by inhalation or ingestion of acetylsalicylic acid in a small group of patients. Good protection was also reached with PGE1-2 in the exercise-induced bronchospasm.