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A Tenabene

Publications and source records attributed to A Tenabene.

12 recordsLinked to original sources
PubMed1993

[Severe asthma].

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Acute Disease↗
PubMed1989

Platelet function: aggregation by PAF or sequestration in lung is not modified during immediate or late allergen-induced bronchospasm in man.

Among the mediators involved in the pathophysiologic mechanisms that underly the reactions of the acute and delayed phases of bronchospasm induced by allergens in man, platelet-activating factor (PAF) could play an important role, in particular by its effects on platelets. In animals, inhalation or injection of PAF causes a platelet-dependent bronchoconstriction that is blocked by prior administration of an antiplatelet antiserum and accompanied by platelet accumulation in the pulmonary vessels. In man, inhalation of PAF causes a bronchospasm and induces a bronchial hyperreactivity. Abnormalities of platelet aggregation and the secretion into plasma of platelet factor 4 and beta-thromboglobulin have been described in patients with asthma during induced bronchospasm. Platelet functions have been studied in 15 patients with asthma before and after allergen bronchial provocation tests. There was no difference between platelet counts, plasma concentrations of platelet factor 4 and beta-thromboglobulin, and platelet aggregation induced by several agonists (adrenaline, arachidonic acid, or PAF) before and immediately after the allergen bronchial provocation test. There was no platelet pulmonary sequestration as studied with 111Indium-labeled platelets during 24 hours after the antigen challenge, and the life span of circulating platelets was normal. Our results do not support an important direct role for PAF in the pathophysiology of asthma. It is still possible that the current methodology is too insensitive to detect amounts of PAF in the circulation or that PAF is acting locally.

Adolescent↗
PubMed1988

Guanine and mite allergenicity in house dust.

Guanine is the major nitrogenous waste product in arachnids. It may serve as an indicator for allergenic mite faecal pellets. The present study assesses the correlation between the mit allergenicity of different house dust (HD) samples and their guanine content. Guanine content in HD samples was evaluated either by the Acarex-Test or determined quantitatively, especially for in-vitro methods. Using intradermal tests in selectively sensitized Dermatophagoides pteronyssinus (Dpt) patients, we evaluated the mite allergenicity of eight extracts obtained from HD samples with varying guanine contents. The weal area appeared to be proportional to the HD samples' guanine content. A three-fold increase in skin reactivity was observed when the guanine content varied from 0.06% to more than 1%. Patients allergic to HD but not to Dpt had no significant reactions with HD extract prepared from a guanine-rich HD sample. For eighteen different HD samples coupled to paper discs, the percentage Dpt RAST binding values obtained with a Dpt-selectively sensitized patient serum pool was correlated with the guanine concentrations of HD samples (P less than 0.01). The potencies of different HD extracts obtained from HD samples that varied in guanine content were also clearly distinguished on histamine-release titration curves. House dust obtained from homes at high altitude or from hospitals was generally guanine free. The HD sample guanine contents in homes where twelve Dpt-sensitized patients experienced symptoms were significantly higher than in homes where these patients were symptom free. The guanine colour test, a quick and easy technique, represents an important new development in indoor environmental investigations. It makes it possible to demonstrate mite faecal exposure and can be used to monitor the effectiveness of mite allergen avoidance measures.

Allergens↗
PubMed1988

[Long-term efficacy of high-dose aerosol corticotherapy in the treatment of severe asthma].

Forty-five patients with severe, poorly controlled asthma, including 23 corticosteroid-dependent patients, were treated with a preparation of beclomethasone dipropionate aerosol delivering 250 mcg per puff. The daily dose ranged from 1000 to 2000 mcg. The mean follow-up period was 14 +/- 7 months, and 11 patients have now been followed up for more than 2 years. Forty-two patients were improved, and total withdrawal of continuous steroid therapy could be achieved in 13 cases. Treatment remained effective in long term use, provided a minimum of 1000 mcg/day was given. However, despite clinical improvement the obstructive syndrome persisted in 65% of the patients.

Administration, Inhalation↗
PubMed1988

[Mechanism of action and mode of administration of high-dose inhaled corticotherapy in the treatment of asthma].

The commercial availability of high-dose inhaled corticosteroid preparations for the treatment of asthma offers an occasion for reviewing the different mechanisms of action of glucocorticoids notably glucocorticoids, notably their interference with lipocortin protein synthesis and arachidonic acid metabolism. A favourable effect on bronchial hyper-reactivity and on delayed hypersensitivity reactions has also been observed. The problems raised by the various preparations responsible for varying degrees of systemic activity, the difficulties inherent in the use of inhalers and the side-effects of these products are discussed. The effectiveness and safety of the current high-dose inhaled preparations are emphasized.

Administration, Inhalation↗