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Biomedical subjects

F Lieutier-Colas

Publications and source records attributed to F Lieutier-Colas.

9 recordsLinked to original sources

Low-dose endotoxin in allergic asthmatics: effect on bronchial and inflammatory response to cat allergen.

BACKGROUND: Endotoxin was proposed to increase the severity of asthma. Endotoxin levels greatly differ according to settings. In domestic environments, airborne concentrations may be dramatically low compared with levels reported in occupational settings. OBJECTIVE: Our first objective was therefore to assess the effect of inhalation of low-level lipopolysaccharide (LPS) on the immediate and late-phase asthmatic bronchial response. Our second objective was to evaluate the effect of exposure to LPS on the local and systemic inflammatory response. METHODS: Nineteen asthmatics sensitized to cat underwent on two separate occasions a bronchial challenge test to cat allergen (cat BCT) preceded randomly by a pre-exposure to either saline or LPS (2 microg). Methacholine challenge test was performed 24 h before exposure to LPS or saline. The Borg scale for dyspnoea and lung function were recorded before and after exposure to LPS or saline, and before and after cat BCT. Induced sputum and blood samples were collected before and after cat BCT, and analysed for cell counts and eosinophil cationic protein (ECP) levels. RESULTS: Inhalation of 2 microg LPS did not induce any changes in forced expiratory volume in 1 s (FEV1), peak expiratory flow (PEF), FEF 25-75 and Borg scale of dyspnoea. It neither modified Fel d 1 PD20 (45.03 ng as compared with 87.03; P=0.42). As well, there was no significant difference in late-phase reaction. Pre-exposure to LPS did not influence eosinophil counts or ECP levels in blood and sputum. CONCLUSION: Our study demonstrated that pre-exposure to LPS at low levels, which may be encountered in domestic environment, had no significant effect on the immediate and late-phase bronchial response to cat allergen. It neither modified local and systemic eosinophilic inflammation.

Adult↗

[Pharmacists' role in the management of asthma: a survey of 120 pharmacists in Bas-Rhin].

INTRODUCTION: The pharmacist plays an essential role in the management of the asthmatic patients on account of their frequent visits to the pharmacy to obtain their medication. METHODS: In order to evaluate the practice and knowledge of asthma among the pharmacists of the department of Bas-Rhin, 120 pharmacists were selected at random to reply to a standardised questionnaire. RESULTS: The 86 pharmacists who replied to the questionnaire had a good general understanding of asthma and its treatment. However, only 26.4% knew all the criteria of the severity of an attack of asthma. Among the 57 pharmacists who gave a demonstration of the use of inhaler devices, 16.3% showed all the steps in the use of a metered dose aerosol. These results are comparable to those of non-specialist doctors and nurses in whom poor techniques were found in 63-100% and 65-96% respectively. The mean scores of the pharmacists were 10.5/12 (+/- 1.2) steps for metered dose aerosols, 10.4/11 (+/- 1.0) for the Tubuhaler, 9.3/12 (+/- 1.7) for the Autohaler and 8.1/9 (+/- 0.9) for the Volumatic spacer. The asthmatic patient's main expectation of the pharmacist concerned the use of the prescribed systems (87.2%), underlining the lack of information received by the patient at the time of prescription. CONCLUSIONS: An improvement in the knowledge of the signs of severity of asthma and the use of inhaled devices could usefully be one of the objectives in the training of a dispensing pharmacist.

Adult↗

Prevalence of symptoms, sensitization to rats, and airborne exposure to major rat allergen (Rat n 1) and to endotoxin in rat-exposed workers: a cross-sectional study.

OBJECTIVE: To analyse the relation between airborne exposure to major rat allergen and to endotoxins in exclusively rat-exposed workers and the prevalence of rat-related symptoms and sensitization. METHODS: A total of 113 workers answered a standardized questionnaire on their atopy status, occupational exposure to rats, and possible work-related symptoms. Specific IgE against rat urinary proteins (RUP) was measured for 73 subjects. Individual airborne exposure to Rat n 1 and endotoxin were determined with static (n = 256) samplings. Rat n 1 was measured with enzyme-linked immunosorbent assay (ELISA) and endotoxin by the Limulus method. RESULTS: Forty-four of 113 subjects (38.9%) reported at least one rat-related symptom: asthma (4.4%), rhinitis (34%) and conjunctivitis (16%). Twelve per cent were sensitized to RUP (specific IgE > 0.35 KU/L). But only 30.8% of all symptomatic subjects were sensitized to rat allergens. Airborne Rat n 1 levels were not related to symptoms in workers. Symptomatic patients not sensitized to rats were exposed to higher endotoxin levels, but airborne exposure to endotoxins did not significantly protect against or increase sensitization to RUP or rat-related symptoms. CONCLUSION: Most symptomatic workers were not sensitized to rat allergen; but no significant relation between rat-related symptoms and endotoxin levels was found. This suggests that more studies are needed to determine causes other than rat allergens or endotoxins that may be responsible for symptoms in rat-exposed workers.

Adult↗

Difference in exposure to airborne major rat allergen (Rat n 1) and to endotoxin in rat quarters according to tasks.

UNLABELLED: Endotoxins found in occupational settings constitute a risk factor in the severity of respiratory allergic symptoms. OBJECTIVES: To assess the airborne concentrations of major rat allergen (Rat n 1) and endotoxin under various circumstances. METHODS: We took 483 airborne samples from 12 sites: 114 individual samples for endotoxin measurements and 113 for Rat n 1, from 38 workers (nine animal technicians, nine laboratory technicians, nine scientists and 11 students); and 256 static samples in rat rooms and experimental rooms, with or without disturbance, for simultaneous endotoxin and Rat n 1 measurements. Rat n 1 was measured with a two-site monoclonal ELISA and endotoxins with the Limulus method. RESULTS: Airborne Rat n 1 and endotoxin were significantly higher in rat rooms than in experimental rooms. Animal technicians had the greatest exposure to both Rat n 1 and endotoxin. Cage cleaning and rat feeding induced the highest exposure to Rat n 1 and endotoxin. Furthermore, we observed no significant difference in endotoxin exposure between researchers with or without rat contact during the sample period. There was no correlation between the number of rats present and airborne endotoxin concentrations. CONCLUSIONS: Exposure to airborne Rat n 1 and endotoxin is higher during cleaning and feeding tasks than during any other task, we feel that a major source of both is contaminated bedding that becomes airborne during disturbance.

Air Pollutants, Occupational↗

Urticaria and rhinitis to shrubs of Ficus benjamina and breadfruit in a banana-allergic road worker: evidence for a cross-sensitization between Moracea, banana and latex.

BACKGROUND: We report the case of a road worker with a food allergy to banana, who developed urticaria and rhinitis when cutting shrubs of Ficus benjamina and breadfruit. He did not develop an allergy to latex of Hevea brasiliensis. RESULTS: Sensitization to latex of F. benjamina, H. brasiliensis, breadfruit and banana was demonstrated using skin tests and specific IgE measurements. RAST inhibitions procedures showed that specific IgE to breadfruit latex cross-reacted more strongly with latex of H. brasiliensis and banana than with latex of F. benjamina with the same extract. CONCLUSION: Given the wide distribution of Moracea trees in tropical regions, sensitization to latex of H. brasiliensis and banana could be a consequence of sensitization to Moracea members; F. benjamina does not seem to be the only Moracea responsible for cross-allergy with latex and fruit. Consequently, it seems interesting to test other members of the Moracea family in patients sensitized to latex of H. brasiliensis and banana. Sensitization to breadfruit could be a risk factor for sensitization to latex of H. brasiliensis.

Adult↗

[Deposition of particles in the respiratory tract].

In order to appraise the site of deposition of an aerosol of particles in the airways, it is important to analyse the size distribution of the particles that form the aerosol by granule size range analysis. The three main different mechanisms involved in deposition of an aerosol are inertia impaction, sedimentation and brownian diffusion, and one or another predominates, according to the size of the inhaled aerosol. Finally, several factors may influence the deposition in the respiratory tract: anatomy of the airways, the respiratory method, the size range and the moisture content of the aerosol, smoking and respiratory pathology. Only by taking into account all these factors can an assessment be made of the deposition site in the airways of the inhaled particles.

Aerosols↗

[Domestic pollution (other than tobacco)].

Pollution of the air of the interior of premises are generally less understood than exterior town atmospheric pollution. Now the time spent at home is considerable, around 80%. Aerocontaminants are of chemical, biological or particulate nature. Amongst asthmatics, internal NO2 is capable of producing an asthmatic crisis, perhaps by a direct effect of the pollutant and perhaps by potentiation of the bronchial response to the allergen. COV and formaldehyde may have a bronchial effect on asthmatics, at significant levels that are rarely found in a domestic environment. Endotoxins present in domestic dust may also be a serious co-factor in asthmatics who are allergic to mites. Concerning allergens, identification and quantification of immunodominant proteins of the principal pneumoallergens of the internal environment has emphasized the great diversity of levels, and given a comparison of the link between the level of allergen in the air and dust, and the development of the sensitization of a predisposed subject. Measurement of the aerodynamic behaviour of pneumoallergens has led to a better understanding of the physiology of allergic asthma. Nevertheless it is appropriate to follow the work that tries to assess the relative importance of each of these factors, both in allergic sensitization and in the clinical response to the allergen. Understanding the respective roles played by the different domestic pollutants should allow an improvement in diagnosis and treatment of pathologies that are linked to the domestic environment.

Adolescent↗