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D Charpin

Publications and source records attributed to D Charpin.

At least 19 recordsLinked to original sources
PubMed2000

Prevalence of asthma and rhinitis in relation to long-term exposure to gaseous air pollutants.

The relationship between long-term exposure to air pollutants, especially with regard to photochemical air pollutants, and asthma prevalence in developed countries is controversial. The objective of this cross-sectional survey was to compare mean levels of the main gaseous air pollutants and prevalence rates of rhinitis, asthma, and asthmatic symptoms. It included 2,445 children from the 8th and 9th school grades who had been living for at least 3 years in an area where some communities undergo the heaviest photochemical exposure in France. Data on rhinitis, asthmatic symptoms, and asthma prevalence were gathered with the ISAAC paper and video questionnaires. The relation between level of air pollutants and asthma was assessed first by comparison of crude prevalence rates (chi-square test), and then by simple regression analysis and multiple logistic regression analysis. No consistent association between mean SO2 and NO2 levels, and prevalence of rhinitis, asthma, or asthmatic symptoms could be demonstrated. In contrast, there were statistically significant associations between prevalence of asthmatic symptoms and mean ozone O3) concentration. The interpretation of such findings is not straightforward, as these symptoms can be interpreted either as respiratory irritation due to exposure to nonspecific airway stimuli or as a true asthmatic state. Additional studies are required to clarify this important issue. In conclusion, this large cross-sectional epidemiologic survey performed in an area of high photochemical air pollution did demonstrate statistically significant associations between the prevalence of asthmatic symptoms and mean O3 concentration.

Adolescent↗
PubMed2000

Relationships of active and passive smoking to total IgE in adults of the Epidemiological Study of the Genetics and Environment of Asthma, Bronchial Hyperresponsiveness, and Atopy (EGEA).

The increase of total IgE in relation to active smoking has been shown in the general population, but little is known about subjects with a personal or family history of asthma. The objective of this report is to analyze the relationships of active and passive smoking to total IgE in the Epidemiological Study of the Genetics and Environment of Asthma, Bronchial Hyperresponsiveness, and Atopy (EGEA). The sample studied includes 122 asthmatic probands, 430 first-degree relatives, and 190 control subjects, age 25 to 54 yr. As expected, first-degree relatives had total IgE intermediate between cases and control subjects and men had higher values than women. Current smokers had significantly higher IgE than never smokers. The relationship was statistically significant restricting the analysis in asthmatic probands. In a model taking into account gender, personal and familial history of asthma, socio- occupational class, and the nonindependence of subjects from the same family, IgE were in current smokers, ex-smokers, and never smokers 128, 61, and 76 IU/ml and 77, 41, and 55 IU/ml in men (p = 0.01) and women (p = 0. 05), respectively. The relation was independent of skin test response. Some increase in IgE was observed in both men and women first-degree relatives in relation to passive smoking. That relation was statistically significant in women only (adjusted for asthma values: 103 IU/ml versus 48 IU/ ml, p = 0.02). Results show that an increase in total IgE in relation to active smoking may be evidenced even in asthmatics despite the healthy smoker effect. Susceptible subjects, such as women who are first-degree relatives of asthmatics, may increase total IgE in relation to passive smoking.

Adult↗
PubMed2000

Genome screen for asthma and related phenotypes in the French EGEA study.

A genome-wide search was conducted in 107 nuclear families with at least two siblings with asthma, as part of the French EGEA study. A two-stage analysis strategy was applied to the 107 families divided into two independent subsets of 46 and 61 families, where all regions detected in the first set of families were tested for replication in the second set. In addition, all regions reported by published genome scans in different populations were examined in the total sample. A total of 254 markers were typed in the first set of families and 70% of them in the second set. Linkage was investigated by model-free methods for asthma and four asthma-related phenotypes: bronchial responsiveness (BR), skin test response, total immunoglobulin E (IgE) levels, and eosinophil count. The two-stage analysis led to the detection of three regions: 11p13 for IgE, 12q24 for eosinophils, and 17q12-21 for asthma and skin tests. Among the regions reported by published genome screens, seven were found in the 107 French EGEA families: three being already detected by the two-stage analysis, 11p13 (p = 0.005), 12q24 (p = 0.0008), and 17q12-21 (p = 0.001), and four additional ones, 1p31 (p = 0.005) for asthma, 11q13 (p = 0.006) for IgE, 13q31 (p = 0.001) for eosinophils, and 19q13 (p = 0.02) for BR.

Adolescent↗
PubMed2000

[Allergy to cypress pollen: preparation of a reference and standardization extract in vivo].

Development of Cypress allergy frequency led to the standardization of commercial cypress extract used for diagnosis and immunotherapy. Previous in vitro studies on two cypress pollen species (Cupressus sempervirens and Cupressus arizonica) allowed us to produce an allergenic solution composed by a mixture of both extracts for in vivo standardization. Dilutions of this allergenic solution were tested by prick-test on 44 patients with clinical allergy to cypress pollen to define the dilution that corresponds to a 6 mm wheal conformed to the definition of 100 IR. The mixture of the two major species found in France is justified by the in vitro study results. Extracts revealed complementary allergenic composition: Cup sempervirens showed a wider diversity of allergens whereas Cup arizonica showed a higher content of the major 43 kDa allergen. Thus, according to in vivo analysis, we are able to produce a standardized extract of Cypress pollen expressed in IR.

Adult↗
PubMed2000

[Epidemiology of respiratory allergies: current data].

Respiratory allergic diseases include seasonal allergic rhinitis or hay fever, perennial allergic rhinitis and allergic asthma. Prevalence of asthma is difficult to assess through epidemiological questionnaires. In France hay fever roughly affects 6% of children and 18% of teenagers and nasal allergies, more than one fourth of young adults. Prevalence of asthma is equal to 10 to 15% in teenagers and 7 to 9% in young adults. Risk factors include genetic as well as environmental factors. The role of the former have been exemplified in family studies, especially twin studies, and surveys of inbred populations. Environmental factors can be allergic or non-allergic. The influence of allergenic exposure on sensitization, occurrence and severity of respiratory allergic disease is well documented. The triggering influence of non-allergenic factors on established allergic diseases is also clear. In contrast, their implication in allergic sensitization and occurrence of allergic diseases need to be clarified.

Adult↗
PubMed2000

[Evaluation of a questionnaire on the home environment of asthmatic patients].

Indoor environment outpatient asthmatics plays a major role in modulating asthma severity. Therefore many surveys devoted to studying risk factors for asthma include a questionnaire about housing characteristics. However no such questionnaire has been to date validated. In this study, we tried to validate such a questionnaire by comparing answers of a group of asthmatics outpatient to a questionnaire to de visu finding performed by a field worker during a home visit. Thirty asthmatic patients were included in the study. Housing characteristics were generally correctly acknowledged. Questions on the heating system should be clearly and simply formulated. Energetic supply of stoves and ventilation system is not always known. In the field of house equipment, especially bedding, photographs or drawings can be useful.

Asthma↗
PubMed1999

The prevalence of reported asthma is independent of exposure in house dust mite-sensitized children.

In areas with low house dust mite (HDM) allergen exposure, both mite sensitization and asthma prevalence are low. In most other areas, HDM allergen exposure is higher than the threshold for sensitization. In this setting, is HDM allergen exposure a factor which is causally related to the development of asthma in HDM-sensitive individuals? To answer this question, the cumulative prevalence of asthma was evaluated in a group of 157 schoolchildren, aged 10 and 11 yrs, who were allergic to HDM allergen, and compared it with HDM allergen exposure and atopic status, using univariate and multivariate analysis. HDM allergen levels were measured in mattress dust using an enzyme-linked immunosorbent assay (ELISA) method. Of mattress dust samples, 94% had an HDM allergen level >2 microg x g dust(-1). Atopy was evaluated by means of skin prick tests using five common allergens. Among the predictive variables studied by means of univariate analysis, only the number of positive skin tests and male sex correlated with asthma prevalence, but not HDM allergen exposure. Logistic regression analysis also demonstrated that the number of positive skin tests correlated with asthma prevalence (odds ratio (OR)=1.38, p=0.05), whereas the OR for HDM allergen exposure was 1.0. This survey suggests that, in a geographical area with high HDM allergen exposure, asthma prevalence is not linked with HDM allergen levels.

Allergens↗
PubMed1999

Prevalence of muscle relaxant sensitivity in a general population: implications for a preoperative screening.

BACKGROUND: Muscle relaxants (MR) are responsible for 59% of peroperative anaphylactic reactions. A major issue would be to determine whether a systematic preoperative screening in the general population should be recommended. OBJECTIVE: The purpose of the study was to evaluate the prevalence of muscle relaxant sensitivity in a sample of the general population and to assess the role of possible risk factors. METHODS: Two hundred and fifty-eight subjects, aged 20-40 years, visiting a health care centre for a check-up were evaluated. Protocol included a questionnaire (occupation, symptoms of atopy, previous surgery, history of drug allergy), skin-prick tests to four commercial muscle relaxants and measurement of specific IgE against quaternary ammonium ions. Atopy was evaluated by skin-prick tests to common inhalant allergens and by a Phadiatop test. RESULTS: Of the study group, 9.3% had either a positive skin test to one or more muscle relaxant or a presence of specific IgE to quaternary ammonium ions. No risk factor was identified in the studied group. CONCLUSION: Since the rate of MR sensitivity is much higher than the anticipated rate of peroperative reactions due to allergy, a systematic preoperative screening for MR allergy should not be recommended for adults in a general population.

Adult↗
PubMed1999

Gaseous air pollution and atopy.

BACKGROUND: Photochemical air pollutants are commonly thought to be implicated in the gradual increase in the prevalence of atopy. However, no epidemiological data are available. METHODS: To clarify this issue, we performed a cross-sectional epidemiological survey in 2604 primary school children, 10 and 11 years old, living in seven communities among which some have the highest photochemical exposure in France. The mean levels of the main gaseous air pollutants (SO2, NO2 and O3) were measured during a 2-month period in 1993. The protocol included a standardized questionnaire, skin prick tests to common aeroallergens and in the atopic children, collection of a sample of mattress dust to measure group 1 mite allergens. Atopy was only defined on the basis of the skin prick tests. RESULTS: Percentage of positive skin tests and the number of positive skin tests were similar in the different communities looked at. The distribution of dust samples with a group 1 allergen level greater than 2 microg/g dust, was also similar. Logistic regression analysis including potential confounding factors, as well as the mean level of air pollutants, did not demonstrate any association between atopy and mean SO2, NO2 and O3 levels. CONCLUSION: The increase in photochemical air pollutants is unlikely to be a major determinant for the recent increase in the prevalence of atopy.

Air Pollutants↗
PubMed1999

Prevalence of self-reported respiratory symptoms in workers exposed to isocyanates.

Until now, no survey had been conducted to assess the prevalence of respiratory symptoms in a large population that had been occupationally exposed to isocyanates, compared with that in a control group. We performed such a survey, using questionnaires administered by occupational physicians. Overall, 1114 workers' questionnaires (585 exposed and 529 control) were analyzed. Exposed workers, primarily painters from small factories, reported significantly (P < 0.05) more wheezing (8.6% vs 3.6%), more breathlessness with wheezing (3.4% vs 0.6%) in the last year, and more rhinitis (33.1% vs 19.1%) than did control workers. A trend for more asthma (2.1% vs 0.8%; P < or = 0.07) was also observed. Furthermore, 16.4%, 16.2%, and 10.6% of exposed workers reported (respectively) cough, rhinitis, and chest tightness when working in contact with isocyanates. We conclude that isocyanate-exposed workers demonstrate significantly higher prevalence rates of rhinitic and asthmatic symptoms than do control subjects.

Adult↗
PubMed1999

Role of allergens in the natural history of childhood asthma.

This review article deals with the role of allergens in the natural history of asthma. Several studies clearly demonstrate a strong relationship between allergen exposure, especially mite-allergen exposure, and risk of sensitization. Those studies have led to the proposed threshold equal to 2 micrograms/g dust. However, more recent evidence shows that there is no threshold for sensitization, especially in children born to atopic parents. As far as occurrence of asthma is concerned, geographical comparisons of asthma prevalence across Europe, Australia or in other populations with contrasted exposure to mite allergens do show such a relationship. The latter is not exemplified in studies performed within the same geographical area, probably because the exposure categories are not contrasted enough. Finally, asthma severity in mite sensitive asthmatics is partly modulated by allergen exposure but repeated exposure to low amounts of allergen can trigger disease activity. In conclusion, allergen exposure is involved at each step of the natural history of asthma. Even low doses can play a significant role. Thus avoidance methods, in order to be efficient in primary and secondary prevention, should lead to a drastic decrease in allergenic exposure.

Allergens↗
PubMed1999

[Knowledge, opinions and attitudes of physicians regarding air pollution in the Bouches-du-Rhône].

OBJECTIVE: To evaluate knowledge, opinions and attitudes of physicians towards prevention of health consequences from air pollution, especially photo-chemical pollution. METHODS: A questionnaire was prepared by a multidisciplinary group from published literature on Health impact of air pollution and from local context. It was administered on line among a random sample of physicians practising in the County of the Bouches du Rhône (Marseille, South-eastern France). The sample consisted in pediatricians (1/2), general practitioners (GP; 1/14) and pneumologists. RESULTS: The answer rate was 79% (112/169 GP, 94/107 pediatricians, 82/91 pneumologists). Among the 288 physicians who answered the questionnaire, 44% declared they felt very concerned by air pollution, especially pediatricians. While 87% were knowledgeable about SO2 regulations, only 59% (48% among pediatricians) were knowledgeable about ozone regulations. While about all physicians knew the health effects of air pollution episodes on respiratory tract, only half knew that mortality rates can increase significantly during such episodes. Forty percent of physicians had never heard about air pollution episodes that occurred in their city, while air quality control networks had identified them. At last, only 15% of physicians had already given recommendations to patients during episodes of ozone pollution (above 180 micrograms/m3). CONCLUSION: That study shows the need for improving knowledge and attitudes of physicians about air pollution, especially photo-chemical air pollution. As physicians are concerned about the Health impact of air pollution, and patients are demanding about this issue, training and information programmes should be implemented rapidly. However, experimental interventions aimed at reducing the acute effects of air pollution episodes should be evaluated to show their efficiency, and to convince physicians with scientific arguments.

Air Pollution↗
PubMed1999

EGEA (Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy)-- descriptive characteristics.

The Epidemiological study on the Genetics and Environment of Asthma (EGEA) was planned to assess genetic, environmental risk factors and their interactions for asthma and for the two related traits of bronchial hyperresponsiveness and atopy. The population examined includes 348 nuclear families ascertained by one asthmatic (213 adult and 135 paediatric probands) and 416 controls, totalling 1,847 subjects (EGEA I). Prevalences of asthma, skin prick test response, high IgE and bronchial hyperresponsiveness were for parents, siblings, and offspring of cases intermediate between cases and spouses or controls, both in adults and children, confirming the familial resemblance for asthma and related traits. With an additional sample of 40 families ascertained by two asthmatic siblings (EGEA II), a total of 119 families with two asthmatic siblings has been ascertained for a genome screening.

Adolescent↗