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Biomedical subjects

D Charpin

Publications and source records attributed to D Charpin.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1998

Rhinitis alone or rhinitis plus asthma: what makes the difference?

This paper examines the clinical expression of asthma in a group of patients displaying rhinitis according to age, sex, associated symptoms, smoking, familial history of asthma, atopy, type of sensitization to aeroallergens (pollens and/or indoor allergens), total serum immunoglobulin E (IgE), and blood eosinophils. A total of 117 adults with rhinitis were analysed on the basis of symptoms. Among them, 51 also displayed asthma, defined as a history of recurrent episodes of dyspnoea with a reversible airflow obstruction or a positive methacholine challenge. The logistic regression analysis carried out in a stepwise approach, combining several factors, showed that various parameters affected the risk of having asthma associated with rhinitis. A further analysis was made in 74 rhinitis patients comparing 42 subjects without nonallergic airway hyperresponsiveness (NAAH) to 32 patients with asthma and NAAH. Atopy, high total serum IgE levels, elevated blood eosinophil count and maternal asthma were associated with asthma. Furthermore, in atopic patients, pollen sensitization was more closely related to rhinitis alone, whereas sensitization to indoor allergens was a major determinant for the association of asthma with the symptoms of rhinitis. The same risk factors as those found in the clinical part of the study discriminated the patients with rhinitis without NAAH from those with rhinitis, asthma and NAAH. In conclusion, this study gives new insights into the relationships between asthma and rhinitis.

Adult↗
PubMed1998

[Risk factors in severe asthma].

Risk factors for severe acute asthma involve the patient, the environment and the society in general. In addition, there are strong interrelationships between these factors. Personal characteristics linked to acute severe asthma include age (teenagers), denial leading to poor compliance, depression with atypical symptoms in children, and some medical features of asthma associated with increased severity. Environmental factors include airborne allergens, infections, irritants such as air pollutants and passive smoking. Life events have not been extensively studied but are likely to play a predominant role. The social setting, particularly the health care system, acts as an interface between the patient and the environment. Most all asthma deaths are avoidable and related to dysfunctions in the health care system.

Adolescent↗
PubMed1998

[Pollution and allergy: the epidemiological data].

This area is controversial, mostly because of disagreement between experimental and epidemiological data. Even though modulation of asthma by the level of atmospheric pollution has been well shown by panel and ecological studies, the relationship between pollution and genesis of allergic diseases has not been confirmed by epidemiological studies. Comparison of the frequency of asthma in urban and rural surroundings in general shows, in the urban environment, an advantage of irritation symptoms but not for asthma. In contrast, the prevalence of atopy seems higher in the urban environment, which is perhaps a reflection of a different way of life, like that shown in east-west studies. Several recent investigations showed that at the centre of a development additional respiratory symptoms related to the intensity of automobile traffic, but no relationship was shown with atopy. In the same way, no epidemiological investigation has shown a relationship between automobile pollution and prevalence of atopy. Thus, at present no solid elements exist to support an increase of the frequency of asthma and especially atopy, in a relationship with modern atmospheric pollution, essentially of automobile origin.

Air Pollutants↗
PubMed1997

Association between latex sensitization and repeated latex exposure in children.

BACKGROUND: Children with spina bifida are at greater risk for latex and ethylene oxide sensitization. The authors' aim in this study was to evaluate the role of previous surgical procedures in the development of sensitization to latex and ethylene oxide. METHODS: The authors investigated 80 children 1-16 yr old, separated into 3 groups. Two groups had a history of 3 or more general anesthetics: 29 children had spina bifida (spina bifida group) and 31 had undergone multiple surgeries for another disease (multiple surgeries group). A control group of 20 children had undergone less than 1 anesthetic. Clinical manifestations with latex, perioperative anaphylactic reactions, and number of previous anesthetics were recorded. Skin prick tests with a commercial extract of latex, four common inhalant allergens, and radioallergosorbent test to latex and ethylene oxide were performed. RESULTS: The three groups did not differ significantly with respect to age, sex, and atopic status. Mean number of anesthetics was comparable in the spina bifida and the multiple surgeries group. Latex sensitization was common in the spina bifida group (59%) and in the multiple surgeries group (55%) but not in the control group (0%, P < 0.05). Ethylene oxide sensitization was significantly more frequent in the spina bifida group than in the multiple surgeries group (44% vs. 19%; P = 0.052) and strongly associated with latex sensitization. Mean number of previous anesthetics was greater in children sensitized to latex (8.4 vs. 3.9; P < 0.05). CONCLUSION: Results suggest that it is the number of surgical procedures rather than spina bifida per se that is related to sensitization to latex.

Adolescent↗
PubMed1997

Morphometry and densitometry of alveolar macrophage cytoplasmic particles in Chernobyl, Ukraine, liquidators.

OBJECTIVE: To characterize intracytoplasmic particles found in alveolar macrophages (AMs) sampled by bronchial alveolar lavage (BAL) performed on Chernobyl, Ukraine, liquidators suffering form chronic obstructive lung disease. STUDY DESIGN: Eight BALs were assessed. BAL products containing AMs were cytocentrifuged, and appropriate fixation and epoxy embedding were performed for ultrastructural study. Morphometry of cells (AMs) and of cytoplasmic particles was then obtained by processing, using dedicated software, digitized ultrastructural images. RESULTS: AM cytoplasm contained crowded phagolysozomes, varying in size, shape and density and enclosing dense particles rich in radionuclides, with particular morphometric features: surface, 387 +/- 543 pixels (mean +/- SD); number, 77 +/- 34; phagozome/cell surface ratio, 23.7%; shape factor, 1.32 +/- 0.23; and mean optical density, 171 +/- 31. CONCLUSION: Processing of digitized ultrastructural images of AMs provides accurate morphometric data that can be used further for clinical purposes, in particular to evaluate BAL performed either for diagnosis or treatment.

Adult↗
PubMed1997

Prevalence of latex sensitization in subjects attending health screening: implications for a perioperative screening.

BACKGROUND: Because latex is a common allergen, the rate of latex sensitization may be high in the general population. A major issue would then 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 latex sensitization in a sample of the general population and to assess the role of possible risk factors. METHODS: The subjects were 258 people, aged from 20 to 40 yr, visiting a health care centre for a check-up. The protocol included: a questionnaire (occupation, symptoms of atopy, use of latex goods and possible reactions, history of previous surgery), a skin-prick test, and a CAP RAST to latex. Atopy was evaluated by a skin-prick test to common allergens and a Phadiatop test. RESULTS: Some 6.6% of the study group had either a positive skin test or a positive RAST to latex. These subjects had a four-fold higher prevalence of symptoms when wearing gloves. The rate of latex sensitization was higher by fivefold in subjects with a history of reactions to latex goods and by fourfold in atopic subjects. CONCLUSIONS: Because the rate of latex sensitization is much higher than the anticipated rate of perioperative reactions due to latex allergy, a systematic preoperative screening for latex allergy should not be recommended for adults.

Adult↗
PubMed1997

[Severe bronchial stenosis with upstream bronchiectasis in an arc welder: causal relation or epiphenomenon?].

This case concerns an arc welder who presented suppurative bronchiectasis and episodes of purulent left side pleurisy in relation to cystic bronchiectasis of the left lower lobe and a very severe stenosis at the origin of the main left bronchus. The medicolegal problem was to assess the causal relationship between these lesions and occupational exposure. They do not come under the heading of table 44 of the General List and we made this the aim of discretionary award in front of a regional committee of compensation for occupational disease.

Bronchial Diseases↗
PubMed1997

[New aero-allergens. Interaction between allergens and the environment].

There is a qualitative as well as a quantitative change in allergen exposure. From a qualitative viewpoint, the relevance of some allergens (domestic allergens i.e. cockroaches, outdoor allergens i.e. plane tree, chestnut and ash tree pollens) has been established. The role of some other allergens has been, strictly speaking, discovered: latex from Hevea and ficus, trichophyton mold, some occupational allergens and very recently transgenic allergens. From a quantitative viewpoint, the concentration and/or distribution of some allergens has increased. Plantation of numerous trees or fortuitous introduction of weeds has led to an increased specific sensitization. In like manner, introduction of new foods or food processing procedures has created new food allergens and allergy. Besides, the distribution of some well-known aero-allergens is better known since discovery of ELISA--technology allowing measurements of minute amounts of these allergens. A burning issue today is to know whether irritant factors could modify allergens. Few data, sometimes contradictory, are available in the field of interaction between air pollutants and allergens.

Air Pollutants↗
PubMed1996

[Specific treatments of allergic manifestations].

Because we now know more about the relationship between environment and allergy, we should aim: at preventing allergic diseases in at-risk populations; at alleviating symptoms in sensitized patient using avoidance methods; and at modifying immunological responses through specific immunotherapy. Recent studies provide a better knowledge of the allergenic levels which induce sensitization and trigger symptoms in allergic patients. This knowledge allows a strategy for avoidance measures. A better understanding of cross allergenicity of several allergens has been drawn from a better knowledge of the epitopes. Specific immunotherapy has proven its efficacy in selected patients suffering from asthma and/or rhinitis and patients with hymenoptera sensitivity.

Desensitization, Immunologic↗