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Biomedical subjects

D Charpin

Publications and source records attributed to D Charpin.

At least 145 records · Page 8Linked to original sources

Atopy and anaphylactic reactions to suxamethonium.

Muscle relaxants are widely used for general anesthesia and may be responsible for IgE-dependent anaphylactic reactions (AR). A controversial issue in the field of drug allergy is whether ARs are more frequent or severe in atopic subjects. Thus, we performed a case-control study comparing the distribution of various clinical and biologic signs of atopy. The case group included 32 patients with a history of AR to suxamethonium, the most commonly used muscle relaxant. The control group included 128 subjects, matched to the case group according to age, gender, and socioeconomic status. The case group consisted mainly of young and middle-aged women. Distribution of symptoms suggestive of atopy and of skin tests and specific IgE to common aeroallergens was similar in both groups. In contrast, total serum IgE level was much higher in the case group, suggesting the presence of specific IgE against suxamethonium or other drugs. Thus, despite previous studies in the literature, atopy is not a risk factor for the occurrence of anaphylactic reactions to muscle relaxants. As AR to suxamethonium is a pure model of an IgE-dependent drug allergy, our data do not support a relationship between atopy and allergic drug reactions.

Allergens↗

Epidemiology of asthma in western Europe.

Asthma deaths are uncommon, but have recently increased in some countries due to problems in the management of the disease. Morbidity rates show large variations, which can be attributed to differences in defining the disease, but also to genuine variations, with a trend towards less asthma in northern Europe. It has been suggested that allergic diseases as a whole, and asthma in particular, may exhibit an upward secular trend. Risk factors include a genetic background and environmental triggering factors. The importance of genetic factors is illustrated by family studies and by extreme prevalence rates observed in some communities. Environmental factors include rapid air pollution variations which act as a trigger for asthma attacks. However, at levels currently prevailing in western Europe, air pollutants do not induce a higher incidence of asthma. Altitude generates a gradual decrease in Dermatophagoides, thus explaining both the clinical improvement in asthmatics living in altitude and a lower prevalence of asthma in populations born and living there. Among the other aero-allergens, grass pollens plays a major role in spring, elicitating asthma attacks. Some natural allergens transformed by man (castor bean, soja) can be responsible for asthma epidemics.

Air Pollution↗

Asthma and allergy to house-dust mites in populations living in high altitudes.

Do subjects living in high altitude where house-dust mites are known to be uncommon exhibit a lower prevalence of asthma and allergy to house-dust mites? To answer this question, we compared the prevalence rates of asthma and skin reactions to house-dust mites in two towns with contrasted environments: Marseille, located on the seashore, and Briançon, 1350 m in altitude. The study population consisted of a random sample of 4,008 people in Marseille and 1,055 people in Briançon. All subjects received a home questionnaire, and a sample of patients and asymptomatic subjects had a skin-prick test evaluation. The cumulative prevalence of asthma was equal to 4.1 percent in Marseille and 2.4 percent in Briançon, a difference which was significant (p = 0.01). The prevalence of positive skin tests to housedust mites in asymptomatic subjects was equal to 27.5 percent in Marseille and 10.2 percent in Briançon (p less than 0.001). This study supports the hypothesis that exposure to environmental factors may have a major influence on developing allergic diseases.

Adult↗

[Does common asthma show intercritical functional anomalies?].

During an epidemiological survey conducted in 1985, we performed spirometric examinations in a group of 133 asthmatic subjects and a group of 168 control subjects. After standardization for sex, height and age, mean FEV1 values were lower in asthmatics than in control subjects and decreased when the frequency of asthma attacks increased. Thus, from observations gathered in asthmatics identified by a questionnaire during a field study, we can confirm previous conclusions drawn from outpatients clinics: most of the time, asymptomatic asthmatics demonstrate an airflow limitation.

Adult↗

[Heredity of asthma].

To compare the heredity of asthma among families of intrinsic, extrinsic and control subjects, we have studied the siblings and offsprings of the 3 groups of subjects (using a standardized questionnaire). The results shown that asthma was genetically transmitted but the clinical manifestations appeared later among the relatives of intrinsic than among the relatives of extrinsic asthmatic patients.

Asthma↗

[Medical history of severe respiratory insufficiency].

To evaluate retrospectively health care in severe chronic respiratory failure, we interviewed 38 patients, admitted for the first time to a pulmonary intensive care unit for an acute episode. A standardised questionnaire was devoted to establishing if the patients were aware of chronic respiratory disease prior to admission, if they had visited a general practitioner or a chest clinic, and had undergone a lung function evaluation. Six patients were unaware of any respiratory disease prior to the acute episode. Six others realised they had suffered from a respiratory disease, but had failed to visit a physician. Among the remaining 26 patients, two-thirds had visited a chest physician. Fourteen of them had undergone spirometry and arterial blood gas measurements. One third had visited a general practitioner but spirometry was performed in only 3 and arterial blood gas analysis in only 1. Thus, chronic respiratory failure is sometimes ignored, and most of the time diagnosed with delay and inadequately evaluated.

Adult↗

[Is there an urban factor in asthma and allergy?].

To evaluate if an "urban factor" could be responsible for an increase of asthma and allergic diseases in developed countries, we compared prevalence rates for these conditions in adults living in urban and rural settings. The urban group consisted of 4,008 adults, randomly selected from the 16 districts of the city of Marseille; the rural group consisted of 1,789 adults, representing 85% of the target population living in a small residential town, Trets. The protocol included, after a mass media information, home-visits by public health physicians. These physicians asked a short standardized questionnaire to all adults 18 to 65 years old. Then, in a subgroup of, hay-fever patients, they performed skin tests to grass pollens. The standardized prevalence rates of asthma and related symptoms, and hay fever, was very similar in both settings. Thus, this study does not support the hypothesis that there is a urban factor in asthma and allergic diseases. In the literature, several studies point out a higher prevalence of these diseases in an urban setting. But these studies have been performed several years ago, when there was a larger difference in air pollutants concentrations between urban and rural settings.

Adolescent↗

[Clinical and spirometric repercussions of chronic exposure to air pollutants in children in the region of the Gardanne coal-basin].

Our goal was to evaluate the long-term effects of exposure to air pollutants in schoolchildren living in the Gardanne coal-basin. The group consisted of 193 children 9 to 11 years old, 128 living in polluted communities, 65 in low polluted communities. The protocol included a standardized questionnaire and a spirometric evaluation. The prevalence of pulmonary and E.N.T. symptoms was higher in the polluted communities, but a statistically significant difference was only observed for the symptom "wheezing in the chest". The spirometric values, FEV1 and FVC, were very similar in both areas. It is likely that spirometric abnormalities will appear later in those schoolchildren. Indeed, in the same area, studies performed in groups of housewives have demonstrated a higher prevalence of respiratory symptoms, as well as spirometric abnormalities in subjects living in high polluted communities.

Air Pollutants↗

Role of the quaternary ammonium ion determinants in allergy to muscle relaxants.

Anaphylaxis to muscle relaxants appears to be a very useful model to study the IgE-dependent mechanisms of mediator release in humans. The serum IgE binding sites of the drugs appeared to be the ammonium ion determinants. In patients allergic to suxamethonium, one of the most frequently used muscle relaxants for general anesthesia, significant histamine release could be obtained in each case with simple diammonium salts. The length of the chain linking the ammonium groups appears to play an important role. In fact, when the length was less than or equal to 4 A, no significant histamine release could be obtained, whereas the optimal length for histamine release appeared to be greater than or equal to 6 A. Furthermore, muscle relaxants with a rigid backbone between the ammonium determinants (such as pancuronium) are less active than flexible molecules (such as suxamethonium) in initiating mediator release. This study suggests that small divalent molecules can induce anaphylactic shock in sensitized patients and that the length and the flexibility of the chain bearing the haptenic determinants appear to be important factors in the elicitation of mediator release.

Drug Hypersensitivity↗

Allergy to suxamethonium: persisting abnormalities in skin tests, specific IgE antibodies and leucocyte histamine release.

Twenty-one patients, who had previously experienced an anaphylactic reaction to suxamethonium during general anaesthesia, were selected for this study. Initially, skin tests with muscle relaxants were carried out in the twenty-one patients, detection of specific anti-choline IgE in nineteen, and leucocyte histamine release in seventeen. These three tests were then repeated between 1 year and 4 years after the initial evaluation. In the majority of patients, sensitization to the muscle relaxants persisted for more than 1 year after the anaphylactic reaction. Only three patients out of twenty-one (4%) had negative skin tests when retested 1-4 years later. A reduction in leucocyte histamine release was noticed in one of the seventeen retested patients (6%). Modifications of anti-choline IgE were observed in five of nineteen patients (26%). The persistence of sensitization to suxamethonium may result from repeated stimulation by occasional contacts with quaternary ammonium compounds. This study demonstrates the reliability of skin tests, leucocyte histamine release and detection of anti-choline IgE to diagnose allergic reactions to suxamethonium, even when they are performed a long time after the initial anaphylactic reaction.

Alcuronium↗

Relationship between skin reactions to common allergens and non-specific bronchial reactivity in young healthy subjects.

In patients with respiratory symptoms, several studies have provided data supporting the hypothesis that there is a casual relationship between allergen exposure and variations in bronchial reactivity. In order to determine if this relationship holds when atopy is defined only on the basis of positive skin tests to common allergens, we compared bronchial reactivity in a group of twelve healthy subjects with positive skin tests and twenty-eight healthy subjects with negative tests. The two groups were comparable in terms of gender, age, smoking habits and family history of atopic diseases. The slopes of the dose-response curves, using airway conductance as an index of response, were similar in the two groups. Thus, in this healthy group of subjects, there was no relationship between skin and bronchial reactivity. It can be hypothesized that, if genetic factors determine bronchial reactivity, such reactivity might not be revealed until skin-test positive subjects have received repeated bronchial stimulation through inhalant allergens.

Adult↗

[Immediate allergy,terrain and allergens].

Different backgrounds may be involved in the elicitation of IgE-dependent reactions; an atopic background, i.e. synthesis of specific IgE against common allergens and an allergic background, in the field of drug allergy and allergy to hymenoptera stings, in which atopy is probably not an important risk factor. Allergens have three-dimensional molecular configurations and this is an important determinant of their immunological reactivity. Only multivalent allergens can induce a specific release of mediators.

Allergens↗

[Pleural plaques and an asbestos environment in Northern Corsica].

As opposed to North-West Corsica, North-East Corsica is rich in asbestos outcrops and a source of environmental pollution as can be seen in the airborne concentration of chrysotile and above all tremolite. We have composed the frequency of asbestos pleural plaques occurring in subjects in the two regions starting with a retrospective analysis of the radiological records of 1,721 patients born in Northern Corsica and having no occupational exposure to asbestos. The frequency is 3.8% in the North-East and 1.1% in the North-West (p less than 5%). The relative East-West risk, which is 3.3%, shows the existence of a link between pleural plaques and environmental exposure to asbestos in North-East Corsica.

Aged↗

[Lung cancer: recent epidemiologic data].

The prognosis of lung cancer is still very poor. However, during the last few years a favorable trend has been observed, consisting in the stabilization and even the decrease of incidence rate in Western countries. Besides, the sex-ratio shows a divergent trend, increasing in France and decreasing in the United States where lung cancer nowadays is the first cause of cancer deaths in women. The major risk factor, tobacco smoke, is now well established, qualitatively as well as quantitatively. Other air contaminants, occupational factors and air pollutants, have a lesser responsibility. The intervention of nutritional or genetic factors could explain why smokers are not equally susceptible to tobacco smoke. Screening for lung cancer is, and will be, reconsidered in the light of the results of prospective studies initiated 10 years ago under the auspices of the American Cancer Society.

Adult↗