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J C Bessot

Publications and source records attributed to J C Bessot.

At least 55 records · Page 3Linked to original sources
PubMed1988

Positive skin tests to aero-allergens and month of birth.

The month of birth distribution for 1301 French patients born between 1953 and 1975 with at least one positive skin test was compared to that of the whole population. A chi-square test was performed, and the expected birth month distribution of the groups calculated from the INSEE* data for 1953-1975. All patients underwent skin testing with house dust, Dermatophagoides pternyssinus (Dpt), cat and dog allergens, grass, tree and weed pollens, and moulds. The only study criterion was a positive skin test unrelated to any specific disorder. A significant difference in month of birth distribution was observed 1) for patients with positive skin test to grass pollen, with a high rate of births from January to May, and 2) for patients with mould sensitization, with a low rate of births in April, May and December. Tree and weed pollens, house dust and Dpt showed no significant relation with month of birth. For cat and dog allergens, the observed and expected distributions of birth month were similar. For the whole sensitized population the birth rate tended to be low in December except for the cat and dog sensitized. Our study confirms the well-known seasonal peak of births in the first 5 months of the year for grass pollen sensitized patients. No consistent monthly or seasonal tendency could be statistically demonstrated for other allergens except moulds.

Air Pollution↗
PubMed1988

[Occupational asthma: methods of diagnosis and principle etiologies].

The diagnosis of occupational asthma requires the integration of a multiplicity of data; the history, cutaneous skin tests, respiratory function tests and non-specific tests of bronchial hyper-reactivity and specific bronchial provocation tests. The history remains fundamental in the investigation of occupational asthma. It should particularly search for the presence of an atopic trait, the occurrence of similar disorders in members of the same firm and also the timing of symptoms in relation to the occupational activities. Cutaneous tests are particularly helpful in IgE-mediated asthma in relation to the inhalation of animal or vegetable materials of glycoprotein origin. For haptens, the need for their prior coupling to a protein carrier causes problems which have not been entirely resolved. Laboratory tests (RAST, histamine liberation, TDBH...) run into the same snags. Respiratory function and non specific bronchial provocation tests confirm the diagnosis of asthma and enable the medium and long term progress to be assessed. Specific bronchial provocation tests are the most appropriate tests to establish an aetiological diagnosis in occupational asthma. Different technical methods are possible: quantitative administration of allergen, aerosols, and realistic tests using exposure chambers to achieve true test doses and to obtain dose dependent responses. The products responsible for occupational asthma are multiple and are gathered into two tables. The different substances are characterised in a simplified manner. First animal matter (mammalian and arthropod allergens), secondly substances of vegetable origin (roots, leaves, flowers, grain and flour, wood and its derivatives) and finally chemical products. The chemical products are primarily from the pharmaceutical and metal industries and above all from the plastics industry.

Allergens↗
PubMed1988

[Drug prevention and physical protection in occupational asthma].

Many means of protection can be used in work-related asthma. Drug protection may be by symptomatic treatment with classical anti-allergic drugs such as Cromoglycate and Ketotifen. Therapy with corticosteroids has a preventative action on the delayed allergic reaction. Drug protection is however only palliative and incomplete. Individual physical protection needs masks that may be filtering, or anti-dust, or anti-gas, or helmets or masks that have air addition, or even autonomous respirators. The main efforts in prevention should be made against the responsible agents, with their identification and reduction of the level of exposure. This reduction of exposure may be done by re-structuring the work place, by sufficient ventilation and extraction or by addition of moisteners. Modification of the manufacturing process may also be affective, by alterations to make the manipulations in a chamber or closed circuit, to the apparatus, automation and computer control or changes or replacement of the agents responsible for the work-related asthma.

Asthma↗
PubMed1988

Celery allergy: clinical and biological study of 20 cases.

In 20 patients, the ingestion of celery was responsible for mucocutaneous symptoms (generalized urticaria and angioedema) (18/20) and respiratory disorders (7/20). Four cases of systemic anaphylaxis were observed. The main associated allergic disorder was pollinosis (16/20). Food allergy to other vegetable products, mainly other Umbelliferae and apples, coexisted with celery allergy in 12 cases. It was found that celery allergy is mediated by IgE antibodies: it is easily diagnosed by skin tests (fresh extracts of celery may be used) and by adequate RAST (17 positive results). Cosensitization with mugwort pollen (14 cases) and birch pollen (9 cases) was found. Celery allergens responsible for clinical sensitization originate chiefly in the tuber and are at least partly thermally labile. The frequent association with pollen sensitization suggests the existence of common antigenic epitopes in celery extracts and mugwort and birch pollens. The immunologic investigations carried out so far (RAST inhibition and immunoprint) seem to support this hypothesis.

Adolescent↗
PubMed1987

[Profile of a respiratory allergy department from computerized data collected between 1968 and 1984 (3962 cases)].

A prospective study of clinical, cutaneous and biological sensitivity to the common air-borne allergens was conducted over a 16-year period in a total of 3,962 patients who reported to a hospital consultation for respiratory allergy. The study confirmed certain widely recognized semiological features, but it did it on the basis of a real population with a large number of subjects and therefore was a true textbook of allergology with a live material. In addition, the study benefited from the major advantage of computer data processing: an accurate and rapid analysis. Yet some uncertainties and omissions remained concerning answers to certain questions, but such gaps are inherent in the natural subjectivity of allergic patients and their doctors.

Adolescent↗
PubMed1986

[Mites: the principal respiratory allergens of house dust].

The Mites are the most frequent of the lung allergens. Three families have a prime importance. The Pyroglyphidae (of which Dermatophagoides pteronyssinus, Dermatophagoides farinae and Euroglyphus maynei are a part), the Acaridae and the Glyciphagidae which comprise the stock acariens responsible for certain occupational asthmas. After the discovery of the role of mites in respiratory allergy numerous studies have specified the ecological conditions favourable to their development (temperature, relative humidity, the nutritional environment) and have emphasised the beneficial role of altitude and the importance of the characteristics of the habitat. Another avenue of research consists in culture of the acariens, to isolate by immunological chemical purification techniques the glycoproteins responsible to their allergic activity, The studies led to the identification of the major allergens most frequently responsible for sensitizing man. Thus for Dermatophagoides pteronyssinus two major allergens have been identified by different teams. Certain common allergens in different species explain the crossed sensitivity which are frequently observed. One of the major allergens of Dermatophagoides pteronyssinus, the allergen P, is contained in faecal particles of the acariens. These particles are identified in the domestic environment and are easily made into a suspension by normal household activities. Current preventative methods are orientated towards the effect of exclusion of the acariens on the respiratory symptomatology. The diminution of the mite numbers, a reduced frequency of crisis after complete eviction of the allergens from the home and diminished bronchial reactivity to pharmacological mediators after very prolonged eviction. The use of acaricides or of fungicides would merit more numerous controlled studies with a view to showing their efficacy on the respiratory symptomatology of sensitive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗
PubMed1986

[Criteria for evaluating specific desensitization in asthma].

In the absence of any satisfactory immunological criteria an objective assessment of the results of desensitization in asthma largely rests on clinical criteria. The use of clinical criteria themselves runs into many difficulties, some of which are inherent in the nature of asthma (chronic cause, temporary variations, variations according to the allergen responsible, the association of non-specific factors to specific allergic factors) and others result from the individual characters of the asthmatic under-study. The assessment of the results of desensitization should not rest solely on the observations of the patient and physician. A clinical score can be gathered thanks to a daily diary card. A drug score can be assessed by a daily record of the amount of medication used. The recording of peak flow in spite of its imperfections is particularly well suited to multiple daily measurements of airflow obstruction. The paper work generated by the daily diary cards can be computerised. A study of the correlations existing between the different daily scores recorded shows, that the selection of patients for a trial of desensitization should be carried out over a long enough period to enable non compliant patients to be discarded namely those patients without any good correlation between the symptoms and functional score. Another approach to assessing the efficacy of desensitization is the study of changes in bronchial provocation tests to allergens; these depend on a good reproducibility of the immediate and delayed responses to allergens in each subject at different times.

Allergens↗
PubMed1985

Celery sensitivity: clinical and immunological correlations with pollen allergy.

The authors studied twenty patients with celery allergy and concomitant hypersensitivity to certain pollens (mugwort, birch). The specific symptoms induced by eating celery were attacks of urticaria and angio oedema (seventeen out of twenty) respiratory complaints (eight out of twenty), systemic anaphylaxis with vascular collapse (three out of twenty). A strong association between clinical reactions to celery and mugwort sensitization, and to a lesser degree between celery allergy and birch pollen sensitization was established. Celery allergy is mediated by IgE antibodies and can be easily diagnosed by cutaneous tests using fresh material and/or by adequate RAST test. RAST inhibitions performed on individual sera suggest the existence of common antigens in celery and mugwort, and in celery and birch pollen. However, the exact nature of these common antigens has not yet been determined.

Adolescent↗
PubMed1984

Clinical and immunologic evaluation of tyrosine-adsorbed Dermatophagoides pteronyssinus extract: a double-blind placebo-controlled trial.

We evaluated the clinical efficacy and immunologic changes associated with the administration of tyrosine-adsorbed Dermatophagoides pteronyssinus (Dpt) extract. The study was carried out in a double-blind, placebo-controlled fashion in 18 patients with Dpt-induced asthma during a trial period of at least 12 mo. Patients initially received six increasing doses once a week; the top dose of 400 Noon units was repeated at monthly intervals. Clinical response was on the basis of diary cards on which symptoms and medication scores were recorded; daily lung function measurements were made by use of a mini Wright's peak flow meter. The entire spectrum of physiologic measurements, medications, and symptoms were taken into account by computing daily scores over a 2-week period. Total IgE, Dpt-specific IgE antibodies, and leukocyte histamine release were measured before treatment and during hyposensitization. Changes in Dpt-specific IgG were evaluated with a double antibody antigen-binding assay by use of the purified fraction of mite extract F4P1. All patients had measurable levels of IgG antibodies to F4P1 before treatment. Treatment with tyrosine-adsorbed Dpt extract resulted in a significant increase of specific-IgG antibodies in the treated group at 2 and 6 mo only (nonparametric rank sum test). Variations relative to the pretreatment values of total and specific IgE were not significantly different in the treated and in the control patients after 2.6 and 12 mo. No significant decrease in leukocyte sensitivity was observed after treatment. It was only possible to demonstrate a significant diminution in the mean medication score (nonparametric sign test) in the first 6 mo for the treated group; independently of the beginning of the treatment, the treated group demonstrated a reduction of the mean medication score and an improvement in peak expiratory flow rate lung function before the midsummer months when seasonal increase in mite density can occur. Particular attention was paid to the methodological problems raised during this study and inherent in a trial in house dust-mite asthma.

Adsorption↗
PubMed1984

[Clinical aspects of occupational asthma].

Although on the increase overall, the actual prevalence of occupational asthma is difficult to assess because of variations seen according to periods, countries, jobs, and the agents responsible. In the authors' experience, this prevalence is slightly less than 10%. Three principal mechanisms, sometimes present together, not always elucidated: immunological, reflex and irritative, are responsible for such asthma. Whilst a positive diagnosis raises few problems, the aetiological diagnosis is difficult and involves two stages: recognition of the occupational characteristic of the asthma and attribution of this asthma to an allergen or substance in the occupational environment. Skin tests and in vitro tests, but above all exposure tests, make an important diagnostic contribution. Personal examples are used to illustrate the principal aetiological factors in occupational asthma of animal, vegetable or chemical origin.

Asthma↗
PubMed1982

Local and serum IgE in vasomotor rhinitis.

Total and specific IgE in serum and nasal secretions were measured in twenty five subjects with vasomotor rhinitis without asthma (21 perennial vasomotor allergic rhinitis and 4 seasonal vasomotor allergic rhinitis) after Carbacholine nasal challenge-test. The level of total and specific IgE was lower in the pure, non diluted nasal secretions than in the serum. The diagnostic usefullness of these measurements and the concept of "localized allergy" are discussed.

Humans↗