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Biomedical subjects

D Vervloet

Publications and source records attributed to D Vervloet.

At least 163 records · Page 9Linked to original sources
PubMed1991

Extrinsic asthma and environmental allergens.

House dust mites allergens are one of the most common antigens able to induce a high degree of sensitization in a general population. Owing to the possibility of quantifying the amount of major mite allergens in the environment, epidemiological studies have led to propose threshold values above which there is an increased risk for the occurrence of mite sensitizing, for the development of asthma and for the occurrence of symptoms. All these studies and some others dealing with the number of mites in house dust support the hypothesis that exposure to house dust mites may have a major influence on developing allergic diseases.

Allergens↗
PubMed1991

[Underestimation of cases of occupational asthma in Provence-Alpes-Côte d'Azur and Corse region].

To evaluate a possible underestimation of disability claims for occupational asthma in the Provence-Alpes-Côte d'Azur-Corse area, we compared the actual figures collected from 1986 to 1988 to the predicted figures. The latter were computed from the number of exposed subjects in at-risk industries and the prevalence of occupational asthma reported in the literature for each exposure category. From 1986 to 1988, only 44 disability claims were submitted and 25 of them were accepted. These disability claims represent about 2% of the occupational asthma cases which would be expected. The reasons for such a large discrepancy could be a selection bias leading disabled subjects to leave the occupation at risk, a failure by the patient and/or the physician to identify the disease, or a poor compensation system which is not an incentive for performing a disability claim.

Asthma↗
PubMed1991

[The epidemiology of allergy to house dust mites].

Currently, several studies show that sensitivity to mites is frequently found in the general population and in people suffering from respiratory allergic disorders. Thus 5 - 30% of the general population has positive skin tests whilst such sensitivity is found in 45 - 85% of asthmatic subjects. Certain studies have tried to establish a threshold of allergenicity beyond which the respiratory manifestations in allergic subjects became important. It seems after different studies that a threshold of 10 micrograms of antigen group I (the sum of the major antigens greater than Der p 1 and Der f 1) per gram of house dust may be a threshold beyond which the risk for the appearance of respiratory manifestation and in particular those of asthma in allergic subjects may be important. Moreover other studies tried to achieve a better understanding of the role of environmental conditions which favour the development of the mites. No or very few mites can develop if the relative internal humidity is less than 45% for an indoor temperature of 22 degrees C. These levels may be obtained in particular at altitude or in regions where the absolute outdoor humidity is low or the indoors are well heated and well ventilated. Epidemiological studies carried out in the last few years show that the relation between allergic respiratory mites disorders again show the frequency of diseases linked to the mites and the major influence of the environment as well as the idea of a tolerable allergenic threshold.

Animals↗
PubMed1990

Influence of the menstrual cycle on theophylline pharmacokinetics in asthmatics.

The effect of menstrual cycle on the pharmacokinetics of theophylline has been studied in 9 female asthmatic patients. At three different times during the cycle (first, tenth and twentieth days) each subject received an i.v. infusion of 240 mg theophylline. Significant changes were found in the kinetics of theophylline according to the menstrual cycle. The maximum plasma drug concentration, minimum mean residence time, and minimum elimination half-life were observed at mid-cycle. The lowest clearance was observed at D 20. The AUC and volume of distribution did not vary significantly during the cycle.

Adult↗
PubMed1990

Immunotherapy in allergic respiratory diseases.

Much more work is needed to specify the correct indications for immunotherapy in respiratory allergic diseases. Immunotherapy with pollen and mite extracts has shown some clinical efficacy versus placebo in controlled studies in allergic rhinitis and/or asthma. However, controlled studies comparing the cost, the risk factors and the efficacy of immunotherapy versus treatment with antihistaminic drugs, bronchodilators and topical steroids are needed. Additional studies are needed to established the place of immunotherapy in animal danders and mould allergy. In any case, before initiating immunotherapy in respiratory allergy the following questions must be answered: is there sufficient evidence of a close relationship between symptoms and allergen exposure? is it possible to achieve efficient allergen avoidance? is simple drug treatment no sufficient? is there evidence in the literature of effectiveness of IT for this allergen? is the patient able to comply with a long and constraining treatment?

Allergens↗
PubMed1990

Cat skin as an important source of Fel d I allergen.

It is generally recognized that cat skin is an important extrasalivary source of the major cat allergen, Fel d I. Nevertheless, since cat saliva is readily applied to the skin during grooming, we tried to demonstrate that Fel d I can accumulate on cat skin without licking. Eight adult female cats were used. On day 0, two separate sites of the trunk were shaved and a 6 cm2 area in each site was washed three times with 5 ml of distilled water. The first and third washes were collected and stored for assay. The areas were then covered with an occlusive dressing. Twenty-four hours later, the site was washed once and the sample stored. On day 7, washes were collected as on day 0, and a collar was attached to the neck to prevent contamination from saliva. A single wash was done 24 hours later. Comparison of data was achieved with an analysis of variance. Repeated washes significantly reduced Fel d I levels from 35 +/- 21 to 10 +/- 9 mU/cm2 on day 0 (p less than 0.01) and from 36 +/- 18 to 12 +/- 7 mU/cm2 on day 7 (p less than 0.01). Fel d I levels increased significantly after 24 hours of occlusion from 10 +/- 9 to 41 +/- 24 mU/cm2 (p less than 0.01) and collar wearing from 12 +/- 7 to 54 +/- 21 mU/cm2 (p less than 0.001). These findings demonstrate that Fel d I is produced by cat skin. Mean daily production of Fel d I by cat skin is estimated to be 36 units. Cat skin is an important extrasalivary source of Fel d I.

Allergens↗
PubMed1990

Atopy and systemic reactions to drugs.

To elucidate whether systemic reactions (SR) to drugs should be included in the atopic status in epidemiological studies, we compared the distribution of atopy in subjects with or without a history of SR to drugs. The studied population comprised 2067 adults, 20 to 60 years old, visiting a health care center for a check-up examination. The protocol included a questionnaire related to history of SR to drugs and a Phadiatop test which evaluates on a blood sample the presence of specific IgE against common aeroallergens. Overall, 14.7% of the study group, including 66% women, reported reliable histories of SR to drugs. The cumulative prevalence of asthma, hay fever and childhood dermatitis was higher in the SR group. By contrast, the percentage of positive Phadiatop tests was similar in subjects with or without a history of SR. Thus atopy, defined by an objective criterion, i.e. the presence of specific IgE against common aero-allergens, is not associated with the occurrence of SR to drugs. Such a history should not be included as part of the atopic status.

Adult↗
PubMed1990

Value of ELISA using A60 antigen in the diagnosis of active pulmonary tuberculosis.

This investigation was undertaken to assess the effectiveness of an enzyme-linked immunosorbent assay (ELISA) using A60 antigen in ascertaining diagnosis in hospitalized patients suspected to have pulmonary tuberculosis (TB) but with negative sputum stains. Cultures were performed to confirm active or inactive disease. IgG and IgM antibody activity was determined by adding a 1:100 dilution of serum to plates coated with A60 antigen. After addition of peroxidase-conjugated antihuman IgG or IgM and color development, optical density (OD) was determined. A total of 83 patients was studied, taking into account their current disease status and prior history. Using as a cutoff value the mean value +/- 2 SD measured in the negative culture, no TB history group, that is, OD = 0.50 for IgG measurements and 0.43 for IgM measurements, the sensitivity, specificity, and positive predictive value of IgG measurements were equal to 48, 71, and 50%, respectively. Using IgM measurements, these parameters were equal to 76, 98, and 95%, respectively. Combining the results of IgG and IgM measurements, sensitivity, specificity, and positive predictive value were equal to 68, 100, and 100%, respectively. Thus, the ELISA described here can greatly facilitate the diagnosis of TB in patients with negative smears.

Antigens, Bacterial↗
PubMed1990

[Pleural fibroma: apropos of a case].

The authors report a case of a pleural fibroma occurring in a 72 year old woman. The tumour presented with both an osteoarthropathy and hypoglycaemia. An X-ray revealed an abundant associated pleural effusion. Immune studies were positive for the presence of vimentin and negative for keratin, as occurred in this case, were in favour of a pure fibroblastic origin for these tumours.

Aged↗
PubMed1990

[Plasma cell granuloma. Report of a case].

The authors report a case of plasma cell granuloma of the lung, an inflammatory tumour occurring in a young Egyptian aged 23 without any history of chest diseases. The patient had had three weeks before his hospital admission light haemoptysis and associated with weight loss. The diagnosis was made on a bronchial biopsy. Thus a diagnosis could be made without recourse to surgery because of the occurrence of bronchial invasion. No aetiological factor was found to explain the pathogenesis of the granuloma.

Adult↗
PubMed1990

Bronchial challenge to house dust can induce immediate bronchoconstriction in allergic asthmatic patients.

The goal of the study was to evaluate whether natural exposure to house dust could elicit immediate bronchoconstriction. Two groups of asthmatic patients were studied: 12 asthmatics allergic to house dust mites and seven nonallergic asthmatics. The baseline FEV1 was similar in the two groups. Each subject was challenged through a nasal mask connected to nebulizer filled with house dust. Patients were randomly assigned to inhale dust with high or low Group I allergenic level. All allergic patients had an FEV1 drop larger than 20% of the baseline value. This drop was maximal at the 30th minute after challenge. FEV1 remained unchanged in nonallergic asthmatics. Allergic patients challenged with high Group I allergenic house dust (8.4 micrograms/g) had a mean FEV1 drop larger (P less than .01) than those challenged with the low Group I allergenic house dust (0.66 micrograms/g). Late asthmatic reactions were found in only two patients who were challenged with the high Group I allergenic house dust. These two patients had immediate FEV1 drops greater than 50% of the baseline value. Occurrence of symptoms during the test and the drop in FEV1 were correlated (r = .3; P less than .05). Natural exposure to house dust can induce immediate bronchial in allergic asthmatics in a dose-dependent manner.

Adult↗
PubMed1989

[Suspicion on sulfites].

The sulfites have anti-oxygen and anti-microbial properties, which explain their great use in the food and drug industry. They may be responsible for anaphylactoid type episodes or more often asthmatic crises. 4 to 8% of asthmatics are sensitive to sulfites. The majority of asthmatics who are sensitive to sulfites are steroid dependent asthmatics. The pathophysiology is not clear: either a reaginic mechanism, reflex bronchoconstriction to SO2, a partial deficit in sulfite-oxidases. The diagnosis rests on oral provocation tests. These tests should be carried out according to a rigorous methodology, because there are frequent false positives (57 to 70%). Tests of alimentary provocation do not always correlate with the results from oral provocation tests to sulfites and pose the double question of sensitivity to the combined forms of sulfites which are present in food, and the reality of the risk of exposure of asthmatics to these foods. The prevention of any such mishaps rests on the eviction of such substances from the food which is often difficult and also of drugs. Vitamin B12, atropine, doxepin and sodium cromoglycate are capable of preventing totally or partially the bronchospasm induced by the absorption of sulfites.

Anaphylaxis↗
PubMed1989

[Respiratory allergy and domestic animals. Survey in a sample of the general population].

To evaluate the role of exposure to furred pets on respiratory allergic disorders, we interviewed 10,338 adults, selected at random from communities of South-East France. All subjects answered a standardized questionnaire related to asthma and perennial rhinitis and to present or past exposure to furred pets and respiratory symptoms related to this exposure. Besides, a sample of the population had a blood analysis for detection of specific IgE directed against common aero-allergens (Phadiatop). Overall, more than half of the households had a pet, more often in rural than urban communities. Among asthmatics 9.3% acknowledged respiratory symptoms when exposed to pets and 5.9% had parted from their pets because of respiratory symptoms; among patients with chronic rhinitis, those figures were 5.1% and 2.6%, respectively. However, these subjects with respiratory symptoms had pets as often as the whole population. In atopic subjects (positive Phadiatop test), exposed to cats, the prevalence of perennial rhinitis was higher than in atopic subjects not exposed to cats and in non-atopic subjects. Thus furred pets have a deleterious influence on patients with asthma or rhinitis, especially in the atopic subgroup. Pet avoidance is an important factor in the management of these diseases.

Adolescent↗