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Biomedical subjects

J Charpin

Publications and source records attributed to J Charpin.

At least 109 records · Page 6Linked to original sources

Cyclic AMP in hypersensitivity reactions.

Phytohemagglutinin (PHA) was capable of inducing non-cytotoxic histamine release from human leucocytes. In the presence of deuterium oxide (D2O), PHA caused significantly greater histamine release. Dibutyryl cyclic AMP (d-cAMP) could enhance the histamine release in the presence of D2O although it was an inhibitor of the release if used alone. However, a beta agonist, isoproterenol, which increases intracellular level of cAMP was inhibitory with or without D2O. These data ask the question about dual effect of cAMP and suggest the possibility of different polls of cAMP in the target cells.

Basophils↗

Mechanisms of the bronchoconstrictor effects of deep inspiration in asthmatic patients.

A single deep inspiration (DI) is commonly followed by transient airflow obstruction in asthmatic patients. In some patients, however, DI results in a sustained response which suggests that more than one mechanism may be responsible. We have studied the characteristics of the response to repeated DI, and their modificatiion by various pharmacological agents, by measuring specific airway resistance (sRaw) in ten subjects who showed reproducible and consistent increases in sRaw after DI. Two types of reaction were observed: type A (n = 8) had an immediate maximum and usually short persistence; type B (n = 2) had a delayed maximum with a progressive increase. In type A reactions repetition of DI showed different patterns of response--either a reproducible reaction to each DI or a plateau effect. In type B reactions the response spontaneously increased with repeated DI. Type A responses to DI were inhibited completely by a beta-adrenergic stimulant (BAS), largely by an anticholinergic drug (AC, ipratropium bromide), but in no case by disodium cromoglycate (DSCG). Type B responses were inhibited completely by BAS, largely by DSCG, and partially by AC. These findings suggest that the response to DI is due to bronchoconstriction, which in type A reactions is of reflex origin, vagally mediated, and is due in part or wholly to mediator-release in type B reactions.

Adolescent↗

[Antifungal activity of aromatic essential oils (author's transl)].

"Paragerm" is commonly used in hospitals where its bactericide action is well known. Preliminary tests have been carried out in the laboratory in order to study the antifungal power of this product. Variation of the different concentrations in the culture medium, variation of the time of contact between "Paragerm" and the fungus and both the mechanical and chemical effects of the product have shown that, among the species selected, certain were more sensitive and others more resistant to this solution and that, in our experimentation, "Paragerm" had a fungistatic effect.

Air Microbiology↗

Denaturization of allergen P: effect on allergenicity, antigenicity and immunogenicity.

When allergen P was denatured by 8M urea, the modified molecule still reacted with IgE specific for the native allergen but not with hemagglutinating antibodies. Heating at 100 degrees C abolished the reaction in both cases. The results suggested differences between allergenic and antigenic capacities which may be based on structural differences of the antigenic determinants.

Allergens↗

Drug allergy: in vitro cross-allergenicity between amoxicillin and benzyl penicillin.

The capacity of amoxicillin to elicit allergenic reactions in vitro was determined on benzyl-penicillin sensitive patients. RAST and histamine release were performed on blood of these patients using B pen linked to human serum albumin (BPO-HSA) as allergen. A relationship was noted between the results of the in vitro tests and the date of the allergic manifestations. When results of RAST and histamine release were significant, amoxicillin was tested for its capacity to elicit histamine release and to inhibit RAST performed with BPO-HSA. A cross-allergenicity was observed in six sera out of eight. The results suggested that amoxicillin may be capable to react with cell-bound or serum IgE to give hypersensitive manifestations in some penicillin sensitive patients.

Allergens↗

Absolute determination of IgE antibodies to grass pollen allergens.

Knowledge of specific IgE bound on immunosorbent as assayed by RAST is useful but cannot give a complete description of the biological states of patients concerning IgE antibodies. Using a computer program based on a least squares error method and knowing the amount of bound specific IgE antibodies to grass pollen antigens in a serum at each of the four tested dilutions it is possible to calculate the absolute value of specific IgE antibody level, the relative value of affinity constant and the relative proportion of IgE antibodies to the total amount of specific (IgE plus non-IgE) antibodies. It is found that specific IgE antibodies account for high percentages of the total IgE protein (mean of 20%). High differences in affinity constant and in the proportion of IgE antibodies to the total amount of antibodies could be found between sera. Severity of grass pollen allergy could be related to the absolute level of IgE antibody, but no definite conclusion could be made on the importance of affinity constant and the proportion of IgE antibodies to the total amount of antibodies.

Allergens↗

Histamine release reaction of basophils in chronic granulocytic leukaemia. Induction by heterologous anti-immunoglobulin E, concanavaline A, and phytohaemagglutinin; effect of heavy water.

Basophils possess membrane bound IgE molecules, and immunological activation leads to a secretory process with cell degranulation and histamine release. Heterologous anti IgE, concanavaline A, and phytohaemagglutinin are potent non-cytotoxic releasing agents. They operate by a mechanism similar to that of immunological activation. Heavy water is not a histamine releasing inducer but it increases histamine release of the cells. We studied the histamine release reaction of leukaemic basophils in 10 patients and found a physiological response such as that previously reported with normal human basophils.

Antibodies, Anti-Idiotypic↗

Polyvinyl chloride pneumoconiosis.

A 53-year-old man, who had been exposed for 23 years to polyvinyl chloride (PVC) in the bagging area of a vinyl chloride polymerisation plant, presented with a diffuse micronodular infiltrate on his chest radiograph. Light microscopy of lung obtained by drill biopsy showed a diffuse infiltration with histiocytes and multinucleated giant cells, with some collagen formation. Ultrastructural studies showed foreign particles in the macrophages, which were identical with PVC powder viewed under the electron microscope. Incubation of PVC powder with human lung macrophages in vitro showed that the macrophages englufed the powder to give a similar ultrastructural appearance.

Cytoplasm↗

Electron-microscopic study of the anaphylactic degranulation of human basophils from atopic subjects.

Leukocytes from subjects allergic to Dermatophagoides pteronyssinus were incubated for 20 min with a solution of D. pteronyssinus extracts. Histamine release was measured at 0, 3, 10 and 20 min. Simultaneously, samples were treated for electron microscopy in such a way as to correlate histamine release and the morphological aspects of basophil leukocytes. The principal features accompanying histamine release were: a progressive activation of the cytoplasmic membrane which showed long processes, densification of the mitochondria, fusion of granulations, progressive dissolution and exocytosis of the contents of the granulations, short segments of rough endoplasmic reticulum, active Golgi apparatus, and thin membrane-bound granules suggesting resynthesis of mediators.

Adult↗

[Treatment of acute asthma. Comparison of the effectiveness of corticosteroids and of a combination of corticosteroids and an adrenergic beta-stimulant (author's transl)].

Two comparable groups of patients hospitalised for acute asthma received an intravenous infusion for two hours, containing corticosteroids in the first group and corticosteroids combined with an adrenergic beta-stimulant in the second. Course was assessed by the hourly measurement of forced expiratory volumen in one second (FEV1), heart rate and blood pressure. It was found that corticosteroids alone had a modest action (5,1% improvement in FEV1). By contrast, the combination of corticosteroids with an adrenergic beta-stimulant resulted in a rapid and pronounced improvement in FEV1 (19,9%), without producing any undisrable side-effects. No changes in arterial blood gases were noted under the influence of treatment. Injectable adrenergic beta-stimulants are therefore worthy of use in the treatment of an asthma attack, in the absencd of any contraindication.

Adrenal Cortex Hormones↗