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Biomedical subjects

F Leynadier

Publications and source records attributed to F Leynadier.

191 records · Page 11Linked to original sources
PubMedDate not supplied

[Inhibition of degranulation of human basophils by calcium antagonists].

The human basophil degranulation test (HBDT) quantifies the apparent disappearance of basophils after contact with the sensitizing allergen. The inhibition of degranulation by pharmacological products can be appreciated by incubating beforehand the basophils with the substance concerned during various times. The inhibitory effect is evaluated by the difference of degranulation with or without it. EDTA, sodium cromoglycate, verapamil and bepridil have been tested at different concentrations and at 3 times of basophils preincubation (0,15 and 30 minutes). Results obtained confirm previous reports concerning cromoglycate which didn't inhibit degranulation of basophils. EDTA at 3.4*10(-2)M and 3.4*10(-3)M concentration has an inhibitory effect, not increasing with the time of preincubation. The inhibition with verapamil is of the same order at 1*10(-4)M for the 3 times of incubation and weaker, but significant, at 1*10-M5 after 30 minutes of preincubation. Bepridil inhibits at 1*10(-4)M, but this effect disappears if basophils are preincubated 30 minutes with the drug. The inhibition of the specific basophil degranulation by these drugs is probably du to their calcium antagonist property. However their effect is not quite similar when cells are preincubated at different times with the drug. On the other hand, one can study with HBDT the inhibitory effect of a new product, even if the therapeutic indications would have to be studied afterwards.

Basophils↗
PubMedDate not supplied

[Correlation of skin test to grass pollen with basophil degranulation test results in 72 patients (author's transl)].

Seventy-two subjects have been tested by skin-test (ST) and human basophil degranulation test (HBDT) with grass pollen extract (GPE). HBDT was done, using a suspension enriched in basophils, by a technic on slide. Results are expressed by an index (DI) which is percentage of basophils having apparently disappeared (i. e. degranulated) in presence of GPE. No less than 100 intact basophils (and often many more) were always counted in absence of GPE (control) for each subject, so that DI higher than 35% are significant (p less than 0,001). DI were higher than 35% in 28 positive ST subjects for at less one of three dilutions of GPE (10(-4), 10(-6), 10(-8)); in the 5 subjects with false-negative result, 3 had a weak ST response. In 39 subjects with negative ST, DI were higher than 35% in two subjects and only for one dilution (10(-4)). So, concordance of results of HBDT and obviously positive ST reaches 94%. In 33 positive ST subjects, a significant correlation appears between DI (at 10(-4) and 10(-6)) and flare diameter and between DI (at 10(-4)) and wheals diameter. HBDT appears to be a suitable and simple technic for routinely study of reaginic allergies.

Basophils↗
PubMedDate not supplied

[Correlation between serum IgE level and human basophil degranulation by anti-IgE antibodies].

The human basophil degranulation test (HBDT) by anti-IgE antibodies was applied in 3 groups of subjects: 20 controls, 26 patients with helminthiasis and 28 allergic patients. Mean degranulation was higher in patients with helminthiasis than in the two other groups. A correlation was found between IgE serum level and HBDT results by anti-IgE (r = 0.373; p less than 0.02) with Spearman's rank correlation test. Therefore, degranulation with anti-IgE antibodies would appear to depend on the quantity of cell-bound IgE rather than on intrinsic basophil sensitivity.

Antibodies, Anti-Idiotypic↗
PubMedDate not supplied

[Human basophil degranulation in pollinosis: correlation with skin-test diameter (author's transl)].

A human basophil degranulation (HBD) performed on an enriched basophil suspension (by gradient density) was applied in 95 subjects with 3 dilutions of grass pollen extract. Concordance with intradermal skin-test (ST) results reached 90% for wheal and 94% for flare. In 45 positive ST subjects, mean (+/- s.e.m.) of degranulation index was 54,1 +/- 4,2, 54,9 +/- 4,7 and 35,7 +/- 4,9 respectively for dilutions of 10(-4), 10(-6) and 10(-8) of grass pollen. Mean was 6,1 +/- 1,6, 8,2 +/- 1,7 and 8,5 +/- 1,6 in 50 negative ST subjects. In positive ST patients, a significant correlation (r = 0,53 p less than 0,001) appeared between ST diameter (flare) and degranulation index. HBD appears as reliable as RAST or automated histamine analysis but more easy to perform. It permits pharmacological studies of drugs inhibiting human basophil degranulation.

Asthma↗
PubMedDate not supplied

[Human basophil degranulation test in the diagnosis of anguilluliasis. Preliminary results].

The human basophil degranulation test was applied to the diagnosis of strongyloidiasis. The preliminary results show an excellent response. 33 of the 35 cases give a definite positive result and in the 15 control cases, with no parasitosis or an other helminthiasis, the test was negative. If these results are confirmed by a more important study of sensitivity and specificity, the test would be of interest when the parasitosis is of difficult evidence and especially by patients needing immunodepressive therapy.

Animals↗
PubMedDate not supplied

[2 new cases of Refsum's disease. Course during diet].

The authors report two cases of Refsum's disease treated with a low phytanic acid and low phytol diet for more than 5 years. The clinical, neurological improvement was undoubted in both cases but it was very gradual, appearing after 10 1/2 and 6 months treatment respectively. During these 5 years, no neurological aggravation occurred in the first patient ; but her sister presented in september 1972, 18 months after she started the diet, a mild attack from which she recovered. On the other hand, the sight and hearing disorders remained unchanged in spite of the considerable fall in phytanemia. In spite of the demanding and unagreeable character of the diet, almost constant moderate diarrhoea, the diet was worth following.

Adult↗