Bronchial hyperresponsiveness in active coke-oven workers.

in Archives of Public Health (1995), 53

Acute Bronchial and Hematologic Effects Following Inhalation of a Single Dose of Paf. Comparison between Asthmatics and Normal Subjects

in CHEST (1994), 106(4), 1094-9

This study compared the acute bronchial and hematologic effects of inhaled platelet activating factor (PAF) (30 micrograms as a single dose) in 19 patients with mild asthma and 19 normal subjects. Each ... [more ▼]

This study compared the acute bronchial and hematologic effects of inhaled platelet activating factor (PAF) (30 micrograms as a single dose) in 19 patients with mild asthma and 19 normal subjects. Each subject underwent a methacholine bronchial challenge 1 week before PAF challenge to determine the concentration of methacholine causing a 20 percent fall in FEV1 (PC20M). On the day of PAF challenge, specific conductance (SGaw), FEV1, FEF25-75, and platelet and leukocyte counts were measured before, and 5, 10, 15, and 20 min after PAF inhalation. Changes in pulmonary and hematologic parameters were expressed as percent of control (saline solution/ethanol solution). Unlike normal subjects, subjects with asthma had bronchial hyperresponsiveness to methacholine: geometric mean (range): 0.59 mg/ml (0.07 to 9.8) vs > 32 mg/ml. Acute bronchial obstruction over the first 20 min after PAF inhalation was more pronounced in asthmatics than in normal subjects whatever the functional index considered (p < 0.01). In asthmatics (n = 19), mean (SEM) maximal fall in SGaw, FEV1, and FEF25-75 reached 50 percent (6), 11 percent (4), and 19 percent (5), respectively, while in normal subjects (n = 19) the maximal decreases were 24 percent (6), 4 percent (1), and 6 percent (1), respectively. In asthmatics, no correlation was found between log PC20M and log fall in FEV1 after PAF (r = 0.04 p > 0.05). In asthmatics and normal subjects, inhaled PAF caused a transient fall in neutrophils and monocytes by 5 min followed by a full recovery at 15 min and 20 min. These hematologic changes were not significantly different between the two groups. While not correlated with their airway responsiveness to methacholine, asthmatics, compared with normal subjects, develop an exaggerated acute airway obstruction in response to PAF. In contrast, hematologic changes induced by PAF do not differ between asthmatics and normal subjects. [less ▲]

Decrease of T-Lymphocyte Proliferation in Exercise-Induced Asthma

in Allergy (1994), 49(8), 605-10

The present study was designed to examine the effect of physical exercise on T-lymphocyte proliferation in patients with exercise-induced asthma (EIA). Indeed, a decrease in different immune functions is ... [more ▼]

The present study was designed to examine the effect of physical exercise on T-lymphocyte proliferation in patients with exercise-induced asthma (EIA). Indeed, a decrease in different immune functions is described in normal man after exercise. Thirty subjects (10 normal and 20 asthmatic subjects with or without EIA) underwent a submaximal exercise test on an electrically driven treadmill. Before and after this test, ventilatory variables were measured, and venous blood was taken to study plasma histamine (RIA) and spontaneous and phytohemagglutinin (PHA)-pulsed T-lymphocyte proliferation (mononuclear cells isolated on Ficoll-Hypaque; tritiated thymidine incorporation). Ten minutes after the end of the exercise, there was a significant FEV1 decrease only in asthmatic subjects with EIA (mean: 24 +/- 5%). In the same group, the mean plasma histamine level was 0.31 ng/ml-1 (+/- 0.06) before the challenge. It rose to 0.62 ng/ml-1 (+/- 0.14) 10 min after the end of the exercise (P < 0.05), and returned to normal limits 20 min after the test. In this group, there was also a significant decrease (by about 35%) of spontaneous and PHA-pulsed T-lymphocyte proliferation 2 and 4 h after the exercise. By contrast, exercise challenge had no effect on either plasma histamine level or T-lymphocyte proliferation in the normal group. Our results show a rapid and transient increase in plasma histamine in EIA. This was followed 2 and 4 h later by a significant decrease of T-lymphocyte proliferation. A possible relationship between these two phenomena is discussed. [less ▲]

Traitement médicamenteux chronique de l'asthme

in Revue Médicale de Liège (1994), 49(8), 429-30

Potentiation of Histamine Release from Human Leucocytes by Paf

in Agents and Actions (1994), 41(1-2), 5-10

Studies on the effects of PAF on histamine release from human leucocytes have yielded conflicting results. We therefore investigated the effects of PAF on leucocytic histamine release (HR) focusing on ... [more ▼]

Studies on the effects of PAF on histamine release from human leucocytes have yielded conflicting results. We therefore investigated the effects of PAF on leucocytic histamine release (HR) focusing on direct as well as on modulating effects. Peripheral blood leucocytes of normal and atopic subjects were incubated with PAF, anti-IgE and FMP for 30 min at 37 degrees C, and histamine was measured fluorometrically. Unlike anti-IgE (1/2000) and FMP (10(-5) M) which caused histamine release (HR) of 34 +/- 7% and 31 +/- 8%, respectively, PAF by itself (10(-11)-10(-5) M) failed to induce any significant HR from human leucocytes (< 3%) in normal (n = 14) and atopic subjects (n = 6). Nevertheless, in normals as well as atopics, PAF, but not lyso-PAF, enhanced anti-IgE (1/2000) and FMP (10(-5) M)-induced HR in a concentration-related manner. Maximal potentiation of histamine release caused by FMP and anti-IgE was achieved with PAF (10(-7)) (mean +/- SEM: 26 +/- 5%, n = 5, p < 0.01) and PAF (10(-5)) (mean +/- SEM: 20 +/- 7%, n = 7, p < 0.05), respectively. This potentiation was suppressed by WEB2086 (10(-5) M), a specific PAF antagonist. The time course of the enhancing effect produced by PAF was dependent on the type of secretagogue. The enhancement was nearly maximal when PAF and FMP were added simultaneously to the leucocytes, whereas a preincubation of 20 min with PAF was required to get maximal enhancement with anti-IgE. The enhancing activity of PAF on HR induced by both anti-IgE and FMP was reversed by washing the cells after preincubation. While PAF enhancement of FMP-induced HR persisted on mononuclear cell fraction containing basophils, that of anti-IgE-induced HR was considerably reduced under these conditions.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

Asthme et hyperréactivité bronchique non spécifique

in Acta Clinica Belgica (1994), 49(3-4), 148-57

Bronchial hyperresponsiveness is a hallmark of asthma although it can also be present, to a lesser extent, in other diseases. The level of bronchial responsiveness depends on immuno-inflammatory processes ... [more ▼]

Bronchial hyperresponsiveness is a hallmark of asthma although it can also be present, to a lesser extent, in other diseases. The level of bronchial responsiveness depends on immuno-inflammatory processes modifying the functional status of airway smooth muscle as well as the structure of the bronchial wall. The responsiveness toward a direct constricting pharmacological agent is poorly correlated to the one toward an indirect constricting agent or a physical stimulus which cause airway obstruction through a more complex mechanism. Transversal studies show a relationship between the severity of asthma and the level of methacholine airway responsiveness. Long term treatment with corticoids can reduce the bronchial hyperresponsiveness of asthmatics. [less ▲]

Ergospirométrie et pratique pneumologique

in Revue Médicale de Liège (1993), 48(9), 523-6

L'hyperréactivité bronchique non spécifique: données épidémiologiques et signification clinique

in Revue Médicale de Liège (1993), 48(4), 213-9

Le traitement général de l'allergie de type 1.

in Radermecker, M (Ed.) Allergologie (1993)

Basophil releasability in patients with hymenoptera venom allergy.

in International Archives of Allergy & Immunology (1993), 101(3), 283-7

Basophils in about 15% of subjects allergic to hymenoptera venom do not release histamine in the presence of antigen. Little is known on the basophil releasability in these patients. We therefore measured ... [more ▼]

Basophils in about 15% of subjects allergic to hymenoptera venom do not release histamine in the presence of antigen. Little is known on the basophil releasability in these patients. We therefore measured maximum percent leukocyte histamine release to antigen (Vespula venom), anti-IgE and formylmethionylphenylalanine (FMP) in 39 patients allergic to wasp venom and compared our results according to basophil responsiveness to antigen. Mean maximum percent histamine release was 39, 34 and 22%, respectively, for venom (100 ng/ml), anti-IgE (0.25 microgram/ml) and FMP (10(-4) M). The amount of histamine specifically released by venom correlated significantly with anti-IgE but not with FMP-induced histamine release. Leukocytes were unresponsive to antigen in 10 subjects. The clinical characteristics and anaphylactic symptoms of these patients were not different from those with antigen-responsive cells. Unresponsive leukocytes responded to FMP in all and to anti-IgE in 8 of the 10 subjects. Mean anti-IgE and FMP-induced histamine release were, respectively, lower and higher than those observed with leukocytes responsive to antigen (p < 0.05). In unresponsive basophils, there was a negative correlation between maximum percent anti-IgE and FMP-induced histamine release. We confirm that basophils of a minority of the subjects allergic to Vespula venom do not release histamine in the presence of antigen. The negative correlation between anti-IgE and FMP-induced histamine release in unresponsive basophils may suggest individual differences in the ratio of Fc epsilon RI and FMP receptors on the surface of basophils. [less ▲]