ZIB

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

Local increase in the number of mast cells and expression of nerve growth factor in the bronchus of asthmatic patients after repeated inhalation of allergen at low-dose (2001)

Kassel, O. ; De Blay, F. ; Duvernelle, C. ; [et al.]

Oxford, UK : Blackwell Science Ltd

Clinical & experimental allergy 31 (2001), S. 0

add to mindlist on the mindlist

Details

ISSN: 1365-2222

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Medicine

Notes: Background Repeated inhalation of allergen at low-dose induces an increase in bronchial hyper-responsiveness, without any associated symptom. The concomitant events in the bronchus have not been described.Objective We have studied the dynamic number of mast cells in the airways of patients with mild asthma before and after repeated inhalation of allergen at low-dose and the expression of nerve growth factor (NGF), which is reported to promote growth and survival of mast cells.Methods Twelve patients with mild asthma to cat allergen were enrolled at random in a blind placebo-controlled study, and submitted to repeated low-dose allergen exposure (1/5 of the provocative dose). Mast cells were immunolocalized using an antibody against mast cell tryptase. NGF and its high affinity receptor, TrkA, were immunolocalized using anti-NGF and anti-TrkA antibodies, respectively. NGF mRNA was quantified by competitive polymerase chain reaction (PCR) after reverse transcription of total RNA extracted from bronchial biopsy. NGF protein levels were measured by ELISA in bronchoalveolar lavage (BAL) fluid.Results Bronchial mast cell number was increased significantly after allergen exposure as compared with before. NGF expression in the bronchus was immunolocalized mainly to epithelial cells, but also to fibroblasts, blood vessels, and a few infiltrated cells. NGF mRNA levels in bronchial biopsies were increased significantly after allergen exposure. The high affinity receptor for NGF, TrkA, was immunolocalized to the infiltrated mast cell membrane.Conclusion Our study shows that the increase in the number of mast cells and in the expression of NGF induced by allergen exposure in the bronchus of asthmatic patients is occurring before the onset of symptoms. In addition, our finding of the presence of the TrkA receptor on the membrane of the infiltrated mast cell in situ brings evidence of the mast cell as a target cell for the growth factor activity of NGF in the airways in asthma.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1046/j.1365-2222.2001.01177.x

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Consistency and efficacy of cetirizine (10 mg) versus ebastine (20 mg) at 4 h on skin reactivity (1999)

Purohit, A. ; Duvernelle, C. ; Melac, M. ; [et al.]

Springer

European journal of clinical pharmacology 55 (1999), S. 589-592

add to mindlist on the mindlist

Details

ISSN: 1432-1041

Keywords: Key words Histamine skin prick test ; Antihistamine ; Allergy

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology , Medicine

Notes: Abstract Objective: We compared the consistency and efficacy of the two antihistamines, cetirizine (10 mg) and ebastine (20 mg) on histamine skin reactivity 4 h after treatment. Methods: Twenty-four healthy volunteers participated in a randomised double-blind cross-over study. The areas of wheals and flares induced by increasing (0, 5, 10, 50, 100, 200, 300 mg/ml) histamine concentrations, administered by prick tests, were measured before and 4 h after intake of cetirizine or ebastine. Results: Before treatment, concentration–response curves were similar and threshold concentrations identical (0.57 mg/ml and 0.57 mg/ml for cetirizine and ebastine, respectively). Both treatments exerted a significant effect. However, cetirizine was significantly more efficient than ebastine 20 mg (P 〈 0.01 both for wheals and flares). After cetirizine, the threshold concentration inducing a 3-mm2 wheal was significantly higher (266 mg/ml) than after ebastine (77 mg/ml) (P 〈 0.01), and total inhibition of the wheal was obtained in 18 of 24 patients for cetirizine and in 4 of 24 for ebastine (P 〈 0.001). The variation coefficient for the wheal reaction was 31% for cetirizine and 159% for ebastine, indicating a much lower variability after cetirizine. Conclusion: Our study shows clearly that the efficacy of a single therapeutic dosage of cetirizine is greater and consistently better than that of ebastine for suppression of cutaneous reactivity to histamine 4 h after treatment in healthy volunteers. The need for ebastine to metabolise into the active carebastine might explain this difference.