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.

The aim of this study was to investigate whether repeated exposure to subclinical doses of cat allergens, not inducing asthma symptoms, could affect eosinophil cationic protein (ECP) levels in bronchoalveolar lavage (BAL) or in peripheral blood, without the appearance of clinical symptoms. Twelve patients with mild asthma, all sensitized to cats and not exposed to cat allergen at home, underwent a series of inhalations of cat allergen or placebo for 8 days over 2 weeks. A methacholine challenge was performed before and after the allergen and saline exposures, and BAL and blood were sampled for ECP measurements and eosinophil counts. No patients experienced asthma symptoms. However, PD20 methacholine (geometric mean) decreased significantly from 263 μg before to 126 μg after inhalation of allergen. Inhalation of saline did not induce any significant change in PD20. The change in log PD20 before and after cat allergen exposure was statistically different from the change in log PD20 before and after saline. Median ECP levels in BAL and serum increased significantly after allergen exposure, from 0.8 to 3.1 μg/l (p<0.02) and from 15.9 to 31.4 μg/l (p<0.05), respectively. No change was observed after saline inhalations. The change in BAL and serum ECP levels was statistically significant compared to that in the control group. The number of eosinophils did not change, however, nor did IL–5 and RANTES levels in BAL and serum. In conclusion, our results show that (1) exposure of asthma patients to repeated low doses of allergen, which did not provoke any clinical symptoms, is capable of inducing a local eosinophil activation associated with an increase in nonspecific bronchial hyperresponsiveness and (2) the increase in serum ECP levels due to eosinophil activation precedes the occurrence of asthma symptoms and may thus be a marker of allergen exposure in allergic asthma.

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ZusammenfassungDieser Artikel untersucht den Stand der immobilienwirtschaftlichen Forschung zu menschlichen Entscheidungen und Entscheidungsunterstützungssystemen (EUS). Er baut auf einer systematischen Literaturrecherche auf, die die Entwicklung der Forschung, untersuchte immobilienwirtschaftliche Felder, angewendete Methoden, Verbindungen zu anderen Disziplinen sowie favorisierte Zeitschriften identifiziert. Es werden Problemstrukturen aufgezeigt, die auf drei Bereiche verdichtet werden können: (1) Die primäre Forschungsleistung fließt in die Bereiche Investitionen und Bewertung. Andere immobilienwirtschaftliche Disziplinen sind bisher unterrepräsentiert. (2) Ein Wissenstransfer zwischen der verhaltensorientierten Immobilienforschung und der Informatik ist kaum zu beobachten. Insgesamt scheint die Forschung über immobilienwirtschaftliche Entscheidungsunterstützungssysteme noch am Anfang zu stehen. (3) Der in der Immobilienwirtschaft vorherrschende Risikobegriff ist unzureichend und muss um eine psychologische Dimension erweitert werden, um sein Potential für immobilienwirtschaftliche EUS-Anwendungen entfalten zu können.