Evaluation of an intranasal house dust mite provocation model as a tool in clinical research.

BACKGROUND: As a result of the all-year-round exposure to house dust mite (HDM), perennial rhinitis patients never have a clear symptom-free period. In this study, we investigated whether, despite these symptoms, we can still use nasal HDM provocations to study perennial allergic rhinitis and the effects of treatment. METHODS: In a parallel-group study, after 1 week treatment with either fluticasone propionate aqueous nasal spray (FPANS) or placebo, 20 patients, allergic to HDM, registered symptoms (nasal obstruction, rhinorrhoea, sneezing, pruritus and eye symptoms) using three different scoring methods [Lebel, categorical and visual analogue scale (VAS)] and peak nasal inspiratory flow (PNIF) after HDM provocations. Provocations were performed with 1000 biological units/ml and 24 h later with 10,000 biological units/ml of HDM. Before and after the provocations, nasal mucosa biopsies were taken for immunohistochemical staining to determine the number of eosinophils. RESULTS: House dust mite provocations resulted in an increase in symptoms and a decrease in PNIF. Even at high-dose provocation, the FPANS group registered significantly lower symptoms than the placebo group for nasal blockage, sneezing, eye symptoms, and PNIF in both early and late phases. FPANS also suppressed rhinorrhoea during the late phase and the influx of eosinophils in the lamina propria. CONCLUSION: Despite the high background of symptoms, allergic responses can be induced in this perennial rhinitis model. The VAS score seems most suited to detect these changes and the suppression of symptoms by 7 days of FPANS treatment. Epithelial eosinophilia at baseline was correlated positively with the severity of the reaction after the first provocation.

Microvascular surgery utilizing the endoscope as the sole source of visual assistance.

With the introduction of endoscopy to surgery, it has become apparent that magnification similar to the magnification provided by the surgical microscope can be achieved with its use. Endoscopic techniques provide both magnification and the ability to operate at a distance, potentially increasing the applications of microsurgery. An endoscopic unit is significantly less expensive than the operating microscope. Furthermore, it enables invasive techniques utilizing smaller incisions. The purpose of this project was to investigate whether the visual assistance provided by the endoscope is sufficient to perform a microvascular anastomosis. An initial experiment with six rats is presented. The right femoral artery was isolated, divided, and reconstructed by standard microanastomosis with the visual assistance provided by a 4-mm endoscope. All anastomoses were patent at 7 days by microangiography and histology. The magnification provided by the endoscope is sufficient for the creation of a microvascular anastomosis.