Tilman Keck

A Controlled Challenge Study on Di(2-ethylhexyl) Phthalate (DEHP) in House Dust and the Immune Response in Human Nasal Mucosa of Allergic Subjects

Background Few studies have yet addressed the effects of di(2-ethylhexyl) phthalate (DEHP) in house dust on human nasal mucosa. Objectives We investigated the effects of house dust containing DEHP on nasal mucosa of healthy and house dust mite (HDM)–allergic subjects in a short-term exposure setting. Methods We challenged 16 healthy and 16 HDM-allergic subjects for 3 hr with house dust at a concentration of 300 μg/m3 containing either low (0.41 mg/g) or high (2.09 mg/g) levels of DEHP. Exposure to filtered air served as control. After exposure, we measured proteins and performed a DNA microarray analysis. Results Nasal exposure to house dust with low or high DEHP had no effect on symptom scores. Healthy subjects had almost no response to inhaled dust, but HDM-allergic subjects showed varied responses: DEHPlow house dust increased eosinophil cationic protein, granulocyte-colony–stimulating factor (G-CSF), interleukin (IL)-5, and IL-6, whereas DEHPhigh house dust decreased G-CSF and IL-6. Furthermore, in healthy subjects, DEHP concentration resulted in 10 differentially expressed genes, whereas 16 genes were differentially expressed in HDM-allergic subjects, among them anti-Müllerian hormone, which was significantly up-regulated after exposure to DEHPhigh house dust compared with exposure to DEHPlow house dust, and fibroblast growth factor 9, IL-6, and transforming growth factor-β1, which were down-regulated. Conclusions Short-term exposure to house dust with high concentrations of DEHP has attenuating effects on human nasal immune response in HDM-allergic subjects, concerning both gene expression and cytokines.

Long-term treatment with aspirin desensitization: a prospective clinical trial comparing 100 and 300 mg aspirin daily

Background:  The daily dose of aspirin in desensitization in aspirin‐sensitive asthmatics with nasal polyps is still a matter of debate.

Nasal biomarker profiles in acute and chronic rhinosinusitis

Background Clinical manifestations of rhinosinusitis include acute rhinosinusitis, chronic rhinosinusitis (CRS) with nasal polyps and CRS without polyps.

Air-conditioning in the human nasal cavity

Healthy humans normally breathe through their nose even though its complex geometry imposes a significantly higher resistance in comparison with mouth breathing. The major functional roles of nasal breathing are defense against infiltrating particles and conditioning of the inspired air to nearly alveolar conditions in order to maintain the internal milieu of the lung. The state-of-the-art of the existing knowledge on nasal air-conditioning will be discussed in this review, including in vivo measurements in humans and computational studies on nasal air-conditioning capacity. Areas where further studies will improve our understanding and may help medical diagnosis and intervention in pathological states will be introduced.

A Numerical Simulation of Intranasal Air Temperature During Inspiration

Objectives/Hypothesis: In vivo measurements of the intranasal air temperature are feasible. The present study was designed to reproduce temperature distributions within the human nasal cavity by means of numerical simulation.

Numerical simulation of airflow patterns and air temperature distribution during inspiration in a nose model with septal perforation.

Background The most typical symptoms of patients with nasal septal perforation (SP) are crusting and recurrent nosebleed. The objective of the study was to determine the influence of SP on intranasal temperature profile and airflow patterns during inspiration by means of numerical simulation. Methods Two realistic bilateral models of the human nose with and without SP were reconstructed based on computed tomography (CT). A numerical simulation was performed. The intranasal air temperature distribution and airflow patterns during inspiration were displayed, analyzed, and compared. Results SP causes a highly disturbed airflow in the area of perforation. A spacious vortex within the perforation including various localized vortices was detected. A disturbed intranasal temperature distribution between the right and left nasal cavities developed. Conclusions The numerical simulation demonstrates the interaction between airflow patterns and heating of respiratory air. The disturbed airflow causes reduced air conditioning. This fact may contribute to crusting and recurrent nosebleed.

Medium-term symptom outcomes after paranasal sinus surgery in children and young adults with cystic fibrosis

Objective: To determine the effectiveness of paranasal sinus surgery (PSS) for individual symptoms and recurrence of nasal polyposis in children and young adults with cystic fibrosis and chronic rhinosinusitis (CRS).

Impact of unilateral sinus surgery with resection of the turbinates by means of midfacial degloving on nasal air conditioning.

Objective/Hypothesis One of the most important functions of the nose is the climatization of inspired air. The aim of the investigation was to determine the influence of radical sinus surgery with complete resection of the turbinates and the lateral nasal wall by means of midfacial degloving as treatment for inverted papilloma on the nasal humidification and heating of inspired air.

Nasal air temperature and airflow during respiration in numerical simulation based on multislice computed tomography scan.

Background Adequate nasal air-conditioning is of greatest importance. Because detailed processes of nasal air-conditioning still are not completely understood, numerical simulations of intranasal temperature distribution and airflow patterns during inspiration and expiration were performed. Methods A three-dimensional model of the human nose based on computed tomography scans was reconstructed. A computational fluid dynamics application was used displaying temperature and airflow during respiration based on time-dependent boundary conditions. Results Absolute air temperature and velocity values vary depending on detection site and time of detection. Areas of low velocities and turbulence show distinct changes in air temperature. The turbinate areas prove to be the main regions for heat exchange. The numerical results showed excellent comparability to our in vivo measurements. Conclusion Numerical simulation of temperature and airflow based on computational fluid dynamics is feasible providing entirely novel information and an insight into air-conditioning of the human nose.

Tracheal climate in laryngectomees after use of a heat and moisture exchanger.

Objective/Hypothesis: Heat and moisture exchangers (HME) are frequently used in the treatment and prevention of tracheobronchial dryness and infections. In this study, the short‐term influence of the HME Prim‐Air System (Heimomed, Kerpen, Germany) in laryngectomized patients was tested.