Gerhard Rettinger

Temperature profile in the nasal cavity.

Objectives/Hypothesis Inspired air is heated and moistened as it passes the nasal cavity. The temperature increase should be similar to a heated tube model, depending on the airflow.

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.

Chitinase enzyme activity in CSF is a powerful biomarker of Alzheimer disease

Objective: DNA damage accumulation in brain is associated with the development of Alzheimer disease (AD), but newly identified protein markers of DNA damage have not been evaluated in the diagnosis of AD and other forms of dementia. Methods: Here, we analyzed the level of novel biomarkers of DNA damage and telomere dysfunction (chitinase activity, N-acetyl-glucosaminidase activity, stathmin, and EF-1α) in CSF of 94 patients with AD, 41 patients with non-AD dementia, and 40 control patients without dementia. Results: Enzymatic activity of chitinase (chitotriosidase activity) and stathmin protein level were significantly increased in CSF of patients with AD and non-AD dementia compared with that of no dementia control patients. As a single marker, chitinase activity was most powerful for distinguishing patients with AD from no dementia patients with an accuracy of 85.8% using a single threshold. Discrimination was even superior to clinically standard CSF markers that showed an accuracy of 78.4% (β-amyloid) and 77.6% (tau). Combined analysis of chitinase with other markers increased the accuracy to a maximum of 91%. The biomarkers of DNA damage were also increased in CSF of patients with non-AD dementia compared with no dementia patients, and the new biomarkers improved the diagnosis of non-AD dementia as well as the discrimination of AD from non-AD dementia. Conclusions: Taken together, the findings in this study provide experimental evidence that DNA damage markers are significantly increased in AD and non-AD dementia. The biomarkers identified outperformed the standard CSF markers for diagnosing AD and non-AD dementia in the cohort investigated.

Diagnostic Accuracy of Peak Nasal Inspiratory Flow and Rhinomanometry in Functional Rhinosurgery

Objectives: Sensitivity and specificity of active anterior rhinomanometry (RMM) and peak nasal inspiratory flow (PNIF) in the diagnosis of functionally relevant structural nasal deformities should be assessed. The reference standard was clinical judgment based on all clinical data available.

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.

The relationship between water vapour saturation of inhaled air and nasal patency.

The nasal cavity volume and the temperature of the nasal mucosa are considered to be the most important predictors of nasal conditioning. The aim of this study was to assess the relationship between the intranasal degree of water vapour saturation of inhaled air and nasal patency. Intranasal humidity values at different locations within the nasal cavity of 15 healthy subjects were compared to nasal airway resistance detected by active anterior rhinomanometry (AAR). Repeated measurements were carried out during one day to obtain varying nasal cavity volumes due to the nasal cycle. The end-inspiratory humidity data were obtained with a miniaturised capacitive humidity sensor at defined detection sites within the anterior nasal segment without interruption of nasal breathing. Measurements were carried out at four different times during one day. The degree of water vapour saturation did not correlate with the values of the AAR at any intranasal detection site and time of detection during one day. The study supports the view that there is no correlation between the degree of water vapour saturation within the anterior nasal segment and the nasal resistance during the nasal cycle over the day. Although nasal patency varies because of the nasal cycle, the changes of nasal cavity volume due to the nasal cycle do not seem to influence the degree of water vapour saturation of the inspiratory air.

Nasal mucosal temperature after exposure to cold, dry air and hot, humid air.

Objective - To determine the influence of variations in the temperature and humidity of inhaled air on the nasal mucosal temperature at various sites int he nasal airways. Materials and Methods - Fifteen volunteers were enrolled int he study. The temperature was measured on the mucosal surface of the nasal septum at the level of the nasal vestibule, in the nasal valve area, anterior turbinate area and choanae. Temperature measurements were made using a miniaturized thermocouple. Continuous temperature readings were performed before and after 10 min of exposure to either cold, dry air, ambient air or hot, humid air. Results - Inhilation of cold, dry air significantly reduced the temperatyre of the septal mucosa at each location of measurement compared to the breathing of ambient air. Inhalation of hot, humid air significantly increased the septal mucosal temperature at all detection sites. Conclusions - The climatic condition of inhaled air can lead to significant changes in nasal mucosal temperature. As the nasal mucosa is important for nasal air conditioning, short term exposure to air of extreme temperature and humidity can rapidly compromise nasal air conditioning.

Effects of low-toxicity particulate matter on human nasal function.

Chronic nasal and paranasal sinus problems affect approximately 15% of the population in industrialized countries. Recent studies suggest that particulate matter might contribute to this condition. The effects of acute exposure to low-toxicity particulate matter on human nasal airflow, mucociliary transport, and nasal discomfort should be assessed. Thirty-two healthy volunteers were exposed to 0 (control), 500, 1000, and 5000 &mgr;g/m3 calcium carbonate dust for 3 hours and nasal saccharin transport time (STT), rhinomanometry, and visual analog scales (VAS) on nasal discomfort were obtained. A dose dependent decrease of STT (P = 0.02) and nasal patency (P = 0.04), and increased sensation of nasal obstruction (P = 0.002) and dryness (P = 0.03) was observed. The results indicate that acute exposure to low-toxicity particulate matter in concentrations frequently encountered in western agglomeration areas may affect nasal functions and cause nasal symptoms.