Changes of mucociliary function during colds

We have investigated, using chicken and Newcastle disease virus, the relationship between the mucociliary function and acute upper respiratory infection. Average nasal transit time of the dye was 53 sec at the age of two to four weeks in controls. The average transit times were significantly longer than those of controls at day 6 and 12 postinoculation. A histopathological study has revealed that repair of the mucosal injury is usually completed within 13 days after virus challenge. This was confirmed with 3H-thymidine autoradiography. However, there were patches where cilia almost disappear as seen in the scanning electron microscope. The mucous blanket was tethered to the mucosal surface by strands of mucus from the acini of the nose after 7 days of infection. More extensive tethers were observed on the 14th day. This phenomenon is one of the factors which may affect mucociliary transport in vivo only. Nasal secretion from patients with a common cold was transported more slowly than that of controls on a frog palate from which mucus had been removed. The reduction in mucociliary transport rate in the nose during a common cold could be due to a combination of damage to the ciliated system, a change in the biorheological property of nasal secretion and in vivo factors, or other causes.