Tsuneki Nozoe

Experimental Study of the Pumping Function of the Eustachian Tube

To determine the muscle responsible for the pumping function of the Eustachian tube and to examine the detailed processes of this function, we conducted (1) a measurement of tympanal pressure during swallowing and during selective stimulation of the tensor and the levator muscles, and (2) visual and radiographic observation of fluid in the tube; in cats, dogs and a monkey. the results were: (1) formation of negative pressure in the tube by contraction of the tensor muscle; and (2) displacement of the fluid from the tympanum to the pharynx through the tube by repeated contractions of the tensor. It was concluded that contractions and relaxations of the tensor muscle cause the pumping function of the tube, which expells any fluid from there into the pharynx.

Role of the Tensor Tympani Muscle in Eustachian Tube Function I

In order to determine the role of the tensor tympani muscle in Eustachian tube function, pressure changes in the external and middle ear of 13 cats were measured under four experimental conditions. It was revealed that contraction of the tensor tympani muscle during swallowing did not result in any tympanic pressure rise which might assist in tubal ventilation. Acoustic stimulation was then used to measure consistent contraction of the tensor tympani muscle. Combined contraction of the tensor veli palatini and tensor tympani muscle under the condition of positive tympanic pressure failed to open the tube. It was concluded that the tensor tympani muscle might not play any part in tubal function.

Cineroentgenographic and electromyographic studies of Eustachian tube function

ZusammenfassungZur Feststellung des Öffnungs- und Schließungsvorganges der Tube während des Schluckens wurden an drei Affen simultan das Röntgenkinematogramm und das Elektromyogramm registriert. Dabei zeigte sich, daß sich die knorpelige Tube synchron zur Aktivität des M. tensor veli palatini für ca. 250 ms durch eine Bewegung der lateralen Wand nach außen öffnet. Daneben erweitert sich die pharyngeale Tubenöffnung für eine relativ lange Zeit synchron mit der Aktivität des M. levator veli palatini. Diese Zeitverzögerung zwischen den beiden Tubenabschnitten scheint die Pumpfunktion der Tube zu unterstützen.SummaryTo determine the opening and closing process of the Eustachian tube during swallowing, the simultaneous recording of cineroentgenograms and electromyograms (EMG) was carried out in three monkeys. It was revealed that synchronous with the activity of the tensor veli palatini muscle, the cartilaginous tube opened for a very short time (ca. 250 ms) by an outward movement of its lateral wall. On the other hand, the pharyngeal orifice of the tube dilated for a relatively long time synchronous with the activity of the levator veli palatini muscle. These time lags between two parts of the tube seemed to help the pumping function of the tube.

Role of the Tensor Veli Palatini Muscle in Movement of the Soft Palate

To examine the role of the tensor veli palatini muscle in palatal movement, we conducted 1) quantitative measurement of palatal movement by selective stimulation of the tensor and levator muscles, and 2) EMG recording of the two muscles during phonation. The results were: 1) negligible palatal movement upon tensor stimulation, despite a marked velar elevation by levator stimulation; and 2) little EMG activity of the tensor and marked EMG activity of the levator during phonation. It was concluded that the tensor plays no role in the palatal function.

Paranasal Cyst with Orbital Complications.

Twenty-four patients with paranasal cysts which accompanied by orbital complications were treated in our hospital from July 1986 to August 1990. A retrospective study of all 24 included the following items: sex, age, location of cyst, past history of paranasal operation, orbital complications, interval between last operation and appearance of orbital complications, accuracy of diagnosis by X-ray. A determined study was made of 7 patients with visual disturbances (6 lost their sight completely), and the relationship between the interval from the onset of the visual disorder and the operation and the outcome was studied. The time from the onset of visual disturbance to the operation and from the onset of blindness to the operation were 2.1 days and 16.7 hours respectively, in 3 patients with a good outcome, and 5.0 days and 62.7 hours, respectively, in 3 patients with a poor outcome. Thus, it is important to operate on cysts accompanied by visual disturbances as soon as they are diagnosed.

Chromosomal analysis of human mixed parotid gland tumors.

The malignant cells of most neoplasms show chromosomal abnormalities, and in many the defects are consistent. The most common of the recurring defects is either a band deletion or a reciprocal translocation between two chromosomes.Using banding techniques, five mixed tumors of the parotid gland were studied in preparations from primary cultures. Two of the tumors had abnormal stemlines. One of them was histopathologically benign and the other one was malignant.The former showed the karyotype: 46, XX, del (8) (p21), while the latter contained pseudohypotetraploid stem line, mn: 87, about 25% were marker chromo-somes.The results are discussed in relation to the previously existing sparse data available on mixed salivary gland tumors and their relationship to the possible general significance of chromosome changes affecting No. 8.