Keisuke Hirata

Hearing Impairment in Relation to Viscoelasticity of Middle Ear Effusions in Children

Both dynamic viscosity (n′) and elasticity (G′) of middle ear effusion were measured with an oscillating sphere magnetic rheometer and compared with the degree of conductive hearing loss in 65 ears of 40 children. There was a significant correlation between n′ and the magnitude of the air-bone gap at 500 and 1,000 Hz, but there was no significant correlation between G′ and the magnitude of the air-bone gap at 2,000 or 4,000 Hz. No significant correlation was noted between G′ and the magnitude of the air-bone gap at 500,1,000, 2,000, or 4,000 Hz. These results indicate that the n′ of middle ear effusion has an effect on the amount of hearing impairment at frequencies below 1,000 Hz.

The effect of an orally administered proteolytic enzyme on the elasticity and viscosity of nasal mucus.

SummaryWe have evaluated the effect of serratiopeptidase (SER), a proteolytic enzyme, on the elasticity and viscosity of the nasal mucus in adult patients with chronic sinusitis. SER was administered in a dose of 30mg/day orally for 4 weeks. Nasal mucus was collected from the nasal cavities of each patient before (week 0) and 4 weeks after the start of the medication (week 4). The storage modulus (G′) and the dynamic viscosity (η′) of each specimen of nasal mucus were determined by an oscillating sphere magnetic rheometer at frequencies of 0.5, 1, 5, 10 and 20 Hz at a constant temperature of 25° C. The dynamic viscosity (η′) of the mucus at week 4 was significantly lower than that at week 0 (at frequencies of 5, 10 and 20 Hz). No significant differences were observed in the storage modulus (G′) between the mucus at week 0 and week 4. SER reduced the viscosity but not the elasticity of the nasal mucus. These findings are discussed in relation to mucociliary clearance.

Prognosis of Secretory Otitis Media in Relation to Viscoelasticity of Effusions in Children

Both elasticity (G′) and viscosity (η′) of middle ear effusions (MEEs) were measured with an oscillating sphere magnetic rheometer and compared with continuance of fluid retention in 93 ears of 69 children with otitis media with effusion (OME). The ears were divided into four groups according to the viscoelastic properties of MEEs at the first myringotomy. Eighty-four percent of the ears in group 2 were free from effusion within 4 months; the difference from the other groups was statistically significant. These results indicate that the mucociliary clearance function plays an important role in the process of recovery from OME.

Rheologic Properties of Nasal Mucus from Patients with Chronic Sinusitis

The rheologic properties of nasal mucus from the patients with chronic sinusitis was determined by the oscillating sphere magnetic rheometer. The increase in the elastic modulus (G’) and the decrease in the dynamic viscosity (η’) of mucoid and mucopurulent nasal mucus indicate that both types of nasal mucus possess the network of transient cross-links between macromolecules. The G’ and the η’ of 12 mucopurulent nasal mucus was significantly high compared with those of 13 mucoid mucus (p < 0.01), and those of mucopurulent mucus were out of the optimal range for mucociliary transport. Results suggest that abnormally high viscoelasticity of nasal mucus is one of the causes of reduced nasal mucociliary clearance in chronic sinusitis.

Role of Transepithelial Ion Transport as a Determinant of Mucus Viscoelasticity in Chronic Inflammation of the Maxillary Sinus

Chronic sinusitis is a chronic inflammatory disease with fluid retention, most frequently in maxillary sinus. We measured both viscoelasticity of maxillary sinus fluid and bioelectric properties of maxillary mucosa in an attempt to correlate the mucus viscoelasticity with bioelectric properties. During sinus surgery, maxillary sinus fluid and maxillary mucosa were obtained from 15 patients with chronic sinusitis. Viscoelasticity was measured with an oscillating sphere magnetic rheometer within 24 h after sampling. Potential difference and short circuit current of maxillary mucosa mounted in Ussing chambers were measured before and after exposure of mucosal surface to amiloride. Both elasticity and viscosity showed significant positive correlation with percent inhibition of short-circuit current by amiloride. Our results indicate that the ion transport process plays a role in the determination of viscoelasticity of maxillary sinus fluid in chronic sinusitis.

Viscoelastic properties of middle ear effusions from pediatric otitis media with effusion and their relation to gross appearance

SummaryThe viscosity and the elasticity were measured in 146 individual middle ear effusions (MEEs) from 93 children with otitis media with effusion (OME). The effusions were classified into serous or mucoid type by their macroscopic appearance. The distribution of elasticity showed two peaks, corresponding to the peaks of serous and mucoid types of effusions. There were a small number of effusions in the intermediate range of elasticity, where the effusions were most effectively transported by the cilia. These findings suggests that the MEEs of pediatric OME are accumulations of rheologically suboptimal fluid in the middle ear cavity.

The effect of a single antral lavage with and without pipemidic acid on chronic sinusitis.

This study was designed to determine the effectiveness of a single antral lavage with and without pipemidic acid (PPA), an oral antibacterial agent, in chronic sinusitis. Fifteen patients, aged 17 to 66 years, were treated with an antral lavage with physiological saline solution at week one (group A). Thirteen patients, aged 14 to 68 years, were treated with an antral lavage at week one and recieved PPA 2, 000mg p. o. per day for two weeks, from week 0 to week 2 (group B).There was no significant difference in the subjective effect between group A and group B. X-ray opacity of the maxillary sinus was evaluated with a microdensitometer at week 0 and week 2. In group A, the x-ray opacity was 0.597±0.166 at week 0., and was 0.595±0.174 at week 2. In group B, the x-ray opacity was 0.665±0.190 and 0.683±0.176 at weeks 0 and 2, respectively. No significant improvement of x-ray opacity was observed after treatment in either group.The results indicate that a single antral lavage with and without an antibacterial agent is ineffective on the conservative treatment of chronic sinusitis.

Effect of Myonal on tinnitus.

Myonal® (a muscle relaxant) was used alone or in combination with other drugs in the treatment of 33 males (53.1±13.6 y. o.) and 26 females (54.8±12.5 y. o.) with tinnitus. The treatment was effective in 42.4% of the patients. A better effect was obtained in the following patients:1. Those in the 5th and 6th decades.2. When Myonal® was used in combination with other drugs.3. When treatment was continued for 8 weeks or longer.Side effects were observed in 4 patients (6.8%).