Jörgen Holmquist

Collagenase Activity in Middle Ear Effusions

Collagenolytic enzyme activity has been demonstrated in middle ear effusions from patients suffering from otitis media with effusion. Collagenase activity was characterized using different biochemical techniques. Various chemical and physical parameters were titrated for optimal enzyme activity. Bivalent cations activated the enzyme with Ca2+ as the most potent activator. Chelators such as EDTA reduced the enzyme at low concentrations. The enzyme was found to have a higher specific activity in mucoid effusions than in serous and had characteristics similar to granulocyte derived collagenase from human leukocytes. Possible relationships between the presence of collagenase activity and tissue destruction in the middle ear after otitis media with effusion are discussed. The collagenase activity showed wide ranges within different categories of middle ear effusions.

Identification of Middle Ear Disease

Since impedance measurements were introduced as a mean of identifying ears affected by middle ear disease, efforts have been concentrated on the identifying of ears in which effusion is present. The shape of the tympanogram has been analysed and it has been proposed that ears producing a shallow tympanometric pattern are more likely to contain fluid in the middle ear, than are ears having a tympanogram with a large peak. In this communication and great individual variation of tympanograms is shown and it is suggested that two categories of tympanogram should be considered, namely 1) flat tympanogram, and 2) tympanograms in which the middle ear pressure can be determined.

Eustachian tube function and healing after myringoplasty.

The function of the eustachian tube (ET) was measured preoperatively among patients with dry, chronic, tympanic membrane perforations. Tympanograms were obtained 1 to 2 years postoperatively. A significantly better healing rate was found in the group classified as “good” ET-function. Also, a significantly greater number of tympanograms with no deflections were found in the “bad” ET-function group. Thus, the ET-testing allows an identification of patients who must be followed up with extra care during the post-operative period, in order that complications such as reperforation of the tympanic membrane may be avoided.

Biochemical characterization of collagenase activity from middle ear effusions.

Collagenolytic enzyme activity has been demonstrated in middle ear effusions from patients suffering from otitis media with effusion. Collagenase activity was characterized using different biochemical techniques. The enzyme was found to have a higher specific activity in mucoid effusions and had characteristics similar to granulocyte derived collagenase from human leucocytes.

Otosurgery in Sweden

In this way bremodeoxyuridine can be identified through the transit of the cell cycle and the cell division rate of the tumor can be determined. Bromodeoxyuridine was intravenously injected 4 to 5 hours before biopsy; the biopsy specimen was obtained while the patients were under either local or general anesthesia. Eighty-nine patients were studied. Results: The mean age of the patients with cancer was 66 + 2 years (SEM). Most of the malignant tumors were localized within the oropharynx, and 68% were stage III and IV tumors. Completely diploid carcinomas constituted 81%. There was a significant correlation of the bromodeoxyuridine uptake and the growth fraction of the DNA distribution, indicating the validity of the methodology. No significant correlation between the degree of histopathologic differentiation and growth rate could be identified. Sixty-three percent demonstrated bromodeoxyuridine uptake of 7% to 15% and corresponding 60% of the patients had a potential doubling time of less than 73 hours. Our preliminary results indicated that the most rapidly growing head and neck carcinomas seemed to be highly sensitive to irradiation. Conclusions: Carcinomas of the head and neck demonstrate one of the most rapid growth rates among malignant tumors recognized in patients with cancer. Determination of the growth rate may be clinically worthwhile for decisions about cancer treatment.

Volume Measurement of Middle Ear and Mastoid Air Cell System with Impedance Audiometry on Patients with Eardrum Perforations

The usefulness of the electroacoustic impedance bridge with a probe tone frequency of 0.22 kHz in the determination of the middle ear and mastoid volumes was evaluated in patients with dry eardrum perforations. The values obtained were compared with the volumes determined by an aspiration technique utilizing the gas laws. Also, a comparison was made between the impedance volumes and the size of the mastoid air cell system as measured on x-ray film in a lateral projection. A significant agreement between the two methods of direct volume determination was found. A good relationship was found between the impedance volume and the mastoid air cell area. The impedance audiometry enables a rapid and valuable estimation of the air reservoir in the middle ear in patients with eardrum perforations.