Characterization of human middle ear mucus glycoprotein in chronic secretory otitis media (CSOM).

Middle ear effusion was obtained from children with chronic secretory otitis media undergoing myringotomy. The effusions contained about 120 mg/ml non-dialysable solids, of which 18-31% was mucus glycoprotein. The purified mucus glycoprotein had a composition characteristic of other mucus glycoproteins. Amino acid analysis of the glycoprotein indicates a protein core consisting of glycosylated regions resistant to proteolysis and non-glycosylated regions susceptible to proteolysis. Analysis of the mucus glycoprotein by gel filtration on Sepharose 2B showed that reduction caused a decrease in hydrodynamic size and proteolysis caused a further decrease. The difference was confirmed by sedimentation coefficient and viscosity measurements. The reduced glycoprotein had an intrinsic viscosity of 0.113 ml/mg and an S0(20) of 15.2S compared to a value of 0.018 ml/mg and 9.6S for the proteolytically digested glycoprotein. These results suggest a model for this middle ear mucus glycoprotein, in which the native glycoprotein is a large molecular mass polymer maintained by disulphide bridges. These disulphide linked glycoprotein units are broken down into smaller units by proteolysis. The mucus glycoprotein could not be purified completely free from low molecular mass components. A glycoprotein, susceptible to proteolysis Mr 28,000-33,000 co-fractionates with the major high molecular mass mucus glycoprotein.

Type II collagen distribution in rodents.

The anatomical distribution of type II collagen in animal ears was studied by immunohistochemical techniques, using defined monoclonal antibodies to type II collagen. Type II collagen was observed in the cartilage plate of the auricle and external auditory meatus, tympanic annulus, lamina propria of tympanic membrane (pars tensa), interossicular joints, stapes footplate, eustachian tube cartilage, enchondral layer and globuli interossei of the otic capsule, Rosenthal canal, cribriform base, osseous spiral lamina, spiral ligament, limbus, tectorial membrane, semicircular canal membrane and subepithelial layer of the ampullary crista, utricular and saccular maculae, and the endolymphatic duct and proximal part of the sac.

Human tracheal mucin: a preliminary study of physicochemical properties and mucociliary transport.

Human tracheal secretions were collected from patients with chronic tracheostomies in the intensive care unit and through an endotracheal tube from pediatric surgical patients under general anesthesia. These secretions were dialyzed, fractionated on an agarose column, and lyophilized to recover the tracheal mucin fraction. Analysis of pooled mucin samples included determination of amino acids, carbohydrates, and sulfates. Intrinsic viscosity, microrheometry, and mucociliary transport studies were also performed. Structural and functional differences between several pools of specimens are cited with an emphasis on possible clinical correlations.

Hyaluronan in experimental serous and purulent otitis media.

The concentration of hyaluronan (hyaluronic acid; sodium hyaluronate; HA), a major component of connective tissue, was analyzed by a specific radioassay in tissue samples from normal rat middle ears and in tissue and effusions from middle ears affected by experimentally induced otitis media. In normal ears the pars flaccida of the tympanic membrane contained a considerably higher concentration of HA (60 to 200 micrograms/g) than the pars tensa and areas of the medial wall (2 to 7 micrograms/g). In purulent otitis media the pars flaccida contained less HA than in normal ears. The HA concentrations were lower in purulent (3 to 40 micrograms/mL) than in serous (20 to 190 micrograms/mL) effusions. The weight average molecular weight of HA in serous fluid was high (greater than 10(6] and comparable to that in lymph. It is inferred from the study that the subepithelial tissue and its matrix components, eg, HA, must be considered when attempting to understand the function of the middle ear normally and in otitis media.

Morphologic and biochemical study of vascular permeability of the middle ear mucosa in experimental otitis media.

The vascular permeability of the middle ear mucosa of chinchillas was examined by light and electron microscopy using horseradish peroxidase (HRP). Two kinds of experimental otitis media were used: serous otitis media (SOM) produced by eustachian tube obstruction and purulent otitis media (POM) produced by inoculation with Streptococcus pneumoniae type 7F. Normal mucosa showed no leakage of HRP. In SOM, vessels were dilated and tortuous, but they did not show HRP leakage. In POM, vessel leakage of HRP was extensive. Biochemically, we measured the middle ear effusion-to-serum ratio of both albumin and alpha 2-macroglobulin by an immunodiffusion method. The ratios of the two marker proteins for vascular permeability were significantly higher in POM than in SOM. This suggests that POM increases vascular permeability to a higher degree than SOM, and morphologic findings in the middle ear mucosa correlate with the biochemical composition of the middle ear effusion.

Middle ear mucosa in Ramsay Hunt syndrome.

We report two patients with Ramsay Hunt syndrome, together with histopathologic findings of the middle ear mucosa near the facial canal. An attempt was made to find specific antigens of varicella zoster virus (VZV) and herpes simplex virus (HSV) by an immunofluorescence method. Histopathologic examination revealed inflammation of the middle ear mucosa. Specific VZV antigens were demonstrated in the cytoplasm and nucleus of elliptically shaped cells and round cells, but no specific antigens of HSV were found. The findings suggest a pathogenetic relationship between VZV infection and inflammatory changes in the middle ear mucosa.

Concentrations of antimicrobial agents in middle ear fluid, saliva and tears.

Antibiotics concentrations in middle ear fluid (MEF), saliva and tears were measured in children with persistent middle ear effusions undergoing tympanostomy tube placement. In 31 children given cefaclor, specimens of serum, saliva and MEF were collected at 0.5, 1, 2, 3 or 5 h after a dose. Another group of 37 children were randomized to receive a single dose of penicillin V, amoxicillin, ampicillin, erythromycin estolate, erythromycin ethylsuccinate, trimethoprim-sulfamethoxazole or cefaclor. Concentrations of antibiotics in saliva and tears bore no consistent relationship to those in MEF. Mean concentrations of all drugs in MEF were several-fold greater than the usual minimal inhibitory concentrations (MIC) of pneumococci, but only with trimethoprim and cefaclor were they greater than in usual MIC's for Haemophilus influenzae. Concentrations of antibiotics in MEF in persistent effusions were comparable to those previously reported in acute purulent effusions.

Human middle ear gas composition studied by mass spectrometry.

The purpose of this study was to develop a procedure for mass spectrometric measurement fitted to analyse the human middle ear gas composition, and to determine the partial pressures of the middle ear gases in adults with healthy ears. To avoid the risks of admixture of the gas sample with atmospheric air we used "on-line" sampling from the middle ear to the analysing equipment, and a new protective technique at the site of puncture. The inlet system was modified to achieve sufficiently low gas consumption. The system had excellent linearity, and model experiments showed that the described procedure gives a very high accuracy. Measurements of the gas composition in the middle ear in 10 adult subjects with healthy ears gave the following values: pO2 = 612.38 +/- 3.97 mmHg, pO2 = 40.85 +/- 3.68 mmHg, pAr = 7.09 +/- 0.08 mmHg and pCO = 52.69 +/- 5.54 mmHg.

The middle ear gas composition in air-ventilated dogs.

The middle ear gas composition has been examined in 5 air-ventilated dogs under sodium thiopentone anesthesia. The gas samples were obtained by transtympanic puncture and analysed by gas chromatography. The following mean +/- S.D. gas composition was obtained: N2 83.2 +/- 5.0; O2 12.1 +/- 2.2; and CO2 4.7 +/- 0.7.

Gas chromatographic analysis and storage of gas samples from the middle ear.

Methods for storage and analysis of gas samples were studied prior to measuring the composition of gas in the human middle ear cavity. Storage and analysis of gas samples are beset with several pitfalls. The dead space of the sampling syringe must be considered and the gas sample can equilibrate with the surrounding atmosphere, especially if the analysis cannot be done immediately. In this study the equilibration rate was found to fit an exponential function with a time constant of 0.004 min-1. The time constant was reduced by more than a factor of ten when butyl rubber stoppers were used to seal the syringes. Silicone rubber stoppers were less efficient. Disposable plastic syringes were found just as efficient as 'gas-tight' syringes.

Localization of filaggrin in human middle ear cholesteatoma.

Filaggrin, a histidine-rich protein, was located immunohistochemically in human middle ear cholesteatoma by specific antibody. It was found to be localized in the cytoplasm of the granular layer cells and cornified layer. The pattern of distribution is similar to that of epidermis. Filaggrin is a major component of keratohyalin which is a distinct component of the differentiating epidermal cells. Thus the presence of filaggrin in cholesteatoma suggests epidermal characteristics of the cholesteatoma.

Middle ear pressure after changes in steady state.

The combined effect of changes in middle ear (ME) gas composition and changes in systemic arterial blood oxygenation on total ME pressure was studied in three anesthetized juvenile Rhesus monkeys (Macaca mulatta). The gas composition of the ME was altered by ME inflation (politzerization) using either pure nitrogen, oxygen, or carbon dioxide while the animal was ventilated with either room air or 100% oxygen at constant carbon dioxide blood gas tension. Total ME pressure was measured indirectly by tympanometry (acoustic impedance) for a 5-hour duration. The changes in ME pressure were consistent and reproducible, exhibiting different pressure-time patterns unique for each gas. Carbon dioxide resulted in the most rapid decrease in ME pressure, followed by oxygen. The slowest decrease was observed in experiments with nitrogen. The systemic hyperoxygenation had little or no effect on the results. The findings were explained by the differences in relative permeabilities of these gases influencing ME gas diffusion, but the lack of systemic hyperoxygenation effect remained unexplained.

Location of intravenously injected kanamycin sulfate in the middle ear mucosa.

Twelve guinea pigs were treated with intravenous kanamycin sulfate (KM) and sacrificed 2, 5, 10, and 30 min later to investigate its location in the middle ear mucosa, especially in the Eustachian tube (ET). Immunological examinations evidenced KM in the epithelial and subepithelial layers of the ET on each occasion of observation. But, it was never recognized in the tubal gland. These observations might indicate that clinically used drugs easily get to the ET except for the tubal gland which might have some barrier mechanism against foreign bodies.

Ultrastructural localization of Ca2(+)-binding sites in the middle ear mucosa of the rat.

Cations were precipitated with potassium-pyroantimonate in the middle ear mucosa of the rat and the distribution of the formed precipitates was studied by electron microscopy. The precipitate density in various cells of the different epithelia of the middle ear mucosa was determined on electron micrographs by counting the number of precipitates per unit area. Electron spectroscopic imaging was also performed to obtain information about the spatial distribution of the precipitates and their elemental composition.

The biochemical composition of tympanosclerotic deposits.

We have studied the quantitative analysis of calcium, phosphate and cholesterol in the tympanosclerotic plaques removed from 25 patients. Our findings confirm that tympanosclerosis has a partly calcified organic matrix, in which the calcification process is probably similar in its qualitative chemical structure to that occurring in other calcified pathological tissues. The degree of calcification varies from one case to another and is even different in various locations of the same sampling. However, calcium levels are usually lower than in other pathological tissues which are calcified. The average quantity of calcium in our studies was 2 mg in 100 mg tissue or 12 mg in 100 mg protein. The average molar ratio between calcium and phosphate was 3, corresponding to the hydroxyapatite ratio. The average total quantity of cholesterol present was only 15 micrograms in 100 mg protein.

Ultracytochemical localization of Ca2(+)-ATPase activity in the middle ear mucosa of the guinea pig.

Ca2(+)-ATPase activity was studied ultra-cytochemically in the middle ear mucosa of the guinea pig. On electron microscopic examination, the most intense reaction was found on the microvilli. Reaction products were also observed on the cilia and around and between the secretory granules on the apical side of the cells in their secretory phase. The basolateral membranes contained few reaction products, while very little or no activity was found on the basal membrane.

Ofloxacin in oral chemotherapy of acute and chronic otitis media.

After ascertaining the bacterial spectrum in 210 patients with Otitis media acuta, Otitis media chronica mesotympanalis and Otitis media chronica epitympanalis, the clinical efficacy of oral therapy with ofloxacin in 40 patients from each of these groups was assessed. The clinical results are comparable with those following conventional local, oral and intravenous antibiotic therapy. The microbiological analysis of the ear secretions revealed Staphylococcus aureus, Streptococcus pyogenes and Haemophilus influenzae to be the main infectious agents of acute otitis media, whereas in chronic otitis media Pseudomonas aeruginosa and Proteus sp. could be detected in most of the cases. Ofloxacin levels of ear secretions, mucosa specimens of the middle ear and serum were measured in some patients by means of HPLC. In most cases, drug levels exceeded the MICs for the bacteria mentioned above. The correlation with the clinical results is discussed. On the basis of these preliminary results, ofloxacin can be considered as a highly efficient oral substance which is effective against S. aureus and P. aeruginosa, two important pathogens of middle ear infections.