The cytology of "glue ear"

Purification and N-terminal characterization of Chinchilla villidera alpha-1-antitrypsin

1. Chinchilla, Chinchilla villidera, alpha-1-antitrypsin has been purified to homogeneity and partially characterized according to mol. wt, amino acid and carbohydrate composition and N-terminal amino acid sequence (30 residues). 2. The mol. wt is between 52,000 and 55,000 as determined by PAGE or sedimentation equilibrium. 3. The best alignment between chinchilla, human and baboon alpha-1-antitrypsin amino acid sequences offsets the chinchilla sequence 6 positions vs the primate structures. 4. This alignment suggests potential importance of the sequence His-Glu-Gln-Glu-His at positions 11-15. 5. Additionally, the segment Leu-Ala-Glu-Phe-Ala, positions 25-29, is strictly conserved. 6. Shorter N-terminal sequences available for rat and rabbit alpha-1-antitrypsin appear to follow the offset alignment vs the primate structures.

Hydrolase Activity in Acute Otitis Media with Effusion

Biochemical studies of middle ear effusions (MEE) from patients with chronic or recurrent otitis media with effusion (OME) have demonstrated the presence of significant levels of certain hydrolytic and oxidative enzymes. We have examined MEE from patients with acute OME for the content of a number of lysosomal hydrolases and find no significant differences in the mean values for acid phosphatase, α-mannosidase, β-galactosidase, β-glucuronidase, hexosaminidase, and neuraminidase between purulent and serous effusions. In every case, the mean activities of these enzymes were greater in culture-positive than in culture-negative effusions although this difference was significant only in the case of neuraminidase. Neuraminidase activity was detected in 78% of those MEEs from which Streptococcus pneumoniae could be cultured and in only 32% to 64% of all other effusions. No correlation was observed between the level of neuraminidase released into the extracellular growth medium and the infectivity of various strains of S pneumoniae.

Neuraminidase activity in middle ear effusions

Analyses of Streptococcus pneumoniae culture filtrates and middle ear effusions (MEE) containing S pneumoniae for various hydrolytic enzymes have demonstrated substantial levels of neuraminidase activity when measured employing a sensitive fluorometric assay. S pneumoniae neuraminidase exhibits optimum activity near neutral pH (6.0 to 6.5), and catalyzes the cleavage of sialic acid residues from glycoproteins, gangliosides and mucopolysaccharides. S pneumoniae begins secreting large amounts of neutral neuraminidase (mean [means] = 43.3 units/mL culture filtrate) when cells enter the stationary phase. Nearly all (96%) human chronic MEEs yielding positive cultures for S pneumoniae contain neuraminidase activity (means = 0.200 units/mg protein), while only 21.1% to 45.5% of all other effusions contain the enzyme. Middle ear effusions obtained from S pneumoniae infected-chinchillas contained large amounts of neuraminidase activity (approximately 200 units/mL), which decayed exponentially in vivo with an apparent half-life of 8 1/2 days. Three neuraminidase isoenzymes (designated I-III) were identified in S pneumoniae culture filtrates, as well as in MEEs from chinchillas infected with the organism, using a combination of ion-exchange and gel filtration chromatography. With 4-methylumbelliferyl-N-acetylneuraminic acid serving as substrate, preparation I from both culture filtrates and MEEs was characterized by a high Michaelis constant (Km), while forms II and III had low Km values. Preferred substrates were orosomucoid and neuramin-lactose; gangliosides, thyroglobulin, and bovine submaxillary mucin were poorer substrates.

Lysosomal hydrolases in middle ear effusions

Biochemical studies of middle ear effusions have demonstrated generally higher levels of certain hydrolytic and oxidative enzymes in mucoid fluids when compared to serous. We have extended these studies by analyzing middle ear effusions for the content of a large number of lysosomal hydrolases. The mean specific activity for alpha-glucosidase in mucoid fluids was found to be ten times that for serous fluids while alpha-mannosidase, beta-glucuronidase, hexosaminidase, acid phosphatase, beta-galactosidase, alkaline phosphatase, and lactate dehydrogenase were found to be three to five times greater in mucoid than serous effusions. In this study the specific enzyme activities for lysosomal hydrolases from purulent effusions were found to be intermediate between the activities in serous and mucoid effusions. No significant correlation was found between the specific activities of lysosomal hydrolases and the presence or absence of bacteria in mucoid or serous middle ear effusions. The hexosaminidase isozyme distribution was found to be identical for serous and mucoid fluids and similar to that found in human serum. However, the isozyme pattern of beta-glucuronidase in mucoid effusions was significantly different than that in normal human serum as mucoid fluids contain a large amount of an anionic isoenzyme of beta-glucuronidase that is barely detectable in human serum.

Adenoidectomy versus tympanostomy in chronic secretory otitis media

Fifty-eight consecutive charts of children suffering from mucoid middle ear effusion proven by myringotomy who were followed for two years were reviewed. Half of the group underwent adenoidectomy and the other half, with similar age distribution, had tympanostomy. Only 20.7% of the adenoidectomized children had normal hearing and aerated middle ears during the two-year follow-up, whereas 59% had normal hearing following tympanostomy. Adenoidectomy had no additional beneficial effect on the cure rate obtained by tympanostomy, which proved to be more effective in all age groups, and in the nonallergic child. In the atopic child, however, both modalities yielded similarly poor results.

Middle ear mucosa and secretory otitis media

Recent investigations have identified the viscous middle ear effusion in secretory otitis media (S.O.M.) as being of the same nature as true mucus--the "backbone" of which is glycoprotein. The source of the mucus is mucus-producing cells in greater number than found in the normal middle ear lining. The pathological state which leads to excessive mucus production and maturation of numerous mucus cells is an inflammation associated with deficient ventilation of the middle ear. In the presence of inflammation, especially when CO2 tension is high, mucosal stem cells differentiate metaplastically into numerous mucus-producing cells, as demonstrated by us in tissue cultures. The higher CO2 tension in S.O.M. is due to eustacian tube insufficiency (not blockage) which is a smaller than normal amount of air introduced into the middle ear per unit of time. Ventilating tubes restore CO2 tension to normal and equalize the slight barometric negative pressure (average 3.35 H2O)--the latter being related to mucociliary clearance. Evidence for an allergic factor as a pathogen is also not available. The mucus in the middle ear is probably not noxious by itself and ears should be ventilated surgically only when hearing is below social level perception. Most S.O.M. ears will clear sooner or later spontaneously. A minority of these ears will progress with time into atelectatic ears and some might perforate later on.

Temporal bone pathology in an active case of glue ear

A child aged 3 1/2 died from a cardiac condition after many and prolonged antibiotic courses: bilateral glue ear had been treated for the previous 18 months. Histopathology showed cholesterol granulomata in the mastoid air cells, with evidence of old hemorrhage, and of former inflammation of bone. The exudate was histiocytic with some giant cells. An 'orange spot' on the tympanic membrane was hyperaemic middle-ear mucosa, heavily infiltrated by plasma cells, lymphocytes and histiocytes. There was no evidence of hypersecretion. Some of the most abnormal areas were around the stapedial niche and the round window.

Middle ear effusions: definitions

Evolution of nomenclature used in middle ear effusions for the last hundred years is researched and followed. It is concluded that in the light of present knowledge the term sero-mucous otitis media is the most appropriate for the nonpurulent effusions here under discussion.

The biopathology of secretory otitis media

Recent investigations have identified the viscous middle ear effusions in secretory otitis media as being of the same nature as true mucus — the “backbone” of which is glycoproteins. The source of the mucus are mucus producing cells found in the normal middle ear lining and producing excessive amounts of mucus in pathological states. The nature of the pathological state which leads to excessive mucus production is an inflammation associated with deficient ventilation of the middle ear. Ventilation deficiency of the middle ear is a pathophysiological phenomenon which is not associated with hermetic blockage of the Eustachian tube. The “ex-vacuo” theory which assumes the tube to be blocked — the effusion to be a proteinous transudate and the middle ear devoid of mucus secreting elements, is no more tenable. Middle ear effusions can be approached by looking at them as questions of: 1) mucus clearance; 2) excessive mucus production; 3) middle ear ventilation and 4) etiology of middle ear inflammation. Clearance of mucus from the middle ear is governed by the mucociliary system, where the number of cilia and specificity of mucus are known today to be critical for clearance. Excessive amounts of mucus are secondary in the middle ear, as in all other mucosa in the body, to a metaplastic process. Mucosal stem cells can differentiate into mucus cells, ciliated cells, and keratin producing cells. In the presence of inflammation, especially when oxygen tension is low (and CO2 tension is high) mucosal stem cells differentiate into numerous mucus producing cells which have been shown, in the middle ear, to be responsible for the excessive mucus production. The nature of the mechanism of middle ear ventilation in health and disease is not yet known, though it is in all probability related to the function of the Eustachian tube muscles.

Distribution of diplococcus pneumoniae types in acute otitis media in children and influence of the types on the clinical course in penicillin v therapy

Abstract Pneumococci isolated from the ear exudate in 245 children under 10 years of age afflicted with acute otitis media were typed. Types 3, 6, 14, 18, 19 and 23 were found in 80% of the cases. In the remaining cases, 15 other types were found. Five strains were not typable with the antisera used. Types 14 and 23 were found twice as often in the age group 0-3 years as in the higher age groups, whereas the opposite was true for type 3. The relapse frequency was highest after types 14 and 19 infections. The frequency of residual secretory otitis was highest after type 14 infections. Types 19 and 23 were never found in infections followed by secretory otitis. Patients with type 14 infections, healed or unhealed, showed the same blood group distribution within the ABO and Lewis systems as a normal Swedish population. Penicillin V therapy failed to eliminate the pneumococcal strain from the nasopharynx in 40% of consecutive cases of otitis media. Relapse after penicillin-treated pneumococcal otitis is to be regarded as a new complication of the primary infection and not as a reinfection from the environment.