Yukiyoshi Hamaguchi

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.

Round window membrane permeability to human serum albumin in antigen-induced otitis media

The round window membrane (RWM) permeability to human serum albumin (HSA) was investigated in both normal chinchillas and chinchillas sensitized with HSA. The effect of a corticosteroid agent (triamcinolone) on the RWM permeability was also analyzed. It was found that HSA could not be detected in either the perilymph or the cerebrospinal fluid of normal chinchillas within 1 hour after instillation into the middle ear bulla. Perilymph levels of HSA peaked 24 hours after instillation. In antigen-induced otitis media, the HSA level in the perilymph at 12 hours after challenge was significantly higher than that in normal chinchillas (P less than .01), but it did not increase with the development of otitis media. A significant difference of HSA level in the perilymph of animals with and without steroid treatment was noted (P less than .025 at 24 hours and P less than .05 at 48 hours). It is concluded that little HSA passes through the normal RWM in a short time and that the RWM permeability to HSA increases in the early stage (about 12 hours) of antigen-induced otitis media. Corticosteroids can affect the RWM permeability to HSA by reducing the level of antigen-induced otitis media.

Quantitation and Immunocytological Identification of lnterleukin-1 in Nasal Polyps from Patients with Chronic Sinusitis

Immunoreactive interleukin-1 (IL-1) alpha and beta levels in nasal polyp (NP) extracts were measured from 22 adult patients with chronic sinusitis (CS) in order to determine their significance in the pathogenesis of NP. The NP sample was separated into mononuclear and polymorphonuclear fractions. In the mononuclear fraction, the mean value of IL-1 beta was 21.5 pg/ml/g, which was significantly higher than that of IL-1 alpha (8.4 pg/ml/g, p < 0.01). In younger adults, the IL-1 alpha and IL-1 beta levels were 21.2 and 59.4 pg/ml/g, which were significantly higher than those in older CS patients (p < 0.01). There was a significant reverse correlation between patients age and IL-1 beta levels in the mononuclear fraction (r = -0.509, p < 0.01). Immunoreactive IL-1, mainly IL-1 beta, was identified in the cytoplasmic area of monocytes. A certain amount of immunoreactive IL-1 is produced in mononuclear leukocytes, particularly activated monocytes, and IL-1 beta production is greater than IL-1 alpha. In younger adult CS patients, NPs contain larger amounts of IL-1 beta in monocytes, compared to those of older patients.

Circadian Variation of Secretory IgA in Nasal Secretions from Normal Subjects

In normal subjects the concentration ratio of secretory IgA (sIgA) to total IgA in nasal secretion was measured by means of enzyme-linked immunosorbent assays (ELISA). No marked circadian variation was disclosed in the sIgA/IgA ratio in nasal secretion.

Antifibrinolytic activity in middle ear effusion

No activity of the plasmin and plasminogen activators could be detected in middle ear effusion (MEE). A streptokinase proactivator, which was not plasminogen and markedly enhanced the activation of plasminogen by streptokinase, could be detected. MEE had an apparent inhibitory activity against both thiol protease (papain) and serine proteases (plasmin and trypsin). All these findings indicate that MEE contains unsaturated protease inhibitors and is in a state of predominance of inhibitors over fibrinolytic activity.

Quantification of interleukin-1 in nasal polyps from patients with chronic sinusitis

SummaryWe have measured interleukin-1α (IL-1α) and β levels in nasal polyps (NP) from patients with chronic sinusitis (CS) in order to determine their significance in the pathogenesis of NP. NP in ten cases (five male and five female; age range, 17–63 years) were removed to separate mononuclear (M) and polymorphonuclear (PMN) fractions through Ficoll-Paque separation media. ELISA measurements of the M fraction showed that the mean value of IL-1β was 17.8 pg/mI per gram, which was significantly higher than that of IL-1α (7.04 pg/ml per gram, P<0.01, Wilcoxon test). In the PMN fraction, the mean value of IL-1α was 8.79 pg/ml per gram and that of IL-β was 7.85 pg/ml per gram, which was not significantly different. Mononuclear leukocytes, particularly activated monocytes, seem to be a major source of IL-1 in the NP taken from patients with CS.

Endotoxin and Lysosomal Protease Activity in Acute and Chronic Otitis Media with Effusion

Endotoxin levels and lysosomal protease (collagenase, cathepsin B, and lysozyme) activity were measured in 104 middle ear effusions (MEEs) from patients with otitis media with effusion (OME). The MEE samples were classified into four groups: Pediatric serous, mucoid, and acute, and adult serous. Endotoxin levels and lysosomal protease activity in MEEs were significantly different in the following order: Adult < serous < mucoid < acute groups, indicating that both endotoxin and lysosomal proteases are more closely related to the pathogenesis of pediatric chronic OME than to adult OME. In pediatric serous and mucoid effusions, endotoxin level had a significant correlation with activity of the lysosomal proteases. In conclusion, endotoxin enhances leukocyte infiltration into the middle ear, and lysosomal proteases released from leukocytes damage the middle ear mucosa and thereby prolong mucosal inflammation, which may be responsible for delayed recovery from acute OME.

Antiinflammatory effects of a corticosteroid and protease inhibitor agents on antigen-induced otitis media in chinchillas***

Using an antigen-induced otitis media (OM) model in chinchillas sensitized with human serum albumin (HSA), we studied the antiinflammatory effect of a corticosteroid (triamcinolone) and a protease (kallikrein) inhibitor (aprotinin) by conducting both biochemical and cytologic analyses of middle ear fluid (MEF). The levels of HSA, alpha 1-antitrypsin, alpha 2-macroglobulin, and total protein concentration were measured in the MEF to evaluate the degree of OM. Both vascular leakage and leukocyte infiltration were significantly reduced by corticosteroid and inhibitor treatments. HSA levels in the MEF were markedly reduced after HSA challenge, and both treatments reduced the drop in HSA levels. In conclusion, the kallikrein-kinin system is related to the early stage of antigen-induced OM. Both corticosteroid and inhibitor treatments effectively reduce the degree of antigen-induced OM in chinchillas, suggesting that both may be useful local therapeutic agents in the treatment of human OM.

Lysosomal thiol proteases (cathepsin B-like proteases) in serous middle ear effusions from adult patients.

Hydrolytic activity of cathepsins B, H and trypsin-like proteases was measured in 38 serous middle ear effusion (MEE) samples. The concentrations of (alpha 1-AT) and alpha 2-macroglobulin (alpha 2-M) were also quantitated. The mean value of cathepsin B activity was 25.0 +/- 20.7 RFU and that of cathepsin H was 14.3 +/- 3.0--both significantly higher than those in plasma (1.8 +/- 0.4 RFU, 1.2 +/- 0.3 RFU, p less than 0.005). Very low trypsin-like protease activity could be observed. The mean concentrations of alpha 1-AT and alpha 2-M were 368 +/- 94.8 mg/dl and 57.5 +/- 57.3 mg/dl. The bulk of alpha 1-AT in MEEs was occupied by free alpha 1-AT, which can saturate exogenous trypsin. Due to the very low molar concentration of alpha 2-M in MEEs, thiol proteases (mainly cathepsin B) could be a possible major factor inflicting proteolytic injury on the middle ear mucosa and reflecting the severity of the inflammatory process.

Quantitation of Nasal Secretory IgA by Enzyme-Linked Immunosorbent Assay

A simple and sensitive technique, enzyme-linked immunosorbent assay (ELISA) was used for the quantitation of secretory IgA (sIgA) in order to study the synthesis and transport of sIgA in the nasal secretion from patients with chronic sinusitis. Rough-surface glass beads coated with antisecretory component antibody were employed as the solid phase. The minimal detectable concentration of sIgA was 50 ng/ml in this study. sIgA averaged 226.3 +/- 217.4 mg/dl and total IgA averaged 302.0 +/- 137.5 mg/dl.