The neutrophil chemotactic activity of middle ear effusions (MEE) was measured in patients with pediatric chronic, adult chronic, and acute otitis media with effusion (OME). Chemotactic activity differed significantly among the three groups of otitis media in the following order: adult chronic less than pediatric chronic less than acute. Culture-positive effusions had higher chemotactic activity than did those that tested culture negative, suggesting that bacterial infection is related to neutrophil chemotactic activity. The chemotactic function of normal peripheral neutrophils was not enhanced by preincubation with MEE, but their bactericidal function was enhanced. In conclusion, bacterial infection in the middle ear is one of the major determining factors of neutrophil infiltration during OME, and MEE enhances the bactericidal function of neutrophils.

Acute Disease↗

PubMedDate not supplied

Lysosomal proteases and protease inhibitors in nasal allergy and non-atopic sinusitis.

Patterns of protease activity and levels of protease inhibitors were analyzed in both nasal secretions and tissue extracts from patients with nasal allergy and non-atopic sinusitis to investigate the role of proteases in the inflammatory reaction. Protease activity was measured using specific methyl-coumaryl-7-amide substrates. The pattern of protease activity in the nasal secretions of chronic sinusitis patients was similar to that in neutrophil lysate and quite different from that in plasma. Both gluthatione activation testing and inhibition testing using synthetic inhibitors revealed that the majority of proteases in both secretions and tissues are lysosomal thiol proteases such as cathepsins B and L. Neutrophilic elastase is also a major protease in nasal secretions. In acute sinusitis, both protease activity and inhibitor levels were very high, suggesting an interaction between proteases and inhibitors. Cathepsin B and B-like thiol proteases appear to play a key role in prolonging chronic inflammation against the healing process, due to their resistance to plasma inhibitors and the shortage of thiol protease inhibitors. Protease activity in the secretions of nasal allergy patients was very weak, and the reaction between proteases and inhibitors appeared to be weak.

Adult↗

PubMedDate not supplied

Kinetics of lysosomal protease activity in human otitis media with effusion.

Hydrolytic activity of various lysosomal proteases--elastase, collagenase, and cathepsins B and H--were measured in 125 middle ear effusions from patients with chronic (serous and mucoid) and acute otitis media with effusion (OME). The levels of cathepsin B activity and alpha-2-macroglobulin during the course of clinical therapies (myringotomy and tympanostomy tubing) were analyzed in 10 chronic OME cases where follow-up evaluation was possible. It is found that the level of lysosomal protease activity (elastase, collagenase and cathepsin B) was higher in acute OME than that in chronic OME; the hydrolytic activity of cathepsin B in middle ear effusions could be used as an indicator to reflect the level of lysosomal proteases activity in the middle ear; in chronic OME, inflammatory reaction including lysosomal protease activity of the middle ear mucosa at the time of the first myringotomy appeared to be more active than that at the time of the final myringotomy, but less than that in acute OME; and the proteolytic damage of lysosomal thiol proteases to the middle ear mucosa, which may be related to the chronicity of OME, could be reduced by both therapeutic myringotomy and tympanostomy.

Cathepsin B↗

PubMedDate not supplied

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.

Adjuvants, Immunologic↗

PubMedDate not supplied

Recurrence of antigen-induced otitis media by thiol compound.

Reduced glutathione (GSH), a potential factor in the chronicity of human otitis media, was tested to determine its potency in the recurrence of antigen-induced otitis media in chinchillas sensitized with human serum albumin (HSA). GSH instillation into the healing middle ear bulla reproduced a level of otitis media similar to the original antigen-induced otitis media with cellular involvement occurring earlier, according to cytologic analyses. This study indicates that GSH is probably a factor in recurrent antigen-induced otitis media, controlling the balance between thiol proteases and thiol protease inhibitors during middle ear inflammation.

Animals↗

PubMedDate not supplied

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.

Animals↗

PubMedDate not supplied

A protein binding to the J kappa recombination sequence of immunoglobulin genes contains a sequence related to the integrase motif.

Site-specific recombination requires conserved DNA sequences specific to each system, and system-specific proteins that recognize specific DNA sequences. The site-specific recombinases seem to fall into at least two families, based on their protein structure and chemistry of strand breakage. One of these is the resolvase-invertase family, members of which seem to form a serine-phosphate linkage with DNA. Members of the other family, called the integrase family, contain a conserved tyrosine residue that forms a covalent linkage with the 3'-phosphate of DNA at the site of recombination. Structural comparison of integrases shows that these proteins share a highly conserved 40-residue motif. V-(D)-J recombination of the immunoglobulin gene requires conserved recombination signal sequences (RS) of a heptamer CACTGTG and a T-rich nonamer GGTTTTTGT, which are separated by a spacer sequence of either 12 or 23 bases We have recently purified, almost to homogeneity, a protein that specifically binds to the immunoglobulin J kappa RS containing the 23-base-pair spacer sequence. By synthesizing probes on the basis of partial amino-acid sequences of the purified protein, we have now isolated and characterized the complementary DNA of this protein. The amino-acid sequence deduced from the cDNA sequence reveals that the J kappa RS-binding protein has a sequence similar to the 40-residue motif of integrases of phages, bacteria and yeast, indicating that this protein could be involved in V-(D)-J recombination as a recombinase.

Amino Acid Sequence↗

PubMedDate not supplied

Rheological properties of middle ear effusions from children with otitis media with effusion.

Freshly harvested middle ear effusions (MEE) were collected from children with otitis media with effusion. Both elasticity (G') and viscosity (eta') of the MEE were determined by an oscillating sphere magnetic rheometer and compared with transportability of the MEE on mucus-depleted frog palates. A maximum value of transport was obtained at G' of about 20 dyne/cm2 (at 1 Hz), and below this value there was a significant positive correlation between the transport rate and log G'. Above 20 dyne/cm2, the negative correlation between the transport rate and log G' was significant. This shows there is a sharp increase in transport with increase in G' up to 20 dyne/cm2, and at the higher value of G' there is a slow decrease in transport with increasing G'. A similar significant correlation between the transport rate and log eta' was observed.

Adolescent↗

PubMedDate not supplied

Significance of kallikrein-kinin system in otitis media with effusion.

Significance of the kallikrein-kinin system in the pathogenesis of otitis media with effusion (OME) was evaluated by prekallikrein level, kallikrein activity, and concentration of high molecular weight (HMW) kininogen in 45 middle ear effusions (MEEs, 38 serous and seven mucoid). All MEEs had varying prekallikrein levels (73.1 +/- 127.5 relative fluoro units [RFU]), and the mean value in serous effusions (82.2 RFU) was much higher than that in mucoid effusions (23.0 RFU). Hydrolytic activity of kallikrein in serous effusions was 18.0 +/- 27.9 RFU, and was significantly higher than that in mucoid effusions (8.0 +/- 4.2 RFU, p less than 0.05). Concentration of HMW kininogen in serous effusions was 51.2 +/- 72.77% of plasma value, but it could not be detected in any mucoid effusions. Analysis of protein composition by polyacrylamide gel electrophoresis indicates that plasma protein that has leaked into the middle ear is a major component of MEEs. The kallikrein-kinin system would be active in serous effusions, and liberated bradykinin enhances vascular permeability in the middle ear mucosa, leading to profuse plasma leakage, which characterizes the component of serous effusions. On the other hand, this system would almost be consumed in mucoid effusions.

Adult↗

PubMedDate not supplied

Lysosomal thiol proteases in middle ear effusions.

Hydrolytic activity of lysosomal cathepsins B and H, and trypsin-like proteases in 115 middle ear effusions (MEEs, 40 serous and 75 mucoid) from chronic otitis media with effusion (OME) patients was measured and compared to that in plasma. The activity of both cathepsins in MEEs was significantly higher than that in plasma (p less than 0.01), and cathepsin B activity in mucoid MEEs was also significantly higher than that in serous MEEs (p less than 0.01). The activity of trypsin-like proteases was very weak in both MEEs and plasma. Profiles of various inhibitors indicated the qualitative difference of proteolytic enzymes between MEEs and plasma. Mucoid MEEs had significantly higher activity of thiol proteases than serous ones (p less than 0.01). Cathepsin B-like lysosomal thiol proteases, derived mainly from macrophages, could become a major proteolytic factor to perpetuate and amplify the inflammatory reaction of chronic OME.

Adult↗

PubMedDate not supplied

Hearing impairment in relation to viscoelasticity of middle ear effusions in children.

Both dynamic viscosity (eta') 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 eta' and the magnitude of the air-bone gap at 500 and 1,000 Hz, but there was no significant correlation between eta' 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 eta' of middle ear effusion has an effect on the amount of hearing impairment at frequencies below 1,000 Hz.

Child↗

PubMedDate not supplied

Biochemical study of protease inhibitors in experimental otitis media with effusion.

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Animals↗

PubMedDate not supplied

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.

Adult↗

PubMedDate not supplied

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.

Adult↗