Comparison of immune-mediated models of acute and chronic otitis media

Summary The distribution of immunoglobulin-bearing cells and the pattern of histopathological changes in the middle ear (ME) mucosa, round window membrane (RWM), and inner ear were compared during acute and chronic immune-mediated otitis media with effusion (OME) in the guinea pig as an animal model. In both acute and chronic immune responses (IRs), mucosal hyperplasia, edema, neovascularization, and cellular infiltration were observed. IgG+ cells were predominant in both the acute and chronic IRs. The number of IgA+ cells, however, increased in the mucosa and RWM during chronic IRs. Only the chronic IR resulted in gland formation within the ME and inflammation within the cochlea. These results indicate that the chronic IR was more similar to reports of clinical OME than the acute IR, The cochlear inflammation associated with chronic OME can lead to sensorineural hearing loss, as reported in clinical studies.     

Lymphocyte subsets in immune-mediated otitis media with effusion

Summary To examine the role of T-cell subsets in immune-mediated otitis media with effusion induced by keyhole limpet hemocyanin (KLH), we used immuno-histochemical methods to investigate the kinetics of immunocytes of the middle ear (ME) and eustachian tube (ET) in healthy BALB/c mice. Antibodies against murine macrophages and granulocytes (anti-Mac-1), helper T cells (anti-Lyt-1), suppressor T cells (anti-Lyt-2), immunoglobulins (anti-IgG, -IgM, -IgA), secretory component (SC) and KLH were used. The ME exhibited a substantial immune response, whereas the response of the ET was minor and was associated with a secondary ME immune response. After KLH challenge, an effusion with an extensive infiltration of inflammatory cells (Mac-1, IgG⁺ and IgM⁺ cells) was observed at days 1 and 3 in the ME cavity and rapidly disappeared by day 7. Within the ME mucosa, a large number of cells was observed at days 1 and 3, peaking on day 7 when a submucosal lymphoid infiltration was detected. In the immune response of the ME mucosa, Mac-1 cells were the predominant cell type followed by helper T cells, IgG⁺ cells, IgA⁺ cells and then IgM⁺ cells. Suppressor T cells were rarely detected after KLH challenge. SC was present within ME epithelial cells from days 1 to 14. From these findings, we conclude (1) that the majority of infiltrating cells in the ME cavity originate from circulating blood; (2) that the ME mucosa has an excellent capacity to mount a strong immune response, including mucosal immunity, through the accumulation of immunocytes for antigen processing and antibody production; (3) that elimination of antigen appears to be the most important factor for returning the immune response to a quiescent state.     

Use of Medical Care and Antibiotics among Preschool Children in Different Day Care Settings

ABSTRACT. The use of medical care among 880 1-5 year olds in different day care settings was studied using register information on physician visits, purchases of antibiotics and municipal day care in 1984. The unit of analysis was months in the different day care settings and not children. The rates of physician visits were 1.4 to 1.8 times higher for acute upper respiratory tract infections and all acute infections and 2 to 3 times higher for secretory otitis media during day care centre months and family day care months as compared to home care months. The rate of visits for bronchial asthma was 5 times higher during day care centre months than during home care months. No differences were found between day care centre months and family day care months with respect to the rates of physician visits for acute upper respiratory tract infections, acute otitis media and all acute infections. Among children in family day care, the daily number of hours in day care, and size, average age and age homogeneity of the groups were not significantly associated with rates of visits for all acute infections or purchases of antibiotics.     

Pneumococcal bacteriology after pneumococcal otitis media with special reference to pneumococcal antigens

Fifty-four ears with evidence of pneumococcus (Pn) in the first acute otitis media (AOM) in 38 infants and with prolongation or recurrence of the MEF during the follow-up were observed for 7-22 months for the presence of Pn by culture or of pneumococcal antigen (Pn-ag) by counterimmunoelectrophoresis or latex agglutination methods in their MEFs. During the first three 1-month observation periods, Pn and/or Pn-ags were detected in 24% to 9% of these ears, always of the initial type/group. Later on new Pn types/groups appeared also. In two of the 9 MEFs persisting for greater than or equal to 3 months, initial Pn-ag, with culturable Pn, was repeatedly found but not for longer than 5 months. Of the 12 ears resulting in secretory otitis media (SOM) only one showed initial Pn-ag (and Pn) in the MEF of SOM. Pneumococcal type/group pattern associated with prolongation or recurrence of infection did not differ from that of initial AOM. In another series of 151 SOM ears in 97 children, Pn-ags were detected in 7 MEFs. Four of them grew Pn, each of the corresponding group. Our studies suggest that the persistence of Pn-ags in the middle ear after AOM is limited and their occurrence in the MEFs of SOM is rare. Thus, the role of the persistence of Pn-ags in prolonged, recurrent or secretory otitis media seems questionable.     

A 5-year Prognosis of Childhood Asthma

ABSTRACT. A series of 207 asthmatic children aged 4-10 years studied during the years 1976-1978 were called for a follow-up study 4-6 years later. Of these, 53 (26 %) children were completely symptom-free and 154 still had symptoms. The proportion of symptom-free patients was highest (45 %) among those having attacks only during respiratory infections. The prognosis was worsened by such factors as a high rate of attacks, an association with eczema and a history of otitis media or adenoidectomy. The clinical picture of disease among children having attacks only during respiratory infections (wheezy bronchitis) was distinctive from that in asthma and may be separated as its own entity. Subgrouping of childhood asthma is beneficial for a clinician when considering the intensity of therapy or the need for controls.     

Treatment of secretory otitis media with Kampo medicine

Summary Kampo medicine is a traditional Japanese herbal medicine that is known as Sairei-to and has been used to treat otitis media. This preparation was given orally for 4 weeks to 35 children with secretory otitis media (SOM). Four of 46 ears (8.7%) completely resolved while 32 ears (69.6%) showed a partial improvement without serious adverse reaction. Our findings indicate that Kampo medicine may resolve the inflammation and immune response associated with SOM. Further studies in its mechanism of action are warranted.     

A study of the effects of contrast change on pattern VEPs, and the transition between onset, reversal and offset modes of stimulation

We studied the relationship between the visual evoked potential (VEP) components by tracing the transition from onset/offset mode of stimulation to the reversal mode by a series of contrast change steps. VEPs on the ipsilateral and contralateral side of the scalp with respect to the left half-field checkerboard stimulus (checksizes: 12, 50 and 80) were recorded in 15 subjects. Eight contrast steps for each checksize were recorded. Each test step consisted of the alternation of a constant high contrast checkerboard (A), with a second checkerboard (B) in which the contrast was changed. Checkerboard B was initially of identical spatial phase to A, but contrast was reduced systematically until B was a uniform grey field (i.e. onset/offset). In subsequent steps checkerboard B was of opposite spatial phase and contrast was increased until the final step when B was of equal high contrast (i.e. full reversal). All ipsilateral and contralateral onset components, ipsilateral offset components, and the reversal P100 component significantly enlarged with increasing contrast. The extent of amplitude change with contrast was greatest for offset, followed by onset and then reversal. A clear association could be discerned between all offset and reversal components. Onset CI and CII appeared to be related to the reversal P100 and N145, respectively. When small 12 checks were used, onset Co appeared to have common features with the reversal N80. The contralateral onset P105 component did not have a comparable component in the reversal mode.     

A rapid sperm motility bioassay procedure for quality-control testing of water and culture media

A rapid bioassay procedure is described for quality-control testing water and apparatus used in the preparation of media for gamete and embryo culture. This bioassay is based on the sensitivity of hamster epididymal spermatozoa to contaminants present in water and/or in the culture apparatus. The bioassay is usually performed using a modified Tyrode's solution as the sperm culture medium, although complex media can be used. The sensitivity of this test is greatly enhanced by the absence of protein in the medium. The bioassay has been used to detect impurities in water prepared by a standard cartridge filtration system and to verify that reverse-osmosis pretreatment of water could eliminate the problem. It has also detected toxic contaminants leached from syringe filters during medium sterilization. The bioassay is simple to perform and can be completed in 1 working day. It may be a useful alternative to the conventional mouse embryo tests that are in widespread use in human in vitro fertilization (IVF) laboratories.     

Experimentally induced otitis media with effusion following inoculation with the outer cell wall of nontypable Haemophilus influenzae

Summary Previously, we extracted lipopolysaccaride endotoxin (LPS) from an axenic culture of Haemophilus influenzae and inoculated it into the middle ears of guinea pigs, inducing temporary serous effusions. In the present study, we tried to clarify whether the immunological mechanism responsible for producing the otitis media following outer cell wall inoculation was persistent. We extracted the outer cell wall from nontypable H. influenzae, using Zollinger's method, and inoculated extracts into the middle ears of guinea pigs that had previously received three injections of nonviable H. influenzae in Freund's complete adjuvant. Histological evaluations were performed from day 2 to day 24. Effusions and mucosal changes persisted for a longer time than in the LPS-inoculated model. Hypertrophied mucosae and increased numbers of goblet cells with hypersecretion were visible in the specimens on days 23–24. The condition seemed to show a greater similarity to chronic otitis media with effusion in children than did the LPS-inoculated model. We concluded that both the biological activity of the outer cell wall and immunological mechanisms might induce prolonged otitis media. We speculate that not only single middle ear infection but also general infections and repetitive middle ear infections may contribute to prolonged otitis media.