Type B Haemophilus influenzae-induced otitis media in the mouse.

To characterize the middle and inner ear cellular inflammatory responses to otitis media using immunohistochemical methods, we inoculated type B Haemophilus influenzae into the middle ears of healthy adult BALB/c mice. Mac-1+ neutrophils and macrophages appeared in the middle ear at 3 days. Lyt-1+ T cells and Lyt-2+ T suppressor/cytotoxic cells entered the middle ear mucosa on days 7 and 14. IgG+ and IgM+ T cells were present at all time points, with IgA+ lymphocytes forming the majority of mucosal immunoglobulin-bearing cells at 2 weeks. The cochlear scala tympani contained Lyt-1+ and Mac-1+ cells and two endolymphatic sacs stained diffusely with anti-IgA and -IgG antibodies. Lyt-1/L3T4+ T lymphocytes greatly outnumbered B lymphocytes, suggesting that helper/inducer T cells play a more important role in acute otitis media than has been recognized. Inner ear changes occurred after a single episode of otitis media.

Endotoxin-induced otitis media with effusion in the mouse. Immunohistochemical analysis.

A model of endotoxin-induced otitis media with effusion was developed in healthy BALB/c mice. Endotoxin extracted from Salmonella typhimurium (10 micrograms/ml) was injected into the middle ear bulla transtympanically and the resultant inflammatory response was analyzed using immunohistochemical methods. Serous effusions were observed otoscopically and mucosal edema and infiltrate were studied histologically, both peaking at 3 days and essentially resolving by 7 days. However, persistence of a small area of inflammation in the round window niche was consistently present at 2 weeks. The specific cellular responses to endotoxin were analysed by histologic and immunohistologic examination of the murine temporal bone. We used antibodies to identify T-lymphocytes (anti-Lyt-1, -Lyt-2), macrophages and neutrophils (anti-Mac-1), and immunoglobulins (anti-IgA, -IgG, -IgM). In the mucosal/submucosal infiltrate Mac-1+ and Lyt-1+ cells peaked from days 1 to 3. Within the luminal effusion Mac-1+ and Lyt-1+ cells as well as diffuse (not cell-associated) IgG, IgM, and IgA staining were most prevalent from days 1 to 3, while IgG-bearing plasma cells formed the majority of the luminal cells observed at 1 to 2 weeks. No significant influx of T-suppressor cells was observed at any time. The round window niche and anterior portion of the tympanic bulla mucosa were found to be the most reactive areas. These results suggest that endotoxin alone is capable of producing an inflammatory infiltrate in the mouse consistent with otitis media with effusion, and that the interaction of endotoxin with resident immunocytes of the middle ear, as well as serum derived immune cells, is consistent with the known phlogistic properties of endotoxin.

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

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.

The transoropalatal approach to the atlantoaxial-clival region: considerations for the head and neck surgeon.

The transoropalatal approach to the atlantoaxial-clival area provides excellent exposure for neurosurgical decompression and fusion procedures. The technique has been effectively applied in the treatment of bony and soft tissue abnormalities of the anterior spinal region. Although this approach is safe and reliable, it is not part of the otolaryngologist's usual surgical armamentarium. In the present study, we describe the case histories of five patients who underwent resection of the odontoid process for cervicomedullary compression. Neurological compromise was manifested by progressive upper and/or lower extremity paresis in all patients. In each patient, a transoropalatal approach was used. The surgical technique is discussed, and the prevention of possible sequelae, including velopharyngeal incompetence and palatal or pharyngeal wound dehiscence, is addressed.