Mastoidectomy update

The long-term results of 375 primary mastoidectomy operations for chronic otitis media and chronic mastoiditis are described and discussed. Two-thirds of these cases were open cavity mastoidectomies and 1/3 closed cavity mastoidectomies. Primary pathology was cholesteatoma in 1/3 and granulation tissue in 2/3 of the cases. The method of reducing the size of the mastoid cavity by sculpturing mastoid cavity by sculpturing mastoid cortical bone is most important in avoiding large postoperative cavity problems. Principles and methods are described. Healing (dry ear) is a more important management objective than hearing and, indeed, enhances the prospects of obtaining a long-term hearing result. Three important phases of controlling mastoid disease (preoperative, operative, and postoperative) are equally stressed. Intact wall tympanomastoidectomy is not recommended in sclerotic mastoids (the majority of our cases) as being unsafe and unnecessary. Revisions, mostly minor, were done in 31% of the cases for a total of 521 procedures. We recomment a one-stage tympanomastoidectomy. Multiple planned procedures are, in the main, unnecessary and should be avoided to reduce unnecessary hospitalization and expense.

Pathogenesis of otitis media

Pathogenesis of otitis media was studied in humans and various animal models primarily from a pathological and chemical point of view. Findings were correlated and interpreted for various forms of otitis media in longitudinal and parallel studies, including acute purulent otitis media (POM), serous otitis media (SOM), mucoid or secretory otitis media (MOM), and chronic suppurative otitis media (COM), especially as regards the continuum or interrelated changes of various groups. Purulent otitis media was produced in chinchillas by direct inoculation of less than 100 pneumococci into the middle ear space. Serous otitis media was produced in chinchillas and cats following Eustachian tube obstruction with silicone. Mucoid otitis media followed the development of SOM in cats after two to four weeks of tubal occlusion. Samples of middle ear effusion (MEE) and serum, obtained from children with SOM and MOM after myringotomy for ventilation tube placement, were evaluated. The three components studied were MEE, epithelium and the subepithelial space (SES). Inflammatory changes in the SES were significant for all forms of otitis media, but especially for POM and SOM. Epithelial metaplasia to secretory cells was most prominent in MOM. Chemical factors involved in pathogenesis and defense were studied. Lactic dehydrogenase and lysozyme, chemical indicators of inflammatory activity, were greater in POM and MOM than in SOM. Immunoglobulins (A, G, & M) were greater in MOM than in SOM. The similarity of findings between the groups suggests a strong relationship between them. The ability of certain types of otitis media to evolve into another substantiates the concept of the continuum for some patients. Pathogenesis is dependent upon various extrinsic factors of etiopathogenesis, while the form that otitis media takes seems to rely mostly on relative activity of the SES and the epithelium.

Light and electron microscopic studies of megakaryocytes in Korean epidemic hemorrhagic fever

A retrospective study was devised to determine the correlation between myelography and computed tomography (CT) in the recognition of abnormalities of the lumbar intervertebral disk. A group of 106 patients was studied who had had both myelography and CT within a 6 week period. Each examination was interpreted separately by a neuroradiologist who had no access to the patients' clinical findings or the results of any radiologic studies. On comparison of 290 interspace levels, there was agreement in definite abnormalities in 70%. Most discrepancies were due to suspicious findings and inconclusive studies of both kinds. In particular, there was poor correlation between the two examinations in the diagnosis of a slightly bulging disk. The major discrepancy rate was less than 5% overall and less than 1% among patients without prior surgery. On the basis of these findings, a diagnostic algorithm is suggested that would facilitate the workup of a similar group of patients.

Microcirculation of the lymph node with metastases

Microangiographic and histologic examination of the popliteal lymph node was performed on 49 rabbits 3 to 55 days after V2 tumor implantation into the hind paw. Control animals received subcutaneous tissue extract from normal rabbit donors. During the first 10 days after the tumor implant from an allogeneic animal donor, the draining lymph node exhibited a hypervascular response which after 2 weeks gradually subsided. Subsequently, during the early stages of lymph node metastasis there was still hypervascularity adjacent to the metastatic deposit. In about 4 weeks the metastases became more established and surrounded by layers of plasma cells. The hypervascular changes of the surrounding lymph node subsided by this time. In lymph node metastases the microvasculature could be an indicator of the immunologic activity of the host.

Unilateral renal aplasia in an African baboon (Papio sp.)

Unilateral renal aplasia in the African baboon (Papio sp.) is first time reported.

Hemagglutination assay of antibodies associated with pulmonary acariasis in rhesus monkeys (Macaca mulatta)

Antibodies associated with infection by lung mites (Pneumonyssus simicola) in rhesus monkeys were measured by passive hemagglutination methods. Tanned human Rh negative O red blood cells or sheep red blood cells coated with soluble acarine antigens were used to detect mite-specific antibodies. Large quantities of host-specific mite antigens (P. simicola) were difficult to obtain, so free-living mite species such as Dermatophagoides farina, Acarina sheldonii, and Tyrophagus putrificiensis were also utilized. Although the best serological specificity and sensitivity were obtained with P. simicola and its derivatives (1:640), several free-living acarine species were useful in detecting antibodies to mites. Skin tests carried out on a limited number of animals were positive for both immediate and delayed hypersensitivity.

Nasal mites parasitic in nasal and upper skull tissues in the baboon (Papio sp.)

Nasal mites (Rhinophagus sp.) were found within the mucosal and submucosal nasal tissues and bone marrow of the upper skull in two of five adult baboons (Papio sp.).