Arndt J. Duvall

Morphological alteration of the stria vascularis after administration of the diuretic bumetanide.

Chinchillas were given either a single injection of the diuretic bumetanide (18 mg/kg body weight) or saline-sodium hydroxide and sacrificed at 10 min, 1 hr and 24 hr after the injection. Slight stria edema was present at 10 min, marked edema at 1 hr and no edema 24 h after bumetanide. The edema began in the first cochlear turn at 10 min and spread to the second turn by 1 hr. Along with edema, marginal cell bulging, potential capillary constriction and the formation of marginal cell membranous structures occurred after bumetanide treatment.

SITE OF ACTION OF STREPTOMYCIN UPON INNER EAR SENSORY CELLS.

The effects of streptomycin on the inner ear sensory epithelia were studied in guinea pigs by means of the electron microscope. The most severe damage was found in the vestibular sensory cells starting with degeneration of, and myelin figure formation in, the mitochondria. Later, swelling appeared in the sensory hairs with deformation of the cell surface, and finally disappearance of the sensory hairs, swelling of the cell surface, often with rupture and ejection of cells and cell debris into the endolymph. Nerve fibers and nerve endings were unchanged. The organ of Corti was less extensively damaged. Changes were confined to the mitochondria and stereocilia of the hair cells. The damage of the sensory cells was explained as an affection mainly of the plasma membrane of the cell and the membrane component of the mitochondria with inhibition of the formation of the rigid component of the membranes and damage to the permeability barrier.

Stria Ultrastructure and Vessel Transport in Acoustic Trauma

One hundred and ten chinchillas were exposed to a 700–2800 Hz noise at 123 dB for 15 minutes. A consistent pattern of ultrastructural pathology within the lateral cochlear wall was found. Significant damage to the stria vascularis was first observed one hour postexposure, reached a peak at 24 hours, and had recovered almost completely by 28 days. Spiral prominence damage was permanent. The pathology included stria widening, temporary disappearance of intermediate cells, alterations of the internal membrane system and abnormal vessel transport. Horseradish peroxidase (HRP) was employed as an indicator of transport from vessels. Transport from the stria vessels was absent when stria ultrastructural abnormality was at a maximum; at other postexposure times, however, abnormally rapid exodus of HRP from the vessels of the stria was observed in animals who had received intravenous injections of HRP 30 seconds prior to sacrifice. On the other hand, no leakage was observed in the animals injected one minute before sacrifice. Theories to explain this transport dichotomy are proposed.

Microcystic adnexal carcinoma: management options based on long-term follow-up.

Microcystic adnexal carcinoma (MAC), a recently described neoplasm that frequently affects the head and neck, presents a confusing problem for the clinician due to its unusual behavior. The individual cells have a bland microscopic appearance, and there is a predilection for neural invasion. Four cases of MAC are reported. All four cases demonstrate the difficulty with pathologic diagnosis. Follow‐up of as long as 33 years begins to delineate the protracted nature of MAC. In addition, this paper includes the first report of a case of lymph node metastasis. Although resection may result in a significant defect, negative margins may not be achieved. Despite this, the defect can heal, as demonstrated by the cases described. In addition, MAC may recur many years later, irrespective of the status of the margins at the time of surgery. Given these unusual characteristics and the slowly progressive nature of MAC, strong consideration must be given to less radical surgical procedures, with close follow‐up for grossly recurrent disease.

Cochlear Fluid Balance A Clinical/Research Overview

Stria edema, and in some cases atrophy, follows osmotic agents, loop-inhibiting diuretics, acoustic trauma, and rupture of Reissners membrane. All have in common an imbalance of fluid and electrolytes in the cochlear duct. The glycerol test causes temporary improvement in hearing in Menières disease. Glycerol causes stria edema and collapse of Reissners membrane in the chinchilla. Stria edema, as well as stria atrophy, are found in Menières disease. Metabolic manipulation of the stria might be the best approach in the search for successful treatment of Menières disease.

Stria Vascularis Pathology and Recovery following Noise Exposure

The time course of chinchilla stria pathology (edema) and recovery after one and two noise exposures is quantitatively and qualitatively described. Gross stria edema is present one, three, and seven days following one noise exposure; stria edema is not as severe nor as frequent following two noise exposures. Stria cell and vessel pathology are also observed at seven and ten days after one, but not two, noise exposures. Possible mechanisms of stria pathology and recovery after noise exposure are discussed.

Hypothyroidism following combined therapy in carcinoma of the laryngopharynx.

There is an increasing trend to combine high dosage pre‐operative radiation with radical surgery for carcinoma of the laryngopharynx. This could be a hazard to thyroid function, especially when surgery includes a partial thyroidectomy. We initiated a study in 1969 to determine the effect on thyroid function produced by external radiation of the neck followed by radical surgery of the laryngopharynx. A group of 24 patients previously treated with external radiation and/or surgery for carcinoma of the laryngopharynx, and without recurrence, were studied with laboratory determinations of PBI and total serum thyroxine (T4).

Spontaneous regression of juvenile nasopharyngeal angiofibroma

There is debate concerning the natural history of juvenile nasopharyngeal angiofibromas, especially whether or not they can spontaneously regress. Often claimed, spontaneous regression has not been well documented. To our knowledge, this is the first report in which a biopsy-proven juvenile nasopharyngeal angiofibroma spontaneously resolved. A second, less well-documented case is discussed.

Total energy and critical intensity concepts in noise damage

Groups of chinchillas were given a series of noise exposures of approximately equal energy ranging from 22 minutes at 120 dB SPL to 150 days at 82 dB. For all exposures involving levels of 112 dB or less, the same average permanent hearing losses (15–20 dB) and degree of outer hair cell destruction (8–10%) resulted, thus confirming the validity of the total energy principle for assessing the hazard associated with single continuous exposures at moderate levels. The 22-minute, 120-dB exposure, however, produced a 60-dB hearing loss and massive hair cell destruction (70–80%), indicating that some critical level had been exceeded, thus producing acoustic trauma. Further histological study suggests that the massive destruction is a result of breaks in the organ of Corti, produced by severe mechanical stress, that permit the mixture of endolymph with perilymph, thus creating a hostile environment for the hair cells.

Atypical mycobacterial otomastoiditis

A typical mycobacterial infections of the middle ear and mastoid are rare; only 4 isolated cases and an outbreak of 17 cases have been reported. Herein are presented three additional cases with chronic otorrhea unresponsive to routine medical therapy. Two were due to Mycobacterium avium‐intracellulare and the third to Mycobacterium chelonei. All three patients had negative tuberculin test results and normal chest radiographs. Pathologic study reveals granulomatous inflammation, usually with negative acid‐fast stains. Tissue culture should be incubated for a minimum of 4 weeks. These patients often undergo multiple otologic procedures and have abundant granulation tissue with normal ossicles. The antibiotic therapy is prolonged, and the organisms may be resistant to the usual antituberculous drugs. Unlike many atypical mycobacterial infections today, those involving the middle ear can occur in immunologically normal individuals.