Thickening of the basement membrane in capillaries is implicated in the microangiopathic complications of diabetes mellitus. This study was designed to evaluate microangiopathic changes of the inner ear associated with insulin-dependent diabetes mellitus (IDDM) and concurrent moderate-intensity noise exposure. Male Sprague-Dawley rats were injected with streptozotocin (65 mg/kg) to induce IDDM. Half of the control and diabetic animals were exposed to chronic noise of 95 dB over the 6-month study period. Photomicrographs of the capillaries in the stria vascularis were obtained by transmission electron microscopy, and basement-membrane thickness was measured with an image processing system. This study quantitatively demonstrates basement-membrane thickening consistent with diabetic microangiopathy in the inner ear of IDDM rats. Noise exposure did not significantly change basement-membrane thickness in either diabetic or control animals.

The present study was undertaken to determine in model studies whether currently available acoustic rhinometry instrumentation might be used to analyze the nasal cavity configuration of infants and children. A simple nasal cavity model was constructed using eight Lucite inserts that were placed between standard nosepieces provided by the manufacturer and a 35-cm-long polyvinyl chloride pipe closed at its distal end. To simulate the nasal valve, the inserts were 12 mm in length and had apertures ranging in diameter from 2 to 9 mm. A series of experiments was conducted to evaluate the accuracy with which the acoustic rhinometer measured the size of each insert aperture and the configuration of the model system distal to that aperture. Transmission losses caused errors in the area measurement of the insert aperture and the tube distal to the insert. When the insert aperture was < 6 mm in diameter (0.28 cm2), the aperture area was overestimated by > 10%, whereas the area of the distal tube was underestimated by > 10%. As a result of response lags, the acoustic rhinometer also failed to provide an accurate indication of insert length. Finally, oscillation artifacts caused estimates of the distal pipe area to fluctuate. These three systematic errors are described, and their potential impact on acoustic rhinometry in children is discussed.

Pleomorphic adenomas account for the majority of parotid masses, typically arising in the tail of the gland and enlarging slowly over time. The vast majority are 2 to 6 cm in size when resected. We report resection of the largest benign mixed tumor recorded in the modern English language literature. An 85-year-old reclusive woman had a 20-year history of an enlarging right periauricular mass that had begun bleeding several days prior to admission. The patient ultimately underwent resection of the mass, which measured 26 cm in diameter, weighed 6.85 kg, and proved on pathologic examination to be a benign mixed tumor without malignant degeneration. The implications of this unusual case for the management of mixed tumors are discussed, and a review of the world literature on giant pleomorphic adenomas is presented.

Intranasal pleomorphic adenoma is rare. We report the CT features this tumor in a 41-year-old woman who presented to us with right nasal obstruction and a 2-day history of epistaxis.

ET dysfunction after tobacco smoke exposure may predispose children to the development of otitis media.