Faculty Bibliography

A simple and rapid method for the determination of human T lymphocyte subclasses in buffy coat preparations or whole blood is described. This technique uses flow cytometry to distinguish lymphocytes from other leukocytes on the basis of their light-scattering properties. Lymnphocyte subclasses were enumerated by cellular immunofluorescence; the immunofluorescent signals were produced by monoclonal antibodies to surface differentiation antigens on T cells. Conventional techniques of enumerating T lymphocyte subclasses entail time-consuming (up to 2 days) density gradient and E rosette enrichement, and require at least 20 ml of blood. The method described here uses as little as 50 microliters of whole blood for each antibody tested and produces results within in 2 hr.

A case of primary chordoma of the maxillary sinus is presented. The embryology of the notochord is reviewed and it is suggested that the frequently used adjective "ectopic" is a misnomer. The literature of primary paranasal sinus chordomas is reviewed and the clinicopathological features described. It is emphasized that these lesions can mimic other benign and malignant processes both clinically, radiographically and histologically. The treatment and prognosis is more favorable than the more common craniocervical chordoma.

Thresholds of the auditory nerve compound action potential (CAP) responses to filtered clicks from 0.5 to 40 kHz, defining a CAP frequency threshold curve, have been determined in the same guinea pigs: (1) in acute conditions, the animal still anesthetized at the end of the operation for permanent implantation of a round-window electrode, and (2) several days later in the implanted awake and unrestrained animal. The results show higher CAP thresholds for high frequencies in acute conditions as compared to chronic recordings. This difference appears above about 12.5 kHz and increases progressively to around 40 dB at 40 kHz. Similar effects, although somewhat less pronounced, were observed during anesthesia alone in already implanted guinea pigs. Thes observations could explain the discrepancies which appear between electrophysiological thresholds, acutely recorded either from single fibers or whole-nerve responses, and behavioral audiograms. Moreover, in the accurate evaluation of the cochlea, slight impairments may be masked by this phenomenon as illustrated in guinea pigs treated with low doses of ototoxic antibiotic.

The harmonic components in hoarse voice were separated from the noise components by using a small laboratory computer. The ratio of harmonics to noise or S/N ratio, was calculated and compared with the auditory impression for 58 subjects. The calculated results showed a definite correlation to the auditory impression, and it is suggested that this would be a useful method for the quantitative evaluation of hoarseness.

The death rate of brain abscesses in a recently reported series is high, ranging from 36% to 50% of all cases. This paper reports experiences with ten cases of intracranial abscesses secondary to ear and sinus infections. Six of these abscesses are secondary to otitic infections with three of them located in the cerebellum. Two of the cerebellar abscesses are surgically drained through the temporal bone by the otologic surgeon, with close neurosurgical cooperation. Computerized axial tomography has revolutionized the treatment of intracranial abscesses optimizing the timing for medical and surgical management.

Between 1969 and 1978 7,000 patients underwent cardiopulmonary bypass at Bellevue and University Hospitals. In seven of these patients, sudden loss of hearing in one ear developed immediately after the operation. Four of the seven patients showed improvement in hearing after the initial loss, although in no case did the hearing return completely to normal. None of the patients had vertigo but two were listless postoperatively. Two of the operations were for congenital heart disease; the remainder were coronary artery bypass procedures. All of the affected patients were male. There was no predilection as to which ear was affected. The most likely cause is particulate emboli generated by cardiopulmonary bypass. Other possible sources of emboli include air, antifoam, fat, and particulate matter from calcified valves and the aorta. Improvement in the kind of pump and the addition of various filters in the period between 1969 and 1978 did not eliminate unilateral hearing loss. The relationship between cerebral emboli and decreased consciousness after operations is also discussed