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Biomedical subjects

H Heffner

Publications and source records attributed to H Heffner.

8 recordsLinked to original sources
PubMed1992

Surgery vs chemotherapy plus surgery for carcinoma of the head and neck.

We reviewed the results of standard therapy (surgery +/- radiation therapy) in 66 patients with advanced resectable head and neck cancer treated between 1984 and 1988 and compared them with a "historical" group of similar resectable patients treated between 1978 and 1984, by induction chemotherapy followed by standard therapy. The median disease-free survival of patients treated by surgery was 18 months, whereas it had not been reached in those receiving chemotherapy. When 2-year disease-free survival was compared according to stage and site, patients receiving chemotherapy fared better. The recurrence rate of all patients receiving chemotherapy was less than half of those receiving standard treatment only. A higher percentage of patients receiving chemotherapy survived their original tumor, only to die of second malignancies, most of these occurring elsewhere in the aerodigestive tract.

Carcinoma, Squamous Cell↗
PubMed1980

Hearing in the elephant (Elephas maximus).

Auditory thresholds were determined for a 7-year-old Indian elephant. The hearing range extended from 17 hertz to 10.5 kilohertz. The results indicate that the inverse relationship between functional interaural distance (that is, the distance between the two ears divided by the speed of sound) and high-frequency hearing limit is valid even for very large mammals.

Animals↗
PubMed1978

Effect of auditory cortex ablation on localization and discrimination of brief sounds.

1. Dogs with bilateral auditory cortex lesions were tested on their ability to localize and discriminate brief sounds. In each test the animals were required to approach one of two goal boxes in order to indicate their response. 2. The results showed: a) that the operated animals could not solve the localization tasks when the goal boxes were located more than 125 cm away, but could solve the task if the goal boxes were located closer to the animal; b) that the operated animals could successfully discriminate brief bursts of click trains (i.e., 100/s versus 10/s, 0.3 s duration) even when required to indicate their discrimination by moving to goal boxes located 250 cm away, in spite of the fact that they could not successfully localize these sounds under similar conditions; c) that the operated animals tracked the source of a continuous sound instead of localizing it in a normal manner. 3. It appears that the deficit in sound localization resulting from cortical ablation is not due to any impairment in auditory attention or memory. Furthermore, the deficit cannot be ascribed to an inability to make a spatial response to an auditory cue. Instead, the deficit may be the result of a disconnection of the sound-localization mechanism from the motor mechanism necessary for some, though not all, behavioral responses.

Animals↗
PubMed1975

Contribution of auditory cortex to sound localization in the monkey (Macaca mulatta).

Monkeys with lesions of auditory cortex were tested for their ability to localize the source of brief sounds. Although those deprived of primary auditory cortex bilaterally were able to indicate the direction of a sound with near-normal acuity, they were unable to locate its source. This dissociation of abilities suggest that the role of auditory cortex in sound localization is not so much sensory or perceptual as it is auditomotor or associative. Thus, sound localization joins loudness, pitch, and most other traditional attributes of sound as dimensions whose discrimination does not depend on auditory cortex. The question would now seem to turn to whether or not auditory cortex is necessary for any sensory discrimination whatever.

Acoustic Stimulation↗