Faculty Bibliography

Mucoepidermoid carcinomas of minor salivary gland origin rarely arise in the nasal cavity. A patient with such a tumor in association with bilateral sphenoid sinus mucoceles is presented. This diagnosis was established preoperatively by CT and allowed an attempt at curative surgery to be made. The CT and pathological findings are discussed

Surface preparations of the stria vascularis from guinea pigs exposed to wide-band noise or intoxicated with quinine monohydrochloride dihydrate were studied by light microscopy and computerized image analysis in order to evaluate quantitatively the effects of these agents on two characteristics of the strial vasculature: vascular density and erythrocyte distribution. An image analyzer was used to measure the area of strial vessel lumen and erythrocyte distribution as a fraction of the total area of strial tissue under observation. The results demonstrate that changes in the strial vessels do occur in guinea pigs exposed to noise or given large doses of quinine. Localized vessel narrowings caused by swollen endothelial cells and possibly by contraction of pericytes were found in both experimental groups, but there was no apparent tonotopical relationship between these effects and the reduction in cochlear potentials. A significant reduction in the number of erythrocytes was found in all turns of the cochlea in both experimental groups. Although a significant difference in vascular density was found among turns of the cochlea in both experimental and control animals, there was no widespread change in vascular density as a result of either noise exposure or quinine treatment.

The transcription patterns of three v-Ha-ras-related cellular oncogenes in Drosophila melanogaster were studied. Each gene coded for at least two distinct transcripts. The larger transcript of each gene was expressed at a similar abundance during the entire life cycle of fruit flies, whereas the shorter transcripts were much more abundant in embryonic stages than at later stages.

Neural activity has been implicated as having both a trophic function and a role in synaptic specificity. Sensory deprivation studies in a large number of developing systems have resulted in the pathological morphology of neurons and abnormal response properties. If the relative timing of discharge among afferent terminals is a cue employed by the developing system to refine the array of synaptic connections, then altering the discharge patterns should hinder this process. In the present experiments, we investigate the role played by the temporal pattern of neural activity during the ontogeny of frequency tuning in the mouse central auditory system. Postnatal animals were exposed to acoustic stimuli, repetitive clicks, that continuously entrained a large proportion of primary afferents from the onset of hearing until an age at which tuning curves should have been adult-like. The amount of fatigue to repetitive clicks was characterized at the level of the eighth nerve and inferior colliculus in normal animals. Frequency tuning curves obtained from the inferior colliculus were used as an assay for the specificity of neural connections. Click-reared animals had significantly broader tuning curves than did normally reared mice, particularly for units with best frequencies in the 10- to 15-kHz range. Furthermore, it was found that this change could not be attributed to the selective loss of the sustained component of the response. The affected range is interpreted in terms of the frequency spectrum of the click and the fact that lower frequency regions of the inferior colliculus were found to habituate rapidly. The click-rearing environment did not appear to affect unit spontaneous activity or response latency, nor did it alter the tonotopic map in the inferior colliculus. We argue against the possibility of cochlear damage based on threshold and high frequency cutoff measurements. Mice were reared in a second acoustic environment, repetitive pulses of two added frequencies, as a control for the effects of the click stimulus. This rearing paradigm did not lead to a broadening of tuning curves. It did, however, alter the properties of bimodal tuning curves. For units with bimodal tuning curves having best frequencies in the range of the rearing frequencies, it was found that the second excitatory area had a lower than normal threshold. In addition, the frequency range separating the peaks of the two excitatory regions was statistically smaller. These results are discussed with reference to the specific frequencies used in the rearing paradigm.(ABSTRACT TRUNCATED AT 400 WORDS)

Pseudoaneurysms of the extracranial arterial tree are uncommon. To our knowledge, four cases of pseudoaneurysm of the internal maxillary artery have been reported, but there have been no reports of pseudoaneurysm of the extracranial segment of the middle meningeal artery. A 15-year-old girl, who suffered a gunshot wound in the right maxillary region, suffered a pseudoaneurysm of the proximal portion of the middle meningeal artery, as shown by carotid angiography six days after injury. The lesion was successfully treated with absorbable gelatin sponge embolization. Treatment of pseudoaneurysms reduces the risk of hemorrhage from subsequent rupture. Although these lesions are amenable to surgery, transvascular embolization or mechanical interruption appears to be simpler and equally effective

Myofacial pain dysfunction (MPD), a commonly occurring illness, presents with a variety of clinical appearances and patient symptoms which mimic many other illnesses. The family physician and medical specialist are often first consulted by patients suffering from the pain and/or limited functions associated with MPD. Although the definitive diagnosis and therapy is usually provided by a dental specialist, the attending physician is often required to make the initial clinical diagnosis of MPD and then select proper referrals and consultations. Physicians with an understanding of the cause and clinical picture of MPD can, by obtaining a comprehensive history and performing a concise clinical examination, make a diagnosis of MPD. A description of the nature of the illness and a clinical examination procedure are presented