Faculty Bibliography

Surface paper strips containing hemin (X factor) were tested on Middlebrook 7H10 agar and Lowenstein-Jensen medium to determine if the growth requirement of Mycobacterium haemophilum for iron-containing complexes could be met by this simplified method. One reference strain and seven strains of this species isolated from patients showed good growth around the strips on 7H10 within 2 weeks but failed to grow on Lowenstein-Jensen medium with X-factor strips. Middlebrook 7H10 medium with X-factor strips may be a useful alternative to the preparation of specialized media for the recovery of M. haemophilum from clinical specimens.

Facial hemihypertrophy, first described by Beck in 1836, aroused some interest in the early part of this century among European and American clinicians. However, a search of the otolaryngologic literature failed to reveal hemihypertrophy of the head and neck area as a well-recognized entity. We recently encountered a case of hemifacial hypertrophy in a 2-year-old. The child presented with airway compromise and swallowing difficulty. The treatment of this child and a review of associated head and neck findings are discussed

The decrement of evoked response amplitudes during the presentation of repetitive clicks was examined quantitatively at the level of the eighth nerve and inferior colliculus in mice aged 13-60 days postnatal. The amplitudes of both these potentials were found to decline during the course of stimulation, this being much more severe at the onset of hearing than in adults. Furthermore the following response at the level of the cochlear nerve was adult-like by day 18, while the response at the level of the inferior colliculus continued to improve through day 24. Recordings in the inferior colliculus were consistently obtained in two different regions along the frequency axis. The regions that responded best to a lower range of frequencies (e.g. 3-9 kHz) showed a more rapid and severe decrement in the evoked response to repetitive stimulation than those regions responding best to a higher range of frequencies (e.g. 8-17 kHz). This was found to be the case for repetitive click stimuli and repetitive tone bursts. Single unit responses in the inferior colliculus were consistent with this differential decline as a function of stimulus rate seen along the frequency axis

In tympanoplasty, trauma to the cochlea is usually caused by the transmission of vibration induced during the removal of cholesteatoma, granulation tissue, and tympanosclerosis surrounding the ossicular chain. In 100 sequential cases 20 showed evidence of cochlear trauma. Hearing was recovered in 10 of these cases during the immediate postoperative period. In nine the hearing was partially recovered but remained below the preoperative bone-conduction level, and in one there was a total cochlear hearing loss. When the stapes footplate was fractured or dislocated and a perilymphatic fistula developed, profound cochlear hearing loss occurred. This complication usually can be avoided by inspection of the round and oval windows under high magnification and by tissue grafts over the fistula. An unanticipated pathologic fistula of the semicircular canals is another common source of major cochlear damage. Despite all precautions and sometimes without apparent cause, a total cochlear hearing loss may result after a tympanoplasty. Although this is rare, as evidenced by the fact that there were only 15 cases in some 1000 tympanoplasties, before surgery the surgeon must inform the patient of the risks involved.

Thromboses in Trousseau's syndrome are typically confined to the vascular system of the extremities and viscera. The authors report a case of sequential bilateral internal and external jugular-vein thromboses secondary to this paraneoplastic hypercoagulable state. The etiologies of commonly encountered head and neck venous thromboses are infection, trauma, and obstruction. This article purports that head and neck venous thromboses without a proximal inflammatory or mechanical cause may be the initial manifestation of an occult malignancy. Upon establishing the presence of a hypercoagulable state, further evaluation may lead to the early diagnosis of such an occult malignancy

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.