Faculty Bibliography

Both spatial and temporal cues determine the fate of immature neurons. A major challenge at the interface of developmental and systems neuroscience is to relate this spatiotemporal trajectory of maturation to circuit-level functional organization. This study examined the development of two extraocular motor nuclei (nIII and nIV), structures in which a motoneuron's identity, or choice of muscle partner, defines its behavioral role. We used retro-orbital dye fills, in combination with fluorescent markers for motoneuron location and birthdate, to probe spatial and temporal organization of the oculomotor (nIII) and trochlear (nIV) nuclei in the larval zebrafish. We describe a dorsoventral organization of the four nIII motoneuron pools, in which inferior and medial rectus motoneurons occupy dorsal nIII, while inferior oblique and superior rectus motoneurons occupy distinct divisions of ventral nIII. Dorsal nIII motoneurons are, moreover, born before motoneurons of ventral nIII and nIV. The order of neurogenesis can therefore account for the dorsoventral organization of nIII and may play a primary role in determining motoneuron identity. We propose that the temporal development of extraocular motoneurons plays a key role in assembling a functional oculomotor circuit. J. Comp. Neurol. 525:65-78, 2017. (c) 2016 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

OBJECTIVES/HYPOTHESIS: Inhalation injury significantly increases morbidity and mortality in burn patients. Approximately one in five burn patients have acute injury to the larynx, trachea, and/or lungs-and as many as 70% have long-term laryngeal abnormalities. Although inhalation injury to the lung has been studied extensively, no models exist to study these insults to the larynx. As such, we developed an in vivo rabbit model to create precise and reproducible laryngeal burn with resultant tissue damage as a foundation for interventional studies. METHODS: Following tubeless tracheotomy, a custom temperature-control device was employed to apply heated air (70 degrees C-80 degrees C, 150 degrees C-160 degrees C, or 310 degrees C-320 degrees C) +/- smoke derived from unbleached cotton to the larynx, endoscopically, minimizing adjacent tissue damage in six rabbits. Pain, nutrition, and level of activity were monitored. Direct laryngoscopy and histological examination were performed 24 hours following insult. RESULTS: All animals survived injury with appropriate pain control; oral intake was initiated and all were adequately ventilating via tracheostomy. Burn sequelae were noted under direct visualization 24 hours after injury, and graded levels of edema and tissue damage were observed as a function of temperature. Edema obstructed true vocal fold visualization at increased temperatures. These injury patterns correlated with graded tissue damage on histology. CONCLUSION: We created an in vivo model of laryngeal burn injury employing a custom burn device resulting in graded tissue injury. This model is critical for investigation of the mechanisms underlying burn injury, and ultimately, the development and evaluation of therapies for this challenging population. LEVEL OF EVIDENCE: N/A. Laryngoscope, 2016.

BACKGROUND: Proficiency with common endocrine operations is expected of graduating, general surgery residents. However, no expert consensus guidelines exist about these expectations. METHODS: Members of the American Association of Endocrine Surgeons were surveyed about their opinions on resident proficiency with common endocrine operations. RESULTS: Overall response rate was 38%. A total of 92% of the respondents operate with residents. On average, they believed that the steps of a total thyroidectomy for benign disease and a well-localized parathyroidectomy could be performed by a postgraduate year 4 surgery resident. Specific steps that they thought might require more training included decisions to divide the strap muscles or leaving a drain. Approximately 66% of respondents thought that a postgraduate year 5 surgery resident could independently perform a total thyroidectomy for benign disease, but only 45% felt similarly for malignant thyroid disease; 79% thought that a postgraduate year 5 surgery resident could independently perform a parathyroidectomy. Respondents' years of experience correlated with their opinions about resident autonomy for total thyroidectomy (benign r = 0.38, P < .001; malignant r = 0.29, P = .001) but not parathyroidectomy. On multivariate analysis, sex and years of experience of the respondents were independently associated with opinions on autonomy but only for total thyroidectomy for benign disease (P = .001). Annual endocrine volume of the respondents did not correlate with beliefs in autonomy. CONCLUSION: There was general agreement among responding members of the AAES about resident proficiency and autonomy with common endocrine operations. As postgraduate year 5 residents may not be proficient in advanced endocrine operations, opportunities exist to improve training prior to the transition to independent practice for graduates that anticipate performing endocrine operations routinely.

One way to provide pitch information to cochlear implant users is through amplitude-modulation rate. It is currently unknown whether amplitude-modulation rate can provide cochlear implant users with pitch information adequate for perceiving melodic information. In the present study, the notes of a song were encoded via amplitude-modulation rate of pulse trains on single electrodes at the apex or middle of long electrode arrays. The melody of the song was either physically correct or modified by compression or expansion. Nine cochlear implant users rated the extent to which the song was out of tune in the different conditions. Cochlear implant users on average did not show sensitivity to melody compression or expansion regardless of place of stimulation. These results were found despite the fact that three of the cochlear implant users showed the expected sensitivity to melody compression and expansion with the same task using acoustic pure tones in a contralateral acoustic ear. Normal-hearing listeners showed an inconsistent and weak effect of melody compression and expansion when the notes of the song were encoded with acoustic pulse rate. The results suggest that amplitude-modulation rate provides insufficient access to melodic information for cochlear-implant and normal-hearing listeners.

OBJECTIVES/HYPOTHESIS:The aim of this study was to evaluate factors raised in malpractice litigation related to the diagnosis and management of melanoma and to further assess issues impacting outcome. STUDY DESIGN:Retrospective chart review. METHODS:The Westlaw legal database was searched for malpractice litigation resolved over the last 20 years relating to melanoma. Cases were evaluated for allegations, defendant specialty, outcome, and other issues raised. RESULTS:Of the 80 cases evaluated, 49% were resolved in the defendants' favor. In greater than 80% of cases, there was alleged misdiagnosis. In 35% of cases, the patient had expired secondary to melanoma at the time of litigation. There was no statistical difference in payments upon comparison of cases with and without mortality. A greater proportion of cases with dermatologists and pathologists as defendants involved alleged misdiagnosis. The most common locations for melanoma were the extremities and the head-and-neck region, at 32.5% and 22.5%, respectively. Location did not significantly impact the outcome of cases. CONCLUSION:Malpractice litigation relating to melanoma involves numerous physicians, including dermatologists, pathologists, and otolaryngologists. Alleged misdiagnosis of a pigmented lesion was the most common cause of litigation and involved physicians from numerous specialties. Patients who were misdiagnosed had a significantly higher likelihood of having active disease at the time of litigation. Ultimately improved methods of detecting concerning pigmented lesions need to be developed. Factors such as death and poor cosmetic outcome did not significantly impact litigation outcome. LEVEL OF EVIDENCE:NA Laryngoscope, 127:134-139, 2017.