Faculty Bibliography

Oxytocin (OT) is a neuropeptide elaborated by the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. Magnocellular OT neurons of these nuclei innervate numerous forebrain regions and release OT into the blood from the posterior pituitary. The PVN also harbors parvocellular OT cells that project to the brainstem and spinal cord, but their function has not been directly assessed. Here, we identified a subset of approximately 30 parvocellular OT neurons, with collateral projections onto magnocellular OT neurons and neurons of deep layers of the spinal cord. Evoked OT release from these OT neurons suppresses nociception and promotes analgesia in an animal model of inflammatory pain. Our findings identify a new population of OT neurons that modulates nociception in a two tier process: (1) directly by release of OT from axons onto sensory spinal cord neurons and inhibiting their activity and (2) indirectly by stimulating OT release from SON neurons into the periphery.

Spoken language is a central part of our everyday lives, but the precise roles that individual cortical regions play in the production of speech are often poorly understood. To address this issue, we focally lowered the temperature of distinct cortical regions in awake neurosurgical patients, and we relate this perturbation to changes in produced speech sequences. Using this method, we confirm that speech is highly lateralized, with the vast majority of behavioral effects seen on the left hemisphere. We then use this approach to demonstrate a clear functional dissociation between nearby cortical speech sites. Focal cooling of pars triangularis/pars opercularis (Broca's region) and the ventral portion of the precentral gyrus (speech motor cortex) resulted in the manipulation of speech timing and articulation, respectively. Our results support a class of models that have proposed distinct processing centers underlying motor sequencing and execution for speech.

Aggression is a prevalent behavior in the animal kingdom that is used to settle competition for limited resources. Given the high risk associated with fighting, the central nervous system has evolved an active mechanism to modulate its expression. Lesioning the lateral septum (LS) is known to cause "septal rage," a phenotype characterized by a dramatic increase in the frequency of attacks. To understand the circuit mechanism of LS-mediated modulation of aggression, we examined the influence of LS input on the cells in and around the ventrolateral part of the ventromedial hypothalamus (VMHvl)-a region required for male mouse aggression. We found that the inputs from the LS inhibited the attack-excited cells but surprisingly increased the overall activity of attack-inhibited cells. Furthermore, optogenetic activation of the projection from LS cells to the VMHvl terminated ongoing attacks immediately but had little effect on mounting. Thus, LS projection to the ventromedial hypothalamic area represents an effective pathway for suppressing male aggression.

PURPOSE: AZD6244 is a MEK1/2 inhibitor with significant preclinical activity in multiple myeloma cells. This phase II study used a two-stage Simon design to determine the AZD6244 response rate in patients with relapsed or refractory multiple myeloma. EXPERIMENTAL DESIGN: AZD6244 (75 mg) was administered orally, twice a day, continuously for 28-day cycles. Response was evaluated after three cycles. RESULTS: Thirty-six patients received therapy. The median age was 65 years (range: 43-81) and the median number of prior therapies was 5 (range: 2-11). The most common grade 3 and 4 toxicities included anemia, neutropenia, thrombocytopenia, diarrhea, and fatigue. Three deaths occurred possibly related to AZD6244 (2 due to sepsis, 1 due to acute kidney injury). After AZD6244 discontinuation, three additional deaths occurred due to disease progression. The response rate (CR + PR) was 5.6% with a mean duration of response of 4.95 months and median progression-free survival time of 3.52 months. One patient had a very good partial response (VGPR), 1 patient had a partial response, 17 patients had stable disease, 13 patients had progressive disease, and 4 patients could not be assessed for response. Pharmacodynamic studies revealed variable effects on bone marrow CD138(+) cell MEK1/2 and ERK1/2 phosphorylation. The best clinical response, a prolonged VGPR, occurred in a patient with an MMSET translocation. CONCLUSIONS: Single-agent AZD6244 was tolerable and had minimal activity in this heavily pretreated population.

The objective of the study is to present a large case series of parapharyngeal space tumors (PPST) and the most comprehensive literature review of tumor histopathologic distribution. The study was designed as internal case series and full Pubmed/MEDLINE electronic database review in a tertiary academic medical center. Tumor histopathology and patient demographics were obtained from a comprehensive Pubmed/MEDLINE database review, as well from an internal case series of 117 patients referred to our center between 1993 and 2013. Main outcome and measures of the study were to define the age, gender, and histopathology of PPST within a large internal case series and among the current body of published literature, and to propose a diagnostic and treatment algorithm for these tumors. Our cohort included 117 cases, 58 females and 59 males, with benign tumors comprising 85 % (n = 99) and malignant tumors 15 % (n = 18). A systematic review of published literature from 1963 to the present revealed 37 case series, and when combined with our present series, yielded a total of 2160 cases. Benign tumors are most common (78.8 %), with tumors of salivary gland (44.4 %), neural (34.4 %), and vascular (2.64 %) origin representing the largest subtypes. Pleomorphic adenomas (30.9 %), paragangliomas (13.1 %), and schwannomas (12.3 %) comprised the majority of all cases. Due to their rarity, data regarding the histopathologic distribution of PPST is scarce. We provide one of the largest case series and the most comprehensive review of these tumors in the literature to date, and offer our algorithm for evaluation and treatment.

OBJECTIVE: To evaluate the association of body mass index (BMI) and spermatic vein diameters (SVDs) in men treated for varicocele. SUBJECTS AND METHODS: One hundred fourteen men who underwent scrotal color duplex ultrasounds prior to microsurgical varicocelectomy were classified as normal (BMI = 18.5-24.9), overweight (25-29.9), or obese (>/=30). SVDs were measured with and without Valsalva, standing and supine. SVD, pre- and postoperative semen analyses (SA) were compared. RESULTS: Forty-six (40.4%) men had normal BMI, 54 (47.3%) were overweight, and 14 (12.3%) were obese. Higher BMI was associated with smaller left testis volume and larger left SVD when supine (with and without Valsalva). The association was absent when standing. Men with higher BMI had smaller differences between their left SVD Valsalva diameters when standing vs supine. There were no differences among BMI classes for right SVD measurements, preoperative SA, and postoperative SA improvement. CONCLUSION: Increased BMI is associated with larger left SVD while supine, suggesting that increased abdominal pressure while recumbent may contribute to varicocele pathology in this population. Interestingly, as in the general population, a majority of the men were overweight.

BACKGROUND: The purpose of this study was to assess the impact of bone harvest length and multiple osteotomies on osteocutaneous radial forearm free flap (RFFF) complication rates. METHODS: A retrospective chart review was conducted for patients undergoing osteocutaneous RFFF reconstruction during an 8-year period. RESULTS: One hundred fifty-five osteocutaneous RFFF procedures were performed. Recipient-site flap complications were 18 of 55 (32.7%) when bone harvest length was less than 7 cm and 40 of 100 (40.0%) when it was >/=7 cm. No osteotomies were performed in 69 of 155 cases with a corresponding complication rate of 30.4% (21 of 69). One osteotomy was utilized in 69 of 155 flaps, whereas 17 of 155 required more than 1 osteotomy; complications were experienced in 42% (29 of 69) and 47% (8 of 17) of these cases, respectively. CONCLUSION: Osteocutaneous RFFF complication rates were only slightly higher when the bone length was >/=7 cm or when multiple osteotomies were required.

OBJECTIVES: Five databases were mined to examine distributions of air-bone gaps obtained by automated and manual audiometry. Differences in distribution characteristics were examined for evidence of influences unrelated to the audibility of test signals. DESIGN: The databases provided air- and bone-conduction thresholds that permitted examination of air-bone gap distributions that were free of ceiling and floor effects. Cases with conductive hearing loss were eliminated based on air-bone gaps, tympanometry, and otoscopy, when available. The analysis is based on 2,378,921 threshold determinations from 721,831 subjects from five databases. RESULTS: Automated audiometry produced air-bone gaps that were normally distributed suggesting that air- and bone-conduction thresholds are normally distributed. Manual audiometry produced air-bone gaps that were not normally distributed and show evidence of biasing effects of assumptions of expected results. In one database, the form of the distributions showed evidence of inclusion of conductive hearing losses. CONCLUSIONS: Thresholds obtained by manual audiometry show tester bias effects from assumptions of the patient's hearing loss characteristics. Tester bias artificially reduces the variance of bone-conduction thresholds and the resulting air-bone gaps. Because the automated method is free of bias from assumptions of expected results, these distributions are hypothesized to reflect the true variability of air- and bone-conduction thresholds and the resulting air-bone gaps.

Channel interaction from a broad spread of excitation is likely to be a limiting factor in performance by cochlear implant users. Although partial tripolar stimulation has been shown to reduce spread of excitation, the magnitude of the reduction is highly variable across subjects. Because the reduction in spread of excitation is typically only measured at one electrode for a given subject, the degree of variability across cochlear locations is unknown. The first goal of the present study was to determine if the reduction in spread of excitation observed from partial tripolar current focusing systematically varies across the cochlea. The second goal was to measure the variability in reduction of spread of excitation relative to monopolar stimulation across the cochlea. The third goal was to expand upon previous results that suggest that scaling of verbal descriptors can be used to predict the reduction in spread of excitation, by increasing the limited number of sites previously evaluated and verify the relationships remain with the larger dataset. The spread of excitation for monopolar and partial tripolar stimulation was measured at 5 cochlear locations using a psychophysical forward masking task. Results of the present study suggest that although partial tripolar stimulation typically reduces spread of excitation, the degree of reduction in spread of excitation was found to be highly variable and no effect of cochlear location was found. Additionally, subjective scaling of certain verbal descriptors (Clean/Dirty, Pure/Noisy) correlated with the reduction in spread of excitation suggesting sound quality scaling might be used as a quick clinical estimate of channels providing a reduction in spread of excitation. This quick scaling technique might help clinicians determine which patients would be most likely to benefit from a focused strategy.

BACKGROUND: Signal transducer and activator 1 (STAT-1) mutations are rare and have been implicated in combined immunodeficiency, enhanced tumorigenesis, and vascular defects. METHODS: A 60-year-old woman with a novel STAT-1 mutation and resulting immunodeficiency, squamous cell carcinoma, and vascular disease presented with profuse epistaxis secondary to rupture of an aberrant artery that she developed in part because of this mutation. After unsuccessful posterior packing, embolization was initiated but subsequently aborted because of a bovine origin carotid artery and a history of multiple carotid dissections. RESULTS: After repeat posterior packing, hemostasis was achieved. No additional episodes of epistaxis occurred in the subsequent 13 months. CONCLUSION: Vascular anomalies can present challenges in epistaxis management. In patients with conditions known to cause vascular anomalies, it is critical to obtain vascular imaging before intervention.