Faculty Bibliography

Once activated at the surface of cells, G protein-coupled receptors (GPCRs) redistribute to endosomes, where they can continue to signal. Whether GPCRs in endosomes generate signals that contribute to human disease is unknown. We evaluated endosomal signaling of protease-activated receptor-2 (PAR₂), which has been proposed to mediate pain in patients with irritable bowel syndrome (IBS). Trypsin, elastase, and cathepsin S, which are activated in the colonic mucosa of patients with IBS and in experimental animals with colitis, caused persistent PAR₂-dependent hyperexcitability of nociceptors, sensitization of colonic afferent neurons to mechanical stimuli, and somatic mechanical allodynia. Inhibitors of clathrin- and dynamin-dependent endocytosis and of mitogen-activated protein kinase kinase-1 prevented trypsin-induced hyperexcitability, sensitization, and allodynia. However, they did not affect elastase- or cathepsin S-induced hyperexcitability, sensitization, or allodynia. Trypsin stimulated endocytosis of PAR₂, which signaled from endosomes to activate extracellular signal-regulated kinase. Elastase and cathepsin S did not stimulate endocytosis of PAR₂, which signaled from the plasma membrane to activate adenylyl cyclase. Biopsies of colonic mucosa from IBS patients released proteases that induced persistent PAR₂-dependent hyperexcitability of nociceptors, and PAR₂ association with β-arrestins, which mediate endocytosis. Conjugation to cholestanol promoted delivery and retention of antagonists in endosomes containing PAR₂ A cholestanol-conjugated PAR₂ antagonist prevented persistent trypsin- and IBS protease-induced hyperexcitability of nociceptors. The results reveal that PAR₂ signaling from endosomes underlies the persistent hyperexcitability of nociceptors that mediates chronic pain of IBS. Endosomally targeted PAR₂ antagonists are potential therapies for IBS pain. GPCRs in endosomes transmit signals that contribute to human diseases.

Posterior fossa ependymoma comprise three distinct molecular variants, termed PF-EPN-A (PFA), PF-EPN-B (PFB), and PF-EPN-SE (subependymoma). Clinically, they are very disparate and PFB tumors are currently being considered for a trial of radiation avoidance. However, to move forward, unraveling the heterogeneity within PFB would be highly desirable. To discern the molecular heterogeneity within PFB, we performed an integrated analysis consisting of DNA methylation profiling, copy-number profiling, gene expression profiling, and clinical correlation across a cohort of 212 primary posterior fossa PFB tumors. Unsupervised spectral clustering and t-SNE analysis of genome-wide methylation data revealed five distinct subtypes of PFB tumors, termed PFB1-5, with distinct demographics, copy-number alterations, and gene expression profiles. All PFB subtypes were distinct from PFA and posterior fossa subependymomas. Of the five subtypes, PFB4 and PFB5 are more discrete, consisting of younger and older patients, respectively, with a strong female-gender enrichment in PFB5 (age: p = 0.011, gender: p = 0.04). Broad copy-number aberrations were common; however, many events such as chromosome 2 loss, 5 gain, and 17 loss were enriched in specific subtypes and 1q gain was enriched in PFB1. Late relapses were common across all five subtypes, but deaths were uncommon and present in only two subtypes (PFB1 and PFB3). Unlike the case in PFA ependymoma, 1q gain was not a robust marker of poor progression-free survival; however, chromosome 13q loss may represent a novel marker for risk stratification across the spectrum of PFB subtypes. Similar to PFA ependymoma, there exists a significant intertumoral heterogeneity within PFB, with distinct molecular subtypes identified. Even when accounting for this heterogeneity, extent of resection remains the strongest predictor of poor outcome. However, this biological heterogeneity must be accounted for in future preclinical modeling and personalized therapies.

Pineoblastoma is a rare and highly aggressive brain cancer of childhood, histologically belonging to the spectrum of primitive neuroectodermal tumors. Patients with germline mutations in DICER1, a ribonuclease involved in microRNA processing, have increased risk of pineoblastoma, but genetic drivers of sporadic pineoblastoma remain unknown. Here, we analyzed pediatric and adult pineoblastoma samples (n = 23) using a combination of genome-wide DNA methylation profiling and whole-exome sequencing or whole-genome sequencing. Pediatric and adult pineoblastomas showed distinct methylation profiles, the latter clustering with lower-grade pineal tumors and normal pineal gland. Recurrent variants were found in genes involved in PKA- and NF-κB signaling, as well as in chromatin remodeling genes. We identified recurrent homozygous deletions of DROSHA, acting upstream of DICER1 in microRNA processing, and a novel microduplication involving chromosomal region 1q21 containing PDE4DIP (myomegalin), comprising the ancient DUF1220 protein domain. Expresion of PDE4DIP and DUF1220 proteins was present exclusively in pineoblastoma with PDE4DIP gain.

Purpose: Rapid dose fall off from planning target volume (PTV) is required to spare organs at risk (OAR) that is hallmark of advanced treatment techniques (IMRT, VMAT, and SBRT). Along with conformity index (CI) and homogeneity index (HI) recently, gradient index (GI) was introduced to provide a measurable quality index for dose fall off from PTV. However, it is not clear if GI can be used in IMRT and if there are consistent differences between the two techniques. Methods: Dose volume histogram data for 700 patients equally divided between SBRT and IMRT were retrospectively analyzed. GI was calculated for each patient which is ratio of the volume of at half the prescription (PIV50%) to prescription isodose volume (PIV100%) which was calculated treatment plan and from PTV and CI. Physical distance ratio between OAR and PTV coverage was determined based on the cube root of the GI as an additional tool along with gradient measure distance (rPIV50%-rPIV100%) for the evaluation of SBRT and IMRT plans. Results: The GI varied widely between IMRT and SBRT patients due to inherent differences in techniques. The GIs are nearly constant 4.3 +/-1.1 and 12.8 +/-4.4 for SBRT and IMRT, respectively. The size of PTV is inversely related to GI with data more consistent in SBRT compared to IMRT. The gradient measure increases with PTV size in a well-defined way (0.5-1.5 cm) compared to IMRT where data is widely spread. This can be used as a surrogate for distance between PTV and OAR in IMRT and SBRT. Conclusion: Gradient index and measure are effective parameters in evaluating dose gradient that show consistent differences between treatment techniques. These tools could provide an opportunity for plan evaluation especially the distance from the PTV to OAR to optimize the dose to reduce complications

OBJECTIVE:To assess changes in the practice patterns of urologists performing male infertility procedures (vasal reconstruction, sperm retrieval, varicocelectomy) from 2004 to 2015 in the United States. DESIGN/METHODS:Examination of self-reported procedural volumes from urologists undergoing certification and recertification using case log data provided by the American Board of Urology. The study period was stratified into early (2004-2007) and recent (2012-2015) time periods. SETTING/METHODS:Not applicable. PATIENT(S)/METHODS:None. INTERVENTION(S)/METHODS:None. MAIN OUTCOMES MEASURE(S)/METHODS:Temporal variations in male infertility practice patterns among different urologic subspecialties between the early and recent time periods. RESULT(S)/RESULTS:The overall proportion of total male infertility procedures performed by andrologists significantly increased between the early and recent groups (23% to 26%). This growth was driven by a significant increase in the proportion of varicocele repairs being performed by andrologists between the early and recent periods (19% to 25%). Most notably, an assessment of total number of male infertility procedures performed by newly certifying urologists showed that there was a significant increase in the overall proportion of all male infertility procedures being performed by recently trained andrologists (24% to 35%). This significant increase was seen individually among all three types of male infertility procedures. CONCLUSION(S)/CONCLUSIONS:With the increased trend in urologists obtaining fellowship training, male infertility surgical volume is beginning to shift from general urologists to subspecialized andrologists.

Chemotherapy-induced peripheral neuropathy (CIPN) is a severe and dose-limiting side effect of cancer treatment that affects millions of cancer survivors throughout the world and current treatment options are extremely limited by their side effects. Cannabinoids are highly effective in suppressing pain symptoms of chemotherapy-induced and other peripheral neuropathies but their widespread use is limited by central nervous system (CNS)-mediated side effects. Here, we tested one compound from a series of recently developed synthetic peripherally restricted cannabinoids (PRCBs) in a rat model of cisplatin-induced peripheral neuropathy. Results show that local or systemic administration of 4-{2-[-(1E)-1[(4-propylnaphthalen-1-yl)methylidene]-1H-inden-3-yl]ethyl}morpholine (PrNMI) dose-dependently suppressed CIPN mechanical and cold allodynia. Orally administered PrNMI also dose-dependently suppressed CIPN allodynia symptoms in both male and female rats without any CNS side effects. Co-administration with selective cannabinoid receptor subtype blockers revealed that PrNMI's anti-allodynic effects are mediated by CB1 receptor (CB1R) activation. Expression of CB2Rs was reduced in dorsal root ganglia from CIPN rats, whereas expression of CB1Rs and various endocannabinoid synthesizing and metabolizing enzymes was unaffected. Daily PrNMI treatment of CIPN rats for two weeks showed a lack of appreciable tolerance to PrNMI's anti-allodynic effects. In an operant task which reflects cerebral processing of pain, PrNMI also dose-dependently suppressed CIPN pain behaviors. Our results demonstrate that PRCBs exemplified by PrNMI may represent a viable option for the treatment of CIPN pain symptoms.

Background/UNASSIGNED:In the digital era when mHealth has emerged as an important venue for health care, the application of computer science, such as machine learning, has proven to be a powerful tool for health care in detecting or predicting various medical conditions by providing improved accuracy over conventional statistical or expert-based systems. Symptoms are often indicators for abnormal changes in body functioning due to illness or side effects from medical treatment. Real-time symptom report refers to the report of symptoms that patients are experiencing at the time of reporting. The use of machine learning integrating real-time patient-centered symptom report and real-time clinical analytics to develop real-time precision prediction may improve early detection of lymphedema and long term clinical decision support for breast cancer survivors who face lifelong risk of lymphedema. Lymphedema, which is associated with more than 20 distressing symptoms, is one of the most distressing and dreaded late adverse effects from breast cancer treatment. Currently there is no cure for lymphedema, but early detection can help patients to receive timely intervention to effectively manage lymphedema. Because lymphedema can occur immediately after cancer surgery or as late as 20 years after surgery, real-time detection of lymphedema using machine learning is paramount to achieve timely detection that can reduce the risk of lymphedema progression to chronic or severe stages. This study appraised the accuracy, sensitivity, and specificity to detect lymphedema status using machine learning algorithms based on real-time symptom report. Methods/UNASSIGNED:A web-based study was conducted to collect patients' real-time report of symptoms using a mHealth system. Data regarding demographic and clinical information, lymphedema status, and symptom features were collected. A total of 355 patients from 45 states in the US completed the study. Statistical and machine learning procedures were performed for data analysis. The performance of five renowned classification algorithms of machine learning were compared: Decision Tree of C4.5, Decision Tree of C5.0, gradient boosting model (GBM), artificial neural network (ANN), and support vector machine (SVM). Each classification algorithm has certain user-definable hyper parameters. Five-fold cross validation was used to optimize these hyper parameters and to choose the parameters that led to the highest average cross validation accuracy. Results/UNASSIGNED:Using machine leaning procedures comparing different algorithms is feasible. The ANN achieved the best performance for detecting lymphedema with accuracy of 93.75%, sensitivity of 95.65%, and specificity of 91.03%. Conclusions/UNASSIGNED:A well-trained ANN classifier using real-time symptom report can provide highly accurate detection of lymphedema. Such detection accuracy is significantly higher than that achievable by current and often used clinical methods such as bio-impedance analysis. Use of a well-trained classification algorithm to detect lymphedema based on symptom features is a highly promising tool that may improve lymphedema outcomes.

Most animals orient their bodies with respect to gravity to facilitate locomotion and perception. The neural circuits responsible for these orienting movements have long served as a model to address fundamental questions in systems neuroscience. Though postural control is vital, we know little about development of either balance reflexes or the neural circuitry that produces them. Recent work in a genetically and optically accessible vertebrate, the larval zebrafish, has begun to reveal the mechanisms by which such vestibular behaviors and circuits come to function. Here we highlight recent work that leverages the particular advantages of the larval zebrafish to illuminate mechanisms of postural development, the role of sensation for balance circuit development, and the organization of developing vestibular circuits. Further, we frame open questions regarding the developmental mechanisms for functional circuit assembly and maturation where studying the zebrafish vestibular system is likely to open new frontiers.

OBJECTIVE:To investigate the individualized learning plan (ILP) as a tool in assessment of residents' milestone achievements as they pertain to Otology subcompetencies: Chronic Ear Disease, Pediatric Otitis Media, and Hearing Loss. STUDY DESIGN/METHODS:Prospective study. METHODS:Twenty otolaryngology residents were instructed to use an ILP and identify six milestones from three otology-related subcompetencies to focus on during the course of a 3-month rotation. They were also asked to plan out specific activities which would help them achieve these milestones, to specify whether or not they successfully achieved them, by what instructional or learning methods and to identify any barriers. The completed ILPs were reviewed by a faculty member. MAIN OUTCOME MEASURES/METHODS:The effectiveness of the ILP was assessed by response compliance rate, corroboration of self-reported milestone achievement with faculty evaluations and the ability to set attainable milestones. RESULTS:There was 95% compliance in using an ILP to achieve milestones. Self-reported milestone scores corresponded to the faculty evaluations in a large majority (89.6%) of patients, and tended to be underestimated by the residents. Out of 114 total milestones identified, 44 (38.6%) were not achieved, with particular overestimation in the use of independent study as a learning method. CONCLUSION/CONCLUSIONS:The ILP is an effective tool in measuring residents' achievement of otology-related milestones, and could possibly be used to supplement or replace faculty assessment. The ILP provides valuable information on barriers to achieving milestones and informs trainees on how to set attainable goals as they pertain to patient care and medical knowledge in otology.

INTRODUCTION/BACKGROUND:Epidermal growth factor receptors EGFR and ErbB2 are overexpressed in schwannomas and meningiomas. Preclinical and clinical data indicate that lapatinib, an EGFR/ErbB2 inhibitor, has antitumor activity against vestibular schwannomas in neurofibromatosis type 2 (NF2) patients. Its antitumor activity against meningiomas, however, is unknown. METHODS:) who received at least five 28-day courses of treatment. Patients received lapatinib 1500 mg daily. Meningioma response was assessed using 3-dimensional MRI volumetrics. Progressive meningioma growth and response were defined as + 20 and - 20% change in tumor volume from baseline, respectively. Off-treatment was defined as any period > 5 months without lapatinib. RESULTS:Eight patients (ages: 20-58 years) who met criteria had 17 evaluable meningiomas with a combined volume of 61.35 cc at baseline, 61.17 cc during treatment, and 108.86 cc (+ 77.44% change) off-treatment, p = 0.0033. Median time on-treatment and off-treatment was 15.5 and 16.7 months, respectively. On-treatment mean and median annualized growth rates were 10.67 and 1.32%, respectively. Off-treatment mean and median annualized growth rates were 20.05 and 10.42%, respectively. The best volumetric response was - 26.1% after 23 months on lapatinib. Two tumors increased > 20% volumetrically on-treatment, compared to eight tumors off-treatment. CONCLUSIONS:These data suggest that lapatinib may have growth-inhibitory effects on meningiomas in NF2 patients, and support prospective studies of lapatinib for NF2 patients with progressive meningiomas.