5 results on '"David D. Limbrick"'
Search Results
2. Non-invasive Auricular Vagus nerve stimulation for Subarachnoid Hemorrhage (NAVSaH): Protocol for a prospective, triple-blinded, randomized controlled trial.
- Author
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Huguenard A, Tan G, Johnson G, Adamek M, Coxon A, Kummer T, Osbun J, Vellimana A, Limbrick D Jr, Zipfel G, Brunner P, and Leuthardt E
- Subjects
- Adult, Female, Humans, Male, Middle Aged, Inflammation therapy, Prospective Studies, Treatment Outcome, Randomized Controlled Trials as Topic, Subarachnoid Hemorrhage therapy, Subarachnoid Hemorrhage complications, Vagus Nerve Stimulation methods
- Abstract
Background: Inflammation has been implicated in driving the morbidity associated with subarachnoid hemorrhage (SAH). Despite understanding the important role of inflammation in morbidity following SAH, there is no current effective way to modulate this deleterious response. There is a critical need for a novel approach to immunomodulation that can be safely, rapidly, and effectively deployed in SAH patients. Vagus nerve stimulation (VNS) provides a non-pharmacologic approach to immunomodulation, with prior studies demonstrating VNS can reduce systemic inflammatory markers, and VNS has had early success treating inflammatory conditions such as arthritis, sepsis, and inflammatory bowel diseases. The aim of the Non-invasive Auricular Vagus nerve stimulation for Subarachnoid Hemorrhage (NAVSaH) trial is to translate the use of non-invasive transcutaneous auricular VNS (taVNS) to spontaneous SAH, with our central hypothesis being that implementing taVNS in the acute period following spontaneous SAH attenuates the expected inflammatory response to hemorrhage and curtails morbidity associated with inflammatory-mediated clinical endpoints., Materials and Methods: The overall objectives for the NAHSaH trial are to 1) Define the impact that taVNS has on SAH-induced inflammatory markers in the plasma and cerebrospinal fluid (CSF), 2) Determine whether taVNS following SAH reduces radiographic vasospasm, and 3) Determine whether taVNS following SAH reduces chronic hydrocephalus. Following presentation to a single enrollment site, enrolled SAH patients are randomly assigned twice daily treatment with either taVNS or sham stimulation for the duration of their intensive care unit stay. Blood and CSF are drawn before initiation of treatment sessions, and then every three days during a patient's hospital stay. Primary endpoints include change in the inflammatory cytokine TNF-α in plasma and cerebrospinal fluid between day 1 and day 13, rate of radiographic vasospasm, and rate of requirement for long-term CSF diversion via a ventricular shunt. Secondary outcomes include exploratory analyses of a panel of additional cytokines, number and type of hospitalized acquired infections, duration of external ventricular drain in days, interventions required for vasospasm, continuous physiology data before, during, and after treatment sessions, hospital length of stay, intensive care unit length of stay, and modified Rankin Scale score (mRS) at admission, discharge, and each at follow-up appointment for up to two years following SAH., Discussion: Inflammation plays a central role in morbidity following SAH. This NAVSaH trial is innovative because it diverges from the pharmacologic status quo by harnessing a novel non-invasive neuromodulatory approach and its known anti-inflammatory effects to alter the pathophysiology of SAH. The investigation of a new, effective, and rapidly deployable intervention in SAH offers a new route to improve outcomes following SAH., Trial Registration: Clinical Trials Registered, NCT04557618. Registered on September 21, 2020, and the first patient was enrolled on January 4, 2021., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: ALH and ECL hold equity in the company Aurenar, LLC. The COI as it relates to this trial has been managed by Washington University., (Copyright: © 2024 Huguenard et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2024
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3. Unraveling the complexity of the senescence-associated secretory phenotype in adamantinomatous craniopharyngioma using multimodal machine learning analysis.
- Author
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Prince EW, Apps JR, Jeang J, Chee K, Medlin S, Jackson EM, Dudley R, Limbrick D, Naftel R, Johnston J, Feldstein N, Prolo LM, Ginn K, Niazi T, Smith A, Kilburn L, Chern J, Leonard J, Lam S, Hersh DS, Gonzalez-Meljem JM, Amani V, Donson AM, Mitra SS, Bandopadhayay P, Martinez-Barbera JP, and Hankinson TC
- Subjects
- Humans, Biomarkers, Tumor metabolism, Biomarkers, Tumor genetics, Phenotype, Gene Expression Regulation, Neoplastic, Child, Male, Female, Craniopharyngioma metabolism, Craniopharyngioma pathology, Craniopharyngioma genetics, Pituitary Neoplasms pathology, Pituitary Neoplasms metabolism, Pituitary Neoplasms genetics, Cellular Senescence, Machine Learning
- Abstract
Background: Cellular senescence can have positive and negative effects on the body, including aiding in damage repair and facilitating tumor growth. Adamantinomatous craniopharyngioma (ACP), the most common pediatric sellar/suprasellar brain tumor, poses significant treatment challenges. Recent studies suggest that senescent cells in ACP tumors may contribute to tumor growth and invasion by releasing a senesecence-associated secretory phenotype. However, a detailed analysis of these characteristics has yet to be completed., Methods: We analyzed primary tissue samples from ACP patients using single-cell, single-nuclei, and spatial RNA sequencing. We performed various analyses, including gene expression clustering, inferred senescence cells from gene expression, and conducted cytokine signaling inference. We utilized LASSO to select essential gene expression pathways associated with senescence. Finally, we validated our findings through immunostaining., Results: We observed significant diversity in gene expression and tissue structure. Key factors such as NFKB, RELA, and SP1 are essential in regulating gene expression, while senescence markers are present throughout the tissue. SPP1 is the most significant cytokine signaling network among ACP cells, while the Wnt signaling pathway predominantly occurs between epithelial and glial cells. Our research has identified links between senescence-associated features and pathways, such as PI3K/Akt/mTOR, MYC, FZD, and Hedgehog, with increased P53 expression associated with senescence in these cells., Conclusions: A complex interplay between cellular senescence, cytokine signaling, and gene expression pathways underlies ACP development. Further research is crucial to understand how these elements interact to create novel therapeutic approaches for patients with ACP., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
- Published
- 2024
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4. Predictors and timing of hydrocephalus treatment in patients undergoing prenatal versus postnatal surgery for myelomeningocele.
- Author
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Karuparti S, Dunbar A, Varagur K, Sudanagunta K, Mingo M, Bligard KH, Odibo A, Vrecenak J, McEvoy S, Limbrick D, Peglar Marsala L, Anadkat J, Mian A, and Strahle JM
- Subjects
- Humans, Female, Male, Retrospective Studies, Infant, Newborn, Pregnancy, Ultrasonography, Prenatal, Gestational Age, Treatment Outcome, Infant, Hydrocephalus surgery, Hydrocephalus etiology, Hydrocephalus diagnostic imaging, Meningomyelocele surgery, Meningomyelocele complications, Meningomyelocele diagnostic imaging
- Abstract
Objective: Although hydrocephalus rates have decreased with intrauterine surgery for myelomeningocele (MMC), 40%-85% of children with MMC still go on to develop hydrocephalus. Prenatal ventricle size is known to be associated with later development of hydrocephalus; however, it is not known how prediction measures or timing of hydrocephalus treatment differ between pre- and postnatal surgery for MMC. The goal of this study was to determine anatomical, clinical, and radiological characteristics that are associated with the need for and timing of hydrocephalus treatment in patients with MMC., Methods: The authors retrospectively identified patients from Barnes Jewish Hospital or St. Louis Children's Hospital between 2016 and 2021 who were diagnosed with MMC prenatally and underwent either pre- or postnatal repair. Imaging, clinical, and demographic data were examined longitudinally between treatment groups and hydrocephalus outcomes., Results: Fifty-eight patients were included (27 females, 46.6%), with a mean gestational age at birth of 36.8 weeks. Twenty-three patients (39.7%) underwent prenatal surgery. For the overall cohort, the ventricle size at prenatal ultrasound (HR 1.175, 95% CI 1.071-1.290), frontal-occipital horn ratio (FOHR) at birth > 0.50 (HR 3.603, 95% CI 1.488-8.720), and mean rate of change in head circumference (HC) in the first 90 days after birth (> 0.10 cm/day: HR 12.973, 95% CI 4.262-39.486) were identified as predictors of hydrocephalus treatment. The factors associated with hydrocephalus in the prenatal cohort were FOHR at birth > 0.50 (HR 27.828, 95% CI 2.980-259.846) and the rate of change in HC (> 0.10 cm/day: HR 39.414, 95% CI 2.035-763.262). The factors associated with hydrocephalus in the postnatal cohort were prenatal ventricle size (HR 1.126, 95% CI 1.017-1.246) and the mean rate of change in HC (> 0.10 cm/day: HR 24.202, 95% CI 5.119-114.431). FOHR (r = -0.499, p = 0.008) and birth HC (-0.409, p = 0.028) were correlated with time to hydrocephalus across both cohorts. For patients who underwent treatment for hydrocephalus, those in the prenatal surgery group were significantly more likely to develop hydrocephalus after 3 months than those treated with postnatal surgery, although the overall rate of hydrocephalus was significantly higher in the postnatal surgery group (p = 0.018)., Conclusions: Clinical and imaging factors associated with hydrocephalus treatment differ between those receiving pre- versus postnatal MMC repair, and while the overall rate of hydrocephalus is lower, those undergoing prenatal repair are more likely to develop hydrocephalus after 3 months of age. This has implications for clinical follow-up timing for patients treated prenatally, who may live at a distance from the treatment site.
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- 2024
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5. Active Teaching Techniques Using Virtual Didactics: Novel Experience From a National Neurosurgery Resident Course.
- Author
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Stippler M, Blitz SE, Quinsey C, Limbrick D, Byrne R, Zipfel G, and Selden NR
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- Humans, Pandemics, Curriculum, Education, Medical, Graduate methods, Teaching, Neurosurgery education, Internship and Residency
- Abstract
Objective: To investigate the attitudes of neurosurgery residents regarding active teaching techniques and virtual didactics based on a national neurosurgery resident sample. We also evaluated the relative cost and time commitment required for faculty participation in virtual versus in-person resident courses., Design: The Society of Neurological Surgeons (SNS) national junior resident courses (JRCs) were reformatted for active teaching in a virtual setting in 2020 due to the COVID-19 pandemic. We analyzed course evaluations from the virtual 2020 courses in comparison to the 2019 in-person SNS JRCs. We also compared course budgets and agendas from these courses to identify comparative costs and the time commitment for faculty participation using these 2 course models., Setting: Survey of nationwide participants in virtual junior resident courses., Participants: A total of 122 residents from 80 ACGME neurosurgery residency training programs attended the 2020 virtual JRC., Results: The survey response rate of attendees was 36%. In-class engagement was thought to be good to great by 73% to 80% of the virtual learners. In-class activities and active learning techniques also were evaluated positively by 61% to 82% of respondents. Expenses were significantly lower for the virtual course, at $118 per course participant, than for the in-person course ($2722 per participant). There also was a 97.3% reduction of faculty hours and a 97.6% reduction of faculty cost for the virtual JRC compared to the in-person course., Conclusions: Neurosurgeon residents embraced the active teaching techniques used to teach portions of the prepandemic JRCs in a virtual format. Other aspects of the course curriculum could not be replicated virtually. Virtual courses were dramatically less expensive to produce, used fewer faculty teachers and required less time per faculty member. The data from this study may inform the choice of active teaching techniques for other neurosurgery residency and continuing medical education courses to optimize learner engagement and participant satisfaction in the virtual setting. We recommend that the curriculum of in-person courses emphasize hands-on, experiential learning and professional enculturation that cannot be recreated in the virtual space. Curricular elements suitable to virtual learning should take advantage of lower costs, reduced faculty time requirements, and scalability. They should also utilize active teaching techniques to improve learner engagement., (Copyright © 2023. Published by Elsevier Inc.)
- Published
- 2024
- Full Text
- View/download PDF
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