Post-traumatic hyperoxia after pediatric TBI.

OBJECTIVE: Hyperoxia has been suggested as a mechanism for secondary injury following adult traumatic brain injury (TBI), but its effects have not been well described in pediatric patients. METHODS: Pediatric (≤18yo) TBI patients were identified in a prospective institutional registry from October 2008 to April 2022. The first, highest, and the Area Under the Curve (AUC) PaO2 in the first 24 hours were collected and calculated for each patient from arterial blood gas reports after admission to the ICU. Neurological outcome after 6 months was measured using dichotomized modified Rankin Scale (mRS) and Glasgow Outcome Scale - Extended (GOS-E). Multivariable logistic regression models were used to determine if the three measurements for hyperoxia predicted an unfavorable outcome after controlling for well-established clinical and imaging predictors of outcome. RESULTS: We identified 98 pediatric patients with severe accidental TBI during the study period. Hyperoxia (PaO2 > 300 mmHg) occurred in 33% of the patients. The presence of elevated PaO2 values, determined by all three evaluations of hyperoxia, was not associated with unfavorable outcome after 6 months. CONCLUSION: Utilizing multiple methods to assess exposure, hyperoxia was present in a substantial number of patients with severe TBI but was not associated with an unfavorable outcome.

Gender Disparity in Pediatric Surgery: An Evaluation of Pediatric Surgery Conference Participation.

BACKGROUND: Leadership in academic conferences is an important factor for academic advancement. Underrepresentation of women in academic surgical conferences has been demonstrated in other subspecialties, but it has not been well-studied in pediatric surgery. METHODS: This retrospective descriptive study analyzes conference participation at 2 national pediatric surgery annual conference programs from 2003 to 2022. Moderator, speakers, and research presenter sex was collected. The primary outcome was the proportion of female participants in each of these roles. Mann-Kendall trend test was conducted to assess for significance. RESULTS: Across 29 meetings, a total of 523 sessions were examined. Overall, female participation in all roles increased from 2003 to 2022. There were statistically positive trends of female participation in leadership roles as moderator (p = 0.003) and speaker (p = 0.01), with moderator role demonstrating the largest proportional female increase over time - with a 7-fold increase from 7.1% in 2003 to 50.0% in 2022. There was also a significant increasing trend in female participation as research presenters (p < 0.01) from 25.4% to 46.4%. CONCLUSION: Gender representation in pediatric surgery conferences has improved over the last two decades. Women now represent approximately half of all participatory roles, and efforts to continue providing equal opportunities for women at pediatric surgery academic conferences should continue. LEVEL OF EVIDENCE: N/A. TYPE OF STUDY: Retrospective Descriptive.

The Molecular Mechanisms Through Which Placental Mesenchymal Stem Cell-Derived Extracellular Vesicles Promote Myelin Regeneration.

Multiple sclerosis (MS) is a debilitating degenerative disease characterized by an immunological attack on the myelin sheath leading to demyelination and axon degeneration. Mesenchymal stem/stromal cells (MSCs) and secreted extracellular vesicles (EVs) have become attractive targets as therapies to treat neurodegenerative diseases such as MS due to their potent immunomodulatory and regenerative properties. The placenta is a unique source of MSCs (PMSCs), demonstrates "fetomaternal" tolerance during pregnancy, and serves as a novel source of MSCs for the treatment of neurodegenerative diseases. PMSCs and PMSC-EVs have been shown to promote remyelination in animal models of MS, however, the molecular mechanisms by which modulation of autoimmunity and promotion of myelination occurs have not been well elucidated. The current review will address the molecular mechanisms by which PMSC-EVs can promote remyelination in MS.

Engineering extracellular vesicles for Alzheimer's disease: An emerging cell-free approach for earlier diagnosis and treatment.

Alzheimer's disease (AD) is a debilitating neurodegenerative disorder affecting over five million people globally and has no established cure. Current AD-related treatments only alleviate cognitive and behavioral symptoms and do not address disease onset or progression, underlining the unmet need to create an effective, innovative AD therapeutic. Extracellular vesicles (EVs) have emerged as a new class of nanotherapeutics. These secreted, lipid-bound cellular signaling carriers show promise for potential clinical applications for neurodegenerative diseases like AD. Additionally, analyzing contents and characteristics of patient-derived EVs may address the unmet need for earlier AD diagnostic techniques, informing physicians of altered genetic expression or cellular communications specific to healthy and diseased physiological states. There are numerous recent advances in regenerative medicine using EVs and include bioengineering perspectives to modify EVs, target glial cells in neurodegenerative diseases like AD, and potentially use EVs to diagnose and treat AD earlier. This article is categorized under: Neurological Diseases > Biomedical Engineering Neurological Diseases > Molecular and Cellular Physiology Neurological Diseases > Stem Cells and Development.

Bioengineered extracellular vesicle-loaded bioscaffolds for therapeutic applications in regenerative medicine.

Extracellular vesicle (EV)-based technologies represent a new advancement for disease treatment. EVs can be administered systemically, injected into the injury site directly, or applied locally in conjunction with bioengineered implantable scaffolds. Matrix-bound vesicles (MBVs), a special class of vesicles localized in association with the extracellular matrix (ECM), have been identified as critical bioactive factors and shown to mediate significant regenerative functions of ECM scaffolds. Loading EVs onto bioscaffolds to mimic the MBV-ECM complex has been shown superior to EV bolus injection in recent in vivo studies, such as in providing enhanced tissue regeneration, EV retention rates, and healing efficacy. Different types of natural biomaterials, synthetic polymers, and ceramics have been developed for EV loading, and these EV functionalized biomaterials have been applied in different areas for disease treatment. The EV functionalized scaffolds can be designed to be biodegradable, off-the-shelf biomaterials as a delivery vehicle for EVs. Overall, the bioengineered EV-loaded bioscaffolds represent a promising approach for cell-free treatment in clinical applications.