Separate and shared sympathetic outflow to white and brown fat coordinately regulates thermoregulation and beige adipocyte recruitment.

White adipose tissue (WAT) and brown adipose tissue (BAT) are innervated and regulated by the sympathetic nervous system (SNS). It is not clear, however, whether there are shared or separate central SNS outflows to WAT and BAT that regulate their function. We injected two isogenic strains of pseudorabies virus, a retrograde transneuronal viral tract tracer, with unique fluorescent reporters into interscapular BAT (IBAT) and inguinal WAT (IWAT) of the same Siberian hamsters to define SNS pathways to both. To test the functional importance of SNS coordinated control of BAT and WAT, we exposed hamsters with denervated SNS nerves to IBAT to 4°C for 16-24 h and measured core and fat temperatures and norepinephrine turnover (NETO) and uncoupling protein 1 (UCP1) expression in fat tissues. Overall, there were more SNS neurons innervating IBAT than IWAT across the neuroaxis. However, there was a greater percentage of singly labeled IWAT neurons in midbrain reticular nuclei than singly labeled IBAT neurons. The hindbrain had ~30-40% of doubly labeled neurons while the forebrain had ~25% suggesting shared SNS circuitry to BAT and WAT across the brain. The raphe nucleus, a key region in thermoregulation, had ~40% doubly labeled neurons. Hamsters with IBAT SNS denervation maintained core body temperature during acute cold challenge and had increased beige adipocyte formation in IWAT. They also had increased IWAT NETO, temperature, and UCP1 expression compared with intact hamsters. These data provide strong neuroanatomical and functional evidence of WAT and BAT SNS cross talk for thermoregulation and beige adipocyte formation.

Clinical Indications for Rapid Sequence MRI in Pediatric Neurosurgical Patients and the Limitations and Barriers to Implementation.

Rapid and fast magnetic resonance imaging (MRI) protocols have become increasingly popular for pediatric neurosurgical patients as they are a great way to reduce ionizing radiation and sedation. While their popularity has increased, there are hurdles to overcome when transitioning to using them clinically, such as cost, staffing training, and motion artifact. Through this paper, we developed a protocol for clinical applications where rapid MRI can be a substitute or adjuvant in diagnostic workup. Further, we outline the relevant literature for the use of RS-MRI for the spine, TBI, and hydrocephalus pathologies while expanding upon the limitations and logistical barriers when transitioning to their use, a few of which are discussed above. Through this, we conclude that RS-MRI can be used diagnostically for spinal pathologies such as syrinx and hydrocephalus. Further, its lack of sensitivity for TBI findings makes rapid sequence magnetic resonance imaging (RS-MRI) a strong adjuvant with other advanced imaging or computed tomography (CT) for traumatic brain injury (TBI) pathologies.

Social Disparities in Helmet Usage in Bicycle Accidents Involving Children.

Background Bicycle helmet use has a known protective health benefit; yet, pediatric populations have suboptimal helmet rates, which increases the risk of severe injuries. It is imperative to have an updated assessment of behavioral social disparities and for providers to be aware of them to better counsel patients. The study objective was to identify social determinants correlated with helmet use in children involved in bicycle accidents. Based on previous literature, we hypothesized that higher socioeconomic status, female sex, and Caucasian race were associated with increased helmet use. Methods A retrospective case series of 140 pediatric cases of bicycle-related traumas assessing helmet status. Participants presented to the emergency room with injuries due to a bicycle-related trauma and were subsequently admitted to the University of North Carolina (UNC) Hospital System in Chapel Hill, North Carolina (NC), from June 2006 to May 2020. The Institutional Review Board (IRB) approved study comprised a retrospective chart review of 140 cases from the pediatric (<18 years of age) trauma database with coding indicating bicycle-related injury. Zip codes were used to approximate the median household income utilizing the Proximity One government database. The primary exposure was helmet status, which was determined from the electronic record chart review. The hypothesis was formulated before the start of the study. The main outcomes measured in the study included age, sex, race, helmet status, zip code, insurance status, injury types, and mortality. Results There were a total of 140 study participants, of which 35 were female and 105 were male. Males comprised 79.6% of the non-helmeted group, while females were in the minority in both helmet status groups, with 65.7% still being non-helmeted. Additionally, 51.9% of patients who were helmeted used private insurance, and 59.3% of those non-helmeted used public insurance. Of the 71 head injuries, 88.7% were non-helmeted. Principally, this study found that 80.7% of children involved in a bicycle-related accident were not helmeted.  Conclusions Despite NC legislation mandating that children under 16 years of age wear helmets while operating bicycles, many children injured in bicycle-related trauma are not complying with this requirement. This study demonstrates that specific populations have decreased rates of helmet usage and emphasize the continued need to monitor helmet behaviors.