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Full-Text Articles in Medicine and Health Sciences

Applications Of Hair As A Record Of Systemic Exposure To Cortisol, Jeffrey Matthew Levine Oct 2019

Applications Of Hair As A Record Of Systemic Exposure To Cortisol, Jeffrey Matthew Levine

Electronic Thesis and Dissertation Repository

Hair cortisol content (HCC) is a novel biomarker that uniquely captures retrospective systemic cortisol exposure. This thesis aimed to assess how different hair growth rates effect HCC timelines in Cushing’s and Addison’s patients, investigate the relationship between HCC and age, puberty, sex and BMI in healthy children and adolescents, and assess novel methods to improve cortisol extraction and recovery. Retrospective HCC timelines derived from a 0.75 cm/month growth rate best matched 50% of patients’ medical records rather than the historically assumed 1 cm/month. HCC correlated positively with age (p<0.0001), puberty status (p<0.001), and BMI (p<0.01) in males and females 7-17 years old. Nitrogen evaporation resulted in greater cortisol recovery than air evaporation (p=0.0003), and hair digestion using NaOH resulted in more rapid extraction of cortisol. These results provide incremental improvements to previous methods and assumptions for HCC analysis and elucidate normal HCC changes in children and adolescents.


High Frequency Oscillations Are Phase-Amplitude Coupled In Stress Induced Seizures Following Traumatic Brain Injury, Paul Jung Oct 2019

High Frequency Oscillations Are Phase-Amplitude Coupled In Stress Induced Seizures Following Traumatic Brain Injury, Paul Jung

Electronic Thesis and Dissertation Repository

Traumatic Brain Injury (TBI) often leads to the development of epilepsy, especially with the occurrence of stressful events. Stressors increase the levels of corticotropin-releasing factor (CRF) in the amygdala, which can be damaged by the secondary effects of TBI. It is hypothesized that the activity of CRF receptor type 1 (CRFR1) in the amygdala is altered post-TBI and supports the generation of epileptiform waves, namely high-frequency oscillations (HFOs). Sprague-Dawley rats were given a moderate TBI and in vivo recordings of the amygdala were taken during the administration of an acute tail pinch stressor. The stressor increased broadband activity …


Crf Mediates Stress-Induced Pathophysiological High-Frequency Oscillations In Traumatic Brain Injury, Chakravarthi Narla, Paul S. Jung, Francisco Bautista Cruz, Michelle Everest, Julio Martinez-Trujillo, Michael O. Poulter Mar 2019

Crf Mediates Stress-Induced Pathophysiological High-Frequency Oscillations In Traumatic Brain Injury, Chakravarthi Narla, Paul S. Jung, Francisco Bautista Cruz, Michelle Everest, Julio Martinez-Trujillo, Michael O. Poulter

Physiology and Pharmacology Publications

Copyright © 2019 Narla et al. It is not known why there is increased risk to have seizures with increased anxiety and stress after traumatic brain injury (TBI). Stressors cause the release of corticotropin-releasing factor (CRF) both from the hypothalamic pituitary adrenal (HPA) axis and from CNS neurons located in the central amygdala and GABAergic interneurons. We have previously shown that CRF signaling is plastic, becoming excitatory instead of inhibitory after the kindling model of epilepsy. Here, using Sprague Dawley rats we have found that CRF signaling increased excitability after TBI. Following TBI, CRF type 1 receptor (CRFR1)-mediated activity caused …