RESUMEN
Alzheimer's Disease (AD) is the 5th leading cause of death in older adults and treatment options are severely lacking. Recent findings demonstrate a strong relationship between skeletal muscle and cognitive function, with evidence supporting that muscle quality and cognitive function are positively correlated in older adults. Conversely, decreased muscle function is associated with a 3-fold increased risk of cognitive decline. Based on these observations, the purpose of this study was to investigate the negative effects of muscle disuse (via a model of hindlimb immobilization (HLI)) on hippocampal insulin sensitivity and mitochondrial function and identify the potential mechanisms involved. HLI for 10 days in 4-month-old female Wistar rats resulted in the following novel findings: 1) hippocampal insulin resistance and deficits in whole body glucose homeostasis, 2) dramatically increased mitochondrial reactive oxygen species (ROS) production in the hippocampus, 3) elevated markers for amyloidogenic cleavage of APP and tau protein in the hippocampus, 4) and reduced BDNF expression. These findings were associated with global changes in iron homeostasis, with muscle disuse producing muscle iron accumulation in association with decreased serum and whole brain iron levels. We report the novel finding that muscle disuse alters brain iron homeostasis and reveal a strong negative correlation between muscle and brain iron content. Overall, HLI-induced muscle disuse has robust negative effects on hippocampal insulin sensitivity and ROS production in association with altered brain iron homeostasis. This work provides potential novel mechanisms that may help explain how loss of muscle function contributes to cognitive decline and AD risk.
RESUMEN
Post-surgical scarring impacts quality of life (QOL) and is a significant source of morbidity. Existing treatments targeted at improving the appearance and morbidity of scarring include laser-based therapies. Although lasers are frequently used to improve scar appearance, the effects on QOL are unclear. A scoping review was conducted to assess the impact of laser-based therapy for patients with surgical facial scarring on QOL. Throughout literature review was conducted with the guidance of a medical librarian. Relevant articles underwent two rounds of screening by two, independent reviewers. Data were extracted from each article and later analyzed. Of the four articles analyzed, laser-based therapies were demonstrated as effective in improving QOL for patients with facial scars resultant from surgical intervention. Laser-based therapy should be considered when treating facial scarring resultant from surgical intervention, as it has been shown to improve patient QOL. Standardization of QOL assessment and further studies expanding scar inclusion should be pursued given the paucity of information found through this review.