Healthy Clinical Trials in Columbia, MO

Alzheimer's disease is a devastating neurodegenerative disease characterized by accumulation of clumps (also called plaques) and bundles of fibers (also called tangles) in the brain, for which there is currently no cure. Sirolimus is an FDA-approved medication which may improve the blood flow to the brain. Part I: This study is designed to see if sirolimus treatment improves MRI blood flow to the brain in individuals with and without a genetic predisposition to Alzheimer's disease. Part I of this study is complete and no longer enrolling participants. Part II: Ongoing research will expand the genetic predisposition cohort and further explore the drug's impact on the lung perfusion via hyperpolarized xenon-129 gas MRI and the brain-vascular connection. Only subjects who are APOE4 carriers will be enrolled in Part II. Hyperpolarized xenon-129 gas MRI is a non-invasive technique in which a subject inhales a bolus of hyperpolarized xenon-129 gas which can be directly imaged by the MRI as it physiologically distributes itself throughout the lung interior and within tissue and red blood cells. It thus allows for direct imaging and quantification of regional lung function: ventilation, gas-exchange, and perfusion. The relationship between pulmonary vascular function and brain perfusion is largely unstudied. We hope to investigate the relationship between pulmonary vascular function and cerebral blood flow by quantifying both lung and brain perfusion before and after the administration of Sirolimus. Read Less

The goal of this study is to evaluate the role of transcription factor EB (TFEB) in adipose (fat) tissue macrophages (ATM) in regulating adipose tissue and systemic metabolic function in obesity. The investigators will assess the differences in ATM lipid metabolism in people with metabolically abnormal obesity and lean individuals. Both groups will have: * screening visit * imaging (body composition testing - dual-energy x-ray absorptiometry (DEXA) scans, magnetic resonance imaging \[MRI\] and magnetic resonance spectroscopy \[MRS\] scans) * Overnight visit with intravenous infusion (IV), muscle, and fat tissue biopsies Participants with obesity will complete meetings with study team members for a weight loss intervention to achieve a 10% body weight loss. Read Less

The goal of this study is to evaluate the role of transcription factor EB (TFEB) in adipose (fat) tissue macrophages (ATM) in regulating adipose tissue and systemic metabolic function in obesity. The investigators will assess the differences in ATM lipid metabolism in people with metabolically abnormal obesity and lean individuals. Both groups will have: * screening visit * imaging (body composition testing - dual-energy x-ray absorptiometry (DEXA) scans, magnetic resonance imaging \[MRI\] and magnetic resonance spectroscopy \[MRS\] scans) * Overnight visit with intravenous infusion (IV), muscle, and fat tissue biopsies Read Less

Patients with sleep apnea are at increased risk of developing cardiovascular disease - with women at potentially greater risk than men. Contributing mechanisms are not well understood, but may be related to how women respond to low oxygen and, given over 70% of patients with sleep apnea are obese, the impact of obesity. This project seeks to increase our understanding of mechanisms that may contribute to sex differences in the cardiovascular response to low oxygen with the hope that this knowledge will improve the efficacy of current therapies and support the discovery of novel therapeutics. Read Less

The purpose of this project is to examine the impact of increases in brain insulin on sympathetic nervous system activity, as well as peripheral and cerebral blood flow in humans. Read Less

The purpose of this project is to examine key mechanisms contributing to sex-differences in hypoxic vasodilation and the impact of obesity, with particular emphasis on the sympathetic nervous system. Read Less