View clinical trials related to Hypoxia.
Filter by:The use of acute intermittent hypoxia (AIH) has been examined in animal and human studies to gain an understanding of its effect on spinal excitability and synaptic strength. Subsequently, the investigators have learned that the use of AIH results in new protein formation and spinal plasticity. The use of acute intermittent hypoxia demonstrates a potential for therapeutic utilization in individuals with neurologic injuries. However, little is known about the effect of AIH in healthy individuals. This work is necessary to understand the mechanisms of AIH-induced plasticity. As such, this research study seeks to evaluate the impact of a single session AIH on upper extremity motor function in healthy individuals.
THRIVE (Transnasal Humidified Rapid-Insufflation Ventilatory Exchange) refers to the use of high-flow nasal cannula to augment the ability to oxygenate and ventilate a patient under general anesthesia. The use of high-flow nasal cannula oxygen supplementation during anesthesia for surgical procedures has been a recent development in the adult population, with limited data analyzing the pediatric population. This study will determine whether high flow nasal cannula oxygen supplementation during surgical or endoscopic procedures can prevent desaturation events in children under anesthesia and improve the outcomes of that surgery.
It is well documented that exercise-induced arterial hypoxemia (EIAH) is highly prevalent among endurance-trained athletes performing heavy intensity exercise, regardless of sex and age. Although it has been shown that a drop in arterial oxyhemoglobin saturation (SaO2) during exercise (i.e. EIAH) negatively affects aerobic capacity measures such as VO2max and time trial performance, there remains a gap in the literature as to the physiological consequences of EIAH, and specifically acute cytokines and stress-related responses to hypoxemia during exercise. Exposure to hypoxic environments in which SaO2 is reduced and exercise can each, independently, alter/activate various pro- and anti-inflammatory markers and increases stress hormones. It follows then that EIAH athletes could be more susceptible to, and encounter more frequently, episodes of elevated levels of inflammatory cytokines and an exaggerated stress response than non-EIAH athletes; however, to the best of the investigators knowledge, this is yet to be confirmed. Therefore, it is hypothesized that highly trained endurance athletes who develop EIAH will experience more pronounced increases in inflammatory cytokines and stress hormones following a bout of heavy intensity exercise compared to athletes without EIAH.
The purpose of this research study is to better understand how blood flow and metabolism are different between normal controls and patients with disease. The investigators will examine brain blood flow and metabolism using magnetic resonance imaging (MRI). The brain's blood vessels expand and constrict to regulate blood flow based on the brain's needs. The amount of expanding and contracting the blood vessels can do varies by age. The brain's blood flow changes in small ways during everyday activities, such as normal brain growth, exercise, or deep concentration. Significant illness or physiologic stress may increase the brain's metabolic demand or cause other bigger changes in blood flow. If blood vessels are not able to expand to give more blood flow when metabolic demand is high, the brain may not get all of the oxygen it needs. In less extreme circumstances, not having as much oxygen as it wants may cause the brain to grow and develop more slowly than it should. One way to test the ability of the blood vessels to expand is by measuring blood flow while breathing in carbon dioxide (CO2). CO2 causes blood vessels in the brain to dilate without increasing brain metabolism. The study team will use a special mask to control the amount of oxygen and carbon dioxide patients breath in so that we can study how their brain reacts to these changes. This device designed to simulate carbon dioxide levels achieved by a breath-hold and target the concentration of carbon dioxide in the blood in breathing patients. The device captures exhaled gas and provides an admixture of fresh gas and neutral/expired gas to target different carbon dioxide levels while maintaining a fixed oxygen level. The study team will obtain MRI images of the brain while the subjects are breathing air controlled by the device.
This study evaluates the effect of hypoxia on blood volumes during Antarctic winter-over confinement. Half of the participants will be evaluated during sea-level winter-over confinement, while the other half will be examined during high-altitude hypoxia winter-over confinement.
The study aims to elucidate hypoxia-induced angiogenesis in tumor development using central nervous system (CNS) hemangioblastoma tumorgenesis as a model. In a pilot-project the investigators will identify genetic drivers of CNS hemangioblastoma progression and associated cyst development using whole genome sequencing and copy number profiling of tumor DNA paired with clinical information about each tumor's growth pattern. The investigators will look for recurrent mutations across tumors to identify common genetic mechanisms involved in early tumorigenesis.
The specific aims of the project are performing a pre-clinical study on a human model and evaluating the oxygenation and other status of human erythrocytes by spectrally-resolved third harmonic generation (srTHG) microscopy . By analyzing the partitioned third harmonic generation (THG) spectra of oxygenated and deoxygenated erythrocytes ex vivo, the investigators aim to provide a reference standard for quantifying oxygenation and molecular status in this project.
This study will test the feasibility of using novel/existing imaging technologies focused on hypoxia measurements to determine "response to therapy" in pediatric soft tissue sarcomas as a pilot study. Specifically, the investigators will compare the sensitivity of Blood Oxygen Level Dependent [BOLD], Diffusion-Weighted [DW] MRI, Magnetic Resonance Spectroscopy (MRS) and 18F-FAZA PET-MRI with that of conventional MRI to detect measurement changes between the start and completion of neoadjuvant therapy ("response to therapy") in children and adolescents (7-18 years) with suspicion of sarcoma tumors. Clinicians and scientists may use results of the proposed hypoxia-imaging surrogate markers to adjust/modify therapeutic schemes to patients on a personalized basis.