Effect of Selective and Nonselective Cyclooxygenase Enzyme Inhibition on Arterial Blood Pressure...
Obstructive Sleep ApneaHypertension2 moreThe study has been designed to assess the effect of cyclooxygenase inhibition on blood pressure, cerebral blood flow, ventilation and renal hemodynamics following chronic intermittent hypoxia exposure.
Recruitment Maneuver After Intubation
HypoxemiaThe purpose of this study is to evaluate the safety and efficacy of a recruitment maneuver immediately after intubation in hypoxemic patients.
Study of [F 18]HX4 Positron Emission Tomography (PET) as a Tool to Detect Hypoxia in Tumors
Head and Neck CancerLung Cancer3 moreThis pilot phase II study is designed as a test and retest study to investigate [F 18]HX4 as a reliable non-invasive PET imaging marker for detection of tumor hypoxia regions and to establish a threshold for [F 18]HX4 uptake in the tumor. The study will evaluate the relationship between hypoxia biomarkers (HIF1α and CA-IX) by immunohistochemistry (IHC) and tumor uptake of [F 18]HX4 by PET imaging.
Mechanisms of Endothelial Cell Dysfunction in Sleep Apnea
Obstructive Sleep ApneaHypoxemiaSleep apnea is a common sleep disorder characterized by temporary stops in breathing during sleep and has been associated with the development of cardiovascular disease. This research will investigate one potential mechanism leading to the development of cardiovascular disorder, specifically, the blockage of blood vessels called "vascular occlusion", in subjects with sleep apnea. A group of healthy controls will be used for comparison. All subjects will undergo clinical evaluation followed by an overnight sleep study and a morning blood draw. Subjects with sleep apnea will be treated according to standard clinical management and followed under the research protocol for one month. At the end of one month, a repeat blood draw will be performed on the sleep apnea subjects for comparative analysis. If a control subject is found to have any abnormality during this research study, he or she will be referred for further clinical evaluation.
Quantification of Clinically Relevant Drug Induced Changes in HbO2 Affinity
Oxygen DeficiencyThe presented study is an experimental in-vitro study without intervention in-vivo. The effects of nitric oxide and prostacyclins, 5-hydroxymethylfurfural and alpha-ketoglutarate, volatile anaesthetics on haemoglobin oxygen (HbO2) affinity will be investigated in-vitro. Venous blood samples of 20 healthy young volunteers (10 female, 10 male) will be collected twice in the period of one week. Informed consent will be given. Every blood collection will be accompanied by a venous blood gas analysis. The blood samples will be transferred to the laboratory for in-vitro recording of the complete oxygen dissociation curve (ODC). A newly developed in-vitro method will be used. On the first study day the blood samples will be exposed to three different concentrations of nitric oxide during the measurement, followed by two different vapourized prostacyclins. In addition, different concentrations of 5-hydroxymethylfurfural and alpha-ketoglutarate will be given to the blood samples for ODC recording. On the second study day the dose dependent effects of three different volatile anaesthetics will be investigated by exposing the blood samples to these drug while the measurements. Following these ODC recordings, aliquots of the blood samples will be frozen and investigated for storage related changes in HbO2 affinity.
Sex Differences in Sympathetic Activity and Vascular Reactivity During Acute and Chronic Hypoxia....
VasodilationVasoconstrictionThis study aims to investigate sex differences in blood pressure control associated with exposure to acute hypoxia (low oxygen), and short term acclimatization to hypoxia at high altitude.
Enhancing Cognition in Older Adults With Intermittent Hypoxia and Cognitive Training
AgingThe current study will investigate methods for enhancing cognitive training (CT) effects in healthy older adults by employing a combination of interventions facilitating neural plasticity and optimizing readiness for learning. Adults over the age of 65 represent the fastest growing group in the US population. As such, age-related cognitive decline represents a major concern for public health. Recent research suggests that cognitive training in older adults can improve cognitive performance, with effects lasting up to 10 years. However, these effects are typically limited to the tasks trained, with little transfer to other cognitive abilities or everyday skills. A pilot randomized clinical trial will examine the individual and combined impact of pairing cognitive training with an intermittent hypoxia (IH) intervention. The investigators will compare changes in cognitive and brain function resulting from CT combined with active IH versus CT combined with sham IH using a comprehensive neurocognitive, clinical, and multimodal neuroimaging assessment of brain structure, function, and metabolic state. Functional magnetic resonance imaging (FMRI) will be used to assess brain response during speed of processing; the active cognitive abilities trained by CT. Magnetic resonance spectroscopy (MRS) will assess cerebral metabolites, including ATP and GABA concentrations sensitive to neural plasticity.
Feasibility of a Music Therapy Intervention to Decrease Stress During Pediatric Critical Care
Critical IllnessHypoxia1 moreAdmission into a pediatric intensive care unit (PICU) is a highly stressful experience for child and family. High levels of stress can negatively impact outcomes, yet non-pharmacological interventions to decrease stress in the PICU are severely lacking. This is a prospective, single-arm feasibility trial that will explore the feasibility and acceptability of a music therapy intervention to decrease stress in the PICU among families of children receiving invasive or noninvasive mechanical ventilation. Objectives: The aims of this study are to: 1) Assess the feasibility of implementing a music therapy intervention in the PICU among children receiving invasive or non-invasive mechanical ventilation; 2) Determine the acceptability of the music therapy intervention in the ICU among caregivers, patients, and pediatric and cardiac ICU staff; 3) Explore the variability in child and caregiver stress outcomes throughout ICU admission. Hypothesis: The music therapy intervention will be feasible, as determined by recruitment, retention, protocol adherence, and data collection rates, and will be acceptable to participants and to PICU staff. Sample: This study will recruit 20 families that include children aged 2 months - 17 years old admitted with an expected length of ICU stay greater than 72 hours. Of these 20 families, the investigators will specifically recruit 10 families whose child is admitted for a hypoxic brain injury. Eligible children are receiving either noninvasive mechanical ventilation (i.e., continuous or bilevel positive airway pressure), invasive mechanical ventilation, or have an established tracheostomy tube and with escalated support settings. One primary caregiver will be enrolled along with the child admitted into the ICU.
Aerobic Interval Training in Patients With Chronic Obstructive Pulmonary Disease (COPD) and Hypoxemia...
Pulmonary DiseaseChronic Obstructive3 morePatients with severe Chronic Obstructive Pulmonary Disease (COPD) and low oxygen levels in the blood are at risk of developing pulmonary hypertension and strain on the right side of the heart, both of which are known to increase symptoms and worsen prognosis It is not fully established whether interval exercise training in patients with severe COPD and concomitant low oxygen levels is beneficial. This study aims to evaluate the effects of aerobic interval exercise training in patients with severe COPD and low oxygen levels in the blood, with a particular emphasis on such effects on the cardiovascular system and pulmonary circulation.
AT1R Blockade and Periodic Breathing During Sleep in Hypoxia
Sleep Disordered BreathingHypoxia2 moreSleep disordered breathing (SDB) is characterized by regular periods of no breathing (apnea) or low levels of breathing (hypopnea) and leads to repeated periods of low oxygenation, termed intermittent hypoxia that causes fluctuations in blood oxygen levels. This leads to increased peripheral chemoreflex sensitivity that is thought to occur through the stimulation of angiotensin-II, type-I receptors (AT1R) that are expressed primarily on glomus cells within the peripheral chemoreflex and ultimately results in long lasting hypertension. The goal of this study is to determine if AT1R receptor blockade can prevent the increase in chemoreflex sensitivity following one night of hypoxia and improve the severity of SDB.