116 Clinical Trials for Various Conditions
Twenty subjects (10 patients and 10 age-matched control volunteers) will be recruited for this study. MRI scans will take place on a 3T MRI Scanner (Skyra or Prisma, Siemens Medical Solutions) located at The NYU Center for Biomedical Imaging. MRI scans will consist of a 1-hour brain scan for both patients and controls. In the first 6 months of the study, investigators will develop and test a uMT-based APT imaging for brain tissue pH measurement and use a hypercapnia paradigm to validate the tissue pH changes between breathing room air and 5% CO2 (by increasing tissue acidity) inhalation. With implementation of hypercapnia MRI, pH-weighted imaging will be validated for its robustness and reproducibility.
Brown adipose tissue is poorly understood fat that can metabolize glucose in order to generate heat. Since activated brown fat has a high metabolic rate, it is of great interest as a potential target to combat obesity. However, the signaling and control of brown fat metabolism is poorly understood. Because brown fat uses glucose as its energy source, brown fat metabolism can be imaged with PET/CT using the positron emitting glucose analog F-18 FDG. We have recently shown in mice a striking circadian variation in brown fat metabolism as evidenced by changes in FDG uptake. In this study we endeavor to generate pilot data on a potential circadian variation in brown fat activation in healthy humans.
This study will use a technique called microperfusion to examine how thyroid hormones are involved in fat metabolism. The thyroid gland produces two kinds of hormones: T3 and T4. Some of the T4 is changed to T3 in various organs after leaving the thyroid. The T3 stimulates the body to burn fat. People have different rates at which they can change T4 to T3, and this may lead to differences in body fat among different people. Microperfusion is based on the exchange of substances across tiny holes of a small plastic tube called a "probe," which is inserted after numbing the skin over a fat pad. Through these openings, the fat pad is continuously rinsed with small amounts of fluid, and an exchange of substances occurs. The fluid drips from the other opening of the probe and is collected in a vial. Small amounts of study drugs are infused and the amount of substances released by the fat pad in response to them are measured. Healthy normal volunteers 18 years of age and older may be eligible for this study. Candidates are screened with a medical history, physical examination and blood tests. Participants undergo microperfusion. A needle is placed in an arm vein for collecting blood samples before and at the end of the experiment for measuring thyroid hormones and other substances in the blood. The skin over the fat pad next to the umbilicus (navel) is numbed and two microperfusion probes are inserted. A salt water solution is infused into the fat pad for one hour and the substances in the fluid are measured as the fluid leaves the fat pad. After 1 hour isoproterenol, a drug that aids in energy production by fat, is added to help determine the level of fat metabolism. After an additional hour small amounts of thyroid hormone are added to the fluid and samples are collected as they leave the body. Two catheters are inserted during each experiment. Small volumes of sterile fluid are circulated continuously in the tubing and samples are collected at regular intervals.
This is a pilot study to establish an arterial venous methodology to measure the activity of the TCA cycle or flux directly in tissues of human beings. It will also perform correlative studies to study the proteome, metabolome, oxygen consumption, carbon dioxide production and exosomes derived from the arterial venous supply of tissues with correlation to the TCA cycle activity.
We will perform blood sugar studies to assess changes in metabolic (biochemical processes that occur within us) profiles associated with high blood sugar and diabetes.
This is a single blinded, randomized, cross-over design. Up to 12 patients will be randomly administered a single 10.0 mCi dose of 123I-MIP-1072 or 123I-MIP-1095 (study drugs). The second (alternate) study drug will be administered approximately 14 days after the first. A final follow-up visit will occur approximately 2 weeks after the injection of the alternate study drug.
This study will examine whether fasting and non-fasting lipid measures can provide similar clinical information in order to guide lipid management by primary physicians. It will compare fasting vs. non-fasting lipid measurements in patients with and without diabetes.
Obstructive sleep apnea (OSA) is the most common type of sleep apnea and is caused by an obstruction of the upper airways. The obstruction results in periods of intermittent hypoxia and re-oxygenation, which lead to increased oxidative stress, increased inflammation, endothelial dysfunction, and insulin resistance. Chronic obstructive pulmonary disease (COPD) is a lung disease that leads to poor airflow. This disease leads to systemic hypoxia, reduced oxidative capacity, and increased inflammation. The direct cause of OSA and COPD is unclear, but OSA and COPD may be linked to other comorbid conditions such as obesity and type II diabetes. Upon onset of OSA and COPD, metabolic disturbances associated with obesity and type II diabetes can be exacerbated. Obesity is a condition characterized by an increase in visceral fat, elevated plasma levels of free fatty acids, inflammation, and insulin resistance. Although the effects of body fat distribution have not been studied in these patients, an increase in both subcutaneous and abdominal fat mass in non-OSA older women was shown to increase morbidity and mortality. Fat/adipose tissue is an active tissue capable of secreting proinflammatory cytokines such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-6, reactive oxygen species and adipokines. Particularly, abdominal fat is a prominent source of pro-inflammatory cytokines, which contributes to a low grade, chronic inflammatory state in these patients. Additionally, an increased inflammatory state is associated with reduced lean body mass, and together with elevated circulating free fatty acids may increase the occurrence of lipotoxicity and insulin resistance. Thus, increased fat deposition is associated with a poor prognosis in OSA and COPD patients and therefore it is of clinical and scientific importance to understand the changes in fat metabolism and digestion as a result of OSA and COPD. It is therefore our hypothesis that fat synthesis and insulin resistance is increased and whole body protein synthesis is decreased in OSA and COPD patients, leading to a poor prognosis.
With the introduction of effective anti-retroviral therapy (ART), HIV-infected persons can now survive for decades, but this success has been accompanied by an increased risk of developing metabolic disease and diabetes in HIV-infected persons compared to the general population. Recent studies from HIV-negative subjects have identified several associations between circulating immune cell populations and impaired glucose tolerance, including increased activated CD4+ and CD8+ T cells, and reduced regulatory T cells. Of note, these same changes in peripheral T cell subsets are frequently observed in patients with chronic HIV infection. The goal of this study is to assess whether the circulating T cell distribution is reflective of the adipose tissue T cell distribution, and to understand whether chronic adipose tissue T cell activation may impair adipocyte (i.e., fat cell) function and insulin sensitivity. If the investigators' hypotheses are correct, this will demonstrate that chronic peripheral immune activation (i.e., high memory T cells, low naïve cells, and increased expression of activation surface markers) is associated with greater adipose-resident CD4+ and CD8+ T cell expression of activation markers, adipose tissue inflammation, and insulin resistance.
This project investigates the anti-obesity mechanisms of glucagon-like peptide-1 (GLP-1) analogs, which are used in the treatment of human obesity and diabetes mellitus. The investigators will test if GLP-1 induces secretion of interleukin-6 (IL-6), a cytokine that may collaborate with GLP-1 analogs to induce the formation of brown fat, which has anti-diabetic properties. The results will guide future obesity and diabetes mellitus therapies.
The goal of this study is to provide a comprehensive evaluation of whole-body and tissue-specific glucose metabolism after consuming a mixed meal in lean people and people with obesity, before and after 20-35% weight loss induced by Roux-en-Y gastric bypass or sleeve gastrectomy surgery.
This study will determine the effects of supplementing beta-hydroxy-beta-methylbutyrate (HMB) on body composition and strength changes during weight loss. When overweight and obese persons lose weight, and in particular in conjunction with dietary restrictions, muscle, bone mass, and muscle strength are also lost. HMB has been shown to preserve muscle mass and strength, and it is thought that HMB may also preserve muscle, bone, and strength during weight-loss.
The purpose of this study is to determine if there is a difference in the short term response in serum folate after a single dose of folic acid in normal weight and obese women of childbearing age.
Vitamin D is a fat soluble vitamin that has important effects on calcium (including absorption of calcium from the diet) and bone metabolism. Vitamin D is known to be stored in fat tissue, and it is also present in the circulation. The purpose of this study is to investigate the relationship between levels of vitamin D in fat tissue and in blood.
St. John's Wort is a popular dietary supplement that many people take to elevate mood or relieve stress. This study will test in normal volunteers whether this preparation may alter mood and if so, by what means. Animal studies suggest that St. John's Wort may work similarly to some antidepressants that affect levels of the chemical serotonin in the brain. Participants in this study must also be enrolled in NIMH protocol #98-M-0094 (SPECT Imaging of Dopamine and Serotonin Transporters in Neuropsychiatric Patients and Normal Volunteers) and protocol #91-M-014 (MRI Imaging of Neuropsychiatric Patients and Controls). Separate consent forms are required for each study. Candidates will undergo medical and psychiatric evaluations that may include blood and urine tests, electroencephalogram and electrocardiogram. Normal volunteers will have a mood assessment at the beginning of the study. They will then be randomly assigned to take either placebo (a pill with no active ingredient) or St. John's Wort 3 times a day for 2 weeks, and will be told what they are taking. After an 11-week hiatus, they will again start treatment on the same schedule, but will not be told which preparation they are receiving. Each evening during the 2-week treatment periods, subjects will complete a brief self-rating mood assessment questionnaire. At the end of each treatment period, they will undergo SPECT brain imaging (a type of CT scan) to determine dopamine and serotonin distribution and density in the brain. For this procedure, study subjects take three drops of potassium iodide solution within 24 hours before the scan and two drops nightly for 3 days following the procedure. About 10 ml (less than two teaspoons) of blood are drawn before a radioactive tracer is injected. SPECT imaging is done the next day. After about 1 hour of imaging, subjects are given either a placebo or St. John's Wort, and then imaging continues for another 2 hours. During the procedure, up to five blood samples of 6 ml each may be drawn. At some point during the study, a MRI scan of the brain will be done.
Brain cells communicate with each other by releasing chemicals called neurotransmitters. In order for brain cells to transfer information, one cell will release a neurotransmitter that will be recognized by a receptor located on surface of another cell. One such neurotransmitter is dopamine. Abnormal dopamine transmission has been seen in patients with substance abuse and different neuropsychiatric disorders including schizophrenia. A radioactive drug called IZBM (I-123 iodobenzamide) can also bind to certain dopamine receptors. IZBM can be seen by Single Photon Emission Tomography (SPECT). Therefore, by using IZBM and SPECT scans, researchers can find and "map" the location of dopamine receptors in the brain. Patients participating in this study must also have been selected for other genetic studies being conducted at the NIMH. Patients with schizophrenia will be selected from a NIMH research study titled, "Neurobiological Investigation of Patients with Schizophrenia Spectrum Disorders and Their Siblings" (95-M-0150). Normal patient volunteers will be selected from another NIMH study titled, "Inpatient Evaluation of Neuropsychiatric Patients" (89-M-0160). All aspects of clinical care and genetic analysis of these patients will be covered in these studies, while information pertaining to IBZM SPECT scans will be covered in this study. This study will not directly benefit patients participating in it. However, information gathered may contribute to faster and more accurate diagnosis of schizophrenia and eventually better treatment for the disorder.
Researchers plan to study the fat-rich particles, called lipoproteins, which circulate in the blood. This study is designed to improve understanding of normal, as well as abnormal, lipoprotein metabolism and the role it plays in the development of hardening of the arteries (atherosclerosis). Patients participating in this study will receive an intravenous (directly into the vein) injection of a small amount of specially prepared amino acids. The amino acids being injected are the same amino acids present in a normal diet. The amount of amino acid given will be less than the amount eaten in a protein-rich meal. The amino acids will be labeled with nonradioactive heavy isotopes which are also present in the environment n low amounts. Patients participating in the study will be required to have blood samples taken, and provide urine samples throughout the course of the study. In addition, patient will be required to follow a specially formulated diet. Patients will be weighed throughout the course of the study.
Researchers plan to study the fat-rich particles, called lipoproteins, which circulate in the blood. This study is designed to improve understanding of normal, as well as abnormal, lipoprotein metabolism and the role it plays in the development of hardening of the arteries (atherosclerosis). Patients participating in this study will receive injections of lipoproteins or apolipoproteins (the protein component of lipoproteins) that have been isolated and purified. These lipoproteins will be labeled with small amounts of radioactive material and sterilized before they are injected into the patient. Patients participating in the study will be required to have blood samples taken, and provide urine samples throughout the course of the study. In addition, patient will be required to follow a specially formulated diet. Patients will be weighed throughout the course of the study....
Background: The body uses energy from calories for basic functions like breathing and digesting food. Over time, when a person eats more calories than they burn, they may become overweight or obese. Obesity is a major health concern. Researchers want to look at fat and muscle tissue to learn more about metabolism. That is how the body uses food and other nutrients for normal function and energy. This research may help to develop new treatments for obesity and related diseases. Objective: To learn more about the role of fat and muscle in metabolism, particularly how fat and muscle store and use energy. Eligibility: Adults 18 years and older who have a planned surgery at NIH in which tissue can be collected by the surgeon. Design: Participants will be screened by their regular NIH doctor. Then researchers will contact them about this study. Participants will not have to make extra visits to NIH for this study. Researchers will collect samples during the participant s surgery. These will be fat tissue and skeletal muscle tissue. Muscle tissue will only be taken from tissue that is going to be discarded. Collecting the tissue will not add any time or any extra incisions than what is required for the surgery. After surgery, blood will be drawn. Some participants will have this done in the pre-op or post-op room. Others will have this done during their hospital stay.
The goal of this study is to define the effect of aging on brown adipose tissue mass in a cohort of older sedentary and older athlete adults.
The purpose of this study is to compare the vascular permeability of blood vessel walls (of the carotid artery) in pre-menopausal women who have metabolic syndrome (syndrome of having at least 3/5 following features- increased abdominal fat, low good cholesterol (HDL-C), elevated fasting blood fats (triglycerides), elevated blood pressure, an elevated fasting glucose) versus those women who are normal weight and with normal cholesterol, blood fats, blood pressure, and blood sugar. We are using a novel technology to measure vascular permeability known as dynamic contrast enhancement magnetic resonance imaging (DCE-MRI). The primary variable is ktrans ratio which is a mathematically derived quantity obtained from DCE-MRI. We are trying to identify novel markers of early atherosclerosis in young women.
Abnormalities in the re-uptake of dopamine and serotonin have been described in various neuropsychiatric disorders and substance abuse. \[I-123\] Beta-CIT is a recently developed radioligand for SPECT imaging of dopamine and serotonin transporters. \[I-123\]Beta-CIT SPECT has been used at the SPECT-lab of the Clinical Brain Disorders Branch in over fifty subjects without adverse events. Due to the trace concentrations used, a pharmacological effect of Beta-CIT is unlikely and has not been observed. The purpose of this study is to use Beta-CIT and SPECT to study the expression of dopamine and serotonin transporters in vivo in normal controls and various patient populations to address hypothesized abnormalities of the transporters in different disorders and to understand the effects of genetic variations in the genes of these transporters on their in vivo expression.
The purpose of this study is to measure the effects of a single session of exercise on changes in the cellular composition of the body fat of humans.
The purpose of this clinical investigation is to evaluate the safety and efficacy of Amnion/Chorion/Amnion allograft , Amnion/Chorion allograft, and/or Amnion/Amnion allograft, plus Standard of Care (SOC) each versus SOC alone in the treatment of chronic non-healing diabetic foot ulcers (DFU) after 12 weeks of treatment.
People who experience repeated bouts of circadian misalignment, such as shift workers, are at higher risk of cardiovascular disease (CVD) and Type 2 diabetes (T2D) compared to daytime workers. However, the mechanism(s) by which shift work and associated circadian misalignment increase CVD and T2D risk are unknown. This project will examine whether elevated plasma lipids are a mechanism by which circadian misalignment impairs vascular function, insulin sensitivity, glucose homeostasis and muscle lipid accumulation, which could be targeted to prevent and treat cardiometabolic disease in people who chronically experience circadian misalignment, which includes more than 20% of the US workforce.
The purpose of this project is to validate a new combined MRI and PET imaging technique as a biomarker or measure of glycolysis in brain tumors. To accomplish this, the investigators propose obtaining image-guided measures of tissue pH and biopsied tissue in tumor areas selected for bulk resection surgery. Investigators will then correlate the imaging measurements with pH, RNA expression, protein expression, and bioenergetics measurements of key glycolytic enzymes.
Caloric restriction has beneficial metabolic effects in humans including weight loss and improvement in blood pressure and lipid levels. Intermittent fasting has emerged as a popular alternative to caloric restriction as it does not require daily adherence to a dietary protocol, but whether the benefits of fasting protocols are dependent on weight loss is not known. In this study, the investigators will explore the metabolic effects of fasting and evaluate whether these effects, including negative effects on bone metabolism, are independent of weight loss.
Background: Scientists have long used simple measures (such as height and weight) to estimate how much a person s body uses food (calories) as energy, as commonly called the metabolic rate. But metabolism varies among people with similar body sizes. Scientists now believe the old formulas for estimating metabolic rates may not work well for all people. Researchers want to find more accurate ways to measure a person s metabolism. Objective: This natural history study will examine the relationships between metabolism, body composition, and body surface area in a wide range of people. Eligibility: Healthy children and adults aged 2 years or older. Also, people aged 2 years or older with conditions that may alter metabolism. These may include diabetes, obesity, renal disease, or cancer. Design: Participants will spend 2 days and 1 night in the hospital. They will provide a medical history and answer questions about their activity levels, the foods they eat, and their lifestyle. They will also eat a special diet. Participants will undergo many tests: They will lie in a bed with a clear hood covering their head for 30 to 45 minutes to measure the gases in their breath. They will lie on a padded table for about 15 minutes while their body is scanned. They will stand on a platform while a 3D scanner measures their body. They will have a test to measure how fast an electric signal moves through their body. They will grip an instrument to measure the strength of their hands. They will drink salty water and provide blood and urine samples. Participants may be invited to return for these 2-day visits up to 8 times per year. Return visits must be at least 2 weeks apart.
The purpose of this study is to identify early cardiovascular disease risk factors in those with "normal-weight obesity" (i.e., normal body, but high body fat percentage) that better track with their long-term cardiovascular disease risk.
The purpose of this study is to determine the effects of a single bout of exercise on changes in the genes and small molecules in blood and fat tissue, before and after a bout of exercise. This research may contribute to a better understanding of the beneficial effects of exercise on the body.