All Clinical Trials

Several studies have reported that diabetic subjects have lower plasma vitamin C concentrations than non-diabetic subjects. Although urinary vitamin C loss in diabetic subjects was reported to be increased in two studies, these are difficult to interpret due to lack of controlled vitamin C intake, inadequate sampling, lack of control subjects, or methodology uncertainties in vitamin C assay and sample processing. Consequently, it is unclear whether diabetic subjects truly have both low plasma and high urine vitamin C concentrations. We propose that low plasma vitamin C concentrations in diabetic subjects are due in part to inappropriate renal loss of vitamin C in these subjects but not in healthy controls. We will study nondiabetic controls and cohorts with diabetes. Vitamin C concentrations in plasma, RBCs, and urine will be measured in outpatients. In those willing to be admitted to the Clinical Center, we will measure vitamin C pharmacokinetics to determine the relative bioavailability for vitamin C in individuals with and without abnormal urinary loss of vitamin C (or renal leak). Single nucleotide polymorphisms (SNPs) will be determined in genomic DNA responsible for the two proteins mediating sodium dependent vitamin C transport, SVCT1 and SVCT2. We will also explore mechanisms underlying abnormal urinary vitamin C loss.... Read Less

This study will collect blood plasma and white blood cells from individuals using a procedure called apheresis. Apheresis is a method of collecting larger quantities of certain blood components that can safely be collected through a simple blood draw. The blood components will be used in laboratory research studies. Patients 18 years of age and older who are currently enrolled in a NIH clinical research protocol may participate in this study. Relatives of patients and normal healthy volunteers will also be enrolled. Individuals will undergo one of the following two apheresis procedures: * Automated pheresis Blood is drawn through a needle placed in an arm vein and circulated through a cell separator machine. The plasma (liquid part of the blood) and white cells are extracted, and the red cells are re-infused into the donor through the same needle or a needle in the other arm. An anticoagulant (medication to prevent blood from clotting) is usually added to the blood while in the machine to prevent it from clotting during processing. * Manual pheresis One unit (1 pint) of blood is drawn through a needle placed in an arm vein, similar to donating a pint of whole blood. The red blood cells, with or without plasma, are separated from the rest of the blood and returned to the donor through the same needle. Manual pheresis will be done only when a person s estimated total blood volume or red cell count is too low to safely permit removal of blood through a pheresis machine. An adult small in size or markedly anemic, for example, may fall into this category. Some of the blood collected through apheresis may be stored for future studies of HIV disease and immune function and for HLA testing, a genetic test of markers of the immune system. Some of the blood may be used to screen for different types of viral liver infections, such as hepatitis A, B, C, D, E, F, or G. ... Read Less

Background: - National Institute on Aging researchers are looking at studies that require large numbers of white blood cells for lab use. Standard blood samples do not provide enough white blood cells for these studies. Researchers want to use cytapheresis to collect white blood cells from volunteer donors. This procedure can collect larger amounts of white blood cells and reduce the amount of fluid and other cells that are lost. Objectives: - To use cytapheresis to collect white blood cells for study. Eligibility: - Healthy blood donors at least 18 years of age. Design: * Participants will be screened according to the usual blood donation procedures. * Participants will provide white blood cells through cytapheresis. The blood cells will be collected in a machine that separates the white blood cells from the rest of the blood. The rest of the blood will be returned to the donor. * Participants may have this type of donation every 56 days (six times per year). They will be asked to become a repeat donor. A donation schedule may be set up. * Once a year, participants will have blood tests to continue to be eligible as a donor. Read Less

This study is not a treatment protocol and no experimental treatments are involved. Study participants may be seen as needed for clinical, translational and basic research studies, or as medically indicated. Subjects will receive their general medical care outside the NIH and will be seen at our clinic or at CNHS with varying frequency. Subjects may be seen for multiple visits. Subjects may be asked to return for additional testing as needed. Clinical care for patients with sickle cell disease will be provided as appropriate through the Sickle Cell Clinic and the inpatient clinical center.... Read Less

There is a variety of tumors affecting the pituitary gland in childhood; some of these tumors (eg craniopharyngioma) are included among the most common central nervous system tumors in childhood. The gene(s) involved in the pathogenesis of these tumors are largely not known; their possible association with other developmental defects or inheritance pattern(s) has not been investigated. The present study serves as a (i) screening/training, and, (ii) a research protocol. As a screening and training study, this protocol allows our Institute to admit children with tumors of the hypothalamic-pituitary unit to the pediatric endocrine clinics and wards of the NIH Clinical Center for the purposes of (i) training our fellows and students in the identification of genetic defects associated with pituitary tumor formation, and (ii) teaching our fellows and students the recognition, management and complications of pituitary tumors As a research study, this protocol aims at (i) developing new clinical studies for the recognition and therapy of pituitary tumors; as an example, two new studies have emerged within the context of this protocol: (a) investigation of a new research magnetic resonance imaging (MRI) tool and its usefulness in the identification of pituitary tumors, and (b) investigation of the psychological effects of cortisol secretion in pediatric patients with Cushing disease. Continuation of this protocol will eventually lead to new, separate protocols that will address all aspects of diagnosis of pituitary tumors and their therapy in childhood. (ii) Identifying the genetic components of pituitary oncogenesis; those will be investigated by (a) studying the inheritance pattern of pituitary tumors in childhood and their possible association with other conditions in the families of the patients, and (ii) collecting tumor tissues and examining their molecular genetics. As with the clinical studies, the present protocol may help generate ideas for future studies on the treatment and clinical follow up of pediatric patients with tumors of the pituitary gland and, thus, lead to the development of better therapeutic regimens for these neoplasms.... Read Less

Background: - Atopic dermatitis, or eczema, is a chronic skin disorder. Patients sometimes have infections with S. aureus bacteria. Researchers want to study how eczema treatments affect the number and the type of bacteria on the skin. Objectives: - To study the effect of eczema treatments on skin bacteria. Eligibility: * Individuals between 2 and 25 years of age who have moderate to severe atopic dermatitis. * Healthy volunteers between 18 and 40 years of age with no history of eczema. Design: * Participants will be screened with a physical exam and medical history. Research samples will be collected. Skin biopsies may also be performed. * All participants will be assigned to one of several study groups. * Healthy volunteers must not have taken antibiotics in the year before the start of the study. * All participants will have regular study visits during their 1-year participation. More research samples will be collected at these visits. * Healthy volunteers may be asked to come in for a one-time follow up after the 1 year mark. Read Less

Background: - Lab studies help researchers better understand cancer biology. This information may lead to new methods for diagnosing or treating cancer. To develop these studies, researchers want to collect samples from people with cancer or precancer conditions of the lymph system. These conditions include multiple myeloma, different types of lymphoma, and adult leukemia/lymphoma. The samples collected will include blood, urine, bone marrow, and tumor and skin tissue. Objectives: - To collect tissue samples to study different types of lymph cancer. Eligibility: - Individuals at least 18 years of age who have a lymphoid cancer or precancer condition. Design: * Participants will be screened with a physical exam and medical history. * Different samples will be collected for study. Blood samples will be collected at the initial testing. More blood samples will be collected at different treatment points. Other liquid samples include urine, bone marrow, and any abnormal fluid. Tumor tissue and skin tissue biopsies will also be collected for study. * Treatment will not be provided as part of this study. Read Less

Background: - Progressive multifocal leukoencephalopathy (PML) is a severe viral infection of the brain. It is caused by JC virus. Many people have this virus in their bodies all their life, but it is usually kept in check by their immune system. If the immune system does not work right because of a disease or medication, the virus becomes active and can damage cells in the brain. Not much is known about PML or how it affects the immune system. Researchers want to study people with PML to better understand the natural history of the disease. Objectives: - To study the natural history of PML. Eligibility: - Individuals at least 2 years of age who have PML. Design: * Participants will be screened with a physical exam, medical history, and imaging studies. * Participants will have several visits to the National Institutes of Health Clinical Center. There will be an initial visit, monthly visits for the next 6 months, a 12-month visit, and possible visits afterward. * At the initial visit, participants will give blood, urine, and spinal fluid samples. They will also have neurological tests and imaging studies of the brain. * For the next five visits, participants will give blood and urine samples. They will also have neurological tests and imaging studies of the brain. * The 6-month and 12-month visits will repeat the tests from the initial visit. * Other optional procedures include bone marrow samples and skin biopsies. Additional blood tests and imaging studies may be performed. * Treatment will not be provided as part of this study. Read Less

The goal of this study is to develop better methods of diagnosis, localization, and treatment for pheochromocytomas. These tumors, which usually arise from the adrenal glands, are often difficult to detect with current methods. Pheochromocytomas release chemicals called catecholamines, causing high blood pressure. Undetected, the tumors can lead to severe medical consequences, including stroke, heart attack and sudden death, in situations that would normally pose little or no risk, such as surgery, general anesthesia or childbirth. Patients with pheochromocytoma may be eligible for this study. Candidates will be screened with a medical history and physical examination, electrocardiogram, and blood and urine tests. Study participants will undergo blood, urine, and imaging tests, described below, to detect pheochromocytoma. If a tumor is found, the patient will be offered surgery. If surgery is not feasible (for example, if there are multiple tumors that cannot be removed), evaluations will continue in follow-up visits. If the tumor cannot be found, the patient will be offered medical treatment and efforts to detect the tumor will continue. Main diagnostic and research tests may include the following: 1. Blood tests - mainly measurements of plasma or urine catecholamines and metanephrines as well as methoxytyramine. If necessary the clonidine suppression test can be carried out. 2. Standard imaging tests - Non-investigational imaging tests include computed tomography (CT), magnetic resonance imaging (MRI), sonography, and 123I-MIBG scintigraphy and FDG (positron emission tomography) PET/CT. These scans may be done before and/or after surgical removal of pheochromocytoma. 3. Research PET scanning is done using an injection of radioactive compounds. Patients may undergo 18F-FDOPA, 18F-DA, as well as 68Ga-DOTATATE PET/CT . Each scan takes up to about 2 hours. 4. Genetic testing - A small blood sample is collected for DNA analysis and other analyses.... Read Less

The purpose of this investigation is to develop improved magnetic resonance imaging (MRI) techniques and hardware for studying brain function. MRI is a diagnostic tool that provides information about brain chemistry and physiology. This study will evaluate new MRI methods for monitoring blood flow to regions of the brain in response to simple tasks. The MRI machine used in this study is more powerful than those in most hospitals, permitting a higher visual resolution. Normal healthy volunteers over 18 years old may be eligible for this study. Candidates will be screened with a medical history and questionnaire, and a neurological examination. Study participants will have a yearly MRI scan. For this procedure, the subject lies on a stretcher that is moved into a donut-shaped machine with a strong magnetic field. A lightweight circular or rectangular coil a device that improves the quality of the images may be placed on the head. The scan time varies from 20 minutes to 3 hours; most scans last between 45 and 90 minutes. During the scan, the subject may perform simple tasks, such as listening to tapes, tapping a finger, moving a hand, watching a screen, or smelling a fragrance. More complex tasks may require thinking about tones or pictures and responding to them by pressing buttons. Information from this study will be used to develop better imaging methods that will, in turn, permit a greater understanding of normal and abnormal brain behaviors. Read Less

This study will provide follow-up evaluation and care of patients who have undergone allogeneic (donor) stem cell transplantation at the NIH Clinical Center. Patients are monitored for their response to treatment, disease relapse, and later-occurring effects of the transplant. Patients between 10 and 80 years of age who received a donor stem cell transplant at the NIH Clinical Center under an NHLBI protocol may be eligible for this study. Candidates must have had their first transplant at least 3 years before entering the current study. Participants are generally seen in the clinic every 12 months for some or all of the following procedures: * Periodic physical examinations, eye examinations, and blood and urine tests. * Bone marrow aspiration and biopsy: A sample of bone marrow is obtained for microscopic examination. The patient is given local anesthesia or conscious sedation. An area of the hipbone is numbed, a thin needle is inserted through the skin into the bone, and a small amount of marrow is withdrawn. * Tissue biopsy: A small piece of tissue or tumor is obtained for microscopic examination. Depending on the site of the biopsy, the tissue may be removed using a cookie cutter-like "punch" instrument, a needle, or a knife. The area is numbed and the tissue is removed with the appropriate tool. * Imaging tests to visualize organs, tissues, and cellular activity in specific tissues. For these tests, the patient lies on a table that slides into the scanner. They may include the following: 1. Nuclear scans use a sensitive camera to track a small amount of radioactive material (radioisotope) that is given to the patient by mouth or through a vein. The scan may show abnormal areas of tissue in the bones, liver, spleen, kidney, brain, thyroid, or spine. 2. Magnetic resonance imaging (MRI) uses a magnetic field and radio waves to examine small sections of body organs and tissues. 3. Computerized tomography (CT) uses x-rays and can be done from different angles to provide a 3-dimensional view of tissues and organs. 4. Positron emission tomography (PET) uses a fluid with a radioisotope attached to it to show cellular activity in specific tissues. The fluid is given through a vein and travels to the cells that are most active (like cancer cells), showing if there is an actively growing tumor. * Pulmonary (lung) function tests: The patient breathes into a machine that measures the volume of air the person can move into and out of the lungs. * Heart function tests may include the following: 1. Electrocardiogram (EKG) evaluates the electrical activity of the heart. Electrodes placed on the chest transmit information from the heart to a machine. 2. Echocardiogram (Echo) is an ultrasound test that uses sound waves to create an image of the heart and examine the function of the heart chambers and valves. 3. Multiple gated acquisition scan (MUGA) is a nuclear medicine test that uses a small amount of radioactive chemical injected into a vein. A special scanner creates an image of the heart for examining the beating motion of the muscle. Disease relapse or progression, or transplant-related problems may be treated with standard medical, radiation, or surgical therapy, or patients may be offered experimental therapy. ... Read Less

Background: Influenza (flu) is a contagious respiratory illness caused by viruses. Flu symptoms can range from mild to severe, and the illness can be fatal. Vaccines help the body learn to prevent or fight infections such as flu. Some vaccines are combined with adjuvants. Adjuvants are special salts or fats that help vaccines work better. Researchers are looking for ways to make flu vaccines more effective. Objective: To test a new flu vaccine with and without a new adjuvant. Eligibility: Healthy adults aged 18 to 50. They must have had at least 1 flu vaccine since 2020. Design: Participants will have 12 clinic visits over 15 months. The vaccine is given as an injection into the muscle of the upper arm. Participants will be vaccinated during 2 visits spaced 4 months apart. Half will receive just the vaccine; half will receive the vaccine plus the adjuvant. They will be monitored for at least 30 minutes after each shot. Participants will keep a diary for 7 days after each shot. They check their temperature every day and record any symptoms. Participants will have 10 follow-up clinic visits plus 4 phone calls. They will have 4 to 10 tablespoons of blood drawn at each clinic visit. Fluid samples will be collected from their nose and mouth. They will be checked for any health changes. Participants may opt to undergo apheresis: Blood will be taken from the body through a needle inserted into a vein. The blood will pass through a machine that separates out the white blood cells. The remaining blood will be returned to the body through a different needle. Read Less