Background: Blood disorders like sickle cell disease and malaria affect many people around the world. Researchers want to learn more about blood disorders. To do this, they need to collect biological samples from people with blood disorders. They also need to collect samples from healthy people. Objective: To collect samples to use for research on blood disorders. Eligibility: People ages 18-70 who have blood disorders. Healthy volunteers without blood disorders are also needed. Design: Participants will be screened with a medical history, physical exam, and blood and urine tests. Participants will give one or more samples. They will give them over 5 years. They can choose not to give any of the samples: Saliva: Participants will spit into a tube. They may also have the inside of their mouth swabbed. Urine: Participants will urinate into a cup. Blood and blood waste products: Blood will be taken through a needle in the participant s arm. Fat samples: An area on the participant s belly or buttock will be numbed. A small cut will be made into the skin and a small piece of fat removed. Mucus and cells from the lungs: The participant will be sedated. A flexible tube will be inserted through the nose or mouth into the lung airways. These participants will also have a physical exam, chest x-ray, and heart tests after the procedure. ...

Type: Observational

Start Date: Sep 2019

open study

Background: Researchers use mixed meal tolerance tests (MMTTs) to look at how people s bodies respond to eating a meal. However, researchers do not agree on how to decide the number of calories to give in each meal. Some use fixed meals, which are the same size for everyone, and some use adjusted meals, based on the size of the person s body. Researchers want to know which MMTT is best to use for future research. Objective: To learn how fixed vs adjusted meals affect blood glucose levels in healthy people. Eligibility: Healthy people aged 18 years or older. Design: Participants will have 3 or 4 clinic visits of up to 8 hours in 8 weeks. Participants will have baseline tests: Their height, weight, and waist size will be measured. They will have an oral glucose tolerance test: A needle attached to a tube (IV) will be inserted into a vein in the arm. They will have a sugary drink. Blood samples will be taken from the tube at intervals up to 3 hours after the drink. They will have a body scan. Participants will have 2 MMTT visits. One will include a fixed meal and one will include an adjusted meal. They will have tests at both visits: Resting metabolic rate: A clear hood will be placed over the participant s head while they rest for 20 minutes. This will measure the oxygen they breathe in and out. MMTT. Participants will have 5 minutes to drink a liquid meal. Blood samples will be taken at intervals for the next 4 hours....

Type: Interventional

Start Date: Aug 2024

open study

Background: Major depressive disorder (MDD) is a psychiatric condition. People with MDD have occasional bouts of depressive symptoms; these bouts are called major depressive episodes (MDEs). Researchers want to know if people having MDEs have lower levels of an enzyme called PDE4B in their brains. Primary Objective: To determine whether PDE4B is reduced in the brains of individuals with MDD experiencing a major depressive episode (MDE). Secondary Objectives: To determine the optimal length of scanning and the retest variability and reliability of [18F]PF-06445974, and whether PDE4B binding correlates with clinical rating scales. To measure if PDE4B radioligand binding can be blocked by taking apremilast. Eligibility: People aged 18-70 years with MDD. Healthy volunteers are also needed. Design: Participants will have up to 5 clinic visits. Participants will be screened. They will have a physical exam with blood tests. They will have a test of their heart function. Some participants may have a psychiatric assessment; they will answer questions about their state of mind and related topics. Participants will have magnetic resonance imaging (MRI) of the brain. They will lie on a table that slides into a metal cylinder. Participants will have a positron emission tomography (PET) scan. A needle will be used to guide a thin plastic tube (catheter) into a vein in one arm. An experimental substance called a radioactive tracer ([18F]PF-06445974) will be injected through the catheter. Participants will lie on a table that slides into a doughnut-shaped machine. The scan will last up to 4 hours with a 15-minute break. Participants blood pressure, heart rate, and breathing will be monitored before, during, and after the PET scan. A second catheter will be inserted in the artery of the wrist so blood can be drawn during the scan. Some participants may return for a second PET scan; have a lung scan or receive apremilast. https://nimhcontent.nimh.nih.gov/start/surveys/?s=KE88DXXPLDFHHTF8

Type: Interventional

Start Date: Jun 2023

open study

Background: About 5 million adults in the U.S. have Alzheimer s disease or another adult-onset neurodegenerative disorder. Many studies have found that inflammation in the brain contributes to these diseases. Researchers want to find a better way to measure this inflammation. Objective: To learn whether COX-1 and/or COX-2 is elevated in the brains of individuals with neurodegenerative brain disease compared to healthy volunteers. Eligibility: Adults age 18 years and older in good general health who have an adult-onset neurodegenerative dementia, such as AD, FTD, corticobasal syndrome, Huntington s disease, or MCI, ALS and healthy adult volunteers enrolled in protocols 01-M-0254 or 17-M-0181. Design: Participants will be screened with medical history, physical exam with vital signs, and lab tests. They will have a neuropsychological testing. Their heart function will be measured. Participants will have a magnetic resonance imaging (MRI) scan. The MRI scanner is a metal tube surrounded by a strong magnetic field. Participants will lie on a table that slides in and out of the tube. The machine makes noise. Participants will get earplugs. Participants will have 2 PET scans. They will be injected with the study drugs through an intravenous catheter placed in an arm vein. The PET scanner is shaped like a doughnut. Participants will lie on a bed that slides in and out of the scanner. A plastic mask will be molded to their head to keep them from moving. A thin plastic tube will be put into an artery at the wrist or elbow crease area. This will be used to draw blood during the scan. Participants will have 2-5 study visits. Participation lasts 1 week to 4 months, depending on scheduling.

Type: Interventional

Start Date: Aug 2021

open study

Background: Influenza (flu) infections are a serious global health threat. Each year, between 3 and 5 million people get the flu, and up to 500,000 die from it. Current vaccines protect against seasonal flus, but broader vaccines are needed to protect against potential flu pandemics. Objective: To test an experimental flu vaccine. Eligibility: Healthy people aged 18 to 55 years. Design: The study will last 5 to 8 months and has 2 phases, A and B. The study vaccine will be given either as a shot in the arm or as a nasal spray. Participants will receive 1 of 3 combinations: (1) study vaccine in the nose and placebo in the arm; (2) placebo in the nose and study vaccine in the arm; or (3) placebo in the nose and placebo in the arm. A placebo is just like the real vaccine but contains no active ingredients. Phase A: Participants will have 5 clinic visits over 56 days. They will receive a shot and a nasal spray at 2 of the visits, 28 days apart. At each visit, they will have a physical exam, with tests of their blood, urine, and nasal secretions. They will check their temperature at home and record any symptoms for 7 days after each vaccine. Phase B: Participants will stay in the hospital for at least 9 days. They will be infected with a flu virus. They will provide blood, urine, and nasal fluid samples. They will have tests of their heart function. They will remain in the hospital until they test negative for the flu 2 days in a row. They will have 2 follow-up visits, 4 and 8 weeks after leaving the hospital. ...

Type: Interventional

Start Date: Aug 2026

open study