Healthy Clinical Trials

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

Background: - Magnetic resonance imaging (MRI) scans must be performed according to specified sets of parameters that provide optimal images of each organ and each area of the body. These scanning parameters are often specific to the institution or organization at which they are employed, and may also depend on the manufacturer of the MRI scanning equipment. Because MRI scanning equipment is always being updated and upgraded, researchers are interested in developing new and optimized scanning parameters for MRI scans. Objectives: - To improve current methods and develop new techniques for magnetic resonance imaging. Eligibility: * Individuals 18 years of age and older who are either volunteers or current NIH protocol participants. * Participants must not have any medical history factors (e.g., extreme claustrophobia, history of metal implants) that would prevent them from receiving MRI scans. Design: * Participants will have at least one MRI scan that will last from 20 minutes to 2 hours (most scans will last between 45 and 90 minutes). The total time commitment for most visits will be approximately 4 hours from start to finish. * Some MRI techniques require standard monitoring equipment or specific procedures during the scanning, such as an electrocardiogram. * Participants will have blood samples taken at the time of the scan. Some MRI studies will require the use of a contrast agent that will be administered during the scan. * Volunteers may be asked to return for additional MRI scans over the course of a few years. Follow-up scans may be done on the same part of the body or on different parts of the body. No more than one MRI scan will be performed in any 4-week period for this protocol. Read Less

Background: Many tasks people do every day require a series of individual movements. Control over these movements is called motor skills. But even highly skilled people can make mistakes. Researchers have found that they can predict when a person will make a mistake 0.1 second before it happens. Now, they want to find out if they can increase that time up to 1 second-long enough to warn the person and prevent the mistake. Objective: To see if motor skill errors can be detected up to 1 second before they occur. Eligibility: Right-handed healthy adults aged 18 to 35. Design: Participants will have 2 to 5 study visits. Each visit will be 1 to 2 hours. They will have a physical and neurological exam. They will have 1 or 2 magnetic resonance imaging (MRI) scans. They will lie on a table that slides into a large cylinder. The MRI uses strong magnets to capture images of the inside of the body, including the brain. They will have another scan, called magnetoencephalography (MEG). Small metal disks attached to wires will be taped to their head. Participants will sit in a padded chair with their head inside of a helmet. The helmet will not cover their eyes or face. Participants will perform a series of typing tasks on a keyboard. They will have short breaks between each round. Their head movements will be tracked, and their eye and finger movements will be videotaped. Read Less

The main purpose of this study is to assess how olomorasib gets into the blood stream and how long it takes the body to remove it when administered to participants with mild, moderate and severe impaired liver function compared to participants with normal liver function. The safety and tolerability of olomorasib will also be evaluated. The study may last up to 6 weeks for each participant including the screening period. Read Less

The goal of this study is to learn how belzutifan (MK-6482) affects the levels of metformin in a healthy person's body over time. Researchers will study levels of metformin in the blood and urine in healthy volunteers after taking metformin alone (Period 1) and metformin with belzutifan (Period 2). Read Less

Researchers are looking for new medicines to prevent Human Immunodeficiency Virus Type 1 (HIV-1) infection. HIV-1 is the most common type of HIV, which is a virus that attacks cells of the immune system. Medicines to prevent HIV-1 infection are called pre-exposure prophylaxis (PrEP). Some people may have trouble following a PrEP plan because it involves either taking medicine everyday by mouth or getting injections (shots) often. MK-8527 is a study medicine designed to prevent HIV-1 infection. MK-8527 is different from standard (usual) PrEP because it is taken once a month, by mouth, as a tablet. The goal of this study is to learn if taking a higher-than-normal dose of MK-8527 increases the QT interval (a measure of heart rhythm) by a certain amount. Read Less

In a neuroimaging session, study participants will repeatedly and intermittently report the content of their ongoing, self-generated experiences based on an experience-sampling protocol in which self-report ratings will be triggered based on real-time analysis of the participant's current brain state. The protocol will be conducted while participants are undergoing MRI scanning. Read Less

The purpose of this study is to learn about the safety of the study medicine called PF-08049820 in healthy adults. The study will also see: * how the body processes the study medicine and * if food affects the amount of study medicine in the blood. The study medicine is developed for the treatment of moderate to severe atopic dermatitis, also known as eczema. People with this condition may have severe itching and rashes on the skin. The study is seeking participants who: 1. Are males or females who can no longer have children. 2. Are 18 to 65 years old. 3. Have a body mass index (BMI) of 16 to 32 kilograms per meter squared and a total body weight of more than 50 kilograms (110 pounds). For group 3 only: 4. Have 4 biological Japanese grandparents who were born in Japan. The study has two parts: Part A and Part B. Part A consists of 3 groups. In groups 1 and 2, there may be up to four dosing periods. During each dosing period, participants will take a single dose of the study medicine or placebo as liquid by mouth with or without food at the study clinic. A placebo does not have any medicine in it but looks just like the medicine being studied. The participants will stay at the study clinic for about 8 days and then can go home. During this time, the study team will observe the participants and take some urine and blood samples to test the level of the study medicine. The participants will return to the study clinic up to three more times to complete up to four dosing periods separated by at least 2 weeks. The participants will take increasing amounts of study medicine during each dosing period. After completion of the final dosing period, the participants will receive a follow-up telephone call about a month later. Group 3 may or may not be needed and will be decided by the study team if needed to collect results from participants who have 4 biological Japanese grandparents who were born in Japan. If group 3 is needed, then there will only be one dosing period as described above. Part B has 4 groups (Groups 4 to 7), each consisting of one dosing period. In all groups, participants will take multiple doses of the study medicine or placebo as tablets by mouth at the study clinic. Participants will be checked as described above and will receive a follow-up telephone call about one month after the last dose of study medicine or placebo. Group 7 may or may not be needed, depending on the results from previous groups, and will be decided by the study team. Read Less

The purpose of the study is to assess the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of AZD1613 in healthy participants, including Japanese and Chinese descent. Read Less

This is a Phase 1, randomized, double-blind, placebo-controlled, single- dose, first in human safety, tolerability, and pharmacokinetic study of SPY002-091 in healthy participants. Read Less

This study is open to adults aged between 18 and 80 years of age with a body mass index (BMI) of 18.5 to 42 kg/m². People with or without liver problems can take part in the study. The purpose of this study is to find out how much of a medicine called BI 1291583 gets into the blood of people with and without liver problems. BI 1291583 is being developed to treat people with bronchiectasis, a chronic disease of the lungs. People living with this condition often also have liver problems. Therefore, it is important to find out whether liver problems influence the amount of BI 1291583 that gets into the blood. Study participants receive a single dose of BI 1291583 as a tablet taken by mouth. Participants are divided into 4 groups based on how well their liver works: 1 group without liver problems, and 3 groups with mild, moderate, and severe liver problems. Each participant without liver problems is matched with participants from the other groups based on factors such as age, sex, smoking habits, and body weight to ensure accurate comparisons. Participants are in the study for about 3 months. They stay for 3 days at the study site and also visit the study site up to 9 times. During these visits, the doctors collect information about participants' health. To assess the study endpoints, the doctors regularly take blood samples from the participants. The doctors regularly check participants' health and take note of any unwanted effects. Read Less

The purpose of this study is to evaluate pulmonary capillary wedge pressure (PCWP) and other hemodynamic measurements at rest and during exercise in healthy volunteers across the age spectrum. Read Less