Healthy Volunteer

Background: People with HIV take drugs to keep the amount of virus in their body low. One type of these drugs, called integrase strand transfer inhibitors (INSTIs), can cause weight gain over time. Weight gain can cause diabetes, heart disease, and other serious issues. Researchers want to understand how INSTIs cause weight changes. Objective: To characterize the change in plasma metabolite profile that 4 weeks of each treatment may induce in the absence of HIV infection Eligibility: Healthy people aged 18 to 55. Design: Participants will be screened in the outpatient clinic. They will have a physical exam and blood tests. They will have a nutritional assessment and tests of their heart function. Participants will be randomized to one of four oral treatments: Tenofovir Disoproxil Fumarate TDF/Viread, Tenovovir Alafenamide TAF/Vemlidy, Dolutegravir DTG/Tivicay, or both TAF and DTG taken together for 4 weeks. Participants will have a Day 0 visit for the Lead-In Baseline visit for an exam and blood tests and continuous glucose monitor placement. Participants will return in 2wks or Day 14/Wk 2 for a DEXA (dual-energy X-ray absorptiometry). DEXA is a kind of X-ray that measures body fat and bone density. Optional adiopse (fat) tissue biopsy in the abdomen, and optional microbiome specimen collections. Continuous glucose monitor changed. Oral once a day dose medication will be started with education. Participants will return in 2wks or Day 28/Wk 4 for exam, labs, and continuous glucose monitor changed. Participants will return in 2wks or Day 42/Wk 6 for final exam, labs, repeat DEXA scan, repeat adipose tissue biopsy, and microbiome specimen collections.

Background: Many people in the United States are overweight or obese. This natural history study will look into how life events during childhood can impact eating behaviors and weight gain as adults. Objective: To explore how childhood experiences affect adult eating behaviors. Eligibility: Healthy people aged 18 to 60 years. Design: Participants will have 3 clinic visits. They will be screened with blood tests. They will answer questions about their alcohol and tobacco use. At the next visit, participants will undergo these activities: Parts of their body (such as waist, neck, and thighs) will be measured with a tape. They will have an imaging scan to find out how much body fat they have. They will start wearing a device like a wristwatch that measures their physical activity. They will wear this device for up to 10 days. They will wear a device on their upper arm or belly that measures blood glucose (sugar) levels. Participants will wear this for 7-10 days. They will answer questions about their education, childhood, and routines. They will receive a kit to collect a stool sample at home. At the last visit, participants will have these tests: Participants will relax and breathe normally while wearing a clear, plastic canopy that fits over their entire head. Blood samples will be taken before and after participants drink a sugary drink. Participants will be offered a large selection of foods for lunch. They will eat as much as they want. Then they will answer questions about how they feel about food and themselves.

Background: Attention deficit hyperactivity disorder (ADHD) is common in children. It can cause problems with attention and the ability to control actions and impulses. Obsessive compulsive disorder (OCD) is less common in children but not rare. It involves ongoing thoughts, urges, impulses, and repeated behaviors. Researchers want to study differences in brain activity between healthy children, those with ADHD, and those with OCD. Objective: To learn more about how the brain controls thinking and behavior. Eligibility: People aged 12 to 17 years with ADHD, OCD, or neither. Design: Participants will have 3 to 10 clinic visits in up to 1 year. Each visit will last 2 to 3 hours. Three visits are required: Behavioral. Participants will complete a computer task. Their mood, memory, attention, and thinking skills will be tested. EEG. Participants will undergo electroencephalography (EEG) to measure signals in their brain. Small electrodes will be placed on the scalp. A cap will be stretched over the head. Signals will be recorded while participants rest or do tasks on a computer. MRI. Participants will have a magnetic resonance imaging scan (MRI). They will lie on a table that rolls into a tube. The MRI will take pictures of their brain while they do tasks on a computer. Seven more visits are optional. These include 2 more EEG visits and 2 more MRI visits. Three will be magnetoencephalography (MEG) visits: MEG measures small magnetic field changes in the brain. A helmet with sensors will be placed on the head. Brain changes will be recorded while participants rest or do tasks on a computer.

Background: Abnormal fats in the blood can lead to many problems, including heart disease. Researchers want to learn more about how eating meals with different levels of nutrients affects fats in the blood. Specifically, they want to study people with too much body fat, too little body fat, and a kidney problem called nephrotic syndrome. Objective: To learn more about how different types of foods affect fat levels in the blood. Eligibility: People aged 18 years or older with a health condition that affects how their body handles fats. Healthy volunteers are also needed. Design: Participants will have 2 overnight stays in the clinic within 6 months. At each visit, after staying overnight, they will eat a breakfast casserole. At 1 visit, breakfast will be a high-fat, low carbohydrate meal. At the other, it will be a high-carbohydrate, low-fat meal. Participants will have a tube inserted into a vein in their arm. They will have blood drawn via the tube 12 times in 8 hours: 2 times before they eat the breakfast and 10 times after. Participants will have other tests during their stays: * A resting metabolic test captures the air they exhale and measures how much energy they use at rest. * A dual energy X-ray absorptiometry (DXA) scan measures how much fat and muscle they have. * A Fibroscan is a special type of ultrasound of the liver. * A body surface scan uses lasers to measure the total area of the body. * A bioelectric impedance (BIS) exam measures how fast small electric currents move through their body. Participants may opt to have a third visit. At this visit, the breakfast will be high in protein....

Background: As people age, the cells in the pancreas that produce insulin begin to release less of this hormone, and levels of blood glucose (sugar) rise. This can lead to illnesses such as diabetes. Urolithin A (UA) is a natural nutritional supplement that may improve how the body controls blood glucose. Objective: To learn if UA improves levels of insulin and other hormones that help control blood glucose. Eligibility: People aged 55 years and older with a body mass index of 27 or higher. Design: Participants will have 6 clinic visits over 8 weeks. Participants will be screened. They will have a physical exam with blood and urine tests and a test of their heart function. UA gelcaps are taken by mouth every morning at home. Half of participants will take UA. The other half will take a placebo. The placebo looks like the study drug but does not contain any medicine. Participants will not know which they are taking. Participants will have tests during the study including: Oral glucose tolerance: Participants will drink a sweet liquid. Blood will be drawn at intervals over the next 3 hours. Continuous glucose monitor: A sensor with a needle that goes just under the skin will be placed on the upper arm. Participants will wear this sensor throughout the study. Exercise. Participants will walk on a treadmill while their heart rate, hearth rhythm, and blood pressure are monitored. They will walk in a hallway at normal and fast paces. Imaging scans of the thigh; scans of the brain are optional....

The purpose of this study is to use brain imaging technology to measure changes in blood flow to areas in the brain as individuals perform intellectual tasks. This study will use functional magnetic resonance imaging (fMRI) to examine blood flow to areas of the brain as participants engage in tasks associated with visual perception, visual recognition, and memory.

Background: Many people in the United States are overweight or obese. Researchers want to learn why some people can overeat and not gain weight, whereas others who do not overeat still gain weight. Objective: To study factors related to food intake that can lead to weight gain over time. Eligibility: Healthy adults aged 18 to 60 years. Design: Participants will have 6 to 8 clinic visits over 2 years. The first 3 or 4 study visits will be 1 week apart. Procedures during visits may include the following: Collection of blood, hair, urine, and stool samples. Measurement of the waist, neck, thighs, and other parts of the body. Dual energy x-ray absorption (DXA) scan: Participants will lie still on a padded table while they are scanned to measure body fat. Physical activity monitor: Participants will wear a monitor on the wrist for 2 weeks. Cognitive tests: Participants will perform tasks to measure attention, memory, and brain function. Continuous glucose monitor. Participants will wear a device that measures their blood glucose for 1 week. Mixed meal test and stomach emptying test. Participants will drink a breakfast shake and swallow a dose of acetaminophen. Blood will be drawn over the next 4 hours. Resting metabolic rate: Participants will wear a clear hood over their head while they rest for 20 minutes. The hood will measure the gases they breathe. Breakfast and lunch test. Participants will eat a standard breakfast. They will be allowed to select from foods and eat as much as they like at lunch. They will be asked how hungry or full they are. Questionnaires. Participants will answer questions about their health, sleep, physical activity, and eating.

Background: Many people in the United States are overweight or obese. Researchers want to learn why some people can overeat and not gain weight, whereas others who do not overeat still gain weight. Objective: To study factors related to food intake that can lead to weight gain over time. Eligibility: Healthy adults aged 18 to 60 years. Design: Participants will have 6 to 8 clinic visits over 2 years. The first 3 or 4 study visits will be 1 week apart. Procedures during visits may include the following: Collection of blood, hair, urine, and stool samples. Measurement of the waist, neck, thighs, and other parts of the body. Dual energy x-ray absorption (DXA) scan: Participants will lie still on a padded table while they are scanned to measure body fat. Physical activity monitor: Participants will wear a monitor on the wrist for 2 weeks. Cognitive tests: Participants will perform tasks to measure attention, memory, and brain function. Continuous glucose monitor. Participants will wear a device that measures their blood glucose for 1 week. Mixed meal test and stomach emptying test. Participants will drink a breakfast shake and swallow a dose of acetaminophen. Blood will be drawn over the next 4 hours. Resting metabolic rate: Participants will wear a clear hood over their head while they rest for 20 minutes. The hood will measure the gases they breathe. Breakfast and lunch test. Participants will eat a standard breakfast. They will be allowed to select from foods and eat as much as they like at lunch. They will be asked how hungry or full they are. Questionnaires. Participants will answer questions about their health, sleep, physical activity, and eating.

Background: Attention deficit hyperactivity disorder (ADHD) is common in children. It can cause problems with attention and the ability to control actions and impulses. Obsessive compulsive disorder (OCD) is less common in children but not rare. It involves ongoing thoughts, urges, impulses, and repeated behaviors. Researchers want to study differences in brain activity between healthy children, those with ADHD, and those with OCD. Objective: To learn more about how the brain controls thinking and behavior. Eligibility: People aged 12 to 17 years with ADHD, OCD, or neither. Design: Participants will have 3 to 10 clinic visits in up to 1 year. Each visit will last 2 to 3 hours. Three visits are required: Behavioral. Participants will complete a computer task. Their mood, memory, attention, and thinking skills will be tested. EEG. Participants will undergo electroencephalography (EEG) to measure signals in their brain. Small electrodes will be placed on the scalp. A cap will be stretched over the head. Signals will be recorded while participants rest or do tasks on a computer. MRI. Participants will have a magnetic resonance imaging scan (MRI). They will lie on a table that rolls into a tube. The MRI will take pictures of their brain while they do tasks on a computer. Seven more visits are optional. These include 2 more EEG visits and 2 more MRI visits. Three will be magnetoencephalography (MEG) visits: MEG measures small magnetic field changes in the brain. A helmet with sensors will be placed on the head. Brain changes will be recorded while participants rest or do tasks on a computer.

Background: Abnormal fats in the blood can lead to many problems, including heart disease. Researchers want to learn more about how eating meals with different levels of nutrients affects fats in the blood. Specifically, they want to study people with too much body fat, too little body fat, and a kidney problem called nephrotic syndrome. Objective: To learn more about how different types of foods affect fat levels in the blood. Eligibility: People aged 18 years or older with a health condition that affects how their body handles fats. Healthy volunteers are also needed. Design: Participants will have 2 overnight stays in the clinic within 6 months. At each visit, after staying overnight, they will eat a breakfast casserole. At 1 visit, breakfast will be a high-fat, low carbohydrate meal. At the other, it will be a high-carbohydrate, low-fat meal. Participants will have a tube inserted into a vein in their arm. They will have blood drawn via the tube 12 times in 8 hours: 2 times before they eat the breakfast and 10 times after. Participants will have other tests during their stays: * A resting metabolic test captures the air they exhale and measures how much energy they use at rest. * A dual energy X-ray absorptiometry (DXA) scan measures how much fat and muscle they have. * A Fibroscan is a special type of ultrasound of the liver. * A body surface scan uses lasers to measure the total area of the body. * A bioelectric impedance (BIS) exam measures how fast small electric currents move through their body. Participants may opt to have a third visit. At this visit, the breakfast will be high in protein....

Background: Many people in the United States are overweight or obese. This natural history study will look into how life events during childhood can impact eating behaviors and weight gain as adults. Objective: To explore how childhood experiences affect adult eating behaviors. Eligibility: Healthy people aged 18 to 60 years. Design: Participants will have 3 clinic visits. They will be screened with blood tests. They will answer questions about their alcohol and tobacco use. At the next visit, participants will undergo these activities: Parts of their body (such as waist, neck, and thighs) will be measured with a tape. They will have an imaging scan to find out how much body fat they have. They will start wearing a device like a wristwatch that measures their physical activity. They will wear this device for up to 10 days. They will wear a device on their upper arm or belly that measures blood glucose (sugar) levels. Participants will wear this for 7-10 days. They will answer questions about their education, childhood, and routines. They will receive a kit to collect a stool sample at home. At the last visit, participants will have these tests: Participants will relax and breathe normally while wearing a clear, plastic canopy that fits over their entire head. Blood samples will be taken before and after participants drink a sugary drink. Participants will be offered a large selection of foods for lunch. They will eat as much as they want. Then they will answer questions about how they feel about food and themselves.

Background: As people age, the cells in the pancreas that produce insulin begin to release less of this hormone, and levels of blood glucose (sugar) rise. This can lead to illnesses such as diabetes. Urolithin A (UA) is a natural nutritional supplement that may improve how the body controls blood glucose. Objective: To learn if UA improves levels of insulin and other hormones that help control blood glucose. Eligibility: People aged 55 years and older with a body mass index of 27 or higher. Design: Participants will have 6 clinic visits over 8 weeks. Participants will be screened. They will have a physical exam with blood and urine tests and a test of their heart function. UA gelcaps are taken by mouth every morning at home. Half of participants will take UA. The other half will take a placebo. The placebo looks like the study drug but does not contain any medicine. Participants will not know which they are taking. Participants will have tests during the study including: Oral glucose tolerance: Participants will drink a sweet liquid. Blood will be drawn at intervals over the next 3 hours. Continuous glucose monitor: A sensor with a needle that goes just under the skin will be placed on the upper arm. Participants will wear this sensor throughout the study. Exercise. Participants will walk on a treadmill while their heart rate, hearth rhythm, and blood pressure are monitored. They will walk in a hallway at normal and fast paces. Imaging scans of the thigh; scans of the brain are optional....

Background: People with HIV take drugs to keep the amount of virus in their body low. One type of these drugs, called integrase strand transfer inhibitors (INSTIs), can cause weight gain over time. Weight gain can cause diabetes, heart disease, and other serious issues. Researchers want to understand how INSTIs cause weight changes. Objective: To characterize the change in plasma metabolite profile that 4 weeks of each treatment may induce in the absence of HIV infection Eligibility: Healthy people aged 18 to 55. Design: Participants will be screened in the outpatient clinic. They will have a physical exam and blood tests. They will have a nutritional assessment and tests of their heart function. Participants will be randomized to one of four oral treatments: Tenofovir Disoproxil Fumarate TDF/Viread, Tenovovir Alafenamide TAF/Vemlidy, Dolutegravir DTG/Tivicay, or both TAF and DTG taken together for 4 weeks. Participants will have a Day 0 visit for the Lead-In Baseline visit for an exam and blood tests and continuous glucose monitor placement. Participants will return in 2wks or Day 14/Wk 2 for a DEXA (dual-energy X-ray absorptiometry). DEXA is a kind of X-ray that measures body fat and bone density. Optional adiopse (fat) tissue biopsy in the abdomen, and optional microbiome specimen collections. Continuous glucose monitor changed. Oral once a day dose medication will be started with education. Participants will return in 2wks or Day 28/Wk 4 for exam, labs, and continuous glucose monitor changed. Participants will return in 2wks or Day 42/Wk 6 for final exam, labs, repeat DEXA scan, repeat adipose tissue biopsy, and microbiome specimen collections.

This study plans to learn more about the safety and tolerability of psychedelic administration (psilocybin) in healthy older adults ages 65-85.

The purpose of this study is to compare how the drug moves through the body following risankizumab subcutaneous (SC) and risankizumab intravenous (IV) doses.

Background: \- Salivary glands in and around the mouth and throat make saliva. Salivary gland disorders can affect a person s quality of life. Studying people who have a disease that affects their salivary gland(s) may teach researchers about the disorders and their genetics. Objectives: \- To study salivary gland diseases and disorders. To collect data and samples from people with salivary gland problems and their relatives. Eligibility: * People more than 4 years old who have or are suspected to have a disease involving salivary glands. * Their relatives more than 4 years old. * Healthy volunteers 18 years or older. Design: * Participants may be screened with: * Medical history * Physical exam * Blood and urine tests * General oral and dental history and exam * Saliva collection * Eye exam and test for dry eyes * Health questionnaires (adults) * Biopsy of some minor salivary glands. A small incision will be made on the inside of the lower lip and several tiny salivary glands will be removed. * Participants will have 2-3 visits. These may include: * Repeats of some screening tests * Ultrasounds of some glands. Researchers will put some gel on the face, then press on it with a smooth wand. * Adults may have other biopsies * A small catheter inserted into the opening of the parotid gland duct on the inside of the cheek. A saline solution (in a syringe) will fill the duct. * Swishing a saltwater solution in the mouth for 10 seconds and then spitting into a cup * Scrapings collected from teeth, tongue, and cheeks

Background: \- Researchers at the National Institutes of Health give many tests of hearing and balance. These tests can help detect problems that affect hearing or balance. It is important to know exactly how healthy people perform on each of these tests. This information will indicate when a test result is normal and when a test result shows a problem. Researchers also want to determine the best methods for each test. Objectives: \- To test different types of hearing and balance tests, and collect information on normal values for each test. Eligibility: \- Healthy volunteers between 5 and 80 years of age. Design: * This study will require a single visit to the National Institutes of Health Clinical Center. It will include both screening tests and study tests of hearing and balance. Sometimes, a second visit may be required if a test is designed to measure the same thing on 2 different days. Each visit will last between 2 and 5 hours, depending on the number of tests scheduled per visit. * Participants will have a physical exam and medical history. They will also have basic tests to check for normal hearing and balance. * Participants may have different hearing tests, including the following: * Auditory Evoked Potentials to study how the ears and brain handle sound information. * Auditory Processing Tests to study how a person processes complex sounds like speech in background noise. * Tests of middle ear and inner ear function. * Participants may have different balance and inner ear tests, including the following: * Balance test on a tilting platform. * Different tests to measure how well the eyes, ears, and brain work together to help maintain balance. * Treatment will not be needed as part of this study.

Background: \- Gum disease is a condition in which the tissue around the tooth root becomes swollen and infected. This condition can cause tooth loss if it is not treated. Who gets gum disease and how bad it will be depends on (1) the different bacteria in the mouth and (2) how the immune system of an individual handles these bacteria. Researchers want to look at the oral bacteria and genetic immune problems of different people to learn how these affect gum disease and other conditions of the mouth. Objectives: \- To study how immune system problems may lead to problems in the mouth, including gum disease. Eligibility: * Children and adults at least 7 years of age who have genetic problems with their immune system. * Healthy adults that have periodontal disease * Health adults that do not have periodontal disease Design: * This study will involve a screening visit and a study visit. * Participants will be screened with a medical history, blood work and a full oral and dental exam, including dental x-rays and photos. * The study visit will involve collection of blood, urine, and other samples, including saliva, plaque, and gum swabs. Any abnormal tissue will sampled for a biopsy. Additional oral and dental exams will be performed. Participants will also answer questions about any current medical or dental problems.

Background: \- Magnetic resonance imaging (MRI) is a widely used scanning technique to obtain images of the human body and evaluate activity in the brain. A particular MRI method called magnetic resonance spectroscopy (MRS) can be used to study brain chemistry as well, which may help researchers who are studying new treatments for psychiatric illnesses. Researchers are interested in improving current MRI and MRS techniques, as well as developing new MRI and MRS techniques to view and measure brain chemicals and brain activity. Objectives: \- To implement, develop, and optimize brain chemistry imaging techniques using magnetic resonance imaging and magnetic resonance spectroscopy. Eligibility: \- Healthy individuals between 18 and 65 years of age. Design: * This study will involve a screening visit and a scanning visit at the National Institutes of Health Clinical Center. * Participants will be screened with a full medical and physical examination, blood and urine tests, and neurological testing. * During the second visit, participants will have an MRI scan of the brain. (Participants who have received an MRI within the past year will not need to have a second one; the images of the previous scan will be used for this study.) All participants will then have an MRS scan using the same scanning equipment....

The purpose of this study is to use brain imaging technology to measure changes in blood flow to areas in the brain as individuals perform intellectual tasks. This study will use functional magnetic resonance imaging (fMRI) to examine blood flow to areas of the brain as participants engage in tasks associated with visual perception, visual recognition, and memory.

This study will assess how different oral formulations of ubrogepant move through the body in healthy adult participants under fasting and fed conditions.

This study aims to find out how much adimanebart gets into the blood circulation of healthy adults. Researchers will measure the amount of adimanebart in blood over time to learn how it moves through the body. The drug's safety will also be assessed. The participants will be assigned to one of 3 parts of the study: part 1 investigates the absolute bioavailability; part 2 investigates the effect of different body weights on adimanebart in blood after subcutaneous (SC) dosing; part 3 investigates formulation adaptations. Participants will be in the study for approximately up to 24 weeks.

This study will assess the adverse events, tolerability, and how bretisilocin intramuscular (IM) Injection moves through the body of healthy adult Japanese, Han Chinese, and Non-Asian volunteers participants.

This study will test a study medicine called REGN20423 to see how effective it is in healthy participants (in Part A) and participants with atopic dermatitis (eczema) (in Part B). REGN20423 is a study medicine that is only used in clinical studies. REGN20423 has not previously been studied in humans. The study is looking at: * What side effects REGN20423 might cause * How much REGN20423 is in the blood at different times * How well REGN20423 works in adults with atopic dermatitis * Whether the body makes antibodies against REGN20423 * How the body changes after having REGN20423, which can help researchers understand why REGN20423 works better in some people than others * What the best dose of REGN20423 is

This is a first-in-human, single ascending dose (SAD) study in healthy adult participants. This is a single-center, randomized, double-blind, placebo-controlled, SAD study to evaluate the safety, tolerability and PK of HSK56630 in healthy adult participants and preliminarily evaluate the PD of HSK56630.