View clinical trials related to Normal Physiology.
Filter by:Background: Researchers want to better understand pain by studying people with and without different kinds of pain. To do this, researchers will expose people to pleasant and unpleasant sensations. They will ask them questions about their pain. Researchers also want to see if these people are eligible for other research studies at the National Center for Complementary and Integrative Health. Objectives: To study the experience of pain. Also to find people eligible to join other NIH studies. Eligibility: People 12 years and older with and without pain disorders. Design: Participants will be screened by phone. Participants will have one required visit. This may include: - Medical history - Physical exam - Questionnaires about themselves and their pain experience - Blood and urine tests - MRI: They will lie on a table that slides into a cylinder. They will feel different sensations while completing tasks on a computer. This lasts 15 minutes to 2 hours. - Quantitative sensory testing: They will be exposed to different pictures, sounds, tastes, and smells. They will also be exposed to pleasant and unpleasant sensations. These could include: - Burning, itching, or cold sensations - Pinpricks - Pressure and pinches - Electrocardiogram: Stickers on the chest record heart activity. - Straps placed around the chest to measure breathing. - Small sensors on the fingers or palms to measure pulse and sweating. Over the next 3 months, participants may have up to 4 other study visits. These last 2 to 4 hours each. They include repeats of some of the tests in the required visit. Participants may be recorded at the visits.
Background: Brain activity creates waste products. The body s glymphatic system removes this waste, especially during sleep. One brain waste product is amyloid-beta (Ab). It plays a role in Alzheimer s disease. Researchers want to study the effect of sleep on Ab in the brain. Objective: To see if sleep affects the amount of waste product removed from the brain. Eligibility: Healthy people at least 18 years of age. Design: Participants will be screened with a medical history, physical exam, and blood and urine tests. They will answer questions about drug use, psychiatric history, and family history of alcoholism or drug use. Participants will complete an MRI screening questionnaire. Participants will stay in the clinic overnight two times. On one night they will sleep through the night. On the other night they will be kept awake all night. These overnight visits can happen in any order. Participants will wear 2 activity monitors, on the wrist and the ankle. Participants will have positron emission tomography (PET) scans. A small amount of a radioactive chemical will be injected through an intravenous (IV) catheter. Participants will lie on a bed that slides into the scanner. A cap or a special mask may be placed on the participant s head. Participants will have magnetic resonance imaging (MRI) scans. The MRI scanner is a metal cylinder in a strong magnetic field. Participants will lie on a table that slides into the cylinder. A device called a coil will be placed over the head. Participants will do a task on a computer screen in the scanner. Participants will have tests of thinking, memory, and attention. They may be interviewed, complete questionnaires, take pen-and-paper or computer tests, and perform simple actions.
Background: An electroencephalogram (EEG) measures the brain s electrical activity. EEG shows that the louder the sound needed to wake a person, the deeper the person s sleep. Researchers are using functional magnetic resonance imaging (fMRI) to study people during sleep so they can view brain activity in 3D. But they still need to correlate fMRI with sound thresholds, like the EEG. Objective: To measure brain activity during sleep using fMRI and EEG. Eligibility: Healthy people ages 18 34 who can sleep on their back for several hours. Design: Participants will be screened online about their sleep and general health. At a screening visit, participants will have: Physical exam Hearing exam MRI scan. A strong magnetic field and radio waves take pictures of the brain. Participants will lie down on a bed that slides into the scanner, which is shaped like a cylinder. Participants will wear an actigraph on their wrist that records their motor activity. Participants will follow a 2-week routine. This includes regular in-to-bed and out-of-bed times and limits on alcohol, caffeine, and nicotine. During the overnight visits, participants will have: Female subjects will have a urine pregnancy test. fMRI. A coil will be placed over the head. Participants will do tasks shown on a computer screen inside the scanner. EEG. Small electrodes on the scalp will record brain waves while sleeping or doing a task in the scanner. Participants will be asked to try to sleep while researchers collect fMRI and EEG data. Participants eyes will be monitored with a video camera. Headphones will deliver sounds to wake them up throughout the night.
Background: Studies suggest that overweight girls may be developing breast tissue, and therefore starting puberty, earlier than normal weight girls. However, it is hard to distinguish breast tissue from fatty tissue. Researchers think that by using breast ultrasound, among other tests, they can do a better job of telling whether an overweight girl has breast tissue. This will help them understand if overweight girls are truly entering puberty before normal weight girls. Objective: To find out if overweight girls go through puberty earlier than normal weight girls. Eligibility: Healthy girls 8-14 years old who: - Are normal weight or overweight - Have some breast development - Have not started their first period Design: Parents of participants will be screened over the phone. Most participants will have 1 visit. However, they can choose to have multiple visits within 4 weeks. The visit will include: - Physical exam that includes examination of the breasts and genital area - Breast ultrasound: A small hand-held device will be passed back and forth over the chest. It uses sound waves to create a picture of the breast tissue. - Pelvic ultrasound: A small, handheld device will be passed back and forth over the lower belly. It uses sound waves to create a picture of the ovaries. - Urine and blood test - A special x-ray called a DXA to measure the amount of fat in the body: The participant will lie still on a table while the x-ray takes pictures of the body. X-ray of the hand: The picture will tell researchers how mature the participant s bones are. Participants may be asked to come back 6 months later to repeat these tests. ...
Background: Abusing alcohol, drugs, and other substances can cause serious health problems. These substances also can affect brain function. Researchers want to learn more about brain function by using magnetic resonance imaging (MRI). This uses a magnetic field and radio waves to take pictures of the brain. Objective: To develop new ways to use MRI to study the brain. Eligibility: Healthy people 18 years of age or older. Design: Participants will be screened with a medical history, physical exam, and blood and urine tests. They will answer questions about their drug use and psychiatric history. They will be asked about family history of alcoholism or drug abuse. Participants will answer questions to see if they can participate in MRI. Participants will have MRI scans. The scanner is a metal cylinder in a strong magnetic field. Participants will lie on a table that slides in and out of the cylinder. A device called a coil may be placed over the head. Each sub-study will include up to 3 different MRI visits. Participants can be in multiple sub-studies. But they can have only 1 MRI per week and 20 per year. During MRI visits, participants may have urine collected. They may get another MRI questionnaire. Participants may have a clinical MRI brain scan. This may show physical problems in the brain. During some scans, participants may perform simple movement, memory, and thinking tasks. Participants may be connected to a machine to monitor brain activity during the scan. Small metal electrodes will be placed on the scalp. A gel will be placed in the space between the electrodes and the scalp.
Background: - Painful stimuli cause changes in a network of brain regions called the "Pain Matrix." But most of these regions respond to many other stimuli, not just pain. Researchers want to understand how different factors influence pain. They want to test what happens when people expect different levels of pain and receive treatments that can modify pain. They want to see if these factors influence decisions about pain and how the body responds to it. They also want to compare pain with responses like taste and vision. Objectives: - To better understand how pain and emotions are processed and influenced by psychological factors. Eligibility: - Healthy volunteers ages 18-50. Design: - This study requires 1 to 2 clinic visits that last 1 to 3 hours. - Participants will be screened with medical history and physical exam. - Some participants will have one or more magnetic resonance imaging (MRI) scans of their brain. For MRI, participants will lie on a table that slides in and out of a cylinder. The scanner makes loud knocking noises. They will get earplugs. - Participants heart activity will be recorded with electrocardiogram. Their pulse, sweating, and breathing will be monitored. - Some participants will take a taste test. Others may perform simple tasks. Others may receive pain in their arm, leg, or hand. The pain will come from heat or electric shocks. Others may judge pain using a topical pain-relieving cream. Some of these tests may be given during MRI. - Participants will fill out questionnaires. - The study will last 3 years.
Background: - The drug filgrastim (rGCSF) increases the number of blood-forming cells in the bloodstream. These cells can be collected from donors bloodstreams and used for transplant. Studies have shown that rGCSF is present in the breast milk of nursing mothers who are taking it. Based on these studies, it is now recommended that a nursing mother should not breastfeed from the time she receives the first dose of the drug until 2 days after the final dose. Researchers want to study the amount of the drug and its effect on the cells present in donor blood and breast milk. They hope to better understand the effects of this drug on breast milk. Objectives: - To understand the effects of filgrastim on breast milk. Eligibility: - Women enrolled in NIH protocol 00-CC-0165 and currently breastfeeding. Design: - Participants will receive rGCSF daily for 5 days. They will have blood taken daily. - Participants will get a freezer bag containing 10 sterile, labeled containers for breast milk collection. - Participants will transfer some of the breast milk they pump into one of the containers. They will write the date and time the milk was collected on the container. They will freeze the samples. Any remaining milk should be disposed of. - Participants will bring the samples to NIH on the day of their stem cell collection procedure. - For days 1 and 2 after stem cell collection, participants will continue to collect and freeze breast milk samples and dispose of any remaining milk. - For days 3 5 after stem cell collection, participants will collect and freeze samples. They can also resume normal breastfeeding. - A research nurse will arrange to collect the samples.
Background: - Magnetic resonance imaging (MRI) is used to investigate brain function. Researchers want to use MRI to better understand the function patterns and connections between brain regions in healthy people. This might help people with brain diseases in the future. Objectives: - To evaluate MRI methods performed twice on the same day. - To evaluate brain function using positron emission tomography (PET). Eligibility: - Healthy volunteers at least 18 years old. Design: - Visit 1: - Participants will be screened with medical history, physical exam, and interview about drug and alcohol use and psychiatric history. - They will give blood and urine samples. Their breath will be tested for alcohol and smoking. - Visit 2: - Participants will have urine collected. They will have MRI scans, some while resting, some while doing tasks on a computer. - The MRI scanner is a metal cylinder in a strong magnetic field. Participants will lie on a table that slides in and out of the cylinder, with a coil over their head. Participants will get earplugs for loud noises. - Visit 3: - Participants will have urine collected. - A needle will guide a thin plastic tube (catheter) into each arm. The needle will be removed, leaving the catheter in the vein. - Participants will then have a PET scan. They will get the chemical 18FDG in the catheter. They will lie on a bed that slides in and out of the PET scanner, with a cap on their head. - Participants may have tests of memory, attention, concentration, and thinking. They may complete interviews, questionnaires, tests on paper or computer, and simple actions. - Participants will wear a device for 1 week between visits to measure activity and sleep.
Background: - One form of the influenza vaccine is a nasal spray. It uses a live but weakened flu virus. Researchers want to better under how the live vaccine interacts with the body s immune system. They will test the nasal spray flu vaccine (called FluMist) against a saline (salt water) nasal spray. They will then look at blood and nasal cell samples to see how the vaccine affects these cells immune response. Objectives: - To look at immune changes in nasal and blood cells in people who receive live flu vaccine. Eligibility: - Healthy volunteers between 18 and 49 years of age. Design: - Participants will have five outpatient visits for this study. Each visit will last up to 2 hours. - At the first visit, participants will have a physical exam and medical history. They will give blood and urine samples. Nasal cell samples will also be collected. - A week later, participants will have either the nasal spray flu vaccine or a saline spray. They will know which spray they will receive. Blood samples will be collected. - Two days after the vaccination, they will have another physical exam. Blood and nasal cell samples will be collected. - At the final two visits (1 week and 1 month after the vaccination), more blood samples will be collected. - Those who had the saline spray will be able to have the actual vaccine spray at the last study visit. - The ratio of participants who receive vaccine to those who receive saline will be 4:1.
Background: - Vaccines and antiviral therapies are critical for preventing and treating viral diseases. Testing these vaccines and drugs often requires healthy volunteers. To ensure that volunteers are healthy and eligible to participate in these studies, they will be screened before the start of the study. This screening may involve a medical history, physical exam, and blood test. Other samples may also be collected. This study will help identify volunteers who are eligible to participate in vaccine or antiviral therapy trials. Objectives: - To screen volunteers for clinical trials of vaccines or drugs to treat or prevent virus infections. Eligibility: - Healthy volunteers at least 18 years of age. Design: - Screening may begin several months before the start of the clinical trial. Participants may come to the National Institutes of Health clinic one or more times. - Participants may be screened with a physical exam and medical history. Blood samples will be collected. Other samples may also be collected, including urine, nasal wash, nasal swab, or stool samples. All samples will be stored for reference by the study researchers....