Clinical Research Directory
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312 clinical studies listed.
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Tundra lists 312 Healthy Volunteers clinical trials. Each listing includes eligibility criteria, study locations, and direct links to research sites in the Tundra directory.
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NCT00442195
Collection and Analysis of Blood, Bone Marrow, and Buccal Mucosa Samples From Healthy Volunteers
The Hematology Branch of the National Heart, Lung, and Blood Institute is doing a variety of laboratory research experiments that require blood and tissue samples from healthy volunteers. This protocol provides a mechanism for collecting these tissue samples. Research includes studies of normal and abnormal formation of blood cells, viral blood diseases, the role of the immune system in marrow failure and genetic risk factors for aplastic anemia. Healthy normal volunteers 8 years of age and older may be eligible for this study. Samples are collected as follows: * Blood samples: Participants 8 years of age and older donate up to 4 tablespoons of blood, which is obtained from a needle placed in an arm vein. * Participants 8 years of age and older donate a buccal mucosa sample (cells from the inside of the cheek). The inside of the cheek is scraped gently with a nylon brush. * Participants 18 years of age and older donate a bone marrow sample. The bone marrow is obtained from the hip bone. The skin over the area is wiped clean with alcohol and iodine, and then a local anesthetic is injected under the skin and also into the bone. When the area is numb, a bone marrow aspiration needle is introduced through the bone surface into the marrow. The marrow cells are collected using a syringe connected to the needle.
Gender: All
Ages: 8 Years - 99 Years
Updated: 2026-05-29
1 state
NCT06868914
Phase I Trial of High-Density Theta Burst Stimulation (hdTBS)
Background: Transcranial magnetic stimulation (TMS) uses magnetic pulses to affect brain activity. A type of TMS called theta burst stimulation (TBS) is approved to treat people with major depression. Researchers have developed a new form of TBS called high-density TBS (hdTBS). They hope hdTBS will work better than TBS. But first they need to test the new treatment in healthy adults. Objective: To test hdTBS in healthy adults. Also, to compare the aftereffects of hdTBS and TBS. Eligibility: Healthy adults aged 22 to 60 years. Design: Participants will have 4 clinic visits over about 3 to 4 weeks. They must abstain from drugs and alcohol and limit caffeine before visits. At their first visit, participants will be oriented to TBS. They will wear a cap and earplugs. A device with round coils will be placed near their head. When a brief electric current passes through the coil, it generates a magnetic pulse that stimulates the brain. Participants may feel a pulling sensation on the skin under the coil. Their fingers may move involuntarily. At their next 3 visits, participants will receive either TBS or sham TBS. A sham TBS uses a low magnetic field to minimize the effects of the treatment. Participants will have up to 9 electrodes placed on 1 arm. These electrodes will measure the electrical activity in their muscles. Each TBS session will be videotaped. At every visit, participants will answer questions about their health, including substance use. They will perform 2 tasks to test their thinking skills. They will perform a test on a computer to test their reaction time....
Gender: All
Ages: 22 Years - 60 Years
Updated: 2026-05-29
1 state
NCT00663611
Growth Hormone Administration and the Human Immune System
Background: \- In elderly individuals, an age-associated decline in the immune system s ability to function is believed to contribute to increased incidence of infection, autoimmune disorders, and cancer. This decline in immune system function may be related to the decline in the body s production of growth hormone, which helps regulate human development and may contribute to the health of the immune system. Researchers are interested in studying whether growth hormone, given as an infusion over time, can improve the function of the immune system and other body systems associated with good health. Objectives: \- To study the effects of growth hormone administration on the immune systems of healthy men. Eligibility: \- Healthy men between 25 and 50 years of age. Design: * This protocol will involve three separate studies: Study I, Study IB, and Study II. Participants in Study I and Study IB may participate in Study II as directed by the researchers. * Participants will be screened with a full medical history and physical examination, and will provide blood, urine, and stool samples; have a glucose tolerance test; and have other tests as required by the researchers. * Participants will have an infusion pump with a small catheter inserted beneath the skin to administer the study chemicals (either growth hormone or placebo). * Study I and Study IB participants will receive pulses of growth hormone through the infusion pump at regular intervals to monitor the body s response to the hormone. Study IB participants will receive a higher dose of growth hormone than Study I participants. * Throughout the study period, all participants will have frequent blood and urine tests, as well as tests of glucose tolerance and metabolism, imaging studies, and other tests as required by the researchers. * Study II participants will be divided into two groups. The first group will receive pulses of either growth hormone or placebo infusion at intervals throughout the day for 4 weeks, followed by an 8-week period without infusions. The second group will receive conventional once-a-day infusion of growth hormone or placebo for 4 weeks, followed by an 8-week period without infusions. * Throughout the study period, all participants will have frequent blood and urine tests, as well as tests of glucose tolerance and metabolism, imaging studies, and other tests as required by the researchers.
Gender: MALE
Ages: 25 Years - 50 Years
Updated: 2026-05-29
1 state
NCT03258580
Sociocultural & Biobehavioral Influences on Pain Expression and Assessment
Objective The current proposal investigates behavioral, psychophysiological, and social processes that may help explain biases and disparate outcomes in pain. Health disparities, or health outcomes that adversely affect disadvantaged populations, are pervasive and apparent in many diseases and symptoms, including pain. Pain is the number one reason individuals seek medical treatment. Health disparities in pain encompass both differences in pain experience and treatment for pain. For instance, research indicates that Black individuals report increased pain and have reduced pain tolerance relative to White individuals, yet doctors are less likely to treat minority patients pain and underestimate their pain experience. This project aims to address this systemic discrepancy by focusing on interpersonal processes that may contribute to these disparities, including socially-relevant responses to pain (i.e. pain expression) and pain assessment (e.g. visual attention). The proposed research aims to determine whether the study of pain expressions and their assessment can yield insights on how social factors shape pain and its treatment. Further, we test the efficacy of potential interventions designed to improve accuracy and reduce biases in pain assessment. If successful, this work will form the foundation of a new research program that will link the field of pain research with the field of social neuroscience, and forge new insights on the critical problem of health disparities in pain. Study population We will accrue up to 700 total healthy volunteers to target 240 completers Design Our overall aim is to understand how social factors influence the assessment and management of pain, and to gain insight into psychosocial processes that may underlie health disparities in pain. We propose a series of studies designed to test these links. First, we will measure pain perception and physiological responses to painful stimuli in a diverse group of individuals to test for sociocultural and biological influences on pain and pain-related responses. In subsequent studies, new participants ("perceivers") will view images of these initial participants ("targets") and will provide estimates of 'targets' pain experience. We will measure a) whether perceivers can accurately estimate 'targets' pain experience; b) whether accuracy differs as a function of similarity between target and perceiver (ingroup vs outgroup); and c) whether individuals can improve accuracy through feedback. Outcome measures Primary outcome measures for all experiments will be decisions about pain (experienced by self or other) measured with visual analogue scales, reaction time, and/or categorical judgments (pain/no pain). We will also measure physiological responses (e.g., facial muscle response, skin conductance, pupil dilation) and brain responses using functional magnetic resonance imaging (fMRI) as secondary outcome measures. We will test whether pain and pain-related responses varies as a function of sociocultural/demographic factors (e.g. race, ethnicity, sex) and whether accuracy in assessing others' pain is influenced by group similarity (i.e. ingroup vs. outgroup) and training (e.g. performance-related feedback)....
Gender: All
Ages: 18 Years - 60 Years
Updated: 2026-05-29
1 state
NCT01237093
Developing Biomarkers of Dietary Intake
Background: \- Researchers who study health and nutrition are interested in developing more accurate methods of determining what people eat from day to day and how it affects their general health. In particular, better methods are needed to determine if people are accurately remembering what they ate. One possible method involves the use of biomarkers, or indicators in urine, blood, saliva, fat, and hair, which are related to the intake of a particular food in a consistent way. One set of biomarkers in blood samples and hair may be used to determine the relative amount of meat, fish, and soda (corn/sugar cane) in a person s diet. However, more research is needed to study the effectiveness of using these biomarkers to accurately track dietary intake. Objectives: \- To validate the use of biomarkers as representative of specific dietary intake patterns (meat/fish/soda). Eligibility: \- Healthy, nondiabetic men between 18 and 65 years of age. Design: * This study involves an initial screening visit and a 12-13 week inpatient dietary study period. * Participants will be screened with a medical history and physical examination, as well as blood and urine samples and a glucose tolerance test to exclude individuals who have diabetes. * After 3 days of a standard weight-maintaining diet, participants will have a glucose tolerance test and a body fat scan; provide hair, blood, and fat tissue samples; and complete questionnaires and performance tests. * Participants will spend one day in a metabolic chamber to measure their energy expenditure and general metabolism. * Participants will then be randomized into one of eight carefully designed diets for 12 weeks. The diets will differ in the amount of meat, fish, and soda, including one diet where none of the three biomarker-related foods will be permitted. Blood samples will be collected throughout the study diet period. * At the end of the 12-week study diet period, participants will provide additional hair, blood, and fat tissue samples, and will have a second metabolism assessment in the metabolic chamber....
Gender: MALE
Ages: 18 Years - 65 Years
Updated: 2026-05-29
1 state
NCT02339012
Genetic and Epigenetic Signatures of Translational Aging Laboratory Testing (GESTALT)
Background: \- Biomarkers are substances in people s blood and tissues. They help researchers understand diseases and signs of aging. Scientists want to do more research on biomarkers to find ways to improve quality of life in old age. Objective: \- To learn more about biomarkers and their relationship to aging. Eligibility: \- Adults at least 20 years old who weigh at least 110 pounds and have a body mass index below 30. They must agree that their genetic samples can be collected, studied, and stored. Design: * Participants will be screened with medical history, physical exam, EKG and blood and urine tests. * Participants will have 3-day visits. They will return every 2 years. * All visits include: * Blood and urine collection * Physical performance tests * Health questionnaires * Memory and problem-solving tests * Magnetic Resonance Imaging (MRI) and Computerized Tomography (CT) scans. * Muscle metabolism/ exercise tests * Taste strips * Muscle and/or skin biopsies/ red light therapy * Retinal imaging/ eye tracking * Sleep study * ODD visits also include: * Cytapheresis * Bone marrow aspirate * EVEN visits also include: * Hyperglycemic CLAMP * Lumbar Puncture (LP) * Continuous Glucose Monitor (CGM)
Gender: All
Ages: 20 Years - 120 Years
Updated: 2026-05-29
1 state
NCT02390765
Children s Growth and Behavior Study
Background: \- Studies show that many factors affect children's eating behavior and health. These include sleep, mood, thinking skills, and genetics. Studying children over time may identify children at higher risk for eating-related health concerns. Objective: \- To understand how genes and environment influence eating behavior and health over time. Eligibility: \- Children ages 8-17 in good general health. Design: * Screening visit 1: Medical history, physical exam, body measurements, and questions. * 14 days: Participants will wear a wrist monitor and answer smartphone prompts about eating and mood. They may give a stool sample. * Screening visit 2: * Body measurements. * Saliva, urine, and blood samples. * Heart tests. * Meals provided (after fasting overnight). * Questionnaires and interview. * Behavior, thinking, and exercise tests. * X-ray of left wrist and full body.\<TAB\> * Some parents may have medical history, physical exam, and questions at screening visits. They may answer questions at the yearly visits. * Participants will have up to 6 yearly visits. They will give a urine sample and body measurements, and repeat the X-rays. They will have questions and behavior and thinking tasks. They may give stool samples. Visits will range from 3 to 8 hours. * Participants may choose to participate in other studies: * Stress and Hormones, 1 visit: While resting, participants will give saliva samples and have their heart monitored. Then they will do math. They will repeat the resting part, then do a computer task. * Brain Imaging, 2 visits: Twice, participants will perform tasks with a magnetic cone on their head then answer questions. Once, they will have an MRI, lying still in a scanner with a coil on their head. Before the first visit, participants will collect at-home saliva samples once a day for three days. During both visits, participants will perform tasks and answer questions that gauge their thinking skills and mood. * Experiment 3 (sleep/fatigue): Participants will complete 2 additional visits. During these visits, participants will complete a task on the computer for 2 hours, or watch a movie for two hours. After completion of the task/movie, they will answer questions and be provided with food. Participants will be compensated for the time and inconvenience involved with completing study procedures. ...
Gender: All
Ages: 8 Years - 100 Years
Updated: 2026-05-29
1 state
NCT00353158
A Pilot of Pediatric/Adult Study of Gene Expression Profiling and Clinical Characterization of Phototoxicity
This study will examine the phototoxicity, a reaction to light that is like exaggerated sunburn, which occurs in people who take medications such as voriconazole, a medication used to fight fungus. Sunscreens might protect the skin from the reaction. Although phototoxicity from voriconazole is not completely understood, it may be related to how that medication is metabolized in the liver by enzymes called cytochrome P450 enzymes-and mainly by one known as 2C19. A way to evaluate phototoxicity is through microarrays, which measure how much each gene is expressed in cells from tissues such as skin. Patients ages 8 and older who are scheduled to begin taking or who currently take voriconazole may be eligible for this study. Also, patients ages 18 to 45 in good health who have skin tone known as Type 2, which usually burns and tans only slightly following sun exposure, may be eligible. All patients will visit the Dermatology Clinic. They will complete two questionnaires, on medical history and medications, as well as the skin response to sunlight, and donate about 3 teaspoons of blood. Patients who are scheduled to take voriconazole will visit the clinic four times, that is, two visits 2 consecutive days before beginning the medication and two visits on 2 consecutive days after taking it for at least 7 days. Each visit will take 1 to 2 hours. Patients about to take voriconazole will have a blood test and undergo a physical exam of the skin test site, on the buttocks. Researchers will take photographs of the specific site and do tests to measure skin reaction to ultraviolet (UV) light. UV light will be shined on 15 small areas of the skin, each 1 x 1 centimeters. After 24 hours, any redness that occurs on the skin will be checked. Afterward, patients will begin taking voriconazole according to directions by the researchers. At 10 or more days later, patients will visit the clinic. Sunscreen will be applied and 1 hour later after administration of voriconazole, a blood sample will be drawn to check the level of medication. Then UV light will be shined on 23 areas of skin 1 x 1 centimeters. More photographs will be taken of test sites to record changes in skin redness. On the next day, the skin response will be evaluated. Participants in the control group will be asked to avoid UV radiation by wearing hats and clothing, and using sunscreen. They will be given the doxycycline, an antibiotic, and undergo procedures with UV light shined on small areas of the skin, on the buttocks. Control participants will have 7 study days, with visits lasting from 1 to 3 hours and probably not exceeding 8 hours. They will have two shave biopsies on Study Day 2 and on Study Day 7 to determine how the skin has responded to UV light exposures. ...
Gender: All
Ages: 8 Years - 100 Years
Updated: 2026-05-29
1 state
NCT00104325
Cytapheresis of Volunteer Donors
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.
Gender: All
Ages: 18 Years - 120 Years
Updated: 2026-05-29
1 state
NCT00428987
Physical and Behavioral Traits of Overweight and Obese Adults
This study will describe the phenotype (physical and behavioral traits) of overweight and obese people. It will characterize the hormones, metabolism, food preferences, fitness and physical activity levels, sleep patterns and thought processes in people with and without weight problems. Genetic material will be collected for studies of the internal codes that influence body weight. People over 18 years of age from all weight categories (lean, overweight, obese) who are reasonably healthy may be eligible for this study. Participants undergo the following tests and procedures: * Physical exam, electrocardiogram, blood and urine tests, instructions for recording food intake for 7 days * Metabolic studies for menstruating women. * Resting metabolic rate to study how many calories the body burns at rest. * Mixed meal test to measure hormones such as insulin that regulate blood sugar. * Glucose tolerance test to determine how sensitive the body is to insulin. * 24-hour energy expenditure to measure the amount of oxygen breathed in and the amount of carbon dioxide breathed out. * Repeat 24-hour energy expenditure. * Diurnal blood sampling and temperature assessment to study the body s internal clock. * Air-displacement plethysmography (Bod Pod) to measure body composition. * Dual energy x-ray absortiometry (DEXA) to measure body fat and bone density. * Repeat Bod Pod and DEXA. * Anthropometric measurements and bioelectrical impedance to measure height, weight, and circumferences, skinfold thickness, fluid status and percentage body fat. * Bromide dilution to measure the amount of water not in cells in the body. * Doubly labeled water to measure the amount of calories burned in a 7-day period. * 24-hour diet reports. * Endothelial reactivity to measure how the blood vessels stretch or dilate for assessing cardiovascular health. * Treadmill or bicycle exercise capacity test. * Physical activity monitor. * Unicorder to detect any breathing difficulties that may interfere with sleep. * Fat and muscle biopsy to look for variations in gene expression in fat tissue and muscle. * Neurocognitive testing to check memory, decision-making, hand-eye coordination, and reasoning. * Evaluation of mood problems and assess personality type. * Evaluation to assess the quantity and quality of pain experienced. * Taste testing to determine the response to bitter, salty, sweet and sour substances. * Occupational therapy evaluation to explore the subject's adaptations, if any, for performing personal, social or professional activities; the subject's views on his or her weight, body size and shape, and strategies to control weight.
Gender: All
Ages: 18 Years - 100 Years
Updated: 2026-05-29
1 state
NCT00084305
Analysis of Specimens From Individuals With Pulmonary Fibrosis
The etiology of pulmonary fibrosis is unknown. Analyses of blood, genomic DNA, and specimens procured by bronchoscopy, lung biopsy, lung transplantation, clinically-indicated extra-pulmonary biopsies, or post-mortem examination from individuals with this disorder may contribute to our understanding of the pathogenic mechanisms of pulmonary fibrosis. The purpose of this protocol is to procure and analyze blood, genomic DNA, and specimens by bronchoscopy, lung biopsy, lung transplantation, extra-pulmonary biopsies, or post-mortem examination from subjects with pulmonary fibrosis. In addition, blood, genomic DNA, clinically-indicated extra-pulmonary biopsies, as well as bronchoscopy and post-mortem examination specimens may be procured and analyzed from relatives of subjects with hereditary forms of pulmonary fibrosis; blood, genomic DNA, and bronchoscopy specimens may be procured from healthy research volunteers.
Gender: All
Ages: 18 Years - 115 Years
Updated: 2026-05-29
1 state
NCT02471352
Studies of Dermatologic Diseases Biospecimen Acquisition Protocol
Background: \- Skin disease can have many causes. It can have widespread consequences, and in rare cases can lead to death. Researchers want to determine the causes of various types of skin diseases and find a way to treat them. Objectives: \- To determine the causes of various skin diseases and find ways to treat them. Eligibility: * People ages 2 and older who have: * A skin disease or at risk of developing a skin disease OR * A family member of persons with a skin disease * Healthy volunteers ages 2 and older Design: * Participants will be screened under a separate protocol. * Participants may take a survey about how their skin condition affects their quality of life. * Participants will have a medical history and a physical exam including a detailed skin exam. Pictures will be taken of their skin to document any skin disease. * Participants will have specimens collected. This may include: * Several teaspoons of blood taken at each visit * Stool samples * Nail and body fluid (like saliva) samples * Cheek swabs. The inside of the cheek will be scraped for about a minute in each direction to collect cells. * Collection of skin samples with: * A swab (like a Q-tip) * Gently scraping skin to remove the outer layers of cells * Applying and removing 1-inch pieces of tape * Participants may have up to 4 skin biopsies in 12 months, with 4 separate biopsies taken each time. * An area of skin will be numbed with an injection. * A piece of skin the size of a pencil eraser will be removed using a small instrument. * A flat scar usually develops at the biopsy site.
Gender: All
Ages: 1 Day - 100 Years
Updated: 2026-05-29
1 state
NCT06615986
Human Milk Oligosaccharide-Based Synbiotic Supplement for Intestinal Microbiota Dysbiosis
Background: Human intestines are home to a complex gut flora, also called microbiome; this is a natural occurring community of bacteria, fungi, yeast, and viruses. Changes in the balances of the gut flora can lead to illnesses, such as diabetes, colorectal cancer, and inflammatory bowel diseases. Synbiotics are dietary supplements people take to maintain proper balances of their gut flora aiming to improve health. Objective: To find out if a synbiotic supplement can increase the type and amount of beneficial gut bacteria in healthy people as well as improve cardio-vascular protection markers. The supplement contains a natural sugar from human milk. Eligibility: Healthy people aged 18 years or older who eat a typical western diet. They must take no medications (with a few exceptions). Design: Participants will have 2 clinic visits. The first visit will start with screening. They will have a blood test and wait around 2 hours for the results of the blood test. The test will determine if they are eligible for the study. Eligible participants will have additional blood drawn during the screening visit. They will be given a kit to collect a stool sample at home with instructions. They may complete a 3-day food diary. They will meet with a nutritionist and a physician by phone, telehealth, or in person. The supplement is a powder that is mixed with water or another noncarbonated drink. Participants will drink 2 doses per day. Each dose will be 1 hour before or after a meal. The second visit will be about 8 weeks after the first. Participants may repeat the 3-day food diary and nutrition visit. The physical exam, blood tests, and stool sample will be repeated.
Gender: All
Ages: 18 Years - 99 Years
Updated: 2026-05-29
1 state
NCT06577454
Measuring the Effects of Neurostimulation on Risky and Ambiguous Decision-Making Capacity in People With and Without Substance Use Disorder
Background: The purpose of this study is to understand how a type of brain stimulation, transcranial magnetic stimulation (TMS), may help those who use opioids such as heroin or methadone. TMS uses brief magnetic pulses to affect brain activity, and is approved by the FDA to treat some mental health problems and substance use. We will evaluate how TMS may help make it easier to make certain kinds of decisions that could help one manage their opioid use. Our findings may provide support for the use of brain stimulation as a treatment to reduce opioid use. Objective: To understand how TMS affects brain activity associated with decision making in people who do and do not use opioids. Eligibility: People aged 18 to 60 years with an OUD. Healthy volunteers are also needed. Design: Participants will have up to 3 clinic visits over 1 to 3 months. All participants will be screened to check if they are eligible to take part in this study. This study is completed in two parts. All eligible participants will complete the first part of the study. In the first part, you will receive one baseline magnetic resonance imaging (MRI) scan so we can take pictures of your brain while you complete computer tasks in the scanner. In these tasks, you will be asked to identify colors of words, view different images and play a game in which you can win money. If you can safely receive TMS, you will be invited to complete the second part of the study. In this part of the study, you will receive TMS and MRI over 2 sessions. For TMS, a coil will be placed on your head and a short electrical current will pass through the coil to create a magnetic pulse that stimulates your brain. You will also repeat the MRI scan and computer tasks. During one of the TMS visits you will receive active or real TMS. In the other, you will receive sham or placebo TMS, which feels like real TMS but does not affect the brain. You will receive both types of TMS. In all sessions, your urine and breath will be tested for drugs and alcohol, and you will complete questionnaires about mood and health....
Gender: All
Ages: 18 Years - 60 Years
Updated: 2026-05-29
1 state
NCT04799301
Developing Biomarkers of Dietary Intake: Dose Dependent Measurement of Sugar Intake
Background: Diet is one of the most modifiable behaviors affecting health. But diet assessment measures that are based on self-report can be inaccurate. Researchers want better ways to address the role of diet in chronic disease. They want to see if stable isotopes can be used to better assess what people eat. Objective: To see if stable isotopes can help scientists identify things people eat. Eligibility: Healthy adults ages 18 to 65 Design: Participants will be screened with a medical history and physical exam. They will have blood and urine tests. These tests will be repeated during the study. Participants will stay in the inpatient unit of the NIH in Phoenix, Arizona, for 13 weeks. For 7 days, participants will eat a diet prepared by the NIH kitchen. They will get balanced meals that are 50% carbohydrates, 20% protein, and 30% fat. Then participants will be randomly placed on one of 3 diets containing different percentages of carbohydrates from soda. Participants height and weight will be measured. The amount of fat and muscle in their body will be measured by body scans that are similar to x-rays. Participants will have oral glucose tolerance tests. They will consume a sugar drink and then give blood samples over 3 hours. Participants will give hair and stool samples. Participants will complete a diet questionnaire. It assesses their food intake over 24 hours. Participants will complete behavioral questionnaires and computer performance tests. Participants will have fat biopsies taken from their stomach and thigh. Participants will have three 24-hour stays in a metabolic chamber. It is used to measure metabolism.
Gender: All
Ages: 18 Years - 65 Years
Updated: 2026-05-29
1 state
NCT03394066
Mechanism of Non-invasive Magnetic Stimulation
Background: Transcranial magnetic stimulation (TMS) is form of non-invasive brain stimulation. It is approved to treat depression. TMS may help decrease drug craving. It is important to understand how TMS affects the brain. Such a better understanding would help to design ways to treat drug addiction. Objectives: To learn how TMS affects the brain when it stimulates an area in the front of the brain. Also, to see how the stimulation affects the area stimulated and other connected areas. Eligibility: Healthy, right-handed adults ages 18-60 who are non-drug users. Design: Participants will be screened under protocol 06-DA-N415. Participants will have at least 3 visits. The first visit will last about 3 hours. All other visits will last up to 6 hours. Participants cannot use drugs or alcohol at least 24 hours before a visit. They cannot have more than half a cup of a caffeinated drink at least 12 hours before a visit. Each visit will include a brief medical history update, urine test for drugs and pregnancy (if female), a breath test for alcohol and smoking, and questionnaires. Participants will have a TMS orientation visit. A wire coil will be placed on the head. An electrical current will pass through the coil to create a magnetic pulse that stimulates the brain. The other visits will include 2 sessions of TMS-MRI. Participants will lie on a table that slides into a cylinder. The TMS coil and the MRI coil will be placed over the head. Pictures will be taken of the brain with and without stimulation. Participants will complete a questionnaire about how they feel before and after each TMS session and in a follow-up call 1-3 days after their last session. ...
Gender: All
Ages: 18 Years - 60 Years
Updated: 2026-05-29
1 state
NCT07207135
Most Effective Knee Joint Angle Pair for Isometric Exercise
This study investigated the effects of isometric exercises applied to the quadriceps and hamstring muscles at different knee joint angles on balance, joint position sense, and functional performance in healthy individuals. Thirty participants aged 18-26 years were randomized into four groups and performed an eight-week training program, three times per week. Outcome measures included the Y Balance Test, digital goniometer assessments for joint position sense, and functional performance tests (stair climb and 30-second sit-to-stand). The results aim to identify which knee joint angles are most effective for improving neuromuscular function and may guide future rehabilitation and training protocols.
Gender: All
Ages: 18 Years - 30 Years
Updated: 2026-05-28
1 state
NCT07612020
A Study to Assess the Absolute Bioavailability of Empasiprubart SC Administered With an Autoinjector and the Pharmacokinetic Noninferiority of Empasiprubart SC Versus Intravenous (IV) in Healthy Adult Participants
This study aims to see how the body reacts to empasiprubart, administered using an autoinjector (AI). The study will also look at other effects of empasiprubart, how it works in the body, and if it is safe. The study consists of 2 parts: parts A and B. In part A, eligible participants will be randomized to receive empasiprubart SC AI via abdomen, empasiprubart SC AI via thigh, or empasiprubart IV (intravenously). In part B, eligible participants will be randomized to receive empasiprubart SC AI via abdomen or empasiprubart IV. Participants from part A will be in the study for approximately up to 37 weeks . Participants from part B will be in the study for up to approximately 43 weeks.
Gender: All
Ages: 18 Years - 65 Years
Updated: 2026-05-28
1 state
NCT07611422
Showers and Stress
The study investigates whether repeated exposure to cold showers can improve the ability to cope with and respond to stress. In particular, it examines both the psychophysiological effects of cold showers and the role of expectations regarding their effectiveness. The research adopts a 2×2 experimental design with approximately 120 healthy adults, randomly assigned to either an experimental group or a control group, and further divided based on the presence or absence of information emphasizing the potential benefits of the intervention. The experimental group takes warm or lukewarm showers with a final 30-second exposure to cold water at least four times per week, while the control group takes only warm or lukewarm showers. In parallel, some participants receive positive information about the effectiveness of the intervention for stress management, while others receive no specific information. At baseline and at the end of the study, participants complete questionnaires assessing perceived stress, psychological well-being, and quality of life, along with a physiological measure and a cognitive stress task (Stroop test with heart rate monitoring). During the four-week intervention period, participants keep a daily diary recording shower habits and perceived stress levels.
Gender: All
Ages: 18 Years - 60 Years
Updated: 2026-05-28
NCT05313555
The Effect of Violet Device Dosed Ultra Violet-C Light (UV-C) Exposure on Healthy Hand Skin
The purpose of this trial is to determine the safety of ultraviolet light (UV-C) irradiation as a method to sanitize hands instead of chemical-based sanitizers. Eligible participants will be enrolled and receive treatment with the Violet UV-C device or UV-B. Punch biopsies will be performed following UV exposure to quantify any changes in cellular and molecular properties of the tissue.
Gender: All
Ages: 18 Years - 55 Years
Updated: 2026-05-28
1 state
NCT05408091
Study to Evaluate Safety and Activity of TRL345 in Healthy Volunteers
This study in healthy volunteers will provide a basis for evaluation of TRL345 as a first in human study, specifically, important safety, tolerability, and pharmacokinetic data, and provide serum samples for ex vivo studies of concentration-dependent antiviral activity to support the dose selection for as well as design and conduct of a clinical study in transplant patients.
Gender: All
Ages: 18 Years - 65 Years
Updated: 2026-05-27
1 state
NCT07474545
A Study to Evaluate the Safety, Tolerability and Pharmacokinetics of KL0011034 Injection in Healthy Volunteers
To evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of single intravenous doses of KL0011034 injection in healthy volunteers.
Gender: All
Ages: 18 Years - 45 Years
Updated: 2026-05-27
1 state
NCT07409649
Influence of Intermittent Hypoxia on Loop Gain in Healthy Subjects
Sleep apnoea-hypopnoea syndrome (SAHOS), which causes numerous comorbidities, particularly cardiovascular ones, is widespread worldwide today and incurs significant healthcare costs. Current research in this field focuses on identifying different phenotypes in affected patients in order to provide more personalised treatment. One of these phenotypes appears to be linked to instability in ventilatory control due to an increase in loop gain (LG) in these subjects. However, the pathophysiology of this ventilatory control instability due to increased LG is not fully understood. It is still difficult to determine whether subjects have an intrinsically high LG or if exposure to intermittent hypoxia during OSA promotes an increase in LG. It has also been demonstrated that OSA causes vascular hyperreactivity by increasing oxidative stress through elevated ROS production. This leads to endothelial dysfunction in response to intermittent hypoxia associated with apnoea. Extracellular vesicles (microvesicles and exosomes) have been shown to play a role in this endothelial response. These extracellular vesicles are essential for intercellular communication in both physiological and pathological situations, such as SAHOS. Therefore, the objective of this research is to determine whether exposure to intermittent hypoxia and changes in microvesicle phenotype could influence LG, which could lead to new therapeutic advances in the context of SAHOS.
Gender: All
Ages: 18 Years - 45 Years
Updated: 2026-05-27
NCT07240675
Single-dose,First-in-human of KLA478
The purpose of this study is to evaluate the safety and tolerability and pharmacokinetics of single doses of KLA478 in healthy volunteers;
Gender: All
Ages: 18 Years - 45 Years
Updated: 2026-05-26
1 state