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229 active trials for Healthy Volunteers

Characterization of Phenotypic and Genotypic Regressors for Imaging

The influence of genes on addictive and neuropsychiatric disorders is complex, especially given that multiple genes likely influence certain behaviors that are correlated with addiction. Researchers are interested in looking at the genetic information of individuals who are enrolled on National Institute for Drug Abuse studies to investigate specific genetic variants that may be related to substance abuse. Researchers will study the effects of genes on several aspects of thinking such as attention, memory, decision making, problem solving, learning, and emotional feelings, and investigate the ways in which genetic information affects addictive behaviors and substance abuse. In addition, researchers will study how genes may explain differences in imaging data in substance users. Objectives: - To collect genetic information for research on genetic aspects of addiction and substance abuse. Eligibility: Adults age 18 or older (1) healthy, non-drug-using nonsmokers, (2) healthy smokers, (3) healthy individuals dependent on other commonly abused drugs, and (4) individuals with other psychiatric disorders. Participants must be right-handed, and must be enrolled in another National Institute on Drug Abuse, Intramural Research Program imaging protocol. Design: This study involves one to two visits to National Institute on Drug Abuse, Intramural Research Program that may be separate from the participant's current research protocol study visits or on the same day as those visits. Participants will provide a blood sample and complete questionnaires about mood, memory, and learning. Participants may also be asked to do a few tasks, such as playing computer games involving coin tosses and money management, or responding to questions on a computer screen.

Start: November 2010
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 2 3 weeks after their last session.

Start: August 2018
Luxembourgish Fiber Cohort

Many human populations across the world are deficient in the intake of dietary fiber. This decline in fiber consumption parallels an increase in prevalence of a multitude of diseases (e.g. colorectal cancer, multiple sclerosis). A possible link for this association between dietary changes and the diseases could rest in the trillions of commensal gut microbes that digest dietary fibers, provide energy for colonic cells, and modulate the immune system. However, the molecular mechanisms that link fiber deficiency via the activities of the gut microbiome to various diseases have been poorly understood. The investigators previously showed that, in a mouse model with a defined human gut microbiota, removal of fiber from the diet favors proliferation of bacteria that degrade the gut's protective mucus lining. In the proposed project, the investigators aim to translate our findings from mouse studies to humans using a 2x2 crossover study among healthy adults. Forty participants will be randomly assigned to a low- or high-fiber dietary intervention and then, following a washout period to reverse any changes, switched to the other diet type. By employing longitudinal sampling of stool collections, the investigators envision that participants will exhibit increased abundance and activities of mucolytic bacteria when fed a low-fiber diet. The unique selling point of the proposed study involves setting up high-throughput culture collections of mucus-degrading bacteria, whose abundances and activities will be investigated by sequencing and enzymatic assays in stool. Additionally, the investigators will measure inflammatory markers in blood using CyTOF to assess whether short-term fiber deficiency exerts detectable changes in the host immune function. Thus, the proposed dietary intervention clinical trial will help elucidate the role of fiber deficiency in various chronic diseases.

Start: February 2021
A Clinical Pharmacology Study to Evaluate the Effect of GYM329 on Disuse Muscle Atrophy in Healthy Volunteer

This study will induce disuse atrophy through unilateral immobilization of the thigh and lower leg in healthy male volunteers to evaluate the PD of a single subcutaneous dose of GYM329 prior to or after unilateral thigh and lower leg immobilization. Healthy male volunteers will receive either GYM329 or placebo by subcutaneous injection at two time points, before and after 2 weeks of unilateral thigh and lower leg immobilization, in an investigator- and subject-blinded, randomized, placebo-controlled, parallel-group design. At enrollment, all subjects will be randomized in a 1:2 ratio to either the pre-immobilization active drug group receiving a single subcutaneous dose of GYM329 before unilateral thigh and lower leg immobilization (Group A) or the pre-immobilization placebo group receiving a single subcutaneous dose of placebo before unilateral thigh and lower leg immobilization (Group B). On Day 15, subjects assigned to Group B and who completed the muscle strength assessment at Day15 will be further randomized in a 1:1 ratio to either the post-immobilization active drug group (Group B-1) or the post-immobilization placebo group (Group B-2). Group A will receive GYM329 on Day 1 and placebo on Day 15. Group B will receive placebo on Day 1. Subsequently, Group B-1 will receive GYM329 on Day 15 and Group B-2 will receive placebo on Day 15. Muscle strength will be measured at pre-immobilization of unilateral thigh and lower leg, post-immobilization of unilateral thigh and lower leg (Day 15), Day 29, and Day 43. Subjects will be observed for 294 days after the second study treatment administration (308 days after the first study treatment administration).

Start: February 2021
Chronic Transcutaneous Stimulation to Promote Motor Function and Recovery in Individuals With Paralysis or Paresis

This is an early feasibility trial to determine whether transcutaneous neuromuscular electrical stimulation, with or without transcutaneous spinal cord stimulation, using an investigational neurostimulation device improves functional arm/hand movements in individuals with paralysis or paresis due to a spinal cord injury or stroke and improves functional arm/hand or leg/foot movements in individuals with paralysis or paresis due to other brain or nerve injuries. In this study, eligible individuals that agree to participate will be asked to attend up to 5 study sessions a week for 1 year (depending on participant availability), with each session lasting up to 4 hours. At the first study session, participants will have their demographic information collected, vital signs assessed, and have measurements performed of their limbs and torso, as appropriate. They will also undergo clinical evaluations and tests to assess their current functional movement and sensation capabilities. During subsequent study sessions, participants will undergo many tasks designed to improve functional movements in paralyzed limbs. Specifically, participants will receive neuromuscular electrical stimulation to the limb(s) and/or electrical stimulation to the spinal cord to evoke specified movements. The stimulation parameters and locations on the spinal column and/or limb(s) that evoke specific movements will be noted. The movements will be assessed with visual inspection, electromyography, and/or sensors. The clinical evaluations and tests to assess functional movement and sensation capabilities will be repeated throughout the study and at the last study session to assess for functional improvements compared to the first study session. Upon completion of these study sessions, the individual's participation in the study is considered complete.

Start: December 2020