View clinical trials related to Healthy Volunteers.
Filter by:This is a double-blind, placebo-controlled study, three-period crossover study to examine the likeability of a single dose of OROS MPH (CONCERTAÒ 90mg) and a single dose of Long-acting MPH (RITALIN LAÒ 90mg). Hypotheses are as follows: Hypothesis 1: OROS-MPH (CONCERTAÒ) will be later than SODOS-MPH (RITALIN LAÒ) in its Tmax (time to Cmax). Hypothesis 2: The subjective feelings of detection and likeability would be greater for SODOS-MPH (RITALIN LAÒ) than for an equivalent total dose of OROS-MPH (CONCERTAÒ).
The specific aim of this study is to document the pharmacokinetics of dopamine transporter DAT receptor occupancy of OROS MPH and Metadate CD using PET scanning with C-11 Altropane as the ligand. We hypothesize that CNS DAT occupancy of OROS MPH will be greater than that of Metadate CD at 10 hours after administration.
To evaluate the bioavailability of celecoxib administered as capsule contents sprinkled onto applesauce relative to intact capsule
The purpose of the study is to test the effect that contrast media (dye) has on cellular integrity (structure)
This study will use positron emission tomography (PET) and magnetic resonance imaging (MRI) to measure peripheral benzodiazepine receptors (PBRs) in the brain. PBRs were initially found in peripheral organs such as kidneys, endocrine glands and lungs, but later studies identified PBRs in the CNS. PBRs can be a marker to detect nervous system inflammation. Development of a test to image PBRs may improve the management of brain disorders such as multiple sclerosis, Alzheimer's disease, Parkinson's disease, and others in which inflammation is involved in progression of the disease. Healthy volunteers from 18 to 40 years old may be eligible for this study. Candidates are screened with tests that may include some or all of the following: diagnostic interview; ratings of mood, anxiety, functioning, and other parameters; neuropsychological testing; physical examination; electrocardiogram; blood and urine tests; and personal, social and family histories. Participants undergo the following procedures: - Evaluation: Subjects provide a medical history, including detailed questions about their psychological health, and have a physical examination and blood and urine tests. - PET scanning: PET uses small amounts of a radioactive chemical called a tracer that "labels" active areas of the brain. The tracer used in this study is [11C]PBR28. For the procedure, the subject lies on the scanner bed. A special mask is fitted to the head and attached to the bed to help keep the head still during the scan so the images will be clear. A brief scan is done just before the radioactive tracer is injected to provide measures of the brain that will help to precisely calculate information from subsequent scans. After the tracer is injected through a catheter (plastic tube) placed in the arm, pictures are taken for 2 to 3 hours, during which the subject lies still on the scanner bed. Subjects return to the clinic the following day for more blood and urine sample collections. - MRI: The MRI scan is done within 1 year of the PET scan (either before or after the PET). MRI uses magnetic fields and radio waves to produce images of the brain. The patient lies on a table that is moved into the scanner (a narrow cylinder), wearing earplugs to muffle loud knocking and thumping sounds that occur during the scanning process. He or she can communicate with the staff at all times during the procedure.
This study is being done to test new way of measuring the relaxation of the stomach after a meal (called gastric accommodation) by using a MRI scan. This new test will be compared with the standard test of measuring stomach relaxation that uses radioactive tracers. These tests will be compared in healthy volunteers and people with upper abdominal symptoms (known as dyspepsia).
Direct stimulation of the cerebral cortex induces an increase in cerebral blood flow. Although this information is known, it has never been documented during Transcranial Cerebral Electrical Stimulation (TCES), which is a non invasive technique. It is used to modulate the opiate endogenous system, mainly in opioid users but no cerebral blood flow mapping of the anatomic regions involved in this modulation of the opiate system under electrical stimulation has been performed in functional Computerized Tomography.
The purpose of this study is to evaluate the local anesthetic properties of neosaxitoxin in humans
Objectives: Plasma levels of catechols have distinct meanings in terms of indicating functions of endogenous catecholamine systems. This Protocol is designed to enable ongoing quality assurance of diagnostic and research assays of catechols and their metabolites and to identify possible influences of demographic and anthropometric factors, dietary constituents, and conditions of sampling on reference values. Study Populations: The study population is healthy volunteers and people who are obese or have untreated hypertension. Design: Arm venous blood is drawn via an indwelling i.v. catheter from healthy volunteers across demographic and anthropometric spectra (age, gender, skin color, ethnicity, body mass, adiposity), to obtain quality control plasma and establish reference values for plasma levels of catechols and their metabolites. Non-invasive physiological measures are obtained concurrently. Levels of catechols and their metabolites are related to results of common clinical pathology tests. Subgroups of subjects are tested more than once, to assess dietary influences (cereal with milk, coffee) and conditions of sampling (temperature at the skin). Outcome Measures: The main non-experimental outcome is an ongoing pool of quality control plasma. The main experimental outcome measures are plasma concentrations of catechols and their metabolites, non-invasive physiological measures, and results of common clinical pathology tests. Subject groups are compared with respect to the above demographic and anthropometric factors. Effects of the experimental manipulations are assessed within subjects
This study will use positron emission tomography (PET) and magnetic resonance imaging (MRI) to measure a serotonin receptor subtype in the brain called 5-HT(1A). This receptor is a target for drug therapy to treat anxiety and depression. The study will see if a newly developed radioligand (radioactive substance used in PET scanning to study the receptor systems of the brain) called [(11)C](-)-RWAY is more effective than other radioligands currently used in brain receptor research. Healthy subjects 18-40 years of age may be eligible for this study. Candidates are screened with a physical examination, electrocardiogram, and blood and urine tests. Participants undergo PET and MRI scanning as follows: PET scan PET uses small amounts of a radioactive chemical called a tracer (in this case, [(11)C](-)-RWAY) that "labels" active areas of the brain. For the procedure, the subject lies on the scanner bed. A special mask is fitted to the subject's head and attached to the bed to help keep the head still during the scan so the images will be clear. A brief scan is done just before the tracer is injected to provide measures of the brain that will help in the precise calculation of information from subsequent scans. Then, the tracer is injected through a catheter (plastic tube) placed in the arm and pictures are taken for about 2 hours, while the subject lies still on the scanner bed. Subjects return to the clinic for blood and urine tests 24 hours after the scan. MRI The MRI scan is done within 1 year of the PET scan. MRI uses a magnetic field and radio waves to produce images of body tissues and organs-in this case, the brain. The subject lies on a table that is moved into the scanner (a tube-like device), wearing earplugs to muffle the noise of the machine during the scanning process. The space in the scanner is confining and may cause some people to be somewhat anxious. An intercom system allows the subject to speak with the staff member performing the study at all times during the procedure, and the procedure can be stopped at any time.