36 Clinical Trials for Various Conditions
This study will examine and compare the effects of intense exercise on the release of catecholamines in patients with congenital adrenal hyperplasia (CAH) and in healthy persons. Catecholamines are hormones (adrenaline and noradrenaline) that are produced by the adrenal glands and released into the blood stream during stress, such as trauma, illness, intense exercise, or low blood sugar. The study will also assess exercise tolerance in patients with CAH, compared with healthy persons. Patients with CAH between the ages of 10 and 40 years who are managing well on standard treatment (glucocorticoids, mineralocorticoids) may be eligible for this study. Healthy volunteers that match the enrolled patients in age, sex, race and body fat will be recruited as control subjects. All candidates will be screened with a medical history, physical examination and electrocardiogram (EKG). Body fat will be measured using an instrument called a Bod Pod. The body fat measurement has two parts: first, the subject sits quietly in a large egg-shaped capsule for about 2 to 3 minutes; then the subject breathes into a plastic tube for one minute, followed by three quick panting breaths. Women will have a urine pregnancy test; pregnant women cannot participate in the study. Participants will undergo three exercise sessions on separate consecutive mornings after fasting overnight. Before each test, patients (not healthy volunteers) will take either an additional morning dose of hydrocortisone or a placebo (a lookalike pill with no active ingredient). Before each test a thin catheter (plastic tube) will be placed into an arm vein through a needle. A numbing cream can be applied to make the needle stick hurt less. Blood will be drawn through this intravenous (IV) line before, during and after the exercise tests. The first test is a maximal exercise test to determine the individual's maximum exercise fitness capacity. The second two and third tests are a standardized exercise tests. Before the two standardized tests, patients (not healthy volunteers) will take either an additional morning dose of hydrocortisone or a placebo (a lookalike pill with no active ingredient). All tests are done on a stationary bicycle. Maximal Exercise Test - The subject pedals on a stationary bicycle for about 10 minutes. After a 3-minute warm-up, the workload is increased continuously until either the subject can no longer continue or the physician stops the test for medical reasons. During the exercise, heart rate and heart activity are monitored with an EKG, and the subject wears a nose clip and mouthpiece connected to a breathing tube to measure oxygen use. Blood is drawn before and during the test, totaling no more than 2 tablespoons. Standardized Exercise Test - The subject pedals on a stationary bicycle for 20 minutes, while wearing the nose clip and mouthpiece to measure oxygen use. For the first 5 minutes, the subject pedals at a speed that elicits 50 percent of maximal effort (determined by the maximal exercise test); the next 10 minutes are at 70 percent of maximal effort; and the last 5 minutes are at 90 percent. Blood samples drawn before, during (at 15 and 20 minutes) and after exercise (at 30, 40 and 60 minutes) total less than 1/2 cup. Heart rate and heart activity are monitored during the test with an EKG, and temperature is measured before and at the end of the test.
In a randomized controlled trial, the investigators intend to measure the health impact of time-restricted eating (TRE) in obese patients (body mass index (BMI) ≥ 30 kg/m2), who habitually eat for more than 14 hours every day. Patients will be randomly assigned to a control group of behavioral nutritional counseling (standard of care) or the intervention group of behavioral nutrition counseling with the addition of adopting a 10-hour eating window for 12 weeks (TRE).
This is a Phase 3, double-blind, randomized study of LJPC-501 (angiotensin II) in adult patients diagnosed with catecholamine-resistant hypotension (CRH) conducted in multiple centers globally.
Traumatic brain injury (TBI) is among the leading causes of trauma death and disability in both civilian and military populations. The damage that occurs at the instant of trauma cannot be modified; the secondary injuries that occur afterward are the impediments to recovery and can be influenced by the physician. Cerebral ischemia is the most important secondary event that determines outcome following TBI. To minimize ischemic episodes once the patient has arrived at the hospital, most treatments are aimed at optimizing cerebral perfusion pressure (CPP). The cornerstones of these treatments include mannitol, to reduce intracranial pressure (ICP), and catecholamines, such as phenylephrine (PE), to increase mean arterial pressure (MAP), but these agents have undesired side effects. Nevertheless, once they lose potency, there are few alternatives. The main objective of this proposal to develop a new therapeutic option for CPP management in TBI patients using arginine vasopressin (AVP). AVP is the endogenous anti-diuretic hormone. It is FDA-approved for use in the diagnosis and treatment of diabetes insipidus, for the prevention and treatment of post-operative abdominal distention, and in abdominal radiography to dispel interfering gas shadows. It has been used off-label for several other conditions. There is minimal information on its therapeutic potential after TBI. The investigators have demonstrated that AVP during fluid resuscitation rapidly restored hemodynamics, CPP, and improves acute survival in a clinically-relevant model of TBI. The investigators observed similar short term benefits after chest and liver trauma. Nevertheless, AVP has actions that could mask any short term benefit. The investigators have already defined risks and benefits of AVP therapy, relative to PE, in four different clinically-relevant laboratory model. The investigators now plan to evaluate this new therapy relative to the current evidence-based guideline for CPP management in TBI patients. The working hypothesis is that the risk/benefit profile for AVP is equal, or superior to, PE at equi-effective doses for the management of CPP following TBI. A corollary is that a higher CPP can be safely tolerated with AVP vs catecholamines. THE INVESTIGATORS AIM TO: Determine whether AVP is safe and effective to maintain CPP = 60 mm Hg in TBI patients.
This study will explore brain function related to depressive symptoms and will examine DNA for genes that may be involved in depressive disorders, particularly genes that regulate synthesis and metabolism of the brain neurotransmitter catecholamine. It will compare findings in patients with major depressive disorders who are in remission with those in normal, healthy volunteers. Patients with remitted major depressive disorders and healthy normal volunteers between 18 and 60 years of age may be eligible for this study. Candidates are screened with a psychiatric and medical history, physical examination, electrocardiogram, and blood and urine tests. Participants undergo the following tests and procedures in up to eight visits to the NIH Clinical Center: Memory Tasks and Problem Solving and Brain Imaging Subjects are tested with measurements of intelligence or memory ability. They also undergo magnetic resonance imaging (MRI), a test that uses a magnetic field and radio waves to produce images of the brain. For this procedure, the patient lies on a table that is moved into the scanner (a narrow cylinder), and wears earplugs to muffle loud knocking and thumping sounds that occur during the scanning process. The MRI lasts about 60 minutes. Catecholamine Depletion Study For this study, subjects take capsules containing either AMPT (a drug that temporarily reduces brain catecholamine activity) or a placebo (lactose capsules, which do not affect brain catecholamine activity) at 9 a.m., 2 p.m., and 7 p.m. on one visit and return the next day to take additional capsules at 7 a.m. and noon. In addition to the study medication, subjects keep a low-monoamine diet (e.g., no chocolate, cheese, smoked meats, and various other foods that will be enumerated) and do not smoke, drink alcohol, or take in food or drink containing caffeine. After taking all the study capsules, the subjects have positron emission tomography (PET) and functional MRI (fMRI) scans, as follows: * fMRI: While lying in the MRI scanner, the subject performs a monetary reward task that is somewhat like playing a computer video game for money. The amount of cash the subject can win depends on his or her performance. It is possible to lose money that was previously won, if performance declines. This portion of the study provides information on how the brain processes reward and about the role of catecholamines in this process. * PET: The subject is injected in the arm with a glucose solution that has a radioactive substance attached that can be detected by the PET scanner. During the scan, the subject looks at photographs of faces on a computer screen and is asked to tell the gender of the persons. This test shows brain blood flow and measures brain glucose (sugar) metabolism, which reflects brain activity. At the end of the scan, subjects are asked about their mood and general well being. They return to the Clinical Center the following day for and evaluation of their emotional state. The catecholamine depletion study is repeated a second time 14 days or more after the first. Subjects who received AMPT capsules for the first study take lactose capsules for the second study, and vice-versa.
The objective of this study is to evaluate the effect of LJPC-501 infusion on mean arterial pressure (MAP) or reduction in sum norepinephrine (NE) equivalent dosing, at Hour 2 after the start of LJPC-501, in pediatric patients who remain hypotensive despite receiving fluid therapy and vasopressor therapy. In addition, this study will evaluate the safety and tolerability of LJPC-501 in pediatric patients, the change in MAP over 24 hours after the start of LJPC-501, the change in serum lactate concentrations, and the change in Pediatric Logistic Organ Dysfunction (PELOD) scores.
This study uses an experimental design to conduct a double-blind, randomized, crossover study where participants receive both diesel exhaust and a mental stress test in a controlled setting. My hypothesis is that the synergistic effect of stress and air pollution will result in higher levels of stress and inflammation (measured via biological markers) as well as poorer cardiovascular disease related outcomes compared to the independent effect of each exposure separately.
Patients that have undergone a Fontan procedure (surgical correction for single ventricle congenital heart disease) may develop a complication known as protein-losing enteropathy (PLE). Some studies suggest PLE is primarily caused by impaired lymph flow. Use of continuous dopamine infusion can improve PLE. Evidence suggests the effect of dopamine may be through its effect on lymphatic function. This observational study looks at markers of lymph flow and PLE symptoms after treatment using dopamine and other standard therapies during disease exacerbations.
Baroreflex sensitivity is integral to blood pressure regulation, and varies among healthy, normotensive individuals. A reduced compensatory ability of baroreflex buffering in patients with carotid denervation results in blood pressure variability and an elevated blood pressure response to mental stress. Furthermore, 24-hour ambulatory blood pressure variability may also be a significant and independent risk determinant of cardiovascular disease. It remains unknown whether the degree of baroreflex sensitivity and ambulatory blood pressure variability are predictive of the pressor response to sympathoexcitatory stress in healthy humans. In this study the investigators propose a comprehensive evaluation of the relationships among the pressor and forearm vasodilator response to sympathoexcitation, ambulatory blood pressure variability, and baroreflex sensitivity in healthy normotensive subjects. Ultimately this study will provide preliminary data and protocol development for large-scale high resolution phenotyping in population-based trials aimed at determining the functional relevance of candidate gene variation in intermediate physiological traits pertinent to the pathogenesis of hypertension and cardiovascular disease.
Topical timolol has been used primarily as eye drops to treat glaucoma for many years. Recent clinical experience has broadened its off-label use for a number of skin conditions, including slow-healing wounds. While there have been extensive safety studies performed on timolol administration to treat the eye, to date, no studies have documented absorption of timolol after applied on chronic wounds. Thus, the purpose of this study is to determine the blood levels of timolol in patients after topical administration to a chronic wound, and compare these levels with those of patients after administration of the same drug formulation on the eye for the indication of glaucoma.
Background: The autonomic nervous system controls automatic body functions. Researchers want to improve the tests used to diagnose autonomic failure. Orthostatic hypertension is a drop in blood pressure when a person stands up. Researchers want to focus on this sign of autonomic failure. Objective: To improve testing for conditions that cause autonomic nervous system failure. Eligibility: People ages 18 and older in one of these categories: * Their blood pressure drops when they get up. * They have had a heart transplant or bilateral endoscopic thoracic sympathectomies or have had or will have renal sympathetic ablation Design: All participants will be screened with: * Medical history * Physical exam * Blood and urine tests Some participants will be screened with: * Heart and breathing tests * IV placement into an arm vein * Tilt table testing: Participants lie on a table that tilts while an IV is used to draw their blood. Participants may stay in the hospital for up to 1 week depending on their tests. Tests may include repeats of screening tests and: * Sweat testing: A drug is placed on the skin to cause sweating. Sensors on the skin measure moisture. * Lumbar puncture: A needle is inserted between the bones in the back to collect fluid. * MRI and PET/CT scan: Participants lie on a table that slides into a scanner. For the PET/CT, a small amount of a radioactive chemical will be injected with a small amount of a radioactive chemical. * Bladder catheter placement to collect urine * Skin biopsies: A punch tool removes a small skin sample. * Tests to see how the pupils react to light * Smelling tests * Thinking and memory tests * Questionnaires Participants may have a visit about 2 years later to repeat tests.
Background: Pheochromocytoma and paraganglioma are rare tumors. They usually form inside and near the adrenal gland or in the neck region. Not all these tumors can be removed with surgery, and there are no good treatments if the disease has spread. Researchers think a new drug may be able to help. Objective: To learn the safety and tolerability of Lu-177-DOTATATE. Also, to see if it improves the length of time it takes for the cancer to return. Eligibility: Adults who have an inoperable tumor of the study cancer that can be detected with Ga-68-DOTATATE PET/CT imaging Design: Participants will be screened with a medical history, physical exam, and blood tests. Eligible participants will be admitted to the NIH Clinical Center. Participants will get the study drug in an intravenous infusion. They will get 4 doses, given about 8 weeks apart. Between 4 and 24 hours after each study drug dose, participants will have scans taken. They will lie on their back on a scanner table. Participants will have vital signs taken. They will give blood and urine samples. During the study, participants will have other scans taken. Some scans will use a radioactive tracer. Participants will complete quality of life questionnaires. Participants will be contacted by phone 1-3 days after they leave the Clinical Center. They will then be followed every 3 to 6 months for 3 years or until their disease gets worse.
Septic shock is a condition that is marked by severe infection causing hypotension requiring vasopressors to maintain adequate perfusion to vital organs. The Surviving Sepsis campaign, an international organization formed for the purpose of guiding the management of sepsis and septic shock, currently recommends norepinephrine as the first-choice vasopressor for septic shock. Phenylephrine, a vasopressor FDA-approved for use in septic shock, is recommended as an alternative vasopressor when septic shock is complicated by tachyarrhythmia to mitigate cardiac complications. This recommendation is based solely on experience with no scientific evidence to support this recommendation. The investigators will conduct an open-label randomized controlled trial (RCT) directly comparing phenylephrine and norepinephrine, two FDA-approved vasopressors that are both used in clinical practice for the management of septic shock. The investigators will perform this study with a population of patients that have septic shock to complete the following aims: Aim 1: Determine the incidence of tachyarrhythmias. Aim 2: Determine which vasopressor, phenylephrine or norepinephrine, is associated with a lower heart rate. Aim 3: Determine which vasopressor, phenylephrine or norepinephrine, is associated with a higher incidence of new tachyarrhythmias. Aim 4: Determine which vasopressor, phenylephrine or norepinephrine, is associated with less time in tachyarrhythmia. Aim 5: Determine which vasopressor, phenylephrine or norepinephrine, is associated with fewer complications, including cardiac complications. The investigators hypothesize that in this setting, phenylephrine will improve the management of septic shock when used as a "first choice" vasopressor by: 1. Decreasing the mean heart rate 2. Decreasing the incidence of new tachyarrhythmias 3. Decreasing the amount of time spent in tachyarrhythmia for patients who develop new onset and recurrent tachyarrhythmias 4. Decreasing the number of cardiac complications
Background: - The autonomic nervous system helps control things that happen automatically in the body, like blood pressure, heart rate, and digestion. When it doesn t work properly, it s called dysautonomia. Researchers want to learn more about dysautonomias and train doctors to learn how to better diagnose them. Objectives: * To allow people with autonomic disorders to be evaluated. * To help fellows in the NIH Autonomic Disorders fellowship program see a variety of diseases in their training. Eligibility: * People age 18 and older with dysautonomia; children over age 2 if they might benefit * Healthy adult volunteers Design: * Participants will have different procedures depending on their symptoms. They will have one or more visits. They will have some but not all of the tests below. * Participants will have a medical history and physical exam. They may be tested for problems thinking. They may complete a symptom questionnaire. They may have their temperature and blood pressure taken. * Participants may have an intravenous line placed. A needle will guide a thin plastic tube into an arm vein. * Participants may have blood drawn several times. They may give a urine sample. * Participants may have an electrocardiogram. * How much blood a participant s heart is pumping and/or how much blood is flowing through their arm may be measured. The total amount of blood in their bloodstream may be measured. * Participants may have their ability to sweat and/or sense of smell tested. * Breathing, bowel sounds, and/or body functions may be monitored. * Pupil size, response to environmental temperature changes, and/or breathing may be measured. * Participants may have a bladder ultrasound. * Small pieces of skin may be taken for study.
Background: - Research has shown that one exercise session may improve a person s ability to recall information they learned before the exercise. Knowing how exercise changes brain activity to improve memory can help researchers understand how memory works and how to improve it in people with memory problems. This study compares two kinds of exercise on a stationary bike for their ability to temporarily improve memory on certain tests. Researchers will look at the effect of exercise on body chemistry by drawing blood and collecting saliva. Objectives: - To understand how a single session of exercise affects memory testing in healthy people and people who have had traumatic brain injury (TBI). Eligibility: * Adults ages 18 through 45 with TBI. * Healthy adult volunteers, ages 18 through 45. Design: * Participants will be screened with medical history and physical exam. This will take about 1 hour. * Participants with TBI will also be screened with a test of their memory. This will take another hour. * Visit 1 will take about 3 hours. Participants will: \<TAB\>- Have a tube inserted in their arm for drawing blood during the tests. \<TAB\>- Take memory tests. They will look at pictures, symbols, and words, then answer questions. \<TAB\>- Give a saliva sample by chewing on a small sponge for 2 minutes. \<TAB\>- Exercise on a stationary bike. \<TAB\>- Take the memory tests again. - Visit 2 will take place 1 week later. Participants will take the memory tests only.
The investigators intend to determine the effect of adrenergic blockade on 1) short-term physiology, behavior, and cognition and 2) long-term neuropsychological outcomes after severe Traumatic Brain Injury (TBI). The primary hypothesis is that adrenergic blockade after severe TBI will be associated with increased ventilator-free days.
The purpose of this study is to test the effect of oral melatonin supplementation (24 mg per night for 4 weeks) on nighttime blood pressure in African Americans with a history of elevated nighttime blood pressure.
This purpose of this study is to test the effect of oral melatonin supplementation (8 mg per night for 4 weeks) on nighttime blood pressure in African Americans with a history of elevated nighttime blood pressure.
This study (https://pdrisk.ninds.nih.gov) will determine if people who have risk factors for Parkinson disease (PD) have biomarkers (objective ways to measure a disease process) that show that the disease process is actually going on, and if people who have abnormal biomarkers go on to develop PD during several years of follow-up. Biomarkers of Parkinson disease (PD) might identify people who are healthy now but may develop the disease later in life. Healthy volunteers and people who have certain risk factors for developing PD who are between 18 and 70 years of age may be eligible for this study. People with the following risk factors are included: * Family history of PD * Loss of sense of smell * Fall in blood pressure when standing up * REM behavior disorder (a type of sleep disturbance) Participants undergo the following tests and procedures: * Screening examination * Medical and neurological history and physical examination * Tests or rating scales for movement, sense of smell, mood, attention, fatigue, pain, and thinking. * Measurement of blood pressure and pulse rate while lying down and then standing up * Blood draw for genetic testing * Inpatient testing at the NIH Clinical Center for 2-3 days, including: * Measurements while blowing against a resistance * Measurements of blood pressure and pulse rate * Blood draws for levels of various chemicals * PET and MRI scanning * Lumbar puncture (spinal tap) * Electrocardiogram * Skin electrical conduction test (test of sweat production) * Skin and core temperature measurements * Transcranial ultrasound (sound-wave test of the head) * Follow-up testing (up to five visits in 18-month intervals) to repeat some of the tests listed above, excluding the genetic testing and spinal tap
The purpose of this study is to determine the cause of low blood pressure in selective patients who have problems with their involuntary (autonomic) nervous system. These patients frequently have had symptoms throughout their life, and their disorder might have a genetic basis. The biochemical, physiological and pharmacological procedures in this study should help us define the problem and perhaps lead to more effective treatment.
It has been found that in some cases, when a person with Diabetes Mellitus has an episode of low blood sugar,or hypoglycemia, and then later exercises, he or she is vulnerable to another bout of hypoglycemia during that exercise. The purpose of this study is to determine what factors during the previous bout of hypoglycemia might cause another bout of hypoglycemia while exercising later.
HYPOTHESIS: The investigators hypothesize that KuvanTM therapy could influence nutritional and body composition parameters and neurotransmitter concentrations in pediatric and adult PKU subjects. SUMMARY: Though the investigators know that KuvanTM lowers blood Phe levels and improves tolerance for natural protein in at least half of the PKU (Phenylketonuria) patient population, investigators do not know the full effects this medicine will have on the patient's diet, or what impact the medicine or diet changes will have on the body composition or nutrient status of PKU patients. Since KuvanTM may also help the body produce neurotransmitters, investigators also want to find out if taking KuvanTM changes neurotransmitter levels in PKU patients, and if PKU patients who are benefitting from KuvanTM feel less stigmatized and have a better outlook on life as a result of the treatment. Therefore, the research study has several objectives. These are to investigate the impact KuvanTM therapy has on (1) body composition parameters of PKU patients: such as lean body mass, percent body fat, bone density, weight gain, and growth (2) dietary changes, and the effect of those changes, on intake of calories and essential nutrients (3) changes in blood biomarkers of certain nutrients (4) blood and urine neurotransmitter levels, since these changes could indicate improved neurological functioning, (5) and quality of life of PKU patients, who may feel less burdened due to the dietary freedom KuvanTM provides.
The purpose of the proposed research is to determine how changes in kidney dopamine (DA) activity influence urinary sodium excretion. We will decrease DA activity in the kidney by inhibiting DA synthesis via carbidopa administration. We want to compare findings in normal volunteers and in patients with postural tachycardia syndrome (POTS). We will test the null hypothesis (Ho) that the effects of oral carbidopa administration on urinary sodium excretion will not differ between patients with POTS and healthy volunteers.
The purpose of this study is to try different medications in patients with low blood pressure and other problems with their involuntary (autonomic) nervous system. The pharmacological trials in this study will perhaps lead to more effective treatment. The protocol includes single dose trials, dose-selection trials, 5-day trials and chronic (approximately 2 months) trials, although only dose-selection trials were consistently performed and have results presented.
This study will examine how body metabolism adjusts to small changes in environmental temperature and how it may be related to weight loss. Healthy, non-obese individuals between 18 and 60 years of age may be eligible for this study. The study consists of one screening visit and one 5-day admission to the NIH Clinical Center for the following procedures: Diet: Participants follow a proscribed diet consisting of 50% carbohydrates, 20% protein and 30% fat. DEXA scan to measure body fat. Subjects lie on a table above a source of X-rays while a very small dose of X-rays is passed through the body. Air displacement plethysmography (Bod-Pod) to study fat composition: Subjects sit in a small booth for 10 minutes wearing a swim suit and breathing normally through a tube. This test measures the person s weight and volume precisely. Metabolic room: Subjects stay 12 hours in a specialized room designed to measure the amount of oxygen breathed in and the amount of carbon dioxide breathed out. The room contains a private toilet and sink, treadmill, bed, desk, window, telephone and computer with television and internet access. While in this room, subjects undergo the following: * Continuous heart rate monitor: Subjects wear an EKG monitor to analyze heart rate variability. * Spontaneous movements: Subjects wear portable accelerometers at the hip and wrist to measure spontaneous physical movements. * Continuous temperature monitor: Subjects swallow a small capsule that transmits internal body temperature via miniature, wireless sensors. Adhesive patches placed on the skin monitor external body temperature. * Blood and urine collections: Subjects collect all of their urine during the 12 hours they are in the metabolic room. Blood samples are taken at specified intervals through a catheter that has been placed in a vein. * Microdialysis: A small needle is placed into fat tissue just under the skin on the abdomen. A solution containing a minimal amount of ethanol is infused and samples of fluid are collected every 20 minutes as it leaves the fat pad. This helps determine the metabolism level. This procedure starts 30 minutes before entering the metabolic room and continues until the subject leaves the room. Fat tissue biopsy: A small piece of fat tissue is withdrawn through a needle from under the skin on the abdomen. The sample is used to study fat tissue size and ability to store sugar.
The purpose of this study is to evaluate the change in measures of physiological arousal before and after behavioral treatment of insomnia.
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 10-week study will examine whether propranolol, a medication that blocks the activity of the stress hormones adrenaline and noradrenaline, can relieve acute stress disorder (ASD) and symptoms from persisting long-term. ASD is a condition that some people develop soon after exposure to trauma. They may be anxious, depressed, have trouble sleeping, startle easily, have difficulties concentrating, and feel as though the event is happening again. Propranolol has been used for many years to treat high blood pressure and heart disease, and has been found useful in treating anxiety states such as social phobia and migraine. Men and women between 18 and 65 years of age who were recently exposed to trauma (between 1 and 3 weeks of evaluation in this study) may be eligible for this study. Candidates must be diagnosed with ASD and must have been mentally healthy before the traumatic event. They will be screened for the study with a medical and psychiatric interview, physical examination, electrocardiogram (EKG), and blood and urine tests. Participants will be evaluated with the following procedures: * Neuropsychological tests using pen-and-paper and computer tests to evaluate cognitive function, particularly memory, learning, attention and concentration, and vocabulary and naming. * Emotion-related performance tasks to determine if the study medication can weaken emotionally arousing information by blocking the activity of adrenaline and noradrenaline. Subjects perform emotion-related and neutral tasks, such as looking at pictures with neutral, pleasant, or unpleasant content, both before and after treatment with the study medication (see below). * Traumatic script exposure: Subjects recount the traumatic event that caused them to develop ASD. The description is summarized, recorded, and played back to the subject. During the playback, physiological responses, such as heart rate and skin conductance (sweating), are recorded using electrodes taped to the hand and chest. * Fear conditioning to evaluate the response to an unpleasant stimulus: Several mild electrical shocks are delivered to the wrists while the subject looks at colored squares. Heart rate and skin conductance are measured. * Magnetic resonance imaging (MRI) to examine brain structure. The subject lies on a table that is moved into the MRI scanner (a narrow cylinder containing a strong magnetic field) and must remain still during the actual scanning. Earplugs are worn to muffle loud noises caused by electrical switching of radio frequency circuits used in the scanning process. After the evaluation, participants are randomly assigned to receive either propranolol or placebo (a look-alike pill with no active ingredient) for 8 weeks During this time they are seen by a doctor once a week for 4 weeks and then once every other week for the rest of the study. At the end of the 8-week treatment period, participants undergo the same evaluation they had before beginning treatment (see above). The decision to continue treatment will then be decided based on the individual's clinical condition and whether he or she received propranolol or placebo.
This study will evaluate whether modafinil improves cognition in patients with schizophrenia and healthy volunteers. Modafinil is a drug that has been FDA approved for day-time sleepiness and allegedly increase the amount of the neurotransmitter dopamine in the frontal cortex of the brain ...
This study will evaluate whether Tolcapone improves cognition in healthy volunteers as well as patients with schizophrenia. Talcapone is a drug that has been FDA approved for Attention Deficit Disorder and allegedly increase the amount of the neurotransmitter dopamine in the frontal cortex of the brain. ...