View clinical trials related to Healthy Subjects.
Filter by:This study aims to identify various time-variant and time-invariant components of EEG signals using advanced signal processing techniques, such as machine learning. The investigators' ultimate goal is to develop universal or customised brain-computer interface that are stable across days or even years.
The purpose of this study is to compare the efficiency of nebulization and positive expiratory pressure combination
The combined pulmonary fibrosis and emphysema syndrome (CPFE) individualized by our group in 2005 is characterized by an often severe dyspnea, almost exclusive male predominance, and often major, profound impairment of gas exchange contrasting with preserved lung volumes and absence of airflow obstruction, and a high risk of pre-capillary pulmonary hypertension responsible for increased mortality. Almost all patients are smokers or ex-smokers. There are some arguments in favor of genetic abnormalities in this syndrome of unknown etiology (other than smoking) including short telomeres and mutations in the telomerase complex genes. There are also emphysematous lesions, in patients with familial pulmonary fibrosis, with mutations in the SFTPC gene (surfactant protein C), and reported cases of CPFE syndrome with SFTPC mutation. No large genetic studies have been conducted to date in the CPFE syndrome. Our main hypothesis is that the proportion of subjects with short telomeres is higher among patients with CPFE syndrome than in subjects of similar age with idiopathic pulmonary fibrosis but without emphysema. It has previously been shown that mutations in the telomerase TERT or TERC genes are mostly found in people whose telomeres are abnormally short. The investigators propose to use that test to identify patients most likely carrying a mutation, and to seek, among them, the mutations in the TERT or TERC telomerase genes. The objective of the study is to compare the proportion of patients with short telomeres in the group of patients with CPFE syndrome to that of other patients (with idiopathic pulmonary fibrosis without emphysema, or with emphysema without fibrosis).
Background: - Computed Tomography (CT) is a scan that makes detailed pictures of the body. It uses radiation to do that. In 2011, about 85.3 million CT scans were done in the United States. But there is growing concern about the health effects of radiation. There are new and different ways to make CT pictures that use less radiation. Researchers want to learn whether these new methods create images that are similar to images from a traditional CT. Objective: - To learn if new CT imaging methods with less radiation make images that are similar to traditional ways. Eligibility: - Adults 18 years of age and older who are scheduled for a CT of the chest, abdomen and pelvis with contrast. Design: - Researchers will review participants medical records to see if they can be in this study. - Participants may have blood drawn from an arm vein by a needle stick. The blood will be used to make sure they can be in this study and that it is safe for them to have contrast. - During the participants CT scan appointment, one extra scan will be done using low radiation methods. - During a CT scan, the participant lies on a table. A large x-ray machine takes pictures of the body.
Characterise cognitive biases resulting from low dose ketamine infusion, used as a pharmacological model of psychosis. Our assumption is that low dose ketamine results in reasoning biases by impairing the way uncertainty is monitored and taken into account for decision making.
Comparison between three modalities of nebulization.
Background: - Gum disease is a condition in which the tissue around the tooth root becomes swollen and infected. This condition can cause tooth loss if it is not treated. Who gets gum disease and how bad it will be depends on (1) the different bacteria in the mouth and (2) how the immune system of an individual handles these bacteria. Researchers want to look at the oral bacteria and genetic immune problems of different people to learn how these affect gum disease and other conditions of the mouth. Objectives: - To study how immune system problems may lead to problems in the mouth, including gum disease. Eligibility: - Children and adults at least 7 years of age who have genetic problems with their immune system. - Healthy adults that have periodontal disease - Health adults that do not have periodontal disease Design: - This study will involve a screening visit and a study visit. - Participants will be screened with a medical history, blood work and a full oral and dental exam, including dental x-rays and photos. - The study visit will involve collection of blood, urine, and other samples, including saliva, plaque, and gum swabs. Any abnormal tissue will sampled for a biopsy. Additional oral and dental exams will be performed. Participants will also answer questions about any current medical or dental problems.
The aim of the current study is set out to find a human model for negative symptoms based on clinical observation that chronic cannabis users express negative symptoms and characterize by the same neurocognitive and electrophysiology characteristics like patient suffer from schizophrenia. Towards that end the first part of the study is set out to explore weather chronic cannabis user's express negative symptoms similar to patient suffer from schizophrenia. The second part of the study will explore the neurocognitive and electrophysiology characteristics of those cannabis users that express negative symptoms. This data will be compared to parallel data of schizophrenia patients with predominantly negative symptom. Several lines of biological and genetic evidence support the cannabinoid hypothesis for schizophrenia. Particularly, it is most significant clinically that the possible involvement of the cannabinoid system in the neural basis for the negative symptoms. This hypothesis based on clinical findings that chronic cannabis use causes a combination of symptoms including apathy, avolition, lack of interest, passivity, and cognitive impairments, the so-called "amotivational syndrome," which resembles the core negative symptoms of schizophrenia in behavioral level as well as the brain level. Both are associated with the functions or integrity of the frontal lobe due to its role in creating self-directed behaviors, deficits in which may underlie alogia, anhedonia, and flat affect. Despite the aforementioned similarities, to date, there is no documentation for such a relationship. Recognition that chronic cannabis users share the same or similar constellation of symptoms and similar neurocognitive and electrophysiology characteristics could provide a key to develop a human model for negative symptoms and an essential tool to comprehensive understanding of the etiology of negative symptoms and development of an innovative therapy. The investigators Hypothesize That Chronic Cannabis Users Would Express the Same Constellation of Behaviors as Negative Symptoms of Schizophrenia; as well as similar neurocognitive and electrophysiology characteristics
This placebo-controlled crossover study is intended to measure the effect of four doses of lorazepam on brain activity measured by magnetoencephalography (MEG) and electroencephalography (EEG). This study will conduct MEG and EEG scans as well as simple cognition testing on 16 healthy male volunteers. On each of five study days subjects will be randomized to receive either 0.2, 0.5, 1.0 or 2.0 mg lorazepam or placebo. Brain activity will be measured by MEG and EEG in each subject a total of 4 times each study day: prior to medication administration and 2, 4, and 6 hours after medication administration. Blood samples to determine medication levels and cognition testing will be performed at pre-medication baseline and immediately after each post-medication scan time. Data will be analyzed to identify changes in brain activity compared to baseline and placebo administration using both standard approaches and the Orasi Synchronous Neural Interaction® (SNI) test. This study will test the hypothesis that dose-response changes in brain functional activity can be accurately measured by MEG/EEG in healthy volunteer subjects after single, acute doses of lorazepam.
Gastroesophageal reflux disease (GERD) is commonly seen in Western countries; however, it is gaining prevalence in Asia countries recently. In addition to the lower esophageal sphincter and the crural fibers of the diaphragm, the flap valve at the gastroesophageal junction is also responsible for maintaining an antireflux barrier. Hill et al developed a grading system of gastroesophageal flap valve (GEFV) and concluded that this flap valve system is simple, reproducible, and offers diagnostic aid in the evaluation of patients with suspicious reflux disease undergoing esophagogastroduodenoscopy (EGD). It is a common belief that large meals provoke considerable postprandial reflux and it results from an increase in the rate of transient lower esophageal sphincter relaxations. One study also revealed that rapid food intake produces more gastroesophageal reflux in healthy volunteers. So this study attempted to evaluate the relationship between dietary habit and GEFV abnormality. The investigators used a questionnaire regarding the dietary habit to the population undergoing EGD in a self-paid health examination.