View clinical trials related to Healthy Adults.
Filter by:Cerebellar ataxia (CA) is a collection of signs and symptoms caused by cerebellar dysfunction, which can be the result of different disease processes including hereditary and acquired conditions. High incidence of falls is reported in people with CA due to poor balance while walking. Therefore, it is crucial to assess the balance of people with CA to identify potential fallers. There are some clinical tests commonly used for assessing the balance of people with CA, including both generic measures of balance and ataxia-specific rating scales. The current best balance outcome measures for CA includes Berg Balance Scale (BBS), Timed Up and Go test (TUG), and the balance related items in Scale for the assessment and rating of ataxia (SARA). TUG is commonly used in clinical settings for the assessment of mobility and fall risk of individuals. However, a study done by Winser et. al (2017) found that the correlation between TUG and ataxia rating scales (SARA and ICARS) is only moderate. This indicates that the gait speed and functional mobility findings of TUG might not truly reflect the balance deficits of CA. Therefore, our study will develop a modified TUG for the assessment of balance in people with CA. Circular TUG (cTUG) is a modified version of the standard TUG. cTUG is an equilibrium test that challenges subjects' ability to maintain balance in response to the constant change in direction of walking. In cTUG, the subject walks a semi-circular pathway instead of a straight line. Walking in a circular pathway targets at challenging the coordination of people with CA as walking in a circle requires constant change in directions and correction after feedback. It is speculated that the cTUG will have better accuracy in predicting the balance and falls risk among people with CA. We will target at recruiting 30 healthy volunteers and 30 individuals with cerebellar ataxia. Besides the cTUG we will also assess disease severity of ataxia using the Scale for the Assessment and Rating of Ataxia (SARA), balance using the Berg Balance Scale, Timed Up and Go test, Sensory Organization test, Limits of Stability test and functional independence using the Barthel Index. For validation of the cTUG, two types of reliability will be examined, including intra-rater reliability and interrater reliability and four types of validity will be assessed, including concurrent validity, convergent validity, discriminant validity, and external validity.
In this research study, the investigators will use a novel approach to measure what people eat. The goal is to find out whether stable isotopes that can be measured in blood, hair, and fingernails are better at measuring what people eat than the surveys that are currently used. To meet the goal, the investigators will do three things. First, the investigators will feed study participants known amounts of foods and nutrients. Second, after study participants have eaten the food, the investigators will measure stable isotopes in samples of study participants' blood, hair, and fingernails. Third, the investigators will determine how well these samples reflect what was eaten. The investigators will also give surveys to study participants to determine how well the surveys reflect what was eaten. This will allow the investigators to do a relative comparison of the measurements from isotopes and surveys.
A randomized, double-blind, single-dose, parallel-group study to compare the pharmacokinetics, pharmacodynamics, safety and immunogenicity of LY01011 and Xgeva® in healthy adults
A recent study with rats showed that electrical stimulation of the vagus nerve (VNS) facilitates extinction of fear (Pena, Engineer, & McIntyre, Biological Psychiatry, 2013). The hypothesized mechanism is that VNS both enhances memory consolidation (by increasing noradrenergic neurotransmission) and reduces anxiety (thus: preventing fear responses to the CS which may re-consolidate the fear memory). The effect was only apparent when VNS occurred during exposure of the fear conditioned stimulus (CS), and not when stimulation was given immediately following exposure. These results may have implications for the treatment of anxiety disorders in humans. However, until recently, the only means to investigate the effects of VNS on human fear learning would have required the invasive implantation of vagus nerve stimulators. This has fortunately changed, as a non-invasive transcutaneous VNS device has been approved for use in the E.U. for the treatment of psychological disorders. This study proposes to use a t-VNS to investigate its effects on fear learning and extinction in (healthy) humans. Previous research has only investigated the effects it has on human mood and memory. The results obtained suggest that it reduces negative affect and enhances memory, findings which are consistent with those reported for rats. It is thus reasonable to expect that t-VNS will facilitate the extinction of fear in humans. The present study aims to answer the following research questions: Does t-VNS during extinction training: 1. accelerates extinction curves 2. reduces spontaneous recovery of previously extinguished fear 3. reduce re-acquisition of fear 4. reduce generalization of fear to other stimuli that resemble the CS+? 5. facilitates the generalization of inhibitory learning to stimuli that resemble the CS-?