8 Clinical Trials for Various Conditions
Accumulation of triglycerides in heart tissue has been associated with changes in left ventricular function which can lead to heart failure. Proton magnetic resonance spectroscopy is currently the only non-invasive in vivo method to measure myocardial triglycerides content. The primary goal of this study was to determine if Magnetic Resonance Spectroscopy could effectively measure myocardial triglyceride content in myocardial heart tissue. Thus, quantitative and reliable techniques to monitor in vivo triglyceride accumulation in the heart are important for disease diagnosis and management. Currently, no such imaging method exists.
This is research study is assessing the effects of 6-g daily use of freeze-dried instant coffee on liver fat and fibrosis and the gut microbiome and metabolome in patients who have completed routine treatment (including surgery, chemotherapy and radiotherapy) for stage I-III colorectal cancer.
Postoperative cognitive decline (POCD) is a significant neurological problem that commonly follows coronary artery bypass grafting surgery (CABG) in elderly patients. This can result in longer hospital stays and generate worsening morbidity and mortality. Furthermore, POCD often persists in some patients for more than a year and puts them at higher risk for developing Alzheimer's Disease or dementia. The cause of POCD is a topic of ongoing work, with recent hypotheses linked with cell dysfunction and death in the brain, and neuroinflammation related to the surgical trauma and related systemic inflammation. In this project, the investigators will test whether the pre-operative use (14 days) of a ketogenic diet (KD), compared to a control diet (CD) will lower the incidence, duration, and severity of POCD in cardiac patients. The ketogenic diet has been associated with improved memory function, as well as reduction of inflammation in conditions such as epilepsy, Alzheimer's Disease and Parkinson's Disease. A subset of patients from each group will also undergo a 7 Tesla magnetic resonance imaging and spectroscopy scan, where key brain metabolites of mitochondrial function and neuronal integrity will be measured in the prefrontal cortex and hippocampus. In the KD group, cerebral b-hydroxybutyrate (BHB) to evaluate cerebral ketosis will also be measured. These will be measured prior to starting the KD/CD and after a minimum of 10 days on the KD/CD. From both CD and KD groups, levels of key cytokines linked with inflammation will be measured during the protocol. Our outcome parameters for POCD will include measures that evaluate cognition, delirium and length of hospitalization. The following hypotheses will be investigated: 1) lower incidence, duration and severity of POCD in the KD group, compared to the CD group; and 2) better pre-operative values of neuronal integrity and in the KD group, higher levels of brain ketone levels will be associated with patients who do not experience POCD or have less severe POCD. This project tests the use of the multi-factorial effects of the KD for an important problem in Anesthesiology. With state-of-the-art imaging technology and cytokine evaluation, the investigators hypothesize this work can have substantial implications for prevention and management of postoperative cognitive decline.
Posttraumatic stress disorder (PTSD) is a common and debilitating neuropsychiatric disorder in which an acute fear response to a traumatic event does not abate. This failure to recover from trauma is thought to be due at least in part to a deficit in learning not to fear situations and stimuli previously associated with the trauma (i.e., specifically due to a failure of extinction recall). Pavlovian fear conditioning can be simulated and measured experimentally in humans using a 2-day fear conditioning paradigm developed by our group, wherein conditioning and extinction learning phases are conducted on Day 1, and extinction recall is tested on Day 2. Recent functional magnetic resonance imaging (fMRI) evidence indicates that PTSD is associated with hyper-responsivity of the insular cortex and hyporesponsivity of the ventromedial prefrontal cortex (VMPFC) during exposure to fear-inducing stimuli, consistent with altered excitability of brain regions mediating fear conditioning and extinction. As the brain's principal inhibitory neurotransmitter, GABA exerts a prominent role in modulating neuronal excitability. Interestingly, there are reports that adjunctive treatment with GABA-enhancing antiepileptics is efficacious in PTSD. There is also evidence, albeit inconsistent, that lower serum GABA levels predict a more chronic course of the illness. However, it is unclear whether serum levels accurately reflect brain GABA, which may contribute to inconsistency of serum findings. Moreover, it is possible that GABA alterations may vary in their presence, nature and significance across brain regions implicated in PTSD. The proposed study will examine the relationship of PTSD symptoms and behavioral fear conditioning deficits with regional brain gamma-aminobutyric acid (GABA) using proton magnetic resonance spectroscopy (1H-MRS). We have the following aims and hypotheses: 1. To determine whether GABA alterations are associated with the categorical diagnosis of PTSD and not merely exposure to trauma. It is hypothesized that PTSD will be associated with higher GABA in VMPFC and lower GABA in the right insula. 2. To determine whether GABA levels are significantly associated with dimensional measures of PTSD symptom severity and individual symptom dimensions. It is predicted that higher GABA in the VMPFC and lower GABA in the right anterior insula will be associated with greater total symptom severity. 3. To determine whether GABA in VMPFC and right anterior insula are significantly associated with measures of extinction recall failure and anxiety sensitivity in PTSD. It is hypothesized that VMPFC GABA will be positively correlated with skin conductance response to a conditioned stimulus that had previously been extinguished and insula GABA will be negatively correlated with anxiety sensitivity.
The purpose of this study is to better understand the different ways our bodies burn fat which may be important for obesity, diabetes, and cardiovascular disease.
The purpose of this study is to examine the effects of a 10-week Omega-3 Fatty Acid treatment phase on brain chemistry of adolescents with major depressive disorder (MDD) using proton magnetic resonance imaging.
On the dual basis of findings indicating GABA increases following acute and eight week SSRI/dopamine agonist administration and those indicating GABA-ergic effects following 14 day pyrimidine administration, the purpose of this study is to assess our following hypotheses: 1. Relative to placebo, an oral dose of 1g of uridine BID for seven days will increase brain GABA levels in a sample of healthy, unmedicated adult males; 2. Relative to placebo, an oral dose of 1g of uridine BID for seven days will increase NTP levels in a sample of healthy, unmedicated adult males; and 3. Brain GABA levels will be directly correlated to high energy phosphate levels in this sample of healthy, unmedicated adult males.
The purpose of this study is to compare pictures of the brain of HIV-infected people with memory problems before and after treatment with selegiline. Selegiline is the study drug received through A5090. HIV patients generally develop memory problems late in the disease. This will be examined using noninvasive proton magnetic resonance spectroscopy (1H-MRS). The effect of the drug selegiline on memory problems also will be examined.