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Discover 17,842 clinical trials near Baltimore, Maryland. Find research studies in your area.
Showing 5061-5080 of 17,842 trials
NCT04234880
In this study, we aim to develop and validate a noninvasive approach for quantifying and imaging energy metabolism, without contrast agents, on widely available clinical MRI scanners. Briefly, this technique allows specific and selective imaging of the energy metabolite phosphocreatine (PCr), in vivo and non-invasively. PCr is one of the predominant high-energy phosphates present in brain and muscle and one that is altered by common diseases. Although energy metabolism and PCr play a vital role in cellular homeostasis, there currently are no routine diagnostic tests to noninvasively quantify or map the distribution of PCr with clinically acceptable spatial resolution or/and scan time. Here, we demonstrate that the exchangeable guanidinium protons of millimolar concentration PCr can be exploited to detect it via the water signal in MRI with greatly enhanced sensitivity (molar signal) using chemical exchange saturation transfer (CEST) MRI, and its concentration can be quantified using an artificial neural network (ANN). This new technique, dubbed ANNCEST, allowed us to obtain a high-resolution PCr map on human skeletal muscle within 1.5 min, on a 3T clinical MRI scanner equipped with just the standard MRI setup. To put this in a larger perspective, energy metabolism is critical for cell viability and is altered by many common acquired and inherited diseases. ANNCEST is arguably the first to use widely available MRI scanners to noninvasively image tissue energy metabolism of PCr, and thus would have appeal to a broad readership of scientists and clinicians interested in neurology, muscular dystrophies and myopathies as well as cardiology, to name a few.
NCT04362865
Background: People who get infected with COVID-19 have an unpredictable risk to worsen and die. This makes it hard to decide who can quarantine at home and who should be treated at a hospital. Researchers think the risk may be related to how a person s B and T cells respond to the virus. B and T cells are the major components of a person s immune response. B and T cells responding to the virus with a favorable pattern may lead to recovery, and this favorable pattern may be helpful to establish. If people in a vaccine trial get this same favorable pattern when responding to a vaccine, this may be a useful early signal that the vaccine will be successful. Objective: To examine how immune cells respond to COVID-19 infection. Eligibility: Adults ages 18 and older who have a confirmed or suspected COVID-19 infection or had COVID-19 in the past. Also, healthy donors with no suspected COVID-19 infection Design: Participants will be screened with medical record review. Participants will be tested with a research assay to determine who was infected with COVID-19 and who was not. This test will be used to understand research results, not to advise patients. Participants with active infection must be isolated, usually in a hospital. Other participants may give blood samples at NIH or at their local doctor s office or lab. Participants may give blood samples up to three times a week for a total of ten times, and may also give blood samples after starting a vaccine trial. Participants will be contacted by phone or email every 2 months for up to 2 years.