Event
CANCELED: Bioengineering Seminar Series: Gerald M. Rosen
Friday, April 27, 2012
11:00 a.m.-12:00 p.m.
Room 1200 Jeong H. Kim Engineering Bldg.
Professor Silvia Muro
muro@umd.edu
This seminar has been canceled. If rescheduled, we will update our calendar to reflect the new date, time and location.
Electron Paramagnetic Resonance (EPR) Imaging of Brain Oxygen: Applications for Stroke
Gerald M. Rosen, Ph.D., J.D.
Isaac E. Emerson Professor
Department of Pharmaceutical Sciences
University of Maryland School of Pharmacy
Magnetic Resonance Imaging (MRI) is a new technique for obtaining cross-sectional pictures through the human body without the harmful effects of x-rays. MR images are exquisite, comparable in anatomic definition to that observed with CT. To study physiological status of an organ or tissue by MRI, contrast media is often used to enhance the image, although in many cases such improvement is difficult to interpret.
More recently, another magnetic resonance modality has been developed, low-frequency electron paramagnetic resonance (EPR) spectroscopy. With the introduction of specific probes, such as nitroxides, EPR imaging can address many important physiological questions without the background associated with MRI. Thus, MRI and EPRI can be viewed as complementary imaging methods, where MRI provides anatomic definition and EPRI presents physiologic data.
For EPRI, paramagnetic probes, compounds with at least one unpaired electron, are used to study specific physiologic questions. The challenge has been the synthesis of probes that can be tailored to provide essential information on important physiologic questions, such as the status of O2 in different regions of the brain after a stroke. Similarly, these probes can be used to localize specific types of solid tumors. Nitroxides are one class of EPR probes, which due to their chemical flexibility, ease of preparation and stability at physiological pH and temperature, are well suited for imaging applications. The purpose of this seminar is to detail the preparation of specific nitroxides, their in vivo pharmacokinetics and pharmacodynamics, as probes for EPR imaging to measure O2 levels in the brain.
