FYI- SEMs: The Analytical Spectroscopy Research Group at the University
of Kentucky is an organization dedicated to basic research in
noninvasive chemical analysis, medical imaging, and technology
development.
The group consists of faculty, staff and students trained in diverse analytical techniques and sophisticated computational methods. Instruments available to the group represent cutting-edge technology, traditional methods, and experimental instruments developed by group members.
kerouac.pharm.uky.edu
Facilities:
The Analytical Spectroscopy Research Group is housed in the University of Kentucky's Advanced Science and Technology Commercialization Center (ASTeCC). Most of the instruments used by the group are located in our laboratories in ASTeCC, including five near- infrared spectrometers and three near-IR video cameras, MAReNIR and acoustic / ultrasonic spectrometers, and a KTP/OPO tunable near-IR laser system. Near-IR imaging systems are also usually located in the University of Kentucky Hospital and Kentucky Clinic. A UV-visible spectrophotometer and fluorescence spectrometer are in the laboratories, along with separations systems including capillary electrophoresis, microbore LC, SDS-PAGE, TLC, and plate and gel CCD imagers . A centrifuge and ultracentrifuge are in ASTeCC for separations on a larger scale. A special chamber for temperature-controlled studies in an inert gas environment enables near-IR spectrometry and imaging to be conducted on samples like carotid plaques along with separations like ultracentrifugation, without ever exposing the sample to the laboratory atmosphere. Computer facilities are also available in ASTeCC, and include Silicon Graphics, Hewlett-Packard, and RS6000 workstation clusters, and an HP Convex Exemplar SPP-1200 32-node parallel supercomputer. The ASRG has its own machine shop and electronic PC board fabrication facility. The group also has access to many additional resources (MRI, MS, STM/AFM, SEM, etc.) available through the University of Kentucky research environment.
kerouac.pharm.uky.edu
kerouac.pharm.uky.edu
Opportunities for collaboration with leading researchers in medical and other fields provides access to expertise and technology that allows the group to expand to suit the needs of almost any commercial project.
The University:
Founded as a land grant institution in 1865, the University of Kentucky began as part of Kentucky University (now Transylvania University). UK has grown from an Agricultural and Medicinal College to a major university with 17 academic colleges and a graduate school spreading over 718 beautifully landscaped acres. In 1916, the institution received its present name, the University of Kentucky. Enrollment has grown from 190 students in 1866 to currently over 24,000, and this year includes 44 National Merit Scholars in the freshman class. Of the 1,600 full-time faculty (which translates into a 15:1 student-faculty ratio), 98% hold their doctorate or highest degree in their discipline.
Recent work conducted by the group includes:
Near-infrared imaging during carotid endarterectomy.
Stroke is a serious problem in the U.S. that affects over 500,000 people annually(1). Approximately 30% of affected individuals succumb to the disease each year, while another 20-30% suffer permanent disability. Research into the causes of stroke and the development and testing of drug therapies to reduce brain damage due to stroke is frustrated by an inability to identify and follow in vivo the physical and chemical events that occur during ischemia and reperfusion.
The role of atherosclerosis in stroke is becoming progressively clearer. Atherosclerosis is a difficult disease to study in terms of the growth and development of an atherosclerotic plaque or lesion. Most available methods for study of this disease use tissue removed from the site of a lesion, making it difficult to examine the progression of the disease. Experiments now being conducted use novel near-IR technology to examine the progression of an atherosclerotic lesion, with particular attention to the presence and role of oxidized LDL in lesion growth and maintenance. Noninvasive analysis of the degree of atherosclerotic plaque present at the carotid bifurcation has been correlated with overall ischemic risk and systemic atherosclerosis. The carotid arteries are particularly good candidates for noninvasive study due to their subcutaneous location and clear role in the pathogenesis of cerebral ischemia and stroke(2). Intraarterial catheters and transcutaneous imaging experiments are also being used to study the progression of atherosclerosis. These experiments recognize the possibility using of carotid atherosclerosis as a marker of overall atherosclerotic insult to vessels.(3)
MAReNIR.
The development of a Magnetohydrodynamic Acoustic-Resonance Near-Infrared (MAReNIR) spectrometer, a novel device for noninvasive chemical analysis, is currently underway. A major application for the device is near-infrared detection and quantification of cholesterol and lipoproteins simultaneously in serum samples and perhaps even in vivo.
Epidemiological studies have shown that reduction of blood cholesterol levels decreases the risk of atherosclerosis, ischemia, and myocardial infarction. It has been shown that a 1% reduction in plasma cholesterol can lead to a 2% reduction in cardiac events for individuals at risk for heart disease. A target level of 185-200 mg/dl total blood cholesterol has been established for healthy individuals. This target level is below the national average serum cholesterol concentration. With many Americans at risk for cardiovascular disease, widespread screening of the population could be instrumental in lowering escalating health care costs in the United States. The tests currently available for cholesterol, however, have several disadvantages. The tests are invasive and cause discomfort to the patient, which usually decreases willingness to submit to regular cholesterol screening. Many tests are also expensive, and some tests for mass screening have been shown to be inaccurate. A 1985 study showed that 47% of 5000 laboratories volunteering for the study could not get a test result within 5% of the true cholesterol value of a standard sample. This error is significant since the clinical risk brackets are only 10% wide. The development of an accurate noninvasive assay for cholesterol in all its forms would be of great benefit in preventive medicine.
The Analytical Spectroscopy Research Group has developed a near-IR technique to create false-color images of cholesterol in developing atheromas in rats. Near-IR spectroscopy also has been used successfully to determine cholesterol in serum samples acquired from human subjects.
The determination of cholesterol by near-IR spectrometry does, however, present several problems, the most important arising from the fact that the near-IR spectrum of an analyte is dependent on the environment of the analyte. Variations in ion concentration constitutes a major source of error in the near-IR determination of cholesterol. If the levels of all background constituents were known, a far more accurate near-IR determination of cholesterol could be made. It is possible to determine sodium, protein, triglycerides, albumin, and glucose through invasive and time consuming procedures, but the goal is a rapid noninvasive analysis. The development of the (MAReNIR) spectrometer is an important step in the direction of noninvasive near-IR imaging and analysis.
The MAReNIR spectrometer collects three spectra simultaneously: a near-IR spectrum, an Acoustic-Resonance (AR) spectrum, and a magnetohydrodynamic (MHD) spectrum. In combination these three spectra give information about specific chemical interactions, bulk properties, and ionic properties of a sample. MAReNIR spectrometry allows the simultaneous determination of cholesterol and the background constituents, reducing the errors obtained with near-IR alone.
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