Computer techniques designed to virtually piece shredded paper back together can be used to piece together Internet cookies to reconstruct an online life.
Drug Development for Dyslipidemia and Atherosclerosis
Natural products provide a basis for a pipeline of drugs that the group is developing at the University of Kentucky College of Pharmacy. These drugs may one day become important agents for preventing heart attack and stroke. Some of these drugs have already been licensed to Spherix, Inc (NASDAQ/SPEX) for testing and development.
Accurately Predicting System Success and Failure
A project designed to predict when and how a complex system comprising many nodes might fail is underway .
A new near-IR InSb focal plane array video camera is being used to image carotid plaques during carotid endarterectomy. We have just completed a new program that manipulates frames from the camera for analysis was just completed. This new program is entirely menu/mouse driven, and enables users to grab a frame collected at any wavelength just by pointing at it. The mouse can be used to zoom in and out on any selected portion of the image, and to rescale the colors and change color weighting schemes on any area of the image. More importantly, the mouse can be used to select any feature in the image at one wavelength, and the complete spectra (absorbances from all frames) are automatically selected simultaneously and stored in a 2-D variable that can be passed to all of the 90+ programs that we have developed over the past ten years. The completion of this new imaging program will accelerate greatly our analysis of spectra obtained with the near-IR imaging system.
Figure 1 is a near-IR image of a carotid endarterectomy taken at 2312 nm, where -CH3 groups in lipids have an absorbance. The carotid plaque is the most dense red area toward the center of the image. The white circle on left is a white marble placed as a reference in the field of the camera (the black marble also used as an intensity reference is not visible at this wavelength, except for a small highlight to the right of the white marble). The long white features of the image are the tissue retractors used to hold the incision open. The marble and stainless steel instruments appear white in the image because they reflect the most near-IR light. The purple area to the far right is the surgical drape, which reflects most of the near-IR light falling upon it. The color scheme, from lowest light absorbance to highest, is white, violet, blue, green, yellow, orange, and red.
Figure 2 is a zoom-in image of the carotid from Figure 1, shown at the protein amide absorbance wavelength at 2180 nm. The carotid artery appears orange and a red plaque appears at the carotid bifurcation.
Near-IR spectra obtained at d wavelengths are represented as single points in a d-dimensional hyperspace. The supercomputer calculates the probability that certain regions of the carotid plaques are normal tissue based on their spatially resolved near-IR spectra. If the tissue is abnormal, the direction of the spectral vector of the abnormal tissue in wavelength hyperspace identifies the constituents that make that region abnormal, and the length of the vector (scaled by the probability of a normal spectrum lying in that direction) gives the amount of constituents present. The probabilities calculated on the supercomputer are converted to images on a workstation.
The development of a magnetohydrodynamic acoustic-resonance near-infrared (MAReNIR) spectrometer is currently underway. The MAReNIR spectrometer is a novel device for noninvasive chemical analysis. 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. Near-IR spectrometry has been shown to be an effective method of determining cholesterol and lipoproteins in a human blood matrix, but variations in sodium ion concentrations constitute a significant interference in results. Knowledge of the ion concentration enables one to overcome the interference to cholesterol, but such knowledge is difficult to obtain noninvasively. The MAReNIR spectrometer overcomes the sodium ion interference by inducing ion motion in a magnetic field with a tunable acoustic wave (see Figure 3). The moving ions create an electrical current that is picked up by electrodes in a cuvette or on the surface of the skin. Measuring the current continuously in a computerized pattern recognition algorithm reveals the ion concentration, and permits accurate analyses of cholesterol. The acoustic wave itself is used to improve identification and quantification of similar apolipoproteins (such as apoA-I and apoA-II) in solution by modulating their conformations and hence their near-IR spectra (through hydrogen bonding). In addition, the acoustic waves help to set the near-IR spectral baseline by establishing the bulk density of tissue samples in vivo.
The MAReNIR spectrometer will be used to create a desktop clinical instrument for analyzing blood for lipoproteins and cholesterol simultaneously and without reagents in physician's offices. Present analytical techniques are error-prone, slow, and expensive. An analytical method that minimizes sample handling and time of analysis will make lipoprotein measurements more accurate by reducing degradation of the sample during the analysis. The spectrometric nature of the instrument may enable it to determine accurately cholesterol and lipoprotein levels directly through the skin as well.