Previous Summer Research
Heat Shock Proteins and Regulation of Systemic Lupus Erythematosus
Steven Christofakis
Institutional Affiliation: University of Mary Washington
Research Advisor: Dr. Nichole Rylander & Dr. Christopher Reilly
Systemic Lupus Erythematosus (SLE) is a pro-inflammatory autoimmune disease characterized by autoantibodies against cellular nuclear components. Failure of the immune system to clear apoptotic debris has been suggested to trigger disease. Recent studies show heat shock proteins (HSP) are critical for macrophages clearance of apoptotic cells and inflammatory mediator production. Our current studies were designed to characterize HSP expression in murine macrophages exposed to apoptotic debris. T-cells were obtained from the thymus and exposed to dexamethasone to induce apoptosis and then cultured with macrophages with or without inflammatory stimulation. HSP expression as determined by Western blot showed HSP60 expression was unaffected by both apoptotic debris and immune stimulation while HSP90 expression was increased with immune stimulation but not by apoptotic debris. Inflammatory mediator production (e.g. nitric oxide) was induced with immune stimulation but not apoptotic debris only; the combination of both did not further enhance nitric oxide production. Taken together, our studies suggest HSP60 expression is not altered in macrophage activation in lupus mice and HSP90 expression is increased with immune stimulation.
Ausculation of Stenosed Arteries by use of an Ionic Polymer Sensor
Daniel Cooper
Institutional Affiliation: Virginia Polytechnic Institute and State University
Research Advisor: Dr. Pavlos Vlachos
Auscultation can be an extremely effective technique for the diagnosis of cardiovascular disease, such as valve disorders and atherosclerosis in arteries, however, its usefulness is limited by the human ear and the experience of the physician. Our goal is to develop a bioacoustic sensor based on an ionic polymer transducer. Such a device could potentially represent a significant increase in sensitivity over current electronic stethoscopes, recording heart sounds and arterial bruits. Here we present our experimental setup and acoustic spectra from 50 and 75% stenosed arteries recorded by hydrophone. This acoustic spectra show increased spectral content between 400-700 Hz. In addition, we also present initial data recorded by an ionic polymer prototype from our experimental setup.
Electrospinning scaffolds for bone tissue engineering: Altering fiber orientation and mechanical properties
Emmanuel Ekweme
Institutional Affiliation: Virginia Polytechnic Institute and State University
Research Advisor: Dr. Joseph Freeman
Trabecular bone, also known as cancellous bone, is a type of bone that has low density and high surface area. There has been a great effort to develop an optimal biodegradable tissue engineering scaffold for trabecular bone. A technique that can be employed in the development of scaffolds is electrospinning. Electrospinning is a process that allows for the fabrication of fibers of polymer down to the submicron dimension. In order to create porous scaffolds that can bear loads similar to those experienced by cancellous bone, we used electrospinning to create scaffolds of poly L-lactic acid (PLLA) nanofibers aligned at various angles. This work will lead to the development of scaffolds with structures and mechanical properties similar to trabecular bone.
Feasibility study of using insulator-based dielectrophoresis to concentrate cancer cells from blood
Zohora Iqbal
Institutional Affiliation: University of California, Berkeley
Research Advisor: Dr. Rafael Davalos
The primary factor determining whether a patient survives most cancers is how early it's detected. Typically some cancer cells exfoliate from epithelial surfaces into biological fluids but initially at concentrations too low to be detected with the high concentration of normal cells present. We hypothesize that dielectrophoresis, the motion of particles in a nonuniform electric field, can be used to selectively enrich abnormal cell populations in blood based on their irregular physical and electrical properties. We designed four device configurations and optimized each through numerical simulations of how different cells would behave in them. The simulations support our hypothesis and show that erythrocytes and leukocytes move through unhindered in the device while abnormal cells can be segregated for downstream analysis.
Truncated Cone Mirror Bioluminescence Imaging
Andreas Merk
Institutional Affiliation: Virginia Polytechnic Institute and State University
Research Advisor: Dr. Ge Wang
Bioluminescence imaging (BLI) of small animals utilizes a naturally occurring process in which near infrared light is emitted by luciferase proteins. Such light can be detected by a CCD camera, thus allowing us to monitor biological processes in vivo. This project demonstrates how a truncated cone mirror can be used to create a 360 degree view of the bioluminescent intensity and transform this view into traditional four side views around a mouse. A mouse model rendered in Solid Works can be placed inside the cone mirror. Every point on the model is reflected to form a deformed planar image of the object behind the cone. Then, a traditional bioluminescent view can be created which presents the image that would be directly obtained by a CCD camera in the current experimental setting. Computer graphics techniques are applied in our numerical simulation and produce excellent results.
Yeast Cell Synchronization
Stephanie Nance
Institutional Affiliation: Sweet Briar College
Research Advisor: David Ball, PhD; Jean Peccoud, PhD
The budding yeast Saccharomyces cerevisiae has been extensively used as a model system for the study of the eukaryotic cell cycle. The development of a stochastic model of the cell cycle is necessary to better understand how noise in gene expression affects cell growth and proliferation. Cell-cycle regulating proteins, of which there are only 10-100 copies in each cell, must be experimentally determined to aid in the development, and verification of this model. Therefore, it is beneficial to synchronize the cells to observe more cells in each stage of the cell cycle simultaneously. Here, two methods for synchronization were attempted including cdc20 block and release, and centrifugation in discontinuous sucrose gradients. These methods were evaluated via flow cytometry.
Automated Endotrachea Tube Cuff Pressure Sensor and Pump System to Help Eliminate the Contraction of VAP and Severe Ischemia Damage to the Trachea
Bryan Orellana
Institutional Affiliation: Virginia Polytechnic Institute and State University, MAOP Intern
Research Advisor: Dr. Alfred Wicks
Ventilator associated pneumonia (VAP) and severe ischemia damage to the trachea are the leading results of improper usage of the endotrachea cuff. When used properly, this balloon like membrane found near the end of the tube acts as a support and seal to allow for smooth ventilation for the patient. A system will be developed as a completely automated system where the device can be set to certain parameters in conjunction with a pressure sensor feedback and pump system to maintain and monitor a pressure range of 15-25 cm H2O within the cuff. A prototype will be developed and tested, and will go through FDA approved clinical trials and implemented into the Carilion Roanoke Memorial Hospital ICU. The device will help eliminate the error caused by user when delivering manual pressure to the cuff, as well as monitor the cuff during operation to insure it is working under stable conditions.
