Student Awards Presented at BEMS Meeting - cont'd

BEST PLATFORM PRESENTATIONS

Herman Schwan Memorial Award for Best Platform

Presentation: David McNamee

Platform 8-8: THE ACUTE EFFECTS OF WHOLE BODY EXPOSURE TO A 1800 MICRO-TESLA , POWER-LINE FREQUENCY MAGNETIC FIELD ON THE HUMAN CARDIOVASCULAR SYSTEM, David A. McNamee with Alexandre G. Legros, Frank S. Prato, and Alex W. Thomas.

David presented work focused on the effects of power line frequency magnetic fields on the human microcirculatory system and provided a “big picture” perspective of how the human cardiovascular system responds to power line fields in general. The goal of this work is to address previous inconsistencies in the literature through a controlled look at changes in peripheral microcirculation, blood pressure, heart rate, heart rate variability and skin surface temperature during and/or after an acute, 60 Hz MF exposure session at 1800 μT.

Curtis Carl Johnson Memorial Award for Best Platform Presentation:

John Robertson

Platform 8-1 FUNCTIONAL IMAGING OF MAGNETIC FIELD THERAPY, John A. Robertson with Jean Theberge, Julie Weller, Dick Drost, Frank S. Prato, and Alex W. Thomas.

John presented research examining the effects of a specific pulsed magnetic field on pain perception in humans. This specific pulsed magnetic field -- known as the Complex Neuroelectromagnetic Pulse, or CNP -- has a long history of use at the lab at Western Ontario University to affect pain perception in snails, mice, and humans. This pulsed magnetic field therapy is in the process of being evaluated as a treatment for chronic pain in an FDA clinical trial being managed by Fralex Therapeutics (TSE:FXI), a spin-off company founded by John’s supervisors Dr. Frank Prato and Dr. Alex Thomas.

To get a better understanding of how the CNP affects human pain perception, John uses functional magnetic resonance imaging (fMRI) to measure the brain activity involved in pain processing. The pain is created acutely with a thermode, and cycles on and off while the MRI acquires data. Then the CNP is applied for 15 minutes, and the fMRI and pain procedure is repeated. Using software tools (e.g., BrainVoyager), John examines how the brain activity processing the heat pain is altered by the magnetic field exposure.

John found significant decreases in activity in brain structures such as the anterior cingulate and insula after CNP exposure as compared to sham exposure. These are brain areas that are responsible for the affective component of pain -- activity here is what makes pain unpleasant. However, there was no significant effect of the CNP on the pain scores reported by the subjects. John reports that this could be because the exposure used here was only 15 minutes, applied just once, whereas subjects in previous studies had been exposed for 40 minutes, and in some studies multiple times per day over the course of a number of days. His next step will be to increase the exposure duration within the MRI to 40 minutes to match up with the exposures previously used.

The fact that significant changes in activity within pain related structures was seen even without a change in the subjective pain scores indicates, according to John, that fMRI might be a more sensitive tool to detect the neuromodulation of the CNP than the subjective pain scores are.

Second Place - Best Platform Presentation:

Sven Kuehn

Platform 7-6 EXPERIMENTAL EVALUATION OF THE SAR INDUCED IN A HEAD PHANTOM OF A THREE YEAR OLD CHILD, Sven Kuehn with Marie-Christine Gosselin, Andreas Christ, Marcel Zefferer, Emilio Cherubini, and Niels Kuster

Sven presented work aimed at resolving the ongoing controversy over whether the current compliance test procedure based on a large adult head (SAM) is also appropriate for children. His studies indicated that using a scaled version of the SAM phantom results in conservative estimates of the peak spatial SAR exposure in the heads of children.

Third Place - Best Platform Presentation:

Stephen Kennedy

Platform 4-6 REAL-TIME QUANTIFICATION OF ELECTROPORATIVE UPTAKE KINETICS AND ELECTRIC FIELD HETEROGENEITY EFFECTS IN CELLS, Stephen M. Kennedy with Zhen Ji, Jonathan Hedstrom, John H. Booske, and Susan C. Hagness.

Stephen described work on real-time quantification of electroporative uptake kinetics and electric field heterogeneity effects in cells. With coauthors Z Ji, JC Hedstrom, JH Booske, and SC Hagness, he measured the delivery of a small molecule, propidium iodide (PI), to human leukemia cells over time resulting from exposure to a single 40 microsecond pulsed electric field (PEF). Experimental data revealed PI uptake signatures consistent with temporary field-induced membrane poration using PEF intensities between 1.6 kV/cm and 2.0 kV/cm. This range in electric field intensities resulted in the delivery of approximately 88 million PI molecules per cell over the course of 500 seconds. Using field intensities between 2 and 4 kV/cm, PI uptake signatures were consistent with irrecoverable membrane damage.

In these experiments, it was also shown that electric field non-uniformity could be used to spatially regulate the delivery of molecules to cells. The data obtained from these experiments will be useful determining what field strengths and electrode configurations are appropriate for gene and drug delivery applications versus tissue destruction. Additionally, the data obtained here will be useful in developing and improving membrane electroporation theories and models.

Steve is an NIH Fellow at the Department of Electrical and Computer Engineering, University of Wisconsin-Madison.

AWARD WINNING POSTERS

Herman Schwan Memorial Award for Best Poster:

Camilla Rozanski

Poster P-77 REAL-TIME MEASUREMENT OF CYTOSOLIC FREE CALCIUM CONCENTRATIONS IN DEM-TREATED HL-60 CELLS DURING STATIC MAGNETIC FIELD EXPOSURE AND ACTIVATION BY ATP, Camilla Rozanski with Michelle Belton, Frank S. Prato, and Jeffrey J. Carson

Camilla examined whether free radicals influence cytosolic free calcium concentrations during static magnetic field exposure. Cytosolic free calcium concentration was monitored using ratiometric fluorescence spectroscopy in HL-60 cells under conditions of reduced endogenous free radical scavengers and 100 mT static magnetic field exposure. While the initial results suggested no effect of a 100 mT static magnetic field on cytosolic free calcium concentration in HL-60 cells, she noted that these results need to be explored further because (1) an effect of SMF might have been present but not measurable with the [Ca2+]c -dependent metrics measured in the study, or (2) potential effects of SMF on HL-60 cells may not be influenced by the presence or absence of diethyl-maleate (DEM) used in the reported work. Additional work proposed by Rozanski included repetitions over a greater range of magnetic field strengths above and below 100 mT and repetition of the experiments at a variety of doses of DEM and with GSH potentiators such as L-NAC and glutathione diesters to allow for a greater range of GSH levels to be tested. This last possibility is driven by the hypothesis that a threshold free radical concentration exists where the action of static magnetic fields becomes apparent.

Curtis Carl Johnson Memorial Award - Best Poster:

Genevieve Albert

Poster P-65 CYTOGENETIC ANALYSIS OF HUMAN LYMPHOCYTES AFTER A 4 HOUR, WHOLE BODY EXPOSURE TO A SINUSOIDAL 200 μT 60 HZ MAGNETIC FIELD, Genevieve C. Albert with James P. McNamee, Frank S. Prato, Vijayalaxmi, and Alex W. Thomas

Genevieve began work on a Master’s degree in Medical Biophysics at the University of Western Ontario under the co-supervision of Drs. Alex Thomas and Frank Prato in September 2006. She was awarded the best student poster at the 29th Annual Bioelectromagnetics Society Meeting in June 2007 in Kanazawa, Japan. She recently completed this work and has begun working on a Master’s degree in Public Health. Her Medical Biophysics thesis research project was titled “Assessment of genetic damage in peripheral blood of human volunteers exposed (whole-body) to a 200 mT, 60 Hz magnetic field” from which this award winning poster was derived.

The aim of this project (performed by Genevieve C. Albert with James P. McNamee, Leonora Marro, Vijayalaxmi, Pascale V. Bellier, Frank S. Prato, and Alex W. Thomas) was to investigate the extent of damage in nucleated cells in peripheral blood of healthy human volunteers exposed to a whole-body 60 Hz, 200 μT magnetic field. In this study, 10 male and 10 female healthy human volunteers received a 4 h whole-body exposure to a 200 μT, 60 Hz magnetic field. In addition, 5 males and 5 females were treated in a similar fashion, but were exposed to sham conditions. For each subject, a blood sample was obtained prior to the exposure period and aliquots were used as negative- (pre-exposure) and positive- (1.5 Gy 60Co y-irradiation) controls. At the end of the 4 h exposure period, a second blood sample was obtained. The extent of DNA damage was assessed in peripheral human blood leukocytes from all samples using the alkaline comet assay. To detect possible clastogenic effects, the incidence of micronuclei was assessed in phytohemagglutinin (PHA)-stimulated lymphocytes using the cytokinesis-block micronucleus assay. There was no evidence of either increased DNA damage, as indicated by the alkaline comet assay, or increased incidence of micronuclei (MN) in the magnetic field exposed group. There was no significant difference between pre- and post-exposure samples (p>0.05). Moreover, magnetic field-exposed volunteers were not significantly different from sham-exposed subjects (p>0.05). However, an in vitro exposure of 1.5 Gy y-irradiation caused a significant increase in both DNA damage and MN induction (p<0.001). This study found no evidence that an acute, whole-body exposure to a 200 μT, 60 Hz magnetic field for 4 hours could cause DNA damage in human blood. (Manuscript submitted to the International Journal of Radiation Biology, August 2008)

Second Place - Best Poster:

Stephen Kennedy

Poster P-51 DEVELOPMENT AND CHARACTERIZATION OF THE MICROCUVETTE: AN EXPOSURE DEVICE FOR REAL-TIME OBSERVATION OF ELECTROPORATIVE MOLECULAR UPTAKE, Stephen M. Kennedy with Zhen Ji, John H. Booske, and Susan C. Hagness.

Stephen Kennedy was awarded 2nd place in the student poster competition for his presentation of work describing the development of a device designed to allow the simultaneous observation of cells under fluorescence microscopy during electric field exposure (Development and characterization of the microcuvette: an exposure device for real-time observation of electroporative molecular uptake by SM Kennedy, Z Ji, JH Booske, and SC Hagness). The device’s inherent electric field non-uniformity was characterized using finite element electrostatic simulations. It was also demonstrated that the characterization of electric field non-uniformity could be used to predict the response of cells based on their location within the device.

As noted above, Stephen M. Kennedy is an NIH Fellow at the Department of Electrical and Computer Engineering, University of Wisconsin-Madison.

Third Place - Best Poster (tie):

Julia McKay and Darragh Crotty

Poster P-6 EXTREMELY LOW FREQUENCY MAGNETIC FIELDS: EFFECTS ON BLOOD FLOW AND BLOOD PRESSURE, Julia C. McKay with Karel Tyml, Frank S. Prato, and Alex W. Thomas

Julia McKay’s work examined the effects of CNP, or complex neuroelectromagnetic pulse on blood flow. Previous experiments at Western Ontario University showed that a specific pulsed magnetic field of extremely low frequency (CNP) is effective in providing pain relief in a variety of species. More specifically, previous experiments in Julia McKay’s lab showed that the particular form of CNP can induce pronounced effects on the opioid system, as well as other reports in the literature of magnetic field effects on microcirculation. This lead her to investigate whether the CNP might also induce changes, even if only subtle, in blood flow and/or blood pressure. In the work she reported at the meeting, potential effects of the CNP on blood flow and blood pressure were investigated using laser Doppler flowmetry and arterial insertion of a pressure catheter in a rat model. Several CNP intensities were tested, as was a 60 Hz sinusoidal magnetic field of varying strengths. No main effect of the 200 μT CNP exposure on blood flow was observed and preliminary analysis of blood pressure and other data indicates a similar finding.

Poster P-85 EFFECT OF 50HZ, 2MT AC ELECTROMAGNETIC FIELD ON PROLIFERATION, MORPHOLOGY AND CBFA1 PROTEIN EXPRESSION IN PRE-OSTEOBLASTS, Darragh Crotty with Gabriel Martinez, Michael Coey, & Adriele Prina-Mello

Darragh Crotty investigated the effect of an AC EMF on proliferation, morphology and expression of the differentiation marker protein, CBFa1, in mouse pre-osteoblasts. Exposed cells were compared to sham-exposed and control cells. No significant differences (ANOVA-1; significant if p < 0.05) were seen for proliferation, CBFa1 protein expression, cell size, nuclear size and number or length of processes extending from the cells. Although average anti-CBFa1 fluorescence intensity was observed to be greater in exposed and sham cells compared with controls, these increases showed high variability in their measured intensities so they were judged not significant. Also, the increase was approximately equal for sham and exposed indicating that the effect was not due to the magnetic field. His results suggest that 2mT, 50 Hz AC fields do not affect pre-osteoblast proliferation, differentiation or morphology significantly.