2003 ABSTRACTS

THE ROLE OF HSP-27 IN THE PROTECTION OF NA,K-ATPASE DURING SUBLETHAL ISCHEMIC INJURY AND SUBSEQUENT RECOVERY
Sacred Heart Academy, Hamden, Connecticut

Sublethal ischemia in the porcine epithelial cells of the proximal tubule causes cytoskeletal damage which disrupts the cells' crucial polar structure, causing displacement of membrane proteins. One such protein is Na,K-ATPase, an insoluble, active-transport pump which, during ischemia, becomes partially-solubilized in detergent and thus ineffectual as a transporter.
This experiment explored the hypothesis that human heat-shock protein HSP-27, which has shown protective effects during sublethal ischemia in human epithelial cells, could lessen cytoskeletal disruption and Na,K-ATPase solubilization during and after ischemia when transfected into porcine cells. Three HSP-27-transfected and one vector-transfected (control) cell lines were subjected to ischemia via a respiration-inhibiting injury-medium for two or four hours. Some samples were given injury-medium for two hours and allowed a subsequent recovery period in regular medium. A comparable control-medium was used in a control setup. Cells were harvested in detergent-containing buffer and the supernatants (containing the solubilized Na,K-ATPase) were isolated. After quantification and protein electrophoresis, Western blot analysis showed that in both the injury and recovery setups, there were much lighter bands for Na,K-ATPase in the supernatants of the HSP-27-transfected cell lines than the control cell line. Because HSP-27 was the only variable condition between the cell lines, these results evidenced that HSP-27 was the cause of the lessened solubilized Na,K-ATPase.
Renal pathology applications of this research abound. Primarily, if a specific level of HSP-27 is found to be protective in vivo during ischemic injury, the protein may lend valuable assistance to porcine (and perhaps human) epithelial cells during renal-failure-induced ischemia.

LISA GLUKHOVSKY

A RAPID, ACCURATE METHOD OF DETERMINING THE DISTANCE
TO NEAR-EARTH ASTEROIDS
New Milford High School, New Milford, Connecticut

Most people have only recently become aware of the threat posed by possible cosmic object impacts with Earth. Although extremely energetic impacts are rare, they have occurred in the past and will happen again in the future. The first step in preventing such events is discovering potentially hazardous Near-Earth Objects (NEOs) and verifying their orbits.
In this project, the distances to several Potentially Hazardous/ Near-Earth Asteroids (PHAs/ NEAs) were determined. This was done by simultaneous telescopic imagery, using amateur astronomy equipment, from observatory sites separated by a long baseline distance. Observatories were located in Europe and the U.S. and operated by students or amateur astronomers. After successful imaging sessions, the target asteroid's positional coordinates were determined with image processing / astrometry software. A spreadsheet was created to calculate the distance to the asteroid, using the observed parallax shift between simultaneous images. Meaningful contributions to science were made; fourteen highly accurate observations were submitted to the Minor Planet Center, enabling NASA to refine the orbits of the target asteroids. The overall accuracy of this method far exceeded original expectations; there was little difference between determined distances and NASA's Jet Propulsion Laboratory's predicted distances. The determined distance error was consistently less than 1%. This project has shown that simultaneous imagery with modern amateur astronomy equipment and techniques is a viable and repeatable way to determine the distance to NEAs. This method of ranging may become a useful new tool in NEO research, especially for refining newly-discovered NEO orbits.

A NOVEL APPROACH FOR DETERMINING NUCLEIC ACID STRUCTURE
Greenwich High School, Greenwich, Connecticut

The recent development of nucleic acid analogues has been prompted by the promise of therapeutic applications and uses in biotechnology and nanotechnology. Before these molecules can be implemented effectively, their structures must be established. The novel technique presented here provides a means of determining nucleic acid structure. The method employs AFM (atomic force microscopy) to image a series of double crossover molecule arrays, with each array designed assuming a different number of base pairs per turn in the nucleic acid structure under investigation. Ordered array formation only occurs in the system that assumes the correct helical repeat. To apply the method, a model system was created using a natural and a nonnatural nucleic acid: DNA and PNA (peptide nucleic acid), respectively. With the method, a DNA-DNA duplex was observed to have ~10.5 base pairs per turn, and a PNA-DNA duplex was observed to have ~14 base pairs per turn, with both values closely matching structural data previously obtained using established techniques. The existing methods of structure determination-NMR (nuclear magnetic resonance) spectroscopy and X-ray crystallography-can be costly and time-consuming. The method of the current study can be used to determine the number of residues per turn of any Watson-Crick base pairing nucleic acid, providing an additional method for obtaining a better understanding of nucleic acid structure.

This investigation explored the effects of simulated microgravity (SMG), the weightless condition of space, on mammalian cell production of monoclonal antibodies (MAbs). This study was designed to a) gain insights into the feasibility of applying SMG to commercial antibody production, and b) to address the concern that the human immune system, particularly its capacity for antibody production, might be inhibited by the microgravity conditions of outer space. A rotary cell culture system (RCCS) that simulates microgravity was used to culture mammalian cells. The RCCS was rotated at three different angles to the gravity vector (0°, 30°, and 90°). At 0° and 90°, the RCCS simulates normal gravity and microgravity, respectively. Each culture was continued for about 8 days.
Cell growth and MAb production were monitored daily. Maximum cell density reached 4.9, 2.6, and 0.77 x 106 cells/mL at 0°, 30°, and 90°respectively. Specific (per cell) MAb production rates averaged 0.80, 0.61, and 1.03 pg/cell-h at 0°, 30°, and 90°. Overall cell growth was inhibited in microgravity, however, the specific MAb production rate was 28% higher than the rate achieved under normal gravity. These results suggest that microgravity has a negative effect of on cell growth, but a positive effect on cell longevity and specific antibody production.
These results are promising because they show that SMG holds the potential to be a viable alternative to current methods of antibody production with further optimization of RCCS protocols. Additionally, findings demonstrate that immune system cell growth could be depressed in the microgravity environment of space, underscoring the need to develop treatments that will strengthen the immune system for extended space travel.

The researcher developed an original methodology designed to provide a deeper insight into the spread of disease. Initially inspired by Milgram's Small World Theory, the research combined his idea of population connectivity with computer simulation-based epidemiology, two previously unrelated fields of study. Two programs were written in Visual C++: one to create 300 sample populations with different connectivity metrics, and another to run 7,500 simulated propagation trials. The average number of individuals removed by the epidemic was found to be an exponential function of the connections per capita in the given population. The average time for the epidemic to burn out was shown to rise and then fall, as the number of connections per capita increased.
Analytically determining the epidemic behavior in a large connected population is virtually impossible. The computer simulations enable the investigation of the variability of the epidemic outcome, as well as its average behavior. Epidemic distributions were discovered which describe this variability and reveal how it changes as the connectivity of the population changes.
The results exhibited three distinct regions of epidemic behavior as the connectivity of the population increased. The epidemic distribution predicts how far and how fast a disease will spread in a population, and how those results are likely to vary. Studies indicated that the presence of even one highly connected individual ("Typhoid Mary") can dramatically alter the spread of disease. Discovering this epidemic behavior is a very significant result, and provides the researcher with simple, but intriguing new strategies to combat epidemics.