A Laser Capture Microdissection (LCM) system has been developed in collaboration with NCI and NCRR. The LCM system permits one-step procurement of selected human cell populations from a much larger section of complex, heterogeneous tissue. The targeted regions are comprised of either cells from a specific pathology, or normal control cells. Due to the high purity of the dissected tissue, there is a significant increase in value of subsequent genetic analysis results. Prior to the development LCM, dissected tissues were often contaminated by wrong cells, therefore limiting the practical value of downstream molecular analysis. The SPCSG is responsible for many aspects of the LCM system design which are critical to the success, and advancement, of the technology. For example, SPCSG design and development responsibilities include: laser diode control electronics, instrumentation computer control software, image and data archiving, system automation, and telemedicine. A cDNA Microarray system has been developed in collaboration with NHGRI and NCRR. The cDNA Microarray system is used to study the development and progression of cancer, and the experimental reversal of tumorigenicity, which are both accompanied by complex changes in patterns of gene expression. The system is comprised of an Arrayer and a Scanner. The Arrayer generates high-density microarrays of DNA sequences used to search for differences in gene expression associated with tumor suppression. The Scanner provides a means of obtaining quantitative measures of the extent of hybridization of flourescently tagged genes to depositions on the microarray. Previously unrecognized alterations in the expression of specific genes have been discovered with this system. The SPCSG is responsible for many aspects of the cDNA Microarray system design. Some example responsibilities are: custom electronics design for signal conditioning and data acquisition; custom software for system control and data processing; and system integration. A High-Speed Optical Multichannel Analyzer (OMA) system has been developed in collaboration with NHLBI and NCRR. The OMA system was designed to obtain data, through the measurement of time-resolved absorption spectra, on the kinetic reaction mechanisms of biological preparations such as cytochrome oxidase and bacteriorhodopsin. Although the OMA system has proven to be a powerful tool over the years, recent studies have shown that an OMA system with higher performance is required. Consequently, the research and design of an advanced, second-generation, OMA instrument has been initiated. With the exception of the optics subsystem, the SPCSG will design the entire system. Design and development areas include: photodiode analog interface circuitry, data acquisition and timing circuitry, system integration, and coordination of a custom software development. An Electron Paramagnetic Resonance (EPR) Spectrometer/Imager system has been developed in collaboration with NCI, NCRR, and NIDDK. The EPR system was designed to measure endogenous in-vivo free radical production, and perform non-invasive in-vivo imaging of free radicals. The EPR system represents the first reported low frequency pulsed EPR spectrometer/imager to be constructed for the purposes of in-vivo imaging of free radicals. Over the recent years, this project has required considerable electrical engineering research and development. For example, a specialized 300 Megasamples per second digitizer- averager was designed by SPCSG staff to increase the signal-to-noise ratio while maintaining high pulse excitation repetition rates. Techniques developed on this project have stimulated developments in other laboratories. The SPCSG design responsibilities on this project could include: data acquisition design, digital signal processing algorithm development, radio-frequency design, control software development, and system integration.
| Subramanian, Sankaran; Koscielniak, Janusz W; Devasahayam, Nallathamby et al. (2007) A new strategy for fast radiofrequency CW EPR imaging: direct detection with rapid scan and rotating gradients. J Magn Reson 186:212-9 |
| Vogel, Abby; Chernomordik, Victor V; Riley, Jason D et al. (2007) Using noninvasive multispectral imaging to quantitatively assess tissue vasculature. J Biomed Opt 12:051604 |
| Hassan, Moinuddin; Riley, Jason; Chernomordik, Victor et al. (2007) Fluorescence lifetime imaging system for in vivo studies. Mol Imaging 6:229-36 |
| Husain, Fatima T; Fromm, Stephen J; Pursley, Randall H et al. (2006) Neural bases of categorization of simple speech and nonspeech sounds. Hum Brain Mapp 27:636-51 |
| Pursley, Randall H; Salem, Ghadi; Devasahayam, Nallathamby et al. (2006) Integration of digital signal processing technologies with pulsed electron paramagnetic resonance imaging. J Magn Reson 178:220-7 |
| Finkel, Julia C; Besch, Virginia G; Hergen, Adrienne et al. (2006) Effects of aging on current vocalization threshold in mice measured by a novel nociception assay. Anesthesiology 105:360-9 |
| Grover, Amelia C; Tangrea, Michael A; Woodson, Karen G et al. (2006) Tumor-associated endothelial cells display GSTP1 and RARbeta2 promoter methylation in human prostate cancer. J Transl Med 4:13 |
| Pursley, Randall H; Salem, Ghadi; Pohida, Thomas J et al. (2005) Direct detection and time-locked subsampling applied to pulsed electron paramagnetic resonance imaging. Rev Sci Instrum 76:1-6 |
| Tangrea, Michael A; Chuaqui, Rodrigo F; Gillespie, John W et al. (2004) Expression microdissection: operator-independent retrieval of cells for molecular profiling. Diagn Mol Pathol 13:207-12 |
| Pollock, Pamela M; Harper, Ursula L; Hansen, Katherine S et al. (2003) High frequency of BRAF mutations in nevi. Nat Genet 33:19-20 |
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