I have studies underway in collaboration with scientists in the departments of Applied Science, Biology, and Physics, as well as the Thomas Jefferson Accelerator Facility to develop very high resolution Single Photon Emission detectors. These detectors are used in a dual modality imaging system with X-ray. We are developing the associated Computed Tomography software and hardware for in vivo SPECT imaging of both gene expression as well as for pharmacodynamic studies of iodine-labeled ligands.
In addition, I am continuing studies on the endocrine bases of reproductive inhibition. More specifically, we have identified a mouse model system for reproductive inhibition that resembles human stress-induced infertility. Our studies have centered on determining the nature of a density-related and reversible reproductive inhibition in two Peromyscus species. These studies involve molecular and cellular approaches to determining the expression of genes and the gene products that may contribute to and maintain reproductive inhibition.
Current Research Projects
- Development of iodine-labeled oligonucleotides and other ligands as reporter molecules for use in our in vivo imager. Work with image analysis and computed tomography.
- Characterization of the endocrine mechanisms that maintain reproductive inhibition.
- Development of microarray technology to identify candidate genes showing increased or decreased expression with stress.
- Development of new approaches to measuring cellular and molecular actions of hormones that may be associated with reproductive inhibition.
- Studies on the role of the adrenal in maintaining a pre-pubertal state in older animals and the induction of puberty upon the release of the inhibited state.
Recent Reports and Publications
Qian, Jianguo, Bradley, Eric L., Majewski, Stan, Popov, Vladimir, Saha, Margaret S., Smith, Mark F., Weisenberger, Andrew G., and Welsh, Robert E. (2008) "A small-animal imaging system capable of multipinhole circular/helical SPECT and parallel-hole SPECT." Nuclear Instruments and Methods in Physics Research A 594 (2008) 102–110.
Hammond, WT., Bradley, EL., Welsh, RE., Qian, J., Weisenberger, AG., Smith, MF., Majewski, S., Saha, MS, (2007) “A Gamma Camera Re-evaluation of Potassium Iodide Blocking Efficiency in Mice.” Health Physics 92(4): 396-406.
Bradley, E.L., Cella, J., Majewski, S., Popov, V., Qian, J., Saha M.S., Smith, M.F., Weisenberger, A.G., and Welsh, R.E. (2006) A Compact Gamma Camera for Biological Imaging. IEEE, Trans. Nucl. Sci. 53(1):59-65.
Saha, M.S., Bradley, E.L., Brewer, P., Gleason, K.K., Kross, B., Majewski, S., Popov, V., Qian, J., Ranck, A., Smith, K., Smith, M.F., Weisenberger, A.G., Wojcik, R., and Welsh, R.E., (2003) An Economical Dual-Modality Small Animal Imaging System with Application to Studies of Diabetes. IEEE Transactions on Nuclear Science 50(3): 333-38.
Weisenberger, A.G., Wojcik, R., Bradley, E.L., Brewer, P., Majewski, S., Qian, J., Ranck, A., Saha, M.S., Smith, M.F., and Welsh, R.E. (2003) SPECT-CT System for Small Animal Imaging. IEEE Transactions on Nuclear Science 50(1): 74-79.
Cherry, B.A., Cadigan, B., Mansourian, N., Nelson, C., and Bradley, E.L. (2002) Adrenal gland differences associated with puberty and reproductive inhibition in Peromyscus maniculatus. Gen. Comp. Endocrinology 129:104-113.
In vivo imaging of the Distribution and Pharmacodynamics of 125 Iodine-labeled Insulin During the Development of Streptozotocin-Induced Hyperglycemia in the C57BL/6J Mouse with a Dedicated Gamma Imager. Bradley, E.L., Gleason K.K., Majewski, S., Ranck A.E., Saha, M.S., Smith, M.F., Weisenberger, A.G., Welsh, R.E., and Wojcik, R. High Resolution Imaging in Small Animals. 9-11 September 2001, Rockville MD.
Development of a Minature SPECT-CT System for Small Animal Imaging. Weisenberger, A.G., Bradley, E.L., Majewski, S., Saha, M.S., Smith, M.F., Welsh, R.E., and Wojcik, R. High Resolution Imaging in Small Animals. 9-11 September 2001, Rockville MD.
Experimental Results and Predictive Calculations for Pinhole Collimators Used in Small Animal Nuclear Imaging. Ng, L., Ranck, A., Feldmann, J., Welsh, R. E., Bradley, E.L., Saha, M.S., Smith, M., Kross, B., Popov, V., Weisenberger, A.and Wojcik, R. American Physical Society, Annual Meeting, April 2001, Wash. DC.
A Novel Technique for Coregistration of Biological Images in a Multimodality Detector Array. Ranck, A., Feldmann, J., Robert E. Welsh, Bradley, E.L. Saha, M.S., Kross, B., Popov, V., Weisenberger, A. and Wojcik, R. American Physical Society, Southeastern Section, November 2000.
Dual-Modality Small Animal Imaging System. Ranck, A., Feldmann, J., Saunders, R.S., Welsh, R.E., E.L., Saha, M.S., Kross, B., Popov, V., Weisenberger, A. and Wojcik, R. American Physical Society, Division of Nuclear Physics, General Meeting, October 2000.
Single Photon Computed Tomography With Large Position-Sensitive Phototubes. Feldmann, J., Ranck, A., Saunders, R.S., Welsh, R.E., Bradley, Saha, M.S., Kross, B., Popov, V., Weisenberger, A., and Wojcik, R. American Physical Society, Division of Nuclear Physics, General Meeting, October 2000.
Weisenberger, A., E. Bradley, S. Majewski, and M. Saha. 1998. Development of a novel radiation imaging detector system for in vivo gene imaging in small animal studies. IEEE Transactions on Nuclear Science 45(3): 1743-1749.
Staubs, P.A. and E.L. Bradley. 1998. Oxygen consumption and carbon dioxide production in male Prairie Deermice in different reproductive conditions and group densities. Comp. Biochem. Physiol. 119A: 287-294.
Weisenberger, A., B. Kross, S. Majewski, S. Wojcik, E. Bradley, and S. Saha. 1998. Design features and performance of a CsI(Na) array based gamma camera for small animal gene research. IEEE Transactions on Nuclear Science 45(6): 3053-3058.
Weisenberger, A.G., S. Majewski, M. Saha and, E. Bradley. 1997. Coincident radiation imaging of idoine 125 for in vivo gene imaging in small animals. Nuclear Instruments and Methods in Physics Research A 392: 299-303.
Last updated 7/1/09
College of William and Mary, Department of Biology