Charles R. Geard

Columbia University

Currently Funded Projects

The Adaptive Response, Genetic Haplo-insufficiency and Genomic Instability

Defining a Possible Low LET Bystander Effect

Technical Abstracts

2006 Workshop:
The Bystander Effect in Normal Human 3-D Tissue: Experiments, Models, and Implications
Brenner, D., Ponnaiya, B., Shuryak, I., Sachs, R., and Geard, D.

2005 Workshop:
The Radiation-Induced Bystander Response: Different Protocols, Similar Effects.
Geard, C.R., Baskar, B.R., Jenkins-Baker, G., Bigelow, A., Marino, S., and Ponnaiya, B.

2003 Workshop:
Detection of Genomic Instability in a-Irradiated and Bystander Human Fibroblasts.
Ponnaiya, B., Jenkins-Baker, G., Bigelow, A., Marino, S., and Geard, C.R.

2002 Workshop:
Investigation of a Radiation-Induced Bystander Effect Using Co-Culturing Protocols. Ponnaiya, B., Jenkins-Baker, G., Zhang, M., Bigelow, A., Marino, S., and Geard, C.R.

2001 Workshop:
Probing the Origins of Radiation-Induced Biological Damage in Normal Human Cells with a Charged-Particle Microbeam.
Geard, C.R., Jenkins-Baker, G., Ponnaiya, B., Zhang, M., Bigelow, A., and Randers-Pehrson, G.

Computer Simulations of Chromosome Aberration Data for Human Cells Subjected to Low-LET Radiation: Mechanistic Implications.
Sachs, R., Cornforth, M., Vazquez, M., Arsuaga, J., Hlatky, L., Geard, C.R., and Brenner, D.

Are Bystander Effects Important at Low Radiation Doses?
Brenner, D.J., Geard, C.R., Hall, E.J., and Sachs, R.K.

1999 Workshop:
The Risk of Cancer Induction Due to Routine Mammographic Screening
Brenner, D.J., Marino, S., and Geard, C.R., Center for Radiological Research, Columbia University.

Site Specific Microbeam Irradiation: Defining a Bystander Effect
Geard, C.R., Ballajee, A.S., Hei, T.K., Ponnaiya, B. and Marino S. Center for Radiological Research.

Cytogenetic Tests of Radiobiological Models Relating Epidemiologically Measurable Risks to Low-Dose Risks
Sachs, R.K., Brenner, D.J., Geard, C.R., and Hlatky, L., Department of Mathematics, Evans Hall.

Publications

Baskar, R., Balajee, A.S., Geard, C.R., and Hande, M.P. (2008) Isoform-specific activation of protein kinase C in irradiated human fibroblasts and their bystander cells. International Journal of Biochemistry & Cell Biology 40(1):125-134.

Baskar, R., Balajee, A.S., and Geard, C.R. (2007) Effects of low and high LET radiations on bystander human lung fibroblast cell survival. International Journal of Radiation Biology 83(8):551-559.

Ponnaiya, B., Jenkins-baker, G., Randers-Pherson, G., and Geard, C.R. (2007). Quantifying a bystander response following microbeam irradiation using single-cell RT-PCR analyses. Experimental Hematology 35(4):64-68.

Braby, L., Brenner, D., Cherubini, R., Cremer, T., Durante, M., Geard, C.R., Kobayashi, K., Miller, J., Prise, K., and Taucher-Scholz, G. (2006). Session 1. Microbeam probes of cellular radiation response. In: Extended Abstracts: Proceedings of the 7th International Workshop: Microbeam Probes of Cellular Radiation Response, Radiation Research 166:652-653.

Ponnaiya, B., Jenkins-Baker, G., Randers-Pherson, G., and Geard, C.R. (2006). Session 7. Comparisons of bystander responses observed in two-dimensional and three-dimensional systems after microbeam irradiation. Proceedings of the 7th International Workshop: Microbeam Probes of Cellular Radiation Response, Radiation Research 166:685-686.

Belyakov, O.V., Mitchell, S.A., Parikh, D., Randers-Pehrson, G., Marino, S.A., Amundson, S.A., Geard, C.R., and Brenner, D.J. (2005). Biological effects in unirradiated human tissue induced by radiation damage up to 1 mn away. Proceeding National of Academy of Science of the United States of America 102(40):14203-14208.

Zhou, H., Ivanov, V.N., Gillespie, J., Geard, C.R., Amundson, S.A., Brenner, D.J., Yu, Z., Lieberman, H.B., and Hei, T.K. (2005). Mechanism of radiation-induced bystander effect: Role of the cyclooxygenase-2 signaling pathway. Proceeding National of Academy of Science of the United States of America 102(41):14641-14646.

Zhu, A., Zhou, H., Leloup, C., Marino, S.A., Geard, C.R., Hei, T.K., and Lieberman, H.B. (2005). Differential impact of mouse Rad9 deletion on ionizing radiation-induced bystander effects. Radiation Research 164:655-661

Balajee, A.S., Ponnaiya, B., Baskar, R., and Geard, C.R. (2004). Induction of replication protein A in bystander cells. Radiation Research 162:677-686.

Ponnaiya, B., Jenkins-Baker, G., Brenner, D.J., Hall, E.J., Randers-Pehrson, G., and Geard, C.R. (2004). Biological responses in known bystander cells relative to known microbeam-irradiated cells. Radiation Research 162:426-432.

Suzuki, M., Zhou, H., Geard, C.R., and Hei, T.K. (2004). Effect of medium on chromatin damage in bystander mammalian cells. Radiation Research 162:264-269.

Mitchell, C.R., Azizova, T.V., Hande, M.P., Burak, L.E., Tsakok, J.M., Khokhryakov, V.F., Geard, C.R., and Brenner, D.J. (2004). Stable intrachromosomal biomarkers of past exposure to densely ionizing radiation in several chromosomes of exposed individuals. Radiation Research 162:257-263.

Zhou, H., Randers-Pehrson, G., Geard, C.R., Brenner, D.J., Hall, E.J., and Hei, T.K. (2003). Interaction between radiation-induced adaptive response and bystander mutagenesis in mammalian cells. Radiation Research 160(5):512-516.

Hande, M.P., Azizova, T.V., Geard, C.R., Burak, L.E., Mitchell, C.R., Khokhryakov, V.F., Vasilenko, E.K., and Brenner, D.J. (2003) Past exposure to densely-ionizing radiation leaves a unique permanent signature in the genome. American Journal of Human Genetics 72:1162-1170.

Zhou, H., Randers-Pehrson, G., Geard, C.R., Brenner, D.J., Hall, E.J., and Hei, T.K. (2003). Interaction between radiation-induced adaptive response and bystander mutagenesis in mammalian cells. Radiation Research 160:512-516.

Geard, C.R., Jenkins-Baker, G., Marino, S.A., and Ponnaiya, B. (2002). Novel approaches with track segment alpha particles and cell co-cultures in studies of bystander effects. Radiation Protection Dosimetry 99(1-4):233-236.

Sawant, S.G., Randers-Pehrson, G., Geard, C.R., Brenner, D.J., and Hall, E.J. (2001). The bystander effect in radiation oncogenesis: I. Oncogenic transformation can be initiated in C3H10T1/2 cells in vitro in the unirradiated neighbors of irradiated cells. Radiation Research 155:397-401.

Brenner, D.J., Okladnikova, N., Hande, P., Burak, L., Geard, C.R., and Azizova, T. (2001). Biomarkers specific to densely-ionizing (high LET) radiations. Radiation Protection Dosimetry 97(1):69-73.

Randers-Pehrson, G., Geard, C.R., Johnson, G., Elliston, C.D., and Brenner, D.J. (2001). The Columbia University single-ion microbeam. Radiation Research 156:210-214.

Miller, R.C., Marino, S.A., Napoli, J., Shah, H., Hall, E.J., Geard, C.R., and Brenner, D.J. (2000). Oncogenic transformation in C3H10T cells by low-energy neutrons. International Journal of Radiation Biology 76:327-334.

Johnson, K.L., Brenner, D.J., Geard, C.R., Nath, J., and Tucker, J.D. (1999). Chromosome aberrations of clonal origin in irradiated and unexposed individuals: Assessment and implications. Radiation Research 152:1-5.

Johnson, K.L., Brenner, D.J., Nath, J., Tucker, J.D., and Geard, C.R. (1999). Radiation-induced breakpoint misrejoining in human chromosomes: Random or non-random? International Journal of Radiation Biology 75:131-41.

Miller, R.C., Randers-Pehrson, G., Geard, C.R., Hall, E.J., and Brenner, D.J. (1999). The oncogenic transforming potential of the passage of single alpha particles through mammalian cell nuclei. Proceeding National of Academy of Science of the United States of America 96(1):19-22.

Pandita, T.K. and Geard, C.R. (1996). Chromosome aberrations in human fibroblasts induced by monoenergetic neutrons. I. Relative biological effectiveness. Radiation Research 145:730-739.

Pandita, T.K., Pathak, S., and Geard, C.R. (1995). Chromosome end associations, telomeres and telomerase activity in ataxia telangiectasia cells. Cytogenetics and Cell Genetics 71:86-93.

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