Molecular and Cellular Radiobiology Effects of Radiation and Chemicals on Control of Hemopoiesis RX-03-02-(b) Project Title: 13. Publications: Sordat, M., Sordat, F., Cottier, H., Hess, M. W,, Riedwyl, H., Chanana, and Cronkite, E. P. Studies on lymphocytes. XV, Analysis of the in vivo division cycle of large lymphoid cells in calf thoracic duct usingcombined microspectropnotometry and autoradiography. Exptl. Cell. Res. 70, 145-53 (1972). . JED Nieto Garcia, M., and Johnson, H. A. Cell Tissue Kinet. 5, 331-9 (1972). Johnson, H. A., and Pavelec, spontaneous less of cell function. Cronkite, E. P, M. Ale Ul» l: Thermal noise in cells. A cause of Am. J. Pathol. 69, No.1, 119-29 (1972), ( Kinetics of granulopoiesis. s foes / 3 Presented at the Gesellschar Fur Nuclearmedizin u zin E.D., Freib reiburg, Germany, S September, 1972. 1972 FIV 3 / JANA Chanana, A. D., Schaedeli, J., Hess, M. W., and Cottier, H. Predominance of theta-positive lymphocytes in gut-associated and peripheral lymphoid tissues of newborn mice. J. Immunol. 110, No. 1, 283-5 (1973). J O98 14, Scope: A) 200 Word Summarv: The broad objective in this research is an understanding of the injurious effects of radiation, drugs and chemicals on hemopoiesis, and the processes of recovery from these effects. Knowledge from these studies should improve understanding of diseases of hemopoietic cell differentiation such as leukemia, hypoplastic anemia, lymphoma, myelofibrosis, polycythemia vera, and thrombopenic and granulopotetic states. Description of the cell-to-cell interactions within bone marrow, definition of the feedback loops controlling differentiation into cell lines, and a quantitative measurement of the kinetics of cell proliferation is attempted in order to define the chemical basis of regulation of new blood cell These mechanisms must be determined in order to define how the production, genes in the hemopoietic stem cell (HSC) are switched on and off to maintain the size of the stem cell pool, replete it and control differentia- ‘tion and amplification upon demand for blood cell production. A battery of techniques are adapted or developed for studies of hemopoiesis following Legpetacics or administration of drugs and chemicals to animals, and n fant and diseased states of animals and human beings. B) in Supplement co 200 Word Summary: hemopoietic Among the techniques utilized in these studies are: blood cell and cell growth in diffusion chambers; in vitro bone marrow culture; splenic colony growth from the HSC; cell kinetics using tritiated (See Continuation Sheet) [119285 1 Cell proliferation kinetics in goldfish acclimated to various temperatures. ' A. RX-225