Molecular and Cellular Radiobiology Effects of Radiation and Chemicals on Control of Hemopoiesis RX-03-02-(b) Project Title: 17. Expected Resuits in FY 1974: cells into erythropoiesis. (Cont'd.) Hypertransfusion of red cells in the intact mouse suppresses input of HSC into erythropoiesis. If the HSC flows into the erythropoietic pathway in the plethoric mouse after Fe-55 suicide continues, it will prove the existence of the proposed intramedullary feedback loop. In addition, a large number of mice will be treated with Fe-55 to induce continued erythropoietic suicide in order to accelerate cell division at the HSC level and to test the validity of Hayflick'’s hypothesis in the intact animal, It is planned cto ascertain the D, of human HSC's in marrow from a sufficient number of individuals to establish the statistical variation. Attempts will continue to produce the diffusible factor that ,tnfluences growth in the diffusion chambers by exposing goats to whole-body irradiation followed by plasmaphoresis. Activity will be sought first in the @,-glycoprotein fraction where CSF and EP are found. Studies will also be performed to see if extracorporeal irradiation of the blod produce CSF, EP, alone will suffice to and the factor that stimulates growth of allogenic, autologous, and xenogenic blood and bone marrow cells in diffusion chambers, Studies on EP will continue with emphasis on determining the optimal pCO9, p07, pH, cultures, and exogenous androgens on production of EP in glomerular It is hoped to develop suspension cultures or large scale monolayer cultures to produce large amounts of EP for purification, fraction- ‘ ation, and the production of antibodies against EP, If the latter is successful the anti-EP immunoglobulins will be separated; and using fluorescent microscopy it is hoped to identify the EP-producing cell in the culture. If : large scale production of EP is successful, radioactive amino acids will be added to the culture in order to produce radioactive EP for autoradiographic studies of its cellular and subcellular localizations. In collaboration with Dr. Charles Saladino, Adelphi University, the ultrastructure of the glomerular cultures will be studied from time of preparation of the glomeruli and at regular intervals after being placed into culture. A microspectrophotometer must be obtained in order that systematic studies on DNA content, cell proliferation, and tritiated thymidine labeling of the normal and leukemic cells in culture may be continued as this phase of the work can no longer be performed for us at the University of Copenhagen. util diffu pts will again be made to produce large numbers of autologous HSC's the system developed by Dr. Laissue to grow autologous cells in chambers implanted in an animal's peritoneum, Marrow will be fractionated to eliminate the differentiated cells, The residual undifferentiated cells will be put into diffusion chambers and implanted into the peritoneum of the mid-lethally irradiated goat and grown for the maximum period of time before there is discernible cell differentiation. At this (See Continuation Sheet) pt192491 RX- 231