Project Title: 13, Exposure to External and Internal Radtation In Vivo Measurement of Radionuclides in Man; Body Burden and Kinetic Factors, Computer Applications Publications: Cohn, S. H. RX-O1-O1-(b) (Cont'd.) Calcium homeostasis: The hard facts about soft bones, Lecture Series, No, 109, March 1972. BNL 303 46 — Cohu,S. H., Roginsky, M. S., Aloia, J. F., Ellis, K. J., and Shukla, K. K. Alteration in elemental body composition in thyroid disorders. J. Clin. G Endocrinol, Metab, (in press). {7 7 Cohn, S. H., Roginsky, M. S., Aloia, J. F., Ellis, K. J., and Shukla, K.K. Alterations in skeletal mass in endocrine dysfunctions as determined by totalbody neutron activation analysis. Presented at the 9th European Symposium on Calcified Tissues, Baden, Austria, October, 1972. SVK O Cohn, S. H., Shukla, K. K., and Ellis, K. J. A multivariate predictor for total body calcium in man. Am. J.. Physiol. (in press). / JA34 Robertson, J. S., Marr, R. B., Rosenblum, M., Radeka, V., and Yamamoto, Y. L. 32-crystal positron transverse section detector. Presented at the Proceedings of the Symposium on Radionuclide Tomography, New York, September, 1972. | Cohn, S. H., Roginsky, M. S., Aloia, J. F., Ellis, K. (723 J., and Shukla, K. Alterations in skeletal calcium and phosphoids in dysfunction of the para- thyroids. J, Clin. Endocrinol. Metab. (in press). 14, K. JS TXGé Jf Scope: A) 200 Word Summary: A long-rang objective of this program is the elucidation of the control of calcium metabolism, particularly in those disorders characterized by losses of calcium from the skeleton (osteoporosis) and in osteodystrophy associated with chronic hemodialysis, Mathematical models have been developed to quantitate Ca metabolism and to provide a reference for measurement of subtle changes in the metabolic parameters resulting from therapeutic efforts. Kinetic tracer studies employ Ca-47 to provide the data for compartmental analysis along with data from whole-body counting and in vivo neutron activatior analysis of whole-body calcium. A second objective is the study of the shape of the radiation dose response curve. The shape of this curve at levels near the natural background dose rate is of interest regarding the role of natural packemgine radiation in producing the normal mutation rate. 4 pecunencacion development for scanning and image processing as well as assoc computer programming are proposed as general objectives in this program. The work described is, in general, supportive of projects in other budget categories of the Medical Research Program. B) Supplement to 200 Word Summary: An essential requirement for the study of calcium metabolism was the (See Continuation Sheet) 419113 | RX-13