606 ISOTOPIC TRACERS AND NUCLEAR RADIATIONS [Chap. 30 



N 59 Schoenheimer, R., S. Ratner, and D. Rittenberg: Studies in protein metabo- 

 lism. VII. The metabolism of tyrosine, /. Biol. Chem., 127, 333-344 (1939). 



N 60 Schoenheimer, R., S. Ratner, and D. Rittenberg: Amino acid metabolism with 

 isotopes as indicators, /. Biol. Chem. (Proc. Am. Soc. Biol. Chem., 33d Meeting), 

 128, lxxxviii (1939). 



N 61 Schoenheimer, R., S. Ratner, and D. Rittenberg: Studies in protein metabolism. 

 X. The metabolic activity of body proteins investigated with /( — ) -leucine con- 

 taining two isotopes, /. Biol. Chem., 130, 703-732 (1939). 



N 62 Schoenheimer, R., S. Ratner, D. Rittenberg, and M. Heidelberger: The 

 interaction of the blood proteins of the rat with dietary nitrogen, /. Biol. Chem., 

 144, 541-544 (1942). 



N 63 Schoenheimer, R., S. Ratner, D. Rittenberg, and M. Heidelberger: The 

 interaction of antibody protein with dietary nitrogen in actively immunized animals, 

 J. Biol. Chem., 144, 545-554 (1942). 



N 64 Schoenheimer, R., and D. Rittenberg: Studies in protein metabolism. I. Gen- 

 eral considerations in the application of isotopes to the study of protein metabolism. 

 The normal abundance of nitrogen isotopes in amino acids, J. Biol. Chem., 127, 

 285-290 (1939). 



N 65 Schoenheimer, R., D. Rittenberg, G. L. Foster, A. S. Keston, and S. Ratner: 

 The application of the nitrogen isotope N 15 for the study of protein metabolism, 

 Science, 88, 599-600 (1938). 



N 66 Schoenheimer, R., D. Rittenberg, M. Fox, A. S. Keston, and S. Ratner: The 

 nitrogen isotope (N 16 ) as a tool in the study of the intermediary metabolism of 

 nitrogenous compounds, /. Am. Chem. Soc, 59, 1768 (1937). 



N 67 Schoenheimer, R., D. Rittenberg, and A. S. Keston: Studies in protein metabo- 

 lism. VIII. The activity of the a-amino group of histidine in animals, /. Biol. 

 Chem., 127, 385-389 (1939). 



N 68 Shemin, D.: Amino acid determinations on crystalline bovine and human serum 

 albumen by the isotope-dilution method, /. Biol. Chem., 169, 439-443 (1945). 



N 69 Shemin, D.: The biological conversion of /-serine to glycine, /. Biol. Chem., 162, 

 297-307 (1946). 



N 70 Shemin, D., and D. Rittenberg: Evidence for the totally asymmetric synthesis 

 of amino acids in vivo, J. Biol. Chem., 151, 507-510 (1943). 



N 71 Shemin, D., and D. Rittenberg: Some interrelations in general nitrogen metabo- 

 lism, /. Biol. Chem., 153, 401-421 (1944). 



N 72 Shemin, D., and D. Rittenberg: On the mechanism of the conversion of ornithine 

 to proline in vivo; intramolecular nitrogen shift, /. Biol. Chem., 158, 71-76 (1945). 



N 73 Shemin, D., and D. Rittenberg: The biological utilization of glycine for the syn- 

 thesis of the protoporphyrin of hemoglobin, /. Biol. Chem , 166, 621-625 (1946). 



N 74 Shemin, D., and D. Rittenberg: The utilization of glycine for the synthesis of a 

 porphyrin, J. Biol. Chem., 159, 567-568 (1945). 



N 75 Shemin, D., and D. Rittenberg: The life span of the human red blood cell, /. Biol. 

 Chem., 166, 627-636 (1946). 



N 76 Shemin, D., and D. Rittenberg: Utilization of glycine for uric acid synthesis in 

 man, /. Biol. Chem., 167, 875-876 (1947). 



N 77 Stetten, D., Jr.: Biological relationships of choline, ethanolamine, and related 

 compounds, /. Biol. Chem., 138, 437-438 (1941). 



N 78 Stetten, D., Jr.: Biological relationships of choline, ethanolamine, and related 

 compounds, /. Biol. Chem., 140, 143-152 (1941). 



N 79 Stetten, D., Jr.: Biological synthesis of choline by rats on diets with and without 

 lipotropic methyl, /. Biol. Chem., 142, 629-633 (1942). 



