448 VITAMIN K GROUP 



performed, the plasma prothrombin falls much more rapidly than that of 

 rats similarly operated on, which, however, had a normal diet.-^"-^ 



In the newborn infant it has been suggested^* that a single intramuscular 

 dose of 10 7 of 4-amino-2-methyl naphthol HCl given at birth will prevent 

 almost completely a prolongation of the "prothrombin time" during the 

 first week of life; daily doses of 1 7 were equally effective. Once the "physi- 

 ologic hypoprothrombinemia" had developed, 1 7 was sufficient to reduce 

 the "prothrombin time" to normal. Hardwicke,"^ using a diphosphoric acid 

 ester of menadiol, reported comparable results when the vitamin was given 

 orally. Adler's^" results also tend to be confirmatory. 



Taylor and coworkers^^ have found that the hypoprothrombinemia of 

 sprue is rectified by administration of cortisone; they suggest that improved 

 intestinal absorption of fats and fat-soluble vitamins is the explanation. 

 An attempt was personally made to find the least daily dose of vitamin 

 K which would elevate the plasma prothrombin in such patients. Re- 

 peated determinations of the plasma prothrombin of an untreated patient 

 with non-tropical sprue yielded values ranging from 2 to 4 % of normal, yet 

 with no signs of bleeding. 4-Amino-2-methyl naphthol HCl given intra- 

 muscularly on consecutive days induced no response in doses of 1 and 2 7; 

 the prothrombin level rose to 11 % with 5 7, to 21 % with 10 7, and to 34 % 

 with 20 7. Although no further vitamin K was given, it seems likely that 

 much less than 1 mg. would have raised this patient's prothrombin to 

 normal. 



" J. D. Greaves, Am. J. Physiol. 125, 429 (1939). 



2^ C. A. Owen, Jr., Studies on the Conversion of Prothrombin to Thrombin; Effect 

 of Conversion Variations on Prothrombin Tests. Thesis, Graduate School, Uni- 

 versity of Minnesota, 1950. 



" J. E. Flynn and E. D. Warner, Proc. Soc. Exptl. Biol. Med. 43, 190 (1940). 



"R. L. Sells, S. A. Walker, and C. A. Owen, Proc. Soc. Exptl. Biol. Med. 47,441 

 (1941). 



23 S. H. Hardwicke, /. Pediat. 24, 259 (1944). 



30 B. Adler, Monatschr. Geburtschulfe u. Gynakol. 118, 225 (1944). 



" A. B. Taylor, M. W. Comfort, E. E. Wollaeger, and M. H. Power, /. Clin. Invest. 

 30, 678 (1951). 



