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JAMA. 1940;114(21):2085-2089. doi:10.1001/jama.1940.02810210017005.
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The control of the coagulability of the blood in vivo by the use of heparin in its present highly purified form constitutes one of the significant achievements of medical science during the past decade. The product available today is 500 times more potent than the original crude heparin described by Howell and Holt1 in 1918 and is 100 times more potent than the material used clinically by Mason2 in the Henry Ford Hospital in 1924. In that year Mason reported the experience with heparin as the anticoagulant in blood transfusions in thirty-three human subjects. He used 100 mg. of heparin in 500 cc. of blood. Reactions were frequent, the incidence for three lots being 33 per cent, 100 per cent and 28 per cent respectively. About one-half hour after the transfusions, symptoms developed which varied in intensity from mild headache and chilly sensations to intense headache, backache, vomiting,


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