Innocent blood: a history of hemorrhagic disease of the newborn.

Hemorrhages occurring in the newborn without trauma have been observed by obstetricians since the 17th century, but have been considered different diseases depending on their location. Umbilical hemorrhage associated with obstructed bile canals was described by Cheyne in 1802. Grandidier in 1871 and Townsend in 1894 grouped together various forms of neonatal bleeds and associated them with disturbed coagulation. When the clotting system became better understood in the last decade of the 19th century, effective symptomatic treatment was developed: gelatin, serum injection, and the transfusion of fresh blood. In 1935, Dam detected the function of vitamin K in the coagulation system and 4 years later, Waddell introduced vitamin K administration into therapy and prevention of neonatal hemorrhagic disease. Kernicterus occurred when high doses of synthetic water-soluble vitamin K analogues were given to preterm infants, reminding physicians that progress in neonatal therapy rests on the cornerstones of controlled trials and follow-up.

[On the history of vitamin K, dicoumarol and warfarin]. / Pionerer bag vitamin K, dikumarol og warfarin.

The history of the discovery and development of vitamin K and its antagonists, the oral anticoagulants dicoumarol and warfarin, are fascinating, triumphant landmarks in the annals of medicine. Vitamin K was found by Carl Peter Henrik Dam and Fritz Schønheyder from the University of Copenhagen. The discovery was initiated by Dam, by a lucky choice of chicks in the dissertation of sterol metabolism, since the vitamin is not formed by intestinal bacteria in these animals. In these experiments the lack of an unknown factor in the synthetic diet caused internal bleeding similar to that found in scurvy, but the bleeding was not reversed by vitamin C and it could not be explained by the lack of classical vitamins. In 1935 the unknown antihaemorrhagic factor was named vitamin K and a few months later the phenomenon was also observed by H.J. Almquist and E.L.R. Stokstad in Berkeley. The activity of the factor was determined by bioassay in different extracts of green vegetables and alfalfa by Dam and Schønheyder. Vitamin K was isolated in 1939 by Dam and Paul Karrer in Zurich and the structure was determined by Edward Adelbert Doisy. Dam and Doisy were awarded the Nobel Prize in 1943. A dramatic story starts the discovery of dicoumarol. In the 1920s cattle in Canada began dying of internal bleeding with no obvious precipitating cause. Frank W. Schofield, a veterinary pathologist in Alberta, found that the mysterious disease was connected to the consumption of spoiled sweet clover hay and noted a prolonged clotting time. Ten years after a farmer traveled in a blizzard with his dead cow and a milk can of the unclotted blood to the University of Wisconsin. Only the door to the biochemical department of Karl Paul Link was open. This event started the isolation of the anticoagulant agent dicou- marol which was formed by microbial induced oxidation of coumarin in the mouldy sweet clover hay. More than hundred dicoumarol-like anticoagulants were synthesized by Link and his co-workers. A potent hemorrhagic agent named warfarin was first used as an effective rat poison. However, warfarin became the drug of choice and the break- through in the treatment of thromboembolic diseases. Today new oral anticoagulants are competing with warfarin.

The discovery of vitamin K and its clinical applications.

Vitamin K was discovered fortuitously in 1929 as part of experiments on sterol metabolism and was immediately associated with blood coagulation. In the decade that followed, the principal K vitamers, phylloquinone and the menaquinones, were isolated and fully characterized. In the early 1940s, the first vitamin K antagonists were discovered and crystallized with one of its derivatives, warfarin, still being widely used in today's clinical setting. However, major progress in our understanding of the mechanisms of action of vitamin K came in the 1970s with the discovery of γ-carboxyglutamic acid (Gla), a new amino acid common to all vitamin K proteins. This discovery not only provided the basis to understanding earlier findings about prothrombin but later led to the discovery of vitamin K-dependent proteins (VKDPs) not involved in hemostasis. The 1970s also saw an important breakthrough with respect to our understanding of the vitamin K cycle and marked the discovery of the first bone VKDP, osteocalcin. Important studies relating to the role of vitamin K in sphingolipid synthesis were also underway at that time and would pave the way to further work 15 years later. The decades that followed saw the discovery of additional VKDPs showing wide tissue distribution and functional scope, the latest members having been identified in 2008. The 1990s and 2000s were also marked by important epidemiological and intervention studies that focused on the translational impact of recent vitamin K discoveries, notably with respect to bone and cardiovascular health. This short review presents an overview of the history of vitamin K and of its recent developments.

Nutritional scientist or biochemist?

When invited by the editors to provide a prefatory article for the Annual Review of Nutrition, I attempted to decide what might be unique about my experiences as a nutritional biochemist. Although a large proportion of contemporary nutritional scientists were trained as biochemists, the impact of the historical research efforts related to nutrition within the Biochemistry Department at the University of Wisconsin 50 to 60 years ago was, I think, unique, and I have tried to summarize that historical focus. My scientific training was rather standard, but I have tried to review the two major, but greatly different, areas of research that I have been involved in over my career: inorganic fluorides as an industrial pollutant and the metabolic role of vitamin K. I have also had the opportunity to become involved with the activities of the societies representing the nutritional sciences (American Society for Nutrition), biochemistry (American Society for Biochemistry and Molecular Biology), Federation of American Societies for Experimental Biology, the Food and Nutrition Board, the Board on Agriculture and Natural Resources, and the U.S. Department of Agriculture National Agricultural Research, Extension, Education, and Economics. These interactions can be productive or frustrating but are always time-consuming.

Control of coagulation: a gift of Canadian agriculture.

Vitamin K, heparin and their antagonists remain the basis of coagulation therapies today, more than half a century after their discovery. Failure of blood clotting in chicks that were fed a fat-depleted diet was observed by William McFarlane, William Graham Jr. and Frederick Richardson of the Ontario Agricultural College; it led to the search that yielded vitamin K. Investigation of hemorrhagic disease in cattle by Francis Schofield of the Ontario Veterinary College found an anti-thrombin substance in spoiled clover which was later characterized as dicoumarol, a vitamin K antagonist, and led to the development of warfarin. In Toronto, a systematic approach lead by Charles Best resulted in the world's first plentiful supply of purified heparin. Clinical usefulness of heparin in thrombosis, embolism, cardiovascular surgery, dialysis and transplantation was demonstrated first by Gordon Murray and Louis Jaques. The roles and the careers of Canadian coagulation research pioneers are briefly presented in this review, which shows how clinical medicine benefited by the systematic development of agricultural science in Guelph, Ontario.

The pharmacology and therapeutics of vitamin K.

Much has been learned in the past 10 years about the mechanism of action of coumarin anticoagulants and the role of vitamin K in the production of functional clotting factors. This paper reviews the mechanism for post-ribosomal modification of precursor proteins into functional clotting factors, the therapeutic uses of vitamin K, pharmacologic and therapeutic uses of vitamin K antagonists, and the current means of testing for vitamin K antagonism. In addition, information concerning newly discovered vitamin K-dependent proteins in other tissues and pathologic processing is discussed.