ANAPHYLAXIS IN THE LIVERLESS DOG AND OBSERVATIONS ON THE ANTICOAGULANT OF ANAPHYLACTIC SHOCK

Transfusion on the Burma Railway: The life of Jacob Markowitz

At the surrender of Singapore on 15 February 1942, over 100,000 men became prisoners of the Japanese. This included many medical officers who, over the ensuing years, treated men (and some women) suffering the ravaging effects of disease, worsened by the inhumane conditions of captivity. Many medical officers stand out for their work. One in particular, Jacob Markowitz, developed a blood transfusion service, under the most extreme conditions, for the sick working as slave labour on the Burma Railway. Although he qualified 20 years before the outbreak of war, little has been written of Markowitz's early life, or of the impact of this on his war-time contributions.

Heparin in thrombosis and embolism

Heparin was discovered by Howell in 1916 and he showed that it increased the coagulation time of blood. No experimental work was done to prove whether it had any effect on thrombosis in blood-vessels. Thrombosis and obliteration of the lumen may result from injury of the intima of blood-vessels by various means, as Welch,2 Zurhelle,3 Schimmelbusch,4 and Zahn5 have shown. They have described the accumulation of platelets at the site of injury. Very soon leucocytes were added to the mass of platelets, and finally fibrin made its appearance, so that, ultimately, the ordinary blood-clotting processes were added to those of the earlier thrombus. As these changes have been fully described by these investigators, no attempt was made to repeat their work in our experiments.

As it was our object to study whether heparin would prevent these processes, different means of producing thrombi with moderate certainty were investigated. We found6 that superficial veins in the extremities of dogs may be moderately severely traumatized without producing thrombosis, but finally we developed a technique by which thrombosis could be produced in well over 80 per cent.

History of drugs for thrombotic disease. Discovery, development, and directions for the future

The history of the antithrombotic agents--aspirin, heparin, warfarin, and the thrombolytics--is a rich and lively odyssey of serendipity, perseverance, vision, and conflict involving a number of striking personalities. The history of aspirin spans ages and continents from Hippocrates' analgesic for women in labor to the rediscovery of the white willow bark by English country scholar Reverend Edward Stone. Bayer chemist Felix Hoffmann reinvented aspirin for his ailing father; suburban physician L.L. Craven pioneered the prophylactic antithrombotic uses of aspirin; and Sir John Vane elucidated aspirin's mechanism of action as the inhibition of prostaglandin synthetase. Heparin was discovered by McLean, working as a medical student in 1915 in search of a pure procoagulant in dog liver. His original impure material differed somewhat from today's heparin, but purified heparin was rapidly accepted for a myriad of clinical uses; to this day, diverse new properties of this complex glycosaminoglycan continue to be elucidated. The oral anticoagulants emerged from veterinary research in the 1920s on a hemorrhagic disorder afflicting cattle that consumed spoiled sweet clover hay. Several chance encounters led Karl Link and his University of Wisconsin team to the identification of dicumarol as the offending agent in 1939 and its widespread therapeutic use by Wright and others in the 1940s. Link later developed warfarin as a rodenticide, but its use in humans soon followed in the 1950s. Vitamin K was discovered in the 1930s; its involvement in the mechanism of the anticoagulant agents was not delineated until the 1970s. The intrinsic ability of clotted blood to liquify and the fibrinolytic properties of normal urine were noted in the 1800s. Tillett and Sherry's group stumbled on the fibrinolytic properties of streptokinase in the 1930s and pioneered the therapeutic use of streptokinase in the 1940s and of urokinase in the 1960s. Several teams found tissue-type plasminogen activator in various body sites beginning in the 1940s, leading to its cloning and widespread use in the 1980s; anisoylated plasminogen-streptokinase activator complex is an example of rational drug design. The discoverers of these diverse agents have not only provided physicians with a potent armamentarium of antithrombotic drugs but also helped elucidate much basic science and vividly demonstrated the merits of perseverance, independent thought, and adherance to the scientific method.