Methods of Treatment:
Antibiotics: Dr. Hamao Umezawa

Hamao Umezawa spent his childhood fishing and swimming in the brooks that ran past the village of Obama, Japan. These brooks wound their way through the rice fields surrounding Obama, eventually emptying into the Sea of Japan. After Umezawa completed his medical degree in 1937, he became interested in the work of Rene Dubos. Dubos, a microbiologist who had moved to the United States from France in the 1920s, studied the microorganisms that abound in the soil. In 1930, Dubos had found that an extract from one of these soil microorganisms—an enzyme —broke down parts of a disease-causing bacterium. He found that this enzyme worked as a drug to treat animals afflicted with the disease that this bacterium caused. Encouraged, Dubos continued his searches. In 1939, he uncovered another "antibacterial" substance from soil microorganisms that he named "tyrothricin." This became the first antibiotic to be produced in vast quantities, that is, on a commercial scale. The path-breaking work of Dubos fascinated Umezawa, the young doctor. However, before Umezawa could take up this kind of work, his career was disrupted by the outbreak of World War II, and he was drafted into the Japanese army.

At war's end, Umezawa became involved in Japan's effort in contend with a sharp rise in tuberculosis. By this time, Selman Waksman had isolated a powerful antibiotic called streptomycin from a microorganism found in soil. Streptomycin proved to be a powerful chemical therapy for the treatment of tuberculosis. Waksman was a microbiologist like Dubos, and he had been inspired by Dubos's work. Interestingly, Waksman—like Dubos—was an immigrant to the United States. Born in the Ukraine, and he became a U.S. citizen in the 1910s. Before the war, Umezawa had, in fact, started to study the same microorganisms from which Waksman had isolated the tuberculosis-fighting streptomycin. By the time that Umezawa turned to the problem of rising tuberculosis rates in Japan, streptomycin alone could not handle the disease alone. New varieties or "strains" of the bacteria that cause tuberculosis had evolved, and they were impervious or "resistant" to streptomycin. Umezawa realized that he would have to search for new antibiotics, new chemical tools, to combat the disease. His search, though arduous, was not long. In 1956, he discovered the antibiotic "kanamycin." Along the way, he had uncovered the compound "kasugmycin." This substance was effective in treating rice plants against harmful molds. His new chemical tool replaced an earlier chemical approach to the rice plant mold problem. Before, farmers had killed the plant molds using compounds with the element mercury within them. Exposure to mercury can be very harmful to humans, and the use of the mold-killing mercury compounds had caused health problems in thousands of Japanese people. Umezawa's antibiotic broke that cycle.

Umezawa's research on antibiotics brought him back to a topic that had been a major interest earlier in his career. This was the issue of cancer. In the early 1950s, he had speculated that if antibiotics killed germs they might also kill cancer cells. By 1956, he had isolated phleomycin, an antibiotic effective against cancer cells but that was much too toxic for human use. However, Umezawa did not give up the search and in 1962 he found bleomycin. Bleomycin, a mixture of 10 active ingredients, proved to be an effective drug for treating cancer, and is still in use today.