Daniel Karlton Gaidusek Nobel Prize in Physiology or Medicine, 1976 jointly with Baruch Blumberg Date of Birth: 09.09.1923 Country: USA

Biography of Daniel Carleton Gajdusek

Daniel Carleton Gajdusek was an American pediatrician and virologist, and winner of the Nobel Prize in Physiology or Medicine in 1976. He was born in 1923, the eldest of two sons of successful butcher Karl Gajdusek, a Slovak immigrant to the United States, and Ottillie (Dobrocky) Gajdusek, the daughter of Hungarian immigrants. Gajdusek's mother's passion for literature and folklore shaped his early education, exposing him to the works of Homer, Hesiod, Sophocles, Plutarch, and Virgil even before he could read. Unlike his brother, who became a poet and critic, Gajdusek developed an early interest in mathematics and other exact sciences.

As a child, Gajdusek would spend hours at the Boyce Thompson Institute for Plant Research in Yonkers, where his aunt Irene Dobrocky worked as an entomologist. This fascination led him to study physics, biology, and mathematics at the University of Rochester, where he enrolled at the age of 16 in 1940. After completing his bachelor's degree in biophysics in 1943, Gajdusek was accepted into Harvard Medical School, where he obtained his medical degree three years later. Although he initially intended to pursue medical research from a young age, Gajdusek developed a passion for clinical pediatrics. "Children fascinated me, and their medical problems seemed more difficult to solve than those of adults," he later admitted. This prompted him to work as a physician at children's hospitals in Boston and New York before completing a two-year residency in physical chemistry at the California Institute of Technology, where he worked alongside Linus C. Pauling and other influential researchers, including George W. Beadle and Max Delbrück.

From 1949 to 1952, Gajdusek conducted virological research at the John F. Enders Laboratory at Harvard, while also serving as a fellow of the National Foundation for Infantile Paralysis. In 1952, he was drafted into the army and served for two years at the Walter Reed Army Medical Center. The following two years were spent at the Pasteur Institute in Tehran, Iran, studying infectious diseases such as rabies, plague, and malaria. These research experiences led him to Australia, where in 1954, he worked on virology with Macfarlane Burnet at the Walter and Eliza Hall Institute of Medical Research in Melbourne.

Studying child development and the spread of diseases among the indigenous population of Australia and New Guinea, Gajdusek met Vincent Zigas, a worker from the Australian Health Service. Zigas told Gajdusek about the Fore tribe, who lived in the highlands of eastern New Guinea and were stuck in the Stone Age. Many members of this tribe suffered from a deadly degenerative brain disease they called "kuru," which had never been studied before. Together with Zigas, Gajdusek settled among the tribe, learned their language, and spent about a year studying this unusual disease. In 1958, Gajdusek became the head of the laboratory at the National Institute of Neurological and Mental Disorders, a part of the National Institutes of Health (NIH), in Bethesda, Maryland. He continued his research on kuru in New Guinea, making regular visits at least once a year.

Initially, Gajdusek and Zigas believed that kuru was caused by a virus. However, they were unable to isolate the infectious agent or induce the disease in animals using traditional virological methods. As the disease seemed to affect members of the same family, the researchers hypothesized that kuru had a complex genetic nature. In 1959, William Hadlow, a specialist in nervous system diseases in animals, analyzed their findings and emphasized that kuru symptoms resembled those of scrapie, a degenerative neurological disease in sheep. Scrapie had an extraordinarily long incubation period, with years passing between possible infection and the appearance of the first disease symptoms, and its infectious agent was named the "slow virus." Although this disease could be transmitted from one animal to another, the virus causing scrapie was not isolated. Gajdusek realized that the transmission of kuru could also be explained by the presence of a slow virus. The Fore tribe practiced ritual cannibalism, where surviving family members would eat the brain of the deceased as a sign of respect, providing a direct route for the virus transmission. In 1963, Gajdusek began experiments transplanting brain tissue samples from deceased kuru patients to non-human primates, and after two years, the first experimental animals showed signs of the disease. Initially, Gajdusek conducted experiments on chimpanzees, but later he was able to infect lower primates with kuru as well.

The successes achieved by Gajdusek and his colleagues prompted them to search for slow viruses as possible causes of other degenerative changes in the brain and spinal cord. By 1971, they obtained results indicating that Creutzfeldt-Jakob disease (CJD) could be transmitted to animals. This rare degenerative disease of the brain and spinal cord has symptoms similar to kuru and is widespread worldwide. Gajdusek's research on scrapie, kuru, and CJD demonstrated that all diseases caused by slow viruses shared several other important characteristics in addition to their long incubation periods. While typical viral infections are usually accompanied by an immune response characterized by inflammation, increased temperature, the production of antibodies and interferon, slow viruses, it appeared, did not elicit such reactions.

The most striking and contradictory results of the slow virus research concerned their structure. Other known viruses consisted of a small amount of nucleic acid - either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) - enclosed in a protein coat. The protein acts as a means of transporting the nucleic acid into the host cell, where it is incorporated into the cellular machinery to produce new viruses. However, slow viruses could not be inactivated by treatments that destroy nucleic acids, such as formaldehyde, ultraviolet radiation, or high temperatures, which render most viruses non-infectious. Viruses can be extremely small but still visible under an electron microscope. However, electron microscopic studies of diseases caused by slow viruses did not reveal virus-like particles. All these facts convinced Gajdusek and other scientists that slow viruses represented a fundamentally new pathogenic agent: an infectious protein. The small protein aggregates found in the infected brain, it is believed, are the cause of the disease. It is still unclear, however, whether the abnormalities in the formation of abnormal-shaped or abnormal-amounts of cellular proteins are due to cellular defects or unusual properties of the protein itself (such as the ability of the cell to reproduce itself). The protein aggregates remarkably resemble structures that form in the brains of individuals suffering from Alzheimer's disease or senile dementia, where brain changes lead to a decline in mental activity. These diseases may also be caused by slow viruses or spontaneous defects similar to those of slow viruses.

Gajdusek shared the Nobel Prize in Physiology or Medicine in 1976 with Baruch S. Blumberg for their discoveries of "new mechanisms for the origin and dissemination of infectious diseases." Gajdusek was awarded not for discovering the origin of kuru but for his research that led to the "recognition of a new category of human diseases caused by unique infectious agents," as stated by Erling Norby of the Karolinska Institute in his congratulatory speech.

Gajdusek continues to work at the NIH, alternating between laboratory research on slow viruses and expeditions to Melanesia, Micronesia, and New Guinea. A man of extensive knowledge and interests, Gajdusek is also known for his works on anthropology and child psychology. He is unmarried but has many adopted children - 27 boys and one girl from various Pacific populations, several of whose languages he speaks in addition to Russian, German, French, Spanish, and Slovak. He has donated a significant portion of his collection of primitive art to the Peabody Museum in Salem, Massachusetts.

In addition to the Nobel Prize, Gajdusek has received the Mid Johnson Award from the American Academy of Pediatrics (1963). He is a member of the Society for Pediatric Research, the American Pediatric Society, the National Academy of Sciences, the American Academy of Arts and Sciences, the American Philosophical Society, and the American Academy of Neurology. He is an honorary member of the Colombian, Slovak, and Mexican Academies of Medicine.