Dr. Medvedev’s twin brother and fellow dissident, historian Roy Medvedev, told Russian news agencies that his brother had a heart attack.
Dr. Medvedev worked at leading Soviet laboratories early in his career and published nearly 100 research papers before his political activism derailed his scientific career. With expertise in microbiology, biochemistry, and genetics, he grew particularly alarmed at the ideas propagated since the 1930s by Trofim Lysenko, a scientific charlatan who captivated the imagination of Soviet leader Joseph Stalin.
Lysenko, who denied the existence of genes, believed that plants and animals could be magically transformed or ‘‘educated’’ by force of will and exposure to Soviet ideals.
Among other things, he said wheat plants could be changed to rye and that seeds soaked in freezing water could adapt to cold climates. Nevertheless, Lysenko held sway over Soviet agricultural practices for years, and his influence could still be felt until Nikita Khrushchev was ousted as the country’s leader in 1964.
By then, Dr. Medvedev had been at work for three years in writing a history of Lysenko and his harmful doctrines. He worked with other scientists to expose Lysenko as a fraud.
Dr. Medvedev’s study of Lysenko was not approved for official publication in the Soviet Union, but clandestine copies circulated among the intelligentsia. In 1969, the book was translated into English and published as ‘‘The Rise and Fall of T.D. Lysenko.’’
Dr. Medvedev was fired from his job at an agricultural research laboratory, and within a few months was summoned to a meeting with a psychiatrist. Instead, Dr. Medvedev was taken to a holding cell, where he managed to pick the lock and walk away.
Soon afterward, on May 29, 1970, as Dr. Medvedev recounted in his book ‘‘A Question of Madness,’’ he was confronted at his home by two psychiatrists accompanied by several police officers. Two lower-ranking officers twisted Medvedev’s arms behind his back and forced him out of his house and into an ambulance. He was driven to a psychiatric hospital in Kaluga, Russia.
The preliminary diagnosis was ‘‘severe mental illness dangerous to the public,’’ and Dr. Medvedev was repeatedly warned to stop his ‘‘publicist activities.’’
Meanwhile, his brother and other activists for greater openness in the Soviet system sent telegrams and published open letters calling for Dr. Medvedev’s release.
Dr. Medvedev was released after 19 days. In the meantime, he and his brother wrote an account of the ordeal, ‘‘A Question of Madness,’’ which was smuggled out of the Soviet Union and published in the United States in 1971.
Officers promptly went to Roy Medvedev’s apartment in Moscow and seized his papers. He was fired from his job at a research institute. Dr. Medvedev, in the meantime, was assigned to a laboratory to study gerontology.
When he tried to present a paper in 1972 at a scientific conference in Kiev, plainclothes officers seized him, fearing what he might say in public, and sent him back to Moscow.
In December 1972, Dr. Medvedev received a rare visa to travel to Great Britain, where he was scheduled to spend a year working in a medical research laboratory. He moved there with his wife and one of their two sons.