Word: mutantes
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...studies abroad cover the whole gamut of diseases and the agents that transmit them to man. At Osaka University Dr. Hideo Kikkawa has painstakingly bred 30 different mutant strains of houseflies to find out how some of them become resistant to insecticides. By a statistical quirk, Norway turns out to be the best place to compare the effects of different psychiatric treatments, including tranquilizers. The Oslo government has been keeping a register of mental illness cases since 1916, and its records are the world's best for a homogeneous, stable population. Among U.S. immigrants, and their descendants, from Mediterranean...
...viruses isolated from selected patients and identified by complicated laboratory techniques have proved to be type B. instead of the Asian mutant of the type A group that caused the last notable epidemic two years ago. Though both virus types cause disease outbreaks in cycles, their peaks occur at different intervals and almost never co incide. Outbreaks of Asian, or A2, flu (which has supplanted the older plain A and A1, or "A prime") run in two-or three-year cycles; they may flare up again later this winter or w?ait until next. Type B flu runs in four...
...Infective Heredity." Recent research, said Dr. Horsfall, has shown that gene mutations can be produced by changes in the environment, and the mutant strains will breed true. It began, he recalled, with the little-recognized achievement of three Rockefeller Institute scientists, Drs. Oswald Avery, Colin MacLeod and Maclyn McCarty in 1944. They showed that if nucleic acid from the genetic material of one strain of pneumococcus germs was stirred in with a batch of pneumococci of another strain, the second strain picked up the inherited traits of the first, and then, "in enduring continuity," bred true from cell to daughter...
...hereditary within cell lines, can be produced by X rays, ultraviolet light, some chemicals, and viruses. Different as these factors seem, said Dr. Horsfall, they are probably identical in that they operate only to produce the first mutation. After that, the cells go on multiplying abnormally, true to their mutant genes, even though the agent that caused the mutation is no longer present. This would explain why viruses that may have triggered human cancers cannot be found after the disease appears...
...less harmful viruses (cowpox instead of smallpox, for example) or weakened viruses, or even killed viruses. But in some individuals, and against some viruses more than others, the antibody memory is short -hence revaccination. If a virus mutates, as often happens with flu, a new vaccine containing the mutant must be prepared...