Word: viruses
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Dates: during 1980-1989
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...addition to causing AIDS and flu, viruses have brought the scourges of smallpox, yellow fever and polio. They bear responsibility for many of the familiar rashes of youth -- chicken pox, measles, rubella -- as well as such disparate disorders as the common cold, gastroenteritis, herpes, shingles, warts and mononucleosis. Viruses are known to cause at least one form of human cancer and are prime suspects in several other kinds of malignancies. Just last week Dr. Robert Gallo of the National Cancer Institute in Bethesda, Md., announced that he and his team had isolated a new virus that may cause certain kinds...
...clue to the activity of viruses emerged during World War I, when a British and a French scientist independently noticed the appearance of clear circular spots in laboratory cultures grown over with bacteria. When material from a clear spot was applied to a different location in the bacteria culture, another circular area devoid of bacteria soon appeared. Felix d'Herelle, the French bacteriologist, thought he knew why. "What caused my clear spots," he wrote, "was in fact an invisible microbe, a filterable virus, but a virus parasitic on bacteria." D'Herelle named the unseen bug a bacteriophage (from the Greek...
While some of the properties of viruses were becoming evident in the 1920s, no one had yet seen one; on the average, scientists now know, viruses are ten to 100 times as small as the typical bacterium, and in fact far smaller than the wavelength of visible light. That makes them too diminutive to be seen with the most powerful optical microscopes. But in 1931 the invention of the electron microscope -- for which German Physicist Ernst Ruska finally won the Nobel Prize this year -- broke the light barrier. The new instrument -- along with a technique called X-ray crystallography...
...Some viruses, like the ones that cause the common cold, look vaguely like soccer balls: round with a surface of bumpy triangular facets. Others, particularly the larger bacteriophages, resemble lunar landing modules. The flu virus looks like the head of a Roman mace, with spikes protruding in all directions; herpes viruses are spherical, as is the AIDS variety. Whatever their shape, all viruses have something in common. They are models of biological minimalism, consisting simply of a core of genetic material -- either a DNA or RNA molecule -- and a protective envelope made of proteins (most varieties have a double coat...
...first-tier defense fails to control the threat, says Fields, "you bring out the guided missiles." These are antibodies -- produced by B cells upon the order of helper T cells -- that are custom-designed to home in on certain antigens, distinctively shaped proteins that characterize a particular type of virus, and destroy the enemy or render it harmless...