Word: viruses
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Dates: during 1980-1989
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...electron beams or are stained to improve contrast, their structure becomes distorted. Klug overcame this major obstacle by manipulating the images mathematically with the help of a computer. Among the viral structures discovered by his new method was that of a common plant blight: the tobacco mosaic virus, a tiny rod-shaped particle consisting of a single-stranded coil of RNA surrounded by a cover of protein that resembles a stack of discs...
Higgins' performance, in only the second meet of his cross country career, is notable since he is known as a half miler. The reemergence of Rippey, victimized by a virus for most of last year, also gives Harvard brighter hopes for the season...
People with ultra-audiometric hearing, says Berlin, are usually born with full-range hearing, but become deaf in the lower registers after suffering a high fever, virus or meningitis in childhood. Some have an extended upper auditory range and can hear dog whistles or the shrill hiss of a department-store electronic security system. Their problem, as in Kam's case, generally goes undetected because of inadequate testing. Most testing devices do not produce sounds above a certain frequency, Berlin says, "and it is precisely at this cutoff that ultra-audiometric patients begin hearing." Worse still, ultra-audio-metrics...
...This agent is probably transmissible in a variety of ways, through lesions caused by anogenital sex, for example, or by dirty hypodermic needles. The hemophiliac cases raise the frightening possibility that it can also be transferred through blood transfusions. One model for such an agent is the hepatitis B virus, which commonly infects homosexuals, drug addicts, donor-blood recipients and, partly because of poor sanitary conditions, most Haitians. A few researchers speculate that the AIDS agent may have originated in Haiti and been sexually transmitted to American homosexuals vacationing there...
...AIDS transmission, others are exploring the nature of the disease. The type of immunosuppression found in AIDS patients appears to be unique, affecting white blood cells called T lymphocytes (T for thymus, which plays a role in their development). Certain of these cells help defend the body against viruses, foreign tissue (like organ transplants) and the growth of cancer cells. There are several types, including helper T cells, which promote the production of antibodies against foreign invaders, and suppressor T cells, which reduce antibody output. Healthy individuals have twice as many helpers as suppressors. In AIDS victims, the ratio...