Word: dna
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Dates: during 1990-1999
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...years scientists doing gene therapy have had to rely on viruses to do their heavy lifting. Doctors would put whatever snatches of DNA they wanted to change into the viruses and then infect their patients with millions of them, hoping that some would hit the target. Unfortunately, the DNA patches would rarely land where they were supposed to, and even when they did, they usually fell out within weeks. A permanent genetic fix always seemed maddeningly out of reach...
...they have eliminated the need for viruses by harnessing the body's own genetic repair processes. In a landmark proof-of-concept experiment, the Minnesota team permanently altered a blood-clotting gene in 40% of the liver cells in a group of rats. The researchers started by splicing their DNA patch into a slip of RNA. Then they encased the hybrid molecule in a protective coating, laced it with sugars that seek out liver cells and injected it into lab rats. True to plan, the hybrid molecules zeroed in on the targeted gene and lined up alongside it. An enzyme...
CLEVELAND: Real-life "Fugitive" Dr. Sam Sheppard was convicted of his wife's murder in 1954. Forty five years later Sam Reese Sheppard is still fighting to clear his father's name -- and collect a $2 million wrongful-arrest payday for himself. His case was bolstered Thursday by new DNA tests that reveal that blood on the elder Sheppard's pants...
...some sort of fetal-cell contamination at less than a million to one. Nonetheless, he and his colleagues are scrambling to track down any other tissue samples taken from Dolly's mom so they can perform the genetic tests that will determine, once and for all, if Dolly's DNA and her mom's DNA are identical...
...some clues. Typically, the nucleus of the donor cell, whether fetal or full grown, is transferred to an unfertilized egg from which the nucleus has been removed. In mysterious ways scientists still do not understand, something in the cytoplasm of the egg appears to reset the donor cell's DNA. That resetting, it has been clear from the beginning, works much less reliably when adult cells are used, even when they are relatively immature fibroblast cells...