Word: tb
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
Paleopathologists had suspected that TB existed in the New World before 1492. Ancient skeletons, for instance, have bone lesions that resemble those caused by TB. But the DNA discovery, reported in the Proceedings of the National Academy of Sciences, is the first firm proof of TB's longevity in the Americas. "It's about the best evidence you could hope for," says biochemist Wilmar Salo of the University of Minnesota, who was on the research team...
...years old, an advanced age for her society. But he expected to find little else remarkable because the body was so poorly preserved. To his surprise, when he opened the chest, he found a lump on the lung and another two in the lymph nodes -- a common sign of TB infection...
...tissue samples he had taken from the woman to his colleague Salo, the biochemist. Using a new technique of dna analysis called polymerase chain reaction, the Minnesota researchers cloned billions of copies of the ancient genetic material. Then they identified a fragment of dna that is found only in TB bacteria...
...native Americans had so much TB in early colonial times," speculates Aufderheide, "because they were crowded into towns and had much poorer living conditions than before." TB spreads rapidly among people with immune systems weakened by malnutrition and poor sanitation. Among the mummies of rural Chiribaya, few showed any sign of TB infection, and the woman from whom TB DNA was isolated did not die of the disease...
...mystery: How did TB get to the Americas? Did people migrating from Asia across the Bering Sea land bridge take the disease to the new land? Those travelers, thousands of years earlier than Columbus, may have carried the answer to their graves. If so, scientists may one day unearth...