HONG KONG (Reuters) – Two existing drugs used to treat osteoporosis may be effective in killing influenza viruses, including the new H1N1 swine flu and the H5N1 bird flu viruses, researchers in Hong Kong have found. The two drugs are pamidronate and zoledronate, which are marketed by Novartis AG under the brand names Aredia and Reclast, respectively. In their experiment, the researchers exposed human cells that had been infected with the influenza viruses to the two drugs. They observed that the drugs triggered extra production of a type of white blood cell called yd-T cells, which went on to kill...