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Mad cow link confirmed

点击量:   时间:2019-02-26 05:13:01

By Peter Aldhous THERE can now be little doubt that BSE has jumped the species barrier from cows to people. Research published this week reveals that the agent that causes mad cow disease is indistinguishable from that responsible for the new variant of Creutzfeldt-Jakob disease (vCJD). The findings, from a team led by Moira Bruce of the Institute for Animal Health’s Neuropathogenesis Unit in Edinburgh, describes experiments in which material from the brains of three patients with vCJD was injected into the brains of mice from four different strains. Bruce has shown that BSE has characteristic incubation times in these mouse strains that distinguish it from other similar diseases, such as the various strains of scrapie that affect sheep. Although she only has complete data from the first strain to succumb to vCJD, the incubation times match precisely with those for BSE—which would be highly improbable if the two agents are not the same. Mice from this strain, called RIII, were struck down about 300 days after inoculation (Nature, vol 389, p 498). The damage seen in the brains of the mice also matched the pattern that is typical of the BSE agent. John Pattison of University College London, who chairs the government’s Spongiform Encephalopathies Advisory Committee, believes the link between BSE and vCJD is now proven. “That’s not a question any more,” he says. In a second experiment, also published in Nature (p 448), a team led by John Collinge of St Mary’s Hospital in London took material from the brains of vCJD patients and injected it into mice carrying one form of the human gene for the PrP protein that is disrupted in CJD. Using a test Collinge developed last year (This Week, 2 November 1996, p 4),