Research Article Letter from . . . Shanghai. Following the line. Br Med J 1978; 1 doi: https://doi.org/10.1136/bmj.1.6118.968 (Published 15 April 1978) Cite this as: Br Med J 1978;1:968 Article Related content Metrics Responses Peer review This is a PDF-only article. The first page of the PDF of this article appears below.