The answers here published have been prepared by competent authorities. They do not, however, represent the opinions of any medical or other organization unless specifically so stated in the reply. Anonymous communications cannot be answered. Every letter must contain the writer's name and address, but these will be omitted on request.
Q uestions and A nswers. JAMA. 1961;176(6):559–564. doi:10.1001/jama.1961.03040190081047