Early changes in limb buds of chick embryos after thalidomide treatment
Since the first observations of hypoplastic and aplastic thalidomide deformities in infants (McBride, 1961; Lenz, 1962), the literature on this subject has grown to many hundreds of communications. Experimental investigations in almost all cases have been undertaken to show whether thalidomide and its metabolites have any teratogenic effects in experimental animals. Numerous review papers are available on this subject, e.g. Giroud, Tuchmann-Duplessis & Mercier-Parot (1962), Somers (1963), and Salzgeber & Wolff (1964). Chick embryos did not seem for some time to be suitable for experimental production of typical thalidomide deformities. However, Kemper (1962a, b), Yang, Yang & Liang (1962). Boylen, Home & Johnson (1963) and Leone (1963) have shown that thalidomide can produce a whole range of ectromelian deformities provided that it is introduced into the egg at a particular period of embryonic development.