Louis J. Pierro

ACTINOMYCIN D: SPECIFIC INHIBITORY EFFECTS ON THE EXPLANTED CHICK EMBRYO.

Chick embryos containing 11 to 13 somites were cultured for 48 hours on media containing various amounts of the antibiotic actinomycin D. Morphological observations as well as quantitative determinations of protein nitrogen, DNA, and RNA indicate that the antibiotic specifically inhibits the growth and development of the embryonic axis posterior to the 12th somite.

Walter Landauer — The Man and his Work

In a span of almost 60 years, Walter Landauer made notable contributions to the fields of genetics, developmental physiology and teratology. In the pages which follow we shall attempt to document the substance and merit of these contributions and to provide an understanding of the person who made them. Walter Landauer was opportunistic, orthodox and bold in his science, committed to truth, often obscured by complexities of genetic data and poorly understood biochemistry. From his early days as a student, he was concerned about economic inequities and social injustice and about a social system that failed to elicit the full potential of all its members.

Cadmium and Teratogenesis of the Central Nervous System

Effects of cadmium on the developing embryo or fetus have been studied by many investigators since the report by Parizek in 196435 that a single maternal injection of cadmium at gestation days 17–21 resulted in a destruction of the fetal portion of the placenta and fetal death. The first published reports of cadmiuminduced teratogenesis described studies with the hamster14,15; cadmiuminduced teratogenicity was subsequently reported for the rat,1,5 and for the mouse 30,31,37–39 Using a different experimental approach, Klein et al.29 reported abnormal development of head-fold stage rat embryos cultured in vitro on serum taken from rats injected with cadmium.