G. W. Kalmus

Further studies on neural tube defects caused by concanavalin A in early chick embryos

Neural tube defects caused by concanavalin A in chick embryos are consequences of change in the cell surface of developing neuroepithelium.

Cytotoxic effect of di(2-ethylhexyl) phthalate on cultured chick embryonic cells.

Nachweis, dass Di(2-ethylhexyl) Phthalat in einer Konzentration von ca. 0,05 mg/ml eine toxische Wirkung auf kultivierte Hühnerembryonalzellen hat, während Konzentrationen von 0,01 mg/ml oder darunter keine deutliche Wirkung mehr haben.

The differential susceptibility of early chick embryos to 5-bromodeoxyuridine.

Thus recent researches :on the chick embryo are directed towards a deeper analysis of the differentiation processes. Biochemical, immunochemical and electron microscopic techniques are called on in an at tempt to explain induction or invagination processes, positioning of migrating cells, and developmental abnormalities. The studies presented in this issue, apart from that concerning the origin of blood cells, lead to explanations which are yet only hypotheses and which call for further experiments. Science progresses by small steps and major problems are still to be solved.

Neural inducing capacity of cyclic AMP on post-nodal pieces of early chick blastoderms.

Cyclic AMP (0.5 mM) induced neural differentiation in post-nodal pieces of early chick blastoderms, at least in part, through promoting cell movement, tissue condensation, and assembly of microtubules.

Some new data concerning effect of actinomycin D on early chick embryos

Actinomycin D führte beim Hühnerembryo zu einer deutlichen Hemmung der Herzentwicklung nach Inkubation im Nährmedium während der Entwicklungsstadien 3 und 3+. Nach Vorbehandlung der Stadien 3–7 und anschliessender Kultur in actinomycin D-freiem Medium fanden sich Fehlbildungen von Herz, ZNS und Somiten, die in ihrer Häufigkeit von den betroffenen Entwicklungsphasen abhängig sind.

Toxicity of di(2-ethylhexyl) phthalate in chick embryos gel electrophoretic analysis of serum proteins

Abstract 1. Effects of commercially available di(2-ethylhexyl) phthalate (DEHP) on the development of 3-day old chick embryos were studied. 2. DEHP (0.05 ml/embryo) was highly toxic, but produced neither specific malformations nor apparent changes in serum proteins. 3. The most conspicuous change in affected embryos was the degeneration of extraembryonic blood vessels.