Effects of metal ions and CCl4 on sea urchin embryo (Paracentrotus lividus).

The determination of embryotoxicity is an experimental tool for detecting the risks of environmental pollutants. In this study, fertilized eggs of sea urchin have been observed morphologically during exposure to heavy metal salts or carbon tetrachloride, with the purpose of testing possible differences in toxicity of various classes of poisons. Mercuric chloride is the most active salt, still harmful at 0.

Inhibition of isolated rat liver RNApolymerases I and II by aminoacridines.

9-Aminoacridine and 2 derivatives which contain hydroxyalkylic or aminoalkylic side chains in the 9-position totally inhibit the transcription of calf thymus DNA by rat liver RNA polymerases I and II. This inhibitory action does not always appear to be completely related to the ability of aminoacridines to intercalate into the DNA template.

Photodynamic effect of 3,4-benzpyrene on thermo-sensitive mutants of Escherichia coli B.

Results obtained with thermo-sensitive mutants of Escherichia coli B have shown that the presence of a protein with impaired structure may be responsible for enhanced sensitivity to the lethal photodynamic effect of 3,4-benzpyrene. Thus, the evidence has been obtained of the in vivo action of excited 3,4-benzpyrene on proteins.