DDT induced ethological changes in estuarine fish

Synopsis Experiments were carried out to study the feeding rates of the predator fish Therapon jarbua (Forsk) on mullet juveniles, before and after treatment with DDT. Mullet juveniles treated with a subacute concentration, were refused by the control predators, whereas predators treated with a subacute concentration consumed more mullet juveniles. In the present study crescent perch T. jarbua were exposed to subacute and acute concentrations of DDT, and their behaviour was compared with that of the control predators. There were changes in oriented behaviour and co-ordinated movements, and in feeding, aggression and comfort behaviour of the fish. Inflammation in the gills, and caudal fin serration, were noticed in treated fishes. The findings presented here throw light on fundamental pathways by which pollutants interact with the behaviour of fishes.     

Activity of the respiratory inhibitor RF in human red cells in anaemia

Stroma-free haemolysates of red cells from patients with acute or latent anaemia inhibit the NADH oxidase activity of submitochondrial particles from beef heart. The inhibitory activities appeared significantly more frequently in anaemic patients than in normal persons and are likely due to the action of a factor which is identical or similar to the inhibitory protein RF present in rabbit reticulocytes. The possible use of the inhibitor assay for clinical purpose is under discussion.     

A particulate DNA polymerase activity in adult rat brain

A particulate fraction of adult rat brain (sucrose buoyant density 1.24 gm/ml) catalyzed the incorporation of [³H]dTTP into an acid-insoluble product in an endogenously templated reaction sensitive to ribonuclease pretreatment. Upon fractionation, this activity was identified in the cerebellum, pons, frontal lobes and base. The DNA polymerase present in these brain fractions exhibited a strong preference for the synthetic template dT_12–18·poly rA rather than dT_12–18·poly dA; dT₁₀ was completely inactive. Purification and equilibrium Cs₂SO₄ gradient centrifugation of the [³H]DNA product-endogenous template complex suggested that RNA was serving as primer for endogenous DNA synthesis.     

Allylic palladium(II) triazenido complexes: synthesis and spectroscopic studies

Reaction of [Pd(1-3-η-allyl)Cl]₂ with lithium triazenide (triazenide = p-XC₆H₄NN-NC₆H₄X-p; X = Cl, H, CH₃) affords dimeric complexes of the type [Pd(1-3-η-allyl)(triazenide)]₂. In the solid state the triazenido ligands are bridging two palladium atoms with their terminal nitrogen atoms, as shown by a preliminary X-ray determination of the complex with X = CH₃. The allyl groups are stereochemically equivalent. ¹H NMR spectra demonstrate the presence of two conformers in solution. The major component has the same configuration found in the solid. The other conformer has stereochemically non equivalent allyl groups. The concentration ratio of the two conformers is independent of the temperature, suggesting the absence of intramolecular processes and of palladium- triazenido bond breaking. This point is discussed also by comparing the (1-3-η-allyl)(triazenide)palladium (II) dimers with the closely related(1-3-η-allyl)(acetate)palladium(II) complexes.