The interaction of free radicals in protein and melanin

Résumé L'addition de mélanine au blanc d'uf frais diminue la concentration des radicaux libres due à la lumière de 366 mµ. Cela permet de supposer que la mélanine agit comme un capteur d'électrons.     

The measurement of the renal clearance of γ-emitting tracers by the use of external counting

Zusammenfassung Eine Methode zur Messung der Nierenclearance mit Hilfe markierter Stoffe (-Strahlern) wird beschrieben, was die Prozeduren der Katheterisierung und kontinuierlichen Veneninfusion erübrigt. Die Methode beruht auf der Messung der Blasenaktivität an der Körperoberfläche mittels Szintillationsmesskopf. Die markierten Stoffe werden intravenös injiziert.     

The acetylcholine content and choline-acetyltransferase activity in human skeletal muscle

Riassunto Sono descritte le tecniche per la determinazione della ACH e attività CHA nel muscolo umano normale. I risultati indicano che il rapporto fra capacità sintetizzante e neurormone è più alto in muscoli con maggior impegno funzionale.     

A new type of neurosecretion in the cerebral ganglion of a sipunculid

Summary A lipid neurosecretion is described in the giant cells of the cerebral ganglion in Sipunculus nudus (Sipunculida).     

Gene controlled condensation in individual chromosomes

Summary When cells were irradiated with variable doses of gamma rays, 0.33% showed the appearance of single decondensed chromosomes (SDC) at the moment at which all the other chromosomes of the complement exhibited the normal condensed state corresponding to metaphase stages. Several hypotheses are discussed to explain the origin of SDC. It appears that the most reasonable mechanism to explain our observations is to assume that the process of chromosome condensation is independently controlled in each individual chromosome by a gene/s located in each one of the chromosomes of the complement. A radiation-induced deficiency in one of these genes may produce an impairement in the normal process of condensation of the carrier chromosome which would give rise to SDC.This work was supported by grants from CIC and CONICET.Acknowledgments. I wish to thank Dr J.M. Andrieu who kindly performed the irradiation of the specimens.     

The Medicago genome provides insight into the evolution of rhizobial symbioses

Legumes (Fabaceae or Leguminosae) are unique among cultivated plants for their ability to carry out endosymbiotic nitrogen fixation with rhizobial bacteria, a process that takes place in a specialized structure known as the nodule. Legumes belong to one of the two main groups of eurosids, the Fabidae, which includes most species capable of endosymbiotic nitrogen fixation. Legumes comprise several evolutionary lineages derived from a common ancestor 60 million years ago (Myr ago). Papilionoids are the largest clade, dating nearly to the origin of legumes and containing most cultivated species. Medicago truncatula is a long-established model for the study of legume biology. Here we describe the draft sequence of the M. truncatula euchromatin based on a recently completed BAC assembly supplemented with Illumina shotgun sequence, together capturing ～94% of all M. truncatula genes. A whole-genome duplication (WGD) approximately 58 Myr ago had a major role in shaping the M. truncatula genome and thereby contributed to the evolution of endosymbiotic nitrogen fixation. Subsequent to the WGD, the M. truncatula genome experienced higher levels of rearrangement than two other sequenced legumes, Glycine max and Lotus japonicus. M. truncatula is a close relative of alfalfa (Medicago sativa), a widely cultivated crop with limited genomics tools and complex autotetraploid genetics. As such, the M. truncatula genome sequence provides significant opportunities to expand alfalfa's genomic toolbox.