Relationships between CTR1 activity and copper status in different rat organs

The putative product of CTR1 (SLC31A1 according to the Entrez data base) is regarded as the main candidate for an eukaryotic transmembrane copper importer. The tissue-specific function of mammalian CTR1 is still unknown. A quasi-steady-state level of the CTR1 mRNA was assayed by semiquantitative RT-PCR and compared with the copper status in rat organs (liver, cerebellum, choroid plexus, and mammary gland), which differed in copper metabolism during development and differentiation. The CTR1 activity correlated with production of intracellular and extracellular cuproenzymes and deceased in nuclei of mesenchymal cells at high copper concentrations when copper metabolism followed the embryonic pattern. According to phylogenetic analysis, the most conserved regions of CTR1 are transmembrane domains (TMD) 2 and 3, which together contain seven amino acid residues capable of coordinating a copper atom. A model of the cuprophylic channel formed by TMD2 and TMD3 of the CTR1 homotrimer was proposed. In this model, copper is transported through the channel to the cytosolic C-terminal motif His-Cys-His. The ability of His-Cys-His to coordinate Cu(I) was evaluated by molecular modeling (MM+, ZINDO/1). Potential copper transfer from His-Cys-His to the Cys-X-X-Cys Cu (I) motif, present in all cytosol Cu-chaperones, was shown. The role of CTR1 as a donor and an acceptor of copper in higher eukaryotes is discussed.     

Euro-amerikanische verwandtschaftliche Beziehungen zweier mediterraner Salix-Arten

The author shows a close affinity between Salix salviifolia Brot., widespead on the Iberian Peninsula, and the East-American Salix tristis Ait. These two species together with the European S. aurita L. and the American S. humilis Marsh. form a group of closely linked species within the subsection Leaves (section Vetrix). Salix pedicellata Desf., a species of a broad Mediterranean area, is related to West American (predominantly Californian) Salix lasiolepis Benth. This relationship is perhaps a more remote one, than in the first case, still it is hardly dubitable. S. lasiolepis with the closely related S. hookerana Barr. forms a West American link of the subsection Vulpinae, substituting here the Old World group of S. pedicellata. In the light of the available botanical evidence, a direct transatlantic origin of the described relationships seems to be more probable than the complex way of migrations across Beringia and East Asia.     

The effect of fermented-milk bifidumbacterin on the intestinal microflora of test pilots]

Bacteriological study of intestinal microflora in test pilots, regularly exposed to excessive physical, as well as nervous and emotional strain, has revealed changes in the composition of their intestinal microflora. Correction of microflora by means of bifidumbacterin, a curative lactic fermentation alimentary product, was carried out. Rapid and effective restoration of intestinal microflora and improvement of the general state of patients were noted, which made it possible to recommend this product as a prophylactic remedy for subjects at risk of development of dysbiotic disturbances.