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Introducció. Les concentracions plasmàtiques dels pèptids natriürètics són biomarcadors útils en el diagnòstic i en el maneig de la insuficiència cardíaca (IC). L'objectiu de l'estudi va consistir en avaluar un nou biomarcador, la vasopressina, per predir la mortalitat i el reingrés a mig termini dels pacients que ingressen per IC aguda. Mètodes. Des del novembre de 2004 fins setembre de 2010 s'estudien de forma prospectiva el pacients que ingressen al Servei de Cardiologia per IC aguda i es distribueixen en dos grups: grup 1, pacients amb nivells baixos de vasopressina ( ≤ 2'9 pg/mL) i grup 2, pacients amb nivells alts de vasopressina (  2'9 pg/mL). Es realitza una anàlisi multivariada de Cox i es construeixen corbes de Kaplan-Meier. Resultats. S'inclouen 322 pacients, amb una mediana de seguiment de 14,6 mesos. Els pacients del grup 1 presenten una major supervivència als 12 i 24 mesos del 93% i 72% respecte els pacients del grup 2 que és del 75% i 61% amb una HR 2.90 (IC 95%: 1.47-5.75, p=0.002), respectivament. Tanmateix s'aprecia una major supervivència cardiovascular en els pacients del grup 1 (97% vs. 87% al 12 mesos i de 87% vs. 75% als 24 mesos) amb HR 2.72 (IC 95%: 1.97 - 6.73, p 0.031). Un 56% i 29% dels pacients del grup 1 estaven lliures de reingrés als 12 i 24 mesos, respectivament, versus el 49% i el 21% del grup 2 amb una HR 1.48 (IC 95%: 1.04 - 2.11, p 0.02). Igualment pel primer reingrés per IC , el 71% i 46% del grup 1 respecte del 60% i 39% del grup 2 als 12 i 24 mesos, respectivament (HR 1.57 (IC 95%: 1.03 - 2.41, p 0.038). Conclusions. Els nivells alts de vasopressina en pacients amb insuficiència cardíaca aguda estabilitzats són un predictor independent de mortalitat i de reingressos als 12 i 24 mesos de seguiment.

Background: The degree of metal binding specificity in metalloproteins such as metallothioneins (MTs) can be crucial for their functional accuracy. Unlike most other animal species, pulmonate molluscs possess homometallic MT isoforms loaded with Cu+ or Cd2+. They have, so far, been obtained as native metal-MT complexes from snail tissues, where they are involved in the metabolism of the metal ion species bound to the respective isoform. However, it has not as yet been discerned if their specific metal occupation is the result of a rigid control of metal availability, or isoform expression programming in the hosting tissues or of structural differences of the respective peptides determining the coordinative options for the different metal ions. In this study, the Roman snail (Helix pomatia) Cu-loaded and Cd-loaded isoforms (HpCuMT and HpCdMT) were used as model molecules in order to elucidate the biochemical and evolutionary mechanisms permitting pulmonate MTs to achieve specificity for their cognate metal ion. Results: HpCuMT and HpCdMT were recombinantly synthesized in the presence of Cd2+, Zn2+ or Cu2+ and corresponding metal complexes analysed by electrospray mass spectrometry and circular dichroism (CD) and ultra violet-visible (UV-Vis) spectrophotometry. Both MT isoforms were only able to form unique, homometallic and stable complexes (Cd6-HpCdMT and Cu12-HpCuMT) with their cognate metal ions. Yeast complementation assays demonstrated that the two isoforms assumed metal-specific functions, in agreement with their binding preferences, in heterologous eukaryotic environments. In the snail organism, the functional metal specificity of HpCdMT and HpCuMT was contributed by metal-specific transcription programming and cell-specific expression. Sequence elucidation and phylogenetic analysis of MT isoforms from a number of snail species revealed that they possess an unspecific and two metal-specific MT isoforms, whose metal specificity was achieved exclusively by evolutionary modulation of non-cysteine amino acid positions. Conclusion: The Roman snail HpCdMT and HpCuMT isoforms can thus be regarded as prototypes of isoform families that evolved genuine metal-specificity within pulmonate molluscs. Diversification into these isoforms may have been initiated by gene duplication, followed by speciation and selection towards opposite needs for protecting copper-dominated metabolic pathways from nonessential cadmium. The mechanisms enabling these proteins to be metal-specific could also be relevant for other metalloproteins. Fil: Palacios, Oscar. Universitat Autonoma de Barcelona; España Fil: Pagani, María Ayelén. Universidad de Barcelona; España. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Perez Rafael, Silvia. Universitat Autonoma de Barcelona; España Fil: Egg, Margit. Universidad de Innsbruck; Austria Fil: Höckner, Martina. Universidad de Innsbruck; Austria Fil: Brandstätter, Anita. Universidad de Innsbruck; Austria Fil: Capdevila, Merce. Universitat Autonoma de Barcelona; España Fil: Atrian, Silvia. Universidad de Barcelona; España Fil: Dallinger, Reinhard. Universidad de Innsbruck; Austria

Metallothioneins (MTs) are a diverse group of proteins responsible for the control of metal homeostasis and detoxification. To investigate the impact that environmental conditions might have had on the metal-binding abilities of these proteins, we have characterized the MTs from the apple snail Pomacea bridgesii, a gastropod species belonging to the class of Caenogastropoda with an amphibious lifestyle facing diverse situations of metal bioavailability. P. bridgesii has two structurally divergent MTs, named PbrMT1 and PbrMT2, that are longer than other gastropod MTs due to the presence of extra sequence motifs and metal-binding domains. We have characterized the Zn(II), Cd(II), and Cu(I) binding abilities of these two MTs after their heterologous expression in E. coli. Our results have revealed that despite their structural differences, both MTs share an unspecific metal-binding character, and a great ability to cope with elevated amounts of different metal ions. Our analyses have also revealed slight divergences in their metal-binding features: PbrMT1 shows a more pronounced Zn(II)-thionein character than PbrMT2, while the latter has a stronger Cu(I)-thionein character. The characterization of these two unconventional PbrMTs supports the loss of the metal-binding specificity during the evolution of the MTs of the Ampullariid family, and further suggests an evolutionary link of this loss with the adaptation of these gastropod lineages to metal-poor freshwater habitats.