Integrating morphological and genetic limits in the taxonomic delimitation of the Cuban taxa of Magnoliasubsect.Talauma (Magnoliaceae).

An accurate taxa delimitation, based on a full understanding of evolutionary processes involved in taxa differentiation, can be gained from a combination of ecological, morphological, and molecular approaches. The taxonomy of Magnoliasubsect.Talauma in Cuba has long been debated and exclusively based on traditional morphological study of a limited number of individuals. A more accurate description of leaf morphology variation using geometric morphometrics combined with genetic data could bring consistency to taxa delimitation in this group. Leaf samples for the morphological (243) and genetic (461) analyses were collected throughout the entire distribution range. The variability of each taxon was analyzed through multivariate and geometric morphometry, and 21 genetic markers (SSR). The observed leaf morphological variability was higher than previously described. Morphological and genetic classifications were highly congruent in two out of four taxa. Our data brought evidence that Magnoliaorbiculata can be considered a true species with very clear genetic and morphological limits. The main taxonomic issues concern the north-eastern Cuban populations of Magnoliasubsect.Talauma. The data supported the existence of two clear groups: corresponding mainly to M.minor-M.oblongifolia and T.ophiticola. However, these two groups cannot be considered fully delimited since genetic markers provided evidence of genetic admixture between them. Due to the likely absence of, at least strong, reproductive barriers between these three taxa, we propose therefore to consider them as a species complex.

Genetic patterns in Neotropical Magnolias (Magnoliaceae) using de novo developed microsatellite markers.

Conserving tree populations safeguards forests since they represent key elements of the ecosystem. The genetic characteristics underlying the evolutionary success of the tree growth form: high genetic diversity, extensive gene flow and strong species integrity, contribute to their survival in terms of adaptability. However, different biological and landscape contexts challenge these characteristics. This study employs 63 de novo developed microsatellite or SSR (Single Sequence Repeat) markers in different datasets of nine Neotropical Magnolia species. The genetic patterns of these protogynous, insect-pollinated tree species occurring in fragmented, highly-disturbed landscapes were investigated. Datasets containing a total of 340 individuals were tested for their genetic structure and degree of inbreeding. Analyses for genetic structure depicted structuring between species, i.e. strong species integrity. Within the species, all but one population pair were considered moderate to highly differentiated, i.e. no indication of extensive gene flow between populations. No overall correlation was observed between genetic and geographic distance of the pairwise species' populations. In contrast to the pronounced genetic structure, there was no evidence of inbreeding within the populations, suggesting mechanisms favouring cross pollination and/or selection for more genetically diverse, heterozygous offspring. In conclusion, the data illustrate that the Neotropical Magnolias in the context of a fragmented landscape still have ample gene flow within populations, yet little gene flow between populations.

La hiponatremia como marcador de riesgo en pacientes sometidos a implante de desfibrilador en prevención primaria / Prognostic impact of hyponatremia in patients receiving implantable cardioverter in primary prevention

Introducción y objetivos: La hiponatremia es un factor de mal pronóstico en pacientes con insuficiencia cardiaca. Nuestro objetivo fue valorar el impacto de la hiponatremia en la evolución de los pacientes sometidos a implante de desfibrilador en prevención primaria. Método: Se trata de un estudio observacional retrospectivo multicéntrico en el que se valoró la natremia periimplante y los eventos adversos (la mortalidad de cualquier causa y la cardiovascular, el primer ingreso por insuficiencia cardiaca, la primera terapia apropiada e inapropiada del desfibrilador), en una cohorte española sometida a implante de desfibrilador en la prevención primaria. Se comparó la hiponatremia ligera (Na ≤ 135 mEq/l) y la moderada-severa (Na ≤ 131 mEq/l) respecto a la ausencia de la hiponatremia. Resultados: Un total de 725 pacientes, con un valor medio de sodio en la sangre periimplante de 139 ± 3,6 mEq/l y un tiempo medio de seguimiento de 34,1 ± 18,5 meses. En los pacientes con Na ≤ 135 mEq/l (n = 105) se observó una mayor incidencia de primer ingreso por insuficiencia cardiaca (odds ratio: 1,701; p = 0,031). En los pacientes con hiponatremia moderada-severa (n = 18) se observó mayor mortalidad total (hazard ratio; 3,552; p = 0,002) y mayor mortalidad cardiovascular (hazard ratio: 4,24; p = 0,003). Ninguno de los grados de la hiponatremia estudiados se asoció con mayor incidencia de terapias apropiadas o inapropiadas. Conclusiones: La hiponatremia ligera en el momento del implante de un desfibrilador se asocia a una mayor incidencia de ingreso por insuficiencia cardiaca en el seguimiento, mientras que en el caso de una hiponatremia moderada-severa, se asocia a un riesgo de muerte 4 veces mayor.

Introduction and objectives: Hyponatremia is a prognostic factor in patients with heart failure. Our objective was to assess the impact of hyponatremia in the evolution of patients undergoing cardioverter implantation in primary prevention. Method: This is a multicenter retrospective observational study in which serum sodium periimplant and adverse events (all-cause and cardiovascular mortality, first admission for heart failure, first appropriate and inappropriate therapy) were assessed in a Spanish cohort receiving cardioverter in primary prevention. Patients with mild hyponatremia (Na ≤ 135 mEq/L) and those with moderate to severe hyponatremia (Na ≤ 131 mEq/L) were compared to those without hyponatremia. Results: 725 patients, with a mean value of sodium in blood peri-implant of 139 ± 3.6 mEq/L and a mean follow-up was 34.1 ± 18.5 months. In patients with Na ≤ 135 mEq/L (n = 105), an increased incidence of first admission for heart failure was observed (Odds Ratio: 1.701; P = .031). In patients with moderate to severe hyponatremia (n = 18), higher total mortality (Hazard Ratio: 3.552; P = .002) and increased cardiovascular mortality (Hazard Ratio: 4.24; P = .003) were observed. None of those values of hyponatremia were associated with increased incidence of appropriate or inappropriate therapies Conclusions: Mild hyponatremia at the time of cardioverter implantation is related with a higher incidence of hospitalization for heart failure during follow-up, while moderate to severe hyponatremia increases the risk of death during follow-up.

[Electrical storm in patients with prophylactic defibrillator implantation]. / Evolución de los pacientes portadores de desfibrilador como prevención primaria tras un episodio de tormenta arrítmica.

INTRODUCTION: Little is known about the prevalence of electrical storm, baseline characteristics and mortality implications of patients with implantable cardioverter defibrillator in primary prevention versus those patients without electrical storm. We sought to assess the prevalence, baseline risk profile and survival significance of electrical storm in patients with implantable defibrillator for primary prevention. METHODS: Retrospective multicenter study performed in 15 Spanish hospitals. Consecutives patients referred for desfibrillator implantation, with or without left ventricular lead (at least those performed in 2010 and 2011), were included. RESULTS: Over all 1,174 patients, 34 (2,9%) presented an electrical storm, mainly due to ventricular tachycardia (82.4%). There were no significant baseline differences between groups, with similar punctuation in the mortality risk scores (SHOCKED, MADIT and FADES). A clear trigger was identified in 47% of the events. During the study period (38±21 months), long-term total mortality (58.8% versus 14.4%, p<0.001) and cardiac mortality (52.9% versus 8.6%, p<0.001) were both increased among electrical storm patients. Rate of inappropriate desfibrillator intervention was also higher (14.7 versus 8.6%, p<0.001). CONCLUSIONS: In the present study of patients with desfibrillator implantation for primary prevention, prevalence of electrical storm was 2.9%. There were no baseline differences in the cardiovascular risk profile versus those without electrical storm. However, all cause mortality and cardiovascular mortality was increased in these patients versus control desfibrillator patients without electrical storm, as was the rate of inappropriate desfibrillator intervention.