Efecto de los irrigantes sobre la resistencia a la fractura de premolares

La endodoncia regenerativa ha sido definida como procedimientos basadosbiológicamente y diseñados para reemplazar estructuras pérdidas, incluyendo dentina y estructurasradiculares, y células del complejo dentino-pulpar con tejidos vivos. Ha sido considerada una alternativapara el tratamiento de dientes permanentes jóvenes con ápices inmaduros y necrosis pulpar. Elprocedimiento clínico se basa en la desinfección y posterior formación de un coágulo de sangre en elconducto radicular. Las soluciones irrigantes como el hipoclorito de sodio (NaOCl) y EDTA se usan nosólo para la desinfección sino también para el acondicionamiento de la dentina, con el fin de liberar factoresde crecimiento de la matriz dentinaria, que guían la diferenciación celular.OBJETIVO: Evaluar el efecto de la irrigación sobre la resistencia a la fractura de premolares tratados conel protocolo para endodoncia regenerativa, con hipoclorito de sodio y con irrigación final con EDTA.MATERIALES Y METODOS: Se seleccionaron 10 pares de premolares humanos extraídos homólogos,alos cuales se tomaron fotografías y radiografías periapicales. Se realizaron las aperturas cameralescorrespondientes, se prepararon los conductos con ensanchador de Peeso para simular un diente inmadurocon ápice abierto y se envolvieron las raíces con teflón para simular el ligamento periodontal.Los 20 dientesse dividieron en 2 grupos de 10 premolares cada uno (n=10), asegurando que en cada grupo hubiera unpremolar homólogo de cada par. Grupo A (control) se irrigó con NaOCl al 2,5% y el grupo B (experimental)se irrigó con NaOCl al 2,5% seguido de EDTA al 17%. Posteriormente, se selló el tercio coronario delconducto y la cavidad de acceso con Biodentine. Las muestras fueron seccionadas transversalmente a 3 mmcoronarios al límite amelo cementario y fueron montadas en una resina de composite para mantener lospremolares verticales en una máquina universal para ensayos mecánicos (Instron Corp,Canton,MA,USA).Se aplicó una carga compresiva con una velocidad de desplazamiento de cabezal de 1 mm/minuto sobre laraíz apoyada sobre un cono de acero que ejerció un efecto cuña y se determinó la fuerza necesaria parafracturar la raíz. Los resultados fueron analizados estadísticamente con prueba T.RESULTADOS: La media de la fuerza (N) necesaria para generar la fractura de las raíces en el grupo dondese usó sólo NaOCl fue de 337,84, mientras que para el grupo donde se usó EDTA e NaOCl fue de 345,54.Al comparar ambos grupos con la prueba de t, las diferencias no resultaron estadísticamentesignificativas(p>0.05).CONCLUSIONES: La irrigación final con EDTA no disminuyó la resistencia a la fractura de premolarescon ápices inmaduros previamente irrigados con hipoclorito de sodio al 2,5%

Distinct mechanisms regulate Cdx2 expression in the blastocyst and in trophoblast stem cells

The first intercellular differences during mammalian embryogenesis arise in the blastocyst, producing the inner cell mass and the trophectoderm. The trophectoderm is the first extraembryonic tissue and does not contribute to the embryo proper, its differentiation instead forming tissues that sustain embryonic development. Crucial roles in extraembryonic differentiation have been identified for certain transcription factors, but a comprehensive picture of the regulation of this early specification is still lacking. Here, we investigated whether the regulatory mechanisms involved in Cdx2 expression in the blastocyst are also utilized in the postimplantation embryo. We analyzed an enhancer that is regulated through Hippo and Notch in the blastocyst trophectoderm, unexpectedly finding that it is inactive in the extraembryonic structures at postimplantation stages. Further analysis identified other Cdx2 regulatory elements including a stem-cell specific regulatory sequence and an element that drives reporter expression in the trophectoderm, a subset of cells in the extraembryonic region of the postimplantation embryo and in trophoblast stem cells. The cross-comparison in this study of cis-regulatory elements employed in the blastocyst, stem cell populations and the postimplantation embryo provides new insights into early mammalian development and suggests a two-step mechanism in Cdx2 regulation.We thank Barbara Pernaute for comments and suggestions; members of the Manzanares lab for comments, technical help and support; Ian Chambers and Austin Smith for the ZHBTc4 ES cell line; Tristan Rodriguez for the B1-TS cell line; Luis Miguel Criado and the CNIC Transgenesis Unit for TS cell morulae injections and support; Roisin Doohan for help with sections; and Simon Bartlett (CNIC) for English editing. This study was funded by grants from the Ministerio de Economia y Competitividad (grant BFU2011-23083 and BFU2014-54608-P to MM; FPU Doctoral Fellowship to TR; FPI-SO Doctoral Fellowship to SM; Severo Ochoa Center of Excellence award SEV-2015-0505 to CNIC), Comunidad Autonoma de Madrid (grant CELLDD-CM to MM), Canadian Institute of Health Research (JR), Imperial College (VA), and the MRC and Genesis Research Trust (AH). The CNIC is supported by the Spanish Ministerio de Economia y Competitividad and the Pro-CNIC Foundation.S

Ensuring Aquatic Food Security in the Philippines

The human population of the Philippines is expected to reach 158 million by the year 2050, or an increase of 37% relative to 2022. This implies increased demand for aquatic food (or “fish” hereafter). This begs the question of whether the Philippines can meet the expected increase in fish demand. We estimate that even if the Philippines can maintain its current fish production, the Philippines will still require 1.67 million metric tons more fish per year by 2050 to at least maintain its current per capita fish consumption of 34.27 kg per year. Continued mismanagement of inland and marine fisheries will further widen the gap in fish supply. However, we argue that simultaneously rebuilding overfished fisheries, restoring degraded habitats crucial to supporting productive fisheries, addressing current threats to fisheries sustainability, and expanding sustainable marine aquaculture (or mariculture) have the potential to meet future fish demand in the Philippines. Sustainably expanding mariculture requires careful siting and management of mariculture development areas so that mariculture can improve food security without disenfranchising and marginalizing local coastal communities

Solving Man-Induced Large-Scale Conservation Problems: The Spanish Imperial Eagle and Power Lines

[Background] Man-induced mortality of birds caused by electrocution with poorly-designed pylons and power lines has been reported to be an important mortality factor that could become a major cause of population decline of one of the world rarest raptors, the Spanish imperial eagle (Aquila adalberti). Consequently it has resulted in an increasing awareness of this problem amongst land managers and the public at large, as well as increased research into the distribution of electrocution events and likely mitigation measures.[Methodology/Principal Findings] We provide information of how mitigation measures implemented on a regional level under the conservation program of the Spanish imperial eagle have resulted in a positive shift of demographic trends in Spain. A 35 years temporal data set (1974–2009) on mortality of Spanish imperial eagle was recorded, including population censuses, and data on electrocution and non-electrocution of birds. Additional information was obtained from 32 radio-tracked young eagles and specific field surveys. Data were divided into two periods, before and after the approval of a regional regulation of power line design in 1990 which established mandatory rules aimed at minimizing or eliminating the negative impacts of power lines facilities on avian populations. Our results show how population size and the average annual percentage of population change have increased between the two periods, whereas the number of electrocuted birds has been reduced in spite of the continuous growing of the wiring network.[Conclusions] Our results demonstrate that solving bird electrocution is an affordable problem if political interest is shown and financial investment is made. The combination of an adequate spatial planning with a sustainable development of human infrastructures will contribute positively to the conservation of the Spanish imperial eagle and may underpin population growth and range expansion, with positive side effects on other endangered species.P. López-López was supported by FPU grant of the Spanish Ministerio de Educación (reference AP2005-0874) and wrote this paper during a pre-doctoral stay at Doñana Biological Station (CSIC) in Sevilla, Spain. The funders of this study (Spanish Ministry of Education, Natural Research Ltd. and Junta de Andalucía) had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe