Large-Scale Production of LGR5-Positive Bipotential Human Liver Stem Cells

Background and Aims: The gap between patients on transplant waiting lists and available donor organs is steadily increasing. H

Reseñas iberoamericanas

Iberoamerican ReviewsReseñas iberoamericana

A 70,000 year multiproxy record of climatic and environmental change from Rano Aroi peatland (Easter Island)

The Rano Aroi mire on Easter Island (also known as Rapa Nui; 27°09′S, 109°27′W, 430 m above sea level) provides a unique non-marine record in the central South Pacific Ocean for reconstructing Late Pleistocene environmental changes. The results of amultiproxy study on twocores fromthe center and margin of the Rano Aroi mire,including peat stratigraphy, facies analysis, elemental and isotope geochemistry on bulk organic matter, X-ray fluorescence (XRF) core scanning and macrofossil analysis, were used to infer past water levels and vegetation changes. The chronology was based on 18 14C AMS dates for the upper 8.7 m. The extrapolated age for the base of the sequence is 70 kyr, which implies that this record is the oldest paleolimnological record on Easter Island.The recovered Rano Aroi sequence consists of a radicel peat formed primarily from the remains of sedges,grasses and Polygonaceae that have accumulated since Marine Isotopic Stage (MIS) 4 (70 kyr BP) to the present. From 60 to 40 kyr BP (MIS 3), high precipitation/runoff events were recorded as organic mud facies with lighter δ13C, low C/N values and high Ti content, indicating higher detritic input to the mire. A gradual shift in δ13C bulk organic matter from −14% to −26%, recorded between 50 and 45 cal kyr BP, suggests a progressive change in local peat-forming vegetation from C4 to C3 plant types. Post-depositional Ca and Fe enrichment during sub-aerial peat exposure and very low sedimentation rates indicate lower water tables during Late MIS 3 (39-31 cal kyr BP). During MIS 2 (27.8-19 cal kyr BP), peat production rates were very low, most likely due to cold temperatures, as reconstructed from other Easter Island records during the Last Glacial Maximum (LGM).Geochemical and macrofossil evidence shows that peat accumulation reactivates at approximately 17.5 cal kyr BP, reaching the highest accumulation rates at 14 cal kyr BP. Peat accretion decreased from 5.0 to 2.5 cal kyr BP, coinciding with a regional Holocene aridity phase. The main hydrological and environmental changes in Rano Aroi reflect variations in the South Pacific Convergence Zone (SPCZ), Southern Westerlies (SW) storm track, and South Pacific Anticyclone (SPA) locations

Evaluation of a Cerebral-Blood-Volume (CBV) pharmaco-MRI (phMRI) assay utilizing low (0.1mg/70kg) and high (0.2mg/70kg) dose buprenorphine infusion and a novel USPIO contrast agent (Ferumoxytol) in healthy human subjects

We present results from a clinical trial of pharmaco-MRI (phMRI) employing cerebral blood volume (CBV) imaging using ferumoxytol (Rienso/Feraheme, AMAG) as a blood pool contrast agent. The study examined the pharmacodynamic effects of two single doses of buprenorphine (0.2mg/70kg and 0.1mg/70kg administered intravenously). We found that contrast-enhanced CBV phMRI signals are more sensitive reporters of pharmacodynamic effects than conventional blood oxygen level dependent (BOLD) phMRI. In particular, higher sensitivity of CBV phMRI compared to BOLD allows for elucidation of PD responses at lower doses of buprenorphine, which has practical implications for similar phMRI studies with centrally acting drugs

Recurrent De Novo Mutations in PACS1 Cause Defective Cranial-Neural-Crest Migration and Define a Recognizable Intellectual-Disability Syndrome

Item does not contain fulltextWe studied two unrelated boys with intellectual disability (ID) and a striking facial resemblance suggestive of a hitherto unappreciated syndrome. Exome sequencing in both families identified identical de novo mutations in PACS1, suggestive of causality. To support these genetic findings and to understand the pathomechanism of the mutation, we studied the protein in vitro and in vivo. Altered PACS1 forms cytoplasmic aggregates in vitro with concomitant increased protein stability and shows impaired binding to an isoform-specific variant of TRPV4, but not the full-length protein. Furthermore, consistent with the human pathology, expression of mutant PACS1 mRNA in zebrafish embryos induces craniofacial defects most likely in a dominant-negative fashion. This phenotype is driven by aberrant specification and migration of SOX10-positive cranial, but not enteric, neural-crest cells. Our findings suggest that PACS1 is necessary for the formation of craniofacial structures and that perturbation of its functions results in a specific syndromic ID phenotype

. 75 (2010) enero-abril. Historias. Revista de la Dirección de Estudios Históricos

- Historia de los aniversarios: tiempo, número y signo por Ernst Hans Josef Gombrich. - Memorias en proceso América Latina, siglos XVI-XX por François-Xavier Guerra. – La pesada herencia del pasado por Luis González y González. - De calendarios, ciclos, celebraciones y centenarios por Antonio Rubial. - El descuido de los héroes. Apuntes sobre historiografía marginal por Salvador Rueda Smithers. - El intercambio del Bicentenario entre México y España en 2010. Estado del conocimiento sobre las banderas de la Independencia por Martha Terán. - Memoria libertaria. Usos del calendario militante del anarquismo hispanoamericano por Anna Ribera Carbó y Alejandro de la Torre. - A propósito del Bicentenario: las temporalidades del análisis histórico de la América española por Antonio García de León. - ¿Qué hacer con nuestro pasado? por Jean Meyer. - La imagen de España en el 100 y 150 aniversario de la Guerra de la Independencia en el periódico ABC por Lara Campos Pérez. - Una bibliografía sobre las conmemoraciones a propósito de los bicentenarios de la Independencia en España y México por Lara Campos Pérez. -La versión vencida por Juan Ortiz y Félix María Calleja. - Biografía heterodoxa por Beatriz Lucía Cano. - Del exilio español por Dolores Pla Brugat. - La habitación y su historia por María Dolores Morales. - Crestomanía por José Mariano Leyva

Significance of coprophagy for the fatty acid profile in body tissues of rabbits fed different diets

Four groups of eight New Zealand hybrid rab- bits were fattened with ad libitum access to the following pelleted experimental diets: ryegrass meal or alfalfa meal fed either alone or with oats meal in a ratio of 1:1. After 25 weeks they were slaughtered and dissected. Fatty acid (FA) profiles of caecotrophs (re-ingested fermentation products of the caecum), perirenal adipose tissue and intramuscular fat in the Musculus quadriceps were deter- mined. With high proportions of branched-chain FA (BFA) and trans FA, and increased proportions of saturated FA relative to the diets, the caecotroph FA profile showed a clear fingerprint of anaerobe microbial lipid metabolism including biohydrogenation. By contrast, the FA profiles of adipose and lean tissue comprised high proportions of polyunsaturated FA (PUFA), whilst BFA and trans FA occurred in much lower proportions compared to the ca- ecotrophs. Thus, coprophagy did not substantially modify the FA composition of the tissues investigated. Use of forage-only diets, compared to the oats supplemented diets, led to extraordinary high proportions of n-3 PUFA (including 18:3 and long-chain n-3) in the fat of adipose (21.3 vs. 6.7%) and lean tissue (15.4 vs. 5.7%). The forage type diet (grass vs. alfalfa) had smaller effects on the FA profiles. Indications of diet effects on endogenous desatu- ration, chain elongation and differential distribution offunctional FA between the two tissues investigated were found