Sipuncula de la región magallánica comparada con zonas adyacentes de la Antártida

The Magellan sipunculan fauna includes 4 families, 7 genera and 16 species. A comparison between this fauna and that from adjacent regions of Antarctica has been made. A total of 8 species and 3 genera are shared by the compared areas. Univariate analyses show no significant statistical differences among the investigated faunas, whereas a multivariate analysis corroborates that the effects of the Antarctic Convergence are stronger at the level of genera than species. Only 3 genera were able to cross over this zoogeographical boundary. However, these 3 genera succeeded in the new biotopes of Antarctica, since a total of 16 species have been recorded, compared with the 8 species only found in the Magellan region.La fauna magallánica de sipuncúlidos presenta 4 familias, 7 géneros y 16 especies. Se lleva a cabo una comparación entre esta fauna y la procedente de zonas adyacentes de la Antártida. Un total de 8 especies y 3 géneros están presentes en ambas zonas. Los resultados del análisis univariante indican la ausencia de diferencias estadísticas significativas entre las faunas investigadas, mientras que el análisis multivariante revela que los efectos de la Convergencia Antártica son más importantes a nivel de género que de especie. Sin embargo, estos géneros tuvieron cierto éxito en la colonización progresiva de los nuevos biotopos antárticos, dado que se han encontrado un total de 16 especies frente a las 8 exclusivas del área magallánica

Macrozoobenthic changes on rocky shores of the Bight of Bilbao: 14 years of monitoring biological recovery

Benthic communities on rocky shores from the Bight of Bilbao, known as the Abra de Bilbao (northern Spain) and the adjacent coast have been studied during 14 years (1984-1998) within the framework of an environmental monitoring programme for both subtidal and intertidal zones. The study area is now experiencing a process of generalised environmental improvement in its water quality, as a result of the region's industrial recession and the implementation of a comprehensive renovation sewage system, which is still in progress. Biological recovery has been analysed with uni- and multivariate techniques, which make it possible to differentiate several recovery stages, grouped according to the littoral zone sampled. A total of 12 taxa have been selected as characteristics of different environmental situations in space and time, the most sensitive of which are Sagartiidae, Mytilidae, Patellidae and Chthamalidae. The need to use alternative analyses in long term studies of hard bot- tom macrozoobenthos is highlighted. A three-phase conceptual model based on own results and previous works is proposed, which describes the current situation, as well as the recorded or expected changes. The model comprises two parts: a) one for the subtidal and lower intertidal levels, where biotic strategies related to the inverse patterns of fauna and flora dominance are emphasised; b) another for the upper intertidal level, where the appearance and development of a barnacle belt play a crucial role. The model is intended to serve as an environmental tool able to detect changes in the recovery process of the Bight of Bilbao and similar bays elsewhere.Se han estudiado las comunidades bénticas de sustrato rocoso del abra de Bilbao y su costa adyacente durante 14 años (1984-1998), dentro de un programa de seguimiento biológico de los medios submareal e intermareal. El área de estudio se encuentra en un proceso de mejora de la calidad ambiental de sus aguas como consecuencia de la recesión industrial y del Plan Integral de Saneamiento, actualmente en desarrollo. Se ha constatado la recuperación biológica por medio de técnicas univariantes y multivariantes, proponiéndose una serie de etapas en dicha recuperación, diferentes según el nivel litoral. Se ha seleccionado un total de doce taxones como los máximos responsables de discriminar situaciones en el espacio y en el tiempo, entre los que destacan por su mayor sensibilidad: Sagartiidae, Mytilidae, Patellidae y Chthamalidae. Se demuestra, asimismo, la necesidad de utilizar diferentes tipos de análisis en los estudios a largo plazo del macrozoobentos de sustrato rocoso. Con base en estos resultados y en trabajos previos, se articula un modelo conceptual en tres fases, describiendo la situación actual del bentos y los cambios registrados o previsibles. El modelo consta de dos partes: a) el correspondiente a los niveles submareal e intermareal inferior, donde se enfatizan las estrategias relacionadas con los patrones inversos de dominancia de la fauna y la flora; b) el concerniente al nivel intermareal superior, donde desempeñan un papel fundamental la aparición y el desarrollo del cinturón de cirrípedos. De este modo, se pretende dotar a los planes de seguimiento ambiental, tanto del abra de Bilbao como de otras áreas similares, de una herramienta para la detección de cambios en sus planes de recuperación.Instituto Español de Oceanografí

NatB-mediated protein N-alpha-terminal acetylation is a potential therapeutic target in hepatocellular carcinoma

The identification of new targets for systemic therapy of hepatocellular carcinoma (HCC) is an urgent medical need. Recently, we showed that hNatB catalyzes the N-α- terminal acetylation of 15% of the human proteome and that this action is necessary for proper actin cytoskeleton structure and function. In tumors, cytoskeletal changes influence motility, invasion, survival, cell growth and tumor progression, making the cytoskeleton a very attractive antitumor target. Here, we show that hNatB subunits are upregulated in in over 59% HCC tumors compared to non-tumor tissue and that this upregulation is associated with microscopic vascular invasion. We found that hNatB silencing blocks proliferation and tumor formation in HCC cell lines in association with hampered DNA synthesis and impaired progression through the S and the G2/M phases. Growth inhibition is mediated by the degradation of two hNatB substrates, tropomyosin and CDK2, which occurs when these proteins lack N-α-terminal acetylation. In addition, hNatB inhibition disrupts the actin cytoskeleton, focal adhesions and tight/adherens junctions, abrogating two proliferative signaling pathways, Hippo/YAP and ERK1/2. Therefore, inhibition of NatB activity represents an interesting new approach to treating HCC by blocking cell proliferation and disrupting actin cytoskeleton function

Are motor inhibition and cognitive flexibility dead ends in ADHD?

Contains fulltext : 53518.pdf (publisher's version ) (Closed access)Executive dysfunction has been postulated as the core deficit in ADHD, although many deficits in lower order cognitive processes have also been identified. By obtaining an appropriate baseline of lower order cognitive functioning light may be shed on as to whether executive deficits result from problems in lower order and/or higher order cognitive processes. We examined motor inhibition and cognitive flexibility in relation to a baseline measure in 816 children from ADHD and control families. Multiple children in a family were tested in order to examine the familiality of the measures. No evidence was found for deficits in motor inhibition or cognitive flexibility in children with ADHD or their nonaffected siblings: Compared to their baseline speed and accuracy of responding, children with ADHD and their (non)affected siblings were not disproportionally slower or inaccurate when demands for motor inhibition or cognitive flexibility were added to the task. However, children with ADHD and their (non)affected siblings were overall less accurate than controls, which could not be attributed to differences in response speed. This suggests that inaccuracy of responding is characteristic of children having (a familial risk for) ADHD. Motor inhibition and cognitive flexibility as operationalized with mean reaction time were found to be familial. It is concluded that poorer performance on executive tasks in children with ADHD and their (non)affected siblings may result from deficiencies in lower order cognitive processes and not (only) from higher order cognitive processes/executive functions

Speed, Variability, and Timing of Motor Output in ADHD: Which Measures are Useful for Endophenotypic Research?

Attention-Deficit/Hyperactivity Disorder (ADHD) shares a genetic basis with motor coordination problems and probably motor timing problems. In line with this, comparable problems in motor timing should be observed in first degree relatives and might, therefore, form a suitable endophenotypic candidate. This hypothesis was investigated in 238 ADHD-families (545 children) and 147 control-families (271 children). A motor timing task was administered, in which children had to produce a 1,000 ms interval. In addition to this task, two basic motor tasks were administered to examine speed and variability of motor output, when no timing component was required. Results indicated that variability in motor timing is a useful endophenotypic candidate: It was clearly associated with ADHD, it was also present in non-affected siblings, and it correlated within families. Accuracy (under- versus over-production) in motor timing appeared less useful: Even though accuracy was associated with ADHD (probands and affected siblings had a tendency to under-produce the 1,000 ms interval compared to controls), non-affected siblings did not differ from controls and sibling correlations were only marginally significant. Slow and variable motor output without timing component also appears present in ADHD, but not in non-affected siblings, suggesting these deficits not to be related to a familial vulnerability for ADHD. Deficits in motor timing could not be explained by deficits already present in basic motor output without a timing component. This suggests abnormalities in motor timing were predominantly related to deficient motor timing processes and not to general deficient motor functioning. The finding that deficits in motor timing run in ADHD-families suggests this to be a fruitful domain for further exploration in relation to the genetic underpinnings of ADHD

Antibiofilm Activity of an Exopolysaccharide from Marine Bacterium Vibrio sp. QY101

Bacterial exopolysaccharides have always been suggested to play crucial roles in the bacterial initial adhesion and the development of complex architecture in the later stages of bacterial biofilm formation. However, Escherichia coli group II capsular polysaccharide was characterized to exert broad-spectrum biofilm inhibition activity. In this study, we firstly reported that a bacterial exopolysaccharide (A101) not only inhibits biofilm formation of many bacteria but also disrupts established biofilm of some strains. A101 with an average molecular weight of up to 546 KDa, was isolated and purified from the culture supernatant of the marine bacterium Vibrio sp. QY101 by ethanol precipitation, iron-exchange chromatography and gel filtration chromatography. High performance liquid chromatography traces of the hydrolyzed polysaccharides showed that A101 is primarily consisted of galacturonic acid, glucuronic acid, rhamnose and glucosamine. A101 was demonstrated to inhibit biofilm formation by a wide range of Gram-negative and Gram-positive bacteria without antibacterial activity. Furthermore, A101 displayed a significant disruption on the established biofilm produced by Pseudomonas aeruginosa, but not by Staphylococcus aureus. Importantly, A101 increased the aminoglycosides antibiotics' capability of killing P. aeruginosa biofilm. Cell primary attachment to surfaces and intercellular aggregates assays suggested that A101 inhibited cell aggregates of both P. aeruginosa and S. aureus, while the cell-surface interactions inhibition only occurred in S. aureus, and the pre-formed cell aggregates dispersion induced by A101 only occurred in P. aeruginosa. Taken together, these data identify the antibiofilm activity of A101, which may make it potential in the design of new therapeutic strategies for bacterial biofilm-associated infections and limiting biofilm formation on medical indwelling devices. The found of A101 antibiofilm activity may also promote a new recognition about the functions of bacterial exopolysaccharides