Reconstrucción de rotura crónica de tendón distal del bíceps braquial: a propósito de un caso

Las roturas inveteradas o crónicas del tendón distal del bíceps braquial son infrecuentes. Su tratamiento supone un reto importante por el grado de retracción y deficiente calidad del tendón y músculo lesionados, que en ocasiones obligan al empleo de injertos para tratar de restaurar la anatomía y mejorar los resultados funcionales. La tasa de complicaciones en las reparaciones de roturas crónicas es mayor con respecto a las reparaciones de lesiones agudas. Presentamos el caso de una reparación quirúrgica de una rotura crónica de 3 meses de evolución mediante la utilización de aloinjerto liofilizado de Aquiles.Chronic or inveterate disruptions of the distal biceps brachii are uncommon. Treatment remains a major challenge by shrinkage and poor quality of the injured tendon and muscle, which sometimes require the use of grafts to try to restore the anatomy and improve the functional outcomes. The rate of complications in surgical treatment of chronic tears is more than the repairs of acute injuries. We report the case of a surgical reconstruction of a chronic tear three months of evolution using lyophilized Achilles allograft

Methylation-independent DNA Binding Modulates Specificity of Repressor of Silencing 1 (ROS1) and Facilitates Demethylation in Long Substrates

DNA cytosine methylation is an epigenetic mark that promotes gene silencing and performs critical roles during reproduction and development in both plants and animals. The genomic distribution of DNA methylation is the dynamic outcome of opposing methylation and demethylation processes. In plants, active demethylation occurs through a base excision repair pathway initiated by 5-methycytosine (5- meC) DNA glycosylases of the REPRESSOR OF SILENCING 1 (ROS1) / DEMETER (DME) family. To gain insight into the mechanism by which Arabidopsis ROS1 recognizes and excises 5-meC we have identified those protein regions that are required for efficient DNA binding and catalysis. We have found that a short aminoterminal lysine-rich domain conserved in members of the ROS1/DME family mediates strong methylation-independent binding of ROS1 to DNA, and is required for efficient activity on 5-meC:G, but not for T:G processing. Removal of this domain does not significantly affect 5-meC excision from short molecules, but strongly decreases ROS1 activity on long DNA substrates. This region is not required for product binding and is not involved in the distributive behavior of the enzyme on substrates containing multiple 5- meC residues. Altogether, our results suggest that methylation-independent DNA binding allows ROS1 to perform a highly redundant search for efficient excision of a nondamaged, correctly-paired base such as 5- meC in long stretches of DNA. These findings may have implications for understanding the evolution of structure and target specificity in DNA glycosylases

On the removal of s-triazine herbicides from waters using commercial low-cost granular carbons

The adsorption capacities of three low-cost granular active carbons, used in a water treatment facility for the removal of the triazine herbicides propazine, prometryn and prometon, was evaluated. Kinetic studies showed that the three carbon samples used could be suitable in practice for the treatment of moderate contents of the herbicides in contaminated waters. The apparent adsorption rate constants were calculated. Equilibrium studies showed that the data fit the Frumkin isotherm. The results show that in the adsorption process there are repulsive lateral interactions that depend mainly on the adsorbate molecules rather than the nature or distribution of the adsorption sites. Such lateral interactions seem to be established mainly between the isopropyl groups of adjacent molecules, being of the same order for the three molecules

Discrete breathers in dissipative lattices

We study the properties of discrete breathers, also known as intrinsic localized modes, in the one-dimensional Frenkel-Kontorova lattice of oscillators subject to damping and external force. The system is studied in the whole range of values of the coupling parameter, from C=0 (uncoupled limit) up to values close to the continuum limit (forced and damped sine-Gordon model). As this parameter is varied, the existence of different bifurcations is investigated numerically. Using Floquet spectral analysis, we give a complete characterization of the most relevant bifurcations, and we find (spatial) symmetry-breaking bifurcations which are linked to breather mobility, just as it was found in Hamiltonian systems by other authors. In this way moving breathers are shown to exist even at remarkably high levels of discreteness. We study mobile breathers and characterize them in terms of the phonon radiation they emit, which explains successfully the way in which they interact. For instance, it is possible to form ``bound states'' of moving breathers, through the interaction of their phonon tails. Over all, both stationary and moving breathers are found to be generic localized states over large values of $C$, and they are shown to be robust against low temperature fluctuations.Comment: To be published in Physical Review

DEMETER and REPRESSOR OF SILENCING 1 encode 5-methylcytosine-DNA glycosylases

Cytosine methylation is an epigenetic mark that promotes gene silencing and plays important roles in development and genome defense against transposons. Methylation patterns are established and maintained by DNA-methyltransferases that catalyze transfer of a methyl group from S-adenosyl-L-methionine to cytosine bases in DNA. Erasure of cytosine methylation occurs during development, but the enzymatic basis of active demethylation remains controversial. In Arabidopsis thaliana, DEMETER (DME) activates the maternal expression of two imprinted genes silenced by methylation, and REPRESSOR OF SILENCING 1 (ROS1) is required for release of transcriptional silencing of a hypermethylated transgene. DME and ROS1 encode two closely related DNA glycosylase domain proteins, but it is unknown if they participate directly in a DNA demethylation process or counteract silencing through an indirect effect on chromatin structure. Here we show that DME and ROS1 catalyze the release of 5-meC from DNA by a glycosylase/lyase mechanism. Both enzymes also remove thymine, but not uracil, mismatched to guanine. DME and ROS1 show a preference for 5-meC over thymine in the symmetric dinucleotide CpG context, where most plant DNA methylation occurs. Nevertheless, they also have significant activity on both substrates at CpApG and asymmetric sequences, which are additional methylation targets in plant genomes. These findings suggest that a function of ROS1 and DME is to initiate erasure of 5-meC through a base excision repair process, and provide strong biochemical evidence for the existence of an active DNA demethylation pathway in plants

Oribatid mites in different Mediterranean crop rotations fertilized with animal droppings

Unsustainable soil management is one of the drivers of soil degradation, but impact assessment requires the development of indicators. Oribatids might be considered as early indicators of disturbances due to the stability of their community. The aim of this study was to investigate the feasibility of oribatids as bioindicators of sustainable agricultural practices. Under a dry Mediterranean climate, three fertilization experiments – two under a two-crop rotation system and one under maize monoculture and established 12 years earlier – were sampled 3× for oribatid identification during the last annual cropping cycle. The hypothesis was that different nutrient and crop managements affect the number of oribatid species and individuals present, and these parameters could be used as indicators of soil degradation. In total, 18 oribatid species were identified, and 1974 adult individuals were recovered. Maximum abundance was found prior to sowing. Pig slurry (PS) vs. control, and dairy cattle manure (CM) vs. mineral fertilization increased oribatid abundance. This increase was evident when the average applied rates with PS were ca. 2 Mg of organic matter (OM) ha− 1 yr− 1, or higher than ca. 4 Mg OM ha− 1 yr− 1 for CM. When the preceding crop was wheat and PS or CM were used, Oribatula (Zygoribatula) excavata (which reproduces sexually) predominated. In maize monoculture fertilized with CM, Tectocepheus sarekensis and Acrotritia ardua americana (which can reproduce through parthenogenesis) prevailed vs. Oribatula, which indicated a heavily disturbed soil. Under this specific Mediterranean environment, the predominance of certain parthenogenic oribatid species and the number of individuals provide advanced warning on soil degradation.info:eu-repo/semantics/publishedVersio

Ejercicio interlaboratorio de bioensayos marinos para la evaluación de la calidad ambiental de sedimentos costeros. IV. Ensayo de toxicidad sobre sedimento con crustáceos anfípodos

9 páginas, 2 figuras, 3 tablas.[EN] Interlaboratory variability was studied for the bioassay using crustacean amphipods. Nine series of data were obtained from different laboratories using four different species (Ampelisca brevicornis, Corophium volutator, Corophium multisetosum and Microdeutopus gryllotalpa), all previously used for sediment toxicity assessment in Spain. Results were studied for interlaboratory variability and according to different confounding factors. The coefficients of variation were similar to those previously reported for this bioassay and sample classification was homogeneous among the laboratories that successfully completed the exercise. No significant tendencies related to test species were identified and it seems that the factor most critically affecting test results and the classification of samples is storage time before testing.[ES] Se estudió la precisión interlaboratorio del bioensayo con crustáceos anfípodos. Se recogieron nueve series de datos procedentes de distintos laboratorios europeos y de cuatro especies distintas (Ampelisca brevicornis, Corophium volutator, Corophium multisetosum y Microdeutopus gryllotalpa), todas ellas usadas previamente para la caracterización de la toxicidad de sedimentos en España. Esos resultados se estudiaron para evaluar la variabilidad interlaboratorio de acuerdo a las diferentes especies y los distintos tiempos de almacenamiento de las muestras antes del ensayo. Los resultados mostraron coeficientes de variación similares a los encontrados en estudios previos y permitieron una clasificación homogénea de las muestras entre los laboratorios que completaron el ejercicio con éxito. No se identificaron tendencias significativas debidas al uso de distintas especies y, al parecer, el factor que puede afectar más críticamente la clasificación de las muestras y, por lo tanto, el uso de los resultados para la toma de decisiones, es el tiempo de almacenamiento de los sedimentos previamente al desarrollo del ensayo.This study was carried out under a joint research project between CEDEX and the University of Cádiz. Part of the work was funded by the Spanish Ministry of Science and Technology REN2002_01699/TECNO). The first author was supported by a grant (FPI) from the Spanish Ministry of Education and Science.Peer reviewe

The ACS Survey of Galactic Globular Clusters XI: The Three-Dimensional Orientation of the Sagittarius Dwarf Spheroidal Galaxy and its Globular Clusters

We use observations from the ACS study of Galactic globular clusters to investigate the spatial distribution of the inner regions of the disrupting Sagittarius dwarf spheroidal galaxy (Sgr). We combine previously published analyses of four Sgr member clusters located near or in the Sgr core (M54, Arp 2, Terzan 7 and Terzan 8) with a new analysis of diffuse Sgr material identified in the background of five low-latitude Galactic bulge clusters (NGC 6624, 6637, 6652, 6681 and 6809) observed as part of the ACS survey. By comparing the bulge cluster CMDs to our previous analysis of the M54/Sgr core, we estimate distances to these background features. The combined data from four Sgr member clusters and five Sgr background features provides nine independent measures of the Sgr distance and, as a group, provide uniformly measured and calibrated probes of different parts of the inner regions of Sgr spanning twenty degrees over the face of the disrupting dwarf. This allows us, for the first time, to constrain the three dimensional orientation of Sgr's disrupting core and globular cluster system and compare that orientation to the predictions of an N-body model of tidal disruption. The density and distance of Sgr debris is consistent with models that favor a relatively high Sgr core mass and a slightly greater distance (28-30 kpc, with a mean of 29.4 kpc). Our analysis also suggests that M54 is in the foreground of Sgr by ~2 kpc, projected on the center of the Sgr dSph. While this would imply a remarkable alignment of the cluster and the Sgr nucleus along the line of sight, we can not identify any systematic effect in our analysis that would falsely create the measured 2 kpc separation. Finally, we find that the cluster Terzan 7 has the most discrepant distance (25 kpc) among the four Sgr core clusters, which may suggest a different dynamical history than the other Sgr core clusters.Comment: 41 pages, 16 figures, accepted to Ap