Evaluation of epigenetic and radiomodifying effects during radiotherapy treatments in zebrafish

Radiotherapy is still a long way from personalizing cancer treatment plans, and its effective-ness depends on the radiosensitivity of tumor cells. Indeed, therapies that are efficient and successful for some patients may be relatively ineffective for others. Based on this, radiobiological research is focusing on the ability of some reagents to make cancer cells more responsive to ionizing radiation, as well as to protect the surrounding healthy tissues from possible side effects. In this scenario, zebrafish emerged as an effective model system to test for radiation modifiers that can potentially be used for radiotherapeutic purposes in humans. The adoption of this experimental organism is fully justified and supported by the high similarity between fish and humans in both their genome sequences and the effects provoked in them by ionizing radiation. This review aims to provide the literature state of the art of zebrafish in vivo model for radiobiological studies, particularly focusing on the epigenetic and radiomodifying effects produced during fish embryos’ and larvae’s exposure to radiotherapy treatments

Two-point wavepacket modelling of jet noise

International audienceThis paper is focused on the study of a kinematic wavepacket model for jet noise based on two-point statistics. The model contains physical parameters that define its structure in terms of wavenumber, envelope shape and coherence decay. These parameters, which are necessary to estimate the sound pressure levels radiated by the source, were educed from a large-eddy simulation database of a Mach 0.4, fully turbulent jet. The sound pressure levels predicted by the model were compared with acoustic data and the results show that when the parameters are carefully educed from the data, the sound-pressure levels generated are in good agreement with experimentally measured values for low Strouhal numbers and polar angles. Furthermore, here we show that a correct representation of both coherence decay and wavepacket envelope shape are key aspects to an accurate sound prediction. A Spectral Proper Orthogonal Decomposition (SPOD) of the model source was also performed motivated by the search for a low-rank model capable of capturing the acoustic efficiency of the full source. It is shown that only a few SPOD modes are necessary to recover acoustically-important wavepacket traits

A systems biology approach to dissection of the effects of small bicyclic peptidomimetics on a panel of Saccharomyces cerevisiae mutants

In recent years, an approach called “chemical genetics” has been adopted in drug research to discover and validate new targets and to identify and optimize leads by high throughput screening. In this work, we tested the ability of a library of small peptidomimetics to induce phenotypic effects with functional implications on a panel of strains of the budding yeast Saccharomyces cerevisiae, both wild type and mutants, for respiratory function and multidrug resistance. Further elucidation of the function of these peptidomimetics was assessed by testing the effects of the compound with the most prominent inhibitory activity, 089, on gene expression using DNA microarrays. Pathway analysis showed the involvement of such a molecule in inducing oxidative damage through alterations in mitochondrial functions. Transcriptional experiments were confirmed by increased levels of ROS and activation of mitochondrial membrane potential. Our results demonstrate the influence of a functional HAP1 gene in the performance of S. cerevisiae as a model system

Alargamientos quirúrgicos de las extremidades en la talla baja patológica

Se presenta nuestra experiencia de elongacione s óseas en 207 paciente s afectos de talla baja patológica: 165 condrodisplasias, 15 síndromas de Turner, 11 casos de pubertad precoz, 9 casos de talla baja constitucional, 2 raquistismos médico-resistentes, 2 enanismos hipotróficos, 2 displasias epifisarias y un síndrome de Schwasman. Se describe la táctica y técnica quirúrgica, destacando la importancia de las tenotomías al inicio del alargamiento. Se han alargado 408 segmentos tibiales, 34 humerale s y 240 femorales. El alargamiento medio obtenido ha sido de 14.74 cm para la tibia, 10.5 cm para el húmer o y 15.5 cm para el fémur. Las complicacione s más frecuente s fueron las desviacione s axiales, pérdida de movilidad articular y fractura postalargamiento; resueltas posteriormente. Se pone de relieve la importancia de un equipo multidisciplina - rio para la planificación y control de los alargamientos.The authors show their experience in the lengthening of the limbs in 207 patients afecte d b y pathologica l shor t height: 165 chondrodysplasia , 1 5 Turne r Syndrome, 11 case s of precocious puberty, 9 cases of constitutional short height, 2 me - dical-resitant rickets, 2 hipotrofic dwarfism, 2 epiphyseal dysplasia and one Schwasman syndrome. Surgical planning and procedure are described, emphasizing the value of tenotomie s at the begining of lengthening . 408 tibial, 34 humera l and 240 femoral segments hav e bee n lengthened. The average lenghening obtained was: 14.74 cm (tibia), 10.5 cm (humerus) and 15.5 cm (femur). The most frequent complications were : axial desviation, lost of articular movility, and fracture after lengthening; resolved later. The authors emphasizing the importance of a multidisciplinary team to plan and control of bone lengthening

Method for High-Resolution Frequency Measurements in the Extreme Ultraviolet Regime: Random-Sampling Ramsey Spectroscopy

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Early asymmetric cues triggering the Dorsal/Ventral Gene Regulatory Network of the sea urchin embryo

Dorsal/ventral (DV) patterning of the sea urchin embryo relies on a ventrally-localized organizer expressing Nodal, a pivotal regulator of the DV gene regulatory network. However, the inceptive mechanisms imposing the symmetry-breaking are incompletely understood. In Paracentrotus lividus, the Hbox12 homeodomain-containing repressor is expressed by prospective dorsal cells, spatially facing and preceding the onset of nodal transcription. We report that Hbox12 misexpression provokes DV abnormalities, attenuating nodal and nodal-dependent transcription. Reciprocally, impairing hbox12 function disrupts DV polarity by allowing ectopic expression of nodal. Clonal loss-of-function, inflicted by blastomere transplantation or gene-transfer assays, highlights that DV polarization requires Hbox12 action in dorsal cells. Remarkably, the localized knock-down of nodal restores DV polarity of embryos lacking hbox12 function. Finally, we show that hbox12 is a dorsal-specific negative modulator of the p38-MAPK activity, which is required for nodal expression. Altogether, our results suggest that Hbox12 function is essential for proper positioning of the DV organizer.