Enfant cancéreux: exploration du stress tel qu'il est vécu par les parents dès l'annonce du diagnostic : une revue de littérature étoffée

Les objectifs du travail sont de comprendre, d’explorer et de décrire le stress vécu par les parents lorsque leur enfant est diagnostiqué cancéreux, ceci afin d’offrir une prise en charge optimale à ces parents

dUTPase activity is critical to maintain genetic stability in Saccharomyces cerevisiae

We identified a viable allele (dut1-1) of the DUT1 gene that encodes the dUTPase activity in Saccharomyces cerevisiae. The Dut1-1 protein possesses a single amino acid substitution (Gly82Ser) in a conserved motif nearby the active site and exhibits a greatly reduced dUTPase activity. The dut1-1 single mutant exhibits growth delay and cell cycle abnormalities and shows a strong spontaneous mutator phenotype. All phenotypes of the dut1-1 mutant are suppressed by the simultaneous inactivation of the uracil DNA N-glycosylase, Ung1. However, the ung1 dut1-1 double mutant accumulates uracil in its genomic DNA. The viability of the dut1-1 mutant is greatly impaired by the simultaneous inactivation of AP endonucleases. These data strongly suggest that the phenotypes of the dut1-1 mutant result from the incorporation of dUMPs into DNA subsequently converted into AP sites. The analysis of the dut1-1 strain mutation spectrum showed that cytosines are preferentially incorporated in front of AP sites in a Rev3-dependent manner during translesion synthesis. These results point to a critical role of the Dut1 protein in the maintenance of the genetic stability. Therefore, the normal cellular metabolism, and not only its byproducts, is an important source of endogenous DNA damage and genetic instability in eukaryotic cells

Validation of a French version of the Athlete Burnout Questionnaire: In Competitive Sport and Physical Education Context.

International audienceThe purpose of this research was to develop a psychometrically sound measure of the Athlete Burnout Questionnaire (ABQ, Raedeke & Smith, 2001) in French. First, a preliminary version was developed. Second, 895 French adolescents involved in competitive sport or physical education at school completed the survey. The results showed good internal consistency (all Cronbach's alphas > .75). Confirmatory factor analysis with the three subscales of the ABQ (emotional and physical exhaustion, reduced sense of accomplishment, and devaluation) confirmed the structure of the instrument and good data fit (NNFI = .95, CFI = .96, GFI = .95, RMSEA = .07) in accordance with the results obtained in previous studies (e.g., Cresswell & Eklund, 2005a, 2005b; Raedeke & Smith, 2001). Furthermore, the patterns of relationships between the ABQ subscales and motivation, self confidence, and anxiety provide concurrent validity of the ABQ

Retos y respuestas en la gestión europea de las aguas: los sistemas de riego por aspersión en el Noroeste de España

Los sistemas eficientes de distribución de aguas están siendo cada vez más reconocidos por su potencial para incrementar la agricultura sostenible en regiones áridas y semiáridas al sur de Europa. En España, los sistemas de riego por aspersión han sido adoptados ampliamente desde la década de los sesenta. La cuenca del río Duero es una de las regiones donde su uso ha sido más acentuado. Al sur del Duero, en donde predominan las grandes propiedades de tierra, los sistemas de pivote central y movimiento lineal permanentes han sido las técnicas más utilizadas. Al norte del Duero, donde las propiedades son más reducidas, las familias de agricultores prefieren los sistemas de riego manuales o fijos. Este artículo trata de la adopción y el uso de sistemas de riego por aspersión por los agricultores en el norte del Duero, en el área del río Órbigo, en la provincia de León. Los datos recogidos provienen de una encuesta que se llevó a cabo en 1997 con 356 agricultores provenientes de dieciséis localidades. Se comprobó que las diferencias agroecológicas en cada lugar son el factor más determinante en la adopción del sistema de riego por aspersión. Distintas variables en cada hogar explican las diferencias individuales en el uso de éste. La sección que concluye este artículo evalúa el papel que juegan los sistemas de riego por aspersión de pequeña escala utilizados por las familias agricultores para la gestión sostenible de las aguas en el sur de Europ

Etude du comportement rhéologique et mécanique de composites recyclés et pollués : recyclage iso fonction, rêve ou réalité ? = Study of rheological and mechanical behaviour of recycled and polluted composites : iso function recycling, dream or reality

National audienceNous étudions les effets de la pollution et du recyclage sur deux composites à matrice polypropylène. Ces effets ont été identifiés non seulement par la mesure du poids moléculaire et des propriétés rhéologiques mais aussi sur les caractéristiques mécaniques. Les polluants modèles choisis sont de l'éthylène glycol majoritairement présent dans le liquide de frein et de l'huile moteur. Ils ont été incorporés dans les composites en cours du process d'extrusion. Le recyclage a été simulé en effectuant plusieurs cycles d'extrusions successifs. Les échantillons ont été recyclés de 1 à 12 fois. Toutes ces nuances ont été testées. L'indice de fluidité, la viscosité, les propriétés en traction quasi statique ainsi que en compression dynamique ont été mesurés. Les polluants affectent davantage les propriétés rhéologiques par rapport aux propriétés mécaniques. Le recyclage thermomécanique, quant à lui, est principalement préjudiciable sur le comportement à rupture. Le résultat remarquable concerne l'effet modérateur des polluants sur la dégradation due au recyclage des propriétés des matériaux

Astroglial expression of the P-glycoprotein is controlled by intracellular CNTF

BACKGROUND: The P-glycoprotein (P-gp), an ATP binding cassette transmembrane transporter, is expressed by astrocytes in the adult brain, and is positively modulated during astrogliosis. In a search for factors involved in this modulation, P-gp overexpression was studied in long-term in vitro astroglial cultures. RESULTS: Surprisingly, most factors that are known to induce astroglial activation in astroglial cultures failed to increase P-gp expression. The only effective proteins were IFNγ and those belonging to the IL-6 family of cytokines (IL-6, LIF, CT-1 and CNTF). As well as P-gp expression, the IL-6 type cytokines - but not IFNγ - stimulated the expression of endogenous CNTF in astrocytes. In order to see whether an increased intracellular level of CNTF was necessary for induction of P-gp overexpression by IL-6 type cytokines, by the same cytokines analysis was carried out on astrocytes obtained from CNTF knockout mice. In these conditions, IFNγ produced increased P-gp expression, but no overexpression of P-gp was observed with either IL-6, LIF or CT-1, pointing to a role of CNTF in the intracellular signalling pathway leading to P-gp overexpression. In agreement with this suggestion, application of exogenous CNTF -which is internalised with its receptor - produced an overexpression of P-gp in CNTF-deficient astrocytes. CONCLUSIONS: These results reveal two different pathways regulating P-gp expression and activity in reactive astrocytes, one of which depends upon the intracellular concentration of CNTF. This regulation of P-gp may be one of the long searched for physiological roles of CNTF

Estimation des paramètres de propagation d'un canal MIMO par l'algorithme ESPRIT-Unitaire multidimentionnel

- Dans ce travail, nous proposons une extension de l'algorithme ESPRIT-Unitaire au cas multidimensionnel (6D) afin d'estimer les différents paramètres du canal radio régi par un modèle de propagation en rayons. Cette méthode nous permet d'estimer pour un système MIMO (Multi-Input Multi-Output) tous les paramètres utiles des rayons, i.e. les angles d'émission et de réception (azimuth et élévation), les retards, les dopplers et les amplitudes complexes. On établit aussi la robustesse de cette méthode vis à vis d'une surestimation du nombre de trajets 'effectifs' du canal. Cette robustesse nous permet, en particulier, de nous affranchir de l'étape 'délicate' de l'estimation du nombre de trajets. Nous présentons quelques résultats de simulation permettant d'évaluer l'efficacité de cette nouvelle méthode et d'illustrer sa robustesse vis à vis de la méconnaissance du nombre de trajets

Impact of an obesogenic diet program on bone densitometry, micro architecture and metabolism in male rat.

International audienceABSTRACT: Background The relationships between fat mass and bone tissue are complex and not fully elucidated. A high-fat/high-sucrose diet has been shown to induce harmful effects on bone micro architecture and bone biomechanics of rat. When such diet leads to obesity, it may induce an improvement of biomechanical bone parameters in rodent. Here, we examined the impact of a high-fat/high-sucrose diet on the body composition and its resulting effects on bone density and structure in male rats. Forty three Wistar rats aged 7 months were split into 3 groups: 1 sacrificed before diet (BD, n=14); 1 subjected to 16 weeks of high-fat/high-sucrose diet (HF/HS, n=14); 1 subjected to standard diet (Control, n=15). Abdominal circumference and insulin sensitivity were measured and visceral fat mass was weighed. The bone mineral density (BMD) was analyzed at the whole body and tibia by densitometry. Microcomputed tomography and histomorphometric analysis were performed at L2 vertebrae and tibiae to study the trabecular and cortical bone structures and the bone cell activities. Osteocalcin and CTX levels were performed to assess the relative balance of the bone formation and resorption. Differences between groups have been tested with an ANOVA with subsequent Scheffe post-hoc test. An ANCOVA with global mass and global fat as covariates was used to determine the potential implication of the resulting mechanical loading on bone. RESULTS: The HF/HS group had higher body mass, fat masses and abdominal circumference and developed an impaired glucose tolerance compared to Control group (p<0.001). Whole body bone mass (p<0.001) and BMD (p<0.05) were higher in HF/HS group vs. Control group. The trabecular thickness at vertebrae and the cortical porosity of tibia were improved (p<0.05) in HF/HS group. Bone formation was predominant in HF/HS group while an unbalance bone favoring bone resorption was observed in the controls. The HF/HS and Control groups had higher total and abdominal fat masses and altered bone parameters vs. BD group. Conclusions The HF/HS diet had induced obesity and impaired glucose tolerance. These changes resulted in an improvement of quantitative, qualitative and metabolic bone parameters. The fat mass increase partly explained these observations

Simultaneous MFN2 and GDAP1 mutations cause major mitochondrial defects in a patient with CMT

Mutations in the MFN2 gene are associated with Charcot-Marie-Tooth disease type 2A (CMT2A), a dominant axonal CMT, whereas mutations in GDAP1 are associated with recessive demyelinating CMT (CMT4A), recessive axonal CMT (AR-CMT2), and dominant axonal CMT (CMT2K). Both proteins are involved in energy metabolism and dynamics of the mitochondrial network. We have previously reported that, in fibroblasts from patients with CMT, MFN2 mutations resulted in a mitochondrial energy coupling defect, whereas dominant mutation in GDAP1 resulted in defective complex I activity. In this study, we investigated mitochondrial bioenergetics from a severely affected patient with CMT harboring combined mutations in both GDAP1 and MFN2 genes