Executive functions profile in extreme eating/weight conditions: from anorexia nervosa to obesity.

BACKGROUND Extreme weight conditions (EWC) groups along a continuum may share some biological risk factors and intermediate neurocognitive phenotypes. A core cognitive trait in EWC appears to be executive dysfunction, with a focus on decision making, response inhibition and cognitive flexibility. Differences between individuals in these areas are likely to contribute to the differences in vulnerability to EWC. The aim of the study was to investigate whether there is a common pattern of executive dysfunction in EWC while comparing anorexia nervosa patients (AN), obese subjects (OB) and healthy eating/weight controls (HC). METHODS Thirty five AN patients, fifty two OB and one hundred thirty seven HC were compared using the Wisconsin Card Sorting Test (WCST); Stroop Color and Word Test (SCWT); and Iowa Gambling Task (IGT). All participants were female, aged between 18 and 60 years. RESULTS There was a significant difference in IGT score (F(1.79); p<.001), with AN and OB groups showing the poorest performance compared to HC. On the WCST, AN and OB made significantly more errors than controls (F(25.73); p<.001), and had significantly fewer correct responses (F(2.71); p<.001). Post hoc analysis revealed that the two clinical groups were not significantly different from each other. Finally, OB showed a significant reduced performance in the inhibition response measured with the Stroop test (F(5.11); p<.001) compared with both AN and HC. CONCLUSIONS These findings suggest that EWC subjects (namely AN and OB) have similar dysfunctional executive profile that may play a role in the development and maintenance of such disorders.

GNSS signal detection based on first-order absolute statistics

Aquest projecte es centra principalment en el detector no coherent d’un GPS. Per tal de caracteritzar el procés de detecció d’un receptor, es necessita conèixer l’estadística implicada. Pel cas dels detectors no coherents convencionals, l’estadística de segon ordre intervé plenament. Les prestacions que ens dóna l’estadística de segon ordre, plasmada en la ROC, són prou bons tot i que en diferents situacions poden no ser els millors. Aquest projecte intenta reproduir el procés de detecció mitjançant l’estadística de primer ordre com a alternativa a la ja coneguda i implementada estadística de segon ordre. Per tal d’aconseguir-ho, s’usen expressions basades en el Teorema Central del Límit i de les sèries Edgeworth com a bones aproximacions. Finalment, tant l’estadística convencional com l’estadística proposada són comparades, en termes de la ROC, per tal de determinar quin detector no coherent ofereix millor prestacions en cada situació.

Modulation of the Endocannabinoids N-Arachidonoylethanolamine (AEA) and 2-Arachidonoylglycerol (2-AG) on Executive Functions in Humans.

Animal studies point to an implication of the endocannabinoid system on executive functions. In humans, several studies have suggested an association between acute or chronic use of exogenous cannabinoids (Δ9-tetrahydrocannabinol) and executive impairments. However, to date, no published reports establish the relationship between endocannabinoids, as biomarkers of the cannabinoid neurotransmission system, and executive functioning in humans. The aim of the present study was to explore the association between circulating levels of plasma endocannabinoids N-arachidonoylethanolamine (AEA) and 2-Arachidonoylglycerol (2-AG) and executive functions (decision making, response inhibition and cognitive flexibility) in healthy subjects. One hundred and fifty seven subjects were included and assessed with the Wisconsin Card Sorting Test; Stroop Color and Word Test; and Iowa Gambling Task. All participants were female, aged between 18 and 60 years and spoke Spanish as their first language. Results showed a negative correlation between 2-AG and cognitive flexibility performance (r = -.37; p<.05). A positive correlation was found between AEA concentrations and both cognitive flexibility (r = .59; p<.05) and decision making performance (r = .23; P<.05). There was no significant correlation between either 2-AG (r = -.17) or AEA (r = -.08) concentrations and inhibition response. These results show, in humans, a relevant modulation of the endocannabinoid system on prefrontal-dependent cognitive functioning. The present study might have significant implications for the underlying executive alterations described in some psychiatric disorders currently associated with endocannabinoids deregulation (namely drug abuse/dependence, depression, obesity and eating disorders). Understanding the neurobiology of their dysexecutive profile might certainly contribute to the development of new treatments and pharmacological approaches.

Cutaneous lesions sensory impairment recovery and nerve regeneration in leprosy patients

It is important to understand the mechanisms that enable peripheral neurons to regenerate after nerve injury in order to identify methods of improving this regeneration. Therefore, we studied nerve regeneration and sensory impairment recovery in the cutaneous lesions of leprosy patients (LPs) before and after treatment with multidrug therapy (MDT). The skin lesion sensory test results were compared to the histopathological and immunohistochemical protein gene product (PGP) 9.5 and the p75 nerve growth factor receptors (NGFr) findings. The cutaneous neural occupation ratio (CNOR) was evaluated for both neural markers. Thermal and pain sensations were the most frequently affected functions at the first visit and the most frequently recovered functions after MDT. The presence of a high cutaneous nerve damage index did not prevent the recovery of any type of sensory function. The CNOR was calculated for each biopsy, according to the presence of PGP and NGFr-immunostained fibres and it was not significantly different before or after the MDT. We observed a variable influence of MDT in the recovery from sensory impairment in the cutaneous lesions of LPs. Nociception and cold thermosensation were the most recovered sensations. The recovery of sensation in the skin lesions appeared to be associated with subsiding inflammation rather than with the regenerative activity of nerve fibres.

Exploring the mechanisms regulating nutrient bioavailability and lipid metabolism through a nutrigenomics approach

SUMMARY Following the complete sequencing of the human genome, the field of nutrition has begun utilizing this vast quantity of information to comprehensively explore the interactions between diet and genes. This approach, coined nutrigenomics, aims to determine the influence of common dietary ingredients on the genome, and attempts to relate the resulting different phenotypes to differences in the cellular and/or genetic response of the biological system. However, complementary to defining the biological outcomes of dietary ingredients, we must also understand the influence of the multiple factors (such as the microbiota, bile, and function of transporters) that may contribute to the bioavailability, and ultimately bioefficacy, of these ingredients. The gastrointestinal tract (GIT) is the body's foremost tissue boundary, interacting with nutrients, exogenous compounds and microbiota, and whose condition is influenced by the complex interplay between these environmental factors and genetic elements. In order to understand GIT nutrient-gene interactions, our goal was to comprehensively elucidate the region-specific gene expression underlying intestinal functions. We found important regional differences in the expression of members of the ATP-binding cassette family of transporters in the mouse intestine, suggesting that absorption of dietary compounds may vary along the GIT. Furthermore, the influence of the microbiota on host gene expression indicated that this luminal factor predominantly influences immune function and water transport throughout the GIT; however, the identification of region-specific functions suggest distinct host-bacterial interactions along the GIT. Thus, these findings reinforce that to understand nutrient bioavailability and GIT function, one must consider the physiologically distinct regions of the gut. Nutritional molecules absorbed by the enterocytes of the GIT enter circulation and will be selectively absorbed and metabolised by tissues throughout the body; however, their bioefficacy in the body will depend on the unique and shared molecular mechanisms of the various tissues. Using a nutrigenomic approach, the biological responses of the liver and hippocampus of mice fed different long chain-polyunsaturated fatty acids diets revealed tissue-specific responses. Furthermore, we identified stearoyl-CoA desaturase as a hepatic target for arachidonic acid, suggesting a potentially novel molecular mechanism that may protect against diet-induced obesity. In summary, this work begins to unveil the fundamentally important role that nutrigenomics will play in unravelling the molecular mechanisms, and those exogenous factors capable of influencing these mechanisms, that regulate the bioefficacy of nutritional molecules. RÉSUMÉ Suite au séquençage complet du génome humain, le domaine de la nutrition a commencé à utiliser cette vaste quantité d'information pour explorer de manière globale les interactions entre la nourriture et les gènes. Cette approche, appelée « nutrigenomics », a pour but de déterminer l'influence d'ingrédients couramment utilisés dans l'alimentation sur le génome, et d'essayer de relier ces différents phénotypes, ainsi révélés, à des différences de réponses cellulaires et/ou génétiques. Cependant, en plus de définir les effets biologiques d'ingrédients alimentaires, il est important de comprendre l'influence des multiples facteurs (telle que la microflore, la bile et la fonction des transporteurs) pouvant contribuer à la bio- disponibilité et par conséquent à l'efficacité de ces ingrédients. Le tractus gastro-intestinal (TGI), qui est la première barrière vers les tissus, interagit avec les nutriments, les composés exogènes et la microflore. La fonction de cet organe est influencée par les interactions complexes entre les facteurs environnementaux et les éléments génétiques. Dans le but de comprendre les interactions entre les nutriments et les gènes au niveau du TGI, notre objectif a été de décrire de manière globale l'expression génique spécifique de chaque région de l'intestin définissant leurs fonctions. Nous avons trouvé d'importantes différences régionales dans l'expression des transporteurs de la famille des « ATP-binding cassette transporter » dans l'intestin de souris, suggérant que l'absorption des composés alimentaires puisse varier le long de l'intestin. De plus, l'étude des effets de la microflore sur l'expression des gènes hôtes a indiqué que ce facteur de la lumière intestinale influence surtout la fonction immunitaire et le transport de l'eau à travers l'intestin. Cependant, l'identification des fonctions spécifiques de chaque région suggère des interactions distinctes entre l'hôte et les bactéries le long de l'intestin. Ainsi, ces résultats renforcent l'idée que la compréhension de la bio-disponibilité des nutriments, et par conséquent la fonction du TGI, doit prendre en considération les différences régionales. Les molécules nutritionnelles transportées par les entérocytes jusqu'à la circulation sanguine, sont ensuite sélectivement absorbées et métabolisées par les différents tissus de l'organisme. Cependant, leur efficacité biologique dépendra du mécanisme commun ou spécifique de chaque tissu. En utilisant une approche « nutriogenomics », nous avons pu mettre en évidence les réponses biologiques spécifiques du foie et de l'hippocampe de souris nourris avec des régimes supplémentés avec différents acides gras poly-insaturés à chaîne longue. De plus, nous avons identifié la stearoyl-CoA desaturase comme une cible hépatique pour l'acide arachidonique, suggérant un nouveau mécanisme moléculaire pouvant potentiellement protéger contre le développement de l'obésité. En résumé, ce travail a permis de dévoiler le rôle fondamental qu'une approche telle que la « nutrigenomics » peut jouer dans le décryptage des mécanismes moléculaires et de leur régulation par des facteurs exogènes, qui ensemble vont contrôler l'efficacité biologique des nutriments.

Coloritto ([Edition augmentée de l'appendice et des 4 pl. (2 versions supplémentaires du visage de femme, accompagnées des deux palettes de couleurs correspondantes) ]) / ; or the harmony of colouring in painting : reduced to mechanical practice, under easy precepts, and infallible rules ; together with some colour'd figures, in order to render the said precepts and rules intelligible, not only to painters, but even to all lovers of painting. By J. C. Le Blon.

Ancien possesseur : Ledoux-Lebard, Guy (1912-2003)

Investigation of memory, executive functions, and anatomic correlates in asymptomatic FMR1 premutation carriers.

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset movement disorder associated with FMR1 premutation alleles. Asymptomatic premutation (aPM) carriers have preserved cognitive functions, but they present subtle executive deficits. Current efforts are focusing on the identification of specific cognitive markers that can detect aPM carriers at higher risk of developing FXTAS. This study aims at evaluating verbal memory and executive functions as early markers of disease progression while exploring associated brain structure changes using diffusion tensor imaging. We assessed 30 aPM men and 38 intrafamilial controls. The groups perform similarly in the executive domain except for decreased performance in motor planning in aPM carriers. In the memory domain, aPM carriers present a significant decrease in verbal encoding and retrieval. Retrieval is associated with microstructural changes of the white matter (WM) of the left hippocampal fimbria. Encoding is associated with changes in the WM under the right dorsolateral prefrontal cortex, a region implicated in relational memory encoding. These associations were found in the aPM group only and did not show age-related decline. This may be interpreted as a neurodevelopmental effect of the premutation, and longitudinal studies are required to better understand these mechanisms.

Critical role of the transcriptional repressor neuron-restrictive silencer factor in the specific control of connexin36 in insulin-producing cell lines.

Connexin36 (Cx36) is specifically expressed in neurons and in pancreatic beta-cells. Cx36 functions as a critical regulator of insulin secretion and content in beta-cells. In order to identify the molecular mechanisms that control the beta-cell expression of Cx36, we initiated the characterization of the human 5' regulatory region of the CX36 gene. A 2043-bp fragment of the human CX36 promoter was identified from a human BAC library and fused to a luciferase reporter gene. This promoter region was sufficient to confer specific expression to the reporter gene in insulin-secreting cell lines. Within this 5' regulatory region, a putative neuron-restrictive silencer element conserved between rodent and human species was recognized and binds the neuron-restrictive silencing factor (NRSF/REST). This factor is not expressed in insulin-secreting cells and neurons; it functions as a potent repressor through the recruitment of histone deacetylase to the promoter of neuronal genes. The NRSF-mediated repression of Cx36 in HeLa cells was abolished by trichostatin A, confirming the functional importance of histone deacetylase activity. Ectopic expression, by viral gene transfer, of NRSF/REST in different insulin-secreting beta-cell lines induced a marked reduction in Cx36 mRNA and protein content. Moreover, mutations in the Cx36 neuron-restrictive silencer element relieved the low transcriptional activity of the human CX36 promoter observed in HeLa cells and in INS-1 cells expressing NRSF/REST. The data showed that cx36 gene expression in insulin-producing beta-cell lines is strictly controlled by the transcriptional repressor NRSF/REST indicating that Cx36 participates to the neuronal phenotype of the pancreatic beta-cells.

Discovery of catalases in members of the Chlamydiales order.

Catalase is an important virulence factor for survival in macrophages and other phagocytic cells. In Chlamydiaceae, no catalase had been described so far. With the sequencing and annotation of the full genomes of Chlamydia-related bacteria, the presence of different catalase-encoding genes has been documented. However, their distribution in the Chlamydiales order and the functionality of these catalases remain unknown. Phylogeny of chlamydial catalases was inferred using MrBayes, maximum likelihood, and maximum parsimony algorithms, allowing the description of three clade 3 and two clade 2 catalases. Only monofunctional catalases were found (no catalase-peroxidase or Mn-catalase). All presented a conserved catalytic domain and tertiary structure. Enzymatic activity of cloned chlamydial catalases was assessed by measuring hydrogen peroxide degradation. The catalases are enzymatically active with different efficiencies. The catalase of Parachlamydia acanthamoebae is the least efficient of all (its catalytic activity was 2 logs lower than that of Pseudomonas aeruginosa). Based on the phylogenetic analysis, we hypothesize that an ancestral class 2 catalase probably was present in the common ancestor of all current Chlamydiales but was retained only in Criblamydia sequanensis and Neochlamydia hartmannellae. The catalases of class 3, present in Estrella lausannensis and Parachlamydia acanthamoebae, probably were acquired by lateral gene transfer from Rhizobiales, whereas for Waddlia chondrophila they likely originated from Legionellales or Actinomycetales. The acquisition of catalases on several occasions in the Chlamydiales suggests the importance of this enzyme for the bacteria in their host environment.

An energy preserving discontinouous Galerkin method for Vlasov-Poisson system

Vegeu el resum a l'inici del document de l'arxiu adjunt

Sobre els mapes de semblança quàntica molecular

Partint de les definicions usuals de Mesures de Semblança Quàntica (MSQ), es considera la dependència d'aquestes mesures respecte de la superposició molecular. Pel cas particular en qnè els sistemes comparats siguin una molècula i un Àtom i que les mesures es calculin amb l'aproximació EASA, les MSQ esdevenen funcions de les tres coordenades de l'espai. Mantenint fixa una de les tres coordenades, es pot representar fàcilment la variació del valor de semblança en un pla determinat, i obtenir els anomenats mapes de semblança. En aquest article, es comparen els mapes de semblança obtinguts amb diferents MSQ per a sistemes senzills

Correlations between motor and intellectual functions in normally developing children between 7 and 18 years.

The relationship between motor and intellectual functions was examined in 252 healthy children from 7 to 18 years using the Zurich Neuromotor Assessment and standardized intelligence tests. The magnitude of Spearman correlations between neuromotor and intellectual scores was generally weak (r = 0.15-0.37). The strongest correlations were found between performance in the pegboard task and visuomotor intelligence (r = 0.35) and between contralateral associated movements and intelligence in boys (r = 0.37). We conclude that specific connections between motor and intellectual functions may exist. However, because the magnitude of correlations is generally weak, we suggest that motor and intellectual domains in healthy children are largely independent.

Sobre les relacions lineals d'energia lliure: mesures de semblança molecular quàntica sobre funcions de densitat electrònica modificad

En aquest treball es presenta l'ús de funcions de densitat electrònica de forat de Fermi per incrementar el paper que pren una regió molecular concreta, considerada com a responsable de la reactivitat molecular, tot i mantenir la mida de la funció de densitat original. Aquestes densitats s'utilitzen per fer mesures d'autosemblança molecular quàntica i es presenten com una alternativa a l'ús de fragments moleculars aillats en estudis de relació entre estructura i propietat. El treball es complementa amb un exemple pràctic, on es correlaciona l'autosemblanca molecular a partir de densitats modificades amb l'energia d'una reacció isodòsmica

Rôle des cellules souches épithéliales de la cornée et de leur micro-environnement dans le traitement des destructions de la surface oculaire [Darwin or Lamarck? Understanding the ocular surface and its normal or abnormal differentiation in order to cure ocular surface destruction with corneal opacification].

According to the World Health Organization, 5.1% of blindnesses or visual impairments are related to corneal opacification. Cornea is a transparent tissue placed in front of the color of the eye. Its transparency is mandatory for vision. The ocular surface is a functional unit including the cornea and all the elements involved in maintaining its transparency i.e., the eyelids, the conjunctiva, the lymphoid tissue of the conjunctiva, the limbus, the lacrymal glands and the tear film. The destruction of the ocular surface is a disease caused by : traumatisms, infections, chronic inflammations, cancers, toxics, unknown causes or congenital abnormalities. The treatment of the ocular surface destruction requires a global strategy including all the elements that are involved in its physiology. The microenvironnement of the ocular surface must first be restored, i.e., the lids, the conjunctiva, the limbus and the structures that secrete the different layers of the tear film. In a second step, the transparency of the cornea can be reconstructed. A corneal graft performed in a healthy ocular surface microenvironnement will have a better survival rate. To achieve these goals, a thorough understanding of the renewal of the epitheliums and the role of the epithelial stem cells are mandatory.