954 resultados para Lines of activity


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Status epilepticus treatment involves the use of several pharmacologic compounds, which are conceptually divided into three successive and additional lines of action. Because of their rapid onset of action, benzodiazepines represent the first approach; these are followed by classic antiepileptic drugs that are administered intravenously. In refractory episodes, pharmacologic coma induction with an appropriate anesthetic is advocated. Apart from first-line compounds, the level of evidence for medications used in status epilepticus is extremely limited. It is important to specifically address etiology in order to maximize the impact of the antiepileptic therapy. Fine-tuning of the treatment strategy, mainly regarding the choice of whether to induce coma, should be approached by balancing the benefits of rapid control of the status epilepticus with the risks of adverse effects. Although each status epilepticus episode should be treated as rapidly as possible, it appears advisable to reserve coma induction for those forms, such as generalized convulsive status, that have been shown to present a consistent risk of neurologic sequelae.

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Metabolic homeostasis is achieved by complex molecular and cellular networks that differ significantly among individuals and are difficult to model with genetically engineered lines of mice optimized to study single gene function. Here, we systematically acquired metabolic phenotypes by using the EUMODIC EMPReSS protocols across a large panel of isogenic but diverse strains of mice (BXD type) to study the genetic control of metabolism. We generated and analyzed 140 classical phenotypes and deposited these in an open-access web service for systems genetics (www.genenetwork.org). Heritability, influence of sex, and genetic modifiers of traits were examined singly and jointly by using quantitative-trait locus (QTL) and expression QTL-mapping methods. Traits and networks were linked to loci encompassing both known variants and novel candidate genes, including alkaline phosphatase (ALPL), here linked to hypophosphatasia. The assembled and curated phenotypes provide key resources and exemplars that can be used to dissect complex metabolic traits and disorders.

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Even though laboratory evolution experiments have demonstrated genetic variation for learning ability, we know little about the underlying genetic architecture and genetic relationships with other ecologically relevant traits. With a full diallel cross among twelve inbred lines of Drosophila melanogaster originating from a natural population (0.75 < F < 0.93), we investigated the genetic architecture of olfactory learning ability and compared it to that for another behavioral trait (unconditional preference for odors), as well as three traits quantifying the ability to deal with environmental challenges: egg-to-adult survival and developmental rate on a low-quality food, and resistance to a bacterial pathogen. Substantial additive genetic variation was detected for each trait, highlighting their potential to evolve. Genetic effects contributed more than nongenetic parental effects to variation in traits measured at the adult stage: learning, odorant perception, and resistance to infection. In contrast, the two traits quantifying larval tolerance to low-quality food were more strongly affected by parental effects. We found no evidence for genetic correlations between traits, suggesting that these traits could evolve at least to some degree independently of one another. Finally, inbreeding adversely affected all traits.

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Neuropathic pain is a clinical manifestation of nerve injury difficult to treat even with potent analgesic compounds. Here, we used different lines of genetically modified mice to clarify the role played by CB2 cannabinoid receptors in the regulation of the central immune responses leading to the development of neuropathic pain. CB2 knock-out mice and wild-type littermates were exposed to sciatic nerve injury, and both genotypes developed a similar hyperalgesia and allodynia in the ipsilateral paw. Most strikingly, knock-outs also developed a contralateral mirror image pain, associated with an enhanced microglial and astrocytic expression in the contralateral spinal horn. In agreement, hyperalgesia, allodynia, and microglial and astrocytic activation induced by sciatic nerve injury were attenuated in transgenic mice overexpressing CB2 receptors. These results demonstrate the crucial role of CB2 cannabinoid receptor in modulating glial activation in response to nerve injury. The enhanced manifestations of neuropathic pain were replicated in irradiated wild-type mice reconstituted with bone marrow cells from CB2 knock-outs, thus demonstrating the implication of the CB2 receptor expressed in hematopoietic cells in the development of neuropathic pain at the spinal cord.

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The development of nuclear hormone receptor antagonists that directly inhibit the association of the receptor with its essential coactivators would allow useful manipulation of nuclear hormone receptor signaling. We previously identified 3-(dibutylamino)-1-(4-hexylphenyl)-propan-1-one (DHPPA), an aromatic β-amino ketone that inhibits coactivator recruitment to thyroid hormone receptor β (TRβ), in a high-throughput screen. Initial evidence suggested that the aromatic β-enone 1-(4-hexylphenyl)-prop-2-en-1-one (HPPE), which alkylates a specific cysteine residue on the TRβ surface, is liberated from DHPPA. Nevertheless, aspects of the mechanism and specificity of action of DHPPA remained unclear. Here, we report an x-ray structure of TRβ with the inhibitor HPPE at 2.3-Å resolution. Unreacted HPPE is located at the interface that normally mediates binding between TRβ and its coactivator. Several lines of evidence, including experiments with TRβ mutants and mass spectroscopic analysis, showed that HPPE specifically alkylates cysteine residue 298 of TRβ, which is located near the activation function-2 pocket. We propose that this covalent adduct formation proceeds through a two-step mechanism: 1) β-elimination to form HPPE; and 2) a covalent bond slowly forms between HPPE and TRβ. DHPPA represents a novel class of potent TRβ antagonist, and its crystal structure suggests new ways to design antagonists that target the assembly of nuclear hormone receptor gene-regulatory complexes and block transcription.

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ABSTRACT Adult neuronal plasticity is a term that corresponds to a set of biological mechanisms allowing a neuronal circuit to respond and adapt to modifications of the received inputs. Mystacial whiskers of the mouse are the starting point of a major sensory pathway that provides the animal with information from its immediate environment. Through whisking, information is gathered that allows the animal to orientate itself and to recognize objects. This sensory system is crucial for nocturnal behaviour during which vision is not of much use. Sensory information of the whiskers are sent via brainstem and thalamus to the primary somatosensory area (S1) of the cerebral cortex in a strictly topological manner. Cell bodies in the layer N of S 1 are arranged in ring forming structures called barrels. As such, each barrel corresponds to the cortical representation in layer IV of a single whisker follicle. This histological feature allows to identify with uttermost precision the part of the cortex devoted to a given whisker and to study modifications induced by different experimental conditions. The condition used in the studies of my thesis is the passive stimulation of one whisker in the adult mouse for a period of 24 hours. It is performed by glueing a piece of metal on one whisker and placing the awake animal in a cage surrounded by an electromagnetic coil that generates magnetic field burst inducing whisker movement at a given frequency during 24 hours. I analysed the ultrastructure of the barrel corresponding the stimulated whisker using serial sections electron microscopy and computer-based three-dimensional reconstructions; analysis of neighbouring, unstimulated barrels as well as those from unstimulated mice served as control. The following elements were structurally analyzed: the spiny dendrites, the axons of excitatory as well as inhibitory cells, their connections via synapses and the astrocytic processes. The density of synapses and spines is upregulated in a barrel corresponding to a stimulated whisker. This upregulation is absent in the BDNF heterozygote mice, indicating that a certain level of activity-dependent released BDNF is required for synaptogenesis in the adult cerebral cortex. Synpaptogenesis is correlated with a modification of the astrocytes that place themselves in closer vicinity of the excitatory synapses on spines. Biochemical analysis revealed that the astrocytes upregulate the expression of transporters by which they internalise glutamate, the neurotransmitter responsible for the excitatory response of cortical neurons. In the final part of my thesis, I show that synaptogenesis in the stimulated barrel is due to the increase in the size of excitatory axonal boutons that become more frequently multisynaptic, whereas the inhibitory axons do not change their morphology but form more synapses with spines apposed to them. Taken together, my thesis demonstrates that all the cellular elements present in the neuronal tissue of the adult brain contribute to activity-dependent cortical plasticity and form part of a mechanism by which the animal responds to a modified sensory experience. Throughout life, the neuronal circuit keeps the faculty to adapt its function. These adaptations are partially transitory but some aspects remain and could be the structural basis of a memory trace in the cortical circuit. RESUME La plasticité neuronale chez l'adulte désigne un ensemble de mécanismes biologiques qui permettent aux circuits neuronaux de répondre et de s'adapter aux modifications des stimulations reçues. Les vibrisses des souris sont un système crucial fournissant des informations sensorielles au sujet de l'environnement de l'animal. L'information sensorielle collectée par les vibrisses est envoyée via le tronc cérébral et le thalamus à l'aire sensorielle primaire (S 1) du cortex cérébral en respectant strictement la somatotopie. Les corps cellulaires dans la couche IV de S 1 sont organisés en anneaux délimitant des structures nommées tonneaux. Chaque tonneau reçoit l'information d'une seule vibrisse et l'arrangement des tonneaux dans le cortex correspond à l'arrangement des vibrisses sur le museau de la souris. Cette particularité histologique permet de sélectionner avec certitude la partie du cortex dévolue à une vibrisse et de l'étudier dans diverses conditions. Le paradigme expérimental utilisé dans cette thèse est la stimulation passive d'une seule vibrisse durant 24 heures. Pour ce faire, un petit morceau de métal est collé sur une vibrisse et la souris est placée dans une cage entourée d'une bobine électromagnétique générant un champ qui fait vibrer le morceau de métal durant 24 heures. Nous analysons l'ultrastructure du cortex cérébral à l'aide de la microscopie électronique et des coupes sériées permettant la reconstruction tridimensionnelle à l'aide de logiciels informatiques. Nous observons les modifications des structures présentes : les dendrites épineuses, les axones des cellules excitatrices et inhibitrices, leurs connections par des synapses et les astrocytes. Le nombre de synapses et d'épines est augmenté dans un tonneau correspondant à une vibrisse stimulée 24 heures. Basé sur cela, nous montrons dans ces travaux que cette réponse n'est pas observée dans des souris hétérozygotes BDNF+/-. Cette neurotrophine sécrétée en fonction de l'activité neuronale est donc nécessaire pour la synaptogenèse. La synaptogenèse est accompagnée d'une modification des astrocytes qui se rapprochent des synapses excitatrices au niveau des épines dendritiques. Ils expriment également plus de transporteurs chargés d'internaliser le glutamate, le neurotransmetteur responsable de la réponse excitatrice des neurones. Nous montrons aussi que les axones excitateurs deviennent plus larges et forment plus de boutons multi-synaptiques à la suite de la stimulation tandis que les axones inhibiteurs ne changent pas de morphologie mais forment plus de synapses avec des épines apposées à leur membrane. Tous les éléments analysés dans le cerveau adulte ont maintenu la capacité de réagir aux modifications de l'activité neuronale et répondent aux modifications de l'activité permettant une constante adaptation à de nouveaux environnements durant la vie. Les circuits neuronaux gardent la capacité de créer de nouvelles synapses. Ces adaptations peuvent être des réponses transitoires aux stimuli mais peuvent aussi laisser une trace mnésique dans les circuits.

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Previous studies demonstrated that both Schwann cell differentiation and de-differentiation (in the situation of a nerve injury or demyelinating disease) are regulated by cell-intrinsic regulators including several transcription factors. In particular, the de-differentiation of mature Schwann cells is driven by the activation of multiple negative regulators of myelination including c-Jun, Notch, Sox-2 and Pax-3, all usually expressed in the immature Schwann cells and suppressed at the onset of myelination. In order to identify new negative regulators of myelination involved in the development of the peripheral nervous system (PNS) we analyzed the data from a previously performed transcriptional analysis of myelinating Schwann cells. Based on its transcriptional expression profile during myelination, Sox4, a member of the Sox gene family, was identified as a potential candidate. Previous studies demonstrated that prolonged Sox4 expression in oligodendrocytes maintains these cells in a premyelinating state, further suggesting its role as a negative regulator of myelination. Concomitantly, we observed upregulation of Sox4 mRNA and protein expression levels in the PNS of three different models of demyelinating neuropathies (Pmp22, Lpin1, and Scap KOs). To better characterize the molecular function of Sox4, we used a viral vector allowing Sox4 overexpression in cultured Schwann cells and in neuron-Schwann cell co-cultures. In parallel, we generated two transgenic lines of mice in which the overexpression of Sox4 is driven specifically in Schwann cells by the Myelin Protein Zero gene promoter. The preliminary data from these in vitro and in vivo experiments show that overexpression of Sox4 in PNS causes a delay in progression of myelination thus indicating that Sox4 acts as a negative regulator of Schwann cell myelination.

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PURPOSE: To investigate the mechanism(s) of resistance to the RAF-inhibitor vemurafenib, we conducted a comprehensive analysis of the genetic alterations occurring in metastatic lesions from a patient with a BRAF(V600E)-mutant cutaneous melanoma who, after a first response, underwent subsequent rechallenge with this drug. EXPERIMENTAL DESIGN: We obtained blood and tissue samples from a patient diagnosed with a BRAF(V600E)-mutant cutaneous melanoma that was treated with vemurafenib and achieved a near-complete response. At progression, he received additional lines of chemo/immunotherapy and was successfully rechallenged with vemurafenib. Exome and RNA sequencing were conducted on a pretreatment tumor and two subcutaneous resistant metastases, one that was present at baseline and previously responded to vemurafenib (PV1) and one that occurred de novo after reintroduction of the drug (PV2). A culture established from PV1 was also analyzed. RESULTS: We identified two NRAS-activating somatic mutations, Q61R and Q61K, affecting two main subpopulations in the metastasis PV1 and a BRAF alternative splicing, involving exons 4-10, in the metastasis PV2. These alterations, known to confer resistance to RAF inhibitors, were tumor-specific, mutually exclusive, and were not detected in pretreatment tumor samples. In addition, the oncogenic PIK3CA(H1047R) mutation was detected in a subpopulation of PV1, but this mutation did not seem to play a major role in vemurafenib resistance in this metastasis. CONCLUSIONS: This work describes the coexistence within the same patient of different molecular mechanisms of resistance to vemurafenib affecting different metastatic sites. These findings have direct implications for the clinical management of BRAF-mutant melanoma. Clin Cancer Res; 19(20); 5749-57. ©2013 AACR.

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The key reference on the labour market and the logics of squad formation in the five main European leagues. One hundred richly coloured pages, illustrated by graphics, maps, rankings, statistical models and analysis in French and English which... - inform managers about potential strategies to put their clubs on the road to success - help managers of federations and players' unions to understand current trends and to take decisions - suggest to journalists new lines of investigation likely to interest the general public - allow researchers and students to benefit from reliable and comparable sources, developed with the greatest possible rigour - give fans the possibility to understand in detail the dynamics at work in their favourite sport and club Demographic Study of Footballers in Europe The Demographic Study of European Footballers is an annual publication destined for anyone who wishes to acquire a scientific understanding of the European football players' labour market. It presents the dynamics at work in 36 first division leagues in UEFA member countries. This edition covers our biggest ever survey comprising more than 520 clubs and 13,000 footballers. Statistical indicators relative to nine thematics (morphology, age, experience training, origin, etc.) allow the comparison of player profiles and squad compositions at league and club level. Through easily-understable regression analyses, the Study brings to light the principle differences between clubs and leagues according to economic and sporting level of championships. The final part presents the list of the most promising players under 23 years of age by league and position

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Tämän diplomityön tavoite on luoda viitekehys kahdesta työn pääteorioista, jotka ovat: "liiketoiminnan ulkoiset menestystekijät" ja "alueiden kilpailukyky". Kummatkin teoriat sisältävät tekijöitä, joilla on vaikutusta yrityksen sijaintipaikkapäätökseen. Viitekehyksen pohjalta tarkastellaan kahta tutkimusaluetta: Landen seutua ja Kuuma-aluetta. Työn tuloksena syntyy kuva kummastakin tutkimusalueesta ja analyysi viitekehyksestä. Työn ensimmäisessä osassa käydään läpi aihealueen tutkimuksen taustaa ja mitä ongelmia tutkimuksissa on tullut esille. Senjälkeen esitellään kaikki liiketoiminnan ulkoiset menestystekijät. Alueiden kilpailukyvyn teoriaosuus täydentää viitekehyksen tekijät. Työn jälkimmäinen empiirinen osa perustuu lähdemateriaaliin, joka on kerätty haastatteluista, lehtiartikkeleista ja seminaareista koskien tutkimusalueita. Tutkimustuloksista selviää, että kummatkin tutkimusalueet ovat erilaisia ja niillä on omat avainklusterinsa ja menestyvät toimialansa. Viitekehys luotiin melko onnistuneesti. Lopulta selvisi, että se sopii hyvin aihealueen tutkimuksen laajentamiseen, mutta heikosti yksittäisenyrityksen sijaintipaikkapäätökseen.

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ABSTRACT: BACKGROUND: An increase in new HIV cases among men who have sex with men (MSM) has been reported in Switzerland since 2001. A rapid result HIV testing for MSM through voluntary counselling and testing (VCT) facility ("Checkpoint") was opened in Geneva in 2005. This gay-friendly facility, the first to open in Switzerland, provides testing for sexually transmitted infections (STI) and rapid result HIV testing and counselling. Our objective was to analyze Checkpoint's activity over its first five years of activity and its ability to attract at-risk MSM. METHODS: We used routine data collected anonymously about the facility activity (number of clients, number of tests, and test results) and about the characteristics of the clientele (sociodemographic data, sexual risk behaviour, and reasons for testing) from 2005 to 2009. RESULTS: The yearly number of HIV tests performed increased from 249 in 2005 to 561 in 2009. The annual proportion of positive tests among tests performed varied between 2% and 3%. Among MSM clients, the median annual number of anal intercourse (AI) partners was three. Roughly 30% of all MSM clients had at least one unprotected anal intercourse (UAI) experience in the previous 12 months with a partner of different/unknown HIV status.The main reason for testing in 2007, 2008, and 2009 was "sexual risk exposure" (~40%), followed by "routine" testing (~30%) and "condom stopping in the beginning of a new steady relationship" (~10%). Clients who came to the facility after a sexual risk exposure, compared to clients who came for "routine testing" or "condom stopping" reasons, had the highest number of AI partners in the previous 12 months, were more likely to have had UAI with a partner of different/unknown HIV status in the previous 12 months (respectively 57.3%, 12.5%, 23.5%), more likely to have had an STI diagnosed in the past (41.6%, 32.2%, 22.9%), and more likely to report recent feelings of sadness or depression (42.6%; 32.8%, 18.5%). CONCLUSION: Many of Checkpoint's clients reported elevated sexual risk exposure and risk factors, and the annual proportion of new HIV cases in the facility is stable. This VCT facility attracts the intended population and appears to be a useful tool contributing to the fight against the HIV epidemic among MSM in Switzerland.

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Several lines of research have documented early-latency non-linear response interactions between audition and touch in humans and non-human primates. That these effects have been obtained under anesthesia, passive stimulation, as well as speeded reaction time tasks would suggest that some multisensory effects are not directly influencing behavioral outcome. We investigated whether the initial non-linear neural response interactions have a direct bearing on the speed of reaction times. Electrical neuroimaging analyses were applied to event-related potentials in response to auditory, somatosensory, or simultaneous auditory-somatosensory multisensory stimulation that were in turn averaged according to trials leading to fast and slow reaction times (using a median split of individual subject data for each experimental condition). Responses to multisensory stimulus pairs were contrasted with each unisensory response as well as summed responses from the constituent unisensory conditions. Behavioral analyses indicated that neural response interactions were only implicated in the case of trials producing fast reaction times, as evidenced by facilitation in excess of probability summation. In agreement, supra-additive non-linear neural response interactions between multisensory and the sum of the constituent unisensory stimuli were evident over the 40-84 ms post-stimulus period only when reaction times were fast, whereas subsequent effects (86-128 ms) were observed independently of reaction time speed. Distributed source estimations further revealed that these earlier effects followed from supra-additive modulation of activity within posterior superior temporal cortices. These results indicate the behavioral relevance of early multisensory phenomena.

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The idea that bacteriophage transduction plays a role in the horizontal transfer of antibiotic resistance genes is gaining momentum. Such transduction might be vital in horizontal transfer from environmental to human bodyassociated biomes and here we review many lines of evidence supporting this notion. It is well accepted that bacteriophages are the most abundant entities in most environments, where they have been shown to be quite persistent. This fact, together with the ability of many phages to infect bacteria belonging to different taxa, makes them suitable vehicles for gene transfer. Metagenomic studies confirm that substantial percentages of the bacteriophage particles present in most environments contain bacterial genes, including mobile genetic elements and antibiotic resistance genes. When specific genes of resistance to antibiotics are detected by real-time PCR in the bacteriophage populations of different environments, only tenfold lower numbers of these genes are observed, compared with those found in the corresponding bacterial populations. In addition, the antibiotic resistance genes from these bacteriophages are functional and generate resistance to the bacteria when these genes are transfected. Finally, reports about the transduction of antibiotic resistance genes are on the increase.

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Simulation is a useful tool in cardiac SPECT to assess quantification algorithms. However, simple equation-based models are limited in their ability to simulate realistic heart motion and perfusion. We present a numerical dynamic model of the left ventricle, which allows us to simulate normal and anomalous cardiac cycles, as well as perfusion defects. Bicubic splines were fitted to a number of control points to represent endocardial and epicardial surfaces of the left ventricle. A transformation from each point on the surface to a template of activity was made to represent the myocardial perfusion. Geometry-based and patient-based simulations were performed to illustrate this model. Geometry-based simulations modeled ~1! a normal patient, ~2! a well-perfused patient with abnormal regional function, ~3! an ischaemic patient with abnormal regional function, and ~4! a patient study including tracer kinetics. Patient-based simulation consisted of a left ventricle including a realistic shape and motion obtained from a magnetic resonance study. We conclude that this model has the potential to study the influence of several physical parameters and the left ventricle contraction in myocardial perfusion SPECT and gated-SPECT studies.

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Differences in development among wheat cultivars are not only restricted to photoperiod and vernalization responses. When both requirements are fully satisfied differences may still arise due to earliness per se. It is not clear at present to what extent this trait is ‘ intrinsically ’ expressed (a constitutive trait) independently of the environmental conditions so that it might be selected under any thermal condition or if it may be altered to the extent of showing a crossover interaction with temperature in which the ranking of wheat genotypes may be altered. The present study assessed the influence of temperature on the intrinsic earliness for lines of diploid wheat characterized for their differences in a major gene for intrinsic earliness, but also possibly differing in their genetic background for other factors controlling this polygenic trait. To do so the lines were grown individually in two temperature regimes (16 and 23 xC) under long days having previously been fully vernalized. Multiple comparisons analyses were carried out among lines of the same allelic group for the Eps-Am1 gene. Results indicated that within each group there were lines that did not differ in their earliness per se, others differed but without exhibiting any linertemperature interaction and finally different types of interaction were shown, including cases where the ranking of lines was altered depending on the growing temperature. It is thus possible that the selection of a genotype based on its earliness per se in an environment might not represent the same performance in another location where temperature varied significantly.