Loss of Cutaneous TSLP-Dependent Immune Responses Skews the Balance of Inflammation from Tumor Protective to Tumor Promoting.

Inflammation can promote or inhibit cancer progression. In this study we have addressed the role of the proinflammatory cytokine thymic stromal lymphopoietin (TSLP) during skin carcinogenesis. Using conditional loss- and gain-of-function mouse models for Notch and Wnt signaling, respectively, we demonstrate that TSLP-mediated inflammation protects against cutaneous carcinogenesis by acting directly on CD4 and CD8 T cells. Genetic ablation of TSLP receptor (TSLPR) perturbs T-cell-mediated protection and results in the accumulation of CD11b(+)Gr1(+) myeloid cells. These promote tumor growth by secreting Wnt ligands and augmenting β-catenin signaling in the neighboring epithelium. Epithelial specific ablation of β-catenin prevents both carcinogenesis and the accumulation of CD11b(+)Gr1(+) myeloid cells, suggesting tumor cells initiate a feed-forward loop that induces protumorigenic inflammation.

Impact of genetic SLC28 transporter and ITPA variants on ribavirin 21 serum level, hemoglobin drop and therapeutic response in patients with HCV infection

Background: T reatment o f chronic hepatitis C i s evolving, a nd direct acting antivirals ( DAAs) are now a dded to p egylated interferon-α ( Peg- INF-α) and ribavirin (RBV) for the treatment o f hepatitis C v irus ( HCV) genotype 1 infection. DAAs c ause d ifferent side effects and can even worsen RBV induced hemolytic anemia. T herefore, identifying host genetic d eterminants of R BV bioavailability and therapeutic e fficacy will remain crucial for individualized treatment. Recent d ata showed associations between R BV induced h emolytic anemia and genetic polymorphisms o f concentrative nucleoside transporters s uch as C NT3 (SLC28A3) and i nosine t riphosphatase (ITPA). T o analyze t he association of genetic variants of SLC28 transporters and ITPA with RBV induced hemolytic anemia and treatment o utcome. Methods: I n our study, 173 patients f rom t he S wiss Hepatitis C C ohort Study and 2 2 patients from Swiss Association for the Study of the Liver study 24 (61% HCV g enotype 1, 3 9% genotypes 2 o r 3) were analyzed for SLC28A2 single nucleotide p olymorphism (SNP) rs11854484, SLC28A3 rs56350726 and SLC28A3 rs10868138 as well as ITPA SNPs rs1127354 and rs7270101. RBV serum levels during treatment were measured in 49 patients. Results: SLC28A2 r s11854484 genotype TT was associated with significantly higher dosage- and body weight-adjusted RBV levels as compared to genotypes TC and CC (p=0.04 and p=0.02 at weeks 4 and 8, respectively). ITPA SNPs rs1127354 and rs7270101 were associated with h emolytic a nemia both in genotype as w ell as i n allelic a nalyses. SLC28A3 rs56350726 genotype TT (vs. AT/AA, RR=2.1; 95% CI 1.1-4.1) as well as the T allele (vs. A; RR=1.8, 95% CI 1.1-3.2) were associated with increased SVR rates. The combined analysis of overall ITPA activity and SLC28 v ariants together revealed n o significant a dditive effects on either treatment-related anemia or SVR. Conclusions: T he newly identified association between RBV serum levels a nd SLC28A2 rs11854484 genotype as well as the replicated association of ITPA and SLC28A3 g enetic p olymorphisms w ith RBV induced hemolytic anemia and treatment r esponse underpin the need for further studies on host genetic d eterminants of R BV bioavailability and therapeutic e fficacy f or individualized treatment of chronic hepatitis C.

Coevolution of restriction factors and retroviruses

Les virus exploitent la machinerie cellulaire de l'hôte pour se répliquer. Ils doivent s'adapter pour infecter la cellule hôte de manière optimale tout en échappant à la vigilance du système de défense de l'hôte. Ainsi l'hôte et les virus se livrent à de constantes batailles évolutives. Mon travail de thèse a porté sur l'étude des signatures évolutives de facteurs de l'hôte agissant comme des 'facteurs de restriction' en bloquant la réplication rétrovirale chez les primates. Plus spécifiquement, mon travail a visé à utiliser des données évolutives pour renseigner les analyses fonctionnelles et la biologie. Nous avons étudié le facteur anti-VIH-1 nommé TRIM5a (i) chez les prosimiens pour mieux comprendre son rôle dans le contrôle d'un lentivirus endogène, (ii) dans son activité contre d'autres anciennes infections représentées par des rétrovirus endogènes humains et (iii) en tant que protéine capable de générer des mutants de la capside. Premièrement nous nous sommes intéressés à TRIM5a chez deux espèces de lémuriens dont Microcebus murinus qui porte le lentivirus endogène PSIV dans son génome depuis plusieurs millions d'années,. Nous avons observé que TRIM5a chez M. murinus a un spectre d'activité antivirale réduit à l'opposé de TRIM5a chez le Lemur catta - non porteur du PSIV endogène - qui bloque une large variété de rétrovirus dont le PSIV. De ce fait TRIM5a aurait pu contribuer à protéger certaines espèces de lémuriens vis-à-vis d'anciennes infections par le PSIV. A l'inverse du PSIV, des virus dérivés des rétrovirus endogènes humains HERV-K and HERV-H se sont révélés largement résistants à l'inhibition par TRIM5a. Ces données illustrent une absence de protection par TRIM5a face à d'autres anciennes infections rétrovirales. Puis, pour évaluer l'impact de la protéine TRIM5a humaine sur le VIH-1, nous avons testé l'effet de mutations des résidues sous sélection positive dans la capside du VIH-1 sur l'inhibition par TRIM5a. Nos résultats montrent que TRIM5a ne jouerait pas un rôle significatif dans l'évolution de la capside du VIH-1. Enfin notre travail a porté sur le facteur anti-VIH-1 SAMHD1 récemment découvert, que nous avons séquencé chez 25 espèces de primates. L'analyse évolutive des sites sous sélection positive et des expériences fonctionnelles ont permis d'identifier le domaine de SAMHD1 interagissant avec la protéine lentivirale Vpx. De même que d'autres protéines virales contrecarrent les facteurs de restriction en les menant à la dégradation, nous avons observé que Vpx induit la dégradation de SAMHD1 de manière spécifique à l'espèce. Ces découvertes contribuent à comprendre comment les facteurs de restriction et les virus co-évoluent pour se neutraliser l'un l'autre. - Viruses hijack the host cellular machinery to replicate. They adapt to infect optimally host cells while escaping host defense systems. Viruses and the host coevolve in an evolutionary struggle. My thesis work has been devoted to study the evolutionary signatures of host factors acting as restriction factors that block retroviral replication in primates. Specifically, my work aimed at using evolutionary data to inform functional analyses and biology. We studied the anti-HIV-1 factor TRIM5a (i) in prosimians to better understand its possible role in the control of an endogenous lentivirus, (ii) in its activity against other ancient infections - as represented by HERVs, and (iii) as a protein capable of generating escape mutants in the viral capsid. First, my work focused on two lemur species, one of which was the gray mouse lemur that carries the endogenous lentivirus PSIV integrated in its genome for several million years. TRIM5a from gray mouse lemur exhibited a limited antiviral spectrum as opposed to TRIM5a from ring-tailed lemur - not a host of PSIV - that is able to block diverse retroviruses notably PSIV. These results support the possible contribution of TRIM5a in protecting lemur species from ancient infection by PSIV. In contrast, chimeric viruses derived from two human endogenous retroviruses were broadly resistant to TRIM5a-mediated restriction, suggesting TRIM5a lack of activity against other types of ancient infections. To evaluate the recent impact of human TRIM5a on HIV-1 evolution, we tested whether variants at positively selected sites in the HIV-1 capsid affected the ability of human TRIM5a alleles to restrict HIV-1. Our results indicate that TRIM5a does not play a significant role in the evolution of HIV1 capsid. At last, our work concentrated on the newly discovered anti-HIV-1 restriction factor SAMHD1. We determined its coding sequence in a panel of 25 species of primates. Evolutionary analyses of positively selected sites in SAMHD1 domains and functional assays identified the domain of SAMHD1 interacting with the lentiviral protein Vpx. Similar to other viral countermeasures targeting cellular restriction factors, Vpx was responsible of the degradation of SAMHD1 orthologs in a species-specific manner. These findings contributed to understanding how restriction factors and viruses evolve to counteract each other.

Effects of selection and drift on G matrix evolution in a heterogeneous environment: a multivariate Qst-Fst Test with the freshwater snail Galba truncatula.

Unraveling the effect of selection vs. drift on the evolution of quantitative traits is commonly achieved by one of two methods. Either one contrasts population differentiation estimates for genetic markers and quantitative traits (the Q(st)-F(st) contrast) or multivariate methods are used to study the covariance between sets of traits. In particular, many studies have focused on the genetic variance-covariance matrix (the G matrix). However, both drift and selection can cause changes in G. To understand their joint effects, we recently combined the two methods into a single test (accompanying article by Martin et al.), which we apply here to a network of 16 natural populations of the freshwater snail Galba truncatula. Using this new neutrality test, extended to hierarchical population structures, we studied the multivariate equivalent of the Q(st)-F(st) contrast for several life-history traits of G. truncatula. We found strong evidence of selection acting on multivariate phenotypes. Selection was homogeneous among populations within each habitat and heterogeneous between habitats. We found that the G matrices were relatively stable within each habitat, with proportionality between the among-populations (D) and the within-populations (G) covariance matrices. The effect of habitat heterogeneity is to break this proportionality because of selection for habitat-dependent optima. Individual-based simulations mimicking our empirical system confirmed that these patterns are expected under the selective regime inferred. We show that homogenizing selection can mimic some effect of drift on the G matrix (G and D almost proportional), but that incorporating information from molecular markers (multivariate Q(st)-F(st)) allows disentangling the two effects.

Molecular variation at a candidate gene implicated in the regulation of fire ant social behavior

The fire ant Solenopsis invicta and its close relatives display an important social polymorphism involving differences in colony queen number. Colonies are headed by either a single reproductive queen (monogyne form) or multiple queens (polygyne form). This variation in social organization is associated with variation at the gene Gp-9, with monogyne colonies harboring only B-like allelic variants and polygyne colonies always containing b-like variants as well. We describe naturally occurring variation at Gp-9 in fire ants based on 185 full-length sequences, 136 of which were obtained from S. invicta collected over much of its native range. While there is little overall differentiation between most of the numerous alleles observed, a surprising amount is found in the coding regions of the gene, with such substitutions usually causing amino acid replacements. This elevated coding-region variation may result from a lack of negative selection acting to constrain amino acid replacements over much of the protein, different mutation rates or biases in coding and non-coding sequences, negative selection acting with greater strength on non-coding than coding regions, and/or positive selection acting on the protein. Formal selection analyses provide evidence that the latter force played an important role in the basal b-like lineages coincident with the emergence of polygyny. While our data set reveals considerable paraphyly and polyphyly of S. invicta sequences with respect to those of other fire ant species, the b-like alleles of the socially polymorphic species are monophyletic. An expanded analysis of colonies containing alleles of this clade confirmed the invariant link between their presence and expression of polygyny. Finally, our discovery of several unique alleles bearing various combinations of b-like and B-like codons allows us to conclude that no single b-like residue is completely predictive of polygyne behavior and, thus, potentially causally involved in its expression. Rather, all three typical b-like residues appear to be necessary.

Diagnostic et traitement des infections d'implants orthopédiques [Update on implant related infections in orthopaedic surgery. Diagnosis and treatment]

Infections associated with implants are increasingly important in modem medicine. Biofilms are the cause that these infections are more difficult to diagnose and to cure. Particularly low-grade infections are difficult to distinguish from aseptic failure, because they often present with early loosening and persisting pain. For an accurate diagnosis, clinical signs and symptoms, laboratory markers of infection, microbiology, histology and imaging examinations are needed. The treatment goal is eradication of infection and an optimal functional result. Successful treatment requires adequate surgical procedure combined with long-term antimicrobial therapy, ideally with an agent acting on biofilms.

Menarche, menopause, and breast cancer risk: individual participant meta-analysis, including 118 964 women with breast cancer from 117 epidemiological studies.

BACKGROUND: Menarche and menopause mark the onset and cessation, respectively, of ovarian activity associated with reproduction, and affect breast cancer risk. Our aim was to assess the strengths of their effects and determine whether they depend on characteristics of the tumours or the affected women. METHODS: Individual data from 117 epidemiological studies, including 118 964 women with invasive breast cancer and 306 091 without the disease, none of whom had used menopausal hormone therapy, were included in the analyses. We calculated adjusted relative risks (RRs) associated with menarche and menopause for breast cancer overall, and by tumour histology and by oestrogen receptor expression. FINDINGS: Breast cancer risk increased by a factor of 1·050 (95% CI 1·044-1·057; p<0·0001) for every year younger at menarche, and independently by a smaller amount (1·029, 1·025-1·032; p<0·0001), for every year older at menopause. Premenopausal women had a greater risk of breast cancer than postmenopausal women of an identical age (RR at age 45-54 years 1·43, 1·33-1·52, p<0·001). All three of these associations were attenuated by increasing adiposity among postmenopausal women, but did not vary materially by women's year of birth, ethnic origin, childbearing history, smoking, alcohol consumption, or hormonal contraceptive use. All three associations were stronger for lobular than for ductal tumours (p<0·006 for each comparison). The effect of menopause in women of an identical age and trends by age at menopause were stronger for oestrogen receptor-positive disease than for oestrogen receptor-negative disease (p<0·01 for both comparisons). INTERPRETATION: The effects of menarche and menopause on breast cancer risk might not be acting merely by lengthening women's total number of reproductive years. Endogenous ovarian hormones are more relevant for oestrogen receptor-positive disease than for oestrogen receptor-negative disease and for lobular than for ductal tumours. FUNDING: Cancer Research UK.

Contact metamorphism and emplacement of the western Adamello tonalite

The geodynamic forces acting in the Earth's interior manifest themselves in a variety of ways. Volcanoes are amongst the most impressive examples in this respect, but like with an iceberg, they only represent the tip of a more extensive system hidden underground. This system consists of a source region where melt forms and accumulates, feeder connections in which magma is transported towards the surface, and different reservoirs where it is stored before it eventually erupts to form a volcano. A magma represents a mixture of melt and crystals. The latter can be extracted from the source region, or form anywhere along the path towards their final crystallization place. They will retain information of the overall plumbing system. The host rocks of an intrusion, in contrast, provide information at the emplacement level. They record the effects of thermal and mechanical forces imposed by the magma. For a better understanding of the system, both parts - magmatic and metamorphic petrology - have to be integrated. I will demonstrate in my thesis that information from both is complementary. It is an iterative process, using constraints from one field to better constrain the other. Reading the history of the host rocks is not always straightforward. This is shown in chapter two, where a model for the formation of clustered garnets observed in the contact aureole is proposed. Fragments of garnets, older than the intrusive rocks are overgrown by garnet crystallizing due to the reheating during emplacement of the adjacent pluton. The formation of the clusters is therefore not a single event as generally assumed but the result of a two-stage process, namely the alteration of the old grains and the overgrowth and amalgamation of new garnet rims. This makes an important difference when applying petrological methods such as thermobarometry, geochronology or grain size distributions. The thermal conditions in the aureole are a strong function of the emplacement style of the pluton. therefore it is necessary to understand the pluton before drawing conclusions about its aureole. A study investigating the intrusive rocks by means of field, geochemical, geochronologi- cal and structural methods is presented in chapter three. This provided important information about the assembly of the intrusion, but also new insights on the nature of large, homogeneous plutons and the structure of the plumbing system in general. The incremental nature of the emplacement of the Western Adamello tonalité is documented, and the existence of an intermediate reservoir beneath homogeneous plutons is proposed. In chapter four it is demonstrated that information extracted from the host rock provides further constraints on the emplacement process of the intrusion. The temperatures obtain by combining field observations with phase petrology modeling are used together with thermal models to constrain the magmatic activity in the immediate intrusion. Instead of using the thermal models to control the petrology result, the inverse is done. The model parameters were changed until a match with the aureole temperatures was obtained. It is shown, that only a few combinations give a positive match and that temperature estimates from the aureole can constrain the frequency of ancient magmatic systems. In the fifth chapter, the Anisotropy of Magnetic Susceptibility of intrusive rocks is compared to 3D tomography. The obtained signal is a function of the shape and distribution of ferromagnetic grains, and is often used to infer flow directions of magma. It turns out that the signal is dominated by the shape of the magnetic crystals, and where they form tight clusters, also by their distribution. This is in good agreement with the predictions made in the theoretical and experimental literature. In the sixth chapter arguments for partial melting of host rock carbonates are presented. While at first very surprising, this is to be expected when considering the prior results from the intrusive study and experiments from the literature. Partial melting is documented by compelling microstructures, geochemical and structural data. The necessary conditions are far from extreme and this process might be more frequent than previously thought. The carbonate melt is highly mobile and can move along grain boundaries, infiltrating other rocks and ultimately alter the existing mineral assemblage. Finally, a mineralogical curiosity is presented in chapter seven. The mineral assemblage magne§site and calcite is in apparent equilibrium. It is well known that these two carbonates are not stable together in the system Ca0-Mg0-Fe0-C02. Indeed, magnesite and calcite should react to dolomite during metamorphism. The presented explanation for this '"forbidden" assemblage is, that a calcite melt infiltrated the magnesite bearing rock along grain boundaries and caused the peculiar microstructure. This is supported by isotopie disequilibrium between calcite and magnesite. A further implication of partially molten carbonates is, that the host rock drastically looses its strength so that its physical properties may be comparable to the ones of the intrusive rocks. This contrasting behavior of the host rock may ease the emplacement of the intrusion. We see that the circle closes and the iterative process of better constraining the emplacement could start again. - La Terre est en perpétuel mouvement et les forces tectoniques associées à ces mouvements se manifestent sous différentes formes. Les volcans en sont l'un des exemples les plus impressionnants, mais comme les icebergs, les laves émises en surfaces ne représentent que la pointe d'un vaste système caché dans les profondeurs. Ce système est constitué d'une région source, région où la roche source fond et produit le magma ; ce magma peut s'accumuler dans cette région source ou être transporté à travers différents conduits dans des réservoirs où le magma est stocké. Ce magma peut cristalliser in situ et produire des roches plutoniques ou alors être émis en surface. Un magma représente un mélange entre un liquide et des cristaux. Ces cristaux peuvent être extraits de la source ou se former tout au long du chemin jusqu'à l'endroit final de cristallisation. L'étude de ces cristaux peut ainsi donner des informations sur l'ensemble du système magmatique. Au contraire, les roches encaissantes fournissent des informations sur le niveau d'emplacement de l'intrusion. En effet ces roches enregistrent les effets thermiques et mécaniques imposés par le magma. Pour une meilleure compréhension du système, les deux parties, magmatique et métamorphique, doivent être intégrées. Cette thèse a pour but de montrer que les informations issues de l'étude des roches magmatiques et des roches encaissantes sont complémentaires. C'est un processus itératif qui utilise les contraintes d'un domaine pour améliorer la compréhension de l'autre. Comprendre l'histoire des roches encaissantes n'est pas toujours aisé. Ceci est démontré dans le chapitre deux, où un modèle de formation des grenats observés sous forme d'agrégats dans l'auréole de contact est proposé. Des fragments de grenats plus vieux que les roches intru- sives montrent une zone de surcroissance générée par l'apport thermique produit par la mise en place du pluton adjacent. La formation des agrégats de grenats n'est donc pas le résultat d'un seul événement, comme on le décrit habituellement, mais d'un processus en deux phases, soit l'altération de vieux grains engendrant une fracturation de ces grenats, puis la formation de zone de surcroissance autour de ces différents fragments expliquant la texture en agrégats observée. Cette interprétation en deux phases est importante, car elle engendre des différences notables lorsque l'on applique des méthodes pétrologiques comme la thermobarométrie, la géochronologie ou encore lorsque l'on étudie la distribution relative de la taille des grains. Les conditions thermales dans l'auréole de contact dépendent fortement du mode d'emplacement de l'intrusion et c'est pourquoi il est nécessaire de d'abord comprendre le pluton avant de faire des conclusions sur son auréole de contact. Une étude de terrain des roches intrusives ainsi qu'une étude géochimique, géochronologique et structurale est présente dans le troisième chapitre. Cette étude apporte des informations importantes sur la formation de l'intrusion mais également de nouvelles connaissances sur la nature de grands plutons homogènes et la structure de système magmatique en général. L'emplacement incrémental est mis en évidence et l'existence d'un réservoir intermédiaire en-dessous des plutons homogènes est proposé. Le quatrième chapitre de cette thèse illustre comment utiliser l'information extraite des roches encaissantes pour expliquer la mise en place de l'intrusion. Les températures obtenues par la combinaison des observations de terrain et l'assemblage métamorphique sont utilisées avec des modèles thermiques pour contraindre l'activité magmatique au contact directe de cette auréole. Au lieu d'utiliser le modèle thermique pour vérifier le résultat pétrologique, une approche inverse a été choisie. Les paramètres du modèle ont été changés jusqu'à ce qu'on obtienne une correspondance avec les températures observées dans l'auréole de contact. Ceci montre qu'il y a peu de combinaison qui peuvent expliquer les températures et qu'on peut contraindre la fréquence de l'activité magmatique d'un ancien système magmatique de cette manière. Dans le cinquième chapitre, les processus contrôlant l'anisotropie de la susceptibilité magnétique des roches intrusives sont expliqués à l'aide d'images de la distribution des minéraux dans les roches obtenues par tomographie 3D. Le signal associé à l'anisotropie de la susceptibilité magnétique est une fonction de la forme et de la distribution des grains ferromagnétiques. Ce signal est fréquemment utilisé pour déterminer la direction de mouvement d'un magma. En accord avec d'autres études de la littérature, les résultats montrent que le signal est dominé par la forme des cristaux magnétiques, ainsi que par la distribution des agglomérats de ces minéraux dans la roche. Dans le sixième chapitre, une étude associée à la fusion partielle de carbonates dans les roches encaissantes est présentée. Si la présence de liquides carbonatés dans les auréoles de contact a été proposée sur la base d'expériences de laboratoire, notre étude démontre clairement leur existence dans la nature. La fusion partielle est documentée par des microstructures caractéristiques pour la présence de liquides ainsi que par des données géochimiques et structurales. Les conditions nécessaires sont loin d'être extrêmes et ce processus pourrait être plus fréquent qu'attendu. Les liquides carbonatés sont très mobiles et peuvent circuler le long des limites de grain avant d'infiltrer d'autres roches en produisant une modification de leurs assemblages minéralogiques. Finalement, une curiosité minéralogique est présentée dans le chapitre sept. L'assemblage de minéraux de magnésite et de calcite en équilibre apparent est observé. Il est bien connu que ces deux carbonates ne sont pas stables ensemble dans le système CaO-MgO-FeO-CO.,. En effet, la magnésite et la calcite devraient réagir et produire de la dolomite pendant le métamorphisme. L'explication présentée pour cet assemblage à priori « interdit » est que un liquide carbonaté provenant des roches adjacentes infiltre cette roche et est responsable pour cette microstructure. Une autre implication associée à la présence de carbonates fondus est que la roche encaissante montre une diminution drastique de sa résistance et que les propriétés physiques de cette roche deviennent comparables à celles de la roche intrusive. Cette modification des propriétés rhéologiques des roches encaissantes peut faciliter la mise en place des roches intrusives. Ces différentes études démontrent bien le processus itératif utilisé et l'intérêt d'étudier aussi bien les roches intrusives que les roches encaissantes pour la compréhension des mécanismes de mise en place des magmas au sein de la croûte terrestre.

Genome-wide patterns of latitudinal differentiation among populations of Drosophila melanogaster from North America.

Understanding the genetic underpinnings of adaptive change is a fundamental but largely unresolved problem in evolutionary biology. Drosophila melanogaster, an ancestrally tropical insect that has spread to temperate regions and become cosmopolitan, offers a powerful opportunity for identifying the molecular polymorphisms underlying clinal adaptation. Here, we use genome-wide next-generation sequencing of DNA pools ('pool-seq') from three populations collected along the North American east coast to examine patterns of latitudinal differentiation. Comparing the genomes of these populations is particularly interesting since they exhibit clinal variation in a number of important life history traits. We find extensive latitudinal differentiation, with many of the most strongly differentiated genes involved in major functional pathways such as the insulin/TOR, ecdysone, torso, EGFR, TGFβ/BMP, JAK/STAT, immunity and circadian rhythm pathways. We observe particularly strong differentiation on chromosome 3R, especially within the cosmopolitan inversion In(3R)Payne, which contains a large number of clinally varying genes. While much of the differentiation might be driven by clinal differences in the frequency of In(3R)P, we also identify genes that are likely independent of this inversion. Our results provide genome-wide evidence consistent with pervasive spatially variable selection acting on numerous loci and pathways along the well-known North American cline, with many candidates implicated in life history regulation and exhibiting parallel differentiation along the previously investigated Australian cline.

Prise en charge de l'ulcère de jambe d'origine veineuse [Management of venous leg ulcers].

Leg ulcers are a major health and economic problem especially in elderly. More than 70% are associated with venous disease. Compressive therapy is the most effective treatment but bandages are often poorly tolerated and well trained nurses are required to apply them effectively. In recent years, the VAC system (vacuum assisted closure) has profoundly changed the wound healing approach. The objective is now to regenerate the tissues and not to replace them with skin grafts which give uncertain results. The other important challenge is to prevent recurrences. New pharmacologic treatments acting on microcirculation and hemostasis would probably appear in the near future opening new therapeutic perspectives.

Dynamin-SNARE interactions control trans-SNARE formation in intracellular membrane fusion.

The fundamental processes of membrane fission and fusion determine size and copy numbers of intracellular organelles. Although SNARE proteins and tethering complexes mediate intracellular membrane fusion, fission requires the presence of dynamin or dynamin-related proteins. Here we study these reactions in native yeast vacuoles and find that the yeast dynamin homologue Vps1 is not only an essential part of the fission machinery, but also controls membrane fusion by generating an active Qa SNARE-tethering complex pool, which is essential for trans-SNARE formation. Our findings provide new insight into the role of dynamins in membrane fusion by directly acting on SNARE proteins.

Integrated care organizations in Switzerland.

INTRODUCTION: The Swiss health care system is characterized by its decentralized structure and high degree of local autonomy. Ambulatory care is provided by physicians working mainly independently in individual private practices. However, a growing part of primary care is provided by networks of physicians and health maintenance organizations (HMOs) acting on the principles of gatekeeping. TOWARDS INTEGRATED CARE IN SWITZERLAND: The share of insured choosing an alternative (managed care) type of basic health insurance and therefore restrict their choice of doctors in return for lower premiums increased continuously since 1990. To date, an average of one out of eight insured person in Switzerland, and one out of three in the regions in north-eastern Switzerland, opted for the provision of care by general practitioners in one of the 86 physician networks or HMOs. About 50% of all general practitioners and more than 400 other specialists have joined a physician networks. Seventy-three of the 86 networks (84%) have contracts with the healthcare insurance companies in which they agree to assume budgetary co-responsibility, i.e., to adhere to set cost targets for particular groups of patients. Within and outside the physician networks, at regional and/or cantonal levels, several initiatives targeting chronic diseases have been developed, such as clinical pathways for heart failure and breast cancer patients or chronic disease management programs for patients with diabetes. CONCLUSION AND IMPLICATIONS: Swiss physician networks and HMOs were all established solely by initiatives of physicians and health insurance companies on the sole basis of a healthcare legislation (Swiss Health Insurance Law, KVG) which allows for such initiatives and developments. The relevance of these developments towards more integration of healthcare as well as their implications for the future are discussed.

Identification and characterization of novel molecular mechanisms involved in initiation and progression of myelination

Schwann cells synthesize a large amount of membrane that form a specialized structure called myelin that surrounds axons and facilitate the transmission of electrical signal along neurons in peripheral nervous system (PNS). 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 Sox2, c-Jun, Notch and Pax3, all usually expressed in immature Schwann cells and suppressed at the onset of myelination. In order to identify new regulators of myelination involved in the development of the PNS, we analyzed the gene-expression profiling data from developing PNS and from three models of demyelinating neuropathies. This analysis led to the identification of Sox4, a member of the Sox family of transcription factors, as a potential candidate. To characterize the molecular function of Sox4 in PNS, we generated two transgenic lines of mice, which overexpress Sox4 specifically in Schwann cells. Detailed analysis of these mice showed that the overexpression of Sox4 in Schwann cells causes a delay in progression of myelination between post-natal day 2 (P2) and P5. Our in vitro analysis suggested that Sox4 cDNA can be overexpressed while the protein translation is tightly regulated. Interestingly, we observed that Sox4 protein is stabilized in nerves of the CMT4C mouse, a model of the human neuropathy. We therefore crossed Sox4 transgenic mice with CMT4C mice and we observed that Sox4 overexpression exacerbated the neuropathy phenotype in these mice. While recognized as being crucial for the normal function of both neurons and myelinating glial cells, the processes that regulate the beginning of myelination and the nature of the neuro-glial cross-talk remains mostly unknown. In order to gain insight into the molecular pathways involved in the interactions between neurons and associated glial cells, we developed a neuron-glia co-culture system based on microfluidic chambers and successfully induced myelination in this system by ascorbic acid. Importantly, we observed that in addition to acting on Schwann cells, ascorbic acid also modulate neuronal/axonal NRG1/ErbB2-B3 signalling. The experimental setting used in our study thus allowed us to discover a novel phenomena of propagation for myelination in vitro. The further characterization of this event brought us to identify other compounds able to induce myelination: ADAMs secretases inhibitor GM6001 and cyclic-AMP. The results generated during my thesis project are therefore not only important for the advancement of our understanding of how the PNS works, but may also potentially help to develop new therapies aiming at improvement of PNS myelination under disease conditions. - Les cellules de Schwann synthétisent une grande quantité de membrane formant une structure spécialisée appelée myéline qui entoure les axones et facilite la transmission du signal électrique le long des neurones du système nerveux périphérique (SNP). Des études antérieures ont démontré que la différenciation et la dédifférenciation des cellules de Schwann (dans la situation d'une lésion nerveuse ou d'une maladie démyélinisante) sont régulées par des régulateurs cellulaires intrinsèques, incluant plusieurs facteurs de transcription. En particulier, la dédifférenciation des cellules de Schwann matures est contrôlée par l'activation de plusieurs régulateurs négatifs de la myélinisation dont Sox2, c-Jun, Notch et Pax3, tous habituellement exprimés dans des cellules de Schwann immatures et supprimés au début de la myélinisation. Afin d'identifier de nouveaux régulateurs de myélinisation impliqués dans le développement du SNP, nous avons analysé le profil d'expression génique durant le développement du SNP ainsi que dans trois modèles de neuropathies démyélinisantes. Cette analyse a mené à l'identification de Sox4, un membre de la famille des facteurs de transcription Sox, comme étant un candidat potentiel. Dans le but de caractériser la fonction moléculaire de Sox4 dans le SNP, nous avons généré deux lignées transgéniques de souris qui surexpriment Sox4 spécifiquement dans les cellules de Schwann. L'analyse détaillée de ces souris a montré que la surexpression de Sox4 dans les cellules de Schwann provoque un retard dans la progression de la myélinisation entre le jour postnatal 2 (P2) et P5. Notre analyse in vitro a suggéré que l'ADNc de Sox4 peut être surexprimé alors que la traduction des protéines est quand à elle étroitement régulée. De façon intéressante, nous avons observé que la protéine Sox4 est stabilisée dans les nerfs des souris CMT4C, un modèle de neuropathie humaine. Nous avons donc croisé les souris transgéniques Sox4 avec des souris CMT4C et avons observé que la surexpression de Sox4 exacerbe le phénotype de neuropathie chez ces souris. Bien que reconnus comme étant cruciaux pour le fonctionnement normal des neurones et des cellules gliales myélinisantes, les processus qui régulent le début de la myélinisation ainsi que la nature des interactions neurone-glie restent largement méconnus. Afin de mieux comprendre les mécanismes moléculaires impliqués dans les interactions entre les neurones et les cellules gliales leur étant associés, nous avons développé un système de co-culture neurone-glie basé sur des chambres microfluidiques et y avons induit avec succès la myélinisation avec de l'acide ascorbique. Étonnamment, nous avons remarqué que, en plus d'agir sur les cellules de Schwann, l'acide ascorbique module également la voie de signalisation neuronale/axonale NRG1/ErbB2-B3. Le protocole expérimental utilisé dans notre étude a ainsi permis de découvrir un nouveau phénomène de propagation de la myélinisation in vitro. La caractérisation plus poussée de ce phénomène nous a menés à identifier d'autres composés capables d'induire la myélinisation: L'inhibiteur de sécrétases ADAMs GM6001 et l'AMP cyclique. Les résultats obtenus au cours de mon projet de thèse ne sont donc pas seulement importants pour l'avancement de notre compréhension sur la façon dont le SNP fonctionne, mais peuvent aussi potentiellement aider à développer de nouvelles thérapies visant à l'amélioration de la myélinisation du SNP dans des conditions pathologiques.

Faire la ville juste : une analyse "in itinere" de la maîtrise publique d'ouvrage du projet urbain Carré de Soie (métropole lyonnaise)

Dans certaines portions des agglomérations (poches de pauvreté de centre-ville, couronnes suburbaines dégradées, espaces périurbains sans aménité), un cumul entre des inégalités sociales (pauvreté, chômage, etc.) et environnementales (exposition au bruit, aux risques industriels, etc.) peut être observé. La persistance de ces inégalités croisées dans le temps indique une tendance de fond : la capacité d'accéder à un cadre de vie de qualité n'est pas équitablement partagée parmi les individus. Ce constat interroge : comment se créent ces inégalités ? Comment infléchir cette tendance et faire la ville plus juste ?¦Apporter des réponses à cette problématique nécessite d'identifier les facteurs de causalités qui entrent en jeu dans le système de (re)production des inégalités urbaines. Le fonctionnement des marchés foncier et immobilier, la « tyrannie des petites décisions » et les politiques publiques à incidence spatiale sont principalement impliqués. Ces dernières, agissant sur tous les éléments du système, sont placées au coeur de ce travail. On va ainsi s'intéresser précisément à la manière dont les collectivités publiques pilotent la production de la ville contemporaine, en portant l'attention sur la maîtrise publique d'ouvrage (MPO) des grands projets urbains.¦Poser la question de la justice dans la fabrique de la ville implique également de questionner les référentiels normatifs de l'action publique : à quelle conception de la justice celle-ci doit- elle obéir? Quatre perspectives (radicale, substantialiste, procédurale et intégrative) sont caractérisées, chacune se traduisant par des principes d'action différenciés. Une méthodologie hybride - empruntant à la sociologie des organisations et à l'analyse des politiques publiques - vient clore le volet théorique, proposant par un détour métaphorique d'appréhender le projet urbain comme une pièce de théâtre dont le déroulement dépend du jeu d'acteurs.¦Cette méthodologie est utilisée dans le volet empirique de la recherche, qui consiste en une analyse de la MPO d'un projet urbain en cours dans la première couronne de l'agglomération lyonnaise : le Carré de Soie. Trois grands objectifs sont poursuivis : descriptif (reconstruire le scénario), analytique (évaluer la nature de la pièce : conte de fée, tragédie ou match d'improvisation ?) et prescriptif (tirer la morale de l'histoire). La description de la MPO montre le déploiement successif de quatre stratégies de pilotage, dont les implications sur les temporalités, le contenu du projet (programmes, morphologies) et les financements publics vont être déterminantes. Sur la base de l'analyse, plusieurs recommandations peuvent être formulées - importance de l'anticipation et de l'articulation entre planification et stratégie foncière notamment - pour permettre à la sphère publique de dominer le jeu et d'assurer la production de justice par le projet urbain (réalisation puis entretien des équipements et espaces publics, financement de logements de qualité à destination d'un large éventail de populations, etc.). Plus généralement, un décalage problématique peut être souligné entre les territoires stratégiques pour le développement de l'agglomération et les capacités de portage limitées des communes concernées. Ce déficit plaide pour le renforcement des capacités d'investissement de la structure intercommunale.¦La seule logique du marché (foncier, immobilier) mène à la polarisation sociale et à la production d'inégalités urbaines. Faire la ville juste nécessite une forte volonté des collectivités publiques, laquelle doit se traduire aussi bien dans l'ambition affichée - une juste hiérarchisation des priorités dans le développement urbain - que dans son opérationnalisation - une juste maîtrise publique d'ouvrage des projets urbains.¦Inner-city neighborhoods, poor outskirts, and peri-urban spaces with no amenities usually suffer from social and environmental inequalities, such as poverty, unemployment, and exposure to noise and industrial hazards. The observed persistence of these inequalities over time points to an underlying trend - namely, that access to proper living conditions is fundamentally unequal, thus eliciting the question of how such inequalities are effected and how this trend can be reversed so as to build a more equitable city.¦Providing answers to such questions requires that the causal factors at play within the system of (re)production of urban inequalities be identified. Real estate markets, "micromotives and macrobehavior", and public policies that bear on space are mostly involved. The latter are central in that they act on all the elements of the system. This thesis therefore focuses on the way public authorities shape the production of contemporary cities, by studying the public project ownership of major urban projects.¦The study of justice within the urban fabric also implies that the normative frames of reference of public action be questioned: what conception of justice should public action refer to? This thesis examines four perspectives (radical, substantialist, procedural, and integrative) each of which results in different principles of action. This theoretical part is concluded by a hybrid methodology that draws from sociology of organizations and public policy analysis and that suggests that the urban project may be understood as a play, whose outcome hinges on the actors' acting.¦This methodology is applied to the empirical analysis of the public project ownership of an ongoing urban project in the Lyon first-ring suburbs: the Carré de Soie. Three main objectives are pursued: descriptive (reconstructing the scenario), analytical (assessing the nature of the play - fairy tale, tragedy or improvisation match), and prescriptive (drawing the moral of the story). The description of the public project ownership shows the successive deployment of four control strategies, whose implications on deadlines, project content (programs, morphologies), and public funding are significant. Building on the analysis, several recommendations can be made to allow the public sphere to control the process and ensure the urban project produces equity (most notably, anticipation and articulation of planning and real- estate strategy, as well as provision and maintenance of equipment and public spaces, funding of quality housing for a wide range of populations, etc.). More generally, a gap can be highlighted between those territories that are strategic to the development of the agglomeration and the limited resources of the municipalities involved. This deficit calls for strengthening the investment abilities of the intermunicipal structure.¦By itself, the real-estate market logic brings about social polarization and urban inequalities. Building an equitable city requires a strong will on the part of public authorities, a will that must be reflected both in the stated ambition - setting priorities of urban development equitably - and in its implementation managing urban public projects fairly.

Are relationship patterns with significant others reenacted with the therapist?: a study of early transference reactions.

This study examines how patients' relationship patterns are reenacted with the therapist during the first sessions of psychotherapy. Forty (N = 40) outpatients treated with a Brief Psychodynamic Intervention were included in the study. Their narratives of relationship episodes with significant others (e.g., mother, father, romantic partner, colleagues) were compared with relationship episodes with their therapist using the Core Conflictual Relationship Theme method. The Core Conflictual Relationship Theme focuses on 3 aspects of patients' relationship narratives: what the patient wants from others or from self; how others react to his/her wish; and how the patient consequently reacts. Results showed that 60% of patients display similar relationship patterns with their therapist and with significant others. The patterns that were reenacted with the therapist were not the most pervasive ones but were similar to those found in relationship episodes involving parents or romantic partners. These findings provide some support for the clinical concept of repetition of internalized relational patterns with the therapist very early in psychotherapy. Clinical implications are discussed.