931 resultados para Vermont and Canada Railroad Co.


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The subject of communication between palliative care physicians and their patients regarding their diagnosis and prognosis has not been extensively researched. The purpose of this survey was to compare the attitudes and beliefs of palliative care specialists regarding communication with the terminally ill in Europe, South America, and Canada. A sample of palliative care physicians from South America (Argentina and Brazil), French-speaking Europe, and Canada were identified, and posted a questionnaire. Physicians who stated that they practised palliative care at least 30% of their time were considered evaluable as palliative care specialists. Of a total of 272 questionnaires, 228 were returned (84%); and 182/228 (81%) respondents were considered to be palliative care specialists. Palliative care physicians in all three regions believed that cancer patients should be informed of their diagnosis and the terminal nature of their illness. Physicians reported that at least 60% of their patients knew their diagnosis and the terminal stage of their illness in 52% and 24% of cases in South America, and 69% and 38% of cases in Europe, respectively. All physicians agreed that 'do not resuscitate' orders should be present, and should be discussed with the patient in all cases. While 93% of Canadian physicians stated that at least 60% of their patients wanted to know about the terminal stage of their illness, only 18% of South American, and 26% of European physicians said this (P < 0.001). Similar results were found when the physicians were asked the percentage of families who want patients to know the terminal stage of their illness. However, almost all of the physicians agreed that if they had terminal cancer they would like to know. There was a significant association between patient based decision-making and female sex (P = 0.007), older age (P = 0.04), and physicians from Canada and South America (P < 0.001). Finally, in their daily decision making, South American physicians were significantly more likely to support beneficence and justice as compared with autonomy. Canadian physicians were more likely to support autonomy as compared with beneficence. In summary, our findings suggest that there are major regional differences in the attitudes and beliefs of physicians regarding communication at the end of life. More research is badly needed on the attitudes and beliefs of patients, families, and health care professionals in different regions of the world.

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Human nares are the main niche of Staphylococcus aureus, but farm animals can be also infected (cows) or colonized (pigs) constituting significant reservoir of this pathogen. Previous studies indicated that human and animal strains are quite distinct but the extent of cross-species specialization and transmission remains largely unknown. However, recent reports from several European countries as well as USA and Canada have indicated that employment in farming is an emerging risk factor for MRSA carriage. Pigs were found to be frequently colonized with MRSA, usually with a strain belonging to CC398. It is not known whether animal-human transmission was specific to this particular MRSA strain. S. aureus isolates from cow mastitis and pig colonization isolates were collected in parallel to nasal swab isolates from the animals' caretakers. The isolates were genotyped by AFLP, spatyping, and when appropriate by MLST. The isolates from cow mastitis were genetically uniform in comparison with human isolates. They were quite distinct from farmers\' carriage isolates, indicating pronounced hostspecialization. However, several cases where an infected cow and a colonized farmer had the same strain were detected, including one farm where two farmers were colonized and two cows were infected with MRSA belonging to CC398. Pig isolates were genetically more diverse than cow isolates. They were different from both human and cow isolates with one notable exception. Large fraction of pigs (20%) and pig caretakers (50%) were colonized with isolates belonging to CC398, majority of which were MSSA (2 cases of MRSA). These results indicate that host specialization in S. aureus is quite pronounced. Transmission between humans and farm animals was consequently quite rare. Both MSSA and MRSA strains belonging to otherwise pig-specific CC398 had increased capacity to colonize humans. Study of the genetic factors responsible for host specialization is underway.

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The interrelation among economic growth, income inequality, and fiscal performance is very complex. The paper provides the analysis of the interrelations among these variables jointly by the structural VAR methodology, examining also transmission channels among them. This approach allows exploring dynamic interactions among them and feedback effects on each other. The empirical analysis is implemented for the Anglo-Saxon countries, the UK, the USA, and Canada. We find that income inequality has negative effect on economic growth in the case of the UK. The effect is positive in the cases of the USA and Canada. The increase in income inequality worsens fiscal performance for all the countries

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This paper asks a simple question: if humans and their actions co-evolve with hydrological systems (Sivapalan et al., 2012), what is the role of hydrological scientists, who are also humans, within this system? To put it more directly, as traditionally there is a supposed separation of scientists and society, can we maintain this separation as socio-hydrologists studying a socio-hydrological world? This paper argues that we cannot, using four linked sections. The first section draws directly upon the concern of science-technology studies to make a case to the (socio-hydrological) community that we need to be sensitive to constructivist accounts of science in general and socio-hydrology in particular. I review three positions taken by such accounts and apply them to hydrological science, supported with specific examples: (a) the ways in which scientific activities frame socio-hydrological research, such that at least some of the knowledge that we obtain is constructed by precisely what we do; (b) the need to attend to how socio-hydrological knowledge is used in decision-making, as evidence suggests that hydrological knowledge does not flow simply from science into policy; and (c) the observation that those who do not normally label themselves as socio-hydrologists may actually have a profound knowledge of socio-hydrology. The second section provides an empirical basis for considering these three issues by detailing the history of the practice of roughness parameterisation, using parameters like Manning's n, in hydrological and hydraulic models for flood inundation mapping. This history sustains the third section that is a more general consideration of one type of socio-hydrological practice: predictive modelling. I show that as part of a socio-hydrological analysis, hydrological prediction needs to be thought through much more carefully: not only because hydrological prediction exists to help inform decisions that are made about water management; but also because those predictions contain assumptions, the predictions are only correct in so far as those assumptions hold, and for those assumptions to hold, the socio-hydrological system (i.e. the world) has to be shaped so as to include them. Here, I add to the ``normal'' view that ideally our models should represent the world around us, to argue that for our models (and hence our predictions) to be valid, we have to make the world look like our models. Decisions over how the world is modelled may transform the world as much as they represent the world. Thus, socio-hydrological modelling has to become a socially accountable process such that the world is transformed, through the implications of modelling, in a fair and just manner. This leads into the final section of the paper where I consider how socio-hydrological research may be made more socially accountable, in a way that is both sensitive to the constructivist critique (Sect. 1), but which retains the contribution that hydrologists might make to socio-hydrological studies. This includes (1) working with conflict and controversy in hydrological science, rather than trying to eliminate them; (2) using hydrological events to avoid becoming locked into our own frames of explanation and prediction; (3) being empirical and experimental but in a socio-hydrological sense; and (4) co-producing socio-hydrological predictions. I will show how this might be done through a project that specifically developed predictive models for making interventions in river catchments to increase high river flow attenuation. Therein, I found myself becoming detached from my normal disciplinary networks and attached to the co-production of a predictive hydrological model with communities normally excluded from the practice of hydrological science.

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Objective: This study investigated patterns of the simultaneous use of alcohol, tobacco and cannabis among young polydrug users, and whether use of one substance might be a cue for use of another and associations with the severity of substance dependence. Methods: The study focused on 3 subsamples from the ongoing Swiss Cohort Study on Substance Use Risk Factors (C-SURF, N=5,990). It used 12 months of data on alcohol/tobacco co-users, alcohol/cannabis co-users and tobacco/cannabis co-users (N=2,660, 1,755 and 1,460 respectively. Simultaneous use, numbers of symptoms of substance dependence, and hazardous use of alcohol, tobacco and cannabis were assessed. The effect of simultaneous polydrug use (SPU) on the numbers of symptoms of substance dependence was tested using analysis of variance. Results: Polydrug use was most common as SPU, and less common as non/occasional SPU. Moreover, when participants started to use one substance while using another, the severity of substance dependence was more strongly associated with the triggered substance than with cue. Conclusions: This study highlights the necessity to take SPU into account. First, SPU rather than separate drug use was the most common pattern for polydrug users. Second, frequent SPU was associated with increased numbers of symptoms of substance dependence compared to non/occasional SPU. Furthermore, SPU may reveal the severity of substance use dependence, when substance use is triggered by a cue substance. For these reasons, SPU should be a serious cause for concern for prevention and intervention purposes.

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Työn tarkoituksena oli tehdä yleiskuvaus wollastoniittimarkkinoista, ja siten auttaa yritystä sisäisesti määrittämään asemansa kyseisillä markkinoillaWollastoniitin suurimmat kuluttajasektorit ovat keraaminen-, muovi-, maali- ja pinnoite-, sekä metallurginen teollisuus. Eniten mineraalin kulutuksen odotetaan kasvavan muoviteollisuudessa. Suurimmat wollastoniitin tuottajamaat ovat Kiina, Intia, Yhdysvallat, Meksiko ja Suomi. Kiinassa aktiivisia kaivoksia on tällä hetkellä noin 60 kappaletta, ja koko maan tuotanto kattaa noin puolet mineraalin kokonaistuotannosta. Kiinan ulkopuolella toimii yhteensä viisi suurta tuottajaa.Suurimmat wollastoniitin tuottajat ovat intialainen Wolkem India Ltd., kiinalaiset Dalian Huanqui Minerals Corp. ja Jilin Shanwei Wollastonite Mining Co. Ltd, yhdysvaltalaiset Nyco Minerals Inc. ja R.T. Vanderbilt Co., meksikolainen Nyco Minera S.A. de C.V. ja suomalainen Nordkalk Oyj Abp. Uusia tuotantolaitoksia suunnitellaan rakennettavaksi Venäjälle, Kanadaan ja Kazakstaniin.

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Pysyäkseen kilpailukykyisenä vapautuneilla sähkömarkkinoilla on voimalaitoksen energiantuotantokustannusten oltava mahdollisimman matalia, tinkimättä kuitenkaan korkeasta käytettävyydestä. Polttoaineen energiasisällön mahdollisimman hyvä hyödyntäminen on ratkaisevan tärkeää voimalaitoksen kannattavuudelle. Polttoainekustannusten osuus on konvektiivisilla laitoksilla yleensä yli puolet koko elinjakson kustannuksista. Kun vielä päästörajat tiukkenevat koko ajan, korostuu polttoaineen korkea hyötykäyttö entisestään. Korkea energiantuotannon luotettavuus ja käytettävyys ovat myös elintärkeitä pyrittäessä kustannusten minimointiin. Tässä työssä on käyty läpi voimalaitoksen kustannuksiin vaikuttavia käsitteitä, kuten hyötysuhdetta, käytettävyyttä, polttoaineen hintoja, ylös- ja alasajoja ja tärkeimpiä häviöitä. Ajostrategiassa ja poikkeamien hallinnassa pyritään hyvään hyötysuhteeseen ja alhaisiin päästöihin joka käyttötilanteessa. Lisäksi on tarkasteltu tiettyjen suureiden, eli höyryn lämpötilan ja paineen, savukaasun hapen pitoisuuden, savukaasun loppulämpötilan, sekä lauhduttimen paineen poikkeamien vaikutusta ohjearvostaan energiantuotantokustannuksiin. Happi / hiilimonoksidi optimoinnissa on otettu huomioon myös pohjatuhkan palamattomat.

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Previous research has shown that different foods are stereotypically associated with gender and that eating in a role-congruent way fulfills an impression management function. On the other hand, other studies revealed that adapting one's food consumption to that of the co-eaters is a means to gain social approval as well. In the present study, we bridge these two distinct lines of research by studying what happens when the two norms (conforming to the gender-based stereotype and imitating the co-eater) conflict, that is with opposite-sex co-eaters. Results indicated that the tendency to match the co-eaters' supposed consumption generally appeared over and above one's gender-congruent choice. In addition, as expected, gender differences also emerged: while men were always willing to adapt to the co-eaters, women's intention to eat the feminine food was independent from the co-eaters' gender.

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BACKGROUND: Information about the impact of cancer treatments on patients' quality of life (QoL) is of paramount importance to patients and treating oncologists. Cancer trials that do not specify QoL as an outcome or fail to report collected QoL data, omit crucial information for decision making. To estimate the magnitude of these problems, we investigated how frequently QoL outcomes were specified in protocols of cancer trials and subsequently reported. DESIGN: Retrospective cohort study of RCT protocols approved by six research ethics committees in Switzerland, Germany, and Canada between 2000 and 2003. We compared protocols to corresponding publications, which were identified through literature searches and investigator surveys. RESULTS: Of the 173 cancer trials, 90 (52%) specified QoL outcomes in their protocol, 2 (1%) as primary and 88 (51%) as secondary outcome. Of the 173 trials, 35 (20%) reported QoL outcomes in a corresponding publication (4 modified from the protocol), 18 (10%) were published but failed to report QoL outcomes in the primary or a secondary publication, and 37 (21%) were not published at all. Of the 83 (48%) trials that did not specify QoL outcomes in their protocol, none subsequently reported QoL outcomes. Failure to report pre-specified QoL outcomes was not associated with industry sponsorship (versus non-industry), sample size, and multicentre (versus single centre) status but possibly with trial discontinuation. CONCLUSIONS: About half of cancer trials specified QoL outcomes in their protocols. However, only 20% reported any QoL data in associated publications. Highly relevant information for decision making is often unavailable to patients, oncologists, and health policymakers.

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Background: Information about the composition of regulatory regions is of great value for designing experiments to functionally characterize gene expression. The multiplicity of available applications to predict transcription factor binding sites in a particular locus contrasts with the substantial computational expertise that is demanded to manipulate them, which may constitute a potential barrier for the experimental community. Results: CBS (Conserved regulatory Binding Sites, http://compfly.bio.ub.es/CBS) is a public platform of evolutionarily conserved binding sites and enhancers predicted in multiple Drosophila genomes that is furnished with published chromatin signatures associated to transcriptionally active regions and other experimental sources of information. The rapid access to this novel body of knowledge through a user-friendly web interface enables non-expert users to identify the binding sequences available for any particular gene, transcription factor, or genome region. Conclusions: The CBS platform is a powerful resource that provides tools for data mining individual sequences and groups of co-expressed genes with epigenomics information to conduct regulatory screenings in Drosophila.

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The role of humans in facilitating the rapid spread of plants at a scale that is considered invasive is one manifestation of the Anthropocene, now framed as a geological period in which humans are the dominant force in landscape transformation. Invasive plant management faces intensified challenges, and can no longer be viewed in terms of 'eradication' or 'restoration of original landscapes'. In this perspectives piece, we focus on the practice and experience of people engaged in invasive plant management, using examples from Australia and Canada. We show how managers 1) face several pragmatic trade-offs; 2) must reconcile diverse views, even within stakeholder groups; 3) must balance competing temporal scales; 4) encounter tensions with policy; and 5) face critical and under-acknowledged labour challenges. These themes show the variety of considerations based on which invasive plant managers make complex decisions about when, where, and how to intervene. Their widespread pragmatic acceptance of small, situated gains (as well as losses) combines with impressive long-term commitments to the task of invasives management. We suggest that the actual practice of weed management challenges those academic perspectives that still aspire to attain pristine nature.

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OBJECTIVES: To investigate the frequency of interim analyses, stopping rules, and data safety and monitoring boards (DSMBs) in protocols of randomized controlled trials (RCTs); to examine these features across different reasons for trial discontinuation; and to identify discrepancies in reporting between protocols and publications. STUDY DESIGN AND SETTING: We used data from a cohort of RCT protocols approved between 2000 and 2003 by six research ethics committees in Switzerland, Germany, and Canada. RESULTS: Of 894 RCT protocols, 289 prespecified interim analyses (32.3%), 153 stopping rules (17.1%), and 257 DSMBs (28.7%). Overall, 249 of 894 RCTs (27.9%) were prematurely discontinued; mostly due to reasons such as poor recruitment, administrative reasons, or unexpected harm. Forty-six of 249 RCTs (18.4%) were discontinued due to early benefit or futility; of those, 37 (80.4%) were stopped outside a formal interim analysis or stopping rule. Of 515 published RCTs, there were discrepancies between protocols and publications for interim analyses (21.1%), stopping rules (14.4%), and DSMBs (19.6%). CONCLUSION: Two-thirds of RCT protocols did not consider interim analyses, stopping rules, or DSMBs. Most RCTs discontinued for early benefit or futility were stopped without a prespecified mechanism. When assessing trial manuscripts, journals should require access to the protocol.

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OBJECTIVES: Randomized clinical trials that enroll patients in critical or emergency care (acute care) setting are challenging because of narrow time windows for recruitment and the inability of many patients to provide informed consent. To assess the extent that recruitment challenges lead to randomized clinical trial discontinuation, we compared the discontinuation of acute care and nonacute care randomized clinical trials. DESIGN: Retrospective cohort of 894 randomized clinical trials approved by six institutional review boards in Switzerland, Germany, and Canada between 2000 and 2003. SETTING: Randomized clinical trials involving patients in an acute or nonacute care setting. SUBJECTS AND INTERVENTIONS: We recorded trial characteristics, self-reported trial discontinuation, and self-reported reasons for discontinuation from protocols, corresponding publications, institutional review board files, and a survey of investigators. MEASUREMENTS AND MAIN RESULTS: Of 894 randomized clinical trials, 64 (7%) were acute care randomized clinical trials (29 critical care and 35 emergency care). Compared with the 830 nonacute care randomized clinical trials, acute care randomized clinical trials were more frequently discontinued (28 of 64, 44% vs 221 of 830, 27%; p = 0.004). Slow recruitment was the most frequent reason for discontinuation, both in acute care (13 of 64, 20%) and in nonacute care randomized clinical trials (7 of 64, 11%). Logistic regression analyses suggested the acute care setting as an independent risk factor for randomized clinical trial discontinuation specifically as a result of slow recruitment (odds ratio, 4.00; 95% CI, 1.72-9.31) after adjusting for other established risk factors, including nonindustry sponsorship and small sample size. CONCLUSIONS: Acute care randomized clinical trials are more vulnerable to premature discontinuation than nonacute care randomized clinical trials and have an approximately four-fold higher risk of discontinuation due to slow recruitment. These results highlight the need for strategies to reliably prevent and resolve slow patient recruitment in randomized clinical trials conducted in the critical and emergency care setting.

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Network neutrality is a growing policy controversy. Traffic management techniques affect not only high-speed, high-money content, but by extension all other content too. Internet regulators and users may tolerate much more discrimination in the interests of innovation. For instance, in the absence of regulatory oversight, ISPs could use Deep Packet Inspection (DPI) to block some content altogether, if they decide it is not to the benefit of ISPs, copyright holders, parents or the government. ISP blocking is currently widespread in controlling spam email, and in some countries in blocking sexually graphic illegal images. In 1999 this led to scrutiny of foreclosure of Instant Messaging and video and cable-telephony horizontal merger. Fourteen years later, there were in 2013 net neutrality laws implemented in Slovenia, the Netherlands, Chile and Finland, regulation in the United States and Canada , co-regulation in Norway, and self-regulation in Japan, the United Kingdom and many other European countries . Both Germany and France in mid-2013 debated new net neutrality legislation, and the European Commission announced on 11 September 2013 that it would aim to introduce legislation in early 2014. This paper analyses these legal developments, and in particular the difficulty in assessing reasonable traffic management and ‘specialized’ (i.e. unregulated) faster services in both EU and US law. It also assesses net neutrality law against the international legal norms for user privacy and freedom of expression

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Le mélanome cutané est un des cancers les plus agressifs et dont l'incidence augmente le plus en Suisse. Une fois métastatique, le pronostic de survie moyenne avec les thérapies actuelles est d'environ huit mois, avec moins de 5% de survie à cinq ans. Les récents progrès effectués dans la compréhension de la biologie de la cellule tumorale mais surtout dans l'importance du système immunitaire dans le contrôle de ce cancer ont permis le développement de nouveaux traitements novateurs et prometteurs. Ces thérapies, appelées immunothérapies, reposent sur la stimulation et l'augmentation de la réponse immunitaire à la tumeur. Alors que les derniers essais cliniques ont démontré l'efficacité de ces traitements chez les patients avec des stades avancés de la maladie, le contrôle de la maladie à long- terme est seulement atteint chez une minorité des patients. La suppression locale et systémique de la réponse immunitaire spécifique anti-tumorale apparaitrait comme une des raisons expliquant la persistance d'un mauvais pronostic clinique chez ces patients. Des études sur les souris ont montré que les vaisseaux lymphatiques joueraient un rôle primordial dans ce processus en induisant une tolérance immune, ce qui permettrait à la tumeur d'échapper au contrôle du système immunitaire et métastatiser plus facilement. Ces excitantes découvertes n'ont pas encore été établi et prouvé chez l'homme. Dans cette thèse, nous montrons pour la première fois que les vaisseaux lymphatiques sont directement impliqués dans la modulation de la réponse immunitaire au niveau local et systémique dans le mélanome chez l'homme. Ces récentes découvertes montrent le potentiel de combiner des thérapies visant le système lymphatique avec les immunothérapies actuellement utilisées afin d'améliorer le pronostic des patients atteint du mélanome. -- Cutaneous melanoma is one of the most invasive and metastatic human cancers and causes 75% of skin cancer mortality. Current therapies such as surgery and chemotherapy fail to control metastatic disease, and relapse occurs frequently due to microscopic residual lesions. It is, thus, essential to develop and optimize novel therapeutic strategies to improve curative responses in these patients. In recent decades, tumor immunologists have revealed the development of spontaneous adaptive immune responses in melanoma patients, leading to the accumulation of highly differentiated tumor-specific T cells at the tumor site. This remains one of the most powerful prognostic markers to date. Immunotherapies that augment the natural function of these tumor-specific T cells have since emerged as highly attractive therapeutic approaches to eliminate melanoma cells. While recent clinical trials have demonstrated great progress in the treatment of advanced stage melanoma, long-term disease control is still only achieved in a minority of patients. Local and systemic immune suppression by the tumor appears to be responsible, in part, for this poor clinical evolution. These facts underscore the need for a better analysis and characterization of immune- related pathways within the tumor microenvironment (TME), as well as at the systemic level. The overall goal of this thesis is, thus, to obtain greater insight into the complexity and heterogeneity of the TME in human melanoma, as well as to investigate immune modulation beyond the TME, which ultimately influences the immune system throughout the whole body. To achieve this, we established two main objectives: to precisely characterize local and systemic immune modulation (i) in untreated melanoma patients and (ii) in patients undergoing peptide vaccination or checkpoint blockade therapy with anti-cytotoxic T- lymphocyte-asisctaed protein-4 (CTLA-4) antibody. In the first and main part of this thesis, we analyzed lymphatic vessels in relation to anti-tumor immune responses in tissues from vaccinated patients using a combination of immunohistochemistry (IHC) techniques, whole slide scanning/analysis, and an automatic quantification system. Strikingly, we found that increased lymphatic vessel density was associated with high expression of immune suppressive molecules, low functionality of tumor-infiltrating CD8+ T cells and decreased cytokine production by tumor-antigen specific CD8+ T cells in the blood. These data revealed a previously unappreciated local and systemic role of lymphangiogenesis in modulating T cell responses in human cancer and support the use of therapies that target lymphatic vessels combined with existing and future T cell based therapies. In the second objective, we describe a metastatic melanoma patient who developed pulmonary sarcoid-like granulomatosis following repetitive vaccination with peptides and CpG. We demonstrated that the onset of this pulmonary autoimmune adverse event was related to the development of a strong and long-lasting tumor-specific CD8+ T cell response. This constitutes the first demonstration that a new generation tumor vaccine can induce the development of autoimmune adverse events. In the third objective, we assessed the use of Fourier Transform Infrared (FTIR) imaging to identify melanoma cells and lymphocyte subpopulations in lymph node (LN) metastasis tissues, thanks to a fruitful collaboration with researchers in Brussels. We demonstrated that the different cell types in metastatic LNs have different infrared spectral features allowing automated identification of these cells. This technic is therefore capable of distinguishing known and novel biological features in human tissues and has, therefore, significant potential as a tool for histopathological diagnosis and biomarker assessment. Finally, in the fourth objective, we investigated the role of colony- stimulating factor-1 (CSF-1) in modulating the anti-tumor response in ipilimumab-treated patients using IHC and in vitro co-cultures, revealing that melanoma cells produce CSF-1 via CTL-derived cytokines when attacked by cytotoxic T lymphocytes (CTLs), resulting in the recruitment of immunosuppressive monocytes. These findings support the combined use of CSF-1R blockade with T cell based immunotherapy for melanoma patients. Taken together, our results reveal the existence of novel mechanisms of immune modulation and thus promote the optimization of combination immunotherapies against melanoma. -- Le mélanome cutané est un des cancers humains les plus invasifs et métastatiques et est responsable de 75% de la mortalité liée aux cancers de la peau. Les thérapies comme la chirurgie et la chimiothérapie ont échoué à contrôler le mélanome métastatique, par ailleurs les rechutes sous ces traitements ont été montrées fréquentes. Il est donc essentiel de développer et d'optimiser de nouvelles stratégies thérapeutiques pour améliorer les réponses thérapeutiques de ces patients. Durant les dernières décennies, les immunologistes spécialisés dans les tumeurs ont démontré qu'un patient atteint du mélanome pouvait développer spontanément une réponse immune adaptative à sa tumeur et que l'accumulation de cellules T spécifiques tumorales au sein même de la tumeur était un des plus puissants facteurs pronostiques. Les immunothérapies qui ont pour but d'augmenter les fonctions naturelles de ces cellules T spécifiques tumorales ont donc émergé comme des approches thérapeutiques très attractives pour éliminer les cellules du mélanome. Alors que les derniers essais cliniques ont démontré un progrès important dans le traitement des formes avancées du mélanome, le contrôle de la maladie à long-terme est seulement atteint chez une minorité des patients. La suppression immune locale et systémique apparaitrait comme une des raisons expliquant la persistance d'un mauvais pronostic clinique chez ces patients. Ces considérations soulignent la nécessité de mieux analyser et caractériser les voies immunitaires non seulement au niveau local dans le microenvironement tumoral mais aussi au niveau systémique dans le sang des patients. Le but de cette thèse est d'obtenir une plus grande connaissance de la complexité et de l'hétérogénéité du microenvironement tumoral dans les mélanomes mais aussi d'investiguer la modulation immunitaire au delà du microenvironement tumoral au niveau systémique. Afin d'atteindre ce but, nous avons établi deux objectifs principaux : caractériser précisément la modulation locale et systémique du système immunitaire (i) chez les patients atteints du mélanome qui n'ont pas reçu de traitement et (ii) chez les patients qui ont été traités soit par des vaccins soit par des thérapies qui bloquent les points de contrôles. Dans la première et majeure partie de cette thèse, nous avons analysé les vaisseaux lymphatiques en relation avec la réponse immunitaire anti-tumorale dans les tissus des patients vaccinés grâce à des techniques d'immunohistochimie et de quantification informatisé et automatique des marquages. Nous avons trouvé qu'une densité élevée de vaisseaux lymphatiques dans la tumeur était associée à une plus grande expression de molécules immunosuppressives ainsi qu'à une diminution de la fonctionnalité des cellules T spécifiques tumoral dans la tumeur et dans le sang des patients. Ces résultats révèlent un rôle jusqu'à là inconnu des vaisseaux lymphatiques dans la modulation directe du système immunitaire au niveau local et systémique dans les cancers de l'homme. Cette recherche apporte finalement des preuves du potentiel de combiner des thérapies visant le système lymphatique avec des autres immunothérapies déjà utilisées en clinique. Dans le second objectif, nous rapportons le cas d'un patient atteint d'un mélanome avec de multiples métastases qui a développé à la suite de plusieurs vaccinations répétées et consécutives avec des peptides et du CpG, un évènement indésirable sous la forme d'une granulomatose pulmonaire sarcoid-like. Nous avons démontré que l'apparition de cet évènement était intimement liée au développement d'une réponse immunitaire durable et spécifique contre les antigènes de la tumeur. Par là- même, nous prouvons pour la première fois que la nouvelle génération de vaccins est aussi capable d'induire des effets indésirables auto-immuns. Pour le troisième objectif, nous avons voulu savoir si l'utilisation de la spectroscopie infrarouge à transformée de Fourier (IRTF) était capable d'identifier les cellules du mélanome ainsi que les différents sous-types cellulaires dans les ganglions métastatiques. Grâce à nos collaborateurs de Bruxelles, nous avons pu établir que les diverses composantes cellulaires des ganglions atteints par des métastases du mélanome présentaient des spectres infrarouges différents et qu'elles pouvaient être identifiées d'une façon automatique. Cette nouvelle technique permettrait donc de distinguer des caractéristiques biologiques connues ou nouvelles dans les tissus humains qui auraient des retombées pratiques importantes dans le diagnostic histopathologique et dans l'évaluation des biomarqueurs. Finalement dans le dernier objectif, nous avons investigué le rôle du facteur de stimulation des colonies (CSF-1) dans la modulation de la réponse immunitaire anti-tumorale chez les patients qui ont été traités par l'Ipilimumab. Nos expériences in vivo au niveau des tissus tumoraux et nos co-cultures in vitro nous ont permis de démontrer que les cytokines secrétées par les cellules T spécifiques anti-tumorales induisaient la sécrétion de CSF-1 dans les cellules du mélanome ce qui résultait en un recrutement de monocytes immunosuppresseurs. Dans son ensemble, cette thèse révèle donc l'existence de nouveaux mécanismes de modulation de la réponse immunitaire anti-tumorale et propose de nouvelles optimisations de combinaison d'immunothérapies contre le mélanome.