56 resultados para emerging pollutants


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Despite using modern microbiological diagnostic approaches, the aetiological agents of pneumonia remain unidentified in about 50% of cases. Some bacteria that grow poorly or not at all in axenic media used in routine clinical bacteriology laboratory but which can develop inside amoebae may be the agents of these lower respiratory tract infections (RTIs) of unexplained aetiology. Such amoebae-resisting bacteria, which coevolved with amoebae to resist their microbicidal machinery, may have developed virulence traits that help them survive within human macrophages, i.e. the first line of innate immune defence in the lung. We review here the current evidence for the emerging pathogenic role of various amoebae-resisting microorganisms as agents of RTIs in humans. Specifically, we discuss the emerging pathogenic roles of Legionella-like amoebal pathogens, novel Chlamydiae (Parachlamydia acanthamoebae, Simkania negevensis), waterborne mycobacteria and Bradyrhizobiaceae (Bosea and Afipia spp.).

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Cancer-related inflammation has emerged in recent years as a major event contributing to tumor angiogenesis, tumor progression and metastasis formation. Bone marrow-derived and inflammatory cells promote tumor angiogenesis by providing endothelial progenitor cells that differentiate into mature endothelial cells, and by secreting pro-angiogenic factors and remodeling the extracellular matrix to stimulate angiogenesis though paracrine mechanisms. Several bone marrow-derived myelonomocytic cells, including monocytes and macrophages, have been identified and characterized by several laboratories in recent years. While the central role of these cells in promoting tumor angiogenesis, tumor progression and metastasis is nowadays well established, many questions remain open and new ones are emerging. These include the relationship between their phenotype and function, the mechanisms of pro-angiogenic programming, their contribution to resistance to anti-angiogenic treatments and to metastasis and their potential clinical use as biomarkers of angiogenesis and anti-angiogenic therapies. Here, we will review phenotypical and functional aspects of bone marrow-derived myelonomocytic cells and discuss some of the current outstanding questions.

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Emerging adulthood is a period of life transition, in which youths are no longer adolescents but have not yet reached full adulthood. Measuring emerging adulthood is crucial because of its association with psychopathology and risky behaviors such as substance use. Unfortunately, the only validated scale for such measurement has a long format (Inventory of Dimensions of Emerging Adulthood [IDEA]-31 items). This study aimed to test whether a shorter form yields satisfactory results without substantial loss of information among a sample of young Swiss men. Data from the longitudinal Cohort Study on Substance Use Risk Factors were used (N = 5,049). IDEA, adulthood markers (e.g., parenthood or financial independence), and risk factors (i.e., substance use and mental health issues) were assessed. The results showed that an 8-item, short-form scale (IDEA-8) with four factors (experimentation, negativity, identity exploration, and feeling in between) returned satisfactory results, including good psychometric properties, high convergence with the initial scale, and strong empirical validity. This study was a step toward downsizing a measure of emerging adulthood. Indeed, this 8-item short form is a good alternative to the 31-item long form and could be more convenient for surveys with constraints on questionnaire length. Moreover, it should help health care practitioners in identifying at-risk populations to prevent and treat risky behaviors.

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During evolution, the immune system has diversified to protect the host from the extremely wide array of possible pathogens. Until recently, immune responses were dissected by use of global approaches and bulk tools, averaging responses across samples and potentially missing particular contributions of individual cells. This is a strongly limiting factor, considering that initial immune responses are likely to be triggered by a restricted number of cells at the vanguard of host defenses. The development of novel, single-cell technologies is a major innovation offering great promise for basic and translational immunology with the potential to overcome some of the limitations of traditional research tools, such as polychromatic flow cytometry or microscopy-based methods. At the transcriptional level, much progress has been made in the fields of microfluidics and single-cell RNA sequencing. At the protein level, mass cytometry already allows the analysis of twice as many parameters as flow cytometry. In this review, we explore the basis and outcome of immune-cell diversity, how genetically identical cells become functionally different, and the consequences for the exploration of host-immune defense responses. We will highlight the advantages, trade-offs, and potential pitfalls of emerging, single-cell-based technologies and how they provide unprecedented detail of immune responses.

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Given the climatic changes around the world and the growing outdoor sports participation, existing guidelines and recommendations for exercising in naturally challenging environments such as heat, cold or altitude, exhibit potential shortcomings. Continuous efforts from sport sciences and exercise physiology communities aim at minimizing the risks of environmental-related illnesses during outdoor sports practices. Despite this, the use of simple weather indices does not permit an accurate estimation of the likelihood of facing thermal illnesses. This provides a critical foundation to modify available human comfort modeling and to integrate bio-meteorological data in order to improve the current guidelines. Although it requires further refinement, there is no doubt that standardizing the recently developed Universal Thermal Climate Index approach and its application in the field of sport sciences and exercise physiology may help to improve the appropriateness of the current guidelines for outdoor, recreational and competitive sports participation. This review first summarizes the main environmental-related risk factors that are susceptible to increase with recent climate changes when exercising outside and offers recommendations to combat them appropriately. Secondly, we briefly address the recent development of thermal stress models to assess the thermal comfort and physiological responses when practicing outdoor activities in challenging environments.

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The aims were twofold: to examine the gambling habits of emerging adult males in the French-speaking regions of Switzerland and to what extent these habits predict problem gambling within this population. We also evaluated problem gambling rates and provided data concerning variables such as gambling location, level of information about problem gambling and awareness of treatment centers. 606 Swiss male conscripts, aged 18-22 years, completed a self-report questionnaire. This was administered during their army recruitment day in 2012. Problem gambling was assessed through the Problem Gambling Severity Index (PGSI) (Ferris and Wynne 2001). 78.5% of the respondents were lifetime gamblers, 56.1% were past-year gamblers. Four out of ten past-year gamblers played in private spaces and in back rooms. The PGSI indicated that 10.8% of past-year gamblers presented with moderate gambling problems, whilst 1.4% appeared to be problem gamblers. The majority of respondents had never received information about problem gambling. Moreover, they were unaware of the existence of treatment centers for problem gambling in their region. PGSI scores were significantly predicted by the variety of games played. Problem gambling rates among young men appear to be higher than those of the general Swiss population. This confirms that emerging adult males are a particularly vulnerable population with regards to gambling addiction. The implications of this are considered for youth gambling-prevention programs.

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In this case-control study, we investigated the seroprevalence and molecular evidence of Chlamydia trachomatis and Waddlia chondrophila in ectopic pregnancies (EP) and uneventful control pregnancies in 343 women from Vietnam. Whereas presence of C. trachomatis IgG was strongly associated with EP [adjusted odds ratio (aOR) 5·41, 95% confidence interval (CI) 2·58-11·32], its DNA remained undetected in all tubal lesions. We confirmed an independent association between antibodies against Waddlia and previous miscarriage (aOR 1·87, 95% CI 1·02-3·42). Further investigations are needed to understand the clinical significance of Waddlia's high seroprevalence (25·9% in control pregnancies) in this urban population.

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Une des meilleures techniques pour décontaminer l'environnement d'éléments toxiques (comme par exemple le dibenzofuan, DBF et le 4-chlorophenol, 4CP) déposés par l'homme, à bas coûts et sans le perturber considérablement, est sans doute la biorémédiation, et particulièrement la bioaugmentation. Malheureusement, si plusieurs microorganismes ont démontré leur efficacité à dégrader les composés toxiques en conditions de laboratoire, plusieurs tentatives afin de les utiliser dans l'environnement n'ont pas abouti. Ces échecs sont probablement le résultat des pauvres connaissances des réactions de ces mêmes microorganismes dans l'environnement. L'objectif de mon travail a été de mieux comprendre les réponses de ces bactéries au niveau de leurs gènes lorsqu'elles sont introduites ou prospèrent dans des conditions plus proches de la réalité, mais encore suffisamment contrôlées pour pouvoir élucider leur comportement. Le fait de résister à des conditions de sécheresse a été considéré en tant que facteur clé dans la survie des bactéries amenées à être utilisées pour la biorémédiation; cela implique une série de mécanismes utilisés par la cellule pour faire face au stress hydrique. Le chapitre II, par une approche métagénomique, compare les réactions de trois souches prometteuses pour la biorémédiation (Arthrobacter chlorophenolicus A6, Sphingomonas wittichii RW1 and Pseudomonas veronii 1YdBTEX2) vis-à-vis du stress hydrique simulé en conditions de laboratoire. L'objectif ici est de découvrir et de décrire les stratégies de résistance au stress, communes ou spécifiques, employées par les bactéries. Mes résultats montrent que les trois souches ont des sensibilités différentes au stress hydrique. Entre les traits communs trouvés, il y a une diminution de l'expression des gènes flagellaires ainsi qu'une augmentation de l'expression de solutes compatibles, mais qui sont souche-spécifiques. J'ai étudié plus en détail la réponse génomique de RW1 par rapport aux inoculations ainsi que sa croissance dans le sable contaminé et non-stérile (chapitre III), et je les ai comparé à des cultures en milieu liquide. Mes résultats indiquent que RW1 peut résister efficacement et peut croître dans des conditions presque sèches et peut également dégrader le contaminant (DBF, dans le cas présent) si les pré-cultures sont réalisées dans le même type de contaminant. Par contre, notre hypothèse du chapitre II se révèle fausse car le comportement de RW1 est très diffèrent de celui observé dans des conditions avec stress hydrique induit par l'addition de sel ou de PEG. Plus intéressant, les réponses de RW1 en milieu liquide sont très différentes de celles observées dans le sable, révélant ainsi que cette souche peut reconnaître le milieu dans lequel elle se trouve. Les mêmes expériences en sable contaminé, cette fois-ci avec 4CP, ont été réalisées pour A6 (chapitre IV) dans l'espoir de compléter la comparaison entre le stress hydrique et l'adaptation dans le sol. Malheureusement, il n'a pas été possible d'obtenir d'échantillons de bonne qualité pour les hybridations des microarrays afin d'étudier la réponse transcriptionnelle dans les différentes phases de croissance dans le sable (contaminé ou non). Toutefois, j'ai appris qu'Arthrobacter ne peut pas croitre dans les sols hautement contaminés si les conditions du sol sont très sèches, elles ont en effet besoin de suffisamment d'eau pour dégrader des quantités importantes de 4CP. Ces observations dirigent l'attention sur le fait que les études sur l'efficacité de l'inoculation de bactéries doivent être testées dans des conditions le plus proche possible de l'environnement ciblé, tout comme les concentrations optimales pour l'inoculum. Finalement, nous avons étudié le comportement de A6 dans la phytosphère avec deux dégrés d'humidité (chapitre V). A6 ne montre pas de réaction particulière face aux changements d'humidité, et à nouveau, ces réponses ne peuvent être liées aux changements d'expression des gènes observées dans les conditions de stress hydrique simulées. Cette étude a permis d'identifier la présence de composés phénoliques dans les feuilles qui peuvent potentiellement améliorer les propriétés de dégradation ou qui permettent d'effectuer de façon plus rapide la réaction de dégradation des contaminants dans un processus de phytoremédiation par A. chlorophenolicus.

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Waddlia chondrophila is an emerging pathogen associated with abortion in cattle. In humans, a growing body of evidence supports its pathogenic role in miscarriage and in respiratory tract infection. The human pathogenicity of W. chondrophila is further supported by the presence of several virulence factors including a catalase, a functional T3SS and several adhesins. Despite this medical importance, no commercial tests are available and diagnostic of this strict intracellular bacterium mainly relies on serology, PCR and immunohistochemistry. So far, the epidemiology of W. chondrophila remains largely unexplored and zoonotic, waterborne or interhuman transmission has been considered. Apart from its pathogenic role, chlamydiologists are also interested in W. chondrophila in order to better understand biological mechanisms conserved and shared with Chlamydia spp. Indeed, W. chondrophila proved to be a useful model organism to study the pathobiology of chlamydiae thanks to its rapid replication, its large size allowing precise subcellular protein localization, as well as its growth in Dictyostelium amoebae.

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Among the negative consequences of video gaming disorder, decreased participation in sport and exercise has received little attention. This study aimed to assess the longitudinal association between video gaming disorder and the level of sport and exercise in emerging adult men. A questionnaire was completed at baseline and 15-month follow-up by a representative national sample of 4,933 respondents. The seven items of the Game Addiction Scale were used to construct a latent variable representing video gaming disorder. Level of sport and exercise was also self-reported. Cross-lagged path modeling indicated a reciprocal causality between video gaming disorder and the level of sport and exercise, even after adjusting for a large set of confounders. These findings support the need for better promotion of sport and exercise among emerging adults in order to contribute to the prevention of video gaming disorder, and to raise the level of sport and exercise activity in addicted gamers.

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Since the 1950s, medical communities have been facing with emerging and reemerging infectious diseases, and emerging pathogens are now considered to be a major microbiologic public health threat. In this review, we focus on bacterial emerging diseases and explore factors involved in their emergence as well as future challenges. We identified 26 major emerging and reemerging infectious diseases of bacterial origin; most of them originated either from an animal and are considered to be zoonoses or from water sources. Major contributing factors in the emergence of these bacterial infections are: (1) development of new diagnostic tools, such as improvements in culture methods, development of molecular techniques and implementation of mass spectrometry in microbiology; (2) increase in human exposure to bacterial pathogens as a result of sociodemographic and environmental changes; and (3) emergence of more virulent bacterial strains and opportunistic infections, especially affecting immunocompromised populations. A precise definition of their implications in human disease is challenging and requires the comprehensive integration of microbiological, clinical and epidemiologic aspects as well as the use of experimental models. It is now urgent to allocate financial resources to gather international data to provide a better understanding of the clinical relevance of these waterborne and zoonotic emerging diseases.