854 resultados para Brown Band Disease, Maldives, prevalence, host range, coral diseases


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Transgenic labeling of innate immune cell lineages within the larval zebrafish allows for real-time, in vivo analyses of microbial pathogenesis within a vertebrate host. To date, labeling of zebrafish macrophages has been relatively limited, with the most specific expression coming from the mpeg1 promoter. However, mpeg1 transcription at both endogenous and transgenic loci becomes attenuated in the presence of intracellular pathogens, including Salmonella typhimurium and Mycobacterium marinum. Here, we describe mfap4 as a macrophage-specific promoter capable of producing transgenic lines in which transgene expression within larval macrophages remains stable throughout several days of infection. Additionally, we have developed a novel macrophage-specific Cre transgenic line under the control of mfap4, enabling macrophage-specific expression using existing floxed transgenic lines. These tools enrich the repertoire of transgenic lines and promoters available for studying zebrafish macrophage dynamics during infection and inflammation and add flexibility to the design of future macrophage-specific transgenic lines.

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In this review, we discuss recent work by the ENIGMA Consortium (http://enigma.ini.usc.edu) - a global alliance of over 500 scientists spread across 200 institutions in 35 countries collectively analyzing brain imaging, clinical, and genetic data. Initially formed to detect genetic influences on brain measures, ENIGMA has grown to over 30 working groups studying 12 major brain diseases by pooling and comparing brain data. In some of the largest neuroimaging studies to date - of schizophrenia and major depression - ENIGMA has found replicable disease effects on the brain that are consistent worldwide, as well as factors that modulate disease effects. In partnership with other consortia including ADNI, CHARGE, IMAGEN and others(1), ENIGMA's genomic screens - now numbering over 30,000 MRI scans - have revealed at least 8 genetic loci that affect brain volumes. Downstream of gene findings, ENIGMA has revealed how these individual variants - and genetic variants in general - may affect both the brain and risk for a range of diseases. The ENIGMA consortium is discovering factors that consistently affect brain structure and function that will serve as future predictors linking individual brain scans and genomic data. It is generating vast pools of normative data on brain measures - from tens of thousands of people - that may help detect deviations from normal development or aging in specific groups of subjects. We discuss challenges and opportunities in applying these predictors to individual subjects and new cohorts, as well as lessons we have learned in ENIGMA's efforts so far.

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The phnA gene that encodes the carbon-phosphorus bond cleavage enzyme phosphonoacetate hydrolase is widely distributed in the environment, suggesting that its phosphonate substrate may play a significant role in biogeochemical phosphorus cycling. Surprisingly, however, no biogenic origin for phosphonoacetate has yet been established. To facilitate the search for its natural source we have constructed a whole-cell phosphonoacetate biosensor. The gene encoding the LysR-type transcriptional activator PhnR, which controls expression of the phosphonoacetate degradative operon in Pseudomonas fluorescens 23F, was inserted in the broad-host-range promoter probe vector pPROBE-NT, together with the promoter region of the structural genes. Cells of Escherichia coli DH5a that contained the resultant construct, pPANT3, exhibited phosphonoacetate-dependent green fluorescent protein fluorescence in response to threshold concentrations of as little as 0.5 µM phosphonoacetate, some 100 times lower than the detection limit of currently available non-biological analytical methods; the pPANT3 biosensor construct in Pseudomonas putida KT2440 was less sensitive, although with shorter response times. From a range of other phosphonates and phosphonoacetate analogues tested, only phosphonoacetaldehyde and arsonoacetate induced green fluorescent protein fluorescence in the E. coli DH5a (pPANT3) biosensor, although at much-reduced sensitivities (50 µM phosphonoacetaldehyde and 500 µM arsonoacetate).

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Current clinical, laboratory or radiological parameters cannot accurately diagnose or predict disease outcomes in a range of autoimmune disorders. Biomarkers which can diagnose at an earlier time point, predict outcome or help guide therapeutic strategies in autoimmune diseases could improve clinical management of this broad group of debilitating disorders. Additionally, there is a growing need for a deeper understanding of multi-factorial autoimmune disorders. Proteomic platforms offering a multiplex approach are more likely to reflect the complexity of autoimmune disease processes. Findings from proteomic based studies of three distinct autoimmune diseases are presented and strategies compared. It is the authors' view that such approaches are likely to be fruitful in the movement of autoimmune disease treatment away from reactive decisions and towards a preventative stand point.

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Taxonomic studies of the past few years have shown that the Burkholderia cepacia complex, a heterogeneous group of B. cepacia-like organisms, consists of at least nine species. B. cepacia complex strains are ubiquitously distributed in nature and have been used for biocontrol, bioremediation, and plant growth promotion purposes. At the same time, B. cepacia complex strains have emerged as important opportunistic pathogens of humans, particularly those with cystic fibrosis. All B. cepacia complex species investigated thus far use quorum-sensing (QS) systems that rely on N-acylhomoserine lactone (AHL) signal molecules to express certain functions, including the production of extracellular proteases, swarming motility, biofilm formation, and pathogenicity, in a population-density-dependent manner. In this study we constructed a broad-host-range plasmid that allowed the heterologous expression of the Bacillus sp. strain 240B1 AiiA lactonase, which hydrolyzes the lactone ring of various AHL signal molecules, in all described B. cepacia complex species. We show that expression of AiiA abolished or greatly reduced the accumulation of AHL molecules in the culture supernatants of all tested B. cepacia complex strains. Phenotypic characterization of wild-type and transgenic strains revealed that protease production, swarming motility, biofilm formation, and Caenorhabditis elegans killing efficiency was regulated by AHL in the large majority of strains investigated.

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Health is a matter of fundamental importance in European societies, both as a human right in itself, and as a factor in a productive workforce and therefore a healthy economy. New health technologies promise improved quality of life for patients suffering from a range of diseases, and the potential for the prevention of incidence of disease in the future. At the same time, new health technologies pose significant challenges for governments, particularly in relation to ensuring the technologies are safe, effective, and provide appropriate value for (public) money.

To guard against the possible dangers arising from new health technologies, and to maximize the benefits, all European governments regulate their development, marketing, and public financing. In addition, several international institutions operating at European level, in particular the European Union, the Council of Europe, and the European Patent Office, have become involved in the regulation of new health technologies. They have done so both through traditional 'command and control' legal measures, and through other regulatory mechanisms, including guidelines, soft law, 'steering' through redistribution of resources, and private or quasi-private regulation.

This collection analyses European law and its relationships with new health technologies. It uses interdisciplinary insights, particularly from law but also drawing on regulation theory, and science and technology studies, to shed new light on some of the key defining features of the relationships and especially the roles of risk, rights, ethics, and markets. The collection explores the way in which European law's engagement with new health technologies is to be legitimized, and discusses the implications for biological or biomedical citizenship.

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Background: A previously described economic model was based on average values for patients diagnosed with chronic periodontitis (CP). However, tooth loss varies among treated patients and factors for tooth loss include CP severity and risk. The model was refined to incorporate CP severity and risk to determine the cost of treating a specific level of CP severity and risk that is associated with the benefit of tooth preservation.

Methods: A population that received and another that did not receive periodontal treatment were used to determine treatment costs and tooth loss. The number of teeth preserved was the difference of the number of teeth lost between the two populations. The cost of periodontal treatment was divided by the number of teeth preserved for combinations of CP severity and risk.

Results: The cost of periodontal treatment divided by the number of teeth preserved ranged from (US) $ 1,405 to $ 4,895 for high or moderate risk combined with any severity of CP and was more than $ 8,639 for low risk combined with mild CP. The cost of a three-unit bridge was $ 3,416, and the cost of a single-tooth replacement was $ 4,787.

Conclusion: Periodontal treatment could be justified on the sole basis of tooth preservation when CP risk is moderate or high regardless of disease severity.

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The bacterial plant pathogen Pseudomonas syringae causes disease in a wide range of plants. The associated decrease in crop yields results in economic losses and threatens global food security. Competition exists between the plant immune system and the pathogen, the basic principles of which can be applied to animal infection pathways. P. syringae uses a type III secretion system (T3SS) to deliver virulence factors into the plant that promote survival of the bacterium. The P. syringae T3SS is a product of the hypersensitive response and pathogenicity (hrp) and hypersensitive response and conserved (hrc) gene cluster, which is strictly controlled by the codependent enhancer-binding proteins HrpR and HrpS. Through a combination of bacterial gene regulation and phenotypic studies, plant infection assays, and plant hormone quantifications, we now report that Chp8 (i) is embedded in the Hrp regulon and expressed in response to plant signals and HrpRS, (ii) is a functional diguanylate cyclase, (iii) decreases the expression of the major pathogen-associated molecular pattern (PAMP) flagellin and increases extracellular polysaccharides (EPS), and (iv) impacts the salicylic acid/jasmonic acid hormonal immune response and disease progression. We propose that Chp8 expression dampens PAMP-triggered immunity during early plant infection.

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Tese de doutoramento, Medicina (Medicina Interna), Universidade de Lisboa, Faculdade de Medicina, 2014

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Tese de doutoramento, Ciências Biomédicas (Neurociências), Universidade de Lisboa, Faculdade de Medicina, 2014

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In this work we employed a hybrid method, combining RF-magnetron sputtering with evaporation, for the deposition of tailor made metallic precursors, with varying number of Zn/Sn/Cu (ZTC) periods and compared two approaches to sulphurization. Two series of samples with 1×, 2× and 4× ZTC periods have been prepared. One series of precursors was sulphurized in a tubular furnace directly exposed to a sulphur vapour and N2+5% H2 flux at a pressure of 5.0×10+4 Pa. A second series of identical precursors was sulphurized in the same furnace but inside a graphite box where sulphur pellets have been evaporated again in the presence of N2+5% H2 and at the same pressure as for the sulphur flux experiments. The morphological and chemical analyses revealed a small grain structure but good average composition for all three films sulphurized in the graphite box. As for the three films sulphurized in sulphur flux grain growth was seen with the increase of the number of ZTC periods whilst, in terms of composition, they were slightly Zn poor. The films' crystal structure showed that Cu2ZnSnS4 is the dominant phase. However, in the case of the sulphur flux films SnS2 was also detected. Photoluminescence spectroscopy studies showed an asymmetric broad band emission whichoccurs in the range of 1–1.5 eV. Clearly the radiative recombination efficiency is higher in the series of samples sulphurized in sulphur flux. We have found that sulphurization in sulphur flux leads to better film morphology than when the process is carried out in a graphite box in similar thermodynamic conditions. Solar cells have been prepared and characterized showing a correlation between improved film morphology and cell performance. The best cells achieved an efficiency of 2.4%.

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Dissertation presented to obtain the PhD degree in Biology/Molecular Biology by Universidade Nova de Lisboa, Instituto de Tecnologia Química e Biológica

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Brown sediment with multiple domains. Grains range from small to large in size, and angular to sub-rounded in shape. Large amounts of grain crushing can be seen in the coarser domains. The sample is mainly dominated with grain crushing. The finer grained domains contain some clay rich material. Some lineations and rotation structures can also be seen throughout the different domains.

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Le béryllium (Be) est un métal dont les propriétés physiques et mécaniques sont très recherchées, notamment dans les secteurs spatial, énergétique et électronique. Les principaux effets associés à l’exposition au Be sont la sensibilisation et la bérylliose chronique. La prévalence des effets associés au Be suggère que les risques sont, entre autres, fonction de sa spéciation. Par ailleurs, il semble que les particules fines constituent la fraction d’intérêt pour l’occurrence de tels effets. Dans cette étude nous avons vérifié l’hypothèse que la forme chimique et la taille des particules du Be jouent un rôle majeur au niveau de la toxicité et de l’apparition d’effets spécifiques à une exposition au Be. Les effets spécifiques se traduisent, entre autres, par la formation de granulomes inflammatoires pulmonaire, par la prolifération de lymphocytes TCD4+ et la production de cytokines de type Th1. Pour chacune des trois formes chimiques visées par la présente étude (le Be métallique ou Be, l’oxyde de Be ou BeO et l’alliage Be aluminium ou BeAl), la toxicité a été évaluée à la suite d’une exposition subchronique par inhalation oro-nasale à des particules fines (F) et totales (T). À cette fin, un modèle animal (souris) a été utilisé. Au total, 245 souris ont été utilisées. Elles ont été subdivisées en sept groupes de 35 souris. Un groupe a servi de contrôle, alors que chacun des six autres a été exposé soit à des particules fines soit à des particules totales, pour chacune des trois formes chimiques de Be (Be-F, Be-T, BeO-F, BeO-T, BeAl-F, BeAl-T). La durée d’exposition pour chacun des groupes s’est étendue sur 3 semaines, 5 jours par semaine, 6 heures par jour. Le niveau d’exposition des souris était de 250 µg/m3. L‘urine des souris a été recueillie avant et durant l’exposition. Au moment du sacrifice, plusieurs tissus (poumon, rate, foie et reins) ainsi que des échantillons de sang ont été prélevés puis immédiatement congelés jusqu’à leur analyse pour la détermination de leur teneur en Be. De plus, certains poumons et rates ont été analysés pour l’évaluation de la sensibilité immunologique et de l'inflammation pulmonaire. Cette étude d’exposition subchronique est la première étude murine qui étudie les effets toxiques de différentes tailles particulaires sur les changements pathologique et immunologique similaires à ceux observés chez l’humain. Cette étude a permis de constater qu’il existait des différences importantes au niveau de la toxicité du Be d’après les différentes tailles particulaires à l’étude. Ces différences seraient reliées au dépôt des particules de Be dans les voies respiratoires et également à la capacité des voies respiratoires à les éliminer totalement ou partiellement. La clairance respiratoire est fonction, notamment, du site de déposition et du caractère soluble ou non des particules. Cette recherche aura également permis de démontrer que les souris C3H/HeJ représentent un bon modèle pour l’étude des effets toxicologiques et immunologiques d’une exposition au Be. De plus, nos résultats démontrent que la sévérité des lésions pulmonaires causées par le Be, tel que l’infiltration interstitielle de lymphocytes et la formation de granulomes non-caséeux, augmente avec le temps de résidence pulmonaire des particules de Be. Combinés à d’autres résultats, nos résultats contribueront à guider les actions de prévention relativement à l’exposition au Be, incluant éventuellement la révision de la valeur limite de l’exposition et possiblement l’établissement de valeurs limites en fonction de la forme chimique et de la taille des particules.

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Mammalian reoviruses exhibit a large host range and infected cells are generally killed; however, most studies examined only a few cell types and host species, and are probably not representative of all possible interactions between virus and host cell. Many questions thus remain concerning the nature of cellular factors that affect viral replication and cell death. In the present work, it was observed that replication of the classical mammalian reovirus serotype 3 Dearing in a bat epithelial cell line, Tb1.Lu, does not result in cell lysis and is rapidly reduced to very low levels. Prior uncoating of virions by chymotrypsin treatment, to generate infectious subviral particles, increased the initial level of infection but without any significant effect on further viral replication or cell survival. Infected cells remain resistant to virus reinfection and secrete an antiviral factor, most likely interferon, that is protective against the unrelated encephalomyocarditis virus. Although, the transformed status of a cell is believed to promote reovirus replication and viral “oncolysis”, resistant Tb1.Lu cells exhibit a classical phenotype of transformed cells by forming colonies in semisolid soft agar medium. Further transduction of Tb.Lu cells with a constitutively-active Ras oncogene does not seem cell growth or reovirus effect on these cells. Infected Tb1.Lu cells can produce low-level of infectious virus for a long time without any apparent effect, although these cells are resistant to reinfection. The results suggest that Tb1.Lu cells can mount an unusual antiviral response. Specific properties of bat cells may thus be in part responsible for the ability of the animals to act as reservoirs for viruses in general and for novel reoviruses in particular. Their peculiar resistance to cell lysis also makes Tb1.Lu cells an attractive model to study the cellular and viral factors that determine the ability of reovirus to replicate and destroy infected cells.