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Penicilina em Portugal (anos 40-50 do século XX): receção, importação e primeiros tratamentos

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Book Series: Ciências e Culturas ISBN: 9789892612232 Year: Pages: 138 DOI: https://doi.org/10.14195/978-989-26-1224-9 Language: Portuguese
Publisher: Coimbra University Press
Subject: Medicine (General)
Added to DOAB on : 2019-04-23 16:21:06
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In September 1944, Portugal began to import a regular supply of penicillin from the US. The Portuguese Red Cross scrupulously controlled the supply distribution of the antibiotic. In 1945, as world production increased, penicillin began to be distributed through regular channels. The analysis of archive material concerning the reception and distribution of penicillin enabled the author to ascertain how they took place and present case study regarding the first treatments with the antibiotic in Portugal, in Coimbra University Hospitals.

CD1- and MR1-restricted T Cells in Antimicrobial Immunity

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197507 Year: Pages: 189 DOI: 10.3389/978-2-88919-750-7 Language: English
Publisher: Frontiers Media SA
Subject: Allergy and Immunology --- Medicine (General)
Added to DOAB on : 2016-04-07 11:22:02
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Cell-mediated immunity to extracellular and intracellular microbes has been traditionally linked to CD4+ and CD8+ T cells that recognize pathogen-derived peptides in the context of major histocompatibility complex (MHC) class II and class I molecules, respectively. Recent progress in our understanding of early host defense mechanisms has brought ‘unconventional’, innate-like T cells into the spotlight. These are a heterogeneous population of non-MHC-restricted T cells that exhibit ‘memory-like’ properties and mount emergency responses to infection. They may directly detect and destroy infected cells, but are best known for their ability to regulate downstream effector cells including but not limited to conventional T cells. Innate-like T cells include among others CD1-restricted natural killer T (NKT) cells and MR1-restricted mucosa-associated invariant T (MAIT) cells. NKT cells recognize lipid antigens, and MAIT cells were recently demonstrated to respond to microbe-derived vitamin B metabolites. However, much remains to be learned about the antigen specificity range of these cells, their activation mode and their true potentials in immunotherapeutic applications. Like in many other areas of biology, uncertainties and controversies surrounding these cells and some of the experimental models, techniques and reagents employed to study them have brought about excitement and sometimes hot debates. This Special Topic was launched to provide updated reviews on protective and/or pathogenic roles of NKT and MAIT cells during infection. Leading experts discuss current controversies, pressing questions and the challenges that lie ahead for the advancement of this intriguing and rapidly evolving area of immunology. Unlike MHC, CD1 and MR1 display very limited polymorphism. Therefore, NKT and MAIT cells may be considered attractive targets for various diseases in diverse human populations. The potential benefits of NKT cell- and MAIT cell-based vaccination and treatment strategies in infectious diseases is an important subject that is also covered in this Topic.

Recent advances in γδ T cell biology: New ligands, new functions, and new translational perspectives

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197842 Year: Pages: 269 DOI: 10.3389/978-2-88919-784-2 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Allergy and Immunology
Added to DOAB on : 2016-04-07 11:22:02
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Gamma/delta (γδ) T-cells are a small subset of T-lymphocytes in the peripheral circulation but constitute a major T-cell population at other anatomical localizations such as the epithelial tissues. In contrast to conventional a/ß T-cells, the available number of germline genes coding for T-cell receptor (TCR) variable elements of γδ T-cells is very small. Moreover, there is a prefential localization of γδ T-cells expressing given Vgamma and Vdelta genes in certain tissues. In humans, γδ T-cells expressing the Vg9Vd2-encoded TCR account for anywhere between 50 and >95% of peripheral blood γδ T-cells, whereas cells expressing non-Vd2 genes dominate in mucosal tissues. In mice, there is an ordered appearance of γδ T-cell „waves“ during embryonic development, resulting in preferential localization of γδ T-cells expressing distinct VgammaVdelta genes in the skin, the reproductive organs, or gut epithelia. The major function of γδ T-cells resides in local immunosurveillance and immune defense against infection and malignancy. This is supported by the identification of ligands that are selectively recognized by the γδ TCR. As an example, human Vgamma9Vdelta2 T-cells recognize phosphorylated metabolites („phosphoantigens“) that are secreted by many pathogens but can also be overproduced by tumor cells, providing a basis for a role of these γδ T-cells in both anti-infective and anti-tumor immunity. Similarly, the recognition of endothelial protein C receptor by human non-Vdelta2 γδ T-cells has recently been identified to provide a link for the role for such γδ T-cells in immunity against epithelial tumor cells and cytomegalovirus-infected endothelial cells. In addition to „classical“ functions such as cytokine production and cytotoxicity, recent studies suggest that subsets of γδ T-cells can exert additional functions such as regulatory activity and – quite surpisingly – „professional“ antigen-presenting capacity. It is currently not well known how this tremendous extent of functional plasticity is regulated and what is the extent of γδ TCR ligand diversity. Due to their non-MHC-restricted recognition of unusual stress-associated ligands, γδ T-cells have raised great interest as to their potential translational application in cell-based immunotherapy. Topics of this Research Focus include: Molecular insights into the activation and differentiation requirements of γδ T-cells, role of pyrophosphates and butyrophilin molecules for the activation of human γδ T-cells, role of γδ T-cells in tumor immunity and in other infectious and non-infectious diseases, and many others. We are most grateful to all colleagues who agreed to write a manuscript. Thanks to their contributions, this E-book presents an up-to-date overview on many facets of the still exciting γδ T-cells.

How Salmonella infection can inform on mechanisms of immune function and homeostasis

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197996 Year: Pages: 143 DOI: 10.3389/978-2-88919-799-6 Language: English
Publisher: Frontiers Media SA
Subject: Allergy and Immunology --- Medicine (General)
Added to DOAB on : 2017-02-03 17:04:57
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The use of model antigens such as haptens and ovalbumin has provided enormous insights into how immune responses develop, particularly to vaccine antigens. Furthermore, these studies are overwhelmingly performed in animals housed in clean facilities and are not known to have experienced overt clinical signs caused by infectious agents. Therefore, this is unlikely to reflect the impact more complex host-pathogen interactions can have on the host, nor the diversity in how immunity is regulated. Humans develop immune responses in the context of the periodic exposure to multiple pathogens and vaccines over a life-time. These are likely to have a long-lasting effect on who and what we are and how we respond to further antigen challenge. Therefore, studies on how infection influences immune homeostasis and how the development of responses to a pathogen reflects what is known on immune regulation will be informative on how we can translate findings from our standard models into treatments usable in humans. One organism allows us to do just this. Bacteria of the genus Salmonella are devastating human pathogens. Nevertheless, many aspects of the diseases they cause can be successfully modelled in murine systems so that the infection is either resolving or non-resolving. This has the advantage of allowing the long-term impact of infection on immune function to be assessed. We propose to welcome key workers to write about their research that examine the consequence of Salmonella infection on the host and the elements of the bacterium that contribute to this.

Insights into Microbe-Microbe Interactions in Human Microbial Ecosystems: Strategies to be Competitive

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889450527 Year: Pages: 116 DOI: 10.3389/978-2-88945-052-7 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2017-07-06 13:27:36
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All parts of our body having communication with the external environment such as the skin, vagina, the respiratory tract or the gastrointestinal tract are colonized by a specific microbial community. The colon is by far the most densely populated organ in the human body. The pool of microbes inhabiting our body is known as “microbiota” and their collective genomes as “microbiome”. These microbial ecosystems regulate important functions of the host, and their functionality and the balance among the diverse microbial populations is essential for the maintenance of a “healthy status”. The impressive development in recent years of next generation sequencing (NGS) methods have made possible to determine the gut microbiome composition. This, together with the application of other high throughput omic techniques and the use of gnotobiotic animals has greatly improved our knowledge of the microbiota acting as a whole. In spite of this, most members of the human microbiota are largely unknown and remain still uncultured. The final functionality of the microbiota is depending not only on nutrient availability and environmental conditions, but also on the interrelationships that the microorganisms inhabiting the same ecological niche are able to establish with their partners, or with their potential competitors. Therefore, in such a competitive environment microorganisms have had to develop strategies allowing them to cope, adapt, or cooperate with their neighbors, which may imply notable changes at metabolic, physiological and genetic level. The main aim of this Research Topic was to contribute to better understanding complex interactions among microorganisms residing in human microbial habitats.All parts of our body having communication with the external environment such as the skin, vagina, the respiratory tract or the gastrointestinal tract are colonized by a specific microbial community. The colon is by far the most densely populated organ in the human body. The pool of microbes inhabiting our body is known as “microbiota” and their collective genomes as “microbiome”. These microbial ecosystems regulate important functions of the host, and their functionality and the balance among the diverse microbial populations is essential for the maintenance of a “healthy status”. The impressive development in recent years of next generation sequencing (NGS) methods have made possible to determine the gut microbiome composition. This, together with the application of other high throughput omic techniques and the use of gnotobiotic animals has greatly improved our knowledge of the microbiota acting as a whole. In spite of this, most members of the human microbiota are largely unknown and remain still uncultured. The final functionality of the microbiota is depending not only on nutrient availability and environmental conditions, but also on the interrelationships that the microorganisms inhabiting the same ecological niche are able to establish with their partners, or with their potential competitors. Therefore, in such a competitive environment microorganisms have had to develop strategies allowing them to cope, adapt, or cooperate with their neighbors, which may imply notable changes at metabolic, physiological and genetic level. The main aim of this Research Topic was to contribute to better understanding complex interactions among microorganisms residing in human microbial habitats.

Infection and Inflammation: Potential Triggers of Sudden Infant Deaths

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889450497 Year: Pages: 94 DOI: 10.3389/978-2-88945-049-7 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Allergy and Immunology
Added to DOAB on : 2018-02-27 16:16:44
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There is a growing body of evidence that infectious agents or their products contribute to events leading to unexpected infant deaths. This issue summarizes the current information on the interactions between genetic background of the infant, environmental and developmental risk factors, and the microbial flora of the infant that could trigger lethal responses to common infections.

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