951 research outputs found

    Trends in the Discovery of New Marine Natural Products from Invertebrates over the Last Two Decades – Where and What Are We Bioprospecting?

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    It is acknowledged that marine invertebrates produce bioactive natural products that may be useful for developing new drugs. By exploring untapped geographical sources and/or novel groups of organisms one can maximize the search for new marine drugs to treat human diseases. The goal of this paper is to analyse the trends associated with the discovery of new marine natural products from invertebrates (NMNPI) over the last two decades. The analysis considers different taxonomical levels and geographical approaches of bioprospected species. Additionally, this research is also directed to provide new insights into less bioprospected taxa and world regions. In order to gather the information available on NMNPI, the yearly-published reviews of Marine Natural Products covering 1990–2009 were surveyed. Information on source organisms, specifically taxonomical information and collection sites, was assembled together with additional geographical information collected from the articles originally describing the new natural product. Almost 10000 NMNPI were discovered since 1990, with a pronounced increase between decades. Porifera and Cnidaria were the two dominant sources of NMNPI worldwide. The exception was polar regions where Echinodermata dominated. The majority of species that yielded the new natural products belong to only one class of each Porifera and Cnidaria phyla (Demospongiae and Anthozoa, respectively). Increased bioprospecting efforts were observed in the Pacific Ocean, particularly in Asian countries that are associated with the Japan Biodiversity Hotspot and the Kuroshio Current. Although results show comparably less NMNPI from polar regions, the number of new natural products per species is similar to that recorded for other regions. The present study provides information to future bioprospecting efforts addressing previously unexplored taxonomic groups and/or regions. We also highlight how marine invertebrates, which in some cases have no commercial value, may become highly valuable in the ongoing search for new drugs from the sea

    Examining methods, messengers and behavioural theories to disseminate physical activity information to individuals with a diagnosis of schizophrenia: a scoping review

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    Background: Many individuals with a diagnosis of schizophrenia are not active and lack the necessary knowledge and confidence to become and stay active. To develop effective physical activity promotion interventions, it is necessary to identify credible messengers and effective methods to disseminate physical activity information to this population. Aims: The purpose of this scoping review was to identify and examine knowledge mobilization theories, messengers and methods used to disseminate physical activity information to individuals with a diagnosis of schizophrenia. Method: This scoping review followed the methodological framework proposed by Arksey and O'Malley. Results: In total, 43 studies and 7 reviews identified multiple messengers and methods used to disseminate physical activity information to individuals with a diagnosis of schizophrenia, but few attempts to structure information theoretically. Findings do not point to which messengers or methods are most effective or which theories should be used to construct information interventions. Studies show that physical activity information should be provided in an individualised manner from staff who could easily connect with patients. Conclusions: Few researchers have addressed the physical activity information needs of individuals with a diagnosis of schizophrenia. Researchers need to examine and implement effective knowledge mobilization strategies for this population

    1989: Abilene Christian College Bible Lectures - Full Text

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    CHRIST AND CULTURE: The Problem of Secularism Being the Abilene Christian University Annual Bible Lectures 1989 Published by ACU PRESS 1634 Campus Court Abilene, Texas 7960

    β-lactam hypersensitivity involves expansion of circulating and skin-resident Th22 cells

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    Background: β-lactam hypersensitivity has been classified according to the phenotype and function of drug-specific T-cells; however, new T-cell subsets have not been considered. Objective: The objective of this study was use piperacillin as a model of β-lactam hypersensitivity to study the nature of the drug-specific T-cell response induced in the blood and skin of hypersensitive patients and healthy volunteers. Methods: Drug-specific T-cells were cloned from blood and inflamed skin and cellular phenotype and function was explored. Naïve T cells from healthy volunteers were primed to piperacillin, cloned and subjected to the similar analyses. Results: PBMC and T-cell clones (n=570, 84% CD4+) from blood of piperacillin hypersensitive patients proliferated and secreted Th1/2 cytokines alongside IL-22 following drug stimulation. IL-17A secretion was not detected. Drug-specific clones from inflamed skin (n=96, 83% CD4+) secreted a similar profile of cytokines, but displayed greater cytolytic activity, secreting perforin, granzyme B and Fas L when activated. Blood- and skin-derived clones expressed high levels of skin-homing chemokine receptors and migrated in the presence of the ligands CCL17 and CCL27. Piperacillin-primed naïve T-cells from healthy volunteers also secreted IFN-γ, IL-13, IL-22 and cytolytic molecules. Aryl hydrocarbon (ArH) receptor blockade prevented differentiation of the naïve T-cells into antigen-specific Il-22 secreting cells. Conclusion: Together our results reveal that circulating and skin resident antigen-specific IL-22 secreting T-cells are detectable in patients with β-lactam hypersensitivity. Furthermore, differentiation of naïve T-cells into antigen-specific Th22 cells is dependent on ArH receptor signalling

    Differences between <i>Trypanosoma brucei gambiense</i> groups 1 and 2 in their resistance to killing by Trypanolytic factor 1

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    &lt;p&gt;&lt;b&gt;Background:&lt;/b&gt; The three sub-species of &lt;i&gt;Trypanosoma brucei&lt;/i&gt; are important pathogens of sub-Saharan Africa. &lt;i&gt;T. b. brucei&lt;/i&gt; is unable to infect humans due to sensitivity to trypanosome lytic factors (TLF) 1 and 2 found in human serum. &lt;i&gt;T. b. rhodesiense&lt;/i&gt; and &lt;i&gt;T. b. gambiense&lt;/i&gt; are able to resist lysis by TLF. There are two distinct sub-groups of &lt;i&gt;T. b. gambiense&lt;/i&gt; that differ genetically and by human serum resistance phenotypes. Group 1 &lt;i&gt;T. b. gambiense&lt;/i&gt; have an invariant phenotype whereas group 2 show variable resistance. Previous data indicated that group 1 &lt;i&gt;T. b. gambiense&lt;/i&gt; are resistant to TLF-1 due in-part to reduced uptake of TLF-1 mediated by reduced expression of the TLF-1 receptor (the haptoglobin-hemoglobin receptor (&lt;i&gt;HpHbR&lt;/i&gt;)) gene. Here we investigate if this is also true in group 2 parasites.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methodology:&lt;/b&gt; Isogenic resistant and sensitive group 2 &lt;i&gt;T. b. gambiense&lt;/i&gt; were derived and compared to other T. brucei parasites. Both resistant and sensitive lines express the &lt;i&gt;HpHbR&lt;/i&gt; gene at similar levels and internalized fluorescently labeled TLF-1 similar fashion to &lt;i&gt;T. b. brucei&lt;/i&gt;. Both resistant and sensitive group 2, as well as group 1 &lt;i&gt;T. b. gambiense&lt;/i&gt;, internalize recombinant APOL1, but only sensitive group 2 parasites are lysed.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusions:&lt;/b&gt; Our data indicate that, despite group 1 &lt;i&gt;T. b. gambiense&lt;/i&gt; avoiding TLF-1, it is resistant to the main lytic component, APOL1. Similarly group 2 &lt;i&gt;T. b. gambiense&lt;/i&gt; is innately resistant to APOL1, which could be based on the same mechanism. However, group 2 &lt;i&gt;T. b. gambiense&lt;/i&gt; variably displays this phenotype and expression does not appear to correlate with a change in expression site or expression of &lt;i&gt;HpHbR&lt;/i&gt;. Thus there are differences in the mechanism of human serum resistance between &lt;i&gt;T. b. gambiense&lt;/i&gt; groups 1 and 2.&lt;/p&gt

    The genome sequence of <i>Trypanosoma brucei gambiense</i>, causative agent of chronic Human African Trypanosomiasis

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    &lt;p&gt;&lt;b&gt;Background:&lt;/b&gt; &lt;i&gt;Trypanosoma brucei gambiense&lt;/i&gt; is the causative agent of chronic Human African Trypanosomiasis or sleeping sickness, a disease endemic across often poor and rural areas of Western and Central Africa. We have previously published the genome sequence of a &lt;i&gt;T. b. brucei&lt;/i&gt; isolate, and have now employed a comparative genomics approach to understand the scale of genomic variation between &lt;i&gt;T. b. gambiense&lt;/i&gt; and the reference genome. We sought to identify features that were uniquely associated with &lt;i&gt;T. b. gambiense&lt;/i&gt; and its ability to infect humans.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods and findings:&lt;/b&gt; An improved high-quality draft genome sequence for the group 1 &lt;i&gt;T. b. gambiense&lt;/i&gt; DAL 972 isolate was produced using a whole-genome shotgun strategy. Comparison with &lt;i&gt;T. b. brucei&lt;/i&gt; showed that sequence identity averages 99.2% in coding regions, and gene order is largely collinear. However, variation associated with segmental duplications and tandem gene arrays suggests some reduction of functional repertoire in &lt;i&gt;T. b. gambiense&lt;/i&gt; DAL 972. A comparison of the variant surface glycoproteins (VSG) in &lt;i&gt;T. b. brucei&lt;/i&gt; with all &lt;i&gt;T. b. gambiense&lt;/i&gt; sequence reads showed that the essential structural repertoire of VSG domains is conserved across &lt;i&gt;T. brucei&lt;/i&gt;.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusions:&lt;/b&gt; This study provides the first estimate of intraspecific genomic variation within &lt;i&gt;T. brucei&lt;/i&gt;, and so has important consequences for future population genomics studies. We have shown that the &lt;i&gt;T. b. gambiense&lt;/i&gt; genome corresponds closely with the reference, which should therefore be an effective scaffold for any &lt;i&gt;T. brucei&lt;/i&gt; genome sequence data. As VSG repertoire is also well conserved, it may be feasible to describe the total diversity of variant antigens. While we describe several as yet uncharacterized gene families with predicted cell surface roles that were expanded in number in &lt;i&gt;T. b. brucei&lt;/i&gt;, no &lt;i&gt;T. b. gambiense&lt;/i&gt;-specific gene was identified outside of the subtelomeres that could explain the ability to infect humans.&lt;/p&gt
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