18 research outputs found

    Structural analyses of \u3ci\u3ePhycodnaviridae\u3c/i\u3e and \u3ci\u3eIridoviridae\u3c/i\u3e

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    The Phycodnaviridae, Iridoviridae and related viruses, with diameters of 1500±2000 A Ê , are formed from large trigonal arrays of hexagonally close-packed capsomers forming the faces of icosahedra [Yan et al. (2000), Nature Struct. Biol. 7, 101-103; Nandhagopal et al. (2002), Proc. Natl Acad. Sci. USA, 99, 14758-14763]. Caspar and Klug predicted that such structures could be assembled from hexameric capsomers [Caspar & Klug (1962), Cold Spring Harbor. Symp. Quant. Biol. 27, 1-24], as was subsequently found in numerous icosahedral viruses. During the course of evolution, some viruses, including the virus families mentioned above, replaced hexameric capsomers with pseudo-hexameric trimers by gene duplication. In large dsDNA icosahedral viruses, the capsomers are organized into `pentasymmetrons\u27 and `trisymmetrons\u27. The interactions between the trimeric capsomers can be divided into three groups, one between similarly oriented trimers and two between oppositely oriented trimers (trimers related by an approximately sixfold rotation). The interactions within a trisymmetron belong to the ®rst class, whereas those between trisymmetrons and within the pentasymmetron are of the other two types. Knowledge of these distances permits a more accurate ®tting of the atomic structure of the capsomer into the cryo-electron microscopy (cryoEM) reconstruction of the whole virus. The adoption of pseudo-hexagonal capsomers places these viruses into a subset of the Caspar and Klug surface lattices

    High-rise apartments and urban mental health—Historical and contemporary views

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    High-rise apartment buildings have long been associated with the poor mental health of their residents. The aims of this paper are to examine whether this connection is necessarily so, by reviewing the evidence relating to the relationships between high-rise living and social wellbeing, occupant’s stress levels, and the influence they have on mental health. From selected literature, psychological stress and poor mental health outcomes of the populations that live in high-rise apartments are indeed apparent, and this is particularly so for apartments in poor neighbourhoods. Yet many apartments in developed cities are in affluent areas (particularly those with views of green/blue space), where residences on higher floors are more expensive. Either way, high-rise living and mental health outcomes are a social justice issue. Our review allows us to propose two models relating to high-rise living relevant today, based on these difference

    The Structure and Evolution of the Major Capsid Protein of a Large, Lipid-Containing DNA Virus

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    Paramecium bursaria Chlorella virus type 1 (PBCV-1) is a very large, icosahedral virus containing an internal membrane enclosed within a glycoprotein coat consisting of pseudohexagonal arrays of trimeric capsomers. Each capsomer is composed of three molecules of the major capsid protein, Vp54, the 2.0-Å resolution structure of which is reported here. Four N-linked and two O-linked glycosylation sites were identified. The N-linked sites are associated with nonstandard amino acid motifs as a result of glycosylation by virus-encoded enzymes. Each monomer of the trimeric structure consists of two eight-stranded, antiparallel β-barrel, “jelly-roll” domains related by a pseudo-sixfold rotation. The fold of the monomer and the pseudo-sixfold symmetry of the capsomer resembles that of the major coat proteins in the double-stranded DNA bacteriophage PRD1 and the double-stranded DNA human adenoviruses, as well as the viral proteins VP2-VP3 of picornaviruses. The structural similarities among these diverse groups of viruses, whose hosts include bacteria, unicellular eukaryotes, plants, and mammals, make it probable that their capsid proteins have evolved from a common ancestor that had already acquired a pseudo-sixfold organization. The trimeric capsid protein structure was used to produce a quasi-atomic model of the 1,900-Å diameter PBCV-1 outer shell, based on fitting of the Vp54 crystal structure into a three-dimensional cryoelectron microscopy image reconstruction of the virus

    The \u3ci\u3eChlorella variabilis\u3c/i\u3e NC64A Genome Reveals Adaptation to Photosymbiosis, Coevolution with Viruses, and Cryptic Sex

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    Chlorella variabilis NC64A, a unicellular photosynthetic green alga (Trebouxiophyceae), is an intracellular photobiont of Paramecium bursaria and a model system for studying virus/algal interactions. We sequenced its 46-Mb nuclear genome, revealing an expansion of protein families that could have participated in adaptation to symbiosis. NC64A exhibits variations in GC content across its genome that correlate with global expression level, average intron size, and codon usage bias. Although Chlorella species have been assumed to be asexual and nonmotile, the NC64A genome encodes all the known meiosis-specific proteins and a subset of proteins found in flagella. We hypothesize that Chlorella might have retained a flagella-derived structure that could be involved in sexual reproduction. Furthermore, a survey of phytohormone pathways in chlorophyte algae identified algal orthologs of Arabidopsis thaliana genes involved in hormone biosynthesis and signaling, suggesting that these functions were established prior to the evolution of land plants. We show that the ability of Chlorella to produce chitinous cell walls likely resulted from the capture of metabolic genes by horizontal gene transfer from algal viruses, prokaryotes, or fungi. Analysis of the NC64A genome substantially advances our understanding of the green lineage evolution, including the genomic interplay with viruses and symbiosis between eukaryotes

    Fecal occult blood and fecal calprotectin as point-of-care markers of intestinal morbidity in Ugandan children with Schistosoma mansoni infection.

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    BACKGROUND: Calprotectin is a calcium-binding cytoplasmic protein found in neutrophils and increasingly used as a marker of bowel inflammation. Fecal occult blood (FOB) is also a dependable indicator of bowel morbidity. The objective of our study was to determine the applicability of these tests as surrogate markers of Schistosoma mansoni intestinal morbidity before and after treatment with praziquantel (PZQ). METHODS: 216 children (ages 3-9 years old) from Buliisa District in Lake Albert, Uganda were examined and treated with PZQ at baseline in October 2012 with 211 of them re-examined 24 days later for S. mansoni and other soil transmitted helminths (STH). POC calprotectin and FOB assays were performed at both time points on a subset of children. Associations between the test results and infection were analysed by logistic regression. RESULTS: Fecal calprotectin concentrations of 150-300 µg/g were associated with S. mansoni egg patent infection both at baseline and follow up (OR: 12.5 P = 0.05; OR: 6.8 P = 0.02). FOB had a very strong association with baseline anemia (OR: 9.2 P = 0.03) and medium and high egg intensity schistosomiasis at follow up (OR: 6.6 P = 0.03; OR: 51.3 P = 0.003). Both tests were strongly associated with heavy intensity S. mansoni infections. There was a significant decrease in FOB and calprotectin test positivity after PZQ treatment in those children who had egg patent schistosomiasis at baseline. CONCLUSIONS: Both FOB and calprotectin rapid assays were found to correlate positively and strongly with egg patent S. mansoni infection with a positive ameloriation response after PZQ treatment indicative of short term reversion of morbidity. Both tests were appropriate for use in the field with excellent operational performance and reliability. Due to its lower-cost which makes its scale-up of use affordable, FOB could be immediately adopted as a monitoring tool for PC campaigns for efficacy evaluation before and after treatment

    Estimation of changes in the force of infection for intestinal and urogenital schistosomiasis in countries with Schistosomiasis Control Initiative-assisted programmes

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    The last decade has seen an expansion of national schistosomiasis control programmes in Africa based on large-scale preventative chemotherapy. In many areas this has resulted in considerable reductions in infection and morbidity levels in treated individuals. In this paper, we quantify changes in the force of infection (FOI), defined here as the per (human) host parasite establishment rate, to ascertain the impact on transmission of some of these programmes under the umbrella of the Schistosomiasis Control Initiative (SCI)

    In Support of a Patient-Driven Initiative and Petition to Lower the High Price of Cancer Drugs

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    Comment in Lowering the High Cost of Cancer Drugs--III. [Mayo Clin Proc. 2016] Lowering the High Cost of Cancer Drugs--I. [Mayo Clin Proc. 2016] Lowering the High Cost of Cancer Drugs--IV. [Mayo Clin Proc. 2016] In Reply--Lowering the High Cost of Cancer Drugs. [Mayo Clin Proc. 2016] US oncologists call for government regulation to curb drug price rises. [BMJ. 2015

    High-Rise Apartments and Urban Mental Health—Historical and Contemporary Views

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    High-rise apartment buildings have long been associated with the poor mental health of their residents. The aims of this paper are to examine whether this connection is necessarily so, by reviewing the evidence relating to the relationships between high-rise living and social wellbeing, occupant’s stress levels, and the influence they have on mental health. From selected literature, psychological stress and poor mental health outcomes of the populations that live in high-rise apartments are indeed apparent, and this is particularly so for apartments in poor neighbourhoods. Yet many apartments in developed cities are in affluent areas (particularly those with views of green/blue space), where residences on higher floors are more expensive. Either way, high-rise living and mental health outcomes are a social justice issue. Our review allows us to propose two models relating to high-rise living relevant today, based on these differences

    The skin microbiome: impact of modern environments on skin ecology, barrier integrity, and systemic immune programming

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    Skin barrier structure and function is essential to human health. Hitherto unrecognized functions of epidermal keratinocytes show that the skin plays an important role in adapting whole-body physiology to changing environments, including the capacity to produce a wide variety of hormones, neurotransmitters and cytokine that can potentially influence whole-body states, and quite possibly, even emotions. Skin microbiota play an integral role in the maturation and homeostatic regulation of keratinocytes and host immune networks with systemic implications. As our primary interface with the external environment, the biodiversity of skin habitats is heavily influenced by the biodiversity of the ecosystems in which we reside. Thus, factors which alter the establishment and health of the skin microbiome have the potential to predispose to not only cutaneous disease, but also other inflammatory non-communicable diseases (NCDs). Indeed, disturbances of the stratum corneum have been noted in allergic diseases (eczema and food allergy), psoriasis, rosacea, acne vulgaris and with the skin aging process. The built environment, global biodiversity losses and declining nature relatedness are contributing to erosion of diversity at a micro-ecological level, including our own microbial habitats. This emphasises the importance of ecological perspectives in overcoming the factors that drive dysbiosis and the risk of inflammatory diseases across the life course
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