1,775 research outputs found

    Missense mutations in the perforin (PRF1) gene as a cause of hereditary cancer predisposition

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    Perforin, a pore-forming toxin released from secretory granules of NK cells and CTLs, is essential for their cytotoxic activity against infected or cancerous target cells. Bi-allelic loss-of-function mutations in the perforin gene are invariably associated with a fatal immunoregulatory disorder, familial haemophagocytic lymphohistiocytosis type 2 (FHL2), in infants. More recently, it has also been recognized that partial loss of perforin function can cause disease in later life, including delayed onset FHL2 and haematological malignancies. Herein we report a family in which a wide range of systemic inflammatory and neoplastic manifestations have occurred across three generations. We found that disease was linked to two missense perforin gene mutations (encoding A91V, R410W) that cause protein misfolding and partial loss of activity. These cases link the partial loss of perforin function with some solid tumours that are known to be controlled by the immune system, as well as haematological cancers. Our findings also demonstrate that perforin gene mutations can contribute to hereditary cancer predisposition

    Experimental summary 1987

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    Barley II. Scald and mildrew : Seed dressings and sprayings(87E26, MT37 and MT38) III. Scald and mildew : Seed dressing and fungicide coated superphosphates. (87E27, MT39, MT40 and WH40) IV. Scald and mildew : Fungicides for longer protection (87ES38 and MT41) V. Mildew : Survey of virulence genes (87ES46, MT56 and PE22) VI. Spot-type net blotch : Potential crop losses (87C49 and C55) VII. Spot-type net blotch : Effect of seed dressings (87C49 and C55) VIII. Spot-type net blotch : Parent-offspring regression (87C51 and C56) IX. Leaf stripe : Effect of seed dressings (87M42, MT33 and NA74) Peas X. Blackspot : Effect of fungicides (87MT42 and WH41) XI. Blackspot : Screening for cultivar resistance (87MD10 and MT43

    Electron Beam Instability in Left-Handed Media

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    We predict that two electron beams can develop an instability when passing through a slab of left-handed media (LHM). This instability, which is inherent only for LHM, originates from the backward Cherenkov radiation and results in a self-modulation of the beams and radiation of electromagnetic waves. These waves leave the sample via the rear surface of the slab (the beam injection plane) and form two shifted bright circles centered at the beams. A simulated spectrum of radiation has well-separated lines on top of a broad continuous spectrum, which indicates dynamical chaos in the system. The radiation intensity and its spectrum can be controlled either by the beams' current or by the distance between the two beams.Comment: 4 pages, 4 figure

    HLA Class-II Associated HIV Polymorphisms Predict Escape from CD4+ T Cell Responses.

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    Antiretroviral therapy, antibody and CD8+ T cell-mediated responses targeting human immunodeficiency virus-1 (HIV-1) exert selection pressure on the virus necessitating escape; however, the ability of CD4+ T cells to exert selective pressure remains unclear. Using a computational approach on HIV gag/pol/nef sequences and HLA-II allelic data, we identified 29 HLA-II associated HIV sequence polymorphisms or adaptations (HLA-AP) in an African cohort of chronically HIV-infected individuals. Epitopes encompassing the predicted adaptation (AE) or its non-adapted (NAE) version were evaluated for immunogenicity. Using a CD8-depleted IFN-γ ELISpot assay, we determined that the magnitude of CD4+ T cell responses to the predicted epitopes in controllers was higher compared to non-controllers (p<0.0001). However, regardless of the group, the magnitude of responses to AE was lower as compared to NAE (p<0.0001). CD4+ T cell responses in patients with acute HIV infection (AHI) demonstrated poor immunogenicity towards AE as compared to NAE encoded by their transmitted founder virus. Longitudinal data in AHI off antiretroviral therapy demonstrated sequence changes that were biologically confirmed to represent CD4+ escape mutations. These data demonstrate an innovative application of HLA-associated polymorphisms to identify biologically relevant CD4+ epitopes and suggests CD4+ T cells are active participants in driving HIV evolution

    Naive B cell output in HIV-infected and HIV-uninfected children.

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    In this study, we aimed to quantify KREC (kappa-deleting recombination excision circle) levels and naive B cell output in healthy HIV-uninfected children, compared with HIV-infected South African children, before and after starting ART (antiretroviral therapy). Samples were acquired from a Child Wellness Clinic (n = 288 HIV-uninfected South African children, 2 weeks-12 years) and the Children with HIV Early Antiretroviral Therapy (CHER) trial (n = 153 HIV-infected South African children, 7 weeks-8 years). Naive B cell output was estimated using a mathematical model combining KREC levels to reflect B cell emigration into the circulation, flow cytometry measures of naive unswitched B cells to quantify total body naive B cells, and their rates of proliferation using the intracellular marker Ki67. Naive B cell output increases from birth to 1 year, followed by a decline and plateau into late childhood. HIV-infected children on or off ART had higher naive B cell outputs than their uninfected counterparts (p = .01 and p = .04). This is the first study to present reference ranges for measurements of KRECs and naive B cell output in healthy and HIV-infected children. Comparison between HIV-uninfected healthy children and HIV-infected children suggests that HIV may increase naive B cell output. Further work is required to fully understand the mechanisms involved and clinical value of measuring naive B cell output in children

    Author Correction: Development of a sensitive, quantitative assay with broad subtype specificity for detection of total HIV-1 nucleic acids in plasma and PBMC

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    Correction to: Scientific Reports https://doi.org/10.1038/s41598-021-03016-1, published online 28 January 202

    The lipids of the common house cricket,Acheta domesticus L. I. Lipid classes and fatty acid distribution

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    The lipids of the common house cricket,Acheta domesticus L., have been examined with the following results. The fatty acids associated with the lipid extracts do not change significantly from the third through the eleventh week of the crickets’ postembryonic life. The major fatty acids are linoleic (30–40%), oleic (23–27%), palmitic (24–30%), and stearic acids (7–11%). There are smaller amounts of palmitoleic (3–4%), myristic (∼1%), and linolenic acids (<1%). The fatty acid composition of the cricket lipids reflects but is not identical to the fatty acids of the dietary lipids: linoleic (53%), oleic (24%), palmitic (15%), stearic (3%), myristic (2%), and linolenic acid (2%).The amount of triglycerides present in the crickets increases steadily from the second through the seventh or eighth week of postembryonic life, then drops sharply. Other lipid classes, such as hydrocarbons, simple esters, diglycerides, monoglycerides, sterols, and free fatty acids remain about constant. The composition of the fatty acids associated with the tri‐, di‐, and monoglycerides and the free fatty acid fraction are all about the same. The fatty acids associated with the simple esters are high in stearic acid.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142007/1/lipd0247.pd

    Dynamical system analysis and forecasting of deformation produced by an earthquake fault

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    We present a method of constructing low-dimensional nonlinear models describing the main dynamical features of a discrete 2D cellular fault zone, with many degrees of freedom, embedded in a 3D elastic solid. A given fault system is characterized by a set of parameters that describe the dynamics, rheology, property disorder, and fault geometry. Depending on the location in the system parameter space we show that the coarse dynamics of the fault can be confined to an attractor whose dimension is significantly smaller than the space in which the dynamics takes place. Our strategy of system reduction is to search for a few coherent structures that dominate the dynamics and to capture the interaction between these coherent structures. The identification of the basic interacting structures is obtained by applying the Proper Orthogonal Decomposition (POD) to the surface deformations fields that accompany strike-slip faulting accumulated over equal time intervals. We use a feed-forward artificial neural network (ANN) architecture for the identification of the system dynamics projected onto the subspace (model space) spanned by the most energetic coherent structures. The ANN is trained using a standard back-propagation algorithm to predict (map) the values of the observed model state at a future time given the observed model state at the present time. This ANN provides an approximate, large scale, dynamical model for the fault.Comment: 30 pages, 12 figure

    Towards the understanding of the cocoa transcriptome: Production and analysis of an exhaustive dataset of ESTs of Theobroma cacao L. generated from various tissues and under various conditions

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    Theobroma cacao L., is a tree originated from the tropical rainforest of South America. It is one of the major cash crops for many tropical countries. T. cacao is mainly produced on smallholdings, providing resources for 14 million farmers. Disease resistance and T. cacao quality improvement are two important challenges for all actors of cocoa and chocolate production. T. cacao is seriously affected by pests and fungal diseases, responsible for more than 40% yield losses and quality improvement, nutritional and organoleptic, is also important for consumers. An international collaboration was formed to develop an EST genomic resource database for cacao. Fifty-six cDNA libraries were constructed from different organs, different genotypes and different environmental conditions. A total of 149,650 valid EST sequences were generated corresponding to 48,594 unigenes, 12,692 contigs and 35,902 singletons. A total of 29,849 unigenes shared significant homology with public sequences from other species. Gene Ontology (GO) annotation was applied to distribute the ESTs among the main GO categories. A specific information system (ESTtik) was constructed to process, store and manage this EST collection allowing the user to query a database. To check the representativeness of our EST collection, we looked for the genes known to be involved in two different metabolic pathways extensively studied in other plant species and important for T. cacao qualities: the flavonoid and the terpene pathways. Most of the enzymes described in other crops for these two metabolic pathways were found in our EST collection. A large collection of new genetic markers was provided by this ESTs collection. This EST collection displays a good representation of the T. cacao transcriptome, suitable for analysis of biochemical pathways based on oligonucleotide microarrays derived from these ESTs. It will provide numerous genetic markers that will allow the construction of a high density gene map of T. cacao. This EST collection represents a unique and important molecular resource for T. cacao study and improvement, facilitating the discovery of candidate genes for important T. cacao trait variation. (Résumé d'auteur
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