1,345 research outputs found

    Expression of soluble, active, fluorescently tagged hephaestin in COS and CHO cell lines

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    Hephaestin (Hp) is a trans-membrane protein, which plays a critical role in intestinal iron absorption. Hp was originally identified as the gene responsible for the phenotype of sex-linked anaemia in the sla mouse. The mutation in the sla protein causes ac-cumulation of dietary iron in duodenal cells, causing severe microcytic hypochromic anaemia. Although mucosal uptake of dietary iron is normal, export from the duodenum is inhibited. Hp is homologous to ceruloplasmin (Cp), a member of the family of multi copper fer-roxidases (MCFs) and possesses ferroxidase activity that facilitates iron release from the duodenum and load onto the serum iron trans-port protein transferrin. In the present study, attempts were made to produce biologically active recombinant mouse hephaestin as a secretory form tagged with green fluorescent protein (GFP), Hpsec-GFP. Plasmid expressing Hpsec-GFP was constructed and transfected into COS and CHO cells. The GFP aided the monitoring expression in real time to select the best conditions to maximise expression and provided a tag for purifying and analysing Hpsec-GFP. The protein had detectable oxidase activity as shown by in-gel and solution-based assays. The methods described here can provide the basis for further work to probe the interaction of hephaestin with other proteins using complementary fluorescent tags on target proteins that would facilitate the fluorescence resonance energy transfer measurements, for example with transferrin or colocalisation studies, and help to discover more about hephaestin works at the molecular level.</jats:p

    Measuring indirect transmission-reducing effects in tuberculosis vaccine efficacy trials: why and how?

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    Tuberculosis is the leading bacterial cause of death globally. In 2021, 10·6 million people developed symptomatic tuberculosis and 1·6 million died. Seven promising vaccine candidates that aim to prevent tuberculosis disease in adolescents and adults are currently in late-stage clinical trials. Conventional phase 3 trials provide information on the direct protection conferred against infection or disease in vaccinated individuals, but they tell us little about possible indirect (ie, transmission-reducing) effects that afford protection to unvaccinated individuals. As a result, proposed phase 3 trial designs will not provide key information about the overall effect of introducing a vaccine programme. Information on the potential for indirect effects can be crucial for policy makers deciding whether and how to introduce tuberculosis vaccines into immunisation programmes. We describe the rationale for measuring indirect effects, in addition to direct effects, of tuberculosis vaccine candidates in pivotal trials and lay out several options for incorporating their measurement into phase 3 trial designs

    Identification of Colletotrichum species associated with anthracnose disease of coffee in Vietnam

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    Colletotrichum gloeosporioides, C. acutatum, C. capsici and C. boninense associated with anthracnose disease on coffee (Coffea spp.) in Vietnam were identified based on morphology and DNA analysis. Phylogenetic analysis of DNA sequences from the internal transcribed spacer region of nuclear rDNA and a portion of mitochondrial small subunit rRNA were concordant and allowed good separation of the taxa. We found several Colletotrichum isolates of unknown species and their taxonomic position remains unresolved. The majority of Vietnamese isolates belonged to C. gloeosporioides and they grouped together with the coffee berry disease (CBD) fungus, C. kahawae. However, C. kahawae could be distinguished from the Vietnamese C. gloeosporioides isolates based on ammonium tartrate utilization, growth rate and pathogenictity. C. gloeosporioides isolates were more pathogenic on detached green berries than isolates of the other species, i.e. C. acutatum, C capsici and C. boninense. Some of the C. gloeosporioides isolates produced slightly sunken lesion on green berries resembling CBD symptoms but it did not destroy the bean. We did not find any evidence of the presence of C. kahawae in Vietnam

    Zebrafish: A See-Through Host and a Fluorescent Toolbox to Probe Host–Pathogen Interaction

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    In many ways, the zebrafish represents a hybrid between mouse and invertebrate infection models. Powerful forwardgenetic tools that have made invertebrates justifiably famous are not only relatively accessible in the zebrafish, but have been exploited to yield new insights into human infectious diseases, including leprosy and tuberculosis [1]. Transgenic technologies have enabled detailed, non-invasive in vivo visualization of macrophages and neutrophils in pitched battle with bacteria and fungi [2,3]. Reverse genetics with morpholinos, vivo-morpholinos, and zinc-finger nucleases (but unfortunately not homologous recombination, which for the moment remains out of reach in this organism) enable examination of the roles of specific genes during infection. Flexible genetic systems such as Gal4-UAS and Cre-Lox permit tissue-specific transformation and ablation ([3]; Figure 1)

    Effect of continuous positive airway pressure therapy on a large hemangioma complicated with obstructive sleep apnea syndrome: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Hemangiomas involving the upper airway can be an uncommon cause of obstructive sleep apnea syndrome.</p> <p>Case presentation</p> <p>A 26-year-old Caucasian man with a known history of a large hemangioma of his head and neck presented with sleep-disordered breathing to the sleep unit of our hospital. Severe obstructive sleep apnea syndrome was revealed on polysomnography. Nasal continuous positive airway pressure was implemented effectively, reducing daytime hypersomnolence and significantly improving sleep parameters. After three years of adherent use, the patient remains in a good condition and the hemangioma is stable.</p> <p>Conclusion</p> <p>Application of continuous positive airway pressure can be an effective treatment for patients with obstructive sleep apnea syndrome complicated with vascular tumors. Periodic follow-up of these patients is necessary, as little is known about the long-term effects of continuous positive airway pressure therapy.</p

    An exposure-effect approach for evaluating ecosystem-wide risks from human activities

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    Ecosystem-based management (EBM) is promoted as the solution for sustainable use. An ecosystem-wide assessment methodology is therefore required. In this paper, we present an approach to assess the risk to ecosystem components from human activities common to marine and coastal ecosystems. We build on: (i) a linkage framework that describes how human activities can impact the ecosystem through pressures, and (ii) a qualitative expert judgement assessment of impact chains describing the exposure and sensitivity of ecological components to those activities. Using case study examples applied at European regional sea scale, we evaluate the risk of an adverse ecological impact from current human activities to a suite of ecological components and, once impacted, the time required for recovery to pre-impact conditions should those activities subside. Grouping impact chains by sectors, pressure type, or ecological components enabled impact risks and recovery times to be identified, supporting resource managers in their efforts to prioritize threats for management, identify most at-risk components, and generate time frames for ecosystem recovery

    Guillain-Barré syndrome: a century of progress

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    In 1916, Guillain, Barré and Strohl reported on two cases of acute flaccid paralysis with high cerebrospinal fluid protein levels and normal cell counts — novel findings that identified the disease we now know as Guillain–Barré syndrome (GBS). 100 years on, we have made great progress with the clinical and pathological characterization of GBS. Early clinicopathological and animal studies indicated that GBS was an immune-mediated demyelinating disorder, and that severe GBS could result in secondary axonal injury; the current treatments of plasma exchange and intravenous immunoglobulin, which were developed in the 1980s, are based on this premise. Subsequent work has, however, shown that primary axonal injury can be the underlying disease. The association of Campylobacter jejuni strains has led to confirmation that anti-ganglioside antibodies are pathogenic and that axonal GBS involves an antibody and complement-mediated disruption of nodes of Ranvier, neuromuscular junctions and other neuronal and glial membranes. Now, ongoing clinical trials of the complement inhibitor eculizumab are the first targeted immunotherapy in GBS

    Root morphology and seed and leaf ionomic traits in a Brassica napus L. diversity panel show wide phenotypic variation and are characteristic of crop habit

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    Background: Mineral nutrient uptake and utilisation by plants are controlled by many traits relating to root morphology, ion transport, sequestration and translocation. The aims of this study were to determine the phenotypic diversity in root morphology and leaf and seed mineral composition of a polyploid crop species, Brassica napus L., and how these traits relate to crop habit. Traits were quantified in a diversity panel of up to 387 genotypes: 163 winter, 127 spring, and seven semiwinter oilseed rape (OSR) habits, 35 swede, 15 winter fodder, and 40 exotic/unspecified habits. Root traits of 14 d old seedlings were measured in a ‘pouch and wick’ system (n = ~24 replicates per genotype). The mineral composition of 3–6 rosette-stage leaves, and mature seeds, was determined on compost-grown plants from a designed experiment (n = 5) by inductively coupled plasma-mass spectrometry (ICP-MS). Results: Seed size explained a large proportion of the variation in root length. Winter OSR and fodder habits had longer primary and lateral roots than spring OSR habits, with generally lower mineral concentrations. A comparison of the ratios of elements in leaf and seed parts revealed differences in translocation processes between crop habits, including those likely to be associated with crop-selection for OSR seeds with lower sulphur-containing glucosinolates. Combining root, leaf and seed traits in a discriminant analysis provided the most accurate characterisation of crop habit, illustrating the interdependence of plant tissues. Conclusions: High-throughput morphological and composition phenotyping reveals complex interrelationships between mineral acquisition and accumulation linked to genetic control within and between crop types (habits) in B. napus. Despite its recent genetic ancestry (<10 ky), root morphology, and leaf and seed composition traits could potentially be used in crop improvement, if suitable markers can be identified and if these correspond with suitable agronomy and quality traits

    MicroRNAs in pulmonary arterial remodeling

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    Pulmonary arterial remodeling is a presently irreversible pathologic hallmark of pulmonary arterial hypertension (PAH). This complex disease involves pathogenic dysregulation of all cell types within the small pulmonary arteries contributing to vascular remodeling leading to intimal lesions, resulting in elevated pulmonary vascular resistance and right heart dysfunction. Mutations within the bone morphogenetic protein receptor 2 gene, leading to dysregulated proliferation of pulmonary artery smooth muscle cells, have been identified as being responsible for heritable PAH. Indeed, the disease is characterized by excessive cellular proliferation and resistance to apoptosis of smooth muscle and endothelial cells. Significant gene dysregulation at the transcriptional and signaling level has been identified. MicroRNAs are small non-coding RNA molecules that negatively regulate gene expression and have the ability to target numerous genes, therefore potentially controlling a host of gene regulatory and signaling pathways. The major role of miRNAs in pulmonary arterial remodeling is still relatively unknown although research data is emerging apace. Modulation of miRNAs represents a possible therapeutic target for altering the remodeling phenotype in the pulmonary vasculature. This review will focus on the role of miRNAs in regulating smooth muscle and endothelial cell phenotypes and their influence on pulmonary remodeling in the setting of PAH

    Extracellular volume quantification in isolated hypertension - changes at the detectable limits?

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    The funding source (British Heart Foundation and UK National Institute for Health Research) provided salaries for research training (FZ, TT, DS, SW), but had no role in study design, collection, analysis, interpretation, writing, or decisions with regard to publication. This work was undertaken at University College London Hospital, which received a proportion of funding from the UK Department of Health National Institute for Health Research Biomedical Research Centres funding scheme. We are grateful to King’s College London Laboratories for processing the collagen biomarker panel
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