180 research outputs found

    Platelet-Derived Growth Factor Preserves Retinal Synapses in a Rat Model of Ocular Hypertension.

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    PURPOSE: Platelet-derived growth factor (PDGF) promotes neuronal survival in experimental glaucoma and recruits glial cells that regulate synapses. We investigated the effects of intravitreal PDGF on the inflammatory milieu and retinal synapses in the presence of raised IOP. METHODS: Animals with laser-induced IOP elevation received intravitreal injections of either saline or 1.5 μg PDGF. At 7 days, a further intravitreal injection was administered so groups received "PDGF-saline" (n = 15), "PDGF-PDGF" (n = 13), or "saline-saline" (n = 20). Platelet-derived growth factor receptor activation was assessed after 2 weeks using Western blot for PI3 kinase. Immunohistochemistry was performed for markers of synapses in the inner plexiform layer (IPL): PSD-95, GluR1, SY38; RGCs: βIII-tubulin, and glial cells: Iba-1, CD45. Real-time quantitative polymerase chain reaction (qPCR) was performed for Arc, selp, MCP-1, IL-6, IL-10, and CX3CR1 (n = 13). RESULTS: A single injection of PDGF increased IPL synaptic density in high IOP eyes (PSD-95 = 8.65 ± 0.43, SY38 = 8.68 ± 0.51, GluR1 = 9.03 ± 0.60 puncta/μm3, P < 0.001) and expression of synaptic modulator Arc (6.92 ± 3.71-fold change/control, P < 0.05) in comparison with vehicle (PSD-95 = 4.59 ± 0.41, SY38 = 4.46 ± 0.38, GluR1 = 5.94 ± 0.50 puncta/μm3, Arc = 1.46 ± 0.31-fold/control). This was associated with more resident microglia (8.16 ± 1.34-fold change/control, P < 0.001) and infiltrating monocyte-derived macrophages in the retina as well as increased Selp expression (26.8 ± 14.12-fold change/control, P < 0.05). Optic nerve head (ONH) showed an increased microglia (saline = 1.44 ± 0.13 versus PDGF = 2.23 ± 0.18-fold change/control, P < 0.01) but not infiltrating macrophages. IL-10 expression was significantly increased in PDGF-treated eyes (5.43 ± 0.47-fold change/control, P < 0.05) relative to vehicle (2.51 ± 0.67-fold change/control). CONCLUSIONS: Platelet-derived growth factor increased microglial and monocyte-derived macrophage populations in the eye and protected intraretinal synapses from degeneration in our experimental glaucoma model.Supported by the Agency for Science Technology and Research Singapore (RC), the Cambridge Eye Trust, the HB Allen Charitable Trust and the Jukes Glaucoma Research Fund, and by Grant 1868 from Fight for Sight (KM).This is the final version of the article. It first appeared from the Association for Research in Vision and Opthalmology via http://dx.doi.org/10.1167/iovs.15-1786

    Glial cell interactions and glaucoma.

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    PURPOSE OF REVIEW: The present review describes new advances in our understanding of the role of glial cells in the pathogenesis of glaucoma. It is becoming clear that retinal glia should not be studied in isolation in glaucoma because glia have dynamic and diverse interactions with a range of different cell types that could influence the disease process. RECENT FINDINGS: Microglial activity is modulated by signals from retinal ganglion cells and macroglia that influence RGC survival in various models of injury. New studies suggest that circulating monocytic populations may play a role in mediating the immune response to glaucoma. Astrocytes have been found to develop discrete localized processes that interact with a specific subset of retinal ganglion cells, possibly responding to the expression of phagocytic signals by stressed retinal ganglion cells. SUMMARY: Retinal glia constitute a highly versatile population that interacts with various cells to maintain homeostasis and limit disease. Defining the mechanisms that underlie glial communication could enable the development of more selective therapeutic targets, with great potential clinical applications.The authors were supported by the Agency for Science, Technology and Research (Singapore), Fight for Sight (UK), the Cambridge Eye Trust (UK) and the Jukes Glaucoma Research Fund (UK).This is the final version. It was first published by Lippincott Williams & Wilkins at http://journals.lww.com/co-ophthalmology/pages/articleviewer.aspx?year=2015&issue=03000&article=00002&type=abstrac

    Retinal glia promote dorsal root ganglion axon regeneration.

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    Axon regeneration in the adult central nervous system (CNS) is limited by several factors including a lack of neurotrophic support. Recent studies have shown that glia from the adult rat CNS, specifically retinal astrocytes and Müller glia, can promote regeneration of retinal ganglion cell axons. In the present study we investigated whether retinal glia also exert a growth promoting effect outside the visual system. We found that retinal glial conditioned medium significantly enhanced neurite growth and branching of adult rat dorsal root ganglion neurons (DRG) in culture. Furthermore, transplantation of retinal glia significantly enhanced regeneration of DRG axons past the dorsal root entry zone after root crush in adult rats. To identify the factors that mediate the growth promoting effects of retinal glia, mass spectrometric analysis of retinal glial conditioned medium was performed. Apolipoprotein E and secreted protein acidic and rich in cysteine (SPARC) were found to be present in high abundance, a finding further confirmed by western blotting. Inhibition of Apolipoprotein E and SPARC significantly reduced the neuritogenic effects of retinal glial conditioned medium on DRG in culture, suggesting that Apolipoprotein E and SPARC are the major mediators of this regenerative response.This work was supported by a van Geest Fight for Sight Early Career Investigator Award, grant number 1868 [BL].This is the final version of the article. It first appeared at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.011599

    Agro-climate tools for a new climate-smart agriculture

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    The way we produce food must adapt to a variable and changing climate. And key to achieving this is to improve the link between climate information and agricultural practices, especially those of smallholder farmers in developing countries. ‘Agro-climate tools’ do just that and some are introduced here

    Nephrogenic Diabetes Insipidus (NDI): Clinical, Laboratory and Genetic Characterization of Five Brazilian Patients

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    INTRODUCTION: Nephrogenic diabetes insipidus is characterized by a lack of response in the distal nephron to the antidiuretic hormone arginine vasopressin. Manifestations include polyuria, polydipsia, hyposthenuria, recurrent episodes of dehydration and fever and growth failure. Most cases are caused by mutations in the AVPR2 gene. The mutant receptors are trapped intracellularly. METHOD: We studied five boys using clinical, laboratory and molecular data. The mean age at diagnosis was 14.6 months (range 6 to 24) and 12.2 years (7.8 to 19) after the follow-up period. The mean period of follow-up was 132.2 ± 50.9 months. RESULTS: The geometric means of the z-scores of weight and stature were -4.5 and -3.6, respectively, at diagnosis. At the last medical appointment, the z-scores of weight and stature were -0.3 and -0.9, respectively. Three patients were diagnosed with ureterohydronephrosis and exhibited increased post-void urine volume. Mutations in the AVPR2 gene were found in all patients, and the carrier status was confirmed in four of five cases. Two unrelated children presented identical mutations (S167L) in arginine vasopressin R2. Two of the patients had a mutation that has already been described in other Brazilian families (R337X), and one patient showed a de novo mutation (Y128D) in arginine vasopressin R2, since his mother's molecular analysis was normal. The recurrence risk for this family was significantly reduced. CONCLUSION: This study reports the clinical and laboratory characterization of Nephrogenic diabetes insipidus and reiterates the importance of the genetic basis that underlies the disease diagnosis and genetic counseling

    The \u3cem\u3eChlamydomonas\u3c/em\u3e Genome Reveals the Evolution of Key Animal and Plant Functions

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    Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the ∼120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella

    Copy number variation in Williams-Beuren syndrome: suitable diagnostic strategy for developing countries

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    <p>Abstract</p> <p>Background</p> <p>Williams-Beuren syndrome (WBS; OMIM 194050) is caused by a hemizygous contiguous gene microdeletion at 7q11.23. Supravalvular aortic stenosis (SVAS), mental retardation, and overfriendliness comprise typical symptoms of WBS. Although fluorescence in situ hybridization (FISH) is considered the gold standard technique, the microsatellite DNA markers and multiplex ligation-dependent probe amplification (MLPA) could be used for to confirm the diagnosis of WBS.</p> <p>Results</p> <p>We have evaluated a total cohort of 88 patients with a suspicion clinical diagnosis of WBS using a collection of five markers (D7S1870, D7S489, D7S613, D7S2476, and D7S489_A) and a commercial MLPA kit (P029). The microdeletion was present in 64 (72.7%) patients and absent in 24 (27.3%) patients. The parental origin of deletion was maternal in 36 of 64 patients (56.3%) paternal in 28 of 64 patients (43.7%). The deletion size was 1.55 Mb in 57 of 64 patients (89.1%) and 1.84 Mb in 7 of 64 patients (10.9%). The results were concordant using both techniques, except for four patients whose microsatellite markers were uninformative. There were no clinical differences in relation to either the size or parental origin of the deletion.</p> <p>Conclusion</p> <p>MLPA was considered a faster and more economical method in a single assay, whereas the microsatellite markers could determine both the size and parental origin of the deletion in WBS. The microsatellite marker and MLPA techniques are effective in deletion detection in WBS, and both methods provide a useful diagnostic strategy mainly for developing countries.</p

    sFDvent: A global trait database for deep‐sea hydrothermal‐vent fauna

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    Motivation: Traits are increasingly being used to quantify global biodiversity patterns, with trait databases growing in size and number, across diverse taxa. Despite grow‐ ing interest in a trait‐based approach to the biodiversity of the deep sea, where the impacts of human activities (including seabed mining) accelerate, there is no single re‐ pository for species traits for deep‐sea chemosynthesis‐based ecosystems, including hydrothermal vents. Using an international, collaborative approach, we have compiled the first global‐scale trait database for deep‐sea hydrothermal‐vent fauna – sFD‐ vent (sDiv‐funded trait database for the Functional Diversity of vents). We formed a funded working group to select traits appropriate to: (a) capture the performance of vent species and their influence on ecosystem processes, and (b) compare trait‐based diversity in different ecosystems. Forty contributors, representing expertise across most known hydrothermal‐vent systems and taxa, scored species traits using online collaborative tools and shared workspaces. Here, we characterise the sFDvent da‐ tabase, describe our approach, and evaluate its scope. Finally, we compare the sFD‐ vent database to similar databases from shallow‐marine and terrestrial ecosystems to highlight how the sFDvent database can inform cross‐ecosystem comparisons. We also make the sFDvent database publicly available online by assigning a persistent, unique DOI. Main types of variable contained: Six hundred and forty‐six vent species names, associated location information (33 regions), and scores for 13 traits (in categories: community structure, generalist/specialist, geographic distribution, habitat use, life history, mobility, species associations, symbiont, and trophic structure). Contributor IDs, certainty scores, and references are also provided. Spatial location and grain: Global coverage (grain size: ocean basin), spanning eight ocean basins, including vents on 12 mid‐ocean ridges and 6 back‐arc spreading centres. Time period and grain: sFDvent includes information on deep‐sea vent species, and associated taxonomic updates, since they were first discovered in 1977. Time is not recorded. The database will be updated every 5 years. Major taxa and level of measurement: Deep‐sea hydrothermal‐vent fauna with spe‐ cies‐level identification present or in progress. Software format: .csv and MS Excel (.xlsx).This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Integrated continuous process design for crystallisation, spherical agglomeration, and filtration of lovastatin

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    Purpose This work seeks to improve the particle processability of needle-like lovastatin crystals and develop a small-footprint continuous MicroFactory for its production. Methods General conditions for optimal spherical agglomeration of lovastatin crystals and subsequent product isolation are developed, first as batch processes, and then transferred to continuous MicroFactory operation. Results Methyl isobutyl ketone is a suitable bridging liquid for the spherical agglomeration of lovastatin. Practical challenges including coupling unit operations and solvent systems; mismatched flow rates and inconsistent suspension solid loading were resolved. The successful continuous production of lovastatin spherical agglomerates (D50 = 336 µm) was achieved. Spherical agglomeration increased the density of the bulk lovastatin powder and improved product flowability from poor to good, whilst maintaining lovastatin tablet performance. Conclusion A continuous, integrated MicroFactory for the crystallisation, spherical agglomeration, and filtration of lovastatin is presented with improved product particle processability. Up to 16,800 doses of lovastatin (60 mg) can be produced per day using a footprint of 23 m2
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