184 research outputs found

    Optical coherence tomography angiography findings in pigmented paravenous chorioretinal atrophy

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    Purpose:To analyze the retino-choroidal vascular characteristics of patients affected by pigmented paravenous chorio-retinal atrophy by means of optical coherence tomography (OCT) angiography.Methods:This study was designed as an observational, cross-sectional case series. Multimodal imaging included fundus autofluorescence, structural OCT, and OCT angiography. The quantitative OCT angiography analyses included the calculation of the vessel density and choriocapillaris porosity.Results:Overall, 12 patients (24 eyes) affected by pigmented paravenous chorio-retinal atrophy were recruited. Structural OCT of the areas involved by pigmented paravenous chorio-retinal atrophy as visualized on the fundus autofluorescence showed a complete ellipsoid zone and external limiting membrane absence, with thinning of ganglion cell complex, outer nuclear layer, and outer plexiform layer, but associated with the optical partial preservation of the retinal pigment epithelium. Optical coherence tomography angiography quantitative assessment of the retinal regions affected by PPRCA, as visualized by fundus autofluorescence, was characterized by normal vessel density at the level of superficial capillary plexus but significantly altered vessel density of deep capillary plexus and choriocapillaris, with higher choriocapillaris porosity. The presence of macular atrophy was significantly correlated with worse deep capillary plexus and choriocapillaris vessel density values. Furthermore, a statistically significant correlation between the fundus autofluorescence patterns and the retinal vascular status was found.Conclusion:Optical coherence tomography angiography quantitative analyses in pigmented paravenous chorio-retinal atrophy demonstrate a specific impairment at the level of the deep capillary plexus, which could in turn bring about a thinning of ganglion cell complex and outer nuclear layer. The alterations at the level of the choriocapillaris and the choroid, in general, could then represent a secondary effect

    Transparent and accurate reporting increases reliability, utility, and impact of your research: reporting guidelines and the EQUATOR Network

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    Although current electronic methods of scientific publishing offer increased opportunities for publishing all research studies and describing them in sufficient detail, health research literature still suffers from many shortcomings. These shortcomings seriously undermine the value and utility of the literature and waste scarce resources invested in the research. In recent years there have been several positive steps aimed at improving this situation, such as a strengthening of journals' policies on research publication and the wide requirement to register clinical trials

    Comprehensive in silico functional specification of mouse retina transcripts

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    BACKGROUND: The retina is a well-defined portion of the central nervous system (CNS) that has been used as a model for CNS development and function studies. The full specification of transcripts in an individual tissue or cell type, like retina, can greatly aid the understanding of the control of cell differentiation and cell function. In this study, we have integrated computational bioinformatics and microarray experimental approaches to classify the tissue specificity and developmental distribution of mouse retina transcripts. RESULTS: We have classified a set of retina-specific genes using sequence-based screening integrated with computational and retina tissue-specific microarray approaches. 33,737 non-redundant sequences were identified as retina transcript clusters (RTCs) from more than 81,000 mouse retina ESTs. We estimate that about 19,000 to 20,000 genes might express in mouse retina from embryonic to adult stages. 39.1% of the RTCs are not covered by 60,770 RIKEN full-length cDNAs. Through comparison with 2 million mouse ESTs, spectra of neural, retinal, late-generated retinal, and photoreceptor -enriched RTCs have been generated. More than 70% of these RTCs have data from biological experiments confirming their tissue-specific expression pattern. The highest-grade retina-enriched pool covered almost all the known genes encoding proteins involved in photo-transduction. CONCLUSION: This study provides a comprehensive mouse retina transcript profile for further gene discovery in retina and suggests that tissue-specific transcripts contribute substantially to the whole transcriptome

    Calculation of Direct Antiretroviral Treatment Costs and Potential Cost Savings by Using Generics in the German HIV ClinSurv Cohort

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    BACKGROUND/AIM OF THE STUDY: The study aimed to determine the cost impacts of antiretroviral drugs by analysing a long-term follow-up of direct costs for combined antiretroviral therapy, cART, -regimens in the nationwide long-term observational multi-centre German HIV ClinSurv Cohort. The second aim was to develop potential cost saving strategies by modelling different treatment scenarios. Antiretroviral regimens (ART) from 10,190 HIV-infected patients from 11 participating ClinSurv study centres have been investigated since 1996. Biannual data cART-initiation, cART-changes, surrogate markers, clinical events and the Centre of Disease Control- (CDC)-stage of HIV disease are reported. Treatment duration was calculated on a daily basis via the documented dates for the beginning and end of each antiretroviral drug treatment. Prices were calculated for each individual regimen based on actual office sales prices of the branded pharmaceuticals distributed by the license holder including German taxes. During the 13-year follow-up period, 21,387,427 treatment days were covered. Cumulative direct costs for antiretroviral drugs of €812,877,356 were determined according to an average of €42.08 per day (€7.52 to € 217.70). Since cART is widely used in Germany, the costs for an entire regimen increased by 13.5%. Regimens are more expensive in the advanced stages of HIV disease. The potential for cost savings was calculated using non-nucleotide-reverse-transcriptase-inhibitor, NNRTI, more frequently instead of ritonavir-boosted protease inhibitor, PI/r, in first line therapy. This calculation revealed cumulative savings of 10.9% to 19.8% of daily treatment costs (50% and 90% substitution of PI/r, respectively). Substituting certain branded drugs by generic drugs showed potential cost savings of between 1.6% and 31.8%. Analysis of the data of this nationwide study reflects disease-specific health services research and will give insights into the cost impacts of antiretroviral therapy, and might allow a more rational allocation of resources within the German health care system

    Overexpression of HTRA1 Leads to Ultrastructural Changes in the Elastic Layer of Bruch's Membrane via Cleavage of Extracellular Matrix Components

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    Variants in the chromosomal region 10q26 are strongly associated with an increased risk for age-related macular degeneration (AMD). Two potential AMD genes are located in this region: ARMS2 and HTRA1 (high-temperature requirement A1). Previous studies have suggested that polymorphisms in the promotor region of HTRA1 result in overexpression of HTRA1 protein. This study investigated the role of HTRA1 overexpression in the pathogenesis of AMD. Transgenic Htra1 mice overexpressing the murine protein in the retinal pigment epithelium (RPE) layer of the retina were generated and characterized by transmission electron microscopy, immunofluorescence staining and Western Blot analysis. The elastic layer of Bruch's membrane (BM) in the Htra1 transgenic mice was fragmented and less continuous than in wild type (WT) controls. Recombinant HTRA1 lacking the N-terminal domain cleaved various extracellular matrix (ECM) proteins. Subsequent Western Blot analysis revealed an overexpression of fibronectin fragments and a reduction of fibulin 5 and tropoelastin in the RPE/choroid layer in transgenic mice compared to WT. Fibulin 5 is essential for elastogenesis by promoting elastic fiber assembly and maturation. Taken together, our data implicate that HTRA1 overexpression leads to an altered elastogenesis in BM through fibulin 5 cleavage. It highlights the importance of ECM related proteins in the development of AMD and links HTRA1 to other AMD risk genes such as fibulin 5, fibulin 6, ARMS2 and TIMP3

    Nef Alleles from All Major HIV-1 Clades Activate Src-Family Kinases and Enhance HIV-1 Replication in an Inhibitor-Sensitive Manner

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    The HIV-1 accessory factor Nef is essential for high-titer viral replication and AIDS progression. Nef function requires interaction with many host cell proteins, including specific members of the Src kinase family. Here we explored whether Src-family kinase activation is a conserved property of Nef alleles from a wide range of primary HIV-1 isolates and their sensitivity to selective pharmacological inhibitors. Representative Nef proteins from the major HIV-1 subtypes A1, A2, B, C, F1, F2, G, H, J and K strongly activated Hck and Lyn as well as c-Src to a lesser extent, demonstrating for the first time that Src-family kinase activation is a highly conserved property of primary M-group HIV-1 Nef isolates. Recently, we identified 4-amino substituted diphenylfuropyrimidines (DFPs) that selectively inhibit Nef-dependent activation of Src-family kinases as well as HIV replication. To determine whether DFP compounds exhibit broad-spectrum Nef-dependent antiretroviral activity against HIV-1, we first constructed chimeric forms of the HIV-1 strain NL4-3 expressing each of the primary Nef alleles. The infectivity and replication of these Nef chimeras was indistinguishable from that of wild-type virus in two distinct cell lines (U87MG astroglial cells and CEM-T4 lymphoblasts). Importantly, the 4-aminopropanol and 4-aminobutanol derivatives of DFP potently inhibited the replication of all chimeric forms of HIV-1 in both U87MG and CEM-T4 cells in a Nef-dependent manner. The antiretroviral effects of these compounds correlated with inhibition of Nef-dependent activation of endogenous Src-family kinases in the HIV-infected cells. Our results demonstrate that the activation of Hck, Lyn and c-Src by Nef is highly conserved among all major clades of HIV-1 and that selective targeting of this pathway uniformly inhibits HIV-1 replication

    The HIV Envelope but Not VSV Glycoprotein Is Capable of Mediating HIV Latent Infection of Resting CD4 T Cells

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    HIV fusion and entry into CD4 T cells are mediated by two receptors, CD4 and CXCR4. This receptor requirement can be abrogated by pseudotyping the virion with the vesicular stomatitis virus glycoprotein (VSV-G) that mediates viral entry through endocytosis. The VSV-G-pseudotyped HIV is highly infectious for transformed cells, although the virus circumvents the viral receptors and the actin cortex. In HIV infection, gp120 binding to the receptors also transduces signals. Recently, we demonstrated a unique requirement for CXCR4 signaling in HIV latent infection of blood resting CD4 T cells. Thus, we performed parallel studies in which the VSV-G-pseudotyped HIV was used to infect both transformed and resting T cells in the absence of coreceptor signaling. Our results indicate that in transformed T cells, the VSV-G-pseudotyping results in lower viral DNA synthesis but a higher rate of nuclear migration. However, in resting CD4 T cells, only the HIV envelope-mediated entry, but not the VSV-G-mediated endocytosis, can lead to viral DNA synthesis and nuclear migration. The viral particles entering through the endocytotic pathway were destroyed within 1–2 days. These results indicate that the VSV-G-mediated endocytotic pathway, although active in transformed cells, is defective and is not a pathway that can establish HIV latent infection of primary resting T cells. Our results highlight the importance of the genuine HIV envelope and its signaling capacity in the latent infection of blood resting T cells. These results also call for caution on the endocytotic entry model of HIV-1, and on data interpretation where the VSV-G-pseudotyped HIV was used for identifying HIV restriction factors in resting T cells

    Nef Decreases HIV-1 Sensitivity to Neutralizing Antibodies that Target the Membrane-proximal External Region of TMgp41

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    Primate lentivirus nef is required for sustained virus replication in vivo and accelerated progression to AIDS. While exploring the mechanism by which Nef increases the infectivity of cell-free virions, we investigated a functional link between Nef and Env. Since we failed to detect an effect of Nef on the quantity of virion-associated Env, we searched for qualitative changes by examining whether Nef alters HIV-1 sensitivity to agents that target distinct features of Env. Nef conferred as much as 50-fold resistance to 2F5 and 4E10, two potent neutralizing monoclonal antibodies (nAbs) that target the membrane proximal external region (MPER) of TMgp41. In contrast, Nef had no effect on HIV-1 neutralization by MPER-specific nAb Z13e1, by the peptide inhibitor T20, nor by a panel of nAbs and other reagents targeting gp120. Resistance to neutralization by 2F5 and 4E10 was observed with Nef from a diverse range of HIV-1 and SIV isolates, as well as with HIV-1 virions bearing Env from CCR5- and CXCR4-tropic viruses, clade B and C viruses, or primary isolates. Functional analysis of a panel of Nef mutants revealed that this activity requires Nef myristoylation but that it is genetically separable from other Nef functions such as the ability to enhance virus infectivity and to downregulate CD4. Glycosylated-Gag from MoMLV substituted for Nef in conferring resistance to 2F5 and 4E10, indicating that this activity is conserved in a retrovirus that does not encode Nef. Given the reported membrane-dependence of MPER-recognition by 2F5 and 4E10, in contrast to the membrane-independence of Z13e1, the data here is consistent with a model in which Nef alters MPER recognition in the context of the virion membrane. Indeed, Nef and Glycosylated-Gag decreased the efficiency of virion capture by 2F5 and 4E10, but not by other nAbs. These studies demonstrate that Nef protects lentiviruses from one of the most broadly-acting classes of neutralizing antibodies. This newly discovered activity for Nef has important implications for anti-HIV-1 immunity and AIDS pathogenesis

    Antimicrobial consumption and resistance in adult hospital inpatients in 53 countries:results of an internet-based global point prevalence survey

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    Summary: Background: The Global Point Prevalence Survey (Global-PPS) established an international network of hospitals to measure antimicrobial prescribing and resistance worldwide. We aimed to assess antimicrobial prescribing and resistance in hospital inpatients. Methods: We used a standardised surveillance method to collect detailed data about antimicrobial prescribing and resistance from hospitals worldwide, which were grouped by UN region. The internet-based survey included all inpatients (adults, children, and neonates) receiving an antimicrobial who were on the ward at 0800 h on one specific day between January and September, 2015. Hospitals were classified as primary, secondary, tertiary (including infectious diseases hospitals), and paediatric hospitals. Five main ward types were defined: medical wards, surgical wards, intensive-care units, haematology oncology wards, and medical transplantation (bone marrow or solid transplants) wards. Data recorded included patient characteristics, antimicrobials received, diagnosis, therapeutic indication according to predefined lists, and markers of prescribing quality (eg, whether a stop or review date were recorded, and whether local prescribing guidelines existed and were adhered to). We report findings for adult inpatients. Findings: The Global-PPS for 2015 included adult data from 303 hospitals in 53 countries, including eight lower-middle-income and 17 upper-middle-income countries. 86 776 inpatients were admitted to 3315 adult wards, of whom 29 891 (34·4%) received at least one antimicrobial. 41 213 antimicrobial prescriptions were issued, of which 36 792 (89·3%) were antibacterial agents for systemic use. The top three antibiotics prescribed worldwide were penicillins with β-lactamase inhibitors, third-generation cephalosporins, and fluoroquinolones. Carbapenems were most frequently prescribed in Latin America and west and central Asia. Of patients who received at least one antimicrobial, 5926 (19·8%) received a targeted antibacterial treatment for systemic use, and 1769 (5·9%) received a treatment targeting at least one multidrug-resistant organism. The frequency of health-care-associated infections was highest in Latin America (1518 [11·9%]) and east and south Asia (5363 [10·1%]). Overall, the reason for treatment was recorded in 31 694 (76·9%) of antimicrobial prescriptions, and a stop or review date in 15 778 (38·3%). Local antibiotic guidelines were missing for 7050 (19·2%) of the 36 792 antibiotic prescriptions, and guideline compliance was 77·4%. Interpretation: The Global-PPS showed that worldwide surveillance can be accomplished with voluntary participation. It provided quantifiable measures to assess and compare the quantity and quality of antibiotic prescribing and resistance in hospital patients worldwide. These data will help to improve the quality of antibiotic prescribing through education and practice changes, particularly in low-income and middle-income countries that have no tools to monitor antibiotic prescribing in hospitals. Funding: bioMérieux
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