311 research outputs found

    H-ficolin binds Aspergillus fumigatus leading to activation of the lectin complement pathway and modulation of lung epithelial immune responses.

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    Aspergillus fumigatus is an opportunistic fungal pathogen that typically infects the lungs of immunocompromised patients leading to a high mortality. H-Ficolin, an innate immune opsonin, is produced by type II alveolar epithelial cells and could participate in lung defences against infections. Here, we used the human type II alveolar epithelial cell line, A549, to determine the involvement of H-ficolin in fungal defence. Additionally, we investigated the presence of H-ficolin in bronchoalveolar lavage fluid from transplant patients during pneumonia. H-Ficolin exhibited demonstrable binding to A. fumigatus conidia via l-fucose, d-mannose and N-acetylglucosamine residues in a calcium- and pH-dependent manner. Moreover, recognition led to lectin complement pathway activation and enhanced fungal association with A549 cells. Following recognition, H-ficolin opsonization manifested an increase in interleukin-8 production from A549 cells, which involved activation of the intracellular signalling pathways mitogen-activated protein kinase MAPK kinase 1/2, p38 MAPK and c-Jun N-terminal kinase. Finally, H-ficolin concentrations were significantly higher in bronchoalveolar lavage fluid of patients with lung infections compared with control subjects (n = 16; P = 0·00726). Receiver operating characteristics curve analysis further highlighted the potential of H-ficolin as a diagnostic marker for lung infection (area under the curve = 0·77; P < 0·0001). Hence, H-ficolin participates in A. fumigatus defence through the activation of the lectin complement pathway, enhanced fungus-host interactions and modulated immune responses

    Common genetic polymorphisms within NFκB-Related genes and the risk of developing invasive aspergillosis

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    Invasive Aspergillosis (IA) is an opportunistic infection caused by Aspergillus, a ubiquitously present airborne pathogenic mold. A growing number of studies suggest a major host genetic component in disease susceptibility. Here, we evaluated whether 14 single-nucleotide polymorphisms within NF kappa B1, NF kappa B2, RelA, RelB, Rel, and IRF4 genes influence the risk of IA in a population of 834 high-risk patients (157 IA and 677 non IA) recruited through a collaborative effort involving the aspBlOmics consortium and four European clinical institutions. No significant overall associations between selected SNPs and the risk of IA were found in this large cohort. Although a hematopoietic stem cell transplantation (HSCT)-stratified analysis revealed that carriers of the IRF4(rs12203592T/T) genotype had a six-fold increased risk of developing the infection when compared with those carrying the C allele (ORREC = 6.24, 95%CI 1.25-31.2, P = 0.026), the association of this variant with IA risk did not reach significance at experiment-wide significant threshold. In addition, we found an association of the IRF4(AATC) and IRF4(GGTC) haplotypes (not including the IRF4(rs12203592T/T) risk allele) with a decreased risk of IA but the magnitude of the association was similar to the one observed in the single-SNP analysis, which indicated that the haplotypic effect on IA risk was likely due to the IRF4(rs12203592) SNP Finally, no evidence of significant interactions among the genetic markers tested and the risk of IA was found. These results suggest that the SNPs on the studied genes do not have a clinically relevant impact on the risk of developing IA.- This study was supported by grants PI12/02688 from Fond de Investigaciones Sanitarias (Institute de Salud Carlos III, Madrid, Spain), the ERA-NET PathoGenoMics (03159000A; Ministerio de Ciencia e Innovation PIM2010EPA-00756, Madrid, Spain), the Collaborative Research Center / Transregio 124 FungiNet, the Austrian Science Fundation (FWF I-656-B09), the Fundacao para a Ciencia e Tecnologia (FCT), cofundcd by Programa Operacional Regional do Norte (ON.2-O Novo Norte), the Quadro de Referencia Estrategico Nacional (QREN) through the Fundo Europeu de Desenvolvimento Regional (FEDER) and the Projeto Estrategico - LA 26 - 2013-2014 (PEst-C/SAU/LA0026/2013). Agostinho Carvalho and Cristina Cunha were supported by the Fundacao para a e Tecnologia (FCT), Portugal (IF/00735/2014 and SFRH/BPD/96176/2013, respectively). The PCRAGA trial was supported by an unrestricted grant from Pfizer, which had no involvement or control over the collection, analysis, and interpretation of data; the writing of the report; or the decision to submit the paper for publication. This study was also supported by Astellas Pharma Inc. and a donation from Consuelo Gonzalez Moreno, an acute myeloid leukemia survivor.info:eu-repo/semantics/publishedVersio

    Hand hygiene compliance and environmental contamination with gram-negative bacilli in a rural hospital in Madarounfa, Niger

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    Abstract Background Healthcare-associated infections pose a major, yet often preventable risk to patient safety. Poor hand hygiene among healthcare personnel and unsanitary hospital environments may contribute to this risk in low-income settings. We aimed to describe hand hygiene behaviour and environmental contamination by season in a rural, sub-Saharan African hospital setting. Methods We conducted a concurrent triangulation mixed-methods study combining three types of data at a hospital in Madarounfa, Niger. Hand hygiene observations among healthcare personnel during two seasons contributed quantitative data describing hand hygiene frequency and its variability in relation to seasonal changes in caseload. Semistructured interviews with healthcare personnel contributed qualitative data on knowledge, attitudes and barriers to hand hygiene. Biweekly environmental samples evaluated microbial contamination from October 2016 to December 2017. Triangulation identified convergences, complements and contradictions across results. Results Hand hygiene compliance, or the proportion of actions (handrubbing or handwashing) performed out of all actions required, was low (11% during non-peak and 36% during peak caseload seasons). Interviews with healthcare personnel suggesting good general knowledge of hand hygiene contradicted the low hand hygiene compliance. However, compliance by healthcare activity was convergent with poor knowledge of precise hand hygiene steps and the motivation to prevent personal acquisition of infection identified during interviews. Contamination of environmental samples with gram-negative bacilli was high (45%), with the highest rates of contamination observed during the peak caseload season. Conclusion Low hand hygiene compliance coupled with high contamination rates of hospital environments may increase the risk of hospital-acquired infections in sub-Saharan African settings. </jats:sec

    Modelling of cohesion and adhesion damage of seal based on dynamic shear rheometer testing

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    Most current seal designs are based on the volumetric properties of materials and voids. In order to improve seal design, the possibility of introducing mechanistic principles into seal design was investigated. Introducing mechanistic concepts into seal design means that principles such as elasticity and viscoelasticity could be used in terms of stress-strain to explain phenomena such as damage in the seal structure. Two main failure parameters of seals – cohesion failure (fatigue cracking due to ageing of binder and loss of elasticity) and adhesion failure or stripping (occurring between stone to bitumen or bitumen to base) – are investigated using the complex modulus (G *) which is one of the viscoelastic parameters of bituminous materials. This paper therefore investigates the testing procedure of cohesion fatigue damage (CFD) and Adhesion Fatigue Damage (AFD) of bituminous seal material using the Dynamic Shear Rheometer (DSR). The CFD and AFD modelling are based on the stiffness reduction principle of materials under the action of cyclic stress. Based on the Lifetime Optimisation Tool (LOT) research programme from Delft University of Technology, a DSR testing procedure and approach was adopted for seals. The tests were performed on 70/100 penetration grade bitumen columns (for CFD) and on stone columns constituted with dolorite glued together with 70/100 penetration grade bitumen (for AFD). It was observed that the model for CFD depends more on stress, while the model for AFD appears to depend more on temperature. This observation agrees with the fact that adhesion damage is more sensitive to temperature change, whereas cohesion damage is more prone to be influenced by applied fatigue stress. The CFD and AFD models provide an indication of non-linear development of the accumulated fatigue damage of seal. This is represented by the modelling of the change of G *, as suggested in this investigation.SANRALhttp://www.tandfonline.com/loi/gpav20hj2019Civil Engineerin

    Acquisition of Escherichia coli carrying extended-spectrum ß-lactamase and carbapenemase genes by hospitalised children with severe acute malnutrition in Niger

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    Hospitalisation and routine antibiotic treatment are recommended for children with complicated severe acute malnutrition (SAM) but this may exacerbate antimicrobial resistance. Here, we investigate carriage of Gram-negative bacteria in children under five years of age receiving treatment for SAM in Niger, comparing the frequency of colonisation with bacteria carrying resistance genes at admission, during hospital stay and at discharge. E. coli isolates carrying a blaNDM-5 gene were selected for whole-genome sequencing. Rectal colonisation with bacteria carrying ß-lactamase genes is high, with 76% (n = 1042/1371) of children harbouring bacteria carrying a blaCTXM-1-group gene and 25% (n = 338/1371) carrying a blaNDM-5 gene. Over two-thirds of children who did not carry bacteria with a carbapenemase gene at admission are colonised with bacteria carrying a carbapenemase gene at discharge (n = 503/729, 69%). E. coli ST167 carrying blaNDM-5 gene is recovered from 11% (n = 144/1371) of children. Here we highlight infection control and bacterial AMR transmission concerns amongst a vulnerable population in need of medical treatment

    Serum proteome analysis for profiling protein markers associated with carcinogenesis and lymph node metastasis in nasopharyngeal carcinoma

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    Nasopharyngeal carcinoma (NPC), one of the most common cancers in population with Chinese or Asian progeny, poses a serious health problem for southern China. It is unfortunate that most NPC victims have had lymph node metastasis (LNM) when first diagnosed. We believe that the 2D based serum proteome analysis can be useful in discovering new biomarkers that may aid in the diagnosis and therapy of NPC patients. To filter the tumor specific antigen markers of NPC, sera from 42 healthy volunteers, 27 non-LNM NPC patients and 37 LNM NPC patients were selected for screening study using 2D combined with MS. Pretreatment strategy, including sonication, albumin and immunoglobulin G (IgG) depletion, was adopted for screening differentially expressed proteins of low abundance in serum. By 2D image analysis and MALDI-TOF-MS identification, twenty-three protein spots were differentially expressed. Three of them were further validated in the sera using enzyme-linked immunosorbent assay (ELISA). Our research demonstrates that HSP70, sICAM-1 and SAA, confirmed with ELISA at sera and immunohistochemistry, are potential NPC metastasis-specific serum biomarkers which may be of great underlying significance in clinical detection and management of NPC

    Tumor-Specific Hsp70 Plasma Membrane Localization Is Enabled by the Glycosphingolipid Gb3

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    Human tumors differ from normal tissues in their capacity to present Hsp70, the major stress-inducible member of the HSP70 family, on their plasma membrane. Membrane Hsp70 has been found to serve as a prognostic indicator of overall patient survival in leukemia, lower rectal and non small cell lung carcinomas. Why tumors, but not normal cells, present Hsp70 on their cell surface and the impact of membrane Hsp70 on cancer progression remains to be elucidated.Although Hsp70 has been reported to be associated with cholesterol rich microdomains (CRMs), the partner in the plasma membrane with which Hsp70 interacts has yet to be identified. Herein, global lipid profiling demonstrates that Hsp70 membrane-positive tumors differ from their membrane-negative counterparts by containing significantly higher amounts of globotriaoslyceramide (Gb3), but not of other lipids such as lactosylceramide (LacCer), dodecasaccharideceramide (DoCer), galactosylceramide (GalCer), ceramide (Cer), or the ganglioside GM1. Apart from germinal center B cells, normal tissues are Gb3 membrane-negative. Co-localization of Hsp70 and Gb3 was selectively determined in Gb3 membrane-positive tumor cells, and these cells were also shown to bind soluble Hsp70-FITC protein from outside in a concentration-dependent manner. Given that the latter interaction can be blocked by a Gb3-specific antibody, and that the depletion of globotriaosides from tumors reduces the amount of membrane-bound Hsp70, we propose that Gb3 is a binding partner for Hsp70. The in vitro finding that Hsp70 predominantly binds to artificial liposomes containing Gb3 (PC/SM/Chol/Gb3, 17/45/33/5) confirms that Gb3 is an interaction partner for Hsp70.These data indicate that the presence of Gb3 enables anchorage of Hsp70 in the plasma membrane of tumors and thus they might explain tumor-specific membrane localization of Hsp70

    What specific modes of internationalization influence SME innovation in Sub-Saharan least developed countries (LDCs)?

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    Small and medium sized enterprises (SMEs) located in the least developed countries (LDCs), operate in distinctively hostile institutional environments compared to those in developed economies. Better understanding of the determinants of SME innovation in such environments is important for the development of private sector in LDCs, because innovative SMEs are crucial for sustainable economic growth. Yet, determinants of SME innovation in LDCs have hardly been studied. Considering the potential relevance of internationalization for SME innovation in LDCs, as means of overcoming domestic environmental constraints, this paper investigates the influence of foreign technology licensing, exports and imports on SME innovation in LDCs. The study employs data from 1058 manufacturing SMEs from Sub-Saharan LDCs - Djibouti, Tanzania, Uganda, Zambia and the Democratic Republic of Congo. The findings suggest that foreign technology licensing is found to be positively and statistically associated with SME product and process innovations in Sub-Saharan LDCs. Findings are compared with those from developed economies in order to identify distinctive features. The implication is that SMEs in Sub-Saharan LDCs need to be supported by different policies compared to developed economies. The results also show that R&D, firm size, sectoral characteristics and access to finance are important determinants of SME innovation

    S100A8/A9 Is Not Involved in Host Defense against Murine Urinary Tract Infection

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    Background: Inflammation is commonly followed by the release of endogenous proteins called danger associated molecular patterns (DAMPs) that are able to warn the host for eminent danger. S100A8/A9 subunits are DAMPs that belong to the S100 family of calcium binding proteins. S100A8/A9 complexes induce an inflammatory response and their expression correlates with disease severity in several inflammatory disorders. S100A8/A9 promote endotoxin-and Escherichia (E.) coli-induced sepsis showing its contribution in systemic infection. The role of S100A8/A9 during a local infection of the urinary tract system caused by E. coli remains unknown. Methodology/Principal Findings: We investigated the contribution of S100A8/A9 in acute urinary tract infection (UTI) by instilling 2 different doses of uropathogenic E. coli transurethrally in wild type (WT) and S100A9 knockout (KO) mice. Subsequently, we determined bacterial outgrowth, neutrophilic infiltrate and inflammatory mediators in bladder and kidney 24 and 48 hours later. UTI resulted in a substantial increase of S100A8/A9 protein in bladder and kidney tissue of WT mice. S100A9 KO mice displayed similar bacterial load in bladder or kidney homogenate compared to WT mice using 2 different doses at 2 different time points. S100A9 deficiency had little effect on the inflammatory responses to E. Coli-induced UTI infection, as assessed by myeloperoxidase activity in bladder and kidneys, histopathologic analysis, and renal and bladder cytokine concentrations. Conclusions: We show that despite high S100A8/A9 expression in bladder and kidney tissue upon UTI, S100A8/A9 does not contribute to an effective host response against E. Coli in the urinary tract syste
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