11 research outputs found

    QADE: a novel trust and reputation model for handling false trust values in e–commerce environments with subjectivity consideration

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    Trust is essential to economic efficiency. Trading partners choose each other and make decisions based on how much they trust one another. The way to assess trust in e-commerce is different from those in brick and mortar businesses, as there are limited indicators available in online environments. One way is to deploy trust and reputation management systems that are based on collecting feedbacks about partners’ transactions. One of the problems within such systems is the presence of unfair ratings. In this paper, an innovative QADE trust model is presented, which assumes the existence of unfairly reported trust assessments. Subjective nature of trust is considered, where differently reported trust values do not necessarily mean false trust values but can also imply differences in dispositions to trust. The method to identify and filter out the presumably false values is defined. In our method, a trust evaluator finds other agents in society that are similar to him, taking into account pairwise similarity of trust values and similarity of agents’ general mindsets. In order to reduce the effect of unfair ratings, the values reported by the non-similar agents are excluded from the trust computation. Simulations have been used to compare the effectiveness of algorithms to decrease the effect of unfair ratings. The simulations have been carried out in environments with varying number of attackers and targeted agents, as well as with different kinds of attackers. The results showed significant improvements of our proposed method. On average 6% to 13% more unfair trust ratings have been detected by our method. Unfair rating effects on trust assessment were reduced with average improvements from 26% to 57% compared to the other most effective filtering methods by Whitby and Teacy. First published online: 02 Jun 201

    Effectiveness of structured patient education on the knowledge level of adolescents and adults with congenital heart disease

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    BACKGROUND: Patients with congenital heart disease (CHD) have poor understanding of their heart condition, treatment and prevention of complications. To improve their level of health-related knowledge, a structured education program was implemented in the adult congenital heart disease program. This study aimed (a) to evaluate the level of knowledge of patients who received structured CHD education as compared to patients who did not receive this education; (b) to explore if the provision of structured education is an independent determinant of knowledge; and (c) to evaluate whether patients who received structured education reached the educational target (>80% correct answers). METHODS AND RESULTS: A total of 317 patients were included: 226 in the education group, and 91 in the comparison group. Knowledge was assessed using the 'Leuven Knowledge Questionnaire for Congenital Heart Disease'. The mean total knowledge score in the education group (57%) was significantly higher as compared to the comparison group (43%) (p<0.001). However, only 24 patients (11%) in the education group reached the educational target of the program. After adjusting for patient's age, educational level and disease complexity, hierarchical multivariable linear regression analysis showed that the provision of structured CHD education was an independent determinant of higher levels of knowledge. CONCLUSION: A structured education program was associated with a higher level of knowledge. However, the educational target for sufficient knowledge was reached in a very limited number of patients. Hence, continuous efforts in educating patients and developing alternative education methods are needed.status: publishe

    Immunomodulation against microbial pathogens through dendritic cells

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    Dendritic cells (DCs) are the most potent antigen presenting cells (APCs), being a key player in the regulation of the adaptive immune response. These immune cells are in their immature form in circulation and peripheral tissues, being able to take up, process and activate the antigen-presenting pathway by the interaction of antigen-loaded Major Histocompatibility Complex molecules class I (MHC class I) and II with, respectively,CD4+ and CD8+ T cells, which will then stimulate Cytotoxic T Lymphocytes (CTL) and Th cells. As a result, this heterogeneous population, present in lymphoid and nonlymphoid organs, is fundamental to survey tissues for foreign antigens and thus to induce an effective immune response, but also, on the other hand, to maintain tolerance against self or harmless antigens. In this review we will explore the interplay between DCs subpopulations and microbial pathogens, highlighting their role as regulators in health and infectious diseases. In addition, we will emphasize progress in our understanding of immunomodulatory strategies, namely those based on nanodelivery systems used to promote host protection through the delivery of antigens to DCs and their presentation to T-cells, being these important factors to have in consideration when developing an effective vaccine

    Tumour inflammation signature and expression of S100A12 and HLA class I improve survival in HPV-negative hypopharyngeal cancer

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    Hypopharyngeal squamous cell carcinoma (HPSCC) has a very poor prognosis. Local surgery may increase survival, but is often avoided due to significant post-op co-morbidities. Since prognostic markers are lacking, the aim was to find predictive biomarkers that identify patients whose response to oncological treatment is poor and who may benefit from primary surgery to increase survival. Pretreatment biopsies from 23 HPSCC patients, 3 human papillomavirus (HPV) positive and 20 HPV-negative, were analyzed for expression of 750 mRNAs using the Nanostring nCounter IO360 panel in relation to 3-year survival. Validation was performed through immunohistochemistry (IHC) for HLA class I and S100A12 in 74 HPV-negative HPSCC samples. Clustering identified a subset of HPV-negative HPSCC with favorable prognosis and a gene expression signature overexpressing calgranulins and immune genes, distinct from that of HPV-positive HPSCC. Enrichment analysis showed immune signaling, including the tumor inflammation signature, to be enriched in surviving patients. IHC validation confirmed high S100A12 and HLA class I expression to correlate with survival in HPV-negative HPSCC. This shows that immune activity is strongly related to survival in HPV-negative HPSCC. Enrichment of the tumor inflammation signature indicates a potential benefit of immunotherapy. Low expression of both HLA class I and S100A12 could be used to select patients for local surgery

    In vivo delivery of peptides and Toll-like receptor ligands by mannose-functionalized polymeric nanoparticles induces prophylactic and therapeutic anti-tumor immune responses in a melanoma model

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    We hypothesized that the co-entrapment of melanoma-associated antigens and the Toll-like receptor (TLR) ligands Poly(I:C) and CpG, known to be Th1-immunopotentiators, in mannose-functionalized aliphatic polyester-based nanoparticles (NPs) could be targeted to mannose receptors on antigen-presenting cells and induce anti-tumor immune responses. High entrapment efficiencies of antigens and immunopotentiators in 150nm NPs were obtained. The co-entrapment of the model antigen ovalbumin and the TLR ligands was crucial to induce high IgG2c/IgG1 ratios and high levels of IFN-γ and IL-2. Mannose-functionalization of NPs potentiated the Th1 immune response. The nanoparticulate vaccines decreased the growth rate of murine B16F10 melanoma tumors in therapeutic and prophylatic settings. The combination of mannose-functionalized NPs containing MHC class I- or class II-restricted melanoma antigens and the TLR ligands induced the highest tumor growth delay. Overall, we demonstrate that the multifunctional properties of NPs in terms of targeting and antigen/adjuvant delivery have high cancer immunotherapeutic potential

    High Levels of FGF11 Correlate with Poor Survival in Patients with Human Papillomavirus (HPV)-Positive Oropharyngeal Squamous Cell Carcinoma

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    Human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) is associated with a favourable prognosis. It has therefore been suggested that treatment should be individualized and separated by HPV status. However, additional prognostic markers are still needed before treatment can be individualized for this patient group. For this purpose, all patients diagnosed with HPV and p16-positive OPSCC in Stockholm 2000–2009, identified as having a partial/nonresponse to treatment and having viable tumour cells in their neck specimen with material available were categorized as cases. These were matched to controls (complete responders), and the differences in the gene expression were analysed. Two separate verification cohorts were identified including patients with HPV- and p16-positive OPSCC, and the data from the case-control study were verified by qPCR and immunohistochemistry (IHC) in the respective cohorts. A separation of gene expression in correlation with survival was observed in the case-control study, and FGF11 expression was identified as significantly differently expressed between the two groups. The prognostic role of FGF11 was validated in the two cohorts on the RNA and protein levels, respectively. Taken together, our findings suggest that FGF11 may indicate a poor prognosis in HPV-positive OPSCC and may serve as a prognostic biomarker
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