128 research outputs found

    Dental implant surfaces and their interaction with the oral microbiome

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    Objective: This review aims to collate the current knowledge in the field of antimicrobial surfaces on dental implant materials, focusing on microbial population and functional responses, predominantly from omics-based studies. Design: Extensive searching of Scopus and Pubmed databases informed a narrative review on the antimicrobial impact of implant surfaces on the complex oral microbiome. Results: The awareness of this issue has led to considerable research resources being directed towards the augmentation of implant surfaces to counteract microbial colonization. Whilst the implant material itself has a direct influence on bacterial adhesion and viability, the surface finish and putative antimicrobial coatings are critical to countering early biofilm formation. Multiple modes of surface modification have been developed to counteract early colonization, including direct physical contact effect, such as anti-adhesion strategies and extract effects, through antimicrobial release chemistry or material leaching. These concepts deploy different techniques, including nano-texturing, surface chemistry alteration and controlled release, each with a diverse set of benefits and drawbacks. Novel surface finishes and coatings require investigation with regards to their influence on oral biofilms, whether on individual bacterial species or against mature biofilms. Conclusion: The search for optimal implant surfaces is necessary for the reduction of the peri-implantitis burden and the longevity of dental implants. To date, next generation sequencing methodologies, enabling a greater depth of understanding of the complex interactions between oral microorganisms, host response, and implant surface coatings are under used in this area of research

    Effect of the Tyrosine Kinase Inhibitors (Sunitinib, Sorafenib, Dasatinib, and Imatinib) on Blood Glucose Levels in Diabetic and Non-diabetic Patients in General Clinical Practice (Poster)

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    Tyrosine kinase is a key enzyme activity utilized in many intracellular messaging pathways. Understanding the role of particular tyrosine kinases in malignancies has allowed for the design of tyrosine kinase inhibitors (TKIs), which can target these enzymes and interfere with downstream signaling. TKIs have proven to be successful in the treatment of chronic myeloid leukemia, renal cell carcinoma and gastrointestinal stromal tumor, and other malignancies. Scattered reports have suggested that these agents appear to affect blood glucose (BG). We retrospectively studied the BG concentrations in diabetic (17) and nondiabetic (61) patients treated with dasatinib (8), imatinib (39), sorafenib (23), and sunitinib (30) in our clinical practice. Mean declines of BG were dasatinib (53 mg/dL), imatinib (9 mg/dL), sorafenib (12 mg/dL), and sunitinib (14 mg/dL). All these declines in BG were statistically significant. Of note, 47% (8/17) of the patients with diabetes were able to discontinue their medications, including insulin in some patients. Only one diabetic patient developed symptomatic hypoglycemia while on sunitinib. The mechanism for the hypoglycemic effect of these drugs is unclear, but of the four agents tested, c-kit and PDGFRβ are the common target kinases. Clinicians should keep the potential hypoglycemic effects of these agents in mind; modification of hypoglycemic agents may be required in diabetic patients. These results also suggest that inhibition of a tyrosine kinase, be it c-kit, PDGFRβ or some other undefined target, may improve diabetes mellitus BG control and it deserves further study as a potential novel therapeutic option

    Robotic ubiquitous cognitive ecology for smart homes

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    Robotic ecologies are networks of heterogeneous robotic devices pervasively embedded in everyday environments, where they cooperate to perform complex tasks. While their potential makes them increasingly popular, one fundamental problem is how to make them both autonomous and adaptive, so as to reduce the amount of preparation, pre-programming and human supervision that they require in real world applications. The project RUBICON develops learning solutions which yield cheaper, adaptive and efficient coordination of robotic ecologies. The approach we pursue builds upon a unique combination of methods from cognitive robotics, machine learning, planning and agent- based control, and wireless sensor networks. This paper illustrates the innovations advanced by RUBICON in each of these fronts before describing how the resulting techniques have been integrated and applied to a smart home scenario. The resulting system is able to provide useful services and pro-actively assist the users in their activities. RUBICON learns through an incremental and progressive approach driven by the feed- back received from its own activities and from the user, while also self-organizing the manner in which it uses available sensors, actuators and other functional components in the process. This paper summarises some of the lessons learned by adopting such an approach and outlines promising directions for future work

    Immunomodulatory streptococci that inhibit CXCL8 secretion and NFκB activation are common members of the oral microbiota

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    Introduction. Oral tissues are generally homeostatic despite exposure to many potential inflammatory agents including the resident microbiota. This requires the balancing of inflammation by regulatory mechanisms and/or anti-inflammatory commensal bacteria. Thus, the levels of anti-inflammatory commensal bacteria in resident populations may be critical in maintaining this homeostatic balance. Hypothesis/Gap Statement. The incidence of immunosuppressive streptococci in the oral cavity is not well established. Determining the proportion of these organisms and the mechanisms involved may help to understand host-microbe homeostasis and inform development of probiotics or prebiotics in the maintenance of oral health. Aim. To determine the incidence and potential modes of action of immunosuppressive capacity in resident oral streptococci. Methodology. Supragingival plaque was collected from five healthy participants and supragingival and subgingival plaque from five with gingivitis. Twenty streptococci from each sample were co-cultured with epithelial cells±flagellin or LL-37. CXCL8 secretion was detected by ELISA, induction of cytotoxicity in human epithelial cells by lactate dehydrogenase release and NFκB-activation using a reporter cell line. Bacterial identification was achieved through partial 16S rRNA gene sequencing and next-generation sequencing. Results. CXCL8 secretion was inhibited by 94/300 isolates. Immunosuppressive isolates were detected in supragingival plaque from healthy (4/5) and gingivitis (4/5) samples, and in 2/5 subgingival (gingivitis) plaque samples. Most were Streptococcus mitis/oralis. Seventeen representative immunosuppressive isolates all inhibited NFκB activation. The immunosuppressive mechanism was strain specific, often mediated by ultra-violet light-labile factors, whilst bacterial viability was essential in certain species. Conclusion. Many streptococci isolated from plaque suppressed epithelial cell CXCL8 secretion, via inhibition of NFκB. This phenomenon may play an important role in oral host-microbe homeostasis

    Cost-effectiveness of non-invasive methods for assessment and monitoring of liver fibrosis and cirrhosis in patients with chronic liver disease: systematic review and economic evaluation

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    BACKGROUND: Liver biopsy is the reference standard for diagnosing the extent of fibrosis in chronic liver disease; however, it is invasive, with the potential for serious complications. Alternatives to biopsy include non-invasive liver tests (NILTs); however, the cost-effectiveness of these needs to be established. OBJECTIVE: To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease. DATA SOURCES: We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists. METHODS: We included studies that assessed the diagnostic accuracy of NILTs using liver biopsy as the reference standard. Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-analysis was conducted using the bivariate random-effects model with correlation between sensitivity and specificity (whenever possible). Decision models were used to evaluate the cost-effectiveness of the NILTs. Expected costs were estimated using a NHS perspective and health outcomes were measured as quality-adjusted life-years (QALYs). Markov models were developed to estimate long-term costs and QALYs following testing, and antiviral treatment where indicated, for chronic hepatitis B (HBV) and chronic hepatitis C (HCV). NILTs were compared with each other, sequential testing strategies, biopsy and strategies including no testing. For alcoholic liver disease (ALD), we assessed the cost-effectiveness of NILTs in the context of potentially increasing abstinence from alcohol. Owing to a lack of data and treatments specifically for fibrosis in patients with non-alcoholic fatty liver disease (NAFLD), the analysis was limited to an incremental cost per correct diagnosis. An analysis of NILTs to identify patients with cirrhosis for increased monitoring was also conducted. RESULTS: Given a cost-effectiveness threshold of £20,000 per QALY, treating everyone with HCV without prior testing was cost-effective with an incremental cost-effectiveness ratio (ICER) of £9204. This was robust in most sensitivity analyses but sensitive to the extent of treatment benefit for patients with mild fibrosis. For HBV [hepatitis B e antigen (HBeAg)-negative)] this strategy had an ICER of £28,137, which was cost-effective only if the upper bound of the standard UK cost-effectiveness threshold range (£30,000) is acceptable. For HBeAg-positive disease, two NILTs applied sequentially (hyaluronic acid and magnetic resonance elastography) were cost-effective at a £20,000 threshold (ICER: £19,612); however, the results were highly uncertain, with several test strategies having similar expected outcomes and costs. For patients with ALD, liver biopsy was the cost-effective strategy, with an ICER of £822. LIMITATIONS: A substantial number of tests had only one study from which diagnostic accuracy was derived; therefore, there is a high risk of bias. Most NILTs did not have validated cut-offs for diagnosis of specific fibrosis stages. The findings of the ALD model were dependent on assuptions about abstinence rates assumptions and the modelling approach for NAFLD was hindered by the lack of evidence on clinically effective treatments. CONCLUSIONS: Treating everyone without NILTs is cost-effective for patients with HCV, but only for HBeAg-negative if the higher cost-effectiveness threshold is appropriate. For HBeAg-positive, two NILTs applied sequentially were cost-effective but highly uncertain. Further evidence for treatment effectiveness is required for ALD and NAFLD. STUDY REGISTRATION: This study is registered as PROSPERO CRD42011001561. FUNDING: The National Institute for Health Research Health Technology Assessment programme

    Early Clinical Experience with the Mobi-C Disc Prosthesis

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    PURPOSE: We have experienced 23 patients who had underwent cervical disc replacement with Mobi-C disc prosthesis and analyzed their radiological results to evaluate its efficacy. PATIENTS AND METHODS: This study was performed on 23 patients with degenerative cervical disc disease who underwent CDR with Mobi-C disc prosthesis from March 2006 to June 2006. RESULTS: The age of the study population ranged from 31 to 62 years with mean of 43 years, and 16 male and 7 female cases. Regarding axial pain, the average preoperative VAS score was 6.47 +/- 1.4, while at final follow-up it was 1.4 +/- 0.7 (p < 0.001). The preoperatively VAS score for radiculopathy was 6.7 +/- 0.7 compared with an average score of 0 +/- 0 at the final follow-up (p < 0.001). At postoperative 6th month, Odom's criteria were excellent, good, or fair for all 23 patients (100%). 7 patients (30.4%) were classified as excellent, 15 patients (65.2%) as good, and 1 patients (4.4%) as fair. Prolo economic and functional rating scale was average 8.9 +/- 0.7 at postoperative 6th month. ROM in C2-7, ROM of FSU, and ROM in upper adjacent level were well preserved after CDR. CONCLUSION: This report would be the first document about the CDR with Mobi-C disc prosthesis in the treatment of degenerative cervical disc disease. CDR with Mobi-C disc prosthesis provided a favorable clinical and radiological outcome in this study. However, Long-term follow-up studies are required to prove its efficacy and ability to prevent adjacent segment disease.ope

    Diferencias intra e inter individuales en inteligencia social de estudiantes portugueses

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    Social intelligence is a favorable condition for career decision-making and development. The social intelligence indices of Portuguese students in school years prior to a career transition are characterized and intra and interindividual differences are analyzed. Participants were 1095 students (552, 50.4% women) with a mean age of 14.78 years (SD = 1.86), in the 8th (542, 49.5%), 10th (295, 26.9%) and 11th (258, 23.6%) grades. The Cognitive Test of Social Intelligence (PCIS) was administered at two moments, six months apart. Results indicate that the 8th grade obtained higher average scores in Problem Solving, Motivation and Self-confidence (time 1), while the 10th grade obtained better results in Problem Solving, Motivation and Familiarity (time 2). Between the assessment moments, all school years register an increase in Problem Solving and Self-confidence in social situations. These results constitute favorable psychological conditions for the promotion of ethical questioning in career guidance interventions.A inteligência social constitui uma condição favorável à tomada de decisão e ao desenvolvimento vocacional. Este trabalho visa caracterizar os níveis de inteligência social, e analisar as diferenças intra e interindividuais, em alunos portugueses em anos de pré-transição vocacional. Participaram 1095 alunos (552, 50% mulheres), com uma média de idades de 14,78 anos (DP = 1,86), do 8º, 10º, e 11º níveis escolares. Administrou-se a Prova Cognitiva de Inteligência Social (PCIS), em dois momentos (T1 e T2), com seis meses de intervalo. Os resultados indicam que o 8º ano obteve resultados médios superiores, nos índices de Resolução de Problemas, Motivação e Autoconfiança (T1), enquanto o 10º ano obteve resultados superiores, em Resolução de Problemas, Motivação e Familiaridade (T2). Entre momentos de avaliação, registra-se, para todos os níveis escolares, um aumento em Resolução de Problemas e Autoconfiança em situações sociais. Estes resultados constituem condições psicológicas favoráveis à promoção do questionamento ético nas intervenções de orientação vocacional.La inteligencia social es una condición favorable para la toma de decisiones y el desarrollo de la carrera. Se caracterizan los niveles de inteligencia social y sus diferencias intra e interindividuales en estudiantes portugueses en transición pre-profesional. Participaron 1095 estudiantes (552, 50.4% mujeres) con una edad media de 14.78 (DE = 1.86), del 8º (542, 49,5%), 10º (295, 26.9%) y 11º (258, 23.6%) años escolares. Se administró la Prueba Cognitiva de Inteligencia Social (PCIS) en dos ocasiones, con seis meses de diferencia. Los resultados indican que los estudiantes del 8º grado obtuvieron puntajes medios más altos en la Resolución de Problemas, Motivación y Confianza (T1), mientras que los del 10º grado obtuvieron mejores resultados en la Resolución de Problemas, Motivación y Familiaridad (T2). Entre momentos de evaluación se registra, para todos los años, un aumento en la Resolución de Problemas y Confianza en situaciones sociales. Estos resultados constituyen condiciones psicológicas favorables a la promoción del cuestionamiento ético en las intervenciones de orientación profesional.Project coordinated by the fourth author and co-funded by the Foundation for Science and Technology and the Compete Program - PTDC/CPE-CED/098896/200

    Economic Impact of Dengue Illness and the Cost-Effectiveness of Future Vaccination Programs in Singapore

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    Dengue illness is a tropical disease transmitted by mosquitoes that threatens more than one third of the worldwide population. Dengue has important economic consequences because of the burden to hospitals, work absenteeism and risk of death of symptomatic cases. Governments attempt to reduce the disease burden using costly mosquito control strategies such as habitat reduction and spraying insecticide. Despite such efforts, the number of cases remains high. Dengue vaccines are expected to be available in the near future and there is an urgent need to evaluate their cost-effectiveness, i.e. whether their cost will be justified by the reduction in disease burden they bring. For such an evaluation, we estimated the economic impacts of dengue in Singapore and the expected vaccine costs for different prices. In this way we estimated price thresholds for which vaccination is not cost-effective. This research provides useful estimates that will contribute to informed decisions regarding the adoption of dengue vaccination programs

    Towards neuro-inspired symbolic models of cognition: linking neural dynamics to behaviors through asynchronous communications

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    A computational architecture modeling the relation between perception and action is proposed. Basic brain processes representing synaptic plasticity are first abstracted through asynchronous communication protocols and implemented as virtual microcircuits. These are used in turn to build mesoscale circuits embodying parallel cognitive processes. Encoding these circuits into symbolic expressions gives finally rise to neuro-inspired programs that are compiled into pseudo-code to be interpreted by a virtual machine. Quantitative evaluation measures are given by the modification of synapse weights over time. This approach is illustrated by models of simple forms of behaviors exhibiting cognition up to the third level of animal awareness. As a potential benefit, symbolic models of emergent psychological mechanisms could lead to the discovery of the learning processes involved in the development of cognition. The executable specifications of an experimental platform allowing for the reproduction of simulated experiments are given in “Appendix”
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