101 research outputs found

    Improving immunotherapy for high grade glioma

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    Glioblastoma multiforme (GBM) is a malignant primary brain tumour that is almost always fatal. Conventional treatment modalities are limited by toxicity. T cell-based immunotherapy is a promising alternative that has the potential to specifically target tumour cells. The author of this thesis was a principal investigator for a recently completed Phase I clinical trial in which patients with recurrent GBM were treated with surgery, dendritic cell-based immunotherapy and chemotherapy. In addition to conducting the trial in collaboration with others, the author used peripheral blood mononuclear cells from trial participants to assess anti-tumour immune responses before and after treatment. A broad correlation was observed between clinical outcome and anti-tumour immunity, with sustained progression-free survival occurring in two patients with baseline responses that persisted or increased after treatment. However, the overall clinical benefit was modest. For progress to be made, there is a need to develop a more potent vaccine. With this in mind, a novel “Glioma-Gal” vaccine was devised and tested in an orthotopic mouse model of glioma, This simple vaccine consisted of irradiated autologous tumour cells pulsed with the glycolipid alpha-galactosylceramide, an immunoadjuvant that induces invariant Natural Killer T cells to licence endogenous dendritic cells. The vaccine was shown to be effective in a therapeutic setting when accompanied by depletion of regulatory T cells. Mechanistically, vaccine efficacy was dependent on CD4 T cells and the mediastinal lymph node was shown to be an important site of T cell priming. It was further shown that components of the immune system necessary for the vaccine to work were present and competent in a cohort of GBM patients. The final chapters explore the idea of enhancing the therapeutic benefit of this vaccine by targeting certain tumour cell subsets or phenotypes. Cancer stem cells (CSC) are proposed to be a subset of tumour cells with a unique capacity for initiating and maintaining tumours. Eliminating these cells may therefore be both necessary and sufficient to achieve cure. Using the same mouse model, a variety of methods were assessed for their ability to isolate or enrich for a CSC subset. Of these, culture in serum-free medium in the presence of certain growth factors was shown to enrich for a more stem cell-like phenotype. However, a vaccine constructed from these stem cell-like cells was not more effective than the standard vaccine. Next, the author tested the hypothesis that a vaccine manipulated to target chemoresistant cells would be more effective than standard vaccine when used in combination with chemotherapy. However, the modified vaccine showed no advantage over standard vaccine in this model. In the course of these experiments, synergy was observed between the vaccine and the chemotherapy agent doxorubicin. The mechanism responsible for this supra-additive effect remains undetermined but is most likely due to an immunomodulatory effect of low dose doxorubicin. The Glioma-Gal vaccine design holds promise but more studies are needed to realise the full potential of this approach. The data presented in the thesis did not support targeting CSC or chemoresistant cells as ways of achieving this. In contrast, combining the vaccine with immunomodulation was effective and merits further exploration

    Cyanoacrylate Dermal Closure in Spine Surgery: Systematic Review and Pooled Analysis

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    Study Design: Systematic review. Objectives: Cyanoacrylate glue closure has been utilized for dermal closure in surgical incisions. Its safety and efficacy in spine surgery are not established. The authors perform a systematic review to determine the rate of surgical site infection (SSI), wound dehiscence, and wound erythema with cyanoacrylate dermal closure in spine surgery. Methods: A systematic review adhering to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed utilizing the PubMed/MEDLINE, EMBASE, and Cochrane databases on patients undergoing spine surgery with cyanoacrylate dermal closure. Pooled analysis was performed with stratification of patients according to spinal level and the presence/absence of instrumentation. Risk-of-bias and methodological quality was appraised using 17 prespecified criteria. Results: Five articles (1 retrospective cohort study, 4 cases series) with a total of 1282 patients were included. A total of 967 patients, all diagnosed with degenerative spine disease, were suitable for pooled analysis. In 290 patients who underwent anterior cervical discectomy and fusion, and in 23 patients with posterior cervical decompression (without instrumentation), there was 0% rate of SSI, wound dehiscence, and erythema. In 489 patients who underwent lumbar microdiscectomy, there was 0.41% rate of SSI, 0.20% rate of wound dehiscence, and 0.20% rate of wound erythema. In 165 lumbar laminectomy patients, there was a 1.82% rate of SSI, 0.61% rate of wound dehiscence, and 0% rate of wound erythema. Conclusion: Cyanoacrylate dermal closure for the aforementioned procedures is associated with low rates of wound complications (SSI, dehiscence, and erythema). Further studies should be performed, especially in nondegenerative surgery, instrumented thoracic and lumbar spine surgery

    Preclinical development of a vaccine against oligomeric alpha-synuclein based on virus-like particles

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    Parkinson's disease (PD) is a progressive and currently incurable neurological disorder characterised by the loss of midbrain dopaminergic neurons and the accumulation of aggregated alpha-synuclein (a-syn). Oligomeric a-syn is proposed to play a central role in spreading protein aggregation in the brain with associated cellular toxicity contributing to a progressive neurological decline. For this reason, a-syn oligomers have attracted interest as therapeutic targets for neurodegenerative conditions such as PD and other alpha-synucleinopathies. In addition to strategies using small molecules, neutralisation of the toxic oligomers by antibodies represents an attractive and highly specific strategy for reducing disease progression. Emerging active immunisation approaches using vaccines are already being trialled to induce such antibodies. Here we propose a novel vaccine based on the RNA bacteriophage (Qbeta) virus-like particle conjugated with short peptides of human a-syn. High titres of antibodies were successfully and safely generated in wild-type and human a-syn over-expressing (SNCA-OVX) transgenic mice following vaccination. Antibodies from vaccine candidates targeting the C-terminal regions of a-syn were able to recognise Lewy bodies, the hallmark aggregates in human PD brains. Furthermore, antibodies specifically targeted oligomeric and aggregated a-syn as they exhibited 100 times greater affinity for oligomeric species over monomer a-syn proteins in solution. In the SNCA-OVX transgenic mice used, vaccination was, however, unable to confer significant changes to oligomeric a-syn bioburden. Similarly, there was no discernible effect of vaccine treatment on behavioural phenotype as compared to control groups. Thus, antibodies specific for oligomeric a-syn induced by vaccination were unable to treat symptoms of PD in this particular mouse model.</p

    ReseArch with Patient and Public invOlvement: a RealisT evaluation - the RAPPORT study

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    Background Patient and public involvement (PPI) is a prerequisite for many funding bodies and NHS research ethics approval. PPI in research is defined as research carried out with or by the public rather than to, about or for them. While the benefits of PPI have been widely discussed, there is a lack of evidence on the impact and outcomes of PPI in research. Objectives To determine the types of PPI in funded research, describe key processes, analyse the contextual and temporal dynamics of PPI and explore the experience of PPI in research for all those involved. Mechanisms contributing to the routine incorporation of PPI in the research process were assessed, the impact of PPI on research processes and outcomes evaluated, and barriers and enablers to effective PPI identified. Design A three-staged realist evaluation drawing on Normalisation Process Theory to understand how far PPI was embedded within health-care research in six areas: diabetes mellitus, arthritis, cystic fibrosis, dementia, public health and learning disabilities. The first two stages comprised a scoping exercise and online survey to chief investigators to assess current PPI activity. The third stage consisted of case studies tracked over 18 months through interviews and document analysis. The research was conducted in four regions of England. Participants Non-commercial studies currently running or completed within the previous 2 years eligible for adoption on the UK Clinical Research Network portfolio. A total of 129 case study participants included researchers and PPI representatives from 22 research studies, and representatives from funding bodies and PPI networks

    Effects of brain tissue oxygen (PbtO2) guided management on patient outcomes following severe traumatic brain injury: A systematic review and meta-analysis.

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    Monitoring and optimisation of brain tissue oxygen tension (PbtO2) has been associated with improved neurological outcome and survival in observational studies of severe traumatic brain injury (TBI). We carried out a systematic review of randomized controlled trials to determine if PbtO2-guided management is associated with differential neurological outcomes, survival, and adverse events. Searches were carried out to 10 February 2022 in Medline (OvidSP), 11 February in EMBASE (OvidSP) and 8 February in Cochrane library. Randomized controlled trials comparing PbtO2 and ICP-guided management to ICP-guided management alone were included. The primary outcome was survival with favourable neurological outcome at 6-months post injury. Data were extracted by two independent authors and GRADE certainty of evidence assessed. There was no difference in the proportion of patients with favourable neurological outcomes with PbtO2-guided management (relative risk [RR] 1.42, 95% CI 0.97 to 2.08; p = 0.07; I2 = 0%, very low certainty evidence) but PbtO2-guided management was associated with reduced mortality (RR 0.54, 95% CI 0.31 to 0.93; p = 0.03; I2 = 42%; very low certainty evidence) and ICP (mean difference (MD) - 4.62, 95% CI - 8.27 to - 0.98; p = 0.01; I2 = 63%; very low certainty evidence). There was no significant difference in the risk of adverse respiratory or cardiovascular events. PbtO2-guided management in addition to ICP-based care was not significantly associated with increased favourable neurological outcomes, but was associated with increased survival and reduced ICP, with no difference in respiratory or cardiovascular adverse events. However, based on GRADE criteria, the certainty of evidence provided by this meta-analysis was consistently very low. MESH: Brain Ischemia; Intensive Care; Glasgow Outcome Scale; Randomized Controlled Trial; Craniocerebral Trauma

    Cognition, culture and utility:Plant classification by Paraguayan immigrant farmers in Misiones, Argentina

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    Background: This study was conducted in three rural communities of small farmers of Paraguayan origin living in the province of Misiones, Argentina. These Criollos (Mestizos) hail chiefly from departments located in the east of Paraguay, where the climate and flora have similar characteristics as those in Misiones. These ecological features contribute to the continuation and maintenance of knowledge and practices related to the use of plants. Methods: Fieldwork was conducted between September 2014 and August 2015. Forty five informants from three rural localities situated along the Parana River participated in an ethno-classification task. For the classification event, photographs of 30 medicinal and edible plants were chosen, specifically those yielding the highest frequency of mention among the members of that community (based on data obtained in the first stage of research in 2014). Variation in local plant classifications was examined and compared using principal component analysis and cluster analysis. Results: We found that people classify plants according to application or use (primarily medicinal, to a lesser extent as edible). Morphology is rarely taken into account, even for very similar and closely-related species such as varieties of palms. In light of our findings, we highlight a dominant functionality model at work in the process of plant cognition and classification among farmers of Paraguayan origin. Salient cultural beliefs and practices associated with rural Paraguayan plant-based medicine are described. Additionally, the manner by which residents’ concepts of plants articulate with local folk epistemology is discussed. Conclusions: Culturally constructed use patterns ultimately override morphological variables in rural Paraguayans’ ethnobotanical classification.Antecedentes: Este trabajo se realizó con pequeños agricultores de origen paraguayo, que habitan en la provincia de Misiones, Argentina. Los criollos (mestizos) en su mayoría provienen de departamentos ubicados al oriente del Paraguay, donde el clima y la flora presentan características similares a la provincia de Misiones. Estas características ecológicas contribuyen a la continuación y el mantenimiento de los conocimientos y las prácticas relacionados al uso de las plantas. Métodos El trabajo de campo se realizó entre septiembre de 2014 y agosto de 2015. En la etnoclasificación participaron 45 informantes, provenientes de tres localidades rurales, situadas a lo largo del río Paraná, frontera entre los dos países. Para la clasificación se utilizaron imágenes fotográficas de 30 especies -comestibles y medicinales- preseleccionadas como las de mayor frecuencia de mención entre los habitantes de la región (a partir de los datos obtenidos en una primera etapa de investigación en el año 2014). Por medio del análisis de componentes principales y el análisis de agrupamiento (cluster) se contrastaron y compararon las variaciones en las etnoclasificaciones locales de plantas. Resultados Se encontró que los pobladores clasifican sus plantas según su aplicación y uso (mayormente asociadas a la categoría medicinal y en menor medida a la comestible). Mientras, la morfología rara vez se tiene en cuenta, incluso en aquellas especies muy similares y estrechamente relacionadas como las palmeras. A la luz de los hallazgos, se destaca un modelo de funcionalidad dominante en el proceso de cognición y de clasificación de las plantas entre los agricultores de origen paraguayo. Se describen las principales creencias y prácticas culturales asociadas a la medicina rural paraguaya. Adicionalmente, se discuten algunos de los conceptos de las plantas que mantienen los paraguayos y su articulación con la epistemología local. Conclusiones En la clasificación etnobotánica de los pobladores de origen paraguayo los patrones de uso construidos culturalmente tienen mayor peso que las variables morfológicas.Fil: Kujawska, Monika. University Of Lodz; ArgentinaFil: Jiménez Escobar, Néstor David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Antropología de Córdoba. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades. Instituto de Antropología de Córdoba; ArgentinaFil: Nolan, Justin M.. University Of Arkansas; Estados UnidosFil: Arias Mutis, Daniel. University of Groningen; Países Bajo

    Re-visiting Meltsner: Policy Advice Systems and the Multi-Dimensional Nature of Professional Policy Analysis

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    10.2139/ssrn.15462511-2

    A ETNOECOLOGIA EM PERSPECTIVA: ORIGENS, INTERFACES E CORRENTES ATUAIS DE UM CAMPO EM ASCENSÃO

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    Casemix, management, and mortality of patients receiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study

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