983 resultados para Hal Porter


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Resting cortical activity is characterized by a distinct spectral peak in the alpha frequency range. Slowing of this oscillatory peak toward the upper theta-band has been associated with a variety of neurological and neuropsychiatric conditions and has been attributed to altered thalamocortical dynamics. Children born very preterm exhibit altered development of thalamocortical systems. To test the hypothesis that peak oscillatory frequency is slowed in children born very preterm, we recorded resting magnetoencephalography (MEG) from school age children born very preterm (= 32 wk gestation) without major intellectual or neurological impairment and age-matched full-term controls. Very preterm children exhibit a slowing of peak frequency toward the theta-band over bilateral frontal cortex, together with reduced alpha-band power over bilateral frontal and temporal cortex, suggesting that mildly dysrhythmic thalamocortical interactions may contribute to altered spontaneous cortical activity in children born very preterm.

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Children born very preterm, even with broadly normal IQ, commonly show selective difficulties in visuospatial processing and executive functioning. Very little, however, is known what alterations in cortical processing underlie these deficits. We recorded MEG while eight children born very preterm (=32 weeks gestational age) and eight full-term controls performed a visual short-term memory task at mean age 7.5 years (range 6.4 - 8.4). Previously, we demonstrated increased long-range alpha and beta band phase synchronization between MEG sensors during STM retention in a group of 17 full-term children age 6-10 years. Here we present preliminary evidence that long-range phase synchronization in very preterm children, relative to controls, is reduced in the alpha-band but increased in the theta-band. In addition, we investigated cortical activation during STM retention employing synthetic aperture magnetometry (SAM) beamformer to localize changes in gamma-band power. Preliminary results indicate sequential activation of occipital, parietal and frontal cortex in control children, as well as reduced activation in very preterm children relative to controls. These preliminary results suggest that children born very preterm exhibit altered inter-regional functional connectivity and cortical activation during cognitive processing.

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Local alpha-band synchronization has been associated with both cortical idling and active inhibition. Recent evidence, however, suggests that long-range alpha synchronization increases functional coupling between cortical regions. We demonstrate increased long-range alpha and beta band phase synchronization during short-term memory retention in children 6-10 years of age. Furthermore, whereas alpha-band synchronization between posterior cortex and other regions is increased during retention, local alpha-band synchronization over posterior cortex is reduced. This constitutes a functional dissociation for alpha synchronization across local and long-range cortical scales. We interpret long-range synchronization as reflecting functional integration within a network of frontal and visual cortical regions. Local desynchronization of alpha rhythms over posterior cortex, conversely, likely arises because of increased engagement of visual cortex during retention.

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Pain and stress have been shown to induce significant physiological and behavioral reactions in newborn infants, even in those born prematurely. Infants who are born prematurely or seriously ill are commonly exposed to multiple painful and stressful events as part of their prolonged hospitalizations and required medical procedures. There is now evidence that these early events not only induce acute changes, but that permanent structural and functional changes may also result. This article reviews the growing body of evidence of likely long-term effects of early pain and stress on the human infant. It is hoped that a better understanding of this literature will promote more responsive and sensitive management of infants and young children during their encounters with the medical community and will ultimately facilitate the healthy growth and development of all children.

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Aim: To explore the perception of palliative care provision for people with non-malignant respiratory disease from the perspective of bereaved caregivers.

Background: It is recognized that the majority of patients diagnosed with a malignant disease will have access to palliative care provision. However, it is less clear if the same standards of palliative care are available to those with non-malignant respiratory disease in Northern Ireland and the Republic of Ireland.

Design: A qualitative study based on broad interpretivism.

Methods: This research is a PhD study funded by the Department of Education and Learning in Northern Ireland (awarded February 2011). Data collection will consist of two stages; interviews with 20 bereaved caregivers of people who have died 3–18 months previously with a diagnosis of non-malignant respiratory disease and four focus groups with healthcare professionals involved in the care of this client group. This study will be carried out at four healthcare sites across the Island of Ireland. The data will be analysed using thematic content analysis. Research Ethics committee approval was obtained (March 2012).

Discussion: This research will explore the experiences of patients with Chronic Obstructive Pulmonary Disease, Interstitial Lung Disease and Bronchiectasis and their caregivers from the perspective of the bereaved caregiver. The outcomes of this study will provide a critical first step in the development of more responsive palliative care for this client group and have important implications for future practice and policy in the palliative care provided to this client group.

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Purpose/Objectives: To explore healthcare professionals' experience, understanding, and perception of the needs of patients with cachexia in advanced cancer.

Research Approach: A qualitative approach based on symbolic interactionism.

Setting: A regional cancer center in a large teaching hospital in the United Kingdom.

Participants: 34 healthcare professionals who had experience providing care to patients with cachexia in advanced cancer.

Methodologic Approach: Data collection consisted of two phases: focus group and semistructured interviews. Interviews were digitally recorded and transcribed verbatim for analysis. This article reports on findings from the second phase of data collection.

Findings: Analysis revealed that professional approaches to cachexia were influenced by three overarching and interthinking themes: knowledge, culture, and resources. Healthcare professionals commonly recognized the impact of the syndrome; however, for nonpalliative healthcare professionals, a culture of avoidance and an overreliance on the biomedical model of care had considerable influence on the management of cachexia in patients with advanced cancer.

Conclusions: Cachexia management in patients with advanced cancer can be difficult and is directed by a variable combination of the influence of knowledge, culture of the clinical area, and available resources. Distinct differences exist in the management of cachexia among palliative and nonpalliative care professionals.

Interpretation: This study presented a multiprofessional perspective on the management of cachexia in patients with advanced cancer and revealed that cachexia is a complex and challenging syndrome that needs to be addressed from a holistic model of care.

Knowledge Translation: Cachexia management in patients with advanced cancer is complex and challenging and is directed by a combination of variables. An overreliance on the biomedical model of health and illness occurs in the management of cachexia in patients with advanced cancer. Cachexia needs to be addressed from a holistic model of care to reflect the multidimensional needs of patients and their families.

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Type II DNA topoisomerases catalyse DNA double-strand cleavage, passage and re-ligation to effect topological changes. There is considerable interest in elucidating topoisomerase II roles, particularly as these proteins are targets for anti-cancer drugs. Here we uncover a role for topoisomerase IIa in RNA polymerase I-directed ribosomal RNA gene transcription, which drives cell growth and proliferation and is upregulated in cancer cells. Our data suggest that topoisomerase IIa is a component of the initiation-competent RNA polymerase Iß complex and interacts directly with RNA polymerase I-associated transcription factor RRN3, which targets the polymerase to promoter-bound SL1 in pre-initiation complex formation. In cells, activation of rDNA transcription is reduced by inhibition or depletion of topoisomerase II, and this is accompanied by reduced transient double-strand DNA cleavage in the rDNA-promoter region and reduced pre-initiation complex formation. We propose that topoisomerase IIa functions in RNA polymerase I transcription to produce topological changes at the rDNA promoter that facilitate efficient de novo pre-initiation complex formation.

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Introduction: Cachexia is a major cause of morbidity and mortality in people who have end-stage renal disease (ESRD). The majority of research into cachexia in ESRD has focused on the biological aspects of the syndrome and potential treatment modalities. While this research is necessary, it predominately focuses on the physical impact of cachexia in ESRD. The multi-dimensional psychosocial ramifications of this syndrome have been highlighted in other end-stage illness trajectories, but have not been systematically explored in persons who have ESRD. Aim: This paper discusses why this research is necessary, alongside further studies to help define the pathophysiology of this syndrome. Conclusion: The rich insightful data gained from understanding the patients' illness experience will positively contribute to the limited knowledge base available and inform future holistic patient-centred care delivery which recognises and responds to not only the biological but also the psychosocial impact of cachexia. © 2013 European Dialysis and Transplant Nurses Association/European Renal Care Association.

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Selective polypharmacology, where a drug acts on multiple rather than single molecular targets involved in a disease, emerges to develop a structure-based system biology approach to design drugs selectively targeting a disease-active protein network. We focus on the bioaminergic receptors that belong to the group of integral membrane signalling proteins coupled to the G protein and represent targets for therapeutic agents against schizophrenia and depression. Among them, it has been shown that the serotonin (5-HT2A and 5-HT6), dopamine (D2 and D3) receptors induce a cognition-enhancing effect (group 1), while the histamine (H1) and serotonin (5-HT2C) receptors lead to metabolic side effects and the 5-HT2B serotonin receptor causes pulmonary hypertension (group 2). Thus, the problem arises to develop an approach that allows identifying drugs targeting only the disease-active receptors, i.e. group 1. The recent release of several crystal structures of the bioaminergic receptors, involving the D3 and H1 receptors provides the possibility to model the structures of all receptors and initiate a study of the structural and dynamic context of selective polypharmacology. In this work, we use molecular dynamics simulations to generate a conformational space of the receptors and subsequently characterize its binding properties applying molecular probe mapping. All-against-all comparison of the generated probe maps of the selected diverse conformations of all receptors with the Tanimoto similarity coefficient (Tc) enable to separate the receptors of group 1 from group 2. The pharmacophore built based on the Tc-selected receptor conformations, using the multiple probe maps discovers structural features that can be used to design molecules selective towards the receptors of group 1. The importance of several predicted residues to ligand selectivity is supported by the available mutagenesis and ligand structure-activity relationships studies. In addition, the Tc-selected conformations of the receptors for group 1 show good performance in isolation of known ligands from a random decoy. Our computational structure-based protocol to tackle selective polypharmacology of antipsychotic drugs could be applied for other diseases involving multiple drug targets, such as oncologic and infectious disorders.

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Realist evaluation is an innovative, multi-method approach to evaluating the effectiveness of complex health care interventions that is having an increasing impact on the research community. Drawing on their experience doing four realist evaluations in diverse areas of healthcare, the authors offer a comprehensive overview and critique of essential theory and practice. The first paper (Realist review and realist evaluation: an introduction) introduces the main components of the approach and shows how realist review can support realist evaluation. The second paper (Concepts and methodology for realist evaluation: help or hindrance?) provides further detail on the key concepts, shows how they can be operationalised, and discusses the advantages and difficulties of using these ideas. Following these two papers introducing and illustrating the major concepts, the third paper (Realist Evaluation: a critical realist critique) takes a step back to re-consider realist evaluation in relation to its critical realist roots, asking whether it leads to evaluators abandoning the attempt to understand (and if necessary challenge) the underlying values of health care interventions and contenting themselves merely with explicating the factors that help or hinder implementation. The fourth and final paper (Data analysis and theory development in realist evaluation) plunges back into the tangled undergrowth of multiple-method data collection and shows how disparate forms of data can be synthesised for theory development, and the results presented in a form that is useful to practitioners and policy-makers.

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In this paper, we examine the postmodernist argument that evidence-based practice (EBP) should be rejected by nurses because it restricts the sources of knowledge used by practitioners. Three main postmodernist criticisms are identified and discussed. First, that the notion of ‘best evidence’ implies a hierarchical and exclusivist approach to knowledge. We accept this argument, noting that such a hierarchy is accepted and justified by many of its proponents. Second, that the hierarchy embraced by the evidence-based practice movement damages health care because it excludes other forms of evidence that are needed to understand the complexity of care. We accept that some manifestations of EBP, notably the Cochrane Collaboration, have devalued qualitative evidence. Using our previous experience of conducting Cochrane reviews (McGaughey et al. 2007), we argue that this limits explanatory scope. Third, that it fails to take account of individuals or their experience. Here, we use evidence of the use by midwives of EBP policies and protocols to the detriment of including women in decision-making processes (Porter et al. 2007) to accept that there is also some merit to this critique. We conclude that, while it is not necessary to concur with the total rejection of EBP that postmodernists advocate, it is necessary to address the issues they raise in order to ensure that EBP better fits the requirements of nursing.
McGaughey, J., Alderdice, F., Fowler, R., Kapila, A., Mayhew, A., Moutray, M., 2007. Outreach and Early Warning Systems (EWS) for the prevention of Intensive Care admission and death of critically ill adult patients on general hospital wards. Cochrane Database of Systematic Reviews 2007, Issue 3. Art. No.: CD005529. DOI: 10.1002/14651858.CD005529.pub2.
Porter, S., Crozier, K., Sinclair, M., Kernohan, W., 2007. New midwifery? A qualitative analysis of midwives’ decision-making strategies. Journal of Advanced Nursing 60 (6), 525-534.

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This paper uses the analytical potential of Geographical Information Systems (GIS) to explore processes of map production and circulation in early-seventeenth century Ireland. The paper focuses on a group of historic maps, attributed to Josias Bodley, which were commissioned in 1609 by the English Crown to assist in the Plantation of Ulster. Through GIS and digitizing map-features, and in particular by quantifying map-distortion, it is possible to examine how these maps were made, and by whom. Statistical analyses of spatial data derived from the GIS are shown to provide a methodological basis for ‘excavating’ historical geographies of Plantation map-making. These techniques, when combined with contemporary written sources, reveal further insight on the ‘cartographic encounters’ taking place between surveyors and map-makers working in Ireland in the early 1600s, opening up the ‘mapping worlds’ which linked Ireland and Britain through the networks and embodied practices of Bodley and his map-makers.

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Paralytic Shellfish Poisoning (PSP) is a serious human illness caused by ingestion of seafood enriched with paralytic shellfish toxins (PSTs). PSTs are neurotoxic compounds produced by marine dinoflagellates, specifically by Alexandrium spp., Gymnodinium catenatum and Pyrodinium bahamense. Every year, massive monitoring of PSTs and their producers is undertaken worldwide to avoid PSP incidences. Here we developed a sensitive, hydrolysis probe-based quantitative PCR (qPCR) assay to detect a gene essential for PST synthesis across different dinoflagellate species and genera and tested it on cDNA generated from environmental samples spiked with Alexandrium minutum or Alexandrium fundyense cells. The assay was then applied to two environmental sample series from Norway and Spain and the results were complemented with cell counts, LSU-based microarray data and toxin measurements (enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) biosensor method). The overall agreement between the results of the qPCR assay and the complementary data was good. The assay reliably detected sxtA transcripts from Alexandrium spp. and G. catenatum, even though Alexandrium spp. cell concentrations were mostly so low that they could not be quantified microscopically. Agreement between the novel assay and toxin measurements or cell counts was generally good; the few inconsistencies observed were most likely due to disparate residence times of sxtA transcripts and PSTs in seawater, or, in the case of cell counts, to dissimilar sxtA4 transcript numbers per cell in different dinoflagellate strains or species. © 2013 Elsevier B.V.

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As increasing incidences in the occurrence of cylindrospermopsin (CYN) appear, in addition to further research on its toxicological nature, improved rapid methods to detect this toxin are required. Antibody based assays are renowned for their ability to provide rapid, portable, simple to use tests. As yet however there are no publications outlining how an antibody to CYN can be produced. A range of chemical approaches was investigated to synthesise CYN immunogens for antibody production but failed to generate a response. Finally, a modified Mannich reaction for immunogen synthesis was employed to couple the toxin to two carrier proteins. Both protein conjugates were successfully used to raise both polyclonal and monoclonal antibodies of high sensitivity to CYN. These antibodies were characterised employing competitive indirect ELISA and an optical biosensor assay. By ELISA the sensitivity achieved ranged from 27 to 131. pg/mL and by SPR 4.4 to 11.1. ng/mL thus demonstrating that the selection of immunoassay platform is important for the detection level required by the end user for their application. Low cross-reactivity to the much less toxic metabolite deoxyCYN was observed. This is the first reported production of antibodies to this toxin. © 2013 Elsevier B.V.