• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2526
  • 648
  • 523
  • 517
  • 501
  • 501
  • 501
  • 501
  • 501
  • 496
  • 315
  • 87
  • 44
  • 38
  • 25
  • Tagged with
  • 8057
  • 2465
  • 2189
  • 1885
  • 1326
  • 1299
  • 1149
  • 1098
  • 939
  • 884
  • 821
  • 769
  • 763
  • 728
  • 695
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
621

Investigating interactions : how do doctors and patients experience the disclosure of significant information in the advanced cancer setting and how do these experiences enhance practice?

Furber, Lynn January 2010 (has links)
This thesis focuses specifically on the transmission of bad news from doctors to patients and their families in the context of a hospital oncology department. It uses awareness context theory as a basis for exploring communication between patients and health care professionals, particularly when the information to be disclosed is sensitive and will have a significant bearing on how people perceive their future. In order to enhance clinical practice, senior health care professionals in particular, have in the past been encouraged through government policy and professional legislation to attend communication skills courses to develop the way they communicate and interact with patients. Yet, in spite of these interventions evidence suggests that doctors and other health care professionals still find it difficult to negotiate sensitive and emotionally challenging discussions, and frequently question whether or not patients are aware and understand the information disclosed to them and whether or not information provided meets the needs and expectations of patients. The premise of this research is that more attention needs to be given to how other more reflective and experiential professional development approaches and techniques might help doctors communicate better with their patients when disclosing sensitive information and bad news. In order to do this however, a better understanding is needed about what is going on in consultations and how each of the individuals involved experience and make sense of these interactions. It is proposed that in order to understand ‘resulting interactions’ more fully it is necessary to explore and compare the multiple perspectives of doctors, patients and others; including relatives and nurses. This thesis seeks to do this in an innovative way by reporting research, which involved observing and recording consultations between doctors and patients and their relatives and then conducting in-depth interviews with such people in order to explore their own insights into this process. In total, 115 episodes of data were collected and analysed from 16 patients and 16 doctors. The insights gained from this study are presented in relation to two main analytic themes; Doctors and Patients Acting their Parts, and Sharing Uncomfortable News. The data analysis highlighted a number of approaches used by patients and doctors to manage and control their interactions within the medical consultation. The implications of the study findings are discussed in relation to both wider theoretical perspectives and ideas for how doctors working in such settings could be assisted to consider alternative strategies for these aspects of their work.
622

The role of the cholecystokinin 2 receptor in cancer

Mayne, Cerys Mary January 2011 (has links)
The gastrointestinal (GI) hormone, gastrin, promotes cancer progression and its down-regulation has been linked to reduced cancer stem cell numbers. Gastrin acts through the cholecystokinin-2 receptor (CCK-2R) and its biological effects are blocked by CCK-2R inhibitors. We investigated the regulation of the CCK-2R and its potential role in promoting survival of cancer stem cells (CSC). A panel of cancer cell-lines, including GI, glioblastoma and lung, with CCK-2R-transfected cells as a positive control, were grown either as monolayers, or, to provide a 3D in vitro tumour model, as spheres. Linear-after-the-Exponential (LATE)-PCR was used to quantify CCK-2R gene expression and this was validated using siRNAs. Flow cytometry was used to investigate receptor protein expression. Activity of CCK-2R promoter reporters was quantified using luciferase assays. LATE-PCR for CCK-2R gene expression is 10,000-fold more sensitive than the Taqman-based assay, and provides a highly precise method for detection of genes which have important biological functions but low expression. This assay showed that primary non-small-cell lung tumours have significantly more expression than normal lung tissue, indicating a potential therapeutic marker. CCK-2R siRNAs resulted in up to 97% (p<0.05) knockdown of the receptor in cancer cells, confirming the specificity of LATE-PCR and offering a therapeutic possibility. The CCK-2R promoter constructs were active in lung, glioma and colorectal cancer cell-lines, demonstrating a potential drug target; however, transcriptional activity did not correlate with gene expression suggesting post-transcriptional or translational regulation is a factor affecting CCK-2R expression. Flow cytometry suggests the presence of a small population of cells within each of these cell-lines which expresses CCK-2R very highly, which was not correlated to CSC markers. However, CCK-2R expression was enriched when cells were grown as spheres, and inhibition caused a delay in sphere-forming, implying that the CCK-2R may play a role in tumour, and CSC, expansion. Thus, CCK2R provides a potential target for therapeutic intervention in cancer.
623

The effects of repeated mild stress on a transgenic mouse model of Alzheimer's disease

Rattray, Ivan January 2010 (has links)
Alzheimer's disease (AD), the most common form of dementia, is a devastating age-related neurodegenerative disorder. There is a growing body of evidence suggesting that leading a stressful lifestyle is associated with a heightened risk of developing AD. This is supported by preclinical evidence using transgenic mice over-expressing genetic mutations leading to overt ß-amyloid protein production, a pathological marker of AD; stress in such mice has been capable of exacerbating AD-associated pathologies, including accelerating memory impairments and elevating ß-amyloid levels. In contrast, a recent study from our group demonstrated that a repeated mild stress procedure, novel cage stress, improved a short-term memory deficit and reduced the normal age-related increase in 3-amyloid levels. This thesis aimed to further characterise the beneficial effects of novel cage stress on AD-associated pathology in the TASTPM mouse model (double transgenic hAPP695swe x PS-I. M146V) which exhibits overt, age-related ß-amyloid pathology. First, age-related changes in AD- associated pathology, with or without exposure to novel cage stress, were assessed using a multidisciplinary approach incorporating measures of cognitive performance, in vivo magnetic resonance imaging and post-mortem analysis of ß-amyloid levels. The aim was to detect an age where we observe the most robust effect of stress; this time window was subsequently targeted to investigate a potential underlying mechanism, namely signalling though the glutamate alpha-amino-3-hydroxy-5- methyl-4-isoxazolepropionic receptor (AMPAr). Studies described throughout this thesis, alongside previously published data, indicate novel cage stress appears to improve AD-associated pathology in TASTPM mice, but independently of AMPAr function. It is likely that novel cage stress is insufficiently severe to induce detrimental effects, but, rather, subsequent repeated stimulation and physical activity may improve pathological status. A better understanding of lifestyle risk factors of AD, such as stress, will aid in identifying those at risk of developing the disorder. Moreover, discovering the underlying mechanisms linking stress with AD may open novel therapeutic avenues to treat the disorder.
624

Medical work or counselling work? : a qualitative study of genetic counselling

Pearce, Melanie D. January 2004 (has links)
This thesis presents a qualitative study of genetic counselling. Using a combination of semi-structured interviews and conversation analysis, it focuses on the role, function and structure of genetic counselling and on its status as medical or counselling work. Semi-structured interviews are used to ascertain genetic counsellors' accounts or perceptions of the nature of their role, their views on client expectations, and genetic counselling clients' perceptions and expectations of the same. Conversation analytic study of recorded genetic counselling consultations is used to identify whether or not they possess an overall shape and whether they appear conversationally as a counselling or a medical interaction. Rose's (1998, 1999) sociological work on the growth of the therapeutic community and the techne of 'psy' provides a framework for a discussion on the strength of the genetic counselling profession's association with a Rogerian counselling philosophy and on the potential difficulties this may bring. The questions are raised; does genetic counselling have many similarities to "personal, emotional or psychological" 'counselling' at all? And is this alliance with the counselling community either fair or possible for the professionals involved? The results were as follows. First, that the genetic counselling consultations in this corpus do not present with one unique overall shape that can encompass all interactions. Second, that the accounts of the genetic counsellors and clients in this sample, and the conversation analytic study of the recorded consultations, suggest that genetic counselling is primarily a medical-based activity and that this is what clients want. Third, that genetic counselling has a number of dissimilarities to psychotherapeutic counselling that suggest it is not so much 'counselling' as using counselling skills, and finally, that the tensions incurred in fulfilling medical-type tasks within what is ostensibly a 'counselling' role are neither fair nor practical for the professionals involved.
625

The roles of hyperoxia and mechanical deformation in alveolar epithelial injury and repair

McKechnie, Stuart R. January 2008 (has links)
The alveolar epithelium is a key functional component of the air-blood barrier in the lung. Comprised of two morphologically distinct cell types, alveolar epithelial type I (ATI) and type II (ATII) cells, effective repair of the alveolar epithelial barrier following injury appears to be an important determinant of clinical outcome. The prevailing view suggests this repair is achieved by the proliferation of ATII cells and the transdifferentiation of ATII cells into ATI cells. Supplemental oxygen and mechanical ventilation are key therapeutic interventions in the supportive treatment of respiratory failure following lung injury, but the effects of hyperoxia and mechanical deformation in the injured lung, and on alveolar epithelial repair in particular, are largely unknown. The clinical impression however, is that poor outcome is associated with exposure of injured (repairing) epithelium to such iatrogenic ‘hits’. This thesis describes studies investigating the hypothesis that hyperoxia & mechanical deformation inhibit normal epithelial repair. The in vitro data presented demonstrate that hyperoxia reversibly inhibits the transdifferentiation of ATII-like cells into ATI-like cells with time in culture. Whilst confirming that hyperoxia is injurious to alveolar epithelial cells, these data further suggest the ATII cell population harbours a subpopulation of cells resistant to hyperoxia-induced injury. This subpopulation of cells appears to generate fewer reactive oxygen species and express lower levels of the zonula adherens protein E-cadherin. Using a panel of antibodies to ATI (RTI40) and ATII (MMC4 & RTII70) cell-selective proteins, the effect of hyperoxia on the phenotype of the alveolar epithelium in a rat model of resolving S. aureus-induced lung injury was investigated. These in vivo studies support the view that, under normoxic conditions, alveolar epithelial repair occurs through ATII cell proliferation & transdifferentiation of ATII cells into ATI cells, with transdifferentiation occurring via a novel intermediate (MMC4/RTI40-coexpressing) immunophenotype. However, in S. aureus-injured lungs exposed to hyperoxia, the resolution of ATII cell hyperplasia was impaired, with an increase in ATII cell-staining membrane and a reduction in intermediate cell-staining membrane compared to injured lungs exposed to normoxia alone. As hyperoxia is pro-apoptotic and known to inhibit ATII cell proliferation, these data support the hypothesis that hyperoxia impairs normal epithelial repair by inhibiting the transdifferentiation of ATII cells into ATI cells in vivo. The effect of mechanical deformation on alveolar epithelial cells in culture was investigated by examining changes in cell viability following exposure of epithelial cell monolayers to quantified levels of cyclic equibiaxial mechanical strain. In the central region of monolayers, deformation-induced injury was a non-linear function of deformation magnitude, with significant injury occurring only following exposure to strains greater than those associated with inflation of the intact lung to total lung capacity. However, these studies demonstrate for the first time that different epithelial cell phenotypes within the same culture system have different sensitivities to deformation-induced injury, with spreading RTI40-expressing cells in the peripheral region of epithelial cell monolayers and in the region of ‘repairing’ wounds being injured even at physiological levels of mechanical strain. These findings are consistent with the hypothesis that alveolar epithelial cells in regions of epithelial repair are highly susceptible to deformation-induced injury.
626

Multiple forms of γ-glutamyltransferase

Wenham, Philip R. January 1985 (has links)
No description available.
627

Ras expression in normal and abnormal breast tissue

Going, James Jensen January 1989 (has links)
No description available.
628

Selection of hard red winter wheat lines with diverse resistance to leaf spot diseases

Manley, Aurora Alexandra 19 August 2016 (has links)
<p> Tan spot and Septoria nodorum blotch cause serious yield losses in winter wheat in North Dakota as the majority of commercially grown cultivars are susceptible. This study aimed to identify lines with improved resistance for use as breeding parents. First, advanced NDSU breeding lines and alternative sources of resistance were inoculated with fungal isolates and tested for necrotrophic effector sensitivity. Second, resistant lines were derived from a highly heterogeneous recurrent mass selection F<sub>2</sub> population using single seed descent inbreeding coupled with selection for resistance. Finally, the best performers from both experiments (total of 52 lines) were evaluated to confirm resistance. In addition the 52 lines were analyzed with markers that detect <i>Tsn1</i> and the 1RS rye translocation. Twenty lines were identified with simultaneous resistance to four or three fungal isolates and insensitivity to three, two, or one necrotrophic effectors (of which 11 can be used directly as new parents).</p>
629

Development of post-traumatic osteoarthritis models to evaluate effects of impact injury on joint health for clinical disease treatment and prevention

Waters, Nicole Poythress 09 December 2016 (has links)
<p>Osteoarthritis is one of the most common, debilitating, musculoskeletal diseases in the world. Currently, there is no cure. It is well-known that a traumatic, joint injury increases the risk of developing post-traumatic osteoarthritis (PTOA). Therefore, in order to improve clinical treatment and prevention strategies for post-traumatic osteoarthritis (PTOA), a series of translational studies were conducted to develop research models to evaluate the effects of impact injury. </p><p> The first section of this dissertation (Ch. 1&ndash;2) provides a comprehensive introduction and literature review related to both clinical PTOA as well as previous research investigations of PTOA. The second section of this dissertation (Ch. 3&ndash;6) describes the methodology of optimizing a servo-hydraulic test machine to deliver a controlled impact injury (Ch. 3) as well as subsequent studies using this device to injure articular cartilage (Ch. 4) and cartilage-bone explants (Ch. 5&ndash;6). Further, the effects of dynamic, compressive loading to mimic walking after impact injury of cartilage-bone explants was investigated (Ch. 6). The third section of this dissertation (Ch. 7&ndash;8) details the development of an impactor device that may be used for pre-clinical, animal models. </p><p> Many significant findings were discovered through this dissertation work. Specifically, by using the proportional-integral-derivative (40, 0, 0) values, a large (25kN) servo-hydraulic test machine may be used to deliver a controlled impact injury to explants (Ch. 3). Biomarkers glycosaminoglycan (GAG) and prostaglandin E2 (PGE<sub>2</sub>) were elevated after cartilage impact injury with PGE2 having the highest mechanosensitivity than any other biomarker (Ch. 4). Energy absorbed during cartilage-bone injury is dependent upon trauma severity; PGE<sub>2</sub> and monocyte attractant protein (MCP-1) were elevated following cartilage-bone injury (Ch. 5). Dynamic, compressive loading retained cell viability in non-impacted cartilage-bone explants and mitigated GAG release in impacted explants; GAG and PGE<sub>2</sub> were elevated due to cartilage-bone injury whereas matrix metalloproteinase-2 (MMP-2) and interleukin-8 (IL-8) were elevated due to injury plus dynamic, compressive loading (Ch. 6). The development of a 8mm diameter impactor does create articular cartilage damage (Ch. 7), albeit a smaller, 2mm diameter impactor creates higher impact stresses and may be used arthroscopically for pre-clinical animal models (Ch. 8). </p>
630

Resistance to rust (Puccinia antirrhini) in Antirrhinum majus

Gawthrop, Frances Mary January 1980 (has links)
A quantitative assessment of the susceptibility of 131 cultivars of Antirrhinum majus L. to the rust fungus Puccinia antirrhini Dietel and Holway by means of replicated trials over two years revealed a wide range of general resistance; there is scope for improvement of rust-resistance by breeding. The loss of immunity was due to genetic change in the fungus because variations in pathogenicity occur among geographical isolates. An investigation of the epidemiology of the rust revealed that during the summer in Britain, uredospores are liberated through the day to germinate and establish infection after dew has fallen in the evening. The local dispersal of the pathogen is largely by wind but the spread between continents throughout the world is more likely to be due to human activity. A breeding programme is suggested for the improvement of A. majus by hybridizing the more resistant cultivars. Meanwhile, some horticulturally acceptable varieties with rate-reducing resistance to the fungus are recommended. These varieties should not become disfigured by the disease provided they are grown away from susceptible varieties.

Page generated in 0.0866 seconds