2,014 research outputs found
An in vitro investigation into the efficacies of chlorhexidine gluconate, povidone iodine and green tea (Camellia sinensis) to prevent surgical site infection in animals
A Multiple-Attribute Decision Model for Retail Store Location
James A. Pope, PhD, is professor of operations and supply chain management at the Hult International Business School, Cambridge, MA 02141.
William R. Lane, PhD, is professor emeritus of finance at the Louisiana State University, Baton Rouge, LA 70803.
Jane Stein, DrPH, is retired from the UNC-CH School of Public Health, Chapel Hill, NC 27514
Significance and therapeutic implications of endothelial progenitorcells in angiogenic-mediated tumour metastasis
Cancer conveys profound social and economic consequences throughout the world. Metastasis is respon-sible for approximately 90% of cancer-associated mortality and, when it occurs, cancer becomes almostincurable. During metastatic dissemination, cancer cells pass through a series of complex steps includingthe establishment of tumour-associated angiogenesis. The human endothelial progenitor cells (hEPCs)are a cell population derived from the bone marrow which are required for endothelial tubulogenesisand neovascularization. They also express abundant inflammatory cytokines and paracrine angiogenicfactors. Clinically hEPCs are highly correlated with relapse, disease progression, metastasis and treatmentresponse in malignancies such as breast cancer, ovarian cancer and non-small-cell lung carcinoma. It hasbecome evident that the hEPCs are involved in the angiogenesis-required progression and metastasis oftumours. However, it is not clear in what way the signalling pathways, controlling the normal cellularfunction of human BM-derived EPCs, are hijacked by aggressive tumour cells to facilitate tumour metas-tasis. In addition, the actual roles of hEPCs in tumour angiogenesis-mediated metastasis are not wellcharacterised. In this paper we reviewed the clinical relevance of the hEPCs with cancer diagnosis, pro-gression and prognosis. We further summarised the effects of tumour microenvironment on the hEPCsand underlying mechanisms. We also hypothesized the roles of altered hEPCs in tumour angiogenesisand metastasis. We hope this review may enhance our understanding of the interaction between hEPCsand tumour cells thus aiding the development of cellular-targeted anti-tumour therapies
Hybrid phosphine-carbene ligands and their use in homogeneous catalysis
Several chelating phosphine-imidazolium salts have been synthesised and their activity tested in a number of palladium catalysed cross-coupling reactions. The in- situ catalyst testing was carried out using parallel screening techniques and moderate catalytic activity was shown by phosphine-imidazolium salts 2, 6 and 16. A number of synthetic routes have been successfully established which have provided viable paths into three main types of phosphine functionalised imidazolium salts. These methodologies have increased the scope for the potential number of interesting chelating phosphine-imidazolium salts. Several group 10 complexes of these new ligands have been prepared and characterised by the reaction of functionalised nucleophilic heterocyclic carbene's (NHC's), which were generated in-situ and reacted with suitable metal precursors. The solid state structure of complex 1 has been obtained, giving an insight into the properties of these chelating ligands. The relative trans influence of the phosphine and carbene functions have been measured for this bidentate ligand. Following the results of the in-situ catalyst testing, two pre-formed palladium(II) complexes, 1 and 2, were tested in the Heck and Suzuki cross-coupling with the reaction performed under stricter anaerobic conditions with more favourable results. The synthesis of several silver(I) complexes was also achieved by the reaction of phosphine- imidazolium salts with Ag2O3. The preparation of a Rh(I) phosphine-NHC complex was achieved via transmetallation
The expression and prognostic value of the guanine nucleotide exchange factors (GEFs) Trio, Vav1 and TIAM-1 in human breast cancer
Background: Development of metastasis in breast cancer is a multi-step process comprising changes in cytoskeletal structure and gene expression of tumour cells leading to changes in cell adhesion and motility. The Rho GTPase proteins, which function as guanine nucleotide regulated binary switches, govern a variety of cellular processes including cell motility and migration, changes in cell adhesion as well as actin cytoskeletal reorganisation and gene expression/transcription. One group of activators which regulate the Rho-GTPases is the guanine nucleotide exchange factors (GEFs), and this study looked at three such GEFs, Trio, Vav1 and TIAM-1. The purpose of this study was to investigate the expression of these GEFs, in human breast cancer and assess the affect on clinical outcome.
Methods: Specimens of fresh, frozen breast tumour tissue (n = 113) and normal background tissue (n = 30) were processed for quantitative PCR analysis. The expression and levels of expression of Trio, Vav1 and TIAM-1 were analysed using RT-PCR and real-time Q-PCR respectively. Sections were also immunostained with Trio and Tiam-1 antibodies.
Results: Tumour tissue exhibited high levels of all three Rho activators Trio, Vav1 and TIAM-1 compared with normal background breast tissue, reaching a level of significance for the GEF Trio (p = 0.013). Trio levels also increased significantly in patients with a poor prognostic index (p = 0.04).
Levels of TIAM-1 were significantly higher in tumour tissue from patients who died from breast cancer compared with those who survived (p = 0.04). No significant correlation was found between tumour grade and histology types.
Conclusion: High expression levels of Trio, Vav1 and TIAM-1 were seen in breast tumours, especially in those with poor prognosis. This suggests that aberrant regulation of Rho family activities by GEFs may have an important prognostic value in breast cancer
NudgeAlong: A Case-Based Approach to Changing User Behaviour
Companies want to change the way that users interact with their services. One of the main ways to do this is through messaging. It is well known that different users are likely to respond to different types of messages. Targeting the right message type at the right user is key to achieving successful behaviour change. This paper frames this as a case based reasoning problem. The case representation captures a summary of a user’s interactions with a company’s services over time. The case solution represents a message type that resulted in a desired change in the user’s behaviour. This paper describes this framework, how it has been tested using simulation and a short description of a test deployment
'Recruitment, recruitment, recruitment' - the need for more focus on retention: a qualitative study of five trials
Abstract Background Loss to follow-up (attrition) is a frequent problem in clinical trials and can introduce bias or reduce power. So, understanding retention issues and strategies to address these are important. As part of a multi-method project, this qualitative study aimed to explore retention strategies used by trial teams and factors which may influence strategy adoption. Method A purposive sample of active trials was selected from the UK NIHR HTA portfolio of ongoing trials in 2014/2015. Semi-structured interviews with several trial team members from each trial and supplementary interviews with experienced trial managers explored strategies in collecting clinical outcome data and retaining participants. Interview data were analysed thematically using techniques of constant comparison. Results Twenty-two semi-structured interviews with trial team members including chief investigators, trial managers, nurses and research administrators revealed strategies used to enhance retention. Some were recognised methods and planned from trial outset whilst others were implemented more responsively. Interviewees placed great value on fostering positive relationships with trial participants to enhance retention. However, these strategies took time which was not always appreciated by the wider trial team or funding bodies. The national focus on recruitment targets in networks posed a challenge to staff and was deemed detrimental to retention. The ‘moral compass’ of individual researchers relied on their own beliefs and values and research experience and the factors affected their confidence to pursue participant data during follow-up. Conclusion The role of trial staff and their underlying behaviours influence retention practices and, combined with emphasis on recruitment targets, can be detrimental to motivation and retention activities. There is a need to consider how to train and support trial staff involved in retention practices and recognition of retention from funding bodies and oversight organisations
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