202 resultados para TRANSITION LOSSES
Resumo:
Metastasis accounts for the poor prognosis of the majority of solid tumors. The phenotypic transition of nonmotile epithelial tumor cells to migratory and invasive “mesenchymal” cells (epithelial-to-mesenchymal transition [EMT]) enables the transit of cancer cells from the primary tumor to distant sites. There is no single marker of EMT; rather, multiple measures are required to define cell state. Thus, the multiparametric capability of high-content screening is ideally suited for the comprehensive analysis of EMT regulators. The aim of this study was to generate a platform to systematically identify functional modulators of tumor cell plasticity using the bladder cancer cell line TSU-Pr1-B1 as a model system. A platform enabling the quantification of key EMT characteristics, cell morphology and mesenchymal intermediate filament vimentin, was developed using the fluorescent whole-cell-tracking reagent CMFDA and a fluorescent promoter reporter construct, respectively. The functional effect of genome-wide modulation of protein-coding genes and miRNAs coupled with those of a collection of small-molecule kinase inhibitors on EMT was assessed using the Target Activation Bioapplication integrated in the Cellomics ArrayScan platform. Data from each of the three screens were integrated to identify a cohort of targets that were subsequently examined in a validation assay using siRNA duplexes. Identification of established regulators of EMT supports the utility of this screening approach and indicated capacity to identify novel regulators of this plasticity program. Pathway analysis coupled with interrogation of cancer-related expression profile databases and other EMT-related screens provided key evidence to prioritize further experimental investigation into the molecular regulators of EMT in cancer cells.
Resumo:
Nurses play a pivotal role in caring for patients during the transition from life-prolonging care to palliative care. This is an area of nursing prone to emotional difficulty, interpersonal complexity, and interprofessional conflict. It is situated within complex social dynamics, including those related to establishing and accepting futility and reconciling the desire to maintain hope. Here, drawing on interviews with 20 Australian nurses, we unpack their accounts of nursing the transition to palliative care, focusing on the purpose of nursing at the point of transition; accounts of communication and strategies for representing palliative care; emotional engagement and burden; and key interprofessional challenges. We argue that in caring for patients approaching the end of life, nurses occupy precarious interpersonal and interprofessional spaces that involve a negotiated order around sentimental work, providing them with both capital (privileged access) and burden (emotional suffering) within their day-to-day work.
Resumo:
Specialist palliative care is a prominent and expanding site of health service delivery, providing highly specialised care to people at the end of life. Its focus on the delivery of specialised life-enhancing care stands in contrast to biomedicine's general tendency towards life-prolonging intervention. This philosophical departure from curative or life-prolonging care means that transitioning patients can be problematic, with recent work suggesting a wide range of potential emotional, communication and relational difficulties for patients, families and health professionals. Yet, we know little about terminally ill patients' lived experiences of this complex transition. Here, through interviews with 40 inpatients in the last few weeks of life, we explore their embodied and relational experiences of the transition to inpatient care, including their accounts of an ethic of resilience in pre-palliative care and an ethic of acceptance as they move towards specialist palliative care. Exploring the relationship between resilience and acceptance reveals the opportunities, as well as the limitations, embedded in the normative constructs that inflect individual experience of this transition. This highlights a contradictory dynamic whereby participants' experiences were characterised by talk of initiating change, while also acquiescing to the terminal progression of their illness.
Resumo:
Epithelial to mesenchymal transition (EMT) has gained widespread acceptance over recent years as a mechanism by which normally sessile epithelial tumour cells can move away from the primary tumour and metastasize. This review article examines the role of a number of growth factors in inducing EMT, and the reverse process mesenchymal to epithelial transition. Unique and common intracellular signalling pathways are highlighted. A comprehensive understanding of the regulation of EMT will be critical in manipulating this process to develop novel anti-metastasis therapies.
Resumo:
This paper presents new schemes for recursive estimation of the state transition probabilities for hidden Markov models (HMM's) via extended least squares (ELS) and recursive state prediction error (RSPE) methods. Local convergence analysis for the proposed RSPE algorithm is shown using the ordinary differential equation (ODE) approach developed for the more familiar recursive output prediction error (RPE) methods. The presented scheme converges and is relatively well conditioned compared with the ...
Resumo:
This paper develops maximum likelihood (ML) estimation schemes for finite-state semi-Markov chains in white Gaussian noise. We assume that the semi-Markov chain is characterised by transition probabilities of known parametric from with unknown parameters. We reformulate this hidden semi-Markov model (HSM) problem in the scalar case as a two-vector homogeneous hidden Markov model (HMM) problem in which the state consist of the signal augmented by the time to last transition. With this reformulation we apply the expectation Maximumisation (EM ) algorithm to obtain ML estimates of the transition probabilities parameters, Markov state levels and noise variance. To demonstrate our proposed schemes, motivated by neuro-biological applications, we use a damped sinusoidal parameterised function for the transition probabilities.
Resumo:
In this paper we propose a new multivariate GARCH model with time-varying conditional correlation structure. The time-varying conditional correlations change smoothly between two extreme states of constant correlations according to a predetermined or exogenous transition variable. An LM–test is derived to test the constancy of correlations and LM- and Wald tests to test the hypothesis of partially constant correlations. Analytical expressions for the test statistics and the required derivatives are provided to make computations feasible. An empirical example based on daily return series of five frequently traded stocks in the S&P 500 stock index completes the paper.
Resumo:
A numerical study is carried out to investigate the transition from laminar to chaos in mixed convection heat transfer inside a lid-driven trapezoidal enclosure. In this study, the top wall is considered as isothermal cold surface, which is moving in its own plane at a constant speed, and a constant high temperature is provided at the bottom surface. The enclosure is assumed to be filled with water-Al2O3 nanofluid. The governing Navier–Stokes and thermal energy equations are expressed in non-dimensional forms and are solved using Galerkin finite element method. Attention is paid in the present study on the pure mixed convection regime at Richandson number, Ri = 1. The numerical simulations are carried out over a wide range of Reynolds (0.1 ≤ Re ≤ 103) and Grashof (0.01 ≤ Gr ≤ 106) numbers. Effects of the presence of nanofluid on the characteristics of mixed convection heat transfer are also explored. The average Nusselt numbers of the heated wall are computed to demonstrate the influence of flow parameter variations on heat transfer. The corresponding change of flow and thermal fields is visualized from the streamline and the isotherm contour plots.
Resumo:
The professional socialisation of paramedics encompasses preconceptions developed during childhood and early adulthood, and subsequent changes in perceptions resulting from university studies, clinical placements and encountering the professional workplace as an employee. This study investigates the professional socialisation of university educated paramedics making the transition from paramedic intern to qualified paramedic. Participants were sought from several of Australia’s larger ambulance services and UK NHS Ambulance Trusts to take part in this study. Participants were recruited through Ambulance Service Research Institutes, Clinical Governance Departments and university databases. To be included in this study, participants were required to be university educated, have completed a professional internship year and achieved qualified or registered paramedic status. Data collection was via face to face semi-structured interviews. Transcripts were analysed using socialisation models from the nursing and allied health disciplines and a grounded theory approach. The study found that participants initially enjoyed their new professional status after completing their internship and becoming qualified paramedics. However, for many the excitement of becoming a qualified paramedic was short lived. Newly qualified paramedics experienced increased levels of responsibility and were required to develop mentoring skills while still adjusting to their new roles. Participants had to contend with inner conflicting views about the reality of paramedic work which were developed though preconceptions and experiences as paramedic interns. The transition from paramedic intern to qualified paramedic is reportedly a challenging experience, as newly qualified paramedics are required to deal with added complexities while still adjusting to their new roles.
Resumo:
Prostate-specific antigen (PSA) and the related kallikrein family of serine proteases are current or emerging biomarkers for prostate cancer detection and progression. Kallikrein 4 (KLK4/hK4) is of particular interest, as KLK4 mRNA has been shown to be elevated in prostate cancer. In this study, we now show that the comparative expression of hK4 protein in prostate cancer tissues, compared with benign glands, is greater than that of PSA and kallikrein 2 (KLK2/hK2), suggesting that hK4 may play an important functional role in prostate cancer progression in addition to its biomarker potential. To examine the roles that hK4, as well as PSA and hK2, play in processes associated with progression, these kallikreins were separately transfected into the PC-3 prostate cancer cell line, and the consequence of their stable transfection was investigated. PC-3 cells expressing hK4 had a decreased growth rate, but no changes in cell proliferation were observed in the cells expressing PSA or hK2. hK4 and PSA, but not hK2, induced a 2.4-fold and 1.7-fold respective increase, in cellular migration, but not invasion, through Matrigel, a synthetic extracellular matrix. We hypothesised that this increase in motility displayed by the hK4 and PSA-expressing PC-3 cells may be related to the observed change in structure in these cells from a typical rounded epithelial-like cell to a spindle-shaped, more mesenchymal-like cell, with compromised adhesion to the culture surface. Thus, the expression of E-cadherin and vimentin, both associated with an epithelial-mesenchymal transition (EMT), was investigated. E-cadherin protein was lost and mRNA levels were significantly decreased in PC-3 cells expressing hK4 and PSA (10-fold and 7-fold respectively), suggesting transcriptional repression of E-cadherin, while the expression of vimentin was increased in these cells. The loss of E-cadherin and associated increase in vimentin are indicative of EMT and provides compelling evidence that hK4, in particular, and PSA have a functional role in the progression of prostate cancer through their promotion of tumour cell migration.
Resumo:
Policies of inclusion challenge the construct of readiness and require schools to prepare for the diversity of children as they transition to school. However, there is limited empirical evidence concerning how this challenge is met. This paper presents two Australian studies that investigate inclusive practices in the transition to school. Study 1 examined the predictors of child outcomes across a sample of 1831 children in 39 schools. The results indicate that both quantity and quality of programme provision influenced outcomes and that programme effects were particularly potent for children with diverse abilities and backgrounds. Study 2 focuses on pedagogy in three of the schools to highlight how this provision can be achieved. Results show that provisions were reactive, that saliency of children’s needs directed school practices and that professional knowledge impacted on measures of quality. Inclusive processes accounting for both child progress and broader family and teaching influences are necessary for improved transition to school.
Resumo:
Various types of layered double hydroxides, a type of clay, were synthesised. They were then electrochemically tested to determine whether the samples would be suitable to store energy as supercapacitors. A manganese aluminium layered double hydroxide was electrochemically tested for the first time and found to have a large capacitance.