456 resultados para noradrenalin blood level
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The biological function of inhibin-a subunit (INHa) in prostate cancer (PCa) is currently unclear. A recent study associated elevated levels of INHa in PCa patients with a higher risk of recurrence. This prompted us to use clinical specimens and functional studies to investigate the pro-tumourigenic and pro-metastatic function of INHa. We conducted a cross-sectional study to determine a link between INHa expression and a number of clinicopathological parameters including Gleason score, surgical margin, extracapsular spread, lymph node status and vascular endothelial growth factor receptor-3 expression, which are well-established prognostic factors of PCa. In addition, using two human PCa cell lines (LNCaP and PC3) representing androgen-dependent and -independent PCa respectively, we investigated the biological function of elevated levels of INHa in advanced cancer. Elevated expression of INHa in primary PCa tissues showed a higher risk of PCa patients being positive for clinicopathological parameters outlined above. Overexpressing INHa in LNCaP and PC3 cells demonstrated two different and cell-type-specific responses. INHa-positive LNCaP demonstrated reduced tumour growth whereas INHa-positive PC3 cells demonstrated increased tumour growth and metastasis through the process of lymphangiogenesis. This study is the first to demonstrate a pro-tumourigenic and pro-metastatic function for INHa associated with androgen-independent stage of metastatic prostate disease. Our results also suggest that INHa expression in the primary prostate tumour can be used as a predictive factor for prognosis of PCa.
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Objective Lower lipid and insulin levels are found during a glucose-tolerance test in obese black than obese white South African women. Therefore, β-cell function and lipid metabolism were compared in these populations during a mixed meal. Research Methods and Procedures Blood concentrations of glucose, free fatty acids (FFAs), insulin, lipograms, and in vivo FFA oxidation were determined at fasting and for 7 hours after oral administration of a mixed emulsion containing glucose-casein-sucrose-lipid and [1-13C] palmitic acid in 8 lean black women (LBW), 10 obese black women (OBW), 9 lean white women (LWW), and 10 obese white women (OWW). Subcutaneous and visceral fat mass was assessed by computerized tomography. Results Visceral fat area was higher in OWW (152.7 ± 17.0 cm2) than OBW (80.0 ± 6.7 cm2; p < 0.01). In OBW, 30-minute insulin levels were higher (604.3 ± 117.6 pM) than OWW (311.0 ± 42.9 pM; p < 0.05). Total triglyceride was higher in OWW (706.7 ± 96.0 mM × 7 hours) than OBW (465.7 ± 48.2 mM × 7 hours; p < 0.05) and correlated with visceral fat area (β = 0.38, p = 0.05). Palmitate oxidation was higher in lean than obese women in both ethnic groups and correlated negatively with fat mass (β = −0.58, p < 0.005). Discussion The higher 30-minute insulin response in OBW may reflect a higher insulinotropic effect of FFAs or glucose. The elevated triglyceride level of OWW may be due to their higher visceral fat mass and possibly reduced clearance by adipose tissue.
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Regeneration and growth of the human endometrium after shedding of the functional layer during menstruation depends on an adequate angiogenic response. We analysed the mRNA expression levels of all known vascular endothelial growth factor (VEGF) ligands and receptors in human endometrium collected in the menstrual and proliferative phases of the menstrual cycle. In addition, we evaluated the expression of VEGF-A, VEGF-R2 and NRP-1 at the protein level. Two periods of elevated mRNA expression of ligands and receptors were observed, separated by a distinct drop at cycle days (CDs) 9 and 10. Immunohistochemical staining showed that VEGF and VEGF-R2 were expressed in epithelial, stromal and endothelial cells. NRP-1 was mainly confined to stroma and blood vessels; only in late-proliferative endometrium, epithelial staining was also observed. Except for endothelial VEGF-R2 expression in CDs 6-8, there were no significant differences in the expression of VEGF, VEGF-R2 or NRP-1 in any of the cell compartments. In contrast, VEGF release by cultured human endometrium explants decreased during the proliferative phase. This output was significantly reduced in menstrual and early-proliferative endometrium by estradiol (E2) treatment. Western blot analysis indicated that part of the VEGF-A was trapped in the extracellular matrix (ECM). Changes in VEGF ligands and receptors were associated with elevated expression of the hypoxia markers HIF1 alpha and CA-IX in the menstrual and early proliferative phases. HIF1 alpha was also detected in late-proliferative phase endometrium. Our findings indicate that VEGF-A exerts its actions mostly during the first half of the proliferative phase. Furthermore, VEGF-A production appears to be triggered by hypoxia in the menstrual phase and subsequently suppressed toy estrogen during the late proliferative phase.
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To identify specific markers of rectovaginal endometriotic nodule vasculature, highly enriched preparations of vascular endothelial cells and pericytes were obtained from endometriotic nodules and control endometrial and myometrial tissue by laser capture microdissection (LCM), and gene expression profiles were screened by microarray analysis. Of the 18 400 transcripts on the arrays, 734 were significantly overexpressed in vessels from fibromuscular tissue and 923 in vessels from stromal tissue of endometriotic nodules, compared with vessels dissected from control tissues. The most frequently expressed transcripts included known endothelial cell-associated genes, as well as transcripts with little or no previous association with vascular cells. The higher expression in blood vessels was further corroborated by immunohistochemical staining of six potential markers, five of which showed strong expression in pericytes. The most promising marker was matrix Gla protein, which was found to be present in both glandular epithelial cells and vascular endothelial cells of endometriotic lesions, although it was barely expressed at all in normal endometrium. LCM, combined with microarray analysis, constitutes a powerful tool for mapping the transcriptome of vascular cells. After immunohistochemical validation, markers of vascular endothelial and perivascular cells from endometriotic nodules could be identified, which may provide targets to improve early diagnosis or to selectively deliver therapeutic agents.
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IN MANY FACTORIES, the feed chute of the first mill is operated with a high chute level for the purpose of maximising the cane rate through the mill. There is a trend towards trying to control chute level within a small control range near the top of a chute that can result in rapid changes in cane feeding rate to maintain the chute level set point. This paper reviews the theory that predicts higher cane rate with higher chute level and discusses the main weakness in the theory that it does not consider the beneficial effect on capacity of cane falling from the top of the chute to the top surface of the cane mat. An extension to the chute theory model is described that predicts higher capacity with lower chute level because of the effect of the falling cane. The original model and this extended model are believed to be the upper and lower limits to the true effect. The paper reports an experiment that measured the real effect of chute level on capacity and finds that increasing chute level does lead to higher capacity but that the trend is only about one-third as strong as the original theory predicted. The paper questions whether the benefits of slightly greater capacity outweigh the costs of operating with the small control range near the top of the chute.
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While existing multi-biometic Dempster-Shafer the- ory fusion approaches have demonstrated promising perfor- mance, they do not model the uncertainty appropriately, sug- gesting that further improvement can be achieved. This research seeks to develop a unified framework for multimodal biometric fusion to take advantage of the uncertainty concept of Dempster- Shafer theory, improving the performance of multi-biometric authentication systems. Modeling uncertainty as a function of uncertainty factors affecting the recognition performance of the biometric systems helps to address the uncertainty of the data and the confidence of the fusion outcome. A weighted combination of quality measures and classifiers performance (Equal Error Rate) are proposed to encode the uncertainty concept to improve the fusion. We also found that quality measures contribute unequally to the recognition performance, thus selecting only significant factors and fusing them with a Dempster-Shafer approach to generate an overall quality score play an important role in the success of uncertainty modeling. The proposed approach achieved a competitive performance (approximate 1% EER) in comparison with other Dempster-Shafer based approaches and other conventional fusion approaches.
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Purpose The purpose of this paper is to test a multilevel model of the main and mediating effects of supervisor conflict management style (SCMS) climate and procedural justice (PJ) climate on employee strain. It is hypothesized that workgroup-level climate induced by SCMS can fall into four types: collaborative climate, yielding climate, forcing climate, or avoiding climate; that these group-level perceptions will have differential effects on employee strain, and will be mediated by PJ climate. Design/methodology/approach Multilevel SEM was used to analyze data from 420 employees nested in 61 workgroups. Findings Workgroups that perceived high supervisor collaborating climate reported lower sleep disturbance, job dissatisfaction, and action-taking cognitions. Workgroups that perceived high supervisor yielding climate and high supervisor forcing climate reported higher anxiety/depression, sleep disturbance, job dissatisfaction, and action-taking cognitions. Results supported a PJ climate mediation model when supervisors’ behavior was reported to be collaborative and yielding. Research limitations/implications The cross-sectional research design places limitations on conclusions about causality; thus, longitudinal studies are recommended. Practical implications Supervisor behavior in response to conflict may have far-reaching effects beyond those who are a party to the conflict. The more visible use of supervisor collaborative CMS may be beneficial. Social implications The economic costs associated with workplace conflict may be reduced through the application of these findings. Originality/value By applying multilevel theory and analysis, we extend workplace conflict theory.
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Deoxyribonucleic acid (DNA) extraction has considerably evolved since it was initially performed back in 1869. It is the first step required for many of the available downstream applications used in the field of molecular biology. Whole blood samples are one of the main sources used to obtain DNA, and there are many different protocols available to perform nucleic acid extraction on such samples. These methods vary from very basic manual protocols to more sophisticated methods included in automated DNA extraction protocols. Based on the wide range of available options, it would be ideal to determine the ones that perform best in terms of cost-effectiveness and time efficiency. We have reviewed DNA extraction history and the most commonly used methods for DNA extraction from whole blood samples, highlighting their individual advantages and disadvantages. We also searched current scientific literature to find studies comparing different nucleic acid extraction methods, to determine the best available choice. Based on our research, we have determined that there is not enough scientific evidence to support one particular DNA extraction method from whole blood samples. Choosing a suitable method is still a process that requires consideration of many different factors, and more research is needed to validate choices made at facilities around the world.
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To complement the existing treatment guidelines for all tumour types, ESMO organises consensus conferences to focus on specific issues in each type of tumour. The 2nd ESMO Consensus Conference on Lung Cancer was held on 11-12 May 2013 in Lugano. A total of 35 experts met to address several questions on non-small-cell lung cancer (NSCLC) in each of four areas: pathology and molecular biomarkers, first-line/second and further lines in advanced disease, early stage disease and locally-advanced disease. For each question, recommendations were made including reference to the grade of recommendation and level of evidence. This consensus paper focuses on 1st line / 2nd and further lines of treatment in advanced disease. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved.
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Converging evidence from epidemiological, clinical and neuropsychological research suggests a link between cannabis use and increased risk of psychosis. Long-term cannabis use has also been related to deficit-like “negative” symptoms and cognitive impairment that resemble some of the clinical and cognitive features of schizophrenia. The current functional brain imaging study investigated the impact of a history of heavy cannabis use on impaired executive function in first-episode schizophrenia patients. Whilst performing the Tower of London task in a magnetic resonance imaging scanner, event-related blood oxygenation level-dependent (BOLD) brain activation was compared between four age and gender-matched groups: 12 first-episode schizophrenia patients; 17 long-term cannabis users; seven cannabis using first-episode schizophrenia patients; and 17 healthy control subjects. BOLD activation was assessed as a function of increasing task difficulty within and between groups as well as the main effects of cannabis use and the diagnosis of schizophrenia. Cannabis users and non-drug using first-episode schizophrenia patients exhibited equivalently reduced dorsolateral prefrontal activation in response to task difficulty. A trend towards additional prefrontal and left superior parietal cortical activation deficits was observed in cannabis-using first-episode schizophrenia patients while a history of cannabis use accounted for increased activation in the visual cortex. Cannabis users and schizophrenia patients fail to adequately activate the dorsolateral prefrontal cortex, thus pointing to a common working memory impairment which is particularly evident in cannabis-using first-episode schizophrenia patients. A history of heavy cannabis use, on the other hand, accounted for increased primary visual processing, suggesting compensatory imagery processing of the task.
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Surface-enhanced Raman spectroscopy (SERS) is a potentially important tool in the rapid and accurate detection of pathogenic bacteria in biological fluids. However, for diagnostic application of this technique, it is necessary to develop a highly sensitive, stable, biocompatible and reproducible SERS-active substrate. In this work, we have developed a silver–gold bimetallic SERS surface by a simple potentiostatic electrodeposition of a thin gold layer on an electrochemically roughened nanoscopic silver substrate. The resultant substrate was very stable under atmospheric conditions and exhibited the strong Raman enhancement with the high reproducibility of the recorded SERS spectra of bacteria (E. coli, S. enterica, S. epidermidis, and B. megaterium). The coating of the antibiotic over the SERS substrate selectively captured bacteria from blood samples and also increased the Raman signal in contrast to the bare surface. Finally, we have utilized the antibiotic-coated hybrid surface to selectively identify different pathogenic bacteria, namely E. coli, S. enterica and S. epidermidis from blood samples.
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I develop a model of individuals’ intentions to discontinue information system use. Understanding these intentions is important because they give insights into users’ willingness to carry out system tasks, and provide a basis for maintenance decisions as well as possible replacement decisions. I offer a first conceptualization of factors determining users’ discontinuance intentions on basis of existing literature on technology use, status quo bias and dual factor concepts. The model is grounded in rational choice theory to distinguish determinants of a conscious decision between continuing or discontinuing IS use. I provide details on the empirical test of the model through a field study of IS users in a retail organization. The work will have implications for theory on information systems continuance and dual-factor logic in information system use. The empirical findings will provide suggestions for managers dealing with cessation of information systems and work routine changes in organizations.
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Bisphenol A (BPA) is used extensively in food-contact materials and has been detected routinely in populations worldwide, and this exposure has been linked to a range of negative health outcomes in humans. There is some evidence of an association between BPA and different socioeconomic variables which may be the result of different dietary patterns. The aim of this study was to conduct a preliminary investigation of the association between BPA and socioeconomic status in Australian children using pooled urine specimens and an area level socioeconomic index. Surplus pathology urine specimens collected from children aged 0-15 years in Queensland, Australia as samples of convenience (n = 469) were pooled by age, sex and area level socioeconomic index (n = 67 pools), and analysed for total BPA using online solid phase extraction LC-MS/MS. Concentration ranged from 1.08-27.4 ng/ml with geometric mean 2.57 ng/ml, and geometric mean exposure was estimated as 70.3 ng/kg d-1. Neither BPA concentration nor excretion was associated with age or sex, and the authors found no evidence of an association with socioeconomic status. These results suggest that BPA exposure is not associated with socioeconomic status in the Australian population due to relatively homogenous exposures in Australia, or that the socioeconomic gradient is relatively slight in Australia compared with other OECD countries.
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Blood donation is a critical part of health services with a viable blood supply underpinning an effective health program in any country. Typically blood is provided by voluntary donations from citizens and is therefore reliant on the goodwill and altruistic commitment of donors. In Australia, like many other developed nations, there are many challenges in maintaining a sufficient and sustainable blood supply. The Australian Red Cross Blood Service Donor and Community research group aim is to understand the barriers, motivations and perceptions of donors. Blood donation is a ‘people-processing’ service (Lovelock 1983, Russell-Bennett et al 2013) with the marketing exchange relating to bodily fluid rather than money and is an altruistic social service that has no direct benefit for the customer donor rather the benefit is for other people and society (Kotler and Zaltman 1971). Emotion has been shown to be a motivator and a barrier in a variety of Blood Service studies, this is a key insight that is further explored in the current study. Other key social factors that impact blood donor behavior are classified as social because they involve perceptions of other people’s beliefs and responses (such as moral or subjective norms), peer pressure, other people’s expectations and other people as a form of support. Given that emotions are social phenomena (Parkinson 1996), this study focuses on the role of other people in the blood donation process and how other people relates to the emotional experience of blood donors. We argue in this paper that overcoming emotional barriers to blood donation by leveraging the role of other people will influence low donation rates in Australia. To date, there has been little evidence in service research that identifies. In this paper we explore how other people influence the emotional experience of donors and how, donor emotions create the need for other people as a coping resource.
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Platelet-derived microparticles that are produced during platelet activation are capable of adhesion and aggregation. Endothelial trauma that occurs during percutaneous transluminal coronary angioplasty (PTCA) may support platelet-derived microparticle adhesion and contribute to development of restenosis. We have previously reported an increase in platelet-derived microparticles in peripheral arterial blood with angioplasty. This finding raised concerns regarding the role of plateletderived microparticles in restenosis, and therefore the aim of this study was to monitor levels in the coronary circulation. The study population consisted of 19 angioplasty patients. Paired coronary artery and sinus samples were obtained following heparinization, following contrast administration, and subsequent to all vessel manipulation. Platelet-derived microparticles were identified with an anti-CD61 (glycoprotein IIIa) fluorescence-conjugated antibody using flow cytometry. There was a significant decrease in arterial platelet-derived microparticles from heparinization to contrast administration (P 0.001), followed by a significant increase to the end of angioplasty (P 0.004). However, there was no significant change throughout the venous samples. These results indicate that the higher level of platelet-derived microparticles after angioplasty in arterial blood remained in the coronary circulation. Interestingly, levels of thrombin–antithrombin complexes did not rise during PTCA. This may have implications for the development of coronary restenosis post-PTCA, although this remains to be determined.