91 research outputs found
Epidermal growth factor and transforming growth factor alpha characteristics of human oral carcinoma cell lines.
This study examined the expression of epidermal growth factor (EGF) cell-surface receptors, the response to exogenous ligand and the autocrine production of transforming growth factor alpha (TGF-alpha) in normal and carcinoma-derived human oral keratinocytes. One of eight malignant cell lines overexpressed EGF receptors, while the remainder expressed receptor numbers similar to normal cells. Exogenous EGF stimulated incorporation of tritiated thymidine in a dose-dependent manner. In keratinocytes expressing normal numbers of EGF receptors, the cellular response to exogenous EGF correlated positively with total EGF receptor number. SCC-derived keratinocytes produced more TGF-alpha than normal cells. There was no statistical correlation between the autocrine production of TGF-alpha, EGF cell-surface receptor expression and cellular response to exogenous EGF. While the growth-stimulatory effects of exogenous TGF-alpha were inhibited by the addition of a neutralising antibody, the presence of this antibody in conditioned medium failed to produce a similar decrease in growth. The results indicate that overexpression of EGF receptors is not an invariable characteristic of human oral squamous carcinoma-derived cell lines. Further, the contribution of TGF-alpha to the growth of normal and carcinoma-derived human oral keratinocytes in vitro may be less significant than previously documented
The CLIMODE field campaign : observing the cycle of convection and restratification over the Gulf Stream
Author Posting. © American Meteorological Society, 2009. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 90 (2009): 1337-1350, doi:10.1175/2009BAMS2706.1.A major oceanographic field experiment is described, which is designed to observe, quantify, and understand the creation and dispersal of weakly stratified fluid known as “mode water” in the region of the Gulf Stream. Formed in the wintertime by convection driven by the most intense air–sea fluxes observed anywhere over the globe, the role of mode waters in the general circulation of the subtropical gyre and its biogeo-chemical cycles is also addressed. The experiment is known as the CLIVAR Mode Water Dynamic Experiment (CLIMODE). Here we review the scientific objectives of the experiment and present some preliminary results.Physical
Oceanography program of NS
Dominant culture and bullying : personal accounts of workers in Malaysia
Workplace bullying has been termed the cancer of the workplace; it is a widespread and often intractable problem. Internationally, a wealth of research has examined the prevalence of workplace bullying and its negative effects. This research base and the scientific definition of workplace bullying are, however, based on Western perspectives and supported by theories, models, and research studies conducted in Western cultures. The differences in cultural perspectives of Western and Eastern countries mean that workplace bullying may not be understood in the same way across different cultural groups, particularly when cultures differ along the Individualism-Collectivism dimension. Given that Malaysia is an Eastern country with a number of ethnic groups, a more comprehensive understanding of workplace bullying in the Malaysian context is important. Through a case study comprising in-depth qualitative interviews with 20 employees from different organisations in Malaysia, this chapter reveals six lay beliefs of workplace bullying and 19 lay beliefs about bullying behaviors. The study also found that the 12 bullying behaviors are work related while the other seven are personal-nature bullying behaviors. These results emphasize the influence of culture on how bullying is perceived within the Malaysian context, and the importance of understanding lay representations of workplace bullying from the Eastern context that apparent across nation. Based on the interviews, a general definition of workplace bullying from Malaysian employees' perspectives is presented and developed. The chapter concludes with implications for understanding bullying as an important psychosocial hazard at work and recommendations for future research and practice across the Asia Pacific region
Validation of a new glucocorticoid-specific patient reported outcome questionnaire (the Steroid PRO
Abstract ObjectivesGlucocorticoids used in the treatment of inflammatory rheumatic conditions can impact on health-related quality of life. An underpinning qualitative study developed a long-list of candidate items for a treatment-specific patient-reported outcome measure. The objective of this paper is to determine scale structure and psychometric properties of the Steroid PRO.MethodsA cross-sectional survey of adults from UK, USA, Australia and New Zealand, taking glucocorticoids for a rheumatic disease. Initial survey collected demographics, clinical information, 40 Steroid PRO candidate items, and EQ-5D-5L. Follow-up, 3-5 days later, collected Steroid PRO candidate items and a condition-change (‘transition’) question. Analysis included Rasch measurement model, exploratory factor analysis (EFA), and hypothesis testing for discriminative validity, convergence validity and test-retest reliability.ResultsTotal responses 946: UK n=743 (79%); USA n=139 (15%); Australia/New Zealand n=64 (7%); mean age 57.6 (SD=13.6); 833 (88%) women. Participants with inflammatory arthritis n=197 (21%), connective tissue disease and/or vasculitis n=402 (42%), giant cell arteritis and/or polymyalgia rheumatica n=347 (37%). Twenty-five items were removed due to lack of fit to Rasch model. Of the remaining items, EFA suggested four sub-scales: Social impact (4 items); Impact on appearance (3 items); Psychological impact (5 items); Treatment concerns (3 items). Rasch modelling supported a 4-sub-scale structure and total score, confirming construct validity and reliability. Hypothesis testing confirmed discriminant and convergence validity. Intra-class correlation coefficient (total score) was 0.809 demonstrating excellent (test-retest) reliability. ConclusionsThe Steroid PRO is a 15-item, valid and reliable scale for measuring the impact of glucocorticoid therapy in people with rheumatic diseases
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