41 research outputs found

    Skin Barrier Homeostasis in Atopic Dermatitis: Feedback Regulation of Kallikrein Activity

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    Atopic dermatitis (AD) is a widely spread cutaneous chronic disease characterised by sensitive reactions (eg. eczema) to normally innocuous elements. Although relatively little is understood about its underlying mechanisms due to its complexity, skin barrier dysfunction has been recognised as a key factor in the development of AD. Skin barrier homeostasis requires tight control of the activity of proteases, called kallikreins (KLKs), whose activity is regulated by a complex network of protein interactions that remains poorly understood despite its pathological importance. Characteristic symptoms of AD include the outbreak of inflammation triggered by external (eg. mechanical and chemical) stimulus and the persistence and aggravation of inflammation even if the initial stimulus disappears. These characteristic symptoms, together with some experimental data, suggest the presence of positive feedback regulation for KLK activity by inflammatory signals. We developed simple mathematical models for the KLK activation system to study the effects of feedback loops and carried out bifurcation analysis to investigate the model behaviours corresponding to inflammation caused by external stimulus. The model analysis confirmed that the hypothesised core model mechanisms capture the essence of inflammation outbreak by a defective skin barrier. Our models predicted the outbreaks of inflammation at weaker stimulus and its longer persistence in AD patients compared to healthy control. We also proposed a novel quantitative indicator for inflammation level by applying principal component analysis to microarray data. The model analysis reproduced qualitative AD characteristics revealed by this indicator. Our results strongly implicate the presence and importance of feedback mechanisms in KLK activity regulation. We further proposed future experiments that may provide informative data to enhance the system-level understanding on the regulatory mechanisms of skin barrier in AD and healthy individuals

    Palliative Care and Health Care Utilization for Patients With End-Stage Liver Disease at the End of Life

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    Background & aimsThere has been increased attention on ways to improve the quality of end-of-life care for patients with end-stage liver disease; however, there have been few reports of care experiences for patients during terminal hospitalizations. We analyzed data from a large national database to increase our understanding of palliative care for and health care utilization by patients with end-stage liver disease.MethodsWe performed a cross-sectional, observational study to examine terminal hospitalizations of adults with decompensated cirrhosis using data from the National Inpatient Sample from 2009 through 2013. We collected data on palliative care consultation and total hospital costs, and performed multivariate regression analyses to identify factors associated with palliative care consultation. We also investigated whether consultation was associated with lower costs.ResultsAmong hospitalized adults with terminal decompensated cirrhosis, 30.3% received palliative care; the mean cost per hospitalization was 48,551±48,551 ± 1142. Palliative care consultation increased annually, and was provided to 18.0% of patients in 2009 and to 36.6% of patients in 2013 (P < .05). The mean cost for the terminal hospitalization did not increase significantly (47,969in2009to47,969 in 2009 to 48,956 in 2013, P = .77). African Americans, Hispanics, Asians, and liver transplant candidates were less likely to receive palliative care, whereas care in large urban teaching hospitals was associated with a higher odds of receiving consultation. Palliative care was associated with lower procedure burden-after adjusting for other factors, palliative care was associated with a cost reduction of $10,062.ConclusionsPalliative care consultation for patients with end-stage liver disease increased from 2009 through 2013. Palliative care consultation during terminal hospitalizations is associated with lower costs and procedure burden. Future research should evaluate timing and effects of palliative care on quality of end-of-life care in this population

    Internationalization of emerging-market firms: The contingent role of board capability

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    Despite extensive research on the internationalization–performance relationship, our understanding of the role of board of directors in the internationalization of emerging-market firms remains relatively limited. In addition, research pertaining to the board’s influence on firm performance has tended to focus more on board content than on its processes. In an attempt to address this research gap, we study the contingent role of the board’s capabilities on the relationship between internationalization and performance, in emerging-market firms. We propose that board tenure will have a negative moderating effect, whereas board members’ experience as CEO or general manager, industry-specific experience, international experience, and level of academic achievement will have positive moderating effects. We argue that, in the context of emerging market firms, board interactions are particularly important, and propose that moderate levels of board interaction will be most beneficial for the internationalization performance relationship
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