1,079 research outputs found

    G-Protein coupled receptor signalling in pluripotent stem cell-derived cardiovascular cells: Implications for disease modelling

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    Human pluripotent stem cell derivatives show promise as an in vitro platform to study a range of human cardiovascular diseases. A better understanding of the biology of stem cells and their cardiovascular derivatives will help to understand the strengths and limitations of this new model system. G-protein coupled receptors (GPCRs) are key regulators of stem cell maintenance and differentiation and have an important role in cardiovascular cell signaling. In this review, we will therefore describe the state of knowledge concerning the regulatory role of GPCRs in both the generation and function of pluripotent stem cell derived-cardiomyocytes, -endothelial, and -vascular smooth muscle cells. We will consider how far the in vitro disease models recapitulate authentic GPCR signaling and provide a useful basis for discovery of disease mechanisms or design of therapeutic strategies

    Indocyanine green elimination test in orthotopic liver recipients.

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    OBJECTIVE: To determine its predictive capability on graft quality and resultant clinical outcome, the indocyanine green (ICG) elimination test was performed by a spectrophotometric method and a noninvasive finger-piece method with 50 orthotopic liver transplantations. BACKGROUND: Early detection of poor-functioning hepatic grafts is one of the most important issues in liver transplantation, but no reliable methods exist. METHODS: The ICG test was performed after 50 orthotopic liver transplantations on postoperative days 1, 3, and 7. Indocyanine green elimination constants (K(ICG)) were measured by both a standard spectrophotometric analysis (K(ICG)-B) and by a finger-piece method (K(ICG)-F). The patients were followed for a minimum of 3 months after transplantation. Results of ICG tests were correlated with various clinical determinations. RESULTS: Twelve of the 50 grafts were lost within three months, of which 7 were related to graft failure. Multivariate analysis using the Cox proportional hazard model revealed that K(ICG) on postoperative day 1 was a better predictor of liver-related graft outcome than any of the conventional liver function tests. Furthermore, K(ICG) values showed significant correlation with the severity of preservation injury, longer intensive care unit (ICU) and hospital stay, prolonged liver dysfunction, and septic complications. Correlation of K(ICG) values by the spectrophotometric method with those by the finger-piece method was highly satisfactory in the grafts that had K(ICG)-B <0.15 min-1 (y = 0.868x -0.011, r = .955). CONCLUSION: The ICG elimination test, conducted spectrophotometrically or optically on the day after liver transplantation, is a reliable indicator of graft quality and subsequent graft outcome early after liver transplantation

    Chromatid recommensuration after segmental duplication

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    <p>Abstract</p> <p>Background</p> <p>Midsegment duplication (dup) of chromatid arms may be symmetric or asymmetric. It can be argued that every dup should yield a discommensured RC with (a) loss of at least one duplicated unit to the template counterpart and; (b) deletion of all sections of the replicating chromatid arm that are distal to both the gap left by the duplicating process and the segment closest to the centromere.</p> <p>Hypothesis</p> <p>Mechanisms capable of recommensuring the stack of chromatids after topological shifts of duplicated units (dups) are discussed. The mechanics might fail in few cases, which are discussed in terms of statistics and scalability.</p> <p>Conclusion</p> <p>The dynamics of the highly non-linear processes discussed here may be relevant to duplications of smaller (epsilon) subunits such as telomeric units within malignant genomes.</p

    Early death or retransplantation in adults after orthotopic liver transplantation: Can outcome be predicted?

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    Early, reliable outcome prediction after a liver transplant would help improve organ use by minimizing unnecessary retransplantations. At the same time, early intervention in those cases destined to fail may ameliorate the high morbidity and mortality associated with retransplantation. The purpose of this study was to analyze several parameters that have been identified in the past as being associated with patient and graft outcome, and to try to develop a model that would allow us to make predictions based on data available in the early postoperative period. A total of 148 patients were followed in a prospective, observational study. Graft failure was defined as patient death or retransplantation within 3 months of surgery. Preoperative variables studied included patient demographics, need for life support, presence of ascites, serum bilirubin, serum albumin, prothrombin time, serum creatinine, and the results of the cytotoxic crossmatch. During the first 5 postoperative days, standard measurements included serum transaminases, serum bilirubin, ketone body ratio, prothrombin time, factor V, and serum lactate. Oxygen consumption was measured shortly after surgery, once the patients had rewarmed to 36°C. There were 131 successful transplants (88.5%) and 17 failures (11.5%). Most of the variables studied were found to be associated with outcome (by univariate analysis) at different points in the early postoperative period. However, receiver operating characteristic curve analysis showed that the predictive ability of even the best parameter was not adequate to make decisions on individual patients. Multivariate analysis, using stepwise logistic regression, yielded a model with an overall accuracy of 92.7%. Again, receiver operating characteristic curve analysis suggested that this model did not achieve the discriminating power needed for routine clinical use. We are still not able to accurately predict outcome in the early posttransplant period. We must be very careful when evaluating parameters, or scoring systems, that are said to accomplish this. It is especially important in this era of cost containment, with its renewed pressures to guide therapy based on our perceived understanding of a patient’s future clinical course. © 1994 by Williams & Wilkins

    Greening hotels: does motivating hotel employees promote in-role green performance? The role of culture

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    In the new global economy, environmentally friendly policies have become a central issue for firms. The increasing attention given to the benefits of those policies has prompted research on the development of environmental management systems that encourage employees to engage in environmental activities. However, there is limited evidence concerning the relationship between employee motivation and employees’ in-role green performance, in addition to the potential impact of culture and organizational citizenship behavior for the environment. Through a quantitative study of 301 managerial and non-managerial employees working in three- to five-star hotels, this study makes a major contribution by demonstrating that practices aimed at motivating hotel employees (e.g. green reward and performance management) are significantly linked with employees’ in-role green performance and organizational citizenship behavior for the environment. The findings also indicate that the influence of green rewards on employees’ in-role green performance and organizational citizenship behaviors for the environment is stronger when hotels are managed by Western corporations. Conversely, the study showed that the effect of green performance management on these two dependent variables is not moderated by culture. This article supports efforts to widen national cultural perspectives in the development and application of green human resource management
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