8 research outputs found
Metabolically exaggerated cardiac reactions to acute psychological stress: The effects of resting blood pressure status and possible underlying mechanisms
The study aimed to: confirm that acute stress elicits metabolically exaggerated increases in cardiac activity; test whether individuals with elevated resting blood pressure show more exaggerated cardiac reactions to stress than those who are clearly normotensive; and explore the underlying mechanisms. Cardiovascular activity and oxygen consumption were measured pre-, during, and post- mental stress, and during graded submaximal cycling exercise in 11 young men with moderately elevated resting blood pressure and 11 normotensives. Stress provoked increases in cardiac output that were much greater than would be expected from contemporary levels of oxygen consumption. Exaggerated cardiac reactions were larger in the relatively elevated blood pressure group. They also had greater reductions in total peripheral resistance, but not heart rate variability, implying that their more exaggerated cardiac reactions reflected greater β-adrenergic activation
A portfolio approach to a cross-sectoral and cross-national investment strategy in transition economies
This paper takes a systematic look at the portfolio choice problem faced by Investment Banks or Funds investing in transition economies. We relate the performance of projects in the transition economies to the broader macroeconomic and international environments, which affect the project through their input-output structures and financial balance sheets. Among the macroeconomic determinanst of enterprise behaviour are productivity growth, real wage growth, movements in the international terms of trade, shocks to the relative price of traded and non-traded goods, domestic and foreign interest rates, currency depreciation and the rate of inflaction. We evaluate the attractiveness of alternative investment strategies and provisioning rules from the perspective of portfoio theory. Copyright The European Bank for Reconstruction and Development, 1997.
Engineering a Therapeutic Lectin by Uncoupling Mitogenicity from Antiviral Activity.
International audienceA key effector route of the Sugar Code involves lectins that exert crucial regulatory controls by targeting distinct cellular glycans. We demonstrate that a single amino-acid substitution in a banana lectin, replacing histidine 84 with a threonine, significantly reduces its mitogenicity, while preserving its broad-spectrum antiviral potency. X-ray crystallography, NMR spectroscopy, and glycocluster assays reveal that loss of mitogenicity is strongly correlated with loss of pi-pi stacking between aromatic amino acids H84 and Y83, which removes a wall separating two carbohydrate binding sites, thus diminishing multivalent interactions. On the other hand, monovalent interactions and antiviral activity are preserved by retaining other wild-type conformational features and possibly through unique contacts involving the T84 side chain. Through such fine-tuning, target selection and downstream effects of a lectin can be modulated so as to knock down one activity, while preserving another, thus providing tools for therapeutics and for understanding the Sugar Code
Engineering a Therapeutic Lectin by Uncoupling Mitogenicity from Antiviral Activity.
International audienceA key effector route of the Sugar Code involves lectins that exert crucial regulatory controls by targeting distinct cellular glycans. We demonstrate that a single amino-acid substitution in a banana lectin, replacing histidine 84 with a threonine, significantly reduces its mitogenicity, while preserving its broad-spectrum antiviral potency. X-ray crystallography, NMR spectroscopy, and glycocluster assays reveal that loss of mitogenicity is strongly correlated with loss of pi-pi stacking between aromatic amino acids H84 and Y83, which removes a wall separating two carbohydrate binding sites, thus diminishing multivalent interactions. On the other hand, monovalent interactions and antiviral activity are preserved by retaining other wild-type conformational features and possibly through unique contacts involving the T84 side chain. Through such fine-tuning, target selection and downstream effects of a lectin can be modulated so as to knock down one activity, while preserving another, thus providing tools for therapeutics and for understanding the Sugar Code
Performance of the PEdiatric Logistic Organ Dysfunction-2 score in critically ill children requiring plasma transfusions
BackgroundOrgan dysfunction scores, based on physiological parameters, have been created to describe organ failure. In a general pediatric intensive care unit (PICU) population, the PEdiatric Logistic Organ Dysfunction-2 score (PELOD-2) score had both a good discrimination and calibration, allowing to describe the clinical outcome of critically ill children throughout their stay. This score is increasingly used in clinical trials in specific subpopulation. Our objective was to assess the performance of the PELOD-2 score in a subpopulation of critically ill children requiring plasma transfusions.MethodsThis was an ancillary study of a prospective observational study on plasma transfusions over a 6-week period, in 101 PICUs in 21 countries. All critically ill children who received at least one plasma transfusion during the observation period were included. PELOD-2 scores were measured on days 1, 2, 5, 8, and 12 after plasma transfusion. Performance of the score was assessed by the determination of the discrimination (area under the ROC curve: AUC) and the calibration (Hosmer–Lemeshow test).ResultsFour hundred and forty-three patients were enrolled in the study (median age and weight: 1 year and 9.1 kg, respectively). Observed mortality rate was 26.9 % (119/443). For PELOD-2 on day 1, the AUC was 0.76 (95 % CI 0.71–0.81) and the Hosmer–Lemeshow test was p = 0.76. The serial evaluation of the changes in the daily PELOD-2 scores from day 1 demonstrated a significant association with death, adjusted for the PELOD-2 score on day 1.ConclusionsIn a subpopulation of critically ill children requiring plasma transfusion, the PELOD-2 score has a lower but acceptable discrimination than in an entire population. This score should therefore be used cautiously in this specific subpopulation.</p
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Factors influencing plasma transfusion practices in paediatric intensive care units around the world
Background and Objectives
Plasma transfusions are a frequent treatment worldwide, but many studies have reported a wide variation in the indications to transfuse. Recently, an international paediatric study also showed wide variation in frequency in the use of plasma transfusions: 25% of the centres transfused plasma to >5% of their patients, whereas another 25% transfused plasma to <1% of their patients. The objective of this study was to explore the factors associated with different plasma transfusion practices in these centres.
Materials and Methods
Online survey sent to the local investigators of the 101 participating centres, in February 2016. Four areas were explored: beliefs regarding plasma transfusion, patients’ case‐mix in each unit, unit's characteristics, and local blood product transfusion policies and processes.
Results
The response rate was 82% (83/101). 43% of the respondents believed that plasma transfusions can arrest bleeding, whereas 27% believe that plasma transfusion can prevent bleeding. Centres with the highest plasma transfusion rate were more likely to think that hypovolaemia and mildly abnormal coagulation tests are appropriate indications for plasma transfusions (P = 0·02 and P = 0·04, respectively). Case‐mix, centre characteristics or local transfusion services were not identified as significant relevant factors.
Conclusion
Factors influencing plasma transfusion practices reflect beliefs about indications and the efficacy of transfusion in the prevention and management of bleeding as well as effects on coagulation tests. Educational and other initiatives to target these beliefs should be the focus of research