267 research outputs found

    Structured benefit-risk assessment: a review of key publications and initiatives on frameworks and methodologies.

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    Introduction The conduct of structured benefit-risk assessment (BRA) of pharmaceutical products is a key area of interest for regulatory agencies and the pharmaceutical industry. However, the acceptance of a standardized approach and implementation are slow. Statisticians play major roles in these organizations, and have a great opportunity to be involved and drive the shaping of future BRA. Method We performed a literature search of recent reviews and initiatives assessing BRA methodologies, and grouped them to assist those new to BRA in learning, understanding, and choosing methodologies. We summarized the key points and discussed the impact of this emerging field on various stakeholders, particularly statisticians in the pharmaceutical industry. Results We provide introductory, essential, special interest, and further information and initiatives materials that direct readers to the most relevant materials, which were published between 2000 and 2013.  Based on recommendations in these materials we supply a toolkit of advocated BRA methodologies. Discussion Despite initiatives promoting these methodologies, there are still barriers, one of which being the lack of a consensus on the most appropriate methodologies among stakeholders. However, this opens up opportunities, for statisticians in the pharmaceutical industry especially, to champion appropriate BRA methodology use throughout the pharmaceutical product lifecycle. Conclusions This article may serve as a starting point for discussions and to reach a mutual consensus for methodology selection in a particular situation. Regulators and pharmaceutical industry should continue to collaborate to develop and take forward BRA methodologies, and by clear communication develop a mutual understanding of the key issues. Copyright © 2015 John Wiley & Sons, Ltd

    High levels of dietary stearate promote adiposity and deteriorate hepatic insulin sensitivity

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    <p>Abstract</p> <p>Background</p> <p>Relatively little is known about the role of specific saturated fatty acids in the development of high fat diet induced obesity and insulin resistance. Here, we have studied the effect of stearate in high fat diets (45% energy as fat) on whole body energy metabolism and tissue specific insulin sensitivity.</p> <p>Methods</p> <p>C57Bl/6 mice were fed a low stearate diet based on palm oil or one of two stearate rich diets, one diet based on lard and one diet based on palm oil supplemented with tristearin (to the stearate level of the lard based diet), for a period of 5 weeks. <it>Ad libitum </it>fed Oxidative metabolism was assessed by indirect calorimetry at week 5. Changes in body mass and composition was assessed by DEXA scan analysis. Tissue specific insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamp analysis and Western blot at the end of week 5.</p> <p>Results</p> <p>Indirect calorimetry analysis revealed that high levels of dietary stearate resulted in lower caloric energy expenditure characterized by lower oxidation of fatty acids. In agreement with this metabolic phenotype, mice on the stearate rich diets gained more adipose tissue mass. Whole body and tissue specific insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamp and analysis of insulin induced PKB<sup>ser473 </sup>phosphorylation. Whole body insulin sensitivity was decreased by all high fat diets. However, while insulin-stimulated glucose uptake by peripheral tissues was impaired by all high fat diets, hepatic insulin sensitivity was affected only by the stearate rich diets. This tissue-specific pattern of reduced insulin sensitivity was confirmed by similar impairment in insulin-induced phosphorylation of PKB<sup>ser473 </sup>in both liver and skeletal muscle.</p> <p>Conclusion</p> <p>In C57Bl/6 mice, 5 weeks of a high fat diet rich in stearate induces a metabolic state favoring low oxidative metabolism, increased adiposity and whole body insulin resistance characterized by severe hepatic insulin resistance. These results indicate that dietary fatty acid composition <it>per sé </it>rather than dietary fat content determines insulin sensitivity in liver of high fat fed C57Bl/6 mice.</p

    Wake up, wake up! It's me! It's my life! patient narratives on person-centeredness in the integrated care context: a qualitative study

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    Person-centered care emphasizes a holistic, humanistic approach that puts patients first, at the center of medical care. Person-centeredness is also considered a core element of integrated care. Yet typologies of integrated care mainly describe how patients fit within integrated services, rather than how services fit into the patient's world. Patient-centeredness has been commonly defined through physician's behaviors aimed at delivering patient-centered care. Yet, it is unclear how 'person-centeredness' is realized in integrated care through the patient voice. We aimed to explore patient narratives of person-centeredness in the integrated care context

    Diabetic cardiomyopathy in Zucker diabetic fatty rats: the forgotten right ventricle

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    <p>Abstract</p> <p>Background</p> <p>In patients with myocardial infarction or heart failure, right ventricular (RV) dysfunction is associated with death, shock and arrhythmias. In patients with type 2 diabetes mellitus, structural and functional alterations of the left ventricle (LV) are highly prevalent, however, little is known about the impact of diabetes on RV characteristics. The purpose of the present study was to investigate whether LV changes are paralleled by RV alterations in a rat model of diabetes.</p> <p>Methods</p> <p>Zucker diabetic fatty (ZDF) and control (ZL) rats underwent echocardiography and positron emission tomography (PET) scanning using [<sup>18</sup>F]-2-fluoro-2-deoxy-D-glucose under hyperinsulinaemic euglycaemic clamp conditions. Glucose, insulin, triglycerides and fatty acids were assessed from trunk blood. Another group of rats received an insulin or saline injection to study RV insulin signaling.</p> <p>Results</p> <p>ZDF rats developed hyperglycaemia, hyperinsulinaemia and dyslipidaemia (all p < 0.05). Echocardiography revealed depressed LV fractional shortening and tricuspid annular plane systolic excursion (TAPSE) in ZDF vs. ZL rats (both p < 0.05). A decrease in LV and RV insulin-mediated glucose utilisation was found in ZDF vs. ZL rats (both p < 0.05). LV associated with RV with respect to systolic function (r = 0.86, p < 0.05) and glucose utilisation (r = 0.74, p < 0.05). TAPSE associated with RV MRglu (r = 0.92, p < 0.05) and <it>M</it>-value (r = 0.91, p < 0.0001) and RV MRglu associated with <it>M</it>-value (r = 0.77, p < 0.05). Finally, reduced RV insulin-stimulated phosphorylation of Akt was found in ZDF vs. ZL (p < 0.05).</p> <p>Conclusions</p> <p>LV changes were paralleled by RV alterations in insulin-stimulated glucose utilisation and RV systolic function in a rat model of diabetes, which may be attributed to ventricular interdependence as well as to the uniform effect of diabetes. Since diabetic patients are prone to develop diabetic cardiomyopathy and myocardial ischaemia, it might be suggested that RV dysfunction plays a central role in cardiac abnormalities in this population.</p

    The effectiveness of adapted schema therapy for cluster C personality disorders in older adults – integrating positive schemas

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    Introduction: Schema therapy (ST) is an efficacious psychotherapy for personality disorders (PDs) in adults. The first empirical support for the effectiveness of ST in older adults with cluster C PDs was provided recently. ST partly focusses on the positive, but there is an increasing awareness of imbalance in the ST community because of the emphasis on negative schemas versus attention to positive schemas. Positive schemas may be important vehicles of therapeutic change in psychotherapy with older people, as it may help strengthen the healthy adult mode, and it might also help change a negative life review. Suggestions were made to increase the efficacy and feasibility of ST in older adults, including adjusting the case conceptualisation, modifying the experiential techniques, making use of the patient's wisdom and reactivating positive schemas. The aim of the current study is to investigate the feasibility and effectiveness of adapted individual ST for older adults. Methods/design: A multiple baseline design is used with positive and negative core beliefs as primary outcome measures. Ten older adults (age > 60 years) with cluster C PDs are treated with schema therapy, with weekly sessions during one year. This treatment phase is preceded by a baseline phase varying randomly from 4 to 8 weeks. After treatment, there is a 6-month follow-up phase with monthly booster sessions. Symptomatic distress, schema modes, early maladaptive schemas (EMS) and early adaptive schemas (EAS) are secondary outcome measures. PD will be diagnosed before baseline and after treatment phase. EAS are assessed with the Dutch version of the Young Positive Schema Questionnaire (YPSQ). Discussion: To the best of our knowledge, this is the first empirical study in which positive schemas are integrated in ST treatment to examine the efficacy of an adapted form of ST for older adults. This is in line with wider developments supporting the integration of positive schema's into ST. It offers the possibility to improve the effectiveness of ST in older adults. Trial registration: The Netherlands National Trial Register NL8346, registered 1 February 2020

    Altered myocardial substrate metabolism is associated with myocardial dysfunction in early diabetic cardiomyopathy in rats: studies using positron emission tomography

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    0.05). CONCLUSION: Using PET and echocardiography, we found increases in myocardial FA oxidation with a concomitant decrease of insulin-mediated myocardial glucose utilisation in early DCM. In addition, the latter was associated with impaired myocardial function. These in vivo data expand previous in vitro findings showing that early alterations in myocardial substrate metabolism contribute to myocardial dysfunctio

    Cardiac contractile dysfunction in insulin-resistant rats fed a high-fat diet is associated with elevated CD36-mediated fatty acid uptake and esterification

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    Changes in cardiac substrate utilisation leading to altered energy metabolism may underlie the development of diabetic cardiomyopathy. We studied cardiomyocyte substrate uptake and utilisation and the role of the fatty acid translocase CD36 in relation to in vivo cardiac function in rats fed a high-fat diet (HFD).Rats were exposed to an HFD or a low-fat diet (LFD). In vivo cardiac function was monitored by echocardiography. Substrate uptake and utilisation were determined in isolated cardiomyocytes.Feeding an HFD for 8 weeks induced left ventricular dilation in the systolic phase and decreased fractional shortening and the ejection fraction. Insulin-stimulated glucose uptake and proline-rich Akt substrate 40 phosphorylation were 41% (p <0.001) and 45% (p <0.05) lower, respectively, in cardiomyocytes from rats on the HFD. However, long-chain fatty acid (LCFA) uptake was 1.4-fold increased (p <0.001) and LCFA esterification into triacylglycerols and phospholipids was increased 1.4- and 1.5-fold, respectively (both p <0.05), in cardiomyocytes from HFD compared with LFD hearts. In the presence of the CD36 inhibitor sulfo-N-succinimidyloleate, LCFA uptake and esterification were similar in LFD and HFD cardiomyocytes. In HFD hearts CD36 was relocated to the sarcolemma, and basal phosphorylation of a mediator of CD36-trafficking, i.e. protein kinase B (PKB/Akt), was increased.Feeding rats an HFD induced cardiac contractile dysfunction, which was accompanied by the relocation of CD36 to the sarcolemma, and elevated basal levels of phosphorylated PKB/Akt. The permanent presence of CD36 at the sarcolemma resulted in enhanced rates of LCFA uptake and myocardial triacylglycerol accumulation, and may contribute to the development of insulin resistance and diabetic cardiomyopathy

    Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves

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    <p>Abstract</p> <p>Background</p> <p>The results of Randomized Controlled Trials (RCTs) on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio. These do not constitute the sufficient statistics required for meta-analysis or cost-effectiveness analysis, and their use in secondary analyses requires strong assumptions that may not have been adequately tested. In order to enhance the quality of secondary data analyses, we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated.</p> <p>Methods</p> <p>We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations, using where available information on number of events and numbers at risk. The reproducibility and accuracy of survival probabilities, median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics (survival probabilities, medians and hazard ratios) with statistics based on repeated reconstructions by multiple observers.</p> <p>Results</p> <p>The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics. Accuracy was excellent for survival probabilities and medians, for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported.</p> <p>Conclusion</p> <p>The algorithm is a reliable tool for meta-analysis and cost-effectiveness analyses of RCTs reporting time-to-event data. It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves.</p
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