Strengthening the ethical assessment of placebo-controlled surgical trials : three proposals

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The Effects of Exercise Duration and Intensity on Breast Cancer-Related DNA Methylation: A Randomized Controlled Trial

Emerging research suggests that one mechanism through which physical activity may decrease cancer risk is through its influence on the methylation of genes associated with cancer. The purpose of the current study was to prospectively test, using a rigorous experimental design, whether aerobic exercise affects DNA methylation in genes associated with breast cancer, as well as whether quantity of exercise completed affects change in DNA methylation in a dose-response manner. 276 women (M age = 37.25, SD = 4.64) were recruited from the Denver metro area for a randomized controlled trial in which participants were assigned to a supervised aerobic exercise program varying in a fully crossed design by intensity (55-65% versus 75-85% of VO2max) and duration (40 versus 20 min per session). DNA methylation was assessed via blood samples provided at baseline, after completing a 16-week supervised exercise intervention, and six months after the intervention. 137 participants completed the intervention, and 81 had viable pre-post methylation data. Contrary to our hypotheses, total exercise volume completed in kcal/kg/week was not associated with methylation from baseline to post-intervention for any of the genes of interest. An increase in VO2max over the course of the intervention, however, was associated with decreased post-intervention methylation of BRCA1, p = 0.01. Higher levels of self-reported exercise during the follow-up period were associated with lower levels of GALNT9 methylation at the six-month follow-up. This study provides hypothesis-generating evidence that increased exercise behavior and or increased fitness might affect methylation of some genes associated with breast cancer to reduce risk. &nbsp;</p

Effect of a pediatric early warning system on all-cause mortality in Hospitalized pediatric patients: The epoch randomized clinical trial

IMPORTANCE: There is limited evidence that the use of severity of illness scores in pediatric patients can facilitate timely admission to the intensive care unit or improve patient outcomes. OBJECTIVE: To determine the effect of the Bedside Paediatric Early Warning System (BedsidePEWS) on all-cause hospital mortality and late admission to the intensive care unit (ICU), cardiac arrest, and ICU resource use. DESIGN, SETTING, AND PARTICIPANTS: A multicenter cluster randomized trial of 21 hospitals located in 7 countries (Belgium, Canada, England, Ireland, Italy, New Zealand, and the Netherlands) that provided inpatient pediatric care for infants (gestational age ≥37 weeks) to teenagers (aged ≤18 years). Participating hospitals had continuous physician staffing and subspecialized pediatric services. Patient enrollment began on February 28, 2011, and ended on June 21, 2015. Follow-up ended on July 19, 2015. INTERVENTIONS: The BedsidePEWS intervention (10 hospitals) was compared with usual care (no severity of illness score; 11 hospitals). MAIN OUTCOMES AND MEASURES: The primary outcome was all-cause hospital mortality. The secondary outcome was a significant clinical deterioration event, which was defined as a composite outcome reflecting late ICU admission. Regression analyses accounted for hospital-level clustering and baseline rates. RESULTS: Among 144539 patient discharges at 21 randomized hospitals, there were 559 443 patient-days and 144539 patients (100%) completed the trial. All-cause hospital mortality was 1.93 per 1000 patient discharges at hospitals with BedsidePEWS and 1.56 per 1000 patient discharges at hospitals with usual care (adjusted between-group rate difference, 0.01 [95% CI, -0.80 to 0.81 per 1000 patient discharges]; adjusted odds ratio, 1.01 [95% CI, 0.61 to 1.69]; P =.96). Significant clinical deterioration events occurred during 0.50 per 1000 patient-days at hospitals with BedsidePEWS vs 0.84 per 1000 patient-days at hospitals with usual care (adjusted between-group rate difference, -0.34 [95% CI, -0.73 to 0.05 per 1000 patient-days]; adjusted rate ratio, 0.77 [95% CI, 0.61 to 0.97]; P =.03). CONCLUSIONS AND RELEVANCE: Implementation of the Bedside Paediatric Early Warning System compared with usual care did not significantly decrease all-cause mortality among hospitalized pediatric patients. These findings do not support the use of this system to reduce mortality

A quantitative approach towards a better understanding of the dynamics of Salmonella spp. in a pork slaughter-line.

Pork contributes significantly to the public health disease burden caused by Salmonella infections. During the slaughter process pig carcasses can become contaminated with Salmonella. Contamination at the slaughter-line is initiated by pigs carrying Salmonella on their skin or in their faeces. Another contamination route could be resident flora present on the slaughter equipment. To unravel the contribution of these two potential sources of Salmonella a quantitative study was conducted. Process equipment (belly openers and carcass splitters), faeces and carcasses (skin and cutting surfaces) along the slaughter-line were sampled at 11 sampling days spanning a period of 4 months. Most samples taken directly after killing were positive for Salmonella. On 96.6% of the skin samples Salmonella was identified, whereas a lower number of animals tested positive in their rectum (62.5%). The prevalence of Salmonella clearly declined on the carcasses at the re-work station, either on the cut section or on the skin of the carcass or both (35.9%). Throughout the sampling period of the slaughter-line the total number of Salmonella per animal was almost 2log lower at the re-work station in comparison to directly after slaughter. Seven different serovars were identified during the study with S. Derby (41%) and S. Typhimurium (29%) as the most prominent types. A recurring S. Rissen contamination of one of the carcass splitters indicated the presence of an endemic 'house flora' in the slaughterhouse studied. On many instances several serotypes per individual sample were found. The enumeration of Salmonella and the genotyping data gave unique insight in the dynamics of transmission of this pathogen in a slaughter-line. The data of the presented study support the hypothesis that resident flora on slaughter equipment was a relevant source for contamination of pork

Mesenchymal Stem Cells Promote Mammosphere Formation and Decrease E-Cadherin in Normal and Malignant Breast Cells

Normal and malignant breast tissue contains a rare population of multi-potent cells with the capacity to self-renew, referred to as stem cells, or tumor initiating cells (TIC). These cells can be enriched by growth as "mammospheres" in three-dimensional cultures.We tested the hypothesis that human bone-marrow derived mesenchymal stem cells (MSC), which are known to support tumor growth and metastasis, increase mammosphere formation.We found that MSC increased human mammary epithelial cell (HMEC) mammosphere formation in a dose-dependent manner. A similar increase in sphere formation was seen in human inflammatory (SUM149) and non-inflammatory breast cancer cell lines (MCF-7) but not in primary inflammatory breast cancer cells (MDA-IBC-3). We determined that increased mammosphere formation can be mediated by secreted factors as MSC conditioned media from MSC spheroids significantly increased HMEC, MCF-7 and SUM149 mammosphere formation by 6.4 to 21-fold. Mammospheres grown in MSC conditioned media had lower levels of the cell adhesion protein, E-cadherin, and increased expression of N-cadherin in SUM149 and HMEC cells, characteristic of a pro-invasive mesenchymal phenotype. Co-injection with MSC in vivo resulted in a reduced latency time to develop detectable MCF-7 and MDA-IBC-3 tumors and increased the growth of MDA-IBC-3 tumors. Furthermore, E-cadherin expression was decreased in MDA-IBC-3 xenografts with co-injection of MSC.MSC increase the efficiency of primary mammosphere formation in normal and malignant breast cells and decrease E-cadherin expression, a biologic event associated with breast cancer progression and resistance to therapy

Ethical considerations in military surgical innovation

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Evidence-based medicine in theory and practice : epistemological and normative issues

Evidence-based medicine (EBM) emerged during the 1990s, with the aim of improving clinical practice by increasing the extent to which clinical care was informed by medical research, particularly randomized controlled trials (RCTs) and systematic reviews of RCTs. This chapter gives an account of EBM, followed by examination of epistemological and ethical justifications and critiques of EBM. EBM relies upon epistemological claims about the ability of RCTs to eliminate certain forms of bias and to establish whether or not there is a causal relationship between an intervention and an outcome. However, epistemological critiques of EBM include reservations about whether EBM can "prove" causation, concerns about the rejection of mechanistic models of causation, challenges associated with applying the results of RCTs to individual patients, and lack of evidence regarding whether EBM has in fact benefitted patients and healthcare systems. The ethical justifications for EBM include its promise of better patient outcomes through better informed clinicians and the idea that public health policy based on EBM can support equity and minimize waste of resources. Ethical critiques of EBM note that despite its potential for reducing particular forms of bias, the research upon which EBM is based is often industry funded, creating conflicts of interest that are associated with new sources of bias. These include bias in the conduct of trials, the publication of results, and the choice of interventions for investigation. EBM also poses challenges for patient and clinician autonomy, especially where evidence-based clinical practice guidelines are enforced through targets or audits. In the face of these concerns, EBM is under pressure to reestablish its credibility. The chapter ends by identifying three current initiatives that seek to reinstate the aims of EBM to better inform healthcare decisions.18 page(s

Challenging the epistemological foundations of EBM : what kind of knowledge does clinical practice require?

This paper raises questions about the epistemological foundations of evidence-based medicine (EBM). We argue that EBM is based upon reliabilist epistemological assumptions, and that this is appropriate - we should focus on identifying the most reliable processes for generating and collecting medical knowledge. However, we note that this should not be reduced to narrow questions about which research methodologies are the best for gathering evidence. Reliable processes for generating medical evidence might lie outside of formal research methods. We also question the notion of the knower that is assumed by EBM. We argue that EBM assumes an enlightenment conception of knowers as autonomous, substitutable individuals. This conception is troubled by the way that clinicians learn the role of anecdote in health care and the role of patient choice, all of which bring into play features of clinicians and patients as situated individuals with particular backgrounds and experiences. EBM's enlightenment conception of the knower is also troubled by aspects of the way evidence is produced. Given these limitations, we argue that EBM should retain its reliabilist bent, but should look beyond formal research methodologies in identifying processes that yield reliable evidence for clinical practice. We suggest looking to feminist epistemology, with its focus on the standpoints of individual situated knowers, and the role of social context in determining what counts as knowledge.8 page(s

Addressing Deficits and Injustices : The Potential Epistemic Contributions of Patients to Research

Acknowledgments The research for this paper was primarily funded by an Australian Research Council (ARC) grant (DP120101092), How do we know what works? Ethics and evidence in surgical research. Katrina Hutchison’s research was also partly funded by the ARC Centre of Excellence for Electromaterials Science, where she has worked since June 2015. Discussions about the paper were facilitated by Macquarie University funding of a visit by Vikki A. Entwistle to participate in a Centre for Agency, Values and Ethics (CAVE) seminar on Capabilities Approaches to Justice. The authors would like to thank the anonymous reviewers for a number of helpful comments.Peer reviewedPostprin