Size exclusion chromatography as a technique for the investigation of novel extracellular vesicles in cancer

Abstract: (1) Background: Cancer cells release extracellular vesicles that are a rich target for biomarker discovery and provide a promising mechanism for liquid biopsy. SEC is an increasingly popular technique which has been rediscovered for the purposes of EV isolation and purification from diverse biofluids. (2) Methods: A review was undertaken to identify all papers which described size exclusion as their primary EV isolation method in cancer research. (3) Results: 37 papers were identified and discussed which showcases the breadth of applications that EVs can be utilised, from proteomics, to RNA, and through to functionality. A range of different methods are highlighted, with Sepharose-based techniques predominating. (4) Conclusions: EVs isolated using SEC are able to identify cancer cells, highlight active pathways in tumourigenesis, clinically distinguish cohorts and remain functionally active for further experiments

Comparison of proteomic profiles in the zebrafish retina during experimental degeneration and regeneration

Zebrafish spontaneously regenerate the retina after injury. Although the gene expression profile has been extensively studied in this species during regeneration, this does not reflect protein function. To further understand the regenerative process in the zebrafish, we compared the proteomic profile of the retina during injury and upon regeneration. Using two-dimensional difference gel electrophoresis (2D-DIGE) and label-free quantitative proteomics (quadrupole time of flight LC-MS/MS), we analysed the retina of adult longfin wildtype zebrafish at 0, 3 and 18 days after Ouabain injection. Gene ontology analysis indicates reduced metabolic processing, and increase in fibrin clot formation, with significant upregulation of fibrinogen gamma polypeptide, apolipoproteins A-Ib and A-II, galectin-1, and vitellogenin-6 during degeneration when compared to normal retina. In addition, cytoskeleton and membrane transport proteins were considerably altered during regeneration, with the highest fold upregulation observed for tubulin beta 2 A, histone H2B and brain type fatty acid binding protein. Key proteins identified in this study may play an important role in the regeneration of the zebrafish retina and investigations on the potential regulation of these proteins may lead to the design of protocols to promote endogenous regeneration of the mammalian retina following retinal degenerative disease

The role of circular RNAs in pancreatic ductal adenocarcinoma and biliary-tract cancers

Pancreatic Ductal Adenocarcinoma (PDAC) and biliary-tract cancers (BTC) often present at a late stage, and consequently patients have poor survival-outcomes. Circular RNAs (circRNAs) are non-coding RNA molecules whose role in tumourigenesis has recently been realised. They are stable, conserved and abundant, with tissue-specific expression profiles. Therefore, significant interest has arisen in their use as potential biomarkers for PDAC and BTC. High-throughput methods and more advanced bioinformatic techniques have enabled better profiling and progressed our understanding of how circRNAs may function in the competing endogenous RNA (ceRNA) network to influence the transcriptome in these cancers. Therefore, the aim of this systematic review was to describe the roles of circRNAs in PDAC and BTC, their potential as biomarkers, and their function in the wider ceRNA network in regulating microRNAs and the transcriptome. Medline, Embase, Scopus and PubMed were systematically reviewed to identify all the studies addressing circRNAs in PDAC and BTC. A total of 32 articles were included: 22 considering PDAC, 7 for Cholangiocarcinoma (CCA) and 3 for Gallbladder Cancer (GBC). There were no studies investigating Ampullary Cancer. Dysregulated circRNA expression was associated with features of malignancy in vitro, in vivo, and ex vivo. Overall, there have been very few PDAC and BTC tissues profiled for circRNA signatures. Therefore, whilst the current studies have demonstrated some of their functions in these cancers, further work is required to elucidate their potential role as cancer biomarkers in tissue, biofluids and biopsies

Multiple imputation approaches for epoch-level accelerometer data in trials.

Clinical trials that investigate physical activity interventions often use accelerometers to measure step count at a very granular level, for example in 5-second epochs. Participants typically wear the accelerometer for a week-long period at baseline, and for one or more week-long follow-up periods after the intervention. The data is aggregated to provide daily or weekly step counts for the primary analysis. Missing data are common as participants may not wear the device as per protocol. Approaches to handling missing data in the literature have defined missingness on the day level using a threshold on daily weartime, which leads to loss of information on the time of day when data are missing. We propose an approach to identifying and classifying missingness at the finer epoch-level and present two approaches to handling missingness using multiple imputation. Firstly, we present a parametric approach which accounts for the number of missing epochs per day. Secondly, we describe a non-parametric approach where missing periods during the day are replaced by donor data from the same person where possible, or data from a different person who is matched on demographic and physical activity-related variables. Our simulation studies show that the non-parametric approach leads to estimates of the effect of treatment that are least biased while maintaining small standard errors. We illustrate the application of these different multiple imputation strategies to the analysis of the 2017 PACE-UP trial. The proposed framework is likely to be applicable to other digital health outcomes and to other wearable devices

Interpreting population reach of a large, successful physical activity trial delivered through primary care.

Abstract Background Failure to include socio-economically deprived or ethnic minority groups in physical activity (PA) trials may limit representativeness and could lead to implementation of interventions that then increase health inequalities. Randomised intervention trials often have low recruitment rates and rarely assess recruitment bias. A previous trial by the same team using similar methods recruited 30% of the eligible population but was in an affluent setting with few non-white residents and was limited to those over 60 years of age. Methods PACE-UP is a large, effective, population-based walking trial in inactive 45-75 year-olds that recruited through seven London general practices. Anonymised practice demographic data were available for all those invited, enabling investigation of inequalities in trial recruitment. Non-participants were invited to complete a questionnaire. Results From 10,927 postal invitations, 1150 (10.5%) completed baseline assessment. Participation rate ratios (95% CI), adjusted for age and gender as appropriate, were lower in men 0.59 (0.52, 0.67) than women, in those under 55 compared with those ≥65, 0.60 (0.51, 0.71), in the most deprived quintile compared with the least deprived 0.52 (0.39, 0.70) and in Asian individuals compared with whites 0.62 (0.50, 0.76). Black individuals were equally likely to participate as white individuals. Participation was also associated with having a co-morbidity or some degree of health limitation. The most common reasons for non-participation were considering themselves as being too active or lack of time. Conclusions Conducting the trial in this diverse setting reduced overall response, with lower response in socio-economically deprived and Asian sub-groups. Trials with greater reach are likely to be more expensive in terms of recruitment and gains in generalizability need to be balanced with greater costs. Differential uptake of successful trial interventions may increase inequalities in PA levels and should be monitored

PACE-UP (Pedometer and consultation evaluation--UP)--a pedometer-based walking intervention with and without practice nurse support in primary care patients aged 45-75 years: study protocol for a randomised controlled trial.

BACKGROUND: Most adults do not achieve the 150 minutes weekly of at least moderate intensity activity recommended for health. Adults' most common physical activity (PA) is walking, light intensity if strolling, moderate if brisker. Pedometers can increase walking; however, most trials have been short-term, have combined pedometer and support effects, and have not reported PA intensity. This trial will investigate whether pedometers, with or without nurse support, can help less active 45-75 year olds to increase their PA over 12 months. METHODS/DESIGN: DESIGN: Primary care-based 3-arm randomized controlled trial with 12-month follow-up and health economic and qualitative evaluations. PARTICIPANTS: Less active 45-75 year olds (n = 993) will be recruited by post from six South West London general practices, maximum of two per household and households randomised into three groups. Step-count and time spent at different PA intensities will be assessed for 7 days at baseline, 3 and 12 months by accelerometer. Questionnaires and anthropometric assessments will be completed. INTERVENTION: The pedometer-alone group will be posted a pedometer (Yamax Digi-Walker SW-200), handbook and diary detailing a 12-week pedometer-based walking programme, using targets from their baseline assessment. The pedometer-plus-support group will additionally receive three practice nurse PA consultations. The handbook, diary and consultations include behaviour change techniques (e.g., self-monitoring, goal-setting, relapse prevention planning). The control group will receive usual care. OUTCOMES: Changes in average daily step-count (primary outcome), time spent sedentary and in at least moderate intensity PA weekly at 12 months, measured by accelerometry. Other outcomes include change in body mass index, body fat, self-reported PA, quality of life, mood and adverse events. Cost-effectiveness will be assessed by the incremental cost of the intervention to the National Health Service and incremental cost per change in step-count and per quality adjusted life year. Qualitative evaluations will explore reasons for trial non-participation and the interventions' acceptability. DISCUSSION: The PACE-UP trial will determine the effectiveness and cost-effectiveness of a pedometer-based walking intervention delivered by post or practice nurse to less active primary care patients aged 45-75 years old. Approaches to minimise bias and challenges anticipated in delivery will be discussed

Comparative proteomic analysis of normal and gliotic PVR retina and contribution of Müller glia to this profile

Müller glia are responsible for the neural retina regeneration observed in fish and amphibians throughout life. Despite the presence of these cells in the adult human retina, there is no evidence of regeneration occurring in humans following disease or injury. It may be possible that factors present in the degenerated retina could prevent human Müller glia from proliferating and neurally differentiating within the diseased retina. On this basis, investigations into the proteomic profile of these cells and the abundance of key proteins associated to Muller glia in the gliotic PVR retina, may assist in the identification of factors with the potential to control Müller proliferation and differentiation in vivo. Label free mass spectrometry identified 1527 proteins in Müller glial cell preparations, 1631 proteins in normal retina and 1074 in gliotic PVR retina. Compared to normal retina, 28 proteins were upregulated and 196 proteins downregulated by 2-fold or more in the gliotic PVR retina. As determined by comparative proteomic analyses, of the proteins highly upregulated in the gliotic PVR retina, the most highly abundant proteins in Müller cell lysates included vimentin, GFAP, polyubiquitin and HSP90a. The observations that proteins highly upregulated in the gliotic retina constitute major proteins expressed by Müller glia provide the basis for further studies into mechanisms that regulate their production. In addition investigations aimed at controlling the expression of these proteins may aid in the identification of factors that could potentially promote endogenous regeneration of the adult human retina after disease or injury

Local reactions after the fourth-dose of acellular pertussis vaccine in South Australia

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.ObjectiveTo assess the reported rate of local reactions after administration of acellular pertussis vaccine (DTPa) according to dose number and type of pertussis vaccine (whole-cell or acellular) used for the primary course, and to document the severity and outcome of fourth-dose local reactions.Design and settingRetrospective review. Reports of adverse events after vaccination in South Australia between 1 January 1997 and 31 December 2000 were reviewed, and a questionnaire administered to all parents who reported a local reaction after the fourth dose of DTPa.Main outcome measuresThe number, and rate per 100 000 administered doses, of local reactions following the primary and booster doses of DTPa, and of local reactions after the fourth-dose in cohorts of children whose primary vaccinations were with either DTPw or DTPa. Redness and/or swelling at the injection site as reported by parents.ResultsOf 581 reported adverse events after vaccination, 138 were local reactions after a pertussis-containing vaccine. Primary vaccinations with DTPa was a significant risk factor for a fourth-dose local reaction (relative risk, 6.7; 95% CI, 2.4-18.5). Parental questionnaires were completed for 45 of the 71 children (63%) with reported local reactions after the fourth dose of DTPa; extensive limb swelling was reported in 8 children (18%) and all except one child had recovered by the time of review.ConclusionsParents should be informed that children receiving booster doses of DTPa vaccine, after primary doses with DTPa, are at increased risk of local reactions (which tend to resolve spontaneously) but not of systemic effects. Studies should be initiated to investigate the pathogenesis and the risk of recurrence of local reactions to further improve vaccination schedules.Michael S Gold, Sara Noonan, Maggi Osbourn, Stella Precepa and Ann E Kemp

The quality and the accuracy of codes for terminations of pregnancy for fetal anomalies recorded in hospital databases in three countries in northern Europe.

BACKGROUND: The number of terminations of pregnancy for fetal anomalies in Europe (TOPFA) has increased over recent decades. Therefore, it is important that TOPFAs, in addition to all other birth outcomes, are included in the surveillance of congenital anomalies and in studies on possible teratogenic risks of pregnancy exposures. The aim of this study was to evaluate the quality and the accuracy of codes identifying TOPFA cases in hospital databases. METHODS: TOPFA cases recorded in three EUROCAT congenital anomaly registries (Finland, 2010-2014; Funen in Denmark, 2005-2014; and northern Netherlands, 2013-2014) were linked to hospital databases using maternal IDs. RESULTS: A total of 2,114 TOPFA cases over the study period were identified in the registries and 2,096 (99%) of these pregnancies were identified in the hospital databases. An end of pregnancy code was present for 91% of the cases and a code for a congenital anomaly was present for 82% (with some differences across registries). The proportion of TOPFA cases with a code for a specific congenital anomaly was <50% for cases with a structural anomaly (range 0%-50%) and 70% for cases with a chromosomal anomaly. CONCLUSION: Hospital databases have limited information or codes to identify TOPFAs for specific anomalies and the data are not detailed enough for surveillance of congenital anomalies or for studies analyzing pregnancy exposures and risk of congenital anomalies. However, hospital data may be used to identify the occurrence of a TOPFA to enable more detailed information to be obtained from the medical records