The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points.

No abstract

2 AbstractPurpose. There is an urgent need to develop diagnostic tests to improve the detection of pathogens causing life-threatening infection (sepsis). SeptiFast is a CEmarked multi-pathogen real-time PCR system capable of detecting DNA sequences of bacteria and fungi present in blood samples within a few hours. We report here a systematic review and meta-analysis of diagnostic accuracy studies of SeptiFast in the setting of suspected sepsis.Methods. A comprehensive search strategy was developed to identify studies that compared SeptiFast with blood culture in suspected sepsis. Methodological quality was assessed using QUADAS. Heterogeneity of studies was investigated using a coupled forest plot of sensitivity and specificity and a scatter plot in Receiver Operator Characteristic space. Bivariate model method was used to estimate summary sensitivity and specificity.Results. From 41 phase III diagnostic accuracy studies, summary sensitivity and specificity for SeptiFast compared with blood culture were 0.68 (95% CI 0.63-0.73) and 0.86 (95% CI 0.84-0.89) respectively. Study quality was judged to be variable with important deficiencies overall in design and reporting that could impact on derived diagnostic accuracy metrics.Conclusions. SeptiFast appears to have higher specificity than sensitivity, but deficiencies in study quality are likely to render this body of work unreliable. Based on the evidence presented here, it remains difficult to make firm recommendations about the likely clinical utility of SeptiFast in the setting of suspected sepsis. We recommend that future studies should include well designed and reported clinical diagnostic accuracy elements measured against all of the features of the STARD criteria to help inform the subsequent design of much needed interventional studies in the management of suspected sepsis. Word count: 225 2413

Objective -The consumption of caffeinated drinks and soft drinks is widespread in society, including 26 by pregnant women. Data regarding the association of caffeine intake and stillbirth are varied. We 27 aimed to investigate the degree of consumption of caffeinated drinks or soft drinks in the last four 28 weeks of pregnancy in women who experienced a late stillbirth compared to women with ongoing 29 live pregnancies at similar gestation. Influences on maternal caffeine intake and soft drink 30 consumption during pregnancy were also investigated. 31Study Design -A case-control study undertaken in 41 maternity units in the United Kingdom. Cases 32 were women who had a singleton non-anomalous stillbirth ≥28 weeks' gestation (n=290) and 33 controls were women with an ongoing pregnancy at the time of interview (n=729). Data were 34 collected using an interviewer-administered questionnaire which included questions regarding 35 consumption of a variety of caffeinated drinks and soft drinks in the last four weeks of pregnancy as 36 well as other behaviours (e.g. cigarette smoking). 37Results -Multivariable analysis adjusting for co-existing demographic and behavioural factors found 38 the consumption of instant coffee, energy drinks and cola were associated with increased risk of 39 stillbirth. There was an independent association between caffeine intake and late stillbirth (adjusted 40 Odds Ratio 1.27, 95% Confidence Interval (95%CI) 1.14, 1.43 for each 100mg increment/day). 15% of 41 cases and 8% of controls consumed more than the World Health Organisation (WHO) 42 recommendation (>300mg of caffeine/day; aOR 2.30, 95% CI 1.40, 4.24). The population attributable 43 risk for stillbirth associated with >300mg of caffeine/day was 7.4%. The majority of respondents 44 reduced caffeine consumption in pregnancy. Midwives and internet resources were the most 45 frequently used sources of information which influenced maternal behaviour with regard to soft 46 drinks and caffeine, and this did not differ between cases and controls. 47Conclusions -Women should be informed that consumption of caffeine during pregnancy is 48 associated with increased risk of stillbirth, particularly at levels greater than recommended by the WHO (>300mg/day). Recommendations from midwives and internet-based resources are likely to be 50 the most effective means to influence maternal behaviour. 51 52 Keywords 53 Caffeine, Perinatal Death, Stillbirth, Cola, Sweetened Soft Drinks. 54 55 65 gestation). 5 Due to their ubiquitous consumption, 80% of the UK population drinks instant coffee 66 and on average 211.5 litres of soft drinks (many of which contain high levels of caffeine) were 67 consumed per capita per year. 6 Accordingly, this study included questions about intake of 68 caffeinated drinks and soft drinks during pregnancy. To date, the evidence linking caffeine intake and 69 stillbirth shows variable effect size and some studies focus on coffee consumption rather than 70 consumption of any source of caffeine. [7][8][9] Presently, the World Heal...