Erythrophages do not develop when lumbar CSF and blood samples are mixed in vitro

Background

Cerebrospinal fluid (CSF) analysis is a crucial method in the diagnostic process for suspected subarachnoid hemorrhage (SAH), especially when cerebral imaging is negative or inconclusive. CSF cytology (detection of erythrophages or siderophages) is used to determine whether a bloodstained CSF resembles a genuine SAH. Whether erythrophages may develop in vitro after a traumatic puncture in case of delayed CSF analysis is unclear. An in vitro development of erythrophages after traumatic puncture would diminish the diagnostic properties of CSF analysis. We assessed whether erythrophagocytosis is detectable in CSF after an imitated traumatic lumbar puncture.

Methods

We mimicked a traumatic lumbar puncture by mixing surplus CSF with whole blood from the same patient. From this mixture, cytological specimens were obtained immediately and repeatedly at time intervals of 1 h, until 7 h after mixing, or until the mixture was exhausted. Each cytological specimen was microscopically examined independently by four experienced CSF cytologists for the presence of erythrophages.

Results

We studied 401 CSF cytological specimens of 96 punctures in 90 patients. We could not identify any erythrophages in all cytological specimens. Fleiss’ Kappa for interrater-reliability was 1.0.

Conclusions

We did not find evidence for an in vitro erythrophagocytosis after a mimicked traumatic lumbar puncture. Therefore, the occurrence of erythrophages in CSF cytology can be regarded as a reliable sign of an autochthonous bleeding in the subarachnoid space. Our results support the crucial role of CSF analysis in clinical practice in case of a suspected SAH but negative cerebral imaging.

Electronic supplementary material

The online version of this article (10.1186/s12987-018-0116-3) contains supplementary material, which is available to authorized users.

Difficult debriefing situations: A toolbox for simulation educators

BACKGROUND

Simulation-based education (SBE) has emerged as an essential modality for health professions education. One of the central tenants of effective SBE is reflective practice, typically guided by a facilitated debriefing. The debriefing conversation has the possibility of becoming a difficult conversation based on learner and situation-related factors. Difficult debriefing situations may threaten the learning environment, thus requiring an appreciation and understanding of the various ways that learners may react adversely to simulation and debriefing.

AIM

This article provides a review of the various phenotypes of difficult debriefing situations and a toolbox of proactive and reactive strategies to help guide the simulation educator to manage these situations, with the ultimate goal of achieving learning objectives.

Levels of agreement in the measurements of carotid artery ultrasound across a regional vascular network

INTRODUCTION

Duplex ultrasound is often the sole imaging modality used in diagnosing carotid artery disease. However, the reproducibility and repeatability of scientists in determining the peak systolic velocity and end diastolic velocity of the internal carotid artery and common carotid artery (CCA) is widely debated.

STUDY AIM

To investigate intra- and inter-operator variability in diagnostic ultrasound of the carotid arteries across a centralised vascular network using a healthy test subject. To identify potential causes of variability and highlight areas for improvement.

METHODS

Fifteen vascular scientists across four hospital Trusts in the Bristol, Bath and Weston vascular network measured the peak systolic velocity and end diastolic velocity of the internal carotid artery and common carotid artery in a subject using a single portable ultrasound machine. A double blind assessment of spectral Doppler images was performed by two vascular clinical scientists for optimal caliper placement, spectral gain and angle correction. Results were compared for intra- and inter-operator variability.

RESULTS

Initial quality assessment of the Doppler images revealed that three out of 15 scientists produced suboptimal results. Box plot analysis of the common carotid artery and internal carotid artery for each scientist revealed significant variance (ANOVA p < 0.05). However, a Levene's test revealed no single operator who consistently produced highly variable results (p = 0.569).

CONCLUSION

This study highlights the difficulty in obtaining consistent velocity measurements from a subject. Despite the variability in absolute peak systolic velocity and end diastolic velocity, scientists were generally consistent in obtaining an optimal spectral Doppler trace. Some issues with consistency were, however, identified which were subsequently addressed.

Abstract PD3-15: Novel cFlip inhibitor suppresses chemotherapy-induced breast cancer stem cell activity through blocking HIF1-α

Background: The emergence of the cancer stem cell (CSC) hypothesis has helped to explain previously poorly understood clinical concepts such as metastases, late tumour recurrence and resistance to chemotherapy. Triple Negative Breast Cancer (TNBC) has the worst prognosis of all types of breast cancer with a more frequent relapse rate and reduced length of survival in metastatic disease. It has been shown to contain a higher proportion of CSCs than other types of breast cancer. Paclitaxel, a taxane in widespread use in breast cancer, induces apoptosis in a ligand-independent manner through the extrinsic apoptosis pathway. cFLIP is both an antagonist of this apoptosis pathway and has the ability to form aggregates that interfere with the ubiquitylation and subsequent degradation of both HIF1α and β-catenin- two molecules involved in CSC-signalling. Using a novel compound targeted against cFLIP, we wanted to assess whether its combination with paclitaxel effectively targeted CSCs, particularly in TNBC.

Methods: In vitro experiments were used to assess the effect on cell viability, mammosphere formation and ALDH+ of both chemotherapy and our novel agent, OH14. We then used siRNA-mediated knockdown of cFLIP to confirm an on-target effect. Annexin V assays were used to assess apoptosis and both Western blotting and qPCR was used to examine the effect of paclitaxel and OH14 on protein levels and gene expression of CSC-signalling pathways. Athymic mice were used to in serial dilution experiments and for in vivo treatmenst with paclitaxel and OH14 on a TNBC cell line.

Results: We established an in vitro model demonstrating that a wide range of chemotherapeutic agents (FEC, Paclitaxel and Docetaxel) increased CSC-like behaviour and the ALDH+ population in a broad range of breast cancer cell lines. A mathematical model demonstrated that chemotherapy increased the absolute number of CSCs after treatment suggesting that CSC-like signaling was being induced. OH14, our novel compound, sensitised Triple Negative Breast Cancer (TNBC) cell lines to paclitaxel by increasing its apoptotic effect but had a more profound effect on mammosphere formation and ALDH positivity. This suggests that it preferentially targets CSCs. Serial dilution experiments demonstrated that chemotherapy increased the tumour forming potential of a TNBC cell line in vivo and that this effect was abrogated with OH14. Treatment of the same cell line in vivo demonstrated that paclitaxel +/- OH14 successfully targeted tumours but that the paclitaxel tumours recurred whereas those subject to combined treatment remained undetectable. Further experiments examining CSC signalling showed that HIF1α-mediated signalling was increased by paclitaxel and abrogated by the addition of OH14.

Conclusion: cFLIP has a dual effect in both increasing apoptosis and targeting signaling in TNBC CSCs. In a breast cancer subtype in desperate need of novel therapeutic strategies, targeting cFLIP warrants further investigation and progression towards clinical trials.

Citation Format: Robinson T, Turnham D, Gruca A, Piggott L, Clarkson R. Novel cFlip inhibitor suppresses chemotherapy-induced breast cancer stem cell activity through blocking HIF1-α [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD3-15.

The SAGES Fundamental Use of Surgical Energy program (FUSE): history, development, and purpose

BACKGROUND

Adverse events due to energy device use in surgical operating rooms are a daily occurrence. These occur at a rate of approximately 1-2 per 1000 operations. Hundreds of operating room fires occur each year in the United States, some causing severe injury and even mortality. The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) therefore created the first comprehensive educational curriculum on the safe use of surgical energy devices, called Fundamental Use of Surgical Energy (FUSE). This paper describes the history, development, and purpose of this important training program for all members of the operating room team.

METHODS

The databases of SAGES and the FUSE committee as well as personal photographs and documents of members of the FUSE task force were used to establish a brief history of the FUSE program from its inception to its current status.

RESULTS

The authors were able to detail all aspects of the history, development, and national as well as global implementation of the third SAGES Fundamentals Program FUSE.

CONCLUSIONS

The written documentation of the making of FUSE is an important contribution to the history and mission of SAGES and allows the reader to understand the idea, concept, realization, and implementation of the only free online educational tool for physicians on energy devices available today. FUSE is the culmination of the SAGES efforts to recognize gaps in patient safety and develop state-of-the-art educational programs to address those gaps. It is the goal of the FUSE task force to ensure that general FUSE implementation becomes multinational, involving as many countries as possible.

Removal of toxic metals during biological treatment of landfill leachates

Progressive implementation of the European Water Framework Directive has resulted in substantial changes in limits for discharges of heavy metals both to watercourses, and to sewer. The objective of this paper is to provide original, real, full-scale data obtained for removal of metals during aerobic biological leachate treatment, and also to report on studies carried out to look at further trace metal removal. Polishing technologies examined and investigated include; the incorporation of ultrafiltration (UF) membranes into biological treatment systems, the use of ion exchange, and of activated carbon polishing processes. Ultrafiltration was able to provide a 60 percent reduction in COD values in treated leachates, compared with COD values found in settled/clarified effluents. Removal rates for COD varied from 30.5 to 79.8 percent. Additionally, ultrafiltration of treated leachates significantly reduced both chromium and nickel concentrations of effluents by 61.6% and 34.3% respectively (median values). Despite mean reductions of chromium (9.7%) and nickel (13.7%) noted during the ion exchange trials, these results would not justify use of this technology for metals removal at full-scale. Further preliminary studies used pulverized activated carbon (PAC) polishing of UF effluents to demonstrate that significant (up to 80 per cent) removal of COD, TOC and heavy metals could readily be achieved by doses of up to 10g/l of suitable activated carbons. Additional evidence is provided that many trace metals are present not in ionic form, but as organic complexes; this is likely to make their removal to low levels more difficult and expensive.

Anomalous Heating and Plasmoid Formation in a Driven Magnetic Reconnection Experiment

We present a detailed study of magnetic reconnection in a quasi-two-dimensional pulsed-power driven laboratory experiment. Oppositely directed magnetic fields (B=3  T), advected by supersonic, sub-Alfvénic carbon plasma flows (V_{in}=50  km/s), are brought together and mutually annihilate inside a thin current layer (δ=0.6  mm). Temporally and spatially resolved optical diagnostics, including interferometry, Faraday rotation imaging, and Thomson scattering, allow us to determine the structure and dynamics of this layer, the nature of the inflows and outflows, and the detailed energy partition during the reconnection process. We measure high electron and ion temperatures (T_{e}=100  eV, T_{i}=600  eV), far in excess of what can be attributed to classical (Spitzer) resistive and viscous dissipation. We observe the repeated formation and ejection of plasmoids, consistent with the predictions from semicollisional plasmoid theory.

The Convective Transport of Active Species in the Tropics (CONTRAST) Experiment

The Convective Transport of Active Species in the Tropics (CONTRAST) experiment was conducted from Guam (13.5° N, 144.8° E) during January-February 2014. Using the NSF/NCAR Gulfstream V research aircraft, the experiment investigated the photochemical environment over the tropical western Pacific (TWP) warm pool, a region of massive deep convection and the major pathway for air to enter the stratosphere during Northern Hemisphere (NH) winter. The new observations provide a wealth of information for quantifying the influence of convection on the vertical distributions of active species. The airborne in situ measurements up to 15 km altitude fill a significant gap by characterizing the abundance and altitude variation of a wide suite of trace gases. These measurements, together with observations of dynamical and microphysical parameters, provide significant new data for constraining and evaluating global chemistry climate models. Measurements include precursor and product gas species of reactive halogen compounds that impact ozone in the upper troposphere/lower stratosphere. High accuracy, in-situ measurements of ozone obtained during CONTRAST quantify ozone concentration profiles in the UT, where previous observations from balloon-borne ozonesondes were often near or below the limit of detection. CONTRAST was one of the three coordinated experiments to observe the TWP during January-February 2014. Together, CONTRAST, ATTREX and CAST, using complementary capabilities of the three aircraft platforms as well as ground-based instrumentation, provide a comprehensive quantification of the regional distribution and vertical structure of natural and pollutant trace gases in the TWP during NH winter, from the oceanic boundary to the lower stratosphere.

Effects of climate change on the occurrence and distribution of livestock diseases

The planet's mean air and ocean temperatures have been rising over the last century because of increasing greenhouse gas (GHG) emissions. These changes have substantial effects on the epidemiology of infectious diseases. We describe direct and indirect processes linking climate change and infectious diseases in livestock with reference to specific case studies. Some of the studies are used to show a positive association between temperature and expansion of the geographical ranges of arthropod vectors (e.g. Culicoides imicola, which transmits bluetongue virus) while others are used to illustrate an opposite trend (e.g. tsetse flies that transmit a range of trypanosome parasites in sub-Saharan Africa). We further describe a positive association between extreme events: droughts and El Niño/southern oscillation (ENSO) weather patterns and Rift Valley fever outbreaks in East Africa and some adaptation practices used to mitigate the impacts of climate change that may increase risk of exposure to infectious pathogens. We conclude by outlining mitigation and adaptation measures that can be used specifically in the livestock sector to minimize the impacts of climate change-associated livestock diseases.