Analyzing Disaster Loss Trends: A Comparison of Normalization Methodologies in South Korea

Increasing concern for climate change adaptation and disaster risk reduction is driving the need for more accurate and sophisticated tools of analysis to protect populations. Standards of analysis that can normalize measurements under various contexts are particularly valuable in the global arena of disaster management. One concern that may benefit from normalizing is the analysis of disaster loss trends. Previous studies have used a combination of inflation, wealth, and societal factors in their normalization of disaster loss methodologies. This study examines the various normalization methods in previous research and applies a selection of eight formulae to 50 years of disaster data in South Korea. The results show both decreasing and increasing trends in disaster damage losses based on the methods, but there are curious biases under the results that may be artifacts of Korea's unique experiences in economic development. The conclusion discusses how the case of Korea may help to clarify the optimal normalization methodology for other countries.

P92 What is a benign notochordal cell tumour?

Objectives

Characteristics from a large systematic review.

Design

The first systematic review of benign notochordal cell tumours.

Subjects

All studies, in any language, published at any time, identified using specified search terms.

Methods

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Results

So-called benign notochordal cell tumours exhibited the following features: pain was the sole presenting symptom in 37/81 (45.7%) and neurological deficit in 36/81 (44.4%). Incidental discovery upon imaging was reported in 8/81 (9.9%). Radiologically, lesions were small, (≤30 millimetres at their maximum diameter) in 57/65 (87.7%), hypointense on T1 sequences and hyperintense on T2 sequences on magnetic resonance imaging (106/130; 81.5%), did not enhance following contrast administration (62/74; 83.8%) and were non-lytic (80/160; 50.0%). Histologically, these tumours lacked myxoid matrix (66/84; 78.6%) and nuclear atypia (100/112; 89.3%). In those managed conservatively, follow up was between 8.5 and 120 months. Most were stable at follow up (22/25; 88.0%), one lesion grew (4.0%), one patient died of an unrelated cause (4.0%) and outcome was not stated in one case (4.0%).

Conclusions

BNCTs exhibit a spectrum of features, none of which are pathognomonic and diagnosis is subjective. The majority of reports describe small, non-progressive, non-lytic lesions that lack contrast enhancement, intercellular myxoid matrix and nuclear atypia. They are nevertheless difficult to distinguish from small chordomas.

P25 Hydrogel systems to enhance the delivery of cell therapy for traumatic spinal cord injury

Objectives

Cell therapies are an emerging therapeutic approach for spinal cord injury. We assessed the survival and phenotype of olfactory ensheathing cells (OECs) in hydrogel delivery systems suitable for clinical use.

Design

Laboratory study.

Methods

Cell survival in different formulations of collagen and fibrin hydrogels was assessed using Syto 9 and propidium iodide. The proportion of cells staining positive for a key repair marker (p75NTR) was also quantified using immunocytochemistry and fluorescence microscopy.

Results

There were significant differences in OEC survival between the various collagen and fibrin hydrogel formulations tested (p<0.001 one-way ANOVA, n=17). 10% v/v fibrin conferred the best cell survival with 85% of OECs remaining alive. Incorporating OECs into collagen hydrogels promoted the highest proportion of p75NTR immunopositive cells (78%) and this was significantly higher than both fibrin hydrogels and traditional monolayer culture (53% and 20%, respectively, p<0.0001 one-way ANOVA, n=24).

Conclusions

Collagen and fibrin hydrogels both have the potential to enhance the delivery, survival and retention of transplanted OECs for spinal cord repair. Both materials are clinically scalable, promote favourable OEC survival and have the potential to increase the proportion of cells expressing a key repair marker (p75NTR). Optimised hydrogel delivery systems may provide a valuable approach to improve the delivery of OECs for spinal cord repair in the future.

Leukocytes as a reservoir of circulating oncogenic DNA and regulatory targets of tumor-derived extracellular vesicles

Essentials Tumor-bearing mice were employed to follow oncogenic HRAS sequences in plasma, and blood cells. Cancer DNA accumulated in leukocytes above levels detected in exosomes, platelets and plasma. Extracellular vesicles and nucleosomes are required for uptake of tumor DNA by leukocytes. Uptake of tumor-derived extracellular vesicles by leukocytes triggers coagulant phenotype.

SUMMARY

Background Tumor-derived extracellular vesicles (EVs) and free nucleosomes (NSs) carry into the circulation a wealth of cancer-specific, bioactive and poorly understood molecular cargoes, including genomic DNA (gDNA). Objective Here we investigated the distribution of extracellular oncogenic gDNA sequences (HRAS and HER2) in the circulation of tumor-bearing mice. Methods and Results Surprisingly, circulating leukocytes (WBCs), especially neutrophils, contained the highest levels of mutant gDNA, which exceeded the amount of this material recovered from soluble fractions of plasma, circulating EVs, platelets, red blood cells (RBCs) and peripheral organs, as quantified by digital droplet PCR (ddPCR). Tumor excision resulted in disappearance of the WBC-associated gDNA signal within 2-9 days, which is in line with the expected half-life of these cells. EVs and nucleosomes were essential for the uptake of tumor-derived extracellular DNA by neutrophil-like cells and impacted their phenotype. Indeed, the exposure of granulocytic HL-60 cells to EVs from HRAS-driven cancer cells resulted in a selective increase in tissue factor (TF) procoagulant activity and interleukin 8 (IL-8) production. The levels of circulating thrombin-antithrombin complexes (TAT) were markedly elevated in mice harboring HRAS-driven xenografts. Conclusions Myeloid cells may represent a hitherto unrecognized reservoir of cancer-derived, EV/NS-associated oncogenic gDNA in the circulation, and a possible novel platform for liquid biopsy in cancer. In addition, uptake of this material alters the phenotype of myeloid cells, induces procoagulant and proinflammatory activity and may contribute to systemic effects associated with cancer.

Molecular subtypes and differentiation programmes of glioma stem cells as determinants of extracellular vesicle profiles and endothelial cell-stimulating activities

We have previously uncovered the impact of oncogenic and differentiation processes on extracellular vesicles (EVs) in cancer. This is of interested in the context of glioma stem cells (GSC) that are responsible for recurrent nature of glioblastoma multiforme (GBM), while retaining the potential to undergo differentiation and self renewal.  GSCs reside in vascular niches where they interact with endothelial cells through a number of mediators including bioactive cargo of EVs. GSCs can be classified as proneural (PN) or mesenchymal (MES) subtypes on the basis of their gene expression profiles and distinct biological characteristics. In the present study we investigated how GSC diversity and differentiation programmes influence their EV-mediated communication potentials. Indeed, molecular subtypes of GBMs and GSCs differ with respect to their expression of EV-related genes (vesiculome) and GSCs with PN or MES phenotypes produce EVs with markedly different characteristics, marker profiles, proteomes and endothelial stimulating activities. For example, while EVs of PN GSC are largely devoid of exosomal markers their counterparts from MES GSCs express ample CD9, CD63 and CD81 tetraspanins. In both GSC subtypes serum-induced differentiation results in profound, but distinct changes of cellular phenotypes including the enhanced EV production, reconfiguration of their proteomes and the related functional pathways. Notably, the EV uptake was a function of both subtype and differentiation state of donor cells. Thus, while, EVs produced by differentiated MES GSCs were internalized less efficiently than those from undifferentiated cells they exhibited an increased stimulatory potential for human brain endothelial cells. Such stimulating activity was also observed for EVs derived from differentiated PN GSCs, despite their even weaker uptake by endothelial cells. These findings suggest that the role of EVs as biological mediators and biomarkers in GBM may depend on the molecular subtype and functional state of donor cancer cells, including cancer stem cells.

Abbreviations: CryoTEM: cryo-transmission electron microscopy; DIFF: differentiated GSCs; EGF: epidermal growth factor; DUC: differential ultracentrifugation; EV: extracellular vesicle; FGF: fibroblast growth factor; GBM: glioblastoma multiforme; GFAP: glial fibrillary acidic protein; GO: gene ontology; GSC: glioma stem cells; HBEC-5i: human brain endothelial cells; MES: mesenchymal cells; MTS - [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt; PMT1: proneural-to-mesenchyman transition cell line 1; PN: proneural cells; TEM: transmission electron microscopy; WB: western blotting

Compressive Sensing with Optical Chaos

Compressive sensing (CS) is a technique to sample a sparse signal below the Nyquist-Shannon limit, yet still enabling its reconstruction. As such, CS permits an extremely parsimonious way to store and transmit large and important classes of signals and images that would be far more data intensive should they be sampled following the prescription of the Nyquist-Shannon theorem. CS has found applications as diverse as seismology and biomedical imaging. In this work, we use actual optical signals generated from temporal intensity chaos from external-cavity semiconductor lasers (ECSL) to construct the sensing matrix that is employed to compress a sparse signal. The chaotic time series produced having their relevant dynamics on the 100 ps timescale, our results open the way to ultrahigh-speed compression of sparse signals.