Fifteen-minute consultation: The efficient investigation of infantile and childhood epileptic encephalopathies in the era of modern genomics

The investigation of children presenting with infantile and childhood epileptic encephalopathies (ICEE) is challenging due to diverse aetiologies, overlapping phenotypes and the relatively low diagnostic yield of MRI, electroencephalography (EEG) and biochemical investigations. Careful history and thorough examination remain essential as these may identify an acquired cause or indicate more targeted investigation for a genetic disorder. Whole exome sequencing (WES) with analysis of a panel of candidate epilepsy genes has increased the diagnostic yield. Whole genome sequencing (WGS), particularly as a trio with both parents' DNA, is likely to supersede WES. Modern genomic investigation impacts on the timing and necessity of other testing. We propose a structured approach for children presenting with ICEE where there is diagnostic uncertainty, emphasising the importance of WGS or, if unavailable, WES early in the investigative process. We note the importance of expert review of all investigations, including radiology, neurophysiology and biochemistry, to confirm the technique used was appropriate as well as the results. It is essential to counsel families on the risks associated with the procedures, the yield of the procedures, findings that are difficult to interpret and implication of 'negative' results. Where children remain without a diagnosis despite comprehensive investigation, we note the importance of ongoing multidisciplinary care

A quantitative assessment of shoot flammability for 60 tree and shrub species supports rankings based on expert opinion

Fire is an important ecological disturbance in vegetated ecosystems across the globe, and also has considerable impacts on human infrastructure. Vegetation flammability is a key bottom-up control on fire regimes, and on the nature of individual fires. Although New Zealand (NZ) historically had low fire frequencies, anthropogenic fires have considerably impacted indigenous vegetation as humans used fire extensively to clear forests. Few studies of vegetation flammability have been undertaken in NZ, and only one has compared the flammability of indigenous plants; this was a qualitative assessment derived from expert opinion. We addressed this knowledge gap by measuring the flammability of terminal shoots from a range of trees and shrubs found in NZ. We quantified shoot flammability of 60 indigenous and exotic species, and compared our experimentally derived ranking with expert opinion. The most flammable species was the invasive exotic shrub Ulex europaeus, followed by Eucalyptus viminalis, Pomaderris kumeraho, Dacrydium cupressinum, and Lophozonia menziesii. Our experimentally derived ranking was strongly correlated with expert opinion, lending support to both methods. Our results are useful to ecologists seeking to understand how fires have and will influence NZ’s ecosystems, and for fire managers identifying high-risk landscapes, and low flammability species for ‘green firebreaks’

Are there biological differences between screen-detected and interval colorectal cancers in the English Bowel Cancer Screening Programme?

Background: We measured biomarkers of tumour growth and vascularity in interval and screen-detected colorectal cancers (CRCs) in the English Bowel Cancer Screening Programme in order to determine whether rapid tumour growth might contribute to interval CRC (a CRC diagnosed between a negative guaiac stool test and the next scheduled screening episode). Methods: Formalin-fixed, paraffin-embedded sections from 71 CRCs (screen-detected 43, interval 28) underwent immunohistochemistry for CD31 and Ki-67, in order to measure the microvessel density (MVD) and proliferation index (PI), respectively, as well as microsatellite instability (MSI) testing. Results: Interval CRCs were larger (P=0.02) and were more likely to exhibit venous invasion (P=0.005) than screen-detected tumours. There was no significant difference in MVD or PI between interval and screen-detected CRCs. More interval CRCs displayed MSI-high (14%) compared with screen-detected tumours (5%). A significantly (P=0.005) higher proportion (51%) of screen-detected CRC resection specimens contained at least one polyp compared with interval CRC (18%) resections. Conclusions: We found no evidence of biological differences between interval and screen-detected CRCs, consistent with the low sensitivity of guaiac stool testing as the main driver of interval CRC. The contribution of synchronous adenomas to occult blood loss for screening requires further investigation

Arsenic exposure and outcomes of antimonial treatment in visceral leishmaniasis patients in bihar, India:a retrospective cohort study

Funding: This work was supported by a Clinical PhD Fellowship to MRP (090665) and a Principal Research Fellowship to AHF (079838) from the Wellcome Trust (http://www.wellcome.ac.uk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Cyclooxygenase activity mediates colorectal cancer cell resistance to the omega-3 polyunsaturated fatty acid eicosapentaenoic acid

Purpose The naturally-occurring omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) is safe, well-tolerated and inexpensive, making it an attractive anti-cancer intervention. However, EPA has only modest anti-colorectal cancer (CRC) activity, when used alone. Both cyclooxygenase (COX) isoforms metabolise EPA and are over-expressed in CRC cells. We investigated whether COX inhibition increases the sensitivity of CRC cells to growth inhibition by EPA. Methods A panel of 18 human and mouse CRC cell lines was used to characterize the differential sensitivity of CRC cells to the growth inhibitory effects of EPA. The effect of CRISPR-Cas9 genetic deletion and pharmacological inhibition of COX-1 and COX-2 on the anti-cancer activity of EPA was determined using in vitro and in vivo models. Results Genetic ablation of both COX isoforms increased sensitivity of CT26 mouse CRC cells to growth inhibition by EPA in vitro and in vivo. The non-selective COX inhibitor aspirin and the selective COX-2 inhibitor celecoxib increased sensitivity of several human and mouse CRC cell lines to EPA in vitro. However, in a MC38 mouse CRC cell tumour model, with dosing that mirrored low-dose aspirin use in humans, thereby producing significant platelet COX-1 inhibition, there was ineffective intra-tumoral COX-2 inhibition by aspirin and no effect on EPA sensitivity of MC38 cell tumours. Conclusion Cyclooxygenase inhibition by non-steroidal anti-inflammatory drugs represents a therapeutic opportunity to augment the modest anti-CRC activity of EPA. However, intra-tumoral COX inhibition is likely to be critical for this drug-nutrient interaction and careful tissue pharmacodynamic profiling is required in subsequent pre-clinical and human studies

High survivability of micrometeorites on Mars: Sites with enhanced availability of limiting nutrients

NASA's strategy in exploring Mars has been to follow the water, because water is essential for life, and it has been found that there are many locations where there was once liquid water on the surface. Now perhaps, to narrow down the search for life on a barren basalt‐dominated surface, there needs to be a refocusing to a strategy of “follow the nutrients.” Here we model the entry of metallic micrometeoroids through the Martian atmosphere, and investigate variations in micrometeorite abundance at an analogue site on the Nullarbor Plain in Australia, to determine where the common limiting nutrients available in these (e.g., P, S, Fe) become concentrated on the surface of Mars. We find that dense micrometeorites are abundant in a range of desert environments, becoming concentrated by aeolian processes into specific sites that would be easily investigated by a robotic rover. Our modeling suggests that micrometeorites are currently far more abundant on the surface of Mars than on Earth, and given the far greater abundance of water and warmer conditions on Earth and thus much more active weather system, this was likely true throughout the history of Mars. Because micrometeorites contain a variety of redox sensitive minerals including FeNi alloys, sulfide and phosphide minerals, and organic compounds, the sites where these become concentrated are far more nutrient rich, and thus more compatible with chemolithotrophic life than most of the Martian surface. Plain Language Summary NASA's exploration program has allowed the scientific community to demonstrate clearly that Mars had a watery past, so the search for life needs to move on to identifying the places where water and nutrients coincided. We have investigated the relative abundance of micrometeorites on Mars compared to the Earth because these contain key nutrients that the earliest life forms on Earth used, and because their contained minerals can be used to investigate past atmospheric chemistry. We suggest that micrometeorites should be far more abundant on the Martian surface than on Earth's, and that wind‐driven modification of sediments is expected to concentrate micrometeorites, and their contained nutrients, in gravel beds and cracks in exposed bedrock

A comprehensive study on the role of the Yersinia pestis virulence markers in an animal model of pneumonic plague

We determined the role of Yersinia pestis virulence markers in an animal model of pneumonic plague. Eleven strains of Y. pestis were characterized using PCR assays to detect the presence of known virulence genes both encoded by the three plasmids as well as chromosomal markers. The virulence of all Y. pestis strains was compared in a mouse model for pneumonic plague. The presence of all known virulence genes correlated completely with virulence in the Balb/c mouse model. Strains which lacked HmsF initially exhibited visible signs of disease whereas all other strains (except wild-type strains) did not exhibit any disease signs. Forty-eight hours post-infection, mice which had received HmsF– strains regained body mass and were able to control infection; those infected with strains possessing a full complement of virulence genes suffered from fatal disease. The bacterial loads observed in the lung and other tissues reflected the observed clinical signs as did the cytokine changes measured in these animals. We can conclude that all known virulence genes are required for the establishment of pneumonic plague in mammalian animal models, the role of HmsF being of particular importance in disease progression

Successful ecosystem-based management of Antarctic krill should address uncertainties in krill recruitment, behaviour and ecological adaptation

Antarctic krill, Euphausia superba, supports a valuable commercial fishery in the Southwest Atlantic, which holds the highest krill densities and is warming rapidly. The krill catch is increasing, is concentrated in a small area, and has shifted seasonally from summer to autumn/winter. The fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources, with the main goal of safeguarding the large populations of krilldependent predators. Here we show that, because of the restricted distribution of successfully spawning krill and high inter-annual variability in their biomass, the risk of direct fishery impacts on the krill stock itself might be higher than previously thought. We show how management benefits could be achieved by incorporating uncertainty surrounding key aspects of krill ecology into management decisions, and how knowledge can be improved in these key areas. This improved information may be supplied, in part, by the fishery itself

The utility of c-Met as a diagnostic tissue biomarker in primary colorectal cancer

The transmembrane protein, c-Met, is thought to be overexpressed and activated in colorectal cancer (CRC). This study explored its potential as a diagnostic tissue biomarker for CRC in a large human CRC tissue collection obtained from a randomized clinical trial. Tissue microarrays of matched normal colorectal epithelium and primary cancer were prepared from specimens obtained from 280 patients recruited to the MRC CLASICC trial (ISRCTN 74883561) and interrogated using immunohistochemistry for c-Met expression. The distribution and intensity of immunopositivity was graded using a validated, semi-quantifiable score, and differences in median scores analysed using the Wilcoxon signed-rank test. A receiver operating characteristic (ROC) curve was plotted to measure the diagnostic accuracy of c-Met as a biomarker in CRC. Epithelial cell membrane expression of c-Met differed significantly between CRC and normal colorectal tissue: median 12.00 (Interquartile range (IQR) 6-15) versus median 6.00 (IQR 2.70-12.00) respectively (P = <.0001). ROC-AUC analysis of c-Met expression yielded a CRC diagnostic probability of 0.66 (95% CI: 0.61 to 0.70; P < .0001). A score of ≥14.50 showed high specificity at 85.32% (95% CI 80.33%-89.45%) but sensitivity of only 30.92% (CI 25.37%-36.90%). Thus c-Met is consistently overexpressed in human CRC as compared to normal colorectal epithelium tissue. c-Met expression may have a role in diagnosis and prognostication if combined with other biomarkers

Inhibiting ABCG2 could potentially enhance the efficacy of hypericin-mediated photodynamic therapy in spheroidal cell models of colorectal cancer

Background: Photodynamic Therapy (PDT) is an attractive modality for treating solid cancers. This study evaluates the efficacy of Hypericin-PDT as a cytotoxic therapy in colorectal cancer (CRC), using 2D cell cultures and 3D multicellular tumour spheroids. Methods: Spheroids were generated through forced-floating and agitation-based techniques. 2D and spheroid models of HT29 and HCT116 CRC cells were incubated with Hypericin (0–200 nM) for 16 h. Cultures were irradiated with light (1 J/cm²) and cytotoxicity assessed using Propidium Iodide fluorescence. Expression of ABCG2 protein was assessed by immunoassays in 2D and spheroid cultures. The effect of ABCG2 inhibition, using 10 μM Ko143, on cytotoxicity following Hypericin-PDT was evaluated. Results: Hypericin-PDT produced a significant reduction in HT29 (p < 0.0001) and HCT116 (p < 0.0001) cell viability in 2D cultures, with negligible non-phototoxicity. Spheroids were more resistant than 2D cultures to Hypericin-PDT (HT29: p = 0.003, HCT116: p = 0.006) and had a greater expression of ABCG2. Inhibition of ABCG2 in spheroids with Ko143 resulted in an enhanced Hypericin-PDT effect compared to Hypericin-PDT alone (HT29: p = 0.04, HCT116: p = 0.01). Conclusions: Hypericin-PDT has reduced efficacy in CRC spheroids as compared to 2D cultures, which may be attributable through upregulation in ABCG2. The clinical efficacy of Hypericin-PDT may be enhanced by ABCG2 inhibition