The RPL/RPS gene signature of melanoma CTCs associates with brain metastasis.

Melanoma brain metastasis (MBM) is linked to poor prognosis and low overall survival. We hypothesized that melanoma circulating tumor cells (CTCs) possess a gene signature significantly expressed and associated with MBM. Employing a multi-pronged approach, we provide first-time evidence identifying a common CTC gene signature for ribosomal protein large/small subunits (RPL/RPS) which associate with MBM onset and progression. Experimental strategies involved capturing, transcriptional profiling and interrogating CTCs, either directly isolated from blood of melanoma patients at distinct stages of MBM progression or from CTC-driven MBM in experimental animals. Second, we developed the first Magnetic Resonance Imaging (MRI) CTC-derived MBM xenograft model (MRI-MBM CDX) to discriminate MBM spatial and temporal growth, recreating MBM clinical presentation and progression. Third, we performed the comprehensive transcriptional profiling of MRI-MBM CDXs, along with longitudinal monitoring of CTCs from CDXs possessing/not possessing MBM. Our findings suggest that enhanced ribosomal protein content/ribogenesis may contribute to MBM onset. Since ribosome modifications drive tumor progression and metastatic development by remodeling CTC translational events, overexpression of the CTC RPL/RPS gene signature could be implicated in MBM development. Collectively, this study provides important insights for relevance of the CTC RPL/RPS gene signature in MBM, and identify potential targets for therapeutic intervention to improve patient care for melanoma patients diagnosed with or at high-risk of developing MBM.

Within-day variability in microbial concentrations at a UK designated bathing water: Implications for regulatory monitoring and the application of predictive modelling based on historical compliance data.

Prediction of bathing water quality is recommended by the World Health Organization (WHO), the European Union (EU) and the United States Environmental Protection Agency (USEPA) and is an established element in bathing water management designed to protect public health. Most commonly, historical regulatory compliance data are used for model calibration and provide the dependent variable for modelling. Independent (or predictor) variables (e.g. rainfall, river flow and received irradiance) measured over some antecedent period are used to deliver prediction of the faecal indicator concentration measured on the day of the regulatory sample collection. The implied linked assumptions of this approach are, therefore, that; (i) the independent variables accurately predict the bathing-day water quality; which is (ii) accurately characterized by the single regulatory sample. Assumption (ii) will not be the case where significant within-day variability in water quality is evident. This study built a detailed record of water quality change through 60 days at a UK coastal bathing water in 2011 using half-hourly samples each subjected to triplicate filtration designed to enhance enumeration precision. On average, the mean daily variation in FIO concentrations exceeded 1 log10 order, with the largest daily variations exceeding 2 log10 orders. Significant diurnality was observed at this bathing water, which would determine its EU Directive compliance category if the regulatory samples were collected at the same time each day. A sampling programme of this intensity has not been reported elsewhere to date and, if this pattern is proven to be characteristic of other bathing waters world-wide, it has significance for: (a) the design of regulatory sampling programmes; (b) the use of historical data to assess compliance, which often comprises a single sample taken at the compliance point on a regular, often weekly, basis; and (c) the use of regulatory compliance data to build predictive models of water quality.

Results of field investigations into the impact of intermittent sewage discharges on the microbiological quality of wild mussels (Mytilus edulis) in a tidal estuary.

Field surveys were designed to examine the effects of sewage contamination from storm overflow effluent on faecal coliform and Escherichia coli concentrations in the flesh of wild mussels (Mytilus edulis). Bags containing 30 mussels each were fixed at known inter-tidal locations and retrieved at intervals following discharge from a nearby combined sewer overflow (CSO). Concentrations of faecal coliform bacteria and E. coli were measured in the shellfish flesh and in samples of overlying water prior to collection of the mussel samples. Faecal coliform and E. coli concentrations in shellfish increased rapidly after CSO discharge. E. coli concentrations exceeded the European shellfish hygiene class C limit of 46,000 100g(-1), and decayed during subsequent CSO discharge-free periods. The concentration and depuration response was independent of the magnitude of CSO spill volume. First-order exponential decay functions were fitted to the data. Decay rates were lower than those found in corresponding microcosm experiments. This relates to the repeated pattern of inundation and exposure associated with the tidal cycles in the estuary. Relationships between E. coli and faecal coliform concentrations in the shellfish and overlying water samples were relatively weak (r<0.60), a pattern often seen with data from uncontrolled environmental experiments.

Predicting faecal indicator fluxes using digital land use data in the UK's sentinel Water Framework Directive catchment: the Ribble study.

The Ribble drainage basin is the single UK sentinel study area chosen for examining the implementation of the EU Water Framework Directive (WFD 20/60/EC). The study which has generated the data for this paper was initiated to quantify 'catchment-derived' fluxes of faecal indicators originating from both point and diffuse sources to inform the competent authorities on the potential for, and prioritization of, further options for reducing the faecal indicator loadings to this crucial coastal environment. It represents the first UK drainage basin-scale 'profile' of faecal indicator sources as recommended by WHO [1999. Health Based Monitoring of Recreational Waters: The Feasibility of a New Approach; the "Annapolis Protocol". World Health Organisation Geneva, Switzerland; 2003. Guidelines for Safe Recreational-Water Environments Volume 1: Coastal and Fresh-Waters. World Health Organisation Geneva, Switzerland] and incorporated into current drafts of the revised Bathing Water Directive [Anon, 2004. Council of the European Communities Amended proposal for a Directive of the European Parliament and of the Council concerning the management of bathing water quality. Brussels 23rd June]. This paper focuses on the relationships between land use and faecal indicator organism concentrations in surface waters within this very large drainage basin (1583 km2) containing some extensive urban areas. A geographical information system comprising readily available digital elevation, remotely sensed land cover and digital map data was used to generate the land use variables for subcatchments draining to 41 locations across the study area. Presumptive concentrations of coliforms, Escherichia coli and enterococci (colony forming unit (cfu) 100 ml(-1)) were measured at each location on at least 20 occasions over a 44-day period within the 2002 bathing season. The sampling programme targeted hydrograph events. Hydrometric records were used to allocate results as either base flow or high flow. At each site, geometric mean faecal indicator organism concentrations were significantly elevated at high flow compared to base flow. Stepwise regression modelling produced statistically significant models predicting geometric mean base and high-flow faecal indicator organism concentrations from land use variables (r2: 49.5-68.1%). The dominant predictor variable in each case was the proportion of built-up land in subcatchments, suggesting that this land use type, with associated sewage-related inputs, is a critical source of faecal indicator organisms in this drainage basin.