Cross-Platform Comparison of Amino Acid Metabolic Profiling in Three Model Organisms Used in Environmental Metabolomics.

Environmental metabolomics is a promising approach to study pollutant impacts to target organisms in both terrestrial and aquatic environments. To this end, both nuclear magnetic resonance (NMR)- and mass spectrometry (MS)-based methods are used to profile amino acids in different environmental metabolomic studies. However, these two methods have not been compared directly which is an important consideration for broader comparisons in the environmental metabolomics field. We compared the quantification of 18 amino acids in the tissue extracts of Daphnia magna, a common model organism used in both ecotoxicology and ecology, using both 1H NMR spectroscopy and liquid chromatography with tandem MS (LC-MS/MS). 1H NMR quantification of amino acids agreed with the LC-MS/MS quantification for 17 of 18 amino acids measured. We also tested both quantitative methods in a D. magna sub-lethal exposure study to copper and lithium. Again, both NMR and LC-MS/MS measurements showed agreement. We extended our analyses with extracts from the earthworm Eisenia fetida and the plant model Nicotiana tabacum. The concentrations of amino acids by both 1H NMR and LC-MS/MS, agreed and demonstrated the robustness of both techniques for quantitative metabolomics. These findings demonstrate the compatibility of these two analytical platforms for amino acid profiling in environmentally relevant model organisms and emphasizes that data from either method is robust for comparisons across studies to further build the knowledge base related to pollutant exposure impacts and toxic responses of diverse environmental organisms.

Splenic artery embolization for spontaneous splenic rupture due to Babesiosis: a case report.

Babesiosis incidence in the United States has been increasing with an 11% rise between 2018 and 2019 based on the latest CDC annual summary, reaching its highest ever reported incidence. This primarily tick-borne disease is particularly prevalent in New England. Despite predominantly nonspecific and at times subtle symptoms, life-threatening complications do occur. One such complication is splenic rupture which has been suggested to be more common in younger and otherwise healthy individuals. This is a report on a successful splenic artery embolization in a 65-year-old male from upstate New York who, unlike most prior studies, showed splenic rupture after he was discharged with negative parasitemia and general improvement following several days of targeted antibiotic therapy. Increased incidence and various presentations of Babesiosis call for an attempt to promote clinical awareness for radiologists among other specialties.

Polychlorinated biphenyl (PCB) concentrations and profiles in marine mammals from the North Atlantic Ocean.

Polychlorinated biphenyls (PCBs) can provide crucial information into the bioaccumulation and biomagnification of POPs in marine mammals. Muscle tissue samples were obtained for detailed PCB congener specific analysis of all 209 PCBs in 11 species of marine mammals stranded across the coast of the UK between 2010 and 2013. At least 145 PCB congeners were found in each individual. The highest concentrations of PCBs were recorded in a killer whale (318 mg/kg lipid) and the highest toxic equivalent in a Risso's dolphin (1687 pg/g TEQ2005 wet). Concentrations of PCBs in the majority of samples exceeded toxic thresholds (9 mg/kg lipid) for marine mammals, highlighting the health risk they face from PCB exposure. Many PCB profiles did not fit typical 'Aroclor' signatures, but instead indicated patterns of congeners that are resistant to biotransformation and elimination. However, this study identified a novel PCB signature in a sei whale that has not yet been previously observed in marine mammals. The whale had a PCB profile that included lighter and inadvertent PCB congeners such as PCB 11, suggesting that the main source of exposure was through atmospheric deposition, rather than terrestrial discharges. Seven subsamples were chosen for chiral analysis of PCB 95, 136 and 149. The enantiomer fractions (EFs) of C-PCBs 95 and 149 were non racemic suggesting there may be enantiomer selective metabolism in marine mammals. Although there has been a shift in the literature towards emerging pollutants, this study acts as a stark reminder that PCBs continue to pose a significant risk to wildlife.

Infant dietary exposure to dioxin-like polychlorinated biphenyls (dlPCBs), polybrominated and mixed halogenated dibenzo-p-dioxins and furans (PBDD/Fs and PXDD/Fs) in milk samples of lactating mothers in Accra, Ghana.

In this study, polybrominated and mixed halogenated dibenzo-p-dioxins and furans (PBDD/Fs and PXDD/Fs), and dioxin-like polychlorinated biphenyls (dlPCBs) were quantified in 24 human milk samples of first-time lactating mothers from Greater Accra region in Ghana. The aims of the study were to determine the concentrations and toxic equivalent concentrations of PBDD/F, PXDD/F and dlPCBs in human milk, and to estimate an infant's daily intake. The samples were analysed for 12 dioxin-like PCBs, 7 congeners of 2,3,7,8-polybrominated dibenzo-p-dioxins and furans (PBDD/Fs), and 7 congeners of 2,3,7,8-mixed halogenated dioxins and furans (PXDD/Fs, where X = Br/Cl). The mean concentrations in human milk ranged from 0.15 to 212.9 pg/g lipid for dlPCB congeners (mean TEQ: 1.67 pg WHO2005-TEQ/g lipid). Lesser concentrations for 2,3,7,8-PXDD/Fs (and PBDD/Fs congeners) ranged between <0.01-1.67 pg/g lipid, with a total mean tentative TEQ of 0.56 pg WHO2005-TEQ/g lipid. For an infant of average weight 7 kg, consuming an estimated volume of 600 mL human milk, the estimated average daily intake of dlPCBs in 21 human milk samples was 4.95 pg TEQ/kg bw/day; contributions from dlPCBs, PXDD/Fs and PBDD/Fs resulted in an average estimated daily intake of 6.56 pg TEQ/kg bw/day. The results obtained in this study, although lower than infant dietary intake estimates in human milk from industrialized countries, exceeded the recommended safety standards of 1 pg TEQ/kg bw/day and 1-4 pg TEQ/kg bw/day from the Agency for Toxic Substances and Disease Registry (ATSDR) and the World Health Organization (WHO), respectively.

Temporal trends of halogenated and organophosphate contaminants in striped dolphins from the Mediterranean Sea.

PBDEs, HBCD, novel DBDPE, PBEB and HBB, dechloranes, OPFRs and natural MeO-PBDEs were monitored in muscle of striped dolphins (Stenella coeruleoalba) from the Mediterranean Sea collected in three time periods (1990, 2004-2009 and 2014-2018). PBDEs levels decreased about 60% in under three decades, from 5067 ± 2210 to 2068 ± 2642ngg-1 lw, evidencing the success of their ban. Most PBDEs were found in all the samples, with BDE-47, -99, -154, -100 and -153 as the main contributors. Found in 71.4% of the samples, α-HBCD was stable through time and usually

Liquid chromatography-ion mobility-high resolution mass spectrometry for analysis of pollutants in indoor dust: Identification and predictive capabilities.

Dust analysis provides a means to assess the degree of exposure of humans in an indoor environment to various contaminant classes such as flame retardants, pesticides and others. There is increasing interest in non-targeted acquisitions using high resolution mass spectrometry (HRMS) to better capture the contaminant profile. However, these studies are confronted with the challenge of assessing confidence in proposed identifications, particularly when authentic standards are not available. Here, we demonstrate the analysis of dust extracts representing various indoor environments (industrial e-waste processing and domestic) for high-abundance environmental contaminants using a data-independent LC-HRMS approach, incorporating ion mobility spectrometry (IMS) to provide additional characterization capability for the complex samples. Twenty-nine xenobiotic compound identifications were made based on both targeted and non-targeted processing approaches using accurate mass precursor and product ion measurement combined with an ion mobility derived collision-cross section (TWCCSN2) determination. Characterization of the repeatability of TWCCSN2 value measurements and their average relative error to compared authentic standards of 0.38% were consistent with various published studies and represent a robust measurement property. TWCCSN2 values were particularly useful in cases where confirmation after the initial dust analysis was performed using a different chromatographic method, due to the gas-phase measurement being unaffected by such changes. Observed compound TWCCSN2 values were then compared to predicted CCSN2 values obtained using two different machine-learning based predictive techniques. Results from one of the predictive programs indicates a promising avenue for use of these models for supporting compound identification in non-targeted analyses.

Organic contaminants formed during fire extinguishing using different firefighting methods assessed by nontarget analysis.

During a fire event, potentially hazardous chemicals are formed from the combustion of burning materials and are released to the surrounding environment, both via gas and soot particles. The aim of this investigation was to study if firefighting techniques influence the emission of chemicals in gas phase and soot particles. Five full-scale fire tests were extinguished using four different firefighting techniques. A nontarget chemical analysis approach showed that important contaminants in gas and soot separating the different tests were brominated flame retardants (BFRs), organophosphate flame retardants (OPFR), polycyclic aromatic hydrocarbons (PAHs) and linear hydrocarbons. Reproducibility was evaluated by a field replicate test and it was determined that the temperature curve during the event had a bigger impact on the released chemicals than the firefighting technique used. However, despite fire intensity being a confounding factor, multivariate statistics concluded that water mist with additive resulted in less BFR emissions compared to foam extinguishing. The analysis also showed that the conventional spray nozzle method released more PAHs compared with the water mist method. The comprehensive chemical analysis of gas and soot released during fire events was able to show that different firefighting techniques influenced the release of chemicals.

Halogenated organic contaminants of concern in urban-influenced waters of Lake Ontario, Canada: Passive sampling with targeted and non-targeted screening.

Passive samplers are useful tools for monitoring hydrophobic, persistent, and potentially bioaccumulative contaminants in the environment. In this study, low density polyethylene passive samplers were deployed in urban-influenced and background nearshore freshwaters of northwestern Lake Ontario and analyzed for a broad range of both legacy halogenated organic contaminants (HOCs) and halogenated flame retardants (HFRs). Non-targeted analysis was conducted for screening additional halogenated substances. For most compounds, concentrations were greatest in the industrialized Hamilton Harbour and more generally at sites that have stronger influences of wastewater effluent discharges and stormwater run-off through rivers and creeks. Polychlorinated biphenyls (PCBs) remain the dominant class of HOCs in water, with dissolved-phase concentrations ranging from 10 to 4100 pg/L (ΣPCBs), followed by polybrominated diphenylethers (ΣPBDEs; 14-960 pg/L) and the organochlorine pesticides (OCPs; 22-290 pg/L). Several non-PBDE brominated flame retardants (nBFRs) and chlorinated Dechlorane-related compounds were detected, with hexabromocyclododecanes (ΣHBCDD; sum of 3 diastereoisomers) the most abundant (1.0-21 pg/L). Non-targeted screening of samples by high resolution mass spectrometry using Kendrick mass defect plots for data analysis indicated that several other halogenated compounds were present in waters at relatively high abundances compared to the flame retardants, based on semi-quantitative estimates. These included methyl-triclosan, four halogenated anisoles (2,4,6-tribromoanisole, dimethyl-trichloroanisole, pentachloroanisole, and pentachlorothioanisole), and pentachloro-aniline. Dissolved-phase methyl-triclosan was estimated to contribute up to approximately 40% of the summed target HOC concentrations. Polyethylene passive samplers provided an excellent medium for both non-targeted screening of HOCs not currently included in monitoring programs and tracking brominated and chlorinated chemicals slated for reductions in uses and emissions through international (Stockholm Convention) and binational (Great Lakes) agreements.

C12-30 α-Bromo-Chloro "Alkenes": Characterization of a Poorly Identified Flame Retardant and Potential Environmental Implications.

Bromo-chloro alkenes (Br-Cl PXAs) have been used for over 30 years as flame retardants and are listed on several national chemical inventories. Very little publicly available information is available on Br-Cl PXAs, and thus preliminary ecological risk screening is challenging due to the lack of basic information such as molecular structure and associated physicochemical properties. Due to their likely similarity with chlorinated paraffins (CPs), Br-Cl PXAs may pose a similar environmental hazard. Several structural databases list such substances as "alkenes", although the industrial synthesis involves halogenation of linear alpha-olefins and would be expected to produce linear alkanes. In this study, a combination of high-resolution separation and mass spectrometric techniques were used to characterize a Br-Cl PXA industrial technical product, C12-30 bromo-chloro alpha-alkenes (CAS RN 68527-01-5). The results show this product is dominated by C18 carbon chain lengths, substituted with 3-7 chlorine atoms and 1-3 bromine atoms on an alkane chain. Long-chain C18 chlorinated paraffins are also present, although they represent a relatively minor component. Experimental log KOW (6.9 to 8.6) and estimated log KOA (10.5 to 13.5) and log KAW (-5.1 to -0.6) partition coefficients suggest that this chemical will behave similarly to medium- and long-chain CPs as well as other persistent organic pollutants, such as highly chlorinated pesticides and polychlorinated biphenyls. The results of this study provide an initial step toward understanding the environmental behavior and persistence of Br-Cl PXAs, highlighting the need for further assessment and re-evaluation of the current structure(s) assigned to these compounds.

Suspect, non-target and target screening of emerging pollutants using data independent acquisition: Assessment of a Mediterranean River basin.

A single workflow based on three approaches (target, suspected and non-target screening) using liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) in data independent acquisition mode (DIA) was developed to assess the presence of emerging pollutants (EPs) in water and sediments from a Mediterranean River Basin. Identification of potential contaminants was based on mass accuracy, isotopic ratio pattern, theoretical fragmentation, and retention time using Waters UNIFI software. In the suspect screening against a library containing 2200 components, 68 contaminants were tentatively identified, 6 of which were confirmed and quantified with analytical standards. Non-target screening (NTS) required additional manual processing and the aid of an on-line database (ChemSpider) to tentatively identify compounds. Eprosartan, an antihypertensive drug not included in the library used for suspected screening, was confirmed and semi-quantified. The identification of Eprosartan proved the workflow to be functional for NTS. Target screening of 171 pesticides and 33 pharmaceuticals and personal care products (PPCPs) including the compounds confirmed using suspect (6) and non target (1) screening achieved monitoring of the most abundant contaminants from the head to the mouth of the Turia basin to establish their spatial distribution. QTOF-MS screening versatility with its high-resolution capability allows for a comprehensive assessment of EPs in the aquatic environment.

Compositional space: A guide for environmental chemists on the identification of persistent and bioaccumulative organics using mass spectrometry.

Since 2001, twenty-eight halogenated groups of persistent organic pollutants (POPs) have been banned or restricted by the Stockholm Convention. Identifying new POPs among the hundreds of thousands of anthropogenic chemicals is a major challenge that is increasingly being met by state-of-the-art mass spectrometry (MS). The first step to identification of a contaminant molecule (M) is the determination of the type and number of its constituent elements, viz. its elemental composition, from mass-to-charge (m/z) measurements and ratios of isotopic peaks (M + 1, M + 2 etc.). Not every combination of elements is possible. Boundaries exist in compositional space that divides feasible and improbable compositions as well as different chemical classes. This study explores the compositional space boundaries of persistent and bioaccumulative organics. A set of ~305,134 compounds (PubChem) was used to visualize the compositional space occupied by F, Cl, and Br compounds, as defined by m/z and isotope ratios. Persistent bioaccumulative organics, identified by in silico screening of 22,049 commercial chemicals, reside in more constrained regions characterized by a higher degree of halogenation. In contrast, boundaries surrounding non-halogenated chemicals could not be defined. Finally, a script tool (R code) was developed to select potential POPs from high resolution MS data. When applied to household dust (SRM 2585), this approach resulted in the discovery of previously unknown chlorofluoro flame retardants.

Background levels of dioxin-like polychlorinated biphenyls (dlPCBs), polychlorinated, polybrominated and mixed halogenated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, PBDD/Fs & PXDD/Fs) in sera of pregnant women in Accra, Ghana.

Human exposure data on dioxins and dioxin-like compounds (DLCs) in Ghana are limited. Based on health risks associated with dioxins and DLCs, the impact of maternal body burdens on foetal exposure is significant. This is the first study that assesses polychlorinated, polybrominated and mixed halogenated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, PBDD/Fs and PXDD/Fs), and dioxin-like polychlorinated biphenyls (dlPCBs) in sera of primiparous Ghanaians. Our sample selection includes 34 participants from two municipalities (Accra and Tema), and explores contributions from environmental and dietary exposures using questionnaire data. Sample preparation involved C18 solid phase extraction, purification with acidified silica and lipid removal cartridges, and detection with gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry. The calculated average toxic equivalent concentration was 5.3 pg TEQ/g lw, with contributions from dlPCBs (1.25 pg TEQ/g lw), PCDD/Fs (3.10 pg TEQ/g lw), PBDD/Fs (0.49 pg TEQ/g lw) and PXDD/Fs (0.50 pg TEQ/g lw). The calculated total TEQ concentration was lower than background TEQ concentrations reported in sera of pregnant women globally. Positive correlations were obtained for total dioxins and DLC concentrations with age and Body Mass Index (BMI). Dietary intake of seafood and dairy products had a strong influence on PCDD/F and dlPCB concentrations. Statistically significant differences were observed for dioxins and DLCs in participants from Accra (in close proximity to Agbogbloshie e-waste site) and Tema. Given the significant TEQ contribution of PBDD/Fs and PXDD/Fs (~20%), it is essential to explore these classes of dioxins and DLCs in future biomonitoring studies as they may pose health risks, and add extra diagnostic information in source exposure investigations.

Dioxins in Great Lakes fish: Past, present and implications for future monitoring.

Dioxins/furans are considered among the most toxic anthropogenic chemicals, and are ubiquitous in the environment including in the North American Great Lakes, which contain one fifth of the world's surface freshwater. Our exposure to dioxins/furans is mainly through contaminated diet. Elevated levels of dioxins/furans in Great Lakes fish have resulted in issuance of fish consumption advisories. Here we examine spatial/temporal trends of dioxins/furans in the edible portion (fillet) of fish from the Canadian waters of the Great Lakes using the data collected by the Province of Ontario, Canada. Our analyses show that the Toxic Equivalent (TEQ) dioxin/furan concentrations declined between 1989 and 2013 in Lake Trout from Lakes Ontario, Huron and Superior by 91%, 78% and 73%, respectively, but increased in Lake Whitefish from Lake Erie by 138%. An expanded dataset created by combining our data with historical Lake Ontario Lake Trout measurements from the literature showed a greater decline of >96% (from 64 to 2.3 pg/g) between 1977 and 2013. Measurements collected for 30 types of fish show overall low levels but local/regional concerns at some locations in Lakes Huron, Erie and Ontario. Dioxins/furans are globally present in foodstuff and "zero concentration" target is considered impractical. Based on the observations for the Great Lakes in the context of risk to human health from eating fish, it is concluded that comprehensive monitoring of dioxins/furans can be replaced with targeted locations and/or indicator species, and the saved resources can be more efficiently utilized for monitoring of other priority or emerging contaminants.

Fast gas chromatography-atmospheric pressure (photo)ionization mass spectrometry of polybrominated diphenylether flame retardants.

Gas chromatography (GC) and mass spectrometry (MS) are powerful, complementary techniques for the analysis of environmental toxicants. Currently, most GC-MS instruments employ electron ionization under vacuum, but the concept of coupling GC to atmospheric pressure ionization (API) is attracting revitalized interest. API conditions are inherently compatible with a wide range of ionization techniques as well high carrier gas flows that enable fast GC separations. This study reports on the application of atmospheric pressure chemical ionization (APCI) and a custom-built photoionization (APPI) source for the GC-MS analysis of polybrominated diphenyl ethers (PBDEs), a ubiquitous class of flame retardants. Photoionization of PBDEs resulted in the abundant formation of molecular ions M•+ with very little fragmentation. Some photo-oxidation was observed, which differentiated critical BDE isomers. Formation of protonated molecules [M+H]+ did not occur in GC-APPI because the ionization energy of H2O (clusters) exceeds the energy of the ionizing photons. Avoiding mixed-mode ionization is a major advantage of APPI over APCI, which requires careful control of the source conditions. A fast GC-API-MS method was developed using helium and nitrogen carrier gases that provides good separation of critical isomers (BDE-49/71) and elution of BDE 209 in less than 7 min (with He) and 15 min (with N2). It will be shown that the GC-APPI and GC-APCI methods match the sensitivity and improve upon the selectivity and throughput of established methods for the analysis of PBDEs using standard reference materials (NIST SRM 1944 and SRM 2585) and selected environmental samples.

The state of POPs in Ghana- A review on persistent organic pollutants: Environmental and human exposure.

Ghana is one of the top pesticide users and highest persistent organic pollutant (POP) emitters in sub-saharan Africa. Despite recent increases in published data, there is limited information on how POP concentrations have changed, post ratification of the Stockholm Convention. As a result, this review aims to address these knowledge gaps by collating available data that reported POPs in Ghanaian environmental matrices, identify spatial and temporal trends, and establish potential health risks. It is worth noting that Ghana has not developed its own regulatory standards for POPs, but adapts United States Environmental Protection Agency (USEPA) standards. Results obtained showed concentrations in excess of USEPA regulatory standards for per- and poly-fluoroalkyl sulphonates (PFASs) and dichlorodiphenyldichloroethane (DDD) in water, polychlorinated and polybrominated dibenzo-p-dioxins and furans (PCDD/Fs and PBDD/Fs) in e-waste soils, and polybrominated diphenyl ethers in aquatic organisms and dairy products. The published studies do not cover major regions nationwide. The inconsistency in methods and analytes measured, along with data scarcity in some regions, makes it challenging to identify temporal trends. However, the data did indicate decreasing concentrations of some legacy POPs in soil/sediment and aquatic organisms, with increasing concentrations of some POPs in water, fish, fruits and vegetables. Studies that performed health risks assessments were limited although the data indicated risks to e-waste workers, some farmers and vulnerable sub-populations. This review identified potential human health risks from POPs in the Ghanaian environment and the need for more consistent and widespread monitoring program.

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans associated with settling particles in Lake Ontario.

Sediment traps were deployed at seven sites in the western and central basins of Lake Ontario for calculation of concentrations and down fluxes for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) to assess ongoing loadings to Lake Ontario from the Niagara River watershed. Traps were deployed at multiple depths (beginning at 20 m) during two seasonal time periods at stations impacted by the outflow of the Niagara River, and stations reflecting deeper water offshore conditions. Settling particles were collected seasonally to assess the influence of physical characteristics of the water column, i.e., isothermal conditions vs. stratified conditions, on concentrations and fluxes of PCDD/Fs. At all stations and for all depth intervals, PCDD/F concentrations were higher in the winter sampling period (range of 3120-10,600 pg g-1), compared to the spring - summer - fall time period (range of 320-6900 pg g-1). These results indicated bottom sediments in central and western Lake Ontario were more highly-contaminated, compared to contemporary particulate material entering the lake via the Niagara River or resulting from shoreline erosion. However, assessment of PCDD/F congener profiles and ratios also indicated source areas within the Niagara River watershed continued to episodically contribute loadings to Lake Ontario. The results also indicated changes in discharges of PCDD/Fs from sources in the Niagara River result in changes in congener profiles in settling particles, which can be detected by continued monitoring.

Maternal Transfer of Flame Retardants in Sharks from the Western North Atlantic Ocean.

The present work represents a comprehensive study of in utero maternal transfer of legacy and emerging flame retardants (FRs) in marine predators. We analyzed liver tissues from pregnant sharks of five viviparous species, including blacknose shark ( Carcharhinus acronotus; n = 12), blacktip shark ( Carcharhinus limbatus; n = 2), bonnethead ( Sphyrna tiburo; n = 2), Atlantic sharpnose shark ( Rhizoprionodon terraenovae; n = 2), and spinner shark ( Carcharhinus brevipinna; n = 2), as well as their embryos ( n = 84 in total from five species), collected from the western North Atlantic Ocean. Concentrations of frequently detected emerging FRs in adult female blacknose sharks were determined to be 6.1-83.3 ng/g lipid weight (lw) for dechlorane analogues, 2.5-29.8 ng/g lw for tetrabromo- o-chlorotoluene, and nondetection -32.6 ng/g lw for hexabromobenzene. These concentrations were 1-2 orders of magnitude lower than those of legacy polybrominated diphenyl ether flame retardants (85.7-398 ng/g lw). Similar contamination profiles were also found in the other four species, although FR concentrations varied in different species. A total of 21 FRs were commonly found in developing embryos of female sharks from five species, demonstrating maternal transfer in utero. The maternal transfer ratio (i.e., ratio of the mean litter concentration to their mother's concentration) determined in blacknose shark mother/embryo groups for each FR chemical was negatively associated with its octanol-water partition coefficient. Our work lays a solid foundation for future investigation of the underlying mechanisms of in utero transfer and additional physical or chemical factors that affect maternal transfer.

Changes to polychlorinated biphenyl (PCB) signatures and enantiomer fractions across different tissue types in Guillemots.

Two Guillemot carcases were dissected, each providing 12 discrete tissue samples and 3 samples of partially digested food. One hundred and five PCBs from the 209 PCBs determined by GCxGC-ToFMS were detected. The relative proportions of individual PCBs did not vary greatly within tissue types, although the PCB profile from undigested food could be distinguished. Enantiomer fractions (EFs) were determined for CB-95, CB-136 and CB-149 by GC-HRqToFMS. EFs in the partially digested food were near racemic, with high levels of enrichment for E1 CB-95 in the kidneys and liver (EF of 0.80 and 0.84 respectively). This provides some of the clearest evidence to date that fractionation takes place in the organs where metabolic biotransformation and elimination of PCBs occurs. Our findings also confirm the ability of non-lethal sampling techniques, such as collection of small (<1 g) blood samples, to provide PCB signatures that are representative of an individual organism.

Development and Application of a Low-Volume Flow System for Solution-State in Vivo NMR.

In vivo nuclear magnetic resonance (NMR) spectroscopy is a particularly powerful technique, since it allows samples to be analyzed in their natural, unaltered state, criteria paramount for living organisms. In this study, a novel continuous low-volume flow system, suitable for in vivo NMR metabolomics studies, is demonstrated. The system allows improved locking, shimming, and water suppression, as well as allowing the use of trace amounts of expensive toxic contaminants or low volumes of precious natural environmental samples as stressors. The use of a double pump design with a sump slurry pump return allows algal food suspensions to be continually supplied without the need for filters, eliminating the possibility of clogging and leaks. Using the flow system, the living organism can be kept alive without stress indefinitely. To evaluate the feasibility and applicability of the flow system, changes in the metabolite profile of 13C enriched Daphnia magna over a 24-h period are compared when feeding laboratory food vs exposing them to a natural algal bloom sample. Clear metabolic changes are observed over a range of metabolites including carbohydrates, lipids, amino acids, and a nucleotide demonstrating in vivo NMR as a powerful tool to monitor environmental stress. The particular bloom used here was low in microcystins, and the metabolic stress impacts are consistent with the bloom being a poor food source forcing the Daphnia to utilize their own energy reserves.

Bleeding after Percutaneous Transhepatic Biliary Drainage: Incidence, Causes and Treatments.

Of all procedures in interventional radiology, percutaneous transhepatic biliary drainage (PTBD) is amongst the most technically challenging. Successful placement requires a high level of assorted skills. While this procedure can be life-saving, it can also lead to significant iatrogenic harm, often manifesting as bleeding. Readers of this article will come to understand the pathophysiology and anatomy underlying post-PTBD bleeding, its incidence, its varied clinical manifestations and its initial management. Additionally, a structured approach to its treatment emphasizing endovascular and percutaneous methods is given.