Comparison of an enzyme-linked immunosorbent assay (ELISA) to gas chromatography (GC) - measurement of polychlorinated biphenyls (PCBs) in selected US fish extracts

The analysis of PCBs in fish tissues by immunoassay methods was evaluated using fish collected from a US monitoring program, the National Contaminant Biomonitoring Program of the US Department of Interior, Fish and Wildlife Service. Selected composite whole fish samples, which represented widely varying concentrations and sources of PCBs, were extracted and subjected to congener PCB analysis by gas chromatography (GC) and total PCB analysis using an ELISA (ePCBs) calibrated against technical Aroclor 1248. PCB congener patterns in these fishes were different from the patterns found in commercial Aroclors or their combinations as demonstrated by principal component analysis of normalized GC congener data. The sum of the PCB congeners measured by GC (total-PCBs) ranged from 37 to 4600 ng/g (wet weight). Concentrations of PCBs as determined by the ELISA method were positively correlated with total-PCBs and the ePCBs/total-PCBs ratios for individual samples ranged from 1 to 6. Ratios of ePCBs/total- PCBs for dilutions of Aroclors 1242, 1254, and 1260 and for matrix spikes range from 0.6 for 1242 to 2.5 for 1254 and 1260. These results suggest that higher chlorinated PCB congeners have higher anffinity for the anti-PCB antibodies. Partial least squares with latent variable analysis of GC and ELISA data of selected Aroclors and fish samples also support the conclusion that ELISA derived PCB concentrations are dependent on the degree of chlorination. © 1999 Elsevier Science Ltd. All rights reserved

Widespread occurrence of intersex in black basses (\u3ci\u3eMicropterus\u3c/i\u3e spp.) from U.S. rivers, 1995–2004

Intersex occurrence in freshwater fishes was evaluated for nine river basins in the United States. Testicular oocytes (predominantly male testes containing female germ cells) were the most pervasive form of intersex observed, even though similar numbers of male (n = 1477) and female (n = 1633) fish were examined. Intersex was found in 3% of the fish collected. The intersex condition was observed in four of the 16 species examined (25%) and in fish from 34 of 111 sites (31%). Intersex was not found in multiple species from the same site but was most prevalent in largemouth bass (Micropterus salmoides; 18% of males) and smallmouth bass (M. dolomieu; 33% of males). The percentage of intersex fish per site was 8–91% for largemouth bass and 14–73% for smallmouth bass. The incidence of intersex was greatest in the southeastern United States, with intersex largemouth bass present at all sites in the Apalachicola, Savannah, and Pee Dee River Basins. Total mercury, trans-nonachlor, p,p\u27-DDE, p,p\u27-DDD, and total PCBs were the most commonly detected chemical contaminants at all sites, regardless of whether intersex was observed. Although the genotype of the intersex fish was not determined, the microscopic appearance of the gonads, the presence of mature sperm, and the concentrations of sex steroid hormones and vitellogenin indicate the intersex bass were males. Fewre productive endpoints differed significantly among male and intersex bass; plasma vitellogenin concentration in males was not a good indicator of intersex presence. Hierarchical linkages of the intersex condition to reproductive function will require a more quantitative measure of intersex (e.g. severity index) rather than presence or absence of the condition. The baseline incidence of intersex gonadal tissue in black basses and other freshwater fishes is unknown, but intersex prevalence may be related to collection season, age, and endocrine active compounds in the environment. Intersex was not found in largemouth bass older than five years and was most common in 1–3-year-old male largemouth bass. The cause(s) of intersex in these species is also unknown, and it remains to be determined whether the intersex we observed in largemouth and smallmouth bass developed during sex differentiation in early life stages, during exposure to environmental factors during adult life stages, or both

Comparison of an enzyme-linked immunosorbent assay (ELISA) to gas chromatography (GC) - measurement of polychlorinated biphenyls (PCBs) in selected US fish extracts

The analysis of PCBs in fish tissues by immunoassay methods was evaluated using fish collected from a US monitoring program, the National Contaminant Biomonitoring Program of the US Department of Interior, Fish and Wildlife Service. Selected composite whole fish samples, which represented widely varying concentrations and sources of PCBs, were extracted and subjected to congener PCB analysis by gas chromatography (GC) and total PCB analysis using an ELISA (ePCBs) calibrated against technical Aroclor 1248. PCB congener patterns in these fishes were different from the patterns found in commercial Aroclors or their combinations as demonstrated by principal component analysis of normalized GC congener data. The sum of the PCB congeners measured by GC (total-PCBs) ranged from 37 to 4600 ng/g (wet weight). Concentrations of PCBs as determined by the ELISA method were positively correlated with total-PCBs and the ePCBs/total-PCBs ratios for individual samples ranged from 1 to 6. Ratios of ePCBs/total- PCBs for dilutions of Aroclors 1242, 1254, and 1260 and for matrix spikes range from 0.6 for 1242 to 2.5 for 1254 and 1260. These results suggest that higher chlorinated PCB congeners have higher anffinity for the anti-PCB antibodies. Partial least squares with latent variable analysis of GC and ELISA data of selected Aroclors and fish samples also support the conclusion that ELISA derived PCB concentrations are dependent on the degree of chlorination. © 1999 Elsevier Science Ltd. All rights reserved

Susceptibility Provision Enhances Effective De-escalation (SPEED): utilizing rapid phenotypic susceptibility testing in Gram-negative bloodstream infections and its potential clinical impact

Abstract Objectives We evaluated the performance and time to result for pathogen identification (ID) and antimicrobial susceptibility testing (AST) of the Accelerate Pheno™ system (AXDX) compared with standard of care (SOC) methods. We also assessed the hypothetical improvement in antibiotic utilization if AXDX had been implemented. Methods Clinical samples from patients with monomicrobial Gram-negative bacteraemia were tested and compared between AXDX and the SOC methods of the VERIGENE® and Bruker MALDI Biotyper® systems for ID and the VITEK® 2 system for AST. Additionally, charts were reviewed to calculate theoretical times to antibiotic de-escalation, escalation and active and optimal therapy Results ID mean time was 21 h for MALDI-TOF MS, 4.4 h for VERIGENE® and 3.7 h for AXDX. AST mean time was 35 h for VITEK® 2 and 9.0 h for AXDX. For ID, positive percentage agreement was 95.9% and negative percentage agreement was 99.9%. For AST, essential agreement was 94.5% and categorical agreement was 93.5%. If AXDX results had been available to inform patient care, 25% of patients could have been put on active therapy sooner, while 78% of patients who had therapy optimized during hospitalization could have had therapy optimized sooner. Additionally, AXDX could have reduced time to de-escalation (16 versus 31 h) and escalation (19 versus 31 h) compared with SOC. Conclusions By providing fast and reliable ID and AST results, AXDX has the potential to improve antimicrobial utilization and enhance antimicrobial stewardship

Variable responses of human and non-human primate gut microbiomes to a Western diet

BACKGROUND: The human gut microbiota interacts closely with human diet and physiology. To better understand the mechanisms behind this relationship, gut microbiome research relies on complementing human studies with manipulations of animal models, including non-human primates. However, due to unique aspects of human diet and physiology, it is likely that host-gut microbe interactions operate differently in humans and non-human primates. RESULTS: Here, we show that the human microbiome reacts differently to a high-protein, high-fat Western diet than that of a model primate, the African green monkey, or vervet (Chlorocebus aethiops sabaeus). Specifically, humans exhibit increased relative abundance of Firmicutes and reduced relative abundance of Prevotella on a Western diet while vervets show the opposite pattern. Predictive metagenomics demonstrate an increased relative abundance of genes associated with carbohydrate metabolism in the microbiome of only humans consuming a Western diet. CONCLUSIONS: These results suggest that the human gut microbiota has unique properties that are a result of changes in human diet and physiology across evolution or that may have contributed to the evolution of human physiology. Therefore, the role of animal models for understanding the relationship between the human gut microbiota and host metabolism must be re-focused.P40 OD010965 - NIH HHS; P40 RR019963 - NCRR NIH HHS; P51 OD011132 - NIH HHS; R01 RR016300 - NCRR NIH HHS; 5R01RR016300 - NCRR NIH HH

Keeping 21st Century Paleontology Grounded: Quantitative Genetic Analyses and Ancestral State Reconstruction Re-Emphasize the Essentiality of Fossils

Advances in genetics and developmental biology are revealing the relationship between genotype and dental phenotype (G:P), providing new approaches for how paleontologists assess dental variation in the fossil record. Our aim was to understand how the method of trait definition influences the ability to reconstruct phylogenetic relationships and evolutionary history in the Cercopithecidae, the Linnaean Family of monkeys currently living in Africa and Asia. We compared the two-dimensional assessment of molar size (calculated as the mesiodistal length of the crown multiplied by the buccolingual breadth) to a trait that reflects developmental influences on molar development (the inhibitory cascade, IC) and two traits that reflect the genetic architecture of postcanine tooth size variation (defined through quantitative genetic analyses: MMC and PMM). All traits were significantly influenced by the additive effects of genes and had similarly high heritability estimates. The proportion of covariate effects was greater for two-dimensional size compared to the G:P-defined traits. IC and MMC both showed evidence of selection, suggesting that they result from the same genetic architecture. When compared to the fossil record, Ancestral State Reconstruction using extant taxa consistently underestimated MMC and PMM values, highlighting the necessity of fossil data for understanding evolutionary patterns in these traits. Given that G:P-defined dental traits may provide insight to biological mechanisms that reach far beyond the dentition, this new approach to fossil morphology has the potential to open an entirely new window onto extinct paleobiologies. Without the fossil record, we would not be able to grasp the full range of variation in those biological mechanisms that have existed throughout evolution. View Full-Tex

Organochlorine Chemical Residues in Northern Cardinal (Cardinalis cardinalis) Eggs from Greater Washington, DC USA

Northern Cardinal eggs from six neighborhoods near Washington DC were analyzed for organochlorine pesticides and PCBs. All compounds were detected more frequently and at higher concentrations in more heavily urbanized neighborhoods. DDT (mostly as p,pʹ-DDE) was detected in all neighborhoods. p,pʹ-DDT was typically 0.5‒16 ng/g (ww) in most suburban neighborhoods but was not detected (\u3c 0.1 ng/g) in more rural areas; however, p,pʹ-DDT was 127‒1130 ng/g in eggs from two suburban Maryland nests and comprised 65.7% of total p,pʹ-DDT isomers in the most contaminated sample, indicating recent exposure to un-weathered DDT. Total chlordane (sum of 5 compounds) was 2‒70 ng/g; concentrations were greatest in older suburban neighborhoods. Total PCB (sum of detected congeners) was \u3c 5‒21 ng/g. Congener patterns were similar in all neighborhoods and resembled those typical of weathered mixtures. Results indicate that wildlife remains exposed to low concentrations of legacy contaminants in suburban neighborhoods and that cardinal eggs can be used to monitor local- ized contamination

Design of a Novel Low Cost Point of Care Tampon (POCkeT) Colposcope for Use in Resource Limited Settings

Introduction: Current guidelines by WHO for cervical cancer screening in low- and middle-income countries involves visual inspection with acetic acid (VIA) of the cervix, followed by treatment during the same visit or a subsequent visit with cryotherapy if a suspicious lesion is found. Implementation of these guidelines is hampered by a lack of: trained health workers, reliable technology, and access to screening facilities. A low cost ultra-portable Point of Care Tampon based digital colposcope (POCkeT Colposcope) for use at the community level setting, which has the unique form factor of a tampon, can be inserted into the vagina to capture images of the cervix, which are on par with that of a state of the art colposcope, at a fraction of the cost. A repository of images to be compiled that can be used to empower front line workers to become more effective through virtual dynamic training. By task shifting to the community setting, this technology could potentially provide significantly greater cervical screening access to where the most vulnerable women live. The POCkeT Colposcope’s concentric LED ring provides comparable white and green field illumination at a fraction of the electrical power required in commercial colposcopes. Evaluation with standard optical imaging targets to assess the POCkeT Colposcope against the state of the art digital colposcope and other VIAM technologies. Results: Our POCkeT Colposcope has comparable resolving power, color reproduction accuracy, minimal lens distortion, and illumination when compared to commercially available colposcopes. In vitro and pilot in vivo imaging results are promising with our POCkeT Colposcope capturing comparable quality images to commercial systems. Methods: Rapid 3D printing, consumer grade light sources, and cameras were used to construct the TVDC. The TVDC’s concentric LED ring provides comparable white and green field illumination at a fraction of the electrical power required in commercial colposcopes, and crossed polarizers provide a reduction in glare. Evaluation was performed using standard optical imaging targets to assess the TVDC against the state of the art digital colposcope and other VIA technologies. Results: Our TVDC has comparable resolving power, color reproduction accuracy, minimal lens distortion, and illumination when compared to commercially available colposcopes. In vitro and pilot in vivo imaging results are promising with our TVDC capturing images of comparable quality to commercial systems. Conclusion: The TVDC is capable of capturing images suitable for cervical lesion analysis. Our portable low cost system will be useful for increasing access to cervical cancer screening and diagnostics in resource-limited settings by providing a more readily portable and easy to use device for medical personnel.The image data and support information that is published in the article "Design of a Novel Low Cost Trans-Vaginal Digital Colposcope for use in Resource Limited Settings" are available at: http://dukespace.lib.duke.edu/dspace/handle/10161/8357.National Institutes of Health (US) 5R21CA162747-0

Zircon as a tracer of plumbing processes in an active magmatic system: insights from mingled magmas of the 2010 dome collapse, Montserrat, Lesser Antilles Arc, Caribbean

This project has received funding from the European Union's Hori-zon 2020 research and innovation programme under the Marie Skodowska-Curie grant agreement No. 749611 (JHS) . We also ac-knowledge funding from the Natural Environment Research Council Isotope Geoscience Facilities Steering Committee, grant IP-1746-1117 (JB) . The work has been financially supported by the Spanish grant CGL 2017-84469-P (JHS) . Funding for open access charge: Universidad de Granada/CBUA. Alexander Varychev at the University of Heidelberg, Germany, and Jeremy Rushton at the British Geological Survey, U.K., are thanked for help with analytical work. Jose Luis Macias is thanked for editorial handling. We are obliged to two anonymous reviewers for the time and effort they took to help us improve the clarity and rigour of our interpretations. 19Soufriere Hills Volcano, Montserrat, erupted from 1995 to 2010, with activity including dome growth, destructive pyroclastic density currents and Vulcanian explosions. Monitoring data, such as gas emissions, show the system is still in a state of unrest. The recent eruptions provide an opportunity to study, in real time, a complex subduction-related subvolcanic transaustal melt-mush reservoir, its magma fluxes, and the timing of crystal and melt storage prior to eruptive paroxysms. How and when mush destabilisation occurs prior to volcanic eruptions continues to be a question of intense debate. Evidence of mafic magma intrusion, a potential eruptive trigger, is preserved in enclaves with quenched and diffuse margins that are mingled with crystal-rich andesite. Here, in this first study of Soufriere Hills Volcano zircon, we report zircon ages and compositions for mafic-intermediate enclaves and host andesites from the most recent dome collapse in 2010 to place temporal constraints on magma reservoir processes. Zircon U-238-Th-230 ages disequilibrium crystallisation ages ranging between c. 2-250 ka constrain the longevity of the magmatic plumbing system. Uniform Hf isotopes, epsilon Hf 11.3 +/- 12 to 14.6 +/- 1.5, indicate invariant compositions that are typical for island arc magma sources. Zircon trace element concentrations and Ti-in-zircon crystallisation temperatures indicate crystallisation in isolated, small-volume, lenses with variable fractions of melt of heterogeneous compositions. We suggest amalgamation of assorted crystal cargoes from these lenses occurred prior to eruption during mush destabilisation triggered by mafic magma recharge. Zircon textures, on the other hand, shed light on recent centimetre-scale magma mingling immediately prior to eruption. Euhedral-subhedral zircon is preferentially preserved in or near quenched contacts of the least-evolved enclave and host andesite. By contrast, reheating of the andesite by the mafic magma recharge in the presence of zircon-undersaturated melts promoted zircon resorption. This led to the formation of subhedral-anhedral corroded zircon that is typical in the host andesite mush. Zircon thus reveals processes ranging from 100,000s of years of andesite storage to short-term partial destruction in response to transient heating and magma mixing events.European Commission 749611Natural Environment Research Council Isotope Geoscience Facilities Steering Committee IP-1746-1117Spanish Government CGL 2017-84469-PUniversidad de Granada/CBU