10 research outputs found

    Lionfish (\u3ci\u3ePterois volitans\u3c/i\u3e) as biomonitoring species for oil pollution effects in coral reef ecosystems

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    With oil spills, and other sources of aromatic hydrocarbons, being a continuous threat to coral reef systems, and most reef fish species being protected or difficult to collect, the use of the invasive lionfish (Pterois volitans) might be a good model species to monitor biomarkers in potentially exposed fish in the Caribbean and western Atlantic. The rapid expansion of lionfish in the Caribbean and western Atlantic, and the unregulated fishing for this species, would make the lionfish a suitable candidate as biomonitoring species for oil pollution effects. However, to date little has been published about the responses of lionfish to environmental pollutants. For this study lionfish were collected in the Florida Keys a few weeks after Hurricane Irma, which sank numerous boats resulting in leaks of oil and fuel, and during the winter and early spring after that. Several biomarkers indicative of exposure to PAHs (bile fluorescence, cytochrome P450-1A induction, glutathione S-transferase activity) were measured. To establish if these biomarkers are inducible in PAH exposed lionfish, dosing experiments with different concentrations of High Energy Water Accommodated Fraction of crude oil were performed. The results revealed no significant effects in the biomarkers in the field collected fish, while the exposure experiments demonstrated that lionfish did show strong effects in the measured biomarkers, even at the lowest concentration tested (0.3% HEWAF, or 25 μg/l ƩPAH50). Based on its widespread distribution, relative ease of collection, and significant biomarker responses in the controlled dosing experiment, it is concluded that lionfish has good potential to be used as a standardized biomonitoring species for oil pollution in its neotropical realm

    Is bicarbonate in Photosystem II the equivalent of the glutamate ligand to the iron atom in bacterial reaction centers?

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    Photosystem II of oxygen-evolving organisms exhibits a bicarbonate-reversible formate effect on electron transfer between the primary and secondary acceptor quinones, QA and QB. This effect is absent in the otherwise similar electron acceptor complex of purple bacteria, e.g. Rhodobacter sphaeroides. This distinction has led to the suggestion that the iron atom of the acceptor quinone complex in PS II might lack the fifth and sixth ligands provided in the bacterial reaction center (RC) by a glutamate residue at position 234 of the M-subunit in Rb. sphaeroides,RCs (M232 in Rps. viridis). By site-directed mutagenesis we have altered GluM234 in RCs from Rb. sphaeroides, replacing it with valine, glutamine and glycine to form mutants M234EV, M234EQ and M234EG, respectively. These mutants grew competently under phototrophic conditions and were tested for the formate-bicarbonate effect. In chromatophores there were no detectable differences between wild type (Wt) and mutant M234EV with respect to cytochrome b-561 reduction following a flash, and no effect of bicarbonate depletion (by incubation with formate). In isolated RCs, several electron transfer activities were essentially unchanged in Wt and M234EV, M234EQ and M234EG mutants, and no formate-bicarbonate effect was observed on: (a) the fast or slow phases of recovery of the oxidized primary donor (P+) in the absence of exogenous donor, i.e., the recombination of P+QA− or P+QB−, respectively; (b) the kinetics of electron transfer from QA− to QB; or (c) the flash dependent oscillations of semiquinone formation in the presence of donor to P+ (QB turnover). The absence of a formate-bicarbonate effect in these mutants suggests that GluM234 is not responsible for the absence of the formate-bicarbonate effect in Wt bacterial RCs, or at least that other factors must be taken into account. The mutant RCs were also examined for the fast primary electron transfer along the active (A-)branch of the pigment chain, leading to reduction of QA. The kinetics were resolved to reveal the reduction of the monomer bacteriochlorophyll (τ = 3.5 ps), followed by reduction of the bacteriopheophytin (τ = 0.9 ps). Both steps were essentially unaltered from the wild type. However, the rate of reduction of QA was slowed by a factor of 2 (τ = 410 ± 30 and 47 ± 30 ps for M234EQ and M234EV, respectively, compared to 220 ps in the wild type). EPR studies of the isolated RCs showed a characteristic g = 1.82 signal for the QA semiquinone coupled to the iron atom, which was indistinguishable from the wild type. It is concluded that GluM234 is not essential to the normal functioning of the acceptor quinone complex in bacterial RCs and that the role of bicarbonate in PS II is distinct from the role of this residue in bacterial RCs

    Third Santorini conference pharmacogenomics workshop report: "Pharmacogenomics at the crossroads: what else than good science will be needed for the field to become part of Personalized Medicine?"

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    This workshop discussed the use of pharmacogenomics knowledge in clinical practice. It was organized in three sections: educational needs, definition of industry as a potential trigger, and regulatory aspects. Regarding pharmacogenomics education, it appears that this is truly lacking, except for patients, who are becoming increasingly educated thanks to the media. Regarding administrators, education is mainly a problem of cost. Indeed, even if cost-effective for society on the whole, pharmacogenomic tests will be expensive for hospitals. Physicians are facing an overabundance of information. They must be helped to bridge the gap between knowledge/research and clinical application. Collaboration between the pharmaceutical industry and the diagnostics industry could be one of the triggers. Moreover, there is a lack of qualification of this information, even though some guidelines are being produced. The Food and Drug Administration organizes workshops that often lead to publications on pharmacogenomic education, genomic data aims and development concepts, which can finally be translated into guidelines. Industry can contribute to pharmacogenomic development, not only through research, but also through marketing activities, which would promote the use of pharmacogenomics by physicians. Legal aspects were also considered in terms of the problem of availability and the degree of qualification of commercial drug tests on the market. The Innovative Medicine Initiative was also presented, which is a public-private partnership to create a biomedical research and development leader to benefit patients and society. Finally, a technical report from the Institute for Prospective Technological Studies on the socioeconomic impact of pharmacogenomics in the EU was presented

    Physiology of the Intrathecal Bolus: The Leptomeningeal Route for Macromolecule and Particle Delivery to CNS

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    The Measurement and Significance Of Changes In The Cholinesterase Activities Of Erythrocytes and Plasma In Man and Animals

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    Pseudocholinesterasen

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