A microcosm study to support aquatic risk assessment of nickel : community-level effects and comparison with bioavailability-normalized species sensitivity distributions

The aquatic risk assessment for nickel (Ni) in the European Union is based on chronic species sensitivity distributions and the use of bioavailability models. To test whether a bioavailability-based safe threshold of Ni (the hazardous concentration for 5% of species [HC5]) is protective for aquatic communities, microcosms were exposed to 5 stable Ni treatments (6-96 mu g/L) and a control for 4mo to assess bioaccumulation and effects on phytoplankton, periphyton, zooplankton, and snails. Concentrations of Ni in the periphyton, macrophytes, and snails measured at the end of the exposure period increased in a dose-dependent manner but did not indicate biomagnification. Abundance of phytoplankton and snails decreased in 48 mu g Ni/L and 96 mu g Ni/L treatments, which may have indirectly affected the abundance of zooplankton and periphyton. Exposure up to 24 mu g Ni/L had no adverse effects on algae and zooplankton, whereas the rate of population decline of the snails at 24 mu g Ni/L was significantly higher than in the controls. Therefore, the study-specific overall no-observed-adverse-effect concentration (NOAEC) is 12 mu g Ni/L. This NOAEC is approximately twice the HC5 derived from a chronic species sensitivity distribution considering the specific water chemistry of the microcosm by means of bioavailability models. Thus, the present study provides support to the protectiveness of the bioavailability-normalized HC5 for freshwater communities

Expanding Theranostic Radiopharmaceuticals for Tumor Diagnosis and Therapy.

Radioligand theranostics (RT) in oncology use cancer-type specific biomarkers and molecular imaging (MI), including positron emission tomography (PET), single-photon emission computed tomography (SPECT) and planar scintigraphy, for patient diagnosis, therapy, and personalized management. While the definition of theranostics was initially restricted to a single compound allowing visualization and therapy simultaneously, the concept has been widened with the development of theranostic pairs and the combination of nuclear medicine with different types of cancer therapies. Here, we review the clinical applications of different theranostic radiopharmaceuticals in managing different tumor types (differentiated thyroid, neuroendocrine prostate, and breast cancer) that support the combination of innovative oncological therapies such as gene and cell-based therapies with RT

Erythropoietin overrides the triggering effect of DNA platination products in a mouse model of Cisplatin-induced neuropathy

<p>Abstract</p> <p>Background</p> <p>Cisplatin mediates its antineoplastic activity by formation of distinct DNA intrastrand cross links. The clinical efficacy and desirable dose escalations of cisplatin are restricted by the accumulation of DNA lesions in dorsal root ganglion (DRG) cells leading to sensory polyneuropathy (PNP). We investigated in a mouse model by which mechanism recombinant erythropoietin (rhEPO) protects the peripheral nervous system from structural and functional damage caused by cisplatin treatment with special emphasis on DNA damage burden.</p> <p>Results</p> <p>A cumulative dose of 16 mg cisplatin/kg resulted in clear electrophysiological signs of neuropathy, which were significantly attenuated by concomitant erythropoietin (cisplatin 32,48 m/s ± 1,68 m/s; cisplatin + rhEPO 49,66 m/s ± 1,26 m/s; control 55,01 m/s ± 1,88 m/s; p < 0,001). The co-application of rhEPO, however, did not alter the level of unrepaired cisplatin-DNA lesions accumulating in DRG target cells. Micro-morphological analyses of the sciatic nerve from cisplatin-exposed mice showed damaged myelin sheaths and mitochondria. Co-administered rhEPO inhibited myelin sheaths from structural injuries and resulted in an increased number of intact mitochondria.</p> <p>Conclusion</p> <p>The protective effect of recombinant erythropoietin is not mediated by reducing the burden of DNA platination in the target cells, but it is likely to be due to a higher resistance of the target cells to the adverse effect of DNA damage. The increased frequency of intact mitochondria might also contribute to this protective role.</p

Beiträge zum 28. Darmstädter Geotechnik-Kolloquium am 09. März 2022

Themenschwerpunkte: 1. Modell- und Feldversuche 2. Digitalisierung und künstliche Intelligenz in der Geotechnik 3. Nationale und internationale Großprojekte 4. Normung und Rechtliche

Beiträge zum 28. Darmstädter Geotechnik-Kolloquium am 09. März 2022

Themenschwerpunkte: 1. Modell- und Feldversuche 2. Digitalisierung und künstliche Intelligenz in der Geotechnik 3. Nationale und internationale Großprojekte 4. Normung und Rechtliche

Bewertung der Grundwasserbelastung durch Wirkstoffe - was wollen wir schützen?

When evaluating groundwater contamination, the protection goal drinking water is still dominant. Especially for active substances it will be more and more accompanied by an ecotoxicological risk assessment for the diverse groundwater community. Already in 2001, a German UBA project investigated whether the existing test methods with surface water species are also protective for groundwater species. Taxonomical representatives of the groundwater community were selected and tested at 10°C for sensitivity to different types of pesticide action: to the fungicide Cyprodinil that inhibits protein anabolism, to the neurotoxic insecticide lambda-Cyhalothrin, and to the herbicide Bromoxynil octanoate, mainly with narcotic action in animals. Cyprodinil acted 5-10fold delayed in groundwater species. The acute effect of lambda-Cyhalothrin depends on neurophysiology and activity; it was similar in lower crustaceans of ground- and surface water. Higher crustaceans, being more sensitive due to their neurophysiology, showed differences due to the higher activity in surface waters. Syncarida were as sensitive as the most sensitive surface water species, but showed 5-10fold delayed effects. The narcotic action of Bromoxynil octanoate was comparable in time and sensitivity, independent of habitat and taxonomy. Thus, the groundwater community is sufficiently represented by the sensitivity spectrum of surface water organisms. Existing standard tests are sufficiently safe for protecting the groundwater community, given that in case of hints to high sensitivity of higher crustaceans a representative of this taxonomic group is tested beside Daphnia magna

Ecological approaches to aquatic ecotoxicology challenged by the needs of risk assessment

The presented work was performed by Christoph Schäfers and his staff at the Fraunhofer Institute for Molecular Biology and Applied Ecology IME in Schmallenberg, Germany. This summarizing report serves as a habilitation thesis in ecotoxicology at the University Koblenz-Landau. We developed and improved experimental approaches to identify the ecological effects of chemical exposure, aiming to minimize uncertainties of regulatory assessments. For hazard assessment of substances, projects on invertebrate species sensitivity distributions in ground and surface water, (endocrine) effects on sensitive fish life stages and performances, and effects on aquatic communities in large-scale microcosms are presented. For water quality evaluation, habitat-specific approaches and multivariate methods to aquatic invertebrate community monitoring are shown. General conclusions are followed by an outlook to current and future research issues, especially with respect to a landscape-level risk assessment