Gene expression profiling to characterize sediment toxicity – a pilot study using Caenorhabditis elegans whole genome microarrays

BACKGROUND: Traditionally, toxicity of river sediments is assessed using whole sediment tests with benthic organisms. The challenge, however, is the differentiation between multiple effects caused by complex contaminant mixtures and the unspecific toxicity endpoints such as survival, growth or reproduction. The use of gene expression profiling facilitates the identification of transcriptional changes at the molecular level that are specific to the bio-available fraction of pollutants. RESULTS: In this pilot study, we exposed the nematode Caenorhabditis elegans to three sediments of German rivers with varying (low, medium and high) levels of heavy metal and organic contamination. Beside chemical analysis, three standard bioassays were performed: reproduction of C. elegans, genotoxicity (Comet assay) and endocrine disruption (YES test). Gene expression was profiled using a whole genome DNA-microarray approach to identify overrepresented functional gene categories and derived cellular processes. Disaccharide and glycogen metabolism were found to be affected, whereas further functional pathways, such as oxidative phosphorylation, ribosome biogenesis, metabolism of xenobiotics, aging and several developmental processes were found to be differentially regulated only in response to the most contaminated sediment. CONCLUSION: This study demonstrates how ecotoxicogenomics can identify transcriptional responses in complex mixture scenarios to distinguish different samples of river sediments

Association of Interprofessional Discharge Planning Using an Electronic Health Record Tool With Hospital Length of Stay Among Patients with Multimorbidity: A Nonrandomized Controlled Trial

Whether interprofessional collaboration is effective and safe in decreasing hospital length of stay remains controversial.; To evaluate the outcomes and safety associated with an electronic interprofessional-led discharge planning tool vs standard discharge planning to safely reduce length of stay among medical inpatients with multimorbidity.; This multicenter prospective nonrandomized controlled trial used interrupted time series analysis to examine medical acute hospitalizations at 82 hospitals in Switzerland. It was conducted from February 2017 through January 2019. Data analysis was conducted from March 2021 to July 2022.; After a 12-month preintervention phase (February 2017 through January 2018), an electronic interprofessional-led discharge planning tool was implemented in February 2018 in 7 intervention hospitals in addition to standard discharge planning.; Mixed-effects segmented regression analyses were used to compare monthly changes in trends of length of stay, hospital readmission, in-hospital mortality, and facility discharge after the implementation of the tool with changes in trends among control hospitals.; There were 54 695 hospitalizations at intervention hospitals, with 27 219 in the preintervention period (median [IQR] age, 72 [59-82] years; 14 400 [52.9%] men) and 27 476 in the intervention phase (median [IQR] age, 72 [59-82] years; 14 448 [52.6%] men) and 438 791 at control hospitals, with 216 261 in the preintervention period (median [IQR] age, 74 [60-83] years; 109 770 [50.8%] men) and 222 530 in the intervention phase (median [IQR] age, 74 [60-83] years; 113 053 [50.8%] men). The mean (SD) length of stay in the preintervention phase was 7.6 (7.1) days for intervention hospitals and 7.5 (7.4) days for control hospitals. During the preintervention phase, population-averaged length of stay decreased by -0.344 hr/mo (95% CI, -0.599 to -0.090 hr/mo) in control hospitals; however, no change in trend was observed among intervention hospitals (-0.034 hr/mo; 95% CI, -0.646 to 0.714 hr/mo; difference in slopes, P = .09). Over the intervention phase (February 2018 through January 2019), length of stay remained unchanged in control hospitals (slope, -0.011 hr/mo; 95% CI, -0.281 to 0.260 hr/mo; change in slope, P = .03), but decreased steadily among intervention hospitals by -0.879 hr/mo (95% CI, -1.607 to -0.150 hr/mo; change in slope, P = .04, difference in slopes, P = .03). Safety analyses showed no change in trends of hospital readmission, in-hospital mortality, or facility discharge over the whole study time.; In this nonrandomized controlled trial, the implementation of an electronic interprofessional-led discharge planning tool was associated with a decline in length of stay without an increase in hospital readmission, in-hospital mortality, or facility discharge.; isrctn.org Identifier: ISRCTN83274049

Nematode communities in contaminated river sediments

Heininger P, Hoess S, Claus E, Pelzer J, Traunspurger W. Nematode communities in contaminated river sediments. ENVIRONMENTAL POLLUTION. 2007;146(1):64-76.Nematode communities of eight sites from three river catchments were investigated in terms of the genera composition, feeding types, and life-history strategists. The sampling sites showed a gradient of anthropogenic contamination with heavy metals and organic pollutants being important factors in differentiating the sites. Nematode community structure was related to sediment pollution and the hydro-morphological structure of the sampling sites. Heavily contaminated sites were characterized by communities with high relative abundances of omnivorous and predacious nematodes (Tobrilus, c-p 3; Mononchus, c-p 4), while sites with low to medium contamination were dominated by bacterivorous nematodes (Monhystera, Daptonema; c-p 2) or suction feeders (Dorylaimus, c-p 4). The relatively high Maturity Index values in the heavily polluted sites were surprising. Nematodes turned out to be a suitable organism group for monitoring sediment quality, with generic composition being the most accurate indicator for assessing differences in nematode community structure. (c) 2006 Elsevier Ltd. All rights reserved

Assessing effects of the pharmaceutical ivermectin on meiobenthic communities using freshwater microcosms

Brinke M, Hoess S, Fink G, Ternes TA, Heininger P, Traunspurger W. Assessing effects of the pharmaceutical ivermectin on meiobenthic communities using freshwater microcosms. AQUATIC TOXICOLOGY. 2010;99(2):126-137.Ivermectin is a widely applied veterinary pharmaceutical that is highly toxic to several non-target organisms. So far, little is known about its impact on benthic freshwater species, although its rapid sorption to sediment particles and high persistence in aquatic sediments have raised concerns about the risk for benthic organisms. In the present study, indoor microcosms were used to assess the impact of ivermectin on freshwater meiobenthic communities over a period of 224 days. Microcosm sediments were directly spiked with ivermectin to achieve nominal concentrations of 0.9, 9, and 45 mu g kg(-1) dw. Initially measured ivermectin concentrations (day 0) were 0.6, 6.2, and 31 mu g kg(-1) dw. In addition to abundance of major meiobenthic organism groups, the nematode community was assessed on the species level, assuming a high risk for free-living nematodes due to their close phylogenetic relationship to the main target organisms of ivermectin, parasitic nematodes. Benthic microcrustaceans (cladocerans, ostracods) and nematodes showed the most sensitive response to ivermectin, while tardigrades profited from the presence of the pharmaceutical. The most pronounced effects on the meiofauna community composition occurred at the highest treatment level (31 mu g kg(-1) dw), leading to a no observed effect concentration (NOECcommunity) of 6.2 mu g kg(-1) dw. However, the nematode community was already seriously affected at a concentration of 6.2 mu g kg(-1) dw with two bacterivorous genera, Monhystera and Eumonhystera, being the most sensitive, whereas species of omnivorous genera (Tripyla, Tobrilus) increased in abundance after the application of ivermectin. Thus, a NOECcommunity of 0.6 mu g kg(-1) dw was derived for nematodes. Direct and indirect effects of ivermectin on meiobenthic communities could be demonstrated. The pharmaceutical is likely to pose a high risk, because its NOECs are close to predicted environmental concentrations (PECs) in sediments (0.45-2.17 mu g kg(-1) dw), resulting in worst case risk quotients (RQs) of 1.05-36.2. This observation lends support to efforts aimed at preventing the repeated entry of ivermectin in aquatic environments and thus its accumulation in sediments. Moreover, this study points out that model ecosystem studies should be part of environmental risk assessments (ERAs) of veterinary medicinal products (VMPs). (C) 2010 Elsevier B.V. All rights reserved

Using meiofauna to assess pollutants in freshwater sediments: A microcosm study with cadmium

Brinke M, Ristau K, Bergtold M, et al. Using meiofauna to assess pollutants in freshwater sediments: A microcosm study with cadmium. Environmental Toxicology and Chemistry. 2011;30(2):427-438.The direct and indirect effects of Cd on benthic communities were assessed in a freshwater microcosm study over a period of seven months (218 d). Cadmium was regarded as a model substance to evaluate the usefulness of small-scale laboratory microcosm with microscopic fauna. In particular, effects on the meiofauna community, an ecologically important but rather neglected benthic component, were investigated. In addition, some microfaunal parameters (protozoan abundance and microbial activity) were determined. The sediment was spiked with nominal Cd concentrations of 10, 100, and 1,000 mg/kg dry weight. Because of the strong binding of Cd to sediment particles, measured Cd pore-water concentrations never exceeded 129.5 +/- 40.7 mu g/L. At 1,000 mg/kg dry weight, the abundances of the two dominant meiofauna taxa, nematodes and oligochaetes, were significantly reduced throughout the present study. Regarding nematodes, species of bacterivorous taxa (Daptonema, Eumonhystera) decreased, whereas species of predacious and omnivorous taxa (Mononcluts, Dorylaimus, and Ironus) increased in dominance in microcosms of the highest Cd concentration. Transient effects on microfauna were observed, especially in the first half of the present study, with a reduction in microbial activity and protozoan abundance. However, in microcosms receiving the highest Cd concentration, the abundance of the flagellate Euglena mutabilis increased significantly toward the end of the present study. The results of the present study support the use of small-scale microcosms with natural meiofauna communities as a suitable tool to assess the impact of pollutants in freshwater sediments. Environ. Toxicol. Chem. 2011;30:427-438. (C) 2010 SETA

Land use contribution to spatiotemporal stream water and ecological quality : Implications for water resources management in peri-urban catchments

Lemaire GG, Jessen Rasmussen J, Höss S, et al. Land use contribution to spatiotemporal stream water and ecological quality: Implications for water resources management in peri-urban catchments. Ecological Indicators. 2022;143: 109360.Climate change and intensifying agricultural production and urbanization are central factors driving the global freshwater biodiversity decline. To design sustainable green transition schemes and support urban planning, a deeper understanding of the numerous interacting physicochemical and biogeochemical processes and their relation to ecological quality becomes essential. This study thus aims to explore links between hydrological regimes and patterns evident for key water quality parameters and benthic invertebrate indicators in a peri-urban catchment that has undergone several stream restoration projects. Results indicate significant seasonal variability in discharge and physico-chemical parameters confounding the identification of sources behind detrimental impacts on ecological quality, which may lead to the implementation of inappropriate mitigation strategies. Notably, sampling at the sub-catchment level underlined the dynamic contributions of both agricultural and urban-like areas for nitrogen and phosphorus, while non-volatile carbon was mainly exported from agricultural lands. Multivariate statistical methods were used to classify benthic macro- and meioinvertebrate (specifically nematode) taxa showing poor-to-moderate and poor-to-good ecological quality, respectively. Poor ecological quality was mostly found in the upstream part of the catchment, driven by a combination of low habitat quality and periodically impaired physico-chemical conditions (e.g. dissolved oxygen, temperature, and suspended solids). In addition, the nematode-based stress index NemaSPEAR[%] (expressing the proportion of species-at-risk within a sample and specifically sensitive to the chemical contamination), indicated a TSS-related transport of contaminants to the sediment. It could also reveal both the negative impacts of different urban features (low ecological quality just downstream of combined sewer overflows), as well as the potential benefits of wastewater effluents (i.e. good ecological quality, via well-treated flow contributions and limited fine sediment accumulation especially in summer) on the stream ecosystem. Our results highlight that the use of this indicator, in combination with high frequency monitoring are promising techniques to better link the dynamic impacts of land use and spatiotemporal changes in ecological quality

Laudation to PD Dr. Wolfgang Ahlf : towards integrated approaches in sediment toxicology and its transfer to sediment quality guidelines

Thanking PD Dr. Wolfgang Ahlf on the occasion of his retirement for his outstanding experimental and conceptual merits in the field of sediment ecotoxicology and his personal 65th anniversary this article will present a laudation. This Editorial furthermore introduces a series of papers on ‘Progress in sediment research and decision making’ which is dedicated to Wolfgang Ahlf, one of the longstanding and leading experts in the field of sediment research. We cordially invite all colleagues who feel they can contribute to the topic to submit a manuscript to ESEU with reference to this series

Soil organisms as an essential element of a monitoring plan to identify the effects of GMO cultivation. Requirements – Methodology – Standardisation

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