Synthesis and investigations on the oxidative degradation of C3/C5-alkyl-1,2,4-triarylpyrroles as ligands for the estrogen receptor

In this study, we synthesized 1,2,4‐triarylpyrroles as ligands for the estrogen receptor (ER). Two pyrrole series were prepared with either C3‐alkyl or C3/C5‐dialkyl residues. Compounds from both series were susceptible to oxidative degradation—dialkylated compounds (t_1/2=33–66 h) to a higher extent than their monoalkylated congeners (t_1/2=140–211 h). Nevertheless, stability was sufficient for determination of in vitro ER binding affinity. The most active agonist in hormone‐dependent, ERα‐positive MCF‐7/2a and U2‐OS/α cells was 1,2,4‐tris(4‐hydroxyphenyl)‐3‐propyl‐1H‐pyrrole ( 6 d ) (MCF‐7/2a: EC₅₀=70 nM ; U2‐OS/α: EC₅₀=1.6 nM ). A corresponding inactivity in U2‐OS/β cells demonstrated the high ERα selectivity. This trend was confirmed in a competition experiment using estradiol (E2) and purified hERα and hERβ proteins (relative binding affinity (RBA) calculated for 6 d : RBA(ERα)=1.85 %; RBA(ERβ) <0.01 %). Generally, C3/C5‐dialkyl substitution led to reduction of activity, possibly due to lower stability.     

Oxide nanocrystal based nanocomposites for fabricating photoplastic AFM probes

We report on the synthesis, characterization and application of a novel nanocomposite made of a negative tone epoxy based photoresist modified with organic-capped Fe(2)O(3) nanocrystals (NCs). The mechanical properties of the nanocomposite drastically improve upon incorporation of a suitable concentration of NCs in the polymer, without deteriorating its photolithography performance. High aspect ratio 3D microstructures made of the nanocomposite have been fabricated with a uniform surface morphology and with a resolution down to few micrometres. The embedded organic-capped Fe(2)O(3) NCs drastically increase the stiffness and hardness of the epoxy based photoresist matrix, making the final material extremely interesting for manufacturing miniaturized polymer based mechanical devices and systems. In particular, the nanocomposite has been used as structural material for fabricating photoplastic Atomic Force Microscopy (AFM) probes with integrated tips showing outstanding mechanical response and high resolution imaging performance. The fabricated probes consist of straight cantilevers with low stress-gradient and high quality factors, incorporating sharp polymeric tips. They present considerably improved performance compared to pure epoxy based photoresist AFM probes, and to commercial silicon AFM probes.     

Oral Treatment with RD2RD2 Impedes Development of Motoric Phenotype and Delays Symptom Onset in SOD1G93A Transgenic Mice

Neuroinflammation is a pathological hallmark of several neurodegenerative disorders and plays a key role in the pathogenesis of amyotrophic lateral sclerosis (ALS). It has been implicated as driver of disease progression and is observed in ALS patients, as well as in the transgenic SOD1^G93A mouse model. Here, we explore and validate the therapeutic potential of the d-enantiomeric peptide RD2RD2 upon oral administration in SOD1^G93A mice. Transgenic mice were treated daily with RD2RD2 or placebo for 10 weeks and phenotype progression was followed with several behavioural tests. At the end of the study, plasma cytokine levels and glia cell markers in brain and spinal cord were analysed. Treatment resulted in a significantly increased performance in behavioural and motor coordination tests and a decelerated neurodegenerative phenotype in RD2RD2-treated SOD1^G93A mice. Additionally, we observed retardation of the average disease onset. Treatment of SOD1^G93A mice led to significant reduction in glial cell activation and a rescue of neurons. Analysis of plasma revealed normalisation of several cytokines in samples of RD2RD2-treated SOD1^G93A mice towards the levels of non-transgenic mice. In conclusion, these findings qualify RD2RD2 to be considered for further development and testing towards a disease modifying ALS treatment.     

Simultaneous detection of allergenic fish,cephalopods and shellfish in food by multiplex ligation-dependent probe amplification

People suffering from food allergy rely on correct food labelling as the ingestion of minimal amounts of the respective allergen can trigger severe allergenic reactions. Probes for the detection of DNA from allergenic fish, shellfish and cephalopod species in food using multiplex ligation-dependent probe amplification were developed. The specificity and the sensitivity of the detection system were investigated. The limit of detection was 20 mg kg^?1 for scallop, fish and bivalve species and 100 mg kg^?1 for cephalopod, gastropod and crustacean species using self-prepared sushi spiked with the analytes in different concentration levels. The analysis of 10 commercial food samples demonstrates the applicability of the developed method and its suitability for food quality control. Therefore, the method can be used to monitor the compliance with labelling rules regarding food allergens.     

Labeling of Anti-MUC-1 Binding Single Chain Fv Fragments to Surface Modified Upconversion Nanoparticles for an Initial in Vivo Molecular Imaging Proof of Principle Approach

In vivo optical Imaging is an inexpensive and highly sensitive modality to investigate and follow up diseases like breast cancer. However, fluorescence labels and specific tracers are still works in progress to bring this promising modality into the clinical day-to-day use. In this study an anti-MUC-1 binding single-chain antibody fragment was screened, produced and afterwards labeled with newly designed and surface modified NaYF(4):Yb,Er upconversion nanoparticles as fluorescence reporter constructs. The MUC-1 binding of the conjugate was examined in vitro and in vivo using modified state-of-the-art small animal Imaging equipment. Binding of the newly generated upconversion nanoparticle based probe to MUC-1 positive cells was clearly shown via laser scanning microscopy and in an initial proof of principal small animal optical imaging approach.     

Bewertung von Altlasten im Grundwasser anhand der Meiofaunagemeinschaften—erste Ergebnisse.

Kurzfassung Im Rahmen eines Pilotprogramms wurden in Rheinland-Pfalz fünf Standorte mit Altlasten unterschiedlicher Herkunft auf das Auftreten und die Verteilung von Grundwassermeiofauna untersucht. Ziel dieser Vorstudie war es, erste Daten zur Verteilung der Grundwassermeiofauna in Altlaststandorten zu sammeln. Die Ergebnisse eines Standortes, hier bezeichnet als militärische Altlastfläche C, werden im Detail vorgestellt. Trotz des vorläufigen Charakters der Ergebnisse konnten für einzelne Organismengruppen deutliche Verteilungsmuster gefunden werden. Während die Crustacea (Krebstiere) mit LCKW (leichtflüchtige chlorierte Kohlenwasserstoffe) belastete Bereiche mieden, traten v. a. Nematoda und Oligochaeta flächendeckend und teilweise in hohen Abundanzen in allen untersuchten Bereichen auf. Diese beobachteten Verteilungen scheinen nicht nur arten- oder taxaabhängig zu sein, sondern möglicherweise auch abhängig von der Art des Schadstoffs. Langfristig ist anzustreben, die Grundwassermeiofauna auf ihre Eignung als Bioindikator zu testen. Bisher praktizierten physikochemischen Analysemethoden soll damit ein kostengünstiges, faunistisch begründetes Monitoringsystem beigestellt werden, wie es sich in Oberflächengewässern seit Jahrzehnten bewährt hat.

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Assessment of contaminated groundwater sites using meiofaunal assemblage patterns—first results.

Abstract In Rhineland-Palatinate, Germany, a pilot program has been carried out to investigate the groundwater meiofauna at five contaminated sites. Aim of the study was to obtain first field data on the distribution of meiofauna at sites with varying contamination. Site C, a former militarily area, is introduced in more detail. In spite of the preliminary character of our data set, the fauna exhibited clear distribution patterns in relation to contamination. Crustaceans were found to colonize areas with low or non-existent concentrations of volatile halogenated hydrocarbons (VOC), whereas nematodes and oligochaetes occurred on site scale in more or less high abundances. The sensitivity to pollution observed seems not only to depend on species or taxa, but probably also on the type of contamination. For the future it is planned to test the suitability of groundwater meiofauna to serve as bioindicators as routinely practised for surface water systems for many decades. Complementary to hydrochemical methods, a faunistical biomonitoring on groundwater fauna can be an economical and effictive tool.

     

Assessing the impact of changes in landuse and management practices on the diffuse pollution and retention of nitrate in a riparian floodplain

In many European lowland rivers and riparian floodplains diffuse nutrient pollution is causing a major risk for the surface waters and groundwater to not achieve a good status as demanded by the European Water Framework Directive. In order to delimit the impact of diffuse nutrient pollution substantial and often controversial changes in landuse and management are under discussion. In this study we investigate the impact of two complex scenarios considering changes in landuse and land management practices on the nitrate loads of a typical lowland stream and the riparian groundwater in the North German Plains. Therefore the impacts of both scenarios on the nitrate dynamics, the attenuation efficiency and the nitrate exchange between groundwater and surface water were investigated for a 998.1 km(2) riparian floodplain of the Lower and Central Havel River and compared with the current conditions. Both scenarios target a substantial improvement of the ecological conditions and the water quality in the research area but promote different typical riparian landscape functions and consider a different grade of economical and legal feasibility of the proposed measures. Scenario 1 focuses on the optimisation of conservation measures for all natural resources of the riparian floodplain, scenario 2 considers measures in order to restore a good status of the water bodies mainly. The IWAN model was setup for the simulation of water balance and nitrate dynamics of the floodplain for a perennial simulation period of the current landuse and management conditions and of the scenario assumptions. The proposed landuse and management changes result in reduced rates of nitrate leaching from the root zone into the riparian groundwater (85% for scenario 1, 43% for scenario 2). The net contributions of nitrate from the floodplain can be reduced substantially for both scenarios. In case of scenario 2 a decrease by 70% can be obtained. For scenario 1 the nitrate exfiltration rates to the river drop even below the infiltration rates from the river, the riparian floodplain in that scenario represents a net sink for river derived nitrate. As the nitrate contributions from the investigated riparian floodplain represent only a small proportion of the total nitrate loads within the river (1% p.a.) the overall impact of the scenario measures on the nitrate loads at the river outlet remains small. However, during the ecologically most sensitive summer periods under current conditions nitrate contributions from the riparian groundwater of the Lower and Central Havel River (which covers only 5% of the area of the Havel catchment) represent more than 20% of the river loads. By the implementation of the investigated landuse changes within the research area the groundwater derived nitrate contributions could be halved to only 10% during summer baseflow conditions.     

Mineralised collagen—an artificial,extracellular bone matrix—improves osteogenic differentiation of bone marrow stromal cells

In the field of bone tissue engineering there is a high demand on bone graft materials which promote bone formation. By combination of collagen type I with nanocrystalline hydroxyapatite (HA) we generated a resorbable material which structure and composition is close to those of the extracellular bone matrix. This nanocomposit material was produced in a biomimetic process in which collagen fibril assembly and mineralisation with hydroxyapatite occur simultaneously. In this study the proliferation and osteogenic differentiation of human bone marrow-derived stromal cells (hBMSC) on membranes of biomimetically mineralised collagen type I was investigated. To this end, we optimised biochemical assays for determination of cell number and alkaline phosphatase activity corresponding to the special properties of this biomaterial. For cell experiments hBMSC were seeded on the mineralised collagen membranes and cultivated over 35 days, both in static and perfusion culture, in the presence and absence of dexamethasone, β-glycerophosphate and ascorbate. Compared to cells grown on tissue culture polystyrene we found attenuated proliferation rates, but markedly increased activity of alkaline phosphatase on the mineralised collagen indicating its promoting effect on the osteogenic differentiation of hBMSC. Therefore this bone-like material may act as a suitable artificial extracellular matrix for bone tissue engineering. Perfusion of the 2D cell matrix constructs with cell culture medium did not improve proliferation and osteogenic differentiation of the hBMSC. Anne Bernhardt and Anja Lode contributed equally to this paper     

Development and critical evaluation of fluorescent chloride nanosensors

In this study, we describe the preparation and evaluation of new fluorescent sensor nanoparticles for the ratiometric measurement of chloride concentrations. Both a chloride-sensitive dye (lucigenin) and a reference dye (sulforhodamine derivative) were incorporated into polyacrylamide nanoparticles via inverse microemulsion polymerization and investigated for their response to chloride ions in buffered suspension as well as in living cells. The fluorescence intensity of lucigenin reversibly decreased in the presence of chloride ions due to a collisional quenching process, which can be described with the Stern-Volmer equation. The determined Stern-Volmer constant K SV for the quenching of lucigenin incorporated into particles was found to be 53 M (-1) and is considerably smaller than the Stern-Volmer constant for quenching of free lucigenin ( K SV = 250 M (-1)) under the same conditions. To test the nanosensors in living cells, we incorporated them into Chinese hamster ovary cells and mouse fibroblasts by using the conventional lipofectamin technique and monitored the response to changing chloride concentrations in the cell.