Das Hepatitis-E-Virus – ein zoonotisches Virus: Verbreitung, Übertragungswege und Bedeutung für die Lebensmittelsicherheit

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Das Hepatitis-E-Virus (HEV) ist ein Erreger einer akuten Hepatitis beim Menschen. Darüber hinaus treten zunehmend auch...     

Uptake and toxicity of copper oxide nanoparticles in cultured primary brain astrocytes

To test for consequences of an exposure of brain cells to copper oxide nanoparticles (CuO-NPs), we synthesised and characterised dimercaptosuccinate-coated CuO-NPs. These particles had a diameter of around 5 nm as determined by transmission electron microscopy, while their average hydrodynamic diameter in aqueous dispersion was 136 ± 4 nm. Dispersion in cell-culture medium containing 10% fetal calf serum increased the hydrodynamic diameter to 178 ± 12 nm and shifted the zeta potential of the particles from –49 ± 7 mV (in water) to –10 ± 3 mV. Exposure of cultured primary brain astrocytes to CuO-NPs increased the cellular copper levels and compromised the cell viability in a time-, concentration- and temperature-dependent manner. Application of CuO-NPs in concentrations above 100 µM copper (6.4 µg/ml) severely compromised the viability of the cells, as demonstrated by a lowered 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction capacity, a lowered cellular lactate dehydrogenase activity and an increased membrane permeability for the fluorescent dye propidium iodide. Copper internalisation as well as cell toxicity of astrocytes exposed to CuO-NPs were similar to that observed for cells that had been incubated with copper salts. The CuO-NP-induced toxicity was accompanied by an increase in the generation of reactive oxygen species (ROS) in the cells. Both, ROS formation and cell toxicity in CuO-NP-treated astrocytes, were lowered in the presence of the cell-permeable copper chelator tetrathiomolybdate. These data demonstrate that CuO-NPs are taken up by cultured astrocytes and suggest that excess of internalised CuO-NPs cause cell toxicity by accelerating the formation of ROS.     

Gitelman syndrome DD thiazide diuretics abuse

Introduction. Gitelman syndrome (GS) is a rare inherited disorder. Mutations in SLC12A3 gene that encode tubular Na+Cl-cotransporter (NCCT) cause hypokalemic metabolic alkalosis, salt loss, hypomagnesaemia and hypocalciuria. The symptoms include weakness, vertigo, hypotension, tetany, paresthesia and nausea. Diagnostic criteria are a normal urine concentrating ability, normal glomerular filtration rate (GFR), hypomagnesaemia (<0,65mmol/l), hypokalemia (<3,6mmol/l) and hypocalciuria (<0,1mmol/mmol creatinine). Previously, the diagnosis was made by exclusion. Today, genetic analysis can ensure diagnosis. Thiazide diuretics (TD) abuse with similar abnormalities can make the differential diagnosis difficult. Causal therapy of GS does not exist. The substitution of potassium and magnesium are therapeutic strategies. Case presentation. A 41-year-old obese woman presented at the emergency department with recurrent episodes of hypokalemia with concomitant weakness, muscle cramps, polyuria and collapse. The results of laboratory testing of blood and urine led to the suspected diagnosis of GS. In the follow-up examinations, the results were inconsistent. Therefore, a transient thiazide diuretics abuse was assumed. Discussion. This case demonstrates the difficulties in making the diagnosis of GS on the basis of only clinical and laboratory tests, without the use of genetic analysis. The differentiation between GS and thiazide diuretic abuse is especially difficult.     

The temporal dynamics of inflected word recognition: A masked ERP priming study of French verbs

Morphological aspects of human language processing have been suggested by some to be reducible to the combination of orthographic and semantic effects, while others propose that morphological structure is represented separately from semantics and orthography and involves distinct neuro-cognitive processing mechanisms. Here we used event-related brain potentials (ERPs) to investigate semantic, morphological and formal (orthographic) processing conjointly in a masked priming paradigm. We directly compared morphological to both semantic and formal/orthographic priming (shared letters) on verbs. Masked priming was used to reduce strategic effects related to prime perception and to suppress semantic priming effects. The three types of priming led to distinct ERP and behavioral patterns: semantic priming was not found, while formal and morphological priming resulted in diverging ERP patterns. These results are consistent with models of lexical processing that make reference to morphological structure. We discuss how they fit in with the existing literature and how unresolved issues could be addressed in further studies.