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Rates of mineral reactions are controlled by two major factors: surface kinetics and element transport. Dissolution and precipitation of minerals in the presence of a hydrous fluid is assumed to occur predominantly by hydrolysis of the outermost charged monolayers of the reacting crystal and subsequent incorporation of atoms from ionic solutions into favorable sites at the product surface. Element transport during mineral reactions is commonly thought to occur via ionic solutions with the mineral solubility in the coexisting fluid being a rate limiting factor. Here we show in high-pressure/low temperature rocks that an alkali-Al-Si-rich amorphous material forms directly by depolymerization of the crystal lattice. Depolymerization starts along grain or phase boundaries, dislocation cores in the crystal lattice or lattice defects in general that serve as element exchange pathways and are also sites of porosity formation. High hydrogen concentrations in such dislocation cores within nominally anhydrous pyroxene has been confirmed by Nano-SIMS measurements and indicates hydrolysis and recrystallization within mineral grains. Element transfer in the alkali-Al-Si-rich amorphous material is thermodynamically decoupled from ionic solutions and therefore enables significantly higher element transport rates than previously thought. The resulting amorphous material occupies large volumes in an interconnected porosity network which has been documented in 3D imaging. Precipitation of product minerals occurs directly by repolymerization of the amorphous material at the product surface. This new dissolution-reprecipitation mechanism has major implications for the role of mineral reactions during geophysical and geochemical processes in the dynamic Earth.

The subduction of hydrated slab mantle is the most important and yet weakly constrained factor in the quantification of the Earth’s deep geologic water cycle. The most critical unknowns are the initial hydration state and the dehydration behavior of the subducted oceanic mantle. Here we present a combined thermomechanical, thermodynamic, and geochemical model of the Kamchatka subduction zone that indicates significant dehydration of subducted slab mantle beneath Kamchatka. Evidence for the subduction of hydrated oceanic mantle comes from across-arc trends of boron concentrations and isotopic compositions in arc volcanic rocks. Our thermodynamic-geochemical models successfully predict the complex geochemical patterns and the spatial distribution of arc volcanoes in Kamchatka assuming the subduction of hydrated oceanic mantle. Our results show that water content and dehydration behavior of the slab mantle beneath Kamchatka can be directly linked to compositional features in arc volcanic rocks. Depending on hydration depth of the slab mantle, our models yield water recycling rates between 1.1 3 103 and 7.4 3 103 Tg/Ma/km corresponding to values between 0.75 3 106 and 5.2 3 106 Tg/Ma for the entire Kamchatkan subduction zone. These values are up to one order of magnitude lower than previous estimates for Kamchatka, but clearly show that subducted hydrated slab mantle significantly contributes to the water budget in the Kamchatkan subduction zone.

Patients with systemic lupus erythematosus (SLE) often develop a wide variety of serological manifestations including the presence of antibodies to double-stranded DNA (anti-dsDNA). Positivity for anti-dsDNA constitutes one of the laboratory criteria for the diagnosis of SLE and is therefore clinically relevant. We analyzed the diagnostic accuracies of four commercial anti-dsDNA immunoassays and compared the results with a recently established surface plasmon resonance (SPR) biosensor chip with covalently chip-immobilized dsDNA. The anti-dsDNA measurements were performed retrospectively in 50 patients with clinically proven SLE, 39 patients with other autoimmunopathies and 20 healthy controls. Data were evaluated by Receiver-Operator Characteristic (ROC) analysis, with special regard to SLE patients suffering from lupus nephritis. The ROC analyses for the four immunoassays and the SPR biosensor resulted in the following area-under-the-curve (AUC) and diagnostic efficiency (DE) values in descending order: Bindazyme AUC, 0.89; DE, 0.88; ELiA AUC, 0.89; DE, 0.86; SPR biosensor AUC, 0.82; DE, 0.80; Farrzyme AUC, 0.77; DE, 0.77; Farr AUC, 0.77; DE, 0.70. When considering the 22 nephritis SLE patients the following AUC were observed: Bindazyme 0.98; EliA 0.95; SPR biosensor 0.93; Farr 0.89; Farrzyme 0.88. Although various methodologies for the determination of anti-dsDNA were compared, the overall diagnostic accuracy was found satisfactory in all immunoassays. Best data were found for the Bindazyme assay. We referenced the measurements to our in-house SPR biosensor device which showed good AUC and DE values. When optimized, this technique, allowing to monitor antigen/ antibody interactions in real-time, may add a new analytical quality to the existing methods, potentially beneficial in diagnosis and clinical monitoring of SLE.

Highly pathogenic avian influenza viruses (HPAIV) cause severe infections of humans, typically characterized by systemic spreading and cytokine burst. In our studies we were interested in the underlying mechanisms and set out to identify the cell types responsible for cytokine burst and failure of immune[for full text, please go to the a.m. URL], 21. Jahrestagung der Deutschen Gesellschaft für Pädiatrische Infektiologie (DGPI)

Genetic drift of influenza virus genomic sequences occurs through the combined effects of sequence alterations introduced by a low fidelity polymerase and the varying selective pressures experienced as the virus migrates through different host environments. While traditional phylogenetic analysis is useful in tracking the evolutionary heritage of these viruses, the specific genetic determinants that dictate important phenotypic characteristics are often difficult to discern within the complex genetic background arising through evolution. Here we describe a novel Influenza Sequence Feature Variant Type (Flu-SFVT) approach, made available through the public Influenza Research Database resource (www.fludb.org), in which variant types (VTs) identified in defined influenza protein sequence features (SFs) are used for genotype-phenotype association studies. Since SFs have been defined for all influenza proteins based on known structural, functional and immune epitope recognition properties, the Flu-SFVT approach allows for the rapid identification of the molecular genetic determinants of important influenza virus characteristics and their connection to underlying biological functions. We demonstrate the use of the SFVT approach to obtain statistical evidence for effects of NS1 protein sequence variations in dictating influenza virus host range restriction.

Glycerophosphorylcholine is one of the four major organic osmolytes in renal medullary cells, changing their intracellular osmolyte concentration in parallel with extracellular tonicity during cellular osmoadaptation. In this study, the tubular content of glycerophosphorylcholine was quantified in untreated and 48-h-dehydrated male rats. A chemiluminescence ultra-micromethod was developed to measure choline at the picomolar level in single tubules microdissected from collagenase-treated kidneys. The glycerophosphorylcholine level was calculated as the difference between total choline after acid hydrolysis and the free tubular choline content. In accordance with the glycerophosphorylcholine distribution pattern in different renal zones of untreated rats, low amounts of glycerophosphorylcholine were found in all cortical and outer medullary structures (