Blocking GPR15 Counteracts Integrin-dependent T Cell Gut Homing in Vivo.

Background And Aims: The G protein coupled receptor GPR15 is expressed on and functionally important for T cells homing to the large intestine. However, the precise mechanisms by which GPR15 controls gut homing have been unclear. Thus, we aimed to elucidate these mechanisms as well as to explore the potential of targeting GPR15 for interfering with T cell recruitment to the colon in inflammatory bowel disease [IBD].

Low energy electron microscopy at cryogenic temperatures.

We describe a cryogenic sample chamber for low energy electron microscopy (LEEM), and present first experimental results. Modifications to our IBM/SPECS aberration-corrected LEEM instrument are presented first. These include incorporation of mechanisms for cooling the sample and its surroundings, and reduction of various sources of heat load.

Species-Specific Variation in Abscisic Acid Homeostasis and Responses Impacts Important Traits in Orphan Crops.

and are plant species native to Africa, but grow in most tropical and subtropical regions of the world. They are rich in vitamins, minerals, and essential oils and are traditional leafy vegetables and medicinal plants in Sub-Saharan Africa. The plants are still mainly collected from the wild but shall be taken into cultivation and an important aim in the domestication of these species is to improve traits that are relevant for crop production.

The Orphan Crop Accumulates the Pyrrolizidine Alkaloid Jacobine in Response to Nitrogen Starvation.

is an African orphan crop that is used as a leafy vegetable and medicinal plant. Although it is of high regional importance in Sub-Saharan Africa, the plant is still mainly collected from the wild and therefore efforts are made to promote its domestication. However, in addition to beneficial properties, there was first evidence that can accumulate the highly toxic pyrrolizidine alkaloid (PA) jacobine and here it was investigated, how jacobine production is controlled.

Determination of the [N]-Nitrate/[N]-Nitrate Ratio in Plant Feeding Studies by GC⁻MS.

Feeding experiments with stable isotopes are helpful tools for investigation of metabolic fluxes and biochemical pathways. For assessing nitrogen metabolism, the heavier nitrogen isotope, [N], has been frequently used. In plants, it is usually applied in form of [N]-nitrate, which is assimilated mainly in leaves.

Pyrrolizidine Alkaloids: Biosynthesis, Biological Activities and Occurrence in Crop Plants.

Pyrrolizidine alkaloids (PAs) are heterocyclic secondary metabolites with a typical pyrrolizidine motif predominantly produced by plants as defense chemicals against herbivores. They display a wide structural diversity and occur in a vast number of species with novel structures and occurrences continuously being discovered. These alkaloids exhibit strong hepatotoxic, genotoxic, cytotoxic, tumorigenic, and neurotoxic activities, and thereby pose a serious threat to the health of humans since they are known contaminants of foods including grain, milk, honey, and eggs, as well as plant derived pharmaceuticals and food supplements.

Dynamic Adhesion Assay for the Functional Analysis of Anti-adhesion Therapies in Inflammatory Bowel Disease.

Gut homing of immune cells is important for the pathogenesis of inflammatory bowel diseases (IBD). Integrin-dependent cell adhesion to addressins is a crucial step in this process and therapeutic strategies interfering with adhesion have been successfully established. The anti-α4β7 integrin antibody, vedolizumab, is used for the clinical treatment of Crohn's disease (CD) and ulcerative colitis (UC) and further compounds are likely to follow.

Quantification of the Pyrrolizidine Alkaloid Jacobine in Crassocephalum crepidioides by Cation Exchange High-Performance Liquid Chromatography.

Introduction: Pyrrolizidine alkaloids (PAs) are secondary plant metabolites with considerable hepatoxic, tumorigenic and genotoxic potential. For separation, reversed phase chromatography is commonly used because of its excellent compatibility with detection by mass spectrometry. However, reversed phase chromatography has a low selectivity for PAs.

Density and confinement effects of glass forming m-toluidine in nanoporous Vycor investigated by depolarized dynamic light scattering.

We investigate the reorientational dynamics of supercooled m-toluidine contained in a matrix of nanoporous Vycor with depolarized dynamic light scattering. Under equilibrium conditions a clear sample is obtained and the dynamics of m-toluidine molecules from inside the nanopores can be accessed via light scattering. However, when supercooling the imbibed liquid at conventional cooling rates, strong non-equilibrium effects occur due to the mismatch of expansion coefficients and the sample gets turbid several tens of Kelvin above the bulk glass transition.

Signature of a type-A glass transition and intrinsic confinement effects in a binary glass-forming system.

We study dynamically highly asymmetric binary mixtures comprised of small methyl tetrahydrofuran (MTHF) molecules and polystyrene. Combined use of dielectric spectroscopy, 2H nuclear magnetic resonance, incoherent quasielastic neutron scattering, and depolarized dynamic light scattering allows us to selectively probe the dynamics of the components in a broad dynamic range. It turns out that the mixtures exhibit two glass transitions in a wide concentration range although being fully miscible on a macroscopic scale.

Mismatch of arterial and central venous blood gas analysis during haemorrhage.

Background And Objective: Arterial base excess and lactate levels are key parameters in the assessment of critically ill patients. The use of venous blood gas analysis may be of clinical interest when no arterial blood is available initially.

Methods: Twenty-four pigs underwent progressive normovolaemic haemodilution and subsequent progressive haemorrhage until the death of the animal.

Concentration fluctuations in a binary glass former investigated by x-ray photon correlation spectroscopy.

We investigate structure and dynamics of concentration fluctuations in the binary glass former methyl-tetrahydrofuran and oligomeric methyl metacrylate by photon correlation spectroscopy with partially coherent x-rays from a synchrotron source. Although the system is macroscopically well miscible and optically clear in the full temperature range, calorimetric and dielectric measurements reveal two distinct glass transition temperatures. The relaxation of long range concentration fluctuations turns out to be diffusive and exponential only well above the upper glass transition temperature.

Layering of [BMIM]+-based ionic liquids at a charged sapphire interface.

The structure of two model room temperature ionic liquids, [BMIM](+)[PF(6)](-) and [BMIM](+)[BF(4)](-), near the solid/liquid interface with charged Al(2)O(3)(0001) (sapphire) was determined with subnanometer resolution by high energy (72.5 keV) x-ray reflectivity. [BMIM](+)[PF(6)](-) exhibits alternately charged, exponentially decaying, near-surface layering.

Validity of an arterial pressure waveform analysis device: does the puncture site play a role in the agreement with intermittent pulmonary artery catheter thermodilution measurements?

Objective: The measurement of cardiac output is a key element in the assessment of cardiac function. Recently, a pulse contour analysis-based device without need for calibration became available (FloTrac/Vigileo, Edwards Lifescience, Irvine, CA). This study was conducted to determine if there is an impact of the arterial catheter site and to investigate the accuracy of this system when compared with the pulmonary artery catheter using the bolus thermodilution technique (PAC).

Molecular layering of fluorinated ionic liquids at a charged sapphire (0001) surface.

Room-temperature ionic liquids (RTILs) are promising candidates for a broad range of "green" applications, for which their interaction with solid surfaces plays a crucial role. In this high-energy x-ray reflectivity study, the temperature-dependent structures of three ionic liquids with the tris(pentafluoroethyl)trifluorophosphate anion in contact with a charged sapphire substrate were investigated with submolecular resolution. All three RTILs show strong interfacial layering, starting with a cation layer at the substrate and decaying exponentially into the bulk liquid.

Impact of the C2/C6 ratio of high-molecular-weight hydroxyethyl starch on pharmacokinetics and blood coagulation in pigs.

Background: High-molecular-weight, low-substituted hydroxyethyl starch (HES) may not affect blood coagulation more than low-molecular-weight, low-substituted HES. The authors assessed in vivo the effect of a lowered C2/C6 ratio on pharmacokinetic characteristics and the impact on blood coagulation of high-molecular-weight, low-substituted HES.

Methods: A prospective, randomized, parallel study in 30 pigs compared HES 650/0.