Application of an androgen receptor assay for the characterisation of the androgenic or antiandrogenic activity of various phenylurea herbicides and their derivatives.

The potency of different substances for [3H]dihydrotestosterone ([3H]DHT) displacement from the bovine androgen receptor was tested. The phenylurea herbicide linuron and its derivative 3,4-dichloroaniline (3,4-DCA), which are found in sediments and surface waters, are known to displace bound testosterone from the rat androgen receptor. Because 3,4-DCA is rapidly taken up by fish and metabolised into 3,4-dichloroacetanilide (3,4-DCAc), it was investigated whether the displacement effects are attributable to 3,4-DCA or to 3,4-DCAc. The potency of 3,4-DCAc androgen receptor binding was compared with that of several phenylurea compounds. In a radioreceptor assay with calf uterus cytosol as androgen receptor preparation, the specific binding of [3H]DHT, the endogenous ligand, was completely displaceable by increasing concentrations of 3,4-DCAc. The relative binding affinities (RBA) of the various compounds were about 1/10(4) to 1/10(5) of that of DHT. 3,4-DCAc had the relative highest affinity (1.31 x 10(-4)), followed by linuron, 3,4-dichlorophenylurea, flutamide, 3,4-DCA and diuron with the lowest RBA (2.4 x 10(-5)). Hence the metabolism of xenobiotic compounds has to be considered to estimate potential ecotoxiocological effects. This test not only can be used to screen for androgen- and antiandrogen-like substances in environmentally relevant samples such as surface waters, but might also be applied for drug testing and for residue monitoring.     

Continuum modeling of the swelling behavior of concrete when modified through superabsorbent polymers

The main purpose of our investigation is to model the physical solidification process of a concrete mixture, involving water absorbing constituents, i. e. Superabsorbent Polymers (SAP). In order to model the chemo-mechanical swelling process, the system is described within the framework of the Theory of Porous Media (TPM). The swelling process is accounted for by including mass exchange terms between free and absorbed water. The chemo-mechanical driving forces are deduced from non-equilibrium thermodynamics while constitutive relations are motivated by appropriate micro-models of the swelling process. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Structure-activity-based design of a synthetic malaria peptide eliciting sporozoite inhibitory antibodies in a virosomal formulation

The circumsporozoite protein (CSP) of Plasmodium falciparum is a leading candidate antigen for inclusion in a malaria subunit vaccine. We describe here the design of a conformationally constrained synthetic peptide, designated UK-39, which has structural and antigenic similarity to the NPNA-repeat region of native CSP. NMR studies on the antigen support the presence of helical turn-like structures within consecutive NPNA motifs in aqueous solution. Intramuscular delivery of UK-39 to mice and rabbits on the surface of reconstituted influenza virosomes elicited high titers of sporozoite crossreactive antibodies. Influenza virus proteins were crucially important for the immunostimulatory activity of the virosome-based antigen delivery system, as a liposomal formulation of UK-39 was not immunogenic. IgG antibodies elicited by UK-39 inhibited invasion of hepatocytes by P. falciparum sporozoites, but not by antigenically distinct P. yoelii sporozoites. Our approach to optimized virosome-formulated synthetic peptide vaccines should be generally applicable for other infectious and noninfectious diseases.     

Doppler picture velocimetry applied to hypersonics: automated DPV fringe pattern analysis using the FFT method

Doppler picture velocimetry (DPV) is a tool for visualizing and measuring the flow velocity distribution of tracer particles in a laser light sheet. A frequency sensitive Michelson interferometer, tuned for detecting the velocity distribution by the Doppler effect, visualizes the velocity information of tracer particles crossing an illuminating laser light sheet as interference fringe patterns. Many efforts have been done to evaluate best these DPV patterns, in order to obtain the frequency distribution and, by applying the Doppler formula, the velocity profile of the tracers. The first processing method, developed in 1982, relied on manual processing of the pictures by the user, due to the unavailability of suitable high performance picture processing algorithms. This drawback made DPV being considered as a rather time-consuming measurement technique with limited accuracy, compared to existing commercial velocity measurement systems (e.g. PIV). This is no more the state of the art: The new DPV analysis software, presented in this paper, allows automated processing of the interference fringe samples obtained by two images, a reference picture without frequency shift and a Doppler picture containing the frequency shift, using single beam velocimetry. Based on Fast Fourier transformation (FFT), the presented algorithm determines the corresponding velocity profile (in pseudo colours) within only a few seconds on a standard personal computer without user intervention.     

Elastic electron deuteron scattering on a tensor polarized solid ND3 target

Elastic electron deuteron scattering has been measured at the Bonn 2.5 GeV electron-synchrotron using a tensor polarized ND₃ target. The scattered electrons and deuterons were detected in coincidence by two magnetic spectrometers. Data were taken at an average value of four momentum transfer ofQ ²=0.495 (GeV/c)² in order to separate the electric monopole and quadrupole form factors of the deuteron. To have a sufficient control of systematic effects, both polarized and unpolarized cross sections were measured with an identical experimental set up. In the ratioR _EXP=dσ_pol/dσ_unp systematic effects are expected to cancel. This ratioR _EXP is related to the theoretical polarized cross section d dσ _T where the spin quantization axis for the deuterons is orientated in the ed-scattering plane, perpendicular to the virtual photon direction. Our final result for the corresponding recoil tensor polarization ist ₂₀=?2.01±1.13.     

Measurement of the magnetic formfactor of the deuteron forQ 2=0.5 to 1.3 (GeV/c)2 by a coincidence experiment

Elastic electron deuteron scattering was measured at the Bonn 2.5 GeV Electron-Synchrotron using a two spectrometer coincidence technique. Data were taken at values of the four momentum transfer squaredQ ²=0.50, 0.60, 0.78, 1.00, and 1.3 (GeV/c)² at electron scattering angles θ _e =77.5° to 139.0° in order to separate the magnetic dipole formfactorF _M (Q ²) from the electric formfactorF _E (Q ²). Experimental cross sections are compared to theoretical predictions and to measurements of other laboratories. The results indicate that contributions from meson exchange currents are not negligible in thisQ ² region.     

Increased milk levels of insulin-like growth factor 1 (IGF-1) for the identification of bovine somatotropin (bST) treated cows.

The present EU moratorium banning the use of bST to increase milk yield implies the need for official controls. Our study aimed to identify milk from bST treated cows via the induced increase of insulin-like growth factor 1 (IGF-1) concentrations. A non-extraction radioimmunoassay for IGF-1 was improved and thoroughly validated for milk. Accuracy was 99% recovery in a fortified sample material, the precision was 5.1% intra-assay variation and 13.4% inter-assay variation. Parallelism was proved by a dilution experiment which yielded a regression line with a slope (-0.7%) not significantly different from zero (P = 0.534). Naturally occurring milk IGF-1 levels were recorded in 5777 random milk samples from the Bavarian dairy cow population. In samples from lactation week 7 to 33, the effect of somatic cell count (SCC), protein content and parity could be quantified and corrected; thus a normal distribution (-0.068 mean +/- 0.440 s) of the corrected logarithmic IGF-1 levels (corr ln IGF-1) was obtained. IGF-1 concentrations occurring in milk from bST treated cows were recorded in 33 Brown Swiss cows treated once with rbST (POSILAC). Mean corr in IGF-1 levels increased by 0.828 and 0.477 in first parity and older cows, respectively. Thus 60% and 29%, respectively, of the positives could be detected at a 95% probability. If our results are confirmed in experiments with more bST treated cows and with prolonged treatment intervals. IGF-1 measurements might be useful to monitor for bST application in milk samples.