UV-induced cis-trans isomerization of zearalenone in contaminated maize

In the literature, it has been shown that the naturally occurring trans-zearalenone (ZEN) is transformed by ultraviolet irradiation to cis-ZEN. However, the practical relevance of this transformation in animal feeding remains unclear. The aim of the present preliminary investigation was to examine the effect of UV-irradiation on the concentration of trans-ZEN in a natural feed matrix at different dry matter contents to simulate the dry and wet feeding techniques usually applied in pig feeding. Four variants, air dry or wet ZEN-contaminated ground maize either irradiated or not were tested and analysed with conventional HPLC-FLD for trans-ZEN changes, which were further examined for cis-ZEN formation by HPLC-MS/MS. In conclusion, it could be shown that, under the investigated wet feed conditions, naturally occurring trans-ZEN was partially converted by ultraviolet irradiation to its cis counterpart. In contrast, the cis/trans isomerization seemed not to be relevant in dry maize. The consequence of this finding for practical liquid feeding systems for pigs requires further investigation. Additionally, an improvement of the analytical method for cis-ZEN determination is needed.     

The Novel Antiobesic HMR1426 Reduces Food Intake without Affecting Energy Expenditure in Rats

Objective: To determine the effect of acute and chronic administration of a new food intake‐reducing compound (HMR1426) with novel mode of action (retardation of gastric emptying) on body weight development, food intake, and energy metabolism in rats. Research Methods and Procedures: Adult male Shoe‐Wistar rats were implanted with transponders allowing registration of body temperature (T_b) and locomotor activity. HMR1426 (10 or 50 mg/kg) was given orally, and acute (8 hours) and chronic (15 days) effects were measured on food intake, T_b, activity, total energy expenditure (indirect calorimetry), and epididymal adipose tissue mass. The effect of chronic treatment was compared with the effect of sibutramine (10 mg/kg). Results: HMR1426 (50 mg/kg) caused an acute and chronic decrease of food intake. There was no effect on the level and daily pattern of total energy expenditure, T_b, and locomotor activity. Respiratory quotient was acutely decreased by HMR1426 due to reduced food intake. Chronic treatment with HMR1426 decreased weight gain by 31% and epididymal white fat by 24%. Sibutramine caused a respective reduction of 48% and 35%. Energy efficiency was not affected by HMR1426 in contrast to sibutramine, which reduced energy efficiency and transiently increased activity. Discussion: HMR1426 showed an anorectic potential in rats and decreased body weight and fat mass. This was achieved solely by reducing food intake without influencing overall energy expenditure or behavior suggesting a peripheral mode of action. Thus, HMR1426 can be considered a potential new drug for obesity treatment.     

Ecosystem services provision today and in the past: a comparative study in two Baltic lagoons

The European Biodiversity Strategy asks EU Member States for an assessment, mapping and valuing of Ecosystem Services (ES). While terrestrial ES concept is advanced and different tools are available, they are largely lacking for coastal and marine systems. We develop a stepwise methodological process to assess ES in coastal and marine systems which we name Marine Ecosystem Services Assessment Tool. We applied it to two large Baltic lagoons, the Szczecin and the Curonian Lagoons demonstrating a quantitative and qualitative assessment approach. Firstly, an initial status is defined reflecting, according to the European Water Framework Directive, a past situation when the ecosystems where in a so called good ecological state. In both Baltic lagoons, this refers to a situation around 1960. Secondly, a present state is defined, assessed and compared to the initial status. Increasing anthropogenic impacts in Szczecin Lagoon caused an overall decrease ecological status which may influence the system’s ability to provide services. Assessing ES changes semi-quantitatively via 39 indicators and 22 services, we show a decrease in provisioning and regulating and maintenance and an increase of cultural services’ provision. According to 15 expert valuations, the Curonian Lagoon displays no changes in provisioning but an increase in regulating and maintenance and cultural service provision. We discuss how these results can serve different marine management approaches and support different polices. Through our application we show how the tool can be used to assess ES changes over time and thus provide key information on sustainable use and ES for future generations.     

Old friends,new story: The role of Slit2C signaling through PlexinA1

Growth cone guidance is driven by attractive and repulsive signaling cues. Until recently, repulsive signaling by semaphorins was thought to be mediated through Plexin receptors, whereas Slits-induced repulsion was solely mediated through Robo receptors. In a recent report published in Nature Neuroscience, Celine Delloye-Bourgeois and colleagues (2015) combined phenotypic analyses of transgenic mouse lines and in vitro biochemical experiments to identify PlexinA1 as a novel receptor for Slits. Strikingly, they uncovered for the very first time that the Slit2C-terminal fragment possesses some unique biological activity as binding partner for PlexinA1. Even more excitingly, the signaling cascade triggered by SlitC binding to PlexinA1 mediates growth cone collapse of commissural axons both in vivo and ex vivo and nicely complements Robo-Slit signaling in the developing spinal cord midline to prevent midline recrossing.     

Adaptive Evolution in Producing Microtiter Cultivations Generates Genetically Stable Escherichia coli Production Hosts for Continuous Bioprocessing

The production of recombinant proteins usually reduces cell fitness and the growth rate of producing cells. The growth disadvantage favors faster-growing non-producer mutants. Therefore, continuous bioprocessing is hardly feasible in Escherichia coli due to the high escape rate. The stability of E. coli expression systems under long-term production conditions and how metabolic load triggered by recombinant gene expression influences the characteristics of mutations are investigated. Iterated fed-batch-like microbioreactor cultivations are conducted under production conditions. The easy-to-produce green fluorescent protein (GFP) and a challenging antigen-binding fragment (Fab) are used as model proteins, and BL21(DE3) and BL21^Q strains as expression hosts. In comparative whole-genome sequencing analyses, mutations that allowed cells to grow unhindered despite recombinant protein production are identified. A T7 RNA polymerase expression system is only conditionally suitable for long-term cultivation under production conditions. Mutations leading to non-producers occur in either the T7 RNA polymerase gene or the T7 promoter. The host RNA polymerase-based BL21^Q expression system remains stable in the production of GFP in long-term cultivations. For the production of Fab, mutations in lacI of the BL21^Q derivatives have positive effects on long-term stability. The results indicate that adaptive evolution carried out with genome-integrated E. coli expression systems in microtiter cultivations under industrial-relevant production conditions is an efficient strain development tool for production hosts.     

Sporadic cardiac myxomas and tumors from patients with Carney complex are not associated with activating mutations of the Gsα gene

Cardiac myxomas are rare tumors that may be encountered sporadically or in the context of the Carney complex. The molecular basis for the development of cardiac myxomas and Carney complex tumors is unclear. Pathological myocardial function and myocardial hypertrophy have been associated with alterations in the heterotrimeric GTP-binding proteins. The postulated proto-oncogenic character of the gene encoding the alpha subunit of the stimulatory GTP-binding protein Gsα (gsp) in pituitary and thyroid tumors, the finding of identical somatic gsp mutations in the myocardium of patients with McCune-Albright syndrome, and the associated endocrine anomalies of the Carney complex prompted us to investigate the occurrence of activating missense mutations in the Gsα gene in 10 sporadically occurring atrial myxomas and in 8 tumors from 7 patients with Carney complex. No gsp mutations could be demonstrated by using the polymerase chain reaction and denaturing gradient gel electrophoresis complemented by direct DNA sequencing. Thus, activating Gsα mutations neither are associated with the development of atrial myxomas, nor can be demonstrated in other tumors from patients with Carney complex. The significance of these mutations in the myocardium of asymptomatic patients with McCune-Albright syndrome remains to be determined. Received: 7 March 1996 / Revised: 10 April 1996