Canine brucellosis--a case report

Brucella (B.) canis was isolated from ejaculate of a 4-year old Korthals-Griffon male dog after occurrence of epididymitis and orchitis. Despite several trials of therapy with different antibiotics relapes occurred, with B. canis being isolated from ejaculate, blood and urine samples, respectively. Bacteriological examinations were added by serological testing over a period of about 1.5 years. During the study SAT serum titre steadily dropped from 1:200 to 1:50. By CFT, B. canis antibodies were detectable at the beginning with a titre of 1:320 and to the end of the study with titres between 1:80 and 1:160.     

Combining agent-based and stock-flow modelling approaches in a participative analysis of the integrated land system in Reichraming, Austria

The integrated modelling of coupled socio-ecological systems in land-change science requires innovative model concepts capable of grasping the interrelations between socioeconomic and natural components. Here, we discuss the integrated socio-ecological model SERD (Simulation of Ecological Compatibility of Regional Development) that was developed for the municipality of Reichraming in Upper Austria in a participative 2-year process involving local stakeholders. SERD includes three main components: (1) an agent-based actors module that simulates decisions of farmsteads, the municipal administration and other important actors; (2) a spatially explicit (GIS based) land-use module that simulates land-use change at the level of individual parcels of land and (3) an integrated socio-ecological stock-flow module that simulates carbon and nitrogen flows through both socioeconomic and ecological system compartments. We report on outcomes of a scenario analysis that outlines possible future trajectories depending on both external (e.g. agricultural subsidies and prices) and internal (e.g. innovation, willingness to co-operate) factors. We find that both external and internal factors can affect the behaviour of the integrated system considerably. Local and regional policies are found to be able to counteract adverse global socioeconomic conditions to some extent, but not to reverse the trend altogether. We also find strong interdependencies between socioeconomic and ecological components of the system. Fully evaluating these interdependencies is, however, not possible at the local scale alone and will require explicit consideration of higher-level effects in future research.     

Investigation of the allergenic potential of wines fined with various proteinogenic fining agents by ELISA

Hidden allergens are a common problem in food safety that has been known for many years. This is why the European Parliament adopted Directive 2003/89/EC amending 2000/13/EC. In addition to specific ingredients, Directive 2003/89/EC also requests the declaration of specific products that were used in the production and could be a risk for allergic individuals. This also includes the declaration of fining agents and lysozyme used in wines. In fact, it could be assumed that fining agents would be almost completely removed during the manufacturing process; however, until now there has been no necessity to analyze wine for these fining agents. By applying enzyme-linked immunosorbent assay (ELISA), residuals of fining agent proteins and the stabilizer lysozyme were investigated in various German wines. The results showed no detectable amounts of fining agents in wines, except for dried egg white and lysozyme, both derived from hen's egg white. For those products, adverse reactions against treated wines could not be excluded.     

Abscisic acid, gibberellin and cell viability in cereal aleurone

The aleurone layer of cereals is a secretory tissue whose activity is regulated by abscisic acid (ABA) and gibberellins (GAs). Whereas GA triggers enzyme synthesis and secretion and initiates a program that culminates in cell death, ABA prevents enzyme production and cell death. Reactive oxygen species (ROS) are key players in regulating cell viability and GA sensitizes the aleurone cell to ROS. Sensitivity of GA-treated cells results in part from a reduction in steady-state amounts of mRNAs encoding enzymes that scavenge ROS. mRNAs encoding catalase, superoxide dismutase and ascorbate peroxidase are almost undetectable in aleurone layers 24 h after incubation in GA. For layers incubated in ABA, however, the amounts of these mRNAs increase. Western blotting and enzyme activity assays confirm that GA but not ABA reduced the amount and activity of ROS scavenging enzymes (Fath et al., 2001b). Substantial amounts of ROS are produced by enzymes engaged in lipid metabolism, and by the electron transport chain in the mitochondria. Aleurone layers contain abundant stores of triglycerides and ROS are produced as these lipids are rapidly converted to sugars. We hypothesize that the ROS produced in GA-treated aleurone cells bring about cell death by disrupting the plasma membrane. Aleurone cells incubated in ABA, on the other hand, are better able to maintain redox balance. ABA does not initiate rapid triglyceride metabolism, and the activities of ROS-scavenging enzymes remain high in ABA-treated cells. We conclude that GA initiates a metabolic cascade in aleurone cells that results in death from ROS. ABA maintains viability by keeping ROS under control. This revised version was published online in August 2006 with corrections to the Cover Date.     

Bioassay-directed Fractionation of Organic Extracts of Marine Surface Sediments from the North and Baltic Sea - Part II: Results of the biotest battery and development of a biotest index (8 pp)

-

Part I: Determination and identification of organic pollutants Part II: Results of the biotest battery and development of a biotest index

-

Preamble. This series of two papers presents the results of an interdisciplinary research project (ISIS) dealing with bioassay-directed fractionation of marine sediment extracts. Part I presents the extraction and fractionation procedure as well as the results of chemical analysis, including non-target analysis of sediments. Part II describes the results of the biotest battery in relation to chemicals possibly causing parts of the observed effects. A biotest index is used to compare the toxicities of the samples.

-

AUTHORS / AFFILIATIONS Ninja Reineke (3), Werner Wosniok (4), Dirk Danischewski (1), Heinrich Hühnerfuss (3), Angelika Kinder (5), Arne Sierts-Herrmann (5), Norbert Theobald (2), Hans-Heinrich Vahl (6), Michael Vobach (1), Johannes Westendorf (6) and Hans Steinhart (5).

-

(1) Federal Research Centre for Fisheries, Institute for Fishery Ecology, Palmaille 9, 22767 Hamburg, Germany (2) Federal Maritime and Hydrographic Agency, Bernhard-Nochtstr. 78, 20359 Hamburg, Germany (3) University of Hamburg, Institute for Organic Chemistry, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany (4) University of Bremen, Institute of Statistics, Bibliothekstr. 1, 28334 Bremen, Germany (5) University of Hamburg, Institute for Food Chemistry, Grindelallee 117, 20146 Hamburg, Germany (6) University of Hamburg, University Hospital Hamburg-Eppendorf, Department for Toxicology, Vogt-Kölln-Str. 30, 22527 Hamburg, Germany (7) Eurofins Wiertz-Eggert-Jörissen, Stenzelring 14b, 21107 Hamburg, Germany

Goal, Scope and Background

The ecological relevance of contaminants in mixtures is difficult to assess, because of possible interactions and due to lacking toxicity data for many substances present in environmental samples. Marine sediment extracts, which contain a mixture of environmental contaminants in low concentrations, were the object of this study. The extracts were investigated with a set of different biotests in order to identify the compound or the substance class responsible for the toxicity. For this goal, a combination of biotests, biotest-directed fractionation and chemical analysis has been applied. Further on, a strategy for the development of a biotest index to describe the toxicity of the fractions without a prior ranking of the test results is proposed. This article (Part II) focuses on the biological results of the approach.

Methods

The toxicological potential of organic extracts of sediments from the North Sea and the Baltic Sea was analyzed in a bioassay-directed fractionation procedure with a set of biotests: luciferase reporter gene assays on hormone receptor and Ah receptor, arabinose resistance test, fish embryo test (Danio rerio), comet assay, acetylcholinesterase inhibition test, heat-shock protein 70 induction, oxidative stress and luminescence inhibition test (Vibrio fischeri). The test results provided the basis for the calculation of a biotest index by factor analysis to compare the toxicity of the samples and fractions.

Results and Discussion

Results of 11 biotests on different fractionation levels of the samples were described and discussed with regard to the occurrence of contaminants and their toxic potentials. Polychlorinated biphenyls, polycyclic aromatic hydrocarbons, quinones, brominated indoles and brominated phenols were in the focus of interest. A biotest index was constructed to compare the toxic responses in the samples and to group the biotest results.

Conclusion

The procedure presented in this study is well suited for bioassay-directed fractionation of marine sediment extracts. However, in relatively low contaminated samples, high enrichment factors and sufficient fractionation is necessary to allow identification of low concentrations of contaminants which is required to link effects and possible causes. In the present case, the relation between substances and effects was difficult to uncover due to relatively low concentrations of pollutants compared to the biogenic matrix and to the remaining complexity of the fractions. The results, with respect to the brominated phenols and indoles in the samples, highlight the successful use of bioassay directed fractionation in the case of high concentrations and high toxicity.

Recommendation and Outlook

In general, it has been shown that a marine risk assessment requires focusing on the input of diffuse sources and taking into account the fact of mixture toxicity. Effects resulting from biogenic substances will make the assessment of the influence of anthropogenic substances even more difficult.     

Role of Polo-like kinase CDC5 in programming meiosis I chromosome segregation

Meiosis is a specialized cell division in which two chromosome segregation phases follow a single DNA replication phase. The budding yeast Polo-like kinase Cdc5 was found to be instrumental in establishing the meiosis I chromosome segregation program. Cdc5 was required to phosphorylate and remove meiotic cohesin from chromosomes. Furthermore, in the absence of CDC5 kinetochores were bioriented during meiosis I, and Mam1, a protein essential for coorientation, failed to associate with kinetochores. Thus, sister-kinetochore coorientation and chromosome segregation during meiosis I are coupled through their dependence on CDC5.     

Phytochemical changes induced by different nitrogen supply forms and radiation levels in two leafy Brassica species

The effect of three different nitrogen (N) supply forms differing in their ammonium-to-nitrate (NH(4):NO(3)) ratio (100% NH(4), 50% NH(4) + 50% NO(3), 100% NO(3)) under three different levels of daily photosynthetic active radiation (PAR) (low, 5.0; medium, 6.8; high, 9.0 mol m(-2) day(-1)) on a range of desirable health-promoting phytochemicals in Brassica rapa subsp. nipposinica var. chinoleifera and Brassica juncea was determined. The 100% NH(4) supply under medium PAR levels led to the highest concentration of glucosinolates based on a low nitrogen/sulfur ratio as well as high levels of carotenoids in the leaves of both Brassica species. However, the 100% NH(4) supply under low and medium PAR levels resulted in low concentrations of flavonoids based on high N concentration in the leaves. Thus, the data provided here have strong implications for crop management strategies aimed at optimizing both the concentration and composition of a range of phytochemicals.