Structure-antioxidant efficiency relationships of phenolic compounds and their contribution to the antioxidant activity of sea buckthorn juice

The phenolic composition of juice derived from fruits of sea buckthorn (Hippophae rhamnoides) was investigated by high-performance liquid chromatography (HPLC) with diode array and electrochemical detection. Flavonols were found to be the predominating polyphenols while phenolic acids and catechins represent minor components. Of the seven flavonols identified, isorhamnetin 3-O-glycosides were the most important representatives quantitatively. However, because of their structural properties, they were poor radical scavengers as shown by electron spin resonance spectroscopy. Phenolic compounds such as quercetin 3-O-glycosides, catechins, and hydroxybenzoic acids with a catechol structure exhibited good antioxidant capacities, but their concentration in sea buckthorn juice was small. These phenolic compounds, determined by HPLC, accounted for less than 5% of the total antioxidant activity of the filtered juice. Ascorbic acid was shown to be the major antioxidant in sea buckthorn juice. Because of its high concentration of 1.22 g/L, it contributes approximately 75% to total antioxidant activity. The remaining difference can be attributed to higher molecular weight flavan-3-ols (proanthocyanidins), which were determined photometrically after acid depolymerization to colored anthocyanidins.     

Value of the clinical examination in diagnosing enzootic pneumonia in fattening pigs

The diagnosis of enzootic pneumonia at the herd level should be based on a combination of different methods. Currently, clinical examination is usually considered to be a low value method, particularly compared to the direct detection of Mycoplasma hyopneumoniae in lung lesions by PCR. The present study compared the value of accurate clinical examination (including the quantitation of coughing), PCR on bronchoalveolar lavage fluid, and serological testing of blood samples for the purpose of diagnosing enzootic pneumonia. The coughing index (average % of pigs coughing per minute of observation) was determined in fattening pigs from 59 herds, and ranged from 0% to 6.7% with a median of 2.4%. Five hundred and ninety bronchiolar lavage samples and 1179 serum samples were taken from pigs in those 59 herds and tested for M. hyopneumoniae specific DNA and antibodies, respectively. In herds where ?50% of lavage fluids were PCR positive, the likelihood of a higher coughing index was increased by 76% (OR: 1.76; 95% CI: 1.14-2.72) compared to herds with <50% of positive samples. For antibodies (determined by ELISA) a seroprevalence of ?50% increased the likelihood of a high coughing index by 50% (OR: 1.50; 95% CI: 1.03-2.20). In 78.1% of all herds with a seroprevalence of ?50% against M. hyopneumoniae, the PCR-prevalence and the coughing index were above the median (50% and 2.4%, respectively). It was concluded that in fattening pigs a quantitative assessment of the onset of coughing - typically dry and non-productive - improves the diagnosis of enzootic pneumonia and can occasionally substitute for the detection of M. hyopneumoniae by PCR.     

Risk assessment of bluetongue disease incursion into Germany using geographic information system (GIS)

Using a geographic information system (GIS), by analysis of the relationship between the spatial distribution of cattle density and the risk factors temperature, altitude and rainfall, we defined geographical habitats enabling optimal development and competence of Culicoides spp. to transmit Bluetongue-Virus (BTV): Risk zones (low, high, highest risk) were identified mainly in Baden-Württemberg, Hessen and Rheinland-Pfalz if persistently infected ruminants are imported into these zones in summer (June to August mainly), based on the current climatic conditions, BTD outbreaks are considered a real possibility. Overwintering of the virus seems unlikely. However, global warming will lead to a steady increase of the size of the risk zones. In addition, the possibility of primary outbreaks increases. The reason for this is not only the expected northern shift of Culicoides imicola, but in addition an increasing vector competence of domestic Culicoides species. We therefore recommend the storage of vaccines as well as conducting ecological studies analysing the presence of Culicoides vectors. Using the data from these studies, it will be possible to produce updated quantitative risk assessment via GIS.     

Incidence and significance of treponemes in animals

The genus Treponema consists of various species. Currently most of them are not cultivable because respective cultivation conditions are unknown. Therefore the biodiversity of treponemes was only appreciated recently by applying comparative 16S rRNA sequence analysis. Treponemes are mainly representatives of the gastrointestinal autochthonal flora, especially in termites, but they have also been described in swine and cattle. On the other hand treponemes are involved in different infectious diseases, the most well known being syphilis in humans or venereal spirochetosis in rabbits. Furthermore, treponemes are associated with several infectious periodontal diseases, e.g. gingivitis or periodontitis, where they can be detected regularly. Culture has not been successful for most of the oral treponemes, so the major part can only be identified by their 16S rRNA sequence. Similar to these oral disorders treponemes are also associated with digital dermatitis (DD), a chronic inflammatory disease of the bovine skin, where different treponemal phylotypes were found in large numbers. Treponema brennaborense was first identified and isolated in DD biopsies. Unravelling the pathogenic potential and aetiological significance of treponemes in chronic infectious diseases like peridontitis or DD remains a costly task. Although treponemes can be frequently detected in such lesions, it is often unclear to what extent treponemes are involved in pathogenesis of these diseases. The possession of various virulence features like high motility, the ability to adhere and invade as well as to cause cytopathic effects in eukaryotic cells are highly indicative of the aetiological relevance of treponemes.     

Effect of nitrogen species supply and mycorrhizal colonization on organosulfur and phenolic compounds in onions

The aim of the present study was to test whether variations in the root environment affect the content of health-related organosulfur compounds, total phenolic compounds, and flavonol glycoside concentrations in onions. For this purpose, greenhouse-grown onions ( Allium cepa L.) were either inoculated with a commercial arbuscular mycorrhizal inoculum or a sterile inoculum and were provided with two NH(4)(+):NO(3)(-) ratios as a nitrogen source. Onion growth, arbuscular mycorrhizal colonization rate, sugars, and nutrient element concentrations were also quantified. The plant antioxidant activity and quercetin monoglucoside and organosulfur compound concentrations increased with dominant nitrate supply. Furthermore, mycorrhizal colonization increased the antioxidant activity and also concentrations of the major quercetin glucosides. The present study provides clear evidence that antioxidant activity, quercetin glycosides, and organosulfur compounds can be increased in sufficiently supplied onion plants by dominant nitrate supply or application of arbuscular mycorrhizal fungi. This was probably due to increased precursor production and induced defense mechanisms.     

Die Standortsbewertung der biologischen Aktivität von Böden über Ermittlung der Bodenatmung und der zellulolytischen Aktivitatät im Feld

Intersite estimation of biological activity of soils by determination respiration and cellulolytical activity in the field A temperature differentiated scale of estimation is presented, which is derived from long-term investigations of respiration and cellulolytic activity. This is suitable for intersite comparison of different soil-ecosystems. Investigations in spring are representative and could be done during mapping the soil-ecosystems. It exists a strong correlation to the quality of the humus body and to the available nutrients.     

Membrane Dialysis Extraction (MDE): A Novel Approach for Extracting Toxicologically Relevant Hydrophobic Organic Compounds from Soils and Sediments for Assessment in Biotests

Goal, Scope and Background   Organic solvents are routinely used to extract toxicants from polluted soils and sediments prior to chemical analysis or bioassay. Conventional extraction methods often require the use of heated organic solvents, in some cases under high pressure. These conditions can result in loss of volatile compounds from the sample and the degradation of thermally labile target analytes. Moreover, extracts of soils and sediments also frequently contain substantial quantities of organic macromolecules which can act as sorbing phases for target analytes and in doing so interfere with both chemical analysis and bioassays. Membrane dialysis extraction (MDE) is described as a simple, passive extraction method for selectively extracting toxicologically relevant hydrophobic organic compounds (HOCs) from polluted soils and sediments and anaylzed for its applicability in ecotoxicological investigations. Methods   Toxicologically relevant hydrophobic organic compounds were extracted from wet and dry sediments by sealing replicate samples in individual lengths of pre-cleaned low-density polyethylene (LD-PE) tubing and then dialysing in n-hexane. The efficacy of the MDE method for use in ecotoxicological investigations was assessed by testing the concentrated extracts in the neutral red assay for acute cytotoxicity, in the EROD assay for the presence of dioxin-like compounds and in the Danio rerio fish egg assay for embryotoxic and teratogenic effects. Conditions of the sediment sample (with or without water content), dialysis membrane length and duration of dialysis were analyzed with respect to their impact on three endpoints. Results of the MDE investigations were compared to data obtained in samples prepared using conventional Soxhlet extraction. Results and Discussion   The membrane dialysis extraction was found to be at least as efficient as Soxhlet methodology to extract toxicologically relevant HOCs from sediment samples. In most cases, MDE-derived extracts showed a higher toxicological potential than the Soxhlet extracts. Lack of any significant effects in any MDE controls indicated these differences were not caused by contamination of the LD-PE membrane used. The elevated toxicological potential of MDE extracts is most likely the result of enhanced bioavailability of toxic compounds in consequence of lower amounts of organic macromolecules (i.e. sorbing phases) in the MDE extracts. This effect is probably the result of a size-selective restriction by the LD-PE membrane. Conclusion   Membrane dialysis extraction was found to be a simple, efficient and cost-effective method for the extraction of sediment samples. MDE can be used to extract toxicologically relevant hydrophobic organic compounds from both wet and dry sediments without the risk of loosing volatile and thermally labile target analytes. The size-selectivity of the LD-PE membrane also appears to have the capacity to increase the bioavailablity of potential target analytes in the resulting extracts by retaining much of the organic macromolecules present in the sample. Thus, results suggest that MDE may be particularly useful for the extraction of toxicologically relevant hydrophobic organic compounds from soils and sediments for bioassays and other ecotoxicological investigations. Recommendation and Perspective   Further validation of MDE has been initiated and the applicability of the methodology to other sample types will be investigated. Of particular interest is the potential application of MDE to recover hydrophobic target analytes from biological samples such as muscle, other soft tissues and blood.