Contaminant and formulation analysis of MSMA using high-pressure liquid chromatography — graphite furnace atomic absorption spectrophotometry

High-pressure liquid chromatography with an ion-exchange column combined with graphite furnace atomic absorption spectrometry was used to analyse commercial formulations of sodium hydrogen methylarsonate (MSMA). No arsenite or arsenate salts or dimethylarsinic acid were detected as contaminants in the formulations, and the MSMA concentrations were found to be in accordance with the concentrations given on the containers.     

Kilimanjaro ice core records: evidence of holocene climate change in tropical Africa

Six ice cores from Kilimanjaro provide an approximately 11.7-thousand-year record of Holocene climate and environmental variability for eastern equatorial Africa, including three periods of abrupt climate change: approximately 8.3, approximately 5.2, and approximately 4 thousand years ago (ka). The latter is coincident with the "First Dark Age," the period of the greatest historically recorded drought in tropical Africa. Variable deposition of F- and Na+ during the African Humid Period suggests rapidly fluctuating lake levels between approximately 11.7 and 4 ka. Over the 20th century, the areal extent of Kilimanjaro's ice fields has decreased approximately 80%, and if current climatological conditions persist, the remaining ice fields are likely to disappear between 2015 and 2020.     

A proposal of clinical breakpoints for amoxicillin applicable to porcine respiratory tract pathogens

In the present position paper, an attempt was made to establish clinical breakpoints of amoxicillin to classify porcine respiratory tract pathogens as susceptible, intermediate or resistant based on their minimum inhibitory concentrations of amoxicillin. For this, a thorough review of the published literature with regard to swine-specific pharmacological data (including dosages of amoxicillin applied and routes of administration used), clinical efficacy, and in vitro susceptibility of the target pathogens was performed. Based on the comparative analysis of the results, the working group "Antibiotic Resistance" of the German Veterinary Medical Society (DVG) proposed to classify porcine respiratory tract pathogens that show MIC values of amoxicillin of < or =0.5microg/ml as "susceptible", those with MICs of 1microg/ml as "intermediate", and those with MICs of > or =2microg/ml as "resistant".     

Comparative evaluation of live marker vaccine candidates "CP7_E2alf" and "flc11" along with C-strain "Riems" after oral vaccination

Due to the tremendous socio-economic impact of classical swine fever (CSF) outbreaks, emergency vaccination scenarios are continuously under discussion. Unfortunately, all currently available vaccines show restrictions either in terms of marker capacities or immunogenicity. Recent research efforts were therefore directed at the design of new modified live marker vaccines. Among the most promising candidates the chimeric pestiviruses "CP7_E2alf" and "flc11" were identified. Within an international research project, these candidates were comparatively tested in challenge experiments after a single oral vaccination. Challenge infection was carried out with highly virulent CSF virus strain "Koslov", 14 or 21 days post vaccination (dpv), respectively. Safety, efficacy, and marker potential were addressed. All assessments were done in comparison with the conventional "gold standard" C-strain "Riems" vaccine. In addition to the challenge trials, multiple vaccinations with both candidates were performed to further assess their marker vaccine potential. All vaccines were safe and yielded full protection upon challenge 21 days post vaccination. Neither serological nor virological investigations showed major differences among the three vaccines. Whereas CP7_E2alf also provided clinical protection upon challenge at 14 days post vaccination, only 50% of animals vaccinated with flc11, and 83% vaccinated with C-strain "Riems" survived challenge at this time point. No marked differences were seen in protected animals. Despite the fact that all multiple-vaccinated animals stayed sero-negative in the accompanying marker test, the discriminatory assay remains a weak point due to delayed or inexistent detection of some of the vaccinated and subsequently infected animals. Nevertheless, the potential as live marker vaccines could be confirmed for both vaccine candidates. Future efforts will therefore be directed at the licensing of "Cp7_E2alf" as the first live marker vaccine for CSF.     

Untersuchungen zum Einfluß des Matrixpotentials im Boden auf Stammdickenänderungen von Fichten (Picea abies (L.) Karst.)

Effects of soil water potential on stem radius changes of Norway spruce (Picea abies (L.) Karst.) The stem radius of 2 mature Norway spruce trees and the soil water potential were continuously measured in situ with dendrometers and tensiometers, respectively. In a period without growth and frost events the stem radius and the soil water potentials correlated closely. A young spruce tree grown under controlled conditions changed its radius in response to the soil water supply likewise. The shrinkage of the stem was reversible, even if the soil was very dry (soil water potential ± ? 1000 hPa). An estimate of the soil water potential seems to be possible even beyond ? 1000 hPa by measurements of stem radius changes.     

Npro of Bungowannah virus exhibits the same antagonistic function in the IFN induction pathway than that of other classical pestiviruses

Bungowannah virus is the most divergent atypical pestivirus that had been detected up to now, and does not fit into any of the four approved species: Bovine viral diarrhea virus type 1 (BVDV-1) and type 2 (BVDV-2), Classical swine fever virus (CSFV) and Border disease virus (BDV). However, the presence of N^pro and E^rns coding regions, which are unique to pestiviruses, provides clear evidence of a pestivirus. Nevertheless, the amino acid identity of Bungowannah virus N^pro and BVDV-1 N^pro (strain CP7) is only 51.5%. By using a BVDV-1 backbone, a novel chimeric construct was generated, in which the genomic region encoding the non-structural protein N^pro was replaced by that of Bungowannah virus (CP7_N^pro-Bungo). In vitro studies of CP7_N^pro-Bungo revealed autonomous replication with the same efficacy as the BVDV backbone CP7 and infectious high-titer virus could be collected. In order to compare the ability of interferon (IFN) suppression, two reporter gene assays, specific for type-I IFN, were carried out. In virus-infected cells, no significant difference in blocking of IFN expression between the parental virus CP7, Bungowannah virus and the chimeric construct CP7_N^pro-Bungo could be detected. In contrast, an N^pro deletion mutant showed an impaired replication in bovine cells and a marked type-I IFN response.Taken together, our findings reveal the compatibility of non-structural protein N^pro of atypical Bungowannah virus with a BVDV type 1 backbone and its characteristic feature as an inhibitor of type-I IFN induction with an inhibitor-activity comparable to other pestiviruses.     

Evaluation of real-time RT-PCR assay for the routine intra vitam diagnosis of classical swine fever

The aim of the study was to evaluate the diagnostic quality of the real-time RT-PCR assay described by Hoffmann et al. [Hoffmann, B., Beer, M., Schelp, C., Schirrmeier, H., Depner, K., 2005. Validation of a real-time RT-PCR assay for sensitive and specific detection of classical swine fever. J. Virol. Methods 130, 36-44] for the routine intra vitam diagnosis of classical swine fever (CSF). We compared the assay with conventional diagnostic methods by using defined diagnostic material from an animal experiment with pigs showing different clinical forms of CSF. Compared to virus isolation and antigen ELISA an enhanced sensitivity of the real-time RT-PCR could be shown. We were able to detect all infected pigs regardless of the clinical course of CSF. CSF infection was detected already during the incubation period, during the entire clinical phase as well as at the beginning of convalescence when the first antibodies were detected and no virus could be isolated any more. In most cases, positive PCR results were obtained 2 days earlier than with virus isolation and 2-4 days earlier than with the antigen ELISA.     

Beeinflussung der Wasserqualität in einem bewaldeten Einzugsgebiet durch biogeochemische Stoffumsetzungen in bachnahen Böden

Transformations of nitrate and sulfate were investigated with respect to streamwater quality in a forested headwater catchment in the Black Forest (SW Germany). Analyses of seepage collected with ceramic cups in the waterlogged riparian zone provide evidence for a distinct removal of nitrate due to reduction processes. This is in accordance with results from a laboratory experiment. Solutions enriched with nitrate were percolated through soil columns from a histic gleysol. Apparently, nitrate removal results from denitrification, whereas in the dynamics of sulfate various processes appear to be superimposed. In total, the reduction processes observed are favoured by higher temperatures as well as by longer times of contact with the solid phase. The effects on other hydrochemical parameters (notably pH-value and acid neutralizing capacity) are discussed.