COMPARISON BETWEEN BOLUS TRACKING AND TIMING‐BOLUS TECHNIQUES FOR RENAL COMPUTED TOMOGRAPHIC ANGIOGRAPHY IN NORMAL CATS

Renal dual‐phase computed tomograpic angiography (CTA) is used to assess suitability of feline donors prior to transplantation. A prerequisite for successful CTA is optimal synchronization between the arterial passage of contrast material and CT data acquisition. This retrospective study was conducted to compare quality of renal vascular enhancement at dual‐phase CTA in normal cats between two techniques of timing of data acquisition: the timing‐bolus and the bolus tracking method. Nine cats were scanned using the timing‐bolus technique and 14 with the bolus tracking technique using otherwise similar scanning parameters in a 16‐slice multidetector row CT scanner. The quality of enhancement of the renal vessels at the scanned arterial phase and venous phase was assessed both subjectively and objectively by three board‐certified radiologists. Arterial enhancement was not observed at the scanned arterial phase in three of the nine cats with the timing‐bolus technique but only 1 of the 14 cats with the bolus tracking technique. Early venous enhancement at the scanned arterial phase was common with the bolus tracking technique. Data acquisition was significantly faster with the bolus tracking technique. We conclude that the bolus tracking technique is a valid technique that could be integrated into the routine protocol for 16‐detector row CT renal angiography in cats.     

A potential biomarker of androgen exposure in European bullhead (Cottus sp.) kidney

The aim of this study was to identify a signal that could be used as an androgen exposure indicator in the European bullhead (Cottus sp.). For this purpose, the ultra-structure of the kidney was characterized to identify normal structure of this organ, and histological changes previously described in the kidney of breeding male bullheads were quantified using the kidney epithelium height (KEH) assay previously developed and validated for the stickleback. In the next step, the effect of trenbolone acetate (TbA), a model androgen, was assessed to identify potential androgenic regulation of bullhead kidney hypertrophy. Measurement of KEH performed on adult non-breeding male and female bullheads exposed for 14 and 21 days to 0, 1.26 and 6.50 μg/L showed that kidney hypertrophy is induced in a dose-dependent manner, confirming the hypothesis that the European bullhead possesses a potential biomarker of androgen exposure. Combined with the wide distribution of the European bullhead in European countries and the potential of this fish species for environmental toxicology studies in field and laboratory conditions, the hypothesis of a potential biomarker of androgen exposure offers interesting perspectives for the use of the bullhead as a relevant sentinel fish species in monitoring studies. Inducibility was observed with high exposure concentrations of TbA. Further studies are needed to identify molecular signals that could be more sensitive than KEH.     

Using summed individual species models and state-of-the-art modelling techniques to identify threatened plant species hotspots

Reliable identification of hotspot areas with high numbers of threatened plant species has a central role in conservation planning. We investigated the potentiality of identifying the distribution, richness and hotspots of threatened plant species at a 25 ha resolution using eight state-of-the-art modelling techniques (GLM, GAM, MARS, ANN, CTA, GBM, MDA and RF) in a taiga landscape in north-eastern Finland. First, the individual species models developed based on occurrence records of 28 species in the 1677 grid squares and derived from different statistical techniques were extrapolated to the whole study area of 41 750 km². Second, the projected presence/absence maps were then combined to create species richness maps, and the top 5% of grid cells ranked by species richness were classified as hotspots. Finally, we created an overall summary map by combining the individual hotspot maps from all eight modelling techniques and identified areas where the individual hotspots maps overlapped most. There were distinguishing differences in projections of the geographic patterns of species richness and hotspots between the modelling techniques. Most of the modelling techniques predicted several hotspot locations sporadically around the study area. However, the overall summary map showed the highest predictive performance based on Kappa statistics, indicating that the locations where the hotspot maps from the eight models coincided most harboured highest observed species richness. Moreover, the summary map filtered out the patchy structures of individual hotspot maps. The results show that the choice of modelling technique may affect the accuracy and prediction of hotspot patterns. Such differences may hamper the development of useful biodiversity model applications for conservation planning, and thus it is beneficial if the conservation decision-making can be based on sets of alternative maps and overlaying of predictions from multiple models.     

Enrichment of the nematode Panagrolaimus sp., a potential live food for marine aquaculture,with essential n-3 fatty acids

The nematode Panagrolaimus sp. (strain NFS-24-5) may have potential as a live food organism for larvae of several marine species. It can be mass-produced in liquid culture and is desiccation tolerant enabling long-term storage and transportation. Nematodes lack the essential fatty acid docosahexaenoic acid (DHA), so this investigation examined an enrichment procedure by incubating nematodes in S.presso^® (INVE Aquaculture, Belgium), a commercial enrichment product. Mass-produced nematodes from liquid cultures on yeast cells were cleaned and then exposed to concentrations of 0.1–3 % S.presso^® for 24 h at 200,000 nematodes ml^?1. Nematode viability was >90 % after the treatment. Following enrichment percentage, total lipid ranged from 23.6 to 33.3 % of nematode dry matter, and nematodes incubated in 3 % S.presso^® had a significantly higher lipid percentage than untreated controls. Enrichment was successful in increasing the percentage of DHA, and a maximum value of 5.8 % of total fatty acids was achieved. The results of enrichment of Panagrolaimus sp. (strain NFS-24-5) following treatment with 3 % S.presso^® should promote the carrying out of feeding trials to test the efficacy of the nematodes as a live food for larval marine fish and crustaceans.     

Use of new immunoglobulin isotype-specific ELISA-systems to detect Salmonella infections in pigs

In Germany, the program for controlling salmonella infections in pigs is based on tests detecting salmonella-lipopolysaccharide (LPS) induced antibodies in meat-juice or blood. These conventional tests which are based on the technology of enzyme-linked immunosorbent assay (ELISA) detect exclusively or mainly immunoglobulin(lg)G antibodies. Meanwhile, novel ELISA systems (WCE-ELISA, 3-Isotype-Screening-ELISA) have been developed, which additionally detect the antibody classes IgM and IgA.This fact enables the registration of fresh salmonella infections (starting with day 5 p.i.) and thus, the distinction between early and older infections.The results show that animals with early salmonella infections appear significantly more often in herds with a high than with a low prevalence. With the newly developed tests this group of animals can be detected much more efficiently and precisely than with the tests used so far. Due to their clearly improved sensitivity the application of the WCE-ELISA and the 3-Isotype-Screening-ELISA in terms of the QS-Salmonella-Monitoring program can therefore significantly improve the selection of farms with potential salmonella excretors. Additionally, the WCE-ELISA can be applied very suitable for the examination of individual animals.     

Modelling exploration of the future of European beech (Fagussylvatica L.) under climate change—Range,abundance, genetic diversity and adaptive response

We explored impacts of climate change on the geographic distribution of European beech by applying state of the art statistical and process-based models, and assessed possible climate change impacts on both adaptive capacity in the centre of its distribution and adaptive responses of functional traits at the leading and trailing edge of the current distribution. The species area models agree that beech has the potential to expand its northern edge and loose habitat at the southern edge of its distribution in a future climate. The change in local population size in the centre of the distribution of beech has a small effect on the genetic diversity of beech, which is projected to maintain its current population size or to increase in population size. Thus, an adaptive response of functional traits of small populations at the leading and trailing edges of the distribution is possible based on genetic diversity available in the local population, even within a period of 2–3 generations.     

Functional characterization of FaCCD1: a carotenoid cleavage dioxygenase from strawberry involved in lutein degradation during fruit ripening

A gene encoding a carotenoid cleavage dioxygenase class 1 enzyme (FaCCD1) was identified among a strawberry fruit expressed sequence tag collection. The full-length cDNA was isolated, and the expression profiles along fruit receptacle development and ripening, determined by quantitative real time polymerase chain reaction, showed that FaCCD1 is a ripening-related gene that reaches its maximal level of expression in the red fully ripe stage. FaCCD1 was expressed in Escherichia coli, and the products formed by the recombinant protein through oxidative cleavage of carotenoids were identified by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry analyses. The FaCCD1 protein cleaves zeaxanthin, lutein, and beta-apo-8'-carotenal in vitro. Although beta-carotene is not a good substrate for FaCCD1 in vitro, the expression of FaCCD1 in an engineered carotenoid-producing E. coli strain caused the degradation of beta-carotene in vivo. Additionally, the carotenoid profile in strawberry was analyzed by high-performance liquid chromatography-photodiode detection, and a correlation between the increase of the expression level of FaCCD1 during ripening and the decrease of the lutein content suggests that lutein could constitute the main natural substrate of FaCCD1 activity in vivo.