Tricuspid valve stenosis caused by fibrous adhesions to an endocardial pacemaker lead in a dog

Acquired tricuspid valve stenosis (TVS) is a rare complication of endocardial lead placement in humans that has not been described in the veterinary literature. We describe a 6.5-year-old Border terrier that was presented with right-sided congestive heart failure 5.5 years after placement of a transvenous pacemaker. Severe TVS was confirmed by cardiac ultrasonography and appeared to be secondary to excessive endocardial pacemaker lead within the right atrium. Repositioning of the lead proved impossible and subsequent postmortem examination demonstrated fusion of the tricuspid valve (TV) leaflets around the endocardial lead with associated narrowing of the tricuspid valve orifice. In addition, the loop of the endocardial lead was anchored by thick fibrous tissue to the right atrial wall. This case report suggests that if sufficient endocardial lead is left inside the heart, in dogs undergoing transvenous pacemaker therapy, the redundant lead can become adherent to the tricuspid valve apparatus and cause valvular stenosis.     

Test performance study of diagnostic procedures for identification and detection of Gibberella circinata in pine seeds in the framework of a EUPHRESCO project

Gibberella circinata (anamorph Fusarium circinatum) is a harmful fungus infecting pine trees that has been subject to European Union emergency phytosanitary measures since 2007. This fungus is spread over long distances primarily via pine seeds, consequently reliable detection tools and methods are needed to test pine seed lots imported and marketed in the EU. Several detection methods are available in the scientific literature but very limited validation data is available. For that purpose, one European EUPHRESCO project called ‘Gibcir‐Diagseed’ was launched, involving 10 countries. This project aimed to select and validate one or more diagnostic procedures targeting this pest via inter‐laboratory tests, as well as a suitable sampling method. Performance criteria were calculated for three procedures chosen by participants: isolation followed by morphological characterization, isolation followed by conventional PCR and biological enrichment followed by real‐time PCR. The results showed that all three procedures provided acceptable performance criteria but also demonstrated that none of them could generate 100% of correct results. Regarding the sampling issue, the National Plant Protection Organizations consultation enabled an agreement to be reached on the number of seeds to be tested: 400 per sample, for a 95% confidence level that an infection of at least 1% will be detected.     

Home gardens: an assessment of their biodiversity and potential contribution to conservation of threatened species and crop wild relatives in Benin

Despite growing literature supporting the importance of home gardens (HG) as biodiversity hotspots, knowledge of patterns of their contribution to conservation of threatened species and crop wild relatives (CWR) across climate and culture in Africa is still limited. This investigation was conducted across three climatic zones to assess the floristic diversity of home gardens and the extent to which they contribute to conservation of threatened species and CWR. Overall, 240 home gardens were sampled and their floristic diversity assessed. The ecological importance of recorded species was determined per climatic zone using the importance value index (IVI). A cluster analysis was performed to group the species according to their IVI-values and a principal component analysis helped to identify the most important species. 285 species were inventoried throughout the study area. Home garden species’ diversity globally declined from the drier to the wetter zone but was highest in the transition zone. The average number of species found per HG was 10.1 and varied weakly across zones (9.07, Guineo-Congolean zone; 10.77, Sudano-Guinean zone; and 10.53, Sudanian zone). The most important home gardens species in the Sudanian, the Sudano-Guinean and the Guineo-Congolean zones were respectively: Abelmoschus esculentus (L.) Moench and Hibiscus asper Hook.f.; Solanum lycopersicum L. and Zea mays L.; Ipomoea aquatica Forssk. and Senna occidentalis (L.) Link. They were mainly vegetables and used as food and/or medicinal plant species. Twenty CWR and twelve threatened species were recorded and were also mainly used for food and medicinal purposes. Thorough research on socioeconomic factors supporting possession of HG and choice of managed species as well as indigenous management strategies of HG and dynamic of traditional knowledge related to HG may help to deeply assess home gardens’ effectiveness in biodiversity conservation.     

Short-term exposure to carbaryl and UV radiation increases the reproduction output of the collembolan Folsomia candida

Purpose

Ecotoxicological risk assessment of chemical compounds is considered more accurate when mixtures of chemicals and/or interactions between chemicals and natural stressors are considered. To further simulate natural conditions, under which organisms are often exposed to combinations of natural and anthropogenic stressors, the combined exposure of a widely used insecticide, carbaryl, under UV radiation was evaluated. It is more than likely that soil organisms are confronted with a combination of chemical exposure and increasing UV irradiance on the terrestrial habitat. Considering the heterogeneity of contamination in field soils and the probability of collembolan to avoid contaminated soil (less time under exposure), combined effects of carbaryl and ultraviolet radiation were evaluated, by using a short exposure to Folsomia candida.

Materials and methods

Single exposures to carbaryl and UV radiation were performed, and adult mortality and number of laid and hatched eggs were reported. Following the results, a combined exposure was carried out, using the same conditions performed previously in the single tests. Organisms were exposed simultaneously to carbaryl (from 1 to 7 mg kg^?1) and UV doses (from 1,121.29 to 3,795.26 J m^?2), the last corresponds to 1 to 4 h of exposure. Mortality was reported, and organisms were left to lay eggs in culture boxes.

Results and discussion

Both ultraviolet radiation and high concentrations of carbaryl as single stressors increased the number of produced eggs of F. candida, with significant differences at higher concentrations (4, 5.5, and 7 mg kg^?1) of carbaryl and an EC50 of 5.93 mg kg^?1. In the case of UV radiation, statistical differences were found at all concentrations compared with control, with an EC50 of 1,248.24 J m^?2. In both cases, no significant mortality was observed. When combined, both stressors acted independently on egg production, showing additivity of effects (independent action (IA) model to data on laid eggs; SS?=?0.00056; r2?=?0.75; p?Conclusions This study highlights the importance of taking UV exposure conditions into account when assessing the impact of pesticides to soil biota and looking for more realistic scenarios while showing that soil sheltering occurs only up to a certain extent and that indirect effects can be observed. The opposite trends on responses obtained under standardized tests and short exposures to carbaryl provided some insight on the possible effects of carbaryl during collembolan life cycle.     

Identification of an alpha-amylase inhibitor from Pterodon pubescens with ability to inhibit cowpea weevil digestive enzymes

Cowpea seeds (Vigna ungiculata) are widely cultivated by poor farmers in Latin America and Africa and are often severely damaged by the cowpea weevil Callosobruchus maculatus. A proteinaceous inhibitor of cowpea weevil digestive enzymes, PpAI, was purified from white sucupira seeds (Pterodon pubescens) and biochemically characterized in this study. Proteins were extracted from seeds and precipitated with ammonium sulfate at 100% saturation. This fraction was applied onto a Red-sepharose CL-6B column, and the retained peak showed 70% inhibitory activity toward larval C. maculatus digestive alpha-amylases. The retained peak was then purified using an analytical reversed-phase HPLC column. Purified PpAI showed 65% inhibitory activity against larval C. maculatus enzymes. Enzymatic assays also showed that the purified P. pubescens inhibitor was unable to reduce the activity of mammalian alpha-amylases, suggesting specificity toward insect enzymes. Moreover, artificial seeds containing PpAI were able to reduce larval weight by 36% and cause 55% mortality. Mass spectrometry and SDS-PAGE analyses indicated that PpAI showed a molecular mass of approximately 5.0 kDa. This alpha-amylase inhibitor, coming from a native Cerrado plant, could be used to construct a genetically engineered cowpea with enhanced resistance against weevil pests.     

Emissions of ammonia,nitrous oxide and carbon dioxide from urban gardens in Niamey,Niger

Urban and peri-urban agriculture (UPA) contributes significantly to meet increasing food demands of the rapidly growing urban population in West Africa. The intensive vegetable cultivation in UPA gardens with its high nutrient inputs is often reported to operate at large surpluses of nutrients and presumably high turnover rates of organic matter (OM) and nitrogen (N) losses via emanation and leaching. Many of these claims are lacking solid data which would allow suggesting mitigation strategies. Therefore, this study aimed at quantifying gaseous emissions of ammonia (NH₃), nitrous oxide (N₂O), and carbon dioxide (CO₂) in three representative urban gardens of Niamey, Niger using a closed chamber gas monitoring system. Mean annual N emissions (NH₃-N and N₂O-N) in two gardens using river water for irrigation reached 53 and 48 kg N ha^?1 yr^?1, respectively, while 25 and 20 Mg C ha^?1 yr^?1 was lost as CO₂-C. In the garden irrigated with sewage water from the city's main wadi, N₂O was the main contributor to N losses (68%) which together with NH₃ reached 92 kg N ha^?1 yr^?1, while CO₂-C emissions amounted to 26 Mg ha^?1 yr^?1. Our data indicate that 28% of the total gaseous C emissions and 30–40% of the N emissions occur during the hot dry season from March to May and another 20–25% and 10–20% during the early rainy season from June to July. Especially during these periods more effective nutrient management strategies in UPA vegetable gardens should be applied to increase the nutrient use efficiency in UPA vegetable gardens.     

Teratosphaeria gauchensis associated with trunk,stem and foliar lesions of Eucalyptus globulus in Portugal

Teratosphaeria gauchensis and T. zuluensis both cause a stem canker of eucalypts that leads to serious damage in various parts of the world. Until recently, this disease was unknown in Portugal. Nevertheless, severe damage to Eucalyptus globulus has been observed in Portugal since 2006 when symptoms appeared as necrotic spots on young green stems and leaves, twig lesions, and dark oval‐shaped lesions on stems and trunks. The isolates from affected E. globulus tree plantations were identified using sequence data of the ITS1‐5.8S‐ITS2 and EF‐1α clusters, together with morphological characteristics. Based on these results, the causal organism was identified as T. gauchensis, which represents the first report of this pathogen from Portugal.     

Tolerance of genetically characterized <Emphasis Type="Italic">Folsomia candida</Emphasis> strains to phenmedipham exposure

Background, Aims, and Scope  The springtail Folsomia candida is a commonly used model species in ecotoxicological soil testing. The species reproduces parthenogenetically and, thus, laboratories use different clonal lineages. In this study, we investigated if genetic divergence between F. candida strains impacts the reaction to chemical stress and may thus affect the outcome of toxicity tests. Methods  In two exposure assays (life-cycle reproduction test and avoidance behaviour test), three laboratory strains of F. candida from Portugal (PTG), Spain (SPN) and Denmark (DNK) were exposed to different concentrations of the reference chemical phenmedipham. Genetic divergence among strains was estimated based on mitochondrial COI sequence data. Results  No significant differences between tolerance towards phenmedipham exposure were observed in a reproduction test. In contrast, one strain (SPN) showed a decreased susceptibility to phenmedipham compared to the other strains (PTG and DNK) in the avoidance assay. Discussion  A phylogenetic tree based on mitochondrial COI sequences revealed clear genetic differentiation between both ‘reaction types’. Thus, we found a potential lineage dependent stress reaction in avoidance behaviour towards the pesticide. Conclusions  Our findings have implications for the comparability of test results among laboratories. Reproduction tests seem to be more robust towards interclonal genetic differentiation than avoidance tests. Recommendations and Perspectives  We recommend the use of molecular tools for simple and cost effective genetic characterization of F. candida strains used in chemical avoidance tests. Closer investigations concerning the relation between genetic relatedness and chemical response will provide a more detailed and comprehensive picture on the role of intraspecific genetic differentiation in stress tolerance. ESS-Submission Editor: Prof. Dr. Henner Hollert (henner.hollert@bio5.rwth-aachen.de)     

Influence of acidity and competition with fish on the development of ducklings in Quebec

In Quebec, in 1984 and 1985, a number of American Black Duck (Anas rubripes) and Common Goldeneye (Bucephala clangula) ducklings were reared on two acid lakes (pH 4.8 to 5.0) and one circumneutral lake (pH 6.0) in which the brook trout (Salvelinus fontinalis) populations had been manipulated. This allowed us to determine how acidity and competition with fish affected duckling feeding and growth. Strong acidity and the presence of fish were both required before the birds' development was restricted, the Black Duck being particularly affected. This result supports hypotheses on competition between fish and some waterfowl species.     

Hydrolysis influence on phytochemical composition, antioxidant activity, plasma concentration, and tissue distribution of hydroethanolic Ilex paraguariensis extract components

The infusion of aerial parts of Ilex paraguariensis is widely consumed. Its antioxidant activity suggests an important role of this plant in the treatment/prevention of oxidative stress related diseases. Plant extract active compounds are frequently found in esterified form that may be poorly absorbed. Hydrolysis of the extract is a possible approach to increase its bioavailability. The aim of this study was to perform a phytochemical analysis and evaluate in rats the plasma concentration and tissue distribution of antioxidant compounds in the hydroethanolic extract of Ilex paraguariensis, before and after enzymatic hydrolysis. Both extracts presented high antioxidant activity and phenolic content. Rats given single or repeated doses of the hydrolyzed extract showed increased plasma antioxidant activity and higher plasma levels of caffeic acid. However, no changes of endogenous antioxidants were observed. In conclusion, hydrolysis of the extract of Ilex paraguariensis is a strategy to improve its bioavailability and in vivo antioxidant activity.