Potential new sources of hypoglycin A poisoning for equids kept at pasture in spring: a field pilot study

The first objective of this pilot study was to measure the concentration of HGA in samaras of sycamore trees fallen on the ground and then in seedlings from germination. The subsequent objective was to examine other possible sources of HGA intoxication

Émergence de la toxicité printanière et influence des conditions météorologiques sur les risques de myopathie atypique

peer reviewedLa myopathie atypique (MA) équine en Europe résulte de l'ingestion d'hypoglycine A (HGA) contenue dans les samares et les plantules de l'érable sycomore (Acer pseudoplatanus). Le taux d’HGA a été déterminé dans des samares tombées au sol et des plantules d’érables sycomores récoltées tous les 15 jours au cours du printemps 2016. Ponctuellement, d’autres échantillons environnementaux ont été également prélevés : fleurs, plants âgés, foin produit sur une de ces prairies. À partir des concentrations maximales d’HGA mesurées dans les échantillons d’érable sycomore et en extrapolant la dose toxique pour un cheval à partir des données basées sur des animaux de laboratoire, il peut être estimé qu’à certaines périodes, moins de 20 g de samares ou moins de 50 plantules sont suffisants pour atteindre la dose maximale tolérée pour un cheval. En outre, cette dose hypothétique peut être atteinte avec 150 g de fleurs et 2 L d’eau de pluie qui a ruisselé sur les plantules. Le foin produit sur une des prairies contenait de l’HGA en une concentration dépendant du nombre de plantules séchées et incluses dans celui-ci.Atypical myopathy (AM) equine in Europe results from the ingestion of hypoglycin A (HGA) contained in samara and seedlings of sycamore maple (Acer pseudoplatanus). The concentration of HGA was determined in samaras fallen on the ground and in seedlings of sycamore maple harvested every 15 days, in spring 2016. Other samples have been also collected: flowers, sycamore saplings and hay. Based on the maximum concentrations of HGA measured in the sycamore samples and extrapolating the toxic dose to a horse from the literature data (dose based on laboratory animals), it can be estimated that at certain times less than 20 g samaras or less than 50 seedlings are enough to reach the maximum tolerated dose for a horse. In addition, this hypothetical toxic dose can be reached with 150 g of inflorescences and 2 L of rainwater that has dripped onto seedlings. The hay produced on one of the grasslands contained HGA in a concentration depending on the number of seedlings dried and included in it

Development of an HPTLC method for determination of hypoglycin A in aqueous extracts of seedlings and samaras of Acer species

International audienceHypoglycin A (HGA) is a toxin contained in seeds of the sycamore maple tree ( Acer pseudoplatanus ). Ingestion of this amino acid causes equine atypical myopathy (AM) in Europe. Another variety, A. negundo, is claimed to be present where AM cases were reported in the US. For unknown reasons, occurrence of this disease has increased. It is important to define environmental key factors that may influence toxicity of samaras from Acer species. In addition, the content of HGA in seedlings needs to be determined since AM outbreaks, during autumn period when the seeds fall but also during spring when seeds are germinating. The present study aims to validate a reliable method using high performance thin layer chromatography for determination and comparison of HGA in samaras and seedlings. The working range of the method was between 20 μg HGA to 408 μg HGA per ml water, corresponding to 12 - 244 mg/kg fresh weight or 40 - 816 mg/kg dry weight, taking into account of an arbitrary average dry matter content of 30%. Instrumental limit of detection and limit of quantification were of 10 μg HGA/ml and 20 μg HGA/ml water, respectively. Instrumental precision was 4% (RSD on 20 repeated measurements) while instrumental accuracy ranged between 86% and 121% of expected value. The HGA recovery of the analytical method estimated from spiked samaras and seedlings samples ranged between 63 and 103%. The method was applied to 9 samples of samaras from Acer pseudoplatanus, A. platanoides and A. campestre and 5 seedlings samples from A. pseudoplatanus. The results confirm detection of HGA in samaras from A. pseudoplatanus and the absence of detection in samaras of other tested species. They also suggest that detected levels of HGA are highly variable. This confirmed the suitability of the method for HGA detection in samaras or seedling

Cell-Seeding Techniques in Vascular Tissue Engineering

Previous studies have demonstrated the benefits of cell seeding in the construction of tissue-engineered vascular grafts (TEVG). However, seeding methods are diverse and no method is clearly superior in either promoting seeding efficiency or improving long-term graft function. As we head into an era during which a variety of different TEVG are under investigation in clinical trials around the world, it is important to consider the regulatory issues surrounding the translation of these technologies. In this review, we summarize important advances in the field of vascular tissue engineering, with particular attention on cell-seeding techniques for TEVG development and special emphasis placed on regulatory issues concerning the clinical translation of these various methods