Detection of equine atypical myopathy-associated hypoglycin A in plant material: Optimisation and validation of a novel LC-MS based method without derivatisation

Hypoglycin A (HGA) toxicity, following ingestion of material from certain plants, is linked to an acquired multiple acyl-CoA dehydrogenase deficiency known as atypical myopathy, a commonly fatal form of equine rhabdomyolysis seen worldwide. Whilst some plants are known to contain this toxin, little is known about its function or the mechanisms that lead to varied HGA concentrations between plants. Consequently, reliable tools to detect this amino acid in plant samples are needed. Analytical methods for HGA detection have previously been validated for the food industry, however, these techniques rely on chemical derivatisation to obtain accurate results at low HGA concentrations. In this work, we describe and validate a novel method, without need for chemical derivatisation (accuracy = 84–94%; precision = 3–16%; reproducibility = 3–6%; mean linear range R2 = 0.999). The current limit of quantitation for HGA in plant material was halved (from 1μg/g in previous studies) to 0.5μg/g. The method was tested in Acer pseudoplatanus material and other tree and plant species. We confirm that A. pseudoplatanus is most likely the only source of HGA in trees found within European pastures

Carney triad. Report of one case

Indexación: Scopus.Carney described a disorder characterized by the presence of several uncommon tumors which were pulmonary chondromas, gastric sarcomas and extra-adrenal paragangliomas. We report a 14 year-old girl in whom multiple gastric tumors were discovered during a study of an iron deficiency anemia and was subjected to a partial gastrectomy. At 25 years of age, she developed several pulmonary chondromas and at 33 years, a mediastinal tumor with features of an extra-adrenal paraganglioma was found. At 35 years of age, a total gastrectomy was performed to remove a gastrointestinal stromal tumor with excision of peritoneal and lymph node metastasis. One year later, the patient died due to liver failure secondary to liver metastases.http://ref.scielo.org/4jhgg

Physiological effects of environmental acidification in the deep-sea urchin <i>Strongylocentrotus fragilis</i>

Anthropogenic CO₂ is now reaching depths over 1000 m in the Eastern Pacific, overlapping the Oxygen Minimum Zone (OMZ). Deep-sea animals are suspected to be especially sensitive to environmental acidification associated with global climate change. We have investigated the effects of elevated <i>p</i>CO₂ and variable O₂ on the deep-sea urchin <i>Strongylocentrotus fragilis</i>, a species whose range of 200–1200 m depth includes the OMZ and spans a <i>p</i>CO₂ range of approx. 600–1200 μatm (approx. pH 7.6 to 7.8). Individuals were evaluated during two exposure experiments (1-month and 4 month) at control and three levels of elevated <i>p</i>CO₂ at in situ O₂ levels of approx. 10% air saturation. A treatment of control <i>p</i>CO₂ at 100% air saturation was also included in experiment two. During the first experiment, perivisceral coelomic fluid (PCF) acid-base balance was investigated during a one-month exposure; results show <i>S. fragilis</i> has limited ability to compensate for the respiratory acidosis brought on by elevated <i>p</i>CO₂, due in part to low non-bicarbonate PCF buffering capacity. During the second experiment, individuals were separated into fed and fasted experimental groups, and longer-term effects of elevated <i>p</i>CO₂ and variable O₂ on righting time, feeding, growth, and gonadosomatic index (GSI) were investigated for both groups. Results suggest that the acidosis found during experiment one does not directly correlate with adverse effects during exposure to realistic future <i>p</i>CO₂ levels

Detection of hypoglycin A and MCPA‐carnitine in equine serum and muscle tissue: optimisation and validation of a LC‐MS based method without derivatisation

Measurement of hypoglycin A (HGA) and its toxic metabolite, methylenecyclopropylacetic acid (MCPA), in equine serum confirms a diagnosis of atypical myopathy (AM), a pasture‐associated toxic rhabdomyolysis with high mortality linked to the ingestion of Acer trees plant material. Supportive diagnostic tests include plasma acyl‐carnitine profiling and urine organic acid testing, but these are not specific for AM. Previously reported HGA and MCPA analytical techniques used liquid chromatography–mass spectrometry (LC‐MS) with a derivatising step, but the latter prolongs testing and increases costs. Objectives To develop a rapid LCMS method for detection of serum and tissue HGA and MCPA that enables expedited diagnosis for horses with AM. Study design Analytical test validation. Methods Validation parameters to industry standards using as criteria precision, accuracy, linearity, reproducibility and stability in analyte‐spiked samples were calculated on 9‐calibration points and 3 different validation concentrations in both serum and muscle tissue. Results The test was successfully validated for the detection of HGA and MCPA‐carnitine in horse serum and muscle. Test linearity was excellent (r2=0.999), accuracy was very good for both analytes (93‐108%), precision did not exceed 10% coefficient of variation and reproducibility met the requirements of the Horwitz equation. Stability was unaffected by storage at a range of temperatures. Main limitations The spectrum of the tested analytes was limited to only two relevant analytes in favour of a quick and easy analysis. Linearity of the muscle method was not evaluated as calibration curves were not produced in this matrix. Conclusion We report an optimised, simplified and validated method for detection of HGA and MCPA‐carnitine in horse serum and muscle suitable for rapid diagnosis of suspected AM cases. The serum based test should also enable risk assessment of toxin exposure in co‐grazing horses and assessment of horses with undiagnosed myopathies, while the tissue detection test should help to confirm cases post‐mortem and to determine toxin distribution, metabolism and clearance across different tissues