1,720,965 research outputs found
The principal toxic glycosidic steroids in Cerbera manghas L. seeds: Identification of cerberin, neriifolin, tanghinin and deacetyltanghinin by UHPLC-HRMS/MS, quantification by UHPLC-PDA-MS
No full textThe toxicity of the sea mango (Cerbera manghas L.) is well known. The plant is ranked as one of the deadliest of the southern Asian coastline. Cardenolidic heterosides are responsible for the cardiotoxicity of trees of the Cerbera genus. We have identified and determined the concentration of the principal glycosidic steroids present in the seeds of sea mangos (Thailand). Drug screening of an extract of the seeds was carried out using ultra-high performance liquid chromatography coupled to photodiode array detection and mass spectrometry (UHPLC-PDA-MS) with quantification at 219. nm. Identification was confirmed by UHPLC-HRMS. Deacetyltanghinin (m/. z 549.3055 ± 2. ppm), neriifolin (m/. z 535.3259 ± 2. ppm), tanghinin (m/. z 591.3169 ± 2. ppm) and cerberin (577.3375 ± 2. ppm) were the most abundant glycosidic steroids present in the sea mango seeds. A seed of the dried ripe fruit had concentrations of 1209.1, 804.2, 621.4 and 285.9. μg/g, respectively. A seed of the fresh unripe fruit had concentrations of 49.4, 47.0, 3.5 and 2.3. μg/g. © 2014 Elsevier B.V
Screening approach by ultra-high performance liquid chromatography-tandem mass spectrometry for the blood quantification of thirty-four toxic principles of plant origin. Application to forensic toxicology
No full textPlant poisonings have left their mark on history and still cause many deaths, whether intentional or accidental. The means to show toxicological evidence of such poisonings should be implemented with great care. This article presents a technique for measuring thirty-nine toxic principles of plant origin in the blood, covering a large amount of toxins from local or exotic plants: α-lobeline, α-solanine, aconitine, ajmaline, atropine, brucine, cephalomannine, colchicine, convallatoxin, cymarine, cytisine, digitoxin, digoxin, emetine, gelsemine, ibogaine, jervine, kavain, lanatoside C, lupanine, mitragynine, neriifolin, oleandrin, ouabain, paclitaxel, physostigmine, pilocarpine, podophyllotoxin, proscillaridin A, reserpine, retrorsine, ricinine, scopolamine, senecionine, sparteine, strophanthidin, strychnine, veratridine and yohimbine. Analysis was carried out using an original ultra-high performance liquid chromatography separation coupled with tandem mass spectrometry detection. Extraction was a standard solid phase extraction performed on Oasis® HLB cartridge. Thirty-four of the thirty-nine compounds were put through a validation procedure. The assay was linear in the calibration curve range from 0.5 or 5μg/L to 1000μg/L according to the compounds. The method is sensitive (LOD from 0.1 to 1.6μg/L). The within-day precision of the assay was less than 22.5% at the LLOQ, and the between-day precision was less than 21.5% for 10μg/L for all the compounds included. The assay accuracy was in the range of 87.4 to 119.8% for the LLOQ. The extraction recovery and matrix effect ranged from 30 to 106% and from -30 to 14%, respectively. It has proven useful and effective in several difficult forensic cases
Fatal intoxication due to ackee (Blighia sapida) in Suriname and French Guyana. GC-MS detection and quantification of hypoglycin-A
No full textBetween 1998 and 2001 the deaths of 16 Surinamese children were recorded along the Maroni River, which forms the border between Suriname and French Guyana. After a metabolic origin was eliminated, ethnobotanical research in the field led to a hypothesis of intoxication through the ingestion of ackee. Ackee (Blighia sapida) is a large green leafy tree of West African origin. Its unripe fruit contains large quantities of two toxic molecules: hypoglycin-A and hypoglycin-B, the former being the more toxic. We have developed a GC-MS procedure allowing us to demonstrate the presence of hypoglycin-A in the gastric fluid of one of the deceased children, and to compare the content of hypoglycin-A in fruit collected on the road to Paramaribo in Suriname (5.1. mg/g) with samples from Burkina Faso (8.1. mg/g) and Jamaica (9.2. mg/g).Field research showed the misuse of this little-known plant by Maroon witch doctors. The Bushinengue witch doctors were informed about the dangers of ackee, and no new cases have been reported to date. © 2011 Elsevier Ireland Ltd
A validated method for quantifying atractyloside and carboxyatractyloside in blood by hplc-hrms/ms, a non-fatal case of intoxication with atractylis gummifera l
No full textAtractyloside (ATR) and carboxyatractyloside (CATR) are diterpene glycosides that are responsible for the toxicity of several Asteraceae plants around the world. Mediterranean gum thistle (Atractylis gummifera L.) and Zulu impila (Callilepis laureola DC.), in particular, are notoriously poisonous and the cause of many accidental deaths, some suicides and even some murders. There is no current method for measuring the two toxins in biological samples that meet the criteria of specificity required in forensic medicine. We have endeavored to fill this analytical gap. Analysis was carried out using a solid-phase extraction and a high-performance liquid chromatography coupled with high-resolution tandem mass spectrometry detection. The method was validated in the whole blood with quantification limits of 0.17 and 0.15 mg/L for ATR and CATR, respectively. The method was applied to a non-fatal case of intoxication with A. gummifera. To the best of the authors' knowledge, this is the first time that a concentration of ATR and CATR in blood (883.1 and 119.0 mg/L, respectively) and urine (230.4 and 140.3 mg/L, respectively) is reported. ATR and CATR were quantified in A. gummifera roots by the standard method addition (3.7 and 5.4 mg/g, respectively)
Fatal intoxication after taking iboga: GC-MS/MS determination of ibogaine and ibogamine in iboga roots and post-mortem material
No full textObjective: Tabernanthe iboga, or iboga, is a shrub native to equatorial Africa. Its root is commonly taken as a stimulant and hallucinogen. Ibogaine, the principal alcaloid in the plant, is the source of its psychotropic effects. We report the case of a 27-year-old man with a long history of drug addiction who was found dead in 2006, 12 hours after ingesting powdered iboga root as part of a detoxification programme. Ibogaine and ibogamine were identified and quantified in the powder ingested and in the body fluid samples taken at the scene of death and during the autopsy. Methods: Analysis was carried out using GC-MS/MS (electron impact - ion trap) after performing liquid-liquid extraction on the body fluids. Results: The concentrations measured in the post-mortem peripheral blood samples taken at the scene, and in the peripheral blood, urine and gastric juice samples taken during the autopsy were: 0.65, 1.27, 1.71 and 53.5 μg mL-1 for ibogaine; and 0.05, 0.10, 1.12 and 4.34 μg mL-1 for ibogamine. The powder was titrated at 7.2 per cent for ibogaine and 0.6 per cent for ibogamine. Conclusion: The presence of the two molecules in the biological samples was consistent with the recent ingestion of Tabernanthe iboga roots. The combined consumption of other central nervous system depressants (diazepam and methadone), revealed by further toxicological analysis, confirms the hypothesis of death caused by mixed overdose, of which the principal toxin was ibogaine. © 2012 Société Française de Toxicologie Analytique
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
A validated method for quantifying hypoglycin A in whole blood by UHPLC-HRMS/MS
No full textHypoglycin A (HGA) is the toxic principle in ackee (Blighia sapida Koenig), a nutritious and readily available fruit which is a staple of the Jamaican working-class and rural population. The aril of the unripe fruit has high concentrations of HGA, the cause of Jamaican vomiting sickness, which is very often fatal. HGA is also present in the samara of several species of maple (Acer spp.) which are suspected to cause seasonal pasture myopathy in North America and equine atypical myopathy in Europe, often fatal for horses. The aim of this study was to develop a method for quantifying HGA in blood that would be sensitive enough to provide toxicological evidence of ackee or maple poisoning. Analysis was carried out using solid-phase extraction (HILIC cartridges), dansyl derivatization and UHPLC-HRMS/MS detection. The method was validated in whole blood with a detection limit of 0.35. μg/L (range: 0.8-500. μg/L). This is the first method applicable in forensic toxicology for quantifying HGA in whole blood. HGA was quantified in two serum samples from horses suffering from atypical myopathy. The concentrations were 446.9 and 87.8. μg/L. HGA was also quantified in dried arils of unripe ackee fruit (Suriname) and seeds of sycamore maple (Acer pseudoplatanus L.) (France). The concentrations were 7.2 and 0.74. mg/g respectively
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