Ingestion of leaves of the European yew tree (Taxus baccata) can result in fatal cardiac arrhythmias and acute cardiogenic shock. This cardiotoxicity derives from taxine alkaloids that block cardiac voltage-gated sodium and calcium channels. Prompt initiation of venoarterial extracorporeal membrane oxygenation is essential to bridge these critically ill patients to recovery, as there is no antidote available. We here report a 39-year old patient with toxic cardiogenic shock after yew poisoning, who was successfully rescued by venoarterial extracorporeal membrane oxygenation and had a full neurological recovery. This report emphasizes the role of intoxications as reversible causes of cardiac arrest and adds further evidence to the body of existing literature thus encouraging the early use of venoarterial extracorporeal membrane oxygenation in patients with yew poisoning and cardiogenic shock.

The mating system is a central parameter of plant biology because it shapes their ecological and evolutionary properties. Therefore, determining ecological variables that influence the mating system is important for a deeper understanding of the functioning of plant populations. Here, using old concepts and recent statistical developments, we propose a new statistical tool to make inferences about ecological determinants of outcrossing in natural plant populations. The method requires codominant genotypes of seeds collected from maternal plants within different locations. Using extensive computer simulations, we demonstrated that the method is robust to the issues expected for real-world data, including the Wahlund effect, inbreeding and genotyping errors such as allele dropout and allele misclassification. Furthermore, we showed that the estimates of ecological effects and outcrossing rates can be severely biased if genotyping errors and genetic differentiation are not treated explicitly. Application of the new method to the case study of a dioecious tree (Taxus baccata) allowed revealing that female trees that grow in lower local densities have a greater tendency towards mating with relatives. Moreover, we also demonstrated that biparental inbreeding is higher in populations that are characterized by a longer mean distance between trees and a smaller mean trunk perimeter. We found these results to agree with both the theoretical predictions and the history of English yew.

Taxus (yew) is one of the most frequently reported plants causing potentially fatal outcome when taken incidentally or for suicidal reasons. A fast and reliable method of detection of poisonous compounds or their metabolites is critical in life-saving procedures in cases of yew ingestion. Previously, several chromatographic analytical procedures have been described usually taking longer than one hour of total analysis time.
In this report we describe a suicide case study and an ad hoc developed fast method of detection and quantitation of 3,5-dimethoxyphenol - the main taxane metabolite in the blood plasma from the patient as well as the determination of major taxine components in the plant material (Taxus baccata). At present, there is no reasonable alternative for mass spectrometry that could match its high sensitivity and accuracy, and Multiple Reaction Monitoring could be adequate and useful mass spectrometry technique in analyzing and identification of plants material compounds that cause severe poisoning in humans. In the reported case, intensive cardiac care together with the astuteness of the treating physicians not only saved the patient\'s life, but also allowed for his complete recovery and return to work.
The development of ultra fast liquid chromatography tandem mass spectrometry UFLC-MS/MS method provides a fast means to confirm yew alkaloids and their metabolite in various material. The applied analytical procedure allows early detection of main metabolite in patient material as well as comparing to those extracted from the plant. In our study, the taxanes remained undetected, probably due to the time elapsing from the patient admittance and collection of plasma. In cases like those reported in this study, retaining the gastric material should be obligatory to confirm the ingestion of yew. The possibility of using this approach in detection of native taxine compounds in human plasma remains to be verified.

Genetic markers used in combination with network analysis can characterize the fine spatial pattern of seed dispersal and assess the differential contribution of dispersers. As a case study, we focus on the seed dispersal service provided by a small guild of frugivorous birds to the common yew, Taxus baccata L., in southern Spain. We build the spatial networks of seed dispersal events between trees and seed-plots within the studied population-local network-and the spatial network that includes all dispersal events-regional network. Such networks are structured in well-defined modules, i.e. groups of tightly connected mother trees and seed-plots. Neither geographical distance, nor microhabitat type explained this modular structure, but when long-distance dispersal events are incorporated in the network it shows a relative increase in overall modularity. Independent field observations suggested the co-occurrence of two complementary groups, short- and long-distance dispersers, mostly contributing to the local and regional seed rain, respectively. The main long-distance disperser at our site, Turdus viscivorus, preferentially visits the most productive trees, thus shaping the seed rain at the landscape scale and affecting the local modular organization. We end by discussing how DNA barcoding could serve to better quantify the role of functional diversity.

Development and testing of Spektraris-NMR, an online spectral resource, is reported for the NMR-based structural identification of plant natural products (PNPs). Spektraris-NMR allows users to search with multiple spectra at once and returns a table with a list of hits arranged according to the goodness of fit between query data and database entries. For each hit, a link to a tabulated alignment of (1)H NMR and (13)C NMR spectroscopic peaks (query versus database entry) is provided. Furthermore, full spectroscopic records and experimental meta information about each database entry can be accessed online. To test the utility of Spektraris-NMR for PNP identification, the database was populated with NMR data (total of 466 spectra) for ∼ 250 taxanes, which are structurally complex diterpenoids (including the anticancer drug taxol) commonly found in the genus Taxus. NMR data generated with metabolites purified from Taxus cell suspension cultures were then used to search Spektraris-NMR, and enabled the identification of eight taxanes with high confidence. A ninth isolated metabolite could be assigned, based on spectral searches, to a taxane skeletal class, but no high confidence hit was produced. Using various spectroscopic methods, this metabolite was characterized as 2-deacetylbaccatin IV, a novel taxane. These results indicate that Spektraris-NMR is a valuable resource for rapid and reliable identification of known metabolites and has the potential to contribute to de-replication efforts in novel PNP discovery.

The Taxus canadensis phenylalanine aminomutase (TcPAM) catalyze the isomerization of (S)-α-phenylalanine to the (R)-β-isomer. The active site of TcPAM contains the signature 5-methylene-3,5-dihydroimidazol-4-one (MIO) prosthesis, observed in the ammonia lyase class of enzymes. Up to now, there are two plausible mechanisms for these MIO-dependent enzymes, i.e., the amino-MIO adduct mechanism and the Friedel-Crafts-type reaction mechanism. In response to this mechanistic uncertainty, the phenylalanine aminomutase mechanism was investigated by using density functional methods. The calculation results indicate that: (1) the reaction prefers the amino-MIO adduct mechanism where the 2,3-amine shift process contains six elementary steps; (2) the ammonia elimination step proceeds through an E2 mechanism; (3) a single C1Cα bond rotation of 180° in the cinnamate skeleton occurs in the active site prior to the rebinding of NH2 group to the cinnamate. This can be used to explain the stereochemistry of the TcPAM reaction product which is contrary to those of the PaPAM and SgTAM enzymes. Based on these calculations, the roles of important residues in the active site were also elucidated.

Although DNA barcoding has become a useful tool for species identification and biodiversity surveys in plant sciences, there remains little consensus concerning appropriate sampling strategies and the treatment of indels. To address these two issues, we sampled 39 populations for nine Taxus species across their entire ranges, with two to three individuals per population randomly sampled. We sequenced one core DNA barcode (matK) and three supplementary regions (trnH-psbA, trnL-trnF and ITS) for all samples to test the effects of sampling design and the utility of indels. Our results suggested that increasing sampling within-population did not change the clustering of individuals, and that meant within-population P-distances were zero for most populations in all regions. Based on the markers tested here, comparison of methods either including or excluding indels indicated that discrimination and nodal support of monophyletic groups were significantly increased when indels were included. Thus we concluded that one individual per population was adequate to represent the within-population variation in these species for DNA barcoding, and that intra-specific sampling was best focused on representing the entire ranges of certain taxa. We also found that indels occurring in the chloroplast trnL-trnF and trnH-psbA regions were informative to differentiate among for closely related taxa barcoding, and we proposed that indel-coding methods should be considered for use in future for closed related plant species DNA barcoding projects on or below generic level.

Japanese yew is a widely used ornamental plant. However, most people are unaware that it is also a poisonous plant. It has potent cardiac toxicities that can lead to sudden cardiac death. A 37-year-old female patient presented to the emergency room with altered mental status and sustained ventricular tachycardia (VT). Electrocardiogram (ECG) after cardioversion showed profound QRS prolongation and ST-segment elevation suggestive of either hyperkalaemia, acute myocardial ischaemia, or Brugada syndrome. Her electrolytes and coronary angiography were normal. After improvement of the patient\'s mental status, she admitted that she has been consuming Japanese yew from her yard for several months. Few hours later, QRS duration normalised, but mild ST-segment elevation persisted in the right pre-cordial leads, making it more suspicious for Brugada syndrome. However, a procainamide challenge test and electrophysiology study failed to induce typical Brugada pattern ECG and VT. The absence of coronary artery disease and electrolytes disturbances points toward the fact that her arrhythmia and ECG changes are secondary to yew intoxication. The patient was monitored for a few days. She was haemodynamically stable and has not had any arrhythmia. This case highlights the importance of public awareness of severe toxicity from Japanese yew or other yew plants. Yews contain taxines that are responsible for the ECG abnormalities due to its inhibitory effect on the cardiac sodium and calcium channels. They cause conduction abnormalities, VT, and ST-segment elevation that can resemble acute myocardial infarction, hyperkalaemia, and Brugada syndrome.

Intoxications with yew (Taxus spp.) pose a challenge to forensic toxicology because a variety of Taxus ingredients have been associated with its toxic effects. To provide preliminary evidence in cases where plant material is available, we introduce a novel direct PCR assay for the detection of DNA traces from Taxus spp. This assay has been successfully applied to a forensic case of suicidal poisoning via ingestion of Taxus leaves. PCR primers were designed to target a sequence located in the internal transcribed spacer 1 (ITS1) of nuclear ribosomal DNA, which is well conserved among species of the genus Taxus and can, therefore, be exploited to discriminate between Taxus and other conifers. Because ITS1 exists as a multicopy sequence within the plant genome, the assay provides enough sensitivity to work with trace amounts that are below the DNA content of a single cell. Specificity of the assay was tested with DNA extracts from Taxaceae and selected representatives from other related plant families (Cephalotaxaceae, Cupressaceae and Pinaceae). When combined with the commercial Phire® Plant Direct PCR Kit (Finnzymes), the primers allowed application of a two-step cycling protocol (without the annealing step), and because direct PCR requires only little sample pre-treatment, results from PCR could be obtained within 1.5 h after analysis had begun. Direct PCR was performed with diluted gastric content from the forensic case. Amplification products of the expected size were purified and sequenced. Sequence data were subjected to Basic Local Alignment Search Tool analysis and affiliated with ITS1 from Taxus spp.

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