Inter-laboratory comparison of plant volatile analyses in the light of intra-specific chemodiversity.

INTRODUCTION: Assessing intraspecific variation in plant volatile organic compounds (VOCs) involves pitfalls that may bias biological interpretation, particularly when several laboratories collaborate on joint projects. Comparative, inter-laboratory ring trials can inform on the reproducibility of such analyses. OBJECTIVES: In a ring trial involving five laboratories, we investigated the reproducibility of VOC collections with polydimethylsiloxane (PDMS) and analyses by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). As model plant we used Tanacetum vulgare, which shows a remarkable diversity in terpenoids, forming so-called chemotypes. We performed our ring-trial with two chemotypes to examine the sources of technical variation in plant VOC measurements during pre-analytical, analytical, and post-analytical steps. METHODS: Monoclonal root cuttings were generated in one laboratory and distributed to five laboratories, in which plants were grown under laboratory-specific conditions. VOCs were collected on PDMS tubes from all plants before and after a jasmonic acid (JA) treatment. Thereafter, each laboratory (donors) sent a subset of tubes to four of the other laboratories (recipients), which performed TD-GC-MS with their own established procedures. RESULTS: Chemotype-specific differences in VOC profiles were detected but with an overall high variation both across donor and recipient laboratories. JA-induced changes in VOC profiles were not reproducible. Laboratory-specific growth conditions led to phenotypic variation that affected the resulting VOC profiles. CONCLUSION: Our ring trial shows that despite large efforts to standardise each VOC measurement step, the outcomes differed both qualitatively and quantitatively. Our results reveal sources of variation in plant VOC research and may help to avoid systematic errors in similar experiments.

Meta-analyses of molecular seafood studies identify the global distribution of legal and illegal trade in CITES-regulated European eels.

Authentication of seafood products by means of molecular techniques has relevance for food sustainability and security, as well as international trade regulation, linked to transparency in food manufacturing. We focus on the molecular detection of the depleted European eel Anguilla anguilla, a species for which strict international trade regulations are in place since 2010, in studies conducted outside Europe. We found thirteen studies from nine countries (Canada, China, Japan, Malaysia, Peru, Singapore, South Korea, Taiwan, and USA) for which, on average, 59 ± 28% of the 330 sequenced eel samples comprised European eel. Only China, Japan, South Korea, and USA reported the import of European eel in the years prior to sampling. The authentication of eel products demonstrates a global, in part illegal, trade in European eel, covered up by incomplete or fraudulent labelling. This calls into question the compliance with existing national and international trade regulations and its implications for food safety and sustainability.

Synthesis of novel carbohydrate based pyridinium ionic liquids and cytotoxicity of ionic liquids for mammalian cells.

The large pool of naturally occurring carbohydrates with their diversity in chirality and structure led to the idea of a systematic investigation of carbohydrate based ILs. To this end, we investigated the influence of different ether groups, mainly methyl or ethyl ether, on the secondary OH groups as well as different configurations on physical properties such as melting point, thermostability and especially the influence on cell toxicity. For this investigation we chose α- and ß-methyl-, ß-allyl- and ß-phenyl d-glucopyranose as well as four 1-deoxy-pentoses. In order to be able to classify the results, more ionic liquids with different structural motives were examined for cytotoxicity. Here, we present data that confirm the biocompatibility of such ILs consisting of naturally occurring molecules or their derivatives. The synthesized carbohydrate based ILs were tested for their suitability as additives in coatings for medical applications such as drug-eluting balloons.

[Advanced Systemic Sclerosis: Endovascular Reconstruction of the Aortic Bifurcation for Limb Salvage]. / Endovaskuläre Rekonstruktion der Aortenbifurkation zum Extremitätenerhalt bei fortgeschrittener systemischer Sklerodermie.

History and admission findings A 69-year-old patient was initially hospitalized because of a 1.5 cm ulceration at the back of the right foot which had existed for the last year and become increasingly swollen and painful. Medical history revealed PmScl-positive systemic sclerosis presenting with a massive calcinosis cutis, advanced pulmonary fibrosis and peripheral artery disease. Examinations Inflammatory markers were normal. MR-Angiography of the lower extremities revealed a multi-segmental high-grade stenosis of the aortic bifurcation due to extensively calcified plaques. Considering the high operative risk and potential excessive scar formation the indication for an interventional procedure was established. Treatment and course After uncomplicated aorto-biiliac stent implantation peripheral pulses had significantly improved and wound debridement led to healing of the ulcer. After additional nutritional advice and caloric substitution the patient was dismissed from the hospital in good condition and without complications. Conclusion Endovascular reconstruction of the aortic bifurcation is a safe alternative to surgery especially when patients present with a severe generalized disease and a high operative risk. Interdisciplinary cooperation is crucial for an optimal treatment regimen.

Correlating coating characteristics with the performance of drug-coated balloons--a comparative in vitro investigation of own established hydrogel- and ionic liquid-based coating matrices.

Drug-coated balloons (DCB), which have emerged as a therapeutic alternative to drug-eluting stents in percutaneous cardiovascular intervention, are well described with regard to clinical efficacy and safety within a number of clinical studies. In vitro studies elucidating the correlation between coating additive and DCB performance are however rare but considered important for the understanding of DCB requirements and the improvement of established DCB. In this regard, we examined three different DCB-systems, which were developed in former studies based on the ionic liquid cetylpyridinium salicylate, the body-own hydrogel hyaluronic acid and the pharmaceutically well-established hydrogel polyvinylpyrrolidone, considering coating morphology, coating thickness, drug-loss, drug-transfer to the vessel wall, residual drug-concentration on the balloon surface and entire drug-load during simulated use in an in vitro vessel model. Moreover, we investigated particle release of the different DCB during simulated use and determined the influence of the three coatings on the mechanical behavior of the balloon catheter. We could show that coating characteristics can be indeed correlated with the performance of DCB. For instance, paclitaxel incorporation in the matrix can reduce the drug wash-off and benefit a high drug transfer. Additionally, a thin coating with a smooth surface and high but delayed solubility can reduce drug wash-off and decrease particle burden. As a result, we suggest that it is very important to characterize DCB in terms of mentioned properties in vitro in addition to their clinical efficacy in order to better understand their function and provide more data for the clinicians to improve the tool of DCB in coronary angioplasty.

MR evaluation of vessel size imaging of human gliomas: Validation by histopathology.

PURPOSE: To compare the vessel size and the cerebral blood volume in human gliomas with histopathology. Vessel size imaging (VSI) is a dynamic susceptibility contrast method for the assessment of the vessel size in normal and pathological tissue. Previous publications in rodents showed a satisfactory conformity with the vessel size derived from histopathology. To assess the clinical value, further, the progression-free interval was determined and correlated. MATERIALS AND METHODS: Twenty-five gliomas (WHO grade °II [n = 10], °III [n = 3], °IV [n = 12]) were prospectively included and received a stereotaxic biopsy after VSI. The vessel size and the cerebral blood volume (CBV) were calculated in regions of interest at the tumor edge and correlated with the vessel size measured by histopathology. RESULTS: Both VSI and CBV showed a good correlation with the vessel size in histopathology (up to r = 0.84, P < 0.001, and r = 0.62, P < 0.001, respectively). Slope and offset of the linear regression (y = 0.77x + 0.36 µm) suggest that the size of normal capillaries is overestimated with VSI, while for grossly enlarged vessels an underestimation occurs. Both VSI and CBV were negatively correlated with the progression-free interval (r = -0.57, P = 0.008, and r = -0.50, P = 0.025, respectively). CONCLUSION: The correlation between VSI and vessel size from histopathology is in good accordance with the animal studies. The overestimation of small capillary sizes is also known from the animal trials. Vessel size and CBV showed similar results, both for the correlation with the histopathological vessel size and the progression-free interval.

Novel paclitaxel-coated angioplasty balloon catheter based on cetylpyridinium salicylate: preparation, characterization and simulated use in an in vitro vessel model.

Drug-coated balloons (DCB), which have emerged as therapeutic alternative to drug-eluting stents in percutaneous cardiovascular intervention, are well described with regard to clinical efficiency and safety within a number of clinical studies. In vitro studies elucidating the correlation of coating method and composition with DCB performance are however rare but considered important for the understanding of DCB requirements and the improvement of established DCB. In this context, we evaluated the applicability of a pipetting, dip-coating, and spray-coating process for the establishment of DCB based on paclitaxel (PTX) and the ionic liquid cetylpyridinium salicylate (Cetpyrsal) as novel innovative additive in three different compositions. Among tested methods and compositions, the pipetting process with 50 wt.% PTX resulted in most promising coatings as drug load was less controllable by the other processes and higher PTX contents led to considerable drug crystallization, as visualized by electron microscopy, accelerating PTX loss during short-term elution. Applying these conditions, homogeneous coatings could be applied on balloon catheter, whose simulated use in an in vitro vessel model revealed percental drug losses of 36 and 28% during transit and percental drug transfers of 12 and 40% under expansion for coatings applied in expanded and folded balloon condition, respectively. In comparison to literature values, these results support the high potential of Cetpyrsal as novel DCB matrix regarding low drug loss and efficient drug transfer.

Ionic liquids for two-phase systems and their application for purification, extraction and biocatalysis.

The development of biotechnological processes using novel two-phase systems based on molten salts known as ionic liquids (ILs) got into the focus of interest. Many new approaches for the beneficial application of the interesting solvent have been published over the last years. ILs bring beneficial properties compared to organic solvents like nonflammability and nonvolatility. There are two possible ways to use the ILs: first, the hydrophobic ones as a substitute for organic solvents in pure two-phase systems with water and second, the hydrophilic ones in aqueous two-phase systems (ATPS). To effectively utilise IL-based two-phase systems or IL-based ATPS in biotechnology, extensive experimental work is required to gain the optimal system parameters to ensure selective extraction of the product of interest. This review will focus on the most actual findings dealing with the basic driving forces for the target extraction in IL-based ATPS as well as presenting some selected examples for the beneficial application of ILs as a substitute for organic solvents. Besides the research focusing on IL-based two-phase systems, the "green aspect" of ILs, due to their negligible vapour pressure, is widely discussed. We will present the newest results concerning ecotoxicity of ILs to get an overview of the state of the art concerning ILs and their utilisation in novel two-phase systems in biotechnology.