Cytotoxicity of Prymnesium parvum extracts and prymnesin analogs on epithelial fish gill cells RTgill-W1 and the human colon cell line HCEC-1CT

Harmful algal blooms kill fish populations worldwide, as exemplified by the haptophyte microalga Prymnesium parvum. The suspected causative agents are prymnesins, categorized as A-, B-, and C-types based on backbone carbon atoms. Impacts of P. parvum extracts and purified prymnesins were tested on the epithelial rainbow trout fish gill cell line RTgill-W1 and on the human colon epithelial cells HCEC-1CT. Cytotoxic potencies ranked A > C > B-type with concentrations spanning from low (A- and C-type) to middle (B-type) nM ranges. Although RTgill-W1 cells were about twofold more sensitive than HCEC-1CT, the cytotoxicity of prymnesins is not limited to fish gills. Both cell lines responded rapidly to prymnesins; with EC50 values for B-types in RTgill-W1 cells of 110 ± 11 nM and 41.5 ± 0.6 nM after incubations times of 3 and 24 h. Results of fluorescence imaging and measured lytic effects suggest plasma membrane interactions. Postulating an osmotic imbalance as mechanisms of toxicity, incubations with prymnesins in media lacking either Cl-, Na+, or Ca2+ were performed. Cl- removal reduced morphometric rearrangements observed in RTgill-W1 and cytotoxicity in HCEC-1CT cells. Ca2+-free medium in RTgill-W1 cells exacerbated effects on the cell nuclei. Prymnesin composition of different P. parvum strains showed that analog composition within one type scarcely influenced the cytotoxic potential, while analog type potentially dictate potency. Overall, A-type prymnesins were the most potent ones in both cell lines followed by the C-types, and lastly B-types. Disturbance of Ca2+ and Cl- ionoregulation may be integral to prymnesin toxicity.

Mycotoxin contamination in the Arab world: Highlighting the main knowledge gaps and the current legislation

Since the discovery of aflatoxins in the 1960s, knowledge in the mycotoxin research field has increased dramatically. Hundreds of review articles have been published summarizing many different aspects, including mycotoxin contamination per country or region. However, mycotoxin contamination in the Arab world, which includes 22 countries in Africa and Asia, has not yet been specifically reviewed. To this end, the contamination of mycotoxins in the Arab world was reviewed not only to profile the pervasiveness of the problem in this region but also to identify the main knowledge gaps imperiling the safety of food and feed in the future. To the best of our knowledge, 306 (non-)indexed publications in English, Arabic, or French were published from 1977 to 2021, focusing on the natural occurrence of mycotoxins in matrices of 14 different categories. Characteristic factors (e.g., detected mycotoxins, concentrations, and detection methods) were extracted, processed, and visualized. The main results are summarized as follows: (i) research on mycotoxin contamination has increased over the years. However, the accumulated data on their occurrences are scarce to non-existent in some countries; (ii) the state-of-the-art technologies on mycotoxin detection are not broadly implemented neither are contemporary multi-mycotoxin detection strategies, thus showing a need for capacity-building initiatives; and (iii) mycotoxin profiles differ among food and feed categories, as well as between human biofluids. Furthermore, the present work highlights contemporary legislation in the Arab countries and provides future perspectives to mitigate mycotoxins, enhance food and feed safety, and protect the consumer public. Concluding, research initiatives to boost mycotoxin research among Arab countries are strongly recommended.

Hazard characterization of Alternaria toxins to identify data gaps and improve risk assessment for human health

Fungi of the genus Alternaria are ubiquitous plant pathogens and saprophytes which are able to grow under varying temperature and moisture conditions as well as on a large range of substrates. A spectrum of structurally diverse secondary metabolites with toxic potential has been identified, but occurrence and relative proportion of the different metabolites in complex mixtures depend on strain, substrate, and growth conditions. This review compiles the available knowledge on hazard identification and characterization of Alternaria toxins. Alternariol (AOH), its monomethylether AME and the perylene quinones altertoxin I (ATX-I), ATX-II, ATX-III, alterperylenol (ALP), and stemphyltoxin III (STTX-III) showed in vitro genotoxic and mutagenic properties. Of all identified Alternaria toxins, the epoxide-bearing analogs ATX-II, ATX-III, and STTX-III show the highest cytotoxic, genotoxic, and mutagenic potential in vitro. Under hormone-sensitive conditions, AOH and AME act as moderate xenoestrogens, but in silico modeling predicts further Alternaria toxins as potential estrogenic factors. Recent studies indicate also an immunosuppressive role of AOH and ATX-II; however, no data are available for the majority of Alternaria toxins. Overall, hazard characterization of Alternaria toxins focused, so far, primarily on the commercially available dibenzo-α-pyrones AOH and AME and tenuazonic acid (TeA). Limited data sets are available for altersetin (ALS), altenuene (ALT), and tentoxin (TEN). The occurrence and toxicological relevance of perylene quinone-based Alternaria toxins still remain to be fully elucidated. We identified data gaps on hazard identification and characterization crucial to improve risk assessment of Alternaria mycotoxins for consumers and occupationally exposed workers.

Estrogen receptor α interaction of zearalenone and its phase I metabolite α-zearalenol in combination with soy isoflavones in hERα-HeLa-9903 cells

Risk assessment primarily relies on toxicological data of individual substances, with limited information on combined effects. Recent in vitro experiments using Ishikawa cells, an endometrial carcinoma cell line expressing both estrogen receptor isoforms, demonstrated interactive effects of phyto- and mycoestrogens. The mycoestrogens, zearalenone (ZEN), and α-zearalenol (α-ZEL) exhibited significantly enhanced estrogenic responses in the presence of isoflavones (ISF), depending on substance ratios and concentrations. This study investigated the impact of phyto- and mycoestrogen combinations on estrogenic response following OECD guideline 455, utilizing hERα-HeLa-9903 cells. Test substances included mycoestrogens (ZEN and α-ZEL) and isoflavones (genistein (GEN), daidzein (DAI), and S-equol (EQ), a gut microbial metabolite of DAI). Mycoestrogens were tested in the range of 0.001 to 100 nM, while isoflavones were used at concentrations 1000 times higher based on relevant occurrence ratios. Results showed that ZEN and α-ZEL induced ERα-dependent luciferase expression in concentrations above 1 nM and 0.01 nM, respectively. However, ISF caused a superinduction of the luciferase signal above 1 µM. A superinduction is characterized by an unusually strong or heightened increase in the activity of the luciferase enzyme. This signal is not affected by the estrogen receptor antagonist 4-hydroxytamoxifen (4-OH-TAM), which was additionally used to verify whether the increase of signal is a true reflection of receptor activation. This superinduction was observed in all combinations of ZEN and α-ZEL with ISFs. Contrary to the luciferase activity findings, RT-qPCR experiments and a stability approach revealed lower real ERα activation by ISFs than measured in the ONE-Glo™ luciferase test system. In conclusion, the OECD protocol 455 appears unsuitable for testing ISFs due to their superinduction of luciferase and interactions with the test system, resulting in experimental artifacts. Further studies are necessary to explore structure-activity relationships within polyphenols and clarify the test system's applicability.

Genotoxic and Mutagenic Effects of the Alternaria Mycotoxin Alternariol in Combination with the Process Contaminant Acrylamide

Humans are constantly exposed to mixtures of different xenobiotics through their diet. One emerging concern is the Alternaria mycotoxin alternariol (AOH), which can occur in foods typically contaminated by the process contaminant acrylamide (AA). AA is a byproduct of the Maillard reaction produced in carbohydrate-rich foods during thermal processing. Given the genotoxic properties of AOH and AA as single compounds, as well as their potential co-occurrence in food, this study aimed to assess the cytotoxic, genotoxic, and mutagenic effects of these compounds in combination. Genotoxicity was assessed in HepG2 cells by quantifying the phosphorylation of the histone γ-H2AX, induced as a response to DNA double-strand breaks (DSBs). Mutagenicity was tested in Salmonella typhimurium strains TA98 and TA100 by applying the Ames microplate format test. Our results showed the ability of AOH and AA to induce DSBs and increase revertant numbers in S. typhimurium TA100, with AOH being more potent than AA. However, no synergistic effects were observed during the combined treatments. Notably, the results of the study suggest that the compounds exert mutagenic effects primarily through base pair substitutions. In summary, the data indicate no immediate cause for concern regarding synergistic health risks associated with the consumption of foods co-contaminated with AOH and AA.

In Vitro Inhibitory Potential of Different Anthocyanin-Rich Berry Extracts in Murine CT26 Colon Cancer Cells

Anti-oxidant, -inflammatory, and -carcinogenic activities of bioactive plant constituents, such as anthocyanins, have been widely discussed in literature. However, the potential interaction of anthocyanin-rich extracts with routinely used chemotherapeutics is still not fully elucidated. In the present study, anthocyanin-rich polyphenol extracts of blackberry (BB), bilberry (Bil), black currant (BC), elderberry (EB), and their respective main anthocyanins (cyanidin-3-O-glucoside, delphinidin-3-O-glucoside, cyanidin-3-O-rutinoside, and cyanidin-3-O-sambubioside) were investigated concerning their cytotoxic and DNA-damaging properties in murine CT26 cells either alone or in combination with the chemotherapeutic agent SN-38. BB exerted potent cytotoxic effects, while Bil, BC, and EB only had marginal effects on cell viability. Single anthocyanins comprised of the extracts could not induce comparable effects. Even though the BB extract further pronounced SN-38-induced cytotoxicity and inhibited cell adhesion at 100-200 µg/mL, no effect on DNA damage was observed. In conclusion, anti-carcinogenic properties of the extracts on CT26 cells could be ranked BB >> BC ≥ Bil ≈ EB. Mechanisms underlying the potent cytotoxic effects are still to be elucidated since the induction of DNA damage does not play a role.

Molecular Mechanisms Associated with Protecting IEC-6 Cells from Acrylamide-Induced Tight Junction Damage by Ganoderma atrum Polysaccharide

SCOPE

The previous in vivo studies show Ganoderma atrum polysaccharide (PSG-F₂ ) has a protective effect against the acrylamide (AA)-induced intestinal oxidative damage in rats. Now, this study aims to explore the protective mechanism with IEC-6 cell model.

METHODS AND RESULTS

Based on RNA Sequencing (RNA-Seq), the study screens MAPK signaling pathway as one of the most crucial pathways for pretreatment with PSG-F₂   against AA-induced damage in IEC-6 cells. In total, six key MAPK signaling pathway-related proteins (p-P38/P38, p-ERK/ERK, and p-JNK/JNK), and three tight junction key proteins (Zonula Occludens protein-1, Claudin-1, and Occludin) are detected by Western blot and immunofluorescence, which verify the RNA-Seq data. Moreover, PD98059 interference inhibits critical proteins in the MAPK signaling pathway, thus uncovering the precise molecular mechanisms of MAPK/ERK signaling pathway involve in the protective effects of PSG-F₂ against AA-induced intestinal barrier damage.

CONCLUSION

These findings confirm that PSG-F₂ can be used as a daily dietary supplement to protect the intestinal cells from damage caused by thermal processing hazards AA.

Impact of environmental factors on ochratoxin A: From natural occurrence to control strategy

Ochratoxin A (OTA) contamination and the associated issues of food security, food safety and economic loss are widespread throughout the world. The occurrence of OTA depends on ochratoxigenic fungi, foodstuffs and their environment. In this review, natural occurrence and control strategy of OTA, with a focus on the impact of environmental factors, are summarized. First, this manuscript introduces potentially contaminated foodstuffs, including the emerging ones which are not regulated in international legislation. Secondly, it gives an update of native producers based on foodstuffs and OTA biosynthesis. Thirdly, complicated environmental regulation is disassembled into individual factors in order to clarify their regulatory effect and mechanism. Finally, to emphasize control OTA at all stages of foodstuffs from farm to table, strategies used at crop planting, harvest, storage and processing stages are discussed.

Investigating chemical and microbial functional indicators of nutrient retention capacity in greenhouse stormwater retention ponds in southwestern Ontario, Canada

The tributaries flowing through Leamington, Ontario are unique in the Canadian Lake Erie watershed due to the broad spatial extent of greenhouse operations, which more than doubled in size and density from 2011 to 2022. These greenhouse operations are considered to be potential nutrient point sources with respect to observed nutrient concentrations in tributaries adjacent to greenhouse stormwater retention ponds (GSWPs). Identifying causal factors of nutrient release, whether this be chemical or biological, within these ponds may be critical for mitigating their impact on the watershed and ultimately the receiving waters of Lake Erie. Specifically, phosphorus and nitrogen accumulation in freshwater ponds can contribute to environmental damage proximal to adjacent streams, serving as a potential catalyst for algal blooms and eutrophication. This study compared correlations between the water column N:P stoichiometry, sediment nutrient retention capacity, and drivers of microbial metabolism within GSWP sediments. Correlations between water column TN:TP ratios and sediment nutrient retention capacity were observed, suggesting an interplay between N and P in terms of nutrient limitation. Further, clear shifts were observed in the bacterial metabolic pathways analyzed through metatranscriptomics. Specifically, genes related to nitrogen fixation, nitrification and denitrification, and other metabolic processes involving sulfur and methane showed differential expression depending on the condition of the respective pond (i.e., naturalized wetland vs. dredged, eutrophic pond). Collectively, this research serves to highlight the interconnected role of chemical-biological processes particularly as they relate to significant ecosystem processes such as nutrient loading and retention dynamics in impaired freshwater systems.

Surface-Dominated Finite-Size Effects in Nanoconfined Superfluid Helium

Superfluid ^{4}He (He II) is a widely studied model system for exploring finite-size effects in strongly confined geometries. Here, we study He II confined in millimeter-scale channels of 25 and 50 nm height at high pressures using a nanofluidic Helmholtz resonator. We find that the superfluid density is measurably suppressed in the confined geometry from the transition temperature down to 0.6 K. Importantly, this suppression can be accounted for by rotonlike thermal excitations with an energy gap of 5 K. We show that the surface-bound excitations lead to the previously unexplained lack of finite-size scaling of suppression of the superfluid density.

Combinatory Exposure to Urolithin A, Alternariol, and Deoxynivalenol Affects Colon Cancer Metabolism and Epithelial Barrier Integrity in vitro

The human gastrointestinal tract is an important site of nutrient absorption and a crucial barrier against xenobiotics. It regularly faces “chemical cocktails” composed of food constituents, their human and microbial metabolites, and foodborne contaminants, such as mycotoxins. Hence, the colonic epithelium adapts to dietary molecules tuning its immune response, structural integrity, and metabolism to maintain intestinal homeostasis. While gut microbiota metabolites of berry ellagitannins, such as urolithin A (Uro A) might contribute to physiological epithelial barrier integrity, foodborne co-contaminating mycotoxins like alternariol (AOH) and deoxynivalenol (DON) could hamper epithelial function. Hence, we investigated the response of differentiated Caco-2 cells (clone C2BBe1) in vitro to the three compounds alone or in binary mixtures. In virtue of the possible interactions of Uro A, AOH, and DON with the aryl hydrocarbon receptor (AhR) pathway, potential effects on phase-I-metabolism enzymes and epithelial structural integrity were taken as endpoints for the evaluation. Finally, Liquid chromatography tandem mass spectrometry measurements elucidated the absorption, secretion, and metabolic capacity of the cells under single and combinatory exposure scenarios. Uro A and AOH as single compounds, and as a binary mixture, were capable to induce CYP1A1/1A2/1B1 enzymes triggered by the AhR pathway. In light of its ribosome inhibiting capacity, the trichothecene suppressed the effects of both dibenzo-α-pyrones. In turn, cellular responsiveness to Uro A and AOH could be sustained when co-exposed to DON-3-sulfate, instead of DON. Colonic epithelial structural integrity was rather maintained after incubation with Uro A and AOH: this was reinforced in the combinatory exposure scenario and disrupted by DON, an effect, opposed in combination. Passage through the cells as well as the metabolism of Uro A and AOH were rather influenced by co-exposure to DON, than by interaction with each other. Therefore, we conclude that although single foodborne bioactive substances individually could either support or disrupt the epithelial structure and metabolic capacity of colon cancer, exposure to chemical mixtures changes the experimental outcome and calls for the need of combinatory investigations for proper risk assessment.

The brain in oral clefting: preliminary results of a systematic review with meta-analyses

Introduction

Previous neuroimaging studies of individuals with nonsyndromic oral clefts have revealed subtle brain structural differences compared to matched controls. Additional studies strongly suggest that the higher incidence of neuropsychiatric issues observed in these individuals may be explained by these neuroanatomical differences. Currently there are no studies that have assessed the overall empirical evidence of the effect of oral clefts on the brain.

Objectives

Our aim was to summarize available evidence on potential brain structure differences in individuals with nonsyndromic oral clefts and their matched controls. In the current presentation, we discuss the results of regional brain structural differences.

Methods

Five databases were systematically searched in September 2020 for case-control studies that reported neuroimaging in healthy individuals and individuals with nonsyndromic oral clefts. Duplicate study selection, data extraction, random effects meta-analyses of mean differences (MDs) and their 95% confidence intervals were performed in order to compare regional brain MRI volumes.

Results

We have identified 245 records following the database searches, from which 12 records met the inclusion criteria. Quantitative data on brain structure were available in three studies.The cerebellum, occipital and temporal lobes were significantly smaller in the cleft group compared to controls (MD: -12.46, 95% CI: -18.26, -6.67, n=3 studies; MD:-7.39, 95% CI: -12.80, -1.99, n=2 studies; MD: -10.53, 95% CI: -18.23, -2.82, n=2 studies, respectively).

Conclusions

There may be structural brain differences between individuals with nonsyndromic oral clefts and their controls based on the available evidence.

Disclosure

No significant relationships.

The effects of reading literary fiction on the measurement and development of mentalization skills among schizophrenic patients

Introduction

Following the mentalization of interpersonal relations can be improved through reading for which the influence of literary fiction can also serve as a model. Schizophrenia is characterized by extensive deficits in mentalization, and the amelioration of these impairments is a major focus in psychosocial treatment research. Reading literature can be a potential tool in improving mentalizing skills.

Objectives

We aimed to examine and compare healthy participants with patients living with schizophrenia, focusing on measuring mentalizing skills and the impact of reading literary fiction on their mentalization skills.

Methods

47 persons with schizophrenia in remission and 48 healthy controls were assessed and compared with Short Story Task (SST) a new measurement of ToM. SST proved to be a sensitive tool, to individual differences. After reading the short story “The End of Something” (Hemingway) a structured interview was done with 14 questions.

Results

We found that patients with schizophrenia performed significantly worse in their ToM scores compared to healthy controls (ANOVA test, p<0,05 ). Previous reading experiences correlated significantly with mentalizing scores not just in healthy controls (Independent Samples T-test, p<0,05) but also in patients with schizophrenia. ToM scores were twice as high among those who had prior reading experiences in the schizophrenia group ((MS= 3,91, SD=3,166, M=8,08, SD=4,542; p<0,05, t=-3,509).

Conclusions

We found that mentalization skills could be improved by regular reading. Our results could also be influenced by several other factors such as empathy skills, identification with the characters etc. Our results and conclusions are in line with the results of international research on this topic.

Disclosure

No significant relationships.

A systematic review and meta-analysis of implicit Theory of Mind in schizophrenia

Introduction

Everyday social interactions are based on Theory of Mind (ToM) or mentalizing, whose complex processes are involved in understanding, representing one’s own and other people’s mental states. ToM is supposed to have two systems. The implicit ToM seems to be a fast, automatic, non-verbal processing. The explicit ToM is characterized by a slower, but more flexible processing, which is mostly verbal, interpretative. Several studies have described explicit ToM deficit in schizophrenic patients. Less research has investigated implicit ToM in patients, however recently, there has been a growing number of articles examining implicit ToM of patients with schizophrenia.

Objectives

The aim of our systematic review and meta-analysis is to summarize the results of the implicit ToM in schizophrenia.

Methods

A systematic search was performed in four major databases. We included 11 publications. 7 studies; and 5 studies were included the quantitative synthesis and the qualitative synthesis, respectively.

Results

We found significant differences in accuracy, reaction time and brain activation patterns during implicit ToM between schizophrenic patients and controls. The systematic review revealed further alterations in visual scanning, cue fixation, face looking time, and difficulties in perspective taking.

Conclusions

Based on our results implicit ToM is affected in schizophrenia in addition to explicit ToM deficit. However, based on these results we cannot exclude the possibility, that implicit ToM or at least some elements of it might be relatively unaffected (e.g. detection of intentionality), however its effectiveness is limited by non-mentalizing deficits (e.g. certain neurocognitive impairments). Our results may have important implications for the remediation of mentalizing skills.

Disclosure

The research is supported by the Hungarian National Excellence Centrum Grant (FIKP II) and Hungarian Brain Research Program (KTIA-13-NAP-A-II/12).

The investigation of implicit Theory of Mind in patients with schizophrenia – a whole brain fMRI study

Introduction

Theory of Mind is the ability to attribute mental states to others. Investigations have distinguished implicit and explicit forms of ToM. It is known, that patients with schizoprenia have deficits in their explicit ToM, and they also show altered brain activations during examining explicit ToM.

Objectives

In this study our aim was to investigate the underlying neural substrates of implicit ToM in patients with schizophrenia with fMRI.

Methods

Seven healthy subjects and two patients with first episode schizophrenia were involved. We used: false belief condition and control condition. All movies consisted of a belief formation phase and an outcome phase. The belief formation phase started with an agent placing a ball on a table in front of an occluder. Then the ball rolled behind the occluder. The movies could continue in different ways leading to a true or false belief. At the end of each movie, the agent reentered the scene and the occluder was lowered. In the outcome phase the ball was either present or absent behind the occluder. The control conditions started with a ball rolled behind the occluder on a table ended up with two different ways as the ball was either present or absent behind the occluder. There was no agent in the control movies.

Results

We found that healthy subjects activated significantly stronger the left lingual gyrus as well as the right temporoparietal junction.

Conclusions

Our findings suggest deficits in implicit ToM in schizophrenia and our findings also might help to clarify the underlying neural substrates of implicit ToM.

Disclosure

This research project was supported by the KTIA-13-NAP-A-II/12 (2018–2022) and the Hungarian National Excellence Centrum Grant 2018–2019.

PeakBot: Machine learning based chromatographic peak picking

Motivation

Chromatographic peak picking is among the first steps in data processing workflows of raw LC-HRMS datasets in untargeted metabolomics applications. Its performance is crucial for the holistic detection of all metabolic features as well as their relative quantification for statistical analysis and metabolite identification. Random noise, non-baseline separated compounds and unspecific background signals complicate this task.

Results

A machine-learning-based approach entitled PeakBot was developed for detecting chromatographic peaks in LC-HRMS profile-mode data. It first detects all local signal maxima in a chromatogram, which are then extracted as super-sampled standardized areas (retention-time versus m/z). These are subsequently inspected by a custom-trained convolutional neural network that forms the basis of PeakBot’s architecture. The model reports if the respective local maximum is the apex of a chromatographic peak or not as well as its peak center and bounding box. In training and independent validation datasets used for development, PeakBot achieved a high performance with respect to discriminating between chromatographic peaks and background signals (accuracy of 0.99). For training the machine-learning model a minimum of 100 reference features are needed to learn their characteristics to achieve high-quality peak-picking results for detecting such chromatographic peaks in an untargeted fashion. PeakBot is implemented in python (3.8) and uses the TensorFlow (2.5.0) package for machine-learning related tasks. It has been tested on Linux and Windows OSs.

Availability and implementation

The package is available free of charge for non-commercial use (CC BY-NC-SA). It is available at https://github.com/christophuv/PeakBot.

Supplementary information

Supplementary data are available at Bioinformatics online.

The coupling between irradiance, growth, photosynthesis and prymnesin cell quota and production in two strains of the bloom-forming haptophyte, Prymnesium parvum

Prymnesium parvum causes harmful algal blooms worldwide that are often associated with massive fish-kills and subsequent economic losses. Most of our knowledge of the toxicity of P. parvum derives from bioassays since methods for the identification and quantification of their toxins have been lacking. Recently, a quantitation method was developed for the causative lytic toxins, the prymnesins. Here, we for the first time present data on the influence of irradiance on cellular content and production of prymnesins under nutrient replete conditions in two P. parvum strains, which both produce B-type prymnesins. Large differences were observed between the two strains with regard to the influence of irradiance on prymnesin cell quota and production rates. At the highest irradiance level (550 µmol photons m-2 s-1), the cellular prymnesin quota was thirty times higher in strain K-0081 strain than in K-0374. The cellular prymnesin quota and production rates were closely linked to rates of growth and photosynthesis in strain K-0081, while this was not the case for K-0374. Yet, growth rate did explain the differences in prymnesin quota in the two strains. Consequently, the maximum prymnesin production rate (414 attomol cell-1 d-1) was only about three times higher in strain K-0081 than in K-0374, and revealed an optimum at the same irradiance of 200 µmol photons m-2 s-1 in both strains. At low irradiance levels, the difference in production rates between both strains became smaller, with 41 and 49 attomol cell-1 d-1 for K-0081 and K-0374, respectively. The carbon content of prymnesins made up for ∼3% and <1% of the total cellular carbon content in strains K-0081 and K-0374, respectively. The fraction of extracellular dissolved prymnesins was measured for strain K-0081, where it accounted for 14-30% of total prymnesin concentration in the cultures, irrespective of irradiance. The concentrations of prymnesins released to the water by the K-0081 strain were not significantly influenced by irradiance. Overall, we observed comparable responses in growth and photosynthesis of both tested strains toward changes in irradiance. However, the effects of irradiance on prymnesin quota and production rates were remarkably different between the two strains.

Isoflavones in Animals: Metabolism and Effects in Livestock and Occurrence in Feed

Soybeans are a common ingredient of animal feed. They contain isoflavones, which are known to act as phytoestrogens in animals. Isoflavones were described to have beneficial effects on farm animals. However, there are also reports of negative outcomes after the consumption of isoflavones. This review summarizes the current knowledge of metabolization of isoflavones (including the influence of the microbiome, phase I and phase II metabolism), as well as the distribution of isoflavones and their metabolites in tissues. Furthermore, published studies on effects of isoflavones in livestock species (pigs, poultry, ruminants, fish) are reviewed. Moreover, published studies on occurrence of isoflavones in feed materials and co-occurrence with zearalenone are presented and are supplemented with our own survey data.

Polyketide synthase genes and molecular trade-offs in the ichthyotoxic species Prymnesium parvum

Prymnesium parvum is a bloom forming haptophyte that has been responsible for numerous fish kill events across the world. The toxicity of P. parvum has been attributed to the production of large polyketide compounds, collectively called prymnesins, which based on their structure can be divided into A-, B- and C-type. The polyketide chemical nature of prymnesins indicates the potential involvement of polyketide synthases (PKSs) in their biosynthesis. However, little is known about the presence of PKSs in P. parvum as well as the potential molecular trade-offs of toxin biosynthesis. In the current study, we generated and analyzed the transcriptomes of nine P. parvum strains that produce different toxin types and have various cellular toxin contents. Numerous type I PKSs, ranging from 37 to 109, were found among the strains. Larger modular type I PKSs were mainly retrieved from strains with high cellular toxin levels and eight consensus transcripts were present in all nine strains. Gene expression variance analysis revealed potential molecular trade-offs associated with cellular toxin quantity, showing that basic metabolic processes seem to correlate negatively with cellular toxin content. These findings point towards the presence of metabolic costs for maintaining high cellular toxin quantity. The detailed analysis of PKSs in P. parvum is the first step towards better understanding the molecular basis of the biosynthesis of prymnesins and contributes to the development of molecular tools for efficient monitoring of future blooms.

Peanut-induced anaphylaxis in children and adolescents: Data from the European Anaphylaxis Registry

BACKGROUND

Peanut allergy has a rising prevalence in high-income countries, affecting 0.5%-1.4% of children. This study aimed to better understand peanut anaphylaxis in comparison to anaphylaxis to other food triggers in European children and adolescents.

METHODS

Data was sourced from the European Anaphylaxis Registry via an online questionnaire, after in-depth review of food-induced anaphylaxis cases in a tertiary paediatric allergy centre.

RESULTS

3514 cases of food anaphylaxis were reported between July 2007 - March 2018, 56% in patients younger than 18 years. Peanut anaphylaxis was recorded in 459 children and adolescents (85% of all peanut anaphylaxis cases). Previous reactions (42% vs. 38%; p = .001), asthma comorbidity (47% vs. 35%; p < .001), relevant cofactors (29% vs. 22%; p = .004) and biphasic reactions (10% vs. 4%; p = .001) were more commonly reported in peanut anaphylaxis. Most cases were labelled as severe anaphylaxis (Ring&Messmer grade III 65% vs. 56% and grade IV 1.1% vs. 0.9%; p = .001). Self-administration of intramuscular adrenaline was low (17% vs. 15%), professional adrenaline administration was higher in non-peanut food anaphylaxis (34% vs. 26%; p = .003). Hospitalization was higher for peanut anaphylaxis (67% vs. 54%; p = .004).

CONCLUSIONS

The European Anaphylaxis Registry data confirmed peanut as one of the major causes of severe, potentially life-threatening allergic reactions in European children, with some characteristic features e.g., presence of asthma comorbidity and increased rate of biphasic reactions. Usage of intramuscular adrenaline as first-line treatment is low and needs to be improved. The Registry, designed as the largest database on anaphylaxis, allows continuous assessment of this condition.

The acyltransferase PMAT1 malonylates brassinolide glucoside

Brassinosteroids (BRs) are steroid hormones of plants that coordinate fundamental growth and development processes. Their homeostasis is controlled by diverse means, including glucosylation of the bioactive BR brassinolide (BL), which is catalyzed by the UDP-glycosyltransferases (UGTs) UGT73C5 and UGT73C6 and occurs mainly at the C-23 position. Additional evidence had suggested that the resultant BL-23-O-glucoside (BL-23-O-Glc) can be malonylated, but the physiological significance of and enzyme required for this reaction had remained unknown. Here, we show that in Arabidopsis thaliana malonylation of BL-23-O-Glc is catalyzed by the acyltransferase phenolic glucoside malonyl-transferase 1 (PMAT1), which is also known to malonylate phenolic glucosides and lipid amides. Loss of PMAT1 abolished BL-23-O-malonylglucoside formation and enriched BL-23-O-Glc, showing that the enzyme acts on the glucoside. An overexpression of PMAT1 in plants where UGT73C6 was also overexpressed, and thus, BL-23-O-Glc formation was promoted, enhanced the symptoms of BR-deficiency of UGT73C6oe plants, providing evidence that PMAT1 contributes to BL inactivation. Based on these results, a model is proposed in which PMAT1 acts in the conversion of both endogenous and xenobiotic glucosides to adjust metabolic homeostasis in spatial and temporal modes.

Karmitoxin production by Karlodinium armiger and the effects of K. armiger and karmitoxin towards fish

The dinoflagellate Karlodinium armiger has a huge impact on wild and caged fish during blooms in coastal waters. Recently, a new toxin, karmitoxin, was chemically characterized from K. armiger and a quantification method was established, thereby allowing investigations of the fish killing mechanism. K. armiger is not able to grow in standard growth media that are based on nitrate as a nitrogen source, and successful cultures of this species have only been achieved in mixotrophic cultures after addition of a prey source. Here we show that addition of ammonium (up to 50 µM) to the growth media is a good alternative, as K. armiger batch cultures achieve growth rates, which are comparable to growth rates reached in mixotrophic cultures. Karmitoxin production (1.9 and 2.9 pg cell^-1 d^-1) and cellular karmitoxin content (8.72 ± 0.25 pg cell^-1 and 7.14 ± 0.29 pg cell^-1) were in the same range, though significantly different, in prey-fed cultures and monocultures supplied with ammonium, respectively. Net production of karmitoxin stopped when the K. armiger cultures reached stationary growth phase, indicating no accumulation of karmitoxin in cells or growth media. Toxicity tests towards sheepshead minnow fish larvae indicated rapid death of the fish larvae when exposed to high K. armiger cell concentrations (LT₅₀ of 2.06 h at 44.9 × 10³ cells mL^-1 cultivated with ammonium). Purified toxins caused the same physical damage to fish larvae as living K. armiger cultures. An exposure of purified karmitoxin to fish larvae and rainbow trout gill cells indicated that the fish larvae were about three times less sensitive than gill cells. When comparing the effect of purified toxins with the effect of whole K. armiger cultures, twice the toxin concentration of the purified toxins was needed to cause the same effect. Although a loss of karmitoxin of twenty percent was observed during the incubation, this could not explain the apparent discrepancy. Other factors, like a direct effect of the K. armiger cells on the fish larvae or other, yet unknown toxins may influence the effect of whole cell cultures. To study the effects of released karmitoxin, fish larvae were exposed to a K. armiger culture that was treated with HP-20 resin, which adsorbs extracellular karmitoxin. The 24 h HP-20 treatment resulted in a K. armiger culture that had 37% less total karmitoxin, without a reduction in cell concentration, and a reduced toxic effect was observed in the HP-20 treated culture, as compared to non-treated controls. Fish larvae that were exposed to HP-20 treated culture were immobilized, but survived during the 12 h exposure, whereas the exposure to non-treated culture led to high mortality of the fish larvae. Direct observations under the microscope revealed no evidence of micropredation of K. armiger on the fish larvae during any of the exposures. Thus, the results presented here, indicate that released karmitoxin is the main cause for fish kills by K. armiger. Finally, we found that juvenile rainbow trout were six times more sensitive than fish larvae towards K. armiger, indicating that juvenile fish are more sensitive to K. armiger in bloom situations than early larval stages.

Microfiltration results in the loss of analytes and affects the in vitro genotoxicity of a complex mixture of Alternaria toxins

Alternaria molds produce a variety of chemically diverse secondary metabolites with potentially adverse effects on human health. However, data on occurrence in food and human exposure is inconsistent for some of these mycotoxins. Membrane filtration is a frequent step in many sample preparation procedures for LC-MS-based methods analyzing food contaminants. Yet, little is known about the possibility of adsorptive phenomena that might result in analyte losses. Thus, we treated a complex extract of Alternaria toxins with several types of syringe filters and unraveled the impact on its chemical composition by LC-MS/MS. We observed significant, and in some cases complete, losses of compounds due to filtration. Particularly, two key Alternaria toxins, alternariol (AOH) and its monomethyl ether (AME), were heavily affected. As a comparison with published food surveys indicating a correlation of the type of filtration used with lower incidence reports in food, our results point at a possible underestimation of AME in past exposure assessment. Also, perylene quinones were greatly affected by filtration, underlining the importance to take this into consideration during analytical method development. Furthermore, we applied the comet assay in HT-29 cells to elucidate the impact of filtration on the genotoxicity of the extract. We observed strong coincidences with the loss of epoxide-carrying metabolites and also an intriguing induction of oxidative DNA damage by yet toxicologically uncharacterized Alternaria toxins. In conclusion, we highlight potential issues with sample filtration and call for a critical re-evaluation of previous food occurrence data in the light of the results at hand.

Gut microbiota and undigested food constituents modify toxin composition and suppress the genotoxicity of a naturally occurring mixture of Alternaria toxins in vitro

Molds of the genus Alternaria produce several mycotoxins, some of which may pose a threat for health due to their genotoxicity. Due to the lack of adequate toxicological and occurrence data, they are currently not regulated. Interactions between mycotoxins, gut microbiota and food constituents might occur after food ingestion, modifying the bioavailability and, therefore, overall toxicity of mycotoxins. The present work aimed to investigate the impact of in vitro short-term fecal incubation on the in vitro DNA-damaging effects exerted by 5 µg/mL of an Alternaria alternata extract, containing, among others, 15 nM alternariol, 12 nM alternariol monomethyl ether, 241 nM altertoxin II and 301 nM stemphyltoxin III, all of which are known as genotoxic. The involvement of microorganisms, undigested food constituents and soluble substances of human fecal samples in modifying the composition and the genotoxicity of the extract was investigated through the application of LC-MS/MS analysis and comet assays in HT-29 cells. Results showed that the potential of the mycotoxins to induce DNA strand breaks was almost completely quenched, even before anaerobic incubation, by contact with the different fractions of the fecal samples, while the potency to induce formamidopyrimidine DNA glycosylase (FPG)-sensitive sites was only slightly reduced. These effects were in line with a reduction of mycotoxin concentrations found in samples analyzed by LC-MS/MS. Although a direct correlation between the metabolic activity of the gut microbiota and modifications in mycotoxin contents was not clearly observed, adsorptive phenomena to bacterial cells and to undigested food constituents might explain the observed modifications.

The BAHD Acyltransferase BIA1 Uses Acetyl-CoA for Catabolic Inactivation of Brassinosteroids

Previous research complemented with results on BIA1 enzymatic activities shows that the enzyme regulates brassinosteroid homeostasis via mono- and diacetylation of castasterone

Observation of Bistable Turbulence in Quasi-Two-Dimensional Superflow

Turbulent flow restricted to two dimensions can spontaneously develop order on large scales, defying entropy expectations and in sharp contrast with turbulence in three dimensions where nonlinear turbulent processes act to destroy large-scale order. In this work we report the observation of unusual turbulent behavior in steady-state flow of superfluid ^{4}He-a liquid with vanishing viscosity and discrete vorticity-in a nearly two-dimensional channel. Surprisingly, for a range of experimental parameters, turbulence is observed to exist in two bistable states. This bistability can be well explained by the appearance of large-scale regions of flow of opposite vorticity.

Is it Necessary to Perform Sentinel Lymph Node Biopsy in Thin Melanoma? A Retrospective Single Center Analysis

Sentinel lymph node biopsy (SLNB) is a standard procedure for regional lymph node staging and still has the most important prognostic value for the outcome of patients with thin melanoma. In addition to ulceration, SLNB had to be considered even for a single mitotic figure in thin (<1 mm) melanoma according to AJCC7th guideline, therefore, a retrospective review was conducted involving 403 pT1 melanoma patients. Among them, 152 patients suffered from pT1b ulcerated or mitotic rate ≥ 1/ mm2 melanomas according to the AJCC7th staging system. SLNB was performed in 78 cases, of which nine (11.5%) showed SLN positivity. From them, interestingly, we found a relatively high positive sentinel rate (6/78-8%) in the case of thin primary melanomas ˂0.8 mm. Moreover, the presence of regression increased the probability of sentinel positivity by 5.796 fold. After reassessing pT stage based on the new AJCC8th, 37 pT1b cases were reordered into pT1a category. There was no significant relation between other characteristics examined (age, gender, Breslow, Clark level, and mitosis index) and sentinel node positivity. Based on our data, we suggest that mitotic rate alone is not a sufficiently powerful predictor of SLN status in thin melanomas. If strict histopathological definition criteria are applied, regression might be an additional adverse feature that aids in identifying T1 patients most likely to be SLN-positive. After reassessing of pT1b cases according to AJCC8th regression proved to be independent prognostic factor on sentinel lymph node positivity. Our results propose that sentinel lymph node biopsy might also be considered at patients with regressive thin (˂0.8 mm) melanomas.

Co-Occurrence and Combinatory Effects of Alternaria Mycotoxins and other Xenobiotics of Food Origin: Current Scenario and Future Perspectives

Mycotoxins are low-molecular weight compounds produced by diverse genera of molds that may contaminate food and feed threatening the health of humans and animals. Recent findings underline the importance of studying the combined occurrence of multiple mycotoxins and the relevance of assessing the toxicity their simultaneous exposure may cause in living organisms. In this context, for the first time, this work has critically reviewed the most relevant data concerning the occurrence and toxicity of mycotoxins produced by Alternaria spp., which are among the most important emerging risks to be assessed in food safety, alone or in combination with other mycotoxins and bioactive food constituents. According to the literature covered, multiple Alternaria mycotoxins may often occur simultaneously in contaminated food, along with several other mycotoxins and food bioactives inherently present in the studied matrices. Although the toxicity of combinations naturally found in food has been rarely assessed experimentally, the data collected so far, clearly point out that chemical mixtures may differ in their toxicity compared to the effect of toxins tested individually. The data presented here may provide a solid foothold to better support the risk assessment of Alternaria mycotoxins highlighting the actual role of chemical mixtures on influencing their toxicity.

Zearalenone and ß-Zearalenol But Not Their Glucosides Inhibit Heat Shock Protein 90 ATPase Activity

The mycotoxin zearalenone (ZEN) is produced by many plant pathogenic Fusarium species. It is well known for its estrogenic activity in humans and animals, but whether ZEN has a role in plant–pathogen interaction and which process it is targeting in planta was so far unclear. We found that treatment of Arabidopsis thaliana seedlings with ZEN induced transcription of the AtHSP90.1 gene. This heat shock protein (HSP) plays an important role in plant–pathogen interaction, assisting in stability and functionality of various disease resistance gene products. Inhibition of HSP90 ATPase activity impairs functionality. Because HSP90 inhibitors are known to induce HSP90 gene expression and due to the structural similarity with the known HSP90 inhibitor radicicol (RAD), we tested whether ZEN and its phase I metabolites α- and ß-zearalenol are also HSP90 ATPase inhibitors. Indeed, AtHSP90.1 and wheat TaHSP90-2 were inhibited by ZEN and ß-zearalenol, while α-zearalenol was almost inactive. Plants can efficiently glycosylate ZEN and α/ß-zearalenol. We therefore tested whether glucosylation has an effect on the inhibitory activity of these metabolites. Expression of the A. thaliana glucosyltransferase UGT73C6 conferred RAD resistance to a sensitive yeast strain. Glucosylation of RAD, ZEN, and α/ß-zearalenol abolished the in vitro inhibitory activity with recombinant HSP90 purified from Escherichia coli. In conclusion, the mycotoxin ZEN has a very prominent target in plants, HSP90, but it can be inactivated by glycosylation. This may explain why there is little evidence for a virulence function of ZEN in host plants.

Development of an Indirect Quantitation Method to Assess Ichthyotoxic B-Type Prymnesins from Prymnesium parvum

Harmful algal blooms of Prymnesium parvum have recurrently been associated with the killing of fish. The causative ichthyotoxic agents of this haptophyte are believed to be prymnesins, a group of supersized ladder-frame polyether compounds currently divided into three types. Here, the development of a quantitative method to assess the molar sum of prymnesins in water samples and in algal biomass is reported. The method is based on the derivatization of the primary amine group and subsequent fluorescence detection using external calibrants. The presence of prymnesins in the underivatized sample should be confirmed by liquid chromatography mass spectrometry. The method is currently only partly applicable to water samples due to the low amounts that are present. The growth and cellular toxin content of two B-type producing strains were monitored in batch cultures eventually limited by an elevated pH. The cellular toxin contents varied by a factor of ~2.5 throughout the growth cycle, with the highest amounts found in the exponential growth phase and the lowest in the stationary growth/death phases. The strain K-0081 contained ~5 times more toxin than K-0374. Further investigations showed that the majority of prymnesins were associated with the biomass (89% ± 7%). This study provides the basis for further investigations into the toxicity and production of prymnesins.

Cross-reactivity of commercial and non-commercial deoxynivalenol-antibodies to emerging trichothecenes and common deoxynivalenol-derivatives

Immunoassay based techniques are an important and fast option for the detection and quantification of mycotoxins. They are frequently used as on-site screening tools in grain elevators, storage and production facilities. However, accurate quantification may be hampered by the co-recognition of structurally related metabolites by the used antibodies. Therefore, it is crucial to assess their cross-reactivity to avoid misinterpretation of the results. Several immunoassays for the determination of deoxynivalenol (DON) are commercially available. Recently, novel trichothecene mycotoxins with structures similar to DON, the NX-toxins (NX-2, NX-3 and NX-4), were discovered, which can potentially co-occur with DON in cereals. So far, no data about the cross-reactivity of those toxins with DON-antibodies are available. The aim of this study was to assess the cross-reactivities of NX-toxins and some other DON-related metabolites with DON-antibodies in buffer solutions. Six commercially available enzyme-linked immunosorbent assays (ELISAs) and two previously developed DON-antibodies (Mab#1 and Mab#22) were tested. Cross-reactivity with NX-metabolites was not observed for any of the ELISA-kits nor Mab#22, whereas Mab#1 reacted moderately against NX-3 and NX-4 (cross-reactivity based on a molar basis of 14 and 30%, respectively). Modifications at position C-3 (3-acetyl-DON and DON-3-glucoside) led to moderate or high cross-reactivity with Mab#22 and the commercial ELISA-kits, whereas these compounds were not recognised by Mab#1. Similar to NX-metabolites, 15-acetyl-DON interacted only weakly with Mab#22 and the commercial ELISA-kits, but strongly with Mab#1. The results demonstrate the importance of proper antibody characterisation. If NX-metabolites prove to be widely distributed and reach significant levels, the development of specific antibodies targeting these novel metabolites might become necessary.

The management and genetic background of pityriasis rubra pilaris: a single-centre experience

BACKGROUND

Pityriasis rubra pilaris (PRP) is a rare chronic inflammatory dermatosis with multifactorial aetiology. It is known that particular caspase recruitment domain family member 14 (CARD14) gene mutations are associated with familial PRP and certain forms of psoriasis. Additionally, few data are available about the role of CARD14 gene variants in sporadic PRP. The clinical picture is variable for the different types of PRP, therefore choosing the adequate treatment is often difficult, furthermore there are no specific guidelines for therapy.

OBJECTIVE

Our aim was to survey the efficacy of the applied therapies and to screen the CARD14 gene variants in our PRP patients.

METHODS

In this retrospective study, patients diagnosed with PRP between 2006 and 2016 at our clinic were involved. Besides the follow-up study of the treatments, the genetic analysis of CARD14 gene was performed.

RESULTS

We analysed 19 patients, among whom 17 were diagnosed with type I, one with type III, and one with type V PRP. The majority of the patients were successfully treated with acitretin in combination with systemic corticosteroids, and the remaining patients were treated with other systemic therapies with diverse effects. The genetic screening of CARD14 gene revealed two previously described mutations (rs114688446, rs117918077) and six polymorphisms (rs28674001, rs2066964, rs34367357, rs11653893, rs11652075, rs2289541). Ten of 19 patients carried different CARD14 genetic variants either alone or in combination.

CONCLUSION

Based on our experience, we propose that acitretin and an initial combination of short-term systemic corticosteroid therapy could be a successful treatment option for PRP. Although we identified several CARD14 variants in almost half of our cases, we did not find a correlation between the therapeutic response and the genetic background. Our data support the previous observation that CARD14 genetic variants are not specific to PRP, although they may indicate chronic inflammation.

Presence of varicella zoster virus in zosteriform leukaemia cutis

Leukaemia cutis is a relatively rare manifestation in chronic lymphocytic leukaemia, characterized by a diverse morphology of skin lesions. We report two patients who developed zosteriform skin symptoms; however, the histological analysis revealed leukaemia infiltration as the cause of their symptoms. Contrary to previous reports, varicella zoster virus DNA was detectable in the lesions. These findings suggest that varicella zoster virus plays an active role in the development of zosteriform leukaemia cutis.

A-, B- and C-type prymnesins are clade specific compounds and chemotaxonomic markers in Prymnesium parvum

Harmful blooms formed by planktonic microalgae (HABs) in both freshwater and coastal waters regularly lead to severe mortalities of fish and invertebrates causing substantial economic losses of marine products worldwide. The mixotrophic haptophyte Prymnesium parvum is one of the most important microalgae associated with fish kills. Here 26 strains of P. parvum with a wide geographical distribution were screened for the production of prymnesins, the suspected causative allelochemical toxins. All investigated strains produced prymnesins, indicating that the toxins play an important role for the organism. The prymnesins can be classified into three types based on the length of the carbon backbone of the compound and each algal strain produced only one of these types. Biogeographical mapping of the prymnesin distribution indicated a global distribution of each type. In addition, phylogenetic analyses based on internal transcribed spacer (ITS) sequences revealed monophyletic origin of all prymnesin types and clades could therefore be defined based on the toxic compound. It might be that evolution of new species within the P. parvum species complex is driven by changes in toxin type or that they are a result of it. Such a correlation between chemotype and phylotype has never been documented before for a harmful microalga. Chemotaxonomy and ITS-type classification may thus be used to further delimit the P. parvum species complex.

A-, B- and C-type prymnesins are clade specific compounds and chemotaxonomic markers in Prymnesium parvum

Harmful blooms formed by planktonic microalgae (HABs) in both freshwater and coastal waters regularly lead to severe mortalities of fish and invertebrates causing substantial economic losses of marine products worldwide. The mixotrophic haptophyte Prymnesium parvum is one of the most important microalgae associated with fish kills. Here 26 strains of P. parvum with a wide geographical distribution were screened for the production of prymnesins, the suspected causative allelochemical toxins. All investigated strains produced prymnesins, indicating that the toxins play an important role for the organism. The prymnesins can be classified into three types based on the length of the carbon backbone of the compound and each algal strain produced only one of these types. Biogeographical mapping of the prymnesin distribution indicated a global distribution of each type. In addition, phylogenetic analyses based on internal transcribed spacer (ITS) sequences revealed monophyletic origin of all prymnesin types and clades could therefore be defined based on the toxic compound. It might be that evolution of new species within the P. parvum species complex is driven by changes in toxin type or that they are a result of it. Such a correlation between chemotype and phylotype has never been documented before for a harmful microalga. Chemotaxonomy and ITS-type classification may thus be used to further delimit the P. parvum species complex.

UDP-Glucosyltransferases from Rice, Brachypodium, and Barley: Substrate Specificities and Synthesis of Type A and B Trichothecene-3-O-β-d-glucosides

Trichothecene toxins are confirmed or suspected virulence factors of various plant-pathogenic Fusarium species. Plants can detoxify these to a variable extent by glucosylation, a reaction catalyzed by UDP-glucosyltransferases (UGTs). Due to the unavailability of analytical standards for many trichothecene-glucoconjugates, information on such compounds is limited. Here, the previously identified deoxynivalenol-conjugating UGTs HvUGT13248 (barley), OsUGT79 (rice) and Bradi5g03300 (Brachypodium), were expressed in E. coli, affinity purified, and characterized towards their abilities to glucosylate the most relevant type A and B trichothecenes. HvUGT13248, which prefers nivalenol over deoxynivalenol, is also able to conjugate C-4 acetylated trichothecenes (e.g., T-2 toxin) to some degree while OsUGT79 and Bradi5g03300 are completely inactive with C-4 acetylated derivatives. The type A trichothecenes HT-2 toxin and T-2 triol are the kinetically preferred substrates in the case of HvUGT13248 and Bradi5g03300. We glucosylated several trichothecenes with OsUGT79 (HT-2 toxin, T-2 triol) and HvUGT13248 (T-2 toxin, neosolaniol, 4,15-diacetoxyscirpenol, fusarenon X) in the preparative scale. NMR analysis of the purified glucosides showed that exclusively β-D-glucosides were formed regio-selectively at position C-3-OH of the trichothecenes. These synthesized standards can be used to investigate the occurrence and toxicological properties of these modified mycotoxins.

Successful second hematopoietic cell transplantation in severe congenital neutropenia

Allogeneic HCT is curative for SCN; however, a standard conditioning regimen or intensity has not been established. We describe a patient with SCN associated with c.1A>G (M1V) mutation in ELANE gene resulting in refractoriness to G-CSF, who received reduced-intensity HCT and developed secondary graft failure requiring a second myeloablative HCT. This case suggests that M1V mutation confers a poor G-CSF response and HCT using the best available donor is beneficial.

Synthesis of Mono- and Di-Glucosides of Zearalenone and α-/β-Zearalenol by Recombinant Barley Glucosyltransferase HvUGT14077

Zearalenone (ZEN) is an estrogenic mycotoxin occurring in Fusarium-infected cereals. Glucosylation is an important plant defense mechanism and generally reduces the acute toxicity of mycotoxins to humans and animals. Toxicological information about ZEN-glucosides is limited due to the unavailability of larger amounts required for animal studies. HvUGT14077, a recently-validated ZEN-conjugating barley UDP-glucosyltransferase was expressed in Escherichia coli, affinity purified, and characterized. HvUGT14077 possesses high affinity (Km = 3 µM) and catalytic efficiency (kcat/Km = 190 s-1·mM-1) with ZEN. It also efficiently glucosylates the phase-I ZEN-metabolites α-zearalenol and β-zearalenol, with kcat/Km of 40 and 74 s-1·mM-1, respectively. HvUGT14077 catalyzes O-glucosylation at C-14 and C-16 with preference of 14-glucoside synthesis. Furthermore, relatively slow consecutive formation of 14,16-di-glucosides was observed; their structures were tentatively identified by mass spectrometry and for ZEN-14,16-di-glucoside confirmed by nuclear magnetic resonance spectroscopy. Recombinant HvUGT14077 allowed efficient preparative synthesis of ZEN-glucosides, yielding about 90% ZEN-14-glucoside and 10% ZEN-16-glucoside. The yield of ZEN-16-glucoside could be increased to 85% by co-incubation with a β-glucosidase highly selective for ZEN-14-glucoside. Depletion of the co-substrate UDP-glucose was counteracted by a sucrose synthase based regeneration system. This strategy could also be of interest to increase the yield of minor glucosides synthesized by other glucosyltransferases.

Measurement of capillary fragility: a useful tool to differentiate lipedema from obesity?

Lipedema is a disproportional obesity featuring spontaneous or light pressure-induce pain and frequent hematoma formation due to even minor traumatic injuries. It is generally distinguished from general obesity primarily based on clinical hallmarks; however, this becomes difficult when appearing in a concomitant form (combination of obesity and lipedema). Our study group has recently demonstrated that lipedema-associated bruising is correlated with increased capillary fragility (CF) and also that CF could be significantly improved by complex decongestive physiotherapy (CDP). In this study, we measured CF in female subjects with lipedema (15) or non-complicated obesity (15) who were body mass index (BMI) and waist-to-hip ratio (WHR) matched. CF was evaluated with the vacuum suction method (VSM) using Parrot's angiosterrometer in both groups. Application of VSM resulted in a significantly higher number of petechiae in subjects with lipedema. Capillary fragility measurement appears to be a useful differential diagnostic tool between lipedema and obesity under these trial parameters.

[Polyphenolic compounds analysis and antioxidant activity in fruits of Prunus spinosa L.]

INTRODUCTION

Prunus spinosa L. (blackthorn, sloe) is a com- mon species in the wild flora of Europe. Marmalade, syrup, and alcoholic beverages have been prepared from fruits. In folk medicine they'are used due to the astringent effect. However there are few studies on these indigenous fruits. According to the literature they contain tannins, anthocyanins, sugars, vitamin C etc.

METHODS

Our objective is to determine the antioxidant activity as related to their phenolic composition. For this purpose we prepared extracts using methanol, methanol-water (1: 1) and water. The antioxidant activity was determined by DPPH method and by photochemiluminescens (PCL) method. The total polyphenols, total anthocyanins and flavonoids were determined by colorimetric methods. Individual polyphenols were identified by a RP-HPLC-UVIVIS method.

RESULTS

The antioxidant activity decreased in the extracts as follows: methanol > methanol-water > water (IC₅₀= 1.33 mg/ml for DPPH; 11.94 μmol AAEIml for PCL > IC₅₀ = 1.87 mg/ml for DPPH; 10.35 μmol AAElml for PCL > IC₅₀ = 15.29 mg/ml for DPPH, 1.89 μmol AAElml for PCL) which is cor- related with the total polyphenol content (369 mg/100g > 244 mg1100g > 101 mg1100g) and total anthocyanin content (37.11 mg/100 g > 16.33 mg/100g > 7.76 mg/100g). The fla- vonoid content is similar in the three extracts (between 35.82 - 37.32 mg1100 g). The HPLC analysis shows high chloro- genic and neochlorogenic acid levels, followed by glycosides of quercetin.

CONCLUSIONS

Our results demonstrated that blackthorn fruits are a rich source of phenolic compounds, with anti- oxidant activity, which are best extracted with methanol or methanol-water.

Comparative in vitro cytotoxicity of modified deoxynivalenol on porcine intestinal epithelial cells

The gastrointestinal tract is the first target after ingestion of the mycotoxin deoxynivalenol (DON) via feed and food. Deoxynivalenol is known to affect the proliferation and viability of animal and human intestinal epithelial cells. In addition to DON, feed and food is often co-contaminated with modified forms of DON, such as 3-acetyldeoxynivalenol (3ADON), 15-acetyl-deoxynivalenol (15ADON) and deoxynivalenol-3-β-D-glucoside (DON3G). The goal of this study was to determine the in vitro intrinsic cytotoxicity of these modified forms towards differentiated and proliferative porcine intestinal epithelial cells by means of flow cytometry. Cell death was assessed by dual staining with Annexin-V-fluorescein isothiocyanate (FITC) and propidium iodide (PI), which allows the discrimination of viable (FITC-/PI-), apoptotic (FITC+/PI-) and necrotic cells (FITC+/PI+). Based on the data from the presented pilot in vitro study, it is concluded that cytotoxicity for proliferative cells can be ranked as follows: DON3G ≪ 3ADON < DON≈15ADON.

Comparison of working length control consistency between hand K-files and Mtwo NiTi rotary system

Background

The purpose of this study was to investigate the consistency of working length control between hand instrumentation in comparison to engine driven Mtwo nickel-titanium rotary files.

Material and Methods

Forty extracted maxillary molars were selected and divided onto two parallel groups. The working lengths of the mesiobuccal root canals were estimated. The teeth were fixed in a phantom head. The root canal preparation was carried out group 1 (n=20) with hand K-files, (VDW, Munich, Germany) and group 2 (n=20) with Mtwo instruments (VDW, Munich, Germany). Vestibulo-oral and mesio-distal directional x-ray images were taken before the preparation with #10 K-file, inserted into the mesiobuccal root canal to the working length, and after preparation with #25, #30 and #40 files. Working lenght changes were detected with measurements between the radiological apex and the instrument tips.

Results

In the Mtwo group a difference in the working competency (p<0.05) could be noticed only in the vestibulo-oral direction from #10 to #40 file. The hand instrument group showed a significant difference in working length competency for each larger file size (p<0.05) (ANOVA). Regression analysis in the hand instrumentation group indicated a working length decrease with a mean of 0,2 mm after each consecutive file size (p<0.01).

Conclusions

The outcome of our trial indicated a high consistency in working length control for root canal preparation under simulated clinical condition using Mtwo rotary files. Mtwo NiTi rotary file did therefore proved to be more accurate in comparison to the conventional hand instrumentation.

Key words:Working length, Mtwo, nickel-titanium, hand preparation, engine driven preparation.