New records on toxic cyanobacteria from Brazil: Exploring their occurrence and geography

Cyanobacterial Harmful Algal Blooms (CyanoHABs) pose a significant threat to communities globally, impacting ecosystems and public health. This study provides an in-depth review of the current state of cyanotoxins and the distribution of CyanoHABs species in Brazil, while also detailing the methods used for their detection. Four hundred and twenty-one incidents were analyzed from 1993 to 2021, compiling cyanotoxin records and toxic CyanoHABs occurrences. The investigation begins with the first detection of microcystins in 1994 and highlights pivotal moments, like the 1996 "Caruaru Syndrome" outbreak. This event encouraged research and updated cyanotoxin-monitoring guidelines. The Brazilian drought period of 2015-2016 exacerbated cyanobacterial growth and saxitoxin levels, coinciding with Zika-related microcephaly. This study delves into methods used for cyanotoxin analysis, including ELISA, bioassays, HPLC, and LC-MS. Additionally, we investigated the toxicity of 37 cyanobacterial strains isolated from various Brazilian environments. Extracts were tested against Artemia salina and analyzed by LC-MS. Results revealed toxicity in extracts from 49 % of cyanobacterial strains. LC-MS results were analyzed using GNPS MS/MS molecular networking for comparing experimental spectra with those of cyanotoxin standards against in-house databases and the existing literature. Our research underscores the variability in cyanotoxin production among species and over time, extending beyond microcystins. LC-MS results, interpreted through the GNPS platform, revealed six cyanotoxin groups in Brazilian strains. Yet, compounds present in 75 % of the toxic extracts remained unidentified. Further research is crucial for fully comprehending the impact of potentially harmful organisms on water quality and public health management strategies. The study highlights the urgent need for continuously monitoring cyanobacteria and the cyanotoxin inclusion of management in public health policies.

Cyanopeptides occurrence and diversity in a Brazilian tropical reservoir: Exploring relationships with water quality

Microcystins (MCs) are a class of toxic secondary metabolites produced by some cyanobacteria strains that endanger aquatic and terrestrial organisms in various freshwater systems. Although patterns in MC occurrence are being recognized, divergences in the global data still hamper our ability to predict the toxicity of cyanobacterial blooms. This study aimed (i) to determine the dynamics of MCs and other cyanopeptides in a tropical reservoir, (ii) to investigate the correlation between peptides and potential cyanotoxin producers (iii) identifying the possible abiotic factors that influence the peptides. We analyzed, monthly, eight MC variants (MC-RR, -LA, -LF, -LR, -LW, -YR, [D-Asp3]-RR and [D-Asp3]-LR) and other peptides in 47 water samples collected monthly, all season long, from two sampling sites in a tropical eutrophic freshwater reservoir, in southeastern Brazil. The cyanopeptides were assessed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The biomass of potential cyanobacterial producers and water quality variables were measured. MCs were detected in both sampling sites year-round; the total MC concentration varied from 0.21 to 4.04 μg L-1, and three MC variants were identified and quantified (MC-RR, [D-Asp3]-RR, -LR). Additionally, we identified 28 compounds belonging to three other cyanopeptide classes: aeruginosin, microginin, and cyanopeptolin. As potential MC producers, Microcystis spp. and Dolichospermum circinalis were dominant during the study, representing up to 75% of the total phytoplankton. Correlational and redundancy analysis suggested positive effects of dissolved oxygen, nitrate, and total phosphorus on MC and microginins concentration, while water temperature appeared to favor aeruginosins. A comparison between our results and historical data showed a reduction in total phosphorus and cyanobacteria, suggesting increased water quality in the reservoir. However, the current MC concentrations indicate a rise in cyanobacterial toxicity over the last eight years. Moreover, our study underscores the pressing need to explore cyanopeptides other than MCs in tropical aquatic systems.

Oxidation of chlortetracycline and its isomers by Botrytis aclada laccase in the absence of mediators: pH dependence and identification of transformation products by LC-MS

Tetracyclines are antibiotics considered emerging pollutants and currently, wastewater treatment plants are not able to remove them efficiently. Laccases are promising enzymes for bioremediation because they can oxidize a wide variety of substrates. The aim of this study was to evaluate the Botrytis aclada laccase for the oxidation of chlortetracycline and its isomers in the absence of a mediator molecule, at a pH range between 3.0 to 7.0, and to characterize the transformation products by LC-MS. Chlortetracycline and three isomers were detected in both, controls and reaction mixtures at 0 h and in controls after 48 h of incubation but in different proportions depending on pH. An additional isomer was also detected, but only in the presence of BaLac. Based on the transformation products identified in the enzymatic reactions and information from literature, we assembled a network of transformation pathways starting from chlortetracycline and its isomers. The spectrometric analysis of the products indicated the probable occurrence of oxygen insertion, dehydrogenation, demethylation and deamination reactions. Four new products were identified, and we also described a novel transformation product without the chloro group. We observed that increasing pH led to higher diversity of main products. This is the first study using the laccase from fungi Botrytis aclada to oxidate chlortetracycline and its isomers and it can be considered as an ecological alternative to be used in bioremediation processes such as wastewater.

A systematic review on guanitoxin: General characteristics and ecological risks

Guanitoxin (GNT) is a potent cyanotoxin, with a relatively low number of publications (n = 51) compared to other cyanotoxins. Among the published studies, 35 % were on the effect of the toxin in animals, mainly in rodents and in vitro testing, followed by studies that identified species of cyanobacteria that produce GNT in aquatic systems and consequently accidental poisoning in wild and domestic animals (27 %). Studies that developed or tested methods for identifying the molecule, based on colorimetric and analytical techniques, represented 14 %, while 8 % were on GNT biosynthesis. Review articles and chemical isolation (6 %) and on the stability of the molecule (4 %) were the topics with the lowest number of publications. The results show the occurrence of GNT was identified mainly in eutrophic environments with a higher incidence in the American continent. Chemical characteristics of the molecule, such as short half-life in the environment, instability in solutions with alkaline pH values, temperature >23 °C, added to the lack of an analytical standard, are factors that make it difficult to identify and quantify it. However, GNT monitoring can be performed using LC-MS-MRM methods or genes specific to the newly discovered molecule.

A rapid LC-MS/MS method for multi-class identification and quantification of cyanotoxins

Cyanobacteria can form harmful blooms in specific environmental conditions due to certain species producing toxic metabolites known as cyanotoxins. These toxins pose significant risks to public health and the environment, making it critical to identify and quantify them in food and water sources to avoid contamination. However, current screening methods only focus on a single class of cyanotoxins, limiting their effectiveness. Thus, fast and sensitive liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed to analyze eighteen cyanotoxins simultaneously. A simplified extraction procedure using lyophilized samples of cyanobacterial biomass was also used, eliminating the need for traditional solid-phase extraction methods. This method uses multiple reaction monitoring and allows accurate determination and quantification of eighteen cyanotoxins, including anatoxin-a, homoanatoxin-a, cylindrospermopsin, deoxy-cylindrospermopsin, nodularin, guanitoxin, seven microcystins (RR, [D-Asp3] RR, LA, LR, LY, LW, and YR), and five saxitoxins (gonyautoxins - GTX-1&4, GTX-2&3, GTX-5), decarbamoylgonyautoxin (dcGTX-2&3), and N-Sulfocarbamoylgonyautoxin (C1&C2), all in a short acquisition time of 8 min. Therefore, this method provides a simple and efficient approach to identify and quantify harmful compounds produced by cyanobacteria. Hence, this represents the first method to detecting guanitoxin among cyanotoxins. By expanding the range of toxins analyzed, this method can help ensure high-quality food and drinking water and protect recreational users from exposure to cyanotoxins.

Lethal and sublethal effects towards zebrafish larvae of microcystins and other cyanopeptides produced by cyanobacteria

Cyanobacterial blooms affect aquatic ecosystems across the globe and one major concern relates to their toxins such as microcystins (MC). Yet, the ecotoxicological risks, particularly non-lethal effects, associated with other co-produced secondary metabolites remain mostly unknown. Here, we assessed survival, morphological alterations, swimming behaviour and cardiovascular functions of zebrafish (Danio rerio) upon exposure to cyanobacterial extracts of two Brazilian Microcystis strains. We verified that only MIRS-04 produced MCs and identified other co-produced cyanopeptides also for the MC non-producer NPCD-01 by LC-HRMS/MS analysis. Both cyanobacterial extracts, from the MC-producer and non-producer, caused acute toxicity in zebrafish with LC50 values of 0.49 and 0.98 mgdw_biomass/mL, respectively. After exposure to MC-producer extract, additional decreased locomotor activity was observed. The cyanopeptolin (micropeptin K139) contributed 52% of the overall mortality and caused oedemas of the pericardial region. Oedemas of the pericardial area and prevented hatching were also observed upon exposure to the fraction with high abundance of a microginin (Nostoginin BN741) in the extract of the MC non-producer. Our results further add to the yet sparse understanding of lethal and sublethal effects caused by cyanobacterial metabolites other than MCs and the need to better understand the underlying mechanisms of the toxicity. We emphasize the importance of considering mixture toxicity of co-produced metabolites in the ecotoxicological risk assessment of cyanobacterial bloom events, given the importance for predicting adverse outcomes in fish and other organisms.

Toxicological effects of cyanobacterial metabolites on zebrafish larval development

Freshwater cyanobacteria are known worldwide for their potential to produce toxins. However, these organisms are also found in marine, terrestrial and extreme environments and produce unique compounds, other than toxins. Nevertheless, their effects on biological systems are still barely known. This work tested extracts of different cyanobacterial strains against zebrafish (Danio rerio) larvae and analyzed their metabolomic profiles using liquid chromatography combined with mass spectrometry. Strains Desertifilum tharense, Anagnostidinema amphibium, and Nostoc sp. promoted morphological abnormalities such as pericardial edema, edema in the digestive system region, curvature of the tail and spine in zebrafish larvae in vivo. In contrast, Microcystis aeruginosa and Chlorogloeopsis sp. did not promote such changes. Metabolomics revealed unique compounds belonging to the classes of terpenoids, peptides, and linear lipopeptides/microginins in the nontoxic strains. The toxic strains were shown to contain unique compounds belonging to the classes of cyclic peptides, amino acids and other peptides, anabaenopeptins, lipopeptides, terpenoids, and alkaloids and derivatives. Other unknown compounds were also detected, highlighting the rich structural diversity of secondary metabolites produced by cyanobacteria. The effects of cyanobacterial metabolites on living organisms, mainly those related to potential human and ecotoxicological risks, are still poorly known. This work highlights the diverse, complex, and unique metabolomic profiles of cyanobacteria and the biotechnological potential and associated risks of exposure to their metabolites.

Ecotoxicological assessment of guanitoxin-producing cyanobacteria in Danio rerio and Daphnia similis

Anthropogenic activity has dramatically deteriorated aquatic ecosystems in recent years. Such environmental alterations could change the primary producers' composition, exacerbating the proliferation of harmful microorganisms such as cyanobacteria. Cyanobacteria can produce several secondary metabolites, including guanitoxin, a potent neurotoxin and the only naturally occurring anticholinesterase organophosphate ever reported in the literature. Therefore, this study investigated the acute toxicity of guanitoxin-producing cyanobacteria Sphaerospermopsis torques-reginae (ITEP-024 strain) aqueous and 50% methanolic extracts in zebrafish (Danio rerio) hepatocytes (ZF-L cell line), zebrafish embryos (fish embryo toxicity - FET) and specimens of the microcrustacean Daphnia similis. For this, hepatocytes were exposed to 1-500 mg/L of the ITEP-024 extracts for 24 h, the embryos to 31.25-500 mg/L for 96 h, and D. similis to 10-3000 mg/L for 48 h. Non-target metabolomics was also performed to analyze secondary metabolites produced by the ITEP-024 using LC-MS/MS. Metabolomics indicated the guanitoxin presence just in the aqueous extract of the ITEP-024 and the presence of the cyanopeptides namalides, spumigins, and anabaenopeptins in the methanolic extract. The aqueous extract decreased the viability of zebrafish hepatocytes (EC(I)_50(24h) = 366.46 mg/L), and the methanolic extract was not toxic. FET showed that the aqueous extract (LC₅₀₍₉₆₎ = 353.55 mg/L) was more toxic than the methanolic extract (LC₅₀₍₉₆₎ = 617.91 mg/L). However, the methanolic extract had more sublethal effects, such as abdominal and cardiac (cardiotoxicity) edema and deformation (spinal curvature of the larvae). Both extracts immobilized daphnids at the highest concentration analyzed. However, the aqueous extract was nine times more lethal (EC(I)_50(48h) = 108.2 mg/L) than the methanolic extract (EC(I)_50(48h) = 980.65 mg/L). Our results showed an imminent biological risk for aquatic fauna living in an ecosystem surrounded by ITEP-024 metabolites. Our findings thus highlight the urgency of understanding the effects of guanitoxin and cyanopeptides in aquatic animals.

Chronic alcohol administration alters metabolomic profile of murine bone marrow

Introduction

People with hazardous alcohol use are more susceptible to viral, bacterial, and fungal infections due to the effect of alcohol on immune system cell function. Metabolized ethanol reduces NAD+ to NADH, affecting critical metabolic pathways. Here, our aim was to investigate whether alcohol is metabolized by bone marrow cells and if it impacts the metabolic pathways of leukocyte progenitor cells. This is said to lead to a qualitative and quantitative alteration of key metabolites which may be related to the immune response.

Methods

We addressed this aim by using C57BL/6 mice under chronic ethanol administration and evaluating the metabolomic profile of bone marrow total cells by gas chromatography-coupled mass spectrometry (GC-MS).

Results

We identified 19 metabolites. Our data demonstrated that chronic ethanol administration alters the metabolomic profile in the bone marrow, resulting in a statistically diminished abundance of five metabolites in ethanol-treated animals: uracil, succinate, proline, nicotinamide, and tyrosine.

Discussion

Our results demonstrate for the first time in the literature the effects of alcohol consumption on the metabolome content of hematopoietic tissue and open a wide range of further studies to investigate mechanisms by which alcohol compromises the cellular function of the immune system.

Evaluation of the Toxicity of Microcyclamide Produced by Microcystis aeruginosa in Danio rerio Embryos

The genus of cyanobacteria Microcystis is one of the most recurrent in blooms and is associated with the hepatotoxin microcystin production. In addition to cyanotoxins, these bacteria produce a wide range of secondary metabolites with a wide repertoire of activities. The co-occurrence of cyanotoxins and other cyanopeptides during blooming is quite common, and the negative effects are not always limited to one class of toxins, which makes it essential to investigate the toxicity of the other compounds individually. The objective of this study was to isolate the cyanopeptide microcyclamide produced by the strain Microcystis aeruginosa LTPNA 08 by liquid chromatography coupled to high-resolution mass spectrometry with a quadrupole-time-of-flight analyzer (LC-HR-QTOF-MS/MS) and to evaluate its acute toxicity in embryos of Danio rerio through the Fish Embryo Acute Toxicity (FET) assay. The fraction containing microcyclamide (95% purity) caused lethality in 62% of the embryos after 96 h exposure (50 µg mL^-1), with evidence of cardiotoxicity (cardiac edema). The calculated LC₅₀ value was 42.98 µg mL^-1 (with a concentration range of 37.79-48.89 µg mL^-1). The characterization of the secondary metabolites produced by cyanobacteria and the investigation of the toxicity of these compounds individually are essential for the identification of the substances responsible for negative effects on living organisms and on the ecosystem, in addition to assisting in the development of risk management policies.

Metabolomics Applied to Cyanobacterial Toxins and Natural Products

The biological and chemical diversity of Cyanobacteria is remarkable. These ancient prokaryotes are widespread in nature and can be found in virtually every habitat on Earth where there is light and water. They are producers of an array of secondary metabolites with important ecological roles, toxic effects, and biotechnological applications. The investigation of cyanobacterial metabolites has benefited from advances in analytical tools and bioinformatics that are employed in metabolomic analyses. In this chapter, we review selected articles highlighting the use of targeted and untargeted metabolomics in the analyses of secondary metabolites produced by cyanobacteria. Here, cyanobacterial secondary metabolites have been didactically divided into toxins and natural products according to their relevance to toxicological studies and drug discovery, respectively. This review illustrates how metabolomics has improved the chemical analysis of cyanobacteria in terms of speed, sensitivity, selectivity, and/or coverage, allowing for broader and more complex scientific questions.

Cardiac myxoma embolic events: characterization and predictors

Introduction

Myxomas are the most common heart tumors. Although, myxomas are often diagnosed incidentally in asymptomatic patients, they are frequently associated with embolic events, becoming an important cause of morbidity and mortality. Whether some myxomas' characteristics predict more embolic risk is not well established.

Objectives

This analysis aims to describe the clinical and echocardiographic data in a long cohort of patients with cardiac myxomas and to establish potential predictors of embolic events int these patients.

Methods

Between 1990 and 2021, 88 patients were diagnosed with cardiac myxoma. 84 were included in this analysis. Baseline characteristics, echocardiographic findings and embolic events were noted retrospectively. A binary logistic regression analysis using SPSS statistics software, version 25.0 was performed to establish possible embolic predictors.

Results

84 patients (mean age 63.1±12.9 years old, 75% female) with cardiac myxoma (sporadic type in 100%) were analyzed (table 1). The majority were located in the left atrium (88.1%, n=74), followed by right atrium (10.7%, n=9) and right ventricle (1.2%, n=1). The average dimension (longer axis) was 36.8±17.4mm. 9.6% of the patients (n=8) had Atrial Fibrillation (AF) rhythm. 22.6% of the patients (n=19) experienced embolic events, the majority to the central nervous system (19.0%, n=6), followed by peripheric/limbs (2.4%, n=2), renal (1.2%, n=1) and coronary (1.2%, n=1). The presence of irregular borders (papillary, bosselated) was the only parameter independently associated with increased risk of embolic events, by 6 times (OR 6.78, 95% confidence interval of 2.14–21.51, p-value 0.001). Neither the presence of AF, myxoma dimensions, presence of calcifications, pediculated insertion, myxoma mobility or heterogeneous aspect predicted embolic events with statistical significance (table 2).

Conclusions

Cardiac myxomas are frequently associated with embolic events (22.6% in our population), posing an important cause of morbidity and mortality in these patients. Besides the presence of irregular borders, the other myxoma's characteristics did not consistently predict the occurrence of embolic events. This data supports the well-recognized fact that all cardiac myxomas have the potential to embolic events, and therefore, should be excised, although those with very irregular borders are at much higher risk of embolization.

Funding Acknowledgement

Type of funding sources: None.

Noncompliance to iodine supplementation recommendation is a risk factor for iodine insufficiency in Portuguese pregnant women: results from the IoMum cohort

PURPOSE

After a recommendation for iodine supplementation in pregnancy has been issued in 2013 in Portugal, there were no studies covering iodine status in pregnancy in the country. The aim of this study was to assess iodine status in pregnant women in Porto region and its association with iodine supplementation.

METHODS

A cross-sectional study was conducted at Centro Hospitalar Universitário São João, Porto, from April 2018 to April 2019. Pregnant women attending the 1st trimester ultrasound scan were invited to participate. Exclusion criteria were levothyroxine use, gestational age < 10 and ≥ 14 weeks, non-evolutive pregnancy at recruitment and non-signing of informed consent. Urinary iodine concentration (UIC) was measured in random spot urine by inductively coupled plasma-mass spectrometry.

RESULTS

Median UIC was 104 μg/L (IQR 62-189) in the overall population (n = 481) of which 19% had UIC < 50 µg/L. Forty three percent (n = 206) were not taking an iodine-containing supplement (ICS) and median UIC values were 146 µg/L (IQR 81-260) and 74 µg/L (IQR 42-113) in ICS users and non-users, respectively (p < 0.001). Not using an ICS was an independent risk factor for iodine insufficiency [adjusted OR (95% CI) = 6.00 (2.74, 13.16); p < 0.001]. Iodised salt use was associated with increased median iodine-to-creatinine ratio (p < 0.014).

CONCLUSIONS

A low compliance to iodine supplementation recommendation in pregnancy accounted for a mild-to-moderately iodine deficiency. Our results evidence the need to support iodine supplementation among pregnant women in countries with low household coverage of iodised salt. Trial registration number NCT04010708, registered on the 8th July 2019.

Ecological risk of imidacloprid on the Brazilian non-target freshwater organisms Chironomus sancticaroli and Poecilia reticulata

Imidacloprid (IMI) is a neonicotinoid insecticide widely used in agriculture worldwide. This pesticide has been found in freshwater ecosystems, including Brazilian freshwaters. For this reason, studies are being conducted to detect the presence of IMI in freshwater and understand its effects on the aquatic biota. In the present study, the acute toxic effect of the imidacloprid commercial formulation (ICF) Galeão^® on the Brazilian non-target aquatic organisms Chironomus sancticaroli and Poecilia reticulata was evaluated. Enzymatic activities (glutathione S-transferase (GST), catalase (CAT), and ascorbate peroxidase (APX)) were also determined. Moreover, we considered 11 studies that detected IMI concentrations up to 3.65 µg.L^-1 in 28 different Brazilian freshwaters to evaluate the acute ecological risk of IMI in these environments. From the ecotoxicological assays, we determined the LC₅₀ values for C. sancticaroli (LC_50-48 h 1.52 µg.L^-1) and P. reticulata (LC_50-96 h 122.65 mg.L^-1). The high sensitivity of C. sancticaroli demonstrates that this species could be used as a bioindicator in studies investigating the contamination of freshwater by IMI. Enzymatic activity changes were observed in both organisms and offered sublethal responses to the effects of the pollution by IMI on aquatic biota. Our results suggest that the presence of IMI in Brazilian aquatic ecosystems can represent a potential ecological risk for the aquatic insect populations and, consequently, cause an imbalance in these ecosystems. The present study provides relevant and comparable toxicity information that may be useful to develop public policies to protect the Brazilian aquatic ecosystem from IMI contamination.

Response of Oreochromis niloticus (Teleostei: Cichlidae) exposed to a guanitoxin-producing cyanobacterial strain using multiple biomarkers

Changes in environmental conditions in aquatic ecosystems caused by anthropic actions can modify the composition of primary producers, promoting the excessive proliferation of cyanobacteria. These organisms can form cyanobacterial blooms, which directly affect aquatic life. The present study investigated the mutagenicity of the cyanobacterium Sphaerospermopsis torques-reginae (strain ITEP-024), guanitoxin-producing (natural organophosphate), and sublethal effects on fish in relevant environment concentrations. For this, the Ames test (Salmonella/microsome) was performed as a mutagenic assay for extracts of the ITEP-024 strain. Specimens of Oreochromis niloticus (Teleostei: Cichlidae) were subjected to acute 96 h exposure to different concentrations of aqueous extract of the strain: C = control group; T1 = 31.25 mg/L; T2 = 62.5 mg/L; T3 = 125 mg/L; and T4 = 250 mg/L. Genotoxic, biochemical, osmoregulatory, and physiologic biomarkers were analyzed. Our results showed that the cyanobacterium had a weak mutagenic response for the TA102 strain of Salmonella with and without metabolic activation by S9. Strains TA98 and TA100 were not affected. Fish from treatments T3 and T4 showed changes in oxidative stress (CAT, SOD, and GST enzymes), inhibition of the enzyme acetylcholinesterase activity, micronucleus formation, and osmoregulatory disorders. No guanitoxin accumulation was detected in the different tissues of O. niloticus by LC-MS/MS. Our results showed unprecedented mutagenicity data of the guanitoxin-producing cyanobacteria by the Ames test and biochemical, osmoregulatory, and genotoxic disorders in fish, providing efficient aquatic contamination biomarkers. Despite the great concern related to the presence of guanitoxin in blooms in freshwater ecosystems, its concentration is not yet regulated, and thus there is no monitoring agenda in current legislation.

Cyanotoxins and water quality parameters as risk assessment indicators for aquatic life in reservoirs

We assessed the extent of pollution in an essential public water supply reservoir (southeastern Brazil). An environmental monitoring study was performed at the Billings Reservoir (at the water catchment site) to assess the water quality in 2017, 2018, and 2019. Physicochemical parameters were analyzed, quantifying the total cyanobacteria and the cyanotoxins microcystins (MCs) and saxitoxins (SXTs), as well as their possible ecological risk to the aquatic environment. We also determined metals and metalloids (As, Ba, Cd, Pb, Cu, Cr, Fe, Mn, Ni, Zn, and Sb) and fecal bacteria (Escherichia coli). Monthly samplings were performed for 2017, 2018, and 2019 (totaling 36 sampling campaigns). Metals, metalloids, and E. coli values were below the maximum limit allowed by the Brazilian legislation. High concentrations of total cyanobacteria (3.07 × 10⁴ - 3.23 × 10⁵ cells/mL), microcystin variants MC-LR (0.67-23.63 μg/L), MC-LA (0.03-8.66 μg/L), MC-RR (0.56-7.92 μg/L), and MC-YR (0.04-1.24 μg/L), as well as the saxitoxins GTX2 (0.18-5.37 μg/L), GTX3 (0.13-4.40 μg/L), and STX (0.12-2.92 μg/L) were detected. From an ecotoxicological point of view, the estimated values for the risk quotient (RQ) for microcystins and saxitoxins were largely greater than 1, indicating a high risk to aquatic life. Therefore, further efforts need to be made to delay the eutrophication of the reservoir.

Biosynthesis of Guanitoxin Enables Global Environmental Detection in Freshwater Cyanobacteria

Harmful cyanobacterial blooms (cyanoHABs) cause recurrent toxic events in global watersheds. Although public health agencies monitor the causal toxins of most cyanoHABs and scientists in the field continue developing precise detection and prediction tools, the potent anticholinesterase neurotoxin, guanitoxin, is not presently environmentally monitored. This is largely due to its incompatibility with widely employed analytical methods and instability in the environment, despite guanitoxin being among the most lethal cyanotoxins. Here, we describe the guanitoxin biosynthesis gene cluster and its rigorously characterized nine-step metabolic pathway from l-arginine in the cyanobacterium Sphaerospermopsis torques-reginae ITEP-024. Through environmental sequencing data sets, guanitoxin (gnt) biosynthetic genes are repeatedly detected and expressed in municipal freshwater bodies that have undergone past toxic events. Knowledge of the genetic basis of guanitoxin biosynthesis now allows for environmental, biosynthetic gene monitoring to establish the global scope of this neurotoxic organophosphate.

Reannotation of Fly Amanita l-DOPA Dioxygenase Gene Enables Its Cloning and Heterologous Expression

The l-DOPA dioxygenase of Amanita muscaria (AmDODA) participates in the biosynthesis of betalain- and hygroaurin-type natural pigments. AmDODA is encoded by the dodA gene, whose DNA sequence was inferred from cDNA and gDNA libraries almost 30 years ago. However, reports on its heterologous expression rely on either the original 5'-truncated cDNA plasmid or artificial gene synthesis. We provide unequivocal evidence that the heterologous expression of AmDODA from A. muscaria specimens is not possible by using the coding sequence previously inferred for dodA. Here, we rectify and reannotate the full-length coding sequence for AmDODA and express a 205-aa His-tagged active enzyme, which was used to produce the l-DOPA hygroaurin, a rare fungal pigment. Moreover, AmDODA and other isozymes from bacteria were submitted to de novo folding using deep learning algorithms, and their putative active sites were inferred and compared. The wide catalytic pocket of AmDODA and the presence of the His-His-His and His-His-Asp motifs can provide insight into the dual cleavage of l-DOPA at positions 2,3 and 4,5 as per the mechanism proposed for nonheme dioxygenases.

Effects of different cultivation conditions on the production of β-cyclocitral and β-ionone in Microcystis aeruginosa

Background

Cyanobacteria blooms have become a major environmental problem and concern because of secondary metabolites produced by cyanobacteria released into the water. Cyanobacteria produce volatile organic compounds (VOCs), such as the compounds β-cyclocitral and β-ionone, which comprise odors, off-flavors, defense compounds, as well as growth regulators. Therefore, the general objective of this work was to evaluate the VOCs produced by two strains of Microcystis aeruginosa, differing in their ability to produce microcystins (LTPNA 01—non-producing and LTPNA 08—toxin-producing). The analysis of VOC production was carried out in (1) normal culture conditions, (2) under different light intensities (LI), and (3) after the external application of β-ionone in both cultures.

Results

The results showed that β-cyclocitral and β-ionone are produced in all growth phases of LTPNA 01 and LTPNA 08. Both strains were producers of β-cyclocitral and β-ionone in normal culture conditions. It was observed that the β-cyclocitral concentration was higher than β-ionone in all light intensities investigated in this study. Additionally, the strain LTPNA 01 produced more β-cyclocitral than LTPNA 08 at almost all times and LIs analyzed. However, the strain LTPNA 08 produced more β-ionone, mainly at the initial times. In addition, the experiment results with the external addition of β-ionone in the cultures showed that the strain LTPNA 01 produced more β-cyclocitral in control conditions than in treatment. Nonetheless, β-ionone production was higher in treatment conditions in LTPNA 08, indicating that the addition of β-ionone may favor the production of these compounds and inhibit the production of β-cyclocitral.

Conclusion

Our results showed that some abiotic factors, such as different light intensities and external application of β-ionone, can be triggers that lead to the production of VOCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02473-6.

Determining the Presence of 5-Fluorouracil in Hamster Saliva by HPLC

AbstractIntroduction: Various methods of analysis for the assay of chemotherapeutic agent 5-Fluorouracil (5-FU) in human and animal biological fluids have previously been reported. However, there is no standardization for detecting 5-FU in the hamsters’ saliva that received the chemotherapeutic agent. Objective: Considering that the administration of 5-FU in some way changes the morphology and function of the salivary glands, and that the presence of the chemotherapeutic agents in the oral mucosa may lead to some oral complications, the aim of this study was to determine the presence of 5-FU in the hamsters’ saliva that received the chemotherapeutic agent, by means of the High Performance Liquid Chromatography technique (HPCL) since this animal model is used in studies of 5-FU induced oral mucositis and glandular hypofunction. Methods: Twelve animals were divided into 4 groups: CP and CPI, in which the animals received pilocarpine (CP) or pilocarpine + isoproterenol (CPI) and the chemotherapy vehicle intraperitoneally; and Groups QP and QPI, in which the animals received the same secretagogues listed above, and the chemotherapeutic agent 5-FU, respectively. After the secretagogue administration, saliva was collected from all the animals for a period of 60 mins. Subsequently, the saliva was frozen at -80 ˚C for later determination of the chemotherapeutic agent by HPLC. After the the chromatograms analysis, and based on the results obtained, it was possible to identify the presence of 5-FU in the saliva samples from hamsters that received the chemotherapeutic agent intraperitonally, by the HPLC technique. Keywords: Antimetabolites. Chromatography, High Pressure Liquid. Saliva ResumoVários métodos de análise para o ensaio do quimioterápico 5-Fluorouracil (5-FU) em fluidos biológicos de humanos e animais, foram previamente relatados. No entanto, não há uma padronização para detecção de 5-FU na saliva de hamsters que receberam o quimioterápico. Considerando que a administração do 5-FU altera de alguma maneira a morfologia e função das glândulas salivares, e que a presença do quimioterápico na mucosa oral pode levar a algumas complicações orais, este trabalho teve como objetivo de determinar a presença de 5-FU na saliva de hamsters que receberam o quimioterápico pela técnica de Cromatografia Líquida de Alta Eficiência (CLAE), uma vez que este modelo animal é usado nos estudos com mucosite oral e hipofunção glandular, induzidas por 5-FU. Doze animais foram divididos em 4 grupos: CP e CPI, onde os animais receberam intraperitonealmente pilocarpina (CP) ou pilocarpina + isoproterenol (CPI) e o veículo do quimioterápico, e os grupos QP e QPI, onde os animais receberam, respectivamente, os mesmos secretagogos listados acima e o quimioterápico 5-FU. Após a administração do secretagogo, foi coletada a saliva de todos os animais, por um período de 60 min. Em seguida, a saliva foi congelada a -80 ˚C para posterior determinação do quimioterápico por CLAE. Após análise dos cromatogramas, e com base nos resultados obtidos, foi possível identificar a presença do 5-FU nas amostras de saliva de hamsters que receberam o quimioterápico via intraperitoneal pela técnica da CLAE. Palavras-chave: Antimetabólitos. Cromatografia Líquida de Alta Pressão. Saliva

Permanent occurrence of Raphidiopsis raciborskii and cyanotoxins in a subtropical reservoir polluted by domestic effluents (Itupararanga reservoir, São Paulo, Brazil)

Toxic cyanobacteria blooms are a frequent problem in subtropical reservoirs and freshwater systems. The purpose of this study was to investigate the occurrence of potentially toxic cyanobacteria and the environmental conditions associated with the presence of cyanotoxins in a Brazilian subtropical reservoir. Five collections were carried out at seven sampling locations in the reservoir, during the rainy and dry seasons, between the years 2016 and 2017. There was permanent occurrence of Raphidiopsis raciborskii (Woloszynska) Aguilera, Berrendero Gómez, Kastovsky, Echenique & Salerno (Phycologia 57(2):130-146, 2018), ranging between dominant and abundant, with an average biomass of 38.8 ± 29.9 mg L^-1. Also abundant were Dolichospermum solitarium, D. planctonicum, Planktothrix isothrix, and Aphanizomenon gracile. Saxitoxin (STX) was detected in all the collected samples (0.11 ± 0.05 µg L^-1). Microcystin (MC) was also detected, but at lower concentrations (0.01 ± 0.0 µg L^-1). Low availability of NO₃^- and phosphorus limitation had significant effects on the R. raciborskii biomass and the levels of STX and MC. It was observed that R. raciborskii was sensitive to thermal stratification, at the same time that STX levels were higher. This suggested that STX was produced under conditions that restricted the growth of R. raciborskii. These are important findings, because they add information about the permanent occurrence of STX and R. raciborskii in an aquatic ecosystem limited by phosphorus, vulnerable to climatic variations, and polluted by domestic effluents.

Malignant cardiac tumors: a single-centre 25-year review

Background

Primary cardiac tumors are extremely rare and are usually diagnosed late due to the nonspecific symptoms. Surgery is the main treatment option, and despite chemotherapy, the prognosis remains poor. Cardiac invasion by metastatic tumors, while more common, also entails an unsatisfactory outcome. The aim of this study was to review patients (P) with malignant cardiac tumors that were diagnosed by transthoracic echocardiogram (TTE) or transoesophageal echocardiogram (TOE) in a tertiary center between 1995 and 2020.

Methods

Retrospective analysis of clinical data, echocardiographic assessment of tumor location and morphology, histology results and survival outcomes.

Results

A total of 44 malignant cardiac tumors were diagnosed: 12 primary tumors (A) and 32 metastatic tumors (B). A: Regarding primary cardiac tumors, the most common types were angiosarcomas (6), undifferentiated pleomorphic sarcomas (2), fibrosarcomas (2), myxofibrosarcoma (1) and primary cardiac lymphoma (1). The mean age of P at time of diagnosis was 43±15 years, 50% male. The most frequent presentation was heart failure symptoms (50%) followed by arrhythmias (20%). 1 P presented with pruritus and polyarthralgias. On TTE, the most prevalent tumor location was in the right-heart chambers (70%) – mostly the right atrium (50%), with mean dimensions of 40±18x27±11 mm. 85% of P had preserved biventricular systolic function and there was severe pericardial effusion in 38%. The most frequent metastatic involvement at diagnosis was pulmonary (33%) and hepatic (33%). 50% of P were submitted to tumor resection and 40% to chemotherapy. Regarding angiosarcomas, the most common immunohistochemical markers were vimentin, CD31 and CD34. The authors found a mortality rate of 10P (83%) in P with primary cardiac tumors, with a median time to mortality of 5.5 (IQR 2–10) months (Figure 1), in a median follow-up of 6.2 (IQR 2.5–15) months (minimum of 20 days and maximum of 19 years). In the latter case, the P was submitted to heart transplantation after diagnosis of a fibrosarcoma and is still alive and well.

B: Regarding secondary cardiac invasion, there was a diagnosis of the following primary tumor sites: 12 lung carcinomas, 7 thymomas, 4 lymphomas, 3 hepatocellular carcinomas, 2 bladder carcinomas, 1 parathyroid carcinoma, 1 soft tissue sarcoma, 1 uterine sarcoma and 1 melanoma. The mean age of P was 57±19 years, 57% male. On TTE/TOE the authors found a right-sided chambers predominance (12 P, 38%) vs left-sided chambers in (8 P, 25%), with pericardial metastasis also present in 13 P (41%). Cardiac tamponade occurred in 6P (19%). The mortality rate was 75% (24P), with a median time to mortality of 1.1 (IQR 0.6–3.8) months (minimum of 7 days, maximum of 44 months), in a median follow-up of 2.3 (IQR 0.8–14) months.

Conclusion

Cardiac malignant tumors generally present in a late stage with a dismal prognosis. When possible, heart transplantation can be an option with a favourable outcome.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Kaplan-Meier analysis

Can the insecticide Imidacloprid affect the health of the Neotropical freshwater fish Astyanax altiparanae (Teleostei: Characidae)?

Female juveniles of the Neotropical fish Astyanax altiparanae were exposed for 96 h to four treatments containing the active ingredient from Imidacloprid® commercial formulation (IMI 1, IMI 2, IMI 3, and IMI 4) and to a control treatment (only dechlorinated tap water). Glutathione content, glutathione S-transferase activity, lipid peroxidation (LPO) and protein carbonylation levels, acetylcholinesterase (AChE) activity, and frequency of micronuclei and erythrocyte nuclear abnormalities (ENA) were measured in the fish. The muscle and gills were the most affected organs; their antioxidant defense was not enough to prevent oxidative damage (LPO) in the IMI 2 and IMI 4 treatment fish. IMI also inhibited AChE activity in the muscle (IMI 3 and IMI 4) and increased ENA frequency (IMI 4). IMI can affect the health of A. altiparanae in environmentally relevant concentrations, causing oxidative damage in different organs, neurotoxic effects in the muscle, and genotoxicity.

'Floc and Sink' Technique Removes Cyanobacteria and Microcystins from Tropical Reservoir Water

Combining coagulants with ballast (natural soil or modified clay) to remove cyanobacteria from the water column is a promising tool to mitigate nuisance blooms. Nevertheless, the possible effects of this technique on different toxin-producing cyanobacteria species have not been thoroughly investigated. This laboratory study evaluated the potential effects of the "Floc and Sink" technique on releasing microcystins (MC) from the precipitated biomass. A combined treatment of polyaluminium chloride (PAC) with lanthanum modified bentonite (LMB) and/or local red soil (LRS) was applied to the bloom material (mainly Dolichospermum circinalis and Microcystis aeruginosa) of a tropical reservoir. Intra and extracellular MC and biomass removal were evaluated. PAC alone was not efficient to remove the biomass, while PAC + LMB + LRS was the most efficient and removed 4.3-7.5 times more biomass than other treatments. Intracellular MC concentrations ranged between 12 and 2.180 µg L^-1 independent from the biomass. PAC treatment increased extracellular MC concentrations from 3.5 to 6 times. However, when combined with ballast, extracellular MC was up to 4.2 times lower in the top of the test tubes. Nevertheless, PAC + LRS and PAC + LMB + LRS treatments showed extracellular MC concentration eight times higher than controls in the bottom. Our results showed that Floc and Sink appears to be more promising in removing cyanobacteria and extracellular MC from the water column than a sole coagulant (PAC).

A bioinspired nitrone precursor to a stabilized nitroxide radical

Nitrones derived from natural antioxidants are emerging as highly specific therapeutics against various human diseases, including stroke, neurodegenerative pathologies, and cancer. However, the development of useful pseudo-natural nitrones requires the judicious choice of a secondary metabolite as the precursor. Betalains are nitrogen-containing natural pigments that exhibit marked antioxidant capacity and pharmacological properties and, hence, are ideal candidates for designing multifunctional nitrones. In this work, we describe the semisynthesis and properties of a biocompatible and antioxidant betalain-nitrone called OxiBeet. This bio-based compound is a better radical scavenger than ascorbic acid, gallic acid, and most non-phenolic antioxidants and undergoes concerted proton-coupled electron transfer. The autoxidation of OxiBeet produces a persistent nitroxide radical, which, herein, is studied via electron paramagnetic resonance spectroscopy. In addition, femtosecond transient absorption spectroscopy reveals that excited state formation is not required for the oxidation of OxiBeet. The results are compared with those obtained using betanin, a natural betalain, and pBeet, the imine analog of OxiBeet. The findings of this study will enable the development of antioxidant and spin-trap nitrones based on the novel N-oxide 1,7-diazaheptamethinium scaffold and betalain dyes with enhanced hydrolytic stability in aqueous alkaline media.

CyanoMetDB, a comprehensive public database of secondary metabolites from cyanobacteria

Harmful cyanobacterial blooms, which frequently contain toxic secondary metabolites, are reported in aquatic environments around the world. More than two thousand cyanobacterial secondary metabolites have been reported from diverse sources over the past fifty years. A comprehensive, publically-accessible database detailing these secondary metabolites would facilitate research into their occurrence, functions and toxicological risks. To address this need we created CyanoMetDB, a highly curated, flat-file, openly-accessible database of cyanobacterial secondary metabolites collated from 850 peer-reviewed articles published between 1967 and 2020. CyanoMetDB contains 2010 cyanobacterial metabolites and 99 structurally related compounds. This has nearly doubled the number of entries with complete literature metadata and structural composition information compared to previously available open access databases. The dataset includes microcytsins, cyanopeptolins, other depsipeptides, anabaenopeptins, microginins, aeruginosins, cyclamides, cryptophycins, saxitoxins, spumigins, microviridins, and anatoxins among other metabolite classes. A comprehensive database dedicated to cyanobacterial secondary metabolites facilitates: (1) the detection and dereplication of known cyanobacterial toxins and secondary metabolites; (2) the identification of novel natural products from cyanobacteria; (3) research on biosynthesis of cyanobacterial secondary metabolites, including substructure searches; and (4) the investigation of their abundance, persistence, and toxicity in natural environments.

Patient-reported outcomes after oesophagectomy in the multicentre LASER study

BACKGROUND

Data on the long-term symptom burden in patients surviving oesophageal cancer surgery are scarce. The aim of this study was to identify the most prevalent symptoms and their interactions with health-related quality of life.

METHODS

This was a cross-sectional cohort study of patients who underwent oesophageal cancer surgery in 20 European centres between 2010 and 2016. Patients had to be disease-free for at least 1 year. They were asked to complete a 28-symptom questionnaire at a single time point, at least 1 year after surgery. Principal component analysis was used to assess for clustering and association of symptoms. Risk factors associated with the development of severe symptoms were identified by multivariable logistic regression models.

RESULTS

Of 1081 invited patients, 876 (81.0 per cent) responded. Symptoms in the preceding 6 months associated with previous surgery were experienced by 586 patients (66.9 per cent). The most common severe symptoms included reduced energy or activity tolerance (30.7 per cent), feeling of early fullness after eating (30.0 per cent), tiredness (28.7 per cent), and heartburn/acid or bile regurgitation (19.6 per cent). Clustering analysis showed that symptoms clustered into six domains: lethargy, musculoskeletal pain, dumping, lower gastrointestinal symptoms, regurgitation/reflux, and swallowing/conduit problems; the latter two were the most closely associated. Surgical approach, neoadjuvant therapy, patient age, and sex were factors associated with severe symptoms.

CONCLUSION

A long-term symptom burden is common after oesophageal cancer surgery.

Effect of ultraviolet radiation on the metabolomic profiles of potentially toxic cyanobacteria

Interactions between climate change and ultraviolet radiation (UVR) have a substantial impact on aquatic ecosystems, especially on photosynthetic organisms. To counteract the damaging effects of UVR, cyanobacteria developed adaptive strategies such as the biosynthesis of secondary metabolites. This study aimed to evaluate the effects of UVR on the metabolomic profiles of potentially toxic cyanobacteria. Twelve strains were irradiated with ultraviolet A and ultraviolet B radiation and parabolic aluminized reflector lamps for 3 days, followed by liquid chromatography-tandem mass spectometry (LC-MS/MS) analysis to assess changes in metabolomic profiles. Matrices were used to generate principal component analysis biplots, and molecular networks were obtained using the Global Natural Products platform. Most strains showed significant changes in their metabolomic profiles after UVR exposure. On average, 7% of MS features were shown to be exclusive to metabolomic profiles before UVR exposure, while 9% were unique to metabolomic profiles after UVR exposure. The identified compounds included aeruginosins, spumigins, cyanopeptolins, microginins, namalides, pseudospumigins, anabaenopeptins, mycosporine-like amino acids, nodularins and microcystins. Data showed that cyanobacteria display broad metabolic plasticity upon UVR exposure, including the synthesis and differential expression of a variety of secondary metabolites. This could result in a competitive advantage, supporting cyanobacterial blooms under various UVR light exposures.

UEPG Abraça Program: The importance of a psychosocial care service in the university context

Introduction

In 2018, it was implanted in a Brazilian public university, the UEPG Abraça Extension Program, which has as objectives to realize psychosocial care and accompaniment, offer psychotherapies and therapeutic groups to the university community, that is, students, professors and university staff to suicide prevention, coping with mental disorders and the problematic use of alcohol and other drugs. The Program has a multi-professional team composed of nurses, social worker, psychologists and psychiatrists, in an exclusive environment, thus guaranteeing comfort and secrecy to users.

Objectives

To characterize the socio-demographic and clinical profile of users assisted by the UEPG Abraça Program and to disclose the importance of the service for the promotion of Mental Health.

Methods

Qualitative, quantitative, descriptive study, with a structured questionnaire as the research instrument. The collection took place in 2019 and the target audience were users who sought psychological care.

Results

There were 469 admissions/visits and 35 of them continued with individual visits in 2020. The majority of users were female (58%) and had the age group between 17 and 20 years. The main mental health problems identified were anxiety, self-knowledge and university-related problems such as interpersonal conflicts and difficulties in the work process. The most attended undergraduate courses were Letters, Journalism and Dentistry.

Conclusions

It is noted the importance of a psychosocial care service at university level for the care and promotion of Mental Health.

Disclosure

No significant relationships.

COVID-19 and psychological support by phone: Demands assisted at a call center service of a brazilian university

Introduction

Throughout the COVID-19 Pandemic, it was recommended to implement mental health care services mediated by Information and Communication Technologies to alleviate the suffering caused by the social distance.

Objectives

To characterize the demands and the possibilities of psychological support at the Call Center of a Brazilian public university, which aims clarifying doubts about COVID-19 and to forward suspected cases of contamination.

Methods

Cross-sectional, quantitative study with secondary data. The data came from 60 Psychological Support attendance records, carried out over 24 weeks. The data were analyzed descriptively and by the paired test and McNemar.

Results

The majority of consultations were for people aged among 51 and 60 years (21.7%). The main demands were social (40.0%), related to feelings (40.0%) and self-reported diagnosis (18.3%), with each service mostly split into two (31.7%) or three (31.7%) conducts. There was a significant increase in the average number of reports of symptoms of psychological distress experienced during the pandemic (p <0.001), including changes in sleep patterns (p <0.001) and appetite (p = 0.002), physical symptoms (p = 0.001), physical and emotional discomfort (p <0.001) and crying / depressive mood attacks (p = 0.002). As conducts, there was a predominance of psychoeducation (78.3%) and strategies for managing suffering (68.3%) at the expense of referrals to specialized in-person services (21.7%).

Conclusions

There were several demands of the evaluated Psychological Support service, which presents an important and promising strategy for meeting the demands of psychological distress in the midst of Pandemic, especially for the adult and elderly public.

Occurrence of caffeine, fluoxetine, bezafibrate and levothyroxine in surface freshwater of São Paulo State (Brazil) and risk assessment for aquatic life protection

The prioritization of active pharmaceutical ingredients (APIs) for monitoring programmes and/or environmental risk assessment (ERA) purposes is based on several criteria, including environmental occurrence data. However, data on API occurrence in Brazilian surface freshwaters are still scarce. The Brazilian Unified Health System (SUS) provides several medicines free-of-charge, including medications that have bezafibrate, fluoxetine and levothyroxine as the API. Thus, our objective was to investigate the occurrence of bezafibrate, fluoxetine and levothyroxine in samples collected at sampling sites included in the surface freshwater monitoring program of the São Paulo State Environmental Agency (CETESB); caffeine was also included in the analysis because it is commonly used as an anthropogenic marker of aquatic environment contamination. Monitoring results showed that levothyroxine was not found in any of the analysed samples. Caffeine was ubiquitous in the analysed samples, thus indicating anthropic contamination in the studied water bodies. Caffeine and bezafibrate presented risk quotient (RQ) < 1 for all the sampling sites and periods evaluated in this study. For fluoxetine, RQs > 1 were found in all water samples in which this API was found, indicating a potential risk for freshwater pelagic biota. Thus, fluoxetine should be regulated in São Paulo State in order to protect the aquatic biota. Additional occurrence studies in other Brazilian states are still needed to evaluate if fluoxetine is a nationwide pollutant.

Responses of Aquatic Nontarget Organisms in Experiments Simulating a Scenario of Contamination by Imidacloprid in a Freshwater Environment

Several studies have indicated the presence of the neonicotinoid insecticide imidacloprid (IMI) in aquatic ecosystems in concentrations up to 320.0 µg L^-1. In the present study, we evaluated the effects of the highest IMI concentration detected in surface water (320.0 µg L^-1) on the survival of Chironomus sancticaroli, Daphnia similis, and Danio rerio in three different scenarios of water contamination. The enzymatic activities of glutathione S-transferase (GST), catalase (CAT), and ascorbate peroxidase (APX) in D. rerio also were determined. For this evaluation, we have simulated a lotic environment using an indoor system of artificial channels developed for the present study. In this system, three scenarios of contamination by IMI (320.0 µg L^-1) were reproduced: one using reconstituted water (RW) and the other two using water samples collected in unpolluted (UW) and polluted (DW) areas of a river. The results indicated that the tested concentration was not able to cause mortality in D. similis and D. rerio in any proposed treatment (RW, UW, and DW). However, C. sancticaroli showed 100% of mortality in the presence of IMI in the three proposed treatments, demonstrating its potential to impact the community of aquatic nontarget insects negatively. Low IMI concentrations did not offer risks to D. rerio survival. However, we observed alterations in GST, CAT, and APX activities in treatments that used IMI and water with no evidence of pollution (i.e., RW and UW). These last results demonstrated that fish are more susceptible to the effects of IMI in unpolluted environments.

Mycosporine-Like Amino Acids (MAAs): Biology, Chemistry and Identification Features

Mycosporines and mycosporine-like amino acids are ultra-violet-absorbing compounds produced by several organisms such as lichens, fungi, algae and cyanobacteria, especially upon exposure to solar ultraviolet radiation. These compounds have photoprotective and antioxidant functions. Mycosporine-like amino acids have been used as a natural bioactive ingredient in cosmetic products. Several reviews have already been developed on these photoprotective compounds, but they focus on specific features. Herein, an extremely complete database on mycosporines and mycosporine-like amino acids, covering the whole class of these natural sunscreen compounds known to date, is presented. Currently, this database has 74 compounds and provides information about the chemistry, absorption maxima, protonated mass, fragments and molecular structure of these UV-absorbing compounds as well as their presence in organisms. This platform completes the previous reviews and is available online for free and in the public domain. This database is a useful tool for natural product data mining, dereplication studies, research working in the field of UV-absorbing compounds mycosporines and being integrated in mass spectrometry library software.

Stability Analyses by HPLC-MS of Guanitoxin Isolated from Sphaerospermopsis torques-reginae

Guanitoxin (GNT) is a natural organophosphate produced by some species of freshwater cyanobacteria, which inhibits the active site of acetylcholinesterase, preventing the hydrolysis of cholinesterases and consequently causing serious disturbances in the neuromuscular system. Despite having a chemical structure like synthetic organophosphates, there is still no analytical standard available for environmental and freshwater monitoring. Therefore, this study investigated the stability of GNT under different storage conditions, pH, and temperature. The toxin is produced by the cyanobacterium Sphaerospermopsis torques-reginae and monitored by liquid chromatography coupled to mass spectrometry (LC-MS) and LC-MS/MS for the identification and verification of its stability. The main degradation product formed is the hydroxy-amino-guanidinic derivative of the toxin. The results also indicate that GNT is stable in acidic medium (pH = 3.0), but can gradually degrade at room temperature (> 23 ºC) over a period of 96 h. Lyophilized biomass of S. torques-reginae containing GNT remained stable when stored in a refrigerator below 4 ºC. In addition, the extraction yield is higher when prepared from fresh S. torques-reginae cells than from lyophilized material. Thus, the results shown here contribute with valuable information for studies that aim at the isolation, identification, and monitoring of GNT in samples of raw water and cyanobacterial blooms.

Removal efficiency of dissolved organic matter from secondary effluent by coagulation-flocculation processes

Wastewater reuse has been widely discussed as an essential strategy to minimize the consumption of drinking water for less noble purposes. During biological wastewater treatment, organic matter is converted into a complex matrix containing a variety of soluble organic compounds. The objective of the present study was to evaluate the removal efficiency of the residual organic load in the final effluent from wastewater treatment plant with a conventional activated sludge process by different coagulants and parameters of coagulation-flocculation process, using dissolved organic carbon (DOC) concentration, molecular weight (MW) size distribution by size exclusion chromatography (SEC) coupled to mass spectrometry (MS), and zeta potential (ZP) analyses. The results showed a DOC removal efficiency up to 45% with iron chloride, and of 38% for aluminum sulfate and 31% for PAC coagulants. ZP was also measured during the procedures and authors conclude that the ZP also does not have a determining role in these removals. SEC and MS assessment was able to detect changes on secondary effluent molecular weight distribution profile after effluent coagulation-flocculation, this technique might be a promising tool to understand the composition of effluent organic matter and be helpful to estimate and optimize the performance of wastewater effluents treatment processes.

Availability of Guanitoxin in Water Samples Containing Sphaerospermopsis torques-reginae Cells Submitted to Dissolution Tests

Guanitoxin (GNT) is a potent neurotoxin produced by freshwater cyanobacteria that can cause the deaths of wild and domestic animals. Through reports of animal intoxication by cyanobacteria cells that produce GNT, this study aimed to investigate the bio-accessibility of GNT in simulated solutions of the gastrointestinal content in order to understand the process of toxicosis promoted by GNT in vivo. Dissolution tests were conducted with a mixture of Sphaerospermopsis torques-reginae (Cyanobacteria; Nostocales) cultures (30%) and gastrointestinal solutions with and without proteolytic enzymes (70%) at a temperature of 37 °C and rotation at 100 rpm for 2 h. The identification of GNT was performed by LC-QqQ-MS/MS through the transitions [M + H]⁺m/z 253 > 58 and [M + H]⁺m/z 253 > 159, which showed high concentrations of GNT in simulated gastric fluid solutions (p-value < 0.001) in comparison to simulated solutions of intestinal content. The gastric solution with pepsin promoted the stability of GNT (p-value < 0.05) compared to the simulated solution of gastric fluid at the same pH without the enzyme. However, the results showed that GNT is also available in intestinal fluids for a period of 2 h, and solutions containing the pancreatin enzyme influenced the bio-accessibility of the toxin more compared to the intestinal medium without enzyme (p-value < 0.05). Therefore, the bio-accessibility of the toxin must be considered both in the stomach and in the intestine, and may help in the diagnosis and prediction of exposure and risk in vivo through the oral ingestion of GNT-producing cyanobacteria cells.

Effects of single and combined exposures of gold (nano versus ionic form) and gemfibrozil in a liver organ culture of Sparus aurata

In vitro methods have gained rising importance in ecotoxicology due to ethical concerns. The aim of this study was to assess the single and combined in vitro effects of gold, as nanoparticle (AuNPs) and ionic (Au⁺) form, and the pharmaceutical gemfibrozil (GEM). Sparus aurata liver organ culture was exposed to gold (4 to 7200 μg·L^-1), GEM (1.5 to 15,000 μg·L^-1) and combination 80 μg·L^-1 gold +150 μg·L^-1 GEM for 24 h. Endpoints related with antioxidant status, peroxidative/genetic damage were assessed. AuNPs caused more effects than Au⁺, increasing catalase and glutathione reductase activities and damaging DNA and cellular membranes. Effects were dependent on AuNPs size, coating and concentration. GEM damaged DNA at an environmentally relevant concentration, 1.5 μg·L^-1. Overall, the effects of the combined exposures were higher than the predicted, based on single exposures. This study showed that liver culture can be a useful model to study contaminants effects.

In vitro toxicity of isolated strains and cyanobacterial bloom biomasses over Paramecium caudatum (ciliophora): Lessons from a non-metazoan model organism

Cyanobacteria have been considered a major global threat because of their widespread ability to proliferate and contaminate inland and marine waters with toxic metabolites. For this reason, to avoid risks to humans and environmental health, regulatory legislation and guidelines have been established based on extensive toxicological data. However, most of what is known in this field come from works on microcystin (MC) variants, which effects were almost exclusively tested in metazoan models. In this work, we used acute end-point toxicological assays and high-resolution hybrid quadrupole time-of-flight mass spectrometer coupled with electrospray ionization source (ESI-Q-TOF-MS) analyses to evaluate the deleterious impact of aqueous extracts prepared from cultures of cyanobacteria and environmental bloom biomasses over a non-metazoan model organism, the cosmopolitan fresh/brackish water unicellular microeukaryote, Paramecium caudatum (Ciliophora). Our data suggest that all extracts produced time-dependent effects on P. caudatum survival, irrespective of their metabolite profile; and that this ciliate is more sensitive to extracts containing microginins than to extracts with only MCs, stressing that more toxicological investigations should be performed on the environmental impact of neglected cyanotoxins. Further, our data provide evidence that P. caudatum may be more sensitive to cyanotoxins than vertebrates, indicating that guidelines values, set on metazoans are likely to be inaccurate to protect organisms from basal food web positions. Thus, we highly recommend the widespread use of microeukaryotes, such as ciliates in environmental risk assessment frameworks for the establishment of more reliable cyanotoxin monitoring guideline values.

Identification and distribution of mycosporine-like amino acids in Brazilian cyanobacteria using ultrahigh-performance liquid chromatography with diode array detection coupled to quadrupole time-of-flight mass spectrometry

RATIONALE

Mycosporine-like amino acids (MAAs) are UV-absorbing compounds produced by fungi, algae, lichens, and cyanobacteria when exposed to UV radiation. These compounds have photoprotective and antioxidant functions and have been widely studied for possible use in sunscreens and anti-aging products. This study aims to identify MAA-producing cyanobacteria with potential application in cosmetics.

METHODS

A method for the identification of MAAs was developed using ultrahigh-performance liquid chromatography with diode array detection coupled to quadrupole time-of-flight mass spectrometry (UHPLC-DAD/QTOFMS). Chromatographic separation was carried out using a Synergi 4 μ Hydro-RP 80A column (150 × 2,0 mm) at 30°C with 0.1% formic acid aqueous solution + 2 mM ammonium formate and acetonitrile/water (8:2) + 0.1% formic acid as a mobile phase.

RESULTS

Out of the 69 cyanobacteria studied, 26 strains (37%) synthesized MAAs. Nine different MAAs were identified using UHPLC-DAD/QTOFMS. Iminomycosporines were the major group detected (7 in 9 MAAs). In terms of abundance, the most representative genera for MAA production were heterocyte-forming groups. Oscilatoria sp. CMMA 1600, of homocyte type, produced the greatest diversity of MAAs.

CONCLUSIONS

The UHPLC-DAD/QTOFMS method is a powerful tool for identification and screening of MAAs in cyanobacterial strains as well as in other organisms such as dinoflagellates, macroalgae, and microalgae. The different cyanobacterial genera isolated from diverse Brazilian biomes and environments are prolific sources of MAAs.

Alternative Isolation Protocol for Desulfo and Zwitterionic Cylindrospermopsin Alkaloids and Comparison of Their Toxicity in HepG2 Cells

The term cylindrospermopsins (CYNs) refers to a structurally related class of cyanobacterial metabolites comprised of a tricyclic guanidine group and a hydroxymethyluracil moiety. Most reports in environmental aquatic samples refer to cylindrospermopsin (CYN), and reports on other CYN alkaloids are scarce, due, in part, to a lack of versatile isolation protocols. Thus, using commercially available solid phase extraction (SPE) cartridges, we optimized an isolation protocol for the complete recovery of CYN, 7-deoxy-cylindrospermopsin (7D-CYN) and 7-deoxy-desulfo-cylindrospermopsin (7D-desulfo-CYN) from the same aliquot. The isolation protocol was adaptable depending on the nature of the sample (solid biomass, culture broth or environmental water sample) and tolerates up to 4 L of dense culture broth or 400 mg of lyophilized biomass. To quantitate the CYN alkaloids, we validated an LC-DAD-MS² method, which takes advantage of the UV absorption of the uracil group (λ 262 nm). Using electrospray ionization (ESI) in a positive ion mode, the high-resolution MS¹ data confirms the presence of the protonated alkaloids, and the MS² fragment assignment is reported as complementary proof of the molecular structure of the CYNs. We isolated three CYN alkaloids with different water solubility using the same lyophilized sample, with a purity that ranged from 95% to 99%. The biological activity of the purified CYNs, along with a synthetic degradation product of CYN (desulfo-cylindrospermopsin), was evaluated by assessing necrosis and apoptosis in vitro using flow cytometry. CYN’s lethal potency in HepG2 cells was greater than the other analogs, due to the presence of all four functional groups: guanidine, uracil, C-7 hydroxyl and the sulfate residue.

Metals, arsenic, pesticides, and microcystins in tilapia (Oreochromis niloticus) from aquaculture parks in Brazil

The production of Nile tilapia (Oreochromis niloticus) in Brazil exhibits the highest growth rate in the world and represents approximately 45% of the total fish production. The objective of the present study was to assess the risk for human health due the consumption of tilapia farmed in net cages in eight aquaculture parks in Brazil. The concentrations of pesticides (40 compounds), metals (Mn, Ni, Zn, Cd, Pb, and Sn), arsenic, and cyanotoxins (microcystins) were evaluated in 16 fish from each park. Among analyzed pesticides, pyraclostrobin (0.18-0.32 mg/kg) and fenthion (0.0026-0.0037 mg/kg) exhibited values above the limit of quantification in the tilapia from Aracoiaba, Castanhão, and Ilha Solteira. The highest concentrations of As (0.44 μg/g) in fish tissues were found in Juara, Mn (0.21 μg/g) in Castanhão, and Zi (11.5 μg/g) were found in Três Marias. Furnas and Linhares exhibited the lowest metal concentrations. The estimated daily intake of muscle by the average Brazilian with 70 kg body weight is below the reference dose for all studied metals in all parks. Total free microcystins showed an accumulation pattern (muscle < gill < liver). The highest concentration in muscle was found in Castanhão (1043 μg/kg) samples. The results showed that fish exhibited metal, As, and pesticide tolerable daily intake (TDI) below the limit and pose low risk for human consumption. Otherwise, TDI for microcystins in fish of all studied parks was above the maximum level recommended by the World Health Organization, indicating that there exists a toxicity risk of fish consumption.

Biological effects and bioaccumulation of gold in gilthead seabream (Sparus aurata) - Nano versus ionic form

The question of whether gold (Au) is more toxic as nanoparticles or in its ionic form remains unclear and controversial. The present work aimed to clarify the effects of 96 h exposure to 4, 80 and 1600 μg·L^-1 of 7 nm gold nanoparticles (AuNPs) - (citrate coated (cAuNPs) or polyvinylpyrrolidone coated (PVP-AuNPs)) - and ionic Au (iAu) on gilthead seabream (Sparus aurata). Effects at different levels of biological organization (behaviour, neurotransmission, biotransformation, oxidative stress/damage and genotoxicity) were assessed. cAuNPs induced oxidative stress and damage (lipid peroxidation increase), even at 4 μg·L^-1, and reduced the ability of S. aurata to swim against a water flow at 1600 μg·L^-1. Exposure to cAuNPs induced more adverse effects than exposure to PVP-AuNPs. All tested concentrations of Au (nano or ionic form) induced DNA breaks and cytogenetic damage in erythrocytes of S. aurata. Generally, iAu induced significantly more effects in fish than the nano form, probably associated with the significantly higher accumulation in the fish tissues. No fish mortality was observed following exposure to AuNPs, but mortality was observed in the group exposed to 1600 μg·L^-1 of iAu.

A metal-free blue chromophore derived from plant pigments

Blue natural pigments are rare, especially among plants. However, flowering species that evolved to attract Hymenoptera pollinators are colored by blue anthocyanin-metal complexes. Plants lacking anthocyanins are pigmented by betalains but are unable to produce blue hues. By extending the π-system of betalains, we designed a photostable and metal-free blue dye named BeetBlue that did not show toxicity to human hepatic and retinal pigment epithelial cells and does not affect zebrafish embryonal development. This chiral dye can be conveniently synthesized from betalamic acid obtained from hydrolyzed red beetroot juice or by enzymatic oxidation of l-dopa. BeetBlue is blue in the solid form and in solution of acidified polar molecular solvents, including water. Its capacity to dye natural matrices makes BeetBlue the prototype of a new class of low-cost bioinspired chromophores suitable for a myriad of applications requiring a blue hue.

Effects of gold nanoparticles in gilthead seabream-A proteomic approach

Despite the widespread use of nanoparticles (NPs), there are still major gaps of knowledge regarding the impact of nanomaterials in the environment and aquatic animals. The present work aimed to study the effects of 7 and 40 nm gold nanoparticles (AuNPs) - citrate and polyvinylpyrrolidone (PVP) coated - on the liver proteome of the estuarine/marine fish gilthead seabream (Sparus aurata). After 96 h, exposure to AuNP elicited alterations on the abundance of 26 proteins, when compared to the control group. AuNPs differentially affected several metabolic pathways in S. aurata liver cells. Among the affected proteins were those related to cytoskeleton and cell structure, gluconeogenesis, amino acids metabolism and several processes related to protein activity (protein synthesis, catabolism, folding and transport). The increased abundance of proteins associated with energy metabolism (ATP synthase subunit beta), stress response (94 kDa glucose-regulated protein) and cytoskeleton structure (actins and tubulins) may represent the first signs of cellular oxidative stress induced by AuNPs. Although higher gold accumulation was found in the liver of S. aurata exposed to 7 nm PVP-AuNPs, the 7 nm cAuNPs were more bioactive, inducing more effects in liver proteome. Gold accumulated more in the spleen than in the other assessed tissues of S. aurata exposed to AuNPs, highlighting its potential role on the elimination of these NPs.

Genomic and Metabolomic Analyses of Natural Products in Nodularia spumigena Isolated from a Shrimp Culture Pond

The bloom-forming cyanobacterium Nodularia spumigena CENA596 encodes the biosynthetic gene clusters (BGCs) of the known natural products nodularins, spumigins, anabaenopeptins/namalides, aeruginosins, mycosporin-like amino acids, and scytonemin, along with the terpenoid geosmin. Targeted metabolomics confirmed the production of these metabolic compounds, except for the alkaloid scytonemin. Genome mining of N. spumigena CENA596 and its three closely related Nodularia strains—two planktonic strains from the Baltic Sea and one benthic strain from Japanese marine sediment—revealed that the number of BGCs in planktonic strains was higher than in benthic one. Geosmin—a volatile compound with unpleasant taste and odor—was unique to the Brazilian strain CENA596. Automatic annotation of the genomes using subsystems technology revealed a related number of coding sequences and functional roles. Orthologs from the Nodularia genomes are involved in the primary and secondary metabolisms. Phylogenomic analysis of N. spumigena CENA596 based on 120 conserved protein sequences positioned this strain close to the Baltic Nodularia. Phylogeny of the 16S rRNA genes separated the Brazilian CENA596 strain from those of the Baltic Sea, despite their high sequence identities (99% identity, 100% coverage). The comparative analysis among planktic Nodularia strains showed that their genomes were considerably similar despite their geographically distant origin.

P1527 Papillary fibroelastomas: diagnostic challenges and clinical and morphologic features

Introduction

Papillary fibroelastomas are rare benign primary cardiac tumors that more frequently involve cardiac valves. They are frequently incidentally discovered by echocardiography but may also cause symptoms.

Purpose

The aim of this study was to characterize several features of histologically confirmed fibroelastomas.

Methods

Retrospective analysis of patients with echocardiographic suspicion of fibroelastoma between 2009 and 2019 in a single tertiary center. Echocardiography was compared with histology, and echocardiographic, surgical and pathological information about confirmed fibroelastomas was collected.

Results

37 patients (P) (54.1% men) with an echocardiographic suspicion and/or histologically confirmed fibroelastoma were included, with a mean age of 58 +- 3 years (min 22, max 82). Echocardiographic report was analyzed in 34P (91.9%), with 32P (94.1%) reporting a likely fibroelastoma and 2P (5.9%) reporting a non-specified mass. 21P (56.8%) had surgery, with 12P (57.1%) having a surgical suspicion of a fibroelastoma, 2P (9.5%) of a mixoma, 1P (4.8%) of a non-specified mass and 6P (28.6%) with undefined suspicion. Of the 21P who had surgery, 66.7% (14P) had a histologically confirmed fibroelastoma, 1P (4.8%) had a mixoma, and 6P (28.6%) had other diagnoses. From the 14P with histologically confirmed fibroelastoma 64.3% had this suspicion by echocardiography and 35.7% had an echocardiogram reporting a non-specified. There was a global concordance between echocardiography and histology in 52.9%. The mean age of confirmed fibroelastoma P was 54 +-5years, and 50% were men. 7P (50%) were asymptomatic, 2 (14.3%) had a stroke, 2 (14.3%) had syncope, 1 (7.1%) had fatigue, 1 (7.1%) had palpitations and 1P had consciousness alteration. In echocardiography most P (71.4%) had only one mass but 1P had 4 different masses. The tumors had a longer axis between 6 and 25mm, with the majority (57.1%) measuring more than 10mm. 12P (85.7%) had valvular fibroelastomas, 50% of these in the aortic valve (3 in non-coronary cusp, 1 in right coronary cusp and 2 non-specified) and 50% in the mitral valve (all in sub-valvular apparatus, involving anterior leaflet, tendinous chord or papillary muscle). 1P had a left ventricular fibroelastoma (apical) and 1P had four masses in the left atrium. Macroscopically 4 lesions had a gelatinous consistency, 2 of them were membranous, 2 were elastic, 2 were friable, 1 was villainous and in 3 of them consistency was not described. The majority (57%) was white, 14% was translucent and in the rest the color was not specified. There was no described recurrence after surgery and there were no deaths registered.

Conclusion

In this population there was a reasonable concordance between echocardiography and histology, but in some cases the diagnosis was undefined or wrong. 50% of the patients were asymptomatic and the majority had valvular fibroelastomas, but a few had a different location.

P229 Primary cardiac angiosarcoma of the right atrium: a rare entity presenting with an atrial arrhythmia

Introduction

Primary cardiac tumors are rare entities and 75% are benign. Angiosarcoma is the most common malignant primary cardiac tumor.

We report the case of cardiac angiosarcoma presenting with an atrial arrhythmia.

Clinical case

A 39-year-old female patient with no past medical history presented to the emergency department with heart palpitations and atypical chest pain.

Electrocardiogram on admission showed atrial flutter with a heart rate of 153 beats per minute.

Laboratory analysis were performed showing elevated D-dimer levels (2210 ug/L).

A thoracic CT scan was performed, which ruled out pulmonary embolism, but showed multiple pulmonary nodules and a right atrial (RA) mass measuring 48 mm that could correspond to a thrombus or neoplasia.

The patient was admitted in the Cardiology ICU of our hospital and was started on beta-blocker and amiodarone with conversion to sinus rhythm. Additional exams were performed:

- Transthoracic echocardiogram (TTE) revealed an heterogenous 32,6 x 17,7 mm mass in the lateral wall of the RA with an adherent mobile mass near the tricuspid valve with 28 mm diameter (possible adherent thrombus).

- Cardiac magnetic resonance imaging confirmed a RA tumor with invasion of the atrial free wall and compression of the superior vena cava.

Due to the unclear etiology of the RA mass, ultrasound-guided intracardiac biopsy was performed. Pathological examination revealed spindle cell proliferation, consistent with the diagnosis of angiosarcoma. Immunohistochemical staining was positive for Vimentin, CD34 and CD31, with 70% Ki67 expression.

Later on, the patient developed melena with significant drop of hemoglobin levels, requiring daily red blood cell transfusions and anticoagulation had to be stopped.

The patient was transferred to the Internal Medicine ward and thoracic-abdomen-pelvis staging computed tomography (CT) scan showed a significant increase in the number of pulmonary nodules, bilateral ovarian masses, 4 hepatic nodules and ileum metastization.

During hospitalization, the patient developed right leg deep venous thrombosis and thoracic CT scan revealed bilateral pulmonary embolism.

After improvement of the clinical status, palliative chemotherapy was started and the patient was discharged, maintaining regular outpatient follow-up in the Oncology Department for 1 month.

Cardiac angiosarcoma generally presents in a late stage of the disease with metastatic involvement. When surgical treatment is not possible, despite agressive chemotherapy, the prognosis remains poor.

Abstract P229 Figure. Echocardiogram: right atrium mass