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The effects of cyanobacterial toxins on herbivorous zooplankton depend on cyanobacterial strains, zooplankton species and environmental conditions. To explore the relationship between zooplankton and cyanobacteria, we investigated the effects of Planktothrix agardhii extracts on Daphnia magna population dynamics. We designed an experiment where individuals were grown in the presence of extracts of two P. agardhii strains. We monitored daily life-history parameters of D. magna individuals subjected to microcystin- RR (MC-RR), intracellular and extracellular extracts of a microcystin-producing strain (MC-strain, PMC 75.02) and a microcystin-free strain (MC-free strain, PMC 87.02) of P. agardhii. Measured life-history parameters of D. magna were used to build population dynamics models and compute expected population growth rate, replacement rate, generation time and proportion of adult and juveniles at demographic equilibrium. Results show that MC-RR tends to slow the life history (reduced growth rate and larger proportion of adults). In contrast, intracellular extracts of the two strains tend to accelerate the life history (increased growth rate, decreased generation time and lower proportion of adults). Extracellular extracts produce the same trends as the intracellular extracts but to a lesser extent. However, the MC-strain has stronger effects than the MC-free strain. Interestingly, extracellular extracts of the MC-free strain may have effects comparable to pure MC-RR. Moreover, in the presence of MC-RR and both cyanobacterial extracts, the daily fecundities present a cyclic pattern. These results suggest that MC-RR and unknown metabolites of cyanobacterial extracts have negative effects on D. magna reproduction processes such as those observed with endocrine-disruptive molecules. [ABSTRACT FROM AUTHOR]

Planktothrix agardhii dynamics, microcystin concentration and limnological variables were monitored every 2 weeks for 2 years (2004–2006) in a shallow hypereutrophic artificial lake (BNV, Viry-Châtillon, France). Time-series analysis identified two components in the P. agardhii biomass dynamics: (1) a significant decreasing trend in P. agardhii biomass (65% of the overall variance) and (2) a residual component without significant seasonal periodicity. A path-analysis model was built to determine the main factors controlling the P. agardhii dynamics over the period studied. The model explained 66% of P. agardhii biomass changes. The decreasing trend in P. agardhii biomass was significantly related to a decrease in the PO43− concentration resulting from an improved treatment of the incoming watershed surface water. The residual component was related to zooplankton dynamics (cyclopoid abundances), supporting the hypothesis of a top-down control of P. agardhii, but only when the biomass was low. Forty-nine percent of the variability in the microcystin (MC) concentration (min:<0.1 μg equivalent MC-LR L−1; max: 7.4 μg equivalent MC-LR L−1) could be explained by changes in the P. agardhii biomass. The highest toxin content was observed when P. agardhii biomass was the lowest, which suggests changes in the proportion of microcystin-producing and -nonproducing subpopulations and/or the physiological status of cells. [ABSTRACT FROM AUTHOR]

Cylindrospermopsis raciborskii is a toxic bloom-forming cyanobacterium that occurs at tropical and temperate latitudes. Despite several reports from Africa, no data were previously available about its dynamics or toxic potential there. We therefore carried out a 1-year survey of the dynamics of C. raciborskii in the main water reservoir in Senegal, Lake Guiers. Cylindrospermopsis raciborskii never formed a bloom in this lake during the period studied, but was dominant during the dry season. The only observed bloom-forming species was a diatom, Fragilaria sp., which displayed a seasonal pattern contrary to that exhibited by C. raciborskii. Principal component analysis applied to environmental and phytoplankton data showed that high C. raciborskii biomasses were mainly related to high temperature and water column stability. Tests for C. raciborskii species-related toxicity and/or toxin synthesis were performed on 21 isolated clones. All the strains isolated tested negative in mouse toxicity bioassays, toxin analysis (MS/MS) and tests for known cylindrospermopsin genes ( ps, pks). The limited number of isolates studied, and the occurrence of toxic and nontoxic clones in natural cyanobacterial populations, mean that we cannot conclude that there is no C. raciborskii-associated health risk in this drinking water reservoir. [ABSTRACT FROM AUTHOR]

We studied the synthesis and binding of phcoerythrin and its associated linkers to the phycobilisome (PBS) in Rhodella violacea (Kornmann) Wehrmeyer and compared the effects of high light and translation inhibitors on these processes. Rhodella violacea has a simple hemidiscoidal PBS structure with a well-known composition. The number of PBSs per cell decreases when irradiance is increased, and at higher irradiances the rods are shortened with a specific loss of the terminal hexamer of phycoerythrin (PE) and its associated linker. To test whether or not the observed variations were due to a coordination between the expression of the chloroplast-encoded PE and the nuclear-encoded linkers, we inhibited the expression of the chloroplast genes by the translation inhibitor chloroamphenicol. In the few PBSs synthesized, the linker associated with the intermediate. PE hexamer was still present. The inhibition by cycloheximide of the translation of the nuclear-encoded linkers did not influence the synthesis of the chloroplast-encoded phycobiliproteins. The absence of linkers prevented the formation of PE hexamers and their binding to the PBSs. We therefore propose the existence of two levels of regulation for PE and associated linkers: the intermediate PE hexamer and associated linker are always present even though their amount is reduced when irradiance is increased. In contrast, the terminal hexamer of PE and its associated linker are no longer present under high light. Their absence can be due to a feedback control between the level of PE and the synthesis of the linker: when the level of PE is lowered below a given value by the action of light on the chloroplast, a signal coming form the chloroplast reaches the nucleus and the synthesis of the linker is repressed. There is no sign of nuclear regulation of the synthesis of PE, but the nuclear-encoded linkers have a structural role in the formation of PE hexamers. [ABSTRACT FROM AUTHOR]

Background: The Balaruc-les-Bains' thermal mud was found to be colonized predominantly by microorganisms, with cyanobacteria constituting the primary organism in the microbial biofilm observed on the mud surface. The success of cyanobacteria in colonizing this specific ecological niche can be explained in part by their taxa-specific adaptation capacities, and also the diversity of bioactive natural products that they synthesize. This array of components has physiological and ecological properties that may be exploited for various applications. Methods: Nine cyanobacterial strains were isolated from Balaruc thermal mud and maintained in the Paris Museum Collection (PMC). Full genome sequencing was performed coupled with targeted and untargeted metabolomic analyses (HPLC-DAD and LC-MS/MS). Bioassays were performed to determine antioxidant, anti-inflammatory, and wound-healing properties. Results: Biosynthetic pathways for phycobiliproteins, scytonemin, and carotenoid pigments and 124 metabolite biosynthetic gene clusters (BGCs) were characterized. Several compounds with known antioxidant or anti-inflammatory properties, such as carotenoids, phycobilins, mycosporine-like amino acids, and aeruginosins, and other bioactive metabolites like microginins, microviridins, and anabaenolysins were identified. Secretion of the proinflammatory cytokines TNF-α, IL-1β, IL-6, and IL-8 appeared to be inhibited by crude extracts of Planktothricoides raciborskii PMC 877.14, Nostoc sp. PMC 881.14, and Pseudo-chroococcus couteii PMC 885.14. The extract of the Aliinostoc sp. PMC 882.14 strain was able to slightly enhance migration of HaCat cells that may be helpful in wound healing. Several antioxidant compounds were detected, but no significant effects on nitric oxide secretion were observed. There was no cytotoxicity on the three cell types tested, indicating that cyanobacterial extracts may have anti-inflammatory therapeutic potential without harming body cells. These data open up promising uses for these extracts and their respective molecules in drugs or thermal therapies. [ABSTRACT FROM AUTHOR]

Benthic cyanobacteria strains from Guadeloupe have been investigated for the first time by combining phylogenetic, chemical and biological studies in order to better understand the taxonomic and chemical diversity as well as the biological activities of these cyanobacteria through the effect of their specialized metabolites. Therefore, in addition to the construction of the phylogenetic tree, indicating the presence of 12 potentially new species, an LC-MS/MS data analysis workflow was applied to provide an overview on chemical diversity of 20 cyanobacterial extracts, which was linked to antimicrobial activities evaluation against human pathogenic and ichtyopathogenic environmental strains. [ABSTRACT FROM AUTHOR]

Background: The risk of severe medical and surgical events during long-duration spaceflight is significant. In space, many environmental and psychological factors may make tracheal intubation more difficult than on Earth. We hypothesised that, in microgravity, tracheal intubation may be facilitated by the use of a videolaryngoscope compared with direct laryngoscopy.Methods: In a non-randomised, controlled, cross-over simulation study, we compared intubation performance of novice operators and experts, using either a direct laryngoscope or a videolaryngoscope, in weightlessness and in normogravity. The primary outcome was the success rate of tracheal intubation. Time to intubation and the confidence score into the success of tube placement were also recorded.Results: When novices attempted to intubate the trachea in microgravity, the success rate of tracheal intubation using a videolaryngoscope was significantly higher (20/25 [80%]; 95% confidence interval [CI], 64.3-95.7 vs eight/20 [40%]; 95% CI, 18.5-61.5; P=0.006), and intubation time was shorter, compared with using a direct laryngoscope. In normogravity, the success rate of tracheal intubation by experts was significantly higher than that by novices (16/20 [80%]; 95% CI, 62.5-97.5 vs seven/25 [28%]; 95% CI, 10.4-45.6; P=0.001), but in microgravity, there was no significant difference between the experts and novices (19/20 [95%]; 95% CI, 85.4-100 vs 20/25 [80%]; 95% CI, 64.3-95.7; P=0.113). Higher confidence scores were achieved with videolaryngoscopy compared with direct laryngoscopy by both experts and novices in both microgravity and normogravity.Conclusions: Videolaryngoscopy was associated with higher intubation success rate and speed, and higher confidence for correct tube placement by novice operators in microgravity, and as such may represent the best technique for advanced airway management during long-duration spaceflight. [ABSTRACT FROM AUTHOR]

• High frequency monitoring of phytoplankton and bacterioplankton dynamics in an eutrophic shallow lake. • Phytoplankton and associated bacterioplankton communities can be seen as a couple in interaction but with flexible species variations. • Free-living bacterioplankton is under less direct influence of the phytoplankton communities and environmental variables dynamics. Bloom-forming phytoplankton dynamics are still unpredictable, even though it is known that several abiotic factors, such as nutrient availability and temperature, are key factors for bloom development. We investigated whether biotic factors, i.e. the bacterioplankton composition (via 16SrDNA metabarcoding), were correlated with phytoplankton dynamics, through a weekly monitoring of a shallow lake known to host recurrent cyanobacterial blooms. We detected concomitant changes in both bacterial and phytoplankton community biomass and diversity. During the bloom event, a significant decrease in phytoplankton diversity, was detected, with a first co-dominance of Ceratium, Microcystis and Aphanizomenon , followed by a co-dominance of the two cyanobacterial genera. In the same time, we observed a decrease of the particle-associated (PA) bacterial richness and the emergence of a specific bacterial consortium that was potentially better adapted to the new nutritional niche. Unexpectedly, changes in PA bacterial communities occurred just before the development the emergence of the phytoplanktonic bloom and the associated modification of the phytoplanktonic community composition, suggesting that changes in environmental conditions leading to the bloom, were first sensed by the bacterial PA community. This last was quite stable throughout the bloom event, even though there were changes in the blooming species, suggesting that the association between cyanobacterial species and bacterial communities may not be as tight as previously described for monospecific blooming communities. Finally, the dynamics of the free-living (FL) bacterial communities displayed a different trajectory from those of the PA and phytoplankton communities. This FL communities can be viewed as a reservoir for bacterial recruitment for the PA fraction. Altogether, these data also highlight s that the spatial organization within these different microenvironments in the water column is a relevant factor in the structuring of these communities. [ABSTRACT FROM AUTHOR]

• Planktothrix responses to abiotic stresses are specific to each genotype. • MC producers do not cope better to high light or high temperature. • MC content does not increase in response to high light or high temperature. • Genotype diversity explain the success of Planktothrix in various environments. • Future studies with cHAB should consider incorporating genetic diversity. Cyanobacterial blooms can modify the dynamic of aquatic ecosystems and have harmful consequences for human activities. Moreover, cyanobacteria can produce a variety of cyanotoxins, including microcystins, but little is known about the role of environmental factors on the prevalence of microcystin producers in the cyanobacterial bloom dynamics. This study aimed to better understand the success of Planktothrix in various environments by unveiling the variety of strategies governing cell responses to sudden changes in light intensity and temperature. The cellular responses (photosynthesis, photoprotection, heat shock response and metabolites synthesis) of four Planktothrix strains to high-light or high-temperature were studied, focusing on how distinct ecotypes (red- or green-pigmented) and microcystin production capability affect cyanobacteria's ability to cope with such abiotic stimuli. Our results showed that high-light and high-temperature impact different cellular processes and that Planktothrix responses are heterogeneous, specific to each strain and thus, to genotype. The ability of cyanobacteria to cope with sudden increase in light intensity and temperature was not related to red- or green-pigmented ecotype or microcystin production capability. According to our results, microcystin producers do not cope better to high-light or high-temperature and microcystin content does not increase in response to such stresses. [ABSTRACT FROM AUTHOR]

Abstract: Aquatic ecosystems are facing increasing environmental pressures, leading to an increasing frequency of cyanobacterial Harmful Algal Blooms (cHABs) that have emerged as a worldwide concern due to their growing frequency and their potential toxicity to the fauna that threatens the functioning of ecosystems. Cyanobacterial blooms raise concerns due to the fact that several strains produce potent bioactive or toxic secondary metabolites, such as the microcystins (MCs), which are hepatotoxic to vertebrates. These strains of cyanobacteria may be potentially toxic to fish via gastrointestinal ingestion and also by direct absorption of the toxin MC from the water. The purpose of our study was to investigate toxic effects observed in fish taken from several lakes in the Ile-de-France region, where MCs-producing blooms occur. This study comprises histological studies and the measurement of MC concentrations in various organs. The histological findings are similar to those obtained following laboratory exposure of medaka fish to MCs: hepatic lesions predominate and include cell lysis and cell detachment. MC concentrations in the organs revealed that accumulation was particularly high in the digestive tract and the liver, which are known to be classical targets of MCs. In contrast concentrations were very low in the muscles. Differences in the accumulation of MC variants produced by blooms indicate that in order to more precisely evaluate the toxic potential of a specific bloom it is necessary not only to consider the concentration of toxins, but also the variants produced. [Copyright &y& Elsevier]

Successive unexplained shellfish toxicity events have been observed in Arcachon Bay (Atlantic coast, France) since 2005. The positive mouse bioassay (MBA) revealing atypical toxicity did not match the phytoplankton observations or the liquid chromatography−tandem mass spectrometry (LC−MS/MS) investigations used to detect some known lipophilic toxins in shellfish. The use of the three cell lines (Caco2, HepG2, and Neuro2a) allows detection of azaspiracid-1 (AZA1), okadaic acid (OA), or pectenotoxin-2 (PTX2). In this study, we proposed the cell-based assays (CBA) as complementary tools for collecting toxicity data about atypical positive MBA shellfish extracts and tracking their chromatographic fractionation in order to identify toxic compound(s). The present study was intended to investigate the responses of these cell lines to shellfish extracts, which were either control or spiked with AZA1, OA, or PTX2 used as positive controls. Digestive glands of control shellfish were extracted using the procedure of the standard MBA for lipophilic toxins and then tested for their cytotoxic effects in CBA. The same screening strategy previously used with pure lipophilic toxins was conducted for determining the intra- and inter-laboratory variabilities of the responses. Cytotoxicity was induced by control shellfish extracts whatever the cell line used and regardless of the geographical origin of the extracts. Even though the control shellfish extracts demonstrated some toxic effects on the selected cell lines, the extracts spiked with the selected lipophilic toxins were significantly more toxic than the control ones. This study is a crucial step for supporting that cell-based assays can contribute to the detection of the toxic compound(s) responsible for the atypical toxicity observed in Arcachon Bay, and which could also occur at other coastal areas. [ABSTRACT FROM AUTHOR]

Human poisoning due to consumption of seafood contaminated with phycotoxins is a worldwide problem, and routine monitoring programs have been implemented in various countries to protect human consumers. Following successive episodes of unexplained shellfish toxicity since 2005 in the Arcachon Bay on the French Atlantic coast, a national research program was set up to investigate these atypical toxic events. Part of this program was devoted to fit-for-purpose cell-based assays (CBA) as complementary tools to collect toxicity data on atypical positive-mouse bioassay shellfish extracts. A collaborative study involving five laboratories was conducted. The responses of human hepatic (HepG2), human intestinal (Caco2), and mouse neuronal (Neuro2a) cell lines exposed to three known lipophilic phycotoxins-okadaic acid (OA), azaspiracid-1 (AZA1), and pectenotoxin-2 (PTX2)-were investigated. A screening strategy composed of standard operating procedures and a decision tree for dose-response modeling and assay validation were designed after a round of 'trial-and-error' process. For each toxin, the shape of the concentration-response curves and the IC values were determined on the three cell lines. Whereas OA induced a similar response irrespective of the cell line (complete sigmoid), PTX2 was shown to be less toxic. AZA1 induced cytotoxicity only on HepG2 and Neuro2a, but not on Caco2. Intra- and inter-laboratory coefficients of variation of cell responses were large, with mean values ranging from 35 to 54 % and from 37 to 48 %, respectively. Investigating the responses of the selected cell lines to well-known toxins is the first step supporting the use of CBA among the panel of methods for characterizing atypical shellfish toxicity. Considering these successful results, the CBA strategy will be further applied to extracts of negative, spiked, and naturally contaminated shellfish tissues. [ABSTRACT FROM AUTHOR]

The dynamics and microcystins (MC) concentrations of a perennial Planktothrix agardhii bloom were investigated in a eutrophic lake (Viry-Châtillon, France). A weak relationship was observed between P. agardhii population biomass and the MC concentrations in a 1-year survey. To further investigate the causes of MC concentration changes, we concurrently conducted experiments on 41 strains isolated from this lake. We first checked the clonal diversity of P. agardhii population (i) by molecular techniques, to assess the presence of MC synthetase gene (mcyB), (ii) by biochemical assay (PP2A inhibition assay), for MC production, and (iii) by mass spectrometry (MS), to identify the MC chemotypes. Our results illustrated the diversity of genotype and MC chemotypes within a P. agardhii natural population. Eleven chemotypes among the 16 possible ones were found by MS. Furthermore, we noticed major differences in the MC content of isolated strains (from 0.02 to 1.86μg equiv. MC-LR mgDW−1, n=25). Growth and MC production of one MC-producing strain and one non-MC-producing strain were also assessed at two temperatures (10 and 20°C). We showed that growth capacities of these strains were similar at the two tested temperatures, and that the MC production rate was correlated to the growth rate for the MC-producing strain. On the basis of these results, several hypotheses are discussed to explain the weakness of relationships between natural P. agardhii biomass and MC concentration. One of the main reasons could lie in the proportion of MC-producing clones and non-MC-producing clones that may change during the sampling period. Also, the MC-producing clones may present different intracellular MC content due to (i) MC chemotypes diversity, (ii) changes in MC variants proportions within a strain, and (iii) changes in MC rate production depending on the physiological state of cells. Finally, we concluded that various biological organization levels have to be considered (population, cellular and molecular), through an integrative approach, in order to provide a better understanding of P. agardhii in situ MC production. [Copyright &y& Elsevier]

The genetic diversity of Cylindrospermopsis strains (cyanobacteria) was examined using mainly the 16S-23S internally transcribed spacer (ITS1) sequences. Strains were grouped in three clusters: (i) America, (ii) Europe, and (iii) Africa and Australia. These results suggested a recent spread of Cylindrospermopsis across the American and European continents from restricted warm refuge areas instead of exchanges between continents. On the other hand, they also suggested a recent colonization of Australia by African strains. [ABSTRACT FROM AUTHOR]

The Proterozoic Era records two periods of abundant positive carbon isotope excursions (CIEs), conventionally interpreted as resulting from increased organic carbon burial and leading to Earth's surface oxygenation. As strong spatial variations in the amplitude and duration of these excursions are uncovered, this interpretation is challenged. Here, by studying the carbon cycle in the Dziani Dzaha Lake, we propose that they could be due to regionally variable methane emissions to the atmosphere. This lake presents carbon isotope signatures deviated by ~ + 12‰ compared to the modern ocean and shares a unique combination of analogies with putative Proterozoic lakes, interior seas or restricted epireic seas. A simple box model of its Carbon cycle demonstrates that its current isotopic signatures are due to high primary productivity, efficiently mineralized by methanogenesis, and to subsequent methane emissions to the atmosphere. By analogy, these results might allow the reinterpretation of some positive CIEs as at least partly due to regionally large methane emissions. This supports the view that methane may have been a major greenhouse gas during the Proterozoic Era, keeping the Earth from major glaciations, especially during periods of positive CIEs, when increased organic carbon burial would have drowned down atmospheric CO2. [ABSTRACT FROM AUTHOR]

Evaluating the causes and consequences of dominance by a limited number of taxa in phytoplankton communities is of huge importance in the current context of increasing anthropogenic pressures on natural ecosystems. This is of particular concern in densely populated urban areas where usages and impacts of human populations on water ecosystems are strongly interconnected. Microbial biodiversity is commonly used as a bioindicator of environmental quality and ecosystem functioning, but there are few studies at the regional scale that integrate the drivers of dominance in phytoplankton communities and their consequences on the structure and functioning of these communities. Here, we studied the causes and consequences of phytoplankton dominance in 50 environmentally contrasted waterbodies, sampled over four summer campaigns in the highly-populated Île-de-France region (IDF). Phytoplankton dominance was observed in 32–52% of the communities and most cases were attributed to Chlorophyta (35.5–40.6% of cases) and Cyanobacteria (30.3–36.5%). The best predictors of dominance were identified using multinomial logistic regression and included waterbody features (surface, depth and connection to the hydrological network) and water column characteristics (total N, TN:TP ratio, water temperature and stratification). The consequences of dominance were dependent on the identity of the dominant organisms and included modifications of biological attributes (richness, cohesion) and functioning (biomass, RUE) of phytoplankton communities. We constructed co-occurrence networks using high resolution phytoplankton biomass and demonstrated that networks under dominance by Chlorophyta and Cyanobacteria exhibited significantly different structure compared with networks without dominance. Furthermore, dominance by Cyanobacteria was associated with more profound network modifications (e.g. cohesion, size, density, efficiency and proportion of negative links), suggesting a stronger disruption of the structure and functioning of phytoplankton communities in the conditions in which this group dominates. Finally, we provide a synthesis on the relationships between environmental drivers, dominance status, community attributes and network structure. Image 1 • Periurban lakes were used to study causes and consequences of phytoplankton dominance. • The main drivers of dominance in phytoplankton communities were identified using MLR. • Chlorophyta and Cyanobacteria were responsible for most cases of dominance. • Dominance impacts on community structure and functioning are taxa-specific. • Cyanobacteria disrupts more phytoplankton co-occurrence networks than other taxa. [ABSTRACT FROM AUTHOR]

Saline-alkaline lakes often shelter high biomasses despite challenging conditions, owing to the occurrence of highly adapted phototrophs. Dziani Dzaha (Mayotte) is one such lake characterized by the stable co-dominance of the cyanobacterium Limnospira platensis and the picoeukaryote Picocystis salinarum throughout its water column. Despite light penetrating only into the uppermost meter, the prevailing co-dominance of these species persists even in light- and oxygen-deprived zones. Here, a depth profile of phototrophs metatranscriptomes, annotated using genomic data from isolated strains, is employed to identify expression patterns of genes related to carbon processing pathways including photosynthesis, transporters and fermentation. The findings indicate a prominence of gene expression associated with photosynthesis, with a peak of expression around 1 m below the surface, although the light intensity is very low and only red and dark red wavelengths can reach it, given the very high turbidity linked to the high biomass of L. platensis . Experiments on strains confirmed that both species do grow under these wavelengths, at rates comparable to those obtained under white light. A decrease in the expression of photosynthesis-related genes was observed in L. platensis with increasing depth, whereas P. salinarum maintained a very high pool of psb A transcripts down to the deepest point as a possible adaptation against photodamage, in the absence and/or very low levels of expression of genes involved in protection. In the aphotic/anoxic zone, expression of genes involved in fermentation pathways suggests active metabolism of reserve or available dissolved carbon compounds. Overall, L. platensis seems to be adapted to the uppermost water layer, where it is probably maintained thanks to gas vesicles, as evidenced by high expression of the gvp A gene. In contrast, P. salinarum occurs at similar densities throughout the water column, with a peak in abundance and gene expression levels which suggests a better adaptation to lower light intensities. These slight differences may contribute to limited inter-specific competition, favoring stable co-dominance of these two phototrophs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The authors declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Duperron, Halary, Bouly, Roussel, Hugoni, Bruto, Oger, Duval, Woo, Jézéquel, Ader, Leboulanger, Agogué, Grossi, Troussellier and Bernard.)

Biofilm-forming cyanobacteria are abundant in mangrove ecosystems, colonizing various niches including sediment surface and periphyton where they can cover large areas, yet have received limited attention. Several filamentous isolates were recently isolated from Guadeloupe, illustrating the diversity and novelty present in these biofilms. In this study, nine strains belonging to three novel lineages found abundantly in Guadeloupe biofilms are characterized by genome sequencing, morphological and ultrastructural examination, metabolome fingerprinting and searched for secondary metabolites biosynthesis pathways. Assignation of two lineages to known genera is confirmed, namely Scytonema and Jaaginema . The third lineage corresponds to a new Coleofasciculales genus herein described as Karukerafilum gen. nov. The four strains belonging to this genus group into two subclades, one of which displays genes necessary for nitrogen fixation as well as the complete pathway for geosmin production. This study gives new insights into the diversity of mangrove biofilm-forming cyanobacteria, including genome-based description of a new genus and the first genome sequence available for the genus Jaaginema ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of FEMS.)

Microorganisms are key contributors of aquatic biogeochemical cycles but their microscale ecology remains largely unexplored, especially interactions occurring between phytoplankton and microorganisms in the phycosphere, that is the region immediately surrounding phytoplankton cells. The current study aimed to provide evidence of the phycosphere taking advantage of a unique hypersaline, hyperalkaline ecosystem, Lake Dziani Dzaha (Mayotte), where two phytoplanktonic species permanently co-dominate: a cyanobacterium, Arthrospira fusiformis, and a green microalga, Picocystis salinarum. To assay phycospheric microbial diversity from in situ sampling, we set up a flow cytometry cell-sorting methodology for both phytoplanktonic populations, coupled with metabarcoding and comparative microbiome diversity. We focused on archaeal communities as they represent a non-negligible part of the phycospheric diversity, however their role is poorly understood. This work is the first which successfully explores in situ archaeal diversity distribution showing contrasted phycospheric compositions, with P. salinarum phycosphere notably enriched in Woesearchaeales OTUs while A. fusiformis phycosphere was enriched in methanogenic lineages affiliated OTUs such as Methanomicrobiales or Methanofastidiosales. Most archaeal OTUs, including Woesearchaeales considered in literature as symbionts, were either ubiquitous or specific of the free-living microbiome (i.e. present in the 3-0.2 μm fraction). Seminally, several archaeal OTUs were enriched from the free-living microbiome to the phytoplankton phycospheres, suggesting (i) either the inhibition or decrease of other OTUs, or (ii) the selection of specific OTUs resulting from the physical influence of phytoplanktonic species on surrounding Archaea., (© 2023 John Wiley & Sons Ltd.)

Long duration spaceflights to the Moon or Mars are at risk for emergency medical events. Managing a hypoxemic distress and performing an advanced airway procedure such as oro-tracheal intubation may be complicated under weightlessness due to ergonomic constraints. An emergency free-floating intubation would be dangerous because of high failure rates due to stabilization issues that prohibits its implementation in a space environment. Nevertheless, we hypothesized that two configurations could lead to a high first-pass success score for intubation performed by a free-floating operator. In a non-randomized, controlled, cross-over simulation study during a parabolic flight campaign, we evaluated and compared the intubation performance of free-floating trained operators, using either a conventional direct laryngoscope in an ice-pick position or an indirect laryngoscopy with a video-laryngoscope in a classic position at the head of a high-fidelity simulation manikin, in weightlessness and in normogravity. Neither of the two tested conditions reached the minimal terrestrial ILCOR recommendations (95% first-pass success) and therefore could not be recommended for general implementation under weightlessness conditions. Free-floating video laryngoscopy at the head of the manikin had a significant better success score than conventional direct laryngoscopy in an ice-pick position. Our results, combined with the preexisting literature, emphasis the difficulties of performing oro-tracheal intubation, even for experts using modern airway devices, under postural instability in weightlessness. ClinicalTrials registration number NCT05303948., (© 2023. Springer Nature Limited.)

In comparison with northern countries, limited data are available on the occurrence and potential toxicity of cyanobacterial blooms in lakes and ponds in sub-Saharan countries. With the aim of enhancing our knowledge on cyanobacteria and their toxins in Africa, we performed a 17-month monitoring of a freshwater ecosystem, Lagoon Aghien (Ivory Coast), which is used for multiple practices by riverine populations and for drinking water production in Abidjan city. The richness and diversity of the cyanobacterial community were high and displayed few variations during the entire survey. The monthly average abundances ranged from 4.1 × 10 4 to 1.8 × 10 5 cell mL -1 , with higher abundances recorded during the dry seasons. Among the five cyanotoxin families analyzed (anatoxin-a, cylindrospermopsin, homoanatoxin, microcystins, saxitoxin), only microcystins (MC) were detected with concentrations ranging from 0 to 0.364 μg L -1 in phytoplankton cells, from 32 to 1092 μg fresh weight (FW) kg -1 in fish intestines, and from 33 to 383 μg FW kg -1 in fish livers. Even if the MC concentrations in water and fish are low, usually below the thresholds defined in WHO guidelines, these data raise the issue of the relevance of these WHO guidelines for sub-Saharan Africa, where local populations are exposed throughout the year to these toxins in multiple ways., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aims: The cyanobacterial genus, Limnospira (anc. Arthrospira Stizenberger ex Gomont 1892), commonly called "Spirulina", is widely used for commercial purposes because of its high protein content and beneficial probiotic metabolites. Thus, the taxonomy of this genus is important because of its consequences for food applications., Methods and Results: We constructed a database with formation on all Limnospira strains plus new ones from 72 new French isolates. We used a polyphasic approach (phylogenetic, phylogenomic, presence or absence of coding DNA sequences, morphological, and ultrastructure analyses) to confirm that the species A. platensis belonged to the genus Limnospira (L. platensis Gomont comb. nov. Basionym. Arthrospira platensis Gomont 1892) and that the genus Limnospira was monospecific, only represented by L. platensis., Conclusions: This study highlighted the large intra-specific diversity of L. platensis, independent of the affiliations of the phylogenetic clades or geographical location of the habitats and the subsequent physiological and metabolic plasticity., (© The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International.)

Cyanobacteria are oxygenic photosynthetic bacteria that perform a substantial part of the global primary production. Some species are responsible for catastrophic environmental events, called blooms, which have become increasingly common in lakes and freshwater bodies as a consequence of global changes. Genotypic diversity is considered essential for marine cyanobacterial population, allowing it to cope with spatio-temporal environmental variations and to adapt to specific micro-niches in the ecosystem. This aspect is underestimated in the study of bloom development, however, and given little notice in studies of the ecology of harmful cyanobacteria. Here we compared the genomes of four strains of Aphanizomenon gracile, a species of filamentous toxinogenic cyanobacteria (Nostocales) found worldwide in fresh and brackish water. Millimeter-sized fascicles were isolated from a single water sample and have been maintained in culture since 2010. A comparative study revealed extensive heterogeneity in gene contents, despite similar genome size and high similarity indices. These variations were mainly associated with mobile genetic elements and biosynthetic gene clusters. For some of the latter, metabolomic analysis confirmed the production of related secondary metabolites, such as cyanotoxins and carotenoids, which are thought to play a fundamental role in the cyanobacterial fitness. Altogether, these results demonstrated that an A. gracile bloom could be a highly diverse population at low spatial scale and raised questions about potential exchanges of essential metabolites between individuals., (© 2023. The Author(s).)

The formation of intracellular amorphous calcium carbonates (iACC) has been recently observed in a few cultured strains of Microcystis, a potentially toxic bloom-forming cyanobacterium found worldwide in freshwater ecosystems. If iACC-forming Microcystis are abundant within blooms, they may represent a significant amount of particulate Ca. Here, we investigate the significance of iACC biomineralization by Microcystis. First, the presence of iACC-forming Microcystis cells has been detected in several eutrophic lakes, indicating that this phenomenon occurs under environmental conditions. Second, some genotypic (presence/absence of ccyA, a marker gene of iACC biomineralization) and phenotypic (presence/absence of iACC) diversity have been detected within a collection of strains isolated from one single lake. This illustrates that this trait is frequent but also variable within Microcystis even at a single locality. Finally, one-third of publicly available genomes of Microcystis were shown to contain the ccyA gene, revealing a wide geographic and phylogenetic distribution within the genus. Overall, the present work shows that the formation of iACC by Microcystis is common under environmental conditions. While its biological function remains undetermined, this process should be further considered regarding the biology of Microcystis and implications on the Ca geochemical cycle in freshwater environments., (© 2022 Applied Microbiology International and John Wiley & Sons Ltd.)

While an increasing number of Informal CareGivers (ICGs) are assisting their dependent loved ones with the daily living tasks and medical care, they are rarely considered in the medical devices design process. The objective of this study is to identify the characteristics of ICGs impacting the use of the iHealth® Sense BP7 medical device, namely a connected wrist blood pressure monitor. For this purpose, user tests were conducted with 29 potential or actual ICGs. First, the participants filled out a socio-demographic questionnaire and then handled the blood pressure monitor. Finally, they completed the System Usability Scale questionnaire. The results revealed an impact of technophilia and age on usability dimensions. To conclude, the consideration of the ICG population in the design process of connected medical devices is discussed, particularly the age and level of technophilia., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Cyanobacteria constitute a pioneer colonizer of specific environments for whom settlement in new biotopes precedes the establishment of composite microbial consortia. Some heterotrophic bacteria constitute cyanobacterial partners that are considered as their cyanosphere, being potentially involved in mutualistic relationships through the exchange and recycling of key nutrients and the sharing of common goods. Several non-axenic cyanobacterial strains have been recently isolated, along with their associated cyanospheres, from the thermal mud of Balaruc-les-Bains (France) and the biofilms of the retention basin where they develop. The community structure and relationships among the members of the isolated cyanobacterial strains were characterized using a metagenomic approach combined with taxonomic and microscopic descriptions of the microbial consortia. The results provided insights into the potential role and metabolic capabilities of the microorganisms of thermal mud-associated cyanobacterial biofilms. Thus, the physical proximity, host-specificity, and genetic potential functions advocate for their complementarity between cyanobacteria and their associated microbiota. Besides these findings, our results also highlighted the great influence of the reference protein database chosen for performing functional annotation of the metagenomes from organisms of the cyanosphere and the difficulty of selecting one unique database that appropriately covers both autotroph and heterotroph metabolic specificities.

Aghien lagoon (Ivory Coast) is a eutrophic freshwater lagoon that harbors high biomasses of phytoplankton. Despite Increasing interest in fish gut microbiomes diversity and functions, little data is currently available regarding wild species from tropical west African lakes. Here, gut-associated bacterial communities are investigated in four fish species that are consumed by locale populations, namely the Cichlidae Hemichromis fasciatus , Tilapia guineensis and Sarotherodon melanotheron , and the Claroteidae Chrysichthys nigrodigitatus . Species-related differences are identified, that can be attributed to host phylogeny and diet. Important variations throughout the year are observed in T. guineensis and C. nigrodigitatus . This result emphasized the importance of time-series sampling and comparison with environmental variables even in tropical regions, that are not often conducted in wild populations. Effects of environmental factors (anthropogenic or not) on the microbiota and potential outcomes for fish health and populations sustainability need to be further explored. Interestingly, fish appear as major reservoirs of bacterial diversity, suggesting that they could contribute to the overall stability and resilience of bacterial communities present in the Aghien lagoon., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gallet, Yao, Foucault, Bernard, Quiblier, Humbert, Coulibaly, Troussellier, Marie and Duperron.)

Africa’s water needs are often supported by eutrophic water bodies dominated by cyanobacteria posing health threats to riparian populations from cyanotoxins, and Lake Victoria is no exception. In two embayments of the lake (Murchison Bay and Napoleon Gulf), cyanobacterial surveys were conducted to characterize the dynamics of cyanotoxins in lake water and water treatment plants. Forty-six cyanobacterial taxa were recorded, and out of these, fourteen were considered potentially toxigenic (i.e., from the genera Dolichospermum, Microcystis, Oscillatoria, Pseudanabaena and Raphidiopsis). A higher concentration (ranging from 5 to 10 µg MC-LR equiv. L−1) of microcystins (MC) was detected in Murchison Bay compared to Napoleon Gulf, with a declining gradient from the inshore (max. 15 µg MC-LR equiv. L−1) to the open lake. In Murchison Bay, an increase in Microcystis sp. biovolume and MC was observed over the last two decades. Despite high cell densities of toxigenic Microcystis and high MC concentrations, the water treatment plant in Murchison Bay efficiently removed the cyanobacterial biomass, intracellular and dissolved MC to below the lifetime guideline value for exposure via drinking water (<1.0 µg MC-LR equiv. L−1). Thus, the potential health threats stem from the consumption of untreated water and recreational activities along the shores of the lake embayments. MC concentrations were predicted from Microcystis cell numbers regulated by environmental factors, such as solar radiation, wind speed in the N−S direction and turbidity. Thus, an early warning through microscopical counting of Microcystis cell numbers is proposed to better manage health risks from toxigenic cyanobacteria in Lake Victoria.

Given the increasing eutrophication of water bodies in Africa due to increasing anthropogenic pressures, data are needed to better understand the responses of phytoplankton communities to these changes in tropical lakes. These ecosystems are used by local human populations for multiple purposes, including fish and drinking water production, potentially exposing these populations to health threats if, for example, an increase in toxic cyanobacterial blooms is associated with increasing eutrophication. To test the short-term response of the phytoplankton community to the addition of nutrients (phosphorus and nitrogen, alone or in combination) and Nile tilapia, we developed an in situ mesocosm experiment in a freshwater lagoon located near Abidjan (Ivory Coast). We found that phytoplankton growth (estimated by chlorophyll-a quantification) was highly stimulated when both nitrogen and phosphorus were added, while there was no clear evidence for such colimitation by these two nutrients when considering their concentrations in the lagoon. Phytoplankton growth was accompanied by significant changes in the diversity and composition of this community and did not lead to an increase in the proportions of cyanobacteria. However, the addition of fish to some mesocosms resulted in a drastic decrease in phytoplankton biomass and a dominance of chlorophytes in this community. Finally, these experiments showed that the addition of nitrogen, alone or combined with phosphorus, stimulated microcystin production by cyanobacteria. In addition, no evidence of microcystin accumulation in the fish was found. Taken together, these data allow us to discuss strategies for controlling cyanobacterial blooms in this tropical ecosystem., (© 2022 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

Understanding the role of microbial interactions in the functioning of natural systems is often impaired by the levels of complexity they encompass. In this study, we used the relative simplicity of an hypersaline crater lake hosting only microbial organisms (Dziani Dzaha) to provide a detailed analysis of the microbial networks including the three domains of life. We identified two main ecological zones, one euphotic and oxic zone in surface, where two phytoplanktonic organisms produce a very high biomass, and one aphotic and anoxic deeper zone, where this biomass slowly sinks and undergoes anaerobic degradation. We highlighted strong differences in the structure of microbial communities from the two zones and between the microbial consortia associated with the two primary producers. Primary producers sedimentation was associated with a major reorganization of the microbial network at several levels: global properties, modules composition, nodes and links characteristics. We evidenced the potential dependency of Woesearchaeota to the primary producers' exudates in the surface zone, and their disappearance in the deeper anoxic zone, along with the restructuration of the networks in the anoxic zone toward the decomposition of the organic matter. Altogether, we provided an in-depth analysis of microbial association network and highlighted putative changes in microbial interactions supporting the functioning of the two ecological zones in this unique ecosystem., (© The Author(s) 2021. Published by Oxford University Press on behalf of FEMS.)

Cyanobacteria are microorganisms able to adapt to a wide variety of environmental conditions and abiotic stresses. They produce a large number of metabolites that can participate in the dynamic adaptation of cyanobacteria to a range of different light, temperature, and nutrient conditions. Studying the metabolite profile is one way to understand how the physiological status of cells is related to their adaptive response. In this study, we sought to understand how the diversity and dynamics of the whole metabolome depended on the growth phase and various abiotic factors such as light intensity and temperature. The cyanobacterium, Aliinostoc sp. PMC 882.14, was selected for its large number of biosynthetic gene clusters. One group of cells was grown under normal conditions as a control, while other groups were grown under higher light or temperature. Metabolomes were analyzed by mass spectrometry (qTOF-MS/MS) combined with untargeted analysis to investigate metabolite dynamics, and significant variation was found between exponential and stationary phases, regardless of culture conditions. In the higher light group, the synthesis of several metabolites, including shinorine, was induced while other metabolites, such as microviridins, were synthesized under higher temperature conditions. Among highly regulated metabolites, we observed the presence of mycosporine-like amino acids (MAAs) and variants of somamides, microginins, and microviridins. This study demonstrated the importance of considering the physiological state of cyanobacteria for comparative global metabolomics and studies of the regulatory processes involved in production of specific metabolites. Our results also open up new perspectives on the use of organisms such as cyanobacteria for the targeted production of bioactive metabolites.

Specific interactions have been highlighted between cyanobacteria and chemotrophic bacteria within the cyanosphere, suggesting that nutrients recycling could be optimized by cyanobacteria/bacteria exchanges. In order to determine the respective metabolic roles of the cyanobacterial and bacterial consortia (microbiome), a day-night metatranscriptomic analysis was performed on Dolichospermum sp. (N 2 -fixer) and Microcystis sp. (non N 2 -fixer) natural blooms occurring successively within a French peri-urban lake. The taxonomical and functional analysis of the metatranscriptoms have highlighted specific association of bacteria within the cyanosphere, driven by the cyanobacteria identity, without strongly modifying the functional composition of the microbiomes, suggesting functional redundancy within the cyanosphere. Moreover, the functional composition of these active communities was driven by the living mode. During the two successive bloom events, it appeared that NH 4 + (newly fixed and/or allochthonous) was preferentially transformed into amino acids for the both the microbiome and the cyanobacteria, while phosphate metabolism was enhanced, suggesting that due to a high cellular growth, P limitation might take place within the cyanosphere consortium., (© 2021 Society for Applied Microbiology and John Wiley & Sons Ltd.)

Background: Palliative care teams face complex medical situations on a daily basis. These situations require joint reflection and decision making to propose appropriate patient care. Sometimes, sedation is one of the options to be considered. In addition to medical and technical criteria justifying the use of sedation, multiple psychosocial criteria impact the decision making of palliative care teams and guide, give sense to, and legitimize professional practices. Objective: The main goal of this study was to explore perceptions, experiences, and beliefs of palliative care teams about sedation practices in a legislative context (Claeys-Leonetti law, 2016; France), which authorizes continuous deep sedation (CDS) until death. Methods: This is a qualitative study using 28 semistructured interviews with physicians and nurses working in a palliative care team in France (PACA region). All verbal productions produced during interviews were fully transcribed and the contents analyzed. Findings: Content analysis revealed four themes: (1) sedation as a "good death," (2) emotional experiences of sedations, (3) the practice of CDS, and (4) the ambiguous relationship with the Claeys-Leonetti law. Conclusions: This qualitative study provides evidence of a form of "naturalization" of the practice of sedation. However, the Claeys-Leonetti law exacerbates differences of opinion between palliative caregivers on sedation and questions the interest of this law for society and palliative care practices. clinicalTrials.gov identifier: NCT04016038., Competing Interests: No competing financial interests exist., (© Margaux Vieille et al., 2021; Published by Mary Ann Liebert, Inc.)

The supply of drinking water is a vital challenge for the people who live on the African continent, as this continent is experiencing strong demographic growth and therefore increasing water demands. To meet these needs, surface water resources are becoming increasingly mobilized because underground resources are not always available or have already been overexploited. This situation is the case in the region of Abidjan in the Ivory Coast, where the drinking water deficit is a growing problem and it is therefore necessary to mobilize new water resources to ensure the supply of drinking water. Among the potential resources, local managers have identified a freshwater lagoon, Lagoon Aghien, That is in close proximity to the city of Abidjan. With the aim of enhancing knowledge on the ecological functioning of the lagoon and contributing to the assessment of its ability to provide drinking water, several physical and chemical parameters of the water and the phytoplankton community of the lagoon were monitored for 17 months (December 2016-April 2018) at six sampling stations. Our findings show that the lagoon is eutrophic, as evidenced by the high concentrations of total phosphorus (>140 μg L-1), nitrogen (1.36 mg L-1) and average chlorophyll-a (26 to 167 μg L-1) concentrations. The phytoplankton community in the lagoon is dominated by genera typical of eutrophic environments including mixotrophic genera such as Peridinium and by cyanobacteria such as Cylindrospermopsis/Raphidiopsis, Microcystis and Dolichospermum that can potentially produce cyanotoxins. The two rainfall peaks that occur in June and October appeared to be major events in terms of nutrient flows entering the lagoon, and the dynamics of these flows are complex. Significant differences were also found in the nutrient concentrations and to a lesser extent in the phytoplankton communities among the different stations, especially during the rainfall peaks. Overall, these results reveal that the quality of the lagoon's water is already severely degraded, and this degradation could increase in future years due to increasing urbanization in the watershed. These results therefore raise questions about the potential use of the lagoon as a source of drinking water if measures are not taken very quickly to protect this lagoon from increasing eutrophication and other pollution sources., Competing Interests: The authors have declared that no competing interests exist.

During the past 15 years, in France, like in many European countries, the attention paid to patients at the end of their lives has continued to grow. But in the meantime, only a few researchers have managed to collect reliable data on End-of-Life Care and to implement scientific studies describing the reality of these situations. This difficulty is due in particular to the lack of a recognized and operational definition of the end of life.Our objective is to explore the possibility of achieving consensus around a definition based on the isolated elements in the literature.A Delphi consensus approach has been conducted. A &#8220;Delphi&#8221; approach allows consensus to be achieved without the influence of leadership effects.The population of this study is the group of care providers who are members of the Soci&#233;t&#233; Fran&#231;aise d&#8217;Accompagnement et de Soins Palliatifs (SFAP), whether they are professionals or volunteers. An electronic survey asked for the degree of approval of individuals for each of the proposed definitions on a Lickert scale. The first round of Delphi was proposed at the end of 2019 among palliative care actors. 1463 people responded to this questionnaire in one month. Two types of definition seem to dominate the other proposals. The first is related to an estimate of life expectancy: life expectancy of less than 15 days and less than one month. The second emerging definition is related to the evolution of a pathology: based on the fact of being in advanced or terminal phase of an incurable pathology.These results confirm that the end-of-life period can be seen from two points of view, the first in relation to the time left to live and the other in relation of the terminal phase of the disease which calls for a less clearly defined time.These two definitions are based on different approaches, one temporal and the other disease-centered. An alternative definition emerges from this study and will be tested in the second round of Delphi.

Background: The Balaruc-les-Bains' thermal mud was found to be colonized predominantly by microorganisms, with cyanobacteria constituting the primary organism in the microbial biofilm observed on the mud surface. The success of cyanobacteria in colonizing this specific ecological niche can be explained in part by their taxa-specific adaptation capacities, and also the diversity of bioactive natural products that they synthesize. This array of components has physiological and ecological properties that may be exploited for various applications. Methods: Nine cyanobacterial strains were isolated from Balaruc thermal mud and maintained in the Paris Museum Collection (PMC). Full genome sequencing was performed coupled with targeted and untargeted metabolomic analyses (HPLC-DAD and LC-MS/MS). Bioassays were performed to determine antioxidant, anti-inflammatory, and wound-healing properties. Results: Biosynthetic pathways for phycobiliproteins, scytonemin, and carotenoid pigments and 124 metabolite biosynthetic gene clusters (BGCs) were characterized. Several compounds with known antioxidant or anti-inflammatory properties, such as carotenoids, phycobilins, mycosporine-like amino acids, and aeruginosins, and other bioactive metabolites like microginins, microviridins, and anabaenolysins were identified. Secretion of the proinflammatory cytokines TNF-α, IL-1β, IL-6, and IL-8 appeared to be inhibited by crude extracts of Planktothricoides raciborskii PMC 877.14, Nostoc sp. PMC 881.14, and Pseudo-chroococcus couteii PMC 885.14. The extract of the Aliinostoc sp. PMC 882.14 strain was able to slightly enhance migration of HaCat cells that may be helpful in wound healing. Several antioxidant compounds were detected, but no significant effects on nitric oxide secretion were observed. There was no cytotoxicity on the three cell types tested, indicating that cyanobacterial extracts may have anti-inflammatory therapeutic potential without harming body cells. These data open up promising uses for these extracts and their respective molecules in drugs or thermal therapies.

Background: The risk of severe medical and surgical events during long-duration spaceflight is significant. In space, many environmental and psychological factors may make tracheal intubation more difficult than on Earth. We hypothesised that, in microgravity, tracheal intubation may be facilitated by the use of a videolaryngoscope compared with direct laryngoscopy., Methods: In a non-randomised, controlled, cross-over simulation study, we compared intubation performance of novice operators and experts, using either a direct laryngoscope or a videolaryngoscope, in weightlessness and in normogravity. The primary outcome was the success rate of tracheal intubation. Time to intubation and the confidence score into the success of tube placement were also recorded., Results: When novices attempted to intubate the trachea in microgravity, the success rate of tracheal intubation using a videolaryngoscope was significantly higher (20/25 [80%]; 95% confidence interval [CI], 64.3-95.7 vs eight/20 [40%]; 95% CI, 18.5-61.5; P=0.006), and intubation time was shorter, compared with using a direct laryngoscope. In normogravity, the success rate of tracheal intubation by experts was significantly higher than that by novices (16/20 [80%]; 95% CI, 62.5-97.5 vs seven/25 [28%]; 95% CI, 10.4-45.6; P=0.001), but in microgravity, there was no significant difference between the experts and novices (19/20 [95%]; 95% CI, 85.4-100 vs 20/25 [80%]; 95% CI, 64.3-95.7; P=0.113). Higher confidence scores were achieved with videolaryngoscopy compared with direct laryngoscopy by both experts and novices in both microgravity and normogravity., Conclusions: Videolaryngoscopy was associated with higher intubation success rate and speed, and higher confidence for correct tube placement by novice operators in microgravity, and as such may represent the best technique for advanced airway management during long-duration spaceflight., (Copyright © 2019 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Among the diverse toxic components produced by cyanobacteria, microcystins (MCs) are one of the most toxic and notorious cyanotoxin groups. Besides their potent hepatotoxicity, MCs have been revealed to induce potential reproductive toxicity in various animal studies. However, little is still known regarding the distribution of MCs in the reproductive organ, which could directly affect reproductive cells. In order to respond to this question, an acute study was conducted in adult medaka fish (model animal) gavaged with 10 μg.g -1 body weight of pure MC-LR. The histological and immunohistochemical examinations reveal an intense distribution of MC-LR within hepatocytes along with a severe liver lesion in the toxin-treated female and male fish. Besides being accumulated in the hepatocytes, MC-LR was also found in the connective tissue of the ovary and the testis, as well as in oocytes and degenerative spermatocyte-like structures but not spermatocytes. Both liver and gonad play important roles in the reproductive process of oviparous vertebrates. This observation constitutes the first observation of the presence of MC-LR in reproductive cells (female, oocytes) of a vertebrate model with in vivo study. Our results, which provide intracellular localization of MC-LR in the gonad, advance our understanding of the potential reproductive toxicity of MC-LR in fish., (Copyright © 2019 Elsevier Ltd. All rights reserved.)