28 research outputs found

    Polymethoxy-1-Alkenes Screening of Chlorella and Spirulina Food Supplements Coupled with In Vivo Toxicity Studies

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    Selected species of cyanobacteria and green algae have been reported to produce lipophilic polymethoxy-1-alkenes (PMAs) which were shown to exhibit in vivo teratogenicity. Considering that information on PMAs in Arthospira sp. (known commercially as Spirulina) and Chlorella sp. cultivated for food supplement production was essentially lacking, the present study screened Chlorella (n = 10) and Spirulina (n = 13) food supplements registered in the European Union. Mass spectrometry analysis of column fractionated extracts was performed. None of the four variants previously reported in some cyanobacteria and green algae, nor any potentially related structures were detected in the studied samples. Since the isolated lipophilic fractions contained various compounds, they were further screened for in vivo teratogenicity in Danio rerio embryo, and for the potential to induce oxidative stress and genotoxicity in the liver and neurotoxicity in the brain of adult zebrafish. None of the tested food supplements had detectable levels of PMAs or any potentially related structures. No teratogenicity was revealed except for spinal curvature induced by fractions obtained from two Chlorella products. Selected fractions revealed cytotoxicity as indicated by an increased level of reactive oxygen species, catalase activity, lipid peroxidation and increased frequency of DNA strand breaks in hepatic tissue. The majority (60%) of Chlorella fractions induced an increase in cholinesterase activity in zebrafish brain homogenate while exposure to 61.5% of Spirulina fractions was associated with its decrease. The present study confirms that Chlorella and Spirulina food supplements are free of teratogenic PMAs, although the observed in vivo toxicities raise questions regarding the quality of selected products

    Unusual complications after occupational exposure to giant hogweed (Heracleum mantegazzianum): A case report

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    Exposure to giant hogweed brings about the risk of serious skin damage, usually in the form of phytophotodermatitis. Initially, skin changes are signaled by a burning sensation, followed by a vesiculobullous rash and long-term hyperpigmentation. Usually, skin disorders improve after the application of topical and oral corticosteroids. In extremely rare instances, full skin thickness burns or epidermal necrosis occur. The study presents a case of occupational exposure to hogweed, which resulted in extensive skin lesions leading to the disablement of a 27-year-old man. The principles of procedure to be followed when contact with giant hogweed is an occupational hazard are also outlined

    Biotope and biocenosis of cryoconite hole ecosystems on Ecology Glacier in the maritime Antarctic

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    Abstract: Despite recent great interest in glacier ecosystems in the continental Antarctic, little is known about their maritime counterparts. Our study presents descriptive data on cryoconite sediments and cryoconite holes on Ecology Glacier (King George Island) to accomplish three main objectives: (a) to identify main eukaryotic (algae, invertebrates) and prokaryotic (cyanobacteria) components of microbial communities; (b) to provide a “baseline” of community composition, organic matter and artificial contamination; and (c) identify key abiotic factors that might be important in community assembly. Cryoconite holes were sampled along an altitudinal gradient of Ecology Glacier in January, mid Austral Summer 2017. Cryoconite holes located in lower altitude were deeper than those located in the middle and the highest altitude. Seventeen species of algae and cyanobacteria with biomass of 0.79 to 5.37 µg/cm3 have been found in sediments. Dominant species were cyanobacterial Pseudanabaena frigida and Bacillariophyceae Microcostaus sp. Biomass of Bacillariophyceae was significantly higher than that of Chlorophyta and Cyanobacteria. We found three species of rotifers (two potentially new to science) and for the first time a glacier dwelling Acari (suspension feeder, Nanorchestes nivalis). Organic matter content ranged from 5.4% to 7.6%. Investigated artificial radionuclides included 137Cs, 238Pu, 239+240Pu and 241Am. 210Pb seems to be related to organic matter content. Overall, cryoconite holes on Ecology Glacier present unique habitats that serve as biodiversity hotspots of psychrophiles, source of organic matter, matrices for radioactivity tracking and model for observing changes in supraglacial ecosystems in Maritime Antarctic

    Is oxygenation related to the decomposition of organic matter in cryoconite holes?

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    Cryoconite is a sediment occurring on glacier surfaces worldwide which reduces ice albedo and concentrates glacier surface meltwater into small reservoirs called cryoconite holes. It consists of mineral and biogenic matter, including active microorganisms. This study presents an experimental insight into the influence of sediment oxygenation on the cryoconite ability to produce and decomposition of organic matter. Samples were collected from five glaciers in the Arctic and the European mainland. Cryoconite from three glaciers was incubated in stagnant and mechanically mixed conditions to imitate inter-hole water–sediment mixing by meltwater occurring on glaciers in Northern Hemisphere, and its effect on oxygen profiles and organic matter content. Moreover, we investigated short-term changes of oxygen conditions in cryoconite from four glaciers in illuminated and dark conditions. An anaerobic zone was present or approaching zero oxygen in all illuminated cryoconite samples, varying in depth depending on the origin of cryoconite: from 1500 µm from Steindalsbreen (Scandinavian Peninsula) and Forni Glacier (The Alps) to 3100 µm from Russell Glacier and Longyearbreen (Arctic) after incubation. Organic matter content varied between glaciers from 6.11% on Longyearbreen to 16.36% on Russell Glacier. The mixed sediment from the Forni Glacier had less organic matter than stagnant, the sediment from Longyearbreen followed this trend, but the difference was not statistically significant, while the sediment from Ebenferner did not differ between groups. Our results have implications for the understanding of biogeochemical processes on glacier surfaces, the adaptation of organisms to changing physical conditions due to abrupt sediment mixing, but also on the estimation of productivity of supraglacial systems

    Stojące i płynące wody Poznania

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    Książka zawiera 139 stron, 153 barwne fotografie oraz 135 pozycji literaturyZamiarem autorów tego opracowania było zebranie i przybliżenie czytelnikowi podstawowych wiadomości o jak największej liczbie zbiorników i cieków wodnych, znajdujących się w granicach administracyjnych Poznania. Do przedstawionych danych należy przede wszystkim położenie zbiorników, przebieg cieków wodnych, ich cechy morfometryczne, ale również tam, gdzie to było możliwe – informacje o walorach przyrodniczych, turystyczno-krajobrazowych i o jakości wody. Mają one zachęcić mieszkańców Poznania do odwiedzania opisanych miejsc w ramach wycieczek, spacerów czy choćby po to, by odpocząć od zgiełku ulic miasta i trudów pracy zawodowej. Mają również rozbudzić zainteresowanie otaczającą przyrodą młodzież szkolną, będąc uzupełnieniem wiedzy zdobywanej w ramach zajęć szkolnych.Wydanie książki dofinansowano ze środków budżetowych Miasta Poznani

    Cryoconite – from minerals and organic matter to bioengineeredsediments on glacier's surfaces

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    Cryoconite is a mixture of mineral and organic material covering glacial ice, playing important roles in biogeochemical cycles and lowering the albedo of a glacier surface. Understanding the differences in structure of cryoconite across the globe can be important in recognizing past and future changes in supraglacial environments and ice-organisms-minerals interactions. Despite the worldwide distribution and over a century of studies, the basic characteristics of cryoconite, including its forms and geochemistry, remain poorly studied. The major purpose of our study is the presentation and description of morphological diversity, chemical and photoautotrophs composition, and organic matter content of cryoconite sampled from 33 polar and mountain glaciers around the globe. Observations revealed that cryoconite is represented by various morphologies including loose and granular forms. Granular cryoconite includes smooth, rounded, or irregularly shaped forms; with some having their surfaces covered by cyanobacteria filaments. The occurrence of granules increased with the organic matter content in cryoconite.Moreover, amajor driver of cryoconite colouringwas the concentration of organicmatter and its interplay with minerals. The structure of cyanobacteria and algae communities in cryoconite differs between glaciers, but representatives of cyanobacteria families Pseudanabaenaceae and Phormidiaceae, and algae families Mesotaeniaceae and Ulotrichaceaewere themost common. Themost of detected cyanobacterial taxa are known to produce polymeric substances (EPS) that may cement granules. Organic matter content in cryoconite varied between glaciers, ranging from 1% to 38%. The geochemistry of all the investigated samples reflected local sediment sources, except of highly concentrated Pb andHg in cryoconite collected fromEuropean glaciers near industrialized regions, corroborating cryoconite as element-specific collector and potential environmental indicator of anthropogenic activity. Our work supports a notion that cryoconite may bemore than just simple sediment and instead exhibits complex structure with relevance for biodiversity and the functioning of glacial ecosystem

    Catchment vegetation can trigger lake dystrophy through changes in runoff water quality

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    Surface runoff can supply lakes with a variety of chemical substances – their type and quantity may significantly vary and depend on the characteristics of the catchment area: geomorphology, phytocoenosis type and degree of human impact. In this study we investigated the physicochemical properties of the surface runoff water collected from the wooded catchment of Lake Piaseczno Duze (LPD, Drawa National Park, Poland) covered by a monoculture of Scots pine (Pinus sylvestris) and mixed forest with white birch (Betula pubescens) as the dominant tree. Experimentally, we also aimed to study the leaching of nutrients from pine and birch litter. Throughout the investigated period runoff waters had low pH, brown colour and high levels of dissolved organic carbon (DOC) – most likely induced by humic acids. Furthermore, considerable levels of nitrogen (N) and phosphorus (P) were found. The highest concentrations of nutrients were observed in runoff collected after heavy rainfall and snow melting. Runoff from the coniferous area contained significantly higher levels of DOC but lower concentrations of N and P compared to runoff collected from the birch-dominated forest. Similar physicochemical conditions were observed in the leaching experiment. Moreover, it was found that the release of chemical substances from both coniferous and deciduous litter was rapid. Our study indicates that surface runoff from forest areas can significantly affect lake chemistry. Based on the simultaneous analyses of littoral water chemistry we suggest that it may contribute to LPD dystrophication through the transportation of high levels of acidic compounds

    The Yellow Knight Fights Back: Toxicological, Epidemiological, and Survey Studies Defend Edibility of <i>Tricholoma equestre</i>

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    Rhabdomyolysis, a condition associated with the consumption of Yellow Knight mushrooms (Tricholoma equestre), was first reported in 2001. In response, some countries began to consider the mushroom as poisonous, whereas in others it is still consumed. In the present study, a nationwide survey of Polish mushroom foragers (n = 1545) was conducted to estimate the frequency of T. equestre consumption. The epidemiological database on mushroom poisonings in Poland was analyzed from the year 2008. Hematological and biochemical parameters were followed for a week in 10 volunteers consuming 300 g of molecularly identified T. equestre. More than half the foragers had consumed T. equestre at least once in their lifetime and a quarter had consumed it consecutively. The frequency of adverse events was low and no rhabdomyolysis was reported. The toxicological database indicated that mushrooms from the Tricholoma genus caused poisonings less frequently than mushrooms with well-established edibility and not a single case of rhabdomyolysis has been reported within the last decade. The volunteers consuming T. equestre revealed no hematological or biochemical alterations and no adverse effects were observed. The findings of this study support the view that T. equestre is edible if consumed in rational amounts by healthy subjects

    Unusual complications after occupational exposure to giant hogweed (Heracleum mantegazzianum): A case report

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    Exposure to giant hogweed brings about the risk of serious skin damage, usually in the form of phytophotodermatitis. Initially, skin changes are signaled by a burning sensation, followed by a vesiculobullous rash and long-term hyperpigmentation. Usually, skin disorders improve after the application of topical and oral corticosteroids. In extremely rare instances, full skin thickness burns or epidermal necrosis occur. The study presents a case of occupational exposure to hogweed, which resulted in extensive skin lesions leading to the disablement of a 27-year-old man. The principles of procedure to be followed when contact with giant hogweed is an occupational hazard are also outlined
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