Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 43 for “"Microcystin"”.
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Mechanisms of microcystin-LR toxicity
Microcystin-LR (MCLR) is a cyanobacterial hepatotoxin that inhibits serine/threonine protein phosphatases types 1 and 2A in hepatocytes in vivo and in vitro, and disrupts actin microfilament (MF), microtubule (MT) and intermediate filament (IF) networks. The sequential ultrastructural and …
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Degradation of microcystin-LR by aquatic bacteria.
Microcystins are cyclic heptapeptide toxins produced by cyanobacteria. They are potentially a threat to human and domestic animals so are of worldwide interest. Microcystin-LR is stable in various environmental conditions. It is important to know the factors affecting microcystin degradation which …
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Implications of Microcystin Production in Microcystis aeruginosa PCC 7806
… also a variety of often toxic peptides such as microcystin. Mass developments, so called blooms, can pose a real threat to the drinking water supply in many parts of the world. This study aimed at characterizing the biological function of microcystin production in one of the most common …
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Toxicopathology of microcystin-LR in vivo and in vitro
Microcystin-LR (MCLR), produced by the blue-green alga Microcystis aeruginosa, causes death of livestock and is a public health hazard. The mechanism of MCLR toxicity was investigated using the rat. Changes in serum chemistry parameters and morphology caused by MCLR were characterized in vivo and …
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The toxicity of microcystin-LR in swine and mice
Microcystin-LR (MCLR) is a monocyclic heptapeptide hepatotoxin produced by the cyanobacterium Microcystis aeruginosa. One gilt given whole M. aeruginosa cells ig containing 0.3% MCLR and des-methyl MCLR at 2.1 g/kg had severe panlobular hepatic necrosis and hemorrhage when euthanatized at 32.5 hr …
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Crayfish as a biomonitor for the algal toxin microcystin-LR
… alga Microcystis produces the hepatotoxin microcystin-LR. Removing this toxin from drinking water requires expensive treatments; current analytical methods are incapable of real-time monitoring. Crayfish are resistant to microcystin-LR toxicity and respond well to operant conditioning. I …
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The destruction of the cyanobacterial toxin microcystin-LR by semiconductor photocatalysis.
… produce toxins. One such group of toxins are the microcystins which are hepatotoxic resulting in haemoraging and tumour promotion in the liver. There have been several reports of human poisonings resulting from the presence of cyanotoxins in potable waters, some of which have resulted in …
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Toxicity of microcystin-LR in hepatocytes and non-hepatocytes in vitro
Microystin-LR (MCLR), a cyanobacterial heptapeptide is an inhibitor of protein phosphatases 1 and 2A (PPs), a potential tumor promoter in rat liver, and selectively toxic to the liver in vivo and isolated hepatocytes in vitro. Inhibition of PPs has been linked to excessive phosphorylation and …
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Chlorine dioxide impacts on microcystis aeruginosa cell stress, growth and microcystin production
… exposed to M. aeruginosa, and the production of microcystin was monitored. The first experiment, batches of M. aeruginosa were exposed to ClO2 (0-10 mg/L) for 30 minites. Chlorophyll a and microcystin concentrations were lowered at higher levels of disinfection, suggesting that ClO2 can treat …
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Pathways of Transport of Microcystin-LR from Microcystis aergonisa to the Benthic Environment
… <em>Microcystis </em>create toxins, including microcystins that can lead to liver damage and cancer in aquatic life, livestock and humans. Microcystins can be stored intracellularly or released into the water column in a dissolved form. Most studies focus on <em>Microcystis </em>in its …
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Sublethal Hepatic Pathology and Evidence of Intranuclear Effects of the Cyanobacterial Toxin Microcystin -Lr
Microcystin-LR (MCLR) is a hepatotoxin and phosphatase inhibitor produced by Microcystis aeruginosa. The pathology of sublethal exposure is not well characterized. MCLR immunohistochemistry (MCLR-IHC) studies indicate that the nucleus may be a target of MCLR. Balb/c mice were given one sublethal …
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An Approach to the Total Synthesis of the Protein Phosphatase 1 and 2A Inhibitor Microcystin -Lr
… to the first synthetic route to the intermediate microcystin-LR-di-Boc-guanidine which can be converted to a constitutional isomer of microcystin-LR. Mass spectral analysis and HPLC retention time show the presence of microcystin-LR although a clean 1H NMR could not be obtained.
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Cyanobacterial Harmful Algal Blooms Vary Within and Across Years at Lake Fayetteville, Arkansas
… likely experienced HABs for many years, microcystin, an algal toxin, was not monitored until 2019. The objectives of this study were to: 1) observe temporal variation in water quality and total microcystin concentrations, 2) quantify thresholds with microcystin and nutrients, algal …
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Evidence for functional drift of bacterial isolates in response to cyanobacterial microcystin-lr and multiple peptide degradation in paucibacter toxinivorans.
… reservoirs from cyanobacterial peptide toxins microcystins (MCs). In previous work carried out in 2008 several bacteria were isolated from Scottish freshwaters that effectively degraded MCs. Rhodococcus sp. C1, among the biocatalytic isolates, exhibited particular catabolic capacities as it …
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The roles of secondary metabolites in microcystis inter-strain interactions
… exemplary for the prevalent hepatotoxin microcystin. The extracellular and intracellular roles of microcystin are tested in microarray-based transcriptomic approaches. While an extracellular effect of microcystin on Microcystis transcription is confirmed and connected to a specific gene …
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Monitoring and regulating cyanobacterial metabolites (microcystins and geosmin) in aquatic systems.
… One of the most prominent cyanotoxins are microcystins and their sister compound nodularin. The biological role of microcystins is poorly understood. A pheromonal effect was observed applying a novel stable isotope labelling (15N) method. Microcystin- LR has been shown to stimulate culture …
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Purification, detection and biological effects of cyanobacterial toxins.
… of another group of cyanobacterial toxins called microcystins was also addressed. The routine monitoring of cyanobacterial cultures and natural bloom samples for microcystins relies on HPLC. However, the lack of purified standards has hindered accurate detection and quantification of many …
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Factors affecting the growth and toxin content of key cyanobacteria species in a changing world.
… Nitrogen was an obligate requirement for microcystin production, but phosphorous was not, indicating that nitrogen eutrophication conditions (caused by agricultural run- off etc) would increase the risk of toxic blooms. Toxin (microcystin) concentrations were positively correlated with …
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Microplastics as a vector for micropollutants in aquatic environments.
… of microplastics as a vector for cyanotoxins (microcystins) and anthropogenic contaminants (pharmaceuticals) in freshwater. To this end, polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyamide (PA), polystyrene (PS), and polyvinyl chloride (PVC) microparticles were …
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Toxic cyanobacteria, cyanotoxins and drinking water production in Ghana: implications to human health
… effects on population health. The cyanotoxin, microcystin, the main focus of this research has been responsible for much documented illness in humans and is the most wildly studied cyanotoxin. The World Health Organization has set a guideline limit of 1 µg/l in drinking water.A number of …
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