| isolation, characterization and pathology of the toxin from a microcystis aeruginosa (= anacystis cyanea) bloom. | the nature of the toxicity of a bloom of blue-green alga, m. aeruginosa (= anacystis cyanea), that occurred in a man-made lake was investigated. crude algal bloom extracts were toxic to laboratory mice when injected intraperitoneally. the lethal dose (ld100) of these extracts was 15-30 mg of lyophilized algal bloom per kilogram body weight. the toxin was purified by a procedure that included ammonium sulphate fractionation, solvent extraction, acid precipitation, sephadex g25 and deae-sephadex c ... | 1978 | 103520 |
| an improved extraction procedure for the endotoxin from microcystis aeruginosa nrc-1. | | 1975 | 805728 |
| photooxidation of cyanobacteria in natural conditions. | photodynamic effects were demonstrated and assayed under field conditions in a number of different laboratory strains and pond isolates of cyanobacteria; parameters assayed for resistance to photooxidation were viable count, turbidity of the cyanobacterial suspension, and protein and pigment contents. the effects of density, colonial structure, and internal gas vacuoles on the lethal outcome were investigated. the stability and formation of superoxide dismutase under photooxidative conditions in ... | 1976 | 821394 |
| release of heptapeptide toxin (microcystin) during the decomposition process of microcystis aeruginosa. | the decomposition process of toxic blue-green alga (cyanobacteria), microcystis aeruginosa, under dark and aerobic condition was investigated in relation to the change of the amounts of heptapeptide toxins (microcystins yr and lr) by two experiments: one with microcystis cells and the other with two purified microcystins. in the experiment with microcystis cells, an increase of heterotrophic bacteria observed from the beginning of the experiment, was followed by decomposition of the algal cells ... | 1992 | 1344901 |
| microcystin-like toxins in different freshwater species of oscillatoria. | in january and september of 1989 and march 1990 blooms of oscillatoria rubescens, oscillatoria tenuis and oscillatoria mougetii were found in lake simbirizzi and lake flumendosa in sardinia, and in lake san puoto in the lazio region of italy. by using different extraction methods and hplc analysis, two microcystin-like toxins (rr-like and yr-like), similar to some of the toxic compounds produced by the cyanophycea microcystis aeruginosa, were detected in these blooms. | 1992 | 1440636 |
| structure determination and toxicity of a new microcystin from microcystis aeruginosa strain 205. | a new hepatotoxic microcystin was isolated from the cyanobacterium microcystis aeruginosa strain 205. its structure was found to be [dha7]microcystin-rr as determined by amino acid analysis, mass spectrometry and 1h nmr spectroscopy. ld50 value (i.p. mouse) of this toxin was 180 micrograms/kg. the 48 hr lethal concentration (48-hr-lc50) of the toxin for larvae of the yellow fever mosquito, aedes aegypti, was 14.9 micrograms/ml. | 1992 | 1440646 |
| inhibitory effect of a microcystis sp (cyanobacteria) toxin on development of preimplantation mouse embryos. | 1. a soluble toxin, purified from the algae bloom of an eutrophic lake dominated by microcystis, is a very effective inhibitor of early embryo development in a dose-response relationship. 2. two- and 8-cell mouse embryos under the influence of microcystis toxin do not reach the developmental stages of morula and blastocyst, respectively. 3. actin cortex is disorganized without change in the microtubules structure. 4. results are discussed in terms of the possible mechanisms by which the toxin ar ... | 1992 | 1360361 |
| cytotoxicity of cyanobacterium microcystis aeruginosa. | cytotoxic effects of crude extracts and fractions of the purification steps towards microcystin-lr (mcyst-lr) were investigated in vitro. cytotoxicity was evaluated by measure of lactate dehydrogenase liberation of chang liver cells and by hemolysis. crude extracts of strain pcc 7806 damaged the cells within a few minutes. in contrast, mcyst-lr did not show any detectable cytotoxic effects. the cytotoxic activity could be related to a heat-labile substance with a molecular weight of about 30,000 ... | 1992 | 1519410 |
| isolation and structures of five microcystins from a russian microcystis aeruginosa strain calu 972. | five microcystins were obtained from microcystis aeruginosa strain calu 972 isolated from a hepatotoxic water bloom collected in lake kroshnosero (russia). the structure of a new toxin (1) was determined as [dha7]microcystin-yr by amino acid analyses and fast atom bombardment mass spectrometry, and the toxins 2, 3, 4, and 5 were assigned the structures as [dha7]microcystin-lr, [d-asp3,dha7]microcystin-lr, [dha7]microcystin-rr, and [d-asp3,dha7]microcystin-rr, respectively, by direct comparison w ... | 1992 | 1485343 |
| [production of the antibiotic-algicide cyanobacterin lu-2 by a filamentous cyanobacterium nostoc sp]. | a strain of cyanobacterium of nostoc has been isolated, and found to produce a new antibiotic cyanobacterin lu-2. the antibiotic is synthesized by the cyanobnacterium under intensive cultivation conditions in a liquid mineral medium. cyanobacterin lu-2 is an exometabolite; its maximum accumulation in the medium is achieved at 34 degrees. cyanobacterin lu-2 is active against many cyanobacteria tested, including those of microcystis and aphanizomenon which are principals to give rise to blooms in ... | 1991 | 1819038 |
| toxicity and toxins of natural blooms and isolated strains of microcystis spp. (cyanobacteria) and improved procedure for purification of cultures. | all samples of cyanobacterial blooms collected from 1986 to 1989 from lake kasumigaura, ibaraki prefecture, japan, were hepatotoxic. the 50% lethal doses (ld50s) of the blooms to mice ranged from 76 to 556 mg/kg of body weight. sixty-eight microcystis cell clones (67 microcystis aeruginosa and 1 m. viridis) were isolated from the blooms. twenty-three strains (including the m. viridis strain) were toxic. however, the ratio of toxic to nontoxic strains among the blooms varied (6 to 86%). microcyst ... | 1991 | 1905521 |
| isolation of two toxic heptapeptide microcystins from an axenic strain of microcystis aeruginosa, k-139. | two toxic heptapeptides were isolated from an axenic microcystis aeruginosa strain, k-139. using mainly a non-destructive nmr method, we determined the structure of the major toxin to be 7-desmethylmicrocystin lr which lacks an n-methyl group of the dehydroalanine moiety of microcystin lr. the minor toxin was deduced to be 3,7-didesmethylmicrocystin lr. the chromatographic and nmr analyses of 7-desmethylmicrocystin lr were compared with those of 3-desmethylmicrocystin lr. | 1991 | 1907412 |
| isolation and structures of microcystins from a cyanobacterial water bloom (finland). | a hepatotoxic cyanobacterial (blue-green algal) water bloom was collected from a constructed water reservoir in finland. the water bloom contained two cyanobacterial species, microcystis aeruginosa and aphanizomenon flos-aquae. two hepatotoxins, 1 and 2, were isolated from extracts of lyophilized cells. the structures of 1 and 2 were assigned based upon their amino acid analyses on a waters pico tag hplc system and a chiral gc capillary column (chirasil val iii), fast atom bombardment mass spect ... | 1992 | 1485342 |
| effect of the cyanobacterial (blue-green algal) toxins from microcystis aeruginosa on isolated enterocytes from the chicken small intestine. | livestock deaths, and clinical reports of human injury, follow the consumption of toxic blue-green algae. the experiments described show that isolated intestinal enterocytes from chicks are both deformed and killed by exposure to microcystis toxins, in a dose-dependent and time-dependent manner. the enterocytes were protected from toxicity by deoxycholate, bromosulphothalein and rifampicin. it was concluded that the gastroenteritis clinically associated with accidental microcystis ingestion is l ... | 1992 | 1509499 |
| interactive effects of nitrogen and copper on growth of cyanobacterium microcystis. | | 1989 | 2493272 |
| acidic cytochrome c6 of unicellular cyanobacteria is an indispensable and kinetically competent electron donor to cytochrome oxidase in plasma and thylakoid membranes. | cytochromes c6 from three cyanobacteria were tested as substrates for membranous cyt. c oxidase(aa3) of anacystis and synechocystis using intact spheroplasts or isolated plasma(cm) and thylakoid(icm) membranes. neither spheroplasts nor cm/icm gave significant o2 uptake rates with nadh without added cyt. c. horse cyt. c (at low ionic strength) or cyt. c6 from anacystis, synechocystis or microcystis (at high ionic strength) supported substantial hcn- & co-sensitive nadh oxidase activity, consisten ... | 1991 | 1665972 |
| actin filament alterations in rat hepatocytes induced in vivo and in vitro by microcystin-lr, a hepatotoxin from the blue-green alga, microcystis aeruginosa. | the morphologic effects of microcystin-lr (mclr) were examined in vitro and in vivo to identify the specific cell type(s) affected and to characterize the actin filament changes occurring in hepatocytes. male sprague dawley rats were used for all studies. for in vitro studies, hepatic cells were isolated by collagenase perfusion of liver, while parenchymal cells (hepatocytes) and nonparenchymal cells were prepared by pronase digestion and metrimazide gradient centrifugation. cell suspensions and ... | 1991 | 1949504 |
| the uptake of the cyanobacterial hepatotoxin microcystin by isolated rat hepatocytes. | microcystin-ym a cyclic heptapeptide hepatotoxin isolated from the cyanobacterium microcystis aeruginosa was radiolabeled with 125i, and used to investigate the uptake of the toxin by freshly isolated rat hepatocytes. the uptake was temperature dependent with apparent activation energy of 18 kcal/mole (77 kj/mole) for the initial rate of uptake. uptake of non-toxic (10-20 nm) doses of microcystin by hepatocytes continued with time, the intracellular to extracellular distribution ratio for the to ... | 1991 | 1903001 |
| evaluation of potential chemoprotectants against microcystin-lr hepatotoxicity in mice. | microcystin-lr (mclr) is a potent cyclic heptapeptide hepatotoxin produced by the blue-green algae, microcystis aeruginosa. toxic blooms of this cyanobacteria have been reported throughout the temperate world. in spite of the potential economic loss and health hazard posed by this toxin, few studies on the development of an antidote have been conducted. thus, a number of biologically active compounds were tested in mice for effectiveness in preventing the toxicity of a lethal dose of mclr (100 m ... | 1991 | 1902496 |
| tumour promotion by microcystis sp., a blue-green alga occurring in water supplies. | | 1989 | 2497311 |
| protection against microcystin-lr-induced hepatotoxicity by silymarin: biochemistry, histopathology, and lethality. | microcystin-lr, a cyclic heptapeptide synthesized by the blue-green algae, microcystis aeruginosa, is a potent hepatotoxin. pathological examination of livers from mice and rats that received microcystin-lr revealed severe, peracute, diffuse, centrilobular hepatocellular necrosis, and hemorrhage. these changes were correlated with increased serum activities of sorbitol dehydrogenase, alanine aminotransferase, and lactate dehydrogenase. pretreatment of either rats or mice with a single dose of si ... | 1991 | 1902564 |
| 7-desmethyl-microcystin-rr, a hepatotoxin from a waterbloom of microcystis aeruginosa. | a peptide toxin was isolated from a waterbloom of microcystis aeruginosa from lake frøylandsvatn in norway. the isolation procedure included liquid and solid phase extraction and reversed phase high performance liquid chromatography. amino acid analysis yielded d-glutamic acid, d-erythro-beta-methylaspartic acid and d-alanine in equimolar and l-arginine in twofold molar ratios. the presence of dehydroalanine was confirmed by hydrogenation and subsequent amino acid analysis with combined gas liqu ... | 1992 | 1418236 |
| cytoskeletal changes in hepatocytes induced by microcystis toxins and their relation to hyperphosphorylation of cell proteins. | the heptapeptide toxins produced by the blue-green alga (cyanobacterium) microcystis aeruginosa are selectively hepatotoxic in mammals. the characteristic post-mortem pathology of the liver is extensive lobular disruption due to sinusoidal breakdown, leakage of blood into the tissue and hepatocyte disintegration. isolated hepatocytes incubated with toxin show severe structural deformity and surface blebbing. this paper demonstrates the effects of microcystis toxins on the contraction and aggrega ... | 1992 | 1370395 |
| structurally different members of the okadaic acid class selectively inhibit protein serine/threonine but not tyrosine phosphatase activity. | the relative potencies of four main types of okadaic acid class compounds as inhibitors of the catalytic subunits of protein serine/threonine phosphatases 1 and 2a and the protein tyrosine phosphatase 1 were determined. these four types of compounds are okadaic acid, calyculin a, microcystin-lr, and tautomycin, which are isolated from different natural sources, a black sponge halichondria okadai, a marine sponge discodermia calyx, a blue-green alga microcystis aeruginosa, and streptomyces spirov ... | 1992 | 1326138 |
| [investigations of the immunomodulatory effect of cyanobacterial extracts]. | resulting from the knowledge that cyanobacteria (blue-green algae) are able to produce pharmacologically active substances the aqueous extracts from several cyanobacteria species and strains (microcystis aeruginosa, synechocystis aquatilis, oscillatoria redekei, anabaena flos-aque, aphanizomenon flos-aquae, oscillatoria rubescens, oscillatoria tenuis) were tested for their immunomodulating activity. extracts from oscillatoria redekei 051, oscillatoria tenuis 01 and synechocystis aquatilis 428 ca ... | 1991 | 1801597 |
| toxicity of microcystin lr, a cyclic heptapeptide hepatotoxin from microcystis aeruginosa, to rats and mice. | rats (sprague-dawley) and mice (balb/c) were given microcystin lr intraperitoneally and were killed at intervals up to 24 hr (rats) or 90 min (mice) and necropsied. the lowest consistently lethal dose was 160 micrograms/kg in rats and 100 micrograms/kg in mice. rats that were clinically unaffected had no lesion. all clinically affected rats in all dose groups died (from 20 to 32 hr after toxin) and had similar hepatic lesions. livers were enlarged and dark red beginning 40 to 60 min after toxin. ... | 1989 | 2503916 |
| the ultrastructure and development of the colonial sheath of microcystis marginata. | the colonial sheath of microcystis marginata has a definite structure as seen by light and electron microscopy, consisting of a relatively smooth inner surface and densely packed, long fibrils on the outer surface. the sheath initially forms around the single cell and expands by continual deposition of sheath material to accomodate the synchronously dividing cells of the colony. | 1975 | 814872 |
| the gas vacuole membrane of microcystis aeruginosa. a partial amino acid sequence. | | 1977 | 402115 |
| [immunostimulating activity of the lipopolysaccharides of blue-green algae]. | the whole cells of blue-gree algae and lipopolysaccharides isolated from these cells were shown to stimulate the production of macro-(mainly) and microglobulin antibodies in rabbits. the macro- and microphage indices in rabbits increased significantly after the injection of lps isolated from blue-green algae 24--48 hours before infecting the animals with a virulent y. pseudotuberculosis strain. besides, the inhibiting action of this strain on the migration of phagocytes to the site of infection ... | 1979 | 117655 |
| a zoogloea sp. associated with blooms of anabaena flos-aquae. | bacteria were found attached to the heterocysts of aphanizomenon flos-aquae and embedded within the mucilage of both anabaena flos-aquae and microcystis aeruginosa in freshwater plankton. electron microscopy of thin sections preceding the peak of an anabaena flos-aquae bloom showed that the density of bacterial cells was 7.4 x 10(5) cells/ml in the planktonic macroenvironment and 2.6 x 10(11) cells/ml within the microenvironment of cyanobacterial mucilage. the bacteria occurred in aggregates and ... | 1978 | 99218 |
| a unique crystalline wall layer in the cyanobacterium microcystis marginata. | | 1978 | 77331 |
| characterization of a soluble inorganic pyrophosphatase from microcystis aeruginosa and preparation of its antibody. | a soluble inorganic pyrophosphatase was isolated from a crude extract of microcystis aeruginosa by adsorption chromatography. the enzyme was purified to homogeneity as judged by sodium dodecyl sulfate (sds) and nondenaturing polyacrylamide gel electrophoresis and n-terminal amino acid analysis. the molecular mass was estimated to be 80 kda by gel filtration chromatography, 87 kda by nondenaturing polyacrylamide gel electrophoresis, and 28 kda by sds-polyacrylamide gel electrophoresis. the enzyme ... | 1991 | 1654852 |
| characterization of microcystin-lr, a potent inhibitor of type 1 and type 2a protein phosphatases. | the level of protein phosphorylation is dependent on the relative activities of both protein kinases and protein phosphatases. by comparison with protein kinases, however, there have been considerably fewer studies on the functions of serine/threonine protein phosphatases. this is partly due to a lack of specific protein phosphatase inhibitors that can be used as probes. in the present study we characterize the inhibitory effects of microcystin-lr, a hepatotoxic cyclic peptide associated with mo ... | 1990 | 2174036 |
| inhibitory effect of a toxic peptide isolated from a waterbloom of microcystis sp. (cyanobacteria) on iron uptake by rabbit reticulocytes. | the effect of a soluble toxin purified from the algae bloom of a eutrophic lake dominated by microcystis on the receptor-mediated endocytosis of ferro-transferrin in rabbit reticulocytes was studied. the toxin was a very effective inhibitor of cell iron uptake. kinetic studies using 125i, 59fe-labeled transferrin indicated that the step of ferrotransferrin internalization was selectively inhibited by the toxin while the surface receptor-binding capacity, the externalization of previously interna ... | 1990 | 2128422 |
| hepatic lipid peroxidation, sulfhydryl status, and toxicity of the blue-green algal toxin microcystin-lr in mice. | microcystin-lr (mclr), a cyclic heptapeptide produced by the blue-green algae microcystis aeruginosa, produces death in female mice treated with 100 micrograms mclr/kg. kupffer-cell hyperplasia was observed histologically after treatment with 50 or 100 micrograms mclr/kg. no other changes or lethality were observed with the 50 micrograms mclr/kg, while 100% lethality occurred in less than 2 h in mice treated with 100 micrograms/kg. in these animals liver weights increased by 45% and hepatic hemo ... | 1990 | 2120461 |
| rapid purification of the peptide toxins microcystin-lr and nodularin. | an isolation procedure was developed to provide within one day microcystin-lr, a cyclic heptapeptide toxin from microcystis aeruginosa pcc 7806. after ods (octadecylsilyl) solid phase extraction, the crude toxin fraction was chromatographed using a strong anion exchange column. the toxin was eluted with 0.02 m ammonium bicarbonate. an at least 95% purity was revealed on hplc separation by monitoring at 214 nm. application of the procedure to the cyclic pentapeptide toxin nodularin from nodularia ... | 1990 | 2110090 |
| isolation and characterization of the minor components associated with microcystins lr and rr in the cyanobacterium (blue-green algae). | two structurally similar analogues of microcystins lr and rr, cyclic peptide hepatotoxins from microcystis, were isolated by chromatographic methods. although they have the same mol. wt and amino acid compositions as those of the parent toxins, they do not possess similar toxicities. ultraviolet and 1h-nmr spectral data for both components demonstrate clear structural difference of these cyclic peptides from the parent toxins, which are probably responsible for the marked decreases in their obse ... | 1990 | 2109908 |
| [determination of the biological damage of water-endangering compounds by means of the inhibition of cell proliferation in the blue alga microcystis]. | | 1975 | 815142 |
| hepatocellular uptake of 3h-dihydromicrocystin-lr, a cyclic peptide toxin. | the cellular uptake of microcystin-lr, a cyclic heptapeptide hepatotoxin from the cyanobacterium microcystis aeruginosa, was studied by means of a radiolabelled derivative of the toxin. 3h-dihydromicrocystin-lr. the uptake of 3h-dihydromicrocystin-lr was shown to be specific for freshly isolated rat hepatocytes whereas the uptake in the human hepatocarcinoma cell line hep g2 as well as the mouse fibroblast cell line nih-3t3, and the human neuroblastoma cell line sh-sy5y, was negligible. by means ... | 1990 | 2369577 |
| [biolgical problems of a manmade small lake (author's transl)]. | in connection with an intensive hygienic supervision of public bathing facilities and the attempts to draw up a law on bathing hygiene, the lack of contamination standards for small lakes available to the public for bathing was particularly conspicuous. in addition to the current chemical and bacteriological routine examinations, a small bathing lake with a surface area of 3000 square metres containing about 7000 m3 of water and which has been in existence for over 10 years was objected to exten ... | 1975 | 239502 |
| physiological effects of the presence and absence of gas vacuoles in the blue-green alga, microcystis aeruginosa kuetz. emend. elenkin. | physiological evidence was obtained for a light shielding role for gas vacuoles in microcystis aeruginosa kuetz. emend. elenkin, by comparing photosynthetic oxygen evolution, growth behaviour and pigment composition of cells with intact or collapsed gas vacuoles. the oxygen evolution rates were strongly dependent on cell concentration, a maximum rate for cells with intact gas vacuoles occurring at about 1.4 x 10(9) cells/ml and for cells with collapsed gas vacuoles at about 2.5 x 10(9) cells/ml. ... | 1976 | 828023 |
| uptake and subcellular localization of tritiated dihydro-microcystin-lr in rat liver. | microcystin-lr (mc-lr), a cyclic heptapeptide hepatotoxin (mol. wt = 994) produced by the blue-green alga (cyanobacterium), microcystis aeruginosa, was reduced with tritium labeled sodium borohydride, converted to [3h]-dihydro-microcystin-lr ( [3h]-2hmc-lr), and purified to greater than 99% purity by c-18 reverse-phase high-performance liquid chromatography. the uptake and subcellular distribution of [3h]-2hmc-lr were determined in suspensions of hepatocytes at 0 degrees c and 37 degrees c, or f ... | 1991 | 1926162 |
| use of rifampin as an effective chemoprotectant and antidote against microcystin-lr toxicity. | microcystin-lr (mclr) is a potent cyclic heptapeptide hepatotoxin that is produced by the blue-green algae, microcystis aeruginosa. this organism forms blooms in freshwater lakes and ponds. following ingestion of contaminated waters, deaths of wildlife and domestic animals frequently occur. due to the lack of available methods and drugs for treating cases of poisoning with this toxin, development of an effective antidote to this toxin is needed. we have examined the ability of the semisynthetic ... | 1990 | 2080233 |
| neutralization of microcystin shock in mice by tumor necrosis factor alpha antiserum. | microcystis aeruginosa is a common cyanobacterium in water blooms that appear widely in nutrient-rich, fresh, and brackish waters, and its toxic blooms cause the death of domestic animals. the administration of a crude toxic cell extract of m. aeruginosa k-139 to mice can produce tumor necrosis factor (tnf) and prompt severe physiological disturbances, especially liver damage, which can lead to death. the in vitro production of tnf-alpha by peritoneal macrophages was observed after stimulation w ... | 1991 | 2036020 |
| occurrence of the hepatotoxic cyanobacterium nodularia spumigena in the baltic sea and structure of the toxin. | water blooms formed by potentially toxic species of cyanobacteria are a common phenomenon in the baltic sea in late summer. twenty-five cyanobacterial bloom samples were collected from open and coastal waters of the baltic sea during 1985 to 1987, and their toxicity was determined by mouse bioassay. all of 5 bloom samples from the southern baltic sea, 6 of 6 from the open northern baltic sea (gulf of finland), and 7 of 14 finnish coastal samples were found to contain hepatotoxic cyanobacteria. n ... | 1989 | 2506812 |
| microcystin-lr-induced ultrastructural changes in rats. | the ultrastructure of hepatic, pulmonary, and renal lesions was evaluated in rats injected intraperitoneally with a lethal dose of microcystin-lr (mclr, 160 micrograms/kg), a cyclic heptapeptide hepatotoxin produced by the blue-green algae, microcystis aeruginosa. hepatic lesions were first seen at 10 minutes post-dosing and consisted of mild widening of hepatocyte intercellular spaces centrilobularly. at 20 minutes post-dosing, hepatocyte plasma membrane alterations were more pronounced, consis ... | 1990 | 2106745 |
| a model system for studying the bioavailability of intestinally administered microcystin-lr, a hepatotoxic peptide from the cyanobacterium microcystis aeruginosa. | sprague-dawley rats were used to evaluate a model system for studying the hepatotoxicity caused by microcystin-lr (mcyst-lr), a toxin produced by the cyanobacterium (blue-green alga) microcystis aeruginosa, and for evaluating the in vivo therapeutic potential of cholestyramine resin (ctr) which was found to bind the toxin in vitro. female rats were treated with either toxin or an equivalent volume of the saline vehicle by direct administration into the lumen of an in situ isolated ileal loop. ma ... | 1989 | 2502775 |
| nontoxic and toxic oligopeptides with d-amino acids and unusual residues in microcystis aeruginosa pcc 7806. | toxic and nontoxic peptides were isolated from the cyanobacterium microcystis aeruginosa pcc 7806 by a procedure including extraction of cells with water-saturated 1-butanol, chromatography of the extract on silica gel plates and high performance liquid chromatography (hplc) on partisil-5. the toxin was shown to be only a minor constituent, being negatively charged and thus separable by electrophoresis, within the hplc-purified fraction. it contained erythro-beta-methyl-d-asp, d-glu, d-ala, l-le ... | 1989 | 2500922 |
| cell wall constituents of microcystis sp. pcc 7806. | cell walls of microcystis sp. pcc 7806 were purified from cell homogenates by sucrose density centrifugation and triton x-100 extraction. the outer membrane contained carotenoids, two major peptidoglycan-associated proteins (mr 49,000 and 52,000), and lipopolysaccharide (lps) as indicated by the presence of 3-hydroxy fatty acids (3-oh-14:0, 3-oh-16:0, 3-oh-18:0), 4-oxo-18:0 fatty acid, and glcn as lipid a components in addition to rare o-methyl sugars (2-o-methyl-6-deoxyhexoses i and ii). the pe ... | 1989 | 2515100 |
| blue-green algae toxicosis in five dairy cows. | five holstein cows developed a sudden clinical syndrome of ataxia, muscle tremors, recumbency, and bloody diarrhea. the pond where these cows obtained water contained a near pure culture of microcystis aeruginosa, a toxic blue-green algae. all cows affected were treated with activated charcoal, procaine penicillin, glucose, and calcium and magnesium gluconate. all 5 cows were clinically normal ten days later. many practicing veterinarians regard blue-green algae toxicosis as a rare syndrome that ... | 1987 | 3119531 |
| purification of an acidic plastocyanin from microcystis aeruginosa. | plastocyanin and cytochrome c-553 are two functionally equivalent electron carriers in the photosynthetic chain of cyanobacteria. microcystis aeruginosa, a unicellular cyanobacterium which grows well at a high ph (8.6) and which was not known to possess plastocyanin, has been studied for its ability to synthesize plastocyanin in culture media with and without cu. in the absence of cu, an acidic cytochrome c-553 alone was isolated. with the inclusion of 2 microm cu, cytochrome c-553 synthesis was ... | 1989 | 2537099 |
| injury to hepatocytes induced by a peptide toxin from the cyanobacterium microcystis aeruginosa. | the freshwater, bloom forming cyanobacterium (blue-green alga) microcystis aeruginosa produces a peptide hepatotoxin which causes death accompanied by liver necrosis. we show here that the time and dose-dependent blebbing of isolated hepatocytes is accompanied by the activation of phosphorylase a, with no changes in cyclic amp levels, and by glutathione (acid-soluble thiols) depletion. these results suggest that the disruption of cytoskeletal structures is accompanied by disturbances in cellular ... | 1987 | 3124300 |
| structure and toxicity of a peptide hepatotoxin from the cyanobacterium oscillatoria agardhii. | a peptide hepatotoxin was isolated by reversed phase liquid chromatography from the cyanobacterium oscillatoria agardhii and characterized structurally and toxicologically. amino acid analyses, proton nuclear magnetic resonance and fast atom bombardment mass spectrometry showed that the toxin is a cyclic heptapeptide (mol. wt 1023.5) with the structure cyclo-(ala-arg-asp-arg-adda-glu-n-methyldehydroala) (adda: 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid). in mice the toxic e ... | 1989 | 2508270 |
| toxicity of microcystis aeruginosa k-139 strain. | toxicity of the cells of a newly established axenic microcystis aeruginosa k-139 strain to mice was studied. ld50 of the cells harvested in the mid-log phase was 7.3 mg/kg. the organs of acute dead mice were examined histopathologically. the blood congestion and necrosis of the parenchymal cells around the central veins in the liver were observed, but other organs seemed to be normal. the liver damage was confirmed by the tests of glutamic oxaloacetic transaminase (got) and glutamic pyruvic tran ... | 1989 | 2511394 |
| toxicity of microcystis species isolated from natural blooms and purification of the toxin. | microcystis strains (2 toxic and 18 nontoxic to mice) were isolated from toxic waterblooms that had been collected from lake kasumigaura, ibaraki prefecture, japan, in august 1985. thirteen of the strains (2 toxic and 11 nontoxic) were microcystis aeruginosa, 2 (nontoxic) were microcystis wesenbergii, and the other 5 were difficult to identify. six (1 toxic and 4 nontoxic m. aeruginosa and 1 m. wesenbergii) of these 20 strains were established as axenic cultures. a toxic and axenic strain of m. ... | 1989 | 2515803 |
| properties of two toxins isolated from the blue-green alga microcystis aeruginosa. | attempts were made to characterize the two toxins (p-1 and p-2) isolated from the blue-green alga microcystis aeruginosa, by amino acid analysis, mass spectrometry, 1h- and 13c-nmr. p-2, the major toxin, had a molecular weight of 1044, and consisted of one molecule each of beta-methylaspartic acid, d-glu, d-ala, l-arg, l-tyr, n-methyldehydroalanine, and 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid (adda). p-1, with a molecular weight of 994, appeared to have almost the same c ... | 1988 | 3129823 |
| toxicity of the cyanobacterium nodularia spumigena mertens. | the bloom forming cyanobacterium (blue-green alga) nodularia spumigena produced a peptide hepatotoxin with an ld50 of 70 micrograms/kg i.p. in mice. the livers of lethally poisoned mice were haemorrhagic and enlarged, the weight doubling to about 10% of total body weight. histologically there was centrilobular to midzonal disruption and lysis of hepatocytes resulting in haemorrhage and formation of blood lakes. death occurred approximately 1 hr after i.p. injection. by 30 min significant increas ... | 1988 | 3129824 |
| preliminary characterization of a toxin isolated from the cyanobacterium nodularia spumigena. | a peptide toxin was isolated from the cyanobacterium nodularia spumigena by high performance liquid chromatography (hplc). the i.p. ld50 of the toxin was 50 micrograms/kg mouse with death within 1-3 hr. the major effects of the toxin were seen in the liver in the form of extensive haemorrhages. amino acid analysis showed the presence of equimolar amounts of glutamic acid, beta-methyl-aspartic acid, and arginine. the toxicological and some of the chemical properties of the isolated toxin were sim ... | 1988 | 3129825 |
| the amino acid sequence of low-potential cytochrome c550 from the cyanobacterium microcystis aeruginosa. | the low-potential cytochrome c550 has been purified from the cyanobacterium microcystis aeruginosa and its amino acid sequence has been determined. the protein contains 135 amino acid residues with the cys-x-x-cys-his heme binding site at residues 37 to 41. the sequence from residue 28 to 45 shows similarity to cytochrome c553 residues 1 to 18 when the heme binding sites are aligned. another region of similarity is in the carboxyl-terminal regions of these two proteins. the two aligning regions ... | 1989 | 2539046 |
| the amino acid sequence of cytochrome c553 from microcystis aeruginosa. | cytochrome c553 is an electron donor to p700 in the photosynthetic electron transfer chain of cyanobacteria and eukaryotic algae. we have purified this cytochrome from the cyanobacterium microcystis aeruginosa and determined its amino acid sequence. when the amino acid sequence of this protein is compared to sequences of cytochromes c553 from other organisms, one sees that the evolution of net charge is more pronounced than the evolution of overall structure, further documenting a pronounced shi ... | 1989 | 2539045 |
| blood pressure and hepatocellular effects of the cyclic heptapeptide toxin produced by the freshwater cyanobacterium (blue-green alga) microcystis aeruginosa strain pcc-7820. | laboratory rats and mice were used to investigate the hepatotoxicity caused by the cyclic heptapeptide (mol. wt 994) termed microcystin-lr. microcystin-lr (also known as cyanoginosin-lr) is produced by the freshwater cyanobacterium (blue-green alga) m. aeruginosa strain pcc-7820. in time course histopathology studies with mice significant liver damage, with an absence of pulmonary emboli, were observed after 15 min. pulmonary emboli did not appear until 1 hr. in rats, significant liver damage an ... | 1988 | 3140425 |
| prophylaxis of cyanobacterial and mushroom cyclic peptide toxins. | the pathogenicity of virulent cyclic peptide toxins of the cyanobacterium, microcystis aeruginosa, and the mushroom, amanita phalloides, was prevented in mice by pretreatment with a variety of chemically unrelated agents including hydrocortisone, shellac, certain diazo and triazine dyes and cyclosporine. a. despite the diverse nature of the protective agents, a feature commonly associated with protection was the ability to impair hepatic uptake of 51cr-labeled sheep erythrocytes, a function of h ... | 1989 | 2724139 |
| comparison of in vivo and in vitro toxic effects of microcystin-lr in fasted rats. | the toxic effects of microcystin-lr, a cyclic heptapeptide isolated from the cyanobacterium microcystis aeruginosa, were studied in the fasted rat model and in subcellular fractions from fasted, toxin-treated and control rats. hepatotoxic effects of a lethal dose (100 micrograms/kg) were examined 15-90 min post-injection. elevations of serum enzymes, particularly sorbitol dehydrogenase, specific for liver mitochondria, correlated with hepatic damage. electron micrographs showed progressive cellu ... | 1989 | 2617540 |
| multimodal liquid chromatography columns for the separation of proteins in either the anion-exchange or hydrophobic-interaction mode. | several high-performance stationary phases suitable for protein chromatography were synthesized. columns packed with these materials could be operated independently in either the anion-exchange or hydrophobic-interaction mode. two approaches were used to prepare these materials. in the first method, a polyamine was adsorbed on the surface of macroporous silica and then crosslinked with a multifunctional oxirane. the hydrophobicity of the crosslinking agent and the extent of interconnection were ... | 1986 | 3016003 |
| optical plankton analyser: a flow cytometer for plankton analysis, ii: specifications. | an analysing flow cytometer, the optical plankton analyser (opa), is presented. the instrument is designed for phytoplankton analysis, having a sensitivity comparable with commercially available flow cytometers, but a significantly extended particle size range. particles of 500 microns in width and over 1,000 microns in length can be analysed. sample flow rates of up to 55 microliters/s can be used. also, the dynamic range of the instrument is significantly increased for particles larger than ab ... | 1989 | 2776569 |
| use of freshly prepared rat hepatocytes to study toxicity of blooms of the blue-green algae microcystis aeruginosa and oscillatoria agardhii. | extracts from blue-green algal blooms (microcystis aeruginosa and oscillatoria agardhii) from different lakes in southeastern norway were tested for toxicity toward freshly prepared rat hepatocytes. the toxicity effects were scored by means of morphological studies of the cells and by measuring leakage of the enzyme lactate dehydrogenase (ldh) from the cells. the results with the hepatocytes correspond well with results from the traditional mouse bioassay, concerning both ability to distinguish ... | 1986 | 3095554 |
| toxicity and delayed type hypersensitivity caused by microcystis blooms from lake kasumigaura. | | 1986 | 3095614 |
| biological half-life, organ distribution and excretion of 125-i-labelled toxic peptide from the blue-green alga microcystis aeruginosa. | m. aeruginosa is a bloom-forming cyanobacterium which is common in fresh-water lakes. it contains a potent hepatotoxin which when purified has been shown to be a heptapeptide of molecular weight 1019. the toxin was iodinated with 125i using the lactoperoxidase method, the labelled toxin administered intravenously to adult female rats and the half-life and organ distribution measured. the blood half-life after redistribution into extracellular pools was 42 min. the liver and kidneys showed accumu ... | 1986 | 3096266 |
| complete amino acid sequence of cyanobacterial gas-vesicle protein indicates a 70-residue molecule that corresponds in size to the crystallographic unit cell. | gas vesicles of cyanobacteria are formed by a protein called 'gas-vesicle protein' (gvp). the complete amino acid sequence has been determined of gvp from anabaena flos-aquae. it is 70 residues long and has an mr of 7388. this corresponds to the size of the repeating unit cell demonstrated by x-ray crystallography of intact gas vesicles. details of the sequence are related to the secondary beta-sheet structure of the protein and its contrasting hydrophilic and hydrophobic surfaces. extensive ami ... | 1986 | 3098234 |
| effect of toxin from the cyanobacterium microcystis aeruginosa on ultrastructural morphology and actin polymerization in isolated hepatocytes. | freshly isolated rat hepatocytes incubated with the hepatotoxin from the cyanobacterium microcystis aeruginosa are rapidly deformed (blebbed). transmission electron microscopy shows the appearance of unusual intracellular structures and rearrangement of cellular organelles, without any change in the polymerization state of actin. cytochalasin e (20 microm), a fungal metabolite that causes blebbing of hepatocytes, had no significant effect on the polymerization state of cellular actin, but if mic ... | 1986 | 3085291 |
| acute toxicity of microcystis aeruginosa and its cardiovascular effects. | the acute toxicity of a water extract from unialgal-cultured blue-green alga microcystis aeruginosa m228 on mice and rats was studied. the mice intraperitoneally injected with the extract became lethargic and piloerection was seen. terminally their ears, tails, limbs, and eyes became chalky white. the ld50 value of the extract for mice was estimated at 14.4 mg dry wt of cells/kg and that of rats was 67.4 mg/kg. tachycardia was shown in the mice injected with the extract. a value of ld50 of coadm ... | 1986 | 3089773 |
| lethal potency and tissue distribution of 125i-labelled toxic peptides from the blue-green alga microcystis aeruginosa. | toxic heptapeptides from a water bloom of the cyanobacterium microcystis aeruginosa were purified by hplc. the unoxidised fraction was iodinated with 125i plus 127i by the lactoperoxidase/h2o2 method, further purified by hplc, and the non-iodinated and three iodinated fractions administered i.p. to male mice. all iodinated fractions were toxic, with symptoms and pathological lesions of the liver identical with those caused by non-iodinated peptide. radioactivity was concentrated in the liver of ... | 1986 | 3087033 |
| morphological parameters and macromolecular organization of gas vacuole membranes of microcystis aeruginosa kuetz. emend. elenkin. | | 1970 | 4191159 |
| toxic peptides from freshwater cyanobacteria (blue-green algae). i. isolation, purification and characterization of peptides from microcystis aeruginosa and anabaena flos-aquae. | toxic peptides from two european microcystis aeruginosa and one canadian anabaena flos-aquae species of freshwater cyanobacteria (blue-green algae) were purified by high performance liquid chromatography (hplc) and examined by amino acid analysis and mass spectrometry. a toxic fraction from a butanol/methanol extract of toxic lyophilized cells was separated by g-25 gel filtration and purified by hplc using a c-18 semi-preparative column. a toxic peak with the same elution time was detected for e ... | 1986 | 3101230 |
| [dynamics of the carbohydrate content in anacystis nidulans and microcystis aeruginosa in the process of culture growth]. | | 1974 | 4219438 |
| isolation and chemical characterization of gas-vacuole membranes from microcystis aeruginosa kuetz. emend. elenkin. | | 1970 | 4193326 |
| diarrhea toxin obtained from a waterbloom-producing species, microcystis aeruginosa kützing. | a diarrhea-producing toxin from a blue-green alga, microcystis aeruginosa kützing, was obtained from standing laboratory cultures. the non-dialyzable fraction of the lysate from whole cells produced fluid accumulation in the ligated small intestinal loops in guinea pigs. | 1974 | 4204656 |
| ultrastructural and conformational changes in gas vacuole membranes isolated from microcystis aeruginosa. | | 1969 | 4312071 |
| counting of gas vacuoles by electron microscopy in lysates and purified fractions of microcystis aeruginosa. | | 1971 | 4331163 |
| symptoms and pathology produced by toxic microcystis aeruginosa nrc-1 in laboratory and domestic animals. | toxicity tests with lyophilized m. aeruginosa nrc-1 cells have been conducted using mice, guinea pigs, rabbits, chickens, ducks, two calves and one lamb as the test animals. the symptoms and pathological changes are described. on an equivalent weight basis it required three to five times the oral dosage to kill the large animals and birds as it did to kill the laboratory animals. the symptoms were less pronounced and the survival times were longer in the more resistant animals. enlargement and c ... | 1965 | 4221987 |
| assembly of gas vacuoles in a cell-free system of the blue-green alga microcystis aeruginosa kuetz. emend. elenkin. | | 1972 | 4621732 |
| a new isolation and structure for the endotoxin from microcystis aeruginosa nrc-1. | | 1970 | 4986730 |
| fatty acid composition of unicellular strains of blue-green algae. | the fatty acids of 34 strains of unicellular blue-green algae provisionally assigned to the genera synechococcus, aphanocapsa, gloeocapsa, microcystis, and chlorogloea by stanier et al. have been chemically characterized. the strains analyzed can be divided into a series of compositional groups based upon the highest degree of unsaturation of the major cellular fatty acids. twenty strains fall into the group characterized by one trienoic fatty acid isomer (alpha-linolenic acid), and seven strain ... | 1972 | 4621688 |
| [the relationship between the ultrastructural organization of the blue-green alga microcystis aeruginosa kutz. emend. elenk and toxinogenesis]. | | 1972 | 4628662 |
| spectroscopic characterization of ferredoxin from the blue-green alga microcystis flos-aquae. | | 1972 | 4632561 |
| [algicidal properties of aquatic and shore plants of the kremenchug reservoir with respect to the blue-green algae microcystis pulverea and anabaena hassalii]. | | 1965 | 5869328 |
| [adenylate kinase activity of phycobilisomes from the blue-green algae microcystis aerogenosa]. | the phycobilisomes (pbs) from the blue-green algae microcystis aerogenosa was found to possess the adenylate kinase activity. the enzyme activity of pbs is kept for 2 weeks, reaching its maximum on th 2nd-4th day after pbs isolation from the cells, and is retained after passage of freshly isolated pbs through a column with sephadex g-25. the adenylate kinase activity of pbs is thermostable, depends on the protein concentration in the sample, undergoes activation by white light and is inhibited b ... | 1981 | 6263373 |
| purification procedure for peptide toxins from the cyanobacterium microcystis aeruginosa involving high-performance thin-layer chromatography. | | 1987 | 3104380 |
| atypical pulmonary thrombosis caused by a toxic cyanobacterial peptide. | parenteral injection into mice of a toxic pentapeptide isolated from the cyanobacterium microcystis aeruginosa induced thrombocytopenia, pulmonary thrombi, and hepatic congestion. the lethality of the toxin was unaffected by several anticoagulants. the acute liver damage that follows injection of the toxin has been attributed to direct action on liver cells but may be due to hypoxemia, heart failure, and shock. | 1983 | 6407109 |
| anomalous behaviour of forward and perpendicular light scattering of a cyanobacterium owing to intracellular gas vacuoles. | extinction, absorption, and forward and perpendicular light scatter of the blue-green alga microcystis aeruginosa with different amounts of intracellular gas vacuoles were determined. the amount of gas vacuoles in the cells was controlled by application of pressure. the presence of the gas vacuoles caused a tenfold increase in perpendicular light scatter, and a fivefold decrease in forward light scatter as measured by flow cytometry. chlorophyll fluorescence showed a 16% decrease. the presence o ... | 1987 | 3113896 |
| cell selective cytotoxicity of a peptide toxin from the cyanobacterium microcystis aeruginosa. | the effects of a cyclic peptide toxin, isolated from the cyanobacterium microcystis aeruginosa, on cell morphology and ion transport in human erythrocytes, isolated rat hepatocytes and mouse fibroblasts (3t3) were studied. neither in erythrocytes nor in fibroblasts did the toxin cause morphological alterations. in hepatocytes the toxin induced marked morphological alterations at a concentration of about 50 nm. in erythrocytes and fibroblasts no effects on ion transport were observed. in hepatocy ... | 1987 | 3115307 |
| blue-green algae (microcystis aeruginosa) hepatotoxicosis in dairy cows. | twenty cows from a dairy herd consisting of 60 healthy, lactating holsteins developed clinical signs of anorexia, mental derangement, dehydration, recumbency, and ruminal atony after ingesting water containing blue-green algae. of the 20 cows, 9 died. the algal bloom, which developed in a stagnant pond during hot, dry weather, was identified as the cyanobacterium microcystis aeruginosa, a potentially hepatotoxic algae. one week after the onset of toxicosis, affected cows seemed healthy, although ... | 1987 | 3116892 |
| gliding motility in aphanothece halophytica: analysis of wall proteins in mot mutants. | the unicellular cyanobacterium aphanothece halophytica (pcc 7418) is motile, and spontaneous nonmotile (mot) mutants accumulate when the organism is subcultured. analysis of mot mutants suggests that a glycoprotein in the cell wall is involved in the motility mechanism. proteins from the wall fraction of the wild type and five mot clones were analyzed by gradient sodium dodecyl sulfate-acrylamide gel electrophoresis. four clones were similar to the wild type, and one clone, mot-3, was missing a ... | 1981 | 6793555 |
| effects of the peptide toxin from microcystis aeruginosa on intracellular calcium, ph and membrane integrity in mammalian cells. | extracts of water blooms of the toxic cyanobacterium microcystis aeruginosa showed a range of toxicities not related to their ability to lyse mammalian red cells. the hplc-purified heptapeptide toxin (mol. wt. 1035) from microcystis did not lyse red cells at up to 500-fold higher concentrations than that required to kill mice. this toxin (ld50 110 micrograms/kg for male mice) was used to investigate in vitro effects on isolated thymocytes, hepatocytes, mammary alveolar cells, and cultured swiss ... | 1987 | 3119237 |
| liquid chromatographic determination of the cyanoginosins, toxins produced by the cyanobacterium microcystis aeruginosa. | | 1987 | 3123509 |
| distribution of microcystis aeruginosa peptide toxin and interactions with hepatic microsomes in mice. | purified 14c-labelled peptide toxin from the cyanobacterium microcystis aeruginosa was administered intraperitoneally to mice and the distribution of label determined between the major organs. seventy per cent of the label was localized in the liver after 1 min.; this value increasing to almost 90 per cent after 3 hours. label associated with the lungs and other individual organs varied between 10 and 1 per cent of the 14c recovered throughout. three microsomal enzyme inducers, beta-naphthoflavo ... | 1987 | 3108872 |
| clinical and pathological changes in sheep experimentally poisoned by the blue-green alga microcystis aeruginosa. | fifteen young sheep were inoculated intraruminally with various doses of an algal bloom of microcystis aeruginosa. lethally poisoned sheep died between 18 and 48 hours after inoculation. findings included marked elevation of serum concentrations of certain enzymes and bilirubin, mild elevations of blood urea nitrogen and serum inorganic phosphorus with marked reduction in blood glucose, a mild neutrophilia with a marked left shift and marked changes in coagulation parameters. necropsy findings i ... | 1984 | 6424323 |
| ultrastructural changes in the mouse liver induced by hepatotoxin from the freshwater cyanobacterium microcystis aeruginosa strain 7820. | the time-course of ultrastructural changes was studied in mouse liver hepatocytes after i.p. injection of lethal (100 micrograms/kg) and sublethal (10 micrograms/kg) doses of the heptapeptide hepatotoxin from microcystis aeruginosa strain 7820, a freshwater blue-green alga (cyanobacterium). at both dose levels the hepatocytes show progressive intracellular changes over time periods of 10, 20, 30, and 60 min. the changes resulting from a lethal dose were more prominent and rapid compared to those ... | 1987 | 3109075 |
| recovery of hepatic function and latent mortalities in sheep exposed to the blue-green alga microcystis aeruginosa. | seventeen sheep died, and many others showed signs of hepatogenous photosensitivity after being exposed to microcystis aeruginosa at lake mokoan, victoria, australia. two groups of sheep were observed, and their hepatic recovery was monitored by means of serum biochemical tests during the subsequent six months. during the first three weeks, their serum gamma-glutamyl transferase activity and bilirubin concentration declined rapidly to normal levels, and the signs of hepatogenous photosensitivity ... | 1995 | 7483225 |
| isolation of water-soluble cytochromes from cyanobacteria by adsorption chromatography. | a simple procedure using ammonium sulfate to fractionate water-soluble cytochromes c553 and c550 on sephacryl s-200 gel is described. the usefulness of this procedure has been studied using the crude extracts of mesophilic cyanobacteria. it was found that almost all the cytochromes were adsorbed on to the gel at 2.34 m ammonium sulfate and were eluted at decreasing salt concentrations. the cytochromes were free of interfering phycobiliproteins and thus were suitable for the study of isoelectric ... | 1988 | 3132107 |