4,451 research outputs found
Fathering and father-child interactions in families of children with attention-deficit hyperactivity disorder
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The role of Ruditapes philippinarum glutathione transferases in the metabolism of microcystin-LR
No full textNo abstracts are to be cited without prior reference to the author. Glutathione transferases (GSTs) are phase II enzymes involved in the microcystin (MC) induced detoxication processes. In this study we analyze and compare the metabolism of MC-LR by the cytosolic GSTs from gills and hepatopancreas of Ruditapes philippinarum. Cytosolic GSTs were purified by glutathione (GSH)–agarose affinity chromatography from exposed and non-exposed bivalves to MC-LR (100 µg/L) representing the inducible and constitutive (Basal) GST fractions, respectively. For each mixture, we examined the in vitro cytosolic GST inhibition efficiency of the conjugation of CDNB to GSH by MC-LR and characterize the inhibition mechanism. Results support the important role of GST enzymes in detoxification of MCs in bivalve mollusk
Transcriptional responses of glutathione transferase genes in Ruditapes philippinarum exposed to microcystin-LR
No full textNo abstracts are to be cited without prior reference to the author. Microcystins (MCs) are potent hepatotoxins produced by bloom-forming species of toxic cyanobacteria. Among these, MC-LR is the most commonly found and toxic variant. Bivalves, due to their benthic and sedentary mode of life, are one of the most threatened organisms by these environmental stressors. Glutathione transferases (GSTs) play a major role in cellular defense against MCs toxicity. The aim of this study was to compare the relative changes of gene expression of the different GSTs isoforms in mollusc bivalves exposed to MCs. The time-dependent changes of relative transcription abundance of several GST isoforms in parallel with enzymatic activity of total GST were investigated in gills and hepatopancreas of Ruditapes philippinarum exposed to dissolved MC-LR. The relative changes of gene expression and enzyme activity were analyzed by quantitative real-time PCR and colorimetric assays respectively. We found that MC-LR could affect the transcriptional activities of these detoxification enzymes in gills and hepatopancreas of the tested bivalves. Most GST isoforms showed differential response profiles depending on the concentrations of MC-LR and exposure times for clams. These results highlight the important role of GSTs in counteracting the potential deleterious effects induced by MCs in bivalve
Fast removal of cyanobacterial toxin microcystin-LR by a low-cytotoxic microgel-Fe(III) complex
No full textEutrophication has become a serious environmental threat throughout the world. In particular, the presence of cyanobacteria toxins, especially microcystins (MCs), has become a severe problem. Inhibition of Microcystis growth in water resources is the most effective way to reduce MCs, but it is a long-term investment. In the present study, a microgel-Fe(III) complex was developed for the fast removal of MC-LR. The microgel-Fe(III) characteristics and the MC-LR removal dynamics in Milli-Q water and natural water were evaluated. The removal efficiency negatively correlated to the initial MC-LR concentration and pH value (2.0-11.5), but the kinetics was not significantly influenced. The presence of natural organic matter (NOM) in water slightly reduced MC-LR removal using microgel-Fe(III). In addition, microgel-Fe(III) removed 98.99% of MC-LR in 12 min, while for activated carbon, it took 15-24 h to reach equilibrium. Furthermore, methanol was found to regenerate the microgel-Fe(III) after MC-LR removal for at least five regeneration cycles. Finally, the microgel-Fe(III) material was made into a membrane so that MCs could be removed by filtration. Therefore, microgel-Fe(III) is an effective technology and has a great potential in removing MC-LR from drinking water resources. (C) 2011 Elsevier Ltd. All rights reserved.Eutrophication has become a serious environmental threat throughout the world. In particular, the presence of cyanobacteria toxins, especially microcystins (MCs), has become a severe problem. Inhibition of Microcystis growth in water resources is the most effective way to reduce MCs, but it is a long-term investment. In the present study, a microgel-Fe(III) complex was developed for the fast removal of MC-LR. The microgel-Fe(III) characteristics and the MC-LR removal dynamics in Milli-Q water and natural water were evaluated. The removal efficiency negatively correlated to the initial MC-LR concentration and pH value (2.0-11.5), but the kinetics was not significantly influenced. The presence of natural organic matter (NOM) in water slightly reduced MC-LR removal using microgel-Fe(III). In addition, microgel-Fe(III) removed 98.99% of MC-LR in 12 min, while for activated carbon, it took 15-24 h to reach equilibrium. Furthermore, methanol was found to regenerate the microgel-Fe(III) after MC-LR removal for at least five regeneration cycles. Finally, the microgel-Fe(III) material was made into a membrane so that MCs could be removed by filtration. Therefore, microgel-Fe(III) is an effective technology and has a great potential in removing MC-LR from drinking water resources. (C) 2011 Elsevier Ltd. All rights reserved
Effects of cyanobacterial toxin microcystin-LR on the transcription levels of immune-related genes in grass carp Ctenopharyngodon idella
No full textRecent studies in mammals have revealed that the cyanobacterial toxin MC-LR suppresses immune functions. Nevertheless, immunotoxic effects of microcystins have been little studied in fish. In this paper, we present the profiles of the immune modulation of MC-LR in grass carp, and quantitative real-time PCR methodology was developed for the measurement of relative transcription changes of six immune-related genes in the spleen and head kidney of the grass carp Ctenopharyngodon idella, which were intraperitoneally injected with 50 mu g MC-LR center dot kg(-1) body weight in a three-week period. This study was focused exclusively on gene transcription level changes at different time points after MC-LR exposure, so, only one dose was given. The investigated genes were interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), type I interferon (Type I IFN), peptidoglycan recognition protein-L (PGRP-L), immunoglobulin M (IgM) and major histocompatibility complex class I (MHC-I) genes. The results demonstrated that the transcription levels of the TNF-alpha, type I IFN, and PGRP-L genes in the spleen and head kidney were significantly low at all time points, and those of IL-1 beta were significantly low in the head kidney at different time points. In addition, IgM and MHC-I transcription levels were only significantly low in the spleen and head kidney at 21 d postinjection. The changes in the transcription levels of immune-related genes induced by MC-LR confirmed its effect on inhibiting immune function at the transcription level.Recent studies in mammals have revealed that the cyanobacterial toxin MC-LR suppresses immune functions. Nevertheless, immunotoxic effects of microcystins have been little studied in fish. In this paper, we present the profiles of the immune modulation of MC-LR in grass carp, and quantitative real-time PCR methodology was developed for the measurement of relative transcription changes of six immune-related genes in the spleen and head kidney of the grass carp Ctenopharyngodon idella, which were intraperitoneally injected with 50 mu g MC-LR center dot kg(-1) body weight in a three-week period. This study was focused exclusively on gene transcription level changes at different time points after MC-LR exposure, so, only one dose was given. The investigated genes were interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), type I interferon (Type I IFN), peptidoglycan recognition protein-L (PGRP-L), immunoglobulin M (IgM) and major histocompatibility complex class I (MHC-I) genes. The results demonstrated that the transcription levels of the TNF-alpha, type I IFN, and PGRP-L genes in the spleen and head kidney were significantly low at all time points, and those of IL-1 beta were significantly low in the head kidney at different time points. In addition, IgM and MHC-I transcription levels were only significantly low in the spleen and head kidney at 21 d postinjection. The changes in the transcription levels of immune-related genes induced by MC-LR confirmed its effect on inhibiting immune function at the transcription level
Incremental Scannerless Generalized LR Parsing
No full textThe Scannerless Generalized LR (SGLR) parsing algorithm supports the development of composed languages seamlessly but does not support incremental parsing. The Incremental Generalized LR (IGLR) parsing algorithm, on the other hand, does not support the seamless composition of languages. This thesis presents the Incremental Scannerless Generalized LR (ISGLR) parsing algorithm and investigates the effects of combining the SGLR and IGLR parsing algorithms. While the algorithmic differences are orthogonal, the fact that scannerless parsing relies on non-deterministic parsing for disambiguation has a negative impact on incrementality. Nonetheless, we show that the ISGLR parsing algorithm performs better than the batch SGLR parsing algorithm in typical scenarios. On average, the ISGLR parser can reuse 99% of a previous parse result. When parsing from scratch, the ISGLR parser has a 24% run time overhead compared to the SGLR parser, but when parsing incrementally for changes that are smaller than 1% of the input size on average, it has a 9× speedup.Successor of https://doi.org/10.1145/3359061.3361085Computer Scienc
Lipid metabolism, immune and apoptosis transcriptomic responses of the hepatopancreas of Chinese mitten crab to the exposure to microcystin-LR
No full text© 2022 The AuthorsGlobal warming is favouring the incidence, intensity and duration of harmful cyanobacterial blooms. Microcystin-LR (MC-LR), a hepatotoxic agent, is produced during cyanobacterial blooms. To understand the molecular mechanisms of acute hepatotoxic effect of low doses of MC-LR in crab, we examined differentially expressed genes in samples of the hepatopancreas of Chinese mitten crab (Eriocheir sinensis) collected in 48 h after injections of MC-LR at doses of 0, 25, 50, and 75 µg/kg. The results revealed that MC-LR induced changes in corresponding gene led to the accumulation of triglycerides. MC-LR exposure affected sterol metabolism. Apoptosis-related genes such as Fas-L, Bcl-XL, Cytc, AiF, p53, PERK, calpain, CASP2, CASP7, α-tubulin, PARP, GF, G12, and PKC were upregulated. Conversely, expression levels of CASP10 and ASK1 were downregulated. Genes related to the regulation of actin cytoskeleton (Rho, ROCK, MLCP, MLC, PAK, and PFN) were upregulated. Further, expression levels of genes encoding fatty acid elongation-related enzymes were upregulated, but the expression of genes related to fatty acid synthesis was slightly down regulated. Taken together, these results demonstrated the hepatic toxicity and molecular mechanisms of changes in lipid metabolism, immune and apoptosis in Chinese mitten crab under the MC-LR-induced stress, which is the first report on crabs and performs a comprehensive analysis and a new insight of the molecular toxicological responses in crabs.Y
TOXIC EFFECTS OF MICROCYSTIN-LR ON MICE ERYTHROCYTES in vitro
No full textHaematological abnormalities have been verified in patients intoxicated by microcystins (MCs) in haemodialysis unit in Caruaru, Brazil, and 60 patients died. In our previous studies, obvious anemia has been determined in rabbit after in vivo exposure to microcystins. As to the cause of the anemia, except for hematopoiesis obstacles, we hypothesized that microcystins result in erythrocyte destruction. In the present study, Kunming mice erythrocytes in vitro were incubated with 1, 10, 100 and 1000 nM microcystin-LR at 37 degrees C. Lipid peroxidation, haemolysis, cell morphology, antioxidative response and some biochemical biomarkers were measured. The results showed that the level of lipid peroxidation significantly increased in microcystin-LR treatment groups. The level of glutathione and activities of glutathione peroxidase, glutathione-S-transferase and superoxide dismutase were significantly increased after incubation with microcystin-LR at 12, 24 and 48 h. Also, significant decreases in activities of acetylcholinesterase, Na+-K+-ATPase and Ca2+-Mg2+-ATPase were observed. Obvious increases of haemolysis were determined in 10, 100 and 1000 nM groups from 12 to 48 h. Additionally, abnormal erythrocytes with bleb-bing and notched cell membrane were observed in both 100 and 1000 nM groups. It is presumed that microcystin-LR triggers lipid peroxidation of erythrocytes and oxidative stress destroys the structure of cell membrane, leading to alterations of antioxidative enzymes and biochemical indicators. Our results demonstrate that in vitro exposure to microcystin-LR resulted in damage of mice erythrocytes.Haematological abnormalities have been verified in patients intoxicated by microcystins (MCs) in haemodialysis unit in Caruaru, Brazil, and 60 patients died. In our previous studies, obvious anemia has been determined in rabbit after in vivo exposure to microcystins. As to the cause of the anemia, except for hematopoiesis obstacles, we hypothesized that microcystins result in erythrocyte destruction. In the present study, Kunming mice erythrocytes in vitro were incubated with 1, 10, 100 and 1000 nM microcystin-LR at 37 degrees C. Lipid peroxidation, haemolysis, cell morphology, antioxidative response and some biochemical biomarkers were measured. The results showed that the level of lipid peroxidation significantly increased in microcystin-LR treatment groups. The level of glutathione and activities of glutathione peroxidase, glutathione-S-transferase and superoxide dismutase were significantly increased after incubation with microcystin-LR at 12, 24 and 48 h. Also, significant decreases in activities of acetylcholinesterase, Na+-K+-ATPase and Ca2+-Mg2+-ATPase were observed. Obvious increases of haemolysis were determined in 10, 100 and 1000 nM groups from 12 to 48 h. Additionally, abnormal erythrocytes with bleb-bing and notched cell membrane were observed in both 100 and 1000 nM groups. It is presumed that microcystin-LR triggers lipid peroxidation of erythrocytes and oxidative stress destroys the structure of cell membrane, leading to alterations of antioxidative enzymes and biochemical indicators. Our results demonstrate that in vitro exposure to microcystin-LR resulted in damage of mice erythrocytes
Construction Methods of LR Parsers
Full text linkThis paper presents five different LR parser generators and an error recovery method which is derived directly from the LR parser. The parsers presented include the original LR (1) parser defined by Knuth. The SLR(1) and LALR(1) parsers defined by DeRemer, and the weak and strong compatible LR parsers presented by Pager. All five parsers have been implemented by the author using two programs. Furthermore, the implementation of the SLR (1) parser generator includes an error recovery method and produces an SLR(1) parser with error recovery built in
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