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991.
Brandão R Santos FW Farina M Zeni G Bohrer D Rocha JB Nogueira CW 《Cell biology and toxicology》2006,22(6):429-438
Acute effects of mercury on mouse blood, kidneys, and liver were evaluated. Mice received a single dose of mercuric chloride
(HgCl2, 4.6 mg/kg, subcutaneously) for three consecutive days. We investigated the possible beneficial effects of antioxidant therapy
(N-acetylcysteine (NAC) and diphenyl diselenide (PhSe)2) compared with the sodium salt of 2,3-dimercapto-1-propanesulfonic acid (DMPS), an effective chelating agent in HgCl2 exposure in mice. We also verified whether metallothionein (MT) induction might be involved in a possible mechanism of protection
against HgCl2 poisoning and whether different treatments would modify MT levels and other toxicological parameters. The results demonstrated
that HgCl2 exposure significantly inhibited δ-aminolevulinate dehydratase (δ-ALA-D) activity in liver and only DMPS treatment prevented
the inhibitory effect. Mercuric chloride caused an increase in renal non-protein thiol groups (NPSH) and none of the treatments
modified renal NPSH levels. Urea concentration was increased after HgCl2 exposure. NAC plus (PhSe)2 was partially effective in protecting against the effects of mercury. DMPS and (PhSe)2 were effective in restoring the increment in urea concentration caused by mercury. Thiobarbituric acid-reactive substances
(TBARS), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) activities and ascorbic acid levels were not
modified after mercury exposure. Mercuric chloride poisoning caused an increase in hepatic and renal MT levels and antioxidant
treatments did not modify this parameter. Our data indicated a lack of therapeutic effect of the antioxidants tested. 相似文献
992.
993.
994.
Ana C. Silva Sandra Almeida Mário Laço Ana I. Duarte Joana Domingues Catarina R. Oliveira Cristina Januário A. Cristina Rego 《Mitochondrion》2013,13(6):801-809
Mitochondrial dysfunction has been implicated in Huntington's disease (HD) pathogenesis. We analyzed the activity of mitochondrial complexes (Cx) I–IV, protein levels of selected Cx subunits and adenine nucleotides in platelet mitochondria from pre-symptomatic versus symptomatic HD human carriers and age-matched control individuals. Mitochondrial platelets exhibited reduced activity of citrate synthase in pre-symptomatic and Cx-I in pre-symptomatic and symptomatic HD carriers. Positive correlation between Cx activity and protein subunits was observed for Cx-I in symptomatic HD patient's mitochondria. Moreover, AMP increased in mitochondria from pre-symptomatic HD carriers. Results highlight mitochondrial changes occurring before the onset of HD clinical symptoms. 相似文献
995.
Nyéssia Fernanda De Sousa Silva MáRcia Regina Simões Adriana Knob Sandra Schmidt De Moraes Caroline Henn Jose Luis Da ConceiçãO Silva 《Biocatalysis and Biotransformation》2016,34(3):119-127
Xylanase produced from the newly isolated Penicillium crustosum FP 11 and its potential in the prebleaching of kraft pulp were evaluated using a statistical approach. A Plackett–Burman design (PBD) was carried out to select the significant variables of the medium, these being NaNO3, KH2PO4, MgSO4, KCl, Fe2(SO4)3, yeast extract, corn stover, and initial pH, in a liquid culture under static conditions for 6 d at 28?°C. Statistical analysis with a central composite design and response surface methodology showed that 0.15% (w/v) KH2PO4, 2% (w/v) corn stover, and an initial pH of 6.0 provided the best conditions for xylanase production. Furthermore, xylanase from P. crustosum FP 11 was effective in the bleaching of Eucalyptus kraft pulp, with a significant kappa efficiency of 35.04%. Therefore, the newly isolated P. crustosum FP 11 from the Atlantic Forest biome in Brazil showed two advantages: xylanase production with agricultural residue (corn stover) as a carbon source and an improvement in the bleaching of kraft pulp. Environmental pollution could thus be minimized because of a reduction in the use of chlorine as a bleaching agent. 相似文献
996.
Since its discovery the cellular prion protein (encoded by the Prnp gene) has been associated with a large number of functions. The proposed functions rank from basic cellular processes such as cell cycle and survival to neural functions such as behavior and neuroprotection, following a pattern similar to that of Moore's law for electronics. In addition, particular interest is increasing in the participation of Prnp in neurodegeneration. However, in recent years a redefinition of these functions has begun, since examples of previously attributed functions were increasingly re-associated with other proteins. Most of these functions are linked to so-called “Prnp-flanking genes” that are close to the genomic locus of Prnp and which are present in the genome of some Prnp mouse models. In addition, their role in neuroprotection against convulsive insults has been confirmed in recent studies. Lastly, in recent years a large number of models indicating the participation of different domains of the protein in apoptosis have been uncovered. However, after more than 10 years of molecular dissection our view is that the simplest mechanistic model in PrPC-mediated cell death should be considered, as Ockham's razor theory suggested. 相似文献
997.
Marta Érica Saidel Karen C. dos Santos Luís F.P. Nagano Carlos Alberto Montanari Andrei Leitão 《Bioorganic & medicinal chemistry letters》2017,27(17):4001-4006
Phenotypic assays were performed in prostate cancer cell lines to describe the biological activity of PI3K-AKT-mTOR pathway inhibitors retrieved from the virtual screening initiative. These novel chemicals share in common the aminopyridine scaffold, hitting PC-3 cells in macromolar range, with selectivity index over fibroblast cell lines. Moreover, a preliminary study of the mode of action by flow cytometry assay pointed out that these compounds had a rapamycin-like response for the PI3K-AKT-mTOR pathway modulation. 相似文献
998.
Acetylcholinesterase is an enzyme whose best-known function is to hydrolyze the neurotransmitter acetylcholine. Acetylcholinesterase is expressed in several noncholinergic tissues. Accordingly, we report for the first time the identification of acetylcholinesterase in human umbilical cord vein endothelial cells. Here we further performed an electrophoretic and biochemical characterization of this enzyme, using protein extracts obtained by solubilization of human endothelial cell membranes with Triton X-100. These extracts were analyzed under polyacrylamide gel electrophoresis in the presence of Triton X-100 and under nondenaturing conditions, followed by specific staining for cholinesterase or acetylcholinesterase activity. The gels revealed one enzymatically active acetylcholinesterase band in the extracts that disappeared when staining was performed in the presence of eserine (an acetylcholinesterase inhibitor). Performing western blotting with the C-terminal anti-acetylcholinesterase IgG, we identified a single protein band of approximately 70 kDa, the molecular mass characteristic of the human monomeric form of acetylcholinesterase. The western blotting with the N-terminal anti-acetylcholinesterase IgG antibody revealed a double band around 66-70 kDa. Using the Ellman's method to measure the cholinesterase activity in human umbilical vein endothelial cells, regarding its substrate specificity, we confirmed the existence of an acetylcholinesterase enzyme. Our studies revealed a predominance of acetylcholinesterase over other cholinesterases in human endothelial cells. In conclusion, we have demonstrated the existence of a membrane-bound acetylcholinesterase in human endothelial cells. In future studies, we will investigate the role of this protein in the endothelial vascular system. 相似文献
999.
Jurado M Vázquez C Patiño B González-Jaén MT 《Systematic and applied microbiology》2005,28(6):562-568
Contamination of small-grain cereals with the fungal species Fusarium graminearum, F. culmorum, F. poae, F. sporotrichioides and F. equiseti is an important source of trichothecenes, Zearalenone and other mycotoxins which cause serious diseases in human and animals. Additionally, these species contribute to Fusarium Head Blight, a disease which produces important losses in cereal yield. Early detection and control of these Fusarium species is crucial to prevent toxins entering the food chain and a useful tool in disease management practices. We describe the development of specific PCR assays to F. graminearum, F. culmorum, F. poae, F. sporotrichioides and F. equiseti using DNA from pure fungal cultures as well as from naturally infected wheat seeds, using in this case a rapid and easy protocol for DNA isolation. The specific primers were designed on the basis of IGS sequences (Intergenic Spacer of rDNA), a multicopy region in the genome that permits to enhance the sensitivity of the assay in comparison with PCR assays based on single-copy sequences. 相似文献
1000.
Trimethylsilylcyanide addition to different carbonyl moieties, i.e. saturated ketones, an enone and an aldehyde, at the steroid side-chain, was studied in the presence of a convenient catalyst. Depending on the nature of the carbonyl group, different outcomes were noticed. Saturated 20-keto pregnanes yielded epimerically pure silylated cyanohydrins, being the absolute configuration unambiguously established by X-ray crystallographic analysis. 相似文献