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571.
Andrea Gozzo Daniel Lesieur Patrick Duriez Jean-Charles Fruchart Elisabeth Teissier 《Free radical biology & medicine》1999,26(11-12):1538-1543
Despite an increasing number of publications concerning the antioxidant activity of melatonin, little is known about the structural features responsible for this kind of activity. To understand the role played by the different elements of melatonin structure in its antioxidant activity, we have designed and tested several compounds related to this molecule in the low-density lipoprotein peroxidation model. We present here the results of this study in terms of structure-activity relationships focusing on the influence of the acetamidoethyl side chain, the methoxy group, and the indole heterocycle. In this model, we found that changing the acyl residue generally resulted in more active products. We obtained particularly good results with the nonanoyl derivative which showed a level of activity comparable to that of phenols despite lacking a phenolic function. The presence of a methoxy group in position 5 generally had a beneficial influence on the activity, but when located in position 6, the effects were various. The substitution of a hydroxy for the methoxy group led to phenolic compounds endowed with very high antioxidant activity. Replacing the amide with a ketone function did not affect the activity while replacement with an amine group in some cases resulted in prooxidant compounds. Finally, we compared the efficacy of different aromatic rings. The indole heterocycle proved to be better than benzofurane and naphthalene rings. 相似文献
572.
Carole Beaumont Jean-Charles Deybach Bernard Grandchamp Vasco Da Silva Hubert De Verneuil Yves Nordmann 《Experimental cell research》1984,154(2):474-484
Heme has been reported to exert a control over its own biosynthesis and to affect the erythroid differentiation process at different sites. In this study, succinylacetone, a powerful inhibitor of δ-aminolevulinic acid dehydrase was used to block heme synthesis and to study the effects of heme depletion on the dimethylsulfoxide (DMSO)-mediated induction of the heme pathway enzymes in Friend virus-transformed erythroleukemia cells. The presence of succinylacetone in the medium during the DMSO treatment (1) potentiates the induction of δ-aminolevulinic acid synthetase (the first enzyme of the pathway) and this effect is reversed by the addition of exogenous hemin; (2) does not affect the induction of δ-aminolevulinic acid dehydrase (the second enzyme); (3) prevents the induction of porphobilinogen deaminase (the third enzyme), since no increase could be detected in either the enzyme activity or the immunoreactive protein and this effect could not be reversed by the addition of exogenous hemin; (4) does not affect the induction of ferrochelatase. The possible role of heme or of intermediate metabolites of the pathway on the induction of these enzymes during the erythroid differentiation process is discussed. 相似文献
573.
Summary Protoporphyrinogen oxidase activity and ferrochelatase activity have been measured in blood lymphocytes from patients with porphyria variegata, and from some members of the family of one patient; the mean activity of protoporphyrinogen oxidase from patients was about 50% of that in lymphocytes from normal subjects; similar results were obtained from asymptomatic carriers in two generations of the patient's family. This finding confirms that a protoporphyrinogen oxidase decreased activity reflects the primary genetic defect in Porphyria Variegata. Data of ferrochelatase activity have been found usually in the normal range and these results are discussed. 相似文献
574.
Kim Wiskott Federica Gilardi Alexandre Hainard Jean-Charles Sanchez Aurelien Thomas Tatjana Sajic Tony Fracasso 《Proteomics》2023,23(3-4):2200078
Abusive head trauma (AHT) is a leading cause of mortality and morbidity in infants. While the reported incidence is close to 40 cases per 100′000 births/year, misdiagnoses are commonly observed in cases with atypical, subacute, or chronic presentation. Currently, standard clinical evaluation of inflicted intracranial hemorrhagic injury (ICH) in infants urgently requires a screening test able to identify infants who need additional investigations. Blood biomarkers characteristic of AHT may assist in detecting these infants, improving prognosis through early medical care. To date, the application of innovative omics technologies in retrospective studies of AHT in infants is rare, due also to the blood serum and cerebrospinal fluid of AHT cases being scarce and not systematically accessible. Here, we explored the circulating blood proteomes of infants with severe AHT and their atraumatic controls. We discovered 165 circulating serum proteins that display differential changes in AHT cases compared with atraumatic controls. The peripheral blood proteomes of pediatric AHT commonly reflect: (i) potentially secreted proteome from injured brain, and (ii) proteome dysregulated in the system's circulation by successive biological events following acute ICH. This study opens up a novel opportunity for research efforts in clinical screening of AHT cases. 相似文献
575.
576.
The Bacillus cereus group sensu lato includes six closely-related bacterial species: Bacillus cereus, Bacillus anthracis, Bacillus thuringiensis, Bacillus mycoides, Bacillus pseudomycoides and Bacillus weihenstephanensis. B. thuringiensis is distinguished from the other species mainly by the appearance of an inclusion body upon sporulation. B. weihenstephanensis is distinguished based on its psychrotolerance and the presence of specific signature sequences in the 16S rRNA gene and cspA genes. A total of seven housekeeping genes (glpF, gmK, ilvD, pta, purH, pycA and tpi) from different B. thuringiensis serovars and B. weihenstephanensis strains were amplified and their nucleotide sequences determined. A maximum likelihood phylogenetic tree was inferred from comparisons of the concatenated sequences. B. thuringiensis serovars navarrensis, bolivia and vazensis clustered not with the other B. thuringiensis serovars but rather with the B. weihenstephanensis strains, indicative of a common phylogeny. In addition, specific signature sequences and single nucleotide polymorphisms common to B. thuringiensis serovars navarrensis, bolivia and vazensis and the B. weihenstephanensis strains, and absent in the other B. thuringiensis serovars, were identified. 相似文献