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排序方式: 共有404条查询结果,搜索用时 832 毫秒
81.
82.
Olivia M. de Goede Daniel C. Nachun Nicole M. Ferraro Michael J. Gloudemans Abhiram S. Rao Craig Smail Tiffany Y. Eulalio François Aguet Bernard Ng Jishu Xu Alvaro N. Barbeira Stephane E. Castel Sarah Kim-Hellmuth YoSon Park Alexandra J. Scott Benjamin J. Strober 《Cell》2021,184(10):2633-2648.e19
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83.
Amino acid and reduced glutathione (GSH) levels in substantia nigra (SN) as well as striatal monoamine levels were measured in acetyl-L-carnitine (ALCar) treated and control Swiss-Webster mice. ALCar, L carnitine, or saline were administered i.p. to mice for 5 days and mice were decapitated 24 hours following the last injection. Substantia nigra and striata were isolated within 2.5 and 3 min., respectively, and frozen immediately on dry ice. A significant dose-dependent increase of nigral GABA was observed following ALCar treatment; GABA levels were also increased by administration of carnitine. Nigral GSH levels were also increased. Striatal levels of dopamine and metabolites were not significantly affected by ALCar or carnitine. These results, suggest that ALCar may be useful in treating symptoms of neuronal dysfunction related to accumulation of metabolic waste. 相似文献
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In this paper, we report the effect of standard NDGA, as compared to that of an aqueous extract of Larrea divaricata Cav., on BW 5147 lymphoma cell-line proliferation. To determine the mechanism of action, the effects of both on the level of intracellular cAMP, protein kinase C activity and calcium influx were studied. Moreover, the NDGA present in the aqueous extract of the plant was quantified. The aqueous extract and the standard NDGA showed antiproliferative action against these cells. While the antiproliferative activity of the aqueous extract was mediated by an increase in cAMP levels, and inhibition of PKC and calcium influx, the antiproliferative activity of NDGA was related only to the inhibition of PKC. Considering the amount of NDGA detected in the aqueous extract of the plant, at the concentrations analyzed in this case, antiproliferative activity of Larrea divaricata cannot be attributed to this compound, but could have an additive effect on the activity of other compounds. 相似文献
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Francesco De Francesco Virginia Tirino Vincenzo Desiderio Giuseppe Ferraro Francesco D'Andrea Mariateresa Giuliano Guido Libondi Giuseppe Pirozzi Alfredo De Rosa Gianpaolo Papaccio 《PloS one》2009,4(8)
Background
Human adult adipose tissue is an abundant source of mesenchymal stem cells (MSCs). Moreover, it is an easily accessible site producing a considerable amount of stem cells.Methodology/Principal Findings
In this study, we have selected and characterized stem cells within the stromal vascular fraction (SVF) of human adult adipose tissue with the aim of understanding their differentiation capabilities and performance. We have found, within the SVF, different cell populations expressing MSC markers – including CD34, CD90, CD29, CD44, CD105, and CD117 – and endothelial-progenitor-cell markers – including CD34, CD90, CD44, and CD54. Interestingly, CD34+/CD90+ cells formed sphere clusters, when placed in non-adherent growth conditions. Moreover, they showed a high proliferative capability, a telomerase activity that was significantly higher than that found in differentiated cells, and contained a fraction of cells displaying the phenotype of a side population. When cultured in adipogenic medium, CD34+/CD90+ quickly differentiated into adipocytes. In addition, they differentiated into endothelial cells (CD31+/VEGF+/Flk-1+) and, when placed in methylcellulose, were capable of forming capillary-like structures producing a high level of VEGF, as substantiated with ELISA tests.Conclusions/Significance
Our results demonstrate, for the first time, that CD34+/CD90+ cells of human adipose tissue are capable of forming sphere clusters, when grown in free-floating conditions, and differentiate in endothelial cells that form capillary-like structures in methylcellulose. These cells might be suitable for tissue reconstruction in regenerative medicine, especially when patients need treatments for vascular disease. 相似文献88.
Thomas W. Plummer Peter W. Ditchfield Laura C. Bishop John D. Kingston Joseph V. Ferraro David R. Braun Fritz Hertel Richard Potts 《PloS one》2009,4(9)
Background
Major biological and cultural innovations in late Pliocene hominin evolution are frequently linked to the spread or fluctuating presence of C4 grass in African ecosystems. Whereas the deep sea record of global climatic change provides indirect evidence for an increase in C4 vegetation with a shift towards a cooler, drier and more variable global climatic regime beginning approximately 3 million years ago (Ma), evidence for grassland-dominated ecosystems in continental Africa and hominin activities within such ecosystems have been lacking.Methodology/Principal Findings
We report stable isotopic analyses of pedogenic carbonates and ungulate enamel, as well as faunal data from ∼2.0 Ma archeological occurrences at Kanjera South, Kenya. These document repeated hominin activities within a grassland-dominated ecosystem.Conclusions/Significance
These data demonstrate what hitherto had been speculated based on indirect evidence: that grassland-dominated ecosystems did in fact exist during the Plio-Pleistocene, and that early Homo was active in open settings. Comparison with other Oldowan occurrences indicates that by 2.0 Ma hominins, almost certainly of the genus Homo, used a broad spectrum of habitats in East Africa, from open grassland to riparian forest. This strongly contrasts with the habitat usage of Australopithecus, and may signal an important shift in hominin landscape usage. 相似文献89.
90.
Augusto Sorrequieta Gisela Ferraro Silvana B. Boggio Estela M. Valle 《Amino acids》2010,38(5):1523-1532
In tomato, free amino acids increase dramatically during fruit ripening and their abundance changed differentially. More evident
is l-glutamate which gives the characteristic “umami” flavor. Glutamate is the principal free amino acid of ripe fruits of cultivated
varieties. In this paper, we examined the capacity of tomato fruits to process endogenous as well as exogenous polypeptides
during the ripening transition, in order to analyze their contribution to the free amino acid pool. In addition, the activity
of some enzymes involved in glutamate metabolism such as γ-glutamyl transpeptidase (γ-GTase), glutamate dehydrogenase (GDH),
α-ketoglutarate-dependent γ-aminobutyrate transaminase (GABA-T), alanine and aspartate aminotransferases was evaluated. Results
showed that peptidases were very active in ripening fruits, and they were able to release free amino acids from endogenous
proteins and glutamate from exogenously added glutamate-containing peptides. In addition, red fruit contained enough γ-GTase
activity to sustain glutamate liberation from endogenous substrates such as glutathione. From all the glutamate metabolizing
enzymes, GDH and GABA-T showed the higher increase in activities when the ripening process starts. In summary, tomato fruits
increase free amino acid content during ripening, most probably due to the raise of different peptidase activities. However,
glutamate level of ripe fruit seems to be mostly related to GDH and GABA-T activities that could contribute to increase l-glutamate level during the ripening transition. 相似文献