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排序方式: 共有519条查询结果,搜索用时 312 毫秒
81.
Romain Bourcier Solena Le Scouarnec Stéphanie Bonnaud Matilde Karakachoff Emmanuelle Bourcereau Sandrine Heurtebise-Chrétien Céline Menguy Christian Dina Floriane Simonet Alexis Moles Cédric Lenoble Pierre Lindenbaum Stéphanie Chatel Bertrand Isidor Emmanuelle Génin Jean-François Deleuze Jean-Jacques Schott Hervé Le Marec 《American journal of human genetics》2018,102(1):133-141
82.
Amancio Carnero Matilde Lleonart 《BioEssays : news and reviews in molecular, cellular and developmental biology》2016,38(Z1):S65-S74
Tumors are often viewed as unique entities with specific behaviors. However, tumors are a mixture of differentially evolved subpopulations of cells in constant Darwinian evolution, selecting the fittest clone and allowing it to outgrow the rest. As in the natural environment, the niche defines the properties the fittest clones must possess. Therefore, there can be multiple fit clones because of the various microenvironments inside a single tumor. Hypoxia is considered to be a major feature of the tumor microenvironment and is a potential contributor to the cancer stem cell (CSC) phenotype and its enhanced tumorigenicity. The acidic microenvironment around hypoxic cells is accompanied by the activation of a subset of proteases that contribute to metastasis. Because of aberrant angiogenesis and the inaccessibility of their locations, hypoxic cells are less likely to accumulate therapeutic concentrations of chemotherapeutics that can lead to therapeutic resistance. Therefore, the targeting of the hypoxic CSC niche in combination with chemotherapy may provide a promising strategy for eradicating CSCs. In this review, we examine the cancer stem cell hypothesis and its relationship to the microenvironment, specifically to hypoxia and the subsequent metabolic switch and how they shape tumor behavior. 相似文献
83.
Corcelli A Lobasso S Palese LL Saponetti MS Papa S 《Biochemical and biophysical research communications》2007,354(3):795-801
Membranes having an a high content of cardiolipin were isolated from an extremely halophilic archaeon Halorubrum sp. Absorbance difference spectra of detergent-solubilized plasma membranes reduced by dithionite suggested the presence of b-type cytochromes. Non-denaturing gel electrophoresis revealed only one fraction having TMPD-oxidase activity in which cardiolipin was the major lipid component. The electroeluted fraction showed a cytochrome c oxidase activity characterized by the reduced minus oxidized difference spectra as a terminal heme-copper oxidase. The cytochrome c oxidase activity of the archaeal cardiolipin-rich membranes was inhibited by the cardiolipin-specific fluorescent marker 10-N-nonyl acridine orange (NAO) in a dose-dependent manner. The results indicate that an archaeal analogue of cardiolipin is tightly associated to archaeal terminal oxidases and is required for its optimal functioning. 相似文献
84.
Involvement of a maize proline-rich protein in secondary cell wall formation as deduced from its specific mRNA localization 总被引:3,自引:0,他引:3
Vignols Florence José-estanyol Matilde Caparrós-ruiz David Rigau Joan Puigdomènech Pere 《Plant molecular biology》1999,39(5):945-952
A clone encoding a proline-rich protein (ZmPRP) has been obtained from maize root by differential screening of a maturing elongation root cDNA library. The amino acid sequence deduced from the full-length cDNA contains a putative signal peptide and a highly repetitive sequence containing the PEPK motif, indicating that the ZmPRP mRNA may code for a cell wall protein. The PEPK repeat is also found in a previously reported wheat sequence but differs from the repeated sequences found in hydroxyproline-rich glycoproteins (HRGP) and in dicot proline-rich proteins (PRP). In the maize genome, the ZmPRP protein is encoded by a single gene that is expressed in maturing regions of the root, in the hypocotyl and in the pericarp. In these organs, the ZmPRP mRNA accumulates in the xylem and surrounding cells, and in the epidermis. No ZmPRP mRNA was found in the phloem. The pattern of mRNA accumulation is very similar to the one observed for genes coding for proteins involved in lignin biosynthesis and, like most cell wall proteins, ZmPRP synthesis is also induced by wounding. These data support the hypothesis that ZmPRP is a member of a new class of fibrous proteins involved in the secondary cell wall formation in monocot species. 相似文献
85.
Virulence determines beneficial trade‐offs in the response of virus‐infected plants to drought via induction of salicylic acid 下载免费PDF全文
Emmanuel Aguilar Carmen Cutrona Francisco J. del Toro José G. Vallarino Sonia Osorio María Luisa Pérez‐Bueno Matilde Barón Bong‐Nam Chung Tomás Canto Francisco Tenllado 《Plant, cell & environment》2017,40(12):2909-2930
It has been hypothesized that plants can get beneficial trade‐offs from viral infections when grown under drought conditions. However, experimental support for a positive correlation between virus‐induced drought tolerance and increased host fitness is scarce. We investigated whether increased virulence exhibited by the synergistic interaction involving Potato virus X (PVX) and Plum pox virus (PPV) improves tolerance to drought and host fitness in Nicotiana benthamiana and Arabidopsis thaliana. Infection by the pair PPV/PVX and by PPV expressing the virulence protein P25 of PVX conferred an enhanced drought‐tolerant phenotype compared with single infections with either PPV or PVX. Decreased transpiration rates in virus‐infected plants were correlated with drought tolerance in N. benthamiana but not in Arabidopsis. Metabolite and hormonal profiles of Arabidopsis plants infected with the different viruses showed a range of changes that positively correlated with a greater impact on drought tolerance. Virus infection enhanced drought tolerance in both species by increasing salicylic acid accumulation in an abscisic acid‐independent manner. Viable offspring derived from Arabidopsis plants infected with PPV increased relative to non‐infected plants, when exposed to drought. By contrast, the detrimental effect caused by the more virulent viruses overcame potential benefits associated with increased drought tolerance on host fitness. 相似文献
86.
Reference values for TSH may be inadequate to define hypothyroidism in persons with morbid obesity: Di@bet.es study 下载免费PDF全文
Sergio Valdés Cristina Maldonado‐Araque Ana Lago‐Sampedro Juan Antonio Lillo‐Muñoz Eduardo Garcia‐Fuentes Vidal Perez‐Valero Carolina Gutiérrez‐Repiso Eva Garcia‐Escobar Albert Goday Inés Urrutia Laura Peláez Alfonso Calle‐Pascual Elena Bordiú Luis Castaño Conxa Castell Elias Delgado Edelmiro Menéndez Josep Franch‐Nadal Sonia Gaztambide Joan Girbés Emilio Ortega Joan Vendrell Matilde R. Chacón F. Javier Chaves Federico Soriguer Gemma Rojo‐Martínez 《Obesity (Silver Spring, Md.)》2017,25(4):788-793
87.
Lobasso S Saponetti MS Polidoro F Lopalco P Urbanija J Kralj-Iglic V Corcelli A 《Chemistry and physics of lipids》2009,157(1):12-20
The dye 10-N-nonyl acridine orange (NAO) is used to label cardiolipin domains in mitochondria and bacteria. The present work represents the first study on the binding of NAO with archaebacterial lipid membranes. By combining absorption and fluorescence spectroscopy with fluorescence microscopy studies, we investigated the interaction of the dye with (a) authentic standards of archaebacterial cardiolipins, phospholipids and sulfoglycolipids; (b) isolated membranes; (c) living cells of a square-shaped extremely halophilic archaeon. Absorption and fluorescence spectroscopy data indicate that the interaction of NAO with archaebacterial cardiolipin analogues is similar to that occurring with diacidic phospholipids and sulfoglycolipids, suggesting as molecular determinants for NAO binding to archaebacterial lipids the presence of two acidic residues or a combination of acidic and carbohydrate residues. In agreement with absorption spectroscopy data, fluorescence data indicate that NAO fluorescence in archaeal membranes cannot be exclusively attributed to bisphosphatidylglycerol and, therefore, different from mitochondria and bacteria, the dye cannot be used as a cardiolipin specific probe in archaeal microorganisms. 相似文献
88.
Accounting for morphological plasticity in phytoplankton populations is relevant for taxonomy, systematic/evolutionary, and
ecological studies. In this work, the green alga Pediastrum tetras (Ehrenberg) Ralfs was used to describe the variation in population size structure over its growth cycle and to analyze responses
to changes in biotic and abiotic factors. Pediastrum cultures reached a final stable concentration in approximately 10 days. This density (8 × 105 cells ml−1) remained stable for at least another 13 days and the intrinsic growth rate was 0.24 ± 0.01 day−1. In the exponential phase, the relative number of single cells and the proportion of large cells (with vesicles inside) within
colonies increased. When density peaked, a relative increase of single cells as well as small cells in new colonies took place.
Finally, during the stationary phase, the trend reversed: fewer single cells and a larger cell size (without vesicles) were
observed. Results indicated that nutrient supply could affect population structure, diminishing the proportion of eight-cell
colonies. Daphnia
magna Straus significantly reduced the Pediastrum population density due to predation, and this led to a significant decrease in the density of the largest colonies. In addition,
info-chemicals induced a slight increase in the density of the largest colonies compared to the control treatment. Our study
suggests a possible trade-off in P. tetras colonial size in natural environments: during the stationary growth period in a lake, Pediastrum populations tend to increase in size for efficient use of nutrients, while they decrease in size in the presence of herbivores.
Handling editor: J. Padisak 相似文献
89.
90.
Gianni Balliano Henrietta Dehmlow Simonetta Oliaro-Bosso Matilde Scaldaferri Silvia Taramino Franca Viola Giulia Caron Johannes Aebi Jean Ackermann 《Bioorganic & medicinal chemistry letters》2009,19(3):718-723
A series of 25 compounds, some of which previously were described as inhibitors of human liver microsomal oxidosqualene cyclase (OSC), were tested as inhibitors of Saccharomyces cerevisiae, Trypanosoma cruzi, Pneumocystis carinii and Arabidopsis thaliana OSCs expressed in an OSC-defective strain of S. cerevisiae. The screening identified three derivatives particularly promising for the development of novel anti-Trypanosoma agents and eight derivatives for the development of novel anti-Pneumocystis agents. 相似文献