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21.
Olive tree (Olea europaea L.) is commonly grown under environmental conditions characterised by water deficit, high temperatures and irradiance levels typical of Mediterranean semi-arid regions. Measurement of gas exchange, chlorophyll content, chlorophyll fluorescence and photoinhibition was carried out on two-year-old olive trees (cv. ‘Coratina’) subjected to a 21-day period of water deficit followed by 23 days of rewatering. At the beginning of the experiment, plants were divided in to two groups and subjected to different light regimes: exposed plants (EP) under a mean photosynthetically active radiation (PAR) at mid-day of 1800 μmol m−2 s−1 and shaded plants (SP) under a mean PAR of 1200 μmol m−2 s−1. The effect of drought and high irradiance levels caused a reduction of gas exchange and photosystem 2 (PSII) efficiency, in terms of quantum yield of PSII (ΦPSII) both in EP and SP. Shading conditions allowed plants to maintain a high photosynthetic activity at low values of stomatal conductance, whereas in EP the reductions in photosynthetic efficiency and intrinsic water efficiency were due to non-stomatal components of photosynthesis. The decrease in photosynthetic activity and the increase of photoinhibition under drought were more marked in EP than in SP. Full sunlight caused in EP a higher non-photochemical quenching, whereas SP showed a better photochemical efficiency. The information here obtained can be important to understand the mechanisms by which olive plants can minimize photoinhibition when subjected to simultaneous abiotic stresses.  相似文献   
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One of the main olive oil phenolic compounds, hydroxytyrosol (3,4-DHPEA), exerts in vitro chemopreventive activities (antiproliferative and pro-apoptotic) on tumor cells through the accumulation of H(2)O(2) in the culture medium. However, the phenol composition of virgin olive oil is complex, and 3,4-DHPEA is present at low concentrations when compared to other secoiridoids. In this study, the in vitro chemopreventive activities of complex virgin olive oil phenolic extracts (VOO-PE, derived from the four Italian cultivars Nocellara del Belice, Coratina, Ogliarola, and Taggiasca) were compared to each other and related to the amount of the single phenolic constituents. A great chemopreventive potential among the different VOO-PE was found following this order: Ogliarola > Coratina > Nocellara > Taggiasca. The antiproliferative and pro-apoptotic activities of VOO-PE were positively correlated to the secoiridoid content and negatively correlated to the concentration of both phenyl alcohols and lignans. All extracts induced H(2)O(2) accumulation in the culture medium, but this phenomenon was not responsible for their pro-apoptotic activity. When tested in a complex mixture, the olive oil phenols exerted a more potent chemopreventive effect compared to the isolated compounds, and this effect could be due either to a synergistic action of components or to any other unidentified extract constituent.  相似文献   
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Platelet derived growth factor receptor (PDGFR)α and PDGFRβ are tyrosine kinase receptors that are overexpressed in 70–80% of human osteosarcomas (OSAs) and may be suitable therapeutic targets for specific kinase inhibitors (TKIs). Canine OSA shows histopathological and clinical features similar to human OSA, and is considered an excellent model in comparative oncology. This study investigated PDGF-A, PDGF-B, PDGFRα and PDGFRβ expression in 33 canine OSA samples by immunohistochemistry and in seven primary canine OSA cell lines by Western blot and quantitative PCR analysis.Immunohistochemical data showed that PDGF-A and PDGF-B are expressed in 42% and 60% of the OSAs analysed, respectively, while PDGFRα and PDGFRβ were expressed in 78% and 81% of cases, respectively. Quantitative PCR data showed that all canine OSA cell lines overexpressed PDGFRα, while 6/7 overexpressed PDGFRβ and PDGF-A relative to a normal osteoblastic cell line. Moreover, in vitro treatment with a specific PDGFR inhibitor, AG1296, caused a dose- and time-dependent decrease in AKT phosphorylation. Collectively, these data show that PDGFRs/PDGFs are co-expressed in canine osteosarcomas, which suggests that an autocrine and/or paracrine loop is involved and that they play an important role in the aetiology of OSA. PDGFRs may be suitable targets for the treatment of canine OSA with a specific TKI.  相似文献   
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DNA barcoding may be particularly important in impacting the current trends of world’s biodiversity crisis, public economic issues and science. Forests play a crucial role in self-sustaining natural ecosystems and human environment at both local and regional scales. Over 39% of the world’s forests are formed by conifers; most species are highly exposed to threats and exploited at high frequency. Conifers have an urgent need to be identified through DNA barcodes, but received little attention up to date. The application of standard barcoding protocols appears to be hampered by a lack of consensus on the selection of markers and low rates of successful species identification. We examined whether four marker regions (trnh-psba, rbcL, rpoc1 and matK) matched conifer species taxonomy in a practical biodiversity survey of Italian forested land. Our objective was to provide a test of future in situ applications of DNA barcodes by evaluating the efficacy of species discrimination under the criteria of uniformity of methods and natural co-occurrence of the species. Twenty-five conifer species were included in a floristic study based on regional samplings. Genetic distance, similarity and phylogeny approaches were used to assess identification of taxa and species monophyly. We obtained 100% total discrimination success, with rbcL?+?trnH-psbA as the suggested two-locus barcode in terms of universality and efficacy. Consistent barcoding gaps, supported monophyly and regional patterns of diversity, were evidenced. Species requiring further investigation to be fully assessed at a broader context are indicated. We conclude that the time seems now ripe for coherent barcoding campaigns of entire forest tree regional floras.  相似文献   
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In this study, mesenchymal stem cells were isolated from rat adipose tissue (AD‐MSCs) to characterize and differentiate them into endothelial‐like cells. AD‐MSCs were isolated by mechanical and enzymatic treatments, and their identity was verified by colony‐forming units (CFU) test and by differentiation into cells of mesodermal lineages. The endothelial differentiation was induced by plating another aliquot of cells in EGM‐2 medium, enriched with specific endothelial growth factors. Five subcultures were performed. The expression of stemness genes (OCT4, SOX2 and NANOG) was investigated. The presence of CD90 and the absence of the CD45 were evaluated by flow cytometry. The endothelial‐like cells were characterized by the evaluation of morphological changes and gene expression analysis for endothelial markers (CD31, CD144, CD146). Characterization of AD‐MSCs showed their ability to form clones, to differentiate in vitro and the OCT‐4, SOX‐2, NANOG genes expression. Immunophenotypic characterization showed the CD90 presence and the CD45 absence. The endothelial‐like cells showed morphological changes, the expression of CD31, CD144, CD146 genes and the presence of CD31 membrane receptor. Matrigel assay showed their ability to form network and vessels‐like structures. This study lays the foundations for future evaluation of the potential AD‐MSCs pro‐angiogenic and therapeutic role.  相似文献   
28.
The Azores provide an excellent field test for research activities aimed at developing conservation strategies for endangered tree species. In this work, the urgency to promote Picconia azorica conservation programs addressed (a) insights into the biotaxonomy of the species (including an evaluation of its origin and relationships with the only congeneric species of P. azorica: P. excelsa from the Canary and Madeira islands) and (b) the evaluation of P. azorica genetic diversity. Plastid DNA sequence analysis and molecular markers (RFLP and SSR) were used for this purpose. Phylogenetic data suggest the monophyly of Picconia and support a late Miocene divergence of the two species. Three polymorphic cpSSR loci allowed the identification of five different haplotypes in P. azorica. Uniqueness and relictuality of lineages are presented and discussed. Picconia azorica intra-specific diversity patterns revealed low genetic diversity and a weak genetic structure, which could result from long-lasting ecological stability and efficient inter-island seed movement that have been severely affected in recent times. The species survival is at risk, and we suggest management practices focusing on ex situ and in situ conservation units based on eco-genetic data. Additional measures contributing to mild erosion of the genepool and to remove barriers to seed dispersal are indicated.  相似文献   
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