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21.
A morphological and anatomical investigation is presented of the two species of Heberdenia, H. bahamensis (Macaronesia) and H. penduliflora (Mexico). A cladistic analysis including 27 taxa of the Myrsinaceae and using Jacquinia (Theophrastaceae) and Manilkara (Sapotaceae) as outgroup was performed to provide a hypothesis of the relationships of the two species of Heberdenia. It was concluded that H. bahamensis and H. penduliflora are not more closely related to each other than either is to many other species of the Myrsinaceae, and that they should not be referred to the same genus. Heberdenia bahamensis appears to be most closely related to the Old World genera Pleiomeris, Embelia , and Grenacheria , whereas H. penduliflora is nested within Ardisia s. L , possibly being most closely related to the segregate genus Gentlea. It is suggested that H. penduliflora is probably best referred to a genus of its own.  相似文献   
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As part of a project aimed at investigating the Matthiola taxa endemic to Sicily (Italy), this study focused on Matthiola incana, an edible species used in the traditional medicine of various countries. Herein, the characterization of phenolic and volatile compounds, the antioxidant capacity in vitro (1,1-diphenyl-2-picrylhydrazil (DPPH), reducing power and Fe2+ chelating activity assays) and the toxicity test (Artemia salina lethality bioassay) of the hydroalcoholic extracts from the aerial parts of M. incana subsp. rupestris from Mt. Pellegrino (Palermo) and Mt. Erice (Trapani), and of M. incana subsp. pulchella are reported. The results are compared with those previously shown for M. incana subsp. incana, to achieve a comprehensive overview of the three subspecies. The HPLC-PDA/ESI-MS and SPME-GC/MS analyses led to the identification of 13 phenolics and 54 volatile compounds. Differences in the qualitative-quantitative profile of these phytochemicals have been highlighted between the M. incana subspecies. The antioxidant tests showed different activity for the extracts, which were found to possess better chelating properties. At last, none of the tested extracts displayed toxicity against brine shrimp larvae. These findings enrich the knowledge on the Matthiola taxa growing wild in Sicily, both from the strictly systematic point of view and for the possible applications as sources bioactive compounds that can be used in the nutraceutical field.  相似文献   
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The Mfolozi–Msunduzi estuarine system is subject to periodic dry and wet cycles, with subsequent changes in the abiotic and biotic characteristics of the system. The aim of the current study was to compare its mesozooplankton composition during relatively dry and wet periods. Mesozooplankton samples were collected between 2007 and 2010 in both the Mfolozi and the Msunduzi, covering a dry period between 2007 and 2008 and a period of relatively high freshwater inputs during 2009 and 2010. High flows during the wet period reduced the densities of most of the dominant estuarine mesozooplankton taxa in the Mfolozi Estuary, such as estuarine calanoids Pseudodiaptomus stuhlmanni (Poppe & Mrázek, 1895) and Acartiella natalensis (Connell & Grindley, 1974). The Msunduzi Estuary functioned as a reservoir from which recolonisation by estuarine taxa would quickly take place after the Mfolozi was scoured by floodwaters. Densities of dominant meroplankton taxa, such as zoeae of the crab Paratylodiplax blephariskios and Macrobrachium spp., were not noticeably different in the Mfolozi–Msunduzi system between the low- and high-flow periods.  相似文献   
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The Notch pathway contributes to self-renewal of tumor-initiating cell and inhibition of normal colonic epithelial cell differentiation. Deregulated expression of Notch1 and Jagged1 is observed in colorectal cancer. Hairy/enhancer of split (HES) family, the most characterized targets of Notch, involved in the development of many cancers. In this study, we explored the role of Hes1 in the tumorigenesis of colorectal cancer. Knocking down Hes1 induced CRC cell senescence and decreased the invasion ability, whereas over-expression of Hes1 increased STAT3 phosphorylation activity and up-regulated MMP14 protein level. We further explored the expression of Hes1 in human colorectal cancer and found high Hes1 mRNA expression is associated with poor prognosis in CRC patients. These findings suggest that Hes1 regulates the invasion ability through the STAT3-MMP14 pathway in CRC cells and high Hes1 expression is a predictor of poor prognosis of CRC.  相似文献   
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Orientation of nucleus, centriole, microtubules, and microfilaments within human neutrophils in a gradient of chemoattractant (5 percent Escherichia coli endotoxin-activated serum) was evaluated by electron microscopy. Purified neutropils (hypaque-Ficoll) were placed in the upper compartment of chemotactic chambers. Use of small pore (0.45 μm) micropore filters permitted pseudopod penetration, but impeded migration. Under conditions of chemotaxis with activated serum beneath the filter, the neutrophil population oriented at the filter surface with nuclei located away from the stimulus, centrioles and associated radial array of microtubules beneath the nuclei, and microfilament-rich pseudopods penetrating the filter pores. Reversal of the direction of the gradient of the stimulus (activated serum above cells) resulted in a reorientation of internal structure which preceded pseudopod formation toward the activated serum and migration off the filter. Coordinated orientation of the entire neutrophil population did not occur in buffer (random migration) or in a uniform concentration of activated serum (activated random migration). Conditions of activated random migration resulted in increased numbers of cells with locomotory morphology, i.e. cellular asymmetry with linear alignment of nucleus, centriole, microtubule array, and pseudopods. Thus, activated serum increased the number of neutrophils exhibiting locomotory morphology, and a gradient of activated serum induced the alignment of neutrophils such that this locomotory morphology was uniform in the observed neutrophil populayion. In related studies, cytochalasin B and colchicines were used to explore the role of microfilaments and microtubules in the neutrophil orientation and migration response to activated serum. Cytochalasin B (3.0 μg/ml) prevented migration and decreased the microfilaments seen, but allowed normal orientation of neutrophil structures. In an activated serum gradient, colchicines, but not lumicolchicine, decreased the orientation of nuclei and centrioles, and caused a decrease in centriole-associated microtubules in concentrations as low as 10(-8) to 10(-7) M. These colchicines effects were associated with the rounding of cells and impairment of pseudopod formation. The impaired pseudopod formation was characterized by an inability to form pseudopods in the absence of a solid substrate, a formation of narrow pseudopods within a substrate, and a defect in pseudopod orientation in an activated serum gradient. Functional studies of migration showed that colchicines, but not lumicolchicine, minimally decreased activated random migration and markedly inhibited directed migration, but had not effect on random migration. These studies show that, although functioning microfilaments are probably necessary for neutrophil migration, intact microtubules are essential for normal pseudopod formation and orientation, and maximal unidirectional migration during chemotaxis.  相似文献   
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AIMS: The microbial and chemical composition of seven different semi-ripened (45 days) Provola dei Nebrodi Sicilian cheese samples were assessed in order to investigate the diversity of the microbial population in cheese made from different geographical areas throughout Sicily. METHODS AND RESULTS: The samples, which were obtained from seven different Provola dei Nebrodi manufacturers, were assessed using selective media. Interestingly, concentrations of presumptive lactobacilli represented over 90% of the total microbial population. In total, 105 presumptive Lactobacillus isolates were characterized to determine the relatedness of the isolates between the seven different cheeses. Randomly amplified polymorphic DNA polymerase chain reaction (RAPD PCR) analysis of the 105 presumptive lactobacilli indicated the presence of 22 distinct isolates. Further investigation of the isolates using pulsed field gel electrophoresis (PFGE) following restriction with the enzyme ApaI revealed the presence of 19 distinct macrorestriction patterns and the presence of between one and four distinct isolates per cheese sample (out of a total of 15 isolates per cheese randomly taken from Lactobacillus selective media plates). Analysis of the 16S rDNA sequence of each genetically distinct isolate demonstrated the dominance of the Lactobacillus casei species in all cheese samples assessed. Lactobacillus delbrueckii and Pediococcus pentosaceus species were also detected. The concentration of free amino acids, used to estimate the extent of proteolysis in each cheese, ranged from 59 to 433 mg 100 g(-1) cheese. CONCLUSIONS: Microbiological assessment of the cheeses demonstrated the dominance of Lactobacillus species after 45 days of ripening with levels ranging from 8.3 to 9.4 log CFU g(-1). SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides new information on the diversity of lactobacilli within an artisanal Sicilian cheese, enabling the identification of 17 strains of Lact. casei, one strain of Lact. delbrueckii and Ped. pentosaceus through the combined use of RAPD PCR, PFGE and 16S rDNA sequencing.  相似文献   
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