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红腹锦鸡肺的组织结构与微血管构筑   总被引:2,自引:0,他引:2  
为了了解红腹锦鸡(Chroysolophus pictus)肺的微细结构和微血管构筑特征,为呼吸生物学研究提供形态学依据,用组织学方法和微血管铸型技术在光镜和扫描电镜下观察研究了红腹锦鸡肺的组织结构与微血管构筑情况。结果表明,红腹锦鸡肺主要由各级支气管构成,从三级支气管上呈辅射状分出许多呼吸毛细管(微气管),并相互吻合成网状,呼吸毛细管外面包围有丰富的毛细血管;红腹锦鸡肺毛细血管垂直围绕在各微气管外,并相互吻合成密集的立体微血管网;毛细血管管径4.5~7.0μm,微气管直径11~50μm。并对肺微血管构筑情况与呼吸效率的关系作了探讨。  相似文献   
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Dysregulation of the Hepatocyte growth factor (HGF)/c-Met signaling axis upregulates diverse tumor cell functions, including cell proliferation, survival, scattering and motility, epithelial-to-mesenchymal transition (EMT), angiogenesis, invasion, and metastasis. (-)-Oleocanthal is a naturally occurring secoiridoid from extra-virgin olive oil, which showed antiproliferative and antimigratory activity against different cancer cell lines. The aim of this study was to characterize the intracellular mechanisms involved in mediating the anticancer effects of (-)-oleocanthal treatment and the potential involvement of c-Met receptor signaling components in breast cancer. Results showed that (-)-oleocanthal inhibits the growth of human breast cancer cell lines MDA-MB-231, MCF-7 and BT-474 while similar treatment doses were found to have no effect on normal human MCF10A cell growth. In addition, (-)-oleocanthal treatment caused a dose-dependent inhibition of HGF-induced cell migration, invasion and G1/S cell cycle progression in breast cancer cell lines. Moreover, (-)-oleocanthal treatment effects were found to be mediated via inhibition of HGF-induced c-Met activation and its downstream mitogenic signaling pathways. This growth inhibitory effect is associated with blockade of EMT and reduction in cellular motility. Further results from in vivo studies showed that (-)-oleocanthal treatment suppressed tumor cell growth in an orthotopic model of breast cancer in athymic nude mice. Collectively, the findings of this study suggest that (-)-oleocanthal is a promising dietary supplement lead with potential for therapeutic use to control malignancies with aberrant c-Met activity.  相似文献   
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用蛙胫前肌小束为材料,研究了提高胞外钾[K+]O对咖啡因挛缩的作用。[K+]O从2mmol/L提高到10或25mmol/L,由3mmol/L咖啡因引起的挛缩明显增强。以PKC/PC(PKC和PC分别为在高钾和正常钾条件下的咖啡因挛缩)表示的咖啡因挛缩增强,依赖[K+]O和高钾作用时间。随着10mmol/L[K+]O作用时间延长,直至10min,增强逐渐增加。但是,25mmol/L[K+]O作用1min时增强达到最大,然后下降到对照。PKC/PC变化时程不能用高钾引起的去极化解释,而与由相似[K+]O引起的胞浆自由钙变化时程相符。提示,至少在蛙骨骼肌,高钾引起的咖啡因挛缩增强主要是由胞浆自由钙升高引起的。  相似文献   
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The Ethiopian Bush-crow Zavattariornis stresemanni is an endangered, co-operatively breeding southern Ethiopian endemic with a remarkably restricted range (c. 6 000 km2). The species’ range was recently found to be almost perfectly predicted by an envelope of cooler, drier and more seasonal climate than surrounding areas, but the proximate determinants of this range restriction remain unclear. We assessed whether specialisation in diet or foraging may restrict the range of the species by conducting foraging watches to determine prey composition, augmented by observations of opportunistic foraging techniques, and by comparing our results to previously published information on diet. Prey composition comprised a range of arthropods, such as insect larvae (62.7%), beetles (Coleoptera) (15.6%), and grasshoppers and crickets (Orthoptera) (11.8%). Prey was primarily obtained by pecks above ground (74.2%) but also frequently dug up (23.8%). Prey capture was most successful during pecks and we also found chicks were preferentially fed larger prey items over smaller ones by adults. We documented opportunistic behaviours such as nest-raiding and ox-pecking. Diet and foraging are varied and unspecialised, and therefore do not appear to explain the restricted range of the Ethiopian Bush-crow.  相似文献   
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The bivalve superfamily Trigoniacea has persisted from the Late Paleozoic to the Recent. Late Jurassic and terminal Cretaceous mass extinctions decimated this once-dominant group in shallow marine facies; only a single genus with seven species survives today in the Austral Province. Trigoniacea retain a vestigial byssus and primitive but efficient schizodont dentition. They have been widely considered as infaunal bivalves, burrowing with a very large foot to shallow depths, with inhalant and exhalant apertures at or slightly below the sediment-water interface (SWI). Yet the Trigoniacea are poorly adapted for this life habit. The mantle in living species is unfused and non-siphonate, and some fossil Trigoniacea have permanent shell gapes over these apertures, enhancing the probability of sediment fouling of feeding and respiratory structures. Some living Neotrigonia , e.g., N. margaritacea , solve this problem by having a semi-infaunal life habit, with the inhalant and exhalant apertures elevated above the SWI and the zone of active sediment transport. Semi-infaunal species commonly have epibionts cohabiting the exposed posterior-posteroventral portion of the shell. Numerous well-preserved species of South American Mesozoic Trigoniacea have phototropically and geotropically oriented epibionts on co-attached valves, strongly suggesting a semi-infaunal life mode for at least some members of these taxa. These shell symbionts allow orientation of extinct trigoniid shells relative to the SWI during life, as well as analysis of their depth of burial. Careful analyses of the kinds, size classes, orientation, and dispersion of various epibionts on fossil Trigoniacea thus yield important new information on their life habits, and demonstrate that semi-infaunal life modes were far more common than previously supposed.  相似文献   
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Rapid progress in genome research creates a wealth of information on the functional annotation of mammalian genome sequences. However, as we accumulate large amounts of scientific information we are facing problems of how to integrate and relate the data produced by various genomic approaches. Here, we propose the novel concept of an organ atlas where diverse data from expression maps to histological findings to mutant phenotypes can be queried, compared and visualized in the context of a three-dimensional reconstruction of the organ. We will seek proof of concept for the organ atlas by elucidating genetic pathways involved in development and pathophysiology of the kidney. Such a kidney atlas may provide a paradigm for a new systems-biology approach in functional genome research aimed at understanding the genetic bases of organ development, physiology and disease.Key Words: EuReGene, kidney, genome, development, pathophysiology, genetics  相似文献   
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