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941.
在应用基因芯片技术筛选胃腺癌转移相关基因的过程中 ,发现CDK抑制因子P18INK4C在人类胃腺癌转移细胞株RF 4 8中的表达较其原发灶细胞株RF 1明显下调 .这提示P18INK4C表达差异与胃腺癌细胞的侵袭转移可能有一定程度的相关性 .通过构建P18INK4C 表达质粒并将其转染入RF 4 8增强P18INK4C的表达 ,研究其对胃腺癌原发灶细胞体外运动、侵袭转移能力以及生长特性的影响 ,进一步明确P18INK4C与人类胃腺癌侵袭转移之间的关系 .结果发现 ,增强P18INK4C表达可以使胃腺癌原发灶细胞的体外侵袭能力明显下降 ,而对RF 4 8的细胞周期和生长增殖能并力未产生影响 .上述结果提示 ,P18INK4C参与人类胃腺癌转移过程 ,在此过程中其主要的作用可能并不是调节细胞周期 ,而是与胃腺癌原发灶细胞侵袭转移能力的调节密切相关 . 相似文献
942.
de Castro AP Quirino BF Pappas G Kurokawa AS Neto EL Krüger RH 《Archives of microbiology》2008,190(2):129-139
Cerrado is a savanna-like region that covers a large area of Brazil. Despite its biological importance, the Cerrado has been the focus of few microbial diversity studies. A molecular approach was chosen to characterize the soil fungal communities in four areas of the Cerrado biome: a native Cerrado, a riverbank forest, an area converted to a soybean plantation, and an area converted to pasture. Global diversity of fungal communities in each area was assessed through Ribosomal intergenic spacer analysis which revealed remarkable differences among the areas studied. Sequencing of approximately 200 clones containing 18S rDNA sequences from each library was performed and, according to the genetic distance between sequences, these were assigned to operational taxonomic units (OTUs). A total of 75, 85, 85, and 70 OTUs were identified for the native Cerrado, riverbank forest, pasture, and soybean plantation, respectively. Analysis of sequences using a similarity cutoff value of 1% showed that the number of OTUs for the native Cerrado area was reduced by 35%; for the soybean plantation, a reduction by more than 50% was observed, indicating a reduction in fungal biodiversity associated with anthropogenic activity. This is the first study demonstrating the anthropogenic impact on Cerrado soil fungal diversity. 相似文献
943.
Cheng CC Liu YH Ho CC Chao WT Pei RJ Hsu YH Yeh KT Ho LC Tsai MC Lai YS 《Journal of molecular histology》2008,39(2):209-216
Intermediate filaments are important in building the cellular architecture. Previously we found cytokeratin18 was modulated
in human hepatocellular carcinoma. Plectin is a cross-linking protein that organizes the cytoskeleton into a stable meshwork,
which can maintain the uniform size and shape of hepatocytes. Because the cells of hepatocellular carcinoma were morphologically
different from the hepatocytes, we speculated that expression of plectin and organization of intermediate filament might play
roles in the pleomorphism of hepatocellular carcinoma cells. In this paper, we studied the plectin expression of hepatocellular
carcinoma and liver tissues by immunohistochemistry and immunoblot. The results revealed that plectin was deficient and cytokeratin18
was modulated in hepatocellular carcinoma. Furthermore, we knockdown the plectin mRNA in Chang cells, the result revealed
the plectin was deficient and the organization of cytokeratin18 was altered. Conclusively, this study offers a hypothesis
that plectin deficient might play an important role in the tumorigenesis of hepatocellular carcinoma.
Dr. Yi-Hsiang Liu contributed equally as the first author. 相似文献
944.
The aim of this research is to investigate the relationship between obesity and wages, using data for nine countries from the European Community Household Panel (ECHP) over the period 1998-2001. We improve upon the existing literature by adopting a Quantile Regression approach to characterize the heterogenous impact of obesity at different points of the wage distribution. Our results show that (i) the evidence obtained from mean regression and pooled analysis hides a significant amount of heterogeneity as the relationship between obesity and wages differs across countries and wages quantiles and (ii) cultural, environmental or institutional settings do not seem to be able to explain differences among countries, leaving room for a pure discriminatory effect hypothesis. 相似文献
945.
Interleukin-18 deficient mice on a BALB/c background display increased resistance to cutaneous infection with Leishmania mexicana, with reduced lesion progression and reduced parasite burdens compared with wild-type mice. Infected IL-18-/- mice had lower antigen specific IgG1 levels and total IgE levels and conversely higher antigen specific IgG2a levels than similarly infected wild-type mice. Splenocytes isolated from infected IL-18-/- mice produced significantly lower levels of antigen induced IL-4 and higher levels of IFN-gamma than wild-type animals. Consequently IL-18 during L. mexicana infection of BALB/c mice promotes a Th2 biased response and thereby has a disease exacerbating role. 相似文献
946.
We treated by nucleophiles derivatives of chlorophyll a with additional six-membered cycles: δ-lactone at pyrrole D and anhydride at pyrrole C bearing a γ-meso-bridge. In the first case, this led to the formation of substituted amides at the propionic acid residue and the introduction of hydroxy group at position 18 of the macrocycle, and, in the second case, to N-substituted cycloimides of chlorin p6. 相似文献
947.
Suzuki N Hoshino K Murakami K Takeyama H Chow S 《Marine biotechnology (New York, N.Y.)》2008,10(1):49-55
To clarify the natural diet of phyllosoma larvae of the Japanese spiny lobster Panulirus
japonicus, the sources of 18S rDNA clones obtained from the hepatopancreas were investigated. Of a total of 1537 clones examined, 160
had different restriction profiles from the host larvae, in which 21 restriction types were observed. Nucleotide sequences
of 16 of 21 restriction types were successfully determined and their assignments were investigated by homology search and
phylogenetic analysis. From seven late-stage larvae collected in spring to early summer, eukaryote DNA molecules of Teleostei,
Oomycetes, Mycetozoa, and Fungi were identified. Exogenous DNA from four younger phyllosoma larvae collected in late autumn
could not be recovered. A previous study identified DNAs of cnidarians and urochordates in late-stage phyllosoma larvae of
a closely related species collected in winter. This indicates that the phyllosoma larvae are opportunistic carnivores, whose
diets correlate with the relative abundance of prey organisms in the ambient water. 相似文献
948.
Antibodies to the human cathelicidin, hCAP18 have been used to examine epithelial tissues of adult and pouch young marsupials. Immunoreactivity was observed in skin, gastrointestinal tract, lung and mammary node of adults as well as skin, gastrointestinal tract, lung and bone marrow of pouch young. The locations of expression were similar to that reported in human tissues. Although the antibody to hCAP18 is primarily directed at the C-terminal antimicrobial peptide LL37, our observations suggest recognition of a common conserved element of this cathelicidin and lead us to conclude that the epithelial tissues of marsupials are sites of production of cathelicidin. This is consistent with observations in other mammals but is the first report of expression of these compounds in marsupials. 相似文献
949.
Antimicrobial peptide P18 markedly inhibited the expression of inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1beta) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells, whereas magainin 2 did not inhibit these activities. P18 dose-dependently reduced nitric oxide (NO) production by LPS-stimulated RAW 264.7 macrophage cells, with complete inhibition at 20 microg P18 ml(-1). In contrast, P18 had no effect on NO production and the expression of iNOS mRNA and iNOS protein by interferon-gamma (IFN-gamma)-stimulated RAW264.7 cells, suggesting P18 selectively inhibits LPS-stimulated inflammatory responses in macrophages. An LAL assay showed that P18 has strong LPS-neutralizing activity, indicating that P18 inhibits the inflammatory responses in LPS-stimulated macrophages by direct binding to LPS. Collectively, our results indicate that P18 has promising therapeutic potential as a novel anti-inflammatory as well as antimicrobial agent. 相似文献
950.
For a single patch SIRS model with a period of immunity of fixed length, recruitment-death demographics, disease related deaths and mass action incidence, the basic reproduction number R(0) is identified. It is shown that the disease-free equilibrium is globally asymptotically stable if R(0)<1. For R(0)>1, local stability of the endemic equilibrium and Hopf bifurcation analysis about this equilibrium are carried out. Moreover, a practical numerical approach to locate the bifurcation values for a characteristic equation with delay-dependent coefficients is provided. For a two patch SIRS model with travel, it is shown that there are several threshold quantities determining its dynamic behavior and that travel can reduce oscillations in both patches; travel may enhance oscillations in both patches; or travel can switch oscillations from one patch to another. 相似文献