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71.
G protein‐coupled receptor 37 (GPR37) is suggested to be implicated in the pathogenesis of Parkinson's disease and is accumulating in Lewy bodies within afflicted brain regions. Over‐expressed GPR37 is prone to misfolding and aggregation, causing cell death via endoplasmic reticulum stress. Although the cytotoxicity of misfolded GPR37 is well established, effects of the functional receptor on cell viability are still unknown. An N2a cell line stably expressing green fluorescent protein (GFP)‐tagged human GPR37 was created to study its trafficking and effects on cell viability upon challenge with the toxins 1‐methyl‐4‐phenylpyridinium (MPP+), rotenone and 6‐hydroxydopamine (6‐OHDA). Neuronal‐like differentiation into a tyrosine hydroxylase expressing phenotype, using dibutyryl‐cAMP, induced trafficking of GPR37 to the plasma membrane. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) cell viability and lactate dehydrogenase (LDH) cell death assays revealed that GPR37 was protective against all three toxins in differentiated cells. In undifferentiated cells, the majority of GPR37 was cytoplasmic and the protective effects were more variable: GPR37 expression protected against rotenone and MPP+ but not against 6‐OHDA in MTT assays, while it protected against 6‐OHDA but not against MPP+ or rotenone in lactate dehydrogenase (LDH) assays. These results suggest that GPR37 functionally trafficked to the plasma membrane protects against toxicity.  相似文献   
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Decorin, a proteoglycan, interacts with extracellular matrix proteins, growth factors and receptors. Decorin expression and spatio-temporal distribution were studied by RT-PCR and immunofluorescence, while decorin function was examined by blocking antibodies in the early chick embryo. Decorin was first detectable at stage XIII (late blastula). During gastrulation (stage HH3-4), decorin fluorescence was intense in epiblast cells immediately adjacent to the streak, and in migrating cells. Decorin fluorescence was intense in endoderm and strong at mesoderm-neural plate surfaces at stage HH5-6 (neurula). At stage HH10-11 (12 somites), decorin fluorescence was intense in myelencephalon and then showed distinct expression patterns along the myelencephalon axes by stage HH17. Decorin fluorescence was intense in neural crest cells, dorsal aorta, heart, somite and neuroepithelial cells apposing the somite, nephrotome, gut and in pancreatic and liver primordia. Antibody-mediated inhibition of decorin function affected the head-to-tail embryonic axis extension, indicating that decorin is essential for convergent extension cell movements during avian gastrulation. Decorin was also essential for retinal progenitor cell polarization, neural crest migration, somite boundary formation and cell polarization, mesenchymal cell polarization and primary endoderm displacement to the embryo periphery. The embryonic blood vessels were deformed, the dorsal mesocardium was thinned and the cardiac jelly was abnormally thickened in the heart. Decorin is known to modulate collagen fibrillogenesis, a key mechanism of matrix assembly, and cell proliferation. Decorin also appears to be essential for the coordination of cell and tissue polarization, which is an important feature in organ patterning of the embryo.  相似文献   
74.
A new continuous supercritical water gasification reactor was designed to investigate glucose gasification in supercritical water at high temperatures and low residence times. A 2(3) full factorial experiment was performed to determine the effects of feed concentration, temperature, and residence time on glucose gasification. The temperature levels (750°C and 800°C) were higher than ever used, while the residence times (4 and 6.5s) were shorter than ever used in previous supercritical water gasification studies. The reactor proved capable of attaining higher gasification rates than previously shown with high efficiencies and yields. In addition, the glucose gasification reaction was modeled by estimating activation energy and reaction order of glucose gasification in supercritical water.  相似文献   
75.
We made use of EXLX1, an expansin from Bacillus subtilis, to investigate protein features essential for its plant cell wall binding and wall loosening activities. We found that the two expansin domains, D1 and D2, need to be linked for wall extension activity and that D2 mediates EXLX1 binding to whole cell walls and to cellulose via distinct residues on the D2 surface. Binding to cellulose is mediated by three aromatic residues arranged linearly on the putative binding surface that spans D1 and D2. Mutation of these three residues to alanine eliminated cellulose binding and concomitantly eliminated wall loosening activity measured either by cell wall extension or by weakening of filter paper but hardly affected binding to whole cell walls, which is mediated by basic residues located on other D2 surfaces. Mutation of these basic residues to glutamine reduced cell wall binding but not wall loosening activities. We propose domain D2 as the founding member of a new carbohydrate binding module family, CBM63, but its function in expansin activity apparently goes beyond simply anchoring D1 to the wall. Several polar residues on the putative binding surface of domain D1 are also important for activity, most notably Asp82, whose mutation to alanine or asparagine completely eliminated wall loosening activity. The functional insights based on this bacterial expansin may be extrapolated to the interactions of plant expansins with cell walls.  相似文献   
76.
Survivin has been implicated as a potential prognostic marker in a wide range of malignant tumours. However, the prognostic impact of survivin in gastric cancer remains to be controversial and published data are sometimes heterogeneous. Thus, aim of this study was to review the literature by performing an electronical database search via PubMed and EMBASE to identify eligible studies that assessed the impact of survivin as prognostic marker and its association with clinicopathological variables. Database search until November 21st 2012 retrieved 20 studies comprising 2,695 gastric cancer patients that assessed expression of survivin by immunohistochemistry or RT-PCR analyses in gastric cancer specimens. Meta-analyses of clinicopathological variables revealed an association between the expression of survivin and the presence of lymph node metastases (pooled OR: 0.58; 95 % CI 0.35–0.96). In addition, a correlation between the expression of survivin and overall survival for patients with gastric cancer (pooled HR 1.93; 95 % CI 1.51–2.48) became evident. More importantly, we were able to exclude a severe heterogeneity (I2 = 31 %) or publication bias for the survival analyses. Furthermore, one-way sensitivity analysis and subgroup analyses regarding the method used to detect survivin, the type of survival analysis, the study quality and whether information was provided regarding neoadjuvant therapy supported our initial results. In conclusion, this meta-analysis indicates the prognostic significance of survivin in patients with gastric cancer.  相似文献   
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78.
希腊莱斯沃斯岛是世界上最为著名的木化石产地之一,出露有由中新世火山活动而形成的大规模矿化森林,保存有大量的植物以及部分动物化石。其中大多数木化石横卧或直立原地埋藏,并保留比较完整的根系,是目前保存最完整的新生代矿化森林生态系统。本文对莱斯沃斯岛已报道的木化石进行详细梳理分析,共计8科15属32种,包括裸子植物6科11属22种,被子植物2科4属10种,并着重介绍了发现自莱斯沃斯的代表性木化石特有类群系统古生物学属性。通过木化石反映的植物类群,初步恢复莱斯沃斯岛中新世属于北半球亚热带气候,总体比较温暖潮湿,有着明显的季节性变化特征。最后对莱斯沃斯岛木化石的埋藏环境进行了简要讨论,并对今后的研究进行了展望。  相似文献   
79.
The HSP70 protein family consists one of the most conserved and important systems for cellular homeostasis under both stress and physiological conditions. The genes of this family are poorly studied in Mollusca, which is the second largest metazoan phylum. To study these genes in Mollusca, we have isolated and identified five HSP70 genes from Mytilus galloprovincialis (Mediterranean mussel) and investigated their short-term evolution within Mollusca and their long-term evolution within Metazoa. Both sequence and phylogenetic analyses suggested that the isolated genes belong to the cytoplasmic (CYT) group of the HSP70 genes. Two of these genes probably represent cognates, whereas the remaining probably represent heat-inducible genes. Phylogenetic analysis including several molluscan CYT HSP70s reveals that the cognate genes in two species have very similar sequences and form intraspecies phylogenetic clades, differently from most metazoan cognate genes studied thus far, implying either recent gene duplications or concerted evolution. The M. galloprovincialis heat-inducible genes show intraspecies phylogenetic clustering, which in combination with the higher amino acid than nucleotide identity suggests that both gene conversion and purifying selection should be responsible for their sequence homogenization. Phylogenetic analysis including several metazoan HSP70s suggests that at least two types of CYT genes were present in the common ancestor of vertebrates and invertebrates, the first giving birth to the heat-inducible genes of invertebrates, whereas the other to both the heat-inducible genes of vertebrates and the cognate genes of all metazoans. These analyses also suggest that inducible and cognate genes seem to undergo divergent evolution. Electronic Supplementary Material Electronic Supplementary material is available for this article at and accessible for authorised users. [Reviewing Editor: Dr. Yves Van de Peer] Elena Drosopoulou and Nikolas Nikolaidis contributed equally to the present report.  相似文献   
80.
12R-lipoxygenase (12R-LOX) and the epidermal LOX-3 (eLOX-3) constitute a novel LOX pathway involved in terminal differentiation in skin. This view is supported by recent studies showing that inactivating mutations in 12R-LOX and eLOX-3 are linked to the development of autosomal recessive congenital ichthyosis. We show that 12R-LOX deficiency in mice results in a severe impairment of skin barrier function. Loss of barrier function occurs without alterations in proliferation and stratified organization of the keratinocytes, but is associated with ultrastructural anomalies in the upper granular layer, suggesting perturbance of the assembly/extrusion of lamellar bodies. Cornified envelopes from skin of 12R-LOX-deficient mice show increased fragility. Lipid analysis demonstrates a disordered composition of ceramides, in particular a decrease of ester-bound ceramide species. Moreover, processing of profilaggrin to monomeric filaggrin is impaired. This study indicates that the 12R-LOX-eLOX-3 pathway plays a key role in the process of epidermal barrier acquisition by affecting lipid metabolism, as well as protein processing.  相似文献   
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