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81.
Otake Y Fujimoto I Tanaka F Nakagawa T Ikeda T Menon KK Hase S Wada H Ikenaka K 《Journal of biochemistry》2001,129(4):537-542
The structures of N-linked oligosaccharides present in human sera from 12 healthy volunteers and from 14 patients with non-small cell lung cancer (NSCLC) were analyzed by our recently developed partially automated systematic method. Thirty different structures of oligosaccharides were deduced, and these accounted for 84.1% of the total N-linked oligosaccharides present in human sera. All of the quantified oligosaccharide levels in healthy human sera were within twice the standard deviation. The amount of a triantennary trigalactosylated structure with one outer arm fucosylation (A3G3Fo) was found to be markedly increased in NSCLC patients in comparison to that in healthy volunteers (p < 0.01). No significant positive correlation with other clinical data was found. Serum A3G3Fo levels can thus be a novel marker for the diagnosis of NSCLC. 相似文献
82.
Debets R Timans JC Homey B Zurawski S Sana TR Lo S Wagner J Edwards G Clifford T Menon S Bazan JF Kastelein RA 《Journal of immunology (Baltimore, Md. : 1950)》2001,167(3):1440-1446
IL-1 is of utmost importance in the host response to immunological challenges. We identified and functionally characterized two novel IL-1 ligands termed IL-1delta and IL-1epsilon. Northern blot analyses show that these IL-1s are highly abundant in embryonic tissue and tissues containing epithelial cells (i.e., skin, lung, and stomach). In extension, quantitative real-time PCR revealed that of human skin-derived cells, only keratinocytes but not fibroblasts, endothelial cells, or melanocytes express IL-1delta and epsilon. Levels of keratinocyte IL-1delta are approximately 10-fold higher than those of IL-1epsilon. In vitro stimulation of keratinocytes with IL-1beta/TNF-alpha significantly up-regulates the expression of IL-1epsilon mRNA, and to a lesser extent of IL-1delta mRNA. In NF-kappaB-luciferase reporter assays, we demonstrated that IL-1delta and epsilon proteins do not initiate a functional response via classical IL-1R pairs, which confer responsiveness to IL-1alpha and beta or IL-18. However, IL-1epsilon activates NF-kappaB through the orphan IL-1R-related protein 2 (IL-1Rrp2), whereas IL-1delta, which shows striking homology to IL-1 receptor antagonist, specifically and potently inhibits this IL-1epsilon response. In lesional psoriasis skin, characterized by chronic cutaneous inflammation, the mRNA expression of both IL-1 ligands as well as IL-1Rrp2 are increased relative to normal healthy skin. In total, IL-1delta and epsilon and IL-1Rrp2 may constitute an independent signaling system, analogous to IL-1alphabeta/receptor agonist and IL-1R1, that is present in epithelial barriers of our body and takes part in local inflammatory responses. 相似文献
83.
This paper focuses on how a methyl group is transferred from a methyl-cobalt(III) species on one protein (the corrinoid iron-sulfur protein (CFeSP)) to a nickel iron-sulfur cluster on another protein (carbon monoxide dehydrogenase/acetyl-CoA synthase). This is an essential step in the Wood-Ljungdahl pathway of anaerobic CO and CO2 fixation. The results described here strongly indicate that transfer of methyl group to carbon monoxide dehydrogenase/acetyl-CoA synthase occurs by an SN2 pathway. They also provide convincing evidence that oxidative inactivation of Co(I) competes with methylation. Under the conditions of our anaerobic assay, Co(I) escapes from the catalytic cycle one in every 100 turnover cycles. Reductive activation of the CFeSP is required to regenerate Co(I) and recruit the protein back into the catalytic cycle. Our results strongly indicate that the [4Fe-4S] cluster of the CFeSP is required for reductive activation. They support the hypothesis that the [4Fe-4S] cluster of the CFeSP does not participate directly in the methyl transfer step but provides a conduit for electron flow from physiological reductants to the cobalt center. 相似文献
84.
Fujimoto I Menon KK Otake Y Tanaka F Wada H Takahashi H Tsuji S Natsuka S Nakakita Si Hase S Ikenaka K 《Analytical biochemistry》1999,267(2):336-343
A partially automated technique for the isolation and characterization of N-linked sugar chains from glycoproteins of crude tissue samples is established. The N-linked sugar chains from the acetone-extracted tissues are made free by a process of hydrazinolysis and subsequently N-acetylated by GlycoPrep 1000 (Oxford Glycosystems). These free sugar chains are further converted to pyridylamino derivatives by GlycoTag (Takara). Characterization of these sugar chains is achieved by a combination of HPLC columns using a highly sensitive fluorescence detector at femtomole levels. Tissue sample can be successfully pyridylaminated and analyzed to give highly reproducible results with consistent yield, requiring fewer purification steps, minimum skills, and less time. Moreover, fixed tissues can also be analyzed employing this technique, giving a similar sugar chain pattern compared to normal tissue samples. Using this method we show that the pattern of N-linked sugar chains present in human sera or in one small region of brain is strikingly similar among the different individuals. However, the absence of a highlighted peak in one of the samples suggests this method can be extrapolated to identify changes, if any, associated with disorders such as inflammation or cancer. Furthermore, this two-dimensional display of sugar chains would discover the function-specific molecules as we see in proteins. 相似文献
85.
The translational repressor Pumilio regulates presynaptic morphology and controls postsynaptic accumulation of translation factor eIF-4E 总被引:6,自引:0,他引:6
Translational repression by Drosophila Pumilio (Pum) protein controls posterior patterning during embryonic development. Here, we show that Pum is an important mediator of synaptic growth and plasticity at the neuromuscular junction (NMJ). Pum is localized to the postsynaptic side of the NMJ in third instar larvae and is also expressed in larval neurons. Neuronal Pum regulates synaptic growth. In its absence, NMJ boutons are larger and fewer in number, while Pum overexpression increases bouton number and decreases bouton size. Postsynaptic Pum negatively regulates expression of the translation factor eIF-4E at the NMJ, and Pum binds selectively to the 3'UTR of eIF-4E mRNA. The GluRIIa glutamate receptor is upregulated in pum mutants. These results, together with genetic epistasis studies, suggest that postsynaptic Pum modulates synaptic function via direct control of eIF-4E expression. 相似文献
86.
Menon AG Fleuren GJ Alphenaar EA Jonges LE Janssen van Rhijn CM Ensink NG Putter H Tollenaar RA van de Velde CJ Kuppen PJ 《Cancer immunology, immunotherapy : CII》2003,52(2):121-126
Epithelial tumours consist of an epithelial compartment and a stromal compartment, which are sometimes separated by a basal membrane-like structure. We sought to determine whether these factors have prognostic value in 84 curatively resected stage II and III colorectal cancer by immunohistochemically staining tumours for leucocytes (CD45) and extracellular matrix, and to assess the presence of a basal membrane-like structure. Leucocyte infiltration was also assessed in hematoxylin-eosin (HE) stained sections. Most leucocytes were located in the tumour stroma. A relatively high intraepithelial leucocyte infiltration was significantly correlated with a lower level of tumour recurrence (P=0.03) and a longer disease-free survival (P=0.05), whereas leucocytes located in the tumour stroma (P=0.92) or at the advancing margin (p=0.06) were not. Intraepithelial leucocyte infiltration was also significantly correlated with leucocyte infiltration in the tumour stroma (P=0.02) and at the advancing tumour margin (P=0.005), and as assessed in HE-stained tumour sections (P=0.05), but each of these parameters on its own did not have a prognostic value in predicting disease-free survival. Moreover, the presence of a basal membrane-like structure surrounding the tumour epithelium was inversely correlated with the number of intraepithelial leucocytes (P=0.05), suggesting that this membrane-like structure functions as a barrier to intraepithelial leucocyte infiltration. We conclude that leucocytes must be in the direct vicinity of tumour cells to affect tumour growth. The presence of an extracellular matrix barrier seems to prevent this interaction. 相似文献
87.
Menon K Rasband MN Taylor CM Brophy P Bansal R Pfeiffer SE 《Journal of neurochemistry》2003,87(4):995-1009
Myelin-axolemmal interactions regulate many cellular and molecular events, including gene expression, oligodendrocyte survival and ion channel clustering. Here we report the biochemical fractionation and enrichment of distinct subcellular domains from myelinated nerve fibers. Using antibodies against proteins found in compact myelin, non-compact myelin and axolemma, we show that a rigorous procedure designed to purify myelin also results in the isolation of the myelin-axolemmal complex, a high-affinity protein complex consisting of axonal and oligodendroglial components. Further, the isolation of distinct subcellular domains from galactolipid-deficient mice with disrupted axoglial junctions is altered in a manner consistent with the delocalization of axolemmal proteins observed in these animals. These results suggest a paradigm for identification of proteins involved in neuroglial signaling. 相似文献
88.
Decruse SW Gangaprasad A Seeni S Menon VS 《Indian journal of experimental biology》2003,41(8):924-927
Leaf explants collected from flowering plants of Vanda spathulata were cultured in Mitra medium with combinations of 6-benzyladenine (BA; 13.2-88.8 microM) and indole-3-acetic acid (IAA; 0.0 -85.6 microM). Combination of BA (66.6 microM) and IAA (28.5 microM) induced maximum shoots (17.33) from foliar meristems (leaf base). BA individually did not induce caulogenesis in leaf explants. For optimized multiplication, BA:IAA (2:1 microM) was essential at 22.2- 88.8 microM of BA. Re-cultured leaf explants produced lesser number of shoots compared to original explants and were nearly equal at combinations of 22.2-44.4 microM of BA and 5.7-28.5 microM of IAA. Rooting of shoots (> 95%) occurred in medium containing banana pulp (75 gl(-1)) and IAA (5.7 microM) within 3-9 weeks. Plantlets with 2-5 roots of 2-5 cm length established easily in community pots at 80-90% rates without hardening. 相似文献
89.
Osteopontin (OPN) is a secreted and integrin-binding protein that has been implicated in a number of pathologies. In this review we will focus on the functional and clinical roles of OPN in cancer and metastasis, with a particular emphasis on breast cancer. While much evidence has suggested that OPN is associated with cancer, its functional contribution to cancer remains poorly understood. Here we will review evidence for mechanisms by which OPN may act to enhance malignancy, including evidence that signaling pathways directly induced by OPN, as well as interactions with growth factor receptor pathways, can combine to activate expression of genes and functions that contribute to metastasis. OPN has been shown to be over-expressed in a variety of human tumors and is present in elevated levels in the blood of some patients with metastatic cancers. We also will discuss recent clinical evidence that suggests that OPN is not only associated with several tumor types, but that levels of OPN in cancer patients' blood or tumors may provide prognostic information. 相似文献
90.
Menon GS Kuchroo K Dasgupta D 《Physiological chemistry and physics and medical NMR》2001,33(2):153-162
Indigenous variety of Xanthium strumarium (X. strumarium) was screened for its antimitotic activity using the microtubule-tubulin system isolated from mammalian tissue. A preliminary phytochemical screening of the whole extracts of the plant was carried out followed by partial purification of the whole extract of X.strumarium. The separated fractions obtained were identified and used for in vitro polymerization studies. The whole as well as partially separated chemical constituents of X. strumarium showed effective inhibition of tubulin polymerization. The results thus suggest that X. strumarium may possess antimitotic components. 相似文献