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81.
Gäde G Auerswald L Simek P Marco HG Kodrík D 《Biochemical and biophysical research communications》2003,309(4):967-973
A peptide that was previously assumed to occur exclusively in crustaceans is found in the corpora cardiaca of the stinkbug, Nezara viridula. The sequence of the peptide was deduced from the multiple MS(N) electrospray mass data as that of an octapeptide: pGlu-Ile/Leu-Asn-Phe-Ser-Pro-Gly-Trp amide. This peptide with Leu at position 2 is known as crustacean red pigment-concentrating hormone and code-named Panbo-RPCH. The ambiguity about the amino acid at position 2, Leu or Ile, was solved by isolating the peptide in a single-step by reversed-phase HPLC and establishing co-elution with authentic Panbo-RPCH but not with the Ile(2)-analog. When injected into stinkbugs, synthetic Panbo-RPCH elicited an increase of lipids in the haemolymph. Thus, it is assumed that Panbo-RPCH functions in the stinkbug as a lipid-mobilizing hormone. 相似文献
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Norman Morrison Dan Bearden Jacob G. Bundy Tim Collette Felicity Currie Matthew P. Davey Nathan S. Haigh David Hancock Oliver A. H. Jones Simone Rochfort Susanna-Assunta Sansone Dalibor Štys Quincy Teng Dawn Field Mark R. Viant 《Metabolomics : Official journal of the Metabolomic Society》2007,3(3):203-210
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Essential oil of Carum copticum seeds, obtained from a local shop, was extracted and content of thymol was analyzed using square-wave voltammetry at boron-doped diamond electrode. The effect of various parameters, such as pH of supporting electrolyte and square-wave voltammetric parameters (modulation amplitude and frequency), was examined. In Britton–Robinson buffer solution (pH 4), thymol provided a single and oval-shaped irreversible oxidation peak at +1.13 V versus silver/silver chloride potassium electrode (3 M). Under optimal experimental conditions, a plot of peak height against concentration of thymol was found to be linear over the range of 4 to 100 μM consisting of two linear ranges: from 4 to 20 μM (R2 = 0.9964) and from 20 to 100 μM (R2 = 0.9993). The effect of potential interferences such as p-cymene and γ-terpinene (major components in essential oil of C. copticum seeds) was evaluated. Thus, the proposed method displays a sufficient selectivity toward thymol with a detection limit of 3.9 μM, and it was successfully applied for the determination of thymol in essential oil of C. copticum seeds. The Prussian blue method was used for validation of the proposed electroanalytical method. 相似文献
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Vukadinović-Tenter D Balzarini J Meier C 《Nucleosides, nucleotides & nucleic acids》2007,26(10-12):1325-1328
New developments of the "lock-in" modified cycloSal-d4TMP are reported. Novel prodrugs with variations in the linker chain were introduced. The synthesis, hydrolysis properties in different media (PBS, CEM/0- and liver extracts) and the antiviral activities against HIV are shown. 相似文献
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A complex of EpCAM, claudin-7, CD44 variant isoforms, and tetraspanins promotes colorectal cancer progression 总被引:3,自引:0,他引:3
Kuhn S Koch M Nübel T Ladwein M Antolovic D Klingbeil P Hildebrand D Moldenhauer G Langbein L Franke WW Weitz J Zöller M 《Molecular cancer research : MCR》2007,5(6):553-567
High expression of EpCAM and the tetraspanin CO-029 has been associated with colorectal cancer progression. However, opposing results have been reported on CD44 variant isoform v6 (CD44v6) expression. We recently noted in rat gastrointestinal tumors that EpCAM, claudin-7, CO-029, and CD44v6 were frequently coexpressed and could form a complex. This finding suggested the possibly that the complex, rather than the individual molecules, could support tumor progression. The expression of EpCAM, claudin-7, CO-029, and CD44v6 expression was evaluated in colorectal cancer (n = 104), liver metastasis (n = 66), and tumor-free colon and liver tissue. Coexpression and complex formation of the molecules was correlated with clinical variables and apoptosis resistance. EpCAM, claudin-7, CO-029, and CD44v6 expression was up-regulated in colon cancer and liver metastasis. Expression of the four molecules did not correlate with tumor staging and grading. However, coexpression inversely correlated with disease-free survival. Coexpression was accompanied by complex formation and recruitment into tetraspanin-enriched membrane microdomains (TEM). Claudin-7 contributes to complex formation inasmuch as in the absence of claudin-7, EpCAM hardly associates with CO-029 and CD44v6 and is not recruited into TEMs. Notably, colorectal cancer lines that expressed the EpCAM/claudin-7/CO-029/CD44v6 complex displayed a higher degree of apoptosis resistance than lines devoid of any one of the four molecules. Expression of EpCAM, claudin-7, CO-029, and CD44v6 by themselves cannot be considered as prognostic markers in colorectal cancer. However, claudin-7-associated EpCAM is recruited into TEM and forms a complex with CO-029 and CD44v6 that facilitates metastasis formation. 相似文献
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The chemical modification of the 2′-O-position of nucleosides proved to be of great importance for the RNA stability. Greater stability of RNA duplexes allows a longer half life in the cell and, therefore, a better effect of RNA Interference. Here we investigated the synthesis of 2′-O-aminoethyl adenosine as a cationic modified building block. 相似文献