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1.
We have demonstrated the in vitro enzymatic synthesis of an ester of indole-3-acetic acid (IAA) and glucose and of IAA and myo-inositol by the following reaction sequence: lt]o| li]1) IAA + UDPG ? IAA-glucose +UDP li]2) IAA-glucose +myo-inositol → IAA-itmyo-inositol +glucose The enzymes were partially purified from extracts of immature kernels of Zea mays sweet corn and the two activities separated on a Sephadex G-150 column. Products were characterized, primarily, by comparison of their 70 eV mass spectra with those of authentic synthetic standards. To our knowledge this is the first example of enzymatically catalyzed acylation by a 1-O-acylsugar.  相似文献   
2.
Particulate phosphorus sedimentation at the river inflow to a lake   总被引:1,自引:0,他引:1  
Lech Kufel 《Hydrobiologia》1993,251(1-3):269-274
Sedimentation at the Krutynia River inflow to Lake Kujno was closely related to hydrological regime. The highest sedimentation rates, recorded in spring, decreased during summer by two orders of magnitude. Granulometric segregation of settling seston along the inflow zone was related to differentiation of phoshorus content. Smaller particles were richer in P, producing a gradient of increasing P concentrations in the settling material. A substantial loss of P from polyphosphate and various organic fractions was found after settlement of river suspensoids. Mechanisms of P losses are discussed and possibilities of P retention within the inflow zone are considered.  相似文献   
3.
International Journal of Peptide Research and Therapeutics - The progressive damage of human articular cartilage is associated with loss of integrity of its extracellular matrix components. Their...  相似文献   
4.

Introduction

Systemic sclerosis (SSc) is an autoimmune disease characterized by chronic inflammation, vascular injury and excessive fibrosis. CD163 is a scavenger receptor which affects inflammatory response and may contribute to connective tissue remodelling. It has recently been demonstrated that CD163 can bind and neutralize the TNF-like weak inducer of apoptosis (TWEAK), a multifunctional cytokine which regulates inflammation, angiogenesis and tissue remodelling. We aimed to investigate the relationships between serum levels of soluble CD163 (sCD163) and soluble TWEAK (sTWEAK) in relation to disease manifestations in SSc patients.

Methods

This study included 89 patients with SSc who had not received immunosuppressive drugs or steroids for at least 6 months and 48 age- and sex-matched healthy controls (HC) from four European centres. Serum concentrations of sTWEAK and sCD163 were measured using commercially available ELISA kits.

Results

The mean serum concentrations of sTWEAK were comparable between SSc patients (mean +/- SD: 270 +/- 171 pg/mL) and HC (294 +/- 147pg/mL, P >0.05). Concentration of sCD163 and sCD163/sTWEAK ratio were significantly greater in SSc patients (984 +/- 420 ng/mL and 4837 +/- 3103, respectively) as compared to HC (823 +/- 331 ng/mL and 3115 +/- 1346 respectively, P <0.05 for both). High sCD163 levels and a high sCD163/sTWEAK ratio (defined as > mean +2SD of HC) were both associated with a lower risk of digital ulcers in SSc patients (OR, 95%CI: 0.09; 0.01, 0.71, and 0.17; 0.06, 0.51, respectively). Accordingly, patients without digital ulcers had a significantly higher sCD163 concentration and sCD163/sTWEAK ratio as compared to SSc patients with digital ulcers (P <0.01 for both) and HC (P <0.05 for both). A high sCD163/sTWEAK ratio, but not high sCD163 levels, was associated with greater skin involvement.

Conclusions

The results of our study indicate that CD163-TWEAK interactions might play a role in the pathogenesis of SSc and that CD163 may protect against the development of digital ulcers in SSc. Further studies are required to reveal whether targeting of the CD163-TWEAK pathway might be a potential strategy for treating vascular disease and/or skin fibrosis in SSc.  相似文献   
5.
Abstract

1-(β-D-Ribofuranosy1)-2(1H)-pyridone-3-carboxamide (6a) and the 6(1H)-pyridone derivative (6b) were prepared by condensation of 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose (3) with 2- and 6-hydroxynicotinic acid, respectively, to 4a and 4b, followed by conversion of the carboxylic acid function of 4a,b into their corresponding carboxamides 5, and then deprotection of 5. Bath 6a and 6b were then treated with 1,3-dichlom-1,1,3,3-tetraisopropyldisiloxane to give the corresponding 3′,5′-O-TPDS derivatives, 7a and 7b. Mesylation of 7a,b with mesyl chloride in pyridine afforded the stable, protected mesylates 8a,b. Upon de-O-silylation of 8a,b with ET3NHF gave a mixture of unprotectd mesylates 9a,b and 2,2-anhydro- and 6,2′-anhydronucleosides, 1a and 1b. Upon storage of 9a,b at man temperature, they are quantitatively converted into 1a,b. Mild alkaline hydrolysis of 1a,b afforded their corresponding arabino nucleosides 10a,b.  相似文献   
6.
Abstract

The 1-β-D-ribofuranosides of several 2-trifluoromethyl benzimidazoles were prepared by the fusion method, and their conformations, particularly about the glycosidic bond, determined by 1H NMR spectroscopy.  相似文献   
7.
Abstract

5-(β-D-Ribofuranosyl)nicotinamide (lie) and 6-(β-D-ribo-furanosyDpicolinamide (IId) and their corresponding o-isomers (III) were synthesized from ribonolactone. The C-nucleoside lie was further converted to its 5′-monophosphate Up which is isosteric to NMN Ip).  相似文献   
8.
Abstract

As an epimerization resistant synthon in the synthesis of oligo-nucleotides consisting of C-nucleoside analogues, hitherto unknown 5-benzyloxy-methyl-3-(2-deoxy-β-D-erythro-pentofuranosyl)pyrrolo[3,2-d]pyrimpyrimidine (7-benzyloxymethyl-2′-deoxy-9-deazaadenosine) was prepared in seven steps from the known 3-amino-2-cyano-4-(2,3-O-isopropylidene-5-O-trityl-β-D-ribofuranosyl)-pyrrolpyrrole (1). Treatment of 1 with benzyl chloromethyl ether in the presence of potassium t-butoxide and 18-crown-6 afforded the N-protected pyrrole 2, which was converted into the 9-deazapurine derivative 3 in high yield by heating in EtOH. 7-Benzyloxymethyl-9-deazaadenosine 4 was obtained from 3 by acid hydrolysis in 2.5% methanolic hydrogen chloride. After protection of the hydroxyl groups of 4 with Markievicz's reagent, the product 5 was converted into the 2′-O-phenoxythiocarbonyl derivative 6. Reduction of 6 with butyltin hydride in the presence of 2,2′-azobis(2-methylpropionitrile), followed by desilylation with triethylammonium fluoride, afforded the desired 7-benzyloxymethyl-2′-deoxy-9-deazaadenosine (8) in high overall yield. The benzyloxymethyl group of 8 was removed by hydrogenolysis over palladium hydroxide (Degussa type) to give 2′-deoxy-9-deazaadenosine (9) in quantitative yield. The structure of 9 is discussed.  相似文献   
9.
Nucleic acids that form G-quadruplex (G4) structure have found applications in a host of research and technology regimes. Numerous G4 based aptamer drugs have been identified with pharmacological activity against cancer, HIV, prions, and blood coagulation (1). In the field of nanotechnology, G4 based sensors and nano-machines have also received much attention. The ability to synthesize nucleic acid ex-vivo allows for the site-specific incorporation of non-natural chemistries into nucleic acids that can be used to tune their physical and pharmacological properties. We summarize the results of a series of studies investigating the effective incorporation of alternative nucleic acid chemistries into G4 DNA. These modified chemistries include C8-modified guanine bases, as well as 2′-F, 2′-F-ANA, and Locked nucleic acid (LNA) modifications to the ribose sugar. We report primarily on the effect of these modifications on G-quadruplex folding topology, thermal stability, and structure. The substitution of LNA-guanosine into the core guanine tetrads disrupts structure in specific structural environments. On the other hand, 2′-F- and 2′-F-ANA guanosine can generally be incorporated without disrupting the structure when substituted into guanine bases in certain structural conformations. We find that 2′-F-ANA-guanosine and 2′-F-guanosine are powerful tools for controling the conformation of G4 structures (2). Functionalization at the C8 of the guanine base stabilizes in a manner dependent on the glycosidic conformation of the base, with different modification chemistries stabilizing to varying extents (3). The results of these studies provide useful insight on how to effectively incorporate some useful chemical tools from the growing toolbox of modified nucleic acid chemistries into G-quadruplex nucleic acid.  相似文献   
10.

Background

Neointima forming after stent implantation consists of vascular smooth muscle cells (VSMCs) in 90%. Growth factors TGF-β1, PDGFB, EGF, bFGF and VEGF-A play an important role in VSMC proliferation and migration to the tunica intima after arterial wall injury. The aim of this paper was an analysis of functional polymorphisms in genes encoding TGF-β1, PDGFB, EGF, bFGF and VEGF-A in relation to in-stent restenosis (ISR).

Materials and Methods

265 patients with a stable coronary artery disease (SCAD) hospitalized in our center in the years 2007–2011 were included in the study. All patients underwent stent implantation at admission to the hospital and had another coronary angiography performed due to recurrence of the ailments or a positive result of the test assessing the coronary flow reserve. Angiographically significant ISR was defined as stenosis >50% in the stented coronary artery segment. The patients were divided into two groups–with angiographically significant ISR (n = 53) and without significant ISR (n = 212). Additionally, the assessment of late lumen loss (LLL) in vessel was performed. EGF rs4444903 polymorphism was genotyped using the PCR-RFLP method whilst rs1800470 (TGFB1), rs2285094 (PDGFB) rs308395 (bFGF) and rs699947 (VEGF-A) were determined using the TaqMan method.

Results

Angiographically significant ISR was significantly less frequently observed in the group of patients with the A/A genotype of rs1800470 polymorphism (TGFB1) versus patients with A/G and G/G genotypes. In the multivariable analysis, LLL was significantly lower in patients with the A/A genotype of rs1800470 (TGFB1) versus those with the A/G and G/G genotypes and higher in patients with the A/A genotype of the VEGF-A polymorphism versus the A/C and C/C genotypes. The C/C genotype of rs2285094 (PDGFB) was associated with greater LLL compared to C/T heterozygotes and T/T homozygotes.

Conclusions

The polymorphisms rs1800470, rs2285094 and rs6999447 of the TGFB1, PDGFB and VEGF-A genes, respectively, are associated with LLL in patients with SCAD treated by PCI with a metal stent implantation.  相似文献   
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