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排序方式: 共有634条查询结果,搜索用时 477 毫秒
71.
Panayiotidis MI Stabler SP Allen RH Ahmad A White CW 《Chemico-biological interactions》2004,147(1):87-97
The effect of cigarette smoke extract (CSE) on S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), and sulfur amino acid metabolism was examined in human lung epithelial-like (A549) cells exposed to various CSE concentrations (2.5-100%) for 24 or 48 h. Intracellular SAM and SAM/SAH ratio were elevated after exposure to CSE for 48 h. Cell SAH content decreased, but the effect was not consistent. Cellular cystathionine, cysteine, and methionine levels were increased after CSE exposure for 48h. Sub-acute exposure to CSE induced increases in cellular SAM and SAM/SAH ratio. The transsulfuration pathway was likely activated by CSE since cystathionine increased, potentially contributing to the increased total intracellular GSH content. 相似文献
72.
Lian ZX Kikuchi K Yang GX Ansari AA Ikehara S Gershwin ME 《Journal of immunology (Baltimore, Md. : 1950)》2004,173(8):5283-5289
Patients with systemic lupus erythematosus have elevated IFN-alpha production. Furthermore, sera IFN-alpha levels correlate with disease activity. We have focused our attention on whether this phenotype is also seen in the New Zealand Black (NZB) mice and simultaneously addressed the underlying mechanisms. Specifically, we analyzed: 1) levels of sera IFN-alpha after type A CpG ODN 2216 injection in autoimmunity-prone NZB and control mice, and 2) levels of IFN-alpha synthesized by IFN-alpha-producing dendritic cells (IPDCs) using highly enriched populations of CD11c+B220+ IPDCs derived from NZB and control mice; IPDCs are divided into two subpopulations (CD4+CD11c+B220+ and CD4-CD11c+B220+). Our data demonstrate that NZB mice produced higher levels of sera IFN-alpha after type A CpG ODN 2216 injection when compared with control mice (p < 0.01). In addition, the cell numbers, frequency, and TLR9 mRNA levels of CD4+ and CD4- IPDC were markedly increased in the bone marrow (BM) of NZB mice. Upon in vitro stimulation with TLR9 ligand-CpG ODN 2216, higher levels of IFN-alpha were synthesized by IPDCs from the BM of NZB. The major contributor of IFN-alpha was the CD4-CD11c+B220+ IPDC subpopulation. Furthermore, NZB BM IPDCs manifest impaired expression of homing chemokine CCR7 and CD62L, and IL-12 production. These data on the functional characteristics of the IPDC lineages explain in part the mechanism of hyper-IFN-alpha production and help clarify the mechanism for the expansion of NZB BM IPDCs. 相似文献
73.
74.
Genomic analysis of the rhg1 locus: candidate genes that underlie soybean resistance to the cyst nematode 总被引:1,自引:0,他引:1
Ruben E Jamai A Afzal J Njiti VN Triwitayakorn K Iqbal MJ Yaegashi S Bashir R Kazi S Arelli P Town CD Ishihara H Meksem K Lightfoot DA 《Molecular genetics and genomics : MGG》2006,276(6):503-516
The rhg1 gene or genes lie at a recessive or co-dominant locus, necessary for resistance to all Hg types of the soybean (Glycine max (L.) Merr.) cyst nematode (Heterodera glycines I.). The aim here was to identify nucleotide changes within a candidate gene found at the rhg1 locus that were capable of altering resistance to Hg types 0 (race 3). A 1.5 ± 0.25 cM region of chromosome 18 (linkage group G) was shown to encompass rhg1 using recombination events from four near isogenic line populations and nine DNA markers. The DNA markers anchored two bacterial artificial chromosome (BAC) clones 21d9 and 73p6. A single receptor like kinase (RLK; leucine rich repeat-transmembrane-protein kinase) candidate resistance gene was amplified from both BACs using redundant primers. The DNA sequence showed nine alleles of the RLK at Rhg1 in the soybean germplasm. Markers designed to detect alleles showed perfect association between allele 1 and resistance to soybean cyst nematode Hg types 0 in three segregating populations, fifteen additional selected recombination events and twenty-two Plant Introductions. A quantitative trait nucleotide in the RLK at rhg1 was inferred that alters A47 to V47 in the context of H297 rather than N297. Contiguous DNA sequence of 315 kbp of chromosome 18 (about 2 cM) contained additional gene candidates that may modulate resistance to other Hg-types including a variant laccase, a hydrogen-sodium ion antiport and two proteins of unknown function. A molecular basis for recessive and co-dominant resistance that involves interactions among paralagous disease-resistance genes was inferred that would improve methods for developing new nematode-resistant soybean cultivars.Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
75.
This article investigates enhancement of the dissolution profile of valdecoxib using solid dispersion with PVP. The article
also describes the preparation of fast-dissolving tablets of valdecoxib by using a high amount of superdisintegrants. A phase
solubility method was used to evaluate the effect of various water-soluble polymers on aqueous solubility of valdecoxib. Polyvinyl
pyrrolidone (PVP K-30) was selected and solid dispersions were prepared by the method of kneading. Dissolution studies, using
the USP paddle method were performed for solid dispersions of valdecoxib. Infrared (IR) spectroscopy, differential scanning
calorimetry (DSC), and x-ray diffractometry (XRD) were performed to identify the physicochemical interaction between drug
and carrier, hence its effect on dissolution. Tablets were formulated containing solid dispersion products and compared with
commercial products. IR spectroscopy, XRD, and DSC showed no change in the crystal structure of valdecoxib. Dissolution of
valdecoxib improved significantly in solid dispersion products (<85% in 5 minutes). Tablets containing solid dispersion exhibited
better dissolution profile than commercial tablets. Thus, the solid dispersion technique can be successfully used for improvement
of dissolution of valdecoxib.
Published: August 18, 2006 相似文献
76.
77.
Porntip Chaichompoo Pavel Bostik Susan Stephenson Jaruda Kobkitjaroen Aftab A. Ansari 《Cellular immunology》2010,263(2):176-187
Innate immune mechanisms play a deterministic role in the rate of disease progression during acute infection in HIV infected humans and SIV infection of non-human primates. The role NK cells play in mediating such an effect has thus gained importance. One of the major sets of molecules that regulate NK cell function are the killer cell immunoglobulin-like molecules (KIR’s). Our laboratory has previously shown an association of KIR3DL alleles 13 and 14 with high plasma viral loads in a cohort of SIV-infected rhesus macaques. To gain a more detailed understanding of the role of KIR polymorphisms, our laboratory herein conducted studies of three additional KIR loci and show that select KIR3DH alleles appear to be more strongly associated with high plasma viral loads than KIR3DL alleles 13 and 14. In addition, we herein document the existence of additional new alleles for the KIR1D, KIR2DL4, and the KIR3DH loci. 相似文献
78.
79.
Systems biology needs to show practical relevance to commercial biological challenges such as those of pharmaceutical development. The aim of this work is to design and validate some applications in anti-cancer therapeutic development. The test system was a group of novel cyclin-dependent kinase (CDK) inhibitors synthesised by Cyclacel Ltd. The measured in vitro IC50s of each compound were used as input data to a proprietary cell cycle model developed by Physiomics plc. The model was able to predict over three orders of magnitude the cytotoxicity of each compound without model adaptation to specific cancer cell types. This pattern matched the experimentally determined data. One class of compounds was predicted to cause an increase of the cell cycle length with a non-linear dose-response curve. Further work will use apoptosis and DNA replication simulations to look at overall cell effects. 相似文献
80.
Ahmad B Khan H Bashir S Ali M 《Journal of enzyme inhibition and medicinal chemistry》2006,21(6):765-769
The methanolic extract of the corms of Colchicum luteum Baker (Liliaceae) and its subsequent fractions in different solvent systems were screened for antibacterial and antifungal activities. The crude extract and all the fractions demonstrated moderate to excellent antifungal activities against tested pathogens in antifungal bioassay. Excellent antifungal activity was shown against trichophyton longifusus, up to 75%, and microsporum canis, up to 85%, while the crude extract and subsequent fractions showed mild to moderate activities in an antibacterial bioassay with maximum antibacterial activity 58% against Bacillus subtilis. 相似文献