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排序方式: 共有178条查询结果,搜索用时 15 毫秒
61.
Minho Moon Hyo Geun Kim Jin Gyu Choi Hyein Oh Paula KJ Lee Sang Keun Ha Sun Yeou Kim Yongkon Park Youngbuhm Huh Myung Sook Oh 《Biochemical and biophysical research communications》2014
Recently, increased attention has been directed towards medicinal extracts as potential new drug candidates for dementia. Ginger has long been used as an important ingredient in cooking and traditional herbal medicine. In particular, ginger has been known to have disease-modifying effects in Alzheimer's disease (AD). However, there is no evidence of which constituents of ginger exhibit therapeutic effects against AD. A growing number of experimental studies suggest that 6-shogaol, a bioactive component of ginger, may play an important role as a memory-enhancing and anti-oxidant agent against neurological diseases. 6-Shogaol has also recently been shown to have anti-neuroinflammatory effects in lipopolysaccharide (LPS)-treated astrocytes and animal models of Parkinson’s disease, LPS-induced inflammation and transient global ischemia. However, it is still unknown whether 6-shogaol has anti-inflammatory effects against oligomeric forms of the Aβ (AβO) in animal brains. Furthermore, the effects of 6-shogaol against memory impairment in dementia models are also yet to be investigated. In this study, we found that administration of 6-shogaol significantly reduced microgliosis and astrogliosis in intrahippocampal AβO-injected mice, ameliorated AβO and scopolamine-induced memory impairment, and elevated NGF levels and pre- and post-synaptic marker in the hippocampus. All these results suggest that 6-shogaol may play a role in inhibiting glial cell activation and reducing memory impairment in animal models of dementia. 相似文献
62.
Nathan J. Wittenberg Timothy W. Johnson Luke R. Jordan Xiaohua Xu Arthur E. Warrington Moses Rodriguez Sang-Hyun Oh 《Journal of visualized experiments : JoVE》2014,(87)
Lipid bilayer membranes form the plasma membranes of cells and define the boundaries of subcellular organelles. In nature, these membranes are heterogeneous mixtures of many types of lipids, contain membrane-bound proteins and are decorated with carbohydrates. In some experiments, it is desirable to decouple the biophysical or biochemical properties of the lipid bilayer from those of the natural membrane. Such cases call for the use of model systems such as giant vesicles, liposomes or supported lipid bilayers (SLBs). Arrays of SLBs are particularly attractive for sensing applications and mimicking cell-cell interactions. Here we describe a new method for forming SLB arrays. Submicron-diameter SiO2 beads are first coated with lipid bilayers to form spherical SLBs (SSLBs). The beads are then deposited into an array of micro-fabricated submicron-diameter microwells. The preparation technique uses a "squeegee" to clean the substrate surface, while leaving behind SSLBs that have settled into microwells. This method requires no chemical modification of the microwell substrate, nor any particular targeting ligands on the SSLB. Microwells are occupied by single beads because the well diameter is tuned to be just larger than the bead diameter. Typically, more 75% of the wells are occupied, while the rest remain empty. In buffer SSLB arrays display long-term stability of greater than one week. Multiple types of SSLBs can be placed in a single array by serial deposition, and the arrays can be used for sensing, which we demonstrate by characterizing the interaction of cholera toxin with ganglioside GM1. We also show that phospholipid vesicles without the bead supports and biomembranes from cellular sources can be arrayed with the same method and cell-specific membrane lipids can be identified. 相似文献
63.
This paper describes the development of a novel optically interrogated enzyme electrode with generic applicability for NAD(P) dependent enzymes. The example reported here employs a multi-enzyme pathway comprising the enzymes pyruvate kinase, hexokinase, glucose-6-phosphate dehydrogenase and diaphorase. The final substrate of this pathway, dichlorophenol indophenol (DCPIP), was immobilised within an ultra-thin polymer film of o-phenylenediamine, itself electrochemically polymerised onto a conductive gold coating on the surface of a support polyethylene sheet. Dichlorophenol indophenol (DCPIP) absorbs within the visible region of the spectrum with a lambda(max) approximately 600 nm. When reduced, the molar absorption coefficient at this wavelength decreases significantly and DCPIP effectively becomes colourless (DCPIPH(3)). Ultra-thin layers of gold (<10 nm thickness) exhibit an optical absorption minimum at wavelengths of approximately 520 nm and therefore light within this region of the spectrum may be transmitted with relative ease through the polymer/gold/polyethylene optrode. Results presented within this paper show how this electro-optical sensor may be used to determine concentrations of adenosine triphosphate (ATP) within a sample. In the presence of ATP a colour change from blue to colourless was observed for DCPIP when the assay was performed in solution. However, when DCPIP was immobilised within a polymeric film onto the surface of gold coated electrodes, a colour change from blue to red was observed corresponding to a third redox state of DCPIP (DCPIPH). 相似文献
64.
Susan M. Jojola Frank Rosell Ian Warrington Jon E. Swenson Andreas Zedrosser 《Mammalian Biology》2012,77(5):363-368
Olfactory cues have been investigated in social carnivores, many of which use anal/anogenital gland secretion (AGS) for scent marking. However, little is known about how solitary carnivores, such as ursids, use AGS in communication. We hypothesized that subadult (1–3 years) brown bears (Ursus arctos) have the ability to discriminate between unfamiliar adult male and female AGS. Confrontations, especially with adult males, carry high risks for dispersing subadults, so they benefit from the ability to assess potential threats based on olfactory cues, including sex, enabling them to avoid risky encounters. We presented AGS from free-ranging adult brown bears (male = 10, female = 10) to subadult brown bears (male = 13, female = 7) in outdoor zoo experiments, and predicted that subadults would avoid male more than female AGS. Neither male nor female AGS were avoided, but subadults quickly habituated to female AGS. However, male AGS was investigated more intensively and the subadults delayed revisiting it. Subadult tended to take longer to complete 6 visits to male than female AGS, which indicated sexual discrimination. We suggest that subadults that store information for the purpose of scent matching in future encounters may reduce their potential costs of conflict based on their prior assessment of the likely outcome of the encounter. 相似文献
65.
Warrington CV Zhu S Parrott WA All JN Boerma HR 《Journal of economic entomology》2008,101(4):1471-1477
The development of superior soybean, Glycine max (L.) Merr., cultivars exhibiting resistance to insects has been hindered due to linkage drag, a common phenomenon when introgressing alleles from exotic germplasm. Simple-sequence repeat (SSR) markers were used previously to map soybean insect resistance (SIR) quantitative trait loci (QTLs) in a'Cobb' X PI 229358 population, and subsequently used to create near-isogenic lines (NILs) with SIR QTL i n a 'Benning' genetic background. SIR QTLs were mapped on linkage groups (LGs) M (SIRQTL-M), G (SIRQTL-G), and H (SIRQTL-H). The objectives of this study were to 1) evaluate linkage drag for seed yield by using Benning-derived NILs selected for SIRQTL-M, SIRQTL-H, and SIRQTL-G; 2) assess the amount of PI 229358 genome surrounding the SIR QTL in each Benning NIL; and 3) evaluate the individual effects these three QTLs on antibiosis and antixenosis to corn earworm, Helicoverpa zea (Boddie), and soybean looper, Pseudoplusia includens (Walker). Yield data collected in five environments indicated that a significant yield reduction is associated with SIRQTL-G compared with NILs without SIR QTL. Overall, there was no yield reduction associated with SIRQTL-M or SIRQTL-H. A significant antixenosis and antibiosis effect was detected for SIRQTL-M in insect feeding assays, with no effect detected in antixenosis or antibiosis assays for SIRQTL-G or SIRQTL-H without the presence of PI 229358 alleles at SIRQTL-M. These results support recent findings concerning these loci. 相似文献
66.
Lawlor DA Harbord RM Timpson NJ Lowe GD Rumley A Gaunt TR Baker I Yarnell JW Kivimäki M Kumari M Norman PE Jamrozik K Hankey GJ Almeida OP Flicker L Warrington N Marmot MG Ben-Shlomo Y Palmer LJ Day IN Ebrahim S Smith GD 《PloS one》2008,3(8):e3011
Background
It is unclear whether C-reactive protein (CRP) is causally related to coronary heart disease (CHD). Genetic variants that are known to be associated with CRP levels can be used to provide causal inference of the effect of CRP on CHD. Our objective was to examine the association between CRP genetic variant +1444C>T (rs1130864) and CHD risk in the largest study to date of this association.Methods and Results
We estimated the association of CRP genetic variant +1444C>T (rs1130864) with CRP levels and with CHD in five studies and then pooled these analyses (N = 18,637 participants amongst whom there were 4,610 cases). CRP was associated with potential confounding factors (socioeconomic position, physical activity, smoking and body mass) whereas genotype (rs1130864) was not associated with these confounders. The pooled odds ratio of CHD per doubling of circulating CRP level after adjustment for age and sex was 1.13 (95%CI: 1.06, 1.21), and after further adjustment for confounding factors it was 1.07 (95%CI: 1.02, 1.13). Genotype (rs1130864) was associated with circulating CRP; the pooled ratio of geometric means of CRP level among individuals with the TT genotype compared to those with the CT/CC genotype was 1.21 (95%CI: 1.15, 1.28) and the pooled ratio of geometric means of CRP level per additional T allele was 1.14 (95%CI: 1.11, 1.18), with no strong evidence in either analyses of between study heterogeneity (I2 = 0%, p>0.9 for both analyses). There was no association of genotype (rs1130864) with CHD: pooled odds ratio 1.01 (95%CI: 0.88, 1.16) comparing individuals with TT genotype to those with CT/CC genotype and 0.96 (95%CI: 0.90, 1.03) per additional T allele (I2<7.5%, p>0.6 for both meta-analyses). An instrumental variables analysis (in which the proportion of CRP levels explained by rs1130864 was related to CHD) suggested that circulating CRP was not associated with CHD: the odds ratio for a doubling of CRP level was 1.04 (95%CI: 0.61, 1.80).Conclusions
We found no association of a genetic variant, which is known to be related to CRP levels, (rs1130864) and having CHD. These findings do not support a causal association between circulating CRP and CHD risk, but very large, extended, genetic association studies would be required to rule this out. 相似文献67.
Marie S. Rye Nicole M. Warrington Elizabeth S. H. Scaman Shyan Vijayasekaran Harvey L. Coates Denise Anderson Craig E. Pennell Jenefer M. Blackwell Sarra E. Jamieson 《PloS one》2012,7(10)
Background
Otitis media (OM) is a common childhood disease characterised by middle ear inflammation and effusion. Susceptibility to recurrent acute OM (rAOM; ≥3 episodes of AOM in 6 months) and chronic OM with effusion (COME; MEE ≥3 months) is 40–70% heritable. Few underlying genes have been identified to date, and no genome-wide association study (GWAS) of OM has been reported.Methods and Findings
Data for 2,524,817 single nucleotide polymorphisms (SNPs; 535,544 quality-controlled SNPs genotyped by Illumina 660W-Quad; 1,989,273 by imputation) were analysed for association with OM in 416 cases and 1,075 controls from the Western Australian Pregnancy Cohort (Raine) Study. Logistic regression analyses under an additive model undertaken in GenABEL/ProbABEL adjusting for population substructure using principal components identified SNPs at CAPN14 (rs6755194: OR = 1.90; 95%CI 1.47–2.45; Padj-PCA = 8.3×10−7) on chromosome 2p23.1 as the top hit, with independent effects (rs1862981: OR = 1.60; 95%CI 1.29–1.99; Padj-PCA = 2.2×10−5) observed at the adjacent GALNT14 gene. In a gene-based analysis in VEGAS, BPIFA3 (PGene = 2×10−5) and BPIFA1 (PGene = 1.07×10−4) in the BPIFA gene cluster on chromosome 20q11.21 were the top hits. In all, 32 genomic regions show evidence of association (Padj-PCA<10−5) in this GWAS, with pathway analysis showing a connection between top candidates and the TGFβ pathway. However, top and tag-SNP analysis for seven selected candidate genes in this pathway did not replicate in 645 families (793 affected individuals) from the Western Australian Family Study of Otitis Media (WAFSOM). Lack of replication may be explained by sample size, difference in OM disease severity between primary and replication cohorts or due to type I error in the primary GWAS.Conclusions
This first discovery GWAS for an OM phenotype has identified CAPN14 and GALNT14 on chromosome 2p23.1 and the BPIFA gene cluster on chromosome 20q11.21 as novel candidate genes which warrant further analysis in cohorts matched more precisely for clinical phenotypes. 相似文献68.
Two soluble glycosyltransferases glycosylate less efficiently in vivo than their membrane bound counterparts 总被引:2,自引:1,他引:1
Zhu G; Allende ML; Jaskiewicz E; Qian R; Darling DS; Worth CA; Colley KJ; Young WW Jr 《Glycobiology》1998,8(8):831-840
Many Golgi glycosyltransferases are type II membrane proteins which are
cleaved to produce soluble forms that are released from cells. Cho and
Cummings recently reported that a soluble form of alpha1, 3-
galactosyltransferase was comparable to its membrane bound counterpart in
its ability to galactosylate newly synthesized glycoproteins (Cho,S.K. and
Cummings,R.D. (1997) J. Biol. Chem., 272, 13622-13628). To test the
generality of their findings, we compared the activities of the full length
and soluble forms of two such glycosyltransferases, ss1,4
N-Acetylgalactosaminyltransferase (GM2/GD2/ GA2 synthase; GalNAcT) and beta
galactoside alpha2,6 sialyltransferase (alpha2,6-ST; ST6Gal I), for
production of their glycoconjugate products in vivo . Unlike the full
length form of GalNAcT which produced ganglioside GM2 in transfected cells,
soluble GalNAcT did not produce detectable GM2 in vivo even though it
possessed in vitro GalNAcT activity comparable to that of full length
GalNAcT. When compared with cells expressing full length alpha2,6-ST, cells
expressing a soluble form of alpha2,6-ST contained 3-fold higher
alpha2,6-ST mRNA levels and secreted 7-fold greater alpha2,6-ST activity as
measured in vitro , but in striking contrast contained 2- to 4-fold less of
the alpha2,6-linked sialic acid moiety in cellular glycoproteins in vivo .
In summary these results suggest that unlike alpha1,3-galactosyltransferase
the soluble forms of these two glycosyltransferases are less efficient at
glycosylation of membrane proteins and lipids in vivo than their membrane
bound counterparts.
相似文献
69.
J A Wilkins L Sigurdson Y Jordon W J Rutherford R J Warrington 《Cellular immunology》1983,77(2):329-337
It has been demonstrated that the human histiocytic lymphoma-derived cell line U937, which has monocytoid characteristics, responds to a concanavalin A-induced T-cell-derived suppressor supernatant (T-SFS) with the release of a factor markedly suppressing mitogen-stimulated proliferation of normal peripheral blood lymphocytes. The suppressor material is not dialyzable, appears within 2 hr of exposure of U937 cells to the T-SFS, persists for at least 24 hr, and has a Mr of approximately 40,000 by gel chromatography. The suppressor factor does not affect the proliferation of continuous T- and B-lymphoid cell lines, distinguishing it from the inhibitor of DNA synthesis also released by U937, but appears to be specific for a stage of activation of normal lymphocytes that is independent of (a) utilization of interleukin-2 and (b) inhibition of production of interleukin-2. 相似文献
70.
Detection of Foot-and-Mouth Disease Virus Antibodies: II. Use of Fractionated Bovine Antisera for Improving the Specificity of a “Passive” Hemagglutination Test1 下载免费PDF全文
Because 7S immunoglobulin (Ig) G antibodies of low type specificity were present in mixtures with highly specific 19S IgM antibodies, many bovine antisera to foot-and-mouth disease virus (FMDV) type A(12), strain 119 cross-reacted with type O of FMDV and to some degree with type C in the passive hemagglutination (HA) test. After 19S IgM antibodies were separated by density gradient centrifugation or precipitated with 4% (w/v) polyethylene glycol, the antigen could be determined with "block" HA tests. Such tests used several antigen concentrations in the titration of each antiserum. Adding 4% (w/v) polyethylene glycol to the serum was especially convenient for rapid precipitation of 19S IgM antibodies for the test. Similar results were obtained with bovine 19S IgM antibodies to FMDV type O, subtype 1, strain Caseros and type C strain Rezende. 相似文献