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排序方式： 共有98条查询结果，搜索用时 15 毫秒
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2.
Background
a decline in immune and endocrine function occurs with aging. The main purpose of this study was to investigate the impact of long-term endurance training on the immune and endocrine system of elderly men. The possible interaction between these systems was also analysed. 相似文献3.
Substitute methadone prescribing is one of the main modes of treatment for opiate dependence. This study examined the relationship between methadone dose (measured by daily dose and methadone's active (R)‐enantiomer blood levels) and opiate receptor function. Nine subjects on substitute methadone (30‐90 mg daily) received three subcutaneous injections 1.5 hours apart (saline, 5 mg and 10 mg hydromorphone, a short‐acting opiate agonist) followed by measures of functional response in particular saccadic eye movements (SEMs), as well as self‐report measures. Ten mg of hydromorphone significantly slowed SEM parameters (peak velocity by 15%, p <0.005; peak acceleration by 20%, p <0.025; peak deceleration by 26%, p <0.025) and the SEM velocity changes correlated significantly with (R)‐methadone levels (r =0.844, p <0.005) and with the oral dose of methadone being taken (r =0.829, p <0.005). Although a similar trend was observed for 5 mg, this was not significant. These finding suggest that, at higher methadone doses (resulting in higher plasma concentrations), there is significant tolerance to the action of agonists. Such studies may help in refining our understanding of the actions of methadone and the SEM measure could help in defining the degree of tolerance in individuals using street heroin. 相似文献
4.
Delarbre C; Kashi Y; Boursot P; Beckmann JS; Kourilsky P; Bonhomme F; Gachelin G 《Molecular biology and evolution》1988,5(2):120-133
We have examined the phylogenetic distribution of two t-specific markersamong representatives of various taxa belonging to the genus Mus. Thecentromeric TCP-1a marker (a testicular protein variant specific for allt-haplotypes so far studied) has also been apparently detected in severalnon-t representatives of the Mus IVA, Mus IVB, and probably M. cervicolorspecies. By contrast, a t-specific restriction- fragment-lengthpolymorphism allele (RFLP) of the telomeric alpha- globin pseudogene DNAmarker alpha-psi-4 was found only in animals belonging to the M.musculus-complex species either bearing genuine t- haplotypes or, like theM. m. bactrianus specimen studied here, likely to do so. This t-specificalpha-psi-4 RFLP allele was found to be as divergent from the RFLP allelesof the latter, non-t, taxonomical groups as it is from Mus 4A, Mus 4B, orM. spretus ones. These results suggest the presence of t-haplotypes and oft-specific markers in populations other than those belonging to the M. m.domesticus and M. m. musculus subspecies, implying a possible origin fort-haplotypes prior to the radiation of the most recent offshoot of the Musgenus (i.e., the spretus/domesticus divergence), some 1-3 Myr ago. 相似文献
5.
The results described in the accompanying article support the model inwhich glucosylphosphoryldolichol (Glc-P-Dol) is synthesized on thecytoplasmic face of the ER, and functions as a glucosyl donor for threeGlc-P-Dol:Glc0-2Man9-GlcNAc2-P-P-Dol glucosyltransferases (GlcTases) in thelumenal compartment. In this study, the enzymatic synthesis and structuralcharacterization by NMR and electrospray-ionization tandem massspectrometry of a series of water-soluble beta-Glc-P-Dol analogs containing2-4 isoprene units with either the cis - or trans - stereoconfiguration inthe beta-position are described. The water- soluble analogs were (1) usedto examine the stereospecificity of the Glc-P-Dol:Glc0-2Man9GlcNAc2-P-P-Dolglucosyltransferases (GlcTases) and (2) tested as potential substrates fora membrane protein(s) mediating the transbilayer movement of Glc-P-Dol insealed ER vesicles from rat liver and pig brain. The Glc-P-Dol-mediatedGlcTases in pig brain microsomes utilized [3H]Glc-labeled Glc-P-Dol10,Glc-P-(omega, c )Dol15, Glc-P(omega, t,t )Dol20, and Glc-P-(omega, t,c)Dol20as glucosyl donors with [3H]Glc3Man9GlcNAc2-P-P-Dol the major productlabeled in vitro. A preference was exhibited for C15-20 substratescontaining an internal cis -isoprene unit in the beta-position. Inaddition, the water-soluble analog, Glc-P-Dol10, was shown to enter thelumenal compartment of sealed microsomal vesicles from rat liver and pigbrain via a protein-mediated transport system enriched in the ER. Theproperties of the ER transport system have been characterized. Glc-P-Dol10was not transported into or adsorbed by synthetic PC-liposomes orbovine erythrocytes. The results of these studies indicate that (1) theinternal cis -isoprene units are important for the utilization of Glc-P-Dolas a glucosyl donor and (2) the transport of the water- soluble analog mayprovide an experimental approach to assay the hypothetical \"flippase\"proposed to mediate the transbilayer movement of Glc-P-Dol from thecytoplasmic face of the ER to the lumenal monolayer. 相似文献
6.
Francisco Martínez Sandra Monfort Mónica Roselló Silvestre Oltra David Blesa Ramiro Quiroga Sonia Mayo Carmen Orellana 《BMC medical genomics》2010,3(1):1-6
Background
In translational cancer research, gene expression data is collected together with clinical data and genomic data arising from other chip based high throughput technologies. Software tools for the joint analysis of such high dimensional data sets together with clinical data are required.Results
We have developed an open source software tool which provides interactive visualization capability for the integrated analysis of high-dimensional gene expression data together with associated clinical data, array CGH data and SNP array data. The different data types are organized by a comprehensive data manager. Interactive tools are provided for all graphics: heatmaps, dendrograms, barcharts, histograms, eventcharts and a chromosome browser, which displays genetic variations along the genome. All graphics are dynamic and fully linked so that any object selected in a graphic will be highlighted in all other graphics. For exploratory data analysis the software provides unsupervised data analytics like clustering, seriation algorithms and biclustering algorithms.Conclusions
The SEURAT software meets the growing needs of researchers to perform joint analysis of gene expression, genomical and clinical data. 相似文献7.
M. A. Rodrigo X. Armengol‐Díaz R. Oltra M. J. Dasí W. Colom 《International Review of Hydrobiology》2001,86(3):299-315
The annual cycle of physical and chemical variables and plankton dynamics was studied in two shallow ponds (East and West Ponds) of the El Hondo wetland, an ecosystem of international importance. Water conductivity increased up to 31–49 mS cm–1 as water level decreased due to high evaporation and minimal water inputs. Initially considered mesohaline, the waters were reclassified as polyhaline during the hot season. EP was subject to successive desiccation‐flooding cycles, and flooding of the dried sediment caused the release of high concentrations of nitrogen and phosphorus compounds, which quickly depleted. The algal species composition was typical of eutrophic ecosystems, and the chlorophyll content indicated that EP was eutrophic and WP mesotrophic. Phytoplanktonic species richness and diversity were low in both ponds. Algal assemblages, in terms of biovolume, were mainly dominated by Dinophyceae in EP and by Cryptophyta in WP. The zooplankton community was dominated by Rotifers (Brachionus and Hexarthra), although Copepods and Ciliates were also important. Different water inputs to the ponds, partial drying in EP during the warm season with the subsequent higher increment of salinity, and the presence of dense populations of submerged macrophytes in WP, explain the differences in plankton communities found between the two ponds. 相似文献
8.
Motile extracts have been prepared from Dictyostelium discoideum by homogenization and differential centrifugation at 4 degrees C in a stabilization solution (60). These extracts gelled on warming to 25 degrees Celsius and contracted in response to micromolar Ca++ or a pH in excess of 7.0. Optimal gelation occurred in a solution containing 2.5 mM ethylene glycol-bis (β-aminoethyl ether)N,N,N',N'-tetraacetate (EGTA), 2.5 mM piperazine-N-N'-bis [2-ethane sulfonic acid] (PIPES), 1 mM MgC1(2), 1 mM ATP, and 20 mM KCI at ph 7.0 (relaxation solution), while micromolar levels of Ca++ inhibited gelation. Conditions that solated the gel elicited contraction of extracts containing myosin. This was true regardless of whether chemical (micromolar Ca++, pH >7.0, cytochalasin B, elevated concentrations of KCI, MgC1(2), and sucrose) or physical (pressure, mechanical stress, and cold) means were used to induce solation. Myosin was definitely required for contraction. During Ca++-or pH-elicited contraction: (a) actin, myosin, and a 95,000-dalton polypeptide were concentrated in the contracted extract; (b) the gelation activity was recovered in the material sqeezed out the contracting extract;(c) electron microscopy demonstrated that the number of free, recognizable F-actin filaments increased; (d) the actomyosin MgATPase activity was stimulated by 4- to 10-fold. In the absense of myosin the Dictyostelium extract did not contract, while gelation proceeded normally. During solation of the gel in the absense of myosin: (a) electron microscopy demonstrated that the number of free, recognizable F- actin filaments increased; (b) solation-dependent contraction of the extract and the Ca++-stimulated MgATPase activity were reconstituted by adding puried Dictyostelium myosin. Actin purified from the Dictyostelium extract did not gel (at 2 mg/ml), while low concentrations of actin (0.7-2 mg/ml) that contained several contaminating components underwent rapid Ca++ regulated gelation. These results indicated : (a) gelation in Dictyostelium extracts involves a specific Ca++-sensitive interaction between actin and several other components; (b) myosin is an absolute requirement for contraction of the extract; (c) actin-myosin interactions capable of producing force for movement are prevented in the gel, while solation of the gel by either physical or chemical means results in the release of F-actin capable of interaction with myosin and subsequent contraction. The effectiveness of physical agents in producting contraction suggests that the regulation of contraction by the gel is structural in nature. 相似文献
9.
Mar&# a B Monz&# n-Nomdedeu Karl J Morten Elisa Oltra 《World journal of stem cells》2021,13(8):1134-1150
10.
David Weinkove Juan Angel Poyatos Heribert Greiner Enrique Oltra Javier Avalos Leonid Fukshansky Alejandro F. Barrero Enrique Cerdá-Olmedo 《Fungal genetics and biology : FG & B》1998,25(3):196-203
Weinkove, D., Poyatos, J. A., Greiner, H., Oltra, E., Avalos, J., Fukshansky, L., Barrero, A. F., and Cerdá-Olmedo, E. 1998. Mutants ofPhycomyceswith decreased gallic acid content.Fungal Genetics and Biology25, 196–203. Most plants and some fungi accumulate phenols. Two hydroxybenzoic acids, gallic and protocatechuic acids, are abundant in the giant sporangiophores of the zygomycetePhycomyces blakesleeanus,much more so than in the basal mycelium or the culture medium. The actual concentrations vary with illumination, age of the culture, and composition of the medium. We devised a simple screening procedure to isolatehbamutants whose sporangiophores contained less gallic acid than the wild type. The most useful mutant had very low concentrations of hydroxybenzoic acids in the sporangiophores, but about the same as the wild type in the basal mycelium and the medium. The mutant was only slightly different from the wild type in growth and morphology. Mutant and wild-type sporangiophores grew away from ultraviolet C sources (260 nm) equally well. Contrary to previous conjectures, ultraviolet tropism does not depend on the ultraviolet absorption of gallic acid or other free hydroxybenzoic acids in the sporangiophore. Against expectations, phenols did not impair DNA extraction: sporangiophores produced better DNA preparations than basal mycelia and thehbamutant only slightly better than the wild type. 相似文献