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991.
Effect of the application of selenium on selenium content of soybean and its products 总被引:3,自引:0,他引:3
Two experiments were conducted to study the effect of the application of selenium on the selenium content of soybean and its
products in two counties with selenium-deficient soil. Selenium-enriched soybean was produced by the application of sodium
selenite and Se-enriched fertilizer. The selenium contents of soybeans, soybean protein and okra were determined by hydride-generation
atomic fluorescence spectrometry. The results showed that the selenium contents of soybean, soybean protein, and okra were
significantly increased by the application of sodium selenite and selenium-enriched fertilizer. Foliar application of selenium
provided a higher efficiency for increasing the selenium content of soybean than soil application. Significant differences
were found in that soybean cultivars exhibited different accumulation of selenium. There was no remarkable difference in soybean
yield, soybean protein, and lipid between selenium and control. The selenium-enriched protein derived from selenium-enriched
soybean could be used as a functional ingredient and soybean okra as a selenium-enriched feed for animals for increasing selenium
intake. 相似文献
992.
Tetrathiomolybdate (TM), a specific copper chelator, has been shown to be a potent antiangiogenic and antimetastatic compound possibly through suppression of the NFkappaB signaling cascade. To further delineate the molecular mechanism of the anticancer effect of TM, we investigated whether TM has antineoplastic activity in the setting of genetic NFkappaB inhibition. In this study, SUM149 inflammatory breast carcinoma cells were transfected with a dominant-negative IkappaBalpha (S32AS36A) expression vector. Similar to TM-treated SUM149 cells, SUM149-IkappaBalphaMut clones secreted lower amounts of proangiogenic mediators, vascular endothelial growth factor, interleukin-1alpha, and interleukin-8 and exhibited a less invasive and motile phenotype. The reduction in the angiogenic and metastatic potential of SUM149-IkappaBalphaMut clones was not further affected by TM in vitro. SUM149-IkappaBalphaMut xenografts grew substantially slower and had less lung metastasis than SUM149 and SUM149-empty vector xenografts. The growth and metastatic potential of SUM149 and SUM149-empty tumors was significantly inhibited with systemic TM treatment, whereas TM had no further antitumor effect on the SUM149-IkappaBalphaMut tumors. Additionally, nuclear proteins isolated from TM-treated SUM149 tumors had lower NFkappaB binding activity, while AP1 and SP1 binding activities were unchanged. Taken together, these results strongly support that suppression of NFkappaB is the major mechanism used by TM to inhibit angiogenesis and metastasis. 相似文献
993.
Liau CY Chang TM Pan JP Chen WL Mao SJ 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2003,790(1-2):209-216
Haptoglobin (Hp) is an acute-phase protein; its plasma levels increase consistently in response to infection and inflammation. The concentration of human plasma Hp is ranged between 1 and 1.5 mg/ml. Similar to blood type, individual human Hp is classified as Hp 1-1, 2-1, or 2-2. The structural and functional analysis of the Hp, however, has not been studied in detail due to its difficult isolation procedure. Previously, we reported a single step for the purification of porcine Hp. In this study, we established a purification method using a high capacity hemoglobin-affinity column. Briefly, DEAE-purified human hemoglobin was first coupled to Sepharose 4B to prepare an affinity column in a 15-ml bed volume. Following a flow through of human plasma and an extensive wash, the bound material was eluted with a solution of 0.15 M NaCl, pH 11 (adjusted by ammonium), to remove low-affinity bound proteins. The high-affinity bound Hp was then eluted with 0.15 M NaCl containing 5 M urea, pH 11, and collected in tubes containing 100 microl of 1 M Tris buffer, pH 7.0. The biological activity of dialyzed Hp was retained as it formed a complex with hemoglobin on a sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Using this procedure, approximately 10 mg of Hp 1-1, with homogeneity greater than 96%, was obtained from 15 ml of human plasma. Affinity purified Hp 2-1 or 2-2, however, contained trace amounts of apoA-I with the similar approach. The Hp could be further purified by HPLC using a Superose 12 gel-permeation chromatography, if desired, to achieve 100% purity. All the phenotypes of purified Hp consisted of alpha and beta chains on SDS-PAGE in the presence of a reducing reagent, further confirmed by a Western blot analysis. We conclude that human hemoglobin-affinity column was most suitable for the isolation of Hp 1-1 in large quantities. Whereas, one additional step using a gel-permeation was necessary for that of Hp 2-1 and 2-2. 相似文献
994.
Insulin signalling is a potent stimulator of cell growth and has been proposed to function, at least in part, through the conserved protein kinase TOR (target of rapamycin) [corrected]. Recent studies suggest that the tuberous sclerosis complex Tsc1-Tsc2 may couple insulin signalling to Tor activity [corrected]. However, the regulatory mechanism involved remains unclear, and additional components are most probably involved. In a screen for novel regulators of growth, we identified Rheb (Ras homologue enriched in brain), a member of the Ras superfamily of GTP-binding proteins. Increased levels of Rheb in Drosophila melanogaster promote cell growth and alter cell cycle kinetics in multiple tissues. In mitotic tissues, overexpression of Rheb accelerates passage through G1-S phase without affecting rates of cell division, whereas in endoreplicating tissues, Rheb increases DNA ploidy. Mutation of Rheb suspends larval growth and prevents progression from first to second instar. Genetic and biochemical tests indicate that Rheb functions in the insulin signalling pathway downstream of Tsc1-Tsc2 and upstream of TOR. Levels of rheb mRNA are rapidly induced in response to protein starvation, and overexpressed Rheb can drive cell growth in starved animals, suggesting a role for Rheb in the nutritional control of cell growth. 相似文献
995.
Background
Desmoid tumors are slow growing deep fibromatoses with aggressive infiltration of adjacent tissue but without any metastatic potential. 相似文献996.
Reconfirmation of antimicrobial activity in the coelomic fluid of the earthwormEisenia fetida andrei by colorimetric assay 总被引:3,自引:0,他引:3
A novel tetrazolium salt, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium (MTS)
was used in the assessment of antimicrobial activity in earthworm in the presence of phenazine methosulphate (PMS) as an electron
coupling reagent. This activity was purified from the coelomic fluid of the earthworm (ECF),Eisenia fetida andrei (Oligochaeta, Lumbricidae, annelids) using a series of column chromatography techniques and was tested against three Gram-negative
strains ofEscherichia coli, Pseudomonas aeruginosa, Aeromonas hydrophila and three Gram-positive strains ofStaphylococcus aureus, Bacillus megaterium, Arthrobacter sp., respectively. Only the pigment-free eluate of coelomic fluid of the earthworm (ECFPE) showed activity againstB. megaterium amongst three isolated active fractions. The anion (DEAE-52) exchange effluent of the ECFPE was reported to have the strongest
activity againstP. aeruginosa amongst the three active fractions. The 20% acetonitrile eluate (AE) by Sep-Pak C18 cartridge was also tested and showed fair resistance againstE. coli, P. aeruginosa andArthrobacter sp., respectively. 相似文献
997.
Ribosomal protein L11 negatively regulates oncoprotein MDM2 and mediates a p53-dependent ribosomal-stress checkpoint pathway 总被引:9,自引:0,他引:9 下载免费PDF全文
Zhang Y Wolf GW Bhat K Jin A Allio T Burkhart WA Xiong Y 《Molecular and cellular biology》2003,23(23):8902-8912
The gene encoding p53 mediates a major tumor suppression pathway that is frequently altered in human cancers. p53 function is kept at a low level during normal cell growth and is activated in response to various cellular stresses. The MDM2 oncoprotein plays a key role in negatively regulating p53 activity by either direct repression of p53 transactivation activity in the nucleus or promotion of p53 degradation in the cytoplasm. DNA damage and oncogenic insults, the two best-characterized p53-dependent checkpoint pathways, both activate p53 through inhibition of MDM2. Here we report that the human homologue of MDM2, HDM2, binds to ribosomal protein L11. L11 binds a central region in HDM2 that is distinct from the ARF binding site. We show that the functional consequence of L11-HDM2 association, like that with ARF, results in the prevention of HDM2-mediated p53 ubiquitination and degradation, subsequently restoring p53-mediated transactivation, accumulating p21 protein levels, and inducing a p53-dependent cell cycle arrest by canceling the inhibitory function of HDM2. Interference with ribosomal biogenesis by a low concentration of actinomycin D is associated with an increased L11-HDM2 interaction and subsequent p53 stabilization. We suggest that L11 functions as a negative regulator of HDM2 and that there might exist in vivo an L11-HDM2-p53 pathway for monitoring ribosomal integrity. 相似文献
998.
999.
Biomass and porosity profiles in microbial granules used for aerobic wastewater treatment 总被引:2,自引:0,他引:2
AIMS: To obtain biomass and porosity profiles for aerobically grown granules of different diameters and to determine a suitable range of granule diameters for application in wastewater treatment. METHODS AND RESULTS: Microbial granules were cultivated in an aerobic granulated sludge reactor with model wastewaters containing acetate, or ethanol plus acetate, or glucose as the main carbon source. Granules were formed by retaining microbial aggregates using a settling time of 2 min. Sampled granules had diameters ranging from 0.45 to 3 mm. Microbial biomass in the granules was detected with the nucleic acid stain SYTO 9 and confocal laser scanning microscopy. The thickness of the microbial biomass layer was proportional to the granule diameter, and had a maximum value of 0.8 mm. The thickness of the microbial biomass layer correlated with the penetration depth of 0.1 microm fluorescent beads into the granule. CONCLUSIONS: The microbial biomass and porosity studies suggest that aerobically grown microbial granules should have diameters less than a critical diameter of 0.5 mm, if deployed for wastewater treatment applications. This critical diameter is based on the assumption that whole granules should have a porous biomass-filled matrix. SIGNIFICANCE AND IMPACT OF THE STUDY: This work could contribute to the development of aerobic granulation technology for effective biological wastewater treatment. 相似文献
1000.
Huang Y Ding ZH Liu JK 《Zeitschrift für Naturforschung. C, Journal of biosciences》2003,58(5-6):347-350
A new highly oxygenated flavone, namely 8,3'-dihydroxy-5,6,7,4'-tetramethoxyflavone (1), together with other five known flavonoids were isolated from the tropical plant Vernonia saligna. Their structures were established on the basis of spectral (MS, IR, UV, 1D & 2D NMR) measurement and chemical evidence. 相似文献