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排序方式: 共有467条查询结果,搜索用时 15 毫秒
91.
Dana Horakova Robert Zivadinov Bianca Weinstock-Guttman Eva Havrdova Jun Qu Miriam Tama?o-Blanco Darlene Badgett Michaela Tyblova Niels Bergsland Sara Hussein Laura Willis Jan Krasensky Manuela Vaneckova Zdenek Seidl Petra Lelkova Michael G. Dwyer Ming Zhang Haoying Yu Xiaotao Duan Tomas Kalincik Murali Ramanathan 《PloS one》2013,8(1)
Objectives
To investigate the associations of environmental MS risk factors with clinical and MRI measures of progression in high-risk clinically isolated syndromes (CIS) after the first demyelinating event.Methods
We analyzed 211 CIS patients (age: 28.9±7.8 years) enrolled in the SET study, a multi-center study of high-risk CIS patients. Pre-treatment samples were analyzed for IgG antibodies against cytomegalovirus (anti-CMV), Epstein Barr virus (EBV) early nuclear antigen-1 (EBNA-1), viral capsid antigen (VCA), early antigen-diffuse (EA-D), 25 hydroxy-vitamin D3 and cotinine levels and HLA DRB1*1501 status. The inclusion criteria required evaluation within 4 months of the initial demyelinating event, 2 or more brain MRI lesions and the presence of two or more oligoclonal bands in cerebrospinal fluid. All patients were treated with interferon-beta. Clinical and MRI assessments were obtained at baseline, 6, 12, and 24 months.Results
The time to first relapse decreased and the number of relapses increased with anti-CMV IgG positivity. Smoking was associated with increased number and volume of contrast-enhancing lesions (CEL) during the 2-year period. The cumulative number of CEL and T2 lesions during the 2-year period was greater for individuals in the highest quartile of anti-EBV VCA IgG antibodies. The percent loss of brain volume was increased for those in the highest quartile of with anti-EBV VCA IgG antibodies.Conclusions
Relapses in CIS patients were associated with CMV positivity whereas anti-EBV VCA positivity was associated with progression on MRI measures, including accumulation of CEL and T2 lesions and development of brain atrophy. 相似文献92.
Ingoglia NA Ramanathan M Zhang N Tzeng B Mathur G Opuni K Donnelly R 《Neurochemical research》2000,25(1):51-58
The N-terminal, posttranslational arginylation of proteins is ubiquitous in eukaryotic cells. Previous experiments, using purified components of the reaction incubated in the presence of exogenous substrates, have shown that only those proteins containing acidic residues at their N-terminals are arginylation substrates. However, data from experiments that used crude extracts of brain and nerve as the source of the arginylating molecules, suggest that the in vivo targets for arginylation are more complex than those demonstrated using purified components. One of the proposed functions for arginylation is as a signal for protein degradation and proteins that have undergone oxidative damage have been shown to be rapidly degraded. In the present experiments we have tested the hypothesis that the presence of an oxidatively damaged residue in a protein is a signal for its arginylation. These experiments have been performed by adding synthetic oxidized peptides to crude extracts of rat brain, incubating them with [3H]Arg and ATP and assaying for arginylated peptides using RP-HPLC. Results showed that while the oxidized A-chain of insulin was arginylated in this system, confirming previous experiments, other peptides containing oxidized residues were not. When a peptide containing Glu in the N-terminus was incubated under the same conditions it too was not a substrate for arginylation. These findings show that neither the presence of an N-terminal acidic residue nor an oxidized residue alone are sufficient to signal arginylation. Thus, another feature of the oxidized A-chain of insulin is required for arginylation. That feature remains to be identified. 相似文献
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Murugesan Sivaranjani Ramanathan Srinivasan Chairmandurai Aravindraja Shunmugiah Karutha Pandian 《Biofouling》2018,34(5):579-593
The present study was designed to investigate the anti-biofilm potential of alpha-mangostin (α-MG) against Acinetobacter baumannii (AB). The biofilm inhibitory concentration (BIC) of α-MG against AB was found to be 2 μg ml?1. α-MG (0.5, 1 and 2 μg ml?1) exhibited non-bactericidal concentration-dependent anti-biofilm activities against AB. However, α-MG failed to disintegrate the mature biofilms of AB even at a 10-fold increased concentration from its BIC. Results from qRT-PCR and in vitro bioassays further demonstrated that α-MG downregulated the expression of bfmR, pgaA, pgaC, csuA/B, ompA, bap, katE, and sodB genes, which correspondingly affects biofilm formation and its associated virulence traits. The present study suggests that α-MG exerts its anti-biofilm property by interrupting initial biofilm formation and the cell-to-cell signaling mechanism of AB. Additional studies are required to understand the mode of action responsible for the anti-biofilm property. 相似文献
96.
Computational genomic analysis of hemorrhagic fever viruses 总被引:6,自引:0,他引:6
A number of distinct viruses are known as hemorrhagic fever viruses based on a shared ability to induce hemorrhage by poorly
understood mechanisms, typically involving the formation of blood clots (“disseminated intravascular coagulation”). It is
well documented that selenium plays a significant role in the regulation of blood clotting via its effects on the thromboxane/prostacyclin
ratio, and effects on the complement system. Selenium has an anticlotting effect, whereas selenium deficiency has a proclotting
or thrombotic effect. It is also well documented that extreme dietary selenium deficiency, which is almost never seen in humans,
has been associated with hemorrhagic effects in animals. Thus, the possibility that viral selenoprotein synthesis might contribute
to hemorrhagic symptoms merits further consideration. Computational genomic analysis of certain hemorrhagic fever viruses
reveals the presence of potential protein coding regions (PPCRs) containing large numbers of in-frame UGA codons, particularly
in the −1 reading frame. In some cases, these clusterings of UGA codons are very unlikely to have arisen by chance, suggesting
that these UGAs may have some function other than being a stop codon, such as encoding selenocysteine. For this to be possible,
a downstream selenocysteine insertion element (SECIS) is required. Ebola Zaire, the most notorious hemorrhagic fever virus,
has a PPCR with 17 UGA codons, and several potential SECIS elements can be identified in the viral genome. One potential viral
selenoprotein may contain up to 16 selenium atoms per molecule. Biosynthesis of this protein could impose an unprecedented
selenium demand on the host, potentially leading to severe lipid peroxidation and cell membrane destruction, and contributing
to hemorrhagic symptoms. Alternatively, even in the absence of programmed selenoprotein synthesis, it is possible that random
slippage errors would lead to increased encounters with UGA codons in overlapping reading frames, and thus potentially to
nonspecific depletion of SeC in the host. 相似文献
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Shyamapada Nandi Santosh Kumar Singh Dinesh Mullangi Rajith Illathvalappil Leena George Chathakudath P. Vinod Sreekumar Kurungot Ramanathan Vaidhyanathan 《Liver Transplantation》2016,6(24)
Covalent organic frameworks (COFs) have structures and morphologies closely resembling graphenes, whose modular construction permits atomic‐level manipulations. This, combined with their porous structure, makes them excellent catalyst supports. Here, the high electrocatalytic activity of a composite, formed by supporting Ni3N nanoparticles on a benzimidazole COF, for oxygen evolution reaction is shown. The composite oxidizes alkaline water with a near‐record low overpotential of 230 mV @ 10 mA cm?2 (η 10). This high activity is attributed to the ability of the COF to confine the Ni3N nanoparticles to size regimes otherwise difficult to obtain and to its low band gap character (1.49 eV) arising from the synergy between the conducting Ni3N nanoparticles and the π‐conjugated COF. The COF itself, as a metal‐free self‐standing framework, has an oxygen evolution reaction activity with η 10 of 400 mV. The periodic structure of the COF makes it serve as a matrix to disperse the catalytically active Ni3N nanoparticles favoring their high accessibility and thereby good charge‐transport within the composite. This is evident from the amount of O2 evolved (230 mmol h?1 g?1), which, to the best of our knowledge, is the highest reported. The work reveals the emergence of COF as supports for electrocatalysts. 相似文献