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排序方式: 共有2927条查询结果,搜索用时 15 毫秒
91.
Tomas Urbina Jean-Rmi Lavillegrand Marc Garnier Arsene Mekinian Jerome Pacanowski Nathalie Mario Guillaume Dumas Geoffroy Hariri Antoine Pilon Lucie Darrivre Muriel Fartoukh Bertrand Guidet Eric Maury Judith Leblanc Yannick Chantran Olivier Fain Karine Lacombe Guillaume Voiriot Hafid Ait-Oufella 《Innate immunity》2022,28(1):3
Little is known about the immuno-inflammatory response to Tocilizumab and its association with outcome in critically-ill SARS-CoV2 pneumonia. In this multicenter retrospective cohort of SARS-CoV-2 patients admitted to three intensive care units between March and April 2020, we matched on gender and SAPS II 21 Tocilizumab-treated patients to 42 non-treated patients. Need for mechanical ventilation was 76% versus 79%. IL-6, C-reactive protein, and fibrinogen had been collected within the first days of admission (T1), 3 d (T2) and 7 d (T3) later. Tocilizumab-treated patients had persistently higher IL-6 plasma levels and persistently lower C-Reactive protein and fibrinogen levels. Among Tocilizumab-treated patients, baseline levels of inflammatory biomarkers were not different according to outcome. Conversely, C-reactive protein and fibrinogen decrease was delayed in non-survivors. C-Reactive protein decreased at T1 in survivors (45 [30–98] vs 170 [69–204] mg/l, P < 0.001) but only at T2 in non-survivors (37 [13–74] vs 277 [235–288], P = 0.03). Fibrinogen decreased at T2 in survivors (4.11 [3.58–4.69] vs 614 [5.61–7.85] g/l, P = 0.005) but not in non-survivors (4.79 [4.12–7.58] vs 7.24 [6.22–9.24] g/l, P = 0.125). Tocilizumab treatment was thus associated with a persistent both increase in plasma IL-6, and decrease in C-reactive protein and fibrinogen. Among Tocilizumab-treated patients, the decrease in inflammatory biomarkers was delayed in non-survivors. 相似文献
92.
de Boer Gert-Jan Testerink Christa Pielage Gerlof Nijkamp H. John J. Stuitje Antoine R. 《Plant molecular biology》1999,39(6):1197-1207
93.
We have discovered a microbial interaction between yeast, bacteria, and nematodes. Upon coculturing, Saccharomyces cerevisiae stimulated the growth of several species of Acinetobacter, including, A. baumannii, A. haemolyticus, A. johnsonii, and A. radioresistens, as well as several natural isolates of Acinetobacter. This enhanced growth was due to a diffusible factor that was shown to be ethanol by chemical assays and evaluation of strains lacking ADH1, ADH3, and ADH5, as all three genes are involved in ethanol production by yeast. This effect is specific to ethanol: methanol, butanol, and dimethyl sulfoxide were unable to stimulate growth to any appreciable level. Low doses of ethanol not only stimulated growth to a higher cell density but also served as a signaling molecule: in the presence of ethanol, Acinetobacter species were able to withstand the toxic effects of salt, indicating that ethanol alters cell physiology. Furthermore, ethanol-fed A. baumannii displayed increased pathogenicity when confronted with a predator, Caenorhabditis elegans. Our results are consistent with the concept that ethanol can serve as a signaling molecule which can affect bacterial physiology and survival. 相似文献
94.
An analysis of determinants of amino acids substitution rates in bacterial proteins 总被引:14,自引:0,他引:14
The variation of amino acid substitution rates in proteins depends on several variables. Among these, the protein's expression level, functional category, essentiality, or metabolic costs of its amino acid residues may play an important role. However, the relative importance of each variable has not yet been evaluated in comparative analyses. To this aim, we made regression analyses combining data available on these variables and on evolutionary rates, in two well-documented model bacteria, Escherichia coli and Bacillus subtilis. In both bacteria, the level of expression of the protein in the cell was by far the most important driving force constraining the amino acids substitution rate. Subsequent inclusion in the analysis of the other variables added little further information. Furthermore, when the rates of synonymous substitutions were included in the analysis of the E. coli data, only the variable expression levels remained statistically significant. The rate of nonsynonymous substitution was shown to correlate with expression levels independently of the rate of synonymous substitution. These results suggest an important direct influence of expression levels, or at least codon usage bias for translation optimization, on the rates of nonsynonymous substitutions in bacteria. They also indicate that when a control for this variable is included, essentiality plays no significant role in the rate of protein evolution in bacteria, as is the case in eukaryotes. 相似文献
95.
96.
Anja T. Rovio Josef Abel Arja L. Ahola Aida M. Andres Jaume Bertranpetit Antoine Blancher Ronald E. Bontrop Leona G. Chemnick Howard J. Cooke James M. Cummins Heidi A. Davis David J. Elliott Ellen Fritsche Timothy B. Hargreave Susan M. G. Hoffman Anne M. Jequier Shu-Huei Kao Heui-Soo Kim David R. Marchington Denise Mehmet Nel Otting Joanna Poulton Oliver A. Ryder Hans-Christian Schuppe Osamu Takenaka Yau-Huei Wei Lars Wichmann Howard T. Jacobs 《Mammalian genome》2004,15(6):492-502
The human nuclear gene for the catalytic subunit of mitochondrial DNA polymerase (POLG) contains within its coding region a CAG microsatellite encoding a polyglutamine repeat. Previous studies demonstrated an association between length variation at this repeat and male infertility, suggesting a mechanism whereby the prevalent (CAG)10 allele, which occurs at a frequency of >80% in different populations, could be maintained by selection. Sequence analysis of the POLG CAG microsatellite region of more than 1000 human chromosomes reveals that virtually all allelic variation at the locus is accounted for by length variation of the CAG repeat. Analysis of POLG from African great apes shows that a prevalent length allele is present in each species, although its exact length is species-specific. In common chimpanzee (Pan troglodytes) a number of different sequence variants contribute to the prevalent length allele, strongly supporting the idea that the length of the POLG microsatellite region, rather than its exact nucleotide or amino acid sequence, is what is maintained. Analysis of POLG in other primates indicates that the repeat has expanded from a shorter, glutamine-rich sequence, present in the common ancestor of Old and New World monkeys. 相似文献
97.
An approach to automatic prediction of the amino acid type from NMR chemical shift values of its nuclei is presented here, in the frame of a model to calculate the probability of an amino acid type given the set of chemical shifts. The method relies on systematic use of all chemical shift values contained in the BioMagResBank (BMRB). Two programs were designed, one (BMRB stats) for extracting statistical chemical shift parameters from the BMRB and another one (RESCUE2) for computing the probabilities of each amino acid type, given a set of chemical shifts. The Bayesian prediction scheme presented here is compared to other methods already proposed: PROTYP RESCUE and PLATON and is found to be more sensitive and more specific. Using this scheme, we tested various sets of nuclei. The two nuclei carrying the most information are C(beta) and H(beta), in agreement with observations made in Grzesiek and Bax, 1993. Based on four nuclei: H(beta), C(beta), C(alpha) and C', it is possible to increase correct predictions to a rate of more than 75%. Taking into account the correlations between the nuclei chemical shifts has only a slight impact on the percentage of correct predictions: indeed, the largest correlation coefficients display similar features on all amino acids. 相似文献
98.
Géraldine?Verquin Ga?lle?Fontaine Marc?Bria Elena?Zhilinskaya Edmond?Abi-Aad Antoine?Abouka?s Brigitte?Baldeyrou Christian?Bailly Jean-Luc?BernierEmail author 《Journal of biological inorganic chemistry》2004,9(3):345-353
Oxovanadium(IV) complexes of hydroxysalen derivatives have been prepared and tested as DNA reactive agents. The nuclease activity has been investigated under oxidative or reducing conditions, on the basis of the various oxidation states of vanadium: VIII, VIV and VV. In the absence of an activating agent, none of the compounds tested was able to induce cleavage of DNA, whereas in the presence of mercaptopropionic acid (MPA) or Oxone the four complexes induced DNA modifications. Under both conditions, the para-hydroxy complex was found to be the most active compound. Reaction of these salen complexes with DNA occurs essentially at guanine residues and is more efficient in the presence of Oxone than under reducing conditions. The extent of Oxone-mediated DNA oxidation by the four vanadyl complexes was clearly superior to VOSO4
and was observed without piperidine treatment. EPR studies provided information on the reactive metal-oxo species involved under each conditions and a mechanism of reaction with DNA is discussed.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00775-004-0529-0Abbreviations BPE buffer
bis-phosphate EDTA buffer
- DMPO
5,5-dimethylpyrroline
N-oxide
- DMS
dimethyl sulfate
- HFS
hyperfine structure
- Lin
linear
- MPA
3-mercaptopropionic acid
- Nck
nicked
- salen
(salicylidene)ethylenediamine
- Sc
supercoiled
- TBE buffer
tris-borate EDTA buffer
- Tris
tris(hydroxymethyl)aminomethane 相似文献
99.
Bily AC Burt AJ Ramputh AI Livesey J Regnault-Roger C Philogène BR Arnason JT 《Phytochemical analysis : PCA》2004,15(1):9-15
A new, rapid HPLC-PAD-APCI/MS assay has been developed in order to measure accurately the amount of p-coumaric, E- and Z-ferulic acid and the dehydrodimers of ferulic acid in cereal grain. In the positive ionisation mode, MS patterns gave additional information for the identification of the dimers. The time required and the quantities of solvents employed in the developed analytical method are much lower than those involved in previously available assays of these compounds, thus making the method suitable for the screening of cereal genotypes. Application of the method to accessions of maize, wheat and sorghum showed that E-ferulic was the most abundant phenylpropanoid, whilst the major dimer was 8-O-4' dehydrodimer of ferulic acid followed by the 5-5' and then the 8-5' forms. Maize grains, especially of the Mexican landraces, contained the highest levels of these dimers. 相似文献
100.
Ehrlich M Boll W Van Oijen A Hariharan R Chandran K Nibert ML Kirchhausen T 《Cell》2004,118(5):591-605
Clathrin-coated vesicles carry traffic from the plasma membrane to endosomes. We report here the real-time visualization of cargo sorting and endocytosis by clathrin-coated pits in living cells. We have detected the formation of coats by monitoring incorporation of fluorescently tagged clathrin or its adaptor AP-2; we have also followed clathrin-mediated uptake of transferrin and of single LDL or reovirus particles. The intensity of a cargo-loaded clathrin cluster grows steadily during its lifetime, and the time required to complete assembly is proportional to the size of the cargo particle. These results are consistent with a nucleation-growth mechanism and an approximately constant growth rate. There are no strongly preferred nucleation sites. A proportion of the nucleation events are weak and short lived. Cargo incorporation occurs primarily or exclusively in a newly formed coated pit. Our data lead to a model in which coated pits initiate randomly but collapse unless stabilized, perhaps by cargo capture. 相似文献