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181.
182.
Stéphane Baudry Malgorzata Klass Jacques Duchateau 《Journal of applied physiology》2005,98(4):1243-1250
The force enhancement of a twitch after a maximal conditioning muscle contraction [i.e., postactivation potentiation (PAP)] is reduced with aging, but its influence on the summation of force in response to repetitive stimulation at different frequencies is not known. The purpose of this work was to compare the electrically evoked mechanical responses of the tibialis anterior muscle between young and elderly adults after a 6-s maximal voluntary contraction (MVC). The results showed that, immediately after the conditioning MVC, twitch torque and its maximal rate of development and relaxation were significantly enhanced in both groups, but the magnitude of potentiation was greater in young (148.0 +/- 14.2, 123.7 +/- 16.5, and 185.4 +/- 36.5%, respectively) compared with elderly adults (87.4 +/- 15.2, 63.8 +/- 9.9, and 62.9 +/- 11.0%, respectively). This age-related difference in potentiation of the twitch disappeared completely 1 min after the conditioning MVC. The potentiation of torque and speed-related parameters in response to two- and three-pulse trains, delivered at a constant interval of 10 ms (100 Hz), was less than for a single pulse for both groups. In young adults, the magnitude of PAP on the successive individual mechanical contributions within a train of stimuli declined progressively such that the third contribution did not differ significantly from the same contribution before the conditioning MVC. In contrast, the second and third contributions did not potentiate (P > 0.05) in elderly adults. Although these contributions did potentiate significantly at a lower frequency of stimulation (20 Hz) in the two groups, the difference in PAP between young and elderly adults still persisted. This overall attenuation of potentiation with aging, however, appears to have a moderate influence on the decrement of the muscular performance. 相似文献
183.
Jens Grote Simone König Doreen Ackermann Claudia Sopalla Malgorzata Benedyk Marek Los Claus Kerkhoff 《BMC molecular biology》2006,7(1):48-10
Background
S100 proteins, a multigenic family of non-ubiquitous cytoplasmic Ca2+-binding proteins, have been linked to human pathologies in recent years. Dysregulated expression of S100 proteins, including S100A9, has been reported in the epidermis as a response to stress and in association with neoplastic disorders. Recently, we characterized a regulatory element within the S100A9 promotor, referred to as MRE that drives the S100A9 gene expression in a cell type-specific, activation- and differentiation-dependent manner (Kerkhoff et al. (2002) J. Biol. Chem. 277, 41879–41887). 相似文献184.
Jamieson SE de Roubaix LA Cortina-Borja M Tan HK Mui EJ Cordell HJ Kirisits MJ Miller EN Peacock CS Hargrave AC Coyne JJ Boyer K Bessieres MH Buffolano W Ferret N Franck J Kieffer F Meier P Nowakowska DE Paul M Peyron F Stray-Pedersen B Prusa AR Thulliez P Wallon M Petersen E McLeod R Gilbert RE Blackwell JM 《PloS one》2008,3(6):e2285
185.
De Camillis Camillo Goralczyk Malgorzata 《The International Journal of Life Cycle Assessment》2013,18(1):263-272
The International Journal of Life Cycle Assessment - The sustainable development challenge that many economies are facing worldwide requires stronger measures because some environmental issues... 相似文献
186.
Paczkowski C Musial A Wlodkowski L Kalinowska M Wojciechowski ZA 《Biotechnology letters》2007,29(9):1403-1408
The regioselective acylation of cholesteryl β-d-glucoside, at the C-6 of the glucose moiety, was achieved using microbial lipases in organic solvents. With palmitic acid
as an acyl donor 81 or 63% conversions of cholesteryl glucoside to its 6′-O-palmitoyl derivative were obtained using Candida antarctica or Rhizomucor miehei enzymes, respectively. High yields (64–92%) were also obtained with fatty acids 6:0–22:0 and 16:1 (n-7). The synthesis of
cholesteryl (6′-O-palmitoyl)glucoside was also achieved via transesterification, using mono-, di- and tri-palmitoylglycerols or methyl and ethyl palmitate as acyl sources. With R. miehei lipase transesterification between methyl palmitate (80 mM) and cholesteryl glucoside (1 mM) proceeded after 24 h with a
nearly quantitative yield (97%). 相似文献
187.
Debika Ojha Malgorzata M Jaszczur Adhirath Sikand John P McDonald Andrew Robinson Antoine
M van
Oijen Chi H Mak Fabien Pinaud Michael
M Cox Roger Woodgate Myron
F Goodman 《Nucleic acids research》2022,50(12):6854
Homologs of the mutagenic Escherichia coli DNA polymerase V (pol V) are encoded by numerous pathogens and mobile elements. We have used Rum pol (RumA′2B), from the integrative conjugative element (ICE), R391, as a model mobile element-encoded polymerase (MEPol). The highly mutagenic Rum pol is transferred horizontally into a variety of recipient cells, including many pathogens. Moving between species, it is unclear if Rum pol can function on its own or requires activation by host factors. Here, we show that Rum pol biochemical activity requires the formation of a physical mutasomal complex, Rum Mut, containing RumA′2B-RecA-ATP, with RecA being donated by each recipient bacteria. For R391, Rum Mut specific activities in vitro and mutagenesis rates in vivo depend on the phylogenetic distance of host-cell RecA from E. coli RecA. Rum pol is a highly conserved and effective mobile catalyst of rapid evolution, with the potential to generate a broad mutational landscape that could serve to ensure bacterial adaptation in antibiotic-rich environments leading to the establishment of antibiotic resistance. 相似文献
188.
Short-term treatment of potato tuber (Solanum tuberosum L.) dises with CdCl2 (1mM) induced an oxidative stress, manifested by higher levels of H2O2, and activated the synthesis of phytochclatins ((γ-Glu-Cys)n-Gly): PC2, PC3 and PC4. If in the tissues with a lower GSH level, the oxidative stress was induced by treatment with 3-aminotriazol (AT), or with
AT and H2O2, the elevation of H2O2 and GSH levels and then some accumulation of thiols, including PC2, PC3 and PC4, were observed. However, this increase of PC concentration was considerably lower when compared with the effects brought
about by Cd+2 treatment. If such a procedure of evoking subsequent moderate oxidative stress in tissues preceded Cd-treatment, a marked
limitation of PC synthesis was observed. The presented results support the role of H2O2 as the second messenger in activating GSH synthesis and thus suggest a possibility of redox type regulation mechanism of
PCs synthesis. 相似文献
189.
Magdalena Wiecek Marcin Maciejczyk Jadwiga Szymura Zbigniew Szygula Malgorzata Kantorowicz 《PloS one》2015,10(11)
Purpose
The aim of this study was to compare changes in total oxidative status (TOS), total antioxidative capacity (TAC) and the concentration of VitA, VitE, VitC, uric acid (UA), reduced (GSH) and oxidized glutathione (GSSG) in blood within 24 hours following anaerobic exercise (AnEx) among men and women.Methods
10 women and 10 men performed a 20-second bicycle sprint (AnEx). Concentrations of oxidative stress indicators were measured before AnEx and 3, 15 and 30 minutes and 1 hour afterwards. UA, GSH and GSSH were also measured 24 hours after AnEx. Lactate and H+ concentrations were measured before and 3 minutes after AnEx.Results
The increase in lactate and H+ concentrations following AnEx was similar in both sexes. Changes in the concentrations of all oxidative stress indicators were significant and did not differ between men and women. In both sexes, TOS, TAC, TOS/TAC and VitA and VitE concentrations were the highest 3 minutes, VitC concentration was the highest 30 minutes, and UA concentration was the highest 1 hour after AnEx. GSH concentration was significantly lower than the initial concentration from 15 minutes to 24 hour after AnEx. GSSG concentration was significantly higher, while the GSH/GSSG ratio was significantly lower than the initial values 1 hour and 24 hour after AnEx.Conclusions
With similar changes in lactate and H+ concentrations, AnEx induces the same changes in TAC, TOS, TOS/TAC and non-enzymatic antioxidants of low molecular weight in men and women. Oxidative stress lasted at least 24 hours after AnEx. 相似文献190.
Cdk11 is a RanGTP-dependent microtubule stabilization factor that regulates spindle assembly rate 下载免费PDF全文
Yokoyama H Gruss OJ Rybina S Caudron M Schelder M Wilm M Mattaj IW Karsenti E 《The Journal of cell biology》2008,180(5):867-875
Production of Ran-guanosine triphosphate (GTP) around chromosomes induces local nucleation and plus end stabilization of microtubules (MTs). The nuclear protein TPX2 is required for RanGTP-dependent MT nucleation. To find the MT stabilizer, we affinity purify nuclear localization signal (NLS)-containing proteins from Xenopus laevis egg extracts. This NLS protein fraction contains the MT stabilization activity. After further purification, we used mass spectrometry to identify proteins in active fractions, including cyclin-dependent kinase 11 (Cdk11). Cdk11 localizes on spindle poles and MTs in Xenopus culture cells and egg extracts. Recombinant Cdk11 demonstrates RanGTP-dependent MT stabilization activity, whereas a kinase-dead mutant does not. Inactivation of Cdk11 in egg extracts blocks RanGTP-dependent MT stabilization and dramatically decreases the spindle assembly rate. Simultaneous depletion of TPX2 completely inhibits centrosome-dependent spindle assembly. Our results indicate that Cdk11 is responsible for RanGTP-dependent MT stabilization around chromosomes and that this local stabilization is essential for normal rates of spindle assembly and spindle function. 相似文献