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91.
Insulin-like growth factor I-dependent regulation of prolidase activity in cultured human skin fibroblasts 总被引:3,自引:0,他引:3
Miltyk Wojciech Karna Ewa Wołczyński Sławomir Pałka Jerzy 《Molecular and cellular biochemistry》1998,186(1-2):177-184
The objectives of this article are to: (i) discuss the origins and the nature of ischemic injury, (ii) identify factors influencing the evolution of injury, (iii) consider various cellular targets for ischemic injury, (iv) assess the overall importance of reperfusion injury, (v) discuss conceptual approaches to cardioprotection and (vi) to identify new ideas and approaches in the realm of myocardial protection. In the human heart, myocardial ischemia may take many forms, it may exist for periods as short as a few seconds or minutes, it may last for hours or it may persist for years. In terms of discussing interventions to combat myocardial ischemia, this article will focus on: (i) regional ischemia as occurs during evolving myocardial infarction and (ii) whole heart or global ischemia as occurs during cardiac surgery and transplantation. 相似文献
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94.
Kostic Ljiljana Nikolic Nina Bosnic Dragana Samardzic Jelena Nikolic Miroslav 《Plant and Soil》2017,419(1-2):447-455
Plant and Soil - Although silicon (Si) is known to improve plant growth under low phosphorus (P) conditions, the in planta mechanisms responsible for this effect are still unknown. Here, we... 相似文献
95.
Close and distant: Contrasting the metabolism of two closely related subspecies of Scots pine under the effects of folivory and summer drought 下载免费PDF全文
Albert Rivas‐Ubach Jordi Sardans José Antonio Hódar Joan Garcia‐Porta Alex Guenther Ljiljana Paša‐Tolić Michal Oravec Otmar Urban Josep Peñuelas 《Ecology and evolution》2017,7(21):8976-8988
Metabolomes, as chemical phenotypes of organisms, are likely not only shaped by the environment but also by common ancestry. If this is the case, we expect that closely related species of pines will tend to reach similar metabolomic solutions to the same environmental stressors. We examined the metabolomes of two sympatric subspecies of Pinus sylvestris in Sierra Nevada (southern Iberian Peninsula), in summer and winter and exposed to folivory by the pine processionary moth. The overall metabolomes differed between the subspecies but both tended to respond more similarly to folivory. The metabolomes of the subspecies were more dissimilar in summer than in winter, and iberica trees had higher concentrations of metabolites directly related to drought stress. Our results are consistent with the notion that certain plant metabolic responses associated with folivory have been phylogenetically conserved. The larger divergence between subspecies metabolomes in summer is likely due to the warmer and drier conditions that the northern iberica subspecies experience in Sierra Nevada. Our results provide crucial insights into how iberica populations would respond to the predicted conditions of climate change under an increased defoliation in the Mediterranean Basin. 相似文献
96.
The Neotropical broad-nosed bats, genus Platyrrhinus, represent a well-defined monophyletic group of 14 recognized species. A recent study of morphological characters confirmed Platyrrhinus monophyly and species diagnosis, but offered little support to their intra-specific relationships. We conducted phylogenetic analyses of the genus, using dense taxonomic sampling in combination with four gene sequences representing both mitochondrial and nuclear DNA transmission systems. Our aim was to elucidate the phylogenetic structure among species, using the resulting 3341 bp of DNA. Maximum parsimony, maximum likelihood, and Bayesian inference analyses produced similar topologies that confirm the monophyly of the genus Platyrrhinus and strongly support many previously unrecognized groups. Paraphyly of Platyrrhinus helleri and the unclear position of P. brachycephalus in the clades were also apparent in the data. Our biogeographical analysis suggests a Brazilian Shield origin for Platyrrhinus, followed by subsequent radiations of lineages in the Amazon Basin and Andes. Secondary dispersal from Amazonian and Andean centers is responsible for the Platyrrhinus inhabiting the Guianan Shield and the Pacific lowlands and Central America, respectively. 相似文献
97.
Muthu Manikandan Lejla Pašić Vijayaraghavan Kannan 《World journal of microbiology & biotechnology》2009,25(12):2247-2256
An extremely halophilic archaeon Haloferax lucentensis VKMM 007, isolated from a solar saltern, was found to produce a protease. This extracellular enzyme consisted of a single
polypeptide chain of 57.8 kDa as determined by SDS–PAGE and was purified by a combination of ultrafiltration, bacitracin–Sepharose
affinity chromatography and Sephadex G-100 gel filtration. The purified protein was stable in a wide range of temperatures
(20–70°C), NaCl concentrations (0.85–5.13 M) and pH (5.0–9.0) with maximal activity observed at 60°C, 4.3 M NaCl and pH 8.0.
Proteolytic activity was enhanced by Ca2+, K+, Mg2+, Na+, and Fe2+ ions and the protein was classified as a trypsin-like serine protease. Further assays indicated highest degree of specificity
when hemoglobin was used as an enzyme substrate. Most importantly, the proteolytic activity remained stable or only marginally
inhibited in the presence of various polar and non-polar solvents, surfactants and reducing agents thus emphasizing the biotechnological
potential of this novel halophilic protease. 相似文献
98.
Vuk Micovic Milovan D. Ivanovic Ljiljana Dosen-Micovic 《Journal of molecular modeling》2009,15(3):267-280
An automated docking procedure was used to study binding of a series of δ-selective ligands to three models of the δ-opioid
receptor. These models are thought to represent the three ligand-specific receptor conformations. Docking results are in agreement
with point mutation studies and suggest that different ligands—agonists and antagonists—may bind to the same binding site
under different receptor conformations. Docking to different receptor models (conformations) also suggests that by changing
to a receptor-specific conformation, the receptor may open or close different binding sites to other ligands.
Figure Ligands 5 (green) and 6 (orange) in bindingpocket BP1 of the R1 δ-opioid receptor model 相似文献
99.
Ljiljana Janjušević Filip Šibul Giuseppina Tommonaro Carmine Iodice Dragica Jakovljević 《Journal of enzyme inhibition and medicinal chemistry》2017,32(1):355-362
This study aimed to determine antiradical (DPPH? and ?OH) and acetylcholinesterase (AChE) inhibitory activities along with chemical composition of autochtonous fungal species Trametes versicolor (Serbia). A total of 38 phenolic compounds with notable presence of phenolic acids were identified using HPLC/MS-MS. Its water extract exhibited the highest antiradical activity against ?OH (3.21?μg/mL), among the rest due to the presence of gallic, p-coumaric and caffeic acids. At the concentration of 100?μg/mL, the same extract displayed a profound AChE inhibitory activity (60.53%) in liquid, compared to donepezil (89.05%), a drug in clinical practice used as positive control. The flavonoids baicalein and quercetin may be responsible compounds for the AChE inhibitory activity observed. These findings have demonstrated considerable potential of T. versicolor water extract as a natural source of antioxidant(s) and/or AChE inhibitor(s) to be eventually used as drug-like compounds or food supplements in the treatment of Alzheimer’s disease. 相似文献
100.
Tomasz Gubica Agnieszka Pe?ka Katarzyna Pa?ka Andrzej Temeriusz Marianna Kańska 《Carbohydrate research》2011,(13):1855
Cyclomaltohexaose (α-cyclodextrin) and cyclomaltoheptaose (β-cyclodextrin) as well as their four methyl ether derivatives, that is, hexakis(2,3-di-O-methyl)cyclomaltohexaose, hexakis(2,3,6-tri-O-methyl)cyclomaltohexaose, heptakis(2,3-di-O-methyl)cyclomaltoheptaose, and heptakis(2,3,6-tri-O-methyl)cyclomaltoheptaose were investigated as the additives in the course of enzymatic decomposition of l-phenylalanine catalyzed by phenylalanine ammonia-lyase. Only a few of those additives behaved like classical inhibitors of the enzymatic reaction under investigation because the values of the Michaelis constants that were obtained, as well as the maximum velocity values depended mostly atypically on the concentrations of those additives. In most cases cyclodextrins caused mixed inhibition, both competitive and noncompetitive, but they also acted as activators for selected concentrations. This atypical behaviour of cyclodextrins is caused by three different and independent effects. The inhibitory effect of cyclodextrins is connected with the decrease of substrate concentration and unfavourable influence on the flexibility of the enzyme molecules. On the other hand, the activating effect is connected with the decrease of product concentration (the product is an inhibitor of the enzymatic reaction under investigation). All these effects are caused by the ability of the cyclodextrins to form inclusion complexes. 相似文献