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1.
Rat brain cortex slices and synaptosomes preincubated with [3H]noradrenaline were used to investigate whether the NMDA-evoked noradrenaline release is modulated by agonists or antagonists at presynaptic alpha 2-adrenoceptors. In experiments on slices, noradrenaline and the preferential alpha-adrenoceptor agonists talipexole (former B-HT 920) and clonidine inhibited the NMDA-evoked tritium overflow whereas the selective alpha 1-adrenoceptor agonists cirazoline and methoxamine were ineffective. The alpha 2-adrenoceptor antagonists rauwolscine and idazoxan facilitated the NMDA-evoked tritium overflow whereas the preferential alpha 1-adrenoceptor antagonist prazosin was ineffective. The concentration-response curve of talipexole for its inhibitory effect on NMDA-evoked overflow was shifted to the right by idazoxan (apparent pA2 = 7.5). The EC50 of NMDA (97 mumol/l) for its stimulating effect on tritium overflow was not substantially changed by blockade of alpha 2-autoreceptors with 1 mumol/l rauwolscine (EC50 of NMDA in the presence of the alpha 2-adrenoceptor antagonist, 155 mumol/l), but the maximal overflow of tritium was increased 2.5 fold by this rauwolscine concentration. In experiments on synaptosomes, talipexole and noradrenaline inhibited the NMDA-evoked tritium overflow. The inhibitory effect of talipexole was abolished by idazoxan which, given alone, was ineffective, as was prazosin. Talipexole did also not produce an inhibition when tritium overflow was evoked by NMDA in the presence of omega-conotoxin GVIA 0.1 mumol/l; the latter, by itself, decreased the response to NMDA by about 55%.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
2.
Zoltán Vitál Nóra Boross István Czeglédi Bálint Preiszner Tibor Erős Kálmán Molnár Gábor Cech Csaba Székely Diána Sándor Péter Takács 《Journal of Great Lakes research》2021,47(1):236-241
In this study, we provide the first genetically verified distribution record beyond its native range of Ligula pavlovskii, a high-impact endoparasite of Ponto-Caspian gobies. According to parasitological surveys, ligulosis was detected for the first time in monkey goby individuals collected from Lake Balaton in 2004, 34 years after the first record of monkey goby in the lake. During a Lake Balaton survey in 2018, we detected tapeworms in 44.4% of the sampled monkey gobies. This prevalence is about two to ten times higher than it was reported from within the native range of the fish hosts. The same survey revealed an uneven spatial distribution of the ligulosis in the monkey gobies inhabiting different shoreline sections of the lake. We assume that the occurrence and recent distribution data of this high-impact endoparasite may provide useful information for potential biocontrol measures of invasive Ponto-Caspian gobies in the future. 相似文献
3.
Jana Zdarova Karasova Martin Mzik Tomas Kucera Zbynek Vecera Jiri Kassa Vit Sestak 《International journal of molecular sciences》2020,21(21)
Antidotes against organophosphates often possess physicochemical properties that mitigate their passage across the blood–brain barrier. Cucurbit[7]urils may be successfully used as a drug delivery system for bisquaternary oximes and improve central nervous system targeting. The main aim of these studies was to elucidate the relationship between cucurbit[7]uril, oxime K027, atropine, and paraoxon to define potential risks or advantages of this delivery system in a complex in vivo system. For this reason, in silico (molecular docking combined with umbrella sampling simulation) and in vivo (UHPLC—pharmacokinetics, toxicokinetics; acetylcholinesterase reactivation and functional observatory battery) methods were used. Based on our results, cucurbit[7]urils affect multiple factors in organophosphates poisoning and its therapy by (i) scavenging paraoxon and preventing free fraction of this toxin from entering the brain, (ii) enhancing the availability of atropine in the central nervous system and by (iii) increasing oxime passage into the brain. In conclusion, using cucurbit[7]urils with oximes might positively impact the overall treatment effectiveness and the benefits can outweigh the potential risks. 相似文献
4.
E. Dhooge and R. J. Hartsuiker (2010) reported experiments showing that picture naming takes longer with low- than high-frequency distractor words, replicating M. Miozzo and A. Caramazza (2003). In addition, they showed that this distractor-frequency effect disappears when distractors are masked or preexposed. These findings were taken to refute models like WEAVER++ (A. Roelofs, 2003) in which words are selected by competition. However, Dhooge and Hartsuiker do not take into account that according to this model, picture-word interference taps not only into word production but also into attentional processes. Here, the authors indicate that WEAVER++ contains an attentional mechanism that accounts for the distractor-frequency effect (A. Roelofs, 2005). Moreover, the authors demonstrate that the model accounts for the influence of masking and preexposure, and does so in a simpler way than the response exclusion through self-monitoring account advanced by Dhooge and Hartsuiker. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
5.
Ergothioneine Biosynthetic Methyltransferase EgtD Reveals the Structural Basis of Aromatic Amino Acid Betaine Biosynthesis
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Allegra Vit Laëtitia Misson Prof. Dr. Wulf Blankenfeldt Prof. Dr. Florian P. Seebeck 《Chembiochem : a European journal of chemical biology》2015,16(1):119-125
Ergothioneine is an N‐α‐trimethyl‐2‐thiohistidine derivative that occurs in human, plant, fungal, and bacterial cells. Biosynthesis of this redox‐active betaine starts with trimethylation of the α‐amino group of histidine. The three consecutive methyl transfers are catalyzed by the S‐adenosylmethionine‐dependent methyltransferase EgtD. Three crystal structures of this enzyme in the absence and in the presence of N‐α‐dimethylhistidine and S‐adenosylhomocysteine implicate a preorganized array of hydrophilic interactions as the determinants for substrate specificity and apparent processivity. We identified two active site mutations that change the substrate specificity of EgtD 107‐fold and transform the histidine‐methyltransferase into a proficient tryptophan‐methyltransferase. Finally, a genomic search for EgtD homologues in fungal genomes revealed tyrosine and tryptophan trimethylation activity as a frequent trait in ascomycetous and basidomycetous fungi. 相似文献
6.
M. C. Barreto J. C. Frisvad T. O. Larsen J. Mogensen Maria Vitória San-Romão 《European Food Research and Technology》2011,232(4):575-582
Fungal species colonize the cork slabs during the manufacturing of cork stoppers process. The most important fungal species
that colonizes cork slabs immediately after boiling is Chrysonilia sitophila. Other fungal species may germinate replacing the C. sitophila mycelium on the cork slabs when the slabs’ water activity decreases below 0.9. The possible production of exo-metabolites
or volatile compounds by some fungal species during the post-boiling stage was verified in pure cultures using three different
media compositions. The results suggest that no deleterious exo-metabolites or mycotoxins are produced by the studied fungal
species, both in cork medium or in cork medium added with C. sitophila extracts. However, the addition of C. sitophila extract to the cork medium enhanced the growth of the other studied fungal isolates and altered the respective exo-metabolome
profile, leading to the assumption that in their natural habitat, the late cork colonizers like Penicillium spp. and Aspergilus spp. could take advantage from an earlier C. sitophila development as a result of its metabolism and/or mycelium remains. Fungal successions may thus not only be a function of
time and substrate, but also they can be dependent of the remains of former colonizers. In fact, the production of the exo-metabolites
by the studied fungal isolates suggests that, under the used experimental conditions, they appear to play an important role
in fungal interactions amongst the cork mycoflora. 相似文献
7.
O. L. Kucherenko I. V. Repin I. N. Yakubovskaya Vit. I. Derevyanchenko M. Yu. Bondarenko 《Steel in Translation》2010,40(1):47-52
The introduction of hot-briquetted iron in batch for steel smelting in arc furnaces is considered. 相似文献
8.
Alexander Pyattaev Jiri Hosek Kerstin Johnsson Radko Krkos Mikhail Gerasimenko Pavel Masek Aleksandr Ometov Sergey Andreev Jakub Sedy Vit Novotny Yevgeni Koucheryavy 《ETRI Journal》2015,37(5):877-887
This paper is a first‐hand summary on our comprehensive live trial of cellular‐assisted device‐to‐device (D2D) communications currently being ratified by the standards community for next‐generation mobile broadband networks. In our test implementation, we employ a full‐featured 3GPP LTE network deployment and augment it with all necessary support to provide real‐time D2D connectivity over emerging Wi‐Fi‐Direct (WFD) technology. As a result, our LTE‐assisted WFD D2D system enjoys the required flexibility while meeting the existing standards in every feasible detail. Further, this paper provides an account on the extensive measurement campaign conducted with our implementation. The resulting real‐world measurements from this campaign quantify the numerical effects of D2D functionality on the resultant system performance. Consequently, they shed light on the general applicability of LTE‐assisted WFD solutions and associated operational ranges. 相似文献
9.
Á. Csanády T. Turmezey I. Imre-Baán Á. Griger D. Marton L. Fodor L. Vitális 《Corrosion Science》1984,24(3):237-248
In the last few years there has been an increased production and application of aluminium foil of under 20 μm thickness all over the world. Household foil is often stored in a wet environment, where the surface is only protected against corrosion by an aluminium oxide layer produced during manufacturing. In this study it has been shown that the aluminium-water vapour reaction is greatly affected by the composition and structure of the amorphous oxide layer on the surface and this depends on the composition of base metal and on the annealing of the foil. The incubation period of aluminium hydroxide nucleation is shortened and its growth rate accelerated by alkali and alkaline earth metal cations incorporated in the oxide layer. In particular the corrosion resistance is decreased by the presence of alkali (Li) and alkaline earth metal (Mg) cations in the oxide layers. 相似文献
10.
Paul M.B. Vitányi 《Information Processing Letters》1985,21(3):147-152
To simulate two pushdown stores, or one queue, on-line by a one-head tape unit requires Ω(n1.618) time. 相似文献