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81.
Terreni M Ubiali D Bavaro T Pregnolato M Fernández-Lafuente R Guisán JM 《Applied microbiology and biotechnology》2007,77(3):579-587
The acylase from Arthrobacter viscosus was immobilized, studied in the enzymatic synthesis of some cephalosporins by kinetically controlled N-acylation (kcNa) of different cephem nuclei, and compared with the penicillin G acylase (PGA) from Escherichia coli. The reaction outcomes were dependent on the acylase microbial source and on the type of immobilization support. Generally,
both enzymes, when immobilized onto hydrophilic resins such as glyoxyl-agarose (activated with aldehyde groups), displayed
higher synthetic performances in comparison with hydrophobic acrylic epoxy-supports like Eupergit C. The kcNa of 7-amino cephalosporanic acid catalyzed by A. viscosus immobilized on glyoxyl-agarose afforded a quantitative conversion in 7-[(1-hydroxy-1-phenyl)-acetamido]-3-acetoxymethyl-Δ3-cephem-4-carboxylic acid, a useful intermediate for the synthesis of Cefamandole and Cefonicid. Similar results were obtained
in the synthesis of these cephalosporins by direct acylation of the corresponding 3′-functionalized nucleus. In these reactions,
A. viscosus displayed higher synthetic performances than the PGA from E. coli. 相似文献
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84.
Tótha M Csonka E Bakcsa F Benedek P Szarukán I Gomboc S Toshova T Subchev M Ujváry I 《Zeitschrift für Naturforschung. C, Journal of biosciences》2007,62(9-10):772-778
In field tests in Hungary, Slovenia and Bulgaria, in allyl isothiocyanate-baited traps significantly more beetles of Phyllotreta cruciferae, Ph. vittula, Ph. undulata, Ph. nigripes, Ph. nodicornis, Ph. balcanica, Ph. atra, Ph. procera, Ph. ochripes, Ph. diademata and Psylliodes chrysocephalus (Coleoptera, Chrysomelidae, Halticinae) were captured than in unbaited control traps. With the exception of Ph. cruciferae, this is the first report on significant field attraction by allyl isothiocyanate for these species. The species spectrum captured included six important agricultural pests. At all sites a great portion of the catch (ranging from ca 30 to 98%) was Ph. cruciferae, irrespective of the plant culture. The second most abundant species present at most sites was Ph. vittula. The present results are very promising from the point of view of applicability of allyl isothiocyanate in Europe as a bait in cabbage flea beetle traps for detection and monitoring. 相似文献
85.
A two-hit mechanism for vitamin D3-mediated transcriptional repression of the granulocyte-macrophage colony-stimulating factor gene: vitamin D receptor competes for DNA binding with NFAT1 and stabilizes c-Jun. 总被引:3,自引:0,他引:3
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Terri L. Towers Teodora P. Staeva Leonard P. Freedman 《Molecular and cellular biology》1999,19(6):4191-4199
86.
Teodora Djikic Yasmina Martí Francesca Spyrakis Thorsten Lau Paolo Benedetti Gavin Davey 《Journal of biomolecular structure & dynamics》2019,37(2):291-306
Parkinson’s disease (PD) is characterized by the loss of dopamine-generating neurons in the substantia nigra and corpus striatum. Current treatments alleviate PD symptoms rather than exerting neuroprotective effect on dopaminergic neurons. New drugs targeting the dopaminergic neurons by specific uptake through the human dopamine transporter (hDAT) could represent a viable strategy for establishing selective neuroprotection. Molecules able to increase the bioactive amount of extracellular dopamine, thereby enhancing and compensating a loss of dopaminergic neurotransmission, and to exert neuroprotective response because of their accumulation in the cytoplasm, are required. By means of homology modeling, molecular docking, and molecular dynamics simulations, we have generated 3D structure models of hDAT in complex with substrate and inhibitors. Our results clearly reveal differences in binding affinity of these compounds to the hDAT in the open and closed conformations, critical for future drug design. The established in silico approach allowed the identification of promising substrate compounds that were subsequently analyzed for their efficiency in inhibiting hDAT-dependent fluorescent substrate uptake, through in vitro live cell imaging experiments. Taken together, our work presents the first implementation of a combined in silico/in vitro approach enabling the selection of promising dopaminergic neuron-specific substrates. 相似文献
87.
Isakovic A Jankovic T Harhaji L Kostic-Rajacic S Nikolic Z Vajs V Trajkovic V 《Bioorganic & medicinal chemistry》2008,16(10):5683-5694
The present study identifies xanthones gentiakochianin and gentiacaulein as the active principles responsible for the in vitro antiglioma action of ether and methanolic extracts of the plant Gentiana kochiana. Gentiakochianin and gentiacaulein induced cell cycle arrest in G(2)/M and G(0)/G(1) phases, respectively, in both C6 rat glioma and U251 human glioma cell lines. The more efficient antiproliferative action of gentiakochianin was associated with its ability to induce microtubule stabilization in a cell-free assay. Both the xanthones reduced mitochondrial membrane potential and increased the production of reactive oxygen species in glioma cells, but only the effects of gentiakochianin were pronounced enough to cause caspase activation and subsequent apoptotic cell death. The assessment of structure-activity relationship in a series of structurally related xanthones from G. kochiana and Gentianella austriaca revealed dihydroxylation at positions 7, 8 of the xanthonic nucleus as the key structural feature responsible for the ability of gentiakochianin to induce microtubule-associated G(2)/M cell block and apoptotic cell death in glioma cells. 相似文献
88.
Davide Colombi Julien Dinkel Oliver Weinheimer Berenike Obermayer Teodora Buzan Diana Nabers Claudia Bauer Ute Oltmanns Karin Palmowski Felix Herth Hans Ulrich Kauczor Nicola Sverzellati Michael Kreuter Claus Peter Heussel 《PloS one》2015,10(6)
Objectives
To describe changes over time in extent of idiopathic pulmonary fibrosis (IPF) at multidetector computed tomography (MDCT) assessed by semi-quantitative visual scores (VSs) and fully automatic histogram-based quantitative evaluation and to test the relationship between these two methods of quantification.Methods
Forty IPF patients (median age: 70 y, interquartile: 62-75 years; M:F, 33:7) that underwent 2 MDCT at different time points with a median interval of 13 months (interquartile: 10-17 months) were retrospectively evaluated. In-house software YACTA quantified automatically lung density histogram (10th-90th percentile in 5th percentile steps). Longitudinal changes in VSs and in the percentiles of attenuation histogram were obtained in 20 untreated patients and 20 patients treated with pirfenidone. Pearson correlation analysis was used to test the relationship between VSs and selected percentiles.Results
In follow-up MDCT, visual overall extent of parenchymal abnormalities (OE) increased in median by 5 %/year (interquartile: 0 %/y; +11 %/y). Substantial difference was found between treated and untreated patients in HU changes of the 40th and of the 80th percentiles of density histogram. Correlation analysis between VSs and selected percentiles showed higher correlation between the changes (Δ) in OE and Δ 40th percentile (r=0.69; p<0.001) as compared to Δ 80th percentile (r=0.58; p<0.001); closer correlation was found between Δ ground-glass extent and Δ 40th percentile (r=0.66, p<0.001) as compared to Δ 80th percentile (r=0.47, p=0.002), while the Δ reticulations correlated better with the Δ 80th percentile (r=0.56, p<0.001) in comparison to Δ 40th percentile (r=0.43, p=0.003).Conclusions
There is a relevant and fully automatically measurable difference at MDCT in VSs and in histogram analysis at one year follow-up of IPF patients, whether treated or untreated: Δ 40th percentile might reflect the change in overall extent of lung abnormalities, notably of ground-glass pattern; furthermore Δ 80th percentile might reveal the course of reticular opacities. 相似文献89.
Optimization of triplex real time PCR for detecting Staphylococcus aureus mecA, pvl and nuc genes 总被引:1,自引:0,他引:1
Vremeră T Iancu LS Logigan C Năstase E Miftode E Luncă C Dorneanu O 《Roumanian archives of microbiology and immunology》2011,70(2):69-73
Multiplex polymerase chain reaction (PCR) allows simultaneous detection of two or more genes, using the same reaction conditions, and so it is possible the rapid detection of methicillin resistant Staphylococcus aureus strains (MRSA) in clinical specimens. This study aimed to implement, for the first time in our laboratory, a triplex real time PCR (RT-PCR) technique for detection of genes encoding resistance to oxacillin and synthesis of Panton Valentine leukocidin (pvl), a pathogenicity factor characteristic for community acquired strains (CA-MRSA). The application of this method will permit the epidemiological surveillance of circulating strains and early application of prevention measures. 相似文献
90.
Martina Dávidová Radim Blažek Teodora Trichkova Emmanuil Koutrakis Özcan Gaygusuz Ertan Ercan Markéta Ondračková 《Aquatic Ecology》2011,45(3):377-387
In aquatic ecosystems, fish play a key role in parasite accumulation and transmission to predacious animals. In the present
study, realized on seven populations of a small cyprinid fish species, the European bitterling Rhodeus amarus, we investigated (1) the role of the European bitterling as a potential intermediate or paratenic host, (2) the ability of
the fish to accumulate parasites with similar final host group, and (3) its significance as a potential source of parasite
infection in the ecosystem in respect to habitat characteristics. A total of 36 parasite species were recorded; 31 species
(90% of all parasite specimens) were classified as endoparasites. Most of the endoparasites were found in the larval life
stage, using bitterling as an intermediate or paratenic host. In particular, parasite community structure showed significantly
higher proportions of allogenic parasites in comparison with autogenic. The supposed co-occurrence of parasite species with
identical final host groups showed only a weak association. The adjacent reservoir areas were a significant determinant of
both the total and infracommunity parasite species richness and for the mean parasite abundance. No relationship between the
distance of sampling site from the adjacent reservoir and parasite community characteristics was found. As a small-sized fish
with a wide distribution range and high local abundances, the European bitterling can represent a natural prey for a wide
range of piscivorous predators. Due to its susceptibility to the number of larval endoparasites, this fish species may therefore
fulfill the role as important transmitter of parasites to their final hosts. 相似文献