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1.
Dagmara Panas Urszula Malinowska Tadeusz Piotrowski Jaros?aw ?ygierewicz Piotr Suffczyński 《PloS one》2013,8(4)
Spindles - a hallmark of stage II sleep - are a transient oscillatory phenomenon in the EEG believed to reflect thalamocortical activity contributing to unresponsiveness during sleep. Currently spindles are often classified into two classes: fast spindles, with a frequency of around 14 Hz, occurring in the centro-parietal region; and slow spindles, with a frequency of around 12 Hz, prevalent in the frontal region. Here we aim to establish whether the spindle generation process also exhibits spatial heterogeneity. Electroencephalographic recordings from 20 subjects were automatically scanned to detect spindles and the time occurrences of spindles were used for statistical analysis. Gamma distribution parameters were fit to each inter-spindle interval distribution, and a modified Wald-Wolfowitz lag-1 correlation test was applied. Results indicate that not all spindles are generated by the same statistical process, but this dissociation is not spindle-type specific. Although this dissociation is not topographically specific, a single generator for all spindle types appears unlikely. 相似文献
2.
Lidia Jabłońska Michał Walski Urszula Rafałowska 《Cellular and molecular neurobiology》1994,14(6):701-709
Summary 1. The effect of lead (in vivo) on the uptake of GABA, dopamine, and histidine as a precursor of histamine in synaptosomes obtained from chronically lead-treated rats was studied.2. Lead decreased the uptake of GABA, increased the uptake of dopamine, and did not change the uptake of histidine. These effects were independent of calcium concentration.3. Lead administration to the rat changed the morphology of the synaptosomes, as manifested in the decreased number of synaptic vesicles and disturbed mitochondrial structure.4. The results suggest the existence of several mechanisms of lead toxicity on uptake, related to individual neurotransmitters, which are not necessarily connected with a Pb2+/Ca2+ interaction. 相似文献
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Denise D. Beusen Janusz Zabrocki Urszula Slomczynska Richard D. Head Jeff L.-F. Kao Garland R. Marshall 《Biopolymers》1995,36(2):181-200
Potent, cyclic hexapeptide analogues of somatostatin are generally believed to adopt some common secondary structural features: a II′ β turn at one end of the cycle, and a type VI turn with a cis amide bond at the other. A proposed cis amide surrogate, the 1,5-disubstituted tetrazole, has been placed into a cyclic hexapeptide analog of somatostatin in order to constrain the putative cis amide bond. The final cyclization was done by either chemical or enzymatic means. The product, cyclo(Ala6-Tyr7-D -Trp8-Lys9-Val10-Phe11-Ψ[CN4]), was found to have 83% of the activity of somatostatin. Solution nmr analysis in DMSO/water revealed that the backbone as well as side chain χ1 and χ2 were well ordered. Relaxation matrix methods were used to extract distance restraints from the nuclear Overhauser effect spectroscopy data set, and these were used in a systematic search of torsional space to identify structures consistent with the nmr data. Restrained minimizations of these structures using a number of different force fields produced structures having the expected βII′ turn at D -Trp8-Lys9 and αβVIa turn in the Phe11-Ψ[CN4]-Ala6 portion of the molecule. The similarity of the minimized structures to those previously reported for cyclic hexapeptide analogues of somatostatin confirms the similarity of the tetrazole geometry to that of the cis amide in solution. © 1995 John Wiley & Sons, Inc. 相似文献
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3-(2-Carboxyethyl)thymine (3-CET) was synthesized from β-propiolactone (BPL) and dThd5′P at pH 9.0–9.5 via the intermediate 3-(2-carboxyethyl)thymidine-5′-monophosphoric acid (3-CEdThd5′P). 3-CEdThd5′P was converted to 3-CET by hydrolysis in 1.5 N HCl at 100°C for 2 h. The structure of 3-CET was assigned on the basis of UV spectra, electron impact (EI) and isobutane chemical ionization mass spectra and the EI mass spectrum of a trimethylsilyl derivative of 3-CET. BPL was reacted in vitro with calf thymus DNA at pH 7.5. 100 A units of BPL-reacted DNA yielded, following perchloric acid hydrolysis and preparative paper chromatography, 3 A units of 3-CET. Reaction of BPL with the phosphodiester thymidylyl-(3′-5′)thymidine gave 3-(2-carboxyethyl)thymidylyl-(3′-5′)-3-(2-carboxyethyl)thymidine (~3%). Phosphotriester formation was not detected. 相似文献
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Perlińska-Lenart U Orlowski J Laudy AE Zdebska E Palamarczyk G Kruszewska JS 《Applied and environmental microbiology》2006,72(12):7778-7784
Expression of the Saccharomyces cerevisiae DPM1 gene (coding for dolichylphosphate mannose synthase) in Trichoderma reesei (Hypocrea jecorina) increases the intensity of protein glycosylation and secretion and causes ultrastructural changes in the fungal cell wall. In the present work, we undertook further biochemical and morphological characterization of the DPM1-expressing T. reesei strains. We established that the carbohydrate composition of the fungal cell wall was altered with an increased amount of N-acetylglucosamine, suggesting an increase in chitin content. Calcofluor white staining followed by fluorescence microscopy indicated changes in chitin distribution. Moreover, we also observed a decreased concentration of mannose and alkali-soluble beta-(1,6) glucan. A comparison of protein secretion from protoplasts with that from mycelia showed that the cell wall created a barrier for secretion in the DPM1 transformants. We also discuss the relationships between the observed changes in the cell wall, increased protein glycosylation, and the greater secretory capacity of T. reesei strains expressing the yeast DPM1 gene. 相似文献
9.
Zalejska-Fiolka J Kasperczyk A Kasperczyk S Błaszczyk U Birkner E 《Biological trace element research》2007,120(1-3):195-204
Effect of garlic supplementation on blood antioxidant status, lipid peroxidation, and coronary plaque formation process was
investigated in oxidized oil-fed rabbits. Eighteen adult male mixed European rabbits were given a balanced diet (21 g% protein,
34 g% fat, 45 g% carbohydrate), which contained isocaloristic addition of nonoxidized or oxidized rapeseed oil in the presence
and absence of garlic. The experiment lasted 24 weeks. At the beginning and every 6 weeks, rabbits were weighed, and blood
was taken. To evaluate the antioxidant status of the rabbits, erythrocytes malondialdehyde (MDA) concentration, total superoxide
dismutase (t-SOD), and glutathione peroxidase (GPX) activations were determined. After the experiment was completed, aortas
were dissected for histological examinations. Changes in the contents of the above parameters and histological examinations
showed that oxidized rapeseed, oil administered to rabbits, caused the development of atherosclerotic changes and disturbed
antioxidant status. The addition of garlic in such diets inhibited atherosclerotic changes in the aorta wall, and it is related
to the homeostatic activity of antioxidative enzymes and lipid peroxidation. 相似文献
10.
Agata Paneth Barbara Kaproń Dominika Hagel Urszula Kosikowska Edyta Kuśmierz 《Journal of enzyme inhibition and medicinal chemistry》2016,31(3):434-440
Twelve 4-benzoyl-1-dichlorobenzoylthiosemicarbazides have been tested as potential antibacterials. All the compounds had MICs between 0.49 and 15.63?µg/ml toward Micrococcus luteus, Bacillus cereus, Bacillus subtilis and Staphylococcus epidermidis indicating, in most cases, equipotent or even more effective action than cefuroxime. In order to clarify if the observed antibacterial effects are universal, further research were undertaken to test inhibitory potency of two most potent compounds 3 and 11 on clinical isolates of Staphylococcus aureus. Compound 11 inhibited the growth of methicillin-sensitive S. aureus (MSSA) at MICs of 1.95–7.81?µg/ml, methicillin-resistant S. aureus (MRSA) at MICs of 0.49–1.95?µg/ml and MDR–MRSA at MIC of 0.98 and 3.90?µg/ml, respectively. Finally, inhibitory efficacy of 3 and 11 on planktonic cells and biofilms formation in clinical isolates of S. aureus and Haemophilus parainfluenzae was tested. The majority of cells in biofilm populations of MSSA and MRSA were eradicated at low level of 3, with MBICs in the range of 7.82–15.63?µg/ml. 相似文献