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141.
B?a?ej Po?niak Tomasz Grabowski Karolina Motykiewicz-Pers Kamila Bobrek Lech Rak Katarzyna Bobusia Andrzej Gawe? Marcin ?wita?a 《PloS one》2015,10(4)
Salicylates were the first non-steroid anti-inflammatory drugs (NSAIDs) to be used in any species and are still widely used in humans and livestock. However, the data on their pharmacokinetics in animals is limited, especially after repeated administration. Evidence exist that in chickens (Gallus gallus) salicylate (SA) may induce its own elimination. The aim of this study was to investigate salicylate pharmacokinetics and egg residues during repeated administration of sodium salicylate (SS) to laying hens. Pharmacokinetics of SA was assessed during 14 d oral administration of SS at daily doses of 50 mg/kg and 200 mg/kg body weight to laying hens. On the 1st, 7th and 14th d a 24 h-long pharmacokinetic study was carried out, whereas eggs were collected daily. Salicylate concentrations in plasma and eggs were determined using high-performance liquid chromatography with ultraviolet detection and pharmacokinetic variables were calculated using a non-compartmental model. Mean residence time (MRT), minimal plasma concentration (Cmin, C16h) and elimination half-life (T1/2el) of SA showed gradual decrease in layers administered with a lower dose. Total body clearance (ClB) increased. Layers administered with the higher dose showed a decrease only in the T1/2el. In the low dose group, SA was found only in the egg white and was low throughout the experiment. Egg whites from the higher dose group showed initially high SA levels which significantly decreased during the experiment. Yolk SA levels were lower and showed longer periods of accumulation and elimination. Repeated administration of SS induces SA elimination, although this effect may differ depending on the dose and production type of a chicken. Decreased plasma drug concentration may have clinical implications during prolonged SS treatment. 相似文献
142.
Przemyslaw Glaza Jerzy Osipiuk Tomasz Wenta Dorota Zurawa-Janicka Miroslaw Jarzab Adam Lesner Bogdan Banecki Joanna Skorko-Glonek Andrzej Joachimiak Barbara Lipinska 《PloS one》2015,10(6)
Human HtrA3 protease, which induces mitochondria-mediated apoptosis, can be a tumor suppressor and a potential therapeutic target in the treatment of cancer. However, there is little information about its structure and biochemical properties. HtrA3 is composed of an N-terminal domain not required for proteolytic activity, a central serine protease domain and a C-terminal PDZ domain. HtrA3S, its short natural isoform, lacks the PDZ domain which is substituted by a stretch of 7 C-terminal amino acid residues, unique for this isoform. This paper presents the crystal structure of the HtrA3 protease domain together with the PDZ domain (ΔN-HtrA3), showing that the protein forms a trimer whose protease domains are similar to those of human HtrA1 and HtrA2. The ΔN-HtrA3 PDZ domains are placed in a position intermediate between that in the flat saucer-like HtrA1 SAXS structure and the compact pyramidal HtrA2 X-ray structure. The PDZ domain interacts closely with the LB loop of the protease domain in a way not found in other human HtrAs. ΔN-HtrA3 with the PDZ removed (ΔN-HtrA3-ΔPDZ) and an N-terminally truncated HtrA3S (ΔN-HtrA3S) were fully active at a wide range of temperatures and their substrate affinity was not impaired. This indicates that the PDZ domain is dispensable for HtrA3 activity. As determined by size exclusion chromatography, ΔN-HtrA3 formed stable trimers while both ΔN-HtrA3-ΔPDZ and ΔN-HtrA3S were monomeric. This suggests that the presence of the PDZ domain, unlike in HtrA1 and HtrA2, influences HtrA3 trimer formation. The unique C-terminal sequence of ΔN-HtrA3S appeared to have little effect on activity and oligomerization. Additionally, we examined the cleavage specificity of ΔN-HtrA3. Results reported in this paper provide new insights into the structure and function of ΔN-HtrA3, which seems to have a unique combination of features among human HtrA proteases. 相似文献
143.
The method of adaptive approximations by Matching Pursuit makes it possible to decompose signals into basic components (called atoms). The approach relies on fitting, in an iterative way, functions from a large predefined set (called dictionary) to an analyzed signal. Usually, symmetric functions coming from the Gabor family (sine modulated Gaussian) are used. However Gabor functions may not be optimal in describing waveforms present in physiological and medical signals. Many biomedical signals contain asymmetric components, usually with a steep rise and slower decay. For the decomposition of this kind of signal we introduce a dictionary of functions of various degrees of asymmetry – from symmetric Gabor atoms to highly asymmetric waveforms. The application of this enriched dictionary to Otoacoustic Emissions and Steady-State Visually Evoked Potentials demonstrated the advantages of the proposed method. The approach provides more sparse representation, allows for correct determination of the latencies of the components and removes the "energy leakage" effect generated by symmetric waveforms that do not sufficiently match the structures of the analyzed signal. Additionally, we introduced a time-frequency-amplitude distribution that is more adequate for representation of asymmetric atoms than the conventional time-frequency-energy distribution. 相似文献
144.
Fluorescence methods (VistaCam iX proof and DIAGNODent pen) for the detection of occlusal carious lesions in teeth recovered from archaeological context 下载免费PDF全文
Jacek Tomczyk Julian Komarnitki Marta Zalewska Tomasz Lekszycki Dorota Olczak‐Kowalczyk 《American journal of physical anthropology》2014,154(4):525-534
Diagnosis of occlusal enamel caries in archaeologically derived collections remains a controversial problem because the accumulation of contaminants in fissures can interfere with diagnosis. Certain novel light‐induced fluorescence methods, such as the DIAGNODent pen 2190 (DD) and VistaCam iX Proof (VC), have been used to detect dental caries in clinical settings. In this study, the abilities of DD and VC to detect initial enamel caries in archaeologically derived material is determined and compared with those of other methods (visual inspection, X‐ray, histology, and micro‐CT). Dental material encompassing the remains of 58 individuals, including a total of 380 teeth from each of three historical periods: modern Islamic (AD 1850–1950), Islamic (AD 600–1200) and late Roman (AD 200–400), obtained from two archaeological sites (Terqa and Tell Masaikh) located in the Middle Euphrates valley (Syria), were analyzed. VC was found to have excellent sensitivity (98), while DD obtained lower sensitivity (76) in detecting dental caries in its early stages. The results obtained by VC and micro‐CT, considered the most reliable imaging technique, were not statistically significant (P = 0.3068). By contrast, results obtained by DD and micro‐CT results, and DD and VC results were statistically significant (P < 0.0001, P = 0.0015, respectively). However the presence of dirt, stain, calculus, and plaque in the pits and fissures of the occlusal surface compromise correct diagnosis of caries by VC and DD. Consequently, for teeth recovered from archaeological contexts where staining, calculus and plaque are present, the best solution remains micro‐CT. Am J Phys Anthropol 154:525–534, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
145.
Magdalena Polak-Berecka Adam Waśko Roman Paduch Tomasz Skrzypek Anna Sroka-Bartnicka 《Antonie van Leeuwenhoek》2014,106(4):751-762
The aim of this study was to analyze the cell envelope components and surface properties of two phenotypes of Lactobacillus rhamnosus isolated from the human gastrointestinal tract. The ability of the bacteria to adhere to human intestinal cells and to aggregate with other bacteria was determined. L. rhamnosus strains E/N and PEN differed with regard to the presence of exopolysaccharides (EPS) and specific surface proteins. Transmission electron microscopy showed differences in the structure of the outer cell surface of the strains tested. Bacterial surface properties were analyzed by Fourier transform infrared spectroscopy, fatty acid methyl esters and hydrophobicity assays. Aggregation capacity and adhesion of the tested strains to the human colon adenocarcinoma cell line HT29 was determined. The results indicated a high adhesion and aggregation ability of L. rhamnosus PEN, which possessed specific surface proteins, had a unique fatty acid content, and did not synthesize EPS. Adherence of L. rhamnosus was dependent on specific interactions and was promoted by surface proteins (42–114 kDa) and specific fatty acids. Polysaccharides likely hindered bacterial adhesion and aggregation by masking protein receptors. This study provides information on the cell envelope constituents of lactobacilli that influence bacterial aggregation and adhesion to intestinal cells. This knowledge will help to understand better their specific contribution in commensal–host interactions and adaptation to this ecological niche. 相似文献
146.
The binding affinity of the two substrate–water molecules to the water-oxidizing Mn4CaO5 catalyst in photosystem II core complexes of the extremophilic red alga Cyanidioschyzon merolae was studied in the S2 and S3 states by the exchange of bound 16O-substrate against 18O-labeled water. The rate of this exchange was detected via the membrane-inlet mass spectrometric analysis of flash-induced oxygen evolution. For both redox states a fast and slow phase of water-exchange was resolved at the mixed labeled m/z 34 mass peak: kf = 52 ± 8 s− 1 and ks = 1.9 ± 0.3 s− 1 in the S2 state, and kf = 42 ± 2 s− 1 and kslow = 1.2 ± 0.3 s− 1 in S3, respectively. Overall these exchange rates are similar to those observed previously with preparations of other organisms. The most remarkable finding is a significantly slower exchange at the fast substrate–water site in the S2 state, which confirms beyond doubt that both substrate–water molecules are already bound in the S2 state. This leads to a very small change of the affinity for both the fast and the slowly exchanging substrates during the S2 → S3 transition. Implications for recent models for water-oxidation are briefly discussed. 相似文献
147.
Sacha P Ojdana D Wieczorek P Szpak A Hauschild T Milewski R Krawczyk M Kaczyńska K Tryniszewska E 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》2010,48(4):663-666
Extended spectrum β-lactamases production is one of the most common mechanism of resistance to extended spectrum β-lactam antibiotics is increasing worldwide. Twenty five strains of Klebsiella pneumoniae isolated from clinical specimens were tested. Based on the phenotypic confirmatory test all these strains were defined as ESBL producers named ESBL(+). The plasmid DNA from each strains was used to investigate the presence of blaSHV genes responsible for extended spectrum β-lactamases production. Moreover, susceptibility of these strains to antibiotic other than β-lactams in was tested. 相似文献
148.
Oxidative stress during aging of Saccharomyces cerevisiae in stationary culture was documented by demonstration of progressive increase in the formation of superoxide, decrease in the content of acid‐soluble thiols and of acid‐soluble antioxidant capacity of cell extracts, and accumulation of aldehydes and protein carbonyl groups in two yeast strains and decreases in activities of antioxidant enzymes. Cells of a CuZn‐SOD (superoxide dismutase)‐1‐deficient strain showed a higher loss of viability than cells of an isogenic wild‐type strain. Cell survival was augmented, and changes in biochemical parameters were ameliorated, by addition of exogenous antioxidants (ascorbic acid, glutathione and melatonin) in both strains. 相似文献
149.
150.
Relationship between genotype and soil environment during colonization of poplar roots by mycorrhizal and endophytic fungi 总被引:1,自引:0,他引:1
Leszek Karliński Maria Rudawska Barbara Kieliszewska-Rokicka Tomasz Leski 《Mycorrhiza》2010,20(5):315-324
Poplars are among the few tree genera that can develop both ectomycorrhizal (ECM) and arbuscular (AM) associations; however,
variable ratios of ECM/AM in dual mycorrhizal colonizations were observed in the roots of a variety of poplar species and
hybrids. The objective of our study was to analyze the effect of internal and external factors on growth and dual AM and ECM
colonization of poplar roots in three 12–15-year-old common gardens in Poland. We also analyzed the abundance of nonmycorrhizal
fungal endophytes in the poplar roots. The Populus clones comprised black poplars (Populus deltoides and P. deltoides × Populus nigra), balsam poplars (Populus maximowiczii × Populus trichocarpa), and a hybrid of black and balsam poplars (P. deltoides × P. trichocarpa). Of the three sites that we studied, one was located in the vicinity of a copper smelter, where soil was contaminated with
copper and lead. Poplar root tip abundance, mycorrhizal colonization, and soil fungi biomass were lower at this heavily polluted
site. The total mycorrhizal colonization and the ratio of ECM and AM colonization differed among the study sites and according
to soil depth. The influence of Populus genotype was significantly pronounced only within the individual study sites. The contribution of nonmycorrhizal fungal endophytes
differed among the poplar clones and was higher at the polluted site than at the sites free of pollution. Our results indicate
that poplar fine root abundance and AM and ECM symbiosis are influenced by environmental conditions. Further studies of different
site conditions are required to characterize the utility of poplars for purposes such as the phytoremediation of polluted
sites. 相似文献