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91.
The non-cytotoxic concentration (20 microM) of menadione (2-methyl-1,4-naphthoquinone), after 1 h of incubation, leads to loss of the activity of rhodanese by 33%, 3-mercaptopyruvate sulfurtransferase by 20%, as well as the level of sulfane sulfur by about 23% and glutathione by 12%, in the culture of U373 cells, in comparison with the control culture. Reactive oxygen species generated by menadione oxidize sulfhydryl groups in active centers of the investigated enzymes, inhibiting them and saving cysteine for glutathione synthesis. A decreased sulfane sulfur level can be correlated with an oxidative stress. 相似文献
92.
Four species of the moss genusRacomitrium Brid. are reported from Brazil:R. subsecundum (Harv.) Wils,R. didymum (Mont.) Lorentz,R. crispipilum (Taylor) A. Jaeger, andR. visnadiae W. R. Buck.Racomitrium subsecundum is reported for the first time from South America in Brazil and Colombia. The species is fully described and illustrated.Racomitrium didymum is recorded for the first time from Brazil; the specimens previously assigned toR. crispulum (Hook.f. & Wils.) Hook.f. & Wils. represent this species.Racomitrium cucullatifolium Hampe andR. crispulum (Hook. f. & Wils.) Hook.f. & Wils. are excluded from the Brazilian bryophyte flora. All Brazilian species ofRacomitrium are briefly assessed taxonomically and bryogeographically and illustrated, and a key to their determination is given. A lectotype
is selected forGrimmia didyma Mont. 相似文献
93.
Circulating concentration of the essential trace element selenium (Se) was significantly lower in inflammatory disorders. Although Se plays physiological roles mainly through the function of 25 selenoproteins, the response of the selenogenome in immune tissues during inflammatory reactions remains unclear. The objective of this study was to determine the Se retention and selenogenome expression in immune tissues during the lipopolysaccharide (LPS)-induced inflammatory response in porcine. A total of 12 male pigs were randomly divided into two groups and injected with LPS or saline. After 4 h postinjection, blood samples were collected and pigs were euthanized. Pigs challenged with LPS had 36.8 and 16.6 % lower (P < 0.05) Se concentrations in the serum and spleen, respectively, than those injected with saline. Moreover, the activities of GPX decreased (P < 0.05) by 23.4, 26.6, and 30.4 % in the serum, thymus, and lymph node, respectively, in the pigs injected with LPS. Furthermore, the LPS challenge altered (P < 0.05) the mRNA expression of 14, 16, 10, and 6 selenoprotein genes in the liver, spleen, thymus, and lymph node, respectively. Along with 10 previously reported selenoprotein genes, the response of Txnrd2, Txnrd3, Sep15, Selh, Seli, Seln, Selo, Selt, Selx, and Sephs2 to inflammatory reaction in immune tissues were newly illustrated in this study. In conclusion, the LPS-induced inflammatory response impaired Se metabolism and was associated with dysregulation of the selenogenome expression in immune tissues. 相似文献
94.
95.
GPR30 contributes to estrogen-induced thymic atrophy 总被引:1,自引:0,他引:1
Wang C Dehghani B Magrisso IJ Rick EA Bonhomme E Cody DB Elenich LA Subramanian S Murphy SJ Kelly MJ Rosenbaum JS Vandenbark AA Offner H 《Molecular endocrinology (Baltimore, Md.)》2008,22(3):636-648
The mechanisms by which prolonged estrogen exposures, such as estrogen therapy and pregnancy, reduce thymus weight, cellularity, and CD4 and CD8 phenotype expression, have not been well defined. In this study, the roles played by the membrane estrogen receptor, G protein-coupled receptor 30 (GPR30), and the intracellular estrogen receptors, estrogen receptor alpha (ERalpha) and beta (ERbeta), in 17beta-estradiol (E2)-induced thymic atrophy were distinguished by construction and the side-by-side comparison of GPR30-deficient mice with ERalpha and ERbeta gene-deficient mice. Our study shows that whereas ERalpha mediated exclusively the early developmental blockage of thymocytes, GPR30 was indispensable for thymocyte apoptosis that preferentially occurs in T cell receptor beta chain(-/low) double-positive thymocytes. Additionally, G1, a specific GPR30 agonist, induces thymic atrophy and thymocyte apoptosis, but not developmental blockage. Finally, E2 treatment attenuates the activation of nuclear factor-kappa B in CD25(-)CD4(-)CD8(-) double-negative thymocytes through an ERalpha-dependent yet ERbeta- and GPR30-independent pathway. Differential inhibition of nuclear factor-kappaB by ERalpha and GPR30 might underlie their disparate physiological effects on thymocytes. Our study distinguishes, for the first time, the respective contributions of nuclear and membrane E2 receptors in negative regulation of thymic development. 相似文献
96.
Despite the extensive literature on the effect on soil properties of afforestation of former arable land, we still lack full
understanding of whether the changes proceed in the same direction and at the same rate, and of how long is required to achieve
a state of soil equilibrium typical of a natural forest ecosystem. Therefore, as part of a study comparing post-arable sandy
soils (Dystric Arenosols) afforested with Scots pine (Pinus silvestris L.) with arable soils and soils of continuous coniferous forests, the range and direction of changes in pH, organic carbon
(Corg), total nitrogen (Ntot), ammonium (N-NH4) and nitrates (N-NO3) in soil solution, total (Ptot) and available (Pav) phosphorus were determined. The studies were carried out in south-east Poland (51°30′-51°37′N, 22°20′-22°35′E). Ten paired
sites of afforested soils (five with 14- to 17-year-old stands and five with 32- to 36-year-old stands) with adjacent cultivated
fields, and five sites of continuous forest with present stands of ca. 130–150 years old were selected. Soil samples were
taken from the whole thickness of master horizons and, in the case of the A horizon of the afforested soils, from three layers:
0–5 (A0–5), 5–10 (A5–10) and 10–20 cm (A10–20). The cultivated soils in the Ap horizon showed higher pH (by ca. 1.0 unit), lower Corg and C:N, similar Ntot, lower N-NH4, higher N-NO3, higher Ptot and Pav contents compared with the Ah horizon of continuous forest soils. The results indicated decreased soil pH in the former plough
layer of the afforested soils, with the greatest decrease observed in the 0–5 cm layer. In these soils, the Corg content was considerably higher in the A0–5 layer, but lower in the two deeper layers and in the whole A horizon (0–20 cm) compared with the Ap horizon of the arable
soils. The results indicate that the Corg content, after an initial phase of decline, again achieved a level characteristic of arable soils. The Ntot content in all layers of the A horizon of the afforested soils was lower than in the Ap horizon of the arable soils, and
showed a reduction with stand age, especially in deeper layers. The C:N ratios in the mineral topsoil increased with stand
age. N-NH4 content increased and N-NO3 decreased after afforestation. The Ptot and Pav contents in all layers and in the whole A horizon of the afforested soils, on stands of both ages, was lower than in the
Ap of the cultivated soils. From the results, it could be concluded that, after more than 30 years of tree growth, the soils
of the A horizon were still more similar to arable than to continuous forest soils with respect to Corg, Ptot and Pav. With respect to pH, N-NH4 and N-NO3, especially in the 0–5 cm layer, they were more similar to continuous forest soils than to cultivated soils, but with respect
to Ntot and C:N ratio they were somewhere in between. 相似文献
97.
Halina Mojzisova Joanna Olesiak Katarzyna Matczyszyn Joseph Zyss 《Biophysical journal》2009,97(8):2348-2357
Highly concentrated DNA solutions exhibit self-ordering properties such as the generation of liquid-crystalline phases. Such organized domains may play an important role in the global chromatin topology but can also be used as a simple model for the study of more complex 3D DNA structures. In this work, using polarized two-photon fluorescence microscopy, we report on the orientation of DNA molecules in liquid-crystalline phases. For this purpose, we analyze the signal emitted by fluorophores that are noncovalently bound to DNA strands. In nonlinear processes, excitation occurs exclusively in the focal volume, which offers advantages such as the reduction of photobleaching of out-of-focus molecules and intrinsic 3D sectioning capability. Propidium iodide and Hoechst, two fluorophores with different DNA binding modes, have been considered. Polarimetric measurements show that the dyes follow the alignment with respect to the DNA strands and allow the determination of the angles between the emission dipoles and the longitudinal axis of the DNA double strand. These results provide a useful starting point toward the application of two-photon polarimetry techniques to determine the local orientation of condensed DNA in physiological conditions. 相似文献
98.
A.?Wiktorek-SmagurEmail author K.?Hnatuszko-Konka A.?K.?Kononowicz 《Russian Journal of Plant Physiology》2009,56(4):560-568
The purpose of this work was to evaluate two methods (floral dip and vacuum infiltration) of in planta transformation of Arabidopsis thaliana. The key issue of this work is the identification of the developmental stages of A. thaliana flower buds subjected to agroinfection, optimal for the successful transformation. Histological tests performed after agroinfection
made it possible to establish the patterns of a GUSPlus reporter gene expression in the examined plants and thus precisely define the range of flower developmental stages most appropriate
for efficient transformation. Two plasmids, CAMBIA 1305.1 and CAMBIA 2301, were used. Verification of the transgenic nature
of plants was carried out by detection of CaMV::gusA and CaMV::GUSPlus transgenes and their expression in transgenic plants by appropriate molecular and histochemical methods. For the flower dip
transformation, three concentrations of Silwet L-77 surfactant and two inoculation times were tested. The most efficient treatment
appeared to be 2-min-long flower bud inoculation and 400 μl/l surfactant (pCAMBIA 1305.1 − 1.73%; pCAMBIA 2301 − 2.01%). In
the case of vacuum infiltration method, the highest efficiency of the transformation occurred when the inoculation time was
4 min (pCAMBIA 2301 − 1.55%; pCAMBIA 1305.1 − 1.37%).
Published in Russian in Fiziologiya Rastenii, 2009, Vol. 56, No. 4, pp. 619–628.
This text was submitted by the authors in English. 相似文献
99.
Musiol R Jampilek J Buchta V Silva L Niedbala H Podeszwa B Palka A Majerz-Maniecka K Oleksyn B Polanski J 《Bioorganic & medicinal chemistry》2006,14(10):3592-3598
The series of quinoline derivatives were prepared. The synthetic approach, analytical, and spectroscopic data of all synthesized compounds are presented. All the prepared derivatives were analyzed using the reversed-phase high performance liquid chromatography (RP-HPLC) method for the lipophilicity measurement. In the present study, the correlation between RP-HPLC retention parameter log K (the logarithm of capacity factor K) and various calculated log P data is shown. The relationships between the lipophilicity and the chemical structure of the studied compounds are discussed as well. The prepared compounds were tested for their in vitro antifungal activity. 2-[(3-Hydroxyphenylimino)methyl]quinolin-8-ol (8), 2-[(4-hydroxyphenylimino)methyl]quinolin-8-ol (9) and 2-[(2,5-dichloro-4-nitrophenylamino)methoxymethyl]quinolin-8-ol (10) showed in vitro antifungal activity comparable to or higher than that of the standard fluconazole. Structure-activity relationships among the chemical structure, the physical properties, and the biological activities of the evaluated compounds are discussed in the article. 相似文献
100.
Czerwicka M Marszewska K Bychowska A Dziadziuszko H Brzozowski K Łojkowska E Stepnowski P Kaczyński Z 《Carbohydrate research》2011,346(18):2978-2981
The lipopolysaccharide (LPS) of the bacterium Pectobacterium atrosepticum SCRI 1039 was hydrolyzed and the products were separated. A study of the obtained O-polysaccharide by means of chemical methods, GLC, GLC–MS, and NMR spectroscopy allowed us to identify a branched polymer with a pentasaccharide repeating unit of the structure shown below, in which the fucose residue was partially O-acetylated at C-2, C-3 or C-4. 相似文献