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141.
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143.
Amarjargal N Mazurek B Haupt H Andreeva N Fuchs J Gross J 《Physiological research / Academia Scientiarum Bohemoslovaca》2008,57(4):631-638
An important mechanism underlying cochlear hair cell (HC) susceptibility to hypoxia/ischemia is the influx of Ca(2+). Two main ATP-dependent mechanisms contribute to maintaining low Ca(2+) levels: uptake of Ca(2+) into intracellular stores via smooth endoplasmic reticulum calcium ATPase (SERCA) and extrusion of Ca(2+) via plasma membrane calcium ATPase (PMCA). The effects of the SERCA inhibitors thapsigargin (10 nM-10 microM) and cyclopiazonic acid (CPA; 10-50 microM) and of the PMCA blockers eosin (1.5-10 microM) and o-vanadate (1-5 mM) on inner and outer hair cells (IHCs/OHCs) were examined in normoxia and ischemia using an in vitro model of the newborn rat cochlea. Exposure of the cultures to ischemia resulted in a significant loss of HCs. Thapsigargin and CPA had no effect. Eosin decreased the numbers of IHCs and OHCs by up to 25 % in normoxia and significantly aggravated the ischemia-induced damage to IHCs at 5 and 10 microM and to OHCs at 10 microM. o-Vanadate had no effect on IHC and OHC counts in normoxia, but aggravated the ischemia-induced HC loss in a dose-dependent manner. The effects of eosin and o-vanadate indicate that PMCA has an important role to play in protecting the HCs from ischemic cell death. 相似文献
144.
Andreeva L. E. Sleptsova L. A. Grigorenko A. P. Gavrushkin A. V. Kuznetsov A. V. 《Russian Journal of Genetics》2003,39(6):627-629
The transfer of plasmid pcDNA3-lacZ by electrotrasfected sperm cells into loach (Misgurnus fossilis L.) ova has been studied. The lacZ gene has been found to express in 3- to 5-day-old prelarvae. 相似文献
145.
Low-temperature (77 K) steady-state fluorescence emission spectroscopy and dynamic light scattering were applied to the main
chlorophyll a/b protein light harvesting complex of photosystem II (LHC II) in different aggregation states to elucidate the mechanism of
fluorescence quenching within LHC II oligomers. Evidences presented that LHC II oligomers are heterogeneous and consist of
large and small particles with different fluorescence yield. At intermediate detergent concentrations the mean size of the
small particles is similar to that of trimers, while the size of large particles is comparable to that of aggregated trimers
without added detergent. It is suggested that in small particles and trimers the emitter is monomeric chlorophyll, whereas
in large aggregates there is also another emitter, which is a poorly fluorescing chlorophyll associate. A model, describing
populations of antenna chlorophyll molecules in small and large aggregates in their ground and first singlet excited states,
is considered. The model enables us to obtain the ratio of the singlet excited-state lifetimes in small and large particles,
the relative amount of chlorophyll molecules in large particles, and the amount of quenchers as a function of the degree of
aggregation. These dependencies reveal that the quenching of the chl a fluorescence upon aggregation is due to the formation of large aggregates and the increasing of the amount of chlorophyll
molecules forming these aggregates. As a consequence, the amount of quenchers, located in large aggregates, is increased,
and their singlet excited-state lifetimes steeply decrease. 相似文献
146.
147.
K. V. Martynova L. A. Andreeva P. A. Klimova Yu. G. Kirillova V. P. Shevchenko I. Yu. Nagaev S. I. Shram V. I. Shvets N. F. Myasoedov 《Russian Journal of Bioorganic Chemistry》2009,35(2):150-156
A synthetic scheme for preparation of (Gly-Pro) n , (Pro-Gly) n (n = 2, 3), and (Pro-Gly-Pro) n (n = 1, 2) peptides was elaborated. The effect of the synthesized peptides and the Gly-Pro and Pro-Gly dipeptides on survival of cultured cells of PC12 rat pheochromocytoma was studied under the conditions of oxidative stress induced by brief incubation of the cells with hydrogen peroxide. Peptides of the general formula (Gly-Pro) n and the Pro-Gly-Pro peptide at a concentration of 0.2–100 μM were shown to decrease the number of damaged cells. The Gly-Pro peptide was the most active and decreased the number of damaged cells by 49% on average at a concentration of 100 μM. 相似文献
148.
The kinetic mechanism of the single-stranded DNA (ssDNA) recognition by the RepA hexameric replicative helicase of the plasmid RSF1010 and the nature of formed intermediates, in the presence of the ATP nonhydrolyzable analog, β,γ-imidoadenosine-5′-triphosphate (AMP-PNP), have been examined, using the fluorescence intensity and anisotropy stopped-flow and analytical ultracentrifugation methods. Association of the RepA hexamer with the ssDNA oligomers that engage the total DNA-binding site and exclusively the strong DNA-binding subsite is a minimum four-step mechanism
149.
JF Yuan SJ Zhang O Jafer RA Furlong OE Chausiaux CA Sargent GH Zhang NA Affara 《BMC microbiology》2009,9(1):246
Background
Pseudorabies virus (PRV) is an alphaherpesviruses whose native host is pig. PRV infection mainly causes signs of central nervous system disorder in young pigs, and respiratory system diseases in the adult. 相似文献150.