Damage to the vascular endothelium by reactive oxygen species causes many cardiovascular diseases including atherosclerosis. Such damage can be prevented by selenium (Se), which is thought to exert ...its actions mainly through the expression of selenoproteins. Se deficiency increased the susceptibility to tert-butylhydroperoxide (t-BuOOH) and enhanced lipid peroxidation in bovine arterial endothelial cells (BAEC). We investigated the effects of Se deficiency on the expression of the selenoproteins in BAEC. 75Se metabolic labeling analysis and RT-PCR analysis revealed that BAEC expressed two glutathione peroxidase (GPx) isozymes, cytosolic GPx (cGPx) and phospholipid hydroperoxide GPx (PHGPx), three thioredoxin reductase (TrxR) isozymes, TrxR1, TrxR2 and TrxR3, and selenoprotein P (SelP). Se deficiency reduced both enzyme activity and mRNA level of cGPx, but did not affect those of PHGPx. SelP mRNA level was also reduced by Se deficiency, although the extent of reduction was much smaller than that of cGPx mRNA. We further found that TrxR activity was also decreased by Se deficiency but none of the mRNA levels of TrxR isozymes were reduced. These results indicate that vascular endothelial cells express several selenoproteins including cGPx, PHGPx, TrxR isozymes and SelP which might play important roles in the defense system against oxidative stresses and that the expressions of these selenoproteins are differently regulated by Se status.
We analyze the dynamics of a quantum mechanical system in interaction with a reservoir when the initial state is not factorized. In the weak-coupling (van Hove) limit, the dynamics can be properly ...described in terms of a master equation, but a consistent application of Nakajima–Zwanzig’s projection method requires that the reference (not necessarily equilibrium) state of the reservoir be endowed with the mixing property.
: Presenilin‐2 (PS2) is a gene of unknown function linked with some forms of familial Alzheimer's disease. To investigate the biological role of PS2 in neurons, we overexpressed PS2 in primary ...cortical neurons using recombinant adenoviral vectors. Western blot and immunohistochemical analyses showed enhanced expression of PS2 proteins in infected neurons after infection of recombinant adenoviruses containing the human wild‐type or mutant PS2 gene. Neuronal survival was decreased by approximately 30% in cultures infected with adenovirus expressing either wild‐type or mutant PS2, as compared with those infected with adenovirus expressing the LacZ gene. Fragmented nuclei were frequently observed in dying neurons. These data suggest that apoptotic death of cultured cortical neurons is enhanced by PS2 over‐expression.
We cloned a novel prolyl 4-hydroxylase (PH; EC 1.14.11.2) homolog cDNA from tobacco (Nicotiana tabacum) BY-2 cells based on expression sequence tag information. Like other PHs, this tobacco PH ...polypeptide has two conserved histidine residues, and it comprises 286 amino acids with a calculated molecular mass of 32 kDa. Interestingly, this protein and homologs in Arabidopsis and rice have predicted transmembrane sequences in their N-terminal regions. This PH homolog was expressed in BY-2 cells as a His-tagged protein, and the expressed protein showed PH activity. Incubation of membranes with high salt, urea, and protease with or without detergents indicated that this protein is an integral membrane protein with a type II configuration. Its membrane-anchored nature is specific for plants because no integral membrane PH has been found in animals. A membrane fractionation study and immunocytochemical studies indicate that this protein localizes in both the endoplasmic reticulum (ER) and Golgi apparatus. Analysis of this protein fused to green fluorescent protein indicated that basic amino acids in the cytoplasmic, N-terminal region of the PH play a role in its export from the ER.
We analyze some solvable models of a quantum mechanical system in interaction with a reservoir when the initial state is not factorized. We apply Nakajima–Zwanzig’s projection method by choosing a ...reference state of the reservoir endowed with the mixing property. In van Hove’s limit, the dynamics is described in terms of a master equation. We observe that Markovianity becomes a valid approximation for timescales that depend both on the form factors of the interaction and on the observables of the reservoir that can be measured.
A scheme for measuring the purity of a quantum system with a finite number of levels is presented. The method makes use of two square root swap gates and hinges only on measurements performed on a ...reference system, prepared in a certain pure state and coupled with the target system. Neither tomographic methods, with the complete reconstruction of the state, nor interferometric setups are needed.
An mRNA-specific reverse transcription (RT)-PCR primer set spanning the exon junction of a spliced putative terminase gene in the koi herpesvirus (KHV) was developed to detect the replicating stage ...of the virus. The proposed RT-PCR amplified a target gene from the RNA template, but not from a DNA template extracted from common carp brain (CCB) cells infected with KHV. In addition, the RT-PCR did not amplify the target gene of templates extracted from specific cell lines infected with either CyHV-1 or CyHV-2. RT-PCR detected mRNA from the scales of koi experimentally infected with KHV at 24 h post exposure (hpe). However, unlike conventional PCR, RT-PCR could not detect KHV DNA in fish at 0 hpe. The results indicate that the RT-PCR developed in this study is mRNA-specific and that the assay can detect the replicating stage of KHV from both fish and cultured cells infected with the virus.
Various magnetic levitation systems using oxide superconductors are developed as strong pinning forces are obtained in melt-processed bulk. However, the trapped flux of superconductor is moved by ...flux creep and fluctuating magnetic field. Therefore, to examine the internal condition of superconductor, the authors measure the dynamic surface flux density distribution of YBCO bulk.
Flux density measurement system has a structure with the air-core coil and the Hall sensors. Ten Hall sensors are arranged in series. The YBCO bulk, which has 25 mm diameter and 13 mm thickness, is field cooled by liquid nitrogen. After that, magnetic field is changed by the air-core coil. This paper describes about the measured results of flux density distribution of YBCO bulk in the various frequencies of air-core coils currents.
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