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排序方式: 共有1294条查询结果,搜索用时 203 毫秒
1.
Tomohiro Hamasaki Takahiro Matsumoto Naoya Sakamoto Akiko Shimahara Shiori Kato Ayumi Yoshitake Ayumi Utsunomiya Hisayoshi Yurimoto Esteban C. Gabazza Tadaaki Ohgi 《Nucleic acids research》2013,41(12):e126
Radioisotopes and fluorescent compounds are frequently used for RNA labeling but are unsuitable for clinical studies of RNA drugs because of the risk from radiation exposure or the nonequivalence arising from covalently attached fluorophores. Here, we report a practical phosphoramidite solid-phase synthesis of 18O-labeled RNA that avoids these disadvantages, and we demonstrate its application to quantification and imaging. The synthesis involves the introduction of a nonbridging 18O atom into the phosphate group during the oxidation step of the synthetic cycle by using 18O water as the oxygen donor. The 18O label in the RNA was stable at pH 3–8.5, while the physicochemical and biological properties of labeled and unlabeled short interfering RNA were indistinguishable by circular dichroism, melting temperature and RNA-interference activity. The 18O/16O ratio as measured by isotope ratio mass spectrometry increased linearly with the concentration of 18O-labeled RNA, and this technique was used to determine the blood concentration of 18O-labeled RNA after administration to mice. 18O-labeled RNA transfected into human A549 cells was visualized by isotope microscopy. The RNA was observed in foci in the cytoplasm around the nucleus, presumably corresponding to endosomes. These methodologies may be useful for kinetic and cellular-localization studies of RNA in basic and pharmaceutical studies. 相似文献
2.
Shigeki Takeura Hiizu Aoki Tatsuya Tsurumi Yukihiro Nishiyama Hisashi Fujioka Saiji Yoshii Koichiro Maeno 《Microbiology and immunology》1984,28(4):427-437
Host-dependent restriction of influenza B virus replication in L cells was analysed in comparison with productive infection in MDCK or 1–5C-4 cells. The synthesis and intracellular distribution of virus-specific proteins and the production of cytoplasmic ribonucleoproteins in nonpermissive L cells were similar to those in permissive MDCK cells. However, an electron microscopic study of infected L cells showed neither extracellular virions nor budding virus particles on the cell surface, in contrast to MDCK cells which produced numerous virus particles. PAGE analysis of the plasma membrane isolated from the cells demonstrated no significant difference in the composition of viral polypeptides between permissive 1-5C-4 and nonpermissive L cells. It was noted that the abortiveness of influenza B virus infection in L cells may be due to a defect in host cell function involved in the initiation of virus budding. 相似文献
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Antizyme inhibitor was highly purified from rat liver by using affinity chromatography. It has some structural resemblance to ornithine decarboxylase (ODC), as judged from Mr, immunoreactivity and reversible binding with antizyme. However, unlike hepatic amounts of ODC and ODC-antizyme complex, that of antizyme inhibitor did not show much fluctuation upon putrescine treatment, whereas it decreased as rapidly as ODC decay in the presence of cycloheximide. These results suggested that antizyme inhibitor is an independent regulatory protein rather than a derivative of ODC. Changes in hepatic amounts of antizyme inhibitor, antizyme and ODC upon feeding suggested that antizyme inhibitor may play a role in ODC regulation by trapping antizyme and thereby suppressing ODC degradation. A monoclonal antibody to rat liver antizyme inhibitor was obtained. This antibody was shown to be utilizable for a simple assay of antizyme-inhibitor activity in tissue extracts. 相似文献
7.
T Nakahara A Shiraishi M Hirano T Matsumoto T Kuroki Y Tatebayashi T Tsutsumi K Nishiyama H Ooboshi K Nakamura 《Analytical biochemistry》1989,180(1):38-42
A highly sensitive assay for guanine was developed using high-performance liquid chromatography with electrochemical detection (ECD). Guanine was susceptible to the electrochemical oxidation, and ECD response was proportional to the amount of guanine in the range 0.25-4 pmol of guanine. The ECD of guanine was applicable to the analysis of nucleic acids. DNA and RNA were hydrolyzed in 0.03 and 3 M HCl, respectively, and guanine liberated from the nucleic acids was separated on a reverse-phase column and determined by ECD. The method allowed detection of 0.2 ng of calf thymus DNA or tRNA. An application of the method is shown for DNA and RNA assays in trichloroacetic acid extracts of rat adrenal and liver. 相似文献
8.
N Yamamoto M M Rahman M Fukushima K Maeno Y Nishiyama 《Biochemical and biophysical research communications》1989,158(1):189-194
Cyclopentenone prostaglandin (PG), delta7-PGA1 was found to induce several polypeptides in human embryonic fibroblast (HEF) cells which were noticed to be dose-related and appeared after 1 h of treatment with a peak at around 5 h and gradual disappearance after 12 h. PG-induced proteins were almost identical in terms of molecular weights with those induced by heat-shock at 42 degrees C. Regarding the mechanism of inhibition of herpes simplex virus (HSV) replication by PG in cell culture, dot blot hybridization has revealed that the level of immediate early (IE) mRNA of the virus was reduced after PG treatment with time dependence. And this delayed inhibitory effect of delta7-PGA1 on HSV was shown to be associated with the production and accumulation of the induced polypeptides. 相似文献
9.
Tatsuo Nakahara Makoto Hirano Takashi Matsumoto Toshihide Kuroki Yoshinori Tatebayashi Tetsuyuki Tsutsumi Kouji Nishiyama Hiroaki Ooboshi Kaoru Nakamura Hiroshi Yao Akio Shiraishi Michinori Waki Hideyuki Uchimura 《Neurochemical research》1990,15(6):609-611
DNA and RNA contents in 20 brain regions or nuclei of the rat were determined by a highly sensitive method using high-performance liquid chromatography with electrochemical detection. The high DNA and RNA contents were found in the hypothalamic nuclei, especially the median eminence-arcuate nucleus. These results may be available for the preparation of nucleic acids as the regional control. 相似文献
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