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991.
Temperature-sensitive (ts) CHO-K1 mutant tsTM3 exhibits chromosomal instability and cell-cycle arrest in the S to G2 phases with decreased DNA synthesis at the nonpermissive temperature, 39°C. Previously, complementation tests with other mutants showed that tsTM3 harbors a genetic defect in the ubiquitin-activating enzyme Uba1. Sequence comparison of the Uba1 gene between wild-type and mutant cells in this study revealed that the mutant phenotype is caused by a G-to-A transition that yields a Met-to-Ile substitution at position 256 in hamster Uba1. The ts defects in tsTM3 were complemented by expression of the wild-type Uba1 tagged with green fluorescent protein. Expression of the Uba1 primarily in the nucleus appeared to rescue tsTM3 cells. Incubation at 39°C resulted in a decrease of nuclear Uba1 in tsTM3 cells, suggesting that loss of Uba1 in the nucleus may lead to the ts defects. Analyses with the fluorescent ubiquitination-based cell cycle indicator revealed that loss of function of Uba1 leads to failure of the ubiquitin system in the nucleus. Incubation at 39°C caused an increase in endogenous geminin in tsTM3 cells. A ts mutation of Uba1 found in tsTM3 cells appears to be a novel mutation reflecting the important roles of Uba1 in nucleus. 相似文献
992.
Tohru Ueda Satoshi Shuto Miyuki Satoh Hideo Inoue 《Nucleosides, nucleotides & nucleic acids》2013,32(3):401-409
Abstract Synthesis of a carbon-bridged cyclouridine,2′-deoxy-6,2′-ethano-cyclouridine, was accomplished starting from a 2′-ketouridine via the 2′-deoxy-2′-iodoethyl-5-chlorouridine derivative through a radical cyclization. 相似文献
993.
Kenshi Katahira Hiroshi Moriwaki Miho Ishitake Yoko Saito-Kokubu Hideo Yamazaki Shusaku Yoshikawa 《Soil & Sediment Contamination》2013,22(8):1003-1012
Sediment core samples were obtained from Nishiyama Reservoir, 3 km east of the hypocenter of the Nagasaki atomic bomb, to evaluate both sources and inventories of lead delivery to the sediments. Using microwave digestions and ICP-MS analytical techniques, elevated concentrations of isotopically unique lead were identified in the 1945 sediment horizon. These results illustrate that the Nagasaki bomb attack can be linked with unique lead loading to the sediments in the region of the hypocenter. There is a possibility that the roll-up of in-situ lead accounted for a majority of the increase in lead flux delivered to reservoir sediments during the atomic bomb attack. 相似文献
994.
Nienke van der Werf Stephen A. Redpath Miyuki Azuma Hideo Yagita Matthew D. Taylor 《PLoS pathogens》2013,9(3)
The suppression of protective Type 2 immunity is a principal factor driving the chronicity of helminth infections, and has been attributed to a range of Th2 cell-extrinsic immune-regulators. However, the intrinsic fate of parasite-specific Th2 cells within a chronic immune down-regulatory environment, and the resultant impact such fate changes may have on host resistance is unknown. We used IL-4gfp reporter mice to demonstrate that during chronic helminth infection with the filarial nematode Litomosoides sigmodontis, CD4+ Th2 cells are conditioned towards an intrinsically hypo-responsive phenotype, characterised by a loss of functional ability to proliferate and produce the cytokines IL-4, IL-5 and IL-2. Th2 cell hypo-responsiveness was a key element determining susceptibility to L. sigmodontis infection, and could be reversed in vivo by blockade of PD-1 resulting in long-term recovery of Th2 cell functional quality and enhanced resistance. Contrasting with T cell dysfunction in Type 1 settings, the control of Th2 cell hypo-responsiveness by PD-1 was mediated through PD-L2, and not PD-L1. Thus, intrinsic changes in Th2 cell quality leading to a functionally hypo-responsive phenotype play a key role in determining susceptibility to filarial infection, and the therapeutic manipulation of Th2 cell-intrinsic quality provides a potential avenue for promoting resistance to helminths. 相似文献
995.
Mayumi Yamato Takeshi Shiba Ken-Ichi Yamada Toshiaki Watanabe Hideo Utsumi 《Free radical research》2013,47(9):844-851
Free radicals are believed to be key factors that promote ischemia reperfusion injury in the brain. This study used the characteristic spectrum of methoxycarbonyl-PROXYL to detect free radical reactions in hydrophilic and lipophilic compartments in a transient middle cerebral artery occlusion (MCAO) mouse model. Methoxycarbonyl-PROXYL, which has a high water/octanol partition coefficient, allows the detection of nitroxyl radical in both compartments simultaneously. Free radicals generation was analysed from the enhanced ESR signal decay rate of methoxycarbonyl-PROXYL. The signal decay rate in the lipidic compartment was significantly enhanced 1 h after reperfusion following MCAO. The enhanced signal decay rate was significantly suppressed by Trolox. The accumulation of lipid peroxidation products increased by 6 h post-reperfusion and was suppressed by methoxycarbonyl-PROXYL or Trolox. These results demonstrate that information pertaining to different sites of free radical generation in vivo can be obtained simultaneously and that lipid-derived radicals are generated in transient MCAO mice. 相似文献
996.
George Imataka Hideo Yamanouchi Junko Hirato Mitsuoki Eguchi Masaru Kojima Koichi Honma Osamu Arisaka 《Cell biochemistry and biophysics》2013,67(2):813-817
We present here a long survival case of a patient with the mosaic form of trisomy 13 who died of aspiration pneumonia at the age of 7 years and 4 months. The autopsy revealed olfactory aplasia and fenestration of the septum pellucidum, and dilated lateral ventricles and atrophic hippocampus. Furthermore, there were numerous “torpedos” (i.e., swollen fusiform Purkinje cell axons), mostly in the granular layer underneath the Purkinje cell layer, and, occasionally, in the granular layer. Similar neuropathological findings have been reported in elderly cases of essential tremor, Parkinson’s disease, or Alzheimer’s disease. Precise mechanism for this axonal change is still unclear. These pathological changes have never previously been reported in the literature on trisomy 13, and the present patient is one of the oldest autopsied individuals with the mosaic trisomy 13. 相似文献
997.
Wei Zhang Hideo Tsurushima Ayako Oyane Yushin Yazaki Yu Sogo Atsuo Ito Akira Matsumura 《Journal of biomedical science》2011,18(1):62
Background
Safe and efficient gene transfer systems are needed for tissue engineering. We have developed an apatite composite layer including the bone morphogenetic protein-2 (BMP-2) gene and fibronectin (FB), and we evaluated its ability to induce bone formation. 相似文献998.
Interferon (IFN)-α was reported to be effective in longterm intrathecal treatment of subacute sclerosing panencephalitis (SSPE).
However, the side effects related with longterm use of IFN-α/β are unclear. We evaluated the therapeutic effects of IFN-α/β
in a 13-years-old patient with SSPE. The cerebrospinal fluid (CSF) measles antibody titer was 64 × NT/128×HI, IgG-index was
4.5, and the SSPE diagnosis was based on electroencephalography (Jabbour-stage II on admission). With Inosiplex (INP) given
orally, IFN-α (3 × 106 units) was infused intraventricularly twice-a-week for 1-year. Resultantly, CSF cell count was elevated (2502/3), total protein
and glucose levels were normal; however, DIAM occurred repeatedly. Consequently, reduced IFN-α (5 × 105 units) with hydrocorton was administered at 2-months interval for 19 months, during which, DIAM occurred four times. Therefore,
IFN-β (3 × 106 units; twice-a-week) therapy was started and continued for 3 years. Although the symptoms were improved considerably, DIAM
recurred after 15-months therapy and CSF cell counts were also elevated (2121/3). Since SSPE progressed to Jabbour-stage IV,
indicated by irreversible consciousness disorder, IFN therapy was discontinued and INP monotherapy was followed for another
3 years. We, therefore, concluded that the longterm intraventricular IFN-α/β infusion therapy of SSPE involved the potential
risk of DIAM with serious irreversible neurological sequelae and should be monitored carefully. 相似文献
999.
Badets M Whittington I Lalubin F Allienne JF Maspimby JL Bentz S Du Preez LH Barton D Hasegawa H Tandon V Imkongwapang R Imkongwapang R Ohler A Combes C Verneau O 《Systematic biology》2011,60(6):762-781
Investigating patterns and processes of parasite diversification over ancient geological periods should involve comparisons of host and parasite phylogenies in a biogeographic context. It has been shown previously that the geographical distribution of host-specific parasites of sarcopterygians was guided, from Palaeozoic to Cainozoic times, mostly by evolution and diversification of their freshwater hosts. Here, we propose phylogenies of neobatrachian frogs and their specific parasites (Platyhelminthes, Monogenea) to investigate coevolutionary processes and historical biogeography of polystomes and further discuss all the possible assumptions that may account for the early evolution of these parasites. Phylogenetic analyses of concatenated rRNA nuclear genes (18S and partial 28S) supplemented by cophylogenetic and biogeographic vicariance analyses reveal four main parasite lineages that can be ascribed to centers of diversity, namely Australia, India, Africa, and South America. In addition, the relationships among these biogeographical monophyletic groups, substantiated by molecular dating, reflect sequential origins during the breakup of Gondwana. The Australian polystome lineage may have been isolated during the first stages of the breakup, whereas the Indian lineage would have arisen after the complete separation of western and eastern Gondwanan components. Next, polystomes would have codiverged with hyloid sensu stricto and ranoid frog lineages before the completion of South American and African plate separation. Ultimately, they would have undergone an extensive diversification in South America when their ancestral host families diversified. Therefore, the presence of polystome parasites in specific anuran host clades and in discrete geographic areas reveals the importance of biogeographic vicariance in diversification processes and supports the occurrence and radiation of amphibians over ancient and recent geological periods. 相似文献
1000.