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排序方式: 共有443条查询结果,搜索用时 15 毫秒
1.
Neuroimaging in Pineal Tumors 总被引:4,自引:0,他引:4
F Reis MD AV Faria MD PhD VA Zanardi MD PhD JR Menezes MD F Cendes MD PhD LS Queiroz MD PhD 《Journal of neuroimaging》2006,16(1):52-58
BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread. 相似文献
2.
S. A. Zaitsev O. A. Onuchina L. M. Alekseeva A. P. Arzamastsev M. A. Kalinkina V. G. Granik 《Pharmaceutical Chemistry Journal》2005,39(12):636-640
Two benzofuran derivatives — analogs of 5-lipoxygenase antagonist zileuton — have been synthesized and tested. It is established
that both compounds possess antiinflammatory activity.
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Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 12, pp. 17–20, December, 2005. 相似文献
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A novel pairing process promoted by Escherichia coli RecA protein: inverse DNA and RNA strand exchange 下载免费PDF全文
Traditionally, recombination reactions promoted by RecA-like proteins initiate by forming a nucleoprotein filament on a single-stranded DNA (ssDNA), which then pairs with homologous double-stranded DNA (dsDNA). In this paper, we describe a novel pairing process that occurs in an unconventional manner: RecA protein polymerizes along dsDNA to form an active nucleoprotein filament that can pair and exchange strands with homologous ssDNA. Our results demonstrate that this "inverse" reaction is a unique, highly efficient DNA strand exchange reaction that is not due to redistribution of RecA protein from dsDNA to the homologous ssDNA partner. Finally, we demonstrate that the RecA protein-dsDNA filament can also pair and promote strand exchange with ssRNA. This inverse RNA strand exchange reaction is likely responsible for R-loop formation that is required for recombination-dependent DNA replication. 相似文献
6.
Ziganshin AU Zaitsev AP Shamsutdinov AF 《Bulletin of experimental biology and medicine》2002,133(3):255-257
We studied contractile responses of isolated smooth muscles from human uterus induced by P2 receptor agonists. In preparations from pregnant uterus all tested P2 receptor agonists caused smooth muscle contractions. The relative activity of P2 receptor agonists decreased in the following order: a,b-methylene-ATP-uridine triphosphate-ATP. Responses induced by ATP and ADP were similar. The amplitude of contractions induced by alpha,beta-methylene-ATP significantly decreased in the presence of P2 receptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid. None of tested P2 receptor agonists induced contractions of isolated myometrium from nonpregnant women. Our results indicate that pregnant human uterus contains P2 receptors mediating the contractile response. 相似文献
7.
Myo-inositol transport in the central nervous system 总被引:18,自引:0,他引:18
8.
Zaitsev S Buchwalow I Haberland A Tkachuk S Zaitseva I Haller H Böttger M 《Acta histochemica》2002,104(1):85-92
Previously, we have shown that the transgene expression in the endothelial cell line ECV 304 strongly depends on the presence of low concentrations of Ca2+. However, it remained unclear, which transfection steps are controlled by Ca2+ ions. In the present study, we constructed transfection complexes of digoxigenin-labelled DNA and FITC-labelled histone H1. We monitored the pathway of these complexes with the use of anti-digoxigenin and anti-cathepsin B antibodies and immunofluorescence microscopy. Double labelling of DNA and cathepsin B permitted the localization of transfection complexes into endosomes/lysosomes which suggests an uptake of transfection complexes via endocytosis. It was also found that the uptake of transfection complexes by the cells was independent of the presence or absence of Ca2+ ions in the transfection medium. On the other hand, the presence of Ca2+ in the transfection medium dramatically changed the composition of the transfection complexes inside the endosome/lysosome compartment, which resulted in a strong reduction of H1 binding to DNA. Presence of Ca2+ in the postincubation medium for 24 h resulted in release of the transfection complexes with reduced H1 content from the endosomes/lysosomes into the cytosol. In the absence of Ca2+ the transfection complexes practically disappeared. These results allow us to come to the following conclusions: Ca2+ ions control the reorganization of the transfection complexes in endosomes/lysosomes and their release into the cytosol, which is an important prerequisite for transgene expression, whereas uptake of transfection complexes by the cells is not dependent on Ca2+. 相似文献
9.
Zaitsev M D'Arcy J Collins DJ Leach MO Zilles K Shah NJ 《Physics in medicine and biology》2005,50(19):4491-4505
A new EPI-based method is presented which features optimized sampling of k-space enabling the integrated acquisition of two gradient echo images. The first of these images is predominantly T1 weighted and the second is T*2 weighted. The new method combines echo sharing of sparsely acquired high spatial frequency components with the keyhole technique and half-Fourier image reconstruction. The feasibility of acquiring high spatial and temporal resolution in vivo images for perfusion mapping is demonstrated. In contrast to most current perfusion methods, which acquire the T1- and T*2-weighted images in separate acquisitions, the need for image co-registration here is obviated since both sets of images are EPI-based and are acquired within the same measurement. 相似文献
10.
Denis A. Mogilenko Oleg Shpynov Prabhakar Sairam Andhey Laura Arthur Amanda Swain Ekaterina Esaulova Simone Brioschi Irina Shchukina Martina Kerndl Monika Bambouskova Zhangting Yao Anwesha Laha Konstantin Zaitsev Samantha Burdess Susan Gillfilan Sheila A. Stewart Marco Colonna Maxim N. Artyomov 《Immunity》2021,54(1):99-115.e12