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91.
We describe the synthesis of 11C-labeled α-aminoisobutyric acid 2 from iodo[11C]methane and methyl N-(diphenylmethylen)-d,l-alaniate (5). The tetrabutylammonium fluoride (TBAF)-promoted α-[11C]methylation of sterically hindered analog 5 was a key step in our synthesis process. Total radiochemical conversion of 2 was high and a remote-controlled synthesis was carried out. A comparative tumor positron emission tomography (PET) imaging study using the same model mouse showed higher uptake of 2 than with 11C-labeled methionine and [18F] fluorodeoxyglucose (FDG). 相似文献
92.
Miyuki Bohgaki Masaki Matsumoto Tatsuya Atsumi Takeshi Kondo Shinsuke Yasuda Tetsuya Horita Keiichi I. Nakayama Fumihiko Okumura Shigetsugu Hatakeyama Takao Koike 《Journal of cellular and molecular medicine》2011,15(1):141-151
Antiphospholipid syndrome (APS) is characterized by thrombosis and the presence of antiphospholipid antibodies (aPL) that directly recognizes plasma β2‐glycoprotein I (β2GPI). Tissue factor (TF), the major initiator of the extrinsic coagulation system, is induced on monocytes by aPL in vitro, explaining in part the pathophysiology in APS. We previously reported that the mitogen‐activated protein kinase (MAPK) pathway plays an important role in aPL‐induced TF expression on monocytes. In this study, we identified plasma gelsolin as a protein associated with β2GPI by using immunoaffinity chromatography and mass spectrometric analysis. An in vivo binding assay showed that endogenous β2GPI interacts with plasma gelsolin, which binds to integrin a5β1 through fibronectin. The tethering of β2GPI to monoclonal anti‐β2GPI autoantibody on the cell surface was enhanced in the presence of plasma gelsolin. Immunoblot analysis demonstrated that p38 MAPK protein was phosphorylated by monoclonal anti‐β2GPI antibody treatment, and its phosphorylation was attenuated in the presence of anti‐integrin a5β1 antibody. Furthermore, focal adhesion kinase, a downstream molecule of the fibronectin‐integrin signalling pathway, was phosphorylated by anti‐β2GPI antibody treatment. These results indicate that molecules including gelsolin and integrin are involved in the anti‐β2GPI antibody‐induced MAPK pathway on monocytes and that integrin is a possible therapeutic target to modify a prothrombotic state in patients with APS. 相似文献
93.
The establishment of transient gene expression systems in the marine red macroalga Porphyra yezoensis has been useful for the molecular analysis of cellular processes in this species. However, there has been no successful report about the expression of foreign genes in other red macroalgae, which has impeded the broader understanding of the molecular biology of these species. We therefore examined whether the P. yezoensis transient gene expression system was applicable to other red macroalgae. The results indicated that a codon-optimized GUS, designated PyGUS, and plant-adapted sGFP(S65T) were successfully expressed under the control of the P. yezoensis PyAct1 promoter in gametophytic cells of six Porphyra species and also in Bangia fuscopurpurea, all of which are classified as Bangiophyceae. In contrast, there were no reporter-expressing cells in the Florideophycean algae examined. These results indicate the availability of PyGUS and sGFP as reporters and the 5' upstream region of the PyAct1 gene as a heterologous promoter for transient gene expression in Bangiophycean algae, which could provide a clue to the efficient expression of foreign genes and transformation in marine red macroalgae. 相似文献
94.
Odaka K Aoki I Moriya J Tateno K Tadokoro H Kershaw J Minamino T Irie T Fukumura T Komuro I Saga T 《PloS one》2011,6(10):e25487
Background
Transplantation of mononuclear cells (MNCs) has previously been tested as a method to induce therapeutic angiogenesis to treat limb ischemia in clinical trials. Non-invasive high resolution imaging is required to track the cells and evaluate clinical relevance after cell transplantation. The hypothesis that MRI can provide in vivo detection and long-term observation of MNCs labeled with manganese contrast-agent was investigated in ischemic rat legs.Methods and Findings
The Mn-labeled MNCs were evaluated using 7-tesla high-field magnetic resonance imaging (MRI). Intramuscular transplanted Mn-labeled MNCs were visualized with MRI for at least 7 and up to 21 days after transplantation in the ischemic leg. The distribution of Mn-labeled MNCs was similar to that of 111In-labeled MNCs measured with single-photon emission computed tomography (SPECT) and DiI-dyed MNCs with fluorescence microscopy. In addition, at 1–2 days after transplantation the volume of the site injected with intact Mn-labeled MNCs was significantly larger than that injected with dead MNCs, although the dead Mn-labeled MNCs were also found for approximately 2 weeks in the ischemic legs. The area covered by CD31-positive cells (as a marker of capillary endothelial cells) in the intact Mn-MNCs implanted site at 43 days was significantly larger than that at a site implanted with dead Mn-MNCs.Conclusions
The present Mn-enhanced MRI method enabled visualization of the transplanted area with a 150–175 µm in-plane spatial resolution and allowed the migration of labeled-MNCs to be observed for long periods in the same subject. After further optimization, MRI-based Mn-enhanced cell-tracking could be a useful technique for evaluation of cell therapy both in research and clinical applications. 相似文献95.
96.
Unfolding intermediates have been found only rarely in earlier studies, and how a protein unfolds is therefore poorly understood. In this paper, we show experimental evidence for multiple pathways and multiple intermediates during unfolding reaction of O(6)-methylguanine-DNA methyltransferase from hyperthermophile Thermococcus kodakaraensis (Tk-MGMT). The unfolding profiles monitored by far-UV CD and tryptophan fluorescence were both biphasic, and unfolding monitored by fluorescence was faster than that monitored by CD. GdnHCl-induced titration curves indicate that the intermediates with significant alpha-helical structure accumulate during unfolding. Dependence of kinetic phases on initial GdnHCl concentrations and cysteine reactivity of Tk-MGMT were investigated, suggesting that the heterogeneity of native conformations and parallel unfolding pathways. 相似文献
97.
We investigated whether angiotensin II (AII) peptide is induced in the rat kidney under endotoxemic conditions. Immunohistochemistry revealed strong AII-like immunoreactivity in the renal tubules of rats given high-dose lipopolysaccharide (LPS; 1000 microg/kg) intraperitoneally (i.p.). AII-like immunoreactivity in renal tubules was slight at 1h after the LPS injection, but marked at 3 h. There were few signals in the kidney in saline-injected control rats. When injected at 0.1, 10, or 1000 microg/kg i.p., LPS-induced a dose-related increase in AII-like immunoreactivity in renal tubules that was unaffected by treatment with the prostaglandin-synthesis blocker indomethacin. ELISA measurement of the AII concentration in the whole kidney supported the above findings. These results suggest that systemically administered LPS induces AII peptide expression in renal tubules by a prostaglandin-independent mechanism. 相似文献
98.
Two sub-strains of the anoxygenic photosynthetic green sulfur bacterium Chlorobium vibrioforme NCIB 8327 were derived from the same clone and could be discriminated only by their possession of either bacteriochlorophyll (BChl) c or d as the major pigment in the peripheral light-harvesting antenna system, chlorosome (Saga Y et al. (2003) Anal Sci 19: 1575–1579). In the presence of a proper amount of oxygen in the initial culture medium, the BChl d strain showed longer retardation on its growth initiation than the BChl c strain, indicating that the latter was advantageous for survival under aerobic light conditions which produced reactive oxygen species in vivo. The result would be ascribable to the difference of the midpoint potentials between two kinds of chlorosomes formed by self-aggregates of BChl c and d as measured by their fluorescence quenching. 相似文献
99.
Yasunaga M Tada S Torikai-Nishikawa S Nakano Y Okada M Jakt LM Nishikawa S Chiba T Era T Nishikawa S 《Nature biotechnology》2005,23(12):1542-1550
Preparation of specific lineages at high purities from embryonic stem (ES) cells requires both selective culture conditions and markers to guide and monitor the differentiation. In this study, we distinguished definitive and visceral endoderm by using a mouse ES cell line that bears the gfp and human IL2R alpha (also known as CD25) marker genes in the goosecoid (Gsc) and Sox17 loci, respectively. This cell line allowed us to monitor the generation of Gsc+ Sox17+ definitive endoderm and Gsc- Sox17+ visceral endoderm and to define culture conditions that differentially induce definitive and visceral endoderm. By comparing the gene expression profiles of definitive and visceral endoderm, we identified seven surface molecules that are expressed differentially in the two populations. One of the seven markers, Cxcr4, to which a monoclonal antibody is available allowed us to monitor and purify the Gsc+ population from genetically unmanipulated ES cells under the condition that selects definitive endoderm. 相似文献
100.