24 research outputs found
Regular-Triangle Trimer and Charge Order Preserving the Anderson Condition in the Pyrochlore Structure of CsWO
Since the discovery of the Verwey transition in magnetite, transition metal
compounds with pyrochlore structures have been intensively studied as a
platform for realizing remarkable electronic phase transitions. We report the
discovery of a unique phase transition that preserves the cubic symmetry of the
beta-pyrochlore oxide CsWO, where each of W 5d electrons are confined
in regular-triangle W3 trimers. This trimer formation is an unprecedented
self-organization of d electrons, which can be resolved into a charge order
satisfying the Anderson condition in a nontrivial way, orbital order caused by
the distortion of WO6 octahedra, and the formation of a spin-singlet pair in a
regular-triangle trimer. Electronic instability due to the unusual
three-dimensional nesting of Fermi surfaces and the localized nature of the 5d
electrons characteristic of the pyrochlore oxides were found to play important
roles in this unique charge-orbital-spin coupled phenomenon.Comment: 7 pages, 3 figure
The activation of Proteinase-Activated Receptor-1 (PAR1) mediates gastric cancer cell proliferation and invasion
<p>Abstract</p> <p>Background</p> <p>In addition to regulating platelet function, the G protein-coupled sub-family member Proteinase-activated receptor-1 (PAR1) has a proposed role in the development of various cancers, but its exact role and mechanism of action in the invasion, metastasis, and proliferation process in gastric cancer have yet to be completely elucidated. Here, we analyzed the relationship between PAR1 activation, proliferation, invasion, and the signaling pathways downstream of PAR1 activation in gastric cancer.</p> <p>Methods</p> <p>We established a PAR1 stably transfected MKN45 human gastric cancer cell line (MKN45/PAR1) and performed cell proliferation and invasion assays employing this cell line and MKN28 cell line exposed to PAR1 agonists (α-thrombin and TFLLR-NH<sub>2</sub>). We also quantified NF-κB activation by electrophoretic mobility shift assay (EMSA) and the level of Tenascin-C (TN-C) expression in conditioned medium by ELISA of MKN45/PAR1 following administration of α-thrombin. A high molecular weight concentrate was derived from the resultant conditioned medium and subsequent cultures of MKN45/PAR1 and MKN28 were exposed to the resultant concentrate either in the presence or absence of TN-C-neutralizing antibody. Lysates of these subsequent cells were probed to quantify levels of phospholyrated Epidermal Growth Factor Receptor (EGFR).</p> <p>Result</p> <p>PAR1 in both PAR1/MKN45 and MKN28 was activated by PAR1 agonists, resulting in cell proliferation and matrigel invasion. We have shown that activation of NF-κB and EGFR phosphorylation initially were triggered by the activation of PAR1 with α-thrombin. Quantitative PCR and Western blot assay revealed up-regulation of mRNA and protein expression of NF-κB target genes, especially TN-C, a potential EGFR activator. The suppressed level of phosphorylated EGFR, observed in cells exposed to concentrate of conditioned medium in the presence of TN-C-neutralizing antibody, identifies TN-C as a putative autocrine stimulatory factor of EGFR possibly involved in the sustained PAR1 activation responses observed.</p> <p>Conclusion</p> <p>Our data indicate that in gastric carcinoma cells, PAR1 activation can trigger an array of responses that would promote tumor cell growth and invasion. Over expression of NF-κB, EGFR, and TN-C, are among the effects of PAR1 activation and TN-C induces EGFR activation in an autocrine manner. Thus, PAR1 is a potentially important therapeutic target for the treatment of gastric cancer.</p
The biosynthesis of astaxanthin-VII. The carotenoids in sea bream, Chrysophrys major Temminck and Schlegel
1. 1. Astaxanthin was the major pigment in the integuments of sea bream. 2. 2. Besides 3,3′-dihydroxy-ε-carotene, lutein, α-doradexanthin ester and astaxanthin, the existence of zeaxanthin and α-carotene was confirmed. 3. 3. In the internal organs, echinenone and 3,3′-dihydroxy-ε-carotene were the dominant pigments and also the existence of β-carotene, zeaxanthin, lutein and astaxanthin was confirmed. © 1973
Response to Modified TEGAFIRI in a Patient with Synchronous Multiple Liver Metastases of Colon Cancer
We report the case of a patient with colon cancer accompanied by multiple unresectable liver metastases who showed complete response (CR) to modified TEGAFIRI (mTEGAFIRI) (tegafur-uracil/leucovorin+irinotecan) chemotherapy. The patient was a 58-year-old Japanese male with cancer of the descending colon accompanied by multiple unresectable liver metastases. Following resection of the sigmoid colon cancer, mTEGAFIRI chemotherapy was administered. Abdominal computed tomography performed upon completion of 12 courses of chemotherapy showed that the unresectable liver metastatic lesions had disappeared, indicating CR. The only adverse drug reactions (ADRs) experienced to date have been stomatitis (grade 1) and neutropenia (grade 1). Anticancer therapy has thus been continued, and CR has been maintained for 15 months. The present patient achieved CR in response to mTEGAFIRI chemotherapy, a regimen that has not previously been reported, while experiencing only mild ADRs and maintaining a good quality of life. mTEGAFIRI chemotherapy is convenient to administer and is thought to be a potentially useful treatment option for patients with unresectable, recurrent colon cancer