132 research outputs found

    Histomorphometric analysis of minimodeling in the vertebrae in postmenopausal patients treated with anti-osteoporotic agents

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    AbstractMinimodeling is a type of focal bone formation that is characterized by the lack of precedent bone erosion by osteoclasts. Although this form of bone formation has been described for more than a decade, how anti-osteoporotic agents that are currently used in clinical practice affect the kinetics of minimodeling is not fully understood. We performed a bone morphometric analysis using human vertebral specimens collected from postmenopausal patients who underwent spinal surgery. Patients were divided into three groups according to osteoporosis medication; non-treated, Eldecalcitol (ELD, a vitamin D derivative that has recently been approved to treat patients with osteoporosis in Japan)-treated, and bisphosphonate-treated groups. Five to six patients were enrolled in each group. There was a trend toward enhanced minimodeling in ELD-treated patients and suppressed of it in bisphosphonate-treated patients compared with untreated patients. The differences of minimodeling activity between ELD-treated and bisphosphonate-treated patients were statistically significant. The present study suggests that ELD and bisphosphonates have opposite effects on minimodeling from one another, and show that minimodeling also takes place in vertebrae as has been described for the ilium and femoral head in humans

    Synthesis and photophysical properties of butterfly-shaped dinuclear Pt(II) complex having NHC-based chelate ligands

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    A butterfly-shaped dinuclear Pt(II) complex having pyridyl-NHC chelate ligands and bridging Me2pz ligands was synthesized. The crystal structure of the Pt2 complex showed short intramolecular Pt?Pt distance (3.129?A) and unique packing structure containing one-dimensional infinite pore that was filled with solvent molecules. The absorbance was proportional to the concentration of Pt2 complex and no significant bands appeared even in high concentration (up to 100?μM). The Pt2 complex showed bluish-green emission (λmax?=?459?nm) in the solid state at 298?K (λex?=?330?nm). TD-DFT calculation revealed that the lowest-energy absorption bands are mainly assigned to the combination of metal-to-ligand charge transfer (MLCT) and ligand-to-ligand charge transfer (LLCT) transitions

    Reversible formation and cleavage of Pt→Ag dative bonds in a pre-organized cavity of a luminescent heteropolynuclear platinum(ii) complex

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    A U-shaped Pt2Ag2 complex [Pt2Ag2(ppy)2(Ph2pz)4] with a pre-organized cavity (ppy = 2-phenylpridinate and Ph2pz = 3,5-diphenylpyrazolate) and related complexes have been prepared. The Pt2Ag2 complexes react with Ag(I) ions to give the corresponding Pt2Ag3 complexes containing Pt→Ag dative bonds. It became obvious that the existence of the C(ipso) atom in the chelate ligand is important as the driving force for forming Pt→Ag dative bonds. However, once the Pt2Ag3 complex is formed, the trapped Ag(I) ion is mainly stabilized by the Pt→Ag dative bonds, which are stronger than the Ag?C(ipso) bond. The trapped Ag(I) ion can be abstracted from the cavity selectively by adding an equivalent amount of chloride ion into the solution of Pt2Ag3 complexes to reproduce the original Pt2Ag2 complexes.Related illustration appears in this issue\u27s inside back cover. The URL is as follows: http://dx.doi.org/10.1039/C7CC90232

    Bridging-arylene effects on spectroscopic and photophysical properties of arylborane–dipyrrinato zinc(ii) complexes

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    Novel bis(dipyrrinato)zinc(ii) derivatives having 4-[bis(2,4,6-trimethylphenyl)boryl]phenyl (ZnBph) or 4-[bis(2,4,6-trimethylphenyl)boryl]-2,3,5,6-tetramethylphenyl groups (ZnBdu) at the 5-position of the dipyrrinato ligands were designed and synthesized.InZnBphwith the smaller dipyrrinate-arylene and arylene-dimesitylboryl dihedral angles, an intramolecular charge transfer arising from the presence of the vacant p orbital on the boron atom participates in the ππ* excited state in character in contrast to the pure ππ* excited state ofZnBdu. The synergistic ππ*/ILCT excited state was weakly fluorescent, and the fluorescence was enhanced upon binding of fluoride to the boron atom

    Metastatic Patterns of Myxoid/Round Cell Liposarcoma: A Review of a 25-Year Experience

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    Myxoid/round cell liposarcoma (MRCL), unlike other soft tissue sarcomas, has been associated with unusual pattern of metastasis to extrapulmonary sites. In an attempt to elucidate the clinical features of MRCL with metastatic lesions, 58 cases, from the medical database of Keio University Hospital were used for the evaluation. 47 patients (81%) had no metastases, whereas 11 patients (11%) had metastases during their clinical course. Among the 11 patients with metastatic lesions, 8 patients (73%) had extrapulmonary metastases and 3 patients (27%) had pulmonary metastases. Patients were further divided into three groups; without metastasis, with extrapulmonary metastasis, and with pulmonary metastasis. When the metastatic patterns were stratified according to tumor size, there was statistical significance between the three groups (P = 0.028). The 8 cases with extrapulmonary metastases were all larger than 10 cm. Similarly, histological grading had a significant impact on metastatic patterns (P = 0.027). 3 cases with pulmonary metastatic lesions were all diagnosed as high grade. In conclusion, large size and low histological grade were significantly associated with extrapulmonary metastasis

    Metformin directly binds the alarmin HMGB1 and inhibits its proinflammatory activity

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    Metformin is the first-line drug in the treatment of type 2 diabetes. In addition to its hypoglycemic effect, metformin has an anti-inflammatory function, but the precise mechanism promoting this activity remains unclear. High mobility group box 1 (HMGB1) is an alarmin that is released from necrotic cells and induces inflammatory responses by its cytokine-like activity and is, therefore, a target of anti-inflammatory therapies. Here we identified HMGB1 as a novel metformin-binding protein by affinity purification using a biotinylated metformin analogue. Metformin directly bound to the C-terminal acidic tail of HMGB1. Both in vitro and in vivo, metformin inhibited inflammatory responses induced by full-length HMGB1 but not by HMGB1 lacking the acidic tail. In an acetaminophen-induced acute liver injury model in which HMGB1 released from injured cells exacerbates the initial injury, metformin effectively reduced liver injury and had no additional inhibitory effects when the extracellular HMGB1 was blocked by anti-HMGB1-neutralizing antibody. In summary, we report for the first time that metformin suppresses inflammation by inhibiting the extracellular activity of HMGB1. Because HMGB1 plays a major role in inflammation, our results suggest possible new ways to manage HMGB1-induced inflammation

    TNF-α–Converting Enzyme/A Disintegrin and Metalloprotease−17 Mediates Mechanotransduction in Murine Tracheal Epithelial Cells

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    Bronchoconstriction applies compressive stress to airway epithelial cells. We show that the application of compressive stress to cultured murine tracheal epithelial cells elicits the increased phosphorylation of extracellular signal–regulated kinase (ERK) and Akt through an epidermal growth factor receptor (EGFR)–dependent process, consistent with previous observations of the bronchoconstriction-induced activation of EGFR in both human and murine airways. Mechanotransduction requires metalloprotease activity, indicating a pivotal role for proteolytic EGF-family ligand shedding. However, cells derived from mice with targeted deletions of the EGFR ligands Tgfα and Hb-egf showed only modest decreases in responses, even when combined with neutralizing antibodies to the EGFR ligands epiregulin and amphiregulin, suggesting redundant or compensatory roles for individual EGF family members in mechanotransduction. In contrast, cells harvested from mice with a conditional deletion of the gene encoding the TNF-α–converting enzyme (TACE/ADAM17), a sheddase for multiple EGF-family proligands, displayed a near-complete attenuation of ERK and Akt phosphorylation responses and compressive stress–induced gene regulation. Our data provide strong evidence that TACE plays a critical central role in the transduction of compressive stress
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