206 research outputs found

    Copper-Catalyzed Regioselective C-H Amination of Phenol Derivatives with Assistance of Phenanthroline-Based Bidentate Auxiliary

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    A copper-catalyzed regioselective direct amination of phenol derivatives with diarylamines via phenanthroline-based bidentate auxiliary-directed C-H cleavage has been developed. This reaction proceeds smoothly with only a copper salt and air as a terminal oxidant to produce the corresponding o-aminophenols in good yields. Moreover, the directing group can be easily attached, detached, and recycled. Additionally, preliminary computational studies of the reaction with DFT have also been performed.Takamatsu K., Hayashi Y., Kawauchi S., et al. Copper-Catalyzed Regioselective C-H Amination of Phenol Derivatives with Assistance of Phenanthroline-Based Bidentate Auxiliary. ACS Catalysis. 9(6), 5336-5344 (2019), 7 June 2019; © 2019 American Chemical Society. https://doi.org/10.1021/acscatal.9b01145

    Copper-Mediated Decarboxylative C–H Arylation of Phenol Derivatives with ortho-Nitrobenzoic Acids Using Phenanthroline-Based Bidentate Auxiliary

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    A copper-mediated decarboxylative C–H arylation of phenol derivatives with ortho-nitrobenzoic acid salts via phenanthroline-directed C–H cleavage has been developed. The N,N-bidentate phenanthroline auxiliary uniquely promotes the reaction only in the presence of a copper salt to produce the corresponding biaryls in acceptable yields. Moreover, the directing group can be easily introduced and removed. Additionally, preliminary computational mechanistic studies with DFT have also been performed.Takamatsu K., Hayashi Y., Kawauchi S., et al. Copper-Mediated Decarboxylative C–H Arylation of Phenol Derivatives with ortho-Nitrobenzoic Acids Using Phenanthroline-Based Bidentate Auxiliary. ChemistrySelect 4, 11833 (2019); https://doi.org/10.1002/slct.201902860

    Rhodium-catalyzed annulative coupling of isothiazoles with alkynes through n-s bond cleavage

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    A Rh(III)-catalyzed annulative coupling of 3,5-diarylisothiazoles and alkynes is reported. The N–S bond in the isothi-azole ring acts as an internal oxidant to regenerate the Rh(III) species in combination with an external Cu(II) oxidant, and the corre-sponding 1:2 coupling products are obtained. The remarkable difference in the reaction outcome between isothiazoles and the relevant isoxazoles has been investigated by DFT calculations, revealing that the relative stability of the enolate intermediates dictates the product selectivity.Mihara G., Noguchi T., Nishii Y., et al. Rhodium-catalyzed annulative coupling of isothiazoles with alkynes through n-s bond cleavage. Organic Letters. 22(2), 661-665, (2020), 17 January 2020; ©2020 American Chemical Society. https://doi.org/10.1021/acs.orglett.9b04437

    A Pediatric Case of Cauda Equina Dermoid Cyst Resected by Minimally Invasive Unilateral Hemilaminectomy

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    A 3-year-old boy had difficulty sitting up and walking for several months. Magnetic resonance imaging (MRI) revealed an intradural tumor at the L3-4 level. The tumor was successfully resected by unilateral hemilaminectomy and diagnosed as dermoid cyst. The patient had an uneventful postoperative course without pain, and MRI found no recurrence after surgery. A small bone defect remained that might be favorably reconstructed with autologous and artificial bone. Hemilaminectomy allowed us to resect the cauda equina dermoid cyst with minimal invasiveness. Pediatric patients require follow-up as they are more likely to experience spinal deformity or instability after surgery

    Infrequent RAS mutation is not associated with specific histological phenotype in gliomas

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    BACKGROUND: Mutations in driver genes such as IDH and BRAF have been identified in gliomas. Meanwhile, dysregulations in the p53, RB1, and MAPK and/or PI3K pathways are involved in the molecular pathogenesis of glioblastoma. RAS family genes activate MAPK through activation of RAF and PI3K to promote cell proliferation. RAS mutations are a well-known driver of mutation in many types of cancers, but knowledge of their significance for glioma is insufficient. The purpose of this study was to reveal the frequency and the clinical phenotype of RAS mutant in gliomas. METHODS: This study analysed RAS mutations and their clinical significance in 242 gliomas that were stored as unfixed or cryopreserved specimens removed at Kyoto University and Osaka National Hospital between May 2006 and October 2017. The hot spots mutation of IDH1/2, H3F3A, HIST1H3B, and TERT promoter and exon 2 and exon 3 of KRAS, HRAS, and NRAS were analysed with Sanger sequencing method, and 1p/19q codeletion was analysed with multiplex ligation-dependent probe amplification. DNA methylation array was performed in some RAS mutant tumours to improve accuracy of diagnosis. RESULTS: RAS mutations were identified in four gliomas with three KRAS mutations and one NRAS mutation in one anaplastic oligodendroglioma, two anaplastic astrocytomas (IDH wild-type in each), and one ganglioglioma. RAS-mutant gliomas were identified with various types of glioma histology. CONCLUSION: RAS mutation appears infrequent, and it is not associated with any specific histological phenotype of glioma

    Transcriptome analysis of a dog model of congestive heart failure shows that collagen-related 2-oxoglutarate-dependent dioxygenases contribute to heart failure

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    Fibrosis is an important pathological mechanism in heart failure (HF) and is associated with poor prognosis. We analyzed fibrosis in HF patients using transcriptomic data. Genes differentially expressed between normal control and congestive HF (CHF) dogs included P3H1, P3H2, P3H4, P4HA2, PLOD1 and PLOD3, which belong to the 2-oxoglutarate-dependent dioxygenases (2OGD) superfamily that stabilizes collagen during fibrosis. Quantitative polymerase chain reaction analysis demonstrated 2OGD gene expression was increased in CHF samples compared with normal left ventricle (LV) samples. 2OGD gene expression was repressed in angiotensin converting enzyme inhibitor-treated samples. These genes, activated the hydroxylation of proline or lysin residues of procollagen mediated by 2-oxoglutaric acid and O2, produce succinic acid and CO2. Metabolic analysis demonstrated the concentration of succinic acid was significantly increased in CHF samples compared with normal LV samples. Fibrosis was induced in human cardiac fibroblasts by TGF-ß1 treatment. After treatment, the gene and protein expressions of 2OGD, the concentration of succinic acid, and the oxygen consumption rate were increased compared with no treatment. This is the first study to show that collagen-related 2OGD genes contribute to HF during the induction of fibrosis and might be potential therapeutic targets for fibrosis and HF

    The usefulness of re-attachability of anti-adhesive cross-linked gelatin film and the required physical and biological properties.

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    Background:To overcome the unfavorable issues associated with conventional anti-adhesive HA/CMC film, we developed an anti-adhesive thermally cross-linked gelatin film.Objective:We tried to clarify the re-attachability of the film and the required properties concerning the film thickness, stiffness and anti-adhesion effect.Methods:To determine the optimal thickness, 5 kinds of the thickness of gelatin film and the conventional film were analyzed by the tensile test, shearing test, buckling test and tissue injury test. Finally, using the optimal film thickness, we tried to clarify the anti-adhesion effect of the reattached film.Results:The tensile and shearing test showed gelatin films ≥30 μm thick had greater tensile strength and a smaller number of film fractures, than the conventional film. The buckling and tissue injury test showed gelatin films ≥60 μm thick had higher buckling strength and worse injury scores than the conventional film. The anti-adhesive effect of re-attached gelatin film using optimal thickness (30-40 μm) found the anti-adhesion score was significantly better than that of the control.Conclusions:Provided it has an optimal thickness, gelatin film can be reattached with enough physical strength not to tear, safety stiffness not to induce tissue injury, and a sufficient anti-adhesion effect

    Cryptotanshinone, a novel PDK 4 inhibitor, suppresses bladder cancer cell invasiveness via the mTOR/β‑catenin/N‑cadherin axis.

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    The phosphorylation of pyruvate dehydrogenase (PDH) by pyruvate dehydrogenase kinase (PDK) 4 inhibits its ability to induce a glycolytic shift. PDK4 expression is upregulated in various types of human cancer. Because PDK4 regulation is critical for metabolic changes in cancer cells, it is an attractive target for cancer therapy given its ability to shift glucose metabolism. It was previously shown that a novel PDK4 inhibitor, cryptotanshinone (CPT), suppressed the three‑dimensional (3D)‑spheroid formation of pancreatic and colorectal cancer cells. In the present study, the effects of CPT on the invasiveness of bladder cancer cells were investigated. CPT significantly suppressed the invasiveness and 3D‑spheroid formation of T24 and J82 bladder cancer cells. CPT also suppressed the phosphorylation of PDH and β‑catenin, as well as the expression of N‑cadherin, which are all critical for inducing epithelial‑mesenchymal transition (EMT). The knockdown of β‑catenin or PDK4 using specific small interfering RNAs suppressed N‑cadherin expression and invasiveness in T24 cells. An mTOR inhibitor also suppressed the phosphorylation of β‑catenin and N‑cadherin expression. Furthermore, CPT injection significantly suppressed pancreatic tumor growth and peritoneal dissemination of highly metastatic SUIT‑2 pancreatic cancer cells in a mouse orthotopic pancreatic cancer model, without evident toxicity. Moreover, immunohistochemistry analyses demonstrated decreased β‑catenin expression in CPT‑treated pancreatic tumors compared with control tumors. Taken together, these results indicate that CPT reduced the invasiveness and metastasis of bladder cancer cells by suppressing EMT via the mTOR/β‑catenin/N‑cadherin pathway
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