Publications by authors named "Motohiro Tanaka"

The articular cartilage is an avascular tissue, and oxygen tensions in its superficial and deeper zones are estimated to be 6% and 1%. Degeneration of the articular cartilage begins from the surface zone in osteoarthritis. We previously reported that monocarboxylate transporter-1, a transmembrane transporter for monocarboxylates, played an essential role in the interleukin-1β-induced expression of NADPH oxidase-2, a reactive oxygen species-producing enzyme, and reactive oxygen species-dependent death of mouse chondrogenic ATDC5 cells cultured in a normal condition (20% oxygen).

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Background/aim: Indoleamine 2,3-dioxygenase (IDO) is regarded as an important molecular target for cancer immune therapy. This study aimed to examine the IDO1 inhibitory activity of newly synthesized indomethacin derivatives to develop an IDO1 inhibitor.

Materials And Methods: The inhibitory effects of indole-containing compounds against recombinant human IDO1 (rhIDO1) were evaluated.

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Bisphosphonates distributed to bone exert toxic effects specifically towards osteoclasts. On the other hand, intravenous administration of a nitrogen-containing bisphosphonate (N-BP) such as zoledronate induces acute-phase reactions (APRs), including influenza-like fever 1 day later, indicating an interaction with immunocompetent cells circulating blood. Although it has been reported that activation of γδ T cells is pivotal to induce an APR following treatment with zoledronate, downstream events, including the production of inflammatory cytokines after activation of γδ T cells, remain obscure.

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Neutrophils are one of the most abundant leukocytes in the sites of lesion of inflammatory diseases such as periodontitis and rheumatoid arthritis. These diseases are accompanied by bone loss, which worsens the quality of life of the patients. However, the role of neutrophils in the inflammatory bone loss has not been fully investigated.

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Background: This study compared the effects of rapid maxillary expansion (RME) and slow maxillary expansion (SME) using cone-beam computed tomography (CBCT).

Aim: To evaluate the skeletal and dentoalveolar effects produced by two different maxillary expansion protocols.

Design: Eligibility criteria included maxillary transverse deficiencies in children (mean age, 8.

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Purpose: To evaluate the accuracy of the maxillary segment positioning method using a splint fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM) and surgical navigation in patients who required two-jaw surgery.

Methods: Subjects were 35 patients requiring two-jaw surgery. A 3-dimensional (3D) skull model was prepared using cone-beam computed tomography (CBCT) data and dentition model scan data.

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Trisubstituted 5-organostibano-1H-1,2,3-triazoles (3a-f) were synthesized by the Cu-catalyzed azide-alkyne cycloaddition of various ethynylstibanes (1) with benzylazide (2) in the presence of CuBr (5 mol%) under aerobic conditions. The reaction of 5-stibanotriazoles with HCl afforded C5-unsubstituted 1,2,3-triazoles (4a-f). The antitumor activity of trisubstituted 5-organostibano-1H-1,2,3-triazoles (3a-f) and their 5-unsubstituted 1,2,3-triazoles (4a-f) were evaluated in several tumor cell lines.

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To investigate the chemical structure-cytotoxicity relationship of methacrylate-based resin monomers, we studied their effects on anti-oxidant responsive element (ARE)-mediated transcription. HepG2 cells stably expressing an ARE-regulated luciferase reporter gene were cultured for 6 h with various concentrations of several resin monomers and subjected to a luciferase assay. The doseresponse curves observed for hydrophobic monomers with different hydrocarbon chains (MMA, EMA, PMA and BMA) began to rise at concentrations between 0.

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The porpose of this study was to determine the optimal length of power arms for achieving controlled anterior tooth movement in segmented arch mechanics combined with power arm. A three-dimensional finite element method was applied for the simulation of en masse anterior tooth retraction in segmented power arm mechanics. The type of tooth movement, namely, the location of center of rotation of the maxillary central incisor in association with power arm length, was calculated after the retraction force was applied.

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Introduction: It has been found that controlled movement of the anterior teeth can be obtained by attaching a certain length of power arm onto an archwire in sliding mechanics. However, the impact of the archwire/bracket play on anterior tooth movement has not been clarified. The purpose of this study was to compare the effect of the power arm on anterior tooth movements with different dimensions of bracket slots and archwires.

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Sapacitabine (CS-682 or CYC682; 1-[2-C-cyano-2-deoxy-β-D-arabino-pentfuranosyl]N4-palmitoyl cytosine), a novel antitumor 2'-deoxycytidine analogue, shows a marked reduction in the water solubility because of the fatty acid side chain on the N4 group of the cytosine moiety. Poor water solubility is one of the important reasons why sapacitabine does not exert maximum antitumor activity. Therefore, we attempted to improve the water solubility of sapacitabine using a novel surfactant, Soluplus®, which consisted of a polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer.

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To develop potent covalent inhibitors, the noncovalent interactions around the transition state to form covalent bonding should be optimized because the potency of the inhibitor can be depending on the energy of the transition state. Here, we report an efficient analysis of the noncovalent binding mode of a potent covalent proteasome inhibitor 3a around the transition state by a combined use of the chemical approach, i.e.

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The natural product belactosin A (1) with a trans-cyclopropane structure is a useful prototype compound for developing potent proteasome (core particle, CP) inhibitors. To date, 1 and its analogues are the only CP ligands that bind to both the nonprimed S1 pocket as well as the primed substrate binding channel; however, these molecules harbor a high IC50 value of more than 1 μM. We have performed structure-activity relationship studies, thereby elucidating unnatural cis-cyclopropane derivatives of 1 that exhibit high potency to primarily block the chymotrypsin-like active site of the human constitutive (cCP) and immunoproteasome (iCP).

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Objective: To elucidate the effect of bone morphometric changes on orthodontic tooth movement (OTM) in zoledronic acid-treated ovariectomized rats.

Materials And Methods: Twenty-one 10-week-old female Wistar rats were divided into ovariectomy (OVX), OVX with zoledronic acid administration (OVX + ZOL), and sham operation (control) groups. Two weeks after OVX, ZOL administration was initiated.

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Objectives: The aim of this study was to clarify the effect of the play between the bracket and the archwire on anterior tooth movement subjected to the retraction force from various lengths of power arms in sliding mechanics.

Materials And Methods: A three-dimensional finite element method was used to simulate en masse anterior tooth retraction in sliding mechanics. The displacements of the maxillary incisor and the archwire deformation were calculated when the retraction force was applied.

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A size-selected argon (Ar) gas-cluster ion beam (GCIB) was applied to the secondary ion mass spectrometry (SIMS) of a 1,4-didodecylbenzene (DDB) thin film. The samples were also analyzed by SIMS using an atomic Ar(+) ion projectile and X-ray photoelectron spectroscopy (XPS). Compared with those in the atomic-Ar(+) SIMS spectrum, the fragment species, including siloxane contaminants present on the sample surface, were enhanced several hundred times in the Ar gas-cluster SIMS spectrum.

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Objective: To determine optimal loading conditions such as height of retraction force on the power arm and its position on the archwire in sliding mechanics.

Materials And Methods: A 3D finite element method (FEM) was used to simulate en masse anterior teeth retraction in sliding mechanics. The degree of labiolingual tipping of the maxillary central incisor was calculated when the retraction force was applied to different heights of a power arm set mesial or distal to the canine.

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Objective: To investigate the precise longitudinal change in the periodontal ligament (PDL) space width and three-dimensional tooth movement with continuous-force magnitudes in living rats.

Materials And Methods: Using nickel-titanium closed-coil springs for 28 days, 10-, 25-, 50-, and 100-g mesial force was applied to the maxillary left first molars. Micro-CT was taken in the same rat at 0, 1, 2, 3, 10, 14, and 28 days.

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Objective: To (1) evaluate the stability of palatal rugae as landmarks for superimposition of dental casts and (2) establish a three-dimensional superimposition method of maxillary dental casts for analyzing orthodontic tooth movement.

Materials And Methods: The sample consisted of dental casts obtained from 10 patients treated with extraction of bilateral maxillary first premolars and placement of three palatal miniscrews as anchorage for retraction of the anterior teeth. Dental casts were measured by means of laser surface scanning system, and three-dimensional images were reconstructed.

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The first asymmetric synthesis of (S)- and (R)-5-hydroxythalidomides, one of thalidomide's major metabolites, was achieved using HMDS/ZnBr(2)-induced imidation as a key reaction. 5-Hydroxythalidomide was found to be configurationally more stable than thalidomide at physiological pH. Stereochemical biological effects of thalidomide and 5-hydroxythalidomide on anti-angiogenesis and antitumor activities were also investigated using racemic and pure enantiomers.

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Background: The efficacy of individual chemotherapy based on chemosensitivity has scarcely been studied.

Methods: We examined the chemosensitivites for four anticancer agents - 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3 (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU), carboplatin, cisplatin, and etoposide - of 43 malignant astrocytic tumors (21 anaplastic astrocytomas and 22 glioblastomas) by using a collagen gel matrix assay, and we also determined the survival periods of the tumor-bearing patients. The chemosensitivity was evaluated in terms of the growth inhibition rate, using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) method.

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3'-beta-Carbamoylmethylcytidine (CAMC) and its derivatives were synthesized using an intramolecular Reformatsky-type reaction promoted by SmI2 as the key step. In vitro tumor cell growth inhibitory activity was evaluated and CAMC was found to exhibit potent cytotoxicity against various human tumor cell lines. From a structure-activity relationship study it was postulated that the cytotoxic mechanism of action of CAMC did not require phosphorylation at the 5'-hydroxyl group.

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In vitro chemosensitivity test using a collagen-gel method was done on 165 primary gastric cancers. All of 5-FU, CBDCA, CDDP and docetaxel showed a high sensitivity. The effects of per oral (po) administration of TS-1, a combination of po TS-1 and intraperitoneal (ip) administration of CDDP, ip 5-FU and ip docetaxel, were evaluated in athymic mice bearing peritoneal dissemination of a gastric cancer cell line (MKN-45-P that shows a high rate of metastasis to the peritoneal cavity of nude mice).

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In this study, the involvement of ATP-binding cassette (ABC) transporters in in vitro chemosensitivity of surgically removed human renal cell carcinomas was investigated. The relative expression levels of transporter mRNAs in the renal tumors from 13 patients were similar to those in the surrounding normal kidney tissues. Five renal cell carcinomas cultured successfully in vitro for 14 days showed significantly decreased expression of multi-drug resistance-associated proteins 2 and 6 (MRP2 and MRP6) mRNAs.

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