Publications by authors named "Tomoki Yokoyama"

Obesity is becoming a major public health problem worldwide. Making charcoal from wood ("Sumi-yaki") has been a traditional activity in the southern part of Nagano Prefecture for centuries, with activated charcoal having reported detoxifying effects. However, it is unclear whether activated charcoal also possesses anti-obesity properties.

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Background: G protein-coupled receptors (GPCRs) are ubiquitous surface proteins mediating various biological responses and thus, important targets for therapeutic drugs. GPCRs individually produce their own signaling as well as modulate the signaling of other GPCRs. Real-time observation of GPCR signaling and modulation in living cells is key to molecular study of biological responses and pharmaceutical development.

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In this study, the picocyanobacterial species composition of Lake Miyagase was examined by analyzing the 16S rRNA gene in a clone library and by amplicon sequencing using a benchtop next-generation sequencer. Five separate samples were analyzed from different days over a ten-month period. In the picocyanobacterial lineage, 9 and 12 OTUs were identified from a clone library and by amplicon sequencing, respectively.

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Memantine is a non-competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, and is an approved drug for the treatment of moderate-to-severe Alzheimer's disease. We identified a mouse strain with a naturally occurring mutation and an ataxic phenotype that presents with severe leg cramps. To investigate the phenotypes of these mutant mice, we screened several phenotype-modulating drugs and found that memantine (10 mg/kg) disrupted the sense of balance in the mutants.

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A mutation of KCNQ1 gene encoding the alpha subunit of the channel mediating the slow delayed rectifier K(+) current in cardiomyocytes may cause severe arrhythmic disorders. We identified KCNQ1(Y461X), a novel mutant gene encoding KCNQ1 subunit whose C-terminal domain is truncated at tyrosine 461 from a man with a mild QT interval prolongation. We made whole-cell voltage-clamp recordings from HEK-293T cells transfected with either of wild-type KCNQ1 [KCNQ1(WT)], KCNQ1(Y461X), or their mixture plus KCNE1 auxiliary subunit gene.

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Objective: Thymic carcinoma is a rare mediastinal neoplasm with frequent pleural or pericardial dissemination. We retrospectively studied ten such cases and analyzed factors that influenced the survival of the patients.

Methods: Ten thymic carcinoma patients with dissemination have been treated since 1987.

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Background: Mutations of the epidermal growth factor receptor (EGFR) gene at kinase domain have been reported in non-small-cell lung cancer (NSCLC), and some common somatic mutations in EGFR have been examined for their ability to predict sensitivity to gefitinib or erlotinib. However, EGFR mutations at exon 20 have been reported to predict resistance to gefitinib therapy.

Materials And Methods: We investigated the EGFR mutations and/or polymorphism statuses at kinase domain in 303 surgically treated non-small cell lung cancer (NSCLC) cases.

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In this study, we examined the expression of excision repair cross-complementation group 1 (ERCC1) protein in 90 completely resected lung cancer samples from patients who received adjuvant or neo-adjuvant platinum-based chemotherapy. Epidermal growth factor receptor (EGFR) was also studied in these samples. We also examined class III beta-tubulin protein expression in 50 patients treated with a platinum-based drug plus paclitaxel.

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Introduction: Thymic carcinoma is a rare and invasive mediastinal neoplasm that often metastasizes. It constitutes a heterogeneous group of tumors that displays different biologic behavior and prognosis. The clinical prognostic factors and treatment of thymic carcinoma are not yet standardized.

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To evaluate the epidermal growth factor receptor (EGFR) protein expression, gene mutations and amplification as predictors of clinical outcome in patients with non-small-cell lung cancer (NSCLC) receiving gefitinib, we have performed fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). We investigated the EGFR amplification and EGFR protein expression statuses in 27 surgically treated non-small-cell lung cancer (NSCLC) cases. These patients experienced relapse after surgery and received gefitinib 250 mg/day.

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Background: Epidermal growth factor receptor (EGFR) stimulation markedly increases cyclin D1 protein expression. Recently, it has been reported that cyclin D1 expression was increased in EGFR mutant cell lines; however, the expression status of CCND1 in EGFR mutant lung cancer tissues has not been reported.

Patients And Methods: We have investigated the CCND1 messenger RNA (mRNA) levels and other clinicopathologic data in 74 lung cancers.

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Mutations of the epidermal growth factor receptor (EGFR) gene have been reported in non-small cell lung cancer (NSCLC), especially in female, never smoker patients with adenocarcinoma. Some common somatic mutations in EGFR, including deletion mutations in exon 19 and leucine to arginine substitution at amino acid position 858 (L858R) in exon 21, have been examined for their ability to predict sensitivity to gefitinib or erlotinib. On the other hand, previous report has shown that the insertion mutation at exon 20 is related to gefitinib resistance.

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We have investigated 92 non-small cell lung cancer tissues and found 11 PIK3CA amplification. PIK3CA amplification incidence was significantly higher in male, smoker and squamous cell carcinoma patients. Among 11 patients with PIK3CA amplification, two patients harbored a PIK3CA mutation.

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Background: Much evidence has accumulated that the epidermal growth factor receptor (EGFR) and its family members are strongly implicated in the development and progression of lung cancers. Recently, erbB4 kinase domain mutations were reported in Korean patients with lung cancer. We hypothesized that erbB4 mutations correlate with clinicopathologic features of lung cancers.

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Activating mutations of Ras gene families have been found in a variety of human malignancies, including lung cancer, suggesting their dominant role in tumorigenesis. Many studies have showed that the Kras gene is activated by point mutations in approximately 15-20% of non-small cell lung cancers (NSCLCs), however, there are only a few reports on Nras mutations in NSCLC. We have genotyped Nras mutation status (n=195) and Kras mutation status (n=190) in surgically treated lung adenocarcinoma cases.

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Introduction: Thymoma is a neoplasm of thymic epithelial cells which is characteristically associated with a large number of non-neoplastic T lymphocytes. These T cells are induced by epithelial cells and show a unique phenotype of CD4(+)8(+) double positive (DP), when studied by flow cytometry. This DP phenotype can be used as one of the diagnostic criteria to indicate a thymoma.

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Background: Invasion to the visceral pleura is an important component of lung cancer staging and an independent prognostic factor. However, the accuracy of pathologic examination depends on how the sections are made, and the pathologist may miss the most invaded part of the pleura. Therefore, we have designed "touch" cytology in an effort to more accurately diagnose the pleural invasion by lung cancer.

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Bcl-2 family proteins regulate programmed cell death, and may play an important role in the selection of lymphocytes. We investigated the expression of Bcl-2, Bcl-x, Bax, Bak and Bim in human lymphocytes using flow-cytometry. Bcl-2 was down-regulated in CD4(+)8(+) (DP) thymocytes and CD19(+)38(+) tonsillar lymphocytes (GC B cells).

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Survivin is a member of the inhibitor-of-apoptosis (IAP) family. It has been reported to be expressed during development, but not in differentiated normal tissue. However, its expression has been reported to be high in the thymus.

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