291 research outputs found

    TP53 Mutations in Nonsmall Cell Lung Cancer

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    The tumor suppressor gene TP53 is frequently mutated in human cancers. Abnormality of the TP53 gene is one of the most significant events in lung cancers and plays an important role in the tumorigenesis of lung epithelial cells. Human lung cancers are classified into two major types, small cell lung cancer (SCLC) and nonsmall cell lung cancer (NSCLC). The latter accounts for approximately 80% of all primary lung cancers, and the incidence of NSCLC is increasing yearly. Most clinical studies suggest that NSCLC with TP53 alterations carries a worse prognosis and may be relatively more resistant to chemotherapy and radiation. A deep understanding of the role of TP53 in lung carcinogenesis may lead to a more reasonably targeted clinical approach, which should be exploited to enhance the survival rates of patients with lung cancer. This paper will focus on the role of TP53 in the molecular pathogenesis, epidemiology, and therapeutic strategies of TP53 mutation in NSCLC

    Mechanisms of Resistance to EGFR TKIs and Development of a New Generation of Drugs in Non-Small-Cell Lung Cancer

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    Gefitinib and erlotinib, which are epidermal growth factor receptor- (EGFR-) specific tyrosine kinase inhibitors (TKIs), are widely used as molecularly targeted drugs for non-small-cell lung cancer (NSCLC). Currently, the search for EGFR gene mutations is becoming essential for the treatment of NSCLC since these have been identified as predictive factors for drug sensitivity. On the other hand, in almost all patients responsive to EGFR-TKIs, acquired resistance is a major clinical problem. Mechanisms of acquired resistance reported in the past few years include secondary mutation of the EGFR gene, amplification of the MET gene, and overexpression of HGF; novel pharmaceutical agents are currently being developed to overcome resistance. This review focuses on these mechanisms of acquired resistance to EGFR-TKIs and discusses how they can be overcome

    Critical states observed in triaxial compression tests on volcanic pumice soil related to debris flow in the 2008 Iwate-Miyagi Nairiku Earthquake

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    The Iwate-Miyagi Nairiku Earthquake (M7.2) that occurred on June 14, 2008, caused a slope failure in Dozo-zawa River near the summit of Mt. Higashi-Kurikoma. The debris flow caused by the slope failure flowed for about 10 km and took the lives of 7 people. The mechanisms of the slope failure and long-distance debris flow have not yet been well understood. In this study, a series of triaxial compression tests was conducted using a highly crushable pumice soil collected from the collapsed area, and shear behavior and particle breakage were discussed. Both reconstituted specimens and intact specimens showed contractancy and reached critical states that implies high flow potential. However, intact specimens preserved looser structure during consolidation and showed stronger contractancy during shearing than the reconstituted specimens, due to their natural soil structure. Significant particle breakage was observed in the tests with reconstituted specimens

    Adenocarcinoma of Ascending Colon Associated with Sarcoid Reaction in Regional Lymph Nodes

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    Lymph node swelling in the setting of malignancy generally suggests metastasis of the primary tumor. A granulomatous reaction, i.e. sarcoid reaction, occurring within the lymph nodes draining carcinomas is a well-known but uncommon occurrence. The phenomenon is especially rarely seen in colon carcinoma. We herein report a rare case of a 56-year-old Japanese male with adenocarcinoma of the ascending colon associated with sarcoid reaction in the regional lymph nodes. A typical ileocecal resection and lymph node dissection were performed. Histopathological examination revealed moderately differentiated adenocarcinoma of the ascending colon, and the dissected lymph nodes included epithelioid granulomas with multinucleated giant cells. These findings suggest the existence of a sarcoid reaction associated with colon carcinoma; there was no metastasis in the dissected lymph nodes. The significance of this rare condition is discussed

    Detectability of Colon Polyp Using Computed Virtual Chromoendoscopy with Flexible Spectral Imaging Color Enhancement

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    The aim of this pilot study was to assess the feasibility of using computed virtual chromoendoscopy with the flexible spectral imaging color enhancement (FICE) for colon neoplasia screening. A modified back-to-back colonoscopy using FICE and white light in the right-sided colon was conducted prospectively for the consecutive patients attending for the postoperative (sigmoidectomy or anterior resection) follow-up colonoscopy. Histopathology of detected lesions was confirmed by evaluation of endoscopic resection or biopsy specimens. One-hundred and two patients were enrolled, and 100 patients (61 males and mean age 63 years) were finally analyzed. The total number of polyps detected by FICE and white light colonoscopy was 65 and 45, respectively. The miss rate for all polyps with FICE (24%) was significantly less than that with white light (46%) (P = 0.03). Colonoscopy using FICE could beneficially enhance the detection of neoplastic lesions in the right-sided colon compared to white light colonoscopy

    Annealing of an AlN buffer layer in N2-CO for growth of a high-quality AlN film on sapphire

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    The annealing of an AlN buffer layer in a carbon-saturated N2–CO gas on a sapphire substrate was investigated. The crystal quality of the buffer layer was significantly improved by annealing at 1650–1700 °C. An AlN buffer layer with a thickness of 300 nm was grown by metalorganic vapor phase epitaxy (MOVPE), and was annealed at 1700 °C for 1 h. We fabricated a 2-µm-thick AlN layer on the annealed AlN buffer layer by MOVPE. The full widths at half maximum of the (0002)- and (101ˉ210\bar{1}2)-plane X-ray rocking curves were 16 and 154 arcsec, respectively, and the threading dislocation density was 4.7 × 108 cm−2

    Nonlinear restoring force of spring with stopper for ferroelectric dipole electret-based electrostatic vibration energy harvesters

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    Previously, we succeeded in developing a new electret [termed a ferroelectric dipole electret (FDE)] having an extremely high electric field using a polarized ferroelectric material. However, the pull-in, in which an oscillator sticks to the FDE under its strong electrostatic force, poses a problem for practical vibration energy harvesters. In this study, we propose use of nonlinear restoring force of a spring with a stopper in order to prevent pull-in for FDE-based vibration energy harvesters. The spring with a stopper was designed using a finite element method (FEM) analysis such that the restoring force of the spring will exceed the electrostatic force of the FDE. The proposed harvester combines the FDE and the spring successfully, and generated electricity without the pull-in. It also showed the highest figure of merit of output power and wide frequency band when compared with other available electret-based vibration energy harvesters. © 2016 Author(s)
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