298 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

    Functional relationships between cyclodextrin glucanotransferase from an alkalophilic Bacillus and α-amylases Site-directed mutagenesis of the conserved two Asp and one Glu residues

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    AbstractComparison of the amino acid sequences of cyclodextrin glucanotransferases (CGTases) with those of α-amylases revealed that two Asp and one Glu residues, which are considered to be the catalytic residues in α-amylases, were also conserved in CGTases. To analyze the function of the three conserved amino acid residues in CGTases, site-directed mutagenesis was carried out. The three mutant CGTases, in which Asp229, Glu257 and Asp328 were individually replaced by Asn or Gln, completely lost both their starch-degrading and β-cyclodextrin-forming activities, whereas another mutant CGTase, in which Glu264 replaced by Gln, retained these activities. The three inactive enzymes retained the ability to be bound to starch. These results suggest that Asp229, Glu257 and Asp328 play an important role in the enzymatic reaction catalyzed by CGTase and that a similar catalytic mechanism is present in both CGTases and α-amylases

    Risk factors for an additional port in single-incision laparoscopic cholecystectomy in patients with cholecystitis

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    Although single-incision laparoscopic cholecystectomy is now widely performed in patients with cholecystitis, some cases require an additional port to complete the procedure. In this study, we focused on risk factor of additional port in this surgery. We performed single-incision cholecystectomy in 75 patients with acute cholecystitis or after cholecystitis between 2010 and 2014 at Gunma University Hospital. Surgical indications followed the TG13 guidelines. Our standard procedure for single-incision cholecystectomy routinely uses two needlescopic devices. We used logistic regression analysis to identify the risk factors associated with use of an additional full-size port (5 or 10 mm). Surgical outcome was acceptable without biliary injury. Nine patients (12.0%) required an additional port, and one patient (1.3%) required conversion to open cholecystectomy because of severe adhesions around the cystic duct and common bile duct. In multivariate analysis, high C-reactive protein (CRP) values (>7.0 mg/dl) during cholecystitis attacks were significantly correlated with the need for an additional port (P = 0.009),with a sensitivity of 55.6%, specificity of 98.5%, and accuracy of 93.3%. This study indicated that the severe inflammation indicated by high CRP values during cholecystitis attacks predicts the need for an additional port

    Primary mediastinal atypical meningioma: Report of a case and literature review

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    Meningiomas are common neoplasms arising from the central nervous system meninges. On the other hand, primary ectopic meningiomas are extremely rare and usually limited to the head and neck region or to the paravertebral soft tissues. Their occurrence in the mediastinum is even rarer. Until now, only 4 cases of primary mediastinal meningioma have been reported in the literature searched on Medline. Because of its rarity and intriguing pathogenesis, we report here a case of primary mediastinal meningioma that was treated by surgical resection. The clinical features, treatment, pathological findings, and prognosis are analyzed, and the literature on ectopic meningioma is reviewed

    The Feature of Solitary Small Nodular Type of Hepatic Epithelioid Hemangioendothelioma

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    Hepatic epithelioid hemangioendothelioma (HEHE) is a rare tumor. Preoperative diagnosis of HEHE is difficult because it does not manifest specific symptoms or tumor markers. We report a resected case of small and solitary HEHE. The patient, a 74-year-old man, had undergone surgical resection for left renal cell carcinoma 20 years ago. During follow-up, a tumor approximately 1.3 cm in diameter was detected by computed tomography (CT) at liver segment VIII. It showed isodensity in the arterial phase, low density in the portal venous phase, and homogeneous enhancement in the late phase on CT and magnetic resonance imaging (MRI). We performed hepatic resection of the right hepatic vein drainage area. A pathological diagnosis of HEHE was made. Although small and solitary HEHE is rare, an enhancement pattern in each phase on CT and MRI, using contrast media, can yield clues for the diagnosis of HEHE

    Esophageal granular cell tumor successfully resected by endoscopic submucosal dissection

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    Granular cell tumors of the esophagus are rare neoplasms and their diagnosis is mainly based on histopathologic examination of endoscopic biopsies. With the development of endoscopic techniques, there has been a marked increase in local treatment modalities for early esophageal neoplasms. In this case report, we describe the removal of a granular cell tumor by the endoscopic submucosal dissection technique, and briefly discuss the literature on clinicopathologic aspects and management of granular cell tumors
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