Masaji Hashimoto

Yuri General Hospital, Honjō, Saitama, Japan

Are you Masaji Hashimoto?

Claim your profile

Publications (7)4.16 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Gene amplification is a relatively frequent event in human malignant tumors and is believed to play an important role in tumor progression. The int-2 and erbB genes are amplified more frequently than any other genes in human esophageal cancer. In order to investigate the correlation between these two proto-oncogenes and the clinical behavior of esophageal cancer, we examined DNA amplification of int-2 and erbB and analyzed their relationship to clinicopathological variables. Genomic DNA was extracted from 21 esophageal squamous carcinomas and normal esopfiageal mucosa, as well as from 4 metastatic tumors. We used Southern blot analysis for detection of gene amplification. Amplification of int-2 was observed in 13 of 21 cases (62%) and in all the metastatic tumors (4/4; 100%). We found a significant correlation between amplification of int-2 and the length of the primary lesion. Amplification of erbB was detected in 3 of 18 patients (17%). All patients who showed amplification of erbB also demonstrated amplification of int-2. These results suggest that amplification of int-2 or neighboring genes on 11q may participate in tumor progression and metastasis in patients with esophageal squamous cancer.
    Cancer Investigation 06/2009; 15(5). · 2.24 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 63-year-old man with a history of acute coronary syndrome presented with anterior chest pain that had lasted more than 3 months. During treatment for acute myocardial infarction on admission, computed tomography (CT) was performed incidentally, revealing an anterior mediastinal tumor 28 mm in diameter. CT findings after 3 months demonstrated an anterior soft tissue mass involving the left brachiocephalic vein and showing rapid growth. Radical resection of the tumor with thymectomy was performed. Histological examination showed storiform-pleomorphic malignant fibrous histiocytoma (MFH) originating from the thymus, and Hassall's bodies were identified. Immunohistochemical staining showed tumor cells with positive results for vimentin and CD68. The Ki-67 index (MIB-1) was >50%, but other markers such as cytokeratin AE1/AE3, smooth muscle actin, S-100 protein, CD34, and CD45 were negative. Mediastinum MFH has been reported in 34 cases, but this appears to be a rare description of MFH originating from the thymus.
    General Thoracic and Cardiovascular Surgery 12/2008; 56(12):606-9.
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 63-year-old female underwent lobectomy with ND2a lymph node dissection for left lung cancer in April 1999. Histopathological examination revealed moderately-differentiated adenocarcinoma (pT2N2M0, pStage III A). She received one course of a combination of etoposide (ETP) and cisplatin(CDDP)as adjuvant therapy, followed by oral intake of UFT. At 9 months post-operatively, she received radiation therapy for lymph node recurrence, at which time new multiple lung metastases were found. After receiving 3 courses of a combination of vinorelbine (VNR) and CDDP, a complete response (CR) of all metastatic lesions was achieved. Three years after the original surgery, metastatic lesions recurred, and a total of 9 courses of a combination of VNR and carboplatin (CBDCA) and partial resection of the right lung for pulmonary metastasis were performed in succession. Following this therapy, treatment with gefitinib was initiated for about 6 months, and computed tomography (CT) showed progressive disease. For 8 years following the original operation, the patient received oral chemotherapy using S-1 and has maintained CR on CT. We conclude that oral administration of S-1 is useful as palliative chemotherapy without serious adverse events or worsening of quality of life. Patients like this case are thus able to continue chemotherapy for a long time.
    Gan to kagaku ryoho. Cancer & chemotherapy 09/2008; 35(8):1415-7.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The criteria for the diagnosis of lymph node metastasis (LNM) in non-small cell lung cancer were investigated using helical computed tomography (hCT). The conventional criterion (1-cm short axis threshold) is generally accepted; however, this criterion is based on conventional CT. New criteria for LNM were investigated because the resolution of hCT is better than that of conventional CT. Ninety-seven NSCLC patients examined with hCT were enrolled. Both the long axis (LA) and short axis (SA) of the nodes were measured using hCT. Based on the receiver operating characteristic curves, the thresholds that gave optimal sensitivity and specificity for LNM were 13 mm for LA and 9 mm for SA. The LNM diagnosis was re-evaluated using the combination of cutoff values. When the LA was > or =13 mm and the SA was > or =9 mm, the sensitivity, specificity, and accuracy were 56.3%, 92.1%, and 88.1%, respectively. When the LA was > or =13 mm or SA was > or =9 mm, sensitivity, specificity, and accuracy were 75.0%, 74.7%, and 74.7%, respectively. These values were not so different from the conventional criterion recalculated from these data. The new criteria are considered to be useful for making a LNM diagnosis. The conventional criteria for the LNM diagnosis might therefore be applicable even for hCT.
    Surgery Today 02/2008; 38(12):1083-90. · 0.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study was conducted to examine the long-term outcome of 500 patients who underwent surgery for cancer of the thoracic esophagus during the past 20 years. Favorable results were obtained with postoperative adjuvant radiation and chemotherapy and there were no surgical deaths in the last 5 years. The mortality rate decreased from 17% prior to 1980 to 5% between 1981 and 1993, this being most probably attributable to the decreased incidence of suture leakage. With respect to changes in surgical techniques, during the initial years we performed intrathoracic anastomosis, after which sternal manubrium resection with anterior mediastinal esophagogastrostomy was carried out. Subsequently, we invented a technique for performing esophagogastrostomy via the posterior mediastinum. The posterior mediastinum was selected as the most physiologic route, based on measurement of tissue oxygen tension. Using blood flow determinations obtained by laser-Doppler velocimetry, we concluded that the effectiveness of thicker gastric tubes was superior to that of thin tubes. Esophagogastrostomy was performed in a shallow field in the cervical region, with the anastomosis ultimately positioned in the superior mediastinum and covered with mediastinal pleura.
    Surgery Today 01/1996; 26(2):77-82. · 0.96 Impact Factor
  • The Journal of The Japanese Association for Chest Surgery. 01/1995; 9(2):129-134.
  • The Journal of The Japanese Association for Chest Surgery. 01/1995; 9(5):586-591.