Biomedical subjects

Soji Ozawa

Publications and source records attributed to Soji Ozawa.

22 records · Page 2Linked to original sources

PubMed2002

[Molecular alterations in esophageal cancer].

The clinicopathological characteristics of esophageal cancer have gradually been clarified using molecular biologic methods developed over the past 20 years. For example, amplification of the c-erb B gene is a prognostic factor and predictive of lymph node involvement, while the amplification of the cyclin D1 gene is also a prognostic factor and predictive of distant organ metastasis. Alteration of the p16 gene is also a prognostic factor and predicts lymph node involvement. As telomerase activity is almost a unique phenomenon of cancer cells, highly sensitive detection of esophageal cancer cells in the peripheral blood can be performed. Recently, such new methods as comparative genomic hybridization analysis and cDNA microarray analysis have been used to determine meaningful genetic changes. For therapeutic purposes, although tailor-made therapy has been proposed for several years, the validity of these approaches should be confirmed in a well-designed clinical trial. As molecular targeted therapies, tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR) and monoclonal antibodies against EGFR are being studied in clinical trials in Western countries. A clinical trial of p53 gene therapy against esophageal cancer is also promising.

Cyclin D1↗

PubMed2002

[Infectious complications after esophageal surgery].

The incidence of wound infection, which is an intrasurgical field infection, is lower than the incidence of pneumonia, which is an extrasurgical field infection, after esophageal cancer surgery. Several trials predicting postoperative infectious complications have been reported. One measured the phytohemagglutinin- and concanavalin A-induced proliferation of peripheral blood mononuclear cells in patients; one measured the white blood cell (WBC) count 2 h after surgery and the decrease in WBC count on first postoperative day; and another showed that the decrease in serum IgG2 level can predict the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) infections. Useful strategies for managing infectious complications have also been reported. Applying mupirocin calcium hydrate ointment to the nasal cavity decreases the incidence of MRSA infections. Autologous blood collection reduces the need for allogeneic transfusion in patients undergoing resection of esophageal cancer, and avoidance of allogeneic transfusion may reduce the risk of postoperative infection. The total exposure to preoperative chemoradiotherapy should be limited to 40 Gy or less to prevent postoperative pneumonia.

Blood Transfusion, Autologous↗

PubMedDate not supplied

A neo-esophagus reconstructed by cultured human esophageal epithelial cells, smooth muscle cells, fibroblasts, and collagen.

The scientists involved in this study attempted to develop an artificial esophagus constructed of autologous cells grown by cell culture methods on an extracellular matrix. An artificial esophagus consisting of human esophageal epithelial cells, dermal fibroblasts, and smooth muscle cells isolated from the aortic media, was attempted. The purpose of this study was to examine whether smooth muscle cells could be used in the transforming matrix. Human fibroblasts were embedded in Type I collagen superimposed on the collagen layer of smooth muscle cells. Next, human esophageal epithelial cells were cultured on the collagen layer of the fibroblasts. The resulting collagen sheets were cultured in vitro for 1 week, then transplanted on the latissimus dorsi muscles of athymic rats. The sheets were examined histologically at 1 and 2 weeks using hematoxylin eosin and immunologic stain methods (antiactin antibody). At the end of 2 weeks after transplantation, on microscopic observation of the collagen sheets, it appeared that the epithelial layer, the submucosal tissue layer, and the proper muscle layer had been reconstructed. Additionally, the authors successfully isolated smooth muscle cells from the media of the left gastric artery as a surgical specimen by explant cell culture. The ability to transform collagen sheets consisting of esophageal epithelial cells, fibroblasts, and smooth muscle cells from a surgical specimen into a luminal structure may enable clinical application of the artificial esophagus.

Animals↗

PubMedDate not supplied

The cytotoxicity of a conjugate composed of human epidermal growth factor and eosinophil cationic protein.

BACKGROUND: Conventional targeted therapy with foreign proteins is highly immunogenic. In this study, we developed targeted therapy composed of human endogenous proteins and evaluated its efficacy in vitro. MATERIALS AND METHODS: Human epidermal growth factor (EGF) was chemically linked to human eosinophil cationic protein (ECP). The cytotoxicity of the EGF-ECP conjugate was evaluated by MTT assay. RESULTS: The conjugate showed dose-dependent cytotoxicity on EGF receptor (EGFR)-overexpressing BT-20 cells with an IC50 of 1.5 x 10(-7) M, whereas the IC50 of ECP alone was almost 10(-4) M. The conjugate had no detectable cytotoxicity against EGF receptor-deficient H69 cells. Excess EGF protected BT-20 cells from the cytotoxicity of the conjugate. Comparing the cytotoxicity and the level of EGFR expression, the cytotoxicity of the conjugate was positively correlated with the level of EGFR expression of each cell line. CONCLUSION: Conjugates composed solely of human proteins might be useful with less immunogenicity and less toxicity than the conventional immunotoxins for targeted therapy.

Blood Proteins↗