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Dive into the research topics where Masaki Miyazawa is active.

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Featured researches published by Masaki Miyazawa.


World Journal of Gastroenterology | 2015

Gastric adenocarcinoma of fundic gland type: Five cases treated with endoscopic resection

Masaki Miyazawa; Mitsuru Matsuda; Masaaki Yano; Yasumasa Hara; Fumitaka Arihara; Yosuke Horita; Koichiro Matsuda; Akito Sakai; Yatsugi Noda

Recently, a new disease entity termed gastric adenocarcinoma of fundic gland type (GA-FG) was proposed. We treated five cases of GA-FG with endoscopic submucosal dissection. All tumors were small and located in the upper third of the stomach. Four tumors were macroscopically identified as 0-IIa and one was identified as 0-IIb. Narrow-band imaging with magnifying endoscopy showed an irregular microvascular pattern in 2 cases and a regular microvascular pattern in the remainder. All tumors arose from the deep layer of the lamina propria mucosae and showed submucosal invasion. Lymphatic invasion was seen only in one case, while no venous invasion was recognized. All tumors were positive for pepsinogen-I  and MUC6 by immunohistochemistry. None showed p53 overexpression, and the labeling index of Ki-67 was low in all cases. All cases have been free from recurrence or metastasis. Herein, we discussed the clinicopathological features of GA-FG in comparison with past reports.


Internal Medicine | 2016

Cytomegalovirus Reactivation Induced Acute Hepatitis and Gastric Erosions in a Patient with Rheumatoid Arthritis under Treatment with an Anti-IL-6 Receptor Antibody, Tocilizumab.

Takuya Komura; Hajime Ohta; Ryotaro Nakai; Jun Seishima; Masatoshi Yamato; Masaki Miyazawa; Kiichiro Kaji; Yohei Marukawa; Takashi Kagaya; Kiyoki Kitagawa; Atsuhiro Kawashima; Shuichi Kaneko; Masashi Unoura

Tocilizumab, an anti-human interleukin 6 receptor (IL-6R) monoclonal antibody, is widely used to treat rheumatoid arthritis (RA) and is expected to exhibit clinical efficacy when used to treat other autoimmune diseases. However, a risk of opportunistic infection is occasionally recognized. A 54-year-old woman had received an oral corticosteroid and methotrexate to treat RA. Despite receiving these treatments, she received additional treatment with tocilizumab due to poor control of the disease activity. She presented at our hospital with a high fever and epigastralgia 19 days after receiving this treatment. A laboratory evaluation revealed liver injury and cytomegalovirus (CMV) viremia. Abdominal ultrasonography and computed tomography (CT) revealed hepatosplenomegaly, but no ascites. Upper gastrointestinal endoscopy revealed gastric erosions induced by CMV, which were confirmed immunohistochemically. Hence, we diagnosed the patient with CMV reactivation-induced acute hepatitis and gastric erosions under tocilizumab treatment. She received an anti-cytomegalovirus drug, ganciclovir, for 14 days due to her viremia and impaired general condition, which was suggestive of a severe infection. Her general condition subsequently improved, the liver function test results normalized, and the gastric erosions disappeared. In conclusion, although tocilizumab is very useful for treating certain autoimmune and inflammatory diseases, and will be prescribed more widely in the future, associated CMV infections must be closely monitored, as these can be lethal.


Regenerative Therapy | 2017

Phase I clinical study of liver regenerative therapy for cirrhosis by intrahepatic arterial infusion of freshly isolated autologous adipose tissue-derived stromal/stem (regenerative) cell

Yoshio Sakai; Masayuki Takamura; Akihiro Seki; Hajime Sunagozaka; Takeshi Terashima; Takuya Komura; Masatoshi Yamato; Masaki Miyazawa; Kazunori Kawaguchi; Alessandro Nasti; Hatsune Mochida; Soichiro Usui; Nobuhisa Otani; Takahiro Ochiya; Takashi Wada; Masao Honda; Shuichi Kaneko

Introduction Adipose tissue stromal cells contain a substantial number of mesenchymal stem cells. As such, their application to regeneration of miscellaneous impaired organs has attracted much attention. Methods We designed a clinical study to investigate freshly isolated autologous adipose tissue-derived stromal/stem (regenerative) cell (ADRC) therapy for liver cirrhosis and conducted treatment in four cirrhotic patients. ADRCs were isolated from autologous subcutaneous adipose tissue obtained by the liposuction method, followed with use of the Celution system adipose tissue dissociation device. The primary endpoint is assessment of safety one month after treatment. We also characterized the obtained ADRCs. Results Two patients had type C cirrhosis, one had nonalcoholic steatohepatitis-cirrhosis, and one had type B cirrhosis. No serious adverse events were observed during the 1-month study period after freshly isolated ADRC infusion. Serum albumin concentrations were maintained or improved during this period as well as during the succeeding follow-up of approximately 1 year in two patients and 6 months in another patient. Liver regeneration-related factors, namely hepatocyte growth factor and interleukin-6, were elevated 1 day after ADRC treatment in all patients. The obtained freshly isolated ADRCs were expanded in culture and found to express mesenchymal stem cell markers. Gene expression profile analysis of ADRCs was shown to involve inflammatory features, suggesting that characteristics of the obtained ADRCs were related to immunomodulatory biological effects. Conclusion This clinical study treatment for liver cirrhosis using ADRCs was proven to be safely conductible, and can be further investigated in future for regeneration/repair of liver cirrhosis.


World Journal of Gastroenterology | 2016

Gastric adenocarcinoma of the fundic gland (chief cell-predominant type): A review of endoscopic and clinicopathological features

Masaki Miyazawa; Mitsuru Matsuda; Masaaki Yano; Yasumasa Hara; Fumitaka Arihara; Yosuke Horita; Koichiro Matsuda; Akito Sakai; Yatsugi Noda

Gastric adenocarcinoma of the fundic gland (chief cell-predominant type, GA-FG-CCP) is a rare variant of well-differentiated adenocarcinoma, and has been proposed to be a novel disease entity. GA-FG-CCP originates from the gastric mucosa of the fundic gland region without chronic gastritis or intestinal metaplasia. The majority of GA-FG-CCPs exhibit either a submucosal tumor-like superficial elevated shape or a flat shape on macroscopic examination. Narrow-band imaging with endoscopic magnification may reveal a regular or an irregular microvascular pattern, depending on the degree of tumor exposure to the mucosal surface. Pathological analysis of GA-FG-CCPs is characterized by a high frequency of submucosal invasion, rare occurrences of lymphatic and venous invasion, and low-grade malignancy. Detection of diffuse positivity for pepsinogen-I by immunohistochemistry is specific for GA-FG-CCP. Careful endoscopic examination and detailed pathological evaluation are essential for early and accurate diagnosis of GA-FG-CCP. Nearly all GA-FG-CCPs are treated by endoscopic resection due to their small tumor size and low risk of recurrence or metastasis.


Cancer Science | 2017

Clinical features of cystatin A expression in patients with pancreatic ductal adenocarcinoma

Takuya Komura; Hisashi Takabatake; Kenichi Harada; Masatoshi Yamato; Masaki Miyazawa; Keiko Yoshida; Masao Honda; Takashi Wada; Hirohisa Kitagawa; Tetsuo Ohta; Shuichi Kaneko; Yoshio Sakai

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal malignancy known, with an extremely poor prognosis due to the lack of an efficient diagnostic scheme and no radical treatment option, except surgery. Therefore, understanding the pathophysiology of, and finding a novel biomarker to detect, PDAC should be prioritized. We observed an increase in mRNA expression of the cysteine protease inhibitor cystatin A (CSTA) in CD4+ T cells in peripheral blood cells of nine patients with PDAC, compared with the expression in seven healthy volunteers. Moreover, we confirmed significantly higher CSTA mRNA expression in a larger cohort of 41 patients with PDAC compared with that in 20 healthy volunteers. Correspondingly, the serum CSTA concentrations in 36 patients with PDAC were higher than those in 37 healthy volunteers, and this increase was correlated with PDAC clinical stage. Furthermore, the expression of CSTA and cathepsin B, which is a lysosomal cysteine protease inhibited by CSTA, was observed in tumor tissues and tumor‐infiltrating immune cells in 20 surgically resected PDAC tissues by immunohistochemical staining. Expression of CSTA was detected in some tumor tissues and many tumor‐infiltrating immune cells. Cathepsin B expression was also observed in most tumor tissues and tumor‐infiltrating immune cells. In conclusion, CSTA and its substrate cathepsin B are involved in PDAC‐related inflammation. The increment of CSTA expression in peripheral blood of patients with PDAC may have a potential role as a PDAC immunopathologic biomarker.


Canadian Journal of Gastroenterology & Hepatology | 2018

Immune Condition of Colorectal Cancer Patients Featured by Serum Chemokines and Gene Expressions of CD4

Takuya Komura; Masaaki Yano; Akimitsu Miyake; Hisashi Takabatake; Masaki Miyazawa; Norihiko Ogawa; Akihiro Seki; Masao Honda; Takashi Wada; Shigeyuki Matsui; Shuichi Kaneko; Yoshio Sakai

Background Colorectal cancer (CRC), the most common malignancy worldwide, causes inflammation. We explored the inflammatory pathophysiology of CRC by assessing the peripheral blood parameters. Methods The differences in gene expression profiles of whole blood cells and cell subpopulations between CRC patients and healthy controls were analyzed using DNA microarray. Serum cytokine/chemokine concentrations in CRC patients and healthy controls were measured via multiplex detection immunoassays. In addition, we explored correlations between the expression levels of certain genes of peripheral CD4+ cells and serum chemokine concentrations. Results The gene expression profiles of peripheral CD4+ cells of CRC patients differed from those of healthy controls, but this was not true of CD8+ cells, CD14+ cells, CD15+ cells, or CD19+ cells. Serum IL-8 and eotaxin-1 levels were significantly elevated in CRC patients, and the levels substantially correlated with the expression levels of certain genes of CD4+ cells. Interestingly, the relationships between gene expression levels in peripheral CD4+ cells and serum IL-8 and eotaxin-1 levels resembled those of monocytes/macrophages, not T cells. Conclusions Serum IL-8 and eotaxin-1 concentrations increased and were associated with changes in the gene expression of peripheral CD4+ cells in CRC patients.


Clinical Journal of Gastroenterology | 2016

Clinical utility of endoscopic ultrasound-guided fine-needle aspiration in mixed adenoneuroendocrine carcinoma with signet-ring cells of the pancreas: a case report and review of the literature

Kiichiro Kaji; Jun Seishima; Masatoshi Yamato; Masaki Miyazawa; Takuya Komura; Yohei Marukawa; Hajime Ohta; Satomi Kasashima; Atsuhiro Kawashima; Masaaki Yano; Masashi Unoura


Gastrointestinal Endoscopy | 2017

Sa1380 The Utility of Endoscopic Examinations for Diagnosis of Igg4-Related Pancreatobiliary Lesions

Masaki Miyazawa; Hajime Takatori; Kazuya Kitamura; Eishiro Mizukoshi; Shuichi Kaneko


Gastroenterology | 2017

Prognosis of Type 1 Autoimmune Pancreatitis after Corticosteroid Therapy-Induced Remission in Terms of Diabetes Mellitus

Masaki Miyazawa; Hajime Takatori; Kazuya Kitamura; Eishiro Mizukoshi; Shuichi Kaneko


Pancreatology | 2016

Analysis of immunological features in blood of patients with pancreatic ductal adenocarcinoma

Takuya Komura; Yoshio Sakai; Hisashi Takabatake; Norihiko Ogawa; Masaki Miyazawa; Shuichi Kaneko

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