Kazumichi Sato
Tokyo Dental College
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Publication
Featured researches published by Kazumichi Sato.
Geriatrics & Gerontology International | 2014
Emiko Sato; Hirohiko Hirano; Yutaka Watanabe; Ayako Edahiro; Kazumichi Sato; Gen-yuki Yamane; Akira Katakura
It is important to understand dysphagia in patients with dementia, as it is associated with malnutrition and aspiration pneumonia. Particularly in patients with Alzheimers disease (AD), mortality from pneumonia is high and accounts for 70% of the causes of death. However, the standard swallowing tests are often difficult to use for patients with dementia, and methods to assess daily swallowing function are required. Therefore, the purpose of the present study was to identify signs of dysphagia in AD patients in daily life.
Oral Oncology | 2002
Kazumichi Sato; Yuichiro Okazaki; Morio Tonogi; Yoichi Tanaka; Gen-yuki Yamane
The aim of this study was to evaluate whether β-catenin accumulation is useful for diagnosing the malignant potential of oral precancerous lesions. We investigated oral epithelial dysplasia adjacent to early cancer induced by 4-nitroquinoline 1-oxide in rats. Localization of β-catenin and cell proliferation were detected immunohistochemically, and exon 3 of the β-catenin gene was analyzed. Accumulation of β-catenin in the cytoplasm and nucleus was evident in 10 of 16 dysplasia lesions. Since almost all of the dysplastic lesions in these rats transformed to invasive cancer, β-catenin accumulation may contribute to the early stage of carcinogenesis. The Ki-67 labeling index was significantly higher in dysplasia and early cancer than in no change. However, there were no significant differences between the expression patterns of β-catenin protein, suggesting that other proliferation pathways are involved in the early stage of tumor development in addition to β-catenin accumulation. No mutations of exon 3 of the β-catenin gene were detected in any of the dysplasia or early cancer lesions. These findings suggested that β-catenin accumulation in the cytoplasm and nucleus without mutation of exon 3 is an early event during carcinogenesis in this tongue cancer model.
Journal of Oral and Maxillofacial Surgery | 2011
Tetsushi Okushi; Morio Tonogi; Takehiro Arisaka; Sayuri Kobayashi; Yusuke Tsukamoto; Hitoshi Morishita; Kazumichi Sato; Chiemi Sano; Shintaro Chiba; Gen-yuki Yamane; Tsuneya Nakajima
PURPOSE The objectives of the present study were to assess the changes in upper airway morphology and function in response to advancement of the maxilla and mandible. PATIENTS AND METHODS Orthognathic surgery was performed. During the surgery, the maxilla and mandible were each advanced as a maxillomandibular advancement simulation. A total of 18 patients with a chief complaint of malocclusion were studied. The distance in jaw advancement and the anteroposterior and left-right diameters of the velopharyngeal space before and after jaw advancement were measured. After the anteroposterior and left-right dilation rates and area enlargement rates were calculated, we compared advancement of the maxilla with that of the mandible. RESULTS Each of the jaw advancements resulted in statistically significant increases in the anteroposterior and left-right diameters of the velopharyngeal space, and the area was significantly enlarged. The anteroposterior dilation rate was significantly greater after advancement of the maxilla, and the left-right dilation rate was significantly greater after advancement of the mandible. The velopharyngeal space area enlargement rate was significantly greater with advancement of the maxilla. CONCLUSIONS These data suggest that the mode of dilation of the velopharyngeal space differs between maxillary advancement and mandibular advancement. Jaw advancement affects the soft palate muscles, and the velopharyngeal space is expanded 3-dimensionally by each of those muscles. The difference in the pattern of expansion of the velopharyngeal space was related to differences in the functions of the soft palate muscles.
Journal of Oral Rehabilitation | 2016
Katsuhiko Sakai; Hirohiko Hirano; Yutaka Watanabe; Haruka Tohara; Emiko Sato; Kazumichi Sato; Akira Katakura
Swallowing disorders are a growing problem among the elderly in long-term care (LTC), and they can cause aspiration pneumonia. In order to detect swallowing disorders early, simple tools are needed to assess aspiration and silent aspiration (SA). To compile a sample of elderly people requiring LTC, and categorise them as having suspected aspiration and/or SA using simple screening tools. In addition, oral ability, severity of dementia, vital functions and nutritional status were compared in these groups. A total of 393 elderly people in LTC (89 men and 304 women; age ranging from 65 to 100 years) were included in the study. The modified water swallow test, cervical auscultation and cough test were used to assess swallowing function. The participants were categorised as having suspected aspiration and/or SA, and the following assessments were performed: (i) oral ability (lips function, tongue function, rinsing and gargling ability), (ii) dementia severity, (iii) vital functions and (iv) nutritional status. Suspected aspiration was apparent in 50.5% of patients, of which 24.0% had suspected SA. Those with suspected aspiration showed worsened oral ability, dementia severity, vital functions and nutritional status. Similarly, those with suspected SA showed worsened dementia severity, vital functions and nutritional status. Logistic regression analysis revealed that lip closure, lingual movement and rinsing ability were significantly associated with suspected aspiration. Dementia severity was the best predictor of suspected SA. Simple screening tools can be used to identify suspected aspiration and SA, which may facilitate early detection of aspiration pneumonia or swallowing disorder risk.
Acta Cytologica | 2014
Mitsumasa Yamashina; Kazumichi Sato; Morio Tonogi; Yoichi Tanaka; Gen-yuki Yamane; Akira Katakura
Objective: Evaluation of combined morphometry and immunoexpression of cytokeratin 13 (CK13) and cytokeratin 17 (CK17) for cytological identification of superficial oral squamous cells. Study Design: Smears from 11 tongue squamous cell carcinoma patients were processed by liquid-based cytology, stained via the Papanicolaou method and divided into multiple specimens by cell transfer. Morphometric indices, including nuclear area, nuclear perimeter, nuclear circular rate, largest-to-smallest dimension ratio of the nucleus and nucleocytoplasmic ratio, were measured using a computerized analysis system. CK13 and CK17 were detected by immunostaining. Morphometric values were compared between cell populations with distinct staining and immunoexpression patterns. Results: Most orange G-stained superficial cells were negative for CK13 (99.4%) and CK17 (98.6%). For light green-stained superficial cells, loss of CK13 was associated with greater cellular atypia in the nuclear area, nuclear perimeter and nucleocytoplasmic ratio (p < 0.01), while expression of CK17 was related to higher-grade cellular atypia in the same parameters (p < 0.01) as well as the nuclear circular rate (p < 0.05). Conclusion: Immunoexpression of CK13 and CK17 in light green-stained superficial cells was associated with more severe morphological atypia. Combined morphometry and immunoexpression of CK13 and CK17 might be useful for cytological diagnosis of this cell population.
The Bulletin of Tokyo Dental College | 2015
Kyoko Yoshida; Kazumichi Sato; Morio Tonogi; Yoichi Tanaka; Gen-yuki Yamane; Akira Katakura
Cytokeratins (CK) are abundant in keratinized cells, particularly CK14 and CK19, which are expressed in stratified squamous epithelial cells. In this study, expression of CK14 and 19 was examined in human epithelial and dysplastic tissues. Surgical specimens from patients with clinically diagnosed oral leukoplakia or early cancer were stained with hematoxylin and eosin and classified into normal, low grade dysplasia (LGD), high grade dysplasia (HGD), or squamous cell carcinoma (SCC). The sections were examined by immunostaining and reverse transcription-polymerase chain reaction (RT-PCR) for CK14 and CK19. Expression and the results of RT-PCR for CK14 showed a decrease in the order of LGD, HGD, and SCC, whereas those of CK19 showed an increase in that order. These results suggest that decreased expression of CK14 and increased expression of CK19 serve as indicators of potential for malignant transformation.
Colorectal Disease | 2014
H. Kishikawa; Kazumichi Sato; Tomohiro Yamauchi; Akira Katakura; Takahiko Shibahara; Nobuo Takano; J. Nishida
Colorectal adenoma and cancer are not regarded as being associated with primary oral cancer. The aim of this study was to determine whether screening colonoscopy should be performed for patients with oral cancer in addition to the upper gastrointestinal endoscopic screening that is now routinely performed.
The Bulletin of Tokyo Dental College | 2016
Tomoyoshi Saitoh; Kazumichi Sato; Morio Tonogi; Yoichi Tanaka; Gen-yuki Yamane
The management of epithelial dysplastic spread around an oral squamous cell carci-noma is very important, particularly intraoperatively. Both cytokeratin (CK) 14 and CK19 are believed to be involved in the development of precancerous lesions, and their expression profiles are quite specific in these and early cancer lesions. Here, expression of CK13, 14, 17, and 19 was investigated in a rat model of 4-nitroquinoline-1-oxide-induced tongue cancer during a series of carcinogenetic processes to determine their value in assessing the features of epithelial dysplastic spread around a cancer. Based on tissue conditions, the results showed that expression levels of CK13 and 14 decreased in the order of no change, dysplasia, and cancer, whereas those of CK17 and 19 increased in the same order. Expression of CK13 showed a significant difference among no change, dysplasia, and cancer. This indicates that comparing the immunohistochemical staining profiles of CKs, especially CK13, could help in assessing the characteristics of epithelial dysplastic spread around a cancer.
The Bulletin of Tokyo Dental College | 2018
Kazumichi Sato; Taiki Suzuki; Yusuke Sanjo; Takashi Ushioda; Kazuhiko Hashimoto; Hirokazu Saito; Satoru Ogane; Nobuo Takano; Takeshi Nomura
Disseminated carcinomatosis of the bone marrow (DCBM) is characterized by diffuse metastasis to bone marrow and sudden mortality. To the best of our knowledge, no studies to date have reported progression of oral squamous cell carcinoma to DCBM. Herein, we report a case of squamous cell carcinoma in the maxillary gingiva suspected of progressing to DCBM. A 64-year-old woman presented with white lesions on the left maxillary gingiva. The lesions were diagnosed as squamous cell carcinoma (T2, N0, M0), and partial maxillectomy performed. Two years and 5 months after surgery, metastasis was noted in the left cervical lymph node and left radical neck dissection carried out. The subsequent diagnosis was right cervical lymph node metastasis and multiple bone metastases. The patient also presented with thrombocytopenia, anemia, and elevated levels of alkaline phosphatase, probably due to metastatic bone disease. Although various antitumor therapies were administered, the patient died 6 months after diagnosis of multiple bone metastases.
The Bulletin of Tokyo Dental College | 2017
Taiki Suzuki; Ichiro Tanaka; Ryuta Osaka; Akira Baba; Kazumichi Sato; Tomohiro Yamauchi; Takeshi Nomura; Nobuo Takano
The purpose of this study was to investigate three-dimensionally temporal change in flap volume after free flap reconstructive surgery in tongue cancer patients. The results revealed an average change in flap volume of 82.3% at 1 year postoperatively. Change in tongue volume at approximately 6 months postoperatively showed a correlation with triglyceride levels. A correlation was also found between albumin levels and tongue volume at 1 year onwards postoperatively. The goal of such surgery in patients with tongue cancer is to reconstruct a functional tongue. Taking postoperative change in tongue volume into consideration is therefore of importance in minimizing postoperative dysphagia.