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Biomedical subjects

Masami Hattori

Publications and source records attributed to Masami Hattori.

5 recordsLinked to original sources
PubMed2006

Global gene expression analyses of mouse fibroblast L929 cells exposed to IC50 MMA by DNA microarray and confirmation of four detoxification genes' expression by real-time PCR.

Methyl methacrylate (MMA) is the main component of methyl methacrylic resin, which is widely used in dentistry. Previous studies have investigated whether MMA has any adverse effects on growth and gene expression in mouse fibroblast L929 cells. The present study was designed to further understand the effects of MMA by focusing on cDNA microarray data after L929 cells were exposed to MMA. MMA was found to inhibit cell growth and induce detoxification response genes in L929 cells. One of the most highly up-regulated genes was glutathione S-transferase, alpha 1 (Ya) (Gsta1), which has recently been shown to participate in Nrf2 regulation and is considered to be related to detoxification response. Molecular biological data obtained in the present study may therefore provide useful insights into the effects of MMA on living tissue.

Animals↗
PubMed2004

Masticatory performance in 80-year-old individuals.

OBJECTIVE: To evaluate the masticatory performance of elderly people at the age of 80 years. SUBJECTS: A total of 283 individuals of 80 years of age took part in a general and dental health survey. MAIN OUTCOME MEASURES: A dental examination including the number of remaining teeth, occlusion, prostheses, bite force recording, and a questionnaire regarding masticatory performance were recorded. SETTING: Five municipalities (Okazaki city, Tokoname city, Tahara town, Atsumi town and Minami-chita town) in Aichi prefecture, Japan. RESULTS: There were 20 or more teeth in 7.4% subjects, and 44.5% were edentulous. Subjects with no occlusion accounted for 77.4% of the total. Subjects with prostheses accounted for 90.8%. Maximum bite force and masticatory ability score for patients with 20 or more teeth or not wearing prostheses were higher than other groups. The non-wearing prostheses group had a low masticatory ability score. CONCLUSION: Most of the 80-year-old individuals recovered their masticatory ability with the assistance of prostheses. Several individuals with 20 or more remaining teeth or without removable dentures present in both jaws had a high score for bite forces and masticatory abilities.

Aged↗
PubMed2004

[Human papillomavirus infection in the oral cavity of denture wearers].

PURPOSE: The purpose of this study was to determine the frequency of human papillomavirus(HPV)infections in the oral cavity of middle-aged and elderly dental patients with dentures. METHODS: In this study, 47 patients (20 men and 27 women), aged from 50 to 78 years, were randomly selected from the patients in the Department of Prosthodontics, Aichi-Gakuin University Affiliated Dental Hospital. Oral squamous cells were collected from swabs of the buccal mucosa. For this procedure, informed consent was obtained. Extracted DNA was evaluated for HPV infections by PCR methods, using consensus and specific primers, and direct DNA sequencing analysis. RESULTS: Twenty-four of 47 specimens (51.1%) were positive for HPV DNA. A statistically significant association was not found in the HPV positivity between men and women. The high rate of infection was recognized from 60 or more years old. A statistically significant association was found in the HPV positivity between non-denture wearers and denture wearers. Frequent HPV types in the specimens of all were HPV11, 4 and 16. Frequent HPV types in the specimens of non-denture wearers and denture wearers were HPV4, 11 and HPV11, 16 and 4, respectively. CONCLUSIONS: The results of the present investigation indicate that HPV is present in the oral cavity, especially those of denture wearers, of middle-aged and elderly patients. It is suggested, therefore, that the oral cavity of middle-aged and elderly patients with dentures is a reservoir of HPVs where later HPV-associated diseases, such as oral cancer and other oral lesions, may develop.

English Abstract↗
PubMed2002

Effect of denture cleaner using ozone against methicillin-resistant Staphylococcus aureus and E. coli T1 phage.

We examined the bactericidal and virucidal effectiveness of a denture cleaner that uses ozone (ozone concentration, 10 ppm) against methicillin-resistant Staphylococcus aureus (MRSA) and T1 phage, respectively. In the bactericidal activity test, with the ozone supply turned on, the number of bacteria was 3.1 x 10(3) CFU/mL at the beginning of the experiment, fell to 1.0 x 10(0) CFU/mL 10 min later, and was 1.0 x 10(0) CFU/mL or less afterwards. In contrast, when the ozone supply was cut off (air bubble only), the number of bacteria was 3.4 x 10(3) CFU/mL at the beginning of the experiment, and had fallen to 3.0 x 10(3) CFU/mL 60 min later (no statistically significant difference). In the virucidal activity test, the number of phages was 1.2 x 10(6) PFU/mL before ozone treatment, fell to about 1/10 of that number 10 min later, and was 6.1 x 10(0) PFU/mL 40 min later. These results indicate that the use of ozone in this denture cleaner is effective against MRSA and viruses.

Anti-Bacterial Agents↗