Biomedical subjects

Manabu Morita

Publications and source records attributed to Manabu Morita.

14 recordsLinked to original sources

PubMed2006

Comparison of antioxidant enzymes in saliva of elderly smokers and non-smokers.

OBJECTIVES: This study was designed to compare the levels of copper/zinc superoxide dismutase (Cu/Zn SOD), peroxidase (POx) and glutathione peroxidase (GSH-Px) in saliva of smokers and those in saliva of non-smokers. METHODS: Unstimulated saliva samples were collected from 88 elderly males (65 years old or over) who visited a private dental clinic. Forty-four subjects were current smokers (more than 20 cigarettes daily for at least 30 years) and 44 were non-smokers. The levels of salivary thiocyanate, Cu/Zn SOD, GSH-Px, and POx activity were measured using standard procedures. RESULTS: The mean levels of salivary thiocyanate (SCN(-)) and SOD were significantly higher (p < 0.01) in the smoking group than in the non-smoking group, whereas the specific activity levels of POx and GSH-Px were significantly higher (p < 0.05) in the non-smoking group than in the smoking group. Significant correlation coefficients were found between the levels of SCN(-) and SOD (r = 0.37, p < 0.001). In the non-smoking group, a significant positive association was found between specific activity of POx and age (r = 0.33, p < 0.05). CONCLUSION: Measurement of SCN(-) and Cu/Zn SOD in human saliva might be useful for estimating the level of oxidative stress caused by cigarette smoke. Despite increased H2O2 level as a defense system induced by SOD, detoxification of H2O2 might be deteriorated in the oral cavity of elderly smokers.

Age Factors↗

PubMed2006

Relationship between salivary histatin 5 levels and Candida CFU counts in healthy elderly.

OBJECTIVES: Few epidemiological studies have confirmed the antifungal activity of histatin 5 in saliva against Candida species. The purpose of this study was to examine the relationship between concentrations of histatin 5 and the number of cultivable Candida in saliva samples from elderly. METHODS: Whole saliva samples were obtained from 124 elderly people, 65 years or older, living in a rural community. The concentrations of histatin 5 in saliva samples were determined by the enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody. Total colony-forming units (CFUs) were counted on a selective medium for Candida. Multiple linear regression analysis was performed to determine the independent contribution of explanatory variables to Candida CFUs using age, sex, histatin 5 concentration and type of denture prosthesis as independent variables. RESULTS: Saliva samples from 104 subjects (84%) were candidal colony-positive. The youngest group (65-69 years old) showed significantly smaller Candida CFU counts than those in the older group. The mean Candida CFU count of denture wearers was significantly higher than that of non-denture wearers. Significantly negative associations were found between Candida CFU counts and histatin 5 level in the oldest group (p < 0.05) and in the full-denture wearers (p < 0.01). Multiple linear regression analysis revealed that Candida CFU counts were mostly associated with type of dentures, followed by histatin 5 concentration. CONCLUSION: Possible activity of histatin 5 against Candida in whole saliva of elderly people was epidemiologically confirmed. The area covered by the prostheses was a strong factor associated with the Candida CFU count.

Age Factors↗

PubMed2006

Reasons for permanent tooth extractions in Japan.

BACKGROUND: There has been no nationwide study in Japan on reasons for extraction of permanent teeth. This survey was aimed to determine the reasons for extraction of permanent teeth in Japan. METHODS: Five thousand, one hudred and thirty-one dentists were selected by systematic selection from the 2004 membership directory of the Japan Dental Association. The dentists selected were asked to record the reason for each extraction of permanent teeth during a period of one week from February 1 through 7, 2005. Reasons for tooth extraction were assigned to five groups: caries, fracture of teeth weakened by caries or endodontics, periodontal diseases, orthodontics, and other reasons. RESULTS: A total of 2,001 dentists (response rate of 39.1%) returned the questionnaires, and information on 9,115 extracted teeth from 7,499 patients was obtained. The results showed that caries and its sequela (totally 43.3%, 32.7% and 10.6%, respectively) and periodontal disease (41.8%) were the main reasons for teeth extraction. Extraction due to caries or fracture was commonly observed in all age groups over 15 years of age, whereas periodontal disease was predominant in the groups over 45 years of age. CONCLUSIONS: Most of the permanent teeth were extracted due to caries and its sequela and periodontal disease. Prevention and care for dental caries for all age groups and periodontal disease for over middle age groups are required.

Adolescent↗

PubMed2005

Relationships between lifestyle and dental health behaviors in a rural population in Japan.

OBJECTIVES: The aim of this study was to determine associations of lifestyle with dental health behaviors such as tooth brushing frequency, use of extra cleaning devices, and regular dental visits to a dentist. METHODS: Data were collected from 1182 dentate residents 18 years of age or older who resided in a typical farming district. The data included data on the demographic factors, dental health behavior, and various aspects of lifestyle, i.e. mental condition, alcohol consumption, smoking habit, physical activity, social activity, dietary habits, and presence of systemic diseases. RESULTS: Multiple logistic regression analysis revealed that subjects in a younger group (18-39 years of age) and subjects who had never smoked brushed their teeth more frequently. Experience of social volunteer work and presence of systemic disease were correlated with use of extra cleaning devices. Associations of female gender with frequency of tooth brushing and use of extra cleaning devices were weakly positive. The subjects who considered dietary combination carefully and those who lived alone were predisposed to visit a dentist regularly. CONCLUSIONS: The results indicate that dental health behavior is associated with lifestyle as well as demographic factors.

Adolescent↗

PubMed2005

Rare earth oxide-containing fluorescent glass filler for composite resin.

In recent dental care, esthetic restorative materials such as composite resin and porcelain have been widely used and studied. However, their good esthetics makes the visual inspection of restored teeth difficult. In this study, a fluorescent glass filler containing rare earth oxides - which are well-known fluorescent materials - was prepared and used in composite resin to enhance visual inspection capability with small change in color. For example, when irradiated with near ultraviolet light, an Eu2O3-containing filler fluoresced clearly and visibly. The fluorescence intensity of the prepared composite resin increased with increase of Eu2O3 content in the glass filler and with filler/resin ratio in the resin. Despite the clear fluorescence, the effect of Eu2O3 on the color change of composite resin was quite small - even when up to 10 wt% Eu2O3 was added to the glass filler. Tb4O(7-) and Dy2O3-added fillers also showed clear fluorescence, just like Eu2O3-added filler. Therefore, fluorescent glass fillers for composite resins, resulting in small color change in the latter, were successfully prepared in this study.

Composite Resins↗

PubMed2004

Relationship between structures and biological activities of mycoplasmal diacylated lipopeptides and their recognition by toll-like receptors 2 and 6.

The lipopeptide FSL-1 [S-(2,3-bispalmitoyloxypropyl)-Cys-Gly-Asp-Pro-Lys-His-Pro-Lys-Ser-Phe, Pam(2)CGDPKHPKSF] synthesized on the basis of the N-terminal structure of a Mycoplasma salivarium lipoprotein capable of activating normal human gingival fibroblasts to induce the cell surface expression of ICAM-1 revealed an activity to induce production of monocyte chemoattractant protein 1, interleukin-6 (IL-6), and IL-8. FSL-1 also activated macrophages to produce tumor necrosis factor alpha as the Mycoplasma fermentans-derived lipopeptide MALP-2 (Pam(2)CGNNDESNISFKEK), a potent macrophage-activating lipopeptide, did. The level of the activity of FSL-1 was higher than that of MALP-2. This result suggests that the difference in the amino acid sequence of the peptide portion affects the activity because the framework structure other than the amino acid sequence of the former is the same as that of the latter. To determine minimal structural requirements for the activity of FSL-1, the diacylglyceryl Cys and the peptide portions were examined for this activity. Both portions did not reveal the activity. A single amino acid substitution from Phe to Arg and a fatty acid substitution from palmitic acid to stearic acid drastically reduced the activity. Similar results were obtained in measuring the NF-kappaB reporter activity of FSL-1 to human embryonic kidney 293 cells transfected with Toll-like receptor 2 and 6, together with a NF-kappaB-dependent luciferase reporter plasmid. These results suggest that both the diacylglyceryl and the peptide portions of FSL-1 are indispensable for the expression of biological activities and for the recognition by Toll-like receptors 2 and 6 and that the recognition of FSL-1 by Toll-like receptors 2 and 6 appears to be hydrophobic.

Acylation↗

PubMed2004

Prevalence of oral malodor and the relationship with habitual mouth breathing in children.

The prevalence of oral malodor and association of habitual mouth breathing with oral malodor were investigated in children residing in rural areas. One hundred and nineteen children participated in this study. A sulfide monitor and organoleptic method were used to evaluate oral malodor. About 8% of children had a sulfide level in mouth air above the socially acceptable limit (75 ppb). Habitual mouth breathing was a factor contributing to oral malodor. Oral malodor was not significantly correlated with plaque index, history of caries or frequency of toothbrushing.

Analysis of Variance↗

PubMed2004

Relationship between blood triglyceride levels and periodontal status.

OBJECTIVES: The literature suggests that a link exists between the presence of periodontal disease and impaired lipid metabolism. However, most studies have focused on patients in private clinics or university hospitals. In the present study, we assessed associations between blood chemistry variables and periodontal disease status in rural communities of Japan. METHODS: A total of 823 residents participated in a comprehensive health screen. The medical screen included measurement of body mass index, blood pressure, hematocrit and blood chemistry, including levels of hemoglobin, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), gamma-glutamyl transpeptidase (gamma-GTP), creatinine, and plasma glucose. Periodontal status was assessed using the CPI scoring method. Of those participating, 133 subjects with a CPI of 4 (periodontal disease group) and age- and gender-matched control subjects with a CPI of less than 3 were selected for analysis. RESULTS: The mean triglyceride level was significantly higher for the diseased group than for the control group (p < 0.05). The mean HDL-C level was higher for the control group than for the diseased group, although the difference was not statistically significant. Logistic regression model analysis revealed a significant relationship between elevated triglycerides (> 149 mg/dl) and the presence of periodontal disease (OR = 2.26 vs. < or = 149 mg/dl, p = 0.014). CONCLUSION: The results indicate that serum triglyceride level might be a potential indicator for the presence of periodontal disease, suggesting the need for community-based longitudinal studies.

Adult↗

PubMed2003

Involvement of leucine residues at positions 107, 112, and 115 in a leucine-rich repeat motif of human Toll-like receptor 2 in the recognition of diacylated lipoproteins and lipopeptides and Staphylococcus aureus peptidoglycans.

S-(2,3-bispalmitoyloxypropyl)Cys-Gly-Asp-Pro-Lys-His-Pro-Lys-Ser-Phe (FSL-1) derived from Mycoplasma salivarium stimulated NF-kappaB reporter activity in human embryonic kidney 293 (HEK293) cells transfected with Toll-like receptor 2 (TLR2) or cotransfected with TLR2 and TLR6, but not in HEK293 cells transfected with TLR6, in a dose-dependent manner. The activity was significantly higher in HEK293 cells transfected with both TLR2 and TLR6 than in HEK293 cells transfected with only TLR2. The deletion mutant TLR2(DeltaS40-I64) (a TLR2 mutant with a deletion of the region of Ser(40) to Ile(64)) failed to activate NF-kappaB in response to FSL-1. The deletion mutant TLR2(DeltaC30-S39) induced NF-kappaB reporter activity, but the level of activity was significantly reduced compared with that induced by wild-type TLR2. A TLR2 point mutant with a substitution of Glu(178) to Ala (TLR2(E178A)), TLR2(E180A), TLR2(E190A), and TLR2(L132E) induced NF-kappaB activation when stimulated with FSL-1, M. salivarium lipoproteins, and Staphylococcus aureus peptidoglycans, but TLR2(L107E), TLR2(L112E) (a TLR2 point mutant with a substitution of Leu(112) to Glu), and TLR2(L115E) failed to induce NF-kappaB activation, suggesting that these residues are essential for their signaling. Flow cytometric analysis demonstrated that TLR2(L115E), TLR2(L112E), and TLR2(DeltaS40-I64) were expressed on the cell surface of the transfectants as wild-type TLR2 and TLR2(E190A) were. In addition, these mutants, except for TLR2(E180A), functioned as dominant negative form of TLR2. This study strongly suggested that the extracellular region of Ser(40)-Ile(64) and leucine residues at positions 107, 112, and 115 in a leucine-rich repeat motif of TLR2 are involved in the recognition of mycoplasmal diacylated lipoproteins and lipopeptides and in the recognition of S. aureus peptidoglycans.

Acylation↗

PubMed2003

Discrimination between composite resin and teeth using fluorescence properties.

The differentiation of composite resin from teeth using fluorescence emission was investigated as basic research for the visual detection of resin filled teeth in mass dental health examinations. Fluorescence spectra were taken from extracted human maxillary central incisors and 12 types of light-cured composite resins with a maximum of 15 shades via excitation using light with wavelengths of 400-500 nm. The fluorescence intensity ratio of resin to tooth was lowest around 500 nm for all the resins. The fluorescent images were taken based on spectroscopic results, which confirmed discrimination between the resin part and the tooth in the resin filled tooth.

Color↗

PubMed2002

Toothbrushing promotes gingival fibroblast proliferation more effectively than removal of dental plaque.

OBJECTIVES: Removal of dental plaque is an essential element of periodontal treatment. However, there have also been studies of the effects of the mechanical stimulation provided by toothbrushing on gingival host-defense mechanisms. The aim of the study was to evaluate the effects of toothbrushing on gingival fibroblast proliferation in dogs over time, compared to effects of plaque removal without brushing. METHODS: The mouths of six mongrel dogs were divided into four quadrants: two for daily toothbrushing, and two for daily plaque removal with a curette. After 1, 3 and 5 weeks of treatment, histometrical analyses were performed to assess inflammatory cell infiltration, proliferating cell nuclear antigen (PCNA)-positive fibroblasts, procollagen type I-positive fibroblasts in the subepithelial connective tissue of junctional epithelium. RESULTS: Toothbrushing increased the number of PCNA-positive fibroblasts in the first week, increased the number of type I procollagen-positive fibroblasts at the fifth week, and reduced inflammatory cell infiltration at the third week. CONCLUSION: These findings suggest that mechanically stimulated fibroblasts begin proliferating within a week, and this cell division results in an increased number of fibroblasts at the third week. It takes 5 weeks before differences in collagen synthesis between brushing and plaque removal areas are detectable.

Animals↗

PubMed2002

Effect of initial periodontal therapy on sulcular/tongue sulfide level. A pilot study.

BACKGROUND: : Volatile sulfur compounds (VSC), such as hydrogen sulfide, methyl mercaptan and dimethyl sulfide, are toxic metabolites produced by periodontal pathogens. These VSC are also released from the tongue dorsum. Currently, limited data are available on how periodontal treatments may affect sulcular/tongue sulfide level. The aim of this study was to determine effect of initial therapy including oral hygiene instruction and scaling and root planing (SRP) on sulcular/tongue sulfide level. METHODS: : Thirteen subjects diagnosed with chronic periodontitis and having three representative periodontal pocket depth (PD) strata in one quadrant (PD or= 7.0 mm: severe disease sites) were selected. Clinical periodontal parameters were recorded at baseline and 3 weeks after completion of the initial therapy. The sulfide levels in three representative periodontal pockets (pS) and on three parts (anterior, middle, and posterior) of the tongue dorsum (tS) were measured using a commercial sulfide-monitoring device. RESULTS: : The pS levels of the three representative sites were reduced significantly following the initial therapy (p < 0.05). However, there was no significant reduction of the tS level in all three parts of the tongue. CONCLUSIONS: : The initial periodontal therapy such as oral hygiene and SRP reduces the sulcular sulfide level but not the tongue sulfide level. This suggests that sulcular sulfide level may be a possible indicator for assessing the outcome of initial periodontal treatment.

Adult↗

PubMed2002

Synergic effects of mycoplasmal lipopeptides and extracellular ATP on activation of macrophages.

Mycoplasmal lipopeptides S-(2,3-bispalmitoyloxypropyl)-CGDPKHSPKSF and S-(2,3-bispalmitoyloxypropyl)-CGNNDESNISFKEK activated a monocytic cell line, THP-1 cells, to produce tumor necrosis factor alpha. The activity of the lipopeptides was augmented by ATP in a dose-dependent manner. In addition, the level of expression of mRNAs for tumor necrosis factor alpha and interleukin-1 beta, -6, and -8 was also upregulated by the lipopeptides and/or extracellular ATP, but that of interleukin-10 was not. The P2X purinergic receptor antagonists pyridoxal phosphate 6-azophenyl 2',4'-disulfonic acid and periodate-oxidized ATP suppressed the activity of ATP to augment the activation of THP-1 cells by the lipopeptides, suggesting that P2X receptors play important roles in the activity of ATP. The nuclear factor kappa B inhibitor dexamethasone also suppressed the activity, suggesting that the activity of ATP is dependent upon the nuclear factor kappa B. Thus, these results suggest that the interaction of extracellular ATP with the P2X receptors is attributed to the activity of ATP to augment the activation of THP-1 cells by mycoplasmal lipopeptides.

Adenosine Triphosphate↗

PubMed2002

The effect of duration and force of mechanical toothbrushing stimulation on proliferative activity of the junctional epithelium.

BACKGROUND: Gingival bleeding is frequently accompanied by an ulcerated epithelium, with repair depending on the proliferative activity of the epithelial cells. The present study examined the proliferative activity of the junctional epithelium (JE) under several different methods of toothbrushing stimulation. METHODS: Twelve dogs were used in this 3-week experiment. Prior to the experiment, all teeth underwent daily removal of plaque and calculus using a scaler. Teeth were then divided into quadrants: 9 teeth in 3 quadrants (test, 3 per quadrant) were mechanically stimulated by toothbrushing for various time intervals (10, 20, or 40 seconds) and at various forces (100, 200, or 250 gf). The 3 teeth in the fourth quadrant served as controls. The proliferative activity of the basal cells of the junctional epithelium was evaluated for expression of proliferating cell nuclear antigen (PCNA). The numbers of PCNA-positive basal cells and total basal cells were counted, and the width of the junctional epithelium was measured. RESULTS: Toothbrushing force significantly affected the PCNA-positive basal cell ratio (P < 0.05). The 200 g toothbrushing force produced the highest PCNA-positive basal cell ratio, which was significantly higher than that using the 100 g force (P < 0.05). CONCLUSION: In junctional epithelium stimulated with a toothbrush, the PCNA-positive basal cell ratio is more sensitive to toothbrushing force than to duration.

Analysis of Variance↗