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Biomedical subjects

N Hanada

Publications and source records attributed to N Hanada.

At least 19 recordsLinked to original sources
PubMed2006

Association between commensal bacteria and opportunistic pathogens in the dental plaque of elderly individuals.

Opportunistic infections in the oral cavity of the elderly may increase the incidence of systemic disease. The objective of this study was to investigate the differences in the oral bacterial flora between dependent elderly (inpatients) and independent elderly (community-dwelling residents). After multiple variables were taken into account, inpatients had significantly lower detection rates than community-dwelling residents for alpha-streptococci (p < 0.001) and Neisseria (p 0.004), and higher detection rates for Pseudomonas aeruginosa (p 0.024), methicillin-resistant Staphylococcus aureus (MRSA) (p 0.011) and Actinomyces spp. (p 0.005). Among inpatients, the requirement for a high degree of care was related negatively to detection of alpha-streptococci, but was related significantly to detection of P. aeruginosa (p 0.018) or MRSA (p 0.004). Tube-fed inpatients had a significantly lower detection rate for alpha-streptococci (p 0.041) and a higher detection rate for P. aeruginosa (p 0.004) than those who did not require tube feeding. Inpatients with a history of antibiotic use had a significantly lower detection rate for alpha-streptococci (p 0.049) and a higher detection rate for MRSA (p 0.007) than those without a history of antibiotic use. The detection rates for P. aeruginosa or MRSA in inpatients without alpha-streptococci were higher than in inpatients with alpha-streptococci after controlling for age and gender (P. aeruginosa, p 0.006; MRSA, p 0.001). Overall, detection of alpha-streptococci had an inverse correlation with the detection of P. aeruginosa and MRSA in the oral cavity and is likely to be an indicator of pathogenic bacterial infection.

Aged↗
PubMed2005

The relationship between bone mineral density and the number of remaining teeth in community-dwelling older adults.

Tooth loss and osteoporosis may share common aetiologic agents which influence the process of both diseases. The purpose of this study was to evaluate the relationship between bone mineral density (BMD) of the os calcis and the number of remaining teeth, controlling the known confounding factors. Among all 70-year-old inhabitants in Niigata City, Japan, 600 people were selected randomly in order to have approximately the same number of each gender. We analysed 460 subjects. We evaluated the BMD of the os calcis using an ultrasound bone densitometer, then we counted the number of remaining teeth excluding the third molars. Stiffness is a clinical index which is calculated by the spread speed of supersonic waves. To monitor the general health condition of the subjects, serum levels of disease markers and smoking habits were also investigated. The mean number of remaining teeth for the osteopenia group (OG) and the no-osteopenia group (NOG) was 15.97+/- 9.98 and 18.31+/- 8.06, respectively in females, and 16.32+/- 9.93 and 18.12+/- 9.33, respectively in males (OG versus NOG, P=0.047 by two-way anova). In addition, stiffness was significantly associated with the number of remaining teeth (CV=-0.157, P=0.005) using linear multiple regression analysis adjusted by four other variables. In this study, there was a significant relationship between the number of remaining teeth and BMD of the os calcis.

Adipose Tissue↗
PubMed2005

Predominant presence of Streptococcus anginosus in the saliva of alcoholics.

Chronic alcohol consumption is known to be a major risk factor for cancers of the upper aerodigestive tract. The incidence of esophageal cancer (4.4%) in alcoholics is reported to be much higher than that in the Japanese population as a whole (0.0001%). This suggests the presence of specific factors in chronic alcohol consumption-related carcinogenesis. Recently, data showing a significant correlation between Streptococcus anginosus and carcinogenesis in the upper aerodigestive tract have been reported. In this study, the ratio of S. anginosus to oral bacteria in the saliva of 38 alcoholic patients was investigated to determine if there is an association between alcoholic patients and S. anginosus infection. The level of S. anginosus in the saliva from 22 healthy people, 41 esophageal cancer patients, 32 gastritis patients, and 24 periodontitis patients was also investigated and compared to the level in alcoholic patients. In the saliva from esophageal cancer patients, the level of S. anginosus was not significantly different from that of healthy people. The levels of S. anginosus in periodontitis and gastritis patients were also similar. In alcoholics, however, there was an extremely high level of S. anginosus, suggesting that they, rather than healthy people and general esophageal cancer patients, have a high risk for S. anginosus infection.

Adult↗
PubMed2005

Serum vitamin C-periodontal relationship in community-dwelling elderly Japanese.

OBJECTIVE: To determine the relationship between serum vitamin C and periodontitis as estimated by clinical attachment loss (CAL) in community-dwelling elderly Japanese. MATERIAL AND METHODS: This analysis was confined to 413 Niigata citizens aged 70 years in whom the data for serum vitamin C and CAL were available. High-pressure liquid chromatography method was used to ascertain the serum vitamin C levels while CAL was assessed on six sites of all teeth present including third molars by means of pressure-sensitive probes. Other variables included gender, smoking, toothbrushing frequency, number of teeth present and random blood sugar levels. RESULTS: Serum vitamin C concentration was inversely related to CAL (r=-0.23, p<0.00005) at bivariate level. Multiple linear regression analysis showed that CAL was 4% greater in subjects with lower serum vitamin C levels than in subjects with higher serum vitamin C levels notwithstanding smoking, diabetes, oral hygiene, gender or number of teeth present. CONCLUSION: The findings suggested that serum vitamin C might have relatively weak but a statistically significant relationship with periodontitis in this elderly population.

Aged↗
PubMed2004

Role of peptide antigen for induction of inhibitory antibodies to Streptococcus mutans in human oral cavity.

The alanine-rich repeating region (A-region) in the surface protein antigen (PAc) of Streptococcus mutans has received much attention as an antigenic component for vaccines against dental caries. The PAc (residue 361-386) peptide in the A-region possesses a multiple binding motif (L- -V-K- -A) to various HLA-DR molecules and a B-cell core epitope (- Y- - -L- -Y- - - -) that recognizes the inhibiting antibody to S. mutans. In the present study, we investigated the immunogenicity of the PAc (361-386) peptide in humans and regulators of induction of the anti-PAc (361-386) peptide IgA antibody (aPPA) in saliva. The PAc (361-386) peptide was confirmed as an ideal peptide antigen for induction of the inhibiting antibody to S. mutans in 151 healthy human subjects (36.6 +/- 12.6 years old) by quantitative analyses of oral bacteria and ELISA, as the aPPA titre in human saliva decreased significantly in an age-dependent manner. Homozygous DRB1*0405 and 1502, and heterozygous DRB1*0405/1502 showed a negative association with production of aPPA and tended to reduce the number of total streptococci in saliva. In contrast, the DRB1*1501 allele was significantly correlated with a high level of induction of the antibodies, and also tended to reduce lactobacilli and mutans streptococci. Further, peptide immunogenicity was confirmed in NOD-SCID mice grafted with human peripheral blood mononuclear cells. Our results indicate that the interplay between regulators such as age, DRB1 genotype, cytokines, and peptide immunogenicity may provide a potential means for developing a vaccine useful for the prevention of dental caries as well as their diagnosis.

Adult↗
PubMed2004

Molecular analysis of age-related changes of Streptococcus anginosus group and Streptococcus mitis in saliva.

The purpose of this study was to survey the prevalence of streptococcal species, especially Streptococcus anginosus (which has been reported to be associated with cancer in the upper digestive tract), Streptococcus constellatus, and Streptococcus intermedius in the saliva of different age groups. A sequence analysis of 16S rDNA was performed and DNA quantified using real-time polymerase chain reaction. The S. anginosus level increased with age, whereas the levels of S. constellatus and S. intermedius did not change. Streptococcus mitis was the predominant species in the saliva of all the age groups but, unlike the S. anginosus, the proportion of S. mitis in the salivary bacteria decreased with age. The increase in S. anginosus with age should be carefully monitored because of its association with diseases, including cancer.

Adult↗
PubMed2003

Real-time interaction of oral streptococci with human salivary components.

Oral streptococci are present in large numbers in dental plaque and several types interact with the enamel salivary pellicle to form a biofilm on tooth surfaces. The respective affinity of individual streptococci for salivary components has an influence on the etiologic properties of oral biofilm in the development of dental caries. We studied real-time biospecific interactions between oral streptococci and salivary components utilizing biosensor technology to analyze surface plasmon resonance. Streptococcus sanguis and Streptococcus mutans showed significant responses for binding to salivary components, in comparison with other bacteria. Further, the association rates (4.1 x 10-11/bacterium) and dissociation rate (5.7 +/- 0.9 x 10-3 Second(s)-1) were higher for S. sanguis than for S. mutans (2.4 x 10-11 and 2.9 +/- 0.8 x 10-3) and Streptococcus mitis (1.3 x 10-11 and 3.5 +/- 1.3 x 10-3). However, the association equilibrium constants (8.2 S/bacterium) for S. mutans was 2 times higher in than S. mitis (3.8) and slightly higher than S. sanguis (7.2). These findings may provide useful information regarding the mechanism of early biofilm formation by streptococci on the tooth surface.

Adult↗
PubMed2003

Association between serum albumin and root caries in community-dwelling older adults.

Recently, associations between dental diseases and the general health condition have been reported. The purpose of this study was to evaluate, by serum albumin concentrations, the relationship between the general health condition and root caries. We randomly selected 763 individuals (600 70-year-olds and 163 80-year-olds) living in Niigata City, Japan. The variables body composition, blood measurements, daily nutrient intakes, and root caries were measured. The relationship between root caries and serum albumin concentration was evaluated. The differences in serum albumin concentrations between subjects with untreated root caries (DT = 0 and DT > 3) were 75.56 mg/dL in 70-year-olds and 202.97 mg/dL in 80-year-olds (p < 0.05, ANOVA). The findings of the present study indicated that a relationship between root caries and serum albumin concentration in these elderly subjects is highly possible.

Aged↗
PubMed2002

Identification of the peptide motifs that interact with HLA-DR8 (DRB1*0802) in Streptococcus mutans proteins.

A glucosyltransferase (GTF) and a surface protein antigen (PAc) of Streptococcus mutans have been suggested as possible components of an effective dental caries vaccine. To identify antigenic peptides in GTF and PAc that bind to MHC class II (HLA-DR8, DRB1*0802) molecules, we investigated binding activities to DR8 molecules of overlapping synthetic peptides at several sites in GTF and in the alanine-rich repeating region of PAc using an ELISA-inhibition competitive binding assay for the interaction between the HLA-DR molecule and the PAc (316-334) peptide. Six GTF peptides and 10 PAc peptides strongly bound to the HLA-DR8 molecule. In a homology analysis of the amino acid sequences of the six GTF peptides, two binding motifs were found in L/Y--Y/L-A/N and Y/L--N/G/E--Y-V/L/P. Moreover, a new binding motif in PAc was found in L--Y-A. It is suggested that these binding motifs could be useful in designing a dental caries vaccine in humans.

Amino Acid Motifs↗
PubMed2002

Streptococcus mutans binding to solid phase dextran mediated by the glucan-binding protein C.

Streptococcus mutans GbpC is a wall-anchored surface protein which is involved in dextran-dependent aggregation. The GbpC phenotype is observed only in cells grown under stress conditions. In order to detect the GbpC protein of S. mutans, we isolated the wall fraction following digestion of the cell wall of this organism by N-acetylmuramidase, and detected the GbpC protein from S. mutans cells by western analysis with anti-GbpC serum. Interestingly, S. mutans cells exhibiting the negative dextran(alpha-1,6 glucan)-dependent aggregation (ddag) phenotype expressed the protein and could bind to immobilized dextran.

Bacterial Adhesion↗
PubMed2002

Sexual differences in smoking behaviour and dental caries experience in young adults.

Smokers have been reported to exhibit a low awareness of their health. However, oral health awareness in smokers has not been fully studied. Having adequate oral care and high awareness of oral health from youth is necessary to prevent the deterioration of oral health in middle and old age. The aim of this study was to investigate the oral health status and oral health behaviour in young smokers. A survey composed of a questionnaire and an oral examination was administrated to adults aged 20-29 y who consulted dentists. The relationship between smoking behaviour and oral health status and oral health behaviour in subjects was analysed. In women, though no significant relationship between smoking behaviour and the number of decayed, missing, and filled teeth was seen, current smokers had significantly more decayed teeth, missing teeth and fewer filled teeth than ex-smokers and non-smokers. Current smokers tended to practice less oral health behaviour than non-smokers. In men, there was no significant relationship between smoking behaviour and each oral health status item. These findings suggested that the smoking group had lower oral health awareness than the non-smoking group in women.

Adult↗
PubMed2002

Oral bacteria influenced by the functional status of the elderly people and the type and quality of facilities for the bedridden.

AIMS: To analyse the relationship between oral bacteria and the health and functional status of the elderly. METHODS AND RESULTS: The bacteria species in the oral cavity of the elderly were examined. It was found that the bedridden subjects staying at two hospitals for long-term (HOBR) showed significantly lower detection rates of commensal bacteria species and significantly higher detection rates of Pseudomonas aeruginosa, of methicillin-resistant Staphylococcus aureus (MRSA) and of coagulase(-) Staph. aureus than those living independently (the independent). In addition, the detection rate of Haemophilus parainfluenzae in NUBR was discovered to be higher than that found in the independent. In HOBR, the detection rate of Ps. aeruginosa was significantly higher among in-patients who required continual care than those in need of partial care, while the detection rate of MRSA was significantly higher among in-patients with low serum albumin than those with normal serum albumin. CONCLUSIONS: Oral bacteria examination analysis proved that the risks of infection of some pathogenic bacteria species were correlated with functional status, physical function and nutritional state. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study suggests that the oral bacteria, especially pathogenic bacteria were influenced by the functional status of the elderly and the type and quality of the facilities for the bedridden, physical function and nutritional state.

Activities of Daily Living↗
PubMed2001

Interleukin-1beta stimulates galectin-9 expression in human astrocytes.

Galectin-9 is an eosinophil chemoattractant produced by activated T lymphocytes. We have addressed expression of galectin-9 in normal human astrocytes in culture. Expression of galectin-9 mRNA and protein were examined by reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and immunofluorescent staining. Interleukin-1beta (IL-1beta) was found to enhance the galectin-9 expression in time- and concentration-dependent manners. Galectin-9 protein was detected in the membrane fraction, 105 000 x g precipitate, and immunofluorescent staining revealed diffuse cellular and perinuclear distributions. Dexamethasone pretreatment almost completely suppressed the production. We conclude that astrocytes produce galectin-9 in response to the stimulation with IL-1beta, and this may contribute to inflammatory reactions in the CNS.

Anti-Inflammatory Agents↗
PubMed2001

Optical coherence tomography of tractional macular elevations in eyes with proliferative diabetic retinopathy.

PURPOSE: To document the findings of optical coherence tomography in eyes with tractional macular elevation associated with proliferative diabetic retinopathy, paying special attention to differentiating between tractional retinal detachment and retinoschisis. DESIGN: Observational case series. METHODS: We retrospectively reviewed images of optical coherence tomography obtained from 17 consecutive eyes (17 patients) with proliferative diabetic retinopathy without vitreous opacity and showing tractional macular elevation with or without foveal involvement. RESULTS: Tractional retinal detachment and retinoschisis could be differentiated in the cross-sectional images of optical coherence tomography. Retinoschisis with or without associated retinal detachment was observed in 16 of 17 eyes (94%), whereas retinal detachment was observed in only six of 17 eyes (35%). Five eyes showed both findings of retinal detachment and retinoschisis. CONCLUSIONS: Optical coherence tomography is useful for distinguishing tractional retinoschisis from retinal detachment in eyes with proliferative diabetic retinopathy and macular elevation. Tractional retinoschisis with or without retinal detachment is the most frequent pattern of tractional macular elevation in eyes with proliferative diabetic retinopathy.

Adult↗
PubMed2001

Optical coherence tomography of tractional macular elevations in eyes with proliferative diabetic retinopathy.

PURPOSE: To document the findings of optical coherence tomography in eyes with tractional macular elevation associated with proliferative diabetic retinopathy, paying special attention to differentiating between tractional retinal detachment and retinoschisis. DESIGN: Observational case series. METHODS: We retrospectively reviewed images of optical coherence tomography obtained from 17 consecutive eyes (17 patients) with proliferative diabetic retinopathy without vitreous opacity and showing tractional macular elevation with or without foveal involvement. RESULTS: Tractional retinal detachment and retinoschisis could be differentiated in the cross-sectional images of optical coherence tomography. Retinoschisis with or without associated retinal detachment was observed in 16 of 17 eyes (94%), whereas retinal detachment was observed in only six of 17 eyes (35%). Five eyes showed both findings of retinal detachment and retinoschisis. CONCLUSIONS: Optical coherence tomography is useful for distinguishing tractional retinoschisis from retinal detachment in eyes with proliferative diabetic retinopathy and macular elevation. Tractional retinoschisis with or without retinal detachment is the most frequent pattern of tractional macular elevation in eyes with proliferative diabetic retinopathy.

Adult↗
PubMed2001

Periodontitis and serum interleukin-6 levels in the elderly.

The elderly lose teeth as a result of dental caries and periodontitis caused by pathogenic oral bacteria. Periodontitis produces inflammatory cytokines due to the presence of lipopolysaccharides from oral gram-negative bacteria. Although the number of circulating inflammatory cytokines is related to the severity of the periodontitis, it is unclear whether the concentrations also correlate with periodontitis in the elderly. We investigated the relationship between periodontitis status and the concentrations of serum interleukin-6 (IL-6) in the serum from 276 subjects of 70- and 80-year-olds. Of the 276 subjects, 227 (82%) were dentate, 149 (54%) were found to be positive for serum IL-6, and 29 (13%) of the dentate subjects had severe periodontitis. However, there were no significant differences between the severity of periodontitis or the number of teeth and the mean serum IL-6 concentrations. These results provided no evidence to support an association between circulating IL-6 and periodontitis in the elderly.

Aged↗