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Porphyromonas gingivalis , a bacterium implicated in periodontal pathogenesis, has a growth requirement for iron protoporphyrin IX. By complementation with a P. gingivalis 381 chromosomal DNA library, we were able to isolate a clone that enhanced the poor growth of a hemG mutant of Escherichia coli . The DNA sequence analysis of this clone revealed three open reading frames (ORFs). ORF3 encoded a protein of 466 amino acids with a calculated molecular weight of 51 695 Da. The deduced amino acid sequence of the ORF3 gene had significant similarity to sequences of protoporphyrinogen oxidase (PPO) from Myxococcus xanthus (30% identical residues). When the ORF3 gene was overexpressed in E. coli , the extract had much higher PPO activity than a control extract, and this activity was inhibited by acifluorfen, a specific inhibitor of PPO. Thus, ORF3 was named PgHemG. Furthermore, several porphyrin-related genes, including hemD , hemN and hemH , were identified in the data bases on the websites available on-line. We postulated that a porphyrin biosynthetic pathway to heme from preuroporphyrin may be conserved in P. gingivalis . [ABSTRACT FROM AUTHOR]

The purpose of this study was to clarify the effect of swallowing disorders on functional decline in community-dwelling older adults receiving home care. This was a 1-year follow-up survey of 176 individuals ≥60 years living at home and receiving homecare services, without total dependence in basic daily living activities, in two mid-sized municipalities in Fukuoka, Japan. Functional decline was measured using the Barthel index ( BI), and the primary outcome was total dependence in basic daily living activities ( BI ≤ 20 points). Swallowing function was assessed using cervical auscultation, and the primary predictor was swallowing disorders. Logistic regression models were used to assess univariate and multivariate associations between baseline swallowing function and functional decline during follow-up. During follow-up 16 (9.1%), the participants became totally dependent in basic daily living activities. The participants with swallowing disorders had 6.41 times higher odds of total dependence in basic daily living activities compared to participants with normal swallowing function. After adjusting for potential confounders, swallowing disorders were significantly associated with higher odds of total dependence in basic daily living activities (odds ratio = 5.21, 95% confidence interval = 1.33-20.44). Regarding swallowing disorders, the corresponding population attributable fraction (%) of the incidence of total dependence in basic daily living activities was 50.4%. The current findings demonstrated that swallowing disorders were associated with greater risk of functional decline in basic daily living activities among older adults living at home and receiving home nursing care. Maintenance and improvement of swallowing function may prevent late-life functional decline. [ABSTRACT FROM AUTHOR]

Methods for preventing aspiration pneumonia are needed soon in order to reduce mortality from aspiration pneumonia and promote the health of the elderly. The aim of this randomised controlled trial was to examine whether oral care with tongue cleaning improves coughing ability in elderly individuals living in geriatric care facilities. Participants comprised of 114 residents of 11 group homes and private nursing homes in Aso City in Kumamoto Prefecture. Participants were randomly assigned to either (i) a group that underwent routine oral care with tongue cleaning (intervention group; n = 58) or (ii) a group that underwent routine oral care alone (control group; n = 56). Coughing ability was evaluated by measuring peak expiratory flow ( PEF) before and after 4 weeks of intervention. Before the intervention, PEF did not differ significantly between the intervention group (1·65 ± 1·11 L s−1) and control group (1·59 ± 1·05 L s−1; P = 0·658). However, on termination of the intervention, PEF was significantly higher in the intervention group (2·54 ± 1·42 L s−1) than in the control group (1·90 ± 1·20 L s−1; P = 0·014). After the intervention, PEF had increased significantly in both groups; however, this increase was significantly greater in the intervention group (0·90 ± 0·95 L s−1) than in the control group (0·31 ± 0·99 L s−1; P < 0·001). Oral care with tongue cleaning led to increased PEF, suggesting improved coughing ability. Oral care incorporating tongue cleaning appears to be important for preventing aspiration pneumonia. [ABSTRACT FROM AUTHOR]

Recently, ultrasound-targeting microbubble destruction has been employed in molecular gene therapy, and a new potent nonviral gene transfer method known as ‘sonoporation’ has been developed. We investigated the efficiency of sonoporation toward growth inhibition of human gingival squamous carcinoma cell line, Ca9-22, in vitro and in vivo. The cytotoxicity of bleomycin (BLM) was investigated using flow-cytometric analysis and Hoechst's staining in vitro assay systems. We found that the delivery of BLM by sonoporation induced cytotoxic effect toward Ca9-22 cells in vitro. Our in vivo results showed that tumors nearly disappeared in Ca9-22 cell-implanted nude KSN/slc mice treated with a low dose of BLM followed by sonoporation during the 4-week experimental period. Histological analysis revealed that the cytotoxic effect was mainly apoptosis. We previously reported that the cytolethal distending toxin B (cdtB) from Actinobacillus actinomycetemcomitans, a periodontopathic bacterium, is responsible for cell cycle arrest and apoptosis in vitro. Thus, we used sonoporation to transfect a cdtB-expressing plasmid into Ca9-22 cells and examined cell viability in vitro and in vivo. We found that an administration of cdtB-expressing plasmid followed by sonoporation-induced marked growth inhibition of Ca9-22 cells and apoptotic cells were also observed in vitro and in vivo. These findings suggest that local administration of cytotoxic agents with sonoporation is a useful method for molecular cancer therapy.Cancer Gene Therapy (2007) 14, 354–363. doi:10.1038/sj.cgt.7701026; published online 2 February 2007 [ABSTRACT FROM AUTHOR]

Objective: Poor oral health has been reported to be a risk indicator of mortality, however, few data are available regarding the relationship between chewing ability and mortality. We examined the relationship between self-assessed chewing ability and mortality in elderly subjects. Design: Prospective study. Subjects and methods: Participating in the study were 697 people (277 males, 420 females) from 1282 individuals (80 years old) residing in Fukuoka Prefecture, Japan. Data on oral and systemic health status through questionnaires, accompanied by physical and laboratory blood examinations were obtained. Chewing ability was assessed based on the number of types of food each subject reported as able to chew by questionnaire. Results: A total of 108 subjects died between 1998 and 2002. Those with the lowest number of chewable foods were associated with higher risk of mortality than those with the ability to chew all of the 15 types of food surveyed [hazard ratio (HR) = 2.38, 95% confidence interval (95% CI) = 1.07–5.29], though other parameters including current smoking, low serum albumin, and poor physical health status were more significant. Further, reduced chewing ability of soft foods increased the risk (HR = 2.65, 95% CI = 1.20–5.87). Conclusion: Chewing ability was associated with mortality in a population of 80-year-old community residents, and may be a predictor for survival rate. [ABSTRACT FROM AUTHOR]

As quality of life (QOL) could be influenced by oral status in the elderly, we examined whether chewing ability or number of teeth affected QOL in 80-year olds. A cross-sectional survey included dental examination, chewing self-assessment, and a QOL questionnaire. A total of 823 people who were 80 years old participated in this study. QOL was assessed in terms of satisfaction with physical condition, meals, daily living and social interactions, and with face-scale scores. After adjustment for gender, spouse and activities of daily living, dissatisfaction with social interactions was 3·9 times more prevalent in individuals able to chew four foods or fewer than in those chewing 15. Dissatisfaction with physical condition, meals and daily living, and poor face-scale scores, were 2·7, 2·4, 3·4, and 2·4 times more prevalent, respectively, in subjects chewing four foods or fewer. The number of teeth showed little effect. In conclusion, self-assessed chewing ability but not number of teeth was associated with QOL in 80-year-old subjects. [ABSTRACT FROM AUTHOR]