Effects of light sources and visible light-activated titanium dioxide photocatalyst on bleaching.

The objective of this study was to evaluate, using methylene blue (MB), the effects of various light sources on the bleaching action of hydrogen peroxide (H(2)O(2)) with two titanium dioxide (TiO(2)) photocatalysts - an ultraviolet light-activated TiO(2) photocatalyst (UVTiO(2)) versus a visible light-activated TiO(2) photocatalyst (VL-TiO(2)). Five experimental solutions (VL-TiO(2)+H(2)O(2), UV-TiO(2)+H(2)O(2), H(2)O(2), VL-TiO(2), UV-TiO(2)) were prepared by mixing varying concentrations of H(2)O(2 )and/or TiO(2 )photocatalyst with MB solution. For H(2)O(2)-containing solutions (VL-TiO(2)+H(2)O(2), UV-TiO(2)+H(2)O(2), and H(2)O(2)), the concentration of H(2)O(2) was adjusted to 3.5%. For the four different light sources, low- and high-intensity halogen lamps and blue LED LCUs were used. All the experimental solutions were irradiated by each of the light sources for 7 minutes, and the absorbance at 660 nm was measured every 30 seconds to determine the concentration of MB as an indicator of the bleaching effect. On the interaction between the effects of light source and bleaching treatment, the high-intensity halogen with VL-TiO(2)+H(2)O(2) caused the most significant reduction in MB concentration. On the effect of light sources, the halogen lamps resulted in a greater bleaching effect than the blue LED LCUs.

Site-specific development of periodontal disease is associated with increased levels of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia in subgingival plaque.

BACKGROUND: Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia (previously T. forsythensis), which are regarded as the principal periodontopathogenic bacteria, exist as a consortium in subgingival biofilms. We aimed to examine quantitative relationships between P. gingivalis, T. denticola, and T. forsythia in subgingival biofilms and the relationship between the quantity and prevalence of these three bacteria and site-specific periodontal health. METHODS: This study was cross-sectional. The study population consisted of 35 adult subjects who visited the Kyushu Dental College Hospital. Plaque samples were collected from 105 periodontal pocket sites. Quantitative analyses of each of the three periodontopathogenic bacteria were performed using real-time polymerase chain reaction with species-specific primers and hybridization probes. RESULTS: The plaque samples were divided into four groups based on the presence or absence of a periodontal pocket (probing depth [PD] > or =4 mm) and bleeding on probing (BOP), regardless of attachment loss. The proportions of all three target bacteria detected in samples from sites of periodontal disease (with PD and BOP) were markedly higher than those in the other sample groups. Cell numbers of P. gingivalis, T. denticola, and T. forsythia in the subgingival plaque of each sampling site were significantly mutually correlated and were increased in the plaque of sites of periodontal disease with PD > or =4 mm and BOP. CONCLUSION: The symbiotic effects of P. gingivalis, T. denticola, and T. forsythia, which coaggregate and exist concomitantly in subgingival biofilms, may be associated with the local development of periodontitis.

The prevalence of periodontopathogenic bacteria in saliva is linked to periodontal health status and oral malodour.

This study investigated whether an improvement in periodontal health resulted in changes in the prevalence of periodontopathogenic bacteria in saliva and tongue coatings and a reduction in volatile sulfur compounds (VSCs: H(2)S and CH(3)SH) linked to oral malodour. The subjects were 35 patients who visited the breath odour clinic of Kyushu Dental College, Japan. Their mean age was 51.2+/-18.3 years (mean+/-sd). A clinical examination performed at baseline and 2 months after periodontal treatment assessed VSCs in mouth air using gas chromatography, periodontal probing depth and bleeding on probing (BOP) in all subjects; saliva and tongue coatings were also collected. Genomic DNA was isolated from the samples, and the proportions of five periodontopathogenic bacteria (Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Prevotella intermedia and Prevotella nigrescens) were investigated using quantitative real-time PCR. The subjects were classified into four groups based on the presence of a periodontal pocket of more than 4 mm (PD) and VSCs above the organoleptic threshold level (VSCT) as follows: -PD/-VSCT group, subjects without PD or VSCT; -PD/+VSCT group, those without PD but with VSCT; +PD/-VSCT group, those with PD but without VSCT; and +PD/+VSCT group, those with PD and VSCT. Although the mean PD values in the +PD/-VSCT and +PD/+VSCT groups, BOP in the +PD/+VSCT group, and H(2)S and CH(3)SH concentrations in the -PD/+VSCT and +PD/+VSCT groups were greater than in the other groups at baseline, we found no significant difference among the four groups after periodontal treatment. The proportion of periodontopathogenic bacteria in saliva was higher in the +PD/-VSCT and +PD/+VSCT groups than in the -PD/-VSCT and -PD/+VSCT groups at baseline and after treatment, but the proportions of bacteria in saliva after treatment were reduced compared to the baseline. Furthermore, the differences in the proportions of the five target bacteria in the tongue coating were not as apparent as those in saliva at baseline or after treatment. The prevalence of periodontopathogenic bacteria in saliva may reflect periodontal health status and influence VSC levels in mouth air.

Volatile sulphide compound levels in mouth air with plaque-related periodontal disease are associated with a change in the proportion of periodontopathic bacteria in saliva.

This study investigated whether oral malodour with plaque-related periodontal disease was associated with the prevalence of periodontopathic bacteria in saliva and tongue debris. The subjects were 30 patients who visited the Breath Odour Clinic. An oral examination was performed at baseline and two months after periodontal treatment, and included measuring the volatile sulphur compounds (VSCs) in mouth air. The proportions of five periodontopathic bacteria versus all bacteria in saliva and tongue debris were determined using real-time polymerase chain reaction. The subjects were classified into four groups based on the existence of VSCs above the organoleptic threshold level (TVSC) and a periodontal pocket ⩾4 mm (PD4). At baseline, the group with TVSC/PD4 had higher proportions of periodontopathic bacteria in saliva compared to those with TVSC/no PD4 and no TVSC/no PD4, but there were no differences in the proportions in tongue debris among the four groups. At follow-up, the proportion of periodontopathic bacteria in the saliva of the group with TVSC/PD4 was significantly reduced, as compared to that at baseline, and the VSCs and periodontal health improved. The results suggested that the reduction in VSCs in mouth air of subjects with periodontal disease might be associated with the prevalence of periodontopathic bacteria in saliva.

The effect of a 12-week combined exercise intervention program on physical performance and gait kinematics in community-dwelling elderly women.

This study aimed to determine if combined exercise intervention improves physical performance and gait joint-kinematics including the joint angle and dynamic range of motion (ROM) related to the risk of falling in community-dwelling elderly women. A 12-week combined exercise intervention program with extra emphasis on balance, muscle strength, and walking ability was designed to improve physical performance and gait. Twenty participants attended approximately two-hour exercise sessions twice weekly for 12 weeks. Participants underwent a physical performance battery, including static balance, sit and reach, whole body reaction time, 10 m obstacle walk, 10 m maximal walk, 30-second chair stand, to determine a physical performance score, and received quantitative gait kinematics measurements at baseline and in 12 weeks. Significant lower extremity strength improvement 13.5% (p<.001) was observed, which was accompanied by significant decreases in time of the 10 m obstacle walk (p<.05) and whole body reaction time (p<.001) in this study. However, no significant differences were seen for static balance and flexibility from baseline. For gait kinematics, in the mid-swing phase, knee and hip joint angle changed toward flexion (p<.01, p<.05, respectively). Ankle dynamic ROM significantly increased (p<.05) following exercise intervention. The plantar flexion angle of the ankle in the toe-off phase was increased significantly (p<.01). However, other gait parameters were not significantly different from baseline. These findings from the present investigation provide evidence of significant improvements in physical performance related to the risk factors of falling and safe gait strategy with a combined exercise intervention program in community-dwelling elderly women. The results suggest this exercise intervention could be an effective approach to ameliorate the risk factors for falls and to promote safer locomotion in elderly community-dwelling women.

Human first-trimester fetal MSC express pluripotency markers and grow faster and have longer telomeres than adult MSC.

The biological properties of stem cells are key to the success of cell therapy, for which MSC are promising candidates. Although most therapeutic applications to date have used adult bone marrow MSC, increasing evidence suggests that MSC from neonatal and mid-gestational fetal tissues are more plastic and grow faster. Fetal stem cells have been isolated earlier in development, from first-trimester blood and hemopoietic organs, raising the question of whether they are biologically closer to embryonic stem cells and thus have advantages over adult bone marrow MSC. In this study, we show that human first-trimester fetal blood, liver, and bone marrow MSC but not adult MSC express the pluripotency stem cell markers Oct-4, Nanog, Rex-1, SSEA-3, SSEA-4, Tra-1-60, and Tra-1-81. In addition, fetal MSC, irrespective of source, had longer telomeres (p < .001), had greater telomerase activity (p < .01), and expressed more human telomerase reverse transcriptase (p < .01). Fetal MSC were also more readily expandable and senesced later in culture than their adult counterparts (p < .01). Compared with adult MSC, first-trimester fetal tissues constitute a source of MSC with characteristics that appear advantageous for cell therapy.

Lower extremity function in terms of shock absorption when landing with unsynchronized feet.

The purpose of this study was to clarify the lower extremity function in terms of the shock absorption during unsynchronized-foot landings. The characteristics of the supination and pronation in the ankle joint at landing were investigated, assuming that the measurements of the impact force on the body could be demonstrated by the changes that occurred during 3 different landing motions: -unsynchronized-foot landings, synchronized-foot landings, and one-foot landings. Subjects jumped to the floor from 10-cm footstools 3 times for each type of landing. For the synchronized-foot landing, the rear foot angle was 92.2 degrees at the start of landing and did not change significantly from landing start to 100 msec. For the one-foot landing, rear foot angle was 95.1 degrees at the start of landing and decreased rapidly to 87.1 degrees by 75 msec, and then increased rapidly to 90.8 degrees by 140 msec. For the unsynchronized-foot landing, the rear foot angle was 93.8 degrees at the start of the landing, decreased rapidly to 88.0 degrees by 75 msec, and then increased rapidly to 89.9 degrees by 115 msec. It was clarified that the lower extremity function for the shock attenuation during landing with the unsynchronized-foot was similar to that with one-foot landings, and the lower extremity function for supporting the body after another foot landing was similar to that after the synchronized-foot landings in this study.

Occurrence of Bacillus cereus in Meat Products, Raw Meat and Meat Product Additives.

One thousand nine hundred and sixty three samples of meat products, raw meat and meat product additives from different slaughterhouses, meat processing factories and retail meat shops in six prefectures of Japan, were examined for the presence and number of Bacillus cereus . Although B. cereus was found in meat products (18.3%) and raw meat (6.6%), the contamination levels were generally lower than 102 per gram. In contrast, meat product additives showed contamination levels ranging from 102 to 104/g with the highest values (104/g) in samples of spices and animal proteins. On the basis of these results, we suggest that the main source of B. cereus contamination in meat products is contaminated meat product additives.