Timing of Primary Tooth Eruption in Infants Observed by Their Parents.

BACKGROUND: The timing of primary teeth eruption is a visible indicator of infant physical growth other than body weight or height. It also reflects neurological integrity and development as well as nutrition, socioeconomic state, or underlying diseases. Therefore, the timing of primary teeth eruption is one of the major concerns for parents in health checkups for infants and children. However, the detailed developmental timing of teeth eruption differs depending on the survey methodology, country, or generation. We hypothesized that the timing of primary teeth eruption differs between the medical checkup by dentists and the daily records by parents. METHODS: We conducted a questionnaire survey on the date of eruption of primary teeth as an adjunct study among Miyagi Regional Center participants in the Japan Environment and Children's Study (JECS), a large-scale birth cohort study. A total of 1695 responses (3793 participants) were analyzed. RESULTS: The median ages of eruption were 7.1 months (male) and 7.6 months (female) for mandibular primary central incisors, 8.7 months (male) and 9.2 months (female) for maxillary primary central incisors, 10.0 months (male) and 10.3 months (female) for maxillary primary lateral incisors, and 10.4 months (male) and 10.8 months (female) for mandibular primary lateral incisors, which were earlier than the reported timings based on dental check-ups. Comparing the eruption time of preterm and term infants, the eruption time was earlier in preterm infants in the corrected ages. CONCLUSIONS: The eruption timing observed and described by the parents is earlier than that examined by dentists at regular check-ups. In addition to examining the primary teeth eruption of full-term birth children, we also examined that of preterm birth children because of the increasing number of premature births. To the best of our knowledge, this is the first report from a large cohort study to clarify the eruption time of primary teeth monitored by parents.

Influence of alcohol sensitivity on bone metastases and skeletal-related events in primary operable breast cancer: A retrospective cohort study.

BACKGROUND: Bone metastases in breast cancer patients are a common concern for medical doctors and dentists. Bone-modifying agents, which are necessary to prevent skeletal-related events (SREs), are associated with osteonecrosis of the jaw as an adverse side effect. Hypersensitivity to alcohol is an unfavorable response caused by deficiency of aldehyde dehydrogenase-2 (ALDH2) activity. Inactive ALDH2 is associated with osteoporosis, but its influence on bone metastases is unclear. The aim of our study was to evaluate the effects of alcohol sensitivity on bone metastases and SREs in primary operable breast cancer patients. METHODS: We retrospectively analyzed patients who were administered docetaxel, an anti-tumor agent, for histologically diagnosed breast cancer between April 2004 and September 2015. Alcohol sensitivity was assessed based on medical records of hypersensitivity to alcohol. The primary endpoint was time to bone metastases and the secondary endpoint was time to first SRE from the initial docetaxel administration. Data were stratified by alcohol sensitivity and tumor stages, and differences were estimated by the Kaplan-Meier method. Prognostic risk factors were analyzed by the multivariate Cox proportional hazards model. RESULTS: The median follow-up period of patients with high sensitivity to alcohol (n = 45) was 54 months and that for those with low sensitivity (n = 287) was 64 months. Stratification by alcohol sensitivity revealed that tumor stage exhibited significant correlations with the cumulative incidence of bone metastases in low-sensitivity patients; however, no differences were found in high-sensitivity patients. In multivariate analysis, alcohol sensitivity was a significant prognostic risk factor for bone metastases (HR 2.721, 95% CI 1.268-5.841, P = 0.010). CONCLUSION: Alcohol sensitivity may be a prognostic risk factor for bone metastases. More detailed genetic investigations and metabolic analyses are needed.

Impact of Dental Referral Prior to Elective Surgery on Postoperative Outcomes.

OBJECTIVES: Oral bacteria may contribute to postoperative infectious complications including postoperative pneumonia or surgical site infection. The aim of this study was to investigate the impact of preoperative dental care on postoperative outcomes among surgical patients under general anesthesia. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: We analyzed clinical records of major surgical patients at a university hospital between 2016 and 2018. Subjects were categorized into either the preoperative dental care group, those being referred to dentists by their surgeons based on an individual surgeon's judgment for dental care before surgery, or the control group. METHODS: The primary outcome was postoperative infectious complications. Secondary outcomes were postoperative inflammation markers (C-reactive protein and fever), and economic outcomes (postoperative length of hospital stay and medical expenses). As the main analysis, the average treatment effects of the preoperative dental care were obtained from the augmented inverse-probability weighting (AIPW) method with consideration of demographics and perioperative risk factors to estimate causal effect of the intervention from the observational data. Then, stratified analyses by age and surgical sites were conducted with the inverse-probability weighting and linear regression methods, respectively. RESULTS: In the AIPW estimation, compared with the control group, the care group saw a significantly lower rate of postoperative infection (average treatment effect -3.02) and shorter fever duration (-2.79 days). The stratified analysis by age revealed significant positive impact of dental care in all age groups, including the highest treatment effects observed among patients younger than 60. Also, treatment effect was observed in wider surgical sites than previously known. CONCLUSION/IMPLICATIONS: This study indicates a significant impact of preoperative dental care on preventing postoperative infection and inflammation. Along with old age or certain types of surgeries in which advantages of dental referral have been already known, preoperative dental referral could be beneficial for broader types of patients.

Dental care using an oral appliance to support hematopoietic stem cell transplantation for NK/T cell lymphoma, nasal type, with palatal perforation.

PATIENT: A 33-year-old man diagnosed with extranodal natural killer cell/T-cell lymphoma, nasal type (ENKTCL-NT) inducing palatal perforation was referred to the perioperative oral care support center of Tohoku University Hospital for dental care to support cancer treatment including chemotherapy and hematopoietic stem cell transplantation (HSCT). Dental review during chemotherapy revealed mucositis suspected to be caused by mucosal trauma from altered jaw function (chewing and speech) due to palatal perforation. Although the patient was already in the cleanroom, an oral appliance as well as conservative care as recommended in oral management guidelines for HSCT were used to prevent worsening of oral mucositis at subsequent HSCT including High-dose chemotherapy and total body irradiation. After HSCT, a prosthodontist fitted a palatal obturator made by a dental technician and an oral surgeon reviewed the necrotic bone and removed the sequestra according to the changes in the palate. This approach involving a multidisciplinary team including a hematologist improved the impaired oral function and minimized oral complications. DISCUSSION: ENKTCL-NT and its treatment have a significant impact on patients' oral status. Hence, it is important to provide customized dental care based on previously endorsed guidelines according to the type of disease, treatment requirements, and oral and systemic status. CONCLUSION: This report indicated the importance of dental care with a customized plan before, during, and after HSCT for ENKTCL-NT with multidisciplinary supportive care for cancer patients to improve the impaired oral function and to minimize oral complications.

Association of cleft lip and palate on mother-to-infant bonding: a cross-sectional study in the Japan Environment and Children's Study (JECS).

BACKGROUND: Cleft lip and/or palate is among the most prevalent congenital birth defects, and negatively affects maternal psychological status and may consequently result in higher prevalence of child maltreatment. However, the association of childbirths of infants with cleft lip and/or palate with maternal emotional involvement still remains unclear. We examined the association between childbirths of infants with cleft lip and/or palate and mother-to-infant bonding, using data from the Japan Environment and Children's Study, a nationwide birth cohort study. METHODS: A cross-sectional study using the jecs-an-20,180,131 dataset was performed. A total 104,065 fetuses in 15 regional centres in Japan were enrolled after obtaining informed written consent. The Mother-to-Infant Bonding Scale, a self-report scale consisting of 10 items, was used to evaluate maternal bonding at one year after childbirth. Finally, the participants consisted of 79,140 mother-infant pairs, of which 211 mothers of infants with cleft lip and/or palate were included in our analyses. Multivariable logistic regression analysis using multiple imputation for missing data was performed to calculate the odds ratio and 95% confidence interval in the estimation of the association between bonding disorders and childbirths with cleft lip and/or palate. RESULTS: No increased risk of bonding disorders was observed among all the mothers of infants with cleft lip and/or palate (odds ratio [95% confidence interval]; 0.97 [0.63-1.48], p = 0.880), however, advanced maternal age or multiple parity may adversely affect the associations between bonding disorders and cleft lip and/or palate, respectively. After stratification with a combination of maternal age and parity, a significant association of cleft lip and/or palate with bonding disorders was found only among advanced-age multiparae (odds ratio [95% confidence interval] = 2.51 [1.17-5.37], p = 0.018), but it was weakened after additional adjustment for maternal depression. CONCLUSIONS: Childbirths of infants with cleft lip and/or palate may increase the risk of bonding disorders among advanced-age multiparae, possibly through maternal depression. This finding provides valuable information for the provision of multidisciplinary cleft care.

Professional Oral Care Reduces Carcinogenic Acetaldehyde Levels in Mouth Air of Perioperative Esophageal Cancer Patients: A Prospective Comparative Study.

Acetaldehyde is a potential carcinogen for esophageal cancer, and some oral microorganisms produce acetaldehyde from ethanol or glucose. In this prospective study, we examined the influence of professional oral care on acetaldehyde levels in mouth air of esophageal cancer patients. Acetaldehyde concentrations in mouth air and breath were measured by a portable gas chromatograph, and acetaldehyde production from oral microbiota was also evaluated. Samples were taken from 21 esophageal cancer patients (median age 68 years) and 20 age-matched healthy volunteers (control group) before and after oral care. Post-operative samples were also taken from 17 patients who had undergone surgery. All samples (mouth air, breath, and saliva) were collected 2 to 3 hours after lunch. Oral microbial samples were prepared from saliva. Genotype analysis of alcohol dehydrogenase 1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) genes revealed no significant differences in the genotypes between the two groups. In the control group, acetaldehyde levels in mouth air showed no significant changes after oral care, while the amount of microbial acetaldehyde production from ethanol was significantly decreased. By contrast, among the patients, acetaldehyde levels in mouth air were significantly decreased after oral care and after operation, while the amount of microbial acetaldehyde production from ethanol showed no significant changes. Moreover, microbial acetaldehyde production from glucose was significantly decreased after operation. Overall, oral health was poorer in the patient group. In conclusion, professional oral care for esophageal cancer patients is effective for reducing acetaldehyde levels in mouth air due to the reduction of microbial count.

Exhaled acetone and isoprene in perioperative lung cancer patients under intensive oral care: possible indicators of inflammatory responses and metabolic changes.

One of the most severe complications of lung resection is postoperative pneumonia, and its prevention and prediction are critical. Exhaled acetone and isoprene are thought to be related to metabolism; however, little is known on their relationship with bacteria living in the oral cavity or their meaning in the acute phase in perioperative lung cancer patients. We measured acetone and isoprene in exhaled breath of 13 Japanese patients with lung cancer (3 women and 10 men, age range 62-82 years, mean 72.4 years) before breakfast during hospitalization, and compared with two acute-phase proteins, C-reactive protein (CRP) and albumin in blood serum, as well as the total number of bacteria in saliva and their activity to produce acetone and isoprene. Before operation, intensive oral care was carried out for each patient to prevent postoperative pneumonia, and swallowing and cough reflexes were measured for 12 of 13 patients to assess risk of postoperative pneumonia. Breath and saliva were sampled before intensive oral care (T1), after oral care but before operation (T2), and after operation (T3) during hospitalization. The total number of oral bacteria in saliva decreased significantly from T1 to T2 among 13 patients. No acetone or isoprene was detected from saliva after in vitro incubation under anaerobic or aerobic conditions, but both acetone and isoprene were detected in breath. After operation, breath acetone correlated significantly with CRP (Spearman's ρ = 0.559, P = 0.03), but not with albumin. Breath isoprene correlated significantly with albumin (Spearman's ρ = 0.659, P = 0.008), but not with CRP after operation. Although the number of subjects was small, our results support the hypothesis that breath acetone and isoprene may be related with these acute-phase proteins, which reflect inflammatory reactions and subsequent changes in metabolism in the early postoperative phase of lung resection.

Lactate dehydrogenase C is required for the protein expression of a sperm-specific isoform of lactate dehydrogenase A.

Metabolites are sensitive indicators of moment-to-moment cellular status and activity. Expecting that tissue-specific metabolic signatures unveil a unique function of the tissue, we examined metabolomes of mouse liver and testis and found that an unusual metabolite, 2-hydroxyglutarate (2-HG), was abundantly accumulated in the testis. 2-HG can exist as D- or L-enantiomer, and both enantiomers interfere with the activities of 2-oxoglutarate (2-OG)-dependent dioxygenases, such as the Jumonji family of histone demethylases. Whereas D-2-HG is produced by oncogenic mutants of isocitrate dehydrogenases (IDH) and known as an oncometabolite, L-2-HG was the major enantiomer detected in the testis, suggesting that a distinct mechanism underlies the testicular production of this metabolite. We clarified that lactate dehydrogenase C (LDHC), a testis-specific lactate dehydrogenase, is responsible for L-2-HG accumulation by generating and analysing Ldhc-deficient mice. Although the inhibitory effects of 2-HG on 2-OG-dependent dioxygenases were barely observed in the testis, the LDHA protein level was remarkably decreased in Ldhc-deficient sperm, indicating that LDHC is required for LDHA expression in the sperm. This unique functional interaction between LDH family members supports lactate dehydrogenase activity in the sperm. The severely impaired motility of Ldhc-deficient sperm suggests a substantial contribution of glycolysis to energy production for sperm motility.

Design of the spacer for brachytherapy using 198Au grain for carcinoma of the tongue as a tool of perioperative oral management.

PATIENTS: Seventy-one and 73 years-old males visited a perioperative oral care support center to receive perioperative oral management during tongue cancer (T1N0M0) treatment. To improve their quality of life (QOL) during brachytherapy while preventing radiation-related complications including osteoradionecrosis due to 198Au grain brachytherapy, spacers for their maxilla and mandible were designed with consideration of wearing condition at an isolation ward. The spacer was created with unilateral design and with consideration of the tongue mobility during day and night. Then, the spacer was thickened on the plaster model, demonstrating the cancer lesion in the tongue in order to secure the distances from the mandibular body, maxilla and sublingual gland to the radiation sources embedded in the tongue. DISCUSSION: Tongue impression made the spacers as small as possible by thickening just around the cancer lesions so that the patients could wear them comfortably, while keeping adequate distance between the radiation sources and peripheral normal tissues. Breakable hard materials were avoided so that the patients were able to utilize the spacers safely without accidentally swallowing a broken fragment. Additionally, considering the upward movement of the tongue in a sleeping posture, the upper spacers were also prepared to protect the maxillae. Computer simulation revealed that the design of our spacers had enough effect on a reduction in radiation to prevent osteoradionecrosis in the maxilla as well as mandibular body. CONCLUSIONS: This report demonstrated the importance of the spacers created with consideration of patients' wearing condition to improve their QOL during brachytherapy.

Factors associated with sports-related dental injuries among young athletes: a cross-sectional study in Miyagi prefecture.

BACKGROUND: Sports-related dental injuries, such as tooth fracture, loosening, and avulsion, are a major concern among young athletes because they directly impair oral function. Although the preventive efficacy of mouthguards has been well established, the prevalence of sports-related dental injuries remains high among young athletes. The aim of this study is to identify the variables contributing to the risk of sports-related dental injuries by conducting a survey on large population of young athletes in Miyagi prefecture. METHODS: A cross-sectional study was conducted with school-aged athletes (aged 6-15 years, n = 5735) using a self-reported questionnaire. The questionnaire examined general variables, including sex, age, and body mass index; sports-related variables, including sports-type, team level, activity schedule, break time, and verbal/physical abuse by coaches; and lifestyle variables related to free time, including screen-time and sleep duration. Their associations with sports-related dental injuries were examined using multivariate logistic regression models. RESULTS: The prevalence of sports-related dental injuries was 13.3% (763 of 5735 young athletes) and was higher in males (14.3%, 592 of 4132) than in females (10.7%, 171 of 1603; adjusted odds ratios [ORs] and 95% confidence intervals [CIs]: 1.48 [1.22-1.79], p < 0.001). After stratification according to sex, significant associations with the prevalence of sports-related dental injuries were evident for three variables-insufficient break time, verbal abuse, and physical punishment-in males (adjusted ORs [95% CI]: 1.35 [1.03-1.77], p = 0.032; 1.31 [1.05-1.62], p = 0.015; and 1.36 [1.06-1.75], p = 0.016, respectively) but not in females (adjusted ORs [95% CI]: 0.88 [0.53-1.47], p = 0.623; 1.29 [0.87-1.91], p = 0.206; and 0.97 [0.57-1.63], p = 0.894, respectively). CONCLUSIONS: Although our results might be based on the individual athlete's self-perception to the sports-related variables, our results suggest that insufficient break time, verbal abuse, and physical punishment from coaches are positively associated with the prevalence of sports-related dental injuries in young male athletes.

Metastasis in the mandibular condyle: a case report.

BACKGROUND: Most bone metastases are observed in the trunk of the body. Metastasis in the mandibular condyle is rare. In many case reports, temporary common temporomandibular joint disorder-like symptoms can be a sign of relapse and metastasis. CASE PRESENTATION: We report a rare case of breast carcinoma metastatic to the left mandibular condyle in a 55-year-old Japanese woman, who visited our department for a dental check-up prior to chemotherapy. She had almost no symptoms, but radiographs suggested the existence of metastasis. CONCLUSIONS: In many case reports, patients had some symptoms. In this case report, our patient had slight symptoms, but we were able to confirm the metastasis from the symptoms and panoramic dental radiograph. When patients complain about discomfort of the temporomandibular joint, we need to consider the possibility of metastasis and notice changes on the panoramic dental radiograph.

The mTOR-Bach2 Cascade Controls Cell Cycle and Class Switch Recombination during B Cell Differentiation.

The transcription factor Bach2 regulates both acquired and innate immunity at multiple steps, including antibody class switching and regulatory T cell development in activated B and T cells, respectively. However, little is known about the molecular mechanisms of Bach2 regulation in response to signaling of cytokines and antigen. We show here that mammalian target of rapamycin (mTOR) controls Bach2 along B cell differentiation with two distinct mechanisms in pre-B cells. First, mTOR complex 1 (mTORC1) inhibited accumulation of Bach2 protein in nuclei and reduced its stability. Second, mTOR complex 2 (mTORC2) inhibited FoxO1 to reduce Bach2 mRNA expression. Using expression profiling and chromatin immunoprecipitation assay, the Ccnd3 gene, encoding cyclin D3, was identified as a new direct target of Bach2. A proper cell cycle was lost at pre-B and mature B cell stages in Bach2-deficient mice. Furthermore, AZD8055, an mTOR inhibitor, increased class switch recombination in wild-type mature B cells but not in Bach2-deficient cells. These results suggest that the mTOR-Bach2 cascade regulates proper cell cycle arrest in B cells as well as immunoglobulin gene rearrangement.

Changes in Cognitive Functions in the Elderly Living in Temporary Housing after the Great East Japan Earthquake.

On March 11, 2011, Japan experienced an earthquake of magnitude 9.0 and subsequent enormous tsunamis. This disaster destroyed many coastal cities and caused nearly 20,000 casualties. In the aftermath of the disaster, many tsunami survivors who lost their homes were forced to live in small temporary apartments. Although all tsunami survivors were at risk of deteriorating health, the elderly people were particularly at a great risk with regard to not only their physical health but also their mental health. In the present study, we performed a longitudinal cohort study to investigate and analyze health conditions and cognitive functions at 28, 32, and 42 months after the disaster in the elderly people who were forced to reside in temporary apartments in Kesennuma, a city severely damaged by the tsunamis. The ratio of people considered to be cognitively impaired significantly increased during the research period. On the other hand, the mean scores of the Kessler Psychological Distress Scale-6 and Athens Insomnia Scale improved based on the comparison between the data at 24 and 42 months. The multiple logistic regression analysis revealed that frequency of "out-of-home activities" and "walking duration" were independently associated with an increase in the ratio of people with cognitive impairment. We concluded that the elderly people living in temporary apartments were at a high risk of cognitive impairment and "out-of-home activities" and "walking" could possibly maintain the stability of cognitive functions.

Analysis of ketone bodies in exhaled breath and blood of ten healthy Japanese at OGTT using a portable gas chromatograph.

Ketone bodies including acetone are disease biomarkers for diabetes that sometimes causes severe ketoacidosis. The present study was undertaken to clarify the significance of exhaled acetone and plasma ketone bodies at bedside in a clinical setting. The oral glucose tolerance test (OGTT) was performed in 10 healthy Japanese volunteers (five females and five males). Exhaled breath acetone and volatile sulfide compounds (VSCs) in mouth air were measured simultaneously with blood sampling during the OGTT using a portable gas chromatograph equipped with an In2O3 thick-film type gas sensor and a VSC monitor. Acetone, ß-hydroxybutyrate (ß-OHB) and acetoacetate (AcAc) in blood plasma as well as glucose and insulin were examined. Oral conditions were examined based on the Community Periodontal Index (CPI) by one dentist. In addition, the same type of analysis was applied to two uncontrolled type 2 diabetes mellitus patients hospitalized at Tohoku University Hospital. Exhaled acetone was measured at the same time as blood withdrawal in the morning before breakfast and at night before bed at the beginning, the middle, and the end of hospitalization. All volunteers showed normal OGTT patterns with no ketonuria and periodontitis; however, there were significant correlations between breath acetone and plasma ß-ΟΗΒ and between breath acetone and plasma AcAc under fasting conditions. Breath acetone of the type 2 diabetes mellitus patients showed positive correlations with plasma glucose when the level of plasma glucose tended to decrease during hospitalization. In spite of a very limited number of cases, our results support the idea that exhaled breath acetone may be related to plasma ß-OHB and AcAc, which reflect glucose metabolism in the body.

Factors associated with dry mouth in dependent Japanese elderly.

OBJECTIVES: To identify factors associated with dry mouth. BACKGROUND: Dry mouth adversely affects oropharyngeal health, particularly in elderly, and can lead to pneumonia. A better understanding of the epidemiology of dry mouth is therefore important in improving treatment strategies and oral health in high-risk elderly patients. METHODS: We conducted a cross-sectional study involving 383 dependent Japanese elderly individuals (65-84 [n = 167] and ≥85 [n = 216] years) at eight long-term care facilities and hospitals. Thirty-four potential factors associated with dry mouth were examined by multiple logistic regression analysis. The primary outcome was dry mouth, as diagnosed by tongue dorsum moisture. RESULTS: We identified that body mass index and severity of physical disability were identified as a potential factors associated with dry mouth in the super-elderly (≥85 years) group, whereas severity of physical disability, outcome measurement time, high daily water consumption, mouth breathing, use of antidepressants and diuretics, and high frequency of daily brushing (≥2 times per day; Odds ratio: 5.56; 95% Confidence Interval: 1.52-20.00) were associated with dry mouth in the 65- to 84-year-old group. CONCLUSION: To our knowledge, this is the first study to identify a link between frequency of daily brushing and dry mouth and suggests that tooth brushing should be encouraged in high-risk dependent Japanese elderly (65-84 years), particularly those taking antidepressants and/or diuretics.

Heparin inhibits osteoclastic differentiation and function.

We investigated the effects of Glycosaminoglycans (GAGs) on mouse monocytic cell line in regard to their differentiation, proliferation, and function in vitro. RAW 264.7 cells were cultured with receptor activator of NF-kappaB ligand (RANKL) and various GAGs. Osteoclastic cells were visualized by staining for tartrate-resistant acid phosphatase (TRAP) and detected using a phenyl-phosphate substrate method. RAW 264.7 cells were also cultured with stimulants contained in BD BioCoat OSTEOLOGIC(TM) kit, and bone resorption activity was assessed by counting the numbers of resorption pits. We also examined the effect of heparin on cell growth using MTT assay, while the expression level of c-Src protein was determined by immunoblot analysis. Heparin suppressed TRAP-positive multinucleated cell formation and TRAP activity induced by RANKL, whereas the other GAGs showed no effects on osteoclast differentiation. Heparin also inhibited the formation of resorption pits, while the others did not. In the MTT assay, none of the tested GAGs had an influence on RAW 264.7 cell proliferation. However, heparin reduced the level of c-Src protein in RAW 264.7 cells stimulated with RANKL. To determine the affinity of heparin and RANKL, they were subjected by HiTrap heparin column chromatography and each fraction was collected. Western blotting analysis revealed the expression of RANKL in the fraction bound to heparin. The binding of RANKL and heparin was confirmed by quartz-crystal microbalance. These results indicate that the inhibitory effect of heparin toward osteoclastogenesis induced by RANKL is due to the binding of heparin to RANKL.

A new portable sulfide monitor with a zinc-oxide semiconductor sensor for daily use and field study.

OBJECTIVE: For measuring oral malodor in daily clinical practice and in field study, we developed and evaluated a highly sensitive portable monitor system. METHODS: We examined sensitivity and specificity of the sensor for volatile sulfur compounds (VSC) and obstructive gases, such as ethanol, acetone, and acetaldehyde. Each mouth air provided by 46 people was measured by this monitor, gas chromatography (GC), and olfactory panel and compared with each other. Based on the result, we used the monitor for mass health examination of a rural town with standardized measuring. RESULTS: The sensor detected hydrogen sulfide, methyl mercaptan, and dimethyl sulfide with 10-1000 times higher sensitivity than the other gases. The monitor's specificity was significantly improved by a VSC-selective filter. There were significant correlations between VSC concentration by the sulfide monitor and by GC, and by organoleptic score. Thirty-six percent of 969 examinees had oral malodor in a rural town. Seventy-eight percent of 969 examinees were motivated to take care of their oral condition by oral malodor measuring with the monitor. CONCLUSIONS: The portable sulfide monitor was useful to promote oral health care not only in clinics, but also in field study. The simple and quick operation system and the standardized measuring make it one of parameters of oral condition.

Potential role of high molecular weight hyaluronan in the anti-Candida activity of human oral epithelial cells.

Candida albicans is both a commensal and a pathogen in the oral mucosa. Previous studies have indicated that epithelial cell-associated carbohydrate moiety can inhibit C. albicans growth. In the present study, the mechanisms by which epithelial cells inhibit Candida growth were studied by examining the effect of hyaluronan (HA). A coculture of C. albicans and KB cells or COS-7 cells inhibited in vitro growth of the fungus by 50-87% at an effector-to-target (E:T) ratio of 80:1. Removing extracellular HA by hyaluronidase caused a significant decrease in the anti-Candida activity of the cells. In addition anti-Candida activity was observed at 1 micro g/ml HA (2000 kDa). The antifungal activity of extracellular HA was further studied by transiently transfecting COS-7 cells with human HSA1, HSA2, or HSA3 in order to produce high levels of extracellular HA. All of the transfectants inhibited C. albicans growth in vitro by 51-65% compared to 38% inhibition by the vector control (P<0.05). These results suggest that the anti-Candida activity of epithelial-cells is mediated by extracellular HA.

Hydrogen sulfide-producing bacteria in tongue biofilm and their relationship with oral malodour.

The aims of this study were to identify hydrogen sulfide (H2S)-producing bacteria among tongue biofilm microflora and to investigate the relationship between bacterial flora and H2S levels in mouth air. Oral malodour levels in 10 subjects (age 21-56 years) were assessed by gas chromatography, and Breathtron and organoleptic scores. Based on these assessments, subjects were divided into two groups: an odour group and a no/low odour group. Tongue coatings were sampled and spread onto Fastidious Anaerobe Agar plates containing 0.05% cysteine, 0.12% glutathione and 0.02% lead acetate, and were then incubated anaerobically at 37 degrees C for 2 weeks. Bacteria forming black or grey colonies were selected as H2S-producing phenotypes. The numbers of total bacteria (P<0.005) and H2S-producing bacteria (P<0.05) in the odour group were significantly larger than those in the no/low odour group. Bacteria forming black or grey colonies (126 isolates from the odour group; 242 isolates from the no/low odour group) were subcultured, confirmed as producing H2S and identified according to 16S rRNA gene sequencing. Species of Veillonella (38.1% in odour group; 46.3% in no/low odour group), Actinomyces (25.4%; 17.7%) and Prevotella (10.3%; 7.8%) were the predominant H2S-producing bacteria in both the odour and no/low odour groups. These results suggest that an increase in the number of H2S-producing bacteria in the tongue biofilm is responsible for oral malodour, although the bacterial composition of tongue biofilm was similar between the two groups.

Mechanisms involved in enhancement of osteoclast formation and function by low molecular weight hyaluronic acid.

Hyaluronic acid (HA) is a component of the extracellular matrix that has been shown to play an important role in bone formation, resorption, and mineralization both in vivo and in vitro. We examined the effects of HA at several molecular weights on osteoclast formation and function induced by RANKL (receptor activator of NF-kappa B ligand) in a mouse monocyte cell line (RAW 264.7). HA at M(r) < 8,000 (low molecular weight HA (LMW-HA)) enhanced tartrate-resistant acid phosphatase-positive multinucleated cell formation and tartrate-resistant acid phosphatase activity induced by RANKL in a dose-dependent manner, whereas HA at M(r) > 900,000 (high molecular weight HA (HMW-HA)) showed no effect on osteoclast differentiation. LMW-HA enhanced pit formation induced by RAW 264.7 cells, whereas HMW-HA did not, and LMW-HA stimulated the expression of RANK (receptor activator of NF-kappa B) protein in RAW 264.7 cells. In addition, we found that LMW-HA enhanced the levels of c-Src protein and phosphorylation of ERKs and p38 MAPK in RAW 264.7 cells stimulated with RANKL, whereas the p38 MAPK inhibitor SB203580 inhibited RANKL-induced osteoclast differentiation. This enhancement of c-Src and RANK proteins induced by LMW-HA was inhibited by CD44 function-blocking monoclonal antibody. These results indicate that LMW-HA plays an important role in osteoclast differentiation and function through the interaction of RANKL and RANK.