Streptococcus mutans, the primary etiological agent of human dental caries and an obligate biofilmforming bacterium, has developed a variety of mechanisms to colonize the tooth surface. Oral transmission of S. mutans through contact between mother and child is thought to be one of the risks of developing dental caries. In this study, I surveyed oral transmission frequency of S. mutans from mother to a 3-year-old child. In 19 (10.9%) of 174 mother-child pairs, S. mutans was isolated from both mother and chihld. The identities of genomic DNA from S. mutans in 5 (45.5%) of the 11 mother-child pairs were presented. Among those, the biofilms formed by S. mutans 3 c and 4 c, respectively, which had high and low ability of biofilm formation, were examined by confocal laser scanning microscopy (CLSM) . Microscopic analysis revealed that the volume of biofilm formation in 3 c was higher than that in 4 c biofilm in the bottom. Furthermore, DNA microarrays were used to study the gene expression profiles of 3 c and 4 c biofilms. In this paper we describe that about 3.8% of genes showed differential expression ; about 2.2% of genes were activated and about 1.6% were repressed in 3 c biofilm compared with 4 c biofilm. The present study suggests that biofilm gene expression is strongly associated with differential biofilm formation. Our identification of biofilm-involved genes points to mechanisms of the virulence of S. mutans and provides a first foothold for studying the natural history of S. mutans infections in mother and child.
Biosynthesis of proteoglycans and glycosaminoglycans in the presence of p-nitrophenyl-xyloside was studied using a primary rat ovarian granulosa cell culture system. Addition of p-nitrophenyl-xyloside into cell culture medium caused about a 700% increase of [35S] sulfate incorporation (ED50 at 0.03 mM) into macromolecules, which included free chondroitin sulfate chains initiated on xyloside and native proteog-lycans. Free chondroitin sulfate chains initiated on xyloside were almost exclusively secreted into the medium. The molecular size of chondroitin sulfate chains decreased from 40, 000 to 21, 000 as the total [35S] sulfate incorporation was enhanced, suggesting that enhanced synthesis of chondroitin sulfate perturbed the normal mechanism of glycosaminoglycan chain termination. Biosynthesis of heparan sulfate proteoglycans was reduced by approximately 50%, likely due to competition at the level of UDP-sugar precursors. [35S] Sulfate incorporation was shut down by the addition of cycloheximide with an initial half time of approximately 2 hr in the presence of xyloside, while that in the absence of xyloside was about 20 min. The difference likely reflects the turnover rate of glycosaminoglycan synthesizing capacity as a whole. The turnover rate of glycosaminoglycan synthesizing capacity observed in ovarian granulosa cells was much shorter than that observed in chondrocytes, reflecting the relative dominance of proteoglycan biosynthetic activity in the total metabolic activity of the cells.
An observational study was conducted to clarify the morphological features of the fine structure of the tongue coating, which is one of the main causes of halitosis. Tongue specimens from cadavers, whom dental students had practiced on for anatomy class, were used as materials to observe the surface structure. Tongue coatings were obtained from patients who were referred to the Fresh Breath Clinic, Dental Hospital, Tokyo Medical and Dental University. After macroscopic observation of the tongue surface, tongue coating and examination of halitosis, the tongue coating was scraped carefully, following which it was observed using a light microscope and transmission electron microscope (TEM) . The results obtained were as follows. The tongue coating consisted mainly of bacteria and desquamated keratinized epithelium which originated chiefly from the filif orm papilla. The desquamated keratinized epithelium was also composed of degenerated epithelium of every level, from a comparatively normal epithelium to a fragmented altered epithelium. In addition, the level of degeneration of the keratinized epithelium differed according to the state of distribution and the revitalization of bacteria located in its surroundings. The intensity of halitosis increased with the amount of tongue coating. Increased amounts of tongue coating, however, did not necessarily correlate with increased halitosis in the patients. It was suggested that the severity of halitosis was probably associated with the level of bacterial invasion-related degeneration of the desquamated keratinized epithelium (tongue coating's quality) .
The effect of acupuncture in sensory paralysis was evaluated in 43 patients. Thiry-two cases in the study group were after mandibular third molar extraction and 11 cases by postoperative injury of orthognathic surgery. Treatment was performed in four forms : needles only (A), A with moxibustion (AK), electrical needle stimulation (ESA) using LEP 4000 OhmPulser Ra direct current 6 V 5-100 Hz, and ESA+A : exercise therapy was also given 1 or 2 times weekly. There were, however, some variations depending on the patient's conditions. Visual analog scale (VAS) measurement was carried out in addition to the estimation of effectiveness. The group receiving ESA+A seemed to improve better than those receiving other forms of treatment. The results indicated that young patients less than 40 years old tend to improve with fewer treatment times of shorter duration. With respect to the relationship between the effect and the time of starting treatment, we noticed that the earlier the treatment is started, the better the improvement. In summary, the study indicated that acupuncture is useful in treating sensory paralysis.
Human immunodeficiency virus type 1 (HIV-1) is one of the lentiviruses, and unlike other retroviruses, HIV-1 is capable of infecting not only dividing cells but also non dividing cells. It has been strongly suggested that this property is due to the viral mechanism which facilitates the integration of the viral genome cDNA into the host chromosome more efficiently than other retroviruses. HIV-1 integrase (IN) is a viral protein which catalyzes insertion of the viral genome cDNA into the host cell chromosome. However, it has been suggested that HIV-1 IN also plays putative roles at the steps prior to integration such as uncoating, reverse transcription and nuclear transport of the viral cDNA. In this study, we tried to identify the novel host factor which interacted with HIV-1 IN using two different kinds of yeast two hybrid methods : the conventional yeast two hybrid method and the mating method. First, the full-length cDNA fragment of HIV-1 IN was amplified using polymerase chain reaction (PCR), and the amplified products were ligated into pGBT 9 vector as bait. Plasmid vectors expressing human lymphocytes cDNA library and HeLa cDNA library were used as prey plasmid in the conventional yeast two hybrid method and the mating method, respectively. These plasmids were transformed into the corresponding yeast strain cells, and several positive clones were isolated. As a result, a known gene product was identified as a candidate. Further analysis revealed that this protein was expressed in HeLa, 293 T cells, primary macrophages and activated T lymphocytes, and that suppression of this protein expression affected HIV-1 replication.
The purpose of this study was to clarify the effects of dementia based on the changes of independence conditions targeting the home-care elderly classified as Care level 1 of care needs or support. The care managers entered the basic information and assessment including oral health care for them. The independence level and other aspects of the elderly with and without dementia were examined comparatively for eight weeks. The results were as follows: 1. The highest independence level was observed for oral health care of the elderly without dementia, and it remained at the highest level for eight weeks. 2. Almost all independence levels of the elderly with dementia were significantly lower than those without dementia. 3. The willingness of the elderly without dementia was high among all areas, it was the highest of oral health care. A significant difference was observed between those with and without dementia. 4. As for cooperation from family members, the lowest value was oral health care. It is suggested that the elderly requiring home-based long-term light care or support have a high independence level concerning oral health care. The willingness toward oral health care of the elderly with mild dementia was still high. The elderly with dementia were less independent regarding oral health care. Moreover, an increasing number of elderly people live by themselves, and do not expect support from their families. Active intervention by experts is necessary to improve their independence concerning oral health care.
Periodontal ligament (PDL) has a heterogeneous cell population, where some of the cells may be capable of differentiating into either cementoblasts or osteoblasts. Recently, C2H2 zinc finger transcription factor Osterix has been reported. Osterix is one of the master regulators of bone cell differentiation and it has two different isoforms. According to a recent report, osteogenic differentiation of murine embryonic stem cells can be induced by overexpression of Osterix. The purpose of this study was to investigate about the expression of Osterix on human PDL (hPDL), and whether the osteogenic differentiation of hPDL cells can be induced by overexpression of Osterix. hPDL cells were obtained from healthy human teeth indicated for extraction for orthodontic treatment. All procedure used in this study was approved by the local ethical committee of Tokyo Medical and Dental University. To investigate expression of Osterix mRNA in hPDL tissues and cells, RT-PCR experiments were performed. Two different isoform Osterix expression vectors were made and transiently transfected into hPDL cells. Osteogenic differentiation was assessed by RT-PCR for genes associated with the osteoblast lineage such as Osteopontin, Osteocalcin, and Bone Sialoprotein. RT-PCR analyses showed that osterix mRNA was expressed in both hPDL tissue and cells. The expression of Osterix short isoform was higher than that of the long isoform. Overexpression of Osterix induced upregulated expression of Bone Sialoprotein mRNA. In expression levels of Osteopontin and Osteocalcin mRNA, compared to the control, no difference was observed. In conclusion, Osterix plays important roles in the osteoblastic differentiation in hPDL cells and modulates the mineralization.
The aim of the present study was to clarify the relationship between the relative/absolute numbers of periodontal bacteria and different types of periodontitis. Fifteen patients with localized aggressive periodontitis (LAgP), 25 patients with generalized aggressive periodontitis (GAgP) and 28 patients with chronic periodontitis (CP) were included in this study. Saliva and subgingival plaque samples were collected from all subjects for microbiological analysis. The prevalence and proportions of Actinobacillus actinomycetemcomitans, Tannerella forsythensis, Porphyromonas gingivalis and Treponema denticola were determined by conventional PCR and real-time PCR. The prevalence of A. actinomycetemcomitans in saliva was significantly higher in LAgP patients (46.7%) and GAgP patients (40.0%) than that in CP patients (14.3%) . The mean proportion of A. actinomycetemcomitans in LAgP patients (4.42%) was significantly higher than that in GAgP patients (0.59%) and CP patients (0.37%) in saliva. In subgingival plaque, LAgP patients showed a significantly higher mean proportion of T. forsythensis (19.8%) than CP patients (7.45%) . In conclusion, A. actinomycetemcomitans was the more predominant periodontopathic bacteria in LAgP than in GAgP and CP. The increased proportion of T forsythensis might relate to LAgP, in addition to A. actinomycetemcomitans. These results indicate that real-time PCR analysis is useful for the evaluation of the bacterial profiles in different types of periodontitis.
This study evaluated the relationship between occlusal force and tooth displacement in function. The three-dimensional tooth displacement transducer Type M-3 was used to measure the tooth displacement path and a three-dimensional small occlusal force sensor was developed to detect the occlusal force. Subjects' teeth were the upper and lower first molars. The three-dimensional tooth displacement and occlusal force of the upper and lower first molars were measured at the same time during light and heavy clenching in vivo. The direction of the tooth displacement and that of the occlusal force of the upper first molar almost coincided and they were along the palato-apical direction. However, in the lower first molar, the direction of occlusal force was in the apical direction, and the tooth displacement path was along the lingual direction. There was no relationship between the direction of occlusal force and clenching intensity at the upper and lower first molars and no relationship was observed between the direction of tooth displacement and occlusal force at the lower first molar. However, the upper molars showed a tendency to move more in the palatal direction as the force increased. In the case of the upper first molar, the energy of force seemed to change with the distortion of the alveolar bone especially around the root surface. However, in the case of the lower first molar, the energy of this occlusal force might be absorbed by the deformation of the mandible.
Color inspection plays an important role in the diagnosis of oral mucosal lesions. However, it is sometimes difficult to diagnose by color, because color is always evaluated subjectively. In order to measure color objectively and quantitatively, we decided to use a newly developed spectrum colorimeter for the oral mucosa. To keep the same angle and distance, a special stick was utilized. Various experiments were performed and suitable conditions for accurate colorimetric measurement were decided, including room temperature with cooling fan, onset time of the device, calibration timing, and the angle between light and the measured surface. The reproducibility of this method was confirmed by measuring the color of the buccal mucosa in healthy persons.
The presence of lymph node metastasis is the most important prognostic factor in oral cancer. The purpose of this study was to find useful markers for predicting occult cervical lymph node metastasis in patients with stage I or II squamous cell carcinoma of the oral cavity. We investigated 6 clinicopathologic factors and 2 genetic markers to predict late or occult cervical metastasis in 33 patients with stage I and II oral squamous cell carcinoma who underwent partial glossectomy through the mouth without elective neck dissection. In this study, we performed fluorescence in situ hybridization (FISH) with specimens obtained by fine-needle aspiration biopsies (FNA biopsies) of primary oral cancer material, to investigate numerical aberration of the gene. Late cervical lymph node metastasis occurred in 16 of the 33 patients (48.5%) during follow-up after treatment of the primary tumor. Factors significantly associated with the development of cervical metastasis were the mode of invasion (p=0.009), cyclin D 1 (p=0.003) and EGFR numerical aberration (p=0.024) . The rate of disease-free survival from metastatic disease was significantly lower in patients with mode of invasion 4C-4D than in those with 1-3, and was significantly lower in patients with cyclin D1 or EGFR gene numerical aberrations than in those without such aberrations (log rank test, p=0.0064, p=0.0016 or p=0.0150) . Our results indicate that patients with stage I-II squamous cell carcinoma of the oral cavity with the mode of invasion 4 C or 4 D, cyclin D 1 and EGFR gene numerical aberration should be considered a high-risk group for late cervical lymph node metastasis.
The purpose of this study was to clarify the relationship between occlusal condition and changes of bolus property during mastication. The methods and results were as follows. Subjects were selected according to the classification of anterior-posterior occlusal condition of the first molars (Angle' Class I, II, III group) . 1. Evaluation of the relationship between occlusal condition and subjective chewing difficulty based on a questionnaire survey using a visual analog scale (VAS) : Class II and Class III groups showed significantly higher subjective chewing difficulty compared to the Class I group. 2. Evaluation of the relationship between occlusal condition and changes of bolus property (chewiness) during mastication. In the Class II and Class III groups, the decrease in chewiness during the initial phase of mastication was significantly low compared to that in the Class I group. 3. To verify the results of 2, we examined bolus destruction for different loading directions using FEM and evaluated the differences among the three groups. We also investigated the correlation of the actual jaw movement and the masticatory efficiency according to the loading direction in the three groups : In the Class II and III groups, actual jaw movement was not significantly correlated with the most efficient loading direction in bolus destruction compared to that in the Class I group. These results indicate the correlation between occlusal condition and changes of bolus property during mastication. The subjective chewing difficulty may be one mediating factor. The efficiency of bolus destruction during mastication may also be associated with the relationship between occlusal condition and bolus property.
The purpose of this study was to observe the morphological relationship between maxillofacial skeleton and masseter by superimposing the masseter image constructed by MR image scanning on the cephalogram. Sixteen subjects with different mandibular plane angle were examined in this study. Cephalogram and MR images of each subject were taken, and the images were input to a computer by using a digitizer. The areas of masseter were selected in each MR scan image which were projected to the mid-sagittal layer of the MR scan images. The synthesized image of cephalogram and masseter was obtained by completely superimposing sagittal images of the masseter with the mid-sagittal-plane MR image on the cephalogram. The inclination of masseter was determined by the center of gravity on the cross-section of masseter. These synthesized images of cephalogram and masseter showed various shapes of masseter according to different mandibular plane angle. The inclination of masseter had a close correlation with some skeletal parameters (mandibular plane angle, ANB, Y-axis, facial angle, saddle angle) of cephalometric analysis. The volume of the masseter also had a close correlation with skeletal parameters (mandibular plane angle, gonial angle, Y-axis) . These results revealed that morphometric analysis using synthesized images of Cephalogram and masseter is useful, and that the inclination and the volume of masseter may have an influence on the shape of the mandibular bone and its vertical and anteroposterior development.
Objectives : The purpose of this study was 1) to obtain polygon data and individual parameters from facial photographs of Crouzon syndrome patients and general patients with malocclusion in order to synthesize facial images using a 3D wire frame model, and 2) to distinguish between Crouzon syndrome patients and general patients with malocclusion using quantitative analysis of characteristic variations of facial features. Materials & Methods : The face images were prepared from standardized full-face photographs of 10 Crouzon patients (Crouzon group) and 10 general patients with malocclusion (General group) . These facial images were fitted to the 3D wire frame model and the polygon data were obtained. Following application of principal component analysis, the individual parameters of the standard face were considered to be individual feature parameters. Linear discriminant analysis using the individual feature parameters was applied to distinguish both groups, and the validity of this statistical method was estimated. Moreover, the discriminant rates of the parts of the face were calculated and compared to those of the full face. Results : A discriminant rate of 90% was obtained. The application of individual feature parameters to facial features could be used to objectively distinguish between these two groups. The discriminant rates of the part of the face were lower than those of the full face. Conclusion : This method seemed to be effective for diagnosing congenital anomalies from facial features. Further research on other congenital anomalies would be necessary to apply this analysis as a new diagnostic step.