We evaluated bone production after combining mesenchymal stem cells (MSCs) derived from the mini-pig posterior iliac crest with 3-D woven fabric composite scaffold, in which regularly arranged pores form a lattice-like porous structure consisting of poly-L-lactic acid (PLLA) and 75/25 Poly lactide-co-glycolide (75/25 PLGA). There were two experimental groups. In the first one cells were injected into the 3-D woven fabric composite scaffold. The second one had the 3-D woven fabric composite scaffold only, with no injected cells. In both cases, the scaffolds were transplanted into mini-pig clavarial defects. A bone defect only group was also created as a control. Microradiographic and histological images showed progressive bone infiltration into the macropores of the 3D scaffolds. The scaffold had a positive effect on the tissue response. However, there was no significant difference in bone defect healing efficiency between the MSC plus scaffold group and the scaffold only group. Further improvements in the design of the 3-D woven fabric composite scaffold, such as optimization of the fiber intervals and porosity, are expected to enhance the osteogenic ability of the material.
In order to examine the color-related specificity of laser absorption at various wave-lengths, we irradiated, with a laser, specimens that had been stained with caries-detecting solution (CDS), measured the energy used, and calculated the rate of absorption. We used a P-LASER as a diode laser, an Erwin AdvErL as an Er: YAG laser and a PanalasC05 as a CO_2 laser. One drop of the CDS was placed on filter paper and artificial carious dentin, and the specimens were then dried. We then measured the energy penetrating the specimens using a laser power meter, and calculated the absorption rate of staining-related irradiation energy, regarding values obtained by laser irradiation without the specimens as controls. The data were statistically analyzed using one-way variance analysis and Scheffe's test. When the filter paper was tested, green showed the highest absorption rate for the diode laser. When the artificial caries dentin was tested, green again had the highest absorption rate for the diode laser. Green had a significantly different absorption rate when compared with red and when compared with purple. There were no significant color-related differences for absorption rates with the Er: YAG laser and CO_2 laser. These findings suggest that caries staining with green CDS facilitates selective caries removal for diode laser treatment.
When periodontal disease develops, many inflammatory cells, mainly lymphocytes, are observed infiltrating the lesion. Chemokines such as MCP-1 and IL-8, which are produced by gingival epithelial cells undergoing stimulation by bacterial cell components from plaque bacteria through the toll-like receptor-2, are involved in the migration of these immunocompetent cells to the lesion site. It has been confirmed that the expression of these inflammatory cytokines is elevated in the gingival tissue and gingival sulcus exudates of periodontal disease patients. We investigated the dynamics of the inflammatory cytokines IL-1β, IL-6, TNF-α, IFN-γ, MCP-1 and anti-inflammatory cytokine IL-10 in rats with spontaneous periodontal disease (ODUS/Odu), an animal model of periodontal disease developed and maintained in our laboratory. In this study, we measured the plasma levels of the eicosanoid PGE_2 and inflammatory cytokines cytokine-induced neutrophil chemoattractant-1 (CINC-1), and the anti-inflammatory cytokine IL-4 in ODUS/Odu. Plasma cytokine levels were measured in these animals and in control rats (Res) at 0 (five weeks after birth), 1, 3, 6, 9 and 12 months after the start of the experiment using an enzyme-linked immunosorbent assay (ELISA) kit. The plasma levels of the eicosanoid PGE_2 and inflammatory cytokine CINC-1 were greater in ODUS/Odu than in Res throughout the experimental period. However, the plasma levels of the anti-inflammatory cytokine IL-4 was lower in ODUS/Odu than in Res. These results, similar to those obtained in patients with periodontal disease, suggest that the ODUS/Odu are a useful animal model of human periodontal disease.
We investigated the influence of botulinum toxin A on the distribution of neuronal nitric oxide synthase in the salivary glands. Using the submandibular glands of male Wistar rats weighing 250-300g. We studied the immunohistochemical reaction of neuronal nitric oxide synthase in the submandibular gland, in both untreated glands and after intraductal injection of botulinum toxin A under general anesthesia. Botulinum toxin A treatment markedly inhibited the chorda-evoked fluid responses, and decreased nNOS in the submandibular glands. In addition, when N^G-Nitro-L-arginine methyl ester treatment was extended over a long period of time it both inhibited fluid responses and decreased the neuronal nitric oxide synthase reaction. These results suggest that botulinum toxin A treatment of the submandibular gland significantly decreases salivary secretion, and has significantly fewer side effects than additional N^G-Nitro-L-arginine methyl ester treatment. The influence of botulinum toxin A on neuronal nitric oxide synthase in the submandibular gland might explain the longer duration of the toxin effect at the neuroglandular junction than at the motor endplate.
Saliva sampling has the advantages of being easy, stress free and non-invasive, allowing for multiple sampling. We examined how xerostomia that was induced by botulinum toxin A treatment affected the salivary cortisol and amylase levels, and compared the characteristics of these parameters. Twenty male Wistar rats weighing 280-320g were used in this experiment. After botulinum toxin A treatment, the stress response was determined using salivary cortisol and amylase levels during chorda-stimulation. The amylase level was significantly decreased on day 7 after botulinum toxin A was administered. However, the cortisol level was increased, and the increase was to a lesser extent than that of amylase. Both the salivary cortisol and amylase levels recovered over time, suggesting that they are good indices of xerostomia. Furthermore, it is suggested that amylase is an index of relaxation.
Calcium phosphate cement (CPC) has been used as a bone substitute because it has a good biocompatibility and osteoconductivity. We investigated how CPC affects the quality of bone response around and fixation of titanium implants. Screw-type pure titanium implants 1.2mm in diameter were placed with and without CPC into pre-drilled 1.2mm diameter cavities in the bilateral hind leg femurs of beagle dogs, and the removal torque strength was measured at 3, 6, 9 and 12 weeks. Higher removal torque strengths were achieved for implants with CPC compared to the controls at three weeks post-insertion (p<0.01). These results may indicate that CPC contributes to the early osseous integration of the interface between implant and bone. This information may be important for the clinical application of early loading.
This study was performed to evaluate the retentive force generated by an electroformed telescope crown on a zirconia inner crown. The inner crowns were made of zirconia with 2° taper and ten outer crowns were made by electroforming on the inner crown. We measured the retentive force generated between the inner and outer crowns when glycerin solutions of different viscosities replaced saliva during removal of the outer crown of the electroformed telescope. The mean value of the peak retentive force was 6.4 N even with no solution, which was an adequate retentive force. The peak retentive force was significantly greater at glycerin concentrations of 40% and 60% when compared with no solution. Significant increases were observed in the distance over which retentive force was generated, especially after peak retentive force, with water and glycerin solutions compared with no solution. The above findings suggest that the viscosity of saliva effectively increased the retentive force in a 2° electroformed telescope using a zirconia inner crown, and that the electroformed telescope crown on the zirconia inner crown combination was as effective as when the inner crown was made of gold.
We attempted to purify lectin from the coelomic fluid of Toxopneustes pileolus. Coelomic fluid samples induced hemagglutination in rabbit erythrocytes and the proliferation of mouse spleen cells. The samples were shown to contain glycoproteins by SDS-PAGE. Coelomic fluid was fractionated using a Phenyl Sepharose CL-4B column to separate coelomic fluid lectins. Of the fractions recovered, PS-I and PS-II were identified as glycoproteins. Hemagglutinating activity was stronger in the PS-I than PS-II fraction. Therefore, the PS-I fraction was fractionated and purified by gel filtration chromatography using a Superdex 200 column. The PS-PI, PS-PII, and PS-PIII fractions were recovered. The PS-PI fraction showed the strongest hemagglutinating activity among the 3 fractions, and had a heparin-binding property. It showed a nearly single protein band at 960kDa on native PAGE, and it was found to consist of glycoprotein. The PS-PI fraction showed a mitogenic effect on mouse spleen cells from a low concentration. The results of this study suggest that coelomic fluid of Toxopneustes pileolus contains physiologically functional lectins.
Early detection of precancerous and early cancerous lesions could greatly reduce both mortality and morbidity of oral cancer. We describe a simple handheld device that facilitates the direct visualization of oral-cavity fluorescence for the detection of precancerous and early cancerous lesions. Blue excitation light (400 to 460nm) is employed to excite green-red fluorescence from fluorophores in the oral mucosa. Tissue fluorescence is viewed directly along an optical axis collinear with the axis of excitation to reduce interand intraoperator variability. This robust, field-of-view device enables the direct visualization of fluorescence in the context of surrounding normal tissue. Results from a pilot study of 17 patients are presented. In conjunction with histological examinations, this device is extremely useful in detecting oral precancerous and early cancerous lesions. We envisage this device as a suitable adjunct for oral cancer screening and margin determination.
Various specialty clinics and research centers have conducted studies of direct tissue fluorescence visualization as a screening technique for oral precancerous and early cancerous lesions. The effectiveness of the VELscope is still not well known. The objective of this study was to analyze specificity of the VELscope system for the detection of precancerous and early cancerous lesions. We studied the use of this simple handheld device that facilitates the direct visualization of oral-cavity fluorescence for the detection of precancerous and early cancerous lesions. Blue excitation light (400 to 460nm) is employed to excite green-red fluorescence from fluorophores in the oral mucosa. Tissue fluorescence is viewed directly along an optical axis collinear with the axis of excitation to reduce inter-and intraoperator variability. This robust, field-of-view device enables the direct visualization of fluorescence in the context of surrounding normal tissue. Results from 17 patients are presented. Histological examination of the lesions showed that the VELscope system has a sensitivity of 95% and specificity of 100% in discriminating normal mucosa from severe dysplasia/carcinoma in situ (CIS) or invasive carcinoma. We envisage this device as a suitable adjunct for oral cancer screening.
The calcifying epithelial odontogenic tumor is a very rare odontogenic lesion. Most cases involve the posterior region of the mandible. Computed tomography (CT) scans and magnetic resonance imaging (MRI) showed that this tumor aggressively advanced from the posterior region of the maxillary sinus near the orbital floor. The images clearly showed the internal structure and range of the lesion which was obscured in conventional radiographs. We also reviewed the literature and discussed the main clinical characteristics of this tumor.
We investigated the effects of the adhesion of artificial sputa with various viscosities on flow resistance in a heat and moisture exchange filter, and found that even water increased flow resistance. The maximum differential pressure was increased more when artificial sputa of varying viscosities were injected into the heat and moisture exchange filter compared with water, although the increase in the differential pressure was not influenced by viscosity.
The ideal endotracheal tube passes easily along the respiratory tract and is resistant to losing its shape. Using Parker Flex-Tip^[○!R] and Sheridan/CF^[○!R] oral endotracheal tubes, we investigated the force required to bend the tube in relation to the thickness of the tube wall. We found that less force was required to bend the Parker Flex-Tip^[○!R] than the Sheridan/CF^[○!R] tubes. The thickness of the tube wall was also significantly thinner in the Parker Flex-Tip^[○!R]. We found that as the inner diameter (ID) of the Sheridan/CF^[○!R] tube became narrower and the tube wall became thinner, less force was needed to bend the tube. Further, the force needed to bend tubes with different IDs also significantly correlated with the narrowness of the ID. The above suggests that tubes may bend with only a mild force, leading to the risk of obstruction.
Many morphological sex differences in the rat brain have been elucidated. The medial amygdala (MeA) also shows sex differences in size and the number of cells. In this study, we focused on the neuronal activity and investigated the presence of sex differences in the olfactory responses of the MeA. Animal and plant odorants were used, and the response patterns were examined by an extracellular recording system. Odor-responding neurons in the MeA area showed sex differences in which male neurons had higher odor selectivity than those in females. These findings suggest that olfactory signals are differentially processed in the MeA area depending on odor type and gender.
An FPD-T-Sports sensor was mounted in the oral cavity of judo athletes to simulate stress effects on the oral and maxillofacial complex when wearing a sports mouth guard (SMG) while performing judo techniques. The intraoral sensors were connected either with an I-SCAN or a T-SCAN III system that can dynamically evaluate and analyze occlusal force distribution and contact area while performing standing and ground-fighting techniques. The results indicated that maximum intercuspal clenching is not necessary for performing judo. Furthermore, we did not find distinct distribution differences in occlusal contact between the dentition and oral mucosa of the athletes. The present findings indicated that judo techniques might induce stress that affects the oral and maxillo-facial complex essentially through non-specific contact between the teeth and the oral mucosa regardless of maximum intercuspal clenching. Hence, the SMG might reduce the incidence of hard-to-soft tissue damage during judo.
EpCAM is a cell surface molecule that is known to be highly expressed in several epithelial carcinomas. We previously reported that a gamma secretase inhibitor decreased the proliferation of oral squamous cell carcinoma (OSCC) cell lines. It was known that substrates of gamma secretase include EpCAM, E-cadherin and Notch. Moreover, it has been noted that gamma secretase induces cleavege of EpCAM in squamous cell carcinoma (SCC) cells, and that the alteration of EpCAM localization is related to cell proliferation. In this study, we confirmed that while EpCAM expression was almost not detectable in the tongue of mice, it was EpCAM expressed in OSCC cell lines. We found that cell proliferation was decreased and the localization of EpCAM was altered by gamma secretase inhibitor in OSCC cell line, indicating that EpCAM expression might be related to carcino-genesis in OSCC. This study suggests that the cleavage of EpCAM is induced by gamma secretase in OSCC cell lines, and that the proliferation of OSCC cells might be affected by changes in EpCAM localization.
To confirm the effectiveness of the use of enamel matrix derivative (EMD) on periodontal tissue regeneration, we performed flap operations applying EMD (EMD group) and without applying it (control group), radiographically observed the size of the alveolar bone defect, and clinically compared the two groups. Based on the size of bone defect and the three clinical parameters of gingival recession (GR), pocket depth (PD), and clinical attachment level (CAL), the EMD group presented a favorable clinical course for each observation criteion compared with the control groups. There were significant differences for all criteria except for the size of the bone defect and GR 3 months after surgery. In particular, the EMD and control groups both showed marked differences in CAL, which is a parameter of periodontal tissue destruction, on each observation, confirming the effectiveness of EMD for periodontal regeneration.