Studies using the enterotoxin cholera toxin and the related heat-labile toxin I of Escherichia coli as adjuvants have established that effective immunity can be provided in mucosal tissues and the general blood stream by vaccines administered by the oral or nasal route. Despite this knowledge and other recognized advantages, needleless mucosal vaccines rarely appear in the health care market and classic injected vaccines remain the norm. Safety issues related to the adjuvants needed for oral and nasal vaccines are the chief factor that hampers their generalized use in humans. Initial strategies to overcome the toxicity of enterotoxin adjuvants consisted of removing the enzymatic activity of these molecules. The binding of these toxins to their ganglioside receptors was later found to be a major source of safety concern regarding nasal vaccines. Non-ganglioside-binding bacterial toxins and their derivatives are being evaluated as alternatives for the development of effective and safe mucosal vaccines. The CTA1-DD adjuvant, which acts by B-cell targeting of the enzymatically active cholera toxin A subunit, represents one of the strategies to induce immunity by nasal immunization without targeting central nervous system tissues. More recently, we found that the edema toxin of Bacillus anthracis, which binds to target cells via the anthrax toxin receptors and delivers its adenylate cyclase subunit, is an effective adjuvant for nasal vaccines. Interestingly, the unique receptors of anthrax toxin derivatives appear to prevent their accumulation in the central nervous system.

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In 2001, a dental anthropological survey of the Hani tribe, one of the Chinese ethnic minorities was carried out in Yuen Jian in Yunnan Province. The subjects were young adults of the tribe, which historically derives from the Tibetan area. Dental impression models were collected from this population, and the frequencies of 22 dental traits were recorded. The results were compared with those of other Asian populations in terms of Turner's Mongoloid dental variation theory. A principal coordinate analysis based on Smith's Mean Measure of Divergence using the frequencies of 17 traits suggested that the Hani tribe belongs to the Sundadont dentition category, which typifies Southeast Asians, despite its Sinodont (Northeast Asia) location. Other anthropological and linguistic studies also suggest that the Hani are closely related to Tibetans. With reference to our findings, and to presumed past and present distributions of Sinodonty and Sundadonty, we postulate that the Hani in Yunnan Province have genetically inherited traits similar to the Sundadont peoples of Southeast Asian, but also exhibit environmentally induced traits similar to those of the Sinodont Han (who comprise the majority of the Chinese population) and other Sinodont tribes in their vicinity. Historical factors both genetic and environmental are, it is argued, reflected in their dental characteristics.

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The purpose of this study was to clarify the effects of imaging direction on susceptibility artifacts caused by dental metallic materials in magnetic resonance images. Magnetic resonance images of five silver alloy cubes (each 5 mm in diameter) were obtained using a 1.5-Tesla superconducting magnetic resonance imager. The images were divided into two groups and comparisons of shapes and artifact volumes were performed. In the perpendicular group (Per-group), the direction of the static magnetic field (B₀) and the frequency-encoding direction were perpendicular, while in the Parallel group (Pal-group), the direction of B₀ and the frequency-encoding direction were parallel. Metal artifacts in both groups consisted of a signal void around the cubes and a high-signal area along B₀, although the shapes were different between the groups. The magnitude of the artifacts tended to be larger, although not significantly larger, in the Pal-group than in the Per-group. We concluded that the directions of the static magnetic field and frequency encoding have effects on the three-dimensional extension of metallic artifacts in magnetic resonance images.

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We evaluated the efficacy of water-soluble monomers in the adhesion of 4-methacryloxyethyl trimellitate anhydride (4-META)/ methyl methacrylate (MMA)- tri-n-butyl borane (TBB) resin to enamel. An original self-etching primer containing an aqueous mixture of 4-methacryloxyethyl trimellitic acid (4-MET) and 35 wt% water-soluble monomers was designed. As water-soluble monomers, Glycerol dimethacrylate (GMR), Glycerol methacrylate acrylate (GAM) and 2,2-Bis(4-methacryloxy polyethoxyphenyl)propane (BPE) were used. Polished bovine enamel surfaces were treated with the self-etching primer for 30 s. The tensile bond strength of 4-META/MMA-TBB resin to enamel was measured after 1-day immersion in water at 37°C. The self-etching primer containing GMR or GAM produced comparable bond strengths with phosphoric acid etching. On the other hand, the bond strength by BPE self-etching primer was significantly lower than GMR and GAM self-etching primer and phosphoric acid etching. This was due to the difference in the viscosity of water-soluble monomers. BPE had higher viscosity than GMR and GAM. The observation by Field-emission scanning electron microscopy showed that the self-etching primer treatment showed less dissolution of enamel surface than phosphoric acid etching. In conclusion, the self-etching primer containing GMR or GAM may be an alternative to phosphoric acid etching for the adhesion of TBB-initiated 4-META/MMA resin cement to enamel, in spite of less dissolution of the enamel surface.

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Background. Oral irritation fibromas (OIFs) are benign fibroblastic proliferations arising from the oral mucosa in response to chronic irritation. Although the nature of fibroblast proliferation has been well studied in wound repair, details of the histopathogenesis of spindle cells in relation to their immunohistochemical features and distribution in OIF are unclear. Methods. Forty cases of OIF were investigated and the spindle cells were examined in detail. The stromas were classified histopathologically, and stained histochemically by the alcian blue (pH-2.5)-PAS double-staining method. Immunohistochemistry was performed using antibodies against vimentin, α-smooth muscle actin (α-SMA), desmin, S-100β, myoD1, and collagen type I and III. Results. Histopathologically, the stromas of OIFs were classified into five types : mature, immature fibroblastic, immature inflammatory, myxoid and mixed type. Inflammation was only seen in a minority of cases with no mitotic figures or any sign of necrosis. Histochemically, the myxoid type stained basophilic while the collagen of other OIF types stained acidophilic. Immunohistochemically, the spindle cells of the mature type expressed vimentin constantly (V phenotype). In contrast, the spindle cells of the immature fibroblastic type expressed α-SMA (VA phenotype) and the immature inflammatory type expressed desmin (VD phenotype). Interestingly, the spindle cells of the myxoid type expressed S-100β (N phenotype), while the mixed type exhibited α-SMA and S-100β positive cells (VA/N phenotype). MyoD1 was expressed constantly in spindle cells of the immature inflammatory and fibroblastic types, but its expression was weak in the mixed type. MyoD1 was not expressed in the mature or myxoid types. All 40 cases stained positive for collagen type III, while collagen type I was detected predominantly in the mature type and only weakly in the other types. Conclusion. These results suggest that spindle cells of OIFs transiently express myofibroblastic characteristics, particular the VA, VD and VA/N phenotypes, through the expression of α-SMA, desmin and myoD1. Thus, with the onset of trauma (weak or chronic irritation) a myofibroblastic stromal reaction appears to be evoked in undifferentiated mesenchymal cells, and collagen type III is produced. As the healing progress proceeds, collagen type III levels decline, collagen type I is secreted and the phenotypic features of myofibroblasts disappear, as seen in the V phenotype. The myxoid type expressed immunohistochemical features of neural differentiation while the mixed type expressed features considered to be of dual origin. The immunohistochemical findings also revealed that the growth of OIF was time-dependent.

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Hayashi et al. recently succeeded in preparing a filling polymer composed of methyl methacrylate and perfluorooctylethyl acrylate (C8F). They suggested that the addition of C8F-added polymer beads could inhibit bacterial adherence to the surface of denture base resin. The objective of this study was to examine the influence of carbon chain length of fluorinated alkyl acrylate on mechanical properties of test specimens ; perfluorobutylethyl acrylate (C4F), perfluorohexylethyl acrylate (C6F), C8F and perfluorodecylethyl acrylate (C10F) were used as fluorinated alkyl acrylates. The glass transition temperature of test specimens appeared to be greater as carbon chain length of fluorinated alkyl acrylate increased. Knoop hardness was lowest in C6F-added specimens (C6FA), while all test specimens gave lower values than the control. The direct tensile strengths of fluoromonomer-added specimens were lower than the control, while relatively lower strengths were seen in C6FA or C8F-added specimens (C8FA). Although Knoop hardness and direct tensile strength decreased after addition of fluorinated alkyl acrylates, these mechanical properties remained within the limits recommended by the Japanese Society for Dental Materials and Devices for denture base resin. This study suggests that the new denture base resin is clinically acceptable with regard to mechanical properties.

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It is well known that bone formation steadily declines with age, resulting in a significant loss of bone mass. Cellular senescence-elevated oxidative stress has been shown to be related to the regulation of cellular functions in physiological and pathological conditions, and it has been clearly demonstrated that oxidative stress inhibits osteoblast differentiation and leads to a reduction in bone formation. However, the precise mechanism of the effect of reactive oxygen species (ROS) on the function of osteoblastic cells involved in bone nodule formation is not clear. In an attempt to establish a useful cell culture experimental model, we examined the effects of H₂O₂ on bone nodule formation in an established cell line, MC3T3-E1, following treatment with H₂O₂ using von Kossa staining. We found that cell viability was not affected by H₂O₂, though 400 μM suppressed the total number, as well total area and bone nodule area in MC3T3-E1 cells. Thus, a cell culture experimental model of bone formation during the aging process was successfully established using MC3T3-E1 cells with an H₂O₂ challenge without the damaging effects of proliferation or cell death. The present experimental model may be useful for studying the mechanism of decline of bone formation that accompanies aging.

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The existence of carbohydrates that promote rapid fermentation as an exogenous factor and the low buffer capacity of secreted saliva at rest are considered to constitute the main factors that influence the rate at which dental plaque pH declines. The present study examined the relationship between salivary buffer capacity and DMFT (carries experience) in order to analyze the buffer capacity of saliva at rest, an important related to clearance capacity in the oral cavity. The results thus obtained are reported below. The total mean±SD of buffer capacity value was 5.09±0.87. The 50 subjects were divided at the median value into the high-buffer capacity sub-group of 25 subjects (5.83±0.37) and the low-buffer capacity sub-group of 25 subjects (4.36±0.52). The average DMFT of the high-buffer capacity sub-group (4.40±4.74) was lower than that of the low-buffer capacity sub-group (8.68±5.39), indicating a significant difference (p<0.01) between the two sub-groups.

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Here, we report a rare case of a natal tooth of the lower primary incisor region associated with a pediculated polyp-like mass lesion. The lesion occurred in a 27-day-old newborn boy. Macroscopically, the natal tooth was not of uniform color and the contour of the cervix was ill-defined. Soft X-ray imaging clarified the shape but there was no root visible. Histopathologically, the natal tooth was immature and incompletely formed.

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Deep mycoses are caused by fungal infections and can lead to serious systemic complications and even death. Some mycoses can present with oral manifestations, and recognizing these different oral manifestations is important for correct diagnosis. Here we describe the oral manifestations of paracoccidioidomycosis.

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